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.

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.

U.S. Army Corps of Engineers Manpower Information System: An Integrated Approach to Manpower Management

DTIC Science & Technology

1994-04-01

engineering and con- struction management services for both military and civil works programs. In FY93, the cost of those programs exceeded $10 billion and...A related issue was to explore the USACE costs , benefits, and barriers to implementing a single Class VI system software package for both the military...provide information in useful ways, track utilization information, I A Class HI system is defined in AR 25-3. It is a system whose total program costs are

Quinceaneras and Quadratics: Experiences of Latinas in State-Supported Residential Schools of Science and Math

ERIC Educational Resources Information Center

Sayman, Donna M.

2013-01-01

This qualitative study sought to understand the experiences of Latinas enrolled in residential state schools of science, technology, engineering, and math (STEM). Goals of the study focused on understanding experiences and identifying factors such as decisions to enroll, barriers and supports, and issues contributing to retention. These schools…

Latino Faculty in STEM Disciplines: Motivation to Engage in Research Activities

ERIC Educational Resources Information Center

Lechuga, Vicente M.

2012-01-01

The scarcity of underrepresented faculty members in the science, technology, engineering, and mathematics (STEM) disciplines is an issue of great concern to education researchers and scholars alike. Despite their low representation, many minority faculty are able to remain motivated, even when facing barriers due to their ethnicity. I present…

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 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.

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.

Workshop report: strategies for setting occupational exposure limits for engineered nanomaterials.

PubMed

Gordon, Steven C; Butala, John H; Carter, Janet M; Elder, Alison; Gordon, Terry; Gray, George; Sayre, Philip G; Schulte, Paul A; Tsai, Candace S; West, Jay

2014-04-01

Occupational exposure limits (OELs) are important tools for managing worker exposures to chemicals; however, hazard data for many engineered nanomaterials (ENMs) are insufficient for deriving OELs by traditional methods. Technical challenges and questions about how best to measure worker exposures to ENMs also pose barriers to implementing OELs. New varieties of ENMs are being developed and introduced into commerce at a rapid pace, further compounding the issue of OEL development for ENMs. A Workshop on Strategies for Setting Occupational Exposure Limits for Engineered Nanomaterials, held in September 2012, provided an opportunity for occupational health experts from various stakeholder groups to discuss possible alternative approaches for setting OELs for ENMs and issues related to their implementation. This report summarizes the workshop proceedings and findings, identifies areas for additional research, and suggests potential avenues for further progress on this important topic. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Tissue engineering of urinary bladder - current state of art and future perspectives.

PubMed

Adamowicz, Jan; Kowalczyk, Tomasz; Drewa, Tomasz

2013-01-01

Tissue engineering and biomaterials science currently offer the technology needed to replace the urinary tract wall. This review addresses current achievements and barriers for the regeneration of the urinary blad- der based on tissue engineering methods. Medline was search for urinary bladder tissue engineering regenerative medicine and stem cells. Numerous studies to develop a substitute for the native urinary bladder wall us- ing the tissue engineering approach are ongoing. Stem cells combined with biomaterials open new treatment methods, including even de novo urinary bladder construction. However, there are still many issues before advances in tissue engineering can be introduced for clinical application. Before tissue engineering techniques could be recognize as effective and safe for patients, more research stud- ies performed on large animal models and with long follow-up are needed to carry on in the future.

Discovering the Barriers to Rural Women in STEM

NASA Astrophysics Data System (ADS)

Kreft Pearce, Jennifer; McCaslin, Sara; Morgan, Leann

2011-10-01

This study investigates the attitudes women and girls from the East Texas region have towards engineering and physics. We use an online survey and interviews to determine what influences women to choose their career paths. Surprisingly, we find that women have more positive attitudes about physics and engineering than their male counterparts. For the group of students interviewed, self assessment of ability, lack of role models, and confusion about work/life balance issues were some of the determining factors in their choice not to pursue a career in a STEM field.

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

Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H.

Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts andmore » the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs.« less

Overview of thermal barrier coatings in diesel engines

NASA Technical Reports Server (NTRS)

Yonushonis, Thomas M.

1995-01-01

An understanding of delamination mechanisms in thermal barrier coatings has been developed for diesel engine applications through rig tests, structural analysis modeling, nondestructive evaluation, 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. Although much conflicting literature now exists regarding the impact of thermal barrier coatings on engine performance and fuel consumption, the changes in fuel consumption appear to be less than a few percent and can be negative for state-of-the-art diesel engines. The ability of the thermal barrier coating to improve fuel economy tends to be dependent on a number of factors including the fuel injection system, combustion chamber design, and the initial engine fuel economy. Limited investigations on state-of-the-art diesel engines have indicated that the surface connected porosity and coating surface roughness may influence engine fuel economy. Current research efforts on thermal barrier coatings are primarily directed at reducing in-cylinder heat rejection, thermal fatigue protection of underlying metal surfaces and a possible reduction in diesel engine emissions. Significant efforts are still required to improve the plasma spray processing capability and the economics for complex geometry diesel engine components.

Communication Problems in Requirements Engineering: A Field Study

NASA Technical Reports Server (NTRS)

Al-Rawas, Amer; Easterbrook, Steve

1996-01-01

The requirements engineering phase of software development projects is characterized by the intensity and importance of communication activities. During this phase, the various stakeholders must be able to communicate their requirements to the analysts, and the analysts need to be able to communicate the specifications they generate back to the stakeholders for validation. This paper describes a field investigation into the problems of communication between disparate communities involved in the requirements specification activities. The results of this study are discussed in terms of their relation to three major communication barriers: (1) ineffectiveness of the current communication channels; (2) restrictions on expressiveness imposed by notations; and (3) social and organizational barriers. The results confirm that organizational and social issues have great influence on the effectiveness of communication. They also show that in general, end-users find the notations used by software practitioners to model their requirements difficult to understand and validate.

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.

Mechanisms and Barriers in Cancer Nanomedicine: Addressing Challenges, Looking for Solutions.

PubMed

Anchordoquy, Thomas J; Barenholz, Yechezkel; Boraschi, Diana; Chorny, Michael; Decuzzi, Paolo; Dobrovolskaia, Marina A; Farhangrazi, Z Shadi; Farrell, Dorothy; Gabizon, Alberto; Ghandehari, Hamidreza; Godin, Biana; La-Beck, Ninh M; Ljubimova, Julia; Moghimi, S Moein; Pagliaro, Len; Park, Ji-Ho; Peer, Dan; Ruoslahti, Erkki; Serkova, Natalie J; Simberg, Dmitri

2017-01-24

Remarkable progress has recently been made in the synthesis and characterization of engineered nanoparticles for imaging and treatment of cancers, resulting in several promising candidates in clinical trials. Despite these advances, clinical applications of nanoparticle-based therapeutic/imaging agents remain limited by biological, immunological, and translational barriers. In order to overcome the existing status quo in drug delivery, there is a need for open and frank discussion in the nanomedicine community on what is needed to make qualitative leaps toward translation. In this Nano Focus, we present the main discussion topics and conclusions from a recent workshop: "Mechanisms and Barriers in Nanomedicine". The focus of this informal meeting was on biological, toxicological, immunological, and translational aspects of nanomedicine and approaches to move the field forward productively. We believe that these topics reflect the most important issues in cancer nanomedicine.

Thermal barrier coating on high temperature industrial gas turbine engines

NASA Technical Reports Server (NTRS)

Carlson, N.; Stoner, B. L.

1977-01-01

The thermal barrier coating used was a yttria stabilized zirconia material with a NiCrAlY undercoat, and the base engine used to establish improvements was the P&WA FT50A-4 industrial gas turbine engine. The design benefits of thermal barrier coatings include simplified cooling schemes and the use of conventional alloys in the engine hot section. Cooling flow reductions and improved heating rates achieved with thermal barrier coating result in improved performance. Economic benefits include reduced power production costs and reduced fuel consumption. Over the 30,000 hour life of the thermal barrier coated parts, fuel savings equivalent to $5 million are projected and specific power (megawatts/mass of engine airflow) improvements on the order of 13% are estimated.

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.

Thick thermal barrier coatings for diesel components

NASA Technical Reports Server (NTRS)

Yonushonis, T. M.

1991-01-01

An engineered thick thermal barrier coating consisting of multiple layers of zirconia and CoCrAlY with a zirconia top layer and having a system thermal conductance less than 410 w/m(exp 2)K exceeded the 100 hour engine durability goals set forth in this program. The thermal barrier coatings were intact at the test conclusion. Back to back single cylinder research engine tests were conducted with watercooled, metal hardware and oil-cooled, thermal barrier coating insulated hardware to determine apparent heat release and fuel economy. Apparent heat release data revealed that the insulated engine had a shorter ignition delay and a longer combustion duration than the metal engine. The insulated engine fuel economy was approximately two percent worse on average for this series of tests. There was no attempt to optimize engine efficiency of the insulated engine by modifying the engine timing, coating, or other techniques.

The North Carolina Coastal Geology Cooperative-a Model of Federal, State, and Academic Cooperation

NASA Astrophysics Data System (ADS)

Hoffman, C. W.; Thieler, E. R.; Riggs, S. R.; Schwab, W. C.

2002-12-01

In June 1999, The U.S. and N.C. Geological Surveys hosted a meeting of coastal geologists and engineers to identify coastal geological issues of greatest importance to North Carolina and to explore the possibility of initiating a cooperative research program to address these issues. Several factors came together to allow a coordinated program to develop: keen state interest in coastal hazards following several significant hurricanes, interest on the part of the USGS in combining work in North Carolina with a similar program in South Carolina, and recognition of the strong knowledge base that existed within the coastal scientific community in N.C. The meeting resulted in a strong consensus for comprehensive study of the entire coastal system and for initiating work in the northern coastal region (the Quaternary section east of the Suffolk Scarp, focusing on the barrier-island and estuarine system). Among the most important issues to be addressed by the data and knowledge developed from this program are: coastal and estuarine shoreline erosion (controls on erosion rates, sediment transport, response of wetlands to sea level rise); sand resources (location, quality, and quantity of offshore, estuarine, or onshore sand); storm impacts (barrier island/inlet migration, estuarine water movement, relative stability of barrier island segments); sea level change (history and potential impacts); water resources (surface and groundwater); habitat (ability to sustain uses, trends, threats). The cooperative will provide a strong science foundation for management of the N.C. coastal zone. Endorsements, support, and cooperation have come from the N.C. Coastal Resources Commission, several state and federal resource agencies, and local government units who all have an interest in information the program is producing. Supplemental federal appropriations have resulted from such support and the National Park Service has provided partnership funding. Additional partnership opportunities exist and are being pursued with the Army Corps of Engineers (two feasibility studies are active in the project area), the N.C. Outer Banks Task Force, and U.S. Minerals Management Service.

Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

1993-01-01

In order to reduce heat transfer between a hot gas heat source and a metallic engine component, a thermal insulating layer of material is placed between them. This thermal barrier coating is applied by plasma spray processing the thin films. The coating has been successfully employed in aerospace applications for many years. Lewis Research Center, a leader in the development engine components coating technology, has assisted Caterpillar, Inc. in applying ceramic thermal barrier coatings on engines. Because these large engines use heavy fuels containing vanadium, engine valve life is sharply decreased. The barrier coating controls temperatures, extends valve life and reduces operating cost. Additional applications are currently under development.

Thermal barrier coatings application in diesel engines

NASA Technical Reports Server (NTRS)

Fairbanks, J. W.

1995-01-01

Commercial use of thermal barrier coatings in diesel engines began in the mid 70's by Dr,. Ingard Kvernes at the Central Institute for Industrial Research in Oslo, Norway. Dr. Kvernes attributed attack on diesel engine valves and piston crowns encountered in marine diesel engines in Norwegian ships as hot-corrosion attributed to a reduced quality of residual fuel. His solution was to coat these components to reduce metal temperature below the threshold of aggressive hot-corrosion and also to provide protection. The Department of Energy has supported thermal barrier coating development for diesel engine applications. In the Clean Diesel - 50 Percent Efficient (CD-50) engine for the year 2000, thermal barrier coatings will be used on piston crowns and possibly other components. The primary purpose of the thermal barrier coatings will be to reduce thermal fatigue as the engine peak cylinder pressure will nearly be doubled. As the coatings result in higher available energy in the exhaust gas, efficiency gains are achieved through use of this energy by turbochargers, turbocompounding or thermoelectric generators.

Edible Oil Barriers for Treatment of Perchlorate Contaminated Groundwater

DTIC Science & Technology

2006-02-16

perchlorate is relatively recent. Work performed in soil at Longhorn Army Ammunition Plant in Texas identified chicken manure, cow manure, and...Missile Plant , NC Pilot July-Aug. 2004 Recirculation of emulsion through source area Other DoD Facilities Confidential Site, MD Pilot Oct...G.M. Birk, 2004. A Dash of Oil and Let Marinate. Pollution Engineering, May 2004, pages 30-34. 6.3 End-User Issues Potential end users of the

Determining when a set of compute nodes participating in a barrier operation on a parallel computer are ready to exit the barrier operation

DOEpatents

Blocksome, Michael A [Rochester, MN

2011-12-20

Methods, apparatus, and products are disclosed for determining when a set of compute nodes participating in a barrier operation on a parallel computer are ready to exit the barrier operation that includes, for each compute node in the set: initializing a barrier counter with no counter underflow interrupt; configuring, upon entering the barrier operation, the barrier counter with a value in dependence upon a number of compute nodes in the set; broadcasting, by a DMA engine on the compute node to each of the other compute nodes upon entering the barrier operation, a barrier control packet; receiving, by the DMA engine from each of the other compute nodes, a barrier control packet; modifying, by the DMA engine, the value for the barrier counter in dependence upon each of the received barrier control packets; exiting the barrier operation if the value for the barrier counter matches the exit value.

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.

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

NASA Astrophysics Data System (ADS)

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

1980-01-01

The functions of components selected for an engineered barrier system for a nuclear waste repository in basalt are defined providing a focal point for barrier material research and development by delineating the purpose and operative lifetime of each component of the engineered system. A five component system (comprised of waste form, canister, buffer, overpack, and tailored backfill) is discussed. Redundancy is provided by subsystems of physical and chemical barriers which act in concert with the geology to provide a formidable barrier to transport of hazardous materials to the biosphere. The barrier system is clarified by examples pertinent to storage in basalt, and a technical approach to barrier design and material selection is proposed.

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

NASA Astrophysics Data System (ADS)

Wentling, Rose Mary; Camacho, Cristina

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

Next gen perception and cognition: augmenting perception and enhancing cognition through mobile technologies

NASA Astrophysics Data System (ADS)

Goma, Sergio R.

2015-03-01

In current times, mobile technologies are ubiquitous and the complexity of problems is continuously increasing. In the context of advancement of engineering, we explore in this paper possible reasons that could cause a saturation in technology evolution - namely the ability of problem solving based on previous results and the ability of expressing solutions in a more efficient way, concluding that `thinking outside of brain' - as in solving engineering problems that are expressed in a virtual media due to their complexity - would benefit from mobile technology augmentation. This could be the necessary evolutionary step that would provide the efficiency required to solve new complex problems (addressing the `running out of time' issue) and remove the communication of results barrier (addressing the human `perception/expression imbalance' issue). Some consequences are discussed, as in this context the artificial intelligence becomes an automation tool aid instead of a necessary next evolutionary step. The paper concludes that research in modeling as problem solving aid and data visualization as perception aid augmented with mobile technologies could be the path to an evolutionary step in advancing engineering.

Thermal and Environmental Barrier Coating Development for Advanced Propulsion Engine Systems

NASA Technical Reports Server (NTRS)

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

2008-01-01

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

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.

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

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.

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.

From concept to reality in implementing the Knowledge Triangle

NASA Astrophysics Data System (ADS)

Sjoer, Ellen; Nørgaard, Bente; Goossens, Marc

2016-05-01

The concept of Knowledge Triangle (KT) links together research, education and innovation and replaces the traditional 'one way' flow of knowledge, essentially from research to education, by a 'both ways' circular motion between all the corners of a triangle that, besides research and education, also includes innovation, the 'poor relation' of many universities. What are the main issues - barriers and drivers - and what could be done in order to make the concept of KT a strong reality in engineering education? In this paper, the authors intend to bring some answers by analysing three cases coming from actors operating at the three corners of the KT: students, academic staff and engineers in industry.

Barriers to optimizing investments in the built environment to reduce youth obesity: policy-maker perspectives.

PubMed

Grant, Jill L; MacKay, Kathryn C; Manuel, Patricia M; McHugh, Tara-Leigh F

2010-01-01

To identify factors which limit the ability of local governments to make appropriate investments in the built environment to promote youth health and reduce obesity outcomes in Atlantic Canada. Policy-makers and professionals participated in focus groups to discuss the receptiveness of local governments to introducing health considerations into decision-making. Seven facilitated focus groups involved 44 participants from Atlantic Canada. Thematic discourse analysis of the meeting transcripts identified systemic barriers to creating a built environment that fosters health for youth aged 12-15 years. Participants consistently identified four categories of barriers. Financial barriers limit the capacities of local government to build, maintain and operate appropriate facilities. Legacy issues mean that communities inherit a built environment designed to facilitate car use, with inadequate zoning authority to control fast food outlets, and without the means to determine where schools are built or how they are used. Governance barriers derive from government departments with distinct and competing mandates, with a professional structure that privileges engineering, and with funding programs that encourage competition between municipalities. Cultural factors and values affect outcomes: people have adapted to car-oriented living; poverty reduces options for many families; parental fears limit children's mobility; youth receive limited priority in built environment investments. Participants indicated that health issues have increasing profile within local government, making this an opportune time to discuss strategies for optimizing investments in the built environment. The focus group method can foster mutual learning among professionals within government in ways that could advance health promotion.

Synthetic constructs in/for the environment: Managing the interplay between natural and engineered Biology

PubMed Central

Schmidt, Markus; de Lorenzo, Víctor

2012-01-01

The plausible release of deeply engineered or even entirely synthetic/artificial microorganisms raises the issue of their intentional (e.g. bioremediation) or accidental interaction with the Environment. Containment systems designed in the 1980s–1990s for limiting the spread of genetically engineered bacteria and their recombinant traits are still applicable to contemporary Synthetic Biology constructs. Yet, the ease of DNA synthesis and the uncertainty on how non-natural properties and strains could interplay with the existing biological word poses yet again the challenge of designing safe and efficacious firewalls to curtail possible interactions. Such barriers may include xeno-nucleic acids (XNAs) instead of DNA as information-bearing molecules, rewriting the genetic code to make it non-understandable by the existing gene expression machineries, and/or making growth dependent on xenobiotic chemicals. PMID:22710182

Barriers to student success in engineering education

NASA Astrophysics Data System (ADS)

Boles, Wageeh; Whelan, Karen

2017-07-01

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

Integrating ergonomics into production system development--the Volvo Powertrain case.

PubMed

Neumann, W Patrick; Ekman, Marianne; Winkel, Jørgen

2009-05-01

Understanding the barriers and assists to integrating ergonomics into production system design remains a research issue. An action research case study at Volvo Powertrain/Sweden was conducted. Researchers worked collaboratively with the firm in efforts to improve the company's ability to handle ergonomics in their daily work of improving and developing production systems. Researchers observed and reflected collectively on the change process using field notes and recordings to support their observations. Observed integration barriers included both individual level issues like life events, and organisational aspects such as communication barriers between groups or assignment of tasks to people not involved in decision-making. Observed assists included the 'political reflective navigation' (c.f. Broberg, O., Hermund, I., 2004. The OHS consultant as a 'political reflective navigator' in technological change processes. International Journal of Industrial Ergonomics 33 (4), 315-326) by the project owner to find new ways to overcome barriers and anchor ergonomics into the organisation. While special 'ergonomics' groups did not survive long, progress was observed in including ergonomics in regular design groups. A cross-functional workshop that fostered discussion across organisational boundaries helped shift focus from retrofitting systems to future production systems and improve engagement of engineering teams. Progress was marked by both success and setbacks and full integration appears to require more than 2 years time. It is concluded that support by senior managers should include succession planning for personnel that are key to the change effort.

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

Dunn, Darrell; Poinssot, Christophe; Begg, Bruce

Management of nuclear waste remains an important international topic that includes reprocessing of commercial nuclear fuel, waste-form design and development, storage and disposal packaging, the process of repository site selection, system design, and performance assessment. Requirements to manage and dispose of materials from the production of nuclear weapons, and the renewed interest in nuclear power, in particular through the Generation IV Forum and the Advanced Fuel Cycle Initiative, can be expected to increase the need for scientific advances in waste management. A broad range of scientific and engineering disciplines is necessary to provide safe and effective solutions and address complexmore » issues. This volume offers an interdisciplinary perspective on materials-related issues associated with nuclear waste management programs. Invited and contributed papers cover a wide range of topics including studies on: spent fuel; performance assessment and models; waste forms for low- and intermediate-level waste; ceramic and glass waste forms for plutonium and high-level waste; radionuclides; containers and engineered barriers; disposal environments and site characteristics; and partitioning and transmutation.« less

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.

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.

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

ERIC Educational Resources Information Center

National Academies Press, 2014

2014-01-01

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

The catchment based approach using catchment system engineering

NASA Astrophysics Data System (ADS)

Jonczyk, Jennine; Quinn, Paul; Barber, Nicholas; Wilkinson, Mark

2015-04-01

The catchment based approach (CaBa) has been championed as a potential mechanism for delivery of environmental directives such as the Water Framework Directive in the UK. However, since its launch in 2013, there has been only limited progress towards achieving sustainable, holistic management, with only a few of examples of good practice ( e.g. from the Tyne Rivers trust). Common issues with developing catchment plans over a national scale include limited data and resources to identify issues and source of those issues, how to systematically identify suitable locations for measures or suites of measures that will have the biggest downstream impact and how to overcome barriers for implementing solutions. Catchment System Engineering (CSE) is an interventionist approach to altering the catchment scale runoff regime through the manipulation of hydrological flow pathways throughout the catchment. A significant component of the runoff generation can be managed by targeting hydrological flow pathways at source, such as overland flow, field drain and ditch function, greatly reducing erosive soil losses. Coupled with management of farm nutrients at source, many runoff attenuation features or measures can be co-located to achieve benefits for water quality and biodiversity. A catchment, community-led mitigation measures plan using the CSE approach will be presented from a catchment in Northumberland, Northern England that demonstrate a generic framework for identification of multi-purpose features that slow, store and filter runoff at strategic locations in the landscape. Measures include within-field barriers, edge of field traps and within-ditch measures. Progress on the implementation of measures will be reported alongside potential impacts on the runoff regime at both local and catchment scale and costs.

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

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

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

2011-09-30

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

Thermal barrier coatings application in diesel engines

NASA Technical Reports Server (NTRS)

Fairbanks, J. W.

1995-01-01

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

Wireless technologies and accessibility for people with disabilities: findings from a policy research instrument.

PubMed

Baker, Paul M A; Moon, Nathan W

2008-01-01

The near universal deployment in the United States of a wide variety of information and communications technologies, both wired and wireless, creates potential barriers to use for several key populations, including the poor, people with disabilities, and the aging. Equal access to wireless technologies and services can be achieved through a variety of mechanisms, including legislation and regulations, market-based solutions, and awareness and outreach-based approaches. This article discusses the results of policy research conducted by the Rehabilitation Engineering Research Center on Wireless Technologies (Wireless RERC) using policy Delphi polling methodology to probe stakeholders' opinions on key access barrier issues and to explore potential policy responses. Participants included disability advocates, disability/wireless technology policy makers, and product developers/manufacturers. Respondent input informed subsequent development of potential policy initiatives to increase access to these technologies. The findings from the Delphi suggest that awareness issues remain most important, especially manufacturer awareness of user needs and availability of consumer information for selecting the most appropriate wireless devices and services. Other key issues included the ability of people with disabilities to afford technologies and inadequacies in legislation and policy making for ensuring their general accessibility, as well as usefulness in emergencies. Technical issues, including interoperability, speech-to-text conversion, and hearing aid compatibility, were also identified by participating stakeholders as important. To address all these issues, Delphi respondents favored goals and options congruent with voluntary market-driven solutions where possible but also supported federal involvement, where necessary, to aid this process.

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

ERIC Educational Resources Information Center

Brush, Kimberly M.

2013-01-01

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

2011 Georgiana Slough non-physical barrier performance evaluation project report

USGS Publications Warehouse

Reeves, Ryan R.; McQuirk, Jacob; Ameri, Khalid; Perry, Russell W.; Romine, Jason G.; Liedtke, Theresa L.; Burau, Jon R.; Blake, Aaron R.; Fitzer, Chris; Smith, Natalie; Pagliughi, Steve; Johnston, Sam; Kumagai, Kevin; Cash, Kenneth

2012-01-01

Under the ESA, the National Marine Fisheries Service (NMFS) issued the 2009 Biological and Conference Opinion for the Long‐Term Operations of the Central Valley Project and State Water Project (BO) for Chinook salmon and other listed anadromous fish species (NMFS 2009). Reasonable and Prudent Alternative (RPA) Action IV.1.3 of the BO requires the California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) to consider engineering solutions to reduce the diversion of juvenile salmonids from the Sacramento River into the interior and south Delta. DWR implemented the 2011 Georgiana Slough NonPhysical Barrier (GSNPB) Study to test the effectiveness of using a non-physical barrier, referred to as a behavioral Bio-Acoustic Fish Fence (BAFF), that combines three stimuli to deter juvenile Chinook salmon from entering Georgiana Slough: sound, high-intensity modulated light (previously known as stroboscopic light), and a bubble curtain. This report presents the results of the experimental tests conducted in 2011.

In-Drift Microbial Communities

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

D. Jolley

2000-11-09

As directed by written work direction (CRWMS M and O 1999f), Performance Assessment (PA) developed a model for microbial communities in the engineered barrier system (EBS) as documented here. The purpose of this model is to assist Performance Assessment and its Engineered Barrier Performance Section in modeling the geochemical environment within a potential repository drift for TSPA-SR/LA, thus allowing PA to provide a more detailed and complete near-field geochemical model and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999).more » This model and its predecessor (the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document, CRWMS M and O 1998a) was developed to respond to the applicable KTIs. Additionally, because of the previous development of the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a), the M and O was effectively able to resolve a previous KTI concern regarding the effects of microbial processes on seepage and flow (NRC 1998). This document supercedes the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a). This document provides the conceptual framework of the revised in-drift microbial communities model to be used in subsequent performance assessment (PA) analyses.« less

BIM: Enabling Sustainability and Asset Management through Knowledge Management

PubMed Central

2013-01-01

Building Information Modeling (BIM) is the use of virtual building information models to develop building design solutions and design documentation and to analyse construction processes. Recent advances in IT have enabled advanced knowledge management, which in turn facilitates sustainability and improves asset management in the civil construction industry. There are several important qualifiers and some disadvantages of the current suite of technologies. This paper outlines the benefits, enablers, and barriers associated with BIM and makes suggestions about how these issues may be addressed. The paper highlights the advantages of BIM, particularly the increased utility and speed, enhanced fault finding in all construction phases, and enhanced collaborations and visualisation of data. The paper additionally identifies a range of issues concerning the implementation of BIM as follows: IP, liability, risks, and contracts and the authenticity of users. Implementing BIM requires investment in new technology, skills training, and development of new ways of collaboration and Trade Practices concerns. However, when these challenges are overcome, BIM as a new information technology promises a new level of collaborative engineering knowledge management, designed to facilitate sustainability and asset management issues in design, construction, asset management practices, and eventually decommissioning for the civil engineering industry. PMID:24324392

BIM: enabling sustainability and asset management through knowledge management.

PubMed

Kivits, Robbert Anton; Furneaux, Craig

2013-11-10

Building Information Modeling (BIM) is the use of virtual building information models to develop building design solutions and design documentation and to analyse construction processes. Recent advances in IT have enabled advanced knowledge management, which in turn facilitates sustainability and improves asset management in the civil construction industry. There are several important qualifiers and some disadvantages of the current suite of technologies. This paper outlines the benefits, enablers, and barriers associated with BIM and makes suggestions about how these issues may be addressed. The paper highlights the advantages of BIM, particularly the increased utility and speed, enhanced fault finding in all construction phases, and enhanced collaborations and visualisation of data. The paper additionally identifies a range of issues concerning the implementation of BIM as follows: IP, liability, risks, and contracts and the authenticity of users. Implementing BIM requires investment in new technology, skills training, and development of new ways of collaboration and Trade Practices concerns. However, when these challenges are overcome, BIM as a new information technology promises a new level of collaborative engineering knowledge management, designed to facilitate sustainability and asset management issues in design, construction, asset management practices, and eventually decommissioning for the civil engineering industry.

Nanomanufacturing-related programs at NSF

NASA Astrophysics Data System (ADS)

Cooper, Khershed P.

2015-08-01

The National Science Foundation is meeting the challenge of transitioning lab-scale nanoscience and technology to commercial-scale through several nanomanufacturing-related research programs. The goal of the core Nanomanufacturing (NM) and the inter-disciplinary Scalable Nanomanufacturing (SNM) programs is to meet the barriers to manufacturability at the nano-scale by developing the fundamental principles for the manufacture of nanomaterials, nanostructures, nanodevices, and engineered nanosystems. These programs address issues such as scalability, reliability, quality, performance, yield, metrics, and cost, among others. The NM and SNM programs seek nano-scale manufacturing ideas that are transformative, that will be widely applicable and that will have far-reaching technological and societal impacts. It is envisioned that the results from these basic research programs will provide the knowledge base for larger programs such as the manufacturing Nanotechnology Science and Engineering Centers (NSECs) and the Nanosystems Engineering Research Centers (NERCs). Besides brief descriptions of these different programs, this paper will include discussions on novel

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.

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.

Adiabatic Wankel type rotary engine

NASA Technical Reports Server (NTRS)

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

1988-01-01

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

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

PubMed

Kalin, Robert M

2004-06-01

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

Analysis and test of insulated components for rotary engine

NASA Technical Reports Server (NTRS)

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

1989-01-01

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

Is There a Foreign Language Barrier in Engineering Research?

ERIC Educational Resources Information Center

Hawks, Carla; And Others

Perception and effects of foreign language publications in engineering research are examined. Through the use of both survey and archival sources, including coverage in major scientific and technical databases as vended by DIALOG, various aspects of the foreign language barrier were measured. A foreign language barrier is said to exist when…

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

NASA Astrophysics Data System (ADS)

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

2017-09-01

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

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2015-01-01

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

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.

Key Barriers for Academic Institutions Seeking to Retain Female Scientists and Engineers: Family-Unfriendly Policies. Low Numbers, Stereotypes, and Harassment

NASA Astrophysics Data System (ADS)

Rosser, Sue V.; Lane, Eliesh O'neil

At the end of a special meeting held at the Massachusetts Institute of Technology in January 2001, a statement released on behalf of the most prestigious U. S. research universities suggested that institutional harriers have prevented viomen from having a level playing field in science and engineering. In 2001, the National Science Foundation initiated a new awards program, ADVANCE, focusing on institutional rather than individual solutions to empower women to participate fully in science and technology. In this study, the authors evaluate survey responses from almost 400 Professional Opportunities for Women in Research and Education awardees from fiscal years 1997 to 2000 to elucidate problems and opportunities identified by female scientists and engineers. Besides other issues, the respondents identified balancing a career and a family as the most significant challenge facing female scientists and engineers today. Institutions must seek to remove or at least lower these and other harriers to attract and retain female scientists and engineers. Grouping the survey responses into four categories forms the basis for four corresponding policy areas, which could be addressed at the institutional level to mitigate the difficulties and challenges currently experienced by female scientists and engineers.

Thermal and Environmental Barrier Coatings for Advanced Propulsion Engine Systems

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

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

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.

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

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

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.

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.

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.

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

NASA Technical Reports Server (NTRS)

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

2017-01-01

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

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

PubMed

Karthikeya Sharma, T

2015-11-01

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

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

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

ERIC Educational Resources Information Center

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

2015-01-01

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

Identifying emerging issues in forestry as a tool for research planning.

Treesearch

Hans M. Gregersen; Allen L. Lundgren; Pamela J. Jakes; David N. Bengston

1989-01-01

A Delphi exercise is used to identify emerging issues in National Forest management and use, the relative importance of the issues, and barriers to resolving issues. USDA Forest Service managers agree on the importance of the 11 issues identified; however, researchers and National Forest managers do not always agree on the importance of issues or barriers.

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.

FY2016 Propulsion Materials Annual Progress Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines and Fuels) teams to develop strategies thatmore » overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

Masculinity and urogenital cancer: sensitive issues in health care.

PubMed

Nobis, Regina; Sand, Inger; Elofsson, Kristina

2007-02-01

The aim of this literature review was to analyse the approaches adopted by patients, health professionals, spouses and other care-givers towards sensitive issues related to male urogenital cancer, and to describe how these findings can be applied in health care practice. The findings revealed five identifiable domains, namely 'the barrier to talking', 'the barrier of sensitivity', 'the barrier of masculinity', 'the barrier to seeking health care' and 'the communicative barrier'. The conclusion was that the phenomenon of a barrier is strongly connected with hegemonic masculinity. The review of literature confirmed that, for many men, talking about genitally-related health problems is not easy and that health care professionals need to learn more about gender and masculinity in order to address urogenitally sensitive issues.

Metallic seal for thermal barrier coating systems

NASA Technical Reports Server (NTRS)

Miller, Robert A. (Inventor)

1990-01-01

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

Natural gas applications for hybrid vehicles. Final report, October 1992-July 1993

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

Bentley, J.M.

1993-08-01

Hybrid vehicle technology holds the potential for improved efficiency and emissions compared with internal combustion (IC) engines and improved range and refueling convenience over electric vehicles. This study evaluated the potential for using natural gas as a hybrid vehicle fuel. Potential regulatory and market drivers were evaluated for hybrids generally and natural gas hybrids in specific. Heat engine options and other configuration issues were investigated to determine efficiency, emissions or other benefits of light- and heavy-duty hybrids. Several hybrid vehicle configurations were evaluated to determine the specific packaging attributes of natural gas in a hybrid configuration. Generally, conventional IC enginesmore » appear adequate for most emissions-sensitive hybrid applications with no great advantage being gained from using turbines or other more advanced heat engines. The largest technology barrier to a near-term hybrid is the weight of available or near-term batteries. Smaller, light-duty hybrid vehicles will be more sensitive to this weight handicap than larger vehicles such as the urban transit bus.« less

Advanced Environmental Barrier Coatings Development for Si-Based Ceramics

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Choi, R. Sung; Robinson, Raymond C.; Lee, Kang N.; Bhatt, Ramakrishna T.; Miller, Robert A.

2005-01-01

Advanced environmental barrier coating concepts based on multi-component HfO2 (ZrO2) and modified mullite systems are developed for monolithic Si3N4 and SiC/SiC ceramic matrix composite (CMC) applications. Comprehensive testing approaches were established using the water vapor cyclic furnace, high pressure burner rig and laser heat flux steam rig to evaluate the coating water vapor stability, cyclic durability, radiation and erosion resistance under simulated engine environments. Test results demonstrated the feasibility and durability of the environmental barrier coating systems for 2700 to 3000 F monolithic Si3N4 and SiC/SiC CMC component applications. The high-temperature-capable environmental barrier coating systems are being further developed and optimized in collaboration with engine companies for advanced turbine engine applications.

MAGNESIUM ALLOYS IN US MILITARY APPLICATIONS: PAST, CURRENT AND FUTURE SOLUTIONS

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

Mathaudhu, Suveen N.; Nyberg, Eric A.

2010-02-26

Since the 1940’s Mg-alloys have been used for military applications, from aircraft components to ground vehicles. The drive for usage was primarily availability and lightweighting of military systems. But the promise of widespread military usage was not met largely based on corrosion and flammability concerns, poor mechanical behavior and inferior ballistic response. This review paper will cover historical, current and potential future applications with a focus on scientific, engineering and social barriers relevant to integration of Mg-alloy. It will also present mechanical and physical property improvements solutions which are currently being developed to address these issues.

40 CFR 194.44 - Engineered barriers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... compliance assessment; (vi) Public comments requesting specific engineered barriers; (vii) The increased or..., after consideration of one or more of the factors in paragraph (c)(1) of this section, the Department... without evaluating the remaining factors in paragraph (c)(1) of this section, then any compliance...

Hydrogen-enriched fuels

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

Roser, R.

1998-08-01

NRG Technologies, Inc. is attempting to develop hardware and infrastructure that will allow mixtures of hydrogen and conventional fuels to become viable alternatives to conventional fuels alone. This commercialization can be successful if the authors are able to achieve exhaust emission levels of less than 0.03 g/kw-hr NOx and CO; and 0.15 g/kw-hr NMHC at full engine power without the use of exhaust catalysts. The major barriers to achieving these goals are that the lean burn regimes required to meet exhaust emissions goals reduce engine output substantially and tend to exhibit higher-than-normal total hydrocarbon emissions. Also, hydrogen addition to conventionalmore » fuels increases fuel cost, and reduces both vehicle range and engine output power. Maintaining low emissions during transient driving cycles has not been demonstrated. A three year test plan has been developed to perform the investigations into the issues described above. During this initial year of funding research has progressed in the following areas: (a) a cost effective single-cylinder research platform was constructed; (b) exhaust gas speciation was performed to characterize the nature of hydrocarbon emissions from hydrogen-enriched natural gas fuels; (c) three H{sub 2}/CH{sub 4} fuel compositions were analyzed using spark timing and equivalence ratio sweeping procedures and finally; (d) a full size pick-up truck platform was converted to run on HCNG fuels. The testing performed in year one of the three year plan represents a baseline from which to assess options for overcoming the stated barriers to success.« less

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

PubMed Central

Karthikeya Sharma, T.

2014-01-01

Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine’s performance within the range studied. PMID:26644918

Thermal and Environmental Barrier Coatings for Advanced Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2005-01-01

Ceramic thermal and environmental barrier coatings (T/EBCs) will play a crucial role in advanced gas turbine engine systems because of their ability to significantly increase engine operating temperatures and reduce cooling requirements, thus help achieve engine low emission and high efficiency goals. Advanced T/EBCs are being developed for the low emission SiC/SiC ceramic matrix composite (CMC) combustor applications by extending the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water vapor containing combustion environments. Low conductivity thermal barrier coatings (TBCs) are also being developed for metallic turbine airfoil and combustor applications, providing the component temperature capability up to 1650 C (3000 F). In this paper, ceramic coating development considerations and requirements for both the ceramic and metallic components will be described for engine high temperature and high-heat-flux applications. The underlying coating failure mechanisms and life prediction approaches will be discussed based on the simulated engine tests and fracture mechanics modeling results.

Barriers to midwives and nurses addressing mental health issues with women during the perinatal period: The Mind Mothers study.

PubMed

Higgins, Agnes; Downes, Carmel; Monahan, Mark; Gill, Ailish; Lamb, Stephen A; Carroll, Margaret

2018-01-03

To explore barriers to midwives and nurses addressing mental health issues with women during the perinatal period. Perinatal mental health is considered an important public health issue with health policy internationally identifying the importance of psychological support for women in the perinatal period. Midwives and primary care nurses are ideally positioned to detect mental distress early, but evidence suggests that they are reluctant to discuss mental health issues with women during pregnancy or in the postnatal period. The research used a descriptive design. A total of 809 midwives and nurses completed an anonymous, online or hard copy survey. Designed by the research team, the survey listed 26 potential barriers to the provision of perinatal mental health care. Participants identified organisational factors as presenting the greatest barriers. Organisational barriers included lack of perinatal mental health services, absence of care pathways, heavy workload, lack of time, lack of privacy and not seeing women regularly enough to build a relationship. Over 50% of participants identified practitioner-related barriers, such as lack of knowledge on perinatal mental health and cultural issues; lack of skill, in particular, skills to respond to a disclosure of a mental health issue; and fears of causing women offence and distress. Findings also indicated that the context of care and education influenced the degree to which participants perceived certain items as barriers. Midwives and primary care nurses encounter many organisational- and practitioner-related barriers that negatively impact on their ability to incorporate mental health care into their practice. Midwifery and nursing services need to develop strategies to address system- and practitioner-related barriers, including the development of services and care pathways, and the provision of culturally sensitive education on perinatal mental health in order to support practitioners to address issues with confidence and competence. © 2018 John Wiley & Sons Ltd.

