Effect of Layer-Graded Bond Coats on Edge Stress Concentration and Oxidation Behavior of Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

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

1998-01-01

Thermal barrier coating (TBC) durability is closely related to design, processing and microstructure of the coating Z, tn systems. Two important issues that must be considered during the design of a thermal barrier coating are thermal expansion and modulus mismatch between the substrate and the ceramic layer, and substrate oxidation. In many cases, both of these issues may be best addressed through the selection of an appropriate bond coat system. In this study, a low thermal expansion and layer-graded bond coat system, that consists of plasma-sprayed FeCoNiCrAl and FeCrAlY coatings, and a high velocity oxyfuel (HVOF) sprayed FeCrAlY coating, is developed to minimize the thermal stresses and provide oxidation resistance. The thermal expansion and oxidation behavior of the coating system are also characterized, and the strain isolation effect of the bond coat system is analyzed using the finite element method (FEM). Experiments and finite element results show that the layer-graded bond coat system possesses lower interfacial stresses. better strain isolation and excellent oxidation resistance. thus significantly improving the coating performance and durability.

Reducing chronic obstructive pulmonary disease readmissions: the role of the durable medical equipment provider.

PubMed

Messenger, Robert W

2012-01-01

Exacerbation and frequent rehospitalization in chronic obstructive pulmonary disease exacts a heavy toll on the US health care system. To address these issues, new initiatives have been proposed that are largely based on financial penalties to promote patient education and postdischarge care. However, as laudable as these goals are, improving outcomes in the chronic obstructive pulmonary disease population is more confounding than it may first appear. Chronic hypoxia, cognitive dysfunction, poor nutrition, and economic disadvantage are just a few of the challenges that require creative solutions and ongoing support. Case managers need to utilize all the potential products and services that can assist in improving outcomes for these patients. Durable medical equipment providers are often viewed as purveyors of medical equipment that offer little in the form of clinical support. However, in many cases these providers represent an overlooked resource that provides individualized, highly structured patient education and ongoing support programs. The challenge is in identifying those durable medical equipment providers that offer patients contemporary technology, and have both the resources and the commitment to provide patient support that is amenable to the goals of the hospital. This article reviews many of the confounding issues that contribute to the frequent rehospitalization of chronic obstructive pulmonary disease patients. Recommendations to improve patient education and oxygen therapy outcomes are provided along with suggestions to aid in the vetting of durable medical equipment providers. Acute care hospitals, long-term acute care hospitals, extended care facilities, integrated delivery systems. 1. An understanding of the complex variables that play in the management of chronic obstructive pulmonary disease will help the case manager to plan an effective course of care. 2. Case managers need to ensure that patients receive long-term oxygen technology that supports their lifestyle, promotes compliance, and ultimately achieves the desired outcomes. 3. Case managers must advocate for coordinated, ongoing patient education and stress the need for continuing reinforcement. 4. Case managers must ensure that patients under their care be matched with durable medical equipment providers that provide the technology and support that favors positive clinical outcomes.

77 FR 45242 - Revisions to Safety Standards for Durable Infant or Toddler Products: Infant Bath Seats and Full...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-31

... direction in the Danny Keysar Child Product Safety Notification Act to issue standards for durable infant or... not usually subject to CPSC's standards, such as child care facilities, family child care homes, and... standard issued under the Danny Keysar Child Product Safety Notification Act was based, the revision...

Effects of transition metal doping in Pt/M-TiO2 (M = V, Cr, and Nb) on oxygen reduction reaction activity

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

Kim, Jun-Hyuk; Kwon, Gihan; Lim, Hankwon

High cost and low durability are unresolved issues that impede the commercialization of proton exchange membrane fuel cells (PEMFCs). To overcome these limitations, Pt/TiO2 is reported as an alternative electrocatalyst for enhancing the oxygen reduction reaction (ORR) activity and/or durability of the system. However, the low electrical conductivity of TiO2 is a drawback that may be addressed by doping. To date, most reports related to Pt/doped-TiO2 focus on changes in the catalyst activity caused by the Pt-TiO2 interaction (metal -support interaction), instead of the effect of doping itself; doping is merely considered to enhance the electrical conductivity of TiO2. Inmore » this study, we discuss the variation in the electronic fine structure of Pt caused by the dopant, and its correlation with the ORR activity. More extensive contraction of the Pt lattice in Pt/M-TiO2 (M = V, Cr, and Nb) relative to Pt/TiO2 and Pt/C leads to outstanding ORR specific activity of Pt/M-TiO2. Notably, a fourfold increase of the specific activity is achieved with Pt/V-TiO2 relative to Pt/C. Furthermore, an accelerated durability test (ADT) of Pt/V-TiO2 demonstrates that this system is three times more durable than conventional Pt/C due to the metal support interaction.« less

76 FR 70227 - Medicare Program; End-Stage Renal Disease Prospective Payment System and Quality Incentive...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

...This final rule updates and makes certain revisions to the End-Stage Renal Disease (ESRD) prospective payment system (PPS) for calendar year (CY) 2012. We are also finalizing the interim final rule with comment period published on April 6, 2011, regarding the transition budget-neutrality adjustment under the ESRD PPS,. This final rule also sets forth requirements for the ESRD quality incentive program (QIP) for payment years (PYs) 2013 and 2014. In addition, this final rule revises the ambulance fee schedule regulations to conform to statutory changes. This final rule also revises the definition of durable medical equipment (DME) by adding a 3-year minimum lifetime requirement (MLR) that must be met by an item or device in order to be considered durable for the purpose of classifying the item under the Medicare benefit category for DME. Finally, this final rule implements certain provisions of section 154 of the Medicare Improvements for Patients and Providers Act of 2008 (MIPPA) related to the durable medical equipment, prosthetics, orthotics and supplies (DMEPOS) Competitive Acquisition Program and responds to comments received on an interim final rule published January 16, 2009, that implemented these provisions of MIPPA effective April 18, 2009. (See the Table of Contents for a listing of the specific issues addressed in this final rule.)

Building America Best Practices Series Volume 13: Energy Performance Techniques and Technologies: Preserving Historic Homes

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

Britt, Michelle L.; Baechler, Michael C.; Gilbride, Theresa L.

2011-03-01

This guide is a resource to help contractors renovate historic houses, while addressing issues such as building durability, indoor air quality, and occupant health, safety, and comfort. The best practices described in this document are based on the results of research and demonstration projects conducted by Building America’s research teams. Building America brings together the nation’s leading building scientists with over 300 production builders to develop, test, and apply innovative, energy-efficient construction practices. The guide is available for download from the DOE Building America website www.buildingamerica.gov.

Efficient Carbon-Based CsPbBr3 Inorganic Perovskite Solar Cells by Using Cu-Phthalocyanine as Hole Transport Material

NASA Astrophysics Data System (ADS)

Liu, Zhiyong; Sun, Bo; Liu, Xingyue; Han, Jinghui; Ye, Haibo; Shi, Tielin; Tang, Zirong; Liao, Guanglan

2018-06-01

Metal halide perovskite solar cells (PSCs) have attracted extensive research interest for next-generation solution-processed photovoltaic devices because of their high solar-to-electric power conversion efficiency (PCE) and low fabrication cost. Although the world's best PSC successfully achieves a considerable PCE of over 20% within a very limited timeframe after intensive efforts, the stability, high cost, and up-scaling of PSCs still remain issues. Recently, inorganic perovskite material, CsPbBr3, is emerging as a promising photo-sensitizer with excellent durability and thermal stability, but the efficiency is still embarrassing. In this work, we intend to address these issues by exploiting CsPbBr3 as light absorber, accompanied by using Cu-phthalocyanine (CuPc) as hole transport material (HTM) and carbon as counter electrode. The optimal device acquires a decent PCE of 6.21%, over 60% higher than those of the HTM-free devices. The systematic characterization and analysis reveal a more effective charge transfer process and a suppressed charge recombination in PSCs after introducing CuPc as hole transfer layer. More importantly, our devices exhibit an outstanding durability and a promising thermal stability, making it rather meaningful in future fabrication and application of PSCs.[Figure not available: see fulltext.

Improving the durability of a drag-reducing nanocoating by enhancing its mechanical stability.

PubMed

Cheng, Mengjiao; Zhang, Songsong; Dong, Hongyu; Han, Shihui; Wei, Hao; Shi, Feng

2015-02-25

The durability of superhydrophobic surface is a major problem to restrict industrial application of superhydrophobic materials from laboratory research, which can be attributed to a more general issue of mechanical stability for superhydrophobic coatings. Therefore, in order to handle this issue, we have fabricated a mechanically stable drag-reducing coating composed of elastic polydimethylsiloxane (PDMS) and hydrophobic copper particles on model ships, which can resist mechanical abrasion and has displayed a durable drag-reducing effect. In comparison with normal Au superhydrophobic coatings, the as-prepared PDMS/copper coatings showed durable drag reduction performance with a similar drag-reducing rate before (26%) and after (24%) mechanical abrasion. The mechanism for the enhanced mechanical stability and maintained drag reduction of the superhydrophobic surfaces was investigated through characterizations of surface morphology, surface wettability, and water adhesive force evaluation before and after abrasion. This is the first demonstration to realize the application of durable drag reduction by improving the mechanical stability of superhydrophobic coatings. We do believe that superhydrophobic surfaces with good resistance to mechanical abrasion or scratching may draw wide attention and gain significant applications with durable drag-reducing properties.

A review of polymer electrolyte membrane fuel cell durability test protocols

NASA Astrophysics Data System (ADS)

Yuan, Xiao-Zi; Li, Hui; Zhang, Shengsheng; Martin, Jonathan; Wang, Haijiang

Durability is one of the major barriers to polymer electrolyte membrane fuel cells (PEMFCs) being accepted as a commercially viable product. It is therefore important to understand their degradation phenomena and analyze degradation mechanisms from the component level to the cell and stack level so that novel component materials can be developed and novel designs for cells/stacks can be achieved to mitigate insufficient fuel cell durability. It is generally impractical and costly to operate a fuel cell under its normal conditions for several thousand hours, so accelerated test methods are preferred to facilitate rapid learning about key durability issues. Based on the US Department of Energy (DOE) and US Fuel Cell Council (USFCC) accelerated test protocols, as well as degradation tests performed by researchers and published in the literature, we review degradation test protocols at both component and cell/stack levels (driving cycles), aiming to gather the available information on accelerated test methods and degradation test protocols for PEMFCs, and thereby provide practitioners with a useful toolbox to study durability issues. These protocols help prevent the prolonged test periods and high costs associated with real lifetime tests, assess the performance and durability of PEMFC components, and ensure that the generated data can be compared.

Research on durability of a concrete continuous rigid frame bridge

NASA Astrophysics Data System (ADS)

Shi, Jing-xian; Ran, Zhi-hong

2018-05-01

The research on the durability of concrete structures has also become one of the most important topics for discussion at international academic institutions and conferences. This paper summarizes and reviews the current research on the durability of bridge structure of the bridge at the index relationship between state lifetime and structure durability. According to the actual situation in this paper on a continuous rigid frame bridge China of Yunnan as an example, this bridge was completed and opened to traffic during the first half of the year, a series of tests are carried out for the durability problem. It is found that all the indicators are good within six months after the bridge opened to traffic, but durability issues should be further studied in future monitoring efforts.

75 FR 73169 - Medicare Program; Payment Policies Under the Physician Fee Schedule and Other Revisions to Part B...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-29

...This final rule with comment period addresses changes to the physician fee schedule and other Medicare Part B payment policies to ensure that our payment systems are updated to reflect changes in medical practice and the relative value of services. It finalizes the calendar year (CY) 2010 interim relative value units (RVUs) and issues interim RVUs for new and revised procedure codes for CY 2011. It also addresses, implements, or discusses certain provisions of both the Affordable Care Act (ACA) and the Medicare Improvements for Patients and Providers Act of 2008 (MIPPA). In addition, this final rule with comment period discusses payments under the Ambulance Fee Schedule (AFS), the Ambulatory Surgical Center (ASC) payment system, and the Clinical Laboratory Fee Schedule (CLFS), payments to end-stage renal disease (ESRD) facilities, and payments for Part B drugs. Finally, this final rule with comment period also includes a discussion regarding the Chiropractic Services Demonstration program, the Competitive Bidding Program for durable medical equipment, prosthetics, orthotics, and supplies (CBP DMEPOS), and provider and supplier enrollment issues associated with air ambulances.

Fibrous composite material for textile heart valve design: in vitro assessment.

PubMed

Amri, Amna; Laroche, Gaetan; Chakfe, Nabil; Heim, Frederic

2018-04-17

With over 150,000 implantations performed over the world, transcatheter aortic valve replacement (TAVR) has become a surgical technique, which largely competes with open surgery valve replacement for an increasing number of patients. The success of the procedure favors the research toward synthetic valve leaflet materials as an alternative to biological tissues, whose durability remains unknown. In particular, fibrous constructions have recently proven to be durable in vivo over a 6-month period of time in animal sheep models. Exaggerated fibrotic tissue formation remains, however, a critical issue to be addressed. This work investigates the design of a composite fibrous construction combining a woven polyethylene terephthalate (PET) layer and a non-woven PET mat, which are expected to provide, respectively, strength and appropriate topography toward limited fibrotic tissue ingrowth. For this purpose, a specific equipment has been developed to produce non-woven PET mats made from fibers with small diameter. These mats were assembled with woven PET substrates using various assembling techniques in order to obtain hybrid fibrous constructions. The physical and mechanical properties of the obtained materials were assessed and valve samples were manufactured to be tested in vitro for hydrodynamic performances. The results show that the composite fibrous construction is characterized by properties suitable for the valve leaflet function, but the durability of the assembling is however limited under accelerated cyclic loading.

75 FR 26196 - Publication of OIG Updated Special Fraud Alert on Telemarketing by Durable Medical Equipment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

... Special Fraud Alert on Telemarketing by Durable Medical Equipment Suppliers AGENCY: Office of Inspector... Special Fraud Alert. Specifically, the Updated Special Fraud Alert addressed the statutory provision...) 205-0007. SUPPLEMENTARY INFORMATION: In our publication of the OIG Updated Special Fraud Alert on...

Key Durability Issues with Mullite-Based Environmental Barrier Coatings for Si-Based Ceramics

NASA Technical Reports Server (NTRS)

Lee, Kang N.

1999-01-01

Plasma-sprayed mullite (3Al2O3 central dot 2SiO2) and mullite/yttria-stabilized-zirconia (YSZ) dual layer coatings have been developed to protect silicon-based ceramics from environmental attack. Mullite-based coating systems show excellent durability in air. However, in combustion environments, corrosive species such as molten salt or water vapor penetrate through cracks in the coating and attack the Si-based ceramics along the interface, Thus modification of the coating system for enhanced crack-resistance is necessary for long-term durability in combustion environments. Other key durability issues include interfacial contamination and coating/substrate bonding. Interfacial contamination leads to enhanced oxidation and interfacial pore formation, while weak coating/substrate bonding leads to rapid attack of the interface by corrosive species, both of which can cause premature failure of the coating. Interfacial contamination can be minimized by limiting impurities in coating and substrate materials. The interface may be modified to improve the coating/substrate bond.

Key Durability Issues with Mullite-Based Environmental Barrier Coatings for Si-Based Ceramics

NASA Technical Reports Server (NTRS)

Lee, Kang N.

2000-01-01

Plasma-sprayed mullite (3Al2O3.2SiO2) and mullite/yttria-stabilized-zirconia (YSZ) dual layer coatings have been developed to protect silicon -based ceramics from environmental attack. Mullite-based coating systems show excellent durability in air. However, in combustion environments, corrosive species such as molten salt or water vapor penetrate through cracks in the coating and attack the Si-based ceramics along the interface. Thus the modification of the coating system for enhanced crack-resistance is necessary for long-term durability in combustion environments. Other key durability issues include interfacial contamination and coating/substrate bonding. Interfacial contamination leads to enhanced oxidation and interfacial pore formation, while a weak coating/substrate bonding leads to rapid attack of the interface by corrosive species, both of which can cause a premature failure of the coating. Interfacial contamination can be minimized by limiting impurities in coating and substrate materials. The interface may be modified to improve the coating/substrate bond.

NREL to Lead New Consortium to Improve Reliability and Performance of Solar

Science.gov Websites

for photovoltaics (PV) and lower the cost of electricity generated by solar power. The Durable Module the cost of electricity from photovoltaics." The Energy Department's Office of Energy Efficiency , DuraMat will address the substantial opportunities that exist for durable, high-performance, low-cost

Structures technology for a new generation of rotorcraft

NASA Technical Reports Server (NTRS)

Bartlett, Felton D., Jr.

1989-01-01

This paper presents an overview of structures research at the U. S. Army Aerostructures Directorate. The objectives of this research are to investigate, explore, and demonstrate emerging technologies that will provide lighter, safer, more survivable, and more cost-effective structures for rotorcraft in the 1990s and beyond. The emphasis of today's R&D is to contribute proven structures technology to the U. S. rotorcraft industry and Army aviation that directly impacts tomorrow's fleet readiness and mission capabilities. The primary contributor toward meeting these challenges is the development of high-strength and durable composites to minimize structural weight while maximizing cost effectiveness. Special aviation issues such as delamination of dynamic components, impact damage to thin skins, crashworthiness, and affordable manufacturing need to be resolved before the full potential of composites technology can be realized. To that end, this paper highlights research into composites structural integrity, crashworthiness, and materials applications which addresses these issues.

Proceedings of the NASA Workshop on Atomic Oxygen Effects. [low earth orbital environment

NASA Technical Reports Server (NTRS)

Brinza, David E. (Editor)

1987-01-01

A workshop was held to address the scientific issues concerning the effects of atomic oxygen on materials in the low Earth orbital (LEO) environment. The program included 18 invited speakers plus contributed posters covering topics such as LEO spaceflight experiments, interaction mechanisms, and atomic oxygen source development. Discussion sessions were also held to organize a test program to evaluate atomic oxygen exposure facilities. The key issues raised in the workshop were: (1) the need to develop a reliable predictive model of the effects of long-term exposure of materials to the LEO environment; (2) the ability of ground-based exposure facilities to provide useful data for development of durable materials; and (3) accurate determination of the composition of the LEO environment. These proceedings include the invited papers, the abstracts for the contributed posters, and an account of the test program discussion sessions.

Insight, working through, and practice: the role of procedural knowledge.

PubMed

Rosenblatt, Allan

2004-01-01

A conception of insight is proposed, based on a systems and information-processing framework and using current neuroscience concepts, as an integration of information that results in a new symbolization of experience with a significant change in self-image and a transformation of non-declarative procedural knowledge into declarative knowledge. Since procedural memory and knowledge, seen to include emotional and relationship issues, is slow to change, durable emotional and behavioral change often requires repeated practice, a need not explicitly addressed in standard psychoanalytic technique. Working through is thus seen as also encompassing nondynamic factors. The application of these ideas to therapeutic technique suggests possible therapeutic interventions beyond interpretation. An illustrative clinical vignette is presented.

Issues and concepts for making durable composites

Treesearch

Frederick A. Kamke; Jerrold E. Winandy

2008-01-01

Perhaps the greatest obstacle facing the acceptance of engineered wood composite products into new markets is the perceived lack of durability. Public perception is that particleboard and other wood-based composites fall apart when exposed to water. This paper will review the unique characteristics of wood based composites that make them more or less susceptible to...

Final Report - High Performance, Durable, Low Cost Membrane Electrode Assemblies for Transportation Applications

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

Steinbach, Andrew

2017-05-31

The primary project objective was development of improved polymer electrolyte membrane fuel cell (PEMFC) membrane electrode assemblies (MEAs) which address the key DOE barriers of performance, durability and cost. Additional project objectives were to address commercialization barriers specific to MEAs comprising 3M nanostructured thin film (NSTF) electrodes, including a larger-than-acceptable sensitivity to operating conditions, an unexplained loss of rated power capability with operating time, and slow break-in conditioning. Significant progress was made against each of these barriers, and most DOE 2020 targets were met or substantially approached.

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.

Turbine engine rotor health monitoring evaluation by means of finite element analyses and spin tests data

NASA Astrophysics Data System (ADS)

Abdul-Aziz, Ali; Woike, Mark R.; Clem, Michelle; Baaklini, George Y.

2014-04-01

Generally, rotating engine components undergo high centrifugal loading environment which subject them to various types of failure initiation mechanisms. Health monitoring of these components is a necessity and is often challenging to implement. This is primarily due to numerous factors including the presence of scattered loading conditions, flaw sizes, component geometry and materials properties, all which hinder the simplicity of applying health monitoring applications. This paper represents a summary work of combined experimental and analytical modeling that included data collection from a spin test experiment of a rotor disk addressing the aforementioned durability issues. It further covers presentation of results obtained from a finite element modeling study to characterize the structural durability of a cracked rotor as it relates to the experimental findings. The experimental data include blade tip clearance, blade tip timing and shaft displacement measurements. The tests were conducted at the NASA Glenn Research Center's Rotordynamics Laboratory, a high precision spin rig. The results are evaluated and examined to determine their significance on the development of a health monitoring system to pre-predict cracks and other anomalies and to assist in initiating a supplemental physics based fault prediction analytical model.

Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells.

PubMed

Miyake, Junpei; Taki, Ryunosuke; Mochizuki, Takashi; Shimizu, Ryo; Akiyama, Ryo; Uchida, Makoto; Miyatake, Kenji

2017-10-01

Proton exchange membrane fuel cells (PEMFCs) are promising devices for clean power generation in automotive, stationary, and portable applications. Perfluorosulfonic acid (PFSA) ionomers (for example, Nafion) have been the benchmark PEMs; however, several problems, including high gas permeability, low thermal stability, high production cost, and environmental incompatibility, limit the widespread dissemination of PEMFCs. It is believed that fluorine-free PEMs can potentially address all of these issues; however, none of these membranes have simultaneously met the criteria for both high performance (for example, proton conductivity) and durability (for example, mechanical and chemical stability). We present a polyphenylene-based PEM (SPP-QP) that fulfills the required properties for fuel cell applications. The newly designed PEM exhibits very high proton conductivity, excellent membrane flexibility, low gas permeability, and extremely high stability, with negligible degradation even under accelerated degradation conditions, which has never been achieved with existing fluorine-free PEMs. The polyphenylene PEM also exhibits reasonably high fuel cell performance, with excellent durability under practical conditions. This new PEM extends the limits of existing fluorine-free proton-conductive materials and will help to realize the next generation of PEMFCs via cost reduction as well as the performance improvement compared to the present PFSA-based PEMFC systems.

Emerging materials: what will durable materials look like in 2020?

Treesearch

Jerrold E. Winandy

2002-01-01

What materials will emerge from today’s research ideas to become the commonly accepted building products of 2020? What will durable materials look like in 2020? This paper attempts to address these questions by considering some current trends and then presenting a series of ideas of what the next 2 decades may hold from an emerging materials standpoint for North...