Development of Advanced Environmental Barrier Coatings for SiC/SiC Composites at NASA GRC: Prime-Reliant Design and Durability Perspectives

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2017-01-01

Environmental barrier coatings (EBCs) are considered technologically important because of the critical needs and their ability to effectively protect the turbine hot-section SiC/SiC ceramic matrix composite (CMC) components in harsh engine combustion environments. The development of NASA's advanced environmental barrier coatings have been aimed at significantly improved the coating system temperature capability, stability, erosion-impact, and CMAS resistance for SiC/SiC turbine airfoil and combustors component applications. The NASA environmental barrier coating developments have also emphasized thermo-mechanical creep and fatigue resistance in simulated engine heat flux and environments. Experimental results and models for advanced EBC systems will be presented to help establishing advanced EBC composition design methodologies, performance modeling and life predictions, for achieving prime-reliant, durable environmental coating systems for 2700-3000 F engine component applications. Major technical barriers in developing environmental barrier coating systems and the coating integration with next generation composites having further improved temperature capability, environmental stability, EBC-CMC fatigue-environment system durability will be discussed.

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.

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

PubMed

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

2018-01-01

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

40 CFR 194.44 - Engineered barriers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... prevent or substantially delay the movement of water or waste toward the accessible environment; (ii) The... reduced total system costs; (viii) The impact, if any, on other waste disposal programs from the... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Engineered barriers. 194.44 Section...

40 CFR 194.44 - Engineered barriers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... prevent or substantially delay the movement of water or waste toward the accessible environment; (ii) The... reduced total system costs; (viii) The impact, if any, on other waste disposal programs from the... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Engineered barriers. 194.44 Section...

40 CFR 194.44 - Engineered barriers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... impact on worker exposure to radiation both during and after incorporation of engineered barriers; (iii... reduced total system costs; (viii) The impact, if any, on other waste disposal programs from the..., after consideration of one or more of the factors in paragraph (c)(1) of this section, the Department...

Cultivating Diversity and Competency in STEM: Challenges and Remedies for Removing Virtual Barriers to Constructing Diverse Higher Education Communities of Success.

PubMed

Whittaker, Joseph A; Montgomery, Beronda L

2012-01-01

The need to increase the number of college graduates in Science, Technology, Engineering, and Mathematics (STEM) disciplines is a national issue. As the demographics of the United States' population grow increasingly more diverse, the recognition that students of color are disproportionately under-represented among those individuals successful at completing STEM degrees requires exigent and sustained intervention. Although a range of efforts and funding have been committed to increasing the success of under-represented minority (URM) students at primarily white, or majority, institutions, widespread progress has been slow. Simultaneously, Historically Black Colleges and Universities and Minority Serving Institutions have demonstrated disproportionate successes in graduating URM students with STEM degrees and those that proceed to completing graduate-level degrees in the sciences. The differential successes of particular institutions with promoting the achievement of diverse individuals in obtaining academic STEM degrees suggest that with committed and strategic leadership, advancements in creating academic communities that promote the success of a diverse range of students in STEM can be achieved in part through assessing and mitigating environmental barriers that impede success at majority institutions. In this paper, we address issues related to the engagement of URM students in majority settings and describe some efforts that have shown success for promoting diversity in STEM and highlight continuing issues and factors associated with cultivating diversity in academic STEM disciplines at majority institutions. Recommended efforts include addressing academic assistance, professional and cultural socialization issues and institutional environmental factors that are associated with success or lack thereof for URMs in STEM.

Hydrologic behavior of two engineered barriers following extreme wetting.

PubMed

Porro, I

2001-01-01

Many engineered barriers are expected to function for hundreds of years or longer. Over the course of time, it is likely that some barriers will experience infiltration to the point of breakthrough. This study compares the recovery from breakthrough of two storage-evapotranspiration type engineered barriers. Replicates of test plots comprising thick soil and capillary-biobarrier covers were wetted to breakthrough in 1997. Test plots were kept cleared of vegetation to maximize hydrologic stress during recovery. Following cessation of drainage resulting from the wetting irrigations, water storage levels in all plots were at elevated levels compared with pre-irrigation levels. As a result, infiltration of melting snow during the subsequent spring overloaded the storage capacity and produced drainage in all plots. Relatively rapid melting of accumulated snowfall produced the most significant infiltration events each year during the study. Capillary barriers yielded less total drainage than thick soil barriers. By limiting drainage, capillary barriers increased water storage in the upper portions of the test plots, which led to increased evaporation from the capillary barrier plots compared with thick soil plots. Increased evaporation in the capillary barrier plots allowed more water to infiltrate in the second season following the wetting tests without triggering drainage. All thick soil plots again yielded drainage in the second season. Within two years of intentionally induced breakthrough, evaporation alone (without transpiration) restored the capability of the capillary barrier covers to function as intended, although water storage in these covers remained at elevated levels.

2000 NASA Seal/Secondary Air System Workshop. Volume 1

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

2001-01-01

The 2000 NASA Seal/Secondary Air System Workshop covered four main areas: (1) overviews of NASA-sponsored Ultra-Efficient Engine Technology (UEET) and Access to Space Programs, with emphasis on program goals and seal needs; (2) review of turbine engine seal issues from the perspective of end users such as United Airlines; (3) reviews of sealing concepts, test results, experimental facilities, and numerical predictions; and (4) reviews of material development programs relevant to advanced seals development. The NASA UEET overview illustrates for the reader the importance of advanced technologies, including seals, in meeting future engine system efficiency and emission goals. GE, Pratt & Whitney, and Honeywell presented advanced seal development work being performed within their organizations. The NASA-funded GE/Stein Seal team has successfully demonstrated a large (3-ft. diam) aspirating seal that can withstand all anticipated pressures, speeds, and rotor runouts anticipated for a GE90 L.P. turbine balance piston location. GE/Stein Seal are fabricating a full-scale seal to be tested in a GE-90 ground test engine in early 2002. Pratt & Whitney and Stein Seal are investigating carbon seals to accommodate large radial movements anticipated in future geared-fan gearbox locations. Honeywell presented a finger seal design being considered for a high-temperature static combustor location incorporating ceramic finger elements. Successful demonstration of the braided carbon rope thermal barriers to extreme temperatures (5500 F) for short durations provide a new form of very high temperature thermal barrier for future Shuttle solid rocket motor nozzle joints. The X-37, X-38, and future highly reusable launch vehicles pose challenging control surface seal demands that require new seal concepts made from emerging high temperature ceramics and other materials.

40 CFR 194.44 - Engineered barriers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... prevent or substantially delay the movement of water or waste toward the accessible environment; (ii) The... reduced total system costs; (viii) The impact, if any, on other waste disposal programs from the... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Engineered barriers. 194.44 Section 194...

Laboratory Barriers in Science, Engineering, and Mathematics for Students with Disabilities.

ERIC Educational Resources Information Center

Heidari, Farzin

This report addresses the barriers college students with disabilities face in the laboratory setting. In engineering, mathematics, and science education most courses require laboratory work which may pose challenges to those with disabilities. Instructors should be aware of the individual needs of students with disabilities and make necessary…

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

ERIC Educational Resources Information Center

Susomrith, Pattanee; Coetzer, Alan

2015-01-01

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

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.

Legal knowledge, needs, and assistance seeking among HIV positive and negative women in Umlazi, South Africa.

PubMed

Hill, Lauren M; Maman, Suzanne; Holness, David; Moodley, Dhayendre

2016-01-22

The rights of women and people living with HIV (PLHIV) are protected under South African law, yet there is a gap in the application of these laws. While there are numerous systemic and social barriers to women's and PLHIV's exercise of their legal rights and rights to access social services, there has been little effort to document these barriers as well as legal needs and knowledge in this context. 1480 HIV-positive and HIV-negative women recruited from an antenatal clinic in Umlazi Township completed a questionnaire on legal knowledge, experience of legal issues, assistance seeking for legal issues, and barriers to seeking assistance. We compared the legal knowledge and experience of legal issues of HIV-positive and HIV-negative women, and described assistance seeking and barriers to assistance seeking among all women. Both HIV-positive and HIV-negative women had high levels of knowledge of their legal rights. There were few important differences in legal knowledge and experience of legal issues by HIV status. The most common legal issues women experienced were difficulty obtaining employment (11 %) and identification documents (7 %). A minority of women who had ever experienced a legal issue had sought assistance for this issue (38 %), and half (50 %) of assistance sought was from informal sources such as family and friends. Women cited lack of time and government bureaucracy as the major barriers to seeking assistance. These results indicate few differences in legal knowledge and needs between HIV-positive and HIV-negative women in this context, but rather legal needs common among women of reproductive age. Legal knowledge may be a less important barrier to seeking assistance for legal issues than time, convenience, and cost. Expanding the power of customary courts to address routine legal issues, encouragement of pro bono legal assistance, and introduction of legal navigators could help to address these barriers.

Perspective on thermal barrier coatings for industrial gas turbine applications

NASA Technical Reports Server (NTRS)

Mutasim, Zaher; Brentnall, William

1995-01-01

Thermal barrier coatings (TBC's) have been used in high thrust aircraft engines for many years, and have proved to be very effective in providing thermal protection and increasing engine efficiencies. TBC life requirements for aircraft engines are typically less than those required for industrial gas turbines. This paper describes current and future applications of TBC's in industrial gas turbine engines. Early testing and applications of TBC's is reviewed. Areas of concern from the engine designer's and materials engineer's perspective are identified and evaluated. This paper focuses on the key factors that are expected to influence utilization of TBC's in advanced industrial gas turbine engines. It is anticipated that reliable, durable and highly effective coating systems will be produced that will ultimately improve engine efficiency and performance.

Translating Research to Practice: Overcoming Barriers to Implementing Effective Off-Campus Party Intervention. Issues in Prevention

ERIC Educational Resources Information Center

Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2012

2012-01-01

This issue of "Issues in Prevention" focuses on overcoming barriers in implementing effective off-campus party intervention. This issue contains the following articles: (1) Confronting the Problems Associated With Off-Campus Parties With Evidence-Based Strategies (John D. Clapp); (2) Overview of Research on Effective Off-Campus Party…

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.

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

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

`Getting stuck' in analogue electronics: threshold concepts as an explanatory model

NASA Astrophysics Data System (ADS)

Harlow, A.; Scott, J.; Peter, M.; Cowie, B.

2011-10-01

Could the challenge of mastering threshold concepts be a potential factor that influences a student's decision to continue in electronics engineering? This was the question that led to a collaborative research project between educational researchers and the Faculty of Engineering in a New Zealand university. This paper deals exclusively with the qualitative data from this project, which was designed to investigate the high attrition rate of students taking introductory electronics in a New Zealand university. The affordances of the various teaching opportunities and the barriers that students perceived are examined in the light of recent international research in the area of threshold concepts and transformational learning. Suggestions are made to help students move forward in their thinking, without compromising the need for maintaining the element of intellectual uncertainty that is crucial for tertiary teaching. The issue of the timing of assessments as a measure of conceptual development or the crossing of thresholds is raised.

Barriers and enablers to the use of high-fidelity patient simulation manikins in nurse education: an integrative review.

PubMed

Al-Ghareeb, Amal Z; Cooper, Simon J

2016-01-01

This integrative review identified, critically appraised and synthesised the existing evidence on the barriers and enablers to using high-fidelity human patient simulator manikins (HPSMs) in undergraduate nursing education. In nursing education, specifically at the undergraduate level, a range of low to high-fidelity simulations have been used as teaching aids. However, nursing educators encounter challenges when introducing new teaching methods or technology, despite the prevalence of high-fidelity HPSMs in nursing education. An integrative review adapted a systematic approach. Medline, CINAHL plus, ERIC, PsychINFO, EMBASE, SCOPUS, Science Direct, Cochrane database, Joanna Brigge Institute, ProQuest, California Simulation Alliance, Simulation Innovative Recourses Center and the search engine Google Scholar were searched. Keywords were selected and specific inclusion/exclusion criteria were applied. The review included all research designs for papers published between 2000 and 2015 that identified the barriers and enablers to using high-fidelity HPSMs in undergraduate nursing education. Studies were appraised using the Critical Appraisal Skills Programme criteria. Thematic analysis was undertaken and emergent themes were extracted. Twenty-one studies were included in the review. These studies adopted quasi-experimental, prospective non-experimental and descriptive designs. Ten barriers were identified, including "lack of time," "fear of technology" and "workload issues." Seven enablers were identified, including "faculty training," "administrative support" and a "dedicated simulation coordinator." Barriers to simulation relate specifically to the complex technologies inherent in high-fidelity HPSMs approaches. Strategic approaches that support up-skilling and provide dedicated technological support may overcome these barriers. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

ERIC Educational Resources Information Center

National Academies Press, 2007

2007-01-01

The United States economy relies on the productivity, entrepreneurship, and creativity of its people. To maintain its scientific and engineering leadership amid increasing economic and educational globalization, the United States must aggressively pursue the innovative capacity of all its people--women and men. However, women face barriers to…

10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false Performance objectives for the geologic repository after permanent closure. 63.113 Section 63.113 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH... and an engineered barrier system. (b) The engineered barrier system must be designed so that, working...

10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false Performance objectives for the geologic repository after permanent closure. 63.113 Section 63.113 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH... and an engineered barrier system. (b) The engineered barrier system must be designed so that, working...

10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Performance objectives for the geologic repository after permanent closure. 63.113 Section 63.113 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH... and an engineered barrier system. (b) The engineered barrier system must be designed so that, working...

10 CFR 63.113 - Performance objectives for the geologic repository after permanent closure.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 2 2012-01-01 2012-01-01 false Performance objectives for the geologic repository after permanent closure. 63.113 Section 63.113 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH... and an engineered barrier system. (b) The engineered barrier system must be designed so that, working...

How Does Service Learning Increase and Sustain Interest in Engineering Education for Underrepresented Pre-Engineering College Students?

ERIC Educational Resources Information Center

Bosman, Lisa; Chelberg, Kelli; Winn, Ryan

2017-01-01

Many barriers exist for American Indian students pursuing STEM degree programs. However, federally recognized Tribal Colleges and Universities (TCUs) are uniquely suited to overcome these barriers because of their shared mission to provide 21st Century educational opportunities for American Indian students. Qualitative and quantitative findings…

Engineered Barrier System: Physical and Chemical Environment

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

P. Dixon

2004-04-26

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

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

NASA Astrophysics Data System (ADS)

Karthickeyan, V.; Balamurugan, P.

2017-10-01

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

FY2014 Propulsion Materials R&D Annual Progress Report

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

None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machinesmore » [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

FY2015 Propulsion Materials Annual Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machinesmore » [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

Breaking Barriers, Building Bridges: Critical Discussion of Social Issues.

ERIC Educational Resources Information Center

Moss, Joy

Noting that picture books can invite students to engage in critical discussion of complex issues of race, class, and gender, this lesson plan helps students to confront the injustice of barriers that separate human beings from one another and to examine the role of prejudice and stereotypes in sustaining these barriers. During the five 45-minute…

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

NASA Technical Reports Server (NTRS)

Moller, Paul S.

1995-01-01

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

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.

Case Study Analysis of the Effect of Contextual Supports and Barriers on African American Students' Persistence in Engineering

ERIC Educational Resources Information Center

Montgomery, Lisa

2009-01-01

Using case study methodology (Stake, 2006), this research examined the environmental influences, or contextual supports and barriers, that were most influential in contributing to African American students' persistence in an engineering major. Social cognitive career theory provides the framework for understanding the role of contextual supports…

Race and Gender Effects on Persistence, Barriers to Engineering and Life Goals by Middle School Children.

ERIC Educational Resources Information Center

Wood, Rose Morgan; Schaer, Barbara B.

The under-representation of women and African Americans in engineering spurred the research documented in this study. This document reports the reults of a study investigating middle school (in a southeastern rural community) children's attitudes toward persistence, life goals and sex-stereotypes, as potential barriers to their pursuit of…

46 CFR 11.501 - Grade and type of engineer endorsements issued.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Grade and type of engineer endorsements issued. 11.501... REQUIREMENTS FOR OFFICER ENDORSEMENTS Professional Requirements for Engineer Officer § 11.501 Grade and type of engineer endorsements issued. (a) Engineer endorsements are issued in the grades of: (1) Chief engineer; (2...

46 CFR 11.501 - Grade and type of engineer endorsements issued.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Grade and type of engineer endorsements issued. 11.501... REQUIREMENTS FOR OFFICER ENDORSEMENTS Professional Requirements for Engineer Officer § 11.501 Grade and type of engineer endorsements issued. (a) Engineer endorsements are issued in the grades of: (1) Chief engineer; (2...

46 CFR 11.501 - Grade and type of engineer endorsements issued.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Grade and type of engineer endorsements issued. 11.501... REQUIREMENTS FOR OFFICER ENDORSEMENTS Professional Requirements for Engineer Officer § 11.501 Grade and type of engineer endorsements issued. (a) Engineer endorsements are issued in the grades of: (1) Chief engineer; (2...

46 CFR 11.501 - Grade and type of engineer endorsements issued.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Grade and type of engineer endorsements issued. 11.501... REQUIREMENTS FOR OFFICER ENDORSEMENTS Professional Requirements for Engineer Officer § 11.501 Grade and type of engineer endorsements issued. (a) Engineer endorsements are issued in the grades of: (1) Chief engineer; (2...

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.

Ceramic thermal barrier coatings for electric utility gas turbine engines

NASA Technical Reports Server (NTRS)

Miller, R. A.

1986-01-01

Research and development into thermal barrier coatings for electric utility gas turbine engines is reviewed critically. The type of coating systems developed for aircraft applications are found to be preferred for clear fuel electric utility applications. These coating systems consists of a layer of plasma sprayed zirconia-yttria ceramic over a layer of MCrAly bond coat. They are not recommended for use when molten salts are presented. Efforts to understand coating degradation in dirty environments and to develop corrosion resistant thermal barrier coatings are discussed.

Predictors of Attitudes toward Disability and Employment Policy Issues among Undergraduate Students at the University of Nairobi

ERIC Educational Resources Information Center

Mamboleo, George Isaboke

2009-01-01

Disability rights issues are an emerging area of discourse in Kenya. Persons with disabilities in Kenya face many barriers to integration into the larger Kenyan society possibly due to barriers such as societal negative attitudes. Research has indicated that the greatest barrier to rehabilitation of persons with disabilities is negative attitudes…

A qualitative, interprofessional analysis of barriers to and facilitators of implementation of the Department of Veterans Affairs' Clostridium difficile prevention bundle using a human factors engineering approach.

PubMed

Yanke, Eric; Moriarty, Helene; Carayon, Pascale; Safdar, Nasia

2018-03-01

Clostridium difficile infection (CDI) is increasingly prevalent, severe, and costly. Adherence to infection prevention practices remains suboptimal. More effective strategies to implement guidelines and evidence are needed. Interprofessional focus groups consisting of physicians, resident physicians, nurses, and health technicians were conducted for a quality improvement project evaluating adherence to the Department of Veterans Affairs' (VA) nationally mandated C difficile prevention bundle. Qualitative analysis with a visual matrix display identified barrier and facilitator themes guided by the Systems Engineering Initiative for Patient Safety model, a human factors engineering approach. Several themes, encompassing both barriers and facilitators to bundle adherence, emerged. Rapid turnaround time of C difficile polymerase chain reaction testing was a facilitator of timely diagnosis. Too few, poorly located, and cluttered sinks were barriers to appropriate hand hygiene. Patient care workload and the time-consuming process of contact isolation precautions were also barriers to adherence. Multiple work system components serve as barriers to and facilitators of adherence to the VA CDI prevention bundle among an interprofessional group of health care workers. Organizational factors appear to significantly influence bundle adherence. Interprofessional perspectives are needed to identify barriers to and facilitators of bundle implementation, which is a necessary first step to address adherence to bundled infection prevention practices. Published by Elsevier Inc.

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.

High Pressure Burner Rig Testing of Advanced Environmental Barrier Coatings for Si3N4 Turbine Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Fox, Dennis S.; Pastel, Robert T.

2007-01-01

Advanced thermal and environmental barrier coatings are being developed for Si3N4 components for turbine engine propulsion applications. High pressure burner rig testing was used to evaluate the coating system performance and durability. Test results demonstrated the feasibility and durability of the coating component systems under the simulated engine environments.

Barriers to the utilization of synthetic fuels for transportation

NASA Technical Reports Server (NTRS)

Parker, H. W.; Reilly, M. J.

1981-01-01

The principal types of engines for transportation uses are reviewed and the specifications for conventional fuels are compared with specifications for synthetic fuels. Synfuel processes nearing the commercialization phase are reviewed. The barriers to using synfuels can be classified into four groups: technical, such as the uncertainty that a new engine design can satisfy the desired performance criteria; environmental, such as the risk that the engine emissions cannot meet the applicable environmental standards; economic, including the cost of using a synfuel relative to conventional transportation fuels; and market, involving market penetration by offering new engines, establishing new distribution systems and/or changing user expectations.

Teaching Climate Change Science in Senior Secondary School: Issues, Barriers and Opportunities

ERIC Educational Resources Information Center

Bunten, Rod; Dawson, Vaille

2014-01-01

This paper argues that, despite its difficulties, climate change can (and perhaps needs to) be taught rigorously to students by enquiry rather than through transmission and that such a method will enable students to make judgments on other issues of scientific controversy. It examines the issues and barriers to the teaching of climate change,…

Thermal barrier coatings for aircraft engines: History and directions

NASA Technical Reports Server (NTRS)

Miller, R. A.

1995-01-01

Thin thermal barrier coatings for protecting aircraft turbine section airfoils are examined. The discussion focuses on those advances that led first to their use for component life extension and more recently as an integral part of airfoil design. It is noted that development has been driven by laboratory rig and furnace testing corroborated by engine testing and engine field experience. The technology has also been supported by performance modeling to demonstrate benefits and life modeling for mission analysis. Factors which have led to the selection of the current state-of-the-art plasma sprayed and physical vapor deposited zirconia-yttria/MCrAlY TBC's is emphasized in addition to observations fundamentally related to their behavior. Current directions in research into thermal barrier coatings and recent progress at NASA is also noted.

Education in Engineering and Ecohydrology for Fish Passage

NASA Astrophysics Data System (ADS)

Ahlfeld, D.; Towler, B.

2011-12-01

Historical fish migration routes linking feeding and spawning habitats have been significantly impacted by culverts, dikes, dams, and other barriers on waterways throughout the world. For example an estimated 2.5 million barriers to fish migration exist in the United States. In recent years, there has been an increased focus on removing or mitigating these barriers as an efficient mechanism to restore habitat. Effective design and implementation of these measures requires specialists with skills at the intersection of engineering, hydrology and biology. Recognizing the need for a cadre of engineers with the additional skills in hydraulics and ecohydrology needed to analyze and design solutions for enhancing fish passage in streams and rivers, the University of Massachusetts Amherst now offers a Master of Science in Civil Engineering (MSCE) degree with a specialization in Fish Passage Engineering. The curriculum is offered in conjunction with the U.S. Fish and Wildlife Service and is informed by the recommendations of the Curriculum Working Group of the Bioengineering Section of the American Fisheries Society. The curriculum is offered through the Department of Civil and Environmental Engineering. This presentation will describe the motivation for the degree, the content of coursework and the challenges inherent in developing an interdisciplinary education program spanning biogeosciences and engineering.

Eliminating Xenoantigen Expression on Swine RBC.

PubMed

Wang, Zheng-Yu; Martens, Gregory R; Blankenship, Ross L; Sidner, Richard A; Li, Ping; Estrada, Jose L; Tector, Matthew; Tector, A Joseph

2017-03-01

The rapidly improving tools of genetic engineering may make it possible to overcome the humoral immune barrier that prevents xenotransplantation. We hypothesize that levels of human antibody binding to donor tissues from swine must approximate the antibody binding occurring in allotransplantation. It is uncertain if this is an attainable goal. Here we perform an initial analysis of this issue by comparing human antibody binding to red blood cells (RBC) isolated from knockout swine and to allogeneic or autologous human RBC. Human sera were incubated with RBC isolated from various genetically engineered swine or from humans. The level of IgG and IgM binding to these cells were compared using either flow cytometry or a novel mass spectrometric assay. Mass spectroscopic quantitation of human antibody binding demonstrated that as few as 3 gene inactivations can reduce the levels human antibody binding to swine RBC that is as low as autologous human RBC. Flow cytometry showed that RBC from 2-gene knockout swine exhibited less human antibody binding than human blood group O allogeneic RBC in 22% of tested sera. Deletion of a third gene from pigs resulted in 30% of human samples having less IgG and IgM RBC xenoreactivity than alloreactivity. Xenoantigenicity of swine RBC can be eliminated via gene disruption. These results suggest that the gene knockout approach may be able reduce antigenicity in other pig tissues to levels that enable the xenotransplantation humoral barrier to be overcome.

Energy efficient engine, high pressure turbine thermal barrier coating. Support technology report

NASA Technical Reports Server (NTRS)

Duderstadt, E. C.; Agarwal, P.

1983-01-01

This report describes the work performed on a thermal barrier coating support technology task of the Energy Efficient Engine Component Development Program. A thermal barrier coating (TBC) system consisting of a Ni-Cr-Al-Y bond cost layer and ZrO2-Y2O3 ceramic layer was selected from eight candidate coating systems on the basis of laboratory tests. The selection was based on coating microstructure, crystallographic phase composition, tensile bond and bend test results, erosion and impact test results, furnace exposure, thermal cycle, and high velocity dynamic oxidation test results. Procedures were developed for applying the selected TBC to CF6-50, high pressure turbine blades and vanes. Coated HPT components were tested in three kinds of tests. Stage 1 blades were tested in a cascade cyclic test rig, Stage 2 blades were component high cycle fatigue tested to qualify thermal barrier coated blades for engine testing, and Stage 2 blades and Stage 1 and 2 vanes were run in factory engine tests. After completion of the 1000 cycle engine test, the TBC on the blades was in excellent condition over all of the platform and airfoil except at the leading edge above midspan on the suction side of the airfoil. The coating damage appeared to be caused by particle impingement; adjacent blades without TBC also showed evidence of particle impingement.

Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines

NASA Technical Reports Server (NTRS)

Stephens, G. E.

1980-01-01

The materials technologies studied included thermal barrier coatings for turbine airfoils, turbine disks, cases, turbine vanes and engine and nacelle composite materials. The cost/benefit of each technology was determined in terms of Relative Value defined as change in return on investment times probability of success divided by development cost. A recommended final ranking of technologies was based primarily on consideration of Relative Values with secondary consideration given to changes in other economic parameters. Technologies showing the most promising cost/benefits were thermal barrier coated temperature nacelle/engine system composites.

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

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

NASA Astrophysics Data System (ADS)

Fergus, Jeffrey W.

2014-06-01

One of the important applications of yttria-stabilized zirconia (YSZ) is as a thermal barrier coating for gas turbine engines. While YSZ performs well in this function, the need for increased operating temperatures to achieve higher energy conversion efficiencies, requires the development of improved materials. To meet this challenge, some rare-earth zirconates that form the cubic fluorite-derived pyrochlore structure are being developed for use in thermal barrier coatings due to their low thermal conductivity, excellent chemical stability, and other suitable properties. In this paper, the thermal conductivities of current and prospective oxides for use in thermal barrier coatings are reviewed. The factors affecting the variations and differences in the thermal conductivities and the degradation behaviors of these materials are discussed.

Delay time and Hartman effect in strain engineered graphene

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

Chen, Xi, E-mail: xchen@shu.edu.cn; Deng, Zhi-Yong; Ban, Yue, E-mail: yban@shu.edu.cn

2014-05-07

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

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 degradation under high-heat-flux and environment load test conditions.

Barriers to vocational effectiveness in ACT: staff perspectives.

PubMed

Waynor, William R; Pratt, Carlos W

2011-01-01

Assertive community treatment (ACT), for persons with serious mental illness, includes a vocational focus as an important aspect of community integration. Nevertheless, research suggests that ACT does not assist significant numbers of consumers in achieving employment goals. A two-step survey of New Jersey ACT team members was designed to identify the key issues that hinder ACT staff members in assisting consumers with obtaining employment. Survey items were categorized into three sections: (a) staff attitudes, (b) consumer barriers, and (c) staff barriers to working on employment. The initial survey asked staff members to rate items in each of these categories. Highly rated items were used in a subsequent paired comparison survey to determine the relative importance of each. This method highlighted the following issues: four staff attitude items-(a) returning to work is positive, (b) employment is key to recovery, (c) abstinence from substance abuse is needed to work, and (d) consumers are too ill to work; four consumer barrier items-(a) fear of loss of Social Security Administration benefits, (b) symptoms related to the illness, (c) lack of motivation, and (d) poor social skills; and three barriers to working on employment issues items-(a) clinical issues take priority, (b) other case management issues takes priority, and (c) too many emergencies. The implications for staff training are discussed.

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 (in air), to investigate the water vapor effect. All cyclic tests were conducted using a 60-min hot-time temperature.

14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...

14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...

14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...

14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...

14 CFR 63.42 - Flight engineer certificate issued on basis of a foreign flight engineer license.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight engineer certificate issued on basis of a foreign flight engineer license. 63.42 Section 63.42 Aeronautics and Space FEDERAL AVIATION... PILOTS Flight Engineers § 63.42 Flight engineer certificate issued on basis of a foreign flight engineer...

Advancing Commercialization of Algal Biofuel through Increased Biomass Productivity and Technical Integration

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

Anton, David

The proposed project built on the foundation of over several years years of intensive and ground-breaking R&D work at Cellana's Kona Demonstration Facility (KDF). Phycological and engineering solutions were provided to tackle key cultivation issues and technical barriers limiting algal biomass productivity identified through work conducted outdoors at industrial (1 acre) scale. The objectives of this project were to significantly improve algal biomass productivity and reduce operational cost in a seawater-based system, using results obtained from two top-performing algal strains as the baseline while technically advancing and more importantly, integrating the various unit operations involved in algal biomass production, processing,more » and refining.« less

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, former associate director of NASA Kennedy Space Center, speaks to workers during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, far left at the podium, former associate director of Kennedy Space Center, was the keynote speaker during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, former associate director of NASA Kennedy Space Center, was the keynote speaker during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, former associate director of Kennedy Space Center, was the keynote speaker during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Resonant tunneling diode based on band gap engineered graphene antidot structures

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

Palla, Penchalaiah, E-mail: penchalaiah.palla@vit.ac.in; Ethiraj, Anita S.; Raina, J. P.

The present work demonstrates the operation and performance of double barrier Graphene Antidot Resonant Tunnel Diode (DBGA-RTD). Non-Equilibrium Green’s Function (NEGF) frame work with tight-binding Hamiltonian and 2-D Poisson equations were solved self-consistently for device study. The interesting feature in this device is that it is an all graphene RTD with band gap engineered graphene antidot tunnel barriers. Another interesting new finding is that it shows negative differential resistance (NDR), which involves the resonant tunneling in the graphene quantum well through both the electron and hole bound states. The Graphene Antidot Lattice (GAL) barriers in this device efficiently improved themore » Peak to Valley Ratio to approximately 20 even at room temperature. A new fitting model is developed for the number of antidots and their corresponding effective barrier width, which will help in determining effective barrier width of any size of actual antidot geometry.« less

75 FR 17829 - Motorcyclist Advisory Council to the Federal Highway Administration

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... FHWA, on infrastructure issues of concern to motorcyclists, including: (1) Barrier design; (2) road design, construction, and maintenance practices; and (3) the architecture and implementation of... Administrator on infrastructure issues of concern to motorcyclists, including-- (1) Barrier design; (2) Road...

Barriers to return to work after burn injuries.

PubMed

Esselman, Peter C; Askay, Shelley Wiechman; Carrougher, Gretchen J; Lezotte, Dennis C; Holavanahalli, Radha K; Magyar-Russell, Gina; Fauerbach, James A; Engrav, Loren H

2007-12-01

To identify barriers to return to work after burn injury as identified by the patient. A cohort study with telephone interview up to 1 year. Hospital-based burn centers at 3 national sites. Hospitalized patients (N=154) meeting the American Burn Association criteria for major burn injury, employed at least 20 hours a week at the time of injury, and with access to a telephone after discharge. Patients were contacted via telephone every 2 weeks up to 4 months, then monthly up to 1 year after discharge. A return to work survey was used to identify barriers that prevented patients from returning to work. A graphic rating scale determined the impact of each barrier. By 1 year, 79.7% of patients returned to work. Physical and wound issues were barriers early after discharge. Although physical abilities continued to be a significant barrier up to 1 year, working conditions (temperature, humidity, safety) and psychosocial factors (nightmares, flashbacks, appearance concerns) became important issues in those with long-term disability. The majority of patients return to work after a burn injury. Although physical and work conditions are important barriers, psychosocial issues need to be evaluated and treated to optimize return to work.

Greener, meaner diesels sport thermal barrier coatings

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

Winkler, M.F.; Parker, D.W.

1992-05-01

The highly reliable diesel engine has long been the workhorse of the transportation, industrial power, utility, and marine industries. Demand for diesels is expected to accelerate well into the next century, driven by the engine's ability to economically produce power in almost any environment. Increasingly stringent environmental, efficiency, and durability requirements, however, present new challenges to diesel engine manufacturers and operators. This paper reports that many of these challenges can be met entirely, or in part, by thermal barrier coatings (TBCs). Diesel engine TBCs are plasma-spray-applied ceramics, which insulate combustion system components, such as pistons, valves, and piston fire decks,more » from heat and thermal shock.« less

Engineering species-like barriers to sexual reproduction.

PubMed

Maselko, Maciej; Heinsch, Stephen C; Chacón, Jeremy M; Harcombe, William R; Smanski, Michael J

2017-10-12

Controlling the exchange of genetic information between sexually reproducing populations has applications in agriculture, eradication of disease vectors, control of invasive species, and the safe study of emerging biotechnology applications. Here we introduce an approach to engineer a genetic barrier to sexual reproduction between otherwise compatible populations. Programmable transcription factors drive lethal gene expression in hybrid offspring following undesired mating events. As a proof of concept, we target the ACT1 promoter of the model organism Saccharomyces cerevisiae using a dCas9-based transcriptional activator. Lethal overexpression of actin results from mating this engineered strain with a strain containing the wild-type ACT1 promoter.Genetic isolation of a genetically modified organism represents a useful strategy for biocontainment. Here the authors use dCas9-VP64-driven gene expression to construct a 'species-like' barrier to reproduction between two otherwise compatible populations.

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.

Perspective on thermal barrier coatings for industrial gas turbine applications

NASA Technical Reports Server (NTRS)

Mutasim, Z. Z.; Hsu, L. L.; Brentnall, W. D.

1995-01-01

Thermal Barrier Coatings (TBC's) have been used in high thrust aircraft engines for many years, and have proved to be very effective in allowing higher turbine inlet temperatures. TBC life requirements for aircraft engines are typically less than those required in industrial gas turbines. The use of TBC's for industrial gas turbines can increase if durability and longer service life can be successfully demonstrated. This paper will describe current and future applications of TBC's in industrial gas turbine engines. Early testing and applications of TBC's will also be reviewed. This paper focuses on the key factors that are expected to influence utilization of TBC's in advanced industrial gas turbine engines. It is anticipated that reliable, durable and high effective coating systems will be produced that will ultimately improve engine efficiency and performance.

Thermal barrier coatings for gas-turbine engine applications.

PubMed

Padture, Nitin P; Gell, Maurice; Jordan, Eric H

2002-04-12

Hundreds of different types of coatings are used to protect a variety of structural engineering materials from corrosion, wear, and erosion, and to provide lubrication and thermal insulation. Of all these, thermal barrier coatings (TBCs) have the most complex structure and must operate in the most demanding high-temperature environment of aircraft and industrial gas-turbine engines. TBCs, which comprise metal and ceramic multilayers, insulate turbine and combustor engine components from the hot gas stream, and improve the durability and energy efficiency of these engines. Improvements in TBCs will require a better understanding of the complex changes in their structure and properties that occur under operating conditions that lead to their failure. The structure, properties, and failure mechanisms of TBCs are herein reviewed, together with a discussion of current limitations and future opportunities.

Preliminary Test Results of Heshe Hydrogeological Experimental Well Station in Taiwan

NASA Astrophysics Data System (ADS)

Chuang, P.; Liu, C.; Lin, M.; Chan, W.; Lee, T.; Chia, Y.; Teng, M.; Liu, C.

2013-12-01

Safe disposal of radioactive waste is a critical issue for the development of nuclear energy. The design of final disposal system is based on the concept of multiple barriers which integrate the natural barriers and engineering barriers for long-term isolation of radioactive wastes. As groundwater is the major medium that can transport radionuclides to our living environment, it is essential to characterize groundwater flow at the disposal site. Taiwan is located at the boundary between the Eurasian plate and the Philippine Sea plate. Geologic formations are often fractured due to tectonic compression and extension. In this study, a well station for the research and development of hydrogeological techniques was established at the Experimental Forest of the National Taiwan University in central Taiwan. There are 10 testing wells, ranging in depth from 25 m to 100 m, at the station. The bedrock beneath the regolith is highly fractured mudstone. As fracture is the preferential pathway of the groundwater flow, the focus of in-situ tests is to investigate the location of permeable fractures and the connection of permeable fractures. Several field tests have been conducted, including geophysical logging, heat-pulse flowmeter, hydraulic test, tracer test and double packer test, for the development of advanced technologies to detect the preferential groundwater flow in fractured rocks.

105-KE Isolation Barrier Leak Rate Acceptance Test Report

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

McCracken, K.J.

1995-06-14

This Acceptance Test Report (ATR) contains the completed and signed Acceptance Procedure (ATP) for the 105-KE Isolations Barrier Leak Rate Test. The Test Engineer`s log, the completed sections of the ATP in the Appendix for Repeat Testing (Appendix K), the approved WHC J-7s (Appendix H), the data logger files (Appendices T and U), and the post test calibration checks (Appendix V) are included.

Integration of air separation membrane and coalescing filter for use on an inlet air system of an engine

DOEpatents

Moncelle, Michael E.

2003-01-01

An intake air separation system suitable for combustion air of an internal combustion engine. An air separation device of the system includes a plurality of fibers, each fiber having a tube with a permeation barrier layer on the outer surface thereof and a coalescing layer on the inner surface thereof, to restrict fluid droplets from contacting the permeation barrier layer.

Durability of zirconia thermal-barrier ceramic coatings on air-cooled turbine blades in cyclic jet engine operation

NASA Technical Reports Server (NTRS)

Liebert, C. H.; Jacobs, R. E.; Stecura, S.; Morse, C. R.

1976-01-01

Thermal barrier ceramic coatings of stabilized zirconia over a bond coat of Ni Cr Al Y were tested for durability on air cooled turbine rotor blades in a research turbojet engine. Zirconia stabilized with either yttria, magnesia, or calcia was investigated. On the basis of durability and processing cost, the yttria stabilized zirconia was considered the best of the three coatings investigated.