Medicare Program; End-Stage Renal Disease Prospective Payment System, Coverage and Payment for Renal Dialysis Services Furnished to Individuals With Acute Kidney Injury, End-Stage Renal Disease Quality Incentive Program, Durable Medical Equipment, Prosthetics, Orthotics and Supplies Competitive Bidding Program Bid Surety Bonds, State Licensure and Appeals Process for Breach of Contract Actions, Durable Medical Equipment, Prosthetics, Orthotics and Supplies Competitive Bidding Program and Fee Schedule Adjustments, Access to Care Issues for Durable Medical Equipment; and the Comprehensive End-Stage Renal Disease Care Model. Final rule.

PubMed

2016-11-04

This rule updates and makes revisions to the End-Stage Renal Disease (ESRD) Prospective Payment System (PPS) for calendar year 2017. It also finalizes policies for coverage and payment for renal dialysis services furnished by an ESRD facility to individuals with acute kidney injury. This rule also sets forth requirements for the ESRD Quality Incentive Program, including the inclusion of new quality measures beginning with payment year (PY) 2020 and provides updates to programmatic policies for the PY 2018 and PY 2019 ESRD QIP. This rule also implements statutory requirements for bid surety bonds and state licensure for the Durable Medical Equipment, Prosthetics, Orthotics, and Supplies (DMEPOS) Competitive Bidding Program (CBP). This rule also expands suppliers' appeal rights in the event of a breach of contract action taken by CMS, by revising the appeals regulation to extend the appeals process to all types of actions taken by CMS for a supplier's breach of contract, rather than limit an appeal for the termination of a competitive bidding contract. The rule also finalizes changes to the methodologies for adjusting fee schedule amounts for DMEPOS using information from CBPs and for submitting bids and establishing single payment amounts under the CBPs for certain groupings of similar items with different features to address price inversions. Final changes also are made to the method for establishing bid limits for items under the DMEPOS CBPs. In addition, this rule summarizes comments on the impacts of coordinating Medicare and Medicaid Durable Medical Equipment for dually eligible beneficiaries. Finally, this rule also summarizes comments received in response to a request for information related to the Comprehensive ESRD Care Model and future payment models affecting renal care.

Durability evaluation of reversible solid oxide cells

NASA Astrophysics Data System (ADS)

Zhang, Xiaoyu; O'Brien, James E.; O'Brien, Robert C.; Housley, Gregory K.

2013-11-01

An experimental investigation on the performance and durability of single solid oxide cells (SOCs) is under way at the Idaho National Laboratory. Reversible operation of SOCs includes electricity generation in the fuel cell mode and hydrogen generation in the electrolysis mode. Degradation is a more significant issue when operating SOCs in the electrolysis mode. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOCs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. Cells were obtained from four industrial partners. Cells from Ceramatec Inc. and Materials and Systems Research Inc. (MSRI) showed improved durability in electrolysis mode compared to previous stack tests. Cells from Saint Gobain Advanced Materials Inc. (St. Gobain) and SOFCPower Inc. demonstrated stable performance in the fuel cell mode, but rapid degradation in the electrolysis mode, especially at high current density. Electrolyte-electrode delamination was found to have a significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the electrode microstructure helped to mitigate degradation. Polarization scans and AC impedance measurements were performed during the tests to characterize cell performance and degradation.

Design and demonstration of a system for the deposition of atomic-oxygen durable coatings for reflective solar dynamic power system concentrators

NASA Technical Reports Server (NTRS)

Mcclure, Donald J.

1988-01-01

A system for the vacuum deposition of atomic-oxygen durable coatings for reflective solar dynamic power systems (SDPS) concentrators was designed and demonstrated. The design issues pertinent to SDPS were developed by the Government Aerospace Systems Division of the Harris Corporation and are described in NASA-CR-179489. Both design and demonstration phases have been completed. At the time of this report the deposition system was ready for coating of facets for SDPS concentrators. The materials issue relevant to the coating work were not entirely resolved. These issues can only be resolved when substrates which are comparable to those which will be used in flight hardware are available. The substrates available during the contract period were deficient in the areas of surface roughness and contamination. These issues are discussed more thoroughly in the body of the report.

76 FR 73025 - Medicare Program; Payment Policies Under the Physician Fee Schedule, Five-Year Review of Work...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

...This final rule with comment period addresses changes to the physician fee schedule and other Medicare Part B payment policies to ensure that our payment systems are updated to reflect changes in medical practice and the relative value of services. It also addresses, implements or discusses certain statutory provisions including provisions of the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively known as the Affordable Care Act) and the Medicare Improvements for Patients and Providers Act (MIPPA) of 2008. In addition, this final rule with comment period discusses payments for Part B drugs; Clinical Laboratory Fee Schedule: Signature on Requisition; Physician Quality Reporting System; the Electronic Prescribing (eRx) Incentive Program; the Physician Resource-Use Feedback Program and the value modifier; productivity adjustment for ambulatory surgical center payment system and the ambulance, clinical laboratory, and durable medical equipment prosthetics orthotics and supplies (DMEPOS) fee schedules; and other Part B related issues.

Progress in Laser Risk Reduction for 1 micron lasers at GSFC

NASA Technical Reports Server (NTRS)

Heaps, William S.

2007-01-01

In recent years, lasers have proven themselves to be invaluable to a variety of remote sensing applications. LIDAR techniques have been used to measure atmospheric aerosols and a variety of trace species, profile winds, and develop high resolution topographical maps. Often it would be of great advantage to make these measurements from an orbiting satellite. Unfortunately, the space environment is a challenging one for the high power lasers that would enable many LIDAR missions. Optical mounts must maintain precision alignment during and after launch. Outgassing materials in the vacuum of space lead to contamination of laser optics. Electronic components and optical materials must survive the space environment, including a vacuum atmosphere, thermal cycling, and radiation exposure. Laser designs must be lightweight, compact, and energy efficient. Many LIDAR applications require frequency conversion systems that have never been designed or tested for use in space. For the last six years the National Aeronautical and Space Administration (NASA) has undertaken a program specifically directed at addressing the durability and long term reliability issues that face space-borne lasers. The effort is shared between NASA Goddard Space Flight Center in Greenbelt, Maryland, and NASA Langley Research Center in Hampton, Virginia. This paper is an overview of the issues facing space-borne lasers and the efforts that Goddard has been pursuing to address them.

Design of piezoelectric transducer layer with electromagnetic shielding and high connection reliability

NASA Astrophysics Data System (ADS)

Qiu, Lei; Yuan, Shenfang; Shi, Xiaoling; Huang, Tianxiang

2012-07-01

Piezoelectric transducer (PZT) and Lamb wave based structural health monitoring (SHM) method have been widely studied for on-line SHM of high-performance structures. To monitor large-scale structures, a dense PZTs array is required. In order to improve the placement efficiency and reduce the wire burden of the PZTs array, the concept of the piezoelectric transducers layer (PSL) was proposed. The PSL consists of PZTs, a flexible interlayer with printed wires and signal input/output interface. For on-line SHM on real aircraft structures, there are two main issues on electromagnetic interference and connection reliability of the PSL. To address the issues, an electromagnetic shielding design method of the PSL to reduce spatial electromagnetic noise and crosstalk is proposed and a combined welding-cementation process based connection reliability design method is proposed to enhance the connection reliability between the PZTs and the flexible interlayer. Two experiments on electromagnetic interference suppression are performed to validate the shielding design of the PSL. The experimental results show that the amplitudes of the spatial electromagnetic noise and crosstalk output from the shielded PSL developed by this paper are - 15 dB and - 25 dB lower than those of the ordinary PSL, respectively. Other two experiments on temperature durability ( - 55 °C-80 °C ) and strength durability (160-1600μɛ, one million load cycles) are applied to the PSL to validate the connection reliability. The low repeatability errors (less than 3% and less than 5%, respectively) indicate that the developed PSL is of high connection reliability and long fatigue life.

Carbon Fiber Reinforced Ceramic Composites for Propulsion Applications

NASA Technical Reports Server (NTRS)

Freedman, Marc (Technical Monitor); Shivakumar, Kunigal N.

2003-01-01

Fiber reinforced ceramic composites are materials of choice for gas turbine engines because of their high thermal efficiency, thrust/weight ratio, and operating temperatures. However, the successful introduction of ceramic composites to hot structures is limited because of excessive cost of manufacturing, reproducibility, nonuniformity, and reliability. Intense research is going on around the world to address some of these issues. The proposed effort is to develop a comprehensive status report of the technology on processing, testing, failure mechanics, and environmental durability of carbon fiber reinforced ceramic composites through extensive literature study, vendor and end-user survey, visits to facilities doing this type of work, and interviews. Then develop a cooperative research plan between NASA GRC and NCA&T (Center for Composite Materials Research) for processing, testing, environmental protection, and evaluation of fiber reinforced ceramic composites.

Keeping up Appearances.

ERIC Educational Resources Information Center

Kennedy, Mike

2003-01-01

Discusses the issues colleges and universities face when choosing furniture for residence halls, including aesthetics, durability, student expectations, technology-friendliness, and encouragement of community. (EV)

Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells

PubMed Central

Miyake, Junpei; Taki, Ryunosuke; Mochizuki, Takashi; Shimizu, Ryo; Akiyama, Ryo; Uchida, Makoto; Miyatake, Kenji

2017-01-01

Proton exchange membrane fuel cells (PEMFCs) are promising devices for clean power generation in automotive, stationary, and portable applications. Perfluorosulfonic acid (PFSA) ionomers (for example, Nafion) have been the benchmark PEMs; however, several problems, including high gas permeability, low thermal stability, high production cost, and environmental incompatibility, limit the widespread dissemination of PEMFCs. It is believed that fluorine-free PEMs can potentially address all of these issues; however, none of these membranes have simultaneously met the criteria for both high performance (for example, proton conductivity) and durability (for example, mechanical and chemical stability). We present a polyphenylene-based PEM (SPP-QP) that fulfills the required properties for fuel cell applications. The newly designed PEM exhibits very high proton conductivity, excellent membrane flexibility, low gas permeability, and extremely high stability, with negligible degradation even under accelerated degradation conditions, which has never been achieved with existing fluorine-free PEMs. The polyphenylene PEM also exhibits reasonably high fuel cell performance, with excellent durability under practical conditions. This new PEM extends the limits of existing fluorine-free proton-conductive materials and will help to realize the next generation of PEMFCs via cost reduction as well as the performance improvement compared to the present PFSA-based PEMFC systems. PMID:29075671

Student Health Clinics.

ERIC Educational Resources Information Center

Jelliffe, James H.; Schipp, Michael K.

2002-01-01

Discusses important issues concerning the design of student health clinics, including convenient access, privacy and security, showers and sinks, durability and safety, and special considerations. (EV)

Cadmium Replacements for High Strength Steel Fasteners

DTIC Science & Technology

2005-03-01

w/o corr expos – strippability (MIL-S-5002D) [fstnr & pnl] • bend test after coating reapplication • stress durability (ISO 15330) @ 96 hr before...Immersion Paint Adhesion -----45 washersGalvanic Bi-Metallic Corrosion Strippability Stress Durability Fatigue COF Torque Tension Breakaway Torque Paint...Patrick Doyle (NAWCADLKE) • Selected Issues – Zn vs Cad as control – Grade 8 (150 ksi) vs 180 ksi or 220 ksi fasteners – Use of dry film lubricants

ACEE composite structures technology

NASA Technical Reports Server (NTRS)

Quinlivan, John T.; Wilson, Robert D.; Smith, Peter J.; Johnson, Ronald W.

1984-01-01

Toppics addressed include: advanced composites on Boeing commercial aircraft; composite wing durability; damage tolerance technology development; heavily loaded wing panel design; and pressure containment and damage tolerance in fuselages.

Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

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

Grin, A.; Lstiburek, J.

The goal of this research is to provide durable and long-term water management solutions using exterior insulating sheathing as part of the water management system. It is possible to tape or seal the joints in insulating sheathing to create a drainage plane and even an air control layer. There exists the material durability component of the tape as well as the system durability component being the taped insulating sheathing as the drainage plane. This measure guideline provides best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant issues weremore » discussed with the group, which are required to make taped insulating sheathing a simple, long-term, and durable drainage plane: horizontal joints should be limited or eliminated wherever possible; where a horizontal joint exists use superior materials; and frequent installation inspection and regular trade training are required to maintain proper installation.« less

Temporal course of vascular healing and neoatherosclerosis after implantation of durable- or biodegradable-polymer drug-eluting stents.

PubMed

Guagliumi, Giulio; Shimamura, Kunihiro; Sirbu, Vasile; Garbo, Roberto; Boccuzzi, Giacomo; Vassileva, Angelina; Valsecchi, Orazio; Fiocca, Luigi; Canova, Paolo; Colombo, Francesco; Tensol Rodriguez Pereira, Gabriel; Nakamura, Daisuke; Attizzani, Guilherme F; Cereda, Alberto; Satogami, Keisuke; De Luca, Leonardo; Saia, Francesco; Capodanno, Davide

2018-05-19

Delayed healing and endothelial dysfunction may occur with drug-eluting stents (DES), promoting accelerated infiltration of lipids in the neointima and development of neoatherosclerosis (NA). Pathology data suggest durable polymer (DP) of DES to play a major role in this process. Whether biodegradable polymer (BP) may address these issues is uncertain. We compared in vivo vessel healing and NA of current generation BP- or DP-DES using serial optical coherence tomography (OCT) assessments. Ninety patients with multivessel coronary artery disease were randomized 1:1 to BP everolimus-eluting stents (EES, Synergy) or DP zotarolimus-eluting stents (ZES, Resolute Integrity). Co-primary endpoints were the maximum length of uncovered struts at 3 months (powered for non-inferiority) and the percentage of patients presenting with frames of NA at 18 months (powered for superiority) as measured by OCT. The maximum length of uncovered struts at 3 months was 10 ± 8 mm in the BP-EES group and 11 ± 7 mm in the DP-ZES group (mean difference -1 mm; upper 97.5% confidence interval +2 mm; P = 0.05 for non-inferiority; P = 0.45 for superiority). The percentage of patients presenting with frames of NA at 18 months was low and similar between BP-EES and DP-ZES groups (11.6% vs. 15.9%; P = 0.56). There was no stent thrombosis in both groups at 24 months. BP-EES and DP-ZES showed a similar healing response at 3 months and a low incidence of NA at 18 months. Biocompatible polymers, regardless of whether they are durable or biodegradable, may favourably impact the long-term vascular response to current-generation DES.

Low Earth orbit atomic oxygen simulation for durability evaluation of solar reflector surfaces

NASA Technical Reports Server (NTRS)

Degroh, Kim K.; Banks, Bruce A.

1992-01-01

To evaluate the performance and durability of solar reflector surfaces in the atomic oxygen environment typical of low Earth orbit (LEO), one must expose the reflector surface either directly to LEO or to ground-laboratory atomic oxygen environments. Although actual LEO exposures are most desired, such opportunities are typically scarce, expensive, and of limited duration. As a result, ground-laboratory exposures must be relied upon as the most practical long-term durability evaluation technique. Plasma ashers are widely used as LEO simulation facilities by producing atomic oxygen environments for durability evaluation of potential spacecraft materials. Atomic oxygen arrival differs between ground and space exposure in that plasma asher exposure produces isotropic arrival and space solar tracking produces sweeping arrival. Differences in initial impact reaction probability occur, dependent upon the energy and species existing in these environments. Due to the variations in ground-laboratory and space atomic oxygen, quantification of in-space performance based on plasma asher testing is not straightforward. The various atomic oxygen interactions that can occur with reflector surfaces, such as undercutting in organic substrates at protective coating defect sites, ground-laboratory techniques recommended for evaluating the atomic oxygen durability of reflectors based on asher exposures, and computational techniques which make use of ground-laboratory atomic oxygen exposure to predict in-space LEO durability are addressed.

Moisture Durability with Vapor-Permeable Insulating Sheathing

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

Lepage, R.; Lstiburek, J.

2013-09-01

Exterior sheathing insulation is an effective strategy in increasing the overall R-value of wall assemblies; other benefits include decreasing the effects of thermal bridging and increasing the moisture durability of the built assembly. Vapor-permeable exterior insulation, such as mineral board or expanded polystyrene foam, are one such product that may be used to achieve these benefits. However,uncertainty exists on the effects of inward driven moisture and the interaction of increased sheathing temperatures on the moisture durability of the edifice. To address these concerns, Building Science Corporation (BSC) conducted a series of hygrothermal models for cities representing a range of differentmore » climate zones. This report describes the research project, key research questions, and theprocedures utilized to analyse the problems.« less

Moisture Durability with Vapor-Permeable Insulating Sheathing

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

Lepage, R.; Lstiburek, J.

2013-09-01

Exterior sheathing insulation is an effective strategy in increasing the overall R-value of wall assemblies; other benefits include decreasing the effects of thermal bridging and increasing the moisture durability of the built assembly. Vapor-permeable exterior insulation, such as mineral board or expanded polystyrene foam, are one such product that may be used to achieve these benefits. However, uncertainty exists on the effects of inward driven moisture and the interaction of increased sheathing temperatures on the moisture durability of the edifice. To address these concerns, Building Science Corporation (BSC) conducted a series of hygrothermal models for cities representing a range ofmore » different climate zones. This report describes the research project, key research questions, and the procedures utilized to analyse the problems.« less

Laser Ignition Technology for Bi-Propellant Rocket Engine Applications

NASA Technical Reports Server (NTRS)

Thomas, Matt; Bossard, John; Early, Jim; Trinh, Huu; Dennis, Jay; Turner, James (Technical Monitor)

2001-01-01

This viewgraph presentation gives an overview of laser ignition technology for bipropellant rocket engines applications. The objectives of this project include: (1) the selection test chambers and flows; (2) definition of the laser ignition setup; (3) pulse format optimization; (4) fiber optic coupled laser ignition system analysis; and (5) chamber integration issues definition. The testing concludes that rocket combustion chamber laser ignition is imminent. Support technologies (multiplexing, window durability/cleaning, and fiber optic durability) are feasible.

Medicare program; competitive acquisition for certain durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) and other issues. Final rule.

PubMed

2007-04-10

This final rule establishes competitive bidding programs for certain Medicare Part B covered items of durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) throughout the United States in accordance with sections 1847(a) and (b) of the Social Security Act. These competitive bidding programs, which will be phased in over several years, utilize bids submitted by DMEPOS suppliers to establish applicable payment amounts under Medicare Part B.

Aligned carbon nanotube based ultrasonic microtransducers for durability monitoring in civil engineering.

PubMed

Lebental, B; Chainais, P; Chenevier, P; Chevalier, N; Delevoye, E; Fabbri, J-M; Nicoletti, S; Renaux, P; Ghis, A

2011-09-30

Structural health monitoring of porous materials such as concrete is becoming a major component in our resource-limited economy, as it conditions durable exploitation of existing facilities. Durability in porous materials depends on nanoscale features which need to be monitored in situ with nanometric resolution. To address this problem, we put forward an approach based on the development of a new nanosensor, namely a capacitive micrometric ultrasonic transducer whose vibrating membrane is made of aligned single-walled carbon nanotubes (SWNT). Such sensors are meant to be embedded in large numbers within a porous material in order to provide information on its durability by monitoring in situ neighboring individual micropores. In the present paper, we report on the feasibility of the key building block of the proposed sensor: we have fabricated well-aligned, ultra-thin, dense SWNT membranes that show above-nanometer amplitudes of vibration over a large range of frequencies spanning from 100 kHz to 5 MHz.

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.

High Performance Nano-Crystalline Oxide Fuel Cell Materials. Defects, Structures, Interfaces, Transport, and Electrochemistry

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

Barnett, Scott; Poeppelmeier, Ken; Mason, Tom

This project addresses fundamental materials challenges in solid oxide electrochemical cells, devices that have a broad range of important energy applications. Although nano-scale mixed ionically and electronically conducting (MIEC) materials provide an important opportunity to improve performance and reduce device operating temperature, durability issues threaten to limit their utility and have remained largely unexplored. Our work has focused on both (1) understanding the fundamental processes related to oxygen transport and surface-vapor reactions in nano-scale MIEC materials, and (2) determining and understanding the key factors that control their long-term stability. Furthermore, materials stability has been explored under the “extreme” conditions encounteredmore » in many solid oxide cell applications, i.e, very high or very low effective oxygen pressures, and high current density.« less

Wire Wise.

ERIC Educational Resources Information Center

Swanquist, Barry

1998-01-01

Discusses how today's technology is encouraging schools to invest in furnishings that are adaptable to computer use and telecommunications access. Explores issues concerning modularity, wiring management, ergonomics, durability, price, and aesthetics. (GR)

Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2000-01-01

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

Synthesis of ‘reactive’ and covalent polymeric multilayer coatings with durable superoleophobic and superoleophilic properties under water† †Electronic supplementary information (ESI) available: Fig. S1–S15 accounting the growth of NC with and without the LbL deposition process, detailed comparisons of the multilayers of BPEI and NC, the change in the underwater oil-wettability with increasing deposition cycles of NC, the change in the optical transparency of the multilayers under water, the underwater oil-wettability of various model oils on post-modified multilayers of NC, bouncing of oil droplets underwater, the change in adhesive interactions with LbL deposition of NC, beading and wetting of oil droplets on post-modified multilayers under water, the effect of heating, freezing, and chemical and physical insults on the oil-wettability of the multilayers under water, LbL coating of various substrates, the guided transfer of oil droplets under water and the cleaning of oil using superoleophilic cotton under water. See DOI: 10.1039/c7sc01055a Click here for additional data file.

PubMed Central

Parbat, Dibyangana

2017-01-01

Bioinspired underwater super-oil-wettability (superoleophilic/superoleophobic) properties are emerging as a potential avenue for developing smart materials for addressing issues related to healthcare, environment, energy, etc. However, the inherent poor durability of the materials that are mostly developed using polymeric hydrogel, metal oxide coatings and electrostatic multilayers often challenges the application of these wettability properties in practical scenarios. Here, ‘amine-reactive’ polymeric multilayers of nano-complex were developed to fabricate ‘internal’ underwater superoleophobic/superoleophilic coatings with impeccable physical/chemical durability. This allows the super-wetting properties to exist beyond the surface of the material and remain intact even after severe physical damage including erosion of the material and continuous exposure to an artificial-marine environment for more than 80 days. Moreover, this current design allowed for independent revalidation of some key hypotheses with direct experimental demonstrations, and provided a basis to develop highly durable super-oil-wettability properties under water. It is believed that this contemporary study will make a worthwhile contribution on developing multifunctional materials for widespread practical applications by exploiting these super-oil-wetting properties. PMID:28989639

A critical study of the role of the surface oxide layer in titanium bonding

NASA Technical Reports Server (NTRS)

Dias, S.; Wightman, J. P.

1983-01-01

Scanning electron microscope/X-ray photoelectron spectroscopy (SEM/XPS) analysis of fractured adhesively bonded Ti 6-4 samples is discussed. The text adhesives incuded NR 056X polyimide, polypheylquinoxaline (PPQ), and LARC-13 polyimide. Differentiation between cohesive and interfacial failure was based on the absence of presence of a Ti 2p XPS photopeak. In addition, the surface oxide layer on Ti-(6A1-4V) adherends is characterized and bond strength and durability are addressed. Bond durability in various environmental conditions is discussed.

Post discharge issues identified by a call-back program: identifying improvement opportunities.