Barriers to Abortion Care and Their Consequences For Patients Traveling for Services: Qualitative Findings from Two States

PubMed Central

Jerman, Jenna; Frohwirth, Lori; Kavanaugh, Megan L.; Blades, Nakeisha

2018-01-01

CONTEXT Abortion availability and accessibility vary by state. Especially in areas where services are restricted or limited, some women travel to obtain abortion services in other states. Little is known about the experience of travel to obtain abortion. METHODS In January and February 2015, in-depth interviews were conducted with 29 patients seeking abortion services at six facilities in Michigan and New Mexico. Eligible women were 18 or older, spoke English, and had traveled either across state lines or more than 100 miles within the state. Respondents were asked to describe their experience from pregnancy discovery to the day of the abortion procedure. Barriers to accessing abortion care and consequences of these barriers were identified through inductive and deductive analysis. RESULTS Respondents described 15 barriers to abortion care while traveling to obtain services, and three major consequences of experiencing those barriers. Barriers were grouped into five categories: travel-related logistical issues, system navigation issues, limited clinic options, financial issues, and state or clinic restrictions. Consequences were delays in care, negative mental health impacts and considering self-induction. The experience of barriers complicated the process of obtaining an abortion, but the effect of any individual barrier was unclear. Instead, the experience of multiple barriers appeared to have a compounding effect, resulting in negative consequences for women traveling for abortion. CONCLUSION The amalgamation of barriers to abortion care experienced simultaneously can have significant consequences for patients. PMID:28394463

Telemedicine: legal and licensure issues

NASA Astrophysics Data System (ADS)

Wood, Michael B.; Whelan, Leo J.

1995-10-01

The National Information Infrastructure program offers a great opportunity for the United States to capitalize on remarkable technological advancements over a broad range of applications benefiting society. One such application, telemedicine, has the potential to offer widespread access to sophisticated medical care, curtailed health care delivery costs, and homogeneous health and health-related educational opportunities. However, there are a variety of barriers to widespread application of telemedicine once the technical infrastructure of the information highway is well established and ubiquitous. These barriers include technical limitations, reimbursement issues, equipment and networking costs, and appropriate scientific studies to document efficacy and cost effectiveness. These issues may prove to be only transient disincentives which can be surmounted. Additional barriers exist, however, that may not be as readily resolved by traditional methods of analysis and more widespread practice applications. These political and regulatory obstacles will require clarification of the issues and solutions based on national consensus. It is the purpose of this discussion to amplify on these particular barriers which include licensure and tort jurisdiction.

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

DOE PAGES

Fergus, Jeffrey W.

2014-04-12

One of the important applications of yttria stabilized zirconia is as a thermal barrier coating for gas turbine engines. While yttria stabilized zirconia performs well in this function, the need for increased operating temperatures to achieve higher energy conversion efficiencies, requires the development of improved materials. To meet this challenge, some rare-earth zirconates that form the cubic fluorite derived pyrochlore structure are being developed for use in thermal barrier coatings due to their low thermal conductivity, excellent chemical stability and other suitable properties. In this paper, the thermal conductivities of current and prospective oxides for use in thermal barrier coatingsmore » are reviewed. The factors affecting the variations and differences in the thermal conductivities and the degradation behaviors of these materials are discussed.« less

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.

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.

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.

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

PubMed

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

2018-01-05

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

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.

Advanced Environmental Barrier Coating Development for SiC-SiC Ceramic Matrix Composite Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna; Kiser, Doug; Wiesner, Valerie L.

2016-01-01

This presentation reviews the NASA advanced environmental barrier coating (EBC) system development for SiCSiC Ceramic Matrix Composite (CMC) components for next generation turbine engines. The emphasis has been placed on the current design challenges of the 2700F environmental barrier coatings; coating processing and integration with SiCSiC CMCs and component systems; and performance evaluation and demonstration of EBC-CMC systems. This presentation also highlights the EBC-CMC system temperature capability and durability improvements through advanced compositions and architecture designs, as shown in recent simulated engine high heat flux, combustion environment, in conjunction with mechanical creep and fatigue loading testing conditions.

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

NASA Astrophysics Data System (ADS)

Hegedus, Theresa

Lingering concerns over the persistent achievement gap amidst the trend of an increasingly diverse society have been compounded by calls from the Oval Office, the National Science Board, and nationwide media to also address our current creativity crisis. Now, more than ever, we have a responsibility to produce a STEM-capable (science, technology, engineering, and mathematics) workforce to meet the demands of our rapidly changing local and global economic landscape. Barriers exist in our traditional educational system, which has historically limited underrepresented groups' affiliation and membership in the disciplines of science and engineering. The recent incorporation of engineering into the latest science education reform efforts presents an opportunity to expose students as early as elementary school to engineering practices and habits of mind, which have the potential to stimulate creative thinking skills through engineering design. This qualitative study was designed to examine the ways in which engineering education has the potential to promote creativity and academic competence in elementary science classrooms. As a part of my study, a diverse group of students from two fifth-grade classrooms took part in a 10-12 hour, engineering-based curriculum unit (Engineering is Elementary) during their regular science instructional time. Using a sociocultural lens, to include cultural production and identities in practice as part of my framework, I analyzed group and individual performances through classroom observations, student interviews, and teacher reflections to better understand the meaning students made of their experiences with engineering. Findings from the study included the ways in which creativity was culturally produced in the classroom to include: 1) idea generation; 2) design and innovation; 3) gumption/resourcefulness; and 4) social value. Opportunities for collaboration increased through each stage of the unit culminating with the design challenge. Engineering teams required cultivation by the teacher as students negotiated spaces for collaboration through challenges of competition versus compromise; assumed versus assigned roles; management of verbal versus non-verbal communication; and shifts from teacher-as-authority-figure to peers as sources of knowledge and inspiration. The engineering design challenge provided an ideal context for broaching socio-scientific issues and attention to ethical considerations. Students made reference to their growing environmental awareness and developing moral reasoning in their definitions and reflections on green engineering. Throughout the course of the unit, successful students, struggling students, and students with uncertain trajectories established themselves as competent and efficacious engineers. Implications of the study include ways to assist teachers in recognizing and cultivating creativity and collaboration in addition to effectively incorporating socio-scientific issues as part of the engineering (and science) curriculum. I also present recommendations for promoting equity in classroom engineering, pre-service teacher initiatives, and strategies for capitalizing on the complementarity between science and engineering.

An analytical study of thermal barrier coated first stage blades in a JT9D engine

NASA Technical Reports Server (NTRS)

Sevcik, W. R.; Stoner, B. L.

1978-01-01

Steady state and transient heat transfer and structural calculations were completed to determine the coating and base alloy temperatures and strains. Results indicate potential for increased turbine life using thin durable thermal barrier coatings on turbine airfoils due to a significant reduction in blade average and maximum temperatures, and alloy strain range. An intepretation of the analytical results is compared to the experimental engine test data.

Structure of Black Male Students Academic Achievement in Science

NASA Astrophysics Data System (ADS)

Rascoe, Barbara

Educational policies and practices have been largely unsuccessful in closing the achievement gap between Black and White students "Schwartz, 2001". This achievement gap is especially problematic for Black students in science "Maton, Hrabrowski, - Schmitt, 2000. Given the fact that the Black-White achievement gap is still an enigma, the purpose of this article is to address the Black female-Black male academic achievement gap in science majors. Addressing barriers that Black male students may experience as college science and engineering majors, this article presents marketing strategies relative to politics, emotional intelligence, and issues with respect to how science teaching, and Black male students' responses to it, are different. Many Black male students may need to experience a paradigm shift, which structures and enhances their science achievement. Paradigm shifts are necessary because exceptional academic ability and motivation are not enough to get Black males from their first year in a science, technology, education, and mathematics "STEM" major to a bachelor's degree in science and engineering. The conclusions focus on the balance of truth-slippery slopes concerning the confluence of science teachers' further ado and Black male students' theories, methods, and values that position their academic achievement in science and engineering majors.

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…

Barriers to Abortion Care and Their Consequences For Patients Traveling for Services: Qualitative Findings from Two States.

PubMed

Jerman, Jenna; Frohwirth, Lori; Kavanaugh, Megan L; Blades, Nakeisha

2017-06-01

Abortion availability and accessibility vary by state. Especially in areas where services are restricted or limited, some women travel to obtain abortion services in other states. Little is known about the experience of travel to obtain abortion. In January and February 2015, in-depth interviews were conducted with 29 patients seeking abortion services at six facilities in Michigan and New Mexico. Eligible women were 18 or older, spoke English, and had traveled either across state lines or more than 100 miles within the state. Respondents were asked to describe their experience from pregnancy discovery to the day of the abortion procedure. Barriers to accessing abortion care and consequences of these barriers were identified through inductive and deductive analysis. Respondents described 15 barriers to abortion care while traveling to obtain services, and three major consequences of experiencing those barriers. Barriers were grouped into five categories: travel-related logistical issues, system navigation issues, limited clinic options, financial issues, and state or clinic restrictions. Consequences were delays in care, negative mental health impacts and considering self-induction. The experience of barriers complicated the process of obtaining an abortion, but the effect of any individual barrier was unclear. Instead, the experience of multiple barriers appeared to have a compounding effect, resulting in negative consequences for women traveling for abortion. The amalgamation of barriers to abortion care experienced simultaneously can have significant consequences for patients. © 2017 The Authors. Perspectives on Sexual and Reproductive Health published by Wiley Periodicals, Inc., on behalf of the Guttmacher Institute.

Fusion antibody for Alzheimer's disease with bidirectional transport across the blood-brain barrier and abeta fibril disaggregation.

PubMed

Boado, Ruben J; Zhang, Yufeng; Zhang, Yun; Xia, Chun-Fang; Pardridge, William M

2007-01-01

Delivery of monoclonal antibody therapeutics across the blood-brain barrier is an obstacle to the diagnosis or therapy of CNS disease with antibody drugs. The immune therapy of Alzheimer's disease attempts to disaggregate the amyloid plaque of Alzheimer's disease with an anti-Abeta monoclonal antibody. The present work is based on a three-step model of immune therapy of Alzheimer's disease: (1) influx of the anti-Abeta monoclonal antibody across the blood-brain barrier in the blood to brain direction, (2) binding and disaggregation of Abeta fibrils in brain, and (3) efflux of the anti-Abeta monoclonal antibody across the blood-brain barrier in the brain to blood direction. This is accomplished with the genetic engineering of a trifunctional fusion antibody that binds (1) the human insulin receptor, which mediates the influx from blood to brain across the blood-brain barrier, (2) the Abeta fibril to disaggregate amyloid plaque, and (3) the Fc receptor, which mediates the efflux from brain to blood across the blood-brain barrier. This fusion protein is a new antibody-based therapeutic for Alzheimer's disease that is specifically engineered to cross the human blood-brain barrier in both directions.

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

Engineering Issue: Technology Alternatives for the Remediation of PCB Contaminated Soils and Sediments

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) Engineering Issue papers are a series of documents that summarize the available information on specific contaminates, selected treatment and site remediation technologies, and related issues. This Engineering Issue paper is intended...

Safety analysis, 200 Area, Savannah River Plant: Separations area operations

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

Perkins, W.C.; Lee, R.; Allen, P.M.

1991-07-01

The nev HB-Line, located on the fifth and sixth levels of Building 221-H, is designed to replace the aging existing HB-Line production facility. The nev HB-Line consists of three separate facilities: the Scrap Recovery Facility, the Neptunium Oxide Facility, and the Plutonium Oxide Facility. There are three separate safety analyses for the nev HB-Line, one for each of the three facilities. These are issued as supplements to the 200-Area Safety Analysis (DPSTSA-200-10). These supplements are numbered as Sup 2A, Scrap Recovery Facility, Sup 2B, Neptunium Oxide Facility, Sup 2C, Plutonium Oxide Facility. The subject of this safety analysis, the, Plutoniummore » Oxide Facility, will convert nitrate solutions of {sup 238}Pu to plutonium oxide (PuO{sub 2}) powder. All these new facilities incorporate improvements in: (1) engineered barriers to contain contamination, (2) barriers to minimize personnel exposure to airborne contamination, (3) shielding and remote operations to decrease radiation exposure, and (4) equipment and ventilation design to provide flexibility and improved process performance.« less

Some aspects of the hot corrosion of thermal barrier coatings

NASA Technical Reports Server (NTRS)

Jones, Robert L.

1995-01-01

This paper provides a pro tem review of the hot corrosion of zirconia-based thermal barrier coatings for engine applications. Emphasis is placed on trying to understand the chemical reactions, and such other mechanisms as can be identified, that cause corrosive degradation of the thermal barrier coating. The various approaches taken in attempts to improve the hot corrosion resistance of thermal barrier coatings are also briefly described and critiqued.

Hydroxyapatite nanobelt/polylactic acid Janus membrane with osteoinduction/barrier dual functions for precise bone defect repair.

PubMed

Ma, Baojin; Han, Jing; Zhang, Shan; Liu, Feng; Wang, Shicai; Duan, Jiazhi; Sang, Yuanhua; Jiang, Huaidong; Li, Dong; Ge, Shaohua; Yu, Jinghua; Liu, Hong

2018-04-15

Controllable osteoinduction maintained in the original defect area is the key to precise bone repair. To meet the requirement of precise bone regeneration, a hydroxyapatite (HAp) nanobelt/polylactic acid (PLA) (HAp/PLA) Janus membrane has been successfully prepared in this study by coating PLA on a paper-like HAp nanobelt film by a casting-pervaporation method. The Janus membrane possesses dual functions: excellent osteoinduction from the hydrophilic HAp nanobelt side and barrier function originating from the hydrophobic PLA film. The cell viability and osteogenic differentiation ability of human adipose-derived stem cells (hADSCs) on the Janus membrane were assessed. The in vitro experimental results prove that the HAp nanobelt side presents high cell viability and efficient osteoinduction without any growth factor and that the PLA side can prohibit cell attachment. The in vivo repair experiments on a rat mandible defect model prove that the PLA side can prevent postoperative adhesion between bone and adjacent soft tissues. Most importantly, the HAp side has a strong ability to promote defect repair and bone regeneration. Therefore, the HAp/PLA Janus membrane will have wide applications as a kind of tissue engineering material in precise bone repair because of its unique dual osteoinduction/barrier functions, biocompatibility, low cost, and its ability to be mass-produced. Precise bone defect repair to keeping tissue integrity and original outline shape is a very important issue for tissue engineering. Here, we have designed and prepared a novel HAp/PLA Janus membrane using a casting-pervaporation method to form a layer of PLA film on paper-like HAp nanobelt film. HAp nanobelt side of the Janus membrane can successfully promote osteogenic differentiation. PLA side of the Janus membrane exhibits good properties as a barrier for preventing the adhesion of cells in vitro. Mandible repair experiments in vivo have shown that the HAp/PLA Janus membrane can promote rat mandible repair on the HAp side and can successfully prevent postoperative adhesion on the PLA side at the same time. Therefore, the HAp/PLA Janus membrane with its osteoinduction/barrier dual functions can be applied to repair bone defect precisely. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Resonant infrared laser deposition of polymer-nanocomposite materials for optoelectronic applications

NASA Astrophysics Data System (ADS)

Park, Hee K.; Schriver, Kenneth E.; Haglund, Richard F.

2011-11-01

Polymers find a number of potentially useful applications in optoelectronic devices. These include both active layers, such as light-emitting polymers and hole-transport layers, and passive layers, such as polymer barrier coatings and light-management films. This paper reports the experimental results for polymer films deposited by resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) and resonant infrared pulsed laser deposition (RIR-PLD) for commercial optoelectronic device applications. In particular, light-management films, such as anti-reflection coatings, require refractive-index engineering of a material. However, refractive indices of polymers fall within a relatively narrow range, leading to major efforts to develop both low- and high-refractive-index polymers. Polymer nanocomposites can expand the range of refractive indices by incorporating low- or high-refractive-index nanoscale materials. RIR-MAPLE is an excellent technique for depositing polymer-nanocomposite films in multilayer structures, which are essential to light-management coatings. In this paper, we report our efforts to engineer the refractive index of a barrier polymer by combining RIR-MAPLE of nanomaterials (for example, high refractive-index TiO2 nanoparticles) and RIR-PLD of host polymer. In addition, we report on the properties of organic and polymer films deposited by RIR-MAPLE and/or RIR-PLD, such as Alq3 [tris(8-hydroxyquinoline) aluminum] and PEDOT:PSS [poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)]. Finally, the challenges and potential for commercializing RIR-MAPLE/PLD, such as industrial scale-up issues, are discussed.

Land Desertification and it’s Control in Gonghe Basin of Qinghai Plateau, China

NASA Astrophysics Data System (ADS)

Zhang, D.; Gao, S.; Lu, R.

2009-12-01

Land desertification is an important environmental and social-economic problems that threatening people’s living conditions and impacting social sustainable development. The Gonghe basin in Qinghai Plateau is a fragile cold alpine area which is one of the places seriously threatened by desertification in China. This paper selected Gonghe basin as a study area to study land sandy desertification and its controlling measures. The engineering measures for sandy desertification control include setting clay sand barrier, Salix cheilophila sand barrier, Tamarix sand barrier, Artemisia sand barrier and straw-checker sand-barriers to fix dunes; the biological measures include closure for natural vegetation recovery, direct seeding forestation, transplanting seedlings, and so on. The combination of engineering and biologic measures can fix dunes 2~3 years earlier than the common single measure; and the costs were basically identical. A synthesized evaluation system established based on experimental results and experience in recent years indicated that the effectiveness of the four kinds of sand barrier for prevention and control of sand in study area were: Tamarix sand barrier > Artemisia sand barrier > clay sand barrier > straw-checker sand-barriers. In addition, different optimized management model can be selected according to local material and geographical place. New plants such as Salix cheilophila and Tamarix, which are available in study area, can change from dead sand barrier to live one set in proper seasons, changing engineering measure to biological one directly speeds the progress of forestation and dunes fixation. In addition, we developed new technique of deep planting Salix cheilophila and Tamarix with their long stem, which can effectively resist drought. We found that it had lower cost and higher live rate, and has a better sand prevention effect than deep planting of Poplar. Finally we choose the optimize management model as follows: Artemisia direct seeding > Caragana direct seeding, Tamarix cutting and seedling > Salix cheilophila deep planting, Sea-buckthorn seedling > Tamarix deep planting > Tamarix seedling > Poplar deep planting > Salix cheilophila seedling > Poplar seedling. It has resolved the key problem of control sand flow speed and low efficiency, sand burying and wind erosion and low conservation rate for forestation in the sandy area.

Monitoring engineered remediation with borehole radar

USGS Publications Warehouse

Lane, J.W.; Day-Lewis, F. D.; Joesten, P.K.

2007-01-01

The success of engineered remediation is predicated on correct emplacement of either amendments (e.g., vegetable-oil emulsion, lactate, molasses, etc.) or permeable reactive barriers (e.g., vegetable oil, zero-valent iron, etc.) to enhance microbial or geochemical breakdown of contaminants and treat contaminants. Currently, site managers have limited tools to provide information about the distribution of injected materials; the existence of gaps or holes in barriers; and breakdown or transformation of injected materials over time. ?? 2007 Society of Exploration Geophysicists.

Barrier Engineered Quantum Dot Infrared Photodetectors

DTIC Science & Technology

2015-06-01

dual-color detectors using InAs/GaSb strained layer superlattices ." In Lester Eastman Conference on High Performance Devices (LEC), 2012, pp. 1-4. IEEE...Gautam, S. S. Krishna, E. P. Smith, S. Johnson, and S. Krishna. "Dual-band pBp detectors based on InAs/GaSb strained layer superlattices ." Infrared ...AFRL-RV-PS- AFRL-RV-PS- TR-2015-0111 TR-2015-0111 BARRIER ENGINEERED QUANTUM DOT INFRARED PHOTODETECTORS Sanjay Krishna Center for High Technology

Cultural Barriers to Change in Assessment Practices in Higher Education

ERIC Educational Resources Information Center

Jenkins, Deborah Bainer

2007-01-01

The culture at the authors' institution raised barriers to changing from traditional assessment to portfolio assessment in the doctoral program. A Culture of Independence presented barriers of time and functional inadequacy. A Culture of Compliance raised trust, group process, and membership issues. These barriers were managed and overcome using…

Factors Affecting Attendance at an Adapted Cardiac Rehabilitation Exercise Program for Individuals with Mobility Deficits Poststroke.

PubMed

Marzolini, Susan; Balitsky, Amaris; Jagroop, David; Corbett, Dale; Brooks, Dina; Grace, Sherry L; Lawrence, Danielle; Oh, Paul I

2016-01-01

The aim of this study was to determine the factors affecting attendance at an adapted cardiac rehabilitation program for individuals poststroke. A convenience sample of ambulatory patients with hemiparetic gait rated 20 potential barriers to attendance on a 5-point Likert scale upon completion of a 6-month program of 24 prescheduled weekly sessions. Sociodemographic characteristics, depressive symptoms, cardiovascular fitness, and comorbidities were collected by questionnaire or medical chart. Sixty-one patients attended 77.3 ± 12% of the classes. The longer the elapsed time from stroke, the lower the attendance rate (r = -.34, P = .02). The 4 greatest barriers influencing attendance were severe weather, transportation problems, health problems, and traveling distance. Health problems included hospital readmissions (n = 6), influenza/colds (n = 6), diabetes and cardiac complications (n = 4), and musculoskeletal issues (n = 2). Of the top 4 barriers, people with lower compared to higher income had greater transportation issues (P = .004). Greater motor deficits of the stroke-affected leg were associated with greater barriers related to health issues (r = .7, P = .001). The only sociodemographic factor associated with a higher total mean barrier score was non-English as the primary language spoken at home (P = .002); this factor was specifically related to the barriers of cost (P = .007), family responsibilities (P = .018), and lack of social support (P = .001). No other associations were observed. Barriers to attendance were predominantly related to logistic/transportation and health issues. People who were more disadvantaged socioeconomically (language, finances), and physically (stroke-related deficits) were more affected by these barriers. Strategies to reduce these barriers, including timely referral to exercise programs, need to be investigated. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Barriers to Student Success in Engineering Education

ERIC Educational Resources Information Center

Boles, Wageeh; Whelan, Karen

2017-01-01

In the UK, the USA and Australia, there have been calls for an increase in the number of engineering graduates to meet the needs of current global challenges. Universities around the world have been grappling with how to both attract more engineering students and to then retain them. Attrition from engineering programmes is disturbingly high. This…

Women's History Month Event

NASA Image and Video Library

2018-03-27

NASA Kennedy Space Center's Deputy Director Janet Petro welcomes workers to the center's Women's History Month event, with the theme "Nevertheless She Persisted." Keynote speaker, JoAnn Morgan, former associate director of the center, spoke to the group about her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, former associate director of Kennedy Space Center, at left, accepts a special coin from Janet Petro, deputy director of Kennedy, during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, former associate director of Kennedy Space Center, was the keynote speaker during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. Third from the left is Charlie Blackwell-Thompson, launch director for Exploration Mission-1. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Process and assembly plans for low cost commercial fuselage structure

NASA Technical Reports Server (NTRS)

Willden, Kurtis; Metschan, Stephen; Starkey, Val

1991-01-01

Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization.

Access to health care for persons with disabilities in rural South Africa.

PubMed

Vergunst, R; Swartz, L; Hem, K-G; Eide, A H; Mannan, H; MacLachlan, M; Mji, G; Braathen, S H; Schneider, M

2017-11-17

Global research suggests that persons with disabilities face barriers when accessing health care services. Yet, information regarding the nature of these barriers, especially in low-income and middle-income countries is sparse. Rural contexts in these countries may present greater barriers than urban contexts, but little is known about access issues in such contexts. There is a paucity of research in South Africa looking at "triple vulnerability" - poverty, disability and rurality. This study explored issues of access to health care for persons with disabilities in an impoverished rural area in South Africa. The study includes a quantitative survey with interviews with 773 participants in 527 households. Comparisons in terms of access to health care between persons with disabilities and persons with no disabilities were explored. The approach to data analysis included quantitative data analysis using descriptive and inferential statistics. Frequency and cross tabulation, comparing and contrasting the frequency of different phenomena between persons with disabilities and persons with no disabilities, were used. Chi-square tests and Analysis of Variance tests were then incorporated into the analysis. Persons with disabilities have a higher rate of unmet health needs as compared to non-disabled. In rural Madwaleni in South Africa, persons with disabilities faced significantly more barriers to accessing health care compared to persons without disabilities. Barriers increased with disability severity and was reduced with increasing level of education, living in a household without disabled members and with age. This study has shown that access to health care in a rural area in South Africa for persons with disabilities is more of an issue than for persons without disabilities in that they face more barriers. Implications are that we need to look beyond the medical issues of disability and address social and inclusion issues as well.

46 CFR 38.05-1 - Design and construction of vessels-general-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... system shall satisfy the requirements for toughness specified in subchapter F (Marine Engineering) of... secondary barrier is required, the material of that barrier and of contiguous hull structure shall have...

Lysosomal storage diseases and the blood-brain barrier.

PubMed

Begley, David J; Pontikis, Charles C; Scarpa, Maurizio

2008-01-01

The blood-brain barrier becomes a crucial issue in neuronopathic lysosomal storage diseases for three reasons. Firstly, the function of the blood-brain barrier may be compromised in many of the lysosomal storage diseases and this barrier dysfunction may contribute to the neuropathology seen in the diseases and accelerate cell death. Secondly, the substrate reduction therapies, which successfully reduce peripheral lysosomal storage, because of the blood-brain barrier may not have as free an access to brain cells as they do to peripheral cells. And thirdly, enzyme replacement therapy appears to have little access to the central nervous system as the mannose and mannose-6-phosphate receptors involved in their cellular uptake and transport to the lysosome do not appear to be expressed at the adult blood-brain barrier. This review will discuss in detail these issues and their context in the development of new therapeutic strategies.

An exploratory qualitative study on perceptions about mosquito bed nets in the Niger Delta: what are the barriers to sustained use?

PubMed Central

Galvin, Kathleen T; Petford, Nick; Ajose, Frances; Davies, Dai

2011-01-01

Background: The effectiveness of malaria control programs is determined by an array of complex factors, including the acceptability and sustained use of preventative measures such as the bed net. A small-scale exploratory study was conducted in several locations in the Niger Delta region, Nigeria, to discover barriers against the use of bed nets, in the context of a current drive to scale up net use in Nigeria. Methods: A qualitative approach with a convenience sample was used. One to one interviews with mostly male adult volunteers were undertaken which explored typical living and sleeping arrangements, and perceptions about and barriers against the use of the mosquito prevention bed net. Results: Several key issues emerged from the qualitative data. Bed nets were not reported as widely used in this small sample. The reasons reported for lack of use included issues of convenience, especially net set up and dismantling; potential hazard and safety concerns; issues related to typical family composition and nature of accommodation; humid weather conditions; and perceptions of cost and effectiveness. Most barriers to net use concerned issues about everyday practical living and sleeping arrangements and perceptions about comfort. Interviewees identified were aware of malaria infection risks, but several also indicated certain beliefs that were barriers to net use. Conclusions: Successful control of malaria and scale up of insecticide-treated net coverage relies on community perceptions and practice. This small study has illuminated a number of important everyday life issues, which remain barriers to sustained net use, and has clarified further questions to be considered in net design and in future research studies. The study highlights the need for further research on the human concerns that contribute to sustained use of nets or, conversely, present significant barriers to their use. PMID:21544249

Aircraft engine-mounted camera system for long wavelength infrared imaging of in-service thermal barrier coated turbine blades

NASA Astrophysics Data System (ADS)

Markham, James; Cosgrove, Joseph; Scire, James; Haldeman, Charles; Agoos, Ian

2014-12-01

This paper announces the implementation of a long wavelength infrared camera to obtain high-speed thermal images of an aircraft engine's in-service thermal barrier coated turbine blades. Long wavelength thermal images were captured of first-stage blades. The achieved temporal and spatial resolutions allowed for the identification of cooling-hole locations. The software and synchronization components of the system allowed for the selection of any blade on the turbine wheel, with tuning capability to image from leading edge to trailing edge. Its first application delivered calibrated thermal images as a function of turbine rotational speed at both steady state conditions and during engine transients. In advance of presenting these data for the purpose of understanding engine operation, this paper focuses on the components of the system, verification of high-speed synchronized operation, and the integration of the system with the commercial jet engine test bed.

Aircraft engine-mounted camera system for long wavelength infrared imaging of in-service thermal barrier coated turbine blades.

PubMed

Markham, James; Cosgrove, Joseph; Scire, James; Haldeman, Charles; Agoos, Ian

2014-12-01

This paper announces the implementation of a long wavelength infrared camera to obtain high-speed thermal images of an aircraft engine's in-service thermal barrier coated turbine blades. Long wavelength thermal images were captured of first-stage blades. The achieved temporal and spatial resolutions allowed for the identification of cooling-hole locations. The software and synchronization components of the system allowed for the selection of any blade on the turbine wheel, with tuning capability to image from leading edge to trailing edge. Its first application delivered calibrated thermal images as a function of turbine rotational speed at both steady state conditions and during engine transients. In advance of presenting these data for the purpose of understanding engine operation, this paper focuses on the components of the system, verification of high-speed synchronized operation, and the integration of the system with the commercial jet engine test bed.

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.

The Great Womanhunt.

ERIC Educational Resources Information Center

Seltz-Petrash, Ann

1980-01-01

Discusses the aggressive recruitment of women by engineering schools and firms, progress in eliminating sex discrimination barriers, and lingering sex bias problems in the field. Offers suggestions to new women engineering graduates. (SK)

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.

MicroRNAs in skin tissue engineering.

PubMed

Miller, Kyle J; Brown, David A; Ibrahim, Mohamed M; Ramchal, Talisha D; Levinson, Howard

2015-07-01

35.2 million annual cases in the U.S. require clinical intervention for major skin loss. To meet this demand, the field of skin tissue engineering has grown rapidly over the past 40 years. Traditionally, skin tissue engineering relies on the "cell-scaffold-signal" approach, whereby isolated cells are formulated into a three-dimensional substrate matrix, or scaffold, and exposed to the proper molecular, physical, and/or electrical signals to encourage growth and differentiation. However, clinically available bioengineered skin equivalents (BSEs) suffer from a number of drawbacks, including time required to generate autologous BSEs, poor allogeneic BSE survival, and physical limitations such as mass transfer issues. Additionally, different types of skin wounds require different BSE designs. MicroRNA has recently emerged as a new and exciting field of RNA interference that can overcome the barriers of BSE design. MicroRNA can regulate cellular behavior, change the bioactive milieu of the skin, and be delivered to skin tissue in a number of ways. While it is still in its infancy, the use of microRNAs in skin tissue engineering offers the opportunity to both enhance and expand a field for which there is still a vast unmet clinical need. Here we give a review of skin tissue engineering, focusing on the important cellular processes, bioactive mediators, and scaffolds. We further discuss potential microRNA targets for each individual component, and we conclude with possible future applications. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

10 CFR 60.113 - Performance of particular barriers after permanent closure.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the engineered barrier system are dominated by fission product decay; and (B) any release of... the time during which the thermal pulse is dominated by the decay heat from the fission products; (3...

10 CFR 60.113 - Performance of particular barriers after permanent closure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the engineered barrier system are dominated by fission product decay; and (B) any release of... the time during which the thermal pulse is dominated by the decay heat from the fission products; (3...

Sun, Sand and Water: A History of the Jacksonville District U.S. Army Corps of Engineers 1821-1975

DTIC Science & Technology

1981-01-01

plan envisioned a dredged cut through the barrier beach to Banana River. On the river there would be a turning basin with terminal facilities, and...intracoastal canal to the west This canal would cut through Merritt Island, which separated Indian River from Banana River.6 District Engineer, Colonel...canal, guarded by two jetties, through the barrier land from the 27 -foot contour line in the Atlantic to a 27 -foot turning basin in the Banana

Tests of NASA ceramic thermal barrier coating for gas-turbine engines

NASA Technical Reports Server (NTRS)

Liebert, C. H.

1979-01-01

A two-layer thermal barrier coating system with a bond coating of nickel-chromium-aluminum-yttrium and a ceramic coating of yttria-stabilized zirconia was tested for corrosion protection, thermal protection and durability. Full-scale gas-turbine engine tests demonstrated that this coating eliminated burning, melting, and warping of uncoated parts. During cyclic corrosion resistance tests made in marine diesel fuel products of combustion in a burner rig, the ceramic cracked on some specimens. Metallographic examination showed no base metal deterioration.

Has ADVANCE Affected Senior Compared to Junior Women Scientists Differently?

NASA Astrophysics Data System (ADS)

Rosser, Sue

2015-01-01

Substantial evidence exists to demonstrate that the NSF ADVANCE Inititiative has made a positive impact upon institutions. Since it began in 2001, ADVANCE has changed the conversation, policies, and practices in ways to remove obstacles and systemic barriers preventing success for academic women scientists and engineers. Results from ADVANCE projects on campuses have facilitated consensus nationally about policies and practices that institutions may implement to help to alleviate issues, particularly for junior women scientists.Although getting women into senior and leadership positions in STEM constituted an initial impetus for ADVANCE, less emphasis was placed upon the needs of senior women scientists. Surveys of academic women scientists indicate that the issues faced by junior and senior women scientists differ significantly. The focus of ADVANCE on junior women in many ways seemed appropriate--the senior cohort of women scinetists is fed by the junior cohort of scientists; senior women serve as mentors, role models, and leaders for the junior colleagues, while continuing to struggle to achieve full status in the profession. This presentation will center on the differences in issues faced by senior compared to junior women scientists to explore whether a next step for ADVANCE should be to address needs of senior academic women scientists.

Better bioinformatics through usability analysis.

PubMed

Bolchini, Davide; Finkelstein, Anthony; Perrone, Vito; Nagl, Sylvia

2009-02-01

Improving the usability of bioinformatics resources enables researchers to find, interact with, share, compare and manipulate important information more effectively and efficiently. It thus enables researchers to gain improved insights into biological processes with the potential, ultimately, of yielding new scientific results. Usability 'barriers' can pose significant obstacles to a satisfactory user experience and force researchers to spend unnecessary time and effort to complete their tasks. The number of online biological databases available is growing and there is an expanding community of diverse users. In this context there is an increasing need to ensure the highest standards of usability. Using 'state-of-the-art' usability evaluation methods, we have identified and characterized a sample of usability issues potentially relevant to web bioinformatics resources, in general. These specifically concern the design of the navigation and search mechanisms available to the user. The usability issues we have discovered in our substantial case studies are undermining the ability of users to find the information they need in their daily research activities. In addition to characterizing these issues, specific recommendations for improvements are proposed leveraging proven practices from web and usability engineering. The methods and approach we exemplify can be readily adopted by the developers of bioinformatics resources.

Critical Propulsion Components. Volume 2; Combustor

NASA Technical Reports Server (NTRS)

2005-01-01

Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Team. Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/Inlet Acoustic Team.

Critical Propulsion Components. Volume 3; Exhaust Nozzle

NASA Technical Reports Server (NTRS)

2005-01-01

Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/Inlet Acoustic Team.

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

ERIC Educational Resources Information Center

Myers, Beth Ann

2016-01-01

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

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

NASA Technical Reports Server (NTRS)

Harrison, E., Jr.

1971-01-01

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

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.

Corrosion resistant thermal barrier coating. [protecting gas turbines and other engine parts

NASA Technical Reports Server (NTRS)

Levine, S. R.; Miller, R. A.; Hodge, P. E. (Inventor)

1981-01-01

A thermal barrier coating system for protecting metal surfaces at high temperature in normally corrosive environments is described. The thermal barrier coating system includes a metal alloy bond coating, the alloy containing nickel, cobalt, iron, or a combination of these metals. The system further includes a corrosion resistant thermal barrier oxide coating containing at least one alkaline earth silicate. The preferred oxides are calcium silicate, barium silicate, magnesium silicate, or combinations of these silicates.

76 FR 34145 - Safety Zone, Barrier Testing Operations, Chicago Sanitary and Ship Canal, Romeoville, IL

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-13

... Michigan and creates an electric field in the water by pulsing low voltage DC current through steel cables... the U.S. Army Corps of Engineers' simultaneous operation of electric barriers IIA and IIB. Under 5 U.S... selected an electric barrier because it is a non-lethal deterrent with a proven history, which does not...

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.

Integrated approach to modeling long-term durability of concrete engineered barriers in LLRW disposal facility

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

Lee, J.H.; Roy, D.M.; Mann, B.

1995-12-31

This paper describes an integrated approach to developing a predictive computer model for long-term performance of concrete engineered barriers utilized in LLRW and ILRW disposal facilities. The model development concept consists of three major modeling schemes: hydration modeling of the binder phase, pore solution speciation, and transport modeling in the concrete barrier and service environment. Although still in its inception, the model development approach demonstrated that the chemical and physical properties of complex cementitious materials and their interactions with service environments can be described quantitatively. Applying the integrated model development approach to modeling alkali (Na and K) leaching from amore » concrete pad barrier in an above-grade tumulus disposal unit, it is predicted that, in a near-surface land disposal facility where water infiltration through the facility is normally minimal, the alkalis control the pore solution pH of the concrete barriers for much longer than most previous concrete barrier degradation studies assumed. The results also imply that a highly alkaline condition created by the alkali leaching will result in alteration of the soil mineralogy in the vicinity of the disposal facility.« less

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

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

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

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.

Damage Accumulation and Failure of Plasma-Sprayed Thermal Barrier Coatings under Thermal Gradient Cyclic Conditions

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Ghosn, Louis J.; Miller, rober A.

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. A fundamental understanding of the sintering and thermal cycling induced delamination of thermal barrier coating systems under engine-like heat flux conditions will potentially help to improve the coating temperature capability. In this study, a test approach is established to emphasize the real-time monitoring and assessment of the coating thermal conductivity, which can initially increase under the steady-state high temperature thermal gradient test due to coating sintering, and later decrease under the thermal gradient cyclic test due to coating cracking and delamination. Thermal conductivity prediction models have been established for a ZrO2-(7- 8wt%)Y2O3 model coating system in terms of heat flux, time, and testing temperatures. The coating delamination accumulation is then assessed based on the observed thermal conductivity response under the combined steady-state and cyclic thermal gradient tests. The coating thermal gradient cycling associated delaminations and failure mechanisms under simulated engine heat-flux conditions will be discussed in conjunction with the coating sintering and fracture testing results.

Russian engineering education in the era of change

NASA Astrophysics Data System (ADS)

Vladimirovich Pukharenko, Yurii; Vladimirovna Norina, Natalia; Aleksandrovich Norin, Veniamin

2017-03-01

The article investigates modern issues of engineering education in Russia related to introduction of the Bologna system. The author shows that the situation in the education in general gives reasons for concern; the issue of qualitative enrolment of students for engineering specialties escalates; graduates with masters and bachelors' degrees are not in demand in industries or agriculture due to poor training for work in the real life. The main cause of problems in the engineering personnel training in Russia (lacking effective relationship with employers and universities) is discussed. The ways to overcome such issues in quality engineering training were investigated. The author has considered new requirements to engineering education and have briefly compare the Russian model of engineering education with the European and American models. The prospects of the Russian engineering education (transiting to the sixth technological mode) and issues of NBIC-convergent engineering education have been examined.

Beyond access: barriers to internet health information seeking among the urban poor

PubMed Central

Okechukwu, Cassandra A; Sorensen, Glorian; Viswanath, K

2016-01-01

Objective Communication inequalities deepen health disparities even when internet access is achieved. The goal of this study is to understand how a range of barriers may inhibit individuals from low socioeconomic position (SEP) from engaging with online health information even when it is freely available. Materials and methods Detailed data were collected from 118 low-SEP individuals from a randomized controlled trial providing internet access. Measures triangulated the health-seeking experience through internet use tracked in real-time, call log data, and self-reported barriers. Negative binomial regression models were fitted with technology and perceived predictors, and our outcome, health information seeking, and then stratified by medical status. Results Participants experienced a median of two computer issues (median 6 days) and two internet issues (median 6.5 days). Duration of internet problems was associated with a decrease in the rate of internet health information seeking by a factor of 0.990 (P = .03) for each additional day. Participants with a medical problem who were frustrated in their search for health information had half the rate of health information seeking of those who were not frustrated (incidence rate ratio = 0.395, P = .030). Discussion Despite IT support, participants still experienced internet connectivity issues that negatively impacted their health information seeking. Frustration in their search to find information may serve as an additional barrier to those who have medical issues. Conclusion After initial internet access, a second-level digital divide emerged due to connectivity issues, highlighting the need to understand the complex network of barriers experienced by low-SEP internet users. PMID:27206459

Helping Homeless Families Overcome Barriers to Successful Functioning

ERIC Educational Resources Information Center

Swick, Kevin J.

2005-01-01

The author articulates key stressors in the lives of families who are homeless. These stresses often combine with barriers such as lack of job opportunities and/or insensitive professionals. Strategies for helping homeless families overcome these barriers and related issues are presented.

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.

A Survey of Gender Biases of Freshman Students toward Engineering.

ERIC Educational Resources Information Center

Schaer, Barbara; And Others

1991-01-01

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

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.

Biomaterials for tissue engineering: summary

NASA Technical Reports Server (NTRS)

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

1997-01-01

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

Science and Engineering Programs: On Target for Women?

ERIC Educational Resources Information Center

Matyas, Marsha Lakes, Ed.; Dix, Linda Skidmore, Ed.

To increase women's participation in science and engineering, many barriers must be overcome. This book, an outcome of a conference held by the National Research Council's Committee on Women in Science and Engineering, summarizes presentations of many experts and presents information on specific strategies for increasing the participation of women…

Key barriers to the use of modern contraceptives among women in Albania: a qualitative study.

PubMed

Kragelund Nielsen, Karoline; Nielsen, Siff Malue; Butler, Robb; Lazarus, Jeffrey V

2012-12-01

In spite of a number of communication campaigns since 1999 promoting modern contraceptives in Albania, their use remains low. In this paper we identify and analyse key barriers to the use of modern contraception among women in Albania. Semi-structured interviews with 11 stakeholders from organisations involved in promoting modern contraception, and four focus group discussions with 40 women from Tirana and a rural village in the periphery of Tirana, divided according to age and residence, were also conducted. Content analysis was used to analyse both the interviews and focus group discussions. Barriers identified included socio-cultural issues such as status of the relationship with partners and the importance of virginity, problems talking about sexual issues and contraception being taboo, health care issues--especially cost and availability--and individual issues such as unfavourable social attitudes towards contraceptives and a lack of knowledge about the use and benefits of modern contraception. To promote contraceptive use in the future, campaigns should address these barriers and expand from a focus on women of reproductive age only to target youth, men, health care providers, parents and schoolteachers as well. Copyright © 2012 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

40 CFR 191.14 - Assurance requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Assurance requirements. 191.14 Section 191.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION... barriers to isolate the wastes from the accessible environment. Both engineered and natural barriers shall...

Money, Math and Engineering: The Relationships between Community Economics, Math Preparation and the Graduation of Racially Underrepresented Engineers

ERIC Educational Resources Information Center

Freeman, Amy Louise

2009-01-01

A primary gateway to a career in engineering is the attainment of the bachelor of science degree in engineering. In contrast, a common barrier to becoming an engineer is failure to attain the degree. Those variables that are related to college graduation are often in place prior to college admission. The purpose of this study was to examine the…

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.

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers... Engineers will assign numbers to Real Estate Directives issued by Air Force Regional Civil Engineers. The...

Microstructure Based Material-Sand Particulate Interactions and Assessment of Coatings for High Temperature Turbine Blades

NASA Technical Reports Server (NTRS)

Murugan, Muthuvel; Ghoshal, Anindya; Walock, Michael; Nieto, Andy; Bravo, Luis; Barnett, Blake; Pepi, Marc; Swab, Jeffrey; Pegg, Robert Tyler; Rowe, Chris;

Design issues for lunar in situ aluminum/oxygen propellant rocket engines

NASA Technical Reports Server (NTRS)

Meyer, Michael L.

1992-01-01

Design issues for lunar ascent and lunar descent rocket engines fueled by aluminum/oxygen propellant produced in situ at the lunar surface were evaluated. Key issues are discussed which impact the design of these rockets: aluminum combustion, throat erosion, and thrust chamber cooling. Four engine concepts are presented, and the impact of combustion performance, throat erosion and thrust chamber cooling on overall engine design are discussed. The advantages and disadvantages of each engine concept are presented.

Geomorphologic Evolution of Barrier Islands along the Northern U.S. Gulf of Mexico and Implications for Engineering Design in Barrier Restoration

DTIC Science & Technology

2009-01-01

Chandeleur Is- lands). Finally, Stage 3 occurs when erosion and subsidence reduce the barrier island to a subaqueous inner shelf shoal (e.g., Ship Shoal...exception is the western- most island, Cat Island, which is primarily protected from offshore waves from the incident wave sheltering of the Chandeleur and...KAHN and ROBERTS (1982) discussed the morpho- logic response of the Chandeleur barrier islands to Hurricane Frederic, a powerful storm that made

SUPERFUND ENGINEERING ISSUE: ISSUES AFFECTING THE APPLICABILITY AND SUCCESS OF REMEDIAL/REMOVAL INCINERATION PROJECTS

EPA Science Inventory

The Regional Superfund Engineering Forum is a group of EPA professionals, representing EPA's Regional Superfund Offices, committed to the identification and resolution of engineering issues impacting the remediation of Superfund sites. The Forum is supported by and advises the ...

Western Wind Strategy: Addressing Critical Issues for Wind Deployment

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

Douglas Larson; Thomas Carr

2012-03-30

The goal of the Western Wind Strategy project was to help remove critical barriers to wind development in the Western Interconnection. The four stated objectives of this project were to: (1) identify the barriers, particularly barriers to the operational integration of renewables and barriers identified by load-serving entities (LSEs) that will be buying wind generation, (2) communicate the barriers to state officials, (3) create a collaborative process to address those barriers with the Western states, utilities and the renewable industry, and (4) provide a role model for other regions. The project has been on the forefront of identifying and informingmore » state policy makers and utility regulators of critical issues related to wind energy and the integration of variable generation. The project has been a critical component in the efforts of states to push forward important reforms and innovations that will enable states to meet their renewable energy goals and lower the cost to consumers of integrating variable generation.« less

Informing watershed connectivity barrier prioritization decisions: A synthesis

USGS Publications Warehouse

McKay, S. K.; Cooper, A. R.; Diebel, M.W.; Elkins, D.; Oldford, G.; Roghair, C.; Wieferich, Daniel J.

2017-01-01

Water resources and transportation infrastructure such as dams and culverts provide countless socio-economic benefits; however, this infrastructure can also disconnect the movement of organisms, sediment, and water through river ecosystems. Trade-offs associated with these competing costs and benefits occur globally, with applications in barrier addition (e.g. dam and road construction), reengineering (e.g. culvert repair), and removal (e.g. dam removal and aging infrastructure). Barrier prioritization provides a unique opportunity to: (i) restore and reconnect potentially large habitat patches quickly and effectively and (ii) avoid impacts prior to occurrence in line with the mitigation hierarchy (i.e. avoid then minimize then mitigate). This paper synthesizes 46 watershed-scale barrier planning studies and presents a procedure to guide barrier prioritization associated with connectivity for aquatic organisms. We focus on practical issues informing prioritization studies such as available data sets, methods, techniques, and tools. We conclude with a discussion of emerging trends and issues in barrier prioritization and key opportunities for enhancing the body of knowledge.

EDITORIAL: Special issue containing papers presented at the 12th International Workshop on H-mode Physics and Transport Barriers Special issue containing papers presented at the 12th International Workshop on H-mode Physics and Transport Barriers

NASA Astrophysics Data System (ADS)

Hahm, T. S.

2010-06-01

The 12th International Workshop on H-mode Physics and Transport Barriers was held at the Princeton Plasma Physics Laboratory, Princeton, New Jersey, USA between September 30 and October 2, 2009. This meeting was the continuation of a series of previous meetings which was initiated in 1987 and has been held bi-annually since then. Following the recent tradition at the last few meetings, the program was sub- divided into six sessions. At each session, an overview talk was presented, followed by two or three shorter oral presentations which supplemented the coverage of important issues. These talks were followed by discussion periods and poster sessions of contributed papers. The sessions were: Physics of Transition to/from Enhanced Confinement Regimes, Pedestal and Edge Localized Mode Dynamics, Plasma Rotation and Momentum Transport, Role of 3D Physics in Transport Barriers, Transport Barriers: Theory and Simulations and High Priority ITER Issues on Transport Barriers. The diversity of the 90 registered participants was remarkable, with 22 different nationalities. US participants were in the majority (36), followed by Japan (14), South Korea (7), and China (6). This special issue of Nuclear Fusion consists of a cluster of 18 accepted papers from submitted manuscripts based on overview talks and poster presentations. The paper selection procedure followed the guidelines of Nuclear Fusion which are essentially the same as for regular articles with an additional requirement on timeliness of submission, review and revision. One overview paper and five contributed papers report on the H-mode pedestal related results which reflect the importance of this issue concerning the successful operation of ITER. Four papers address the rotation and momentum transport which play a crucial role in transport barrier physics. The transport barrier transition condition is the main focus of other four papers. Finally, four additional papers are devoted to the behaviour and control of Edge Localized Modes. The selection of topics and overview speakers and the scientific programme were carried out by the International Advisory Committee, consisting of: R. Groebner (GA, USA), T.S. Hahm (PPPL, USA--Chair), A. Hubbard (MIT, USA), K. Ida (NIFS, Japan), S. Lebedev (Ioffe Institute, Russia), N. Oyama (JAEA, Japan), G. Saibene (F4E, EU) and W. Suttrop (IPP, Germany). Their work, advice, and participation contributed to the success of the meeting. Finally, I would like to express deep gratitude to J. Jones and B. Sarfaty who took care of numerous issues relating to the organization of the meeting, and to J.K. Park and several graduate students of the Princeton University Plasma Physics Program for helping with the transportation of participants.

On the asteroid hazard

NASA Astrophysics Data System (ADS)

Eneev, T. M.; Akhmetshin, R. Z.; Efimov, G. B.

2012-04-01

The concept of "space patrol" is considered, aimed at discovering and cataloging the majority of celestial bodies that constitute a menace for the Earth [1, 2]. The scheme of "optical barrier" formed by telescopes of the space patrol is analyzed, requirements to the observation system are formulated, and some schemes of sighting the optical barrier region are suggested (for reliable detection of the celestial bodies approaching the Earth and for determination of their orbits). A comparison is made of capabilities of electro-jet engines and traditional chemical engines for arrangement of patrol spacecraft constellation in the Earth's orbit.

Life modeling of thermal barrier coatings for aircraft gas turbine engines

NASA Technical Reports Server (NTRS)

Miller, Robert A.

1988-01-01

Thermal barrier coating life models developed under the NASA Lewis Research Center's Hot Section Technology (HOST) program are summarized. An initial laboratory model and three design-capable models are discussed. Current understanding of coating failure mechanisms are also summarized.

77 FR 59243 - Aviation Rulemaking Advisory Committee Meeting on Transport Airplane and Engine Issues

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-26

... Committee Meeting on Transport Airplane and Engine Issues AGENCY: Federal Aviation Administration (FAA), DOT... Rulemaking Advisory Committee (ARAC) to discuss transport airplane and engine (TAE) issues. DATES: The... Prioritization Working Group Transport Canada Report Materials Flammability Working Group Report Avionics...

Input and output constraints-based stabilisation of switched nonlinear systems with unstable subsystems and its application

NASA Astrophysics Data System (ADS)

Chen, Chao; Liu, Qian; Zhao, Jun

2018-01-01

This paper studies the problem of stabilisation of switched nonlinear systems with output and input constraints. We propose a recursive approach to solve this issue. None of the subsystems are assumed to be stablisable while the switched system is stabilised by dual design of controllers for subsystems and a switching law. When only dealing with bounded input, we provide nested switching controllers using an extended backstepping procedure. If both input and output constraints are taken into consideration, a Barrier Lyapunov Function is employed during operation to construct multiple Lyapunov functions for switched nonlinear system in the backstepping procedure. As a practical example, the control design of an equilibrium manifold expansion model of aero-engine is given to demonstrate the effectiveness of the proposed design method.

William W. Lang's contributions to the development of the International Institute of Noise Control Engineering

NASA Astrophysics Data System (ADS)

Kihlman, Tor

2005-09-01

Bill Lang has been a member of the Board of I-INCE since its first meeting in 1975 in Sendai, Japan. From 1988 to 1999 he served as the President, and to this day remains a very active member of the Board. The INTER-NOISE congress series has been the core activity of I-INCE, and in every case Bill has contributed very actively to secure an excellent congress. He has also taken a number of initiatives both to improve the organization itself and to develop new activities, especially the Technical Study Groups that have prepared consensus reports on important issues such as noise barrier effectiveness and industrial noise hearing conservation policy. At present, he is very active in attempting to develop a global noise control policy.

Katrina: macro-ethical issues for engineers.

PubMed

Newberry, Byron

2010-09-01

Hurricane Katrina was one of the worst disasters in United States history. Failures within New Orleans' engineered hurricane protection system (levees and floodwalls) contributed to the severity of the event and have drawn considerable public attention. In the time since Katrina, forensic investigations have uncovered a range of issues and problems related to the engineering work. In this article, my goal is to distill from these investigations, and the related literature that has accumulated, some overarching macro-ethical issues that are relevant for all engineers. I attempt to frame these issues, using illustrative examples taken from Katrina, in a way that might be of pedagogical use and benefit for engineering educators interested in engaging their students in discussions of engineering ethics, societal impact of engineered systems, engineering design, or related topics. Some of the issues discussed are problems of unanticipated failure modes, faulty assumptions, lack or misuse of information, the importance of resiliency, the effects of time, balancing competing interests, attending to the details of interfaces, the fickleness of risk perception, and how the past constrains the present.

An investigation of enhanced capability thermal barrier coating systems for diesel engine components

NASA Technical Reports Server (NTRS)

Holtzman, R. L.; Layne, J. L.; Schechter, B.

1984-01-01

Material systems and processes for the development of effective and durable thermal barriers for heavy duty diesel engines were investigated. Seven coating systems were evaluated for thermal conductivity, erosion resistance, corrosion/oxidation resistance, and thermal shock resistance. An advanced coating system based on plasma sprayed particle yttria stabilized zirconia (PS/HYSZ) was judged superior in these tests. The measured thermal conductivity of the selected coating was 0.893 W/m C at 371 C. The PS/HYSZ coating system was applied to the piston crown, fire deck and valves of a single cylinder low heat rejection diesel engine. The coated engine components were tested for 24 hr at power levels from 0.83 MPa to 1.17 MPa brake mean effective pressure. The component coatings survived the engine tests with a minimum of distress. The measured fire deck temperatures decreased 86 C (155 F) on the intake side and 42 C (75 F) on the exhaust side with the coating applied.

Applying Costs, Risks and Values Evaluation (CRAVE) methodology to Engineering Support Request (ESR) prioritization

NASA Technical Reports Server (NTRS)

Joglekar, Prafulla N.

1994-01-01

Given limited budget, the problem of prioritization among Engineering Support Requests (ESR's) with varied sizes, shapes, and colors is a difficult one. At the Kennedy Space Center (KSC), the recently developed 4-Matrix (4-M) method represents a step in the right direction as it attempts to combine the traditional criteria of technical merits only with the new concern for cost-effectiveness. However, the 4-M method was not adequately successful in the actual prioritization of ESRs for the fiscal year 1995 (FY95). This research identifies a number of design issues that should help us to develop better methods. It emphasizes that given the variety and diversity of ESR's one should not expect that a single method could help in the assessment of all ESR's. One conclusion is that a methodology such as Costs, Risks, and Values Evaluation (CRAVE) should be adopted. It also is clear that the development of methods such as 4-M requires input not only from engineers with technical expertise in ESR's but also from personnel with adequate background in the theory and practice of cost-effectiveness analysis. At KSC, ESR prioritization is one part of the Ground Support Working Teams (GSWT) Integration Process. It was discovered that the more important barriers to the incorporation of cost-effectiveness considerations in ESR prioritization lie in this process. The culture of integration, and the corresponding structure of review by a committee of peers, is not conducive to the analysis and confrontation necessary in the assessment and prioritization of ESR's. Without assistance from appropriately trained analysts charged with the responsibility to analyze and be confrontational about each ESR, the GSWT steering committee will continue to make its decisions based on incomplete understanding, inconsistent numbers, and at times, colored facts. The current organizational separation of the prioritization and the funding processes is also identified as an important barrier to the pursuit of cost-effectiveness. Perhaps the greatest barrier is that, at the working level, KSC's culture is so preoccupied with technical concerns that it seems almost oblivious to any cost concerns, let alone cost-effectiveness concerns. It is recommended that we must urgently begin to change that culture and seek a better balance between these two concerns.

To Educate Engineers or to Engineer Educators?: Exploring Access to Engineering Careers

ERIC Educational Resources Information Center

Eastman, Michael G.; Christman, Jeanne; Zion, George H.; Yerrick, Randy

2017-01-01

Although studies claim increases in underrepresented populations choosing STEM majors, barriers to retention, and higher education degree completion in STEM still exist. This study examined efforts of a prominent technical university to attract and retain urban high school graduates through a tuition scholarship program. We sought to determine the…

Confronting Cyberterrorism with Cyber Deception

DTIC Science & Technology

2003-12-01

break into computer systems. A further development in social engineering is the use of online translators and 41 relay telephony services that...allow social engineers to exploit and overcome language barriers [Ollmann, 2003]. Relay telephony services are online services provided by...open source media or actively seeking the information through unscrupulous means. - Desk checking - Social engineering - Dumpster diving

The Transferability and Retraining of Defense Engineers.

ERIC Educational Resources Information Center

Rittenhouse, Carl H.

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

75 FR 55393 - Aviation Rulemaking Advisory Committee Meeting on Transport Airplane and Engine Issues

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-10

... Committee Meeting on Transport Airplane and Engine Issues AGENCY: Federal Aviation Administration (FAA), DOT... Rulemaking Advisory Committee (ARAC) to discuss transport airplane and engine (TAE) issues. DATES: The...: Opening Remarks, Review Agenda and Minutes. FAA Report. ARAC Executive Committee Report. Transport Canada...

78 FR 57672 - Aviation Rulemaking Advisory Committee Meeting on Transport Airplane and Engine Issues

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-19

... Committee Meeting on Transport Airplane and Engine Issues AGENCY: Federal Aviation Administration (FAA), DOT... Rulemaking Advisory Committee (ARAC) Transport Airplane and Engine (TAE) Subcommittee to discuss TAE issues... meeting is as follows: Opening Remarks, Review Agenda and Minutes FAA Report ARAC Report Transport Canada...

Systems Engineering

NASA Technical Reports Server (NTRS)

Pellerano, Fernando

2015-01-01

This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Teaching ethics to engineers: ethical decision making parallels the engineering design process.

PubMed

Bero, Bridget; Kuhlman, Alana

2011-09-01

In order to fulfill ABET requirements, Northern Arizona University's Civil and Environmental engineering programs incorporate professional ethics in several of its engineering courses. This paper discusses an ethics module in a 3rd year engineering design course that focuses on the design process and technical writing. Engineering students early in their student careers generally possess good black/white critical thinking skills on technical issues. Engineering design is the first time students are exposed to "grey" or multiple possible solution technical problems. To identify and solve these problems, the engineering design process is used. Ethical problems are also "grey" problems and present similar challenges to students. Students need a practical tool for solving these ethical problems. The step-wise engineering design process was used as a model to demonstrate a similar process for ethical situations. The ethical decision making process of Martin and Schinzinger was adapted for parallelism to the design process and presented to students as a step-wise technique for identification of the pertinent ethical issues, relevant moral theories, possible outcomes and a final decision. Students had greatest difficulty identifying the broader, global issues presented in an ethical situation, but by the end of the module, were better able to not only identify the broader issues, but also to more comprehensively assess specific issues, generate solutions and a desired response to the issue.

Global Science Share: Connecting young scientists from developing countries with science writing mentors to strengthen and widen the international science community

NASA Astrophysics Data System (ADS)

Hasenkopf, C. A.

2012-12-01

Collaborative science in which scientists are able to form research questions based on the current body of scientific knowledge and get feedback from colleagues on their ideas and work is essential for pushing science forward. However, not all scientists are able to fully participate in the international science community. Scientists from developing countries can face barriers to communicating with the international community due to, among other issues: fewer scientists in their home country, difficulty in getting language-specific science writing training, fewer established pre-existing international collaborations and networks, and sometimes geographic isolation. These barriers not only result in keeping individual scientists from contributing their ideas, but they also slow down the progress of the scientific enterprise for everyone. Global Science Share (http://globalscienceshare.org/) is a new project, entering its pilot phase in Fall 2012, which will work to reduce this disparity by connecting young scientists and engineers from developing countries seeking to improve their technical writing with other scientists and engineers around the world via online collaborations. Scientist-volunteers act as mentors and are paired up with mentees according to their academic field and writing needs. The mentors give feedback and constructive technical and editorial criticisms on mentees' submitted pieces of writing through a four-step email discussion. Mentees gain technical writing skills, as well as make international connections with other scientists and engineers in fields related to their own. Mentors also benefit by gaining new international scientific colleagues and honing their own writing skills through their critiques. The Global Science Share project will begin its pilot phase by first inviting Mongolian science students to apply as mentees this fall. This abstract will introduce the Global Science Share program, present a progress report from its first semester, and inform members of the geoscience community about this unique outreach opportunity to help strengthen and widen the international science community that can be done in the comfort of one's office or home.

Revisiting the Birth of 7YSZ Thermal Barrier Coatings: Steve Stecura

NASA Technical Reports Server (NTRS)

Smialek, James L.; Miller, Robert A.

2017-01-01

Thermal barrier coatings are widely used in all turbine engines, typically using a 7 wt% Y2O3-ZrO2 formulation. Extensive research and development over many decades have refined the processing and structure of these coatings for increased durability and reliability. New compositions demonstrate some unique advantages and are gaining in application. However, the "7YSZ" formulation predominates and is still in widespread use. This special composition has been universally found to produce nanoscale precipitates of metastable t' tetragonal phase, giving rise to a unique toughening mechanism via ferro-elastic switching under stress. This note recalls the original study that identified superior properties of 6 to 8 wt% YSZ plasma sprayed thermal barrier coatings, published in 1978. The impact of this discovery, arguably, continues in some form to this day. At one point, 7YSZ thermal barrier coatings were used in every new aircraft and ground power turbine engine produced worldwide. It is a tribute to its inventor, Dr. Stephan J. Stecura, NASA retiree.

CaO-MgO-Al 2O 3-SiO 2 (CMAS) corrosion of Gd 2Zr 2O 7 and Sm 2Zr 2O 7

DOE PAGES

Wang, Honglong; Bakal, Ahmet; Zhang, Xingxing; ...

2016-08-08

Ceramic thermal barrier coatings are applied to superalloys used in gas turbine engineering to increase the operating temperature and the energy conversion efficiency. However, dust consisting of CaO-MgO-Al 2O 3-SiO 2 (CMAS) from the air can be injected into the engines and corrode the thermal barrier coatings. Lanthanide zirconates are promising materials in thermal barrier coatings due to their low thermal conductivities, good phase stability and good corrosion resistance. However, the corrosion resistance mechanism of CMAS on lanthanide zirconates is still not clearly understood. In this work, the corrosion mechanism of Gd 2Zr 2O 7 and Sm 2Zr 2O 7more » in CMAS is studied. Here, the results show that the CMAS can easily react with lanthanide zirconate thermal barrier coatings to form a dense layer, which can resist further corrosion« less

Barrier, weakness and utilization of pre-pregnancy clinic services.

PubMed

Rahman, Mizanur; Rahim, Natazcza Abdul; Arif, Mohd Taha

2017-01-01

Despite being one of the plausible measures towards achieving Sustainable Development Goals (SDGs), various issues pertaining to pre-pregnancy clinic (PPC) services still need to be pondered upon. Based on this view, an attempt was made to identify and understand the barriers and weaknesses of current utilisation of pre-pregnancy care services, since its establishment and implementation in Sarawak from the year 2011. This cross-sectional study was conducted in selected health care facilities throughout Sarawak. A multistage cluster sampling technique was followed to select the health facilities. An unstructured open-ended questionnaire was administered as a part of quantitative data analysis. The open-ended questions were administered to get the in-depth perceived views and current practice of utilisation of pre-pregnancy clinic services. A total of 553 clients from nine selected health care facilities gave their feedback. The results of the study were narrated in textual form and a thematic analysis was done manually. The identified themes for perceived barriers for utilisation of pre-pregnancy care were perception, attitude and acceptance of PPC services, socio-economic issues, services and client factors. The perceived weaknesses of the services are listed under two main themes: working environment and service factors, whereas, the strength of services produced three thematic areas which are preparation for pregnancy, prevention of mortality and morbidity and comprehensive services. Though there is ample evidence that pre-pregnancy services are beneficial for maternal health and wellbeing, various issues still need to be addressed for the improvement of the quality of services. Lack of awareness among clients, socio-economic barriers, lack of resources, organisational barriers and perceptions towards family planning issues are some of the issues which need to be addressed. Nonetheless, promotional and health educational activities are important keys; in ensuring the sustainability of the services.

Beyond access: barriers to internet health information seeking among the urban poor.

PubMed

McCloud, Rachel F; Okechukwu, Cassandra A; Sorensen, Glorian; Viswanath, K

2016-11-01

Communication inequalities deepen health disparities even when internet access is achieved. The goal of this study is to understand how a range of barriers may inhibit individuals from low socioeconomic position (SEP) from engaging with online health information even when it is freely available. Detailed data were collected from 118 low-SEP individuals from a randomized controlled trial providing internet access. Measures triangulated the health-seeking experience through internet use tracked in real-time, call log data, and self-reported barriers. Negative binomial regression models were fitted with technology and perceived predictors, and our outcome, health information seeking, and then stratified by medical status. Participants experienced a median of two computer issues (median 6 days) and two internet issues (median 6.5 days). Duration of internet problems was associated with a decrease in the rate of internet health information seeking by a factor of 0.990 (P = .03) for each additional day. Participants with a medical problem who were frustrated in their search for health information had half the rate of health information seeking of those who were not frustrated (incidence rate ratio = 0.395, P = .030). Despite IT support, participants still experienced internet connectivity issues that negatively impacted their health information seeking. Frustration in their search to find information may serve as an additional barrier to those who have medical issues. After initial internet access, a second-level digital divide emerged due to connectivity issues, highlighting the need to understand the complex network of barriers experienced by low-SEP internet users. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

75 FR 52591 - Seventh Meeting: RTCA Special Committee 221: Aircraft Secondary Barriers and Alternative Flight...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-26

... Committee 221: Aircraft Secondary Barriers and Alternative Flight Deck Security Procedures AGENCY: Federal... Secondary Barriers and Alternative Flight Deck Security Procedures. SUMMARY: The FAA is issuing this notice... Alternative Flight Deck Security Procedures. DATES: The meeting will be held September 14-15, 2010. September...

A follow-up program in India for patients with spinal cord injury: paraplegia safari.

PubMed

Prabhaka, M M; Thakker, Tejas H

2004-01-01

Once patients with spinal cord injury (SCI) were discharged from the hospital, it was very difficult for them to return for follow-up, particularly during the first year, due to problems regarding finances and social issues, as well as extreme physical barriers. Because of these barriers, a large number of patients were presenting for re-admission for reasons that might have been prevented if they had come for routine follow-up. Therefore, it was felt that an attempt to visit the patient's residence to conduct a follow-up would be of great help. To evaluate and improve the status of rehabilitation of community-dwelling SCI patients in their homes and attempt to decrease the rate of re-admissions. In this program, the home visit team consisted of an orthopedic surgeon, physiotherapist, occupational therapist, prosthetist and orthotist engineer, medical social worker, and a nurse. Rehabilitated discharged patients received needed medical treatment, orthotics, and vocational guidance at their residences. Patients who required re-admission were assisted back to the hospital. The home visit program decreased the number of re-admissions by improving the status of rehabilitation, which raised the quality of care for patients with SCI.

Enabling fast charging - Infrastructure and economic considerations

NASA Astrophysics Data System (ADS)

Burnham, Andrew; Dufek, Eric J.; Stephens, Thomas; Francfort, James; Michelbacher, Christopher; Carlson, Richard B.; Zhang, Jiucai; Vijayagopal, Ram; Dias, Fernando; Mohanpurkar, Manish; Scoffield, Don; Hardy, Keith; Shirk, Matthew; Hovsapian, Rob; Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.; Keyser, Matthew; Kreuzer, Cory; Markel, Anthony; Meintz, Andrew; Pesaran, Ahmad; Tanim, Tanvir R.

2017-11-01

The ability to charge battery electric vehicles (BEVs) on a time scale that is on par with the time to fuel an internal combustion engine vehicle (ICEV) would remove a significant barrier to the adoption of BEVs. However, for viability, fast charging at this time scale needs to also occur at a price that is acceptable to consumers. Therefore, the cost drivers for both BEV owners and charging station providers are analyzed. In addition, key infrastructure considerations are examined, including grid stability and delivery of power, the design of fast charging stations and the design and use of electric vehicle service equipment. Each of these aspects have technical barriers that need to be addressed, and are directly linked to economic impacts to use and implementation. This discussion focuses on both the economic and infrastructure issues which exist and need to be addressed for the effective implementation of fast charging at 400 kW and above. In so doing, it has been found that there is a distinct need to effectively manage the intermittent, high power demand of fast charging, strategically plan infrastructure corridors, and to further understand the cost of operation of charging infrastructure and BEVs.

Enabling fast charging – Infrastructure and economic considerations

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

Burnham, Andrew; Dufek, Eric J.; Stephens, Thomas

The ability to charge battery electric vehicles (BEVs) on a time scale that is on par with the time to fuel an internal combustion engine vehicle (ICEV) would remove a significant barrier to the adoption of BEVs. However, for viability, fast charging at this time scale needs to also occur at a price that is acceptable to consumers. Therefore, the cost drivers for both BEV owners and charging station providers are analyzed. In addition, key infrastructure considerations are examined, including grid stability and delivery of power, the design of fast charging stations and the design and use of electric vehiclemore » service equipment. Each of these aspects have technical barriers that need to be addressed, and are directly linked to economic impacts to use and implementation. This discussion focuses on both the economic and infrastructure issues which exist and need to be addressed for the effective implementation of fast charging at 400 kW and above. In so doing, it has been found that there is a distinct need to effectively manage the intermittent, high power demand of fast charging, strategically plan infrastructure corridors, and to further understand the cost of operation of charging infrastructure and BEVs.« less

Enabling fast charging – Infrastructure and economic considerations

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

Burnham, Andrew; Dufek, Eric J.; Stephens, Thomas

The ability to charge battery electric vehicles (BEVs) on a time scale that is on par with the time to fuel an internal combustion engine vehicle (ICEV) would remove a significant barrier to the adoption of BEVs. However, for viability, fast charging at this time scale needs to also occur at a price that is acceptable to consumers. Therefore, the cost drivers for both BEV owners and charging station providers are analyzed. In addition, key infrastructure considerations are examined, including grid stability and delivery of power, the design of fast charging stations and the design and use of electric vehiclemore » service equipment. Each of these aspects have technical barriers that need to be addressed, and are directly linked to economic impacts to use and implementation. Here, this discussion focuses on both the economic and infrastructure issues which exist and need to be addressed for the effective implementation of fast charging up to 350 kW. In doing so, it has been found that there is a distinct need to effectively manage the intermittent, high power demand of fast charging, strategically plan infrastructure corridors, and to further understand the cost of operation of charging infrastructure and BEVs.« less

Converging, pervasive technologies: chronic and emerging issues and policy adequacy.

PubMed

Seelman, Katherine D

2008-01-01

This article is a thought piece with the expansive goal of identifying policy facilitators and barriers to the development of usable and accessible advanced information and communications technology for people with disabilities across the age span at the research and development and marketing stages. The working hypothesis is as follows: The lack of participation in and representation of the interests of people with disabilities in the technology resource system is a barrier to availability of affordable consumer goods that enable independence and community integration. Converging, pervasive computing technology, especially in housing applications, is used as a case example, drawing especially from research and development conducted by the National Science Foundation Quality of Life Technology Engineering Research Center. A critical theory approach is used to identify problems and seek solutions to the apparent lack of balance between the demand and needs of disabled users and the supply and availability of usable, affordable consumer goods produced by the technology resource system in which allocation decisions are made. The approach uses policy analysis tools such as a technology assessment framework; the participation and environment components of the World Health Organization's International Classification of Functioning, Disability and Health; and participatory action research.

Enabling fast charging – Infrastructure and economic considerations

DOE PAGES

Burnham, Andrew; Dufek, Eric J.; Stephens, Thomas; ...

2017-10-23

The ability to charge battery electric vehicles (BEVs) on a time scale that is on par with the time to fuel an internal combustion engine vehicle (ICEV) would remove a significant barrier to the adoption of BEVs. However, for viability, fast charging at this time scale needs to also occur at a price that is acceptable to consumers. Therefore, the cost drivers for both BEV owners and charging station providers are analyzed. In addition, key infrastructure considerations are examined, including grid stability and delivery of power, the design of fast charging stations and the design and use of electric vehiclemore » service equipment. Each of these aspects have technical barriers that need to be addressed, and are directly linked to economic impacts to use and implementation. Here, this discussion focuses on both the economic and infrastructure issues which exist and need to be addressed for the effective implementation of fast charging up to 350 kW. In doing so, it has been found that there is a distinct need to effectively manage the intermittent, high power demand of fast charging, strategically plan infrastructure corridors, and to further understand the cost of operation of charging infrastructure and BEVs.« less

Permanence of Temporary Security Barriers

DTIC Science & Technology

2009-05-01

such as the ones in Baghdad. A strategic impact or perspective is defined for the purpose of this paper as affecting the instruments of national...use of security barriers and more importantly complex issues regarding their removal. This paper examines the use of security barriers across the...world and delves into the circumstances leading to the removal of security barriers. This paper proposes that there are definable, prerequisite

Vacuum application of thermal barrier plasma coatings

NASA Technical Reports Server (NTRS)

Holmes, R. R.; Mckechnie, T. N.

1988-01-01

Coatings are presently applied to Space Shuttle Main Engine (SSME) turbine blades for protection against the harsh environment realized in the engine during lift off-to-orbit. High performance nickel, chromium, aluminum, and yttrium (NiCrAlY) alloy coatings, which are applied by atmospheric plasma spraying, crack and spall off because of the severe thermal shock experienced during start-up and shut-down of the engine. Ceramic coatings of yttria stabilized zirconia (ZrO2-Y2O3) were applied initially as a thermal barrier over coating to the NiCrAlY but were removed because of even greater spalling. Utilizing a vacuum plasma spraying process, bond coatings of NiCrAlY were applied in a low pressure atmosphere of argon/helium, producing significantly improved coating-to-blade bonding. The improved coatings showed no spalling after 40 MSFC burner rig thermal shock cycles, cycling between 1700 and -423 F. The current atmospheric plasma NiCrAlY coatings spalled during 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2-Y2O3 to the turbine blades of first stage high-pressure fuel turbopumps utilizing the vacuum plasma process. The improved thermal barrier coating has successfully passed 40 burner rig thermal shock cycles without spalling. Hot firing in an SSME turbine engine is scheduled for the blades. Tooling was installed in preparation for vacuum plasma spray coating other SSME hardware, e.g., the titanium main fuel valve housing (MFVH) and the fuel turbopump nozzle/stator.

Engineering assessment of low-level liquid waste disposal caisson locations at the 618-11 Burial Grounds

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

Phillips, S.J.; Fischer, D.D.; Crawford, R.C.

1982-06-01

Rockwell Hanford Operations is currently involved in an extensive effort to perform interim ground surface stabilization activities at retired low-level waste burial grounds located at the Hanford Site, Richland, Washington. The principal objective of these activities is to promote increased occupational and radiological safety at burial grounds. Interim stabilization activities include: (1) load testing (traversing burial ground surfaces with heavy equipment to promote incipient collapse of void spaces within the disposal structure and overburden), (2) barrier placement (placement of a {ge} 0.6 m soil barrier over existing overburden), and (3) revegetation (establishment of shallow rooted vegetation on the barrier tomore » mitigate deep rooted plant growth and to reduce erosion). Low-level waste disposal caissons were used in 300 Area Burial Grounds as internment structures for containerized liquid wastes. These caissons, by virtue of their contents, design and methods of closure, require long-term performance evaluation. As an initial activity to evaluate long-term performance, the accurate location of these structures is required. This topical report summarizes engineering activities used to locate caissons in the subsurface environment at the Burial Ground. Activities were conducted to locate caissons during surface stabilization activities. The surface locations were marked, photographed, and recorded on an as built engineering drawing. The recorded location of these caissons will augment long-term observations of confinement structure and engineered surface barrier performance. In addition, accurate caisson location will minimize occupational risk during monitoring and observation activities periodically conducted at the burial ground.« less

Feasibility study for early removal of HEU from CPP-651-Phase II

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

Smith, C.V.; Henry, R.; Milligan, C.

1997-09-01

A two-phase feasibility study was initiated in late 1996 to identify a way to expedite the removal of SNM from the CPP-651 vault. The first phase of this study provided preliminary information that appeared promising, but needed additional detailed planning and evaluate to validate the concepts and conclusions. The focus of Phase 2 was to provide the validation via resource-loaded schedules and more detailed cost estimates. Section 1 describes the purpose and objectives of the Phase 2 tasks and the programmatic drivers that influence related CPP-651 high-enriched uranium (HEU) management issues. Section 2 identifies the evaluation criteria and methodology andmore » the transfer issues and barriers preventing shipment. Section 3 provides site-specific background information for the CPP-651 facility and the Idaho National Engineering and Environmental Laboratory (INEEL) and describes the development of the basic material removal schedule, the proposed base case plan for removal of SNM, and the proposed HEU material management/shipping issues and strategies. Section 4 identifies the proposed options for accelerated removal of SNM and how they were evaluated via detailed scheduling, resource histograms, and cost analysis. Section 5 summarizes principal tasks for implementing this plan and other related HEU CPP-651 management issues that require continued planning efforts to assure successful implementation of this proposed early removal strategy.« less

Public policy issues in animal bioacoustics

NASA Astrophysics Data System (ADS)

Bowles, Ann E.; Hastings, Mardi C.

2002-05-01

Control of anthropogenic noise in many terrestrial and underwater environments is crucial for maintaining communication, health, and normal behavior of animals. Noise can be an issue for any species; usually, however, endangered and threatened species and marine mammals are the ones provided legal protection under the Endangered Species Act and/or the Marine Mammal Protection Act. Recent substantiated noise effects in the ocean have received much publicity and generated a more global approach to noise control. However, there are also cases where publicity was not accompanied by scientific data substantiating effects (e.g., an incident involving a $1 million noise barrier installed to protect passerine birds). The public and environmental managers have had difficulty developing adequate guidelines not only because necessary data are often lacking, but also because the manner in which funding is allocated-noise-producing agencies or private organizations are often pressured to fund studies-gives rise to inevitable conflicts of interest (or the perception thereof). Examples of recent noise-related controversies will be presented to examine the role of scientists, engineers, and professional organizations such as ASA in dealing with conflicts of interest and formulating public policy.

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

PubMed

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

2015-11-01

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

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

ERIC Educational Resources Information Center

Brody, Herb

1985-01-01

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

Barriers to treatment for older adults seeking psychological therapy.

PubMed

Wuthrich, Viviana M; Frei, Jacqueline

2015-07-01

Older adults with mental health disorders underutilize mental health services more than other adults. While there are well known general barriers to help seeking across the population, specific barriers for older adults include difficulties with transportation, beliefs that it is normal to be anxious and depressed in old age, and beliefs by referrers that psychological therapy is less likely to be effective. This study examined barriers related to identifying the need for help, seeking help and participating in therapy in a clinical population of older adults. Sixty older adults (aged 60-79 years) with comorbid anxiety and unipolar mood disorders completed barriers to treatment questionnaires before and after psychological group treatment, as well as measures of cognitive ability, anxiety, depression, and quality of life at baseline. The greatest barriers to help seeking related to difficulties identifying the need for help, with 50% of the sample reporting their belief that their symptoms were normal as a major barrier. Other major barriers identified were related to: self-reliance, cost of treatment, and fear of medication replicating previous findings. The main barriers reported for difficulties in continuing therapy included not finding therapy helpful, cost of treatment, and thinking that the therapist did not understand their issues. The main barriers identified related to issues with identifying the need to seek help. More attention is needed to educate older adults and professionals about the need for, and effectiveness of, psychological therapies for older adults with anxiety and depression to reduce this barrier to help seeking.