PubMed

Ojeda, Patricia I; Kara, Areeba

2017-12-01

The period following discharge from the hospital is one of heightened vulnerability. Discharge instructions serve as a guide during this transition. Yet, clinicians receive little feedback on the quality of this document that ties into the patients' experience. We reviewed the issues voiced by discharged patients via a call-back program and compared them to the discharge instructions they had received. At our institution, patients receive an automated call forty-eight hours following discharge inquiring about progress. If indicated by the response to the call, they are directed to a nurse who assists with problem solving. We reviewed the nursing documentation of these encounters for a period of nine months. The issues voiced were grouped into five categories: communication, medications, durable medical equipment/therapies, follow up and new or ongoing symptoms. The discharge instructions given to each patient were reviewed. We retrieved data on the number of discharges from each specialty from the hospital over the same period. A total of 592 patients voiced 685 issues. The numbers of patients discharged from medical or surgical services identified as having issues via the call-back line paralleled the proportions discharged from medical and surgical services from the hospital during the same period. Nearly a quarter of the issues discussed had been addressed in the discharge instructions. The most common category of issues was related to communication deficits including missing or incomplete information which made it difficult for the patient to enact or understand the plan of care. Medication prescription related issues were the next most common. Resource barriers and questions surrounding medications were often unaddressed. Post discharge issues affect patients discharged from all services equally. Data from call back programs may provide actionable targets for improvement, identify the inpatient team's 'blind spots' and be used to provide feedback to clinicians.

Long-Term benefits of stabilizing soil subgrades.

DOT National Transportation Integrated Search

2002-06-01

The main intent of this study was an attempt to address questions concerning bearing strengths, longevity, durability, structural credit, economics, and performance of pavements resting on soil subgrades mixed with chemical admixtures. In-depth field...

TTK Chitra tilting disc heart valve model TC2: An assessment of fatigue life and durability.

PubMed

Subhash, N N; Rajeev, Adathala; Sujesh, Sreedharan; Muraleedharan, C V

2017-08-01

Average age group of heart valve replacement in India and most of the Third World countries is below 30 years. Hence, the valve for such patients need to be designed to have a service life of 50 years or more which corresponds to 2000 million cycles of operation. The purpose of this study was to assess the structural performance of the TTK Chitra tilting disc heart valve model TC2 and thereby address its durability. The TC2 model tilting disc heart valves were assessed to evaluate the risks connected with potential structural failure modes. To be more specific, the studies covered the finite element analysis-based fatigue life prediction and accelerated durability testing of the tilting disc heart valves for nine different valve sizes. First, finite element analysis-based fatigue life prediction showed that all nine valve sizes were in the infinite life region. Second, accelerated durability test showed that all nine valve sizes remained functional for 400 million cycles under experimental conditions. The study ensures the continued function of TC2 model tilting disc heart valves over duration in excess of 50 years. The results imply that the TC2 model valve designs are structurally safe, reliable and durable.

Degradation mechanisms and accelerated testing in PEM fuel cells

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

Borup, Rodney L; Mukundan, Rangachary

2010-01-01

The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. Although there has been recent progress in improving durability, further improvements are needed to meet the commercialization targets. Past improvements have largely been made possible because of the fundamental understanding of the underlying degradation mechanisms. By investigating component and cell degradation modes; defining the fundamental degradation mechanisms of components and component interactions new materials can be designed to improve durability. Various factors have been shown to affect the useful life of PEM fuel cells. Other issues arise frommore » component optimization. Operational conditions (such as impurities in either the fuel and oxidant stream), cell environment, temperature (including subfreezing exposure), pressure, current, voltage, etc.; or transient versus continuous operation, including start-up and shutdown procedures, represent other factors that can affect cell performance and durability. The need for Accelerated Stress Tests (ASTs) can be quickly understood given the target lives for fuel cell systems: 5000 hours ({approx} 7 months) for automotive, and 40,000 hrs ({approx} 4.6 years) for stationary systems. Thus testing methods that enable more rapid screening of individual components to determine their durability characteristics, such as off-line environmental testing, are needed for evaluating new component durability in a reasonable turn-around time. This allows proposed improvements in a component to be evaluated rapidly and independently, subsequently allowing rapid advancement in PEM fuel cell durability. These tests are also crucial to developers in order to make sure that they do not sacrifice durability while making improvements in costs (e.g. lower platinum group metal [PGM] loading) and performance (e.g. thinner membrane or a GDL with better water management properties). To achieve a deeper understanding and improve PEM fuel cell durability LANL is conducting research to better define fuel cell component degradation mechanisms and correlate AST measurements to component in 'real-world' situations.« less

Social acceptability and durability of two different house screening interventions against exposure to malaria vectors, Plasmodium falciparum infection, and anemia in children in the Gambia, West Africa.

PubMed

Kirby, Matthew J; Bah, Pateh; Jones, Caroline O H; Kelly, Ann H; Jasseh, Momodou; Lindsay, Steve W

2010-11-01

The social acceptability and durability of two house screening interventions were addressed using focus group discussions, questionnaires, indoor climate measurements, and durability surveys. Participants recognized that screening stopped mosquitoes (79-96%) and other insects (86-98%) entering their houses. These and other benefits were appreciated by significantly more recipients of full screening than users of screened ceilings. Full screened houses were 0.26°C hotter at night (P = 0.05) than houses with screened ceilings and 0.51°C (P < 0.001) hotter than houses with no screening (28.43°C), though only 9% of full screened house users and 17% of screened ceiling users complained about the heat. Although 71% of screened doors and 85% of ceilings had suffered some damage after 12 months, the average number of holes of any size was < 5 for doors and < 7 for ceilings. In conclusion, house screening is a well-appreciated and durable vector control tool.

Social Acceptability and Durability of Two Different House Screening Interventions against Exposure to Malaria Vectors, Plasmodium falciparum Infection, and Anemia in Children in The Gambia, West Africa

PubMed Central

Kirby, Matthew J.; Bah, Pateh; Jones, Caroline O. H.; Kelly, Ann H.; Jasseh, Momodou; Lindsay, Steve W.

2010-01-01

The social acceptability and durability of two house screening interventions were addressed using focus group discussions, questionnaires, indoor climate measurements, and durability surveys. Participants recognized that screening stopped mosquitoes (79–96%) and other insects (86–98%) entering their houses. These and other benefits were appreciated by significantly more recipients of full screening than users of screened ceilings. Full screened houses were 0.26°C hotter at night (P = 0.05) than houses with screened ceilings and 0.51°C (P < 0.001) hotter than houses with no screening (28.43°C), though only 9% of full screened house users and 17% of screened ceiling users complained about the heat. Although 71% of screened doors and 85% of ceilings had suffered some damage after 12 months, the average number of holes of any size was < 5 for doors and < 7 for ceilings. In conclusion, house screening is a well-appreciated and durable vector control tool. PMID:21036822

Directable weathering of concave rock using curvature estimation.

PubMed

Jones, Michael D; Farley, McKay; Butler, Joseph; Beardall, Matthew

2010-01-01

We address the problem of directable weathering of exposed concave rock for use in computer-generated animation or games. Previous weathering models that admit concave surfaces are computationally inefficient and difficult to control. In nature, the spheroidal and cavernous weathering rates depend on the surface curvature. Spheroidal weathering is fastest in areas with large positive mean curvature and cavernous weathering is fastest in areas with large negative mean curvature. We simulate both processes using an approximation of mean curvature on a voxel grid. Both weathering rates are also influenced by rock durability. The user controls rock durability by editing a durability graph before and during weathering simulation. Simulations of rockfall and colluvium deposition further improve realism. The profile of the final weathered rock matches the shape of the durability graph up to the effects of weathering and colluvium deposition. We demonstrate the top-down directability and visual plausibility of the resulting model through a series of screenshots and rendered images. The results include the weathering of a cube into a sphere and of a sheltered inside corner into a cavern as predicted by the underlying geomorphological models.

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

NASA Technical Reports Server (NTRS)

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

2010-01-01

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

A longitudinal investigation into the functional and physical durability of insoles used for the preventive management of neuropathic diabetic feet.

PubMed

Paton, Joanne S; Stenhouse, Elizabeth; Bruce, Graham; Jones, Ray

2014-01-01

Insoles are commonly used to assist in the prevention of diabetic neuropathic foot ulceration. Insole replacement is often triggered only when foot lesions deteriorate, an indicator that functional performance is comprised and patients are exposed to unnecessary ulcer risk. We investigated the durability of insoles used for ulcer prevention in neuropathic diabetic feet over 12 months. Sixty neuropathic individuals with diabetes were provided with insoles and footwear. Insole durability over 12 months was evaluated using an in-shoe pressure measurement device and through repeated measurement of material depth at the first metatarsal head and the heel seat. Analysis of variance was performed to assess change across time (at issue, 6 months, and 12 months). Analyses were conducted using all available data (n = 43) and compliant data (n = 18). No significant difference was found in the reduction of mean peak pressure tested across time (P < .05). For both sites, significant differences in insole depth were identified between issue and 6 months and between issue and 12 months but not between 6 and 12 months (P < .05). Most insole compression occurred during the initial 6 months. Visual material compression does not seem to be a reliable indicator of insole usefulness. Frequency of insole replacement is best informed by a functional review of effect determined using an in-shoe pressure measurement system. These results suggest that insoles for diabetic neuropathic patients can be effective in maintaining peak pressure reduction for 12 months regardless of wear frequency.

Durability assessment of prefabricated bridge elements and systems.

DOT National Transportation Integrated Search

2015-02-01

This study aims to address some of the concerns related to implementation of prefabricated bridge elements and systems (PBES) : and accelerated bridge construction (ABC) in Maryland, where some barriers included assessment of the quality and durabili...

Durability and robustness of tubular molten carbonate fuel cells

NASA Astrophysics Data System (ADS)

Kawase, Makoto

2017-12-01

One anticipated system for high-efficiency power generation is the combination of syngas from gasification and high temperature fuel cells. The system uses a pressurization system, and it takes into account poisoning by impurities in the syngas. The durability and robustness of the fuel cells used in this system are an important issue for commercial applications. This study focuses on tubular molten carbonate fuel cells (MCFCs), which seem to be relatively durable compared with conventional planar-type MCFCs. Various power generation tests were performed in order to evaluate the durability and robustness of the tubular MCFCs. After continuous generation tests at 0.3 MPa, the cell voltage decay rate was found to be 0.8 mV/1000 h at 0.2 A/cm2. Moreover, it was found to be possible to generate power stably with fuel gas containing 20 ppm H2S. When the differential pressure between the anode and cathode was set to 0.1 MPa, the power generation tests were performed without gas leakage. In addition, starting (heating) and stopping (cooling) could be done in a short period, meaning that the cold start/stop characteristics are favorable. Therefore, the tubular MCFC was confirmed to have the durability necessary for a power generation system.

Linear Cracking in Bridge Decks

DOT National Transportation Integrated Search

2018-03-01

Concrete cracking in bridge decks remains an important issue relative to deck durability. Cracks can allow increased penetration of chlorides, which can result in premature corrosion of the reinforcing steel and subsequent spalling of the concrete de...

Improving Urban Student Achievement Through Early Childhood Reform: What State Policymakers Can Do. Issue Paper. Early Childhood Reform Issue Paper

ERIC Educational Resources Information Center

Kagan, Sharon Lynn

2004-01-01

For over four decades, American policymakers have focused their attention on readying young children for school. Despite noble policy efforts, durable investments and a persistent belief in the ability of early childhood education to offset social inequities, significant challenges exist for America's urban young children as they enter school.…

Super Heavy-Duty Door Hardware.

ERIC Educational Resources Information Center

Fickes, Michael

2000-01-01

Discusses the new generation of durable school-door hardware and innovations that can resist everyday abuse. Concluding comments address cross-corridor door innovations that can help doorways more easily accommodate the passage of oversized items, and classroom door locking systems. (GR)

Medicare program; payment policies under the physician fee schedule, five-year review of work relative value units, clinical laboratory fee schedule: signature on requisition, and other revisions to part B for CY 2012. Final rule with comment period.

PubMed

2011-11-28

This final rule with comment period addresses changes to the physician fee schedule and other Medicare Part B payment policies to ensure that our payment systems are updated to reflect changes in medical practice and the relative value of services. It also addresses, implements or discusses certain statutory provisions including provisions of the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively known as the Affordable Care Act) and the Medicare Improvements for Patients and Providers Act (MIPPA) of 2008. In addition, this final rule with comment period discusses payments for Part B drugs; Clinical Laboratory Fee Schedule: Signature on Requisition; Physician Quality Reporting System; the Electronic Prescribing (eRx) Incentive Program; the Physician Resource-Use Feedback Program and the value modifier; productivity adjustment for ambulatory surgical center payment system and the ambulance, clinical laboratory, and durable medical equipment prosthetics orthotics and supplies (DMEPOS) fee schedules; and other Part B related issues.

Metallurgical effects on chloride ion corrosion threshold of steel in concrete.

DOT National Transportation Integrated Search

2001-11-30

The chloride-induced corrosion of reinforcing steel bars (rebar) in concrete seriously limits durability of reinforcing concrete structures. This investigation examines key issues in pitting corrosion and chloride corrosion threshold of rebar in alka...

0-6723 : development of rapid, cement-based repair materials for transportation structures.

DOT National Transportation Integrated Search

2014-08-01

The state of Texas has been plagued by various : durability-related issues in recent years, : including deterioration from alkali-silica : reaction, delayed ettringite formation, corrosion : of reinforcing steel, volume changes (plastic : shrinkage, ...

Issues and Consequences of Atomic Oxygen Undercutting of Protected Polymers in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Banks, Bruce A.; Snyder, Aaron; Miller, Sharon K.; Demko, Rikako

2002-01-01

Hydrocarbon based polymers that are exposed to atomic oxygen in low Earth orbit are slowly oxidized which results in recession of their surface. Atomic oxygen protective coatings have been developed which are both durable to atomic oxygen and effective in protecting underlying polymers. However, scratches, pin window defects, polymer surface roughness and protective coating layer configuration can result in erosion and potential failure of protected thin polymer films even though the coatings are themselves atomic oxygen durable. This paper will present issues that cause protective coatings to become ineffective in some cases yet effective in others due to the details of their specific application. Observed in-space examples of failed and successfully protected materials using identical protective thin films will be discussed and analyzed. Proposed approaches to prevent the failures that have been observed will also be presented.

Durability and Intelligent Nondestructive Evaluation of Adhesive Composite Joints

DTIC Science & Technology

2000-09-22

PERFORMING ORGANIZATION NAME(S) AND ADDRESS( ES ) 8. PERFORMING ORGANIZATION University of Nebraska-Lincoln, Research Grants REPORTNUMBER & Contracts Office...Lincoln, NE 68588-0430 9. SPONSORING / MONrrORLNG AGENCY NAIME(S) AND ADDRESS( ES ) 10. SPONSORING / MONITORING AGENCY REPORT NUMBER * AFOSR 801 North...An MTS 10 MT load cell was used to measure loads. The tests were performed with a Satec spherical alignment coupling attached to the top grip. Acoustic

Roadway lighting and safety : phase II--monitoring quality, durability and efficiency.

DOT National Transportation Integrated Search

2011-10-01

This Phase II project follows a previous project titled Strategies to Address Nighttime Crashes at Rural, Unsignalized Intersections. Based on the results of the previous study, the Iowa Highway Research Board (IHRB) indicated interest in pursuing fu...

Toward a new spacecraft optimal design lifetime? Impact of marginal cost of durability and reduced launch price

NASA Astrophysics Data System (ADS)

Snelgrove, Kailah B.; Saleh, Joseph Homer

2016-10-01

The average design lifetime of satellites continues to increase, in part due to the expectation that the satellite cost per operational day decreases monotonically with increased design lifetime. In this work, we challenge this expectation by revisiting the durability choice problem for spacecraft in the face of reduced launch price and under various cost of durability models. We first provide a brief overview of the economic thought on durability and highlight its limitations as they pertain to our problem (e.g., the assumption of zero marginal cost of durability). We then investigate the merging influence of spacecraft cost of durability and launch price, and we identify conditions that give rise cost-optimal design lifetimes that are shorter than the longest lifetime technically achievable. For example, we find that high costs of durability favor short design lifetimes, and that under these conditions the optimal choice is relatively robust to reduction in launch prices. By contrast, lower costs of durability favor longer design lifetimes, and the optimal choice is highly sensitive to reduction in launch price. In both cases, reduction in launch prices translates into reduction of the optimal design lifetime. Our results identify a number of situations for which satellite operators would be better served by spacecraft with shorter design lifetimes. Beyond cost issues and repeat purchases, other implications of long design lifetime include the increased risk of technological slowdown given the lower frequency of purchases and technology refresh, and the increased risk for satellite operators that the spacecraft will be technologically obsolete before the end of its life (with the corollary of loss of value and competitive advantage). We conclude with the recommendation that, should pressure to extend spacecraft design lifetime continue, satellite manufacturers should explore opportunities to lease their spacecraft to operators, or to take a stake in the ownership of the asset on orbit.

Durability enhancement of intermetallics electrocatalysts via N-anchor effect for fuel cells.

PubMed

Li, Xiang; An, Li; Chen, Xin; Zhang, Nanlin; Xia, Dingguo; Huang, Weifeng; Chu, Wangsheng; Wu, Ziyu

2013-11-18

Insufficient durability and catalytic activity of oxygen reduction reaction (ORR) electrocatalyst are key issues that have to be solved for the practical application of low temperature fuel cell. This paper introduces a new catalyst design strategy using N-anchor to promote the corrosion resistance of electrocatalyst. The as-synthesized N-Pt3Fe1/C shows a high electrocatalytic activity and a superior durability towards ORR. The kinetic current density of N-Pt3Fe1/C as normalized by ECSA is still as high as 0.145 mA cm(-2) and only 7% loss after 20,000 potential cycles from 0.6 to 1.2 V (vs. NHE) in O2-bubbling perchloric acid solution, whereas Pt3Fe1/C shows 49% loss under the same tests. The N-anchor approach offers novel opportunities for the development of ORR catalyst with excellent electrochemical properties.

Highly active and durable methanol oxidation electrocatalyst based on the synergy of platinum-nickel hydroxide-graphene.

PubMed

Huang, Wenjing; Wang, Hongtao; Zhou, Jigang; Wang, Jian; Duchesne, Paul N; Muir, David; Zhang, Peng; Han, Na; Zhao, Feipeng; Zeng, Min; Zhong, Jun; Jin, Chuanhong; Li, Yanguang; Lee, Shuit-Tong; Dai, Hongjie

2015-11-25

Active and durable electrocatalysts for methanol oxidation reaction are of critical importance to the commercial viability of direct methanol fuel cell technology. Unfortunately, current methanol oxidation electrocatalysts fall far short of expectations and suffer from rapid activity degradation. Here we report platinum-nickel hydroxide-graphene ternary hybrids as a possible solution to this long-standing issue. The incorporation of highly defective nickel hydroxide nanostructures is believed to play the decisive role in promoting the dissociative adsorption of water molecules and subsequent oxidative removal of carbonaceous poison on neighbouring platinum sites. As a result, the ternary hybrids exhibit exceptional activity and durability towards efficient methanol oxidation reaction. Under periodic reactivations, the hybrids can endure at least 500,000 s with negligible activity loss, which is, to the best of our knowledge, two to three orders of magnitude longer than all available electrocatalysts.

Highly active and durable methanol oxidation electrocatalyst based on the synergy of platinum–nickel hydroxide–graphene

PubMed Central

Huang, Wenjing; Wang, Hongtao; Zhou, Jigang; Wang, Jian; Duchesne, Paul N.; Muir, David; Zhang, Peng; Han, Na; Zhao, Feipeng; Zeng, Min; Zhong, Jun; Jin, Chuanhong; Li, Yanguang; Lee, Shuit-Tong; Dai, Hongjie

2015-01-01

Active and durable electrocatalysts for methanol oxidation reaction are of critical importance to the commercial viability of direct methanol fuel cell technology. Unfortunately, current methanol oxidation electrocatalysts fall far short of expectations and suffer from rapid activity degradation. Here we report platinum–nickel hydroxide–graphene ternary hybrids as a possible solution to this long-standing issue. The incorporation of highly defective nickel hydroxide nanostructures is believed to play the decisive role in promoting the dissociative adsorption of water molecules and subsequent oxidative removal of carbonaceous poison on neighbouring platinum sites. As a result, the ternary hybrids exhibit exceptional activity and durability towards efficient methanol oxidation reaction. Under periodic reactivations, the hybrids can endure at least 500,000 s with negligible activity loss, which is, to the best of our knowledge, two to three orders of magnitude longer than all available electrocatalysts. PMID:26602295

An intraventricular axial flow blood pump integrated with a bearing purge system.

PubMed

Yamazaki, K; Kormos, R; Mori, T; Umezu, M; Kameneva, M; Antaki, J; Outa, E; Litwak, P; Kerrigan, J; Tomczak, J

1995-01-01

The future development of implantable axial flow blood pumps must address two major issues: mechanically induced hemolysis and shaft seal reliability. The recent revisions to our miniature intraventricular axial flow left ventricular assist device (LVAD) were aimed particularly at addressing these concerns. To improve hemocompatibility, a new impeller has been designed according to the following criteria: 1) gradual pressure rise along the blade chord; 2) minimized local fluid acceleration to prevent cavitation; 3) minimum surface roughness; and 4) radius edges. Subsequent in vitro hemolysis tests conducted with bovine and ovine blood have demonstrated very low hemolysis (normalized index of hemolysis = 0.0051 +/- 0.0047 g/100 L) with this new impeller design. To address the need for a reliable seal, we have developed a purged seal system consisting of a miniature lip seal and ceramic pressure groove journal bearing that also acts as a purge pump. Several spiral grooves formed on the bearing surface provide viscous pumping of the purge fluid, generating more than 3,000 mmHg at 10,000 rpm. This purge flow flushes the lip seal and prevents blood backflow into the bearing. We have found this purge pump to offer several advantages because it is simple, compact, durable, does not require separate actuation, and offers a wide range of flow, depending upon the groove design. In vivo animal tests demonstrated the potential of the purged seal system.

Reflecting on the tensions faced by a community-based multicultural health navigator service.

PubMed

Henderson, Saras; Kendall, Elizabeth

2014-11-01

The community navigator model was developed to assist four culturally and linguistically diverse communities (Sudanese, Burmese, Pacific Islander Group, Afghani) in south-east Queensland to negotiate the Australian health system and promote health. Using participatory action research, we developed the model in partnership with community leaders and members, the local health department and two non-governmental organisations. Following implementation, we evaluated the model, with the results published elsewhere. However, our evaluation revealed that although the model was accepted by the communities and was associated with positive health outcomes, the financial, social and organisational durability of the model was problematic. Ironically, this situation was inadvertently created by critical decisions made during the development process to enhance the durability and acceptability of the model. This paper explores these critical decisions, our rationale for making those decisions and the four hidden tensions that subsequently emerged. Using a reflective case study method to guide our analysis, we provide possible resolutions to these tensions that may promote the longevity and utility of similar models in the future. WHAT IS KNOWN ABOUT THE TOPIC?: The use of community navigators to assist culturally diverse communities to access health services is not new. Many benefits have been documented for communities, individuals and heath service providers following the use of such models. What is not well documented is how to maintain these models in a safe and cost-effective way within the Australian health system while respecting cultural and community practices and reducing the burden of service delivery on the navigators. WHAT DOES THIS PAPER ADD?: This paper provides a perspective on how the development of community-based service models inherently places them in a position of tension that must be resolved if they are to be long lasting. Four core tensions experienced during the development and implementation of our model in south-east Queensland are explored to develop potential resolutions. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Reducing the tensions inherent in culturally appropriate community-based service models will increase the durability of the approach. By addressing these tensions, we can create a more durable pool of community navigators that can facilitate community empowerment, self-governance of health issues and a sense of community ownership of health services.

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.

Relating Convective System Durability with Vertical Wind Profile extracted from NCEP/NCAR Reanalysis

NASA Astrophysics Data System (ADS)

Bergès, Jean-Claude; Beltrando, Gérard; Cacault, Philippe

2014-05-01

Various theoretical models focus on the relationship between wind characteristic and convective system durability. Yet in 1988, Rotuno, Klemp and Weisman state that an optimal live length result from a balance between cold pool thickness and low level wind shear. However these models require a knowledge of local upper air environment and these data are scarcely available for climatological studies. Our presentation address the issue of relating the wind vertical profile extracted from reanalysis fields with a convective system type index. Whereas getting wind data from the NCEP/NCAR database is a straightforward task, assessing convective system extension from geostationary satellite data raise both methodological and practical issues. In a climatological view of convective systems, the initiating steps can be be neglected and a tropopause temperature threshold could be sufficient to delineate systems area. Thus the dynamic parameters between two consecutive would be obtained by a maximum recovery algorithm. But this simple method has to be enhanced to avoid two drawbacks: a rough system area overestimation due to the trailing cirrus and an over-segmentation of active systems. To mitigate the first bias a watershed image segmentation is carry out and the patches with a negative growing rate are eliminated. In order to properly join different parts of the same system, a 3D labeling algorithm has been implemented. Moreover, as motion retrieval methods are based on overlapping area, spatial and temporal resolution imports and full data processing require optimized computation procedures. Based on these methods, we have produced a base of convective systems trajectory based on MSG and Meteosat data. To avoid parallax effects only the central part of the acquisition disk has been considered. System extension and duration has been compared with wind shear in amplitude and direction. The preliminary results shows a global effect consistent with simulation models, but statistical data significance has yet to be investigated.

Measure Guideline: Guide to Attic Air Sealing

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

Lstiburek, Joseph

2014-09-01

The purpose of this measure guideline is to provide information and recommendations for the preparation work necessary prior to adding attic insulation. Even though the purpose of this guide is to save energy, health, safety, and durability should not be compromised by energy efficiency. Accordingly, combustion safety and ventilation for indoor air quality are addressed first. Durability and attic ventilation then follow. Finally, to maximize energy savings, air sealing is completed prior to insulating. The guide is intended for home remodelers, builders, insulation contractors, mechanical contractors, general contractors who have previously done remodeling and homeowners as a guide to themore » work that needs to be done.« less

157-nm photomask handling and infrastructure: requirements and feasibility

NASA Astrophysics Data System (ADS)

Cullins, Jerry; Muzio, Edward G.

2001-09-01

Photomask handling is significantly more challenging for 157nm lithography than for any previous generation of optical lithography. First, pellicle materials are not currently available which meet all the requirements for 157nm lithography. Polymeric materials used at 193nm higher wavelengths are not transmissive at 157nm, while modified fused silica materials have adequate transmission and durability but have mechanical issues that need to be resolved. Second, the problem of molecular level contamination on the reticle must be solved. This contamination is due to the presence of oxygen, carbon dioxide, water, and other attenuators of 157nm radiation on the mask surface. It must be removed using something other than the lithography laser due to throughput and cost of ownership considerations. Third, there is the issue of removing attenuators from under the pellicle after a material becomes available. Both the ambient atmosphere and other introduced contaminants must be removed from the space between the reticle and pellicle after cleaning but before exposure. Forth are the potential issues for storage of reticles both during transportation from the mask shop and after it is in the wafer fab. Finally, the problems associated with operating in an optically inert dry environment must be addressed. The lack of moisture in the environment removes one of the key electrical discharge paths off of the reticle, which greatly increases the risk of electro-static damage to the pattern (ESD).

Locker Rooms: The Durable Design.

ERIC Educational Resources Information Center

Viklund, Roy; Coons, John

1997-01-01

Offers advice on heavy-use locker-room design that provides easier maintenance and vandal resistance. Design features and materials used for flooring, ceilings, and walls are addressed as are built-in systems and equipment, toilet and shower fixtures and partitions, lockers, and mechanical and electrical systems. (GR)

Durable bonds at the adhesive/dentin interface: an impossible mission or simply a moving target?

PubMed Central

SPENCER, Paulette; Jonggu PARK, Qiang YE; MISRA, Anil; BOHATY, Brenda S.; SINGH, Viraj; PARTHASARATHY, Ranga; SENE, Fábio; de Paiva GONÇALVES, Sérgio Eduardo; LAURENCE, Jennifer

2013-01-01

Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface. PMID:24855586

Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of bladder carcinoma.

PubMed

Kamat, Ashish M; Bellmunt, Joaquim; Galsky, Matthew D; Konety, Badrinath R; Lamm, Donald L; Langham, David; Lee, Cheryl T; Milowsky, Matthew I; O'Donnell, Michael A; O'Donnell, Peter H; Petrylak, Daniel P; Sharma, Padmanee; Skinner, Eila C; Sonpavde, Guru; Taylor, John A; Abraham, Prasanth; Rosenberg, Jonathan E

2017-08-15

The standard of care for most patients with non-muscle-invasive bladder cancer (NMIBC) is immunotherapy with intravesical Bacillus Calmette-Guérin (BCG), which activates the immune system to recognize and destroy malignant cells and has demonstrated durable clinical benefit. Urologic best-practice guidelines and consensus reports have been developed and strengthened based on data on the timing, dose, and duration of therapy from randomized clinical trials, as well as by critical evaluation of criteria for progression. However, these reports have not penetrated the community, and many patients do not receive appropriate therapy. Additionally, several immune checkpoint inhibitors have recently been approved for treatment of metastatic disease. The approval of immune checkpoint blockade for patients with platinum-resistant or -ineligible metastatic bladder cancer has led to considerations of expanded use for both advanced and, potentially, localized disease. To address these issues and others surrounding the appropriate use of immunotherapy for the treatment of bladder cancer, the Society for Immunotherapy of Cancer (SITC) convened a Task Force of experts, including physicians, patient advocates, and nurses, to address issues related to patient selection, toxicity management, clinical endpoints, as well as the combination and sequencing of therapies. Following the standard approach established by the Society for other cancers, a systematic literature review and analysis of data, combined with consensus voting was used to generate guidelines. Here, we provide a consensus statement for the use of immunotherapy in patients with bladder cancer, with plans to update these recommendations as the field progresses.

Final Report - MEA and Stack Durability for PEM Fuel Cells

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

Yandrasits, Michael A.

2008-02-15

Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets.more » The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain the same. (6) Through the use of statistical lifetime analysis methods, it is possible to develop new MEAs with predicted durability approaching the DOE 2010 targets. (7) A segmented cell was developed that extend the resolution from ~ 40 to 121 segments for a 50cm2 active area single cell which allowed for more precise investigation of the local phenomena in a operating fuel cell. (8) The single cell concept was extended to a fuel size stack to allow the first of its kind monitoring and mapping of an operational fuel cell stack. An internal check used during this project involved evaluating the manufacturability of any new MEA component. If a more durable MEA component was developed in the lab, but could not be scaled-up to ‘high speed, high volume manufacturing’, then that component was not selected for the final MEA-fuel cell system demonstration. It is the intent of the team to commercialize new products developed under this project, but commercialization can not occur if the manufacture of said new components is difficult or if the price is significantly greater than existing products as to make the new components not cost competitive. Thus, the end result of this project is the creation of MEA and fuel cell system technology that is capable of meeting the DOEs 2010 target of 40,000 hours for stationary fuel cell systems (although this lifetime has not been demonstrated in laboratory or field testing yet) at a cost that is economically viable for the developing fuel cell industry. We have demonstrated over 2,000 hours of run time for the MEA and system developed under this project.« less

High Temperature Chemistry at NASA: Hot Topics

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.

2014-01-01

High Temperature issues in aircraft engines Hot section: Ni and Co based Superalloys Oxidation and Corrosion (Durability) at high temperatures. Thermal protection system (TPS) and RCC (Reinforced Carbon-Carbon) on the Space Shuttle Orbiter. High temperatures in other worlds: Planets close to their stars.

Li-Ion Pouch Cell Designs; Performance and Issues for Crewed Vehicle Applications

NASA Technical Reports Server (NTRS)

Darcy, Eric

2011-01-01

The purpose of this work: Are there any performance show stoppers for spinning them into spacecraft applications? (1) Are the seals compatible with extended vacuum operations? (2) How uniformly and cleanly are they made? (3) How durable are they?

High Class

ERIC Educational Resources Information Center

Waldecker, Mark

2005-01-01

Education administrators make buying decisions for furniture based on many factors. Cost, durability, functionality, safety and aesthetics represent just a few. Those issues always will be important, but gaining greater recognition in recent years has been the role furniture plays in creating positive, high-performance learning environments. The…

Propulsion Systems Panel

NASA Technical Reports Server (NTRS)

Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; Mcgaw, Mike; Munafo, Paul M.

1993-01-01

Topics addressed are: (1) cryogenic tankage; (2) launch vehicle TPS/insulation; (3) durable passive thermal control devices and/or coatings; (4) development and characterization of processing methods to reduce anisotropy of material properties in Al-Li; (5) durable thermal protection system (TPS); (6) unpressurized Al-Li structures (interstages, thrust structures); (7) near net shape sections; (8) pressurized structures; (9) welding and joining; (10) micrometeoroid and debris hypervelocity shields; (11) state-of-the-art shell buckling structure optimizer program to serve as a rapid design tool; (12) test philosophy; (13) reduced load cycle time; (14) structural analysis methods; (15) optimization of structural criteria; and (16) develop an engineering approach to properly trade material and structural concepts selection, fabrication, facilities, and cost.

Propulsion Systems Panel

NASA Astrophysics Data System (ADS)

Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; McGaw, Mike; Munafo, Paul M.

1993-02-01

Topics addressed are: (1) cryogenic tankage; (2) launch vehicle TPS/insulation; (3) durable passive thermal control devices and/or coatings; (4) development and characterization of processing methods to reduce anisotropy of material properties in Al-Li; (5) durable thermal protection system (TPS); (6) unpressurized Al-Li structures (interstages, thrust structures); (7) near net shape sections; (8) pressurized structures; (9) welding and joining; (10) micrometeoroid and debris hypervelocity shields; (11) state-of-the-art shell buckling structure optimizer program to serve as a rapid design tool; (12) test philosophy; (13) reduced load cycle time; (14) structural analysis methods; (15) optimization of structural criteria; and (16) develop an engineering approach to properly trade material and structural concepts selection, fabrication, facilities, and cost.

Fluid mechanics of heart valves.

PubMed

Yoganathan, Ajit P; He, Zhaoming; Casey Jones, S

2004-01-01

Valvular heart disease is a life-threatening disease that afflicts millions of people worldwide and leads to approximately 250,000 valve repairs and/or replacements each year. Malfunction of a native valve impairs its efficient fluid mechanic/hemodynamic performance. Artificial heart valves have been used since 1960 to replace diseased native valves and have saved millions of lives. Unfortunately, despite four decades of use, these devices are less than ideal and lead to many complications. Many of these complications/problems are directly related to the fluid mechanics associated with the various mechanical and bioprosthetic valve designs. This review focuses on the state-of-the-art experimental and computational fluid mechanics of native and prosthetic heart valves in current clinical use. The fluid dynamic performance characteristics of caged-ball, tilting-disc, bileaflet mechanical valves and porcine and pericardial stented and nonstented bioprostheic valves are reviewed. Other issues related to heart valve performance, such as biomaterials, solid mechanics, tissue mechanics, and durability, are not addressed in this review.

Interactions between hydrated cement paste and organic acids: Thermodynamic data and speciation modeling

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

De Windt, Laurent, E-mail: laurent.dewindt@mines-paristech.fr; Bertron, Alexandra; Larreur-Cayol, Steeves

2015-03-15

Interactions of short-chain organic acids with hydrated cement phases affect structure durability in the agro-food and nuclear waste industries but can also be used to modify cement properties. Most previous studies have been experimental, performed at fixed concentrations and pH, without quantitatively discriminating among polyacidity effects, or complexation and salt precipitation processes. This paper addresses such issues by thermodynamic equilibrium calculations for acetic, citric, oxalic, succinic acids and a simplified hydrated CEM-I. The thermodynamic constants collected from the literature allow the speciation to be modeled over a wide range of pH and concentrations. Citric and oxalic had a stronger chelatingmore » effect than acetic acid, while succinic acid was intermediate. Similarly, Ca-citrate and Ca-oxalate salts were more insoluble than Ca-acetate and Ca-succinate salts. Regarding aluminium complexation, hydroxyls, sulfates, and acid competition was highlighted. The exploration of acid mixtures showed the preponderant effect of oxalate and citrate over acetate and succinate.« less

Quantitative measurement of solvation shells using frequency modulated atomic force microscopy

NASA Astrophysics Data System (ADS)

Uchihashi, T.; Higgins, M.; Nakayama, Y.; Sader, J. E.; Jarvis, S. P.

2005-03-01

The nanoscale specificity of interaction measurements and additional imaging capability of the atomic force microscope make it an ideal technique for measuring solvation shells in a variety of liquids next to a range of materials. Unfortunately, the widespread use of atomic force microscopy for the measurement of solvation shells has been limited by uncertainties over the dimensions, composition and durability of the tip during the measurements, and problems associated with quantitative force calibration of the most sensitive dynamic measurement techniques. We address both these issues by the combined use of carbon nanotube high aspect ratio probes and quantifying the highly sensitive frequency modulation (FM) detection technique using a recently developed analytical method. Due to the excellent reproducibility of the measurement technique, additional information regarding solvation shell size as a function of proximity to the surface has been obtained for two very different liquids. Further, it has been possible to identify differences between chemical and geometrical effects in the chosen systems.

Infrared sensor and window system issues

NASA Astrophysics Data System (ADS)

Hargraves, Charles H., Jr.; Martin, James M.

1992-12-01

EO/IR windows are a significant challenge for the weapon system sensor designer who must design for high EO performance, low radar cross section (RCS), supersonic flight, durability, producibility and affordable initial and life cycle costs. This is particularly true in the 8 to 12 micron IR band at which window materials and coating choices are limited by system design requirements. The requirements also drive the optimization of numerous mechanical, optical, materials, and electrical parameters. This paper addresses the EO/IR window as a system design challenge. The interrelationship of the optical, mechanical, and system design processes are examined. This paper presents a summary of the test results, trade studies and analyses that were performed for multi-segment, flight-worthy optical windows with superior optical performance at subsonic and supersonic aircraft velocities and reduced radar cross section. The impact of the window assembly on EO system modulation transfer function (MTF) and sensitivity will be discussed. The use of conductive coatings for shielding/signature control will be discussed.

In search of durable positive psychology interventions: Predictors and consequences of long-term positive behavior change

PubMed Central

Cohn, Michael A.; Fredrickson, Barbara L.

2011-01-01

A number of positive psychology interventions have successfully helped people learn skills for improving mood and building personal resources (e.g., psychological resilience and social support). However, little is known about whether intervention activities remain effective in the long term, or whether new resources are maintained after the intervention ends. We address these issues in a 15-month follow-up survey of participants from a loving-kindness meditation intervention. Many participants continued to practice meditation, and they reported more positive emotions (PEs) than those who had stopped meditating or had never meditated. All participants maintained gains in resources made during the initial intervention, whether or not they continued meditating. Continuing meditators did not differ on resources at baseline, but they did show more PE and a more rapid PE response to the intervention. Overall, our results suggest that positive psychology interventions are not just efficacious but of significant value in participants' real lives. PMID:21709728

Final Project Report: Development of Micro-Structural Mitigation Strategies for PEM Fuel Cells: Morphological Simulations and Experimental Approaches

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

Wessel, Silvia; Harvey, David

2013-06-28

The durability of PEM fuel cells is a primary requirement for large scale commercialization of these power systems in transportation and stationary market applications that target operational lifetimes of 5,000 hours and 40,000 hours by 2015, respectively. Key degradation modes contributing to fuel cell lifetime limitations have been largely associated with the platinum-based cathode catalyst layer. Furthermore, as fuel cells are driven to low cost materials and lower catalyst loadings in order to meet the cost targets for commercialization, the catalyst durability has become even more important. While over the past few years significant progress has been made in identifyingmore » the underlying causes of fuel cell degradation and key parameters that greatly influence the degradation rates, many gaps with respect to knowledge of the driving mechanisms still exist; in particular, the acceleration of the mechanisms due to different structural compositions and under different fuel cell conditions remains an area not well understood. The focus of this project was to address catalyst durability by using a dual path approach that coupled an extensive range of experimental analysis and testing with a multi-scale modeling approach. With this, the major technical areas/issues of catalyst and catalyst layer performance and durability that were addressed are: 1. Catalyst and catalyst layer degradation mechanisms (Pt dissolution, agglomeration, Pt loss, e.g. Pt in the membrane, carbon oxidation and/or corrosion). a. Driving force for the different degradation mechanisms. b. Relationships between MEA performance, catalyst and catalyst layer degradation and operational conditions, catalyst layer composition, and structure. 2. Materials properties a. Changes in catalyst, catalyst layer, and MEA materials properties due to degradation. 3. Catalyst performance a. Relationships between catalyst structural changes and performance. b. Stability of the three-phase boundary and its effect on performance/catalyst degradation. The key accomplishments of this project are: • The development of a molecular-dynamics based description of the carbon supported-Pt and ionomer system • The development of a composition-based, 1D-statistical Unit Cell Performance model • A modified and improved multi-pathway ORR model • An extension of the existing micro-structural catalyst model to transient operation • The coupling of a Pt Dissolution model to the modified ORR pathway model • The Development A Semi-empirical carbon corrosion model • The integration and release of an open-source forward predictive MEA performance and degradation model • Completion of correlations of BOT (beginning of test) and EOT (end of test) performance loss breakdown with cathode catalyst layer composition, morphology, material properties, and operational conditions • Catalyst layer durability windows and design curves • A design flow path of interactions from materials properties and catalyst layer effective properties to performance loss breakdown for virgin and degraded catalyst layers In order to ensure the best possible user experience we will perform a staged release of the software leading up to the webinar scheduled in October 2013. The release schedule will be as follows (please note that the manual will be released with the beta release as direct support is provided in Stage 1): • Stage 0 - Internal Ballard Release o Cross check of compilation and installation to ensure machine independence o Implement code on portable virtual machine to allow for non-UNIX use (pending) • Stage 1 - Alpha Release o The model code will be made available via a GIT, sourceforge, or other repository (under discussion at Ballard) for download and installation by a small pre-selected group of users o Users will be given three weeks to install, apply, and evaluate features of the code, providing feedback on issues or software bugs that require correction prior to beta release • Stage 2 - Beta Release o The model code repository is opened to the general public on a beta release concept, with a mechanism for bug tracking and feedback from a large user group o Code will be tracked and patched for any discovered bugs or relevant feedback from the user community, upon the completion of three months without a major bug submission the code will be moved to a full version release • Stage 3 - Full Version Release o Code is version to revision 1.0 and that version is frozen in development/patching« less

Concrete pavement mixture design and analysis (MDA) : application of a portable x-ray fluorescence technique to assess concrete mix proportions.

DOT National Transportation Integrated Search

2012-03-01

Any transportation infrastructure system is inherently concerned with durability and performance issues. The proportioning and : uniformity control of concrete mixtures are critical factors that directly affect the longevity and performance of the po...

Selecting the Best Furniture for Your Classroom.

ERIC Educational Resources Information Center

Troup, Wilson

2002-01-01

Offers advice on furnishing a technology classroom, asserting that the overriding selection criteria must be quality. This is defined as furniture that functions smoothly and looks attractive with regular maintenance for up to two decades. Addresses eye appeal, versatility versus performance, and durability. A sidebar also discusses ergonomics and…

Durability Issues for the Protection of Materials from Atomic Oxygen Attack in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Banks, Bruce; Lenczewski, Mary; Demko, Rikako

2002-01-01

Low Earth orbital atomic oxygen is capable of eroding most polymeric materials typically used on spacecraft. Solar array blankets, thermal control polymers, and carbon fiber matrix composites are readily oxidized to become thinner and less capable of supporting the loads imposed upon them. Protective coatings have been developed that are durable to atomic oxygen to prevent oxidative erosion of the underlying polymers. However, the details of the surface roughness, coating defect density, and coating configuration can play a significant role as to whether or not the coating provides long duration atomic oxygen protection. Identical coatings on different surface roughness surfaces can have drastically different durability results. Examples and analysis of the causes of resultant differences in atomic oxygen protection are presented. Implications based on in-space experiences, ground laboratory testing, and computational modeling indicate that thin film vacuum-deposited aluminum protective coatings offer much less atomic oxygen protection than sputter-deposited silicon dioxide coatings.

Operational durability of a giant ER valve for Braille display

NASA Astrophysics Data System (ADS)

Luning, Xu; Han, Li; Yufei, Li; Shen, Rong; Kunquan, Lu

2017-05-01

The compact configuration of giant ER (electrorheological) valves provides the possibility of realizing a full-page Braille display. The operational durability of ER valves is a key issue in fulfilling a Braille display. A giant ER valve was used to investigate the variations in pressure drops and critical pressure drops of the valves over a long period under some typical operational parameters. The results indicate that neither the pressure drops nor critical pressure drops of giant ER valves show apparent deterioration over a long period. Without ER fluid exchange, a blockage appears in the channel of the valve because the ER structures induced by an external electric field cannot be broken by the Brownian motion of hydraulic oil molecules when the external electric field is removed. Forcing ER fluid flow is an effective and necessary method to keep the channel of the valve unblocked. Thus the operational durability of the valve using giant ER fluids is able to meet the demands of Braille display.

Integrated health management and control of complex dynamical systems

NASA Astrophysics Data System (ADS)

Tolani, Devendra K.

2005-11-01

A comprehensive control and health management strategy for human-engineered complex dynamical systems is formulated for achieving high performance and reliability over a wide range of operation. Results from diverse research areas such as Probabilistic Robust Control (PRC), Damage Mitigating/Life Extending Control (DMC), Discrete Event Supervisory (DES) Control, Symbolic Time Series Analysis (STSA) and Health and Usage Monitoring System (HUMS) have been employed to achieve this goal. Continuous-domain control modules at the lower level are synthesized by PRC and DMC theories, whereas the upper-level supervision is based on DES control theory. In the PRC approach, by allowing different levels of risk under different flight conditions, the control system can achieve the desired trade off between stability robustness and nominal performance. In the DMC approach, component damage is incorporated in the control law to reduce the damage rate for enhanced structural durability. The DES controller monitors the system performance and, based on the mission requirements (e.g., performance metrics and level of damage mitigation), switches among various lower-level controllers. The core idea is to design a framework where the DES controller at the upper-level, mimics human intelligence and makes appropriate decisions to satisfy mission requirements, enhance system performance and structural durability. Recently developed tools in STSA have been used for anomaly detection and failure prognosis. The DMC deals with the usage monitoring or operational control part of health management, where as the issue of health monitoring is addressed by the anomaly detection tools. The proposed decision and control architecture has been validated on two test-beds, simulating the operations of rotorcraft dynamics and aircraft propulsion.

mobilityRERC state of the science: How science influences public policy in seating and mobility.