Development of an Integrative Program of Nanosafety: Promote the Coordination Between Industries and Risk Assessor

NASA Astrophysics Data System (ADS)

Emond, Claude; Kouassi, Serge; Schuster, Frédéric

2013-04-01

Nanomaterials are widely present in many industrial sectors (e.g., chemical, biomedical, environment), and their application is expected to significantly expand in the coming years. However, nanomaterial use raises many questions about the potential risks to human health and the environment and, more specifically, to occupational health. The available literature supports the ability of the lung, gastrointestinal tract, and skin to act as significant barriers against systemic exposure to many nanomaterials. However, because a potential risk issue exists about the toxicity of nanomaterials to the biological material, tools need to be developed for improving the risk management of the regulators. The goal is to develop a tool that examines the current knowledge base regarding the health risks posed by engineered nanoparticles to improve nanotechnology safety prior to the marketing phase. The approach proposed during this work was to establish a safety assessment constructed on a decision-control pathway regarding nanomaterial production and consumer's product to integrate different aspects. These aspects include: (1) primarily research and identification of the nanomaterial base of physicochemical properties, toxicity, and application; (2) the occupational exposure risk during the manufacturing process; (3) and the engineered nanomaterial upon the consumer product. This approach provides important parameters to reduce the uncertainty related to the production of nanomaterials prior their commercialization, reduce the reluctance from the industry, and provide a certification tool of sanitary control for the regulators. This work provides a better understanding of a critical issue of nanomaterials and consumer safety.

A transatlantic perspective on 20 emerging issues in biological engineering.

PubMed

Wintle, Bonnie C; Boehm, Christian R; Rhodes, Catherine; Molloy, Jennifer C; Millett, Piers; Adam, Laura; Breitling, Rainer; Carlson, Rob; Casagrande, Rocco; Dando, Malcolm; Doubleday, Robert; Drexler, Eric; Edwards, Brett; Ellis, Tom; Evans, Nicholas G; Hammond, Richard; Haseloff, Jim; Kahl, Linda; Kuiken, Todd; Lichman, Benjamin R; Matthewman, Colette A; Napier, Johnathan A; ÓhÉigeartaigh, Seán S; Patron, Nicola J; Perello, Edward; Shapira, Philip; Tait, Joyce; Takano, Eriko; Sutherland, William J

2017-11-14

Advances in biological engineering are likely to have substantial impacts on global society. To explore these potential impacts we ran a horizon scanning exercise to capture a range of perspectives on the opportunities and risks presented by biological engineering. We first identified 70 potential issues, and then used an iterative process to prioritise 20 issues that we considered to be emerging, to have potential global impact, and to be relatively unknown outside the field of biological engineering. The issues identified may be of interest to researchers, businesses and policy makers in sectors such as health, energy, agriculture and the environment.

Bioprinting Perfusion-Enabled Liver Equivalents for Advanced Organ-on-a-Chip Applications.

PubMed

Grix, Tobias; Ruppelt, Alicia; Thomas, Alexander; Amler, Anna-Klara; Noichl, Benjamin P; Lauster, Roland; Kloke, Lutz

2018-03-22

Many tissue models have been developed to mimic liver-specific functions for metabolic and toxin conversion in in vitro assays. Most models represent a 2D environment rather than a complex 3D structure similar to native tissue. To overcome this issue, spheroid cultures have become the gold standard in tissue engineering. Unfortunately, spheroids are limited in size due to diffusion barriers in their dense structures, limiting nutrient and oxygen supply. Recent developments in bioprinting techniques have enabled us to engineer complex 3D structures with perfusion-enabled channel systems to ensure nutritional supply within larger, densely-populated tissue models. In this study, we present a proof-of-concept for the feasibility of bioprinting a liver organoid by combining HepaRG and human stellate cells in a stereolithographic printing approach, and show basic characterization under static cultivation conditions. Using standard tissue engineering analytics, such as immunohistology and qPCR, we found higher albumin and cytochrome P 450 3A4 (CYP3A4) expression in bioprinted liver tissues compared to monolayer controls over a two-week cultivation period. In addition, the expression of tight junctions, liver-specific bile transporter multidrug resistance-associated protein 2 (MRP2), and overall metabolism (glucose, lactate, lactate dehydrogenase (LDH)) were found to be stable. Furthermore, we provide evidence for the perfusability of the organoids' intrinsic channel system. These results motivate new approaches and further development in liver tissue engineering for advanced organ-on-a-chip applications and pharmaceutical developments.

Understanding the Role of Academic Language on Conceptual Understanding in an Introductory Materials Science and Engineering Course

ERIC Educational Resources Information Center

Kelly, Jacquelyn

2012-01-01

Students may use the technical engineering terms without knowing what these words mean. This creates a language barrier in engineering that influences student learning. Previous research has been conducted to characterize the difference between colloquial and scientific language. Since this research had not yet been applied explicitly to…

A Qatari Perspective on Women in the Engineering Pipeline: An Exploratory Study

ERIC Educational Resources Information Center

Sulaiman, Noor Fauziah; AlMuftah, Hend

2010-01-01

Under-representation of women in engineering has received a great deal of attention, but remained limited largely to a Western context. Thus, this article aims to unveil the barriers to progress, tracking the performance and the emerging trend of success at the undergraduate level of women in engineering in a different cultural dimension.…

Barriers to the Implementation of Project Lead the Way as Perceived by Indiana High School Principals

ERIC Educational Resources Information Center

Shields, C. J.

2007-01-01

Technology education (TE) has come to encompass many facets of curriculum, ranging from industrial arts (IA) to integrating problem-solving and engineering concepts into the curriculum. For technology educators who have chosen the pre-engineering problem-solving route there is a pre-engineering curriculum called Project Lead The Way (PLTW), that…

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

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

Lin, Wen-Sheng; Liu, Chen-Wuing; Tsao, Jui-Hsuan

2012-07-01

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

Critical Propulsion Components. Volume 4; Inlet and Fan/Inlet Accoustics Team

NASA Technical Reports Server (NTRS)

2005-01-01

Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/Inlet Acoustic Team.

Critical Propulsion Components. Volume 1; Summary, Introduction, and Propulsion Systems Studies

NASA Technical Reports Server (NTRS)

2005-01-01

Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/ Inlet Acoustic Team.

FAA Rotorcraft Research, Engineering, and Development Bibliography, 1962-1988. Supplement

DTIC Science & Technology

1989-03-01

fires, the aircraft engine was the major fire origin for twin- and single- engine air - craft. Only in single- engine aircraft was the instrument panel a...Certification Issues. The topics of Operational Requirements, Procedures, Air - worthiness and Engineering Capabilities are discussed. Volume II presents the...Issues. The topics of Operational Requirements, Procedures, Air - worthiness and Engineering Capabilities are discussed. Volume II presents the operator

Selected Readings in Genetic Engineering

ERIC Educational Resources Information Center

Mertens, Thomas R.; Robinson, Sandra K.

1973-01-01

Describes different sources of readings for understanding issues and concepts of genetic engineering. Broad categories of reading materials are: concerns about genetic engineering; its background; procedures; and social, ethical and legal issues. References are listed. (PS)

75 FR 9016 - Fifth Meeting: RTCA Special Committee 221: Aircraft Secondary Barriers and Alternative Flight...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

... 221: Aircraft Secondary Barriers and Alternative Flight Deck Security Procedures AGENCY: Federal... Secondary Barriers and Alternative Flight Deck Security Procedures. SUMMARY: The FAA is issuing this notice... Alternative Flight Deck Security Procedures. DATES: The meeting will be held March 16-17, 2010. March 16th...

76 FR 38741 - Tenth Meeting: RTCA Special Committee 221: Aircraft Secondary Barriers and Alternative Flight...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

... 221: Aircraft Secondary Barriers and Alternative Flight Deck Security Procedures AGENCY: Federal... Secondary Barriers and Alternative Flight Deck Security Procedures. SUMMARY: The FAA is issuing this notice... Alternative Flight Deck Security Procedures. DATES: The meeting will be held July 19-20, from 9:00 a.m. to 5...

76 FR 22163 - Ninth Meeting: RTCA Special Committee 221: Aircraft Secondary Barriers and Alternative Flight...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-20

... 221: Aircraft Secondary Barriers and Alternative Flight Deck Security Procedures AGENCY: Federal... Secondary Barriers and Alternative Flight Deck Security Procedures. SUMMARY: The FAA is issuing this notice... Alternative Flight Deck Security Procedures. DATES: The meeting will be held May 10-11, 2011, from 9 a.m. to 5...

Barriers to Providing the Sexuality Education That Teachers Believe Students Need

ERIC Educational Resources Information Center

Eisenberg, Marla E.; Madsen, Nikki; Oliphant, Jennifer A.; Sieving, Renee E.

2013-01-01

Background: Sexuality education teachers' perspectives are important to gain a full understanding of the issues surrounding teaching this subject. This study uses a statewide sample of public school teachers to examine what sexuality education content is taught, what barriers teachers face, and which barriers are associated with teaching specific…

Barriers to Successful Implementation of Technology Integration in Educational Settings: A Case Study

ERIC Educational Resources Information Center

Laferrière, T.; Hamel, C.; Searson, M.

2013-01-01

Representing issues discussed at the EduSummIT 2011 relative to essential conditions and barriers to successful technology integration, this article presents a systemic analysis of barriers that needed to be overcome for an information technology initiative (Remote Networked School project) to be successfully implemented. The analysis was…

75 FR 29810 - Sixth Meeting: RTCA Special Committee 221: Aircraft Secondary Barriers and Alternative Flight...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-27

... 221: Aircraft Secondary Barriers and Alternative Flight Deck Security Procedures. AGENCY: Federal... Secondary Barriers and Alternative Flight Deck Security Procedures. SUMMARY: The FAA is issuing this notice... Alternative Flight Deck Security Procedures. DATES: The meeting will be held June 15-16, 2010. June 15th from...

Barriers to Immunizations and Strategies to Enhance Immunization Rates in Adults with Autoimmune Inflammatory Diseases.

PubMed

Kirchner, Elizabeth; Ruffing, Victoria

2017-02-01

For as long as there have been immunizations, there have been barriers to them. Immunization rates in the United States are below target. Rheumatologists and rheumatology practitioners need to understand the issues of immunizations in patients with autoimmune inflammatory disease to identify and overcome barriers to immunization. Several strategies for overcoming these barriers are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Overview of ORNL/NRC programs addressing durability of concrete structures

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

Naus, D.J.; Oland, C.B.

1994-06-01

The role of reinforced concrete relative to its applications as either safety-related structures in nuclear power or engineered barriers of low-level radioactive waste disposal facilities is described. Factors that can affect the long-term durability of reinforced concrete are identified. Overviews are presented of the Structural Aging Program, which is addressing the aging management of safety-related concrete structures in nuclear power plants, and the Permeability Test Methods and Data Program, which is identifying pertinent data and information for use in performance assessments of engineered barriers for low-level radioactive waste disposal.

Panel Resource Management (PRM) Implementation and Effects within Safety Review Panel Settings and Dynamics

NASA Technical Reports Server (NTRS)

Taylor, Robert W.; Nash, Sally K.

2007-01-01

While technical training and advanced degree's assure proficiency at specific tasks within engineering disciplines, they fail to address the potential for communication breakdown and decision making errors familiar to multicultural environments where language barriers, intimidating personalities and interdisciplinary misconceptions exist. In an effort to minimize these pitfalls to effective panel review, NASA's lead safety engineers to the ISS Safety Review Panel (SRP), and Payload Safety Review Panel (PSRP) initiated training with their engineers, in conjunction with the panel chairs, and began a Panel Resource Management (PRM) program. The intent of this program focuses on the ability to reduce the barriers inhibiting effective participation from all panel attendees by bolstering participants confidence levels through increased communication skills, situational awareness, debriefing, and a better technical understanding of requirements and systems.

Luminescence-Based Diagnostics of Thermal Barrier Coating Health and Performance

NASA Technical Reports Server (NTRS)

Eldridge, Jeffrey I.

2013-01-01

Thermal barrier coatings (TBCs) are typically composed of translucent ceramic oxides that provide thermal protection for metallic components exposed to high-temperature environments in both air- and land-based turbine engines. For advanced turbine engines designed for higher temperature operation, a diagnostic capability for the health and performance of TBCs will be essential to indicate when a mitigating action needs to be taken before premature TBC failure threatens engine performance or safety. In particular, it is shown that rare-earth-doped luminescent sublayers can be integrated into the TBC structure to produce luminescence emission that can be monitored to assess TBC erosion and delamination progression, and to map surface and subsurface temperatures as a measure of TBC performance. The design and implementation of these TBCs with integrated luminescent sublayers are presented.

Updating the Behavior Engineering Model.

ERIC Educational Resources Information Center

Chevalier, Roger

2003-01-01

Considers Thomas Gilbert's Behavior Engineering Model as a tool for systematically identifying barriers to individual and organizational performance. Includes a detailed case study and a performance aid that incorporates gap analysis, cause analysis, and force field analysis to update the original model. (Author/LRW)

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

PubMed Central

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

2015-01-01

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

Understanding safety and production risks in rail engineering planning and protection.

PubMed

Wilson, John R; Ryan, Brendan; Schock, Alex; Ferreira, Pedro; Smith, Stuart; Pitsopoulos, Julia

2009-07-01

Much of the published human factors work on risk is to do with safety and within this is concerned with prediction and analysis of human error and with human reliability assessment. Less has been published on human factors contributions to understanding and managing project, business, engineering and other forms of risk and still less jointly assessing risk to do with broad issues of 'safety' and broad issues of 'production' or 'performance'. This paper contains a general commentary on human factors and assessment of risk of various kinds, in the context of the aims of ergonomics and concerns about being too risk averse. The paper then describes a specific project, in rail engineering, where the notion of a human factors case has been employed to analyse engineering functions and related human factors issues. A human factors issues register for potential system disturbances has been developed, prior to a human factors risk assessment, which jointly covers safety and production (engineering delivery) concerns. The paper concludes with a commentary on the potential relevance of a resilience engineering perspective to understanding rail engineering systems risk. Design, planning and management of complex systems will increasingly have to address the issue of making trade-offs between safety and production, and ergonomics should be central to this. The paper addresses the relevant issues and does so in an under-published domain - rail systems engineering work.

Engineering and Design: Indoor Radon Prevention and Mitigation

DTIC Science & Technology

1993-09-15

slabs on grade, capillary water barrier below floor slabs on grade, dampproofing or waterproofing and protection board on below grade walls, sealants in...will be lapped 12 inches and sealed with adhesives or pressure sensitive tape and sealed at foundation walls with mastic. Capillary water barrier will...Systems, Letter Codes B, C, and D. Sub- slab suction systems consist of 4 inch diameter perforated PVC pipe laid in the capillary water barrier below floor

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

ERIC Educational Resources Information Center

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

2018-01-01

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

Perceived Gender and Racial/Ethnic Barriers to STEM Success

ERIC Educational Resources Information Center

Grossman, Jennifer M.; Porche, Michelle V.

2014-01-01

This mixed-methods study examined urban adolescents' perceptions of gender and racial/ethnic barriers to STEM (science, technology, engineering, and mathematics) success, and their meaning-making and coping regarding these experiences. The sample includes surveys from 1024 high school-aged students and interviews from 53 students. Logistic…

Evaluation of Subsurface Engineered Barriers at Waste Sites

DTIC Science & Technology

1998-08-01

28 3-4 MATRIX FOR EVALUATING BARRIER CQA/CQC AGAINST ACCEPTABLE INDSUTRY PRACTICES...STANDARDS................................................................. 66 4-2 MATRIX FOR EVALUATING CAP AGAINST ACCEPTABLE INDSUTRY PRACTICES...stated previously, the most widely used technique for containment is the soil-bentonite slurry wall. It is typically the most economical , utilizes low

Adoption Space and the Idea-to-Market Process of Health Technologies.

PubMed

Saranummi, Niilo; Beuscart, Regis; Black, Norman; Maglaveras, Nicos; Strano, Chiara; Karavidopoulou, Youla

2016-01-01

Although Europe 'produces' excellent science, it has not been equally successful in translating scientific results into commercially successful companies in spite of European and national efforts invested in supporting the translation process. The Idea-to-Market process is highly complex due to the large number of actors and stakeholders. ITECH was launched to propose recommendations which would accelerate the Idea-to-Market process of health technologies leading to improvements in the competitiveness of the European health technology industry in the global markets. The project went through the following steps: defining the Idea-to-Market process model; collection and analysis of funding opportunities; identification of 12 gaps and barriers in the Idea-to-Market process; a detailed analysis of these supported by interviews; a prioritization process to select the most important issues; construction of roadmaps for the prioritized issues; and finally generating recommendations and associated action plans. Seven issues were classified as in need of actions. Three of these are part of the ongoing Medical Device Directive Reform (MDR), namely health technology assessment, post-market surveillance and regulatory process, and therefore not within the scope of ITECH. Recommendations were made for eHealth taxonomy; Education and training; Clinical trials and Adoption space and Human Factors Engineering (HFE).

Improving Female Participation in Professional Engineering Geology to Bring New Perspectives to Ethics in the Geosciences

PubMed Central

Pereira, Dolores

2014-01-01

Many papers have been published related to the retention and advancement of women in sciences. Engineering geology is one of the professional areas where women have not yet broken the gender barrier. The research issues of this paper are focused on why female students “leak out” at the end of engineering geology studies, and what can be done to encourage them to complete their degrees with an engineering career in mind. The author has studied students’ preferences of the final year project required to complete their degree at the University of Salamanca (Salamanca, Spain). It has been found that most female students are choosing a more theoretical final project instead of a practical one relevant to professional employment, contrary to their male peers. Focus group meetings with the students showed that at the end of five years of engineering geology training, many female students, unsatisfied with the content of their courses, feel that their expectations had not been met. They often have preferences for traditional geology rather than applied branches of the subject. Also, they do not feel comfortable with future job prospects in the profession. From the findings of this research it is clear that tutoring and mentoring would be valuable from the beginning of studies to allow all students to become aware of the content and the potential outcomes of engineering geology studies. In the case of female students, it is particularly important for them to know from the very start that they are about to join what is still a man’s world but that they are capable of achieving just as much as men can in the profession. Most importantly, the involvement of more female engineers in professional engineering, including teaching duties, should serve as example and role models in students’ education and future careers. PMID:25216254

Improving female participation in professional engineering geology to bring new perspectives to ethics in the geosciences.

PubMed

Pereira, Dolores

2014-09-11

Many papers have been published related to the retention and advancement of women in sciences. Engineering geology is one of the professional areas where women have not yet broken the gender barrier. The research issues of this paper are focused on why female students "leak out" at the end of engineering geology studies, and what can be done to encourage them to complete their degrees with an engineering career in mind. The author has studied students' preferences of the final year project required to complete their degree at the University of Salamanca (Salamanca, Spain). It has been found that most female students are choosing a more theoretical final project instead of a practical one relevant to professional employment, contrary to their male peers. Focus group meetings with the students showed that at the end of five years of engineering geology training, many female students, unsatisfied with the content of their courses, feel that their expectations had not been met. They often have preferences for traditional geology rather than applied branches of the subject. Also, they do not feel comfortable with future job prospects in the profession. From the findings of this research it is clear that tutoring and mentoring would be valuable from the beginning of studies to allow all students to become aware of the content and the potential outcomes of engineering geology studies. In the case of female students, it is particularly important for them to know from the very start that they are about to join what is still a man's world but that they are capable of achieving just as much as men can in the profession. Most importantly, the involvement of more female engineers in professional engineering, including teaching duties, should serve as example and role models in students' education and future careers.

A case report in health information exchange for inter-organizational patient transfers.

PubMed

Richardson, J E; Malhotra, S; Kaushal, R

2014-01-01

To provide a case report of barriers and promoters to implementing a health information exchange (HIE) tool that supports patient transfers between hospitals and skilled nursing facilities. A multi-disciplinary team conducted semi-structured telephone and in-person interviews in a purposive sample of HIE organizational informants and providers in New York City who implemented HIE to share patient transfer information. The researchers conducted grounded theory analysis to identify themes of barriers and promoters and took steps to improve the trustworthiness of the results including vetting from a knowledgeable study participant. Between May and October 2011, researchers recruited 18 participants: informaticians, healthcare administrators, software engineers, and providers from a skilled nursing facility. Subjects perceived the HIE tool's development a success in that it brought together stakeholders who had traditionally not partnered for informatics work, and that they could successfully share patient transfer information between a hospital and a skilled nursing facility. Perceived barriers included lack of hospital stakeholder buy-in and misalignment with clinical workflows that inhibited use of HIE-based patient transfer data. Participants described barriers and promoters in themes related to organizational, technical, and user-oriented issues. The investigation revealed that stakeholders could develop and implement health information technology that technically enables clinicians in both hospitals and skilled nursing facilities to exchange real-time information in support of patient transfers. User level barriers, particularly in the emergency department, should give pause to developers and implementers who plan to use HIE in support of patient transfers. Participants' experiences demonstrate how stakeholders may succeed in developing and piloting an electronic transfer form that relies on HIE to aggregate, communicate, and display relevant patient transfer data across health care organizations. Their experiences also provide insights for others seeking to develop HIE applications to improve patient transfers between emergency departments and skilled nursing facilities.

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

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

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

2009-09-01

Engineered surface barriers are recognized as a remedial alternative to the removal, treatment and disposal of near-surface contaminants at a variety of waste sites within the DOE complex. One issue impacting their acceptance by stakeholders the use of limited data to predict long-term performance. In 1994, a 2-ha multi-component barrier was constructed over an existing waste disposal site at Hanford using natural materials. Monitoring has been almost continuous for the last 15 yrs and has focused on barrier stability, vegetative cover, plant and animal intrusion, and the components of the water balance, including precipitation, runoff, storage, drainage, and percolation. Themore » total precipitation received from October 1994 through August 2008 was 3311 mm on the northern half (formerly irrigated), and 2638 mm on the southern, non-irrigated half. Water storage in the fine-soil layer shows a cyclic pattern, increasing in the winter and decreasing in the spring and summer to a lower limit of around 100 mm, regardless of precipitation, in response to evapotranspiration. Topographic surveys show the barrier and side slopes to be stable and the pea-gravel admix has proven effective in minimizing erosion through the creation of a desert pavement during deflationary periods. Three runoff events have been observed but the 600-mm design storage capacity has never been exceeded. Total percolation ranged from near zero amounts under the soil-covered plots to over 600 mm under the side slopes. The asphaltic concrete prevented any of this water from reaching the buried waste thereby eliminating the driving force for the contaminant remobilization. Plant surveys show a relatively high coverage of native plants still persists after the initial revegetation although the number of species decreased from 35 in 1994 to 10 in 2009. Ample evidence of insect and small mammal use suggests that the barrier is behaving like a recovering ecosystem. In September 2008, the north half of the barrier was burned to remove vegetation and study the effects of fire on barrier performance. The most immediate effects has been on water storage patterns with the bare surface showing a slower accumulation of water, a smaller peak storage and a delayed release relative to the unburned side due to evaporation . Nonetheless the residual storage at the end of the year was similar for the burned and unburned sides.« less

An exploratory survey on the views of European tissue engineers concerning the ethical issues of tissue engineering research.

PubMed

Trommelmans, Leen; Selling, Joseph; Dierickx, Kris

2009-09-01

We present the first exploratory survey about the views of tissue engineers on the ethical issues of tissue engineering (TE), conducted among participants of a large European TE consortium. We analyzed the topics for which ethical guidance is necessary and the preferred dissemination channels, which are relevant issues and goals of clinical trials with human tissue-engineered products, and which information is to be given to trial participants. The need for comprehensive, specific ethical guidance of TE is a first key finding of this survey. Second, it becomes clear that little clarity exists on some crucial issues in the setup and conduct of clinical trials in TE. Identifying the unique features of TE and their repercussions for the ethical conduct of TE research and therapy is necessary. Third, prospective trial participants are to be informed about a wide variety of issues before taking part in the trial.

Fitness and Independence after SCI: Defining Meaningful Change and Thresholds

DTIC Science & Technology

2017-10-01

would you prefer to get this report from a health care provider, like a Doctor or Physical Therapist, or would you prefer to be able to get this...month. Lack of participant transportation and cancellations secondary to health issues are the primary barriers. MIA has over N=200 screen passes. The...3 update: Accrual rates at both centers are below target secondary to participation barriers, primarily transportation and short term health issues

FUNGIBLE AND COMPATIBLE BIOFUELS: LITERATURE SEARCH, SUMMARY, AND RECOMMENDATIONS

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

Bunting, Bruce G; Bunce, Michael; Barone, Teresa L

2011-04-01

The purpose of the study described in this report is to summarize the various barriers to more widespread distribution of bio-fuels through our common carrier fuel distribution system, which includes pipelines, barges and rail, fuel tankage, and distribution terminals. Addressing these barriers is necessary to allow the more widespread utilization and distribution of bio-fuels, in support of a renewable fuels standard and possible future low-carbon fuel standards. These barriers can be classified into several categories, including operating practice, regulatory, technical, and acceptability barriers. Possible solutions to these issues are discussed; including compatibility evaluation, changes to bio-fuels, regulatory changes, and changesmore » in the distribution system or distribution practices. No actual experimental research has been conducted in the writing of this report, but results are used to develop recommendations for future research and additional study as appropriate. This project addresses recognized barriers to the wider use of bio-fuels in the areas of development of codes and standards, industrial and consumer awareness, and materials compatibility issues.« less

A New Approach to Increasing Diversity in Engineering at the Example of Women in Engineering

ERIC Educational Resources Information Center

Schafer, Andrea I.

2006-01-01

A new initiative to incorporate diversity issues into the common engineering curriculum at the University of Wollongong (UoW) in Australia is outlined and the effect on student awareness quantified. The diversity issues were illustrated in the example of women in engineering, seeing that the numbers of women in engineering have dropped drastically…

A transatlantic perspective on 20 emerging issues in biological engineering

PubMed Central

Rhodes, Catherine; Molloy, Jennifer C; Millett, Piers; Adam, Laura; Breitling, Rainer; Carlson, Rob; Casagrande, Rocco; Dando, Malcolm; Doubleday, Robert; Drexler, Eric; Edwards, Brett; Ellis, Tom; Evans, Nicholas G; Hammond, Richard; Haseloff, Jim; Kahl, Linda; Kuiken, Todd; Lichman, Benjamin R; Matthewman, Colette A; Napier, Johnathan A; ÓhÉigeartaigh, Seán S; Patron, Nicola J; Perello, Edward; Shapira, Philip; Tait, Joyce; Takano, Eriko; Sutherland, William J

2017-01-01

Advances in biological engineering are likely to have substantial impacts on global society. To explore these potential impacts we ran a horizon scanning exercise to capture a range of perspectives on the opportunities and risks presented by biological engineering. We first identified 70 potential issues, and then used an iterative process to prioritise 20 issues that we considered to be emerging, to have potential global impact, and to be relatively unknown outside the field of biological engineering. The issues identified may be of interest to researchers, businesses and policy makers in sectors such as health, energy, agriculture and the environment. PMID:29132504

Women's History Month Event

NASA Image and Video Library

2018-03-27

JoAnn Morgan, at right, former associate director of Kennedy Space Center, was the keynote speaker during a Women's History Month event at the center. With the theme "Nevertheless She Persisted," Morgan described her experience as the first female engineer working in the space program in the 1960s. Morgan was the first female in the Launch Control Center firing room during the Apollo 11 launch. Morgan is speaking to Charlie Blackwell-Thompson, the first female launch director, who will lead countdown and launch for Exploration Mission-1. The event was hosted by the center's Kennedy Networking Opportunities for Women (KNOW) and Launching Leaders organizations. The purpose of KNOW is to provide focus on issues such as employment, retention, promotion, training, career and personal development, education, and identify and eliminate barriers that hinder the advancement of women in the workforce.

Does this interface make my sensor look bad? Basic principles for designing usable, useful interfaces for sensor technology operators

NASA Astrophysics Data System (ADS)

McNamara, Laura A.; Berg, Leif; Butler, Karin; Klein, Laura

2017-05-01

Even as remote sensing technology has advanced in leaps and bounds over the past decade, the remote sensing community lacks interfaces and interaction models that facilitate effective human operation of our sensor platforms. Interfaces that make great sense to electrical engineers and flight test crews can be anxiety-inducing to operational users who lack professional experience in the design and testing of sophisticated remote sensing platforms. In this paper, we reflect on an 18-month collaboration which our Sandia National Laboratory research team partnered with an industry software team to identify and fix critical issues in a widely-used sensor interface. Drawing on basic principles from cognitive and perceptual psychology and interaction design, we provide simple, easily learned guidance for minimizing common barriers to system learnability, memorability, and user engagement.

Understanding Barriers and Facilitators to the use of Clinical Information Systems for Intensive Care Units and Anesthesia Record Keeping: A Rapid Ethnography

PubMed Central

Saleem, Jason J.; Plew, William R.; Speir, Ross C.; Herout, Jennifer; Wilck, Nancy R.; Ryan, Dale Marie; Cullen, Theresa A.; Scott, Jean M.; Beene, Murielle S.; Phillips, Toni

2017-01-01

Objective This study evaluated the current use of commercial-off-the-shelf Clinical Information Systems (CIS) for intensive care units (ICU) and Anesthesia Record Keeping (ARK) for operating rooms and post-anesthesia care recovery settings at three Veterans Affairs Medical Centers (VAMCs). Clinicians and administrative staff use these applications at bedside workstations, in operating rooms, at nursing stations, in physician’s rooms, and in other various settings. The intention of a CIS or an ARK system is to facilitate creation of electronic records of data, assessments, and procedures from multiple medical devices. The US Department of Veterans Affairs (VA) Office of the Chief of Nursing Informatics sought to understand usage barriers and facilitators to optimize these systems in the future. Therefore, a human factors study was carried out to observe the CIS and ARK systems in use at three VAMCs in order to identify best practices and suggested improvements to currently implemented CIS and ARK systems. Methods We conducted a rapid ethnographic study of clinical end-users interacting with the CIS and ARK systems in the critical care and anesthesia care areas in each of three geographically distributed VAMCs. Two observers recorded interactions and/or interview responses from 88 CIS and ARK end-users. We coded and sorted into logical categories field notes from 69 shadowed participants. The team transcribed and combined data from key informant interviews with 19 additional participants with the observation data. We then integrated findings across observations into meaningful patterns and abstracted the data into themes, which translated directly to barriers to effective adoption and optimization of the CIS and ARK systems. Results Effective optimization of the CIS and ARK systems was impeded by: (1) integration issues with other software systems; (2) poor usability; (3) software challenges; (4) hardware challenges; (5) training concerns; (6) unclear roles and lack of coordination among stakeholders; and (7) insufficient technical support. Many of these barriers are multi-faceted and have associated sub-barriers, which are described in detail along with relevant quotes from participants. In addition, regionalized purchases of different CIS and ARK systems, as opposed to enterprise level purchases, contributed to some of the identified barriers. Facilitators to system use included (1) automation and (2) a dedicated facility-level CIS-ARK coordinator. Conclusions We identified barriers that explain some of the challenges with the optimization of the CIS and ARK commercial systems across the Veterans Health Administration (VHA). To help address these barriers, and evolve them into facilitators, we categorized report findings as (1) interface and system-level changes that vendors or VA healthcare systems can implement; (2) implementation factors under VA control and not under VA control; and (3) factors that may be used to inform future application purchases. We outline several recommendations for improved adoption of CIS and ARK systems and further recommend that human factors engineering and usability requirements become an integral part of VA health information technology (HIT) application procurement, customization, and implementation in order to help eliminate or mitigate some of the barriers of use identified in this study. Human factors engineering methods can be utilized to apply a user-centered approach to application requirements specification, application evaluation, system integration, and application implementation. PMID:25843931

Understanding barriers and facilitators to the use of Clinical Information Systems for intensive care units and Anesthesia Record Keeping: A rapid ethnography.

PubMed

Saleem, Jason J; Plew, William R; Speir, Ross C; Herout, Jennifer; Wilck, Nancy R; Ryan, Dale Marie; Cullen, Theresa A; Scott, Jean M; Beene, Murielle S; Phillips, Toni

2015-07-01

This study evaluated the current use of commercial-off-the-shelf Clinical Information Systems (CIS) for intensive care units (ICUs) and Anesthesia Record Keeping (ARK) for operating rooms and post-anesthesia care recovery settings at three Veterans Affairs Medical Centers (VAMCs). Clinicians and administrative staff use these applications at bedside workstations, in operating rooms, at nursing stations, in physician's rooms, and in other various settings. The intention of a CIS or an ARK system is to facilitate creation of electronic records of data, assessments, and procedures from multiple medical devices. The US Department of Veterans Affairs (VA) Office of the Chief of Nursing Informatics sought to understand usage barriers and facilitators to optimize these systems in the future. Therefore, a human factors study was carried out to observe the CIS and ARK systems in use at three VAMCs in order to identify best practices and suggested improvements to currently implemented CIS and ARK systems. We conducted a rapid ethnographic study of clinical end-users interacting with the CIS and ARK systems in the critical care and anesthesia care areas in each of three geographically distributed VAMCs. Two observers recorded interactions and/or interview responses from 88 CIS and ARK end-users. We coded and sorted into logical categories field notes from 69 shadowed participants. The team transcribed and combined data from key informant interviews with 19 additional participants with the observation data. We then integrated findings across observations into meaningful patterns and abstracted the data into themes, which translated directly to barriers to effective adoption and optimization of the CIS and ARK systems. Effective optimization of the CIS and ARK systems was impeded by: (1) integration issues with other software systems; (2) poor usability; (3) software challenges; (4) hardware challenges; (5) training concerns; (6) unclear roles and lack of coordination among stakeholders; and (7) insufficient technical support. Many of these barriers are multi-faceted and have associated sub-barriers, which are described in detail along with relevant quotes from participants. In addition, regionalized purchases of different CIS and ARK systems, as opposed to enterprise level purchases, contributed to some of the identified barriers. Facilitators to system use included (1) automation and (2) a dedicated facility-level CIS-ARK Coordinator. We identified barriers that explain some of the challenges with the optimization of the CIS and ARK commercial systems across the Veterans Health Administration (VHA). To help address these barriers, and evolve them into facilitators, we categorized report findings as (1) interface and system-level changes that vendors or VA healthcare systems can implement; (2) implementation factors under VA control and not under VA control; and (3) factors that may be used to inform future application purchases. We outline several recommendations for improved adoption of CIS and ARK systems and further recommend that human factors engineering and usability requirements become an integral part of VA health information technology (HIT) application procurement, customization, and implementation in order to help eliminate or mitigate some of the barriers of use identified in this study. Human factors engineering methods can be utilized to apply a user-centered approach to application requirements specification, application evaluation, system integration, and application implementation. Published by Elsevier Ireland Ltd.

Barriers to Women in Science

ERIC Educational Resources Information Center

Butler, Rosemary

2013-01-01

The Presiding Officer of the National Assembly for Wales, Rosemary Butler AM, has put the issue of barriers to women in public life at the top of the political agenda in Wales. She has held sessions with women across Wales to find out what those barriers are and how they can be tackled. On International Women's Day in February, she invited…

76 FR 8661 - Airworthiness Directives; Lycoming Engines, Fuel Injected Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... engine models requiring inspections. We are proposing this AD to prevent failure of the fuel injector... repetitive inspection compliance time. We issued that AD to prevent failure of the fuel injector fuel lines... engine models requiring inspection. We are issuing this AD to prevent failure of the fuel injector fuel...

Market and policy barriers to deployment of energy storage

DOE PAGES

Sioshansi, Ramteen; Denholm, Paul; Jenkin, Thomas

2012-04-01

There has recently been resurgent interest in energy storage, due to a number of developments in the electricity industry. Despite this interest, very little storage, beyond some small demonstration projects, has been deployed recently. While technical issues, such as cost, device efficiency, and other technical characteristics are often listed as barriers to storage, there are a number of non-technical and policy-related issues. This paper surveys some of these main barriers and proposes some potential research and policy steps that can help address them. Furthermore, while the discussion is focused on the United States, a number of the findings and observationsmore » may be more broadly applicable.« less

Engineering Students' Sustainability Approaches

ERIC Educational Resources Information Center

Haase, S.

2014-01-01

Sustainability issues are increasingly important in engineering work all over the world. This article explores systematic differences in self-assessed competencies, interests, importance, engagement and practices of newly enrolled engineering students in Denmark in relation to environmental and non-environmental sustainability issues. The…

Life modeling of thermal barrier coatings for aircraft gas turbine engines

NASA Technical Reports Server (NTRS)

Miller, R. A.

1989-01-01

Thermal barrier coating life models developed under the NASA Lewis Research Center's Hot Section Technology (HOST) Program are summarized. An initial laboratory model and three design-capable models are discussed. Current understanding of coating failure mechanisms are also summarized. The materials and structural aspects of thermal barrier coatings have been successfully integrated under the HOST program to produce models which may now or in the near future be used in design. Efforts on this program continue at Pratt and Whitney Aircraft where their model is being extended to the life prediction of physical vapor deposited thermal barrier coatings.

IN-SITU CHEMICAL OXIDATION--ENGINEERING ISSUE

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) Engineering Issue Papers are a series of technology transfer documents that summarize the latest available information on specific technical issues, including fate and transport, specific contaminants, selected treatment and site rem...

Low-Thermal-Conductivity Pyrochlore Oxide Materials Developed for Advanced Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.; Zhu, Dong-Ming

2005-01-01

When turbine engines operate at higher temperatures, they consume less fuel, have higher efficiencies, and have lower emissions. The upper-use temperatures of the base materials (superalloys, silicon-based ceramics, etc.) used for the hot-section components of turbine engines are limited by the physical, mechanical, and corrosion characteristics of these materials. Thermal barrier coatings (TBCs) are applied as thin layers on the surfaces of these materials to further increase the operating temperatures. The current state-of-the-art TBC material in commercial use is partially yttria-stabilized zirconia (YSZ), which is applied on engine components by plasma spraying or by electron-beam physical vapor deposition. At temperatures higher than 1000 C, YSZ layers are prone to sintering, which increases thermal conductivity and makes them less effective. The sintered and densified coatings can also reduce thermal stress and strain tolerance, which can reduce the coating s durability significantly. Alternate TBC materials with lower thermal conductivity and better sintering resistance are needed to further increase the operating temperature of turbine engines.

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.

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.

Enzyme as catalytic wheel powered by a Markovian engine: conformational coupling and barrier surfing models

NASA Astrophysics Data System (ADS)

Tsong, Tian Yow; Chang, Cheng-Hung

2005-05-01

We examine a typical Michaelis-Menten Enzyme (MME) and redress it to form a transducer of free energy, and electric, acoustic, or other types of energy. This amendment and extension is necessary in lieu of recent experiments in which enzymes are shown to perform pump, motor, and locomotion functions resembling their macroscopic counterparts. Classical textbook depicts enzyme, or an MME, as biocatalyst which can enhance the rate of a chemical reaction by lowering the activation barrier but cannot shift the thermodynamic equilibrium of the biochemical reaction. An energy transducer, on the other hand, must also be able to harvest, store, or divert energy and in doing so alter the chemical equilibrium, change the energy form, fuel an energy consuming process, or perform all these functions stepwise in one catalytic turnover. The catalytic wheel presented in this communication is both a catalyst and an energy transducer and can perform all these tasks with ease. A Conformational Coupling Model for the rotary motors and a Barrier Surfing Model for the track-guided stepping motors and transporters, are presented and compared. It is shown that the core engine of the catalytic wheel, or a Brownian motor, is a Markovian engine. It remains to be seen if this core engine is the basic mechanism for a wide variety of bio-molecular energy transducers, as well as certain other dynamic systems, for example, the Parrondo's Games.

Delamination-Indicating Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Eldridge, Jeffrey I.