PubMed

Hostak, Rita S; Edwards, Doran; Sprigle, Stephen

2013-11-01

In the United States (US), wheeled mobility and seating equipment is classified as Durable Medical Equipment (DME). DME includes a wide array of devices including canes, walkers, home oxygen equipment, hospital beds, and wheelchairs. Seating and mobility devices reflect a wide range of DME, from relatively simple standard manual wheelchairs and cushions to highly complex manual and power wheelchairs and custom seating systems. This wide range of complexity results in a wide range of policies that govern the provision of seating and mobility equipment. This article results from a presentation during the Wheeled Mobility Rehabilitation Engineering Research Center's (RERC's) State of the Science Conference in 2012. The presentation was designed to proffer key concepts related to coverage policies and policy decision-making. Topics covered include an introduction to key policy issues impacting seating and mobility equipment, a description of the barriers that prevent or hinder research being used to inform coverage policy decisions, discussion of the challenges surrounding evidence-based policy decisions regarding seating and mobility, and suggestions of strategies for including policy makers and other stakeholders in setting research priorities and in reporting research findings. In the United States, wheeled mobility and seating equipment are classified as Durable Medical Equipments which are governed by a wide range of policies. Researchers should be encouraged to supplement research articles with articles that explicitly address clinical and policy implications of the work. Policy-makers should be encouraged to engage researchers to insure the breadth of knowledge and evidence is represented and understood.

Sensitivity analysis of bi-layered ceramic dental restorations.

PubMed

Zhang, Zhongpu; Zhou, Shiwei; Li, Qing; Li, Wei; Swain, Michael V

2012-02-01

The reliability and longevity of ceramic prostheses have become a major concern. The existing studies have focused on some critical issues from clinical perspectives, but more researches are needed to address fundamental sciences and fabrication issues to ensure the longevity and durability of ceramic prostheses. The aim of this paper was to explore how "sensitive" the thermal and mechanical responses, in terms of changes in temperature and thermal residual stress of the bi-layered ceramic systems and crown models will be with respect to the perturbation of the design variables chosen (e.g. layer thickness and heat transfer coefficient) in a quantitative way. In this study, three bi-layered ceramic models with different geometries are considered: (i) a simple bi-layered plate, (ii) a simple bi-layer triangle, and (iii) an axisymmetric bi-layered crown. The layer thickness and convective heat transfer coefficient (or cooling rate) seem to be more sensitive for the porcelain fused on zirconia substrate models. The resultant sensitivities indicate a critical importance of the heat transfer coefficient and thickness ratio of core to veneer on the temperature distributions and residual stresses in each model. The findings provide a quantitative basis for assessing the effects of fabrication uncertainties and optimizing the design of ceramic prostheses. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Self-Formed Hybrid Interphase Layer on Lithium Metal for High-Performance Lithium-Sulfur Batteries.

PubMed

Li, Guoxing; Huang, Qingquan; He, Xin; Gao, Yue; Wang, Daiwei; Kim, Seong H; Wang, Donghai

2018-02-27

Lithium-sulfur (Li-S) batteries are promising candidates for high-energy storage devices due to high theoretical capacities of both the sulfur cathode and lithium (Li) metal anode. Considerable efforts have been devoted to improving sulfur cathodes. However, issues associated with Li anodes, such as low Coulombic efficiency (CE) and growth of Li dendrites, remain unsolved due to unstable solid-electrolyte interphase (SEI) and lead to poor capacity retention and a short cycling life of Li-S batteries. In this work, we demonstrate a facile and effective approach to fabricate a flexible and robust hybrid SEI layer through co-deposition of aromatic-based organosulfides and inorganic Li salts using poly(sulfur-random-1,3-diisopropenylbenzene) as an additive in an electrolyte. The aromatic-based organic components with planar backbone conformation and π-π interaction in the SEI layers can improve the toughness and flexibility to promote stable and high efficient Li deposition/dissolution. The as-formed durable SEI layer can inhibit dendritic Li growth, enhance Li deposition/dissolution CE (99.1% over 420 cycles), and in turn enable Li-S batteries with good cycling stability (1000 cycles) and slow capacity decay. This work demonstrates a route to address the issues associated with Li metal anodes and promote the development of high-energy rechargeable Li metal batteries.

Transient analysis of gas transport in anode channel of a polymer electrolyte membrane fuel cell with dead-ended anode under pressure swing operation

NASA Astrophysics Data System (ADS)

Ichikawa, Yasushi; Oshima, Nobuyuki; Tabuchi, Yuichiro; Ikezoe, Keigo

2014-12-01

Further cost reduction is a critical issue for commercialization of fuel-cell electric vehicles (FCEVs) based on polymer electrolyte fuel cells (PEFCs). The cost of the fuel-cell system is driven by the multiple parts required to maximize stack performance and maintain durability and robustness. The fuel-cell system of the FCEV must be simplified while maintaining functionality. The dead-ended anode is considered as a means of simplification in this study. Generally, if hydrogen is supplied under constant pressure during dead-ended operation, stable power generation is impossible because of accumulation of liquid water produced by power generation and of nitrogen via leakage from the cathode through the membrane. Herein, pressure oscillation is applied to address this issue. Empirical and CFD data are employed to elucidate the mechanism of stable power generation using the pressure swing supply. Simultaneous and time-continuous measurements of the current distribution and gas concentration distribution are also conducted. The results demonstrate that the nitrogen concentration in the anode channel under pressure constant operation differs from that under pressure swing supply conditions. The transient two-dimensional CFD results indicate that oscillatory flow is generated by pressure swing supply, which periodically sweeps out nitrogen from the active area, resulting in stable power generation.

Photostabilization of wood flour filled HDPE composites

Treesearch

Nicole M. Stark; Laurent M. Matuana

2002-01-01

Wood/plastic composites are increasingly examined for non-structural building applications. As outdoor applications become more widespread, durability becomes an issue. Ultraviolet exposure can lead to photodegradation, resulting in a change in appearance and/or mechanical properties. Photodegradation can be slowed through the addition of photostabilizers. This study...

Cyclic Fatigue Durability of Uncoated and EBC Coated 3D SiC/SiC Composites Under Thermal Gradient Conditions at 2700F in Air

NASA Technical Reports Server (NTRS)

Smith, Craig; Harder, Bryan; Zhu, Dongming; Bhatt, Ramakrishna; Kalluri, Sreeramesh

2017-01-01

Ceramic matrix composites (CMCs) such as SiC/SiC are currently being designed and implemented in high temperature sections of aerospace turbine engines. Such components will be subject to through-thickness thermal gradients, which may affect the durability. In this study, SiC/SiC CMCs with a hybrid chemical vapor infiltrated (CVI) and polymer infiltration and pyrolysis (PIP) matrix were loaded in tension while one surface was heated with a laser and the opposite surface was cooled. Issues associated with laser testing will be discussed, along with initial results for coated and uncoated samples.

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

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

Atomic Oxygen Durability of Second Surface Silver Microsheet Glass Concentrators

NASA Technical Reports Server (NTRS)

deGroh, Kim K.; Jaworske, Donald A.; Smith, Daniela C.; Mroz, Thaddeus S.

1996-01-01

Second surface silver microsheet glass concentrators are being developed for potential use in future solar dynamic space power systems. Traditional concentrators are aluminum honeycomb sandwich composites with either aluminum or graphite epoxy face sheets, where a reflective aluminum layer is deposited onto an organic leveling layer on the face sheet. To protect the underlying layers, a SiO2 layer is applied on top of the aluminum reflective layer. These concentrators may be vulnerable to atomic oxygen degradation due to possible atomic oxygen attack of the organic layers at defect sites in the protective and reflective coatings. A second surface microsheet glass concentrator would be inherently more atomic oxygen durable than these first surface concentrators. In addition, a second surface microsheet glass concentrator design provides a smooth optical surface and allows for silver to be used as a reflective layer, which would improve the reflectivity of the concentrator and the performance of the system. A potential threat to the performance of second surface microsheet glass concentrators is atomic oxygen attack of the underlying silver at seams and edges or at micrometeoroid and debris (MMD) impacts sites. Second surface silver microsheet glass concentrator samples were fabricated and tested for atomic oxygen durability. The samples were iteratively exposed to an atomic oxygen environment in a plasma asher. Samples were evaluated for potential degradation at fabrication seams, simulated MMD impact sites, and edges. Optical microscopy was used to evaluate atomic oxygen degradation. Reflectance was obtained for an impacted sample prior to and after atomic oxygen exposure. After an initial atomic oxygen exposure to an effective fluence of approx. 1 x 10(exp 21) atoms/cm(exp 2), oxidation of the silver at defect sites and edges was observed. Exposure to an additional approx. 1 x 10(exp 21) atoms/cm(exp 2) caused no observed increase in oxidation. Oxidation at an impact site caused negligible changes in reflectance. In all cases oxidation was found to be confined to the vicinity of the seams, impact sites, edges or defect sites. Asher to in-space atomic oxygen correlation issues will be addressed.

78 FR 36029 - CDFI Bond Guarantee Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-14

... the extent a Secondary Loan is financed on a corporate finance basis (i.e., through a Credit... Issue. Bonds will be used to finance Bond Loans to Eligible CDFIs for Eligible Purposes for a period not... financial strength, stability, durability and liquidity as reflected in its corporate credit ratings and...

A laboratory facility for research on wind-driven rain intrusion in building envelope assemblies

Treesearch

Samuel V. Glass

2010-01-01

Moisture management is critical for durable, energy-efficient buildings. To address the need for research on wind-driven rain intrusion in wall assemblies, the U.S. Forest Products Laboratory is developing a new facility. This paper describes the underlying principle of this facility and its capabilities.

Beyond Evolution: Addressing Broad Interactions between Science and Religion in Science Teacher Education

ERIC Educational Resources Information Center

Shane, Joseph W.; Binns, Ian C.; Meadows, Lee; Hermann, Ronald S.; Benus, Matthew J.

2016-01-01

Science and religion are two indisputably profound and durable cultural forces with a complex history of interaction. As ASTE members are aware, these interactions often manifest themselves in classrooms and in the surrounding communities. In this essay, we encourage science teacher educators to broaden their perspectives of science-religion…

Trace analysis in the food and beverage industry by capillary gas chromatography: system performance and maintenance.

PubMed

Hayes, M A

1988-04-01

Gas chromatography (GC) is the most widely used analytical technique in the food and beverage industry. This paper addresses the problems of sample preparation and system maintenance to ensure the most sensitive, durable, and efficient results for trace analysis by GC in this industry.

Will permanent LVADs be better than heart transplantation?

PubMed

Massad, M G; McCarthy, P M

1997-04-01

Current interest in permanent mechanical support systems has been renewed as a result of the present shortage of human heart donors, and in view of the satisfactory results obtained with their use as a bridge-to-transplant. As the number of donors is unlikely to increase dramatically in the near future, there is an urgent need to develop mechanical alternatives to transplantation. Preliminary data on the use of the implantable electric LVAD as a bridge-to-transplant indicate that the adverse clinical and mechanical events in outpatients are few and do not preclude use of the device on a permanent basis. Except for infections, transplant issues relating to need for endomyocardial biopsies, rejection, malignancies, and graft arteriosclerosis do not apply to LVAD recipients who face important issues relating to device durability, cost, and potential need for concomitant right heart support. This lack of data on long-term durability contrasts with a yearly mortality rate of about 5% after the first year of transplant. With the initiation of clinical trials on the permanent use of the electric LVAD, several design modifications and upgrading of the currently available devices are expected. Completely sealed systems with steadily improving durability will hopefully appear. Inductive coupling techniques under investigation and development appear to be able to transmit energy without damage across the skin. It is anticipated that with more reliable electronic microprocessors, the future generation of implantable LVADs will be smaller, more reliable and longer lasting.

How agro-ecological research helps to address food security issues under new IPM and pesticide reduction policies for global crop production systems.

PubMed

E Birch, A Nicholas; Begg, Graham S; Squire, Geoffrey R

2011-06-01

Drivers behind food security and crop protection issues are discussed in relation to food losses caused by pests. Pests globally consume food estimated to feed an additional one billion people. Key drivers include rapid human population increase, climate change, loss of beneficial on-farm biodiversity, reduction in per capita cropped land, water shortages, and EU pesticide withdrawals under policies relating to 91/414 EEC. IPM (Integrated Pest Management) will be compulsory for all EU agriculture by 2014 and is also being widely adopted globally. IPM offers a 'toolbox' of complementary crop- and region-specific crop protection solutions to address these rising pressures. IPM aims for more sustainable solutions by using complementary technologies. The applied research challenge now is to reduce selection pressure on single solution strategies, by creating additive/synergistic interactions between IPM components. IPM is compatible with organic, conventional, and GM cropping systems and is flexible, allowing regional fine-tuning. It reduces pests below economic thresholds utilizing key 'ecological services', particularly biocontrol. A recent global review demonstrates that IPM can reduce pesticide use and increase yields of most of the major crops studied. Landscape scale 'ecological engineering', together with genetic improvement of new crop varieties, will enhance the durability of pest-resistant cultivars (conventional and GM). IPM will also promote compatibility with semiochemicals, biopesticides, precision pest monitoring tools, and rapid diagnostics. These combined strategies are urgently needed and are best achieved via multi-disciplinary research, including complex spatio-temporal modelling at farm and landscape scales. Integrative and synergistic use of existing and new IPM technologies will help meet future food production needs more sustainably in developed and developing countries, in an era of reduced pesticide availability. Current IPM research gaps are identified and discussed.

Reaction and Protection of Electrical Wire Insulators in Atomic-oxygen Environments

NASA Technical Reports Server (NTRS)

Hung, Ching-Cheh; Cantrell, Gidget

1994-01-01

Atomic-oxygen erosion on spacecraft in low Earth orbit is an issue which is becoming increasingly important because of the growing number of spacecraft that will fly in the orbits which have high concentrations of atomic oxygen. In this investigation, the atomic-oxygen durability of three types of electrical wire insulation (carbon-based, fluoropolymer, and polysiloxane elastomer) were evaluated. These insulation materials were exposed to thermal-energy atomic oxygen, which was obtained by RF excitation of air at a pressure of 11-20 Pa. The effects of atomic-oxygen exposure on insulation materials indicate that all carbon-based materials erode at about the same rate as polyamide Kapton and, therefore, are not atomic-oxygen durable. However, the durability of fluoropolymers needs to be evaluated on a case by case basis because the erosion rates of fluoropolymers vary widely. For example, experimental data suggest the formation of atomic fluorine during atomic-oxygen amorphous-fluorocarbon reactions. Dimethyl polysiloxanes (silicone) do not lose mass during atomic-oxygen exposure, but develop silica surfaces which are under tension and frequently crack as a result of loss of methyl groups. However, if the silicone sample surfaces were properly pretreated to provide a certain roughness, atomic oxygen exposure resulted in a sturdy, non-cracked atomic-oxygen durable SiO2 layer. Since the surface does not crack during such silicone-atomic oxygen reaction, the crack-induced contamination by silicone can be reduced or completely stopped. Therefore, with proper pretreatment, silicone can be either a wire insulation material or a coating on wire insulation materials to provide atomic-oxygen durability.

Evaluation of the durability and antiadhesive action of 2-methacryloyloxyethyl phosphorylcholine grafting on an acrylic resin denture base material.

PubMed

Takahashi, Nana; Iwasa, Fuminori; Inoue, Yuuki; Morisaki, Hirobumi; Ishihara, Kazuhiko; Baba, Kazuyoshi

2014-08-01

The polymer 2-methacryloyloxyethyl phosphorylcholine is currently used on medical devices to prevent infection. Denture plaque-associated infection is regarded as a source of serious dental and medical complications in the elderly population, and denture hygiene, therefore, is an issue of considerable importance for denture wearers. Furthermore, because denture bases are exposed to mechanical stresses, for example, denture brushing, the durability of the coating is important for retaining the antiadhesive function of 2-methacryloyloxyethyl phosphorylcholine. The purpose of this study is to investigate the durability and antiadhesive activity of two 2-methacryloyloxyethyl phosphorylcholine polymer coating techniques: poly-2-methacryloyloxyethyl phosphorylcholine grafting and poly-2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate coating. It was revealed that 2-methacryloyloxyethyl phosphorylcholine polymer coating of the denture base resin polymethyl methacrylate decreases bacterial biofilm formation. Durability was examined by rhodamine staining and elemental surface analysis and by determining the wetting properties of the 2-methacryloyloxyethyl phosphorylcholine polymer-modified polymethyl methacrylate after a friction test that comprised 500 brushing cycles. Antiadhesive activity was examined by using a Streptococcus mutans biofilm formation assay. Poly-2-methacryloyloxyethyl phosphorylcholine-grafted polymethyl methacrylate retained 2-methacryloyloxyethyl phosphorylcholine units and antiadhesive activity even after repetitive mechanical stress, whereas co-n-butyl methacrylate-coated polymethyl methacrylate did not. These results demonstrated that graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on denture surfaces may contribute to the durability of the coating and prevent microbial retention. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

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.

Nitrogen–doped graphitized carbon shell encapsulated NiFe nanoparticles: A highly durable oxygen evolution catalyst

DOE PAGES

Du, Lei; Luo, Langli; Feng, Zhenxing; ...

2017-07-05

Oxygen evolution reaction (OER) plays a crucial role in various energy conversion devices such as water electrolyzers and metal–air batteries. Precious metal catalysts such as Ir, Ru and their oxides are usually used for enhancing reaction kinetics but are limited by their scarcity. The challenges associated with alternative non–precious metal catalysts such as transition metal oxides and (oxy)hydroxides are their low electronic conductivity and durability. The carbon encapsulating transition metal nanoparticles are expected to address these challenges. However, the relationship between precursor compositions and catalyst properties, and the intrinsic functions of each component has been rarely studied. In this paper,more » we report a highly durable (no degradation after 20,000 cycles) and highly active (360 mV overpotential at 10 mA cm –2 GEO) OER catalyst derived from bimetallic metal–organic frameworks (MOFs) precursors. This catalyst consists of NiFe nanoparticles encapsulated by nitrogen–doped graphitized carbon shells. The electron–donation/deviation from Fe and tuned lattice and electronic structures of metal cores by Ni are revealed to be primary contributors to the enhanced OER activity, whereas N concentration contributes negligibly. Finally, we further demonstrated that the structure and morphology of encapsulating carbon shells, which are the key factors influencing the durability, are facilely controlled by the chemical state of precursors.« less

Nitrogen–doped graphitized carbon shell encapsulated NiFe nanoparticles: A highly durable oxygen evolution catalyst

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

Du, Lei; Luo, Langli; Feng, Zhenxing

Oxygen evolution reaction (OER) plays a crucial role in various energy conversion devices such as water electrolyzers and metal–air batteries. Precious metal catalysts such as Ir, Ru and their oxides are usually used for enhancing reaction kinetics but are limited by their scarcity. The challenges associated with alternative non–precious metal catalysts such as transition metal oxides and (oxy)hydroxides are their low electronic conductivity and durability. The carbon encapsulating transition metal nanoparticles are expected to address these challenges. However, the relationship between precursor compositions and catalyst properties, and the intrinsic functions of each component has been rarely studied. In this paper,more » we report a highly durable (no degradation after 20,000 cycles) and highly active (360 mV overpotential at 10 mA cm –2 GEO) OER catalyst derived from bimetallic metal–organic frameworks (MOFs) precursors. This catalyst consists of NiFe nanoparticles encapsulated by nitrogen–doped graphitized carbon shells. The electron–donation/deviation from Fe and tuned lattice and electronic structures of metal cores by Ni are revealed to be primary contributors to the enhanced OER activity, whereas N concentration contributes negligibly. Finally, we further demonstrated that the structure and morphology of encapsulating carbon shells, which are the key factors influencing the durability, are facilely controlled by the chemical state of precursors.« less

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.

Habitats and Surface Construction Technology and Development Roadmap

NASA Technical Reports Server (NTRS)

Cohen, Marc; Kennedy, Kriss J.

1997-01-01

The vision of the technology and development teams at NASA Ames and Johnson Research Centers is to provide the capability for automated delivery and emplacement of habitats and surface facilities. The benefits of the program are as follows: Composites and Inflatables: 30-50% (goal) lighter than Al Hard Structures; Capability for Increased Habitable Volume, Launch Efficiency; Long Term Growth Potential; and Supports initiation of commercial and industrial expansion. Key Habitats and Surface Construction (H&SC) technology issues are: Habitat Shell Structural Materials; Seals and Mechanisms; Construction and Assembly: Automated Pro-Deploy Construction Systems; ISRU Soil/Construction Equipment: Lightweight and Lower Power Needs; Radiation Protection (Health and Human Performance Tech.); Life Support System (Regenerative Life Support System Tech.); Human Physiology of Long Duration Space Flight (Health and Human Performance Tech.); and Human Psychology of Long Duration Space Flight (Health and Human Performance Tech.) What is being done regarding these issues?: Use of composite materials for X-38 CRV, RLV, etc.; TransHAB inflatable habitat design/development; Japanese corporations working on ISRU-derived construction processes. What needs to be done for the 2004 Go Decision?: Characterize Mars Environmental Conditions: Civil Engineering, Material Durability, etc.; Determine Credibility of Inflatable Structures for Human Habitation; and Determine Seal Technology for Mechanisms and Hatches, Life Cycle, and Durability. An overview encompassing all of the issues above is presented.

Materials Science of Electrodes and Interfaces for High-Performance Organic Photovoltaics

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

Marks, Tobin

The science of organic photovoltaic (OPV) cells has made dramatic advances over the past three years with power conversion efficiencies (PCEs) now reaching ~12%. The upper PCE limit of light-to-electrical power conversion for single-junction OPVs as predicted by theory is ~23%. With further basic research, the vision of such devices, composed of non-toxic, earth-abundant, readily easily processed materials replacing/supplementing current-generation inorganic solar cells may become a reality. Organic cells offer potentially low-cost, roll-to-roll manufacturable, and durable solar power for diverse in-door and out-door applications. Importantly, further gains in efficiency and durability, to that competitive with inorganic PVs, will require fundamental,more » understanding-based advances in transparent electrode and interfacial materials science and engineering. This team-science research effort brought together an experienced and highly collaborative interdisciplinary group with expertise in hard and soft matter materials chemistry, materials electronic structure theory, solar cell fabrication and characterization, microstructure characterization, and low temperature materials processing. We addressed in unconventional ways critical electrode-interfacial issues underlying OPV performance -- controlling band offsets between transparent electrodes and organic active-materials, addressing current loss/leakage phenomena at interfaces, and new techniques in cost-effective low temperature and large area cell fabrication. The research foci were: 1) Theory-guided design and synthesis of advanced crystalline and amorphous transparent conducting oxide (TCO) layers which test our basic understanding of TCO structure-transport property relationships, and have high conductivity, transparency, and tunable work functions but without (or minimizing) the dependence on indium. 2) Development of theory-based understanding of optimum configurations for the interfaces between oxide electrodes/interfacial layers and OPV active layer organic molecules/polymers. 3) Exploration and perfection of new processing strategies and cell architectures for the next-generation, large-area flexible OPVs. The goal has been to develop for the solar energy community the fundamental scientific understanding needed to design, fabricate, prototype, and ultimately test high-efficiency cells incorporating these new concepts. We achieved success in all of these directions.« less

Dynamics of a durable commodity market involving trade at disequilibrium

NASA Astrophysics Data System (ADS)

Panchuk, A.; Puu, T.