2007-01-01

The risk of premature failure of thermal barrier coatings (TBCs), typically composed of yttria-stabilized zirconia (YSZ), compromises the reliability of TBCs used to provide thermal protection for turbine engine components. Unfortunately, TBC delamination proceeds well beneath the TBC surface and cannot be monitored by visible inspection. Nondestructive diagnostic tools that could reliably probe the subsurface damage state of TBCs would alleviate the risk of TBC premature failure by indicating when the TBC needs to be replaced before the level of TBC damage threatens engine performance or safety. To meet this need, a new coating design for thermal barrier coatings (TBCs) that are self-indicating for delamination has been successfully implemented by incorporating a europium-doped luminescent sublayer at the base of a TBC composed of YSZ. The luminescent sublayer has the same YSZ composition as the rest of the TBC except for the addition of low-level europium doping and therefore does not alter TBC performance.

In vivo architectonic stability of fully de novo designed protein-only nanoparticles.

PubMed

Céspedes, María Virtudes; Unzueta, Ugutz; Tatkiewicz, Witold; Sánchez-Chardi, Alejandro; Conchillo-Solé, Oscar; Álamo, Patricia; Xu, Zhikun; Casanova, Isolda; Corchero, José Luis; Pesarrodona, Mireia; Cedano, Juan; Daura, Xavier; Ratera, Imma; Veciana, Jaume; Ferrer-Miralles, Neus; Vazquez, Esther; Villaverde, Antonio; Mangues, Ramón

2014-05-27

The fully de novo design of protein building blocks for self-assembling as functional nanoparticles is a challenging task in emerging nanomedicines, which urgently demand novel, versatile, and biologically safe vehicles for imaging, drug delivery, and gene therapy. While the use of viruses and virus-like particles is limited by severe constraints, the generation of protein-only nanocarriers is progressively reachable by the engineering of protein-protein interactions, resulting in self-assembling functional building blocks. In particular, end-terminal cationic peptides drive the organization of structurally diverse protein species as regular nanosized oligomers, offering promise in the rational engineering of protein self-assembling. However, the in vivo stability of these constructs, being a critical issue for their medical applicability, needs to be assessed. We have explored here if the cross-molecular contacts between protein monomers, generated by end-terminal cationic peptides and oligohistidine tags, are stable enough for the resulting nanoparticles to overcome biological barriers in assembled form. The analyses of renal clearance and biodistribution of several tagged modular proteins reveal long-term architectonic stability, allowing systemic circulation and tissue targeting in form of nanoparticulate material. This observation fully supports the value of the engineered of protein building blocks addressed to the biofabrication of smart, robust, and multifunctional nanoparticles with medical applicability that mimic structure and functional capabilities of viral capsids.

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.

Sexuality education in Malaysia: perceived issues and barriers by professionals.

PubMed

Khalaf, Zahra Fazli; Low, Wah Yun; Merghati-Khoei, Effat; Ghorbani, Behzad

2014-07-01

This research explored the perspectives of Malaysian professionals on the issues and barriers affecting the implementation of sexuality education in Malaysia. This qualitative study involved in-depth interviews with 15 key professionals working in the field of sexuality and reproductive health in Malaysia. Thematic analysis was selected to analyze data. Barriers to sexuality education were perceived from 5 aspects: feasibility, acceptability, accountability, strategies, and community unawareness. Respondents believed that implementing national sexuality education is a time-consuming project. They regarded Malaysian multicultural society as a barrier to national sexuality education, and they believed that school-based sexuality education is not easily accomplished in Malaysia; also abstinence-only policy restricts the access of young people to accurate information. Lack of community involvement was perceived as a key concern to sexuality education. Campaigning to promote awareness of families, teachers, community leaders, and policy makers are recommended to help establishing national sexuality education in Malaysia. © 2014 APJPH.

Financial barriers to implementing combination vaccines: perspectives from pediatricians and policy makers.

PubMed

Gidengil, Courtney A; Rusinak, Donna; Allred, Norma J; Luff, Donna; Lee, Grace M; Lieu, Tracy A

2009-06-01

To describe the factors that affect the use of new combination vaccines, the authors conducted qualitative interviews with pediatricians (n = 7), state immunization program managers (n = 7), and health insurance plan representatives (n = 6 plans). Respondents from each group identified reduction in pain and potentially increased immunization coverage as key benefits of new combination vaccines. For several pediatricians, low reimbursement for cost of vaccine doses and potential loss of fees for vaccine administration were barriers to using combination vaccines. For most state immunization programs, the higher cost of combination vaccines relative to separate vaccines was an important consideration but not a barrier to adoption. Most insurers were not aware of the financial issues for providers, but some had changed or were willing to change reimbursement to support the use of new combination vaccines. Financial issues for pediatric practices that purchase and provide vaccines for children may be an important barrier to offering combination vaccines.

Oncologists' strategies and barriers to effective communication about the end of life.

PubMed

Granek, Leeat; Krzyzanowska, Monika K; Tozer, Richard; Mazzotta, Paolo

2013-07-01

Communicating about the end of life with patients has been reported as one of the most difficult and stressful part of the work of oncologists. Despite this fact, oncologists receive little training in this area, and many do not communicate effectively with patients. The purpose of this analysis, part of a larger study examining oncologists' experiences of patient loss, was to explore oncologists' communication strategies and communication barriers when discussing end-of-life issues with patients. Twenty oncologists were interviewed at three hospitals about their communication strategies on end-of-life issues with patients. The data were analyzed using the grounded theory method. The findings revealed the strategies to effective communication about the end of life included: being open and honest; having ongoing, early conversations; communicating about modifying treatment goals; and balancing hope and reality. Barriers to implementing these strategies fell broadly into three domains, including physician factors, patient factors, and institutional factors. Physician factors included difficulty with treatment and palliation, personal discomfort with death and dying, diffusion of responsibility among colleagues, using the "death-defying mode," lack of experience, and lack of mentorship. Patient factors included, patients and/or families being reluctant to talk about the end of life, language barriers, and younger age. Institutional factors included stigma around palliative care, lack of protocol about end-of-life issues; and lack of training for oncologists on how to talk with patients about end-of-life issues. We conclude by drawing implications from our study and suggest that further research and intervention are necessary to aid oncologists in achieving effective communication about end-of-life issues.

Engineering issue: Indoor Air Vapor Intrusion Mitigation Approaches

EPA Science Inventory

The US Environmental Protection Agency (EPA) Engineering Issues are a new series of technology transfer documents that summarize the latest available information on selected treatment and site remeediation technologies and related issues. They are designed to help remedial projec...

Integrated Sensitivity Analysis Workflow

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

Friedman-Hill, Ernest J.; Hoffman, Edward L.; Gibson, Marcus J.

2014-08-01

Sensitivity analysis is a crucial element of rigorous engineering analysis, but performing such an analysis on a complex model is difficult and time consuming. The mission of the DART Workbench team at Sandia National Laboratories is to lower the barriers to adoption of advanced analysis tools through software integration. The integrated environment guides the engineer in the use of these integrated tools and greatly reduces the cycle time for engineering analysis.

Youth Exploring Science

NASA Astrophysics Data System (ADS)

Miller, Diane

2008-04-01

This session features Youth Exploring Science (YES), Saint Louis Science Center's nationally recognized work-based teen development program. In YES, underserved audiences develop interest and understanding in physics through design engineering projects. I will discuss breaking down barriers, helping youth develop skills, and partnering with community organizations, universities and engineering firms.

77 FR 70424 - Pacific Gas and Electric Company; Notice of Application Accepted for Filing, Soliciting Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

.... Description of Request: Pacific Gas and Electric Company (licensee) is proposing to change the design of an... issued August 25, 2009. Rather than locating the barrier on top of the Asbury Diversion Dam, the barrier would be located approximately 500 feet downstream of the diversion dam. The fish barrier would be a...

Work-related barriers, facilitators, and strategies of breast cancer survivors working during curative treatment.

PubMed

Sun, Wenjun; Chen, Karen; Terhaar, Abigail; Wiegmann, Douglas A; Heidrich, Susan M; Tevaarwerk, Amye J; Sesto, Mary E

2016-01-01

Research has identified barriers and facilitators affecting cancer survivors' return to work (RTW) following the end of active treatment (surgery, chemotherapy and/or radiation therapy). However, few studies have focused on barriers and facilitators that cancer survivors experience while working during active treatment. Strategies used by cancer survivors to solve work-related problems during active treatment are underexplored. The aim of this study was to describe factors that impact, either positively or negatively, breast cancer survivors' work activities during active treatment. Semi-structured, recorded interviews were conducted with 35 breast cancer survivors who worked during active treatment. Transcripts of interviews were analyzed using inductive content analysis to identify themes regarding work-related barriers, facilitators and strategies. Barriers identified included symptoms, emotional distress, appearance change, time constraints, work characteristics, unsupportive supervisors and coworkers, family issues and other illness. Facilitators included positive aspects of work, support outside of work, and coworker and supervisor support. Strategies included activities to improve health-related issues and changes to working conditions and tasks. Breast cancer survivors encounter various barriers during active treatment. Several facilitators and strategies can help survivors maintain productive work activities.

Work-related barriers, facilitators, and strategies of breast cancer survivors working during curative treatment

PubMed Central

Sun, Wenjun; Chen, Karen; Terhaar, Abigail; Wiegmann, Douglas A.; Heidrich, Susan M.; Tevaarwerk, Amye J.; Sesto, Mary E.

2017-01-01

BACKGROUND Research has identified barriers and facilitators affecting cancer survivors’ return to work (RTW) following the end of active treatment (surgery, chemotherapy and/or radiation therapy). However, few studies have focused on barriers and facilitators that cancer survivors experience while working during active treatment. Strategies used by cancer survivors to solve work-related problems during active treatment are underexplored. OBJECTIVE The aim of this study was to describe factors that impact, either positively or negatively, breast cancer survivors’ work activities during active treatment. METHODS Semi-structured, recorded interviews were conducted with 35 breast cancer survivors who worked during active treatment. Transcripts of interviews were analyzed using inductive content analysis to identify themes regarding work-related barriers, facilitators and strategies. RESULTS Barriers identified included symptoms, emotional distress, appearance change, time constraints, work characteristics, unsupportive supervisors and coworkers, family issues and other illness. Facilitators included positive aspects of work, support outside of work, and coworker and supervisor support. Strategies included activities to improve health-related issues and changes to working conditions and tasks. CONCLUSIONS Breast cancer survivors encounter various barriers during active treatment. Several facilitators and strategies can help survivors maintain productive work activities. PMID:28059814

Engineering and Development Support of General Decon Technology for the U.S. Army’s Installation Restoration Program. Task 1. Literature Review on Ground Water Containment and Diversion Barriers.

DTIC Science & Technology

1982-04-01

number) This report presents a review and evaluation of the available information on the use of physical and hydrological barriers for containment or...UNCLASSIFIED 1 $SCCuRITY CLASSIFICATION OF T.qiS *&GE When Daa Entered SUMMARY The available literature on methods for containment or diversion of ground...II. Preliminary Considerations for Installation of a Ground Water Containment or Diversion Barrier .. ... ....... ...... 13 III. Slurry-Trench Cutoff

Influence of Temperature on CaO-MgO-Al2O3-SiO2 (CMAS) Corrosion on Thermal Barrier Coatings

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

Wang, Honglong; Zhang, Xingxing; Agubra, Victor

2015-10-23

Higher operating temperature improves the energy efficiency in gas turbine engines and thermal barrier coatings are applied to protect the blades from high temperature and dust corrosion. Dust composed by CaO-MgO-Al2O3-SiO2 (CMAS) can melt and react with pyrochlore zirconates thermal barrier materials and degrade the performance or cause failure of the coatings. This paper discusses the relationship of the reaction product and corrosion temperature.

Infectious Disease Issues in Xenotransplantation

PubMed Central

Boneva, Roumiana S.; Folks, Thomas M.; Chapman, Louisa E.

2001-01-01

Xenotransplantation, the transplantation of living organs, tissues, or cells from one species to another, is viewed as a potential solution to the existing shortage of human organs for transplantation. While whole-organ xenotransplantation is still in the preclinical stage, cellular xenotransplantation and extracorporeal perfusion applications are showing promise in early clinical trials. Advances in immunosuppressive therapy, gene engineering, and cloning of animals bring a broader array of xenotransplantation protocols closer to clinical trials. Despite several potential advantages over allotransplantation, xenotransplantation encompasses a number of problems. Immunologic rejection remains the primary hindrance. The potential to introduce infections across species barriers, another major concern, is the main focus of this review. Nonhuman primates are unlikely to be a main source for xenotransplantation products despite their phylogenetic proximity to humans. Genetically engineered pigs, bred under special conditions, are currently envisaged as the major source. Thus far, there has been no evidence for human infections caused by pig xenotransplantation products. However, the existence of xenotropic endogenous retroviruses and the clinical evidence of long-lasting porcine cell microchimerism indicate the potential for xenogeneic infections. Thus, further trials should continue under regulatory oversight, with close clinical and laboratory monitoring for potential xenogeneic infections. PMID:11148000

When access is an issue: exploring barriers to predictive testing for Huntington disease in British Columbia, Canada.

PubMed

Hawkins, Alice K; Creighton, Susan; Hayden, Michael R

2013-02-01

Predictive testing (PT) for Huntington disease (HD) requires several in-person appointments. This requirement may be a barrier to testing so that at risk individuals do not realize the potential benefits of PT. To understand the obstacles to PT in terms of the accessibility of services, as well as exploring mechanisms by which this issue may be addressed, we conducted an interview study of individuals at risk for HD throughout British Columbia, Canada. Results reveal that the accessibility of PT can be a barrier for two major reasons: distance and the inflexibility of the testing process. Distance is a structural barrier, and relates to the time and travel required to access PT, the financial and other opportunity costs associated with taking time away from work and family to attend appointments and the stress of navigating urban centers. The inflexibility of the testing process barrier relates to the emotional and psychological accessibility of PT. The results of the interview study reveal that there are access barriers to PT that deter individuals from receiving the support, information and counseling they require. What makes accessibility of PT services important is not just that it may result in differences in quality of life and care, but because these differences may be addressed with creative and adaptable solutions in the delivery of genetic services. The study findings underscore the need for us to rethink and personalize the way we deliver such services to improve access issues to prevent inequities in the health care system.

A Sociological Framework to Address Gender Equity in the Geosciences

NASA Astrophysics Data System (ADS)

Holmes, Mary Anne

2017-04-01

Lack of equity in the science workforce is a sociological problem; those wishing to seek its amelioration can benefit by viewing the issue with a sociological lens (and a sociologist). One useful framework that we have used to think strategically about how to lower barriers to equity is Barbara Risman's (2004): this framework views barriers to equity as individual, interpersonal ("interactional"), and institutional. Any given barrier may fit into one or more of these frames. Individual barriers include those intrinsic to an individual and may include: lack of access to vital networks and mentors, lack of preparation, etc. Such barriers can be addressed through mentoring programs and attention to building networks (e.g., through professional society memberships). Interpersonal or "interactional" barriers are those that arise from how we perceive and treat one another. Implicit bias underlies many of these barriers, including whether we perceive women as scientists, as competent, as dedicated (etc) as men. Such barriers can be reduced through implicit bias awareness. Institutional barriers arise from the structure and history of the academy itself, from its policies and procedures. Many such policies and procedures have a differential impact on men or women, generally without that intention. Policies that reduce equity barriers include family leave, childcare facilities, search committee training, clearly articulated practices for evaluation of applications and personnel reviews, equal starting pay and startup packages, equable canvassing for names to consider for nominations for honors and awards, to name a few. By viewing the issue through such a framework, the appropriate response can be generated for a more effective result.

Notes from the Margins: Integrating Lesbian Experience into the Vocational Psychology of Women.

ERIC Educational Resources Information Center

Fassinger, Ruth E.

1996-01-01

Explores internal and external barriers to women's career choice, implementation, and adjustment, especially how such barriers function for lesbians. Examines issues related to coming out, workplace discrimination, and the home-work interface. (SK)

Advanced Thermal Barrier and Environmental Barrier Coating Development at NASA GRC

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Robinson, Craig

2017-01-01

This presentation summarizes NASA's advanced thermal barrier and environmental barrier coating systems, and the coating performance improvements that has recently been achieved and documented in laboratory simulated rig test conditions. One of the emphases has been placed on the toughness and impact resistance enhancements of the low conductivity, defect cluster thermal barrier coating systems. The advances in the next generation environmental barrier coatings for SiCSiC ceramic matrix composites have also been highlighted, particularly in the design of a new series of oxide-silicate composition systems to be integrated with next generation SiC-SiC turbine engine components for 2700F coating applications. Major technical barriers in developing the thermal and environmental barrier coating systems are also described. The performance and model validations in the rig simulated turbine combustion, heat flux, steam and calcium-magnesium-aluminosilicate (CMAS) environments have helped the current progress in improved temperature capability, environmental stability, and long-term fatigue-environment system durability of the advanced thermal and environmental barrier coating systems.

Branding the bio/biomedical engineering degree.

PubMed

Voigt, Herbert F

2011-01-01

The future challenges to medical and biological engineering, sometimes referred to as biomedical engineering or simply bioengineering, are many. Some of these are identifiable now and others will emerge from time to time as new technologies are introduced and harnessed. There is a fundamental issue regarding "Branding the bio/biomedical engineering degree" that requires a common understanding of what is meant by a B.S. degree in Biomedical Engineering, Bioengineering, or Biological Engineering. In this paper we address some of the issues involved in branding the Bio/Biomedical Engineering degree, with the aim of clarifying the Bio/Biomedical Engineering brand.

Barriers to access and minority ethnic carers' satisfaction with social care services in the community: a systematic review of qualitative and quantitative literature

PubMed Central

Greenwood, Nan; Habibi, Ruth; Smith, Raymond; Manthorpe, Jill

2015-01-01

As populations age, the numbers of carers overall and numbers of carers from minority ethnic groups in particular are rising. Evidence suggests that carers from all sections of the community and particularly carers from minority groups often fail to access care services. This may relate to barriers in accessing services and service dissatisfaction. The aim of this systematic review was to identify and summarise minority ethnic carers' perceptions of barriers to accessing community social care services and their satisfaction with these services if accessed. The following databases were searched from their start until July 2013: Social Care Online, Social Policy and Research, Scopus, PsychINFO, HMIC, ASSIA, MEDLINE, Embase, CINAHL Plus and AMED. Thirteen studies met the inclusion criteria. Most investigated either barriers to access or satisfaction levels, although three explored both. Only 4 studies investigated minority ethnic carers' satisfaction with social care, although 12 studies reported perceived barriers to accessing services. Few studies compared minority ethnic carers' perceptions with majority ethnic groups, making it difficult to identify issues specific to minority groups. Most barriers described were potentially relevant to all carers, irrespective of ethnic group. They included attitudinal barriers such as not wanting to involve outsiders or not seeing the need for services and practical barriers such as low awareness of services and service availability. Issues specific to minority ethnic groups included language barriers and concerns about services' cultural or religious appropriateness. Studies investigating satisfaction with services reported a mixture of satisfaction and dissatisfaction. Barriers common to all groups should not be underestimated and a better understanding of the relationship between perceived barriers to accessing services and dissatisfaction with services is needed before the experiences of all carers can be improved. PMID:25135207

Signs of Autonomy: Facilitating Independence and Inquiry in Deaf Science Classrooms

ERIC Educational Resources Information Center

Kahn, Sami; Feldman, Allan; Cooke, Michele L.

2013-01-01

Deaf and hard of hearing (DHH) persons are underrepresented in the fields of science, technology, engineering, and mathematics (STEM). One of the major barriers to STEM careers is DHH students' extremely low college graduation rates. While social and literacy barriers play a critical role in this phenomenon, student autonomy has also been cited as…

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.

Stigma and Barriers to Care: Caring for Those Exposed to War, Disaster and Terrorism. Executive Summary and Recommendations

DTIC Science & Technology

2012-03-06

Proceedings Executive Summary 3. DATES COVERED (From - To) 3/25/2010-3/26/2010 4. TITLE AND SUBTITLE Stigma and Barriers To Care: Caring for Those...Health and National Security, directed to addressing stigma and barriers to care, brought together a diverse group of leaders in order to expand our...researchers and health care planners across mental health, health care systems, military and disaster care and the specific issues of stigma and barriers

Materials & Engineering: Propelling Innovation MRS Bulletin Special Issue Session

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

Rao, Gopal

Materials enable engineering; and, engineering in turn depends on materials to transform design concepts and equations into physical entities. This relationship continues to grow with expanding societal demand for new products and processes. MRS Bulletin, a publication of the Materials Research Society (MRS) and Cambridge University Press, planned a special issue for December 2015 on Materials and Engineering: Propelling Innovation. This special issue of MRS Bulletin captured the unique relationship between materials and engineering, which are closely intertwined. A special half day session at the 2015 MRS Fall Meeting in Boston captured this discussion through presentations by high level expertsmore » followed by a panel discussion on what it takes to translate materials discoveries into products to benefit society. The Special Session included presentations by experts who are practitioners in materials as well as engineering applications, followed by a panel discussion. Participants discussed state-of-the-art in materials applications in engineering, as well as how engineering needs have pushed materials developments, as also reflected in the 20 or so articles published in the special issue of MRS Bulletin. As expected, the discussions spanned the broad spectrum of materials and provided very strong interdisciplinary interactions and discussions by participants and presenters.« less

Department of Defense Program Solicitation 94; Small Business Technology Transfer (STTR) Program; Fiscal Year 1994.

DTIC Science & Technology

1994-01-01

advanced diesel engine components; high-temperature titanium aluminide and Al-Fe alloys for aircraft and missile engines; environmentally compliant...gun-chamber liners and KE penetrator stabilizer fins, tips, and leading edges; low cost, ceramic thermal barrier coatings for gas turbine blades and

Navigating Community College Transfer in Science, Technical, Engineering, and Mathematics Fields

ERIC Educational Resources Information Center

Packard, Becky Wai-Ling; Gagnon, Janelle L.; Senas, Arleen J.

2012-01-01

Given financial barriers facing community college students today, and workforce projections in science, technical, engineering, and math (STEM) fields, the costs of unnecessary delays while navigating transfer pathways are high. In this phenomenological study, we analyzed the delay experiences of 172 students (65% female) navigating community…

History of the Pacific Ocean Division Corps of Engineers 1957-1967

DTIC Science & Technology

1972-01-01

mound barrier; designed by HED civil engineer Robert Q. Palmer, these concrete three-bar struc- tures provided a sturdy substitute for scarce rock...that metal buildings would require high main- tenance costs, while the termite problem eliminates construction in wood. Not only for these reasons

Predictive GT-Power Simulation for VNT Matching on a 1.6 L Turbocharged GDI Engine

EPA Science Inventory

The thermal efficiency benefits of low-pressure (LP) exhaust gas recirculation (EGR) in spark-ignition engine combustion are well known. One of the greatest barriers facing adoption of LP-EGR for high power-density applications is the challenge of boosting. Variable nozzle turbin...

Developing and Designing Online Engineering Ethics Instruction for International Graduate Students

ERIC Educational Resources Information Center

Austin, Katherine A.; Gorsuch, Greta J.; Lawson, William D.; Newberry, Byron P.

2011-01-01

The present project embarked on an educational intervention, consisting of a series of online ethics learning modules, to aid international graduate students in overcoming the acculturation barriers to understanding and inculcating normative ethical obligations associated with engineering practice and research in the United States. A fundamental…

Identifying Barriers to and Outcomes of Interdisciplinarity in the Engineering Classroom

ERIC Educational Resources Information Center

Richter, David M.; Paretti, Marie C.

2009-01-01

In addition to developing deep knowledge of a single discipline, engineers must also be able to collaborate across disciplinary boundaries and develop interdisciplinary expertise to successfully address the complex challenges of the contemporary workplace. While numerous descriptions of interdisciplinary courses and projects appear in the…

Next-Gen Search Engines

ERIC Educational Resources Information Center

Gupta, Amardeep

2005-01-01

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

Key Barriers for Academic Institutions Seeking To Retain Female Scientists and Engineers: Family-Unfriendly Policies, Low Numbers, Stereotypes, and Harassment.

ERIC Educational Resources Information Center

Rosser, Sue V.; Lane, Eliesh O'Neil

2002-01-01

Evaluates survey responses from almost (n=400) Professional Opportunities for Women in Research and Education (POWRE) awardees from fiscal years 1997-2000 to elucidate problems and opportunities identified by female scientists and engineers. (Contains 25 references.) (Author/YDS)

Collaborative Systems Thinking: A Response to the Problems Faced by Systems Engineering's 'Middle Tier'

NASA Technical Reports Server (NTRS)

Phfarr, Barbara B.; So, Maria M.; Lamb, Caroline Twomey; Rhodes, Donna H.

2009-01-01

Experienced systems engineers are adept at more than implementing systems engineering processes: they utilize systems thinking to solve complex engineering problems. Within the space industry demographics and economic pressures are reducing the number of experienced systems engineers that will be available in the future. Collaborative systems thinking within systems engineering teams is proposed as a way to integrate systems engineers of various experience levels to handle complex systems engineering challenges. This paper uses the GOES-R Program Systems Engineering team to illustrate the enablers and barriers to team level systems thinking and to identify ways in which performance could be improved. Ways NASA could expand its engineering training to promote team-level systems thinking are proposed.

Regenerative Endodontics: Barriers and Strategies for Clinical Translation

PubMed Central

Kim, Sahng G.; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y.; Yang, Rujing; Zhou, Xuedong; Mao, Jeremy J.

2014-01-01

SYNOPSIS Despite a great deal of enthusiasm and effort, regenerative endodontics has encountered substantial challenges towards clinical translation. Recent adoption by the American Dental Association (ADA) of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for the majority of endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Dental pulp stem cells may appear to be a priori choice for dental pulp regeneration. However, dental pulp stem cells may not be available in a patient who is in need of pulp regeneration. Even if dental pulp stem cells are available autologously or perhaps allogeneically, one must address a multitude of scientific, regulatory and commercialization barriers, and unless these issues are resolved, transplantation of dental pulp stem cells will remain a scientific exercise, rather than a clinical reality. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. Given the functions and scale of dental pulp and dentin, regenerative endodontics is poised to become one of the early biological solutions in regenerative dental medicine. PMID:22835543

Interface engineering and reliability characteristics of hafnium dioxide with poly silicon gate and dual metal (ruthenium-tantalum alloy, ruthenium) gate electrode for beyond 65 nm technology

NASA Astrophysics Data System (ADS)

Kim, Young-Hee

Chip density and performance improvements have been driven by aggressive scaling of semiconductor devices. In both logic and memory applications, SiO 2 gate dielectrics has reached its physical limit, direct tunneling resulting from scaling down of dielectrics thickness. Therefore high-k dielectrics have attracted a great deal of attention from industries as the replacement of conventional SiO2 gate dielectrics. So far, lots of candidate materials have been evaluated and Hf-based high-k dielectrics were chosen to the promising materials for gate dielectrics. However, lots of issues were identified and more thorough researches were carried out on Hf-based high-k dielectrics. For instances, mobility degradation, charge trapping, crystallization, Fermi level pinning, interface engineering, and reliability studies. In this research, reliability study of HfO2 were explored with poly gate and dual metal (Ru-Ta alloy, Ru) gate electrode as well as interface engineering. Hard breakdown and soft breakdown were compared and Weibull slope of soft breakdown was smaller than that of hard breakdown, which led to a potential high-k scaling issue. Dynamic reliability has been studied and the combination of trapping and detrapping contributed the enhancement of lifetime projection. Polarity dependence was shown that substrate injection might reduce lifetime projection as well as it increased soft breakdown behavior. Interface tunneling mechanism was suggested with dual metal gate technology. Soft breakdown (l st breakdown) was mainly due to one layer breakdown of bi-layer structure. Low weibull slope was in part attributed to low barrier height of HfO 2 compared to interface layer. Interface layer engineering was thoroughly studied in terms of mobility, swing, and short channel effect using deep sub-micron MOSFET devices. In fact, Hf-based high-k dielectrics could be scaled down to below EOT of ˜10A and it successfully achieved the competitive performance goals. However, it is still necessary to understand what is intrinsic we can not change, or what is extrinsic one we can improve.

Cancer Survivorship Care Plan Utilization and Impact on Clinical Decision-Making at Point-of-Care Visits with Primary Care: Results from an Engineering, Primary Care, and Oncology Collaborative for Survivorship Health.

PubMed

Donohue, SarahMaria; Haine, James E; Li, Zhanhai; Feldstein, David A; Micek, Mark; Trowbridge, Elizabeth R; Kamnetz, Sandra A; Sosman, James M; Wilke, Lee G; Sesto, Mary E; Tevaarwerk, Amye J

2017-11-02

Every cancer survivor and his/her primary care provider should receive an individualized survivorship care plan (SCP) following curative treatment. Little is known regarding point-of-care utilization at primary care visits. We assessed SCP utilization in the clinical context of primary care visits. Primary care physicians and advanced practice providers (APPs) who had seen survivors following provision of an SCP were identified. Eligible primary care physicians and APPs were sent an online survey, evaluating SCP utilization and influence on decision-making at the point-of-care, accompanied by copies of the survivor's SCP and the clinic note. Eighty-eight primary care physicians and APPs were surveyed November 2016, with 40 (45%) responding. Most respondents (60%) reported discussing cancer or related issues during the visit. Information needed included treatment (66%) and follow-up visits, and the cancer team was responsible for (58%) vs primary care (58%). Respondents acquired this information by asking the patient (79%), checking oncology notes (75%), the SCP (17%), or online resources (8%). Barriers to SCP use included being unaware of the SCP (73%), difficulty locating it (30%), and finding needed information faster via another mechanism (15%). Despite largely not using the SCP for the visit (90%), most respondents (61%) believed one would be quite or very helpful for future visits. Most primary care visits included discussion of cancer or cancer-related issues. SCPs may provide the information necessary to deliver optimal survivor care but efforts are needed to reduce barriers and design SCPs for primary care use.

Pathways to lean software development: An analysis of effective methods of change

NASA Astrophysics Data System (ADS)

Hanson, Richard D.

This qualitative Delphi study explored the challenges that exist in delivering software on time, within budget, and with the original scope identified. The literature review identified many attempts over the past several decades to reform the methods used to develop software. These attempts found that the classical waterfall method, which is firmly entrenched in American business today was to blame for this difficulty (Chatterjee, 2010). Each of these proponents of new methods sought to remove waste, lighten out the process, and implement lean principles in software development. Through this study, the experts evaluated the barriers to effective development principles and defined leadership qualities necessary to overcome these barriers. The barriers identified were issues of resistance to change, risk and reward issues, and management buy-in. Thirty experts in software development from several Fortune 500 companies across the United States explored each of these issues in detail. The conclusion reached by these experts was that visionary leadership is necessary to overcome these challenges.

Methods for Prediction of High-Speed Reacting Flows in Aerospace Propulsion

NASA Technical Reports Server (NTRS)

Drummond, J. Philip

2014-01-01

Research to develop high-speed airbreathing aerospace propulsion systems was underway in the late 1950s. A major part of the effort involved the supersonic combustion ramjet, or scramjet, engine. Work had also begun to develop computational techniques for solving the equations governing the flow through a scramjet engine. However, scramjet technology and the computational methods to assist in its evolution would remain apart for another decade. The principal barrier was that the computational methods needed for engine evolution lacked the computer technology required for solving the discrete equations resulting from the numerical methods. Even today, computer resources remain a major pacing item in overcoming this barrier. Significant advances have been made over the past 35 years, however, in modeling the supersonic chemically reacting flow in a scramjet combustor. To see how scramjet development and the required computational tools finally merged, we briefly trace the evolution of the technology in both areas.

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, mentoring, and personal barriers, Hispanics most frequently reported economic barriers, language barriers, institutional and workplace environment barriers, and gender-role barriers. Examining barriers using the "Individual-Institutional" theoretical framework indicated that barriers do not occur in isolation, but due to an interaction between the individual and its institution. Additionally, the barriers of the two groups are qualitatively different and the "one size fits all" approach may not be suitable for interventions. Implications and recommendations were stated.

TARGET: Rapid Capture of Process Knowledge

NASA Technical Reports Server (NTRS)

Ortiz, C. J.; Ly, H. V.; Saito, T.; Loftin, R. B.

1993-01-01

TARGET (Task Analysis/Rule Generation Tool) represents a new breed of tool that blends graphical process flow modeling capabilities with the function of a top-down reporting facility. Since NASA personnel frequently perform tasks that are primarily procedural in nature, TARGET models mission or task procedures and generates hierarchical reports as part of the process capture and analysis effort. Historically, capturing knowledge has proven to be one of the greatest barriers to the development of intelligent systems. Current practice generally requires lengthy interactions between the expert whose knowledge is to be captured and the knowledge engineer whose responsibility is to acquire and represent the expert's knowledge in a useful form. Although much research has been devoted to the development of methodologies and computer software to aid in the capture and representation of some types of knowledge, procedural knowledge has received relatively little attention. In essence, TARGET is one of the first tools of its kind, commercial or institutional, that is designed to support this type of knowledge capture undertaking. This paper will describe the design and development of TARGET for the acquisition and representation of procedural knowledge. The strategies employed by TARGET to support use by knowledge engineers, subject matter experts, programmers and managers will be discussed. This discussion includes the method by which the tool employs its graphical user interface to generate a task hierarchy report. Next, the approach to generate production rules for incorporation in and development of a CLIPS based expert system will be elaborated. TARGET also permits experts to visually describe procedural tasks as a common medium for knowledge refinement by the expert community and knowledge engineer making knowledge consensus possible. The paper briefly touches on the verification and validation issues facing the CLIPS rule generation aspects of TARGET. A description of efforts to support TARGET's interoperability issues on PCs, Macintoshes and UNIX workstations concludes the paper.

Defining and Exposing Privacy Issues with Social Media

DTIC Science & Technology

2012-06-11

Twitter, and Linked In[ I 0). VI. SEARCH ENGINES In addition to social networking sites, search engines pose new issues to privacy. As...networking, search engines , and storing personal information online in general have been accepted worldwide due to the benefits they provide. Social...networking provides even more communication in an information-demanding age, allowing users to interact across great distances. Search engines allow

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2012 CFR

2012-07-01

... vested in the Real Property Division, Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers may issue Real Estate Directives for acquisitions not... Air Force Regional Civil Engineers. The numbers will be in a consecutive series for each Division and...

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2014 CFR

2014-07-01

... vested in the Real Property Division, Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers may issue Real Estate Directives for acquisitions not... Air Force Regional Civil Engineers. The numbers will be in a consecutive series for each Division and...

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... vested in the Real Property Division, Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers may issue Real Estate Directives for acquisitions not... Air Force Regional Civil Engineers. The numbers will be in a consecutive series for each Division and...

Russian Engineering Education in the Era of Change

ERIC Educational Resources Information Center

Vladimirovich Pukharenko, Yurii; Vladimirovna Norina, Natalia; Aleksandrovich Norin, Veniamin

2017-01-01

The article investigates modern issues of engineering education in Russia related to introduction of the Bologna system. The author shows that the situation in the education in general gives reasons for concern; the issue of qualitative enrolment of students for engineering specialties escalates; graduates with masters and bachelors' degrees are…

Diversity Issues in the Engineering Curriculum

ERIC Educational Resources Information Center

Ihsen, Susanne; Gebauer, Sabrina

2009-01-01

Teaching engineering studies students about diversity issues as part of the curriculum in engineering programs is an essential part of preparing the students for their professional life. By teaching them what this is and what it means for their (professional) lives sensitises them towards more responsibility. The idea is to connect diversity…

[Current status and prospect of translational medicine in nanotechnology].

PubMed

Gao, Guang-yu; Chen, Mei-ling; Li, Ming-yuan; Yang, Zhen-bo; Li, Zhi-ping; Mei, Xing-guo

2015-08-01

Nowadays, nanotechnologies have shown wide application foreground in the biomedical field of medicine laboratory tests, drug delivery, gene therapy and bioremediation. However, in recent years, nanomaterials have been labeled poisonous, because of the disputes and misunderstandings of mainstream views on their safety. Besides, for the barriers of technical issues in preparation like: (1) low efficacy (poor PK & PD and low drug loading), (2) high cost (irreproducibility and difficulty in scale up), little of that research has been successfully translated into commercial products. Currently, along with the new theory of "physical damage is the origin of nanotoxicity", biodegradability and biocompatibility of nanomaterials are listed as the basic principle of safe application of nanomaterials. Combining scientific design based on molecular level with precision control of process engineering will provide a new strategy to overcome the core technical challenges. New turning point of translational medicine in nanotechnology may emerge.

Collaboration: It Is Much More Than the Technology

NASA Technical Reports Server (NTRS)

Elfrey, Priscilla; Conroy, Michael

2005-01-01

A joint study conducted with the University of Central Florida and the National Aeronautics and Space Agency's (NASA) Kennedy Space Center (KSC) resulted in a new approach to the collaboration issues that had troubled the Agency. We believe in teams. We believe in the concept of collaboration. We never doubted Douglas Engelbart's thesis-- "Our very survival depends on our ability to work together, more effectively, to get collectively smarter. Computers -- when used properly -- can help us do that". It was not lack of trying. Predictably, NASA engineers had worked as if better and better technology would resolve the matter. It had not. The study itself provided an insight, an "aha! moment that pointed us toward the problems of collaboration we had to solve. People quickly saw that we had to remove barriers and make it easier to share data, coordinate efficiently, work together to add value and create corporate memory. This paper describes what happened.

DARPA Concurrent Design/Concurrent Engineering Workshop Held in Key West, Florida on December 6-8, 1988

DTIC Science & Technology

1988-12-01

engineering disciplines. (Here I refer to training in multifunction team mana ement dir’lplines, quality engineering methods, experimental design by such...4001 SSOME ISSUES S• View of strategic issues has been evolving - Speed of design and product deployment - to accelerate experimentation with new...manufacturingprocess design n New technologies (e.g., composites) which can revolutionize prod-uct technical design in some cases Issue still to be faced: " non

Enhancing Power System Operational Flexibility With Flexible Ramping Products: A Review

DOE PAGES

Wang, Qin; Hodge, Bri-Mathias

2016-12-09

With the increased variability and uncertainty of net load induced from high penetrations of renewable energy resources and more flexible interchange schedules, power systems are facing great operational challenges in maintaining balance. Among these, the scarcity of ramp capability is an important culprit of power balance violations and high scarcity prices. To address this issue, market-based flexible ramping products (FRPs) have been proposed in the industry to improve the availability of ramp capacity. This paper presents an in-depth review of the modeling and implementation of FRPs. The major motivation is that although FRPs are widely discussed in the literature, itmore » is still unclear to many how they can be incorporated into a co-optimization framework that includes energy and ancillary services. The concept and a definition of power system operational flexibility as well as the needs for FRPs are introduced. The industrial practices of implementing FRPs under different market structures are presented. Market operation issues and future research topics are also discussed. In conclusion, this paper can provide researchers and power engineers with further insights into the state of the art, technical barriers, and potential directions for FRPs.« less

Advances in SiC/SiC Composites for Aerospace Applications

NASA Technical Reports Server (NTRS)

DiCarlo, James A.

2006-01-01

In recent years, supported by a variety of materials development programs, NASA Glenn Research Center has significantly increased the thermostructural capability of SiC/SiC composite materials for high-temperature aerospace applications. These state-of-the-art advances have occurred in every key constituent of the composite: fiber, fiber coating, matrix, and environmental barrier coating, as well as processes for forming the fiber architectures needed for complex-shaped components such as turbine vanes for gas turbine engines. This presentation will briefly elaborate on the nature of these advances in terms of performance data and underlying mechanisms. Based on a list of first-order property goals for typical high-temperature applications, key data from a variety of laboratory tests are presented which demonstrate that the NASA-developed constituent materials and processes do indeed result in SiC/SiC systems with the desired thermal and structural capabilities. Remaining process and microstructural issues for further property enhancement are discussed, as well as on-going approaches at NASA to solve these issues. NASA efforts to develop physics-based property models that can be used not only for component design and life modeling, but also for constituent material and process improvement will also be discussed.