2018-05-01

The present work considers a simple model of a durable commodity market involving two agents who trade stocks of two different types. Stock commodities, in contrast to flow commodities, remain on the market from period to period and, consequently, there is neither unique demand function nor unique supply function exists. We also set up exact conditions for trade at disequilibrium, the issue being usually neglected, though a fact of reality. The induced iterative system has infinite number of fixed points and path dependent dynamics. We show that a typical orbit is either attracted to one of the fixed points or eventually sticks at a no-trade point. For the latter the stock distribution always remains the same while the price displays periodic or chaotic oscillations.

An Interdisciplinary Design Project in Second Life: Creating a Virtual Marine Science Learning Environment

ERIC Educational Resources Information Center

Triggs, Riley; Jarmon, Leslie; Villareal, Tracy A.

2010-01-01

Virtual environments can resolve many practical and pedagogical challenges within higher education. Economic considerations, accessibility issues, and safety concerns can all be somewhat alleviated by creating learning activities in a virtual space. Because of the removal of real-world physical limitations like gravity, durability and scope,…

The Impact of Training and Equipment at the Battle of Attu, Aleutian Campaign - Historical Study and Current Perspective

DTIC Science & Technology

2015-06-12

Waterproofed - Not durable past a few days Jacket Reversible ski parka (R) - Hood - More protection from wind and rain Arctic field jacket (I...No hood - Less protection from wind and rain Sweater Recommended - Necessity in extreme cold based on Alaska experience Not issued - Not

Elite Education and the State in France: Durable Ties and New Challenges

ERIC Educational Resources Information Center

van Zanten, Agnès; Maxwell, Claire

2015-01-01

Employing a Weberian understanding of the centrality of a strong bureaucracy in the modern nation-state, this article examines the relationship between the state and elite education in France. Through a historical analysis and an examination of two current issues facing education--widening participation and pressures to internationalise--we…

Ultraviolet weathering of photostabilized wood-flour-filled high-density polyethylene composites

Treesearch

Nicole M. Stark; Laurent M. Matuana

2003-01-01

Wood–plastic composites are being increasingly examined for nonstructural or semistructural building applications. As outdoor applications become more widespread, durability becomes an issue. Ultraviolet exposure can lead to photodegradation, which results in a change in appearance and/or mechanical properties. Photodegradation can be slowed through the addition of...

Turbine Engine Hot Section Technology (HOST)

NASA Technical Reports Server (NTRS)

1982-01-01

Research and plans concerning aircraft gas turbine engine hot section durability problems were discussed. Under the topics of structural analysis, fatigue and fracture, surface protective coatings, combustion, turbine heat transfer, and instrumentation specific points addressed were the thermal and fluid environment around liners, blades, and vanes, material coatings, constitutive behavior, stress-strain response, and life prediction methods for the three components.

Eco-friendly GGBS Concrete: A State-of-The-Art Review

NASA Astrophysics Data System (ADS)

Saranya, P.; Nagarajan, Praveen; Shashikala, A. P.

2018-03-01

Concrete is the most commonly used material in the construction industry in which cement is its vital ingredient. Although the advantages of concrete are many, there are side effects leading to environmental issues. The manufacturing process of cement emits considerable amount of carbon dioxide (CO2). Therefore is an urgent need to reduce the usage of cement. Ground Granulated Blast furnace Slag (GGBS) is a by-product from steel industry. It has good structural and durable properties with less environmental effects. This paper critically reviews the literatures available on GGBS used in cement concrete. In this paper, the literature available on GGBS are grouped into engineering properties of GGBS concrete, hydraulic action of GGBS in concrete, durability properties of GGBS concrete, self- compacting GGBS concrete and ultrafine GGBS are highlighted. From the review of literature, it was found that the use of GGBS in concrete construction will be eco-friendly and economical. The optimum percentage of replacement of cement by GGBS lies between 40 - 45 % by weight. New materials that can be added in addition to GGBS for getting better strength and durability also highlighted.

RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: SINGLE CELL TESTS

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

X. Zhang; J. E. O'Brien; R. C. O'Brien

2012-07-01

An experimental investigation on the performance and durability of single solid oxide electrolysis cells (SOECs) is under way at the Idaho National Laboratory. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOECs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. A new test apparatus has been developed for single cell and small stack tests from different vendors. Single cells from Ceramatec Inc. show improved durability compared to our previous stack tests. Single cells from Materials and Systems Research Inc. (MSRI) demonstrate low degradation both in fuel cellmore » and electrolysis modes. Single cells from Saint Gobain Advanced Materials (St. Gobain) show stable performance in fuel cell mode, but rapid degradation in the electrolysis mode. Electrolyte-electrode delamination is found to have significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the microstructure help to mitigate degradation. Polarization scans and AC impedance measurements are performed during the tests to characterize the cell performance and degradation.« less

Assessment of structural valve deterioration of transcatheter aortic bioprosthetic balloon-expandable valves using the new European consensus definition.

PubMed

Eltchaninoff, Hélène; Durand, Eric; Avinée, Guillaume; Tron, Christophe; Litzler, Pierre-Yves; Bauer, Fabrice; Dacher, Jean-Nicolas; Werhlin, Camille; Bouhzam, Najime; Bettinger, Nicolas; Candolfi, Pascal; Cribier, Alain

2018-03-30

Durability of transcatheter aortic bioprosthetic valves remains a major issue. Standardised definitions of deterioration and failure of bioprosthetic valves have recently been proposed. The aim of this study was to assess structural transcatheter valve deterioration (SVD) and bioprosthetic valve failure (BVF) using these new definitions. All TAVI patients implanted up to September 2012 with a minimal theoretical five-year follow-up were included. Systematic clinical and echocardiographic follow-up was performed annually. New standardised definitions were used to assess durability of transcatheter aortic bioprosthetic valves. From 2002 to 2012, 378 patients were included. Mean age and logistic EuroSCORE were 83.3±6.8 years and 22.8±13.1%. Thirty-day mortality was 13.2%. Nine patients had SVD including two severe forms and two patients had definite late BVF. The incidence of SVD and BVF at eight years was 3.2% (95% CI: 1.45-6.11) and 0.58% (95% CI: 0.15-2.75), respectively. Even though limited by the poor survival of the very high-risk/compassionate early population, our data do not demonstrate any alarm concerning transcatheter aortic valve durability. Careful prospective assessment in younger and lower-risk patients and comparison with surgical bioprosthetic valves are required for further assessment of the long-term durability of transcatheter valves.

DROP: Durable Reconnaissance and Observation Platform

NASA Technical Reports Server (NTRS)

Parness, Aaron; McKenzie, Clifford F.

2012-01-01

Robots have been a valuable tool for providing a remote presence in areas that are either inaccessible or too dangerous for humans. Having a robot with a high degree of adaptability becomes crucial during such events. The adaptability that comes from high mobility and high durability greatly increases the potential uses of a robot in these situations, and therefore greatly increases its usefulness to humans. DROP is a lightweight robot that addresses these challenges with the capability to survive large impacts, carry a usable payload, and traverse a variety of surfaces, including climbing vertical surfaces like wood, stone, and concrete. The platform is crash-proof, allowing it to be deployed in ways including being dropped from an unmanned aerial vehicle or thrown from a large MSL-class (Mars Science Laboratory) rover.

Beyond Evolution: Addressing Broad Interactions Between Science and Religion in Science Teacher Education

NASA Astrophysics Data System (ADS)

Shane, Joseph W.; Binns, Ian C.; Meadows, Lee; Hermann, Ronald S.; Benus, Matthew J.

2016-03-01

Science and religion are two indisputably profound and durable cultural forces with a complex history of interaction. As ASTE members are aware, these interactions often manifest themselves in classrooms and in the surrounding communities. In this essay, we encourage science teacher educators to broaden their perspectives of science-religion interactions so that they may better assist pre- and in-service science teachers with addressing topics such as the age and origins of the universe and biological evolution in an appropriate manner. We first introduce some foundational scholarship into the historical interactions between science and religion as well as current efforts to maintain healthy dialogue between perspectives that are frequently characterized as innately in conflict with or mutually exclusive of one another. Given that biological evolution is the dominant science-religion issue of our day, in particular in the USA, we next summarize the origins and strategies of anti-evolution movements via the rise and persistence of Christian Fundamentalism. We then summarize survey and qualitative sociological research indicating disparities between academic scientists and the general public with regard to religious beliefs to help us further understand our students' worldviews and the challenges they often face in campus-to-classroom transitions. We conclude the essay by providing resources and practical suggestions, including legal considerations, to assist science teacher educators with their curriculum and outreach.

An Improved Metal-Packaged Strain Sensor Based on A Regenerated Fiber Bragg Grating in Hydrogen-Loaded Boron–Germanium Co-Doped Photosensitive Fiber for High-Temperature Applications

PubMed Central

Tu, Yun; Ye, Lin; Zhou, Shao-Ping; Tu, Shan-Tung

2017-01-01

Local strain measurements are considered as an effective method for structural health monitoring of high-temperature components, which require accurate, reliable and durable sensors. To develop strain sensors that can be used in higher temperature environments, an improved metal-packaged strain sensor based on a regenerated fiber Bragg grating (RFBG) fabricated in hydrogen (H2)-loaded boron–germanium (B–Ge) co-doped photosensitive fiber is developed using the process of combining magnetron sputtering and electroplating, addressing the limitation of mechanical strength degradation of silica optical fibers after annealing at a high temperature for regeneration. The regeneration characteristics of the RFBGs and the strain characteristics of the sensor are evaluated. Numerical simulation of the sensor is conducted using a three-dimensional finite element model. Anomalous decay behavior of two regeneration regimes is observed for the FBGs written in H2-loaded B–Ge co-doped fiber. The strain sensor exhibits good linearity, stability and repeatability when exposed to constant high temperatures of up to 540 °C. A satisfactory agreement is obtained between the experimental and numerical results in strain sensitivity. The results demonstrate that the improved metal-packaged strain sensors based on RFBGs in H2-loaded B–Ge co-doped fiber provide great potential for high-temperature applications by addressing the issues of mechanical integrity and packaging. PMID:28241465

An Improved Metal-Packaged Strain Sensor Based on A Regenerated Fiber Bragg Grating in Hydrogen-Loaded Boron-Germanium Co-Doped Photosensitive Fiber for High-Temperature Applications.

PubMed

Tu, Yun; Ye, Lin; Zhou, Shao-Ping; Tu, Shan-Tung

2017-02-23

Local strain measurements are considered as an effective method for structural health monitoring of high-temperature components, which require accurate, reliable and durable sensors. To develop strain sensors that can be used in higher temperature environments, an improved metal-packaged strain sensor based on a regenerated fiber Bragg grating (RFBG) fabricated in hydrogen (H₂)-loaded boron-germanium (B-Ge) co-doped photosensitive fiber is developed using the process of combining magnetron sputtering and electroplating, addressing the limitation of mechanical strength degradation of silica optical fibers after annealing at a high temperature for regeneration. The regeneration characteristics of the RFBGs and the strain characteristics of the sensor are evaluated. Numerical simulation of the sensor is conducted using a three-dimensional finite element model. Anomalous decay behavior of two regeneration regimes is observed for the FBGs written in H₂-loaded B-Ge co-doped fiber. The strain sensor exhibits good linearity, stability and repeatability when exposed to constant high temperatures of up to 540 °C. A satisfactory agreement is obtained between the experimental and numerical results in strain sensitivity. The results demonstrate that the improved metal-packaged strain sensors based on RFBGs in H₂-loaded B-Ge co-doped fiber provide great potential for high-temperature applications by addressing the issues of mechanical integrity and packaging.

Durability of Ti-6Al-4V/LaRC-PETI-5 adhesive bonded system for HSCT applications

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

Parvatareddy, H.; Pasricha, A.; Dillard, D.A.

1996-12-31

Structural adhesive joints are being widely used and studied as alternatives to conventional fasteners in the aerospace, automotive, and other industries. Adhesive bonding offers advantages such as lower weight and lower manufacturing costs. Furthermore, high performance adhesives which are currently being synthesized (e.g. epoxies, phenolics, acrylics, thermoplastic polyimides) offer other useful properties such as higher modulus, higher toughness, and stability at high temperatures. In the present study, the durability of the Ti-6Al-4V/LaRC PETI-5 adhesive bonded system is being evaluated utilizing double cantilever beam (DCB) fracture specimens. These DCB tests have been used extensively to study adhesive joints. The current studymore » is part of a comprehensive study to develop a durable material system for application in the proposed mach 2.4 high speed civil transport (HSCT) aircraft. According to the design criteria, the material system to be used on the aircraft should be durable for over 60,000 hours of flight encountering temperatures during flight in the range of 177{degrees}C. Physical aging and chemical aging of the adhesive material are some of the important issues which have to be evaluated and taken into consideration for predicting the bond durability. In order to simulate the service environment conditions of the HSCT, the Ti-6Al-4V/LaRC PETI-5 bonds were aged in one of three temperatures; 150, 177, and 204{degrees}C, at one of three different environments; atmospheric air, and reduced air pressures of 2 psi air (13.8 KPa) and 0.2 psi air (1.38 KPa).« less

Improving Injectable Medicines Prescription in Outpatient Services: A Path Towards Rational Use of Medicines in Iran

PubMed Central

Bairami, Firoozeh; Soleymani, Fatemeh; Rashidian, Arash

2016-01-01

Injection is one of the most common medical procedures in the health sector. Annually up to 16 billion injections are prescribed in low- and middle-income countries (LMICs), many of them are not necessary for the patients, increase the healthcare costs and may result in side effects. Currently over 40% of outpatient prescriptions in Iran contain at least one injectable medicine. To address the issue, a working group was established (August 2014 to April 2015) to provide a comprehensive policy brief to be used by national decision-makers. This report is the extract of methods that were followed and the main policy options for improving injectable medicines prescribing in outpatient services. Thirty-three potential policy options were developed focusing on different stakeholders. The panel reached consensus on seven policy options, noting effectiveness, cost, durability, and feasibility of each policy. The recommended policy options are targeted at patients and public (2 policies), insurers (2), physicians (1), pharmacies (1), and the Ministry of Health and Medical Education (MoHME) (1). PMID:27239881

Lunar Dust on Heat Rejection System Surfaces: Problems and Prospects

NASA Technical Reports Server (NTRS)

Gaier, James R.; Jaworske, Donald A.

2007-01-01

Heat rejection from power systems will be necessary for human and robotic activity on the lunar surface. Functional operation of such heat rejection systems is at risk of degradation as a consequence of dust accumulation. The Apollo astronauts encountered marked degradation of performance in heat rejection systems for the lunar roving vehicle, science packages, and other components. Although ground testing of dust mitigation concepts in support of the Apollo mission identified mitigation tools, the brush concept adopted by the Apollo astronauts proved essentially ineffective. A better understanding of the issues associated with the impact of lunar dust on the functional performance of heat rejection systems and its removal is needed as planning gets underway for human and robotic missions to the Moon. Renewed emphasis must also be placed on ground testing of pristine and dust-covered heat rejection system surfaces to quantify degradation and address mitigation concepts. This paper presents a review of the degradation in performance of heat rejection systems encountered on the lunar surface to-date, and will discuss current activities underway to evaluate the durability of candidate heat rejection system surfaces and current dust mitigation concepts.

Study of the surfactant role in latex-aerogel systems by scanning transmission electron microscopy on aqueous suspensions.

PubMed

Perret, A; Foray, G; Masenelli-Varlot, K; Maire, E; Yrieix, B

2018-01-01

For insulation applications, boards thinner than 2 cm are under design with specific thermal conductivities lower than 15 mW m -1  K -1 . This requires binding slightly hydrophobic aerogels which are highly nanoporous granular materials. To reach this step and ensure insulation board durability at the building scale, it is compulsory to design, characterise and analyse the microstructure at the nanoscale. It is indeed necessary to understand how the solid material is formed from a liquid suspension. This issue is addressed in this paper through wet-STEM experiments carried out in an Environmental Scanning Electron Microscope (ESEM). Latex-surfactant binary blends and latex-surfactant-aerogel ternary systems are studied, with two different surfactants of very different chemical structures. Image analysis is used to distinguish the different components and get quantitative morphological parameters which describe the sample architecture. The evolution of such morphological parameters during water evaporation permits a good understanding of the role of the surfactant. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Suppressing Shuttle Effect Using Janus Cation Exchange Membrane for High-Performance Lithium-Sulfur Battery Separator.

PubMed

Li, Zhen; Han, Yu; Wei, Junhua; Wang, Wenqiang; Cao, Tiantian; Xu, Shengming; Xu, Zhenghe

2017-12-27

Suppressing the shuttle effect of polysulfide ions to obtain high durability and good electrochemical performance is of great concern in the field of lithium-sulfur batteries. To address this issue, a Janus membrane consisting of an ultrathin dense layer and a robust microporous layer is fabricated using cation exchange resin. Different from the composite membranes made from polyolefin membranes, the multiple layers of the Janus membrane in this study are synchronously generated by one step, getting rid of the additional complex coating processes. Excellent overall performance is obtained by the cooperation of multiple factors. The excellent ionic selectivity of cation exchange resin renders a great suppression of the shuttle effect, endowing the lithium-sulfur battery with high Coulombic efficiency of 92.0-99.0% (LiNO 3 -free electrolyte). The ultrathin property of a dense layer renders a low ionic resistance, resulting in 60% higher discharge capacity over the entire C-rates (versus the control sample with Celgard 2400 membrane). The robust macroporous layer supports the ultrathin layer to achieve a free-standing property, ensuring the usability of the Janus membrane.

A Simplified Test for Blanching Susceptibility of Copper Alloys

NASA Technical Reports Server (NTRS)

Thomas-Ogbuji, Linus U.; Humphrey, Donald; Setlock, John

2003-01-01

GRCop-84 (Cu-8Cr-4Nb) is a dispersion-strengthened alloy developed for space-launch rocket engine applications, as a liner for the combustion chamber and nozzle ramp. Its main advantage over rival alloys, particularly NARloy-Z (Cu-Ag-Zr), the current liner alloy, is in high temperature mechanical properties. Further validation required that the two alloys be compared with respect to service performance and durability. This has been done, under conditions resembling those expected in reusable launch engine applications. GRCop-84 was found to have a superior resistance to static and cyclic oxidation up to approx. 700 C. In order to improve its performance above 700 C, Cu-Cr coatings have also been developed and evaluated. The major oxidative issue with Cu alloys is blanching, a mode of degradation induced by oxidation-reduction fluctuations in hydrogen-fueled engines. That fluctuation cannot be addressed with conventional static or cyclic oxidation testing. Hence, a further evaluation of the alloy substrates and Cu-Cr coating material necessitated our devising a test protocol that involves oxidaton-reduction cycles. This paper describes the test protocols used and the results obtained.

Self-Formed Hybrid Interphase Layer on Lithium Metal for High-Performance Lithium–Sulfur Batteries

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

Li, Guoxing; Huang, Qingquan; He, Xin

Lithium–sulfur (Li–S) batteries are promising candidates for high-energy storage devices due to high theoretical capacities of both the sulfur cathode and lithium (Li) metal anode. Considerable efforts have been devoted to improving sulfur cathodes. However, issues associated with Li anodes, such as low Coulombic efficiency (CE) and growth of Li dendrites, remain unsolved due to unstable solid-electrolyte interphase (SEI) and lead to poor capacity retention and a short cycling life of Li–S batteries. In this paper, we demonstrate a facile and effective approach to fabricate a flexible and robust hybrid SEI layer through co-deposition of aromatic-based organosulfides and inorganic Limore » salts using poly(sulfur-random-1,3-diisopropenylbenzene) as an additive in an electrolyte. The aromatic-based organic components with planar backbone conformation and π–π interaction in the SEI layers can improve the toughness and flexibility to promote stable and high efficient Li deposition/dissolution. The as-formed durable SEI layer can inhibit dendritic Li growth, enhance Li deposition/dissolution CE (99.1% over 420 cycles), and in turn enable Li–S batteries with good cycling stability (1000 cycles) and slow capacity decay. Finally, this work demonstrates a route to address the issues associated with Li metal anodes and promote the development of high-energy rechargeable Li metal batteries.« less

Space propulsion

NASA Astrophysics Data System (ADS)

Kazaroff, John M.

1993-02-01

Lewis Research Center is developing broad-based new technologies for space chemical engines to satisfy long-term needs of ETO launch vehicles and other vehicles operating in and beyond Earth orbit. Specific objectives are focused on high performance LO2/LH2 engines providing moderate thrusts of 7,5-200 klb. This effort encompasses research related to design analysis and manufacturing processes needed to apply advanced materials to subcomponents, components, and subsystems of space-based systems and related ground-support equipment. High-performance space-based chemical engines face a number of technical challenges. Liquid hydrogen turbopump impellers are often so large that they cannot be machined from a single piece, yet high stress at the vane/shroud interface makes bonding extremely difficult. Tolerances on fillets are critical on large impellers. Advanced materials and fabricating techniques are needed to address these and other issues of interest. Turbopump bearings are needed which can provide reliable, long life operation at high speed and high load with low friction losses. Hydrostatic bearings provide good performance, but transients during pump starts and stops may be an issue because no pressurized fluid is available unless a separate bearing pressurization system is included. Durable materials and/or coatings are needed that can demonstrate low wear in the harsh LO2/LH2 environment. Advanced materials are also needed to improve the lifetime, reliability and performance of other propulsion system elements such as seals and chambers.

Self-Formed Hybrid Interphase Layer on Lithium Metal for High-Performance Lithium–Sulfur Batteries

DOE PAGES

Li, Guoxing; Huang, Qingquan; He, Xin; ...

2018-01-29

Lithium–sulfur (Li–S) batteries are promising candidates for high-energy storage devices due to high theoretical capacities of both the sulfur cathode and lithium (Li) metal anode. Considerable efforts have been devoted to improving sulfur cathodes. However, issues associated with Li anodes, such as low Coulombic efficiency (CE) and growth of Li dendrites, remain unsolved due to unstable solid-electrolyte interphase (SEI) and lead to poor capacity retention and a short cycling life of Li–S batteries. In this paper, we demonstrate a facile and effective approach to fabricate a flexible and robust hybrid SEI layer through co-deposition of aromatic-based organosulfides and inorganic Limore » salts using poly(sulfur-random-1,3-diisopropenylbenzene) as an additive in an electrolyte. The aromatic-based organic components with planar backbone conformation and π–π interaction in the SEI layers can improve the toughness and flexibility to promote stable and high efficient Li deposition/dissolution. The as-formed durable SEI layer can inhibit dendritic Li growth, enhance Li deposition/dissolution CE (99.1% over 420 cycles), and in turn enable Li–S batteries with good cycling stability (1000 cycles) and slow capacity decay. Finally, this work demonstrates a route to address the issues associated with Li metal anodes and promote the development of high-energy rechargeable Li metal batteries.« less

76 FR 22311 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-21

... a report of fatigue cracking of the wing upper and lower rainbow fittings during durability testing... are susceptible to multiple site fatigue damage. We are issuing this AD to detect and correct such fatigue cracks, which could grow large and lead to the failure of the fitting and a catastrophic failure...

Predicting current serviceability and residual service life of plywood roof sheathing using kinetics-based models

Treesearch

J.E. Winandy; P.K. Lebow; J.F. Murphy

2002-01-01

Research programs throughout North America are increasingly focusing on understanding and defining the salient issues of wood durability and maintaining and extending the serviceability of existing wood structures. This report presents the findings and implications of a 10-year research program, carried out at the USDA Forest Service, Forest Products Laboratory, to...

Natural durability of tropical and native woods against termite damage by Reticulitermes flavipes (Kollar)

Treesearch

Rachel A. Arango; Frederick Green; Kristina Hintz; Patricia K. Lebow; Regis B. Miller

2006-01-01

Environmental pressure has resulted in voluntary removal of chromated copper arsenate (CCA) from wood preservatives in residential applications in the United States. A new generation of copper organic preservatives was formulated as replacements, but these preservatives may not provide a permanent solution to all related problems. Some of these issues include concern...

19 CFR 18.4a - Containers or road vehicles accepted for transport under customs seal; requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... under customs seal; requirements. 18.4a Section 18.4a Customs Duties U.S. CUSTOMS AND BORDER PROTECTION... General Provisions § 18.4a Containers or road vehicles accepted for transport under customs seal... under Customs seal (see § 18.4) if (i) durably marked with the name and address of the owner...

Keratin Durability Has Implications for the Fossil Record: Results from a 10 Year Feather Degradation Experiment

PubMed Central

Moyer, Alison E.; Zheng, Wenxia; Schweitzer, Mary H.

2016-01-01

Keratinous ‘soft tissue’ structures (i.e. epidermally derived and originally non-biomineralized), include feathers, skin, claws, beaks, and hair. Despite their relatively common occurrence in the fossil record (second only to bone and teeth), few studies have addressed natural degradation processes that must occur in all organic material, including those keratinous structures that are incorporated into the rock record as fossils. Because feathers have high preservation potential and strong phylogenetic signal, in the current study we examine feathers subjected to different burial environments for a duration of ~10 years, using transmission electron microscopy (TEM) and in situ immunofluorescence (IF). We use morphology and persistence of specific immunoreactivity as indicators of preservation at the molecular and microstructural levels. We show that feather keratin is durable, demonstrates structural and microstructural integrity, and retains epitopes suitable for specific antibody recognition in even the harshest conditions. These data support the hypothesis that keratin antibody reactivity can be used to identify the nature and composition of epidermal structures in the rock record, and to address evolutionary questions by distinguishing between alpha- (widely distributed) and beta- (limited to sauropsids) keratin. PMID:27384819

U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications.

PubMed

Houchins, Cassidy; Kleen, Greg J; Spendelow, Jacob S; Kopasz, John; Peterson, David; Garland, Nancy L; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C

2012-12-18

Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed.

Complexing Agents and pH Influence on Chemical Durability of Type I Molded Glass Containers.

PubMed

Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

2017-01-01

Among the factors that affect the glass surface chemical durability, pH and complexing agents present in aqueous solution have the main role. Glass surface attack can be also related to the delamination issue causing glass particles' appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed. The present study emphasizes the possible synergy between a few complexing agents with pH on borosilicate glass chemical durability.Hydrolytic attack was performed in small-volume 23 mL type I glass containers autoclaved according to the European Pharmacopoeia or United States Pharmacopeia for 1 h at 121 °C, in order to enhance the chemical attack due to time, temperature, and the unfavorable surface/volume ratio. Solutions of 0.048 M or 0.024 M (M/L) of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid), together with sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ±0.05 units at fixed values 5.5, 6.6, 7, 7.4, 8, and 9 by LiOH diluted solution.Because silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by inductively coupled plasma atomic emission spectrophotometry. The work was completed by the analysis of the silicon release in the worst attack conditions of molded glass, soda lime type II glass, and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by scanning electron microscopy was finally performed to check for the surface status after the worst chemical attack condition by citric acid. LAY ABSTRACT: Glass, like every packaging material, can have some usage limits, mainly in basic pH solutions. The issue of glass surface degradation particles that appear in vials (delamination) has forced a number of drug product recalls in recent years. To prevent such situations, pharmaceutical and biopharmaceutical manufacturers need to understand the reasons for accelerate surface glass corrosion mainly in the case of injectables.Some drugs can contain active components with known ability to corrode glass silica networks. Sometimes these ingredients are dissolved in an alkaline medium that dramatically increases the glass corrosion and potentially causes the issue. As this action is strongly affected by time and temperature, flaking may become visible only after a long storage time. The purpose of this investigation is to verify the borosilicate glass chemical durability during controlled conditions of time and temperature when in contact with testing solutions containing different complexing agents by varying the pH. Si concentration in the extract solution is taken as an index of glass dissolution during constant autoclaving conditions for 1 h at 121 °C, which simulates approximately five years of contact at room temperature.Acetate, citrate, ethylenediaminetetraacetic acid (EDTA), phosphate, and glutarate 0.048 M or 0.024 M solutions were used at increasing pH from 5.5 to 9.0. The chemical durability of two borosilicate tubing glass vials of different glass compositions were compared with the molded one in the worst attack conditions by citric acid. Even if no delamination issue has been experienced by this study in type I molded and tubing containers, the conclusions developed can provide pharmaceutical manufacturers with useful information to prevent glass delamination risk in their processes. © PDA, Inc. 2017.

Evaluation of the durability of composite tidal turbine blades.

PubMed

Davies, Peter; Germain, Grégory; Gaurier, Benoît; Boisseau, Amélie; Perreux, Dominique

2013-02-28

The long-term reliability of tidal turbines is critical if these structures are to be cost effective. Optimized design requires a combination of material durability models and structural analyses. Composites are a natural choice for turbine blades, but there are few data available to predict material behaviour under coupled environmental and cycling loading. The present study addresses this problem, by introducing a multi-level framework for turbine blade qualification. At the material scale, static and cyclic tests have been performed, both in air and in sea water. The influence of ageing in sea water on fatigue performance is then quantified, and much lower fatigue lives are measured after ageing. At a higher level, flume tank tests have been performed on three-blade tidal turbines. Strain gauging of blades has provided data to compare with numerical models.

Durability Issues for the Protection of Materials from Atomic Oxygen Attack in Low Earth Orbit

NASA Astrophysics Data System (ADS)

Banks, B. A.; Lenczewski, M.; Demko, R.

2002-01-01

Low Earth orbital atomic oxygen is capable of eroding most polymeric materials typically used on spacecraft. Solar array blankets, thermal control polymers, and carbon fiber matrix composites are readily oxidized to become thinner and less capable of supporting the loads imposed upon them. Protective coatings have been developed that are or become durable to atomic oxygen to prevent oxidative erosion of the underlying polymers. However, the details of the chemistry, surface roughness and coating configuration can play a significant role as to whether or not the coating provides long duration atomic oxygen protection. Identical coatings on different surface roughness surfaces can produce drastically have drastically different durability results. Poor choice of protective coatings or self-protecting materials can also result in contamination of surrounding spacecraft surfaces. Such contamination can deposit on optical or thermal control surfaces resulting in changes in solar absorbtance, transmittance and reflectance of surfaces. Examples of successful and unsuccessful techniques used for atomic oxygen durability or protection will be presented based on actual results from low Earth orbital spacecraft. Investigations of the causes of undesired consequences or protective coating failures will be presented including ground laboratory experimental analysis as well as computational modeling. Atomic oxygen protective coating results from various low Earth orbital missions including the Long Duration Exposure Facility, the European Retrievable Carrier, Mir, and International Space Station will be presented to illustrate examples of protection successes as well as failures including analyses of the causes for the differences and proposed solutions.

Rambutan-like CNT-Al2O3 scaffolds for high-performance cathode catalyst layers of polymer electrolyte fuel cells

NASA Astrophysics Data System (ADS)

Chang, KwangHyun; Cho, Seonghun; Lim, Eun Ja; Park, Seok-Hee; Yim, Sung-Dae

2018-03-01

Rambutan-like CNT-Al2O3 scaffolds are introduced as a potential candidate for CNT-based catalyst supports to overcome the CNT issues, such as the easy bundling in catalyst ink and the poor pore structure of the CNT-based catalyst layers, and to achieve high MEA performance in PEFCs. Non-porous α-phase Al2O3 balls are introduced to enable the growth of multiwalled CNTs, and Pt nanoparticles are loaded onto the CNT surfaces. In a half-cell, the Pt/CNT-Al2O3 catalyst shows much higher durability than those of a commercial Pt/C catalyst even though it shows lower oxygen reduction reaction (ORR) activity than Pt/C. After using the decal process for MEA formation, the Pt/CNT-Al2O3 shows comparable initial performance characteristics to Pt/C, overcoming the lower ORR activity, mainly due to the facile oxygen transport in the cathode catalyst layers fabricated with the CNT-Al2O3 scaffolds. The Pt/CNT-Al2O3 also exhibits much higher durability against carbon corrosion than Pt/C owing to the durable characteristics of CNTs. Systematic analysis of single cell performance for both initial and after degradation is provided to understand the origin of the high initial performance and durable behavior of Pt/CNT-Al2O3-based catalyst layers. This will provide insights into the design of electrocatalysts for high-performance MEAs in PEFCs.

Enhancing the Chemical and Mechanical Durability of Polymer Electrolyte Membranes for Fuel Cell Applications

NASA Astrophysics Data System (ADS)

Baker, Andrew M.

Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices which generate electricity from the electrochemical reaction of hydrogen and oxygen. Currently, widespread adoption of PEM fuel cell technology is hindered by low component durability and high costs. In this work, strategies were investigated to improve the mechanical and chemical durability of the ion conducting polymer, or ionomer, which comprises the PEM, in order to directly address these limitations. Owing to their exceptional mechanical properties, carbon nanotubes (CNTs) were investigated for mechanical reinforcement of the PEM. Because of their electronic conductivity, which diminishes cell performance, two strategies were developed to enable the use of CNTs as PEM reinforcement. These systems result in enhanced mechanical properties without sacrificing performance of the PEM during operation. Further, when coated with ceria (CeO2), which scavenges radicals that are generated during operation and cause PEM chemical degradation by attacking vulnerable chemical groups in the ionomer, MWCNTs further improved PEM chemical durability. During cell fabrication, conditioning, and discharge, Ce rapidly migrates between the PEM and catalyst layers (CLs), which reduces catalyst efficiency and leaves areas of the cell defenseless against radical attacks. Therefore, in order to stabilize Ce and localize it to areas of highest radical generation, it is critical to understand and identify the relative influences of different migration mechanisms. Using a novel elemental analysis technique, Ce migration was characterized due to potential and concentration gradients, water flux, and degradation of Ce-exchanged sulfonic acid groups within the PEM. Additionally, Zr-doped ceria was employed to resist migration due to ionomer degradation which improved cell durability, without reducing performance, resulting in PEM Ce stabilization near its initial concentrations after > 1,400 hours of testing. Ce was not observed to leave the cell during stress testing, however, it does irreversibly accumulate in the CLs, which reduces its scavenging efficacy in the system. In order to model Ce migration during fuel cell operation, the relevant Ce transport coefficients were determined under a range of conditions. This knowledge enables the development of additional system control and material engineering strategies to mitigate Ce migration in order to reduce performance losses and improve cell durability.

Optimizing dentin bond durability: control of collagen degradation by matrix metalloproteinases and cysteine cathepsins

PubMed Central

Tjäderhane, Leo; Nascimento, Fabio D.; Breschi, Lorenzo; Mazzoni, Annalisa; Tersariol, Ivarne L.S.; Geraldeli, Saulo; Tezvergil-Mutluay, Arzu; Carrilho, Marcela R.; Carvalho, Ricardo M.; Tay, Franklin R.; Pashley, David H.

2012-01-01

Objectives Contemporary adhesives lose their bond strength to dentin regardless of the bonding system used. This loss relates to the hydrolysis of collagen matrix of the hybrid layers. The preservation of the collagen matrix integrity is a key issue in the attempts to improve the dentin bonding durability. Methods Dentin contains collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins, which are responsible for the hydrolytic degradation of collagen matrix in the bonded interface. Results The identities, roles and function of collagenolytic enzymes in mineralized dentin has been gathered only within last 15 years, but they have already been demonstrated to have an important role in dental hard tissue pathologies, including the degradation of the hybrid layer. Identifying responsible enzymes facilitates the development of new, more efficient methods to improve the stability of dentin-adhesive bond and durability of bond strength. Significance Understanding the nature and role of proteolytic degradation of dentin-adhesive interfaces has improved immensely and has practically grown to a scientific field of its own within only 10 years, holding excellent promise that stable resin-dentin bonds will be routinely available in a daily clinical setting already in a near future. PMID:22901826

Management of tricuspid regurgitation

PubMed Central

Taramasso, Maurizio; Lapenna, Elisabetta; Alfieri, Ottavio

2014-01-01

Secondary tricuspid regurgitation is the most frequent type of tricuspid insufficiency in western countries. Its surgical treatment is still an object of debate both in terms of timing and surgical techniques. Until recently, the avoidance of surgery for tricuspid repair was commonly accepted in patients with less than severe secondary tricuspid regurgitation undergoing left-sided valve surgery. More recently, compelling evidence in favour of a more aggressive surgical approach in this setting has emerged. The surgical technique should be tailored to the stage of disease. Ring annuloplasty is more durable than suture annuloplasty and represents the method of choice in the presence of isolated annular dilatation. In patients in whom the dilatation of the tricuspid annulus is combined with significant leaflet tethering, annuloplasty alone is unlikely to be durable and additional procedures have been proposed in order to achieve a more durable repair. In this review, pathophysiology, surgical indications, techniques of repair and outcomes of secondary tricuspid regurgitation will be discussed. We will also focus on the challenging issue of significant tricuspid regurgitation occurring late after left-sided valve surgery. Finally, the current and future role of percutaneous tricuspid valve technologies will be briefly described. PMID:25184048

Durability Assessment of TiAl Alloys

NASA Technical Reports Server (NTRS)

Draper, Susan L.; Lerch, Bradley A.

2008-01-01

The durability of TiAl is a prime concern for the implementation of TiAl into aerospace engines. Two durability issues, the effect of high temperature exposure on mechanical properties and impact resistance, have been investigated and the results are summarized in this paper. Exposure to elevated temperatures has been shown to be detrimental to the room temperature ductility of gamma alloys with the most likely mechanisms being the ingress of interstitials from the surface. Fluorine ion implantation has been shown to improve the oxidation resistance of gamma alloys, and ideally it could also improve the environmental embrittlement of high Nb content TiAl alloys. The effect of F ion implantation on the surface oxidation and embrittlement of a third generation, high Nb content TiAl alloy (Ti-45Al-5Nb-B-C) were investigated. Additionally, the ballistic impact resistance of a variety of gamma alloys, including Ti-48Al-2Cr- 2Nb, Ti-47Al-2Cr-2Nb, ABB-2, ABB-23, NCG359E, 95A and Ti-45Al-5Nb-B-C was accessed. Differences in the ballistic impact properties of the various alloys will be discussed, particularly with respect to their manufacturing process, microstructure, and tensile properties.

Bridge Workshop : Enhancing Bridge Performance, February 21-22, 2008, Reston, Virginia : workshop report

Treesearch

Sreenivas Alampalli; Sheila Rimal Duwadi; Reagan Sentelle Herman; Danielle D. Kleinhans; Khaled Mahmoud; James C. Ray; James P. Wacker; Nur Yazdani

2008-01-01

The participants to the workshop were given the charge to discuss (1) bridge design issues including best practices in design and detailing that could be used to improve durability, extend service life and prevent premature deterioration, (2) performance measures needed to better determine bridge condition, (3) technologies that could be used to monitor bridge life and...

Issues related to durability and protection affecting the acceptance and use of engineered wood composites in Europe

Treesearch

Mark Hughes; Jerrold E. Winandy

2007-01-01

Engineered wood composites (EWC) offer significant potential in applications in the built environment, ranging from domestic dwellings to bridges and public buildings. Nevertheless, EWCs, which include products such as glulam, laminated veneer lumber, oriented stand-board, and plywood enjoy a relatively small market share of total wood-based material production and...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2014 CFR

2014-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2010 CFR

2010-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2011 CFR

2011-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

10 CFR 32.29 - Conditions of licenses issued under § 32.26: Quality control, labeling, and reports of transfer.

Code of Federal Regulations, 2013 CFR

2013-01-01

... standards approved by the Commission; (b) Label or mark each detector and its point-of-sale package so that: (1) Each detector has a durable, legible, readily visible label or marking on the external surface of the detector containing: (i) The following statement: “CONTAINS RADIOACTIVE MATERIAL”; (ii) The name...

Doing Windows: Non-Traditional Military Responses to Complex Emergencies

DTIC Science & Technology

1997-09-01

achieving civil stability and durable peace in states embroiled in complex emergencies. A complex emergency is one which draws every sector of society ...a stable, civil society ? The project involved three distinct phases. First, we conducted an extensive literature review to frame the issues used in...Pursue sustainable security through prevention, mitigation, and preparedness Integrate existing capacities of all elements of society

Children's books and the nature of science: A multisite naturalistic case study of three elementary teachers in the rural southeast

NASA Astrophysics Data System (ADS)

Bricker, Patricia Lynn

This naturalistic case study describes the efforts of three elementary teachers in a rural southeastern school to use children's books in support of inquiry-based science and specifically addresses issues related to the nature of science. Data were collected through 26 classroom and meeting observations, 16 semi-structured and informal interviews, 35 documents and 76 children's books used by the teachers. Three themes were identified related to the nature of science and the selection and use of children's books in the teachers' second, fourth, and fifth grade classrooms. (1) Science was portrayed as a human endeavor that connects to the lives of people and that involves fascination, passion, and interest; imagination and creativity; values; and diverse views. The collection of books was analyzed to look specifically at race, culture, and gender issues. While women, people of color, and different cultures were represented in the book collection, they were not represented well when considering the collection as a whole. (2) Books and the teachers' use of them supported firsthand investigation of the natural world and the idea that empirical evidence underlies scientific understanding. This theme involved observation and journaling, identification of questions to investigate and procedures to use, reasonable interpretations of results, and inferential thinking. (3) Books helped teach about the durable body of scientific knowledge we have discovered over time. They were used to broaden background knowledge and as references after firsthand investigations. The complexity of science education is revealed in these cases. The teachers were able to artfully balance multiple aspects of the nature of science in their book selection and presentation. Particularly promising aspects include their work to use fiction and poetry to promote connections between imagination, creativity and science and their innovative use of books to help students interpret data and infer. Important aspects of the nature of science were not addressed in these themes---including the tentative nature of knowledge, the unknowns we have about the natural world, and an understanding of scientific theories and laws. Issues of race, culture, and gender in the books revealed the crucial need to help teachers embrace critical ways of thinking.

(Durability of building materials and components)

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

Naus, D.J.

1990-11-27

The traveler participated in the fourth meeting of RILEM 100-TSL, Techniques for Service Life Prediction,'' and The Fifth International Conference on Durability of Building Materials and Components.'' In addition, the traveler met with staff members at Taywood Engineering Ltd., Electricite de France, and AEA Technology. The meeting pertained to performance of concrete materials in nuclear power plant structures, time variation of concrete material properties, methods for evaluating concrete structures, and modeling to predict the effects of degradation factors on concrete materials. As many of the concrete structures in general civil engineering applications as well as nuclear power plant applications inmore » Europe are aging, there is increasing emphasis on assessing the durability of these structures. Information was provided of direct application to the Structural Aging Program which would not have been available without these visits. Of equal, or possibly more importance, was the individual contacts established at the organizations visited. Each organization was extremely interested in both the approach and scope of the Structural Aging Program and requested that they be informed of progress. The initial steps were taken to cooperate with several of these researchers and this should help the Structural Aging Program keep abreast of related European activities. In summary, information obtained during this trip will benefit the ongoing Structural Aging Program by informing Oak Ridge National Laboratory (ORNL) of the extensive European research programs addressing the durability of concrete structures, and also by forming and strengthening acquaintances with counterparts in other countries, thus enhancing the basis for possible international cooperation.« less

Comparison of 3 biodegradable polymer and durable polymer-based drug-eluting stents in all-comers (BIO-RESORT): rationale and study design of the randomized TWENTE III multicenter trial.

PubMed

Lam, Ming Kai; Sen, Hanim; Tandjung, Kenneth; van Houwelingen, K Gert; de Vries, Arie G; Danse, Peter W; Schotborgh, Carl E; Scholte, Martijn; Löwik, Marije M; Linssen, Gerard C M; Ijzerman, Maarten J; van der Palen, Job; Doggen, Carine J M; von Birgelen, Clemens

2014-04-01

To evaluate the safety and efficacy of 2 novel drug-eluting stents (DES) with biodegradable polymer-based coatings versus a durable coating DES. BIO-RESORT is an investigator-initiated, prospective, patient-blinded, randomized multicenter trial in 3540 Dutch all-comers with various clinical syndromes, requiring percutaneous coronary interventions (PCI) with DES implantation. Randomization (stratified for diabetes mellitus) is being performed in a 1:1:1 ratio between ORSIRO sirolimus-eluting stent with circumferential biodegradable coating, SYNERGY everolimus-eluting stent with abluminal biodegradable coating, and RESOLUTE INTEGRITY zotarolimus-eluting stent with durable coating. The primary endpoint is the incidence of the composite endpoint target vessel failure at 1 year, consisting of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization. Power calculation assumes a target vessel failure rate of 8.5% with a 3.5% non-inferiority margin, giving the study a power of 85% (α level .025 adjusted for multiple testing). The impact of diabetes mellitus on post-PCI outcome will be evaluated. The first patient was enrolled on December 21, 2012. BIO-RESORT is a large, prospective, randomized, multicenter trial with three arms, comparing two DES with biodegradable coatings versus a reference DES with a durable coating in 3540 all-comers. The trial will provide novel insights into the clinical outcome of modern DES and will address the impact of known and so far undetected diabetes mellitus on post-PCI outcome. Copyright © 2014 The Authors. Published by Mosby, Inc. All rights reserved.

On the physics of the emergence of sensorimotor control in the absence of the brain.

PubMed

Matsuno, Koichiro

2015-12-01

The evolutionary origin of sensorimotor control requires a sort of physical durability, other than Galilean inertia being accessible in third-person description in the present tense. One candidate to address this need is the 'class property' of a material body's durability remaining invariant during the exchange of component elements. Using grammatical tense as a descriptive attribute, this durability is accessible only in the frequent update of the present perfect tense in the present progressive tense at the 'now' of the present moment. In this view, the update of the perfect tense is equated with the onset and occurrence of on/off switching behavior of physical origin underlying the phenomena of sensorimotor control. Notably, the physical update of the perfect tense is specific only to the 'now and here' that is central in the tradition of phenomenology. The phenomena upholding thermodynamics, when taken apart from its theory, are decisive in facilitating the onset of sensorimotor control. Instrumental to the emergence of both life in general and sensorimotor control in particular may be the occurrence of a 'physical and chemical affinity' of the material bodies of whatever type. Such will let the constant exchange of component elements be feasible, so that the class identity equipped with the capacity for measurement is made available within the phenomenon. Material bodies constantly exchanging such component elements would make the material world open to biology by allowing each element to experience the organizational whole from within. The internal observer responsible for the origins of life may do double duty of letting itself be durable on the material basis while observing the conditions making it durable on the linguistic ground. The origins of life appear to us a material phenomenon when they are approached with use of our linguistic tools that can get rid of the strict stipulation of an abstract nature applied to the description of dynamical laws in physics. Copyright © 2015. Published by Elsevier Ltd.

Graphitic Carbon Nitride Supported Catalysts for Polymer Electrolyte Fuel Cells

PubMed Central

2014-01-01

Graphitic carbon nitrides are investigated for developing highly durable Pt electrocatalyst supports for polymer electrolyte fuel cells (PEFCs). Three different graphitic carbon nitride materials were synthesized with the aim to address the effect of crystallinity, porosity, and composition on the catalyst support properties: polymeric carbon nitride (gCNM), poly(triazine) imide carbon nitride (PTI/Li+Cl–), and boron-doped graphitic carbon nitride (B-gCNM). Following accelerated corrosion testing, all graphitic carbon nitride materials are found to be more electrochemically stable compared to conventional carbon black (Vulcan XC-72R) with B-gCNM support showing the best stability. For the supported catalysts, Pt/PTI-Li+Cl– catalyst exhibits better durability with only 19% electrochemical surface area (ECSA) loss versus 36% for Pt/Vulcan after 2000 scans. Superior methanol oxidation activity is observed for all graphitic carbon nitride supported Pt catalysts on the basis of the catalyst ECSA. PMID:24748912

Reliability Testing Using the Vehicle Durability Simulator

DTIC Science & Technology

2017-11-20

remote parameter control (RPC) software. The software is specifically designed for the data collection, analysis, and simulation processes outlined in...4516. 3. TOP 02-2-505 Inspection and Preliminary Operation of Vehicles, 4 February 1987. 4. Multi-Shaker Test and Control : Design , Test, and...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 20-11-2017 2. REPORT

U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications

PubMed Central

Houchins, Cassidy; Kleen, Greg J.; Spendelow, Jacob S.; Kopasz, John; Peterson, David; Garland, Nancy L.; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C.

2012-01-01

Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed. PMID:24958432

Archaeology and public perception of a trans-scientific problem; disposal of toxic wastes in the unsaturated zone

USGS Publications Warehouse

Winograd, Isaac Judah

1986-01-01

Predicting the effects of toxic-waste disposal on the environment over periods of millenia to hundreds of millenia is a transscientific problem; that is, one not fully addressed by quantitative scientific and engineering endeavors. Archaeology is a pertinent adjunct to such predictions in several ways. First, and foremost, archaeological records demonstrate that delicate, as well as durable, objects buried in thick unsaturated zones of arid and semiarid environments may survive intact for millenia to tens of millenia. This successful preservation of Late Paleolithic to Iron Age artifacts provides independent support for the tentative favorable conclusions of earth scientists regarding the general utility of thick unsaturated zones for toxic-waste isolation. By analogy with the archaeological record, solidified toxic wastes of low solubility that are buried in arid unsaturated zones should remain isolated from the environment indefinitely; modern man presumably should be able to improve upon the techniques used by his ancestors to isolate and preserve their sacred and utilitarian objects. Second, archaeological evidence pertinent to the fate of objects buried in unsaturated zones-although qualitative in nature and subject to the limitations of arguments by analogy-is meaningful to the public and to the courts who, with some scientists and engineers, are reluctant to rely exclusively on computer-generated predictions of the effects of buried toxic wastes on the environment. Third, the archaeological record issues a warning that our descendants may intrude into our waste disposal sites and that we must therefore take special measures to minimize such entry and, if it occurs, to warn of the dangers by a variety of symbols. And fourth, archaeology provides a record of durable natural and manmade materials that may prove to be suitable for encapsulation of our wastes and from which we can construct warning markers that will last for millenia. For these four reasons, archaeologists must join with earth scientists, and other scientists and engineers, in addressing the likely fate of solidfied toxic wastes buried in the thick (200-600 m) unsaturated zones of arid and semiarid regions. Indeed, the input of archaeology might be crucial to public acceptance of even the most carefully chosen and technically sound waste repository.

Genetic Predictors of Response to Systemic Therapy in Esophagogastric Cancer.

PubMed

Janjigian, Yelena Y; Sanchez-Vega, Francisco; Jonsson, Philip; Chatila, Walid K; Hechtman, Jaclyn F; Ku, Geoffrey Y; Riches, Jamie C; Tuvy, Yaelle; Kundra, Ritika; Bouvier, Nancy; Vakiani, Efsevia; Gao, Jianjiong; Heins, Zachary J; Gross, Benjamin E; Kelsen, David P; Zhang, Liying; Strong, Vivian E; Schattner, Mark; Gerdes, Hans; Coit, Daniel G; Bains, Manjit; Stadler, Zsofia K; Rusch, Valerie W; Jones, David R; Molena, Daniela; Shia, Jinru; Robson, Mark E; Capanu, Marinela; Middha, Sumit; Zehir, Ahmet; Hyman, David M; Scaltriti, Maurizio; Ladanyi, Marc; Rosen, Neal; Ilson, David H; Berger, Michael F; Tang, Laura; Taylor, Barry S; Solit, David B; Schultz, Nikolaus

2018-01-01

The incidence of esophagogastric cancer is rapidly rising, but only a minority of patients derive durable benefit from current therapies. Chemotherapy as well as anti-HER2 and PD-1 antibodies are standard treatments. To identify predictive biomarkers of drug sensitivity and mechanisms of resistance, we implemented prospective tumor sequencing of patients with metastatic esophagogastric cancer. There was no association between homologous recombination deficiency defects and response to platinum-based chemotherapy. Patients with microsatellite instability-high tumors were intrinsically resistant to chemotherapy but more likely to achieve durable responses to immunotherapy. The single Epstein-Barr virus-positive patient achieved a durable, complete response to immunotherapy. The level of ERBB2 amplification as determined by sequencing was predictive of trastuzumab benefit. Selection for a tumor subclone lacking ERBB2 amplification, deletion of ERBB2 exon 16, and comutations in the receptor tyrosine kinase, RAS, and PI3K pathways were associated with intrinsic and/or acquired trastuzumab resistance. Prospective genomic profiling can identify patients most likely to derive durable benefit to immunotherapy and trastuzumab and guide strategies to overcome drug resistance. Significance: Clinical application of multiplex sequencing can identify biomarkers of treatment response to contemporary systemic therapies in metastatic esophagogastric cancer. This large prospective analysis sheds light on the biological complexity and the dynamic nature of therapeutic resistance in metastatic esophagogastric cancers. Cancer Discov; 8(1); 49-58. ©2017 AACR. See related commentary by Sundar and Tan, p. 14 See related article by Pectasides et al., p. 37 This article is highlighted in the In This Issue feature, p. 1 . ©2017 American Association for Cancer Research.

Integrating the 3Ds: a nursing perspective.

PubMed

Villarruel, Antonia M; Bigelow, April; Alvarez, Carmen

2014-01-01

The 3Ds (diversity, disparities, and determinants) that serve as a framework for this supplement are concepts that are key foundations of nursing education, practice, and research. Despite this fact, however, the nursing profession has faced challenges recognizing the full potential of these concepts. While their importance is documented and acknowledged, they are not clearly evident or easily recognized within the nursing profession. In fact, there are many barriers to the integration of these concepts. We identify and address two barriers to addressing health disparities and increasing diversity: disconnects and discrimination. Furthermore, we discuss three factors-dissemination, durability, and data-that may facilitate nursing's efforts to integrate the 3Ds into the profession. Five pivotal models that address these barriers and facilitators are presented as exemplars that have the potential to guide efforts to address diversity, disparities, and social determinants of health and act as catalysts for change within the nursing profession.

Integrating the 3Ds: A Nursing Perspective

PubMed Central

Bigelow, April; Alvarez, Carmen

2014-01-01

The 3Ds (diversity, disparities, and determinants) that serve as a framework for this supplement are concepts that are key foundations of nursing education, practice, and research. Despite this fact, however, the nursing profession has faced challenges recognizing the full potential of these concepts. While their importance is documented and acknowledged, they are not clearly evident or easily recognized within the nursing profession. In fact, there are many barriers to the integration of these concepts. We identify and address two barriers to addressing health disparities and increasing diversity: disconnects and discrimination. Furthermore, we discuss three factors—dissemination, durability, and data—that may facilitate nursing's efforts to integrate the 3Ds into the profession. Five pivotal models that address these barriers and facilitators are presented as exemplars that have the potential to guide efforts to address diversity, disparities, and social determinants of health and act as catalysts for change within the nursing profession. PMID:24385663

Thermal Conductivity and Sintering Behavior of Advanced Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2002-01-01

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

Autologous islet transplantation: challenges and lessons.

PubMed

Dunn, Ty B; Wilhelm, Joshua J; Bellin, Melena D; Pruett, Timothy L

2017-08-01

Human islet isolation and autotransplantation [autologous islet transplant (AUTX)] is performed to prevent or ameliorate brittle diabetes after total pancreatectomy performed for benign disease. The success or failure of the transplant can be associated with a profound impact on the individual's quality of life and even survival. AUTX offers unique insights into the effects of pancreas quality, islet number, isolation technique and alternate site engraftment on transplant efficacy. Herein, we review islet isolation with a focus on potential pathways to further optimize the endocrine outcome of AUTX, and compare and contrast differences in islet processing for AUTX and allotransplantation (allogeneic islet transplant). New knowledge of human islet biology and issues surrounding the engraftment process offer opportunities for innovative approaches toward optimizing islet cell transplantation. Improving the rate and durability of insulin independence in the often-times marginal dose model of AUTX may provide new insight toward improving the efficiency and durability of single donor islet (allogeneic islet transplant).

Quantification of water penetration into concrete through cracks by neutron radiography

NASA Astrophysics Data System (ADS)

Kanematsu, M.; Maruyama, I.; Noguchi, T.; Iikura, H.; Tsuchiya, N.

2009-06-01

Improving the durability of concrete structures is one of the ways to contribute to the sustainable development of society, and it has also become a crucial issue from an environmental viewpoint. It is well known that moisture behavior in reinforced concrete is linked to phenomena such as cement hydration, volume change and cracking caused by drying shrinkage, rebar corrosion and water leakage that affect the durability of concrete. In this research, neutron radiography was applied for visualization and quantification of water penetration into concrete through cracks. It is clearly confirmed that TNR can make visible the water behavior in/near horizontal/vertical cracks and can quantify the rate of diffusion and concentration distribution of moisture with high spatial and time resolution. On detailed analysis, it is observed that water penetrates through the crack immediately after pouring and its migration speed and distribution depend on the moisture condition in the concrete.

Highly durable organic electrode for sodium-ion batteries via a stabilized α-C radical intermediate

NASA Astrophysics Data System (ADS)

Wu, Shaofei; Wang, Wenxi; Li, Minchan; Cao, Lujie; Lyu, Fucong; Yang, Mingyang; Wang, Zhenyu; Shi, Yang; Nan, Bo; Yu, Sicen; Sun, Zhifang; Liu, Yao; Lu, Zhouguang

2016-11-01

It is a challenge to prepare organic electrodes for sodium-ion batteries with long cycle life and high capacity. The highly reactive radical intermediates generated during the sodiation/desodiation process could be a critical issue because of undesired side reactions. Here we present durable electrodes with a stabilized α-C radical intermediate. Through the resonance effect as well as steric effects, the excessive reactivity of the unpaired electron is successfully suppressed, thus developing an electrode with stable cycling for over 2,000 cycles with 96.8% capacity retention. In addition, the α-radical demonstrates reversible transformation between three states: C=C α-C.radical and α-C- anion. Such transformation provides additional Na+ storage equal to more than 0.83 Na+ insertion per α-C radical for the electrodes. The strategy of intermediate radical stabilization could be enlightening in the design of organic electrodes with enhanced cycling life and energy storage capability.

Development of Advanced Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

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

HSCT Sector Combustor Evaluations for Demonstration Engine

NASA Technical Reports Server (NTRS)

Greenfield, Stuart; Heberling, Paul; Kastl, John; Matulaitis, John; Huff, Cynthia

2004-01-01

In LET Task 10, critical development issues of the HSCT lean-burn low emissions combustor were addressed with a range of engineering tools. Laser diagnostics and CFD analysis were applied to develop a clearer understanding of the fuel-air premixing process and premixed combustion. Subcomponent tests evaluated the emissions and operability performance of the fuel-air premixers. Sector combustor tests evaluated the performance of the integrated combustor system. A 3-cup sector was designed and procured for laser diagnostics studies at NASA Glenn. The results of these efforts supported the earlier selection of the Cyclone Swirler as the pilot stage premixer and the IMFH (Integrated Mixer Flame Holder) tube as the main stage premixer of the LPP combustor. In the combustor system preliminary design subtask, initial efforts to transform the sector combustor design into a practical subscale engine combustor met with significant challenges. Concerns about the durability of a stepped combustor dome and the need for a removable fuel injection system resulted in the invention and refinement of the MRA (Multistage Radial Axial) combustor system in 1994. The MRA combustor was selected for the HSR Phase II LPP subscale combustor testing in the CPC Program.

Recent progress in flexible OLED displays

NASA Astrophysics Data System (ADS)

Hack, Michael G.; Weaver, Michael S.; Mahon, Janice K.; Brown, Julie J.

2001-09-01

Organic light emitting device (OLED) technology has recently been shown to demonstrate excellent performance and cost characteristics for use in numerous flat panel display (FPD) applications. OLED displays emit bright, colorful light with excellent power efficiency, wide viewing angle and video response rates. OLEDs are also demonstrating the requisite environmental robustness for a wide variety of applications. OLED technology is also the first FPD technology with the potential to be highly functional and durable in a flexible format. The use of plastic and other flexible substrate materials offers numerous advantages over commonly used glass substrates, including impact resistance, light weight, thinness and conformability. Currently, OLED displays are being fabricated on rigid substrates, such as glass or silicon wafers. At Universal Display Corporation (UDC), we are developing a new class of flexible OLED displays (FOLEDs). These displays also have extremely low power consumption through the use of electrophosphorescent doped OLEDs. To commercialize FOLED technology, a number of technical issues related to packaging and display processing on flexible substrates need to be addressed. In this paper, we report on our recent results to demonstrate the key technologies that enable the manufacture of power efficient, long-life flexible OLED displays for commercial and military applications.

European developments in the application of structural austenitic and duplex stainless steels

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

Cochrane, D.J.

1995-12-31

Stainless steel is increasingly being specified for structural applications. Principally, this is due to the aesthetic appeal of the material, no need for surface protection, durability, and the growing awareness, and use, of Life Cycle Cost analysis for assessing costs over the longer term, However, use of stainless steel in the U.K. offshore oil and gas platforms for fire and blast walls, has highlighted valuable properties of stainless steel that may be unfamiliar to structural designers. It is the purpose of this paper to demonstrate these properties. Additionally, new design guidance has become available in Europe as a result ofmore » a 4 year research program into the structural use of stainless steel. The ``Design Manual for Structural Stainless Steel`` was issued by Euro Inox and the Nickel Development Institute in 1994. This new manual will be outlined in this paper together with its influence on new European Building Standards and new European material standards for structural stainless steel. Currently in preparation, these include high strength grades with significantly higher strength than structural carbon steels. Finally, this paper will address the use of stainless steel for the reinforcement of concrete structures.« less

Admixtures in Cement-Matrix Composites for Mechanical Reinforcement, Sustainability, and Smart Features

PubMed Central

Bastos, Guillermo; Patiño-Barbeito, Faustino; Patiño-Cambeiro, Faustino; Armesto, Julia

2016-01-01

For more than a century, several inclusions have been mixed with Portland cement—nowadays the most-consumed construction material worldwide—to improve both the strength and durability required for construction. The present paper describes the different families of inclusions that can be combined with cement matrix and reviews the achievements reported to date regarding mechanical performance, as well as two other innovative functionalities of growing importance: reducing the high carbon footprint of Portland cement, and obtaining new smart features. Nanomaterials stand out in the production of such advanced features, allowing the construction of smart or multi-functional structures by means of thermal- and strain-sensing, and photocatalytic properties. The first self-cleaning concretes (photocatalytic) have reached the markets. In this sense, it is expected that smart concretes will be commercialized to address specialized needs in construction and architecture. Conversely, other inclusions that enhance strength or reduce the environmental impact remain in the research stage, in spite of the promising results reported in these issues. Despite the fact that such functionalities are especially profitable in the case of massive cement consumption, the shift from the deeply established Portland cement to green cements still has to overcome economic, institutional, and technical barriers. PMID:28774091

Revisiting the role of durable polymers in cardiovascular devices.

PubMed

Mori, Hiroyoshi; Otsuka, Fumiyuki; Gupta, Anuj; Jinnouchi, Hiroyuki; Torii, Sho; Harari, Emanuel; Virmani, Renu; Finn, Aloke V

2017-11-01

Polymers are an essential component of drug-eluting stents (DES) used to control drug release but remain the most controversial component of DES technology. There are two types of polymers employed in DES: durable polymer based DES (DP-DES) and biodegradable polymer DES (BP-DES). First-generation DES were exclusively composed of DP and demonstrated increased rates of late stent failure due in part to poor polymer biocompatibility. Newer generations DES use more biocompatible durable polymers or biodegradable polymers. Areas covered: We will cover issues identified with 1st-generation DP-DES, areas of success and failure in 2nd-generation DP-DES and examine the promise and shortcomings of BP-DES. Briefly, fluorinated polymers used in 2nd-generation DP-DES have excellent anti-thrombogenicity and better biocompatibility than 1st-generation DES polymers. However, these devices lead to persistent drug exposure to the endothelium which impairs endothelial function and predisposes towards neoatherosclerosis. Meanwhile, BP-DES has shortened the duration of drug exposure which might be beneficial for endothelial functional recovery leading to less neoatherosclerosis. However, it remains uncertain whether the long-term biocompatibility of bare metal surfaces is better than that of polymer-coated metals. Expert commentary: Each technology has distinct advantages, which can be optimized depending upon the particular characteristics of the patient being treated.

Service lifetime prediction for encapsulated photovoltaic cells/minimodules

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

Czanderna, A.W.; Jorgensen, G.J.

The overall purposes of this paper are to elucidate the crucial importance of predicting the service lifetime (SLP) for photovoltaics (PV) modules and to present an outline for developing a SLP methodology for encapsulated PV cells and minimodules. The specific objectives are (a) to illustrate the generic nature of SLP for several types of solar energy conversion or conversion devices, (b) to summarize the major durability issues concerned with these devices, (c) to justify using SLP in the triad of cost, performance, and durability instead of only durability, (d) to define and explain the seven major elements that comprise amore » generic SLP methodology, (e) to provide background about implementing the SLP methodology for PV cells and minimodules including the complexity of the encapsulation problems, (f) to summarize briefly the past focus of our task for improving and/or replacing ethylene vinyl acetate (EVA) as a PV pottant, and (g) to provide an outline of our present and future studies using encapsulated PV cells and minimodules for improving the encapsulation of PV cells and predicting a service lifetime for them using the SLP methodology outlined in objective (d). By using this methodology, our major conclusion is that predicting the service lifetime of PV cells and minimodules is possible. {copyright} {ital 1997 American Institute of Physics.}« less

Construction Guide to Next-Generation High-Performance Walls in Climate Zones 3-5 - Part 1: 2x6 Walls

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

Kochkin, V.; Wiehagen, J.

2017-08-31

Part 1 of this Construction Guide to High-Performance Walls in Climate Zones 3-5 provides time-proven, practical, and cost-effective strategies for constructing durable, energy-efficient walls. It addresses walls constructed with 2x6 wood frame studs, wood structural panel (WSP) exterior sheathing, and a cladding system installed over WSP sheathing in low-rise residential buildings up to three stories high.

40% Whole-House Energy Savings in the Hot-Humid Climate

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

none,

This guide book is a resource to help builders design and construct highly energy-efficient homes, while addressing building durability, indoor air quality, and occupant health, safety, and comfort. With the measures described in this guide, builders in the hot-humid climate can build homes that achieve whole house energy savings of 40% over the Building America benchmark (the 1993 Model Energy Code) with no added overall costs for consumers.

Construction Guide to Next-Generation High-Performance Walls in Climate Zones 3-5 - Part 1: 2x6 Walls

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

Kochkin, V.; Wiehagen, J.

Part 1 of this Construction Guide to High-Performance Walls in Climate Zones 3-5 provides time-proven, practical, and cost-effective strategies for constructing durable, energy-efficient walls. It addresses walls constructed with 2x6 wood frame studs, wood structural panel (WSP) exterior sheathing, and a cladding system installed over WSP sheathing in low-rise residential buildings up to three stories high.

40% Whole-House Energy Savings in the Mixed-Humid Climate

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

Baechler, Michael C.; Gilbride, T. L.; Hefty, M. G.

2011-09-01

This guide book is a resource to help builders design and construct highly energy-efficient homes, while addressing building durability, indoor air quality, and occupant health, safety, and comfort. With the measures described in this guide, builders in the mixed-humid climate can build homes that achieve whole house energy savings of 40% over the Building America benchmark (the 1993 Model Energy Code) with no added overall costs for consumers.

Joint Force Quarterly. Number 31, Summer 2002

DTIC Science & Technology

2002-09-01

College of the Armed Forces COL Timothy S. Heinemann, USA ■ U.S. Army Command and General Staff College CAPT Chester E. Helms, USN ■ Naval War College...Announcing the next event in the 2002– 2003 symposia program Pacific Symposium Towards a Durable Security Strategy (Co-sponsored with U.S. Pacific...Command) March 25–27, 2003 Information on symposia is available via the National Defense University World Wide Web server. Access by addressing

Durability Characterization of Advanced Polymeric Composites at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Gates, T. S.

2001-01-01

The next generation of reusable launch vehicles will require technology development in several key areas. Of these key areas, the development of polymeric composite cryogenic fuel tanks promises to present one of the most difficult technical challenges. It is envisioned that a polymer matrix composite (PMC) tank would be a large shell structure capable of containing cryogenic fuels and carrying a range of structural loads. The criteria that will be imposed on such a design include reduced weight, conformal geometry, and impermeability. It is this last criterion, impermeability, that will provide the focus of this paper. The essence of the impermeability criterion is that the tank remains leak free throughout its design lifetime. To address this criterion, one of the first steps is to conduct