Alternating InGaN barriers with GaN barriers for enhancing optical performance in InGaN light-emitting diodes

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

Yang, Yujue; Zeng, Yiping, E-mail: ypzeng@semi.ac.cn

2015-01-21

InGaN-based light-emitting diodes (LEDs) with some specific designs on the quantum barrier layers by alternating InGaN barriers with GaN barriers are proposed and studied numerically. In the proposed structure, simulation results show that the carriers are widely dispersed in the multi-quantum well active region, and the radiative recombination rate is efficiently improved and the electron leakage is suppressed accordingly, due to the appropriate band engineering. The internal quantum efficiency and light-output power are thus markedly enhanced and the efficiency droop is smaller, compared to the original structures with GaN barriers or InGaN barriers. Moreover, the gradually decrease of indium compositionmore » in the alternating quantum barriers can further promote the LED performance because of the more uniform carrier distribution, which provides us a simple but highly effective approach for high-performance LED applications.« less

'We can't get anything done because...': making sense of 'barriers' to Practice-based Commissioning.

PubMed

Checkland, Kath; Coleman, Anna; Harrison, Stephen; Hiroeh, Urara

2009-01-01

To investigate the issues raised by participants as 'barriers' to the development of Practice-based Commissioning (PBC) in 'early adopter' sites in England. Detailed case studies of five PBC consortia in three Primary Care Trusts (PCTs). Data collection included interviews with a wide range of respondents (46 in total), including general practitioners, PCT employees, Local Authority employees and patient representatives, observation of many different types of meetings (68 in total), and analysis of documents tabled at meetings and circulated at other times. It has been claimed that progress in developing PBC has been slow. Our respondents articulated a number of factors that they felt were holding them back, which could have been identified as 'barriers' preventing change. The issues raised were consistent across our sites (lack of time, resources and personnel, and difficult relationships with the PCT), but observation suggested that these issues arose out of very different organizational 'sensemaking', and as a result the apparent 'barriers' had different meanings in different organizational contexts. Weick's concept of 'organizational sensemaking' provides a useful framework within which to explore the problems encountered when implementing policy. Observational methods are a powerful tool in understanding sensemaking. The variations in sensemaking that we observed suggest that the use of 'barrier' metaphors in descriptions of implementation problems risks homogenizing the portrayal of situations that differ greatly in reality. This implies that top-down or centrally driven solutions to such situations will often be inappropriate.

Broadening the Participation of Native Americans in Earth Science

NASA Astrophysics Data System (ADS)

Bueno Watts, Nievita

Climate change is not a thing of the future. Indigenous people are being affected by climate changes now. Native American Earth scientists could help Native communities deal with both climate change and environmental pollution issues, but are noticeably lacking in Earth Science degree programs. The Earth Sciences produce the lowest percentage of minority scientists when compared with other science and engineering fields. Twenty semi-structured interviews were gathered from American Indian/ Alaska Native Earth Scientists and program directors who work directly with Native students to broaden participation in the field. Data was analyzed using qualitative methods and constant comparison analysis. Barriers Native students faced in this field are discussed, as well as supports which go the furthest in assisting achievement of higher education goals. Program directors give insight into building pathways and programs to encourage Native student participation and success in Earth Science degree programs. Factors which impede obtaining a college degree include financial barriers, pressures from familial obligations, and health issues. Factors which impede the decision to study Earth Science include unfamiliarity with geoscience as a field of study and career choice, the uninviting nature of Earth Science as a profession, and curriculum that is irrelevant to the practical needs of Native communities or courses which are inaccessible geographically. Factors which impede progress that are embedded in Earth Science programs include educational preparation, academic information and counseling and the prevalence of a Western scientific perspective to the exclusion of all other perspectives. Intradepartmental relationships also pose barriers to the success of some students, particularly those who are non-traditional students (53%) or women (80%). Factors which support degree completion include financial assistance, mentors and mentoring, and research experiences. Earth scientists can begin broaden participation by engaging in community-inspired research, which stems from the needs of a community and is developed in collaboration with it. Designed to be useful in meeting the needs of the community, it should include using members of the community to help gather and analyze data. These community members could be students or potential students who might be persuaded to pursue an Earth Science degree.

Simultaneous protection of organic p- and n-channels in complementary inverter from aging and bias-stress by DNA-base guanine/Al2O3 double layer.

PubMed

Lee, Junyeong; Hwang, Hyuncheol; Min, Sung-Wook; Shin, Jae Min; Kim, Jin Sung; Jeon, Pyo Jin; Lee, Hee Sung; Im, Seongil

2015-01-28

Although organic field-effect transistors (OFETs) have various advantages of lightweight, low-cost, mechanical flexibility, and nowadays even higher mobility than amorphous Si-based FET, stability issue under bias and ambient condition critically hinder its practical application. One of the most detrimental effects on organic layer comes from penetrated atmospheric species such as oxygen and water. To solve such degradation problems, several molecular engineering tactics are introduced: forming a kinetic barrier, lowering the level of molecule orbitals, and increasing the band gap. However, direct passivation of organic channels, the most promising strategy, has not been reported as often as other methods. Here, we resolved the ambient stability issues of p-type (heptazole)/or n-type (PTCDI-C13) OFETs and their bias-stability issues at once, using DNA-base small molecule guanine (C5H5N5O)/Al2O3 bilayer. The guanine protects the organic channels as buffer/and H getter layer between the channels and capping Al2O3, whereas the oxide capping resists ambient molecules. As a result, both p-type and n-type OFETs are simultaneously protected from gate-bias stress and 30 days-long ambient aging, finally demonstrating a highly stable, high-gain complementary-type logic inverter.

A Model for Reform. Two-Year Colleges in the Twenty-First Century: Breaking Down Barriers (TYC21).

ERIC Educational Resources Information Center

Palmer, James C., Ed.

This book describes the TYC21 project (Two-Year Colleges in the Twenty-First Century: Breaking Down Barriers), which provided a framework to implement reform in science, engineering, and physics education at two-year colleges via the cooperative efforts of faculty in cross-educational activities. The project sought to increase the quality of…

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

PubMed

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

2016-01-01

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

Giant tunnelling electroresistance in metal/ferroelectric/semiconductor tunnel junctions by engineering the Schottky barrier

PubMed Central

Xi, Zhongnan; Ruan, Jieji; Li, Chen; Zheng, Chunyan; Wen, Zheng; Dai, Jiyan; Li, Aidong; Wu, Di

2017-01-01

Recently, ferroelectric tunnel junctions have attracted much attention due to their potential applications in non-destructive readout non-volatile memories. Using a semiconductor electrode has been proven effective to enhance the tunnelling electroresistance in ferroelectric tunnel junctions. Here we report a systematic investigation on electroresistance of Pt/BaTiO3/Nb:SrTiO3 metal/ferroelectric/semiconductor tunnel junctions by engineering the Schottky barrier on Nb:SrTiO3 surface via varying BaTiO3 thickness and Nb doping concentration. The optimum ON/OFF ratio as great as 6.0 × 106, comparable to that of commercial Flash memories, is achieved in a device with 0.1 wt% Nb concentration and a 4-unit-cell-thick BaTiO3 barrier. With this thinnest BaTiO3 barrier, which shows a negligible resistance to the tunnelling current but is still ferroelectric, the device is reduced to a polarization-modulated metal/semiconductor Schottky junction that exhibits a more efficient control on the tunnelling resistance to produce the giant electroresistance observed. These results may facilitate the design of high performance non-volatile resistive memories. PMID:28513590

Giant tunnelling electroresistance in metal/ferroelectric/semiconductor tunnel junctions by engineering the Schottky barrier

NASA Astrophysics Data System (ADS)

Xi, Zhongnan; Ruan, Jieji; Li, Chen; Zheng, Chunyan; Wen, Zheng; Dai, Jiyan; Li, Aidong; Wu, Di

2017-05-01

Recently, ferroelectric tunnel junctions have attracted much attention due to their potential applications in non-destructive readout non-volatile memories. Using a semiconductor electrode has been proven effective to enhance the tunnelling electroresistance in ferroelectric tunnel junctions. Here we report a systematic investigation on electroresistance of Pt/BaTiO3/Nb:SrTiO3 metal/ferroelectric/semiconductor tunnel junctions by engineering the Schottky barrier on Nb:SrTiO3 surface via varying BaTiO3 thickness and Nb doping concentration. The optimum ON/OFF ratio as great as 6.0 × 106, comparable to that of commercial Flash memories, is achieved in a device with 0.1 wt% Nb concentration and a 4-unit-cell-thick BaTiO3 barrier. With this thinnest BaTiO3 barrier, which shows a negligible resistance to the tunnelling current but is still ferroelectric, the device is reduced to a polarization-modulated metal/semiconductor Schottky junction that exhibits a more efficient control on the tunnelling resistance to produce the giant electroresistance observed. These results may facilitate the design of high performance non-volatile resistive memories.

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.

CMC Technology Advancements for Gas Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Grady, Joseph E.

2013-01-01

CMC research at NASA Glenn is focused on aircraft propulsion applications. The objective is to enable reduced engine emissions and fuel consumption for more environmentally friendly aircraft. Engine system studies show that incorporation of ceramic composites into turbine engines will enable significant reductions in emissions and fuel burn due to increased engine efficiency resulting from reduced cooling requirements for hot section components. This presentation will describe recent progress and challenges in developing fiber and matrix constituents for 2700 F CMC turbine applications. In addition, ongoing research in the development of durable environmental barrier coatings, ceramic joining integration technologies and life prediction methods for CMC engine components will be reviewed.

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 integrated with advanced EBC top coats, showed promise to achieve 1500 C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and long-term durability.

Career Issues and Laboratory Climates: Different Challenges and Opportunities for Women Engineers and Scientists (survey of Fiscal Year 1997 Powre Awardees)

NASA Astrophysics Data System (ADS)

Rosser, Sue V.; Zieseniss, Mireille

A survey of fiscal year 1997 POWRE (Professional Opportunities for Women in Research and Education) awardees from the National Science Foundation revealed that women engineers and scientists face similar issues, challenges, and opportunities and think that the laboratory climate has similar impacts on their careers. Separating responses of women scientists from those of women engineers revealed that 70% of both groups listed balancing work with family responsibilities as the most difficult issue. Discrepancies in percentages of women, coupled with differences among disciplinary and subdisciplinary cultures within science, engineering, mathematics, and technology fields, complicate work climates and their impact on women's careers. More frequently than women scientists, women engineers listed issues such as (a) low numbers of women leading to isolation, (b) lack of camaraderie and mentoring, (c) gaining credibility/respect from peers and administrators, (d) time management, (e) prioritizing responsibilities due to disproportionate demands, and (f) learning the rules of the game to survive in a male-dominated environment. Women engineers also listed two positive issues more frequently than women scientists: active recruitment/more opportunities for women and impact of successful women in the profession. The small number of women engineers may explain these results and suggests that it may be inappropriate to group them with other women scientists for analysis, programs, and policies.

Mental Health Care for LGBT Older Adults in Long-Term Care Settings: Competency, Training, and Barriers for Mental Health Providers.

PubMed

Smith, Ronald W; Altman, Jennifer K; Meeks, Suzanne; Hinrichs, Kate Lm

2018-06-07

To assess mental health providers' experience with LGBT older adults in long-term care (LTC) settings and perceived barriers to quality care. Providers (N = 57) completed an online survey on demographics and practice characteristics. They were also asked about: number of LGBT residents they've worked with, relevance of LGBT issues to their practice, preparedness, willingness to learn, hours of formal/informal training, and barriers to providing care to LGBT patients. Respondents were 63% psychologists, 16% social workers, 14% psychiatrists, and 5% nurses, most of whom practiced in LTC consulting roles. Most providers felt working with LGBT issues was relevant to their practice and felt well-prepared and willing to learn, though they were unaware of evidence based practices (EBTs), especially for LTC settings. They had little coursework on LGBT issues, and identified lack of training, stigma, and residents concealing their identity as the greatest barriers to quality care. Mental health providers in LTC facilities would benefit from more training in LGBT-specific mental health problems and evidence-based treatments, and efforts to destigmatize LGBT identities in these settings might improve access to mental health care. LGBT-specific training and EBTs are needed. Facilities need to address stigma with residents and providers.

Gender Equity in Science and Engineering: Advancing Change in Higher Education. Routledge Studies in Management, Organizations and Society

ERIC Educational Resources Information Center

Bilimoria, Diana; Liang, Xiangfen

2011-01-01

Women faculty's participation in academic science and engineering is critical for future US global competitiveness, yet their underrepresentation particularly in senior positions remains a widespread problem. To overcome persistent institutional resistance and barriers to change, the "NSF ADVANCE" institutional transformation initiative,…

Clinical Implementation of Pharmacogenomics for Personalized Precision Medicine: Barriers and Solutions.

PubMed

Klein, Michelle E; Parvez, Md Masud; Shin, Jae-Gook

2017-09-01

Clinical implementation of pharmacogenomics (PGx) leads to personalized medicine, which improves the efficacy, safety, and cost-effectiveness of treatments. Although PGx-based research has been conducted for more than a decade, several barriers have slowed down its widespread implementation in clinical practice. Globally, there is an imbalance in programs and solutions required to empower the clinical implementation of PGx between countries. Therefore, we aimed to review these issues comprehensively, determine the major barriers, and find the best solutions. Through an extensive review of ongoing clinical implementation programs, scientific, educational, ethical, legal, and social issues, information technology, and reimbursement were identified as the key barriers. The pace of global implementation of genomic medicine coincided with the resource limitations of each country. The key solutions identified for the earlier mentioned barriers are as follows: building of secure and suitable information technology infrastructure with integrated clinical decision support systems along with increasing PGx evidence, more regulations, reimbursement strategies for stakeholder's acceptance, incorporation of PGx education in all institutions and clinics, and PGx promotion to all health care professionals and patients. In conclusion, this review will be helpful for the better understanding of common barriers and solutions pertaining to the clinical application of PGx. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Free energy and hidden barriers of the β-sheet structure of prion protein.

PubMed

Paz, S Alexis; Abrams, Cameron F

2015-10-13

On-the-fly free-energy parametrization is a new collective variable biasing approach akin to metadynamics with one important distinction: rather than acquiring an accelerated distribution via a history-dependent bias potential, sampling on this distribution is achieved from the beginning of the simulation using temperature-accelerated molecular dynamics. In the present work, we compare the performance of both approaches to compute the free-energy profile along a scalar collective variable measuring the H-bond registry of the β-sheet structure of the mouse Prion protein. Both methods agree on the location of the free-energy minimum, but free-energy profiles from well-tempered metadynamics are subject to a much higher degree of statistical noise due to hidden barriers. The sensitivity of metadynamics to hidden barriers is shown to be a consequence of the history dependence of the bias potential, and we detail the nature of these barriers for the prion β-sheet. In contrast, on-the-fly parametrization is much less sensitive to these barriers and thus displays improved convergence behavior relative to that of metadynamics. While hidden barriers are a frequent and central issue in free-energy methods, on-the-fly free-energy parametrization appears to be a robust and preferable method to confront this issue.

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 initiated mainly in the bond and intermediate coating materials then propagated to the substrate. Results related to damage initiation and propagation; behavior and life assessment of the coating at the interface of the EBC/CMC are presented and discussed.

The Effects of Thermal Barrier Coating, Common-Rail Injection, and Reduced Compression Ratio on the Efficiency of Single-Cylinder Diesel Engines

DTIC Science & Technology

2010-05-12

m) YXX:........................................Molar Fraction of Compound XX 12 1 Introduction and Background Small internal combustion...Heywood, John B. Internal Combustion Engine Fundamentals. New York: McGraw-Hill, 1988. [9] Judge, A.W. High Speed Diesel Engines. London...performance and exergy potential of the exhaust gas. Energy Conversion and Management 46:489-499. [11] Parlak A., Yasar H., and Sahin B. 2003. Performance

Technology-driven dietary assessment: a software developer’s perspective

PubMed Central

Buday, Richard; Tapia, Ramsey; Maze, Gary R.

2015-01-01

Dietary researchers need new software to improve nutrition data collection and analysis, but creating information technology is difficult. Software development projects may be unsuccessful due to inadequate understanding of needs, management problems, technology barriers or legal hurdles. Cost overruns and schedule delays are common. Barriers facing scientific researchers developing software include workflow, cost, schedule, and team issues. Different methods of software development and the role that intellectual property rights play are discussed. A dietary researcher must carefully consider multiple issues to maximize the likelihood of success when creating new software. PMID:22591224

Product qualification: a barrier to point-of-care microfluidic-based diagnostics?

PubMed

Tantra, Ratna; van Heeren, Henne

2013-06-21

One of the most exciting applications of microfluidics-based diagnostics is its potential use in next generation point-of-care (POC) devices. Many prototypes are already in existence, but, as of yet, few have achieved commercialisation. In this article, we consider the issue surrounding product qualification as a potential barrier to market success. The study discusses, in the context of POC microfluidics-based diagnostics, what the generic issues are and potential solutions. Our findings underline the need for a community-based effort that is necessary to speed up the product qualification process.

Social workers in pediatric primary care: communication, gender, and scope of practice.

PubMed

Lynch, Sean

2014-01-01

While many child mental health issues manifest themselves in primary care, few pediatricians have received mental health training, and their communication with social workers may be limited due to unfamiliarity with mental health professions. The purpose of this study was to use ethnographic interviews to investigate factors affecting communication satisfaction between social workers and pediatricians. The study found that scope of practice issues were a communication barrier. This barrier is significant because health reform may lead social workers and pediatricians to collaborate more frequently in the future.

Evaluation of median barrier safety issues.

DOT National Transportation Integrated Search

2008-01-01

The objective of this study was to evaluate the effectiveness of the Brifen TL-4 and Trinity CASS median cable barrier systems in preventing cross-median collisions on sections of I-64, I-71, and I-265 (Brifen system) and I-265 (Trinity system) in Je...

Barriers to Teaching Introductory Physical Geography Online

ERIC Educational Resources Information Center

Ritter, Michael E.

2012-01-01

Learning geography online is becoming an option for more students but not without controversy. Issues of faculty resources, logistics, professional recognition, and pedagogical concerns are cited as barriers to teaching online. Offering introductory physical geography online presents special challenges. As a general education course, an…

The Contribution of Qualitative Research Towards the Issues Affecting Female Undergraduate Engineering Students

ERIC Educational Resources Information Center

Duggan, Louise Maria

2015-01-01

This article explores the use of qualitative research methods towards our understanding of the issues affecting female undergraduate engineers. As outlined in this article female engineering students face many challenges during their undergraduate studies. Qualitative research methods provide an opportunity to gain a deeper understanding of the…

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

NASA Astrophysics Data System (ADS)

Vijil, Veronica G.

2011-12-01

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

Coupled Heat and Moisture Transport Simulation on the Re-saturation of Engineered Clay Barrier

NASA Astrophysics Data System (ADS)

Huang, W. H.; Chuang, Y. F.

2014-12-01

Engineered clay barrier plays a major role for the isolation of radioactive wastes in a underground repository. This paper investigates the resaturation processes of clay barrier, with emphasis on the coupling effects of heat and moisture during the intrusion of groundwater to the repository. A reference bentonite and a locally available clay were adopted in the laboratory program. Soil suction of clay specimens was measured by psychrometers embedded in clay specimens and by vapor equilibrium technique conducted at varying temperatures so as to determine the soil water characteristic curves of the two clays at different temperatures. And water uptake tests were conducted on clay specimens compacted at various densities to simulate the intrusion of groundwater into the clay barrier. Using the soil water characteristic curve, an integration scheme was introduced to estimate the hydraulic conductivity of unsaturated clay. It was found that soil suction decreases as temperature increases, resulting in a reduction in water retention capability. The finite element method was then employed to carry out the numerical simulation of the saturation process in the near field of a repository. Results of the numerical simulation were validated using the degree of saturation profile obtained from the water uptake tests on the clays. The numerical scheme was then extended to establish a model simulating the resaturation process after the closure of a repository. Finally, the model was then used to evaluate the effect of clay barrier thickness on the time required for groundwater to penetrate the clay barrier and approach saturation. Due to the variation in clay suction and thermal conductivity with temperature of clay barrier material, the calculated temperature field shows a reduction as a result of incorporating the hydro-properties in the calculations.

Turbomachine Sealing and Secondary Flows - Part 3. Part 3; Review of Power-Stream Support, Unsteady Flow Systems, Seal and Disk Cavity Flows, Engine Externals, and Life and Reliability Issues

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Steinetz, B. M.; Zaretsky, E. V.; Athavale, M. M.; Przekwas, A. J.

2004-01-01

The issues and components supporting the engine power stream are reviewed. It is essential that companies pay close attention to engine sealing issues, particularly on the high-pressure spool or high-pressure pumps. Small changes in these systems are reflected throughout the entire engine. Although cavity, platform, and tip sealing are complex and have a significant effect on component and engine performance, computational tools (e.g., NASA-developed INDSEAL, SCISEAL, and ADPAC) are available to help guide the designer and the experimenter. Gas turbine engine and rocket engine externals must all function efficiently with a high degree of reliability in order for the engine to run but often receive little attention until they malfunction. Within the open literature statistically significant data for critical engine components are virtually nonexistent; the classic approach is deterministic. Studies show that variations with loading can have a significant effect on component performance and life. Without validation data they are just studies. These variations and deficits in statistical databases require immediate attention.

Self-Advocacy. Feature Issue.

ERIC Educational Resources Information Center

Hayden, Mary F., Ed.; Ward, Nancy, Ed.

1994-01-01

This feature issue newsletter looks at issues the self-advocacy movement is raising and the contributions it is making to the lives of people with developmental disabilities. Articles by self-advocates and advisors to self-advocacy organizations talk about their self-advocacy experiences, barriers to self-advocacy, and ways to support it. Primary…

PILOT-SCALE EVALUATION OF ENGINEERED BARIER SYSTEMS FOR THE YUCCA MOUNTAIN PROJECT

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

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

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

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

PubMed

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

2018-02-21

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

Further industrial tests of ceramic thermal barrier coatings

NASA Technical Reports Server (NTRS)

Liebert, C. H.; Levine, S. R.

1982-01-01

The NASA Lewis Research Center made technical assistance arrangements (contracts) with several commercial organizations under which Lewis designed plasma-sprayed thermal-barrier coatings (TBC) for their products. Lewis was then furnished with the test conditions and evaluations of coating usefulness. The coating systems were developed and sprayed at Lewis. All of the systems incorporated a two-layer, ceramic-bond coating concept. Coating thickness and chemical composition were varied to fit three applications: the leading edges of first-stage turbine vanes for an advanced gas turbine engine; the flame impingement surfaces of a combustor transition section; and diesel engine valves and head surfaces. The TBC incorporated yytria-stabilized zirconia, which lowered metal temperatures, protected metal parts, and increased metal part life. In some cases metal burning, melting, and warping were eliminated. Additional benefits were realized from these endeavors: hands-on experience with thermal-barrier coatings was provided to industry; the success of these endeavors encourages these and other organizations to accelerate the implementation of TBC technology.

Biological intrusion of low-level-waste trench covers

NASA Astrophysics Data System (ADS)

Hakonson, T. E.; Gladney, E. S.

The long-term integrity of low-level waste shallow land burialsites is dependent on the interaction of physical, chemical, and biological factors that modify the waste containment system. The need to consider biological processes as being potentially important in reducing the integrity of waste burial site cover treatment is demonstrated. One approach to limiting biological intrusion through the waste cover is to apply a barrier within the profile to limit root and animal penetration with depth. Experiments in the Los Alamos Experimental Engineered Test Facility were initiated to develop and evaluate biological barriers that are effective in minimizing intrusion into waste trenches. The experiments that are described employ four different candidate barrier materials of geologic origin. Experimental variables that will be evaluated, in addition to barrier type, are barrier depth and sil overburden depth.

Microbiota-gut-brain axis: Interaction of gut microbes and their metabolites with host epithelial barriers.

PubMed

Bhattarai, Y

2018-06-01

The gastrointestinal barrier and the blood brain barrier represent an important line of defense to protect the underlying structures against harmful external stimuli. These host barriers are composed of epithelial and endothelial cells interconnected by tight junction proteins along with several other supporting structures. Disruption in host barrier structures has therefore been implicated in various diseases of the gastrointestinal tract and the central nervous system. While there are several factors that influence host barrier, recently there is an increasing appreciation of the role of gut microbiota and their metabolites in regulating barrier integrity. In the current issue of Neurogastroenterology and Motility, Marungruang et al. describe the effect of gastrointestinal barrier maturation on gut microbiota and the blood brain barrier adding to the growing evidence of microbiota-barrier interactions. In this mini-review I will discuss the effect of gut microbiota on host epithelial barriers and its implications for diseases associated with disrupted gut-brain axis. © 2018 John Wiley & Sons Ltd.

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

PubMed

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

Deconstructing barriers: perceptions of students labeled with learning disabilities in higher education.

PubMed

Denhart, Hazel

2008-01-01

This phenomenological study investigated barriers to higher education faced by 11 college students labeled with learning disabilities (LD) using their voice as the primary data. Data were analyzed and interpreted through a disability theory perspective revealing barriers stemmed largely from external social causes rather than individual pathology. Barriers included being misunderstood by faculty, being reluctant to request accommodations for fear of invoking stigma, and having to work considerably longer hours than nonlabeled peers. Findings indicated barriers could be overcome through raising faculty awareness about LD issues, engaging the assistance of the college LD specialist, and participation in a LD democratic empowerment community on campus.

Experimental evaluation of optimization method for developing ultraviolet barrier coatings

NASA Astrophysics Data System (ADS)

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

2014-01-01

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

XLR-11 - X-1 rocket engine display

NASA Technical Reports Server (NTRS)

1996-01-01

What started as a hobby for four rocket fanatics went on to break the sound barrier: Lovell Lawrence, Hugh Franklin Pierce, John Shesta, and Jimmy Wyld the four founders of Reaction Motors, Inc. that built the XLR-11 Rocket Engine. The XLR-11 engine is shown on display in the NASA Exchange Gift Shop, NASA Hugh L. Dryden Flight Research Center at Edwards, California. This engine, familiarly known as Black Betsy, a 4-chamber rocket that ignited diluted ethyl alcohol and liquid oxygen into 6000 pounds or more of thrust powered the X-1 series airplanes.

14 CFR 21.271 - Airworthiness approval tags.

Code of Federal Regulations, 2010 CFR

2010-01-01

... may issue an airworthiness approval tag (FAA Form 8130-3) for each engine and propeller covered by... shall be stamped on the engine or propeller identification data place instead of issuing an...

Catalytic thermal barrier coatings

DOEpatents

Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

2009-06-02

A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

Enabling High Efficiency Ethanol Engines

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

Szybist, J.; Confer, K.

2011-03-01

Delphi Automotive Systems and ORNL established this CRADA to explore the potential to improve the energy efficiency of spark-ignited engines operating on ethanol-gasoline blends. By taking advantage of the fuel properties of ethanol, such as high compression ratio and high latent heat of vaporization, it is possible to increase efficiency with ethanol blends. Increasing the efficiency with ethanol-containing blends aims to remove a market barrier of reduced fuel economy with E85 fuel blends, which is currently about 30% lower than with petroleum-derived gasoline. The same or higher engine efficiency is achieved with E85, and the reduction in fuel economy ismore » due to the lower energy density of E85. By making ethanol-blends more efficient, the fuel economy gap between gasoline and E85 can be reduced. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has extensive knowledge and experience in powertrain components and subsystems as well as overcoming real-world implementation barriers. ORNL has extensive knowledge and expertise in non-traditional fuels and improving engine system efficiency for the next generation of internal combustion engines. Partnering to combine these knowledge bases was essential towards making progress to reducing the fuel economy gap between gasoline and E85. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, usually on a bi-weekly basis, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided substantial hardware support to the project by providing components for the single-cylinder engine experiments, engineering support for hardware modifications, guidance for operational strategies on engine research, and hardware support by providing a flexible multi-cylinder engine to be used for optimizing engine efficiency with ethanol-containing fuels.« less

Integrating Religion and Spirituality into Counselor Education: Barriers and Strategies

ERIC Educational Resources Information Center

Adams, Christopher M.; Puig, Ana; Baggs, Adrienne; Wolf, Cheryl Pence

2015-01-01

Despite a professionally recognized need for training in religion/spirituality, literature indicates that religious and spirituality issues continue to be inconsistently addressed in counselor education. Ten experts were asked to identify potential barriers to integrating religion and spirituality into counselor education and indicate strategies…

Computational fluid dynamics modeling to assess the impact of roadside barriers on near-road air quality

EPA Science Inventory

Near-road air quality is an issue of emerging concern, with field studies consistently showing elevated air pollutant concentrations adjacent to major roads, usually decreasing to background levels within several hundred meters. Roadside barriers, both vegetative and structural, ...

Planning for Accessibility.

ERIC Educational Resources Information Center

Spoor, Dana L.

1997-01-01

Argues that barrier-free designs should be incorporated in the first steps of school facility planning to avoid the difficulties in meeting Americans with Disabilities Act (ADA) guidelines during renovations. Explains why not all barriers need be removed to make a facility accessible to everyone. Discusses issues involving ADA guidelines and child…

Rexin-G, a targeted genetic medicine for cancer.

PubMed

Gordon, Erlinda M; Hall, Frederick L

2010-05-01

Rexin-G, a tumor-targeted retrovector bearing a cytocidal cyclin G1 construct, is the first targeted gene therapy vector to gain fast track designation and orphan drug priorities for multiple cancer indications in the US. This review describes the major milestones in the clinical development of Rexin-G: from the molecular cloning and characterization of the human cyclin G1 proto-oncogene in 1994, to the design of the first knockout constructs and genetic engineering of the targeted delivery system from 1995 to 1997, through the initial proofs-of-concept, molecular pharmacology and toxicology studies of Rexin-G in preclinical cancer models from 1997 to 2001, to the pioneering clinical studies in humans from 2002 to 2004, which--together with the advancements in bioprocess development of high-potency clinical grade vectors circa 2005 - 2006--led to the accelerated approval of Rexin-G for all solid tumors by the Philippine FDA in 2007 and the rapid progression of clinical studies from 2007 to 2009 to the cusp of pivotal Phase III trials in the US. In recording the development of Rexin-G as a novel form of targeted biological therapy, this review also highlights important aspects of vector design engineering which served to overcome the physiological barriers to gene delivery as it addresses the key regulatory issues involved in the development of a targeted gene therapy product. Progressive clinical development of Rexin-G demonstrates the potential safety and efficacy of targeted genetic medicine, while validating the design engineering of the molecular biotechnology platform.

The web of silence: a qualitative case study of early intervention and support for healthcare workers with mental ill-health.

PubMed

Moll, Sandra E

2014-02-08

There is a high rate of stress and mental illness among healthcare workers, yet many continue to work despite symptoms that affect their performance. Workers with mental health issues are typically ostracized and do not get the support that they need. If issues are not addressed, however, they could become worse and compromise the health and safety, not only of the worker, but his/her colleagues and patients. Early identification and support can improve work outcomes and facilitate recovery, but more information is needed about how to facilitate this process in the context of healthcare work. The purpose of this study was to explore the key individual and organizational forces that shape early intervention and support for healthcare workers who are struggling with mental health issues, and to identify barriers and opportunities for change. A qualitative, case study in a large, urban healthcare organization was conducted in order to explore the perceptions and experiences of employees across the organization. In-depth interviews were conducted with eight healthcare workers who had experienced mental health issues at work as well as eight workplace stakeholders who interacted with workers who were struggling (managers, coworkers, union leaders). An online survey was completed by an additional 67 employees. Analysis of the interviews and surveys was guided by a process of interpretive description to identify key barriers to early intervention and support. There were many reports of silence and inaction in response to employee mental health issues. Uncertainty in identifying mental health problems, stigma regarding mental ill health, a discourse of professional competence, social tensions, workload pressures, confidentiality expectations and lack of timely access to mental health supports were key forces in preventing employees from getting the help that they needed. Although there were a few exceptions, the overall study findings point to many barriers to supporting employees with mental health issues. In order to address the complex knowledge, attitudinal, interpersonal and organizational barriers to action, a multi-layered knowledge translation strategy is needed, that considers not only mental health literacy and anti-stigma interventions, but addresses the unique context of the work environment that can act as a barrier to change.

The web of silence: a qualitative case study of early intervention and support for healthcare workers with mental ill-health

PubMed Central

2014-01-01

Background There is a high rate of stress and mental illness among healthcare workers, yet many continue to work despite symptoms that affect their performance. Workers with mental health issues are typically ostracized and do not get the support that they need. If issues are not addressed, however, they could become worse and compromise the health and safety, not only of the worker, but his/her colleagues and patients. Early identification and support can improve work outcomes and facilitate recovery, but more information is needed about how to facilitate this process in the context of healthcare work. The purpose of this study was to explore the key individual and organizational forces that shape early intervention and support for healthcare workers who are struggling with mental health issues, and to identify barriers and opportunities for change. Methods A qualitative, case study in a large, urban healthcare organization was conducted in order to explore the perceptions and experiences of employees across the organization. In-depth interviews were conducted with eight healthcare workers who had experienced mental health issues at work as well as eight workplace stakeholders who interacted with workers who were struggling (managers, coworkers, union leaders). An online survey was completed by an additional 67 employees. Analysis of the interviews and surveys was guided by a process of interpretive description to identify key barriers to early intervention and support. Results There were many reports of silence and inaction in response to employee mental health issues. Uncertainty in identifying mental health problems, stigma regarding mental ill health, a discourse of professional competence, social tensions, workload pressures, confidentiality expectations and lack of timely access to mental health supports were key forces in preventing employees from getting the help that they needed. Although there were a few exceptions, the overall study findings point to many barriers to supporting employees with mental health issues. Conclusions In order to address the complex knowledge, attitudinal, interpersonal and organizational barriers to action, a multi-layered knowledge translation strategy is needed, that considers not only mental health literacy and anti-stigma interventions, but addresses the unique context of the work environment that can act as a barrier to change. PMID:24507543

Strategies for Limiting Engineers' Potential Liability for Indoor Air Quality Problems.

PubMed

von Oppenfeld, Rolf R; Freeze, Mark E; Sabo, Sean M

1998-10-01

Engineers face indoor air quality (IAQ) issues at the design phase of building construction as well as during the investigation and mitigation of potential indoor air pollution problems during building operation. IAQ issues that can be identified are "building-related illnesses" that may include problems of volatile organic compounds (VOCs). IAQ issues that cannot be identified are termed "sick building syndrome." Frequently, microorganism-caused illnesses are difficult to confirm. Engineers who provide professional services that directly or indirectly impact IAQ face significant potential liability to clients and third parties when performing these duties. Potential theories supporting liability claims for IAQ problems against engineers include breach of contract and various common law tort theories such as negligence and negligent misrepresentation. Furthermore, an increasing number of federal, state, and local regulations affect IAQ issues and can directly increase the potential liability of engineers. A duty to disclose potential or actual air quality concerns to third parties may apply for engineers in given circumstances. Such a duty may arise from judicial precedent, the Model Guide for Professional Conduct for Engineers, or the Code of Ethics for Engineers. Practical strategies engineers can use to protect themselves from liability include regular training and continuing education in relevant regulatory, scientific, and case law developments; detailed documentation and recordkeeping practices; adequate insurance coverage; contractual indemnity clauses; contractual provisions limiting liability to the scope of work performed; and contractual provisions limiting the extent of liability for engineers' negligence. Furthermore, through the proper use of building materials and construction techniques, an engineer or other design professional can effectively limit the potential for IAQ liability.

Advocating for responsible oil and natural gas extraction policies; FracTracker as a mechanism for overcoming the barriers to scientific advocacy for academics and communities

NASA Astrophysics Data System (ADS)

Ferrar, K. J.; Malone, S.; Kelso, M.; Lenker, B.

2013-12-01

The inability to translate data to scientific information that can readily be incorporated by citizens into the public arena is an obstacle for science-based advocacy. This issue is particularly poignant for shale oil and natural gas development via hydraulic fracturing, as the issue has become highly politicized. Barriers to engaging in policy debate are different but highly related for community members and scientists. For citizens and interest groups, barriers including accessibility, public awareness and data presentation limit the motivation for community involvement in political interactions. To overcome such barriers, social researchers call for public engagement to move upstream and many call for a broad engagement of scientists in science-based advocacy. Furthermore surveys have shown that citizens, interest groups, and decision-makers share a broad desire for scientists to engage in environmental policy development. Regardless, scientists face a number of perceived barriers, with academics expressing the most resistance to overcoming the tension created by adherence to the scientific method and the need to engage with the broader society, described by Schneider (1990) as the 'double ethical bind'. For the scientific community the appeal of public dissemination of information beyond the scope of academic journals is limited for a number of reasons. Barriers include preservation of credibility, peer attitudes, training, and career trajectory. The result is a lack of translated information available to the public. This systematic analysis of the FracTracker platform provides an evaluation of where the features of the public engagement, GIS platform has been successful at overcoming these barriers to public dissemination, where the platform needs further development or is ill-suited to address these issues, and the development of FracTracker as an outlet for scientific researchers to engage with citizens. The analysis will also provide insight into what information the public is most interested in concerning hydraulic fracturing and unconventional oil and natural gas development. The evaluations in consideration of these core barriers to public engagement and science-based advocacy will provide insight into the future development of programs, as well as the improvement of the FracTracker platform.

Facilitators and Barriers to HIV Activities in Religious Congregations: Perspectives of Clergy and Lay Leaders from a Diverse Urban Sample

PubMed Central

Derose, Kathryn Pitkin; Werber, Laura; Palar, Kartika; Kanouse, David E.; Mata, Michael

2013-01-01

This paper examines facilitators and barriers to HIV activities within religious congregations, the relative internal or external sources of these influences, and suggestive differences across congregational types. Results are based on in-depth interviews with clergy and lay leaders (n = 57) from 14 congregations in Los Angeles County, California, purposively selected to reflect diversity in racial-ethnic composition, denomination, size, and HIV activity level. Many common facilitators and barriers were related to norms and attitudes, only a few of which appeared overtly associated with theological orientations. Clergy support was a facilitator particularly prevalent among congregations having higher HIV activity levels, indicating its importance in sustaining and expanding HIV programs. Resource issues were also prominent, with material resource barriers more frequently mentioned by smaller congregations and human resource barriers more among larger congregations. Organizational structure issues were mostly centered on external linkages with various social service, public health, and faith-based entities. Analysis of internal versus external sources highlights the roles of different stakeholders within and outside congregations in promoting HIV activities. Potential differences across congregational types represent fruitful areas for future research. PMID:23990037

Exploring barriers and facilitators to participation of male-to-female transgender persons in preventive HIV vaccine clinical trials.

PubMed

Andrasik, Michele Peake; Yoon, Ro; Mooney, Jessica; Broder, Gail; Bolton, Marcus; Votto, Teress; Davis-Vogel, Annet

2014-06-01

Observed seroincidence and prevalence rates in male-to-female (MTF) transgender individuals highlight the need for effective targeted HIV prevention strategies for this community. In order to develop an effective vaccine that can be used by transgender women, researchers must understand and address existing structural issues that present barriers to this group's participation in HIV vaccine clinical trials. Overcoming barriers to participation is important for ensuring HIV vaccine acceptability and efficacy for the MTF transgender community. To explore barriers and facilitators to MTF transgender participation in preventive HIV vaccine clinical trials, the HIV Vaccine Trials Network conducted focus groups among transgender women in four urban areas (Atlanta, Boston, Philadelphia, and San Francisco). Barriers and facilitators to engagement of transgender women in preventive HIV vaccine clinical trials led to the following recommendations: (a) transgender cultural competency training, (b) creating trans-friendly environments, (c) true partnerships with local trans-friendly organizations and health care providers, (d) protocols that focus on transgender specific issues, and (e) data collection and tracking of transgender individuals. These results have implications for the conduct of HIV vaccine trials, as well as engagement of transgender women in research programs in general.

Data dialogues: critical connections for designing and implementing future nanomaterial research

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

Powers, Christina M.; Grieger, Khara D.; Beaudrie, Christian

2014-11-07

Individuals and organizations in the engineered nanomaterial (ENM) community have increasingly recognized two related but distinct concerns: 1) discordant data due to differences in experimental design (e.g., material characteristics, experimental model, exposure concentration) or reporting (e.g., dose metric, material characterization details), and 2) a lack of data to inform decisions about ENM environmental, health, and safety (EHS). As one way to help address these issues, this Commentary discusses the important role of “data dialogues” or structured discussions between ENM researchers in EHS fields (e.g., toxicology, exposure science, and industrial hygiene) and decision makers who use the data researchers collect. Themore » importance of these structured discussions is examined here in the context of barriers, solutions, and incentives: barriers to developing research relevant for human and ecological risk assessments; potential solutions to overcome such barriers; and incentives to help implement these or other solutions. These barriers, solutions, and incentives were identified by a group of expert stakeholders and ENM community members at the December 2013 Society for Risk Analysis panel discussion on research needed to support decision making for multiwalled carbon nanotubes (MWCNTs). Key topics discussed by experts and ENM community members include: (1) the value of researchers collaborating with EHS decision makers (e.g., risk analysts, product developers, regulators) to design research that can inform ENM EHS-related decisions (e.g., occupational exposure limits, product safety determinations), (2) the importance of funding incentives for such collaborative research, (3) the need to improve mechanisms for data-sharing within and between sectors (e.g., academia, government, and industry), and (4) the critical need to educate the “next generation” of nanotechnology researchers in EHS topics (e.g., risk assessment, risk management). In presenting these outcomes, this Commentary is not intended to conclude the conversation that took place in December 2013 but rather to support a broader dialogue that helps ensure important risk assessment questions are answered for ENMs.« less

Barriers and Opportunities for 2-Year and 4-Year STEM Degrees: Systemic Change to Support Students' Diverse Pathways

ERIC Educational Resources Information Center

Malcom, Shirley, Ed.; Feder, Michael, Ed.

2016-01-01

Nearly 40 percent of the students entering 2- and 4-year postsecondary institutions indicated their intention to major in science, technology, engineering, and mathematics (STEM) in 2012. But the barriers to students realizing their ambitions are reflected in the fact that about half of those with the intention to earn a STEM bachelor's degree and…

Assessing the Fragile X Syndrome Newborn Screening Landscape.

PubMed

Riley, Catharine; Wheeler, Anne

2017-06-01

Fragile X syndrome (FXS) is the most common known inherited form of intellectual disability. Early identification is an important step in linking FXS individuals with appropriate and timely medical and social services. Newborn screening (NBS) is 1 approach that has been used for other conditions to facilitate early identification. A literature review was conducted to identify issues, barriers, challenges, and approaches to addressing challenges related to NBS for FXS. Search terms included: fragile X syndrome, FMR1, newborn screening, screening, and genetic testing. To supplement the literature review, 9 key informant interviews were conducted. Information gathered through these interviews supplemented what was identified in the literature. Information from both the literature review and supplemental interviews was reviewed by 3 researchers who discussed and came to consensus on thematic areas and categorization of issues. The barriers and challenges related to NBS for FXS identified in the literature and by experts and stakeholders are categorized into 5 thematic areas: public health burden, treatment, timing, screening/testing methodologies, and translating results. Summaries of these issues and barriers are provided, along with potential approaches to addressing them. The issues and barriers described in this article highlight limited areas of knowledge that need be addressed to improve our understanding of FXS and the potential benefit of NBS. The landscape of NBS for FXS could be influenced by a series of research findings over time or a larger breakthrough that demonstrates an effective targeted treatment that has to be implemented early in life. Copyright © 2017 by the American Academy of Pediatrics.

Benthic substrate classification map: Gulf Islands National Seashore

USGS Publications Warehouse

Lavoie, Dawn; Flocks, James; Twichell, Dave; Rose, Kate

2013-01-01

The 2005 hurricane season was devastating for the Mississippi Gulf Coast. Hurricane Katrina caused significant degradation of the barrier islands that compose the Gulf Islands National Seashore (GUIS). Because of the ability of coastal barrier islands to help mitigate hurricane damage to the mainland, restoring these habitats prior to the onset of future storms will help protect the islands themselves and the surrounding habitats. During Hurricane Katrina, coastal barrier islands reduced storm surge by approximately 10 percent and moderated wave heights (Wamsley and others, 2009). Islands protected the mainland by preventing ocean waves from maintaining their size as they approached the mainland. In addition to storm protection, it is advantageous to restore these islands to preserve the cultural heritage present there (for example, Fort Massachusetts) and because of the influence that these islands have on marine ecology. For example, these islands help maintain a salinity regime favorable to oysters in the Mississippi Sound and provide critical habitats for many migratory birds and endangered species such as sea turtles (Chelonia mydas, Caretta caretta, and Dermochelys coriacea), Gulf sturgeon (Acipenser oxyrinchus desotoi), and piping plovers (Charadrius melodus) (U.S. Army Corps of Engineers, 2009a). As land manager for the GUIS, the National Park Service (NPS) has been working with the State of Mississippi and the Mobile District of the U.S. Army Corps of Engineers to provide a set of recommendations to the Mississippi Coastal Improvements Program (MsCIP) that will guide restoration planning. The final set of recommendations includes directly renourishing both West Ship Island (to protect Fort Massachusetts) and East Ship Island (to restore the French Warehouse archaeological site); filling Camille Cut to recreate a continuous Ship Island; and restoring natural regional sediment transport processes by placing sand in the littoral zone just east of Petit Bois Island. Prevailing sediment transport processes will provide natural renourishment of the westward islands in the barrier system (U.S. Army Corps of Engineers, 2009b). One difficulty in developing the final recommendations is that few data are available to incorporate into restoration plans related to bathymetry, sediment type, and biota. For example, the most recent bathymetry available dates to when East and West Ship Islands were a single continuous island (1917). As a result, the MsCIP program has encouraged post-hurricane bathymetric data collection for future reference. Furthermore, managing a complex environment such as this barrier island system for habitat conservation and best resource usage requires significant knowledge about those habitats and resources. To effectively address these issues, a complete and comprehensive understanding of the type, geographic extent, and condition of marine resources included within the GUIS is required. However, the data related to the GUIS marine resources are limited either spatially or temporally. Specifically, there is limited knowledge and information about the distribution of benthic habitats and the characteristics of the offshore region of the GUIS, even though these are the habitats that will be most affected by habitat restoration. The goal of this project is to develop a comprehensive map of the benthic marine habitats within the GUIS to give park managers the ability to develop strategies for coastal and ocean-resource management and to aid decisionmakers in evaluating conservation priorities.

Resilient actions in the diagnostic process and system performance.

PubMed

Smith, Michael W; Davis Giardina, Traber; Murphy, Daniel R; Laxmisan, Archana; Singh, Hardeep

2013-12-01

Systemic issues can adversely affect the diagnostic process. Many system-related barriers can be masked by 'resilient' actions of frontline providers (ie, actions supporting the safe delivery of care in the presence of pressures that the system cannot readily adapt to). We explored system barriers and resilient actions of primary care providers (PCPs) in the diagnostic evaluation of cancer. We conducted a secondary data analysis of interviews of PCPs involved in diagnostic evaluation of 29 lung and colorectal cancer cases. Cases covered a range of diagnostic timeliness and were analysed to identify barriers for rapid diagnostic evaluation, and PCPs' actions involving elements of resilience addressing those barriers. We rated these actions according to whether they were usual or extraordinary for typical PCP work. Resilient actions and associated barriers were found in 59% of the cases, in all ranges of timeliness, with 40% involving actions rated as beyond typical. Most of the barriers were related to access to specialty services and coordination with patients. Many of the resilient actions involved using additional communication channels to solicit cooperation from other participants in the diagnostic process. Diagnostic evaluation of cancer involves several resilient actions by PCPs targeted at system deficiencies. PCPs' actions can sometimes mitigate system barriers to diagnosis, and thereby impact the sensitivity of 'downstream' measures (eg, delays) in detecting barriers. While resilient actions might enable providers to mitigate system deficiencies in the short run, they can be resource intensive and potentially unsustainable. They complement, rather than substitute for, structural remedies to improve system performance. Measures to detect and fix system performance issues targeted by these resilient actions could facilitate diagnostic safety.

'Not Hard to Sway': A Case Study of Student Engagement in Two Large Engineering Classes

ERIC Educational Resources Information Center

Shekhar, Prateek; Borrego, Maura

2018-01-01

Although engineering education research has empirically validated the effectiveness of active learning in improving student learning over traditional lecture-based methods, the adoption of active learning in classrooms has been slow. One of the greatest reported barriers is student resistance towards engagement in active learning exercises. This…

Women of Color in Mathematics, Science & Engineering: A Review of the Literature.

ERIC Educational Resources Information Center

Clewell, Beatriz Chu; Anderson, Bernice

This review of the literature on women of color in mathematics, science, and engineering helps define the need for a national agenda for equity in these fields sponsored by the Educational Equity Policy Studies Program of the Center for Women Policy Studies, and for a comprehensive research program that examines barriers to the participation of…

Women's Leadership in Science, Technology, Engineering and Mathematics: Barriers to Participation

ERIC Educational Resources Information Center

McCullough, Laura

2011-01-01

Despite gains overall, women are still under-represented in leadership positions in science, technology, engineering, and mathematics (STEM) fields. Data in the US suggest around one-quarter of deans and department heads are women; in science this drops to nearly 1 in 20. Part of this problem of under-representation stems from the population pool:…

Gender Stereotypes among Women Engineering and Technology Students in the UK: Lessons from Career Choice Narratives

ERIC Educational Resources Information Center

Powell, Abigail; Dainty, Andrew; Bagilhole, Barbara

2012-01-01

In the UK, women remain under-represented in engineering and technology (E&T). Research has, therefore, investigated barriers and solutions to women's recruitment, retention and progression. Recruitment into the sector may be supported by exploring the career decisions of women and men who have chosen to study E&T. Triangulating…

Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels: Next Generation Hydroccarbon Biorefineries

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

none,

2008-03-01

This roadmap to “Next Generation Hydrocarbon Biorefineries” outlines a number of novel process pathways for biofuels production based on sound scientific and engineering proofs of concept demonstrated in laboratories around the world. This report was based on the workshop of the same name held June 25-26, 2007 in Washington, DC.

Living Learning Communities: An Intervention in Keeping Women Strong in Science, Technology, Engineering, and Mathematics

ERIC Educational Resources Information Center

Belichesky, Jennifer

2013-01-01

The purpose of this study was to expand on the current research pertaining to women in science, technology, engineering, and mathematics (STEM) majors, better understand the experiences of undergraduate women in the sciences, identify barriers to female persistence in their intended STEM majors, and understand the impact of the STEM co-educational…

Lighting issues in the 1980's. Summary and proceedings

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

Rubin, A. I.

1980-01-01

The Lighting Roundtable described in this report was conducted to foster an open discussion of the goals, issues, and responsibilities of the lighting community. It was not a problem-solving session, but rather a time to examine the long-term aspirations and objectives of lighting and the barriers that may stand in the way of achieving them. Eight major issues were addressed by nine panelists and a number of invited auditors. The issues are as follows: (1) The Public Image of the Lighting Community; (2) US Role in the Worldwide Lighting Community; (3) Factors Affecting Human Activities in the Built Environment; (4)more » Effect of Lighting on Environmental Quality; (5) Effects of Barriers; (6) Establishment of Illuminance Levels; (7) Integration of Subsystems; and (8) Professional Development and Lighting Education. Two parts presented are: (1) a summary of the proceedings; and (2) a complete transcript.« less

A review on the current issues and barriers of Industrialised Building System (IBS) adoption in Malaysia’s construction industry

NASA Astrophysics Data System (ADS)

Amin, M. A. Mohd; Abas, N. H.; Shahidan, S.; Rahmat, M. H.; Suhaini, N. A.; Nagapan, S.; Rahim, R. Abdul

2017-11-01

Malaysia considers the construction industry as one of the main contributors to its Gross Domestic Product (GDP). However, there are some unresolved issues arising from the ongoing and widespread adoption of the conventional method of construction such as the resultant fragmentation of the industry itself; delays in production and delivery time of unnecessary wastages and lack of sustainability practice. Malaysian Government has been continuously encouraging the industry to use, partly or if not wholly, the Industrialized Building System (IBS), which is considered to be an important part of sustainable construction initiative. IBS was introduced to Malaysia as the solution to issues related to dependencies of foreign workers, raising demand for affordable accommodations and improving image, quality and productivity of construction industry. However, the IBS adoption in Malaysia remains low. This paper presents the review of the current issues and barriers of IBS adoption in Malaysian construction industry.

Industry tests of NASA ceramic thermal barrier coating. [for gas turbine engine applications

NASA Technical Reports Server (NTRS)

Liebert, C. H.; Stepka, F. S.

1979-01-01

Ceramic thermal barrier coating (TBC) system was tested by industrial and governmental organizations for a variety of aeronautical, marine, and ground-based gas turbine engine applications. This TBC is a two-layer system with a bond coating of nickel-chromium-aluminum-yttrium (Ni-16Cr-6Al-0.6Y, in wt. percent) and a ceramic coating of yttria-stabilized zirconia (ZrO2-12Y2O3, in wt. percent). Seven tests evaluated the system's thermal protection and durability. Five other tests determined thermal conductivity, vibratory fatigue characteristics, and corrosion resistance of the system. The information presented includes test results and photographs of the coated parts. Recommendations are made for improving the coating procedures.

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

Huff, Kathryn D.

Component level and system level abstraction of detailed computational geologic repository models have resulted in four rapid computational models of hydrologic radionuclide transport at varying levels of detail. Those models are described, as is their implementation in Cyder, a software library of interchangeable radionuclide transport models appropriate for representing natural and engineered barrier components of generic geology repository concepts. A proof of principle demonstration was also conducted in which these models were used to represent the natural and engineered barrier components of a repository concept in a reducing, homogenous, generic geology. This base case demonstrates integration of the Cyder openmore » source library with the Cyclus computational fuel cycle systems analysis platform to facilitate calculation of repository performance metrics with respect to fuel cycle choices. (authors)« less

Barriers to access and minority ethnic carers' satisfaction with social care services in the community: a systematic review of qualitative and quantitative literature.

PubMed

Greenwood, Nan; Habibi, Ruth; Smith, Raymond; Manthorpe, Jill

2015-01-01

As populations age, the numbers of carers overall and numbers of carers from minority ethnic groups in particular are rising. Evidence suggests that carers from all sections of the community and particularly carers from minority groups often fail to access care services. This may relate to barriers in accessing services and service dissatisfaction. The aim of this systematic review was to identify and summarise minority ethnic carers' perceptions of barriers to accessing community social care services and their satisfaction with these services if accessed. The following databases were searched from their start until July 2013: Social Care Online, Social Policy and Research, Scopus, PsychINFO, HMIC, ASSIA, MEDLINE, Embase, CINAHL Plus and AMED. Thirteen studies met the inclusion criteria. Most investigated either barriers to access or satisfaction levels, although three explored both. Only 4 studies investigated minority ethnic carers' satisfaction with social care, although 12 studies reported perceived barriers to accessing services. Few studies compared minority ethnic carers' perceptions with majority ethnic groups, making it difficult to identify issues specific to minority groups. Most barriers described were potentially relevant to all carers, irrespective of ethnic group. They included attitudinal barriers such as not wanting to involve outsiders or not seeing the need for services and practical barriers such as low awareness of services and service availability. Issues specific to minority ethnic groups included language barriers and concerns about services' cultural or religious appropriateness. Studies investigating satisfaction with services reported a mixture of satisfaction and dissatisfaction. Barriers common to all groups should not be underestimated and a better understanding of the relationship between perceived barriers to accessing services and dissatisfaction with services is needed before the experiences of all carers can be improved. © 2014 The Authors. Health and Social Care in the Community published by John Wiley & Sons Ltd.

Investigating the Language of Engineering Education

NASA Astrophysics Data System (ADS)

Variawa, Chirag

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

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

ERIC Educational Resources Information Center

Hall, Jean P.; Parker, Kathy

2010-01-01

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

78 FR 5860 - Eighth Meeting: RTCA Next Gen Advisory Committee (NAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-28

...] Preliminary report to identify and mitigate barriers to implementing PBN. Issues associated with Implementing RNAV/RNP [cir] An open discussion by the Committee of Non-technical barriers of PBN procedures... NextGen. Cat Ex 2 Task Group [cir] Preliminary report on the recommendation for implementing new...

Overcoming Barriers to Engaging in College Academics

ERIC Educational Resources Information Center

Hensley, Lauren; Shaulskiy, Stephanie; Zircher, Andrew; Sanders, Megan

2015-01-01

Underprepared college students face transition issues that prevent full academic engagement. The written responses of 176 students in a learning-strategies course were used to develop a grounded model of overcoming barriers to academic engagement. Findings revealed contexts in which academic engagement involved high costs (i.e., effort, trade-off,…

Overcoming Barriers to the Sexual Expression of Women with Developmental Disabilities.

ERIC Educational Resources Information Center

Stinson, Jennifer; Christian, LeeAnn; Dotson, Lori Ann

2002-01-01

This article discusses barriers to sexual fulfillment faced by women with developmental disabilities, including: access to gynecological healthcare, limited choices regarding reproductive issues, lack of sex education, and prevailing negative stereotypes that affect the way women are viewed by others and the way they view themselves.…

Population Growth and Global Security: Toward an American Strategic Commitment.

ERIC Educational Resources Information Center

Mumford, Steven

1981-01-01

Addresses the world population problem by highlighting three crucial areas: the relationship between population growth control and national security issues, the role of American leadership in resolving the problem, and the barriers to effective action. One barrier discussed in detail is the Roman Catholic Church's stand on abortion and…

Sociocultural Paradoxes and Issues in E-Learning Use in Higher Education Africa

ERIC Educational Resources Information Center

Njenga, James Kariuki

2018-01-01

Sociocultural issues are major contributing factors in mass acceptance and effective use of technology. These issues are often perceived to contradict the benefits the technology brings about. E-learning use in higher education in Africa, as a technology, faces some sociocultural barriers that contradict its promise and benefits. This paper…

Reducing barriers associated with delivering health care services to migratory agricultural workers.

PubMed

Schmalzried, Hans D; Fallon, L Fleming

2012-01-01

Between one and two million migratory agricultural workers (MAWs), primarily from Mexico and Central America, leave their homes each year to plant, cultivate, harvest and pack fruits, vegetables, and nuts in the USA. While in the USA, most lack health insurance, a permanent residence, and a regular healthcare provider. Publications over the past two decades in the USA have reported that a majority of MAWs encounter barriers to receiving medical services. Migratory agricultural workers experience high rates of occupational illness and injury. Poor access to medical care continues to exacerbate health problems among members of this population related to their working environments. In most studies concerning healthcare access issues for this population, researchers collected their information from healthcare service providers; rarely have they included input from migratory agricultural workers. This study was different in that opinions about healthcare access issues were collected directly from MAWs. The primary purpose of this study was to describe issues related to barriers associated with the delivery of healthcare services to migratory agricultural workers. A secondary purpose was to suggest strategies for reducing these barriers. In this study, data from focus group sessions were used to develop a survey questionnaire. Four certified bilingual interpreters were trained to administer the questionnaire. A total of 157 usable questionnaires were returned from MAWs living in employer-provided camps in Northwest Ohio. The statistical analyses were primarily descriptive. The most significant barriers hampering access to medical services among the 157 respondents were cost (n=113; 72.0%), crop demands (n=102; 65.0%), the lack of an interpreter (n=98; 62.4%), travel distance (n=88; 56.1%) and transportation (n=82; 52.2%). Approximately half (n=82; 52.2%) said that they had access to transportation for traveling to a medical clinic. As a group, respondents were willing to travel an average of 29.1 km (18.1 miles) (range 0-129 km [0-80 miles]) to obtain medical services. Female heads of households had significantly less access to transportation compared with male heads of households (t=2.35; df=74; p<0.05). Three general categories of barriers to health care for MAWs surfaced in this study: (1) work environment; (2) migratory agricultural worker resources; and (3) healthcare clinic practices. Work environment issues relate mostly to the employers. Resources are barriers for MAWs because they are poor and have limited funds for the cost of transportation to clinics and the fees associated with accessing health care. Most of the barriers identified related to healthcare clinic practices. Some strategies to address healthcare clinic practice barriers were developed by the group conducting the study. By listening to what MAWs described as barriers to health care, providers can help improve access which can reduce the use of high cost hospital emergency room care.

Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies

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

Szybist, J. P.; Confer, K.

2012-09-11

Delphi Automotive Systems and ORNL established this CRADA to advance the commercialization potential of the homogeneous charge compression ignition (HCCI) advanced combustion strategy for gasoline engine platforms. HCCI combustion has been shown by others to produce high diesel-like efficiency on a gasoline engine platform while simultaneously producing low NOX and particulate matter emissions. However, the commercialization barriers that face HCCI combustion are significant, with requirements for a more active engine control system, likely with next-cycle closed-loop feedback control, and with advanced valve train technologies to enable negative valve overlap conditions. In the partnership between Delphi and ORNL, each organization broughtmore » a unique and complementary set of skills to the project. Delphi has made a number of breakthroughs with production-intent valve train technologies and controls in recent years to make a part time production-intent HCCI engine plausible. ORNL has extensive knowledge and expertise with HCCI combustion, and also has a versatile research engine with hydraulic valve actuation (HVA) that is useful for guiding production of a cam-based HCCI system. Partnering these knowledge bases and capabilities was essential towards making progress to better understand HCCI combustion and the commercialization barriers that it faces. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided guidance to ORNL regarding operational strategies to investigate on their single-cylinder research engine with HVA and data from their experimental multi-cylinder engine for modeling. ORNL provided single-cylinder engine data and modeling results.« less

Biomedical engineers and participation in judicial executions: capital punishment as a technical problem.

PubMed

Doyle, John

2007-01-01

This paper discusses the topic of judicial execution from the perspective of the intersection of the technological issues and the professional ethics issues. Although physicians are generally ethically forbidden from any involvement in the judicial execution process, this does not appear to be the case for engineering professionals. This creates an interesting but controversial opportunity for the engineering community (especially biomedical engineers) to improve the humaneness and reliability of the judicial execution process.

Barriers to telemedicine: survey of current users in acute care units.

PubMed

Rogove, Herbert J; McArthur, David; Demaerschalk, Bart M; Vespa, Paul M

2012-01-01

The present study of current telemedicine users is a unique attempt to understand the barriers and motivational factors related to the utilization of telemedicine. A survey of emergency and critical care remote presence telemedicine users was conducted to determine the factors that motivate and the barriers that impede the acceptance and maintenance of a robotic telemedicine (RTM) program. The majority of the survey users were in the Emergency Department or in the Intensive Care Unit. E-mail invitations were sent to 483 individuals representing 63 healthcare institutions and groups in North America and Europe. Respondents were directed to a Web-based survey. The survey consisted of 96 separate questions, addressing user familiarity and 5-point Likert scales, addressing issues spanning the conceptual and practical issues surrounding adoption of telemedicine. A total of 106 surveys were completed, representing an individual response rate of 21.9% but an institutional response rate of 60.3%. More than two-thirds of the respondents were physicians who participated in active RTM programs. Across seven different topics related to barriers to implementing RTM, the majority of all respondents indicated that cultural issues did not constitute meaningful hurdles, technological matters were generally favorable, and that most personnel were agreeable to both achieving the buy-in to start an RTM program and to maintaining RTM once started. However, respondents proclaimed that RTM's success was still hampered by licensing, credentialing, and malpractice protection, as well as costs, billing, and reimbursement issues. Achieving immediate patient access, overcoming service gaps, improving quality, providing clinical support, maintaining patient satisfaction, and adhering to practice guidelines were viewed as significant motives for RTM implementation. The leading applications of RTM included emergency response and consultation. The patients, physicians, nurses, nor hospital executives served as barriers to implementation. However, licensing, costs for technology, and reimbursement for RTM continue to impede progress.

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

PubMed

Pardridge, William M

2016-12-01

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

Approaches to formalization of the informal waste sector into municipal solid waste management systems in low- and middle-income countries: Review of barriers and success factors.

PubMed

Aparcana, Sandra

2017-03-01

The Municipal Solid Waste Management (MSWM) sector represents a major challenge for low-and middle-income countries due to significant environmental and socioeconomic issues involving rapid urbanization, their MSWM systems, and the existence of the informal waste sector. Recognizing its role, several countries have implemented various formalization measures, aiming to address the social problems linked to this sector. However, regardless of these initiatives, not all attempts at formalization have proved successful due to the existence of barriers preventing their implementation in the long term. Along with this, there is a frequent lack of knowledge or understanding regarding these barriers and the kind of measures that may enable formalization, thereby attaining a win-win situation for all the stakeholders involved. In this context, policy- and decision-makers in the public and private sectors are frequently confronted with the dilemma of finding workable approaches to formalization, adjusted to their particular MSWM contexts. Building on the review of frequently implemented approaches to formalization, including an analysis of the barriers to and enabling measures for formalization, this paper aims to address this gap by explaining to policy- and decision-makers, and to waste managers in the private sector, certain dynamics that can be observed and that should be taken into account when designing formalization strategies that are adapted to their particular socioeconomic and political-institutional context. This includes possible links between formalization approaches and barriers, the kinds of barriers that need to be removed, and enabling measures leading to successful formalization in the long term. This paper involved a literature review of common approaches to formalization, which were classified into three categories: (1) informal waste workers organized in associations or cooperatives; (2) organized in CBOs or MSEs; and (3) contracted as individual workers by the formal waste sector. This was followed by the identification and subsequent classification of measures for removing common barriers to formalization into five categories: policy/legal, institutional/organizational, technical, social, and economic/financial. The approaches to formalization, as well as the barrier categories, were validated through the assessment of twenty case studies of formalization. Building on the assessment, the paper discussed possible links between formalization approaches and barriers, the 'persistent' challenges that represent barriers to formalization, as well as key enabling factors improving the likelihood of successful formalization. Regardless of the type of approach adopted to formalization, the review identifies measures to remove barriers in all five categories, with a stronger link between the approaches 1 and 2 and the existence of measures in the policy, institutional, and financial categories. Regarding persistent barriers, the review identified ones arising from the absence of measures to address a particular issue before formalization or due to specific country- or sector-related conditions, and their interaction with the MSWM context. 75% of the case studies had persistent barriers in respect of policy/legal issues, 50% of institutional/organizational, 45% of financial/economic, and 40%, and 35% of social and technical issues respectively. This paper concludes that independently of the formalization approach, the lack of interventions or measures in any of the five categories of barriers may lead formalization initiatives to fail, as unaddressed barriers become 'persistent' after formalization is implemented. Furthermore, 'persistent barriers' may also appear due to unfavorable country-specific conditions. The success of a formalization initiative does not depend on a specific approach, but most likely on the inclusion of country-appropriate measures at the policy, economic and institutional levels. The empowerment of informal waste-workers is again confirmed as a further key success factor for their formalization. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Significance of Content Knowledge for Informal Reasoning regarding Socioscientific Issues: Applying Genetics Knowledge to Genetic Engineering Issues

ERIC Educational Resources Information Center

Sadler, Troy D.; Zeidler, Dana L.

2005-01-01

This study focused on informal reasoning regarding socioscientific issues. It sought to explore how content knowledge influenced the negotiation and resolution of contentious and complex scenarios based on genetic engineering. Two hundred and sixty-nine students drawn from undergraduate natural science and nonnatural science courses completed a…

Enhancing the diversity of the pediatrician workforce.

PubMed

Friedman, Aaron L

2007-04-01

This policy statement describes the key issues related to diversity within the pediatrician and health care workforce to identify barriers to enhancing diversity and offer policy recommendations to overcome these barriers in the future. The statement addresses topics such as health disparities, affirmative action, recent policy developments and reports on workforce diversity, and research on patient and provider diversity. It also broadens the discussion of diversity beyond the traditional realms of race and ethnicity to include cultural attributes that may have an effect on the quality of health care. Although workforce diversity is related to the provision of culturally effective pediatric care, it is a discrete issue that merits separate discussion and policy formulation. At the heart of this policy-driven action are multiorganizational and multispecialty collaborations designed to address substantive educational, financial, organizational, and other barriers to improved workforce diversity.

Status, Vision, and Challenges of an Intelligent Distributed Engine Control Architecture

NASA Technical Reports Server (NTRS)

Behbahani, Alireza; Culley, Dennis; Garg, Sanjay; Millar, Richard; Smith, Bert; Wood, Jim; Mahoney, Tim; Quinn, Ronald; Carpenter, Sheldon; Mailander, Bill;

IBC’s 23rd Annual Antibody Engineering, 10th Annual Antibody Therapeutics International Conferences and the 2012 Annual Meeting of The Antibody Society

PubMed Central

Klöhn, Peter-Christian; Wuellner, Ulrich; Zizlsperger, Nora; Zhou, Yu; Tavares, Daniel; Berger, Sven; Zettlitz, Kirstin A.; Proetzel, Gabriele; Yong, May; Begent, Richard H.J.; Reichert, Janice M

2013-01-01

The 23rd Annual Antibody Engineering, 10th Annual Antibody Therapeutics international conferences, and the 2012 Annual Meeting of The Antibody Society, organized by IBC Life Sciences with contributions from The Antibody Society and two Scientific Advisory Boards, were held December 3–6, 2012 in San Diego, CA. The meeting drew over 800 participants who attended sessions on a wide variety of topics relevant to antibody research and development. As a prelude to the main events, a pre-conference workshop held on December 2, 2012 focused on intellectual property issues that impact antibody engineering. The Antibody Engineering Conference was composed of six sessions held December 3–5, 2012: (1) From Receptor Biology to Therapy; (2) Antibodies in a Complex Environment; (3) Antibody Targeted CNS Therapy: Beyond the Blood Brain Barrier; (4) Deep Sequencing in B Cell Biology and Antibody Libraries; (5) Systems Medicine in the Development of Antibody Therapies/Systematic Validation of Novel Antibody Targets; and (6) Antibody Activity and Animal Models. The Antibody Therapeutics conference comprised four sessions held December 4–5, 2012: (1) Clinical and Preclinical Updates of Antibody-Drug Conjugates; (2) Multifunctional Antibodies and Antibody Combinations: Clinical Focus; (3) Development Status of Immunomodulatory Therapeutic Antibodies; and (4) Modulating the Half-Life of Antibody Therapeutics. The Antibody Society’s special session on applications for recording and sharing data based on GIATE was held on December 5, 2012, and the conferences concluded with two combined sessions on December 5–6, 2012: (1) Development Status of Early Stage Therapeutic Antibodies; and (2) Immunomodulatory Antibodies for Cancer Therapy. PMID:23575266

IBC's 23rd Annual Antibody Engineering, 10th Annual Antibody Therapeutics international conferences and the 2012 Annual Meeting of The Antibody Society: December 3-6, 2012, San Diego, CA.

PubMed

Klöhn, Peter-Christian; Wuellner, Ulrich; Zizlsperger, Nora; Zhou, Yu; Tavares, Daniel; Berger, Sven; Zettlitz, Kirstin A; Proetzel, Gabriele; Yong, May; Begent, Richard H J; Reichert, Janice M

2013-01-01

The 23rd Annual Antibody Engineering, 10th Annual Antibody Therapeutics international conferences, and the 2012 Annual Meeting of The Antibody Society, organized by IBC Life Sciences with contributions from The Antibody Society and two Scientific Advisory Boards, were held December 3-6, 2012 in San Diego, CA. The meeting drew over 800 participants who attended sessions on a wide variety of topics relevant to antibody research and development. As a prelude to the main events, a pre-conference workshop held on December 2, 2012 focused on intellectual property issues that impact antibody engineering. The Antibody Engineering Conference was composed of six sessions held December 3-5, 2012: (1) From Receptor Biology to Therapy; (2) Antibodies in a Complex Environment; (3) Antibody Targeted CNS Therapy: Beyond the Blood Brain Barrier; (4) Deep Sequencing in B Cell Biology and Antibody Libraries; (5) Systems Medicine in the Development of Antibody Therapies/Systematic Validation of Novel Antibody Targets; and (6) Antibody Activity and Animal Models. The Antibody Therapeutics conference comprised four sessions held December 4-5, 2012: (1) Clinical and Preclinical Updates of Antibody-Drug Conjugates; (2) Multifunctional Antibodies and Antibody Combinations: Clinical Focus; (3) Development Status of Immunomodulatory Therapeutic Antibodies; and (4) Modulating the Half-Life of Antibody Therapeutics. The Antibody Society's special session on applications for recording and sharing data based on GIATE was held on December 5, 2012, and the conferences concluded with two combined sessions on December 5-6, 2012: (1) Development Status of Early Stage Therapeutic Antibodies; and (2) Immunomodulatory Antibodies for Cancer Therapy.

Similarity tests of turbine vanes, effects of ceramic thermal barrier coatings

NASA Technical Reports Server (NTRS)

Gladden, H. J.

1980-01-01

The role of material thermal conductivity was analyzed for its effect on the thermal performance of air-cooled gas turbine components coated with a ceramic thermal barrier material when tested at reduced temperatures and pressures. It is shown that the thermal performance can be evaluated reliably at reduced gas and coolant conditions; however, thermal conductivity corrections are required for the data at reduced conditions. Corrections for a ceramic thermal barrier coated vane are significantly different than for an uncoated vane. Comparison of uncorrected test data, therefore, would show erroneously that the thermal barrier coating was ineffective. When thermal conductivity corrections are applied to the test data these data are then shown to be representative of engine data and also show that the thermal barrier coating increases the vane cooling effectiveness by 12.5 percent.

Mechanical Properties and Durability of Advanced Environmental Barrier Coatings in Calcium-Magnesium-Alumino-Silicate Environments

NASA Technical Reports Server (NTRS)

Miladinovich, Daniel S.; Zhu, Dongming

2011-01-01

Environmental barrier coatings are being developed and tested for use with SiC/SiC ceramic matrix composite (CMC) gas turbine engine components. Several oxide and silicate based compositons are being studied for use as top-coat and intermediate layers in a three or more layer environmental barrier coating system. Specifically, the room temperature Vickers-indentation-fracture-toughness testing and high-temperature stability reaction studies with Calcium Magnesium Alumino-Silicate (CMAS or "sand") are being conducted using advanced testing techniques such as high pressure burner rig tests as well as high heat flux laser tests.

Thermal barrier coating life prediction model development

NASA Technical Reports Server (NTRS)

Demasi, J. T.; Sheffler, K. D.

1986-01-01

The objective of this program is to establish a methodology to predict Thermal Barrier Coating (TBC) life on gas turbine engine components. The approach involves experimental life measurement coupled with analytical modeling of relevant degradation modes. The coating being studied is a flight qualified two layer system, designated PWA 264, consisting of a nominal ten mil layer of seven percent yttria partially stabilized zirconia plasma deposited over a nominal five mil layer of low pressure plasma deposited NiCoCrAlY. Thermal barrier coating degradation modes being investigated include: thermomechanical fatigue, oxidation, erosion, hot corrosion, and foreign object damage.

Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction

NASA Astrophysics Data System (ADS)

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

2014-07-01

The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.

Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory

PubMed Central

Marino, Kristen A.; Hinnemann, Berit; Carter, Emily A.

2011-01-01

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are comprised. This feat is accomplished in part via the deposition of a multilayer, multicomponent thermal barrier coating (TBC), which lasts up to approximately 40,000 h before failing. Understanding failure mechanisms can aid in designing circumvention strategies. We review results of quantum mechanics calculations used to test hypotheses about impurities that harm TBCs and transition metal (TM) additives that render TBCs more robust. In particular, we discovered a number of roles that Pt and early TMs such as Hf and Y additives play in extending the lifetime of TBCs. Fundamental insight into the nature of the bonding created by such additives and its effect on high-temperature evolution of the TBCs led to design principles that can be used to create materials for even more efficient engines.

Overcoming barriers to public understanding of climate change

NASA Astrophysics Data System (ADS)

Hayhoe, K.

2012-12-01

Humans are interfering with global climate, increasing the risk of serious consequences for human society and the natural environment. As the scientific evidence builds, however, so does the public controversy surrounding this issue. Why is climate change so contentious? What makes it so hard to comprehend? I argue that there is no single reason for this, but rather a perfect storm of multiple confounding factors; scientific, historical, ideological, psychological and even physiological in nature. Education—of both the messengers and the audience—can play a critical role in surmounting many of the common barriers to understanding, accepting, and acting this important issue.

Reproductive tract infections: Attitude and barriers among marginalized fisher women in Kerala, South India.

PubMed

Thomas, Manoj A; Narayan, Poornima

2017-04-01

Reproductive tract infections (RTIs) are the cause of severe gynecological and maternal morbidity in India. In marginalized communities, women persevere quietly when faced with a culturally sensitive health issue such as an RTI. To hypothesize on the differential health behavior and low levels of reported incidents among women living in marginalized communities, we undertake an exploratory study in a coastal fishermen community in South India. We identify barriers influencing decisions to seek curative and preventive medical care. Public health practitioners and social workers may find our recommendations relevant for addressing health issues in marginalized communities.

The 2017 Academic Emergency Medicine Consensus Conference: Catalyzing System Change Through Healthcare Simulation: Systems, Competency, and Outcomes.

PubMed

Bond, William F; Hui, Joshua; Fernandez, Rosemarie

2018-02-01

Over the past decade, emergency medicine (EM) took a lead role in healthcare simulation in part due to its demands for successful interprofessional and multidisciplinary collaboration, along with educational needs in a diverse array of cognitive and procedural skills. Simulation-based methodologies have the capacity to support training and research platforms that model micro-, meso-, and macrosystems of healthcare. To fully capitalize on the potential of simulation-based research to improve emergency healthcare delivery will require the application of rigorous methods from engineering, social science, and basic science disciplines. The Academic Emergency Medicine (AEM) Consensus Conference "Catalyzing System Change Through Healthcare Simulation: Systems, Competency, and Outcome" was conceived to foster discussion among experts in EM, engineering, and social sciences, focusing on key barriers and opportunities in simulation-based research. This executive summary describes the overall rationale for the conference, conference planning, and consensus-building approaches and outlines the focus of the eight breakout sessions. The consensus outcomes from each breakout session are summarized in proceedings papers published in this issue of Academic Emergency Medicine. Each paper provides an overview of methodologic and knowledge gaps in simulation research and identifies future research targets aimed at improving the safety and quality of healthcare. © 2017 by the Society for Academic Emergency Medicine.

Process-Property Relationship for Air Plasma-Sprayed Gadolinium Zirconate Coatings

NASA Astrophysics Data System (ADS)

Dwivedi, Gopal; Tan, Yang; Viswanathan, Vaishak; Sampath, Sanjay

2015-02-01

The continuous need of elevating operating temperature of gas turbine engines has introduced several challenges with the current state-of-the-art yttria-stabilized zirconia (YSZ)-based thermal barrier coatings (TBCs), requiring examination of new TBC material with high temperature phase stability, lower thermal conductivity, and resistance to environmental ash particles. Gadolinium zirconate (Gd2Zr2O7) (GDZ) has been shown to meet many of these requirements, and has, in fact, been successfully implemented in to engine components. However, several fundamental issues related to the process-ability, toughness, and microstructural differences for GDZ when compared to equivalent YSZ coating. This study seeks to critically address the process-structure-property correlations for plasma-sprayed GDZ coating subjected to controlled parametric exploration. Use of in-flight diagnostics coupled with in situ and ex situ coating property monitoring allows examination and comparison of the process-property interplay and the resultant differences between the two TBC compositions. The results indicate that it is feasible to retain material chemistry and fabricate relevant microstructures of interest with GDZ with concomitant performance advantages such as low conductivity, mechanical compliance, sintering resistance, and suppression of environmentally induced damage from ash particles. This study provides a framework for optimal design and manufacturing of emergent multi-layer and multi-material TBCs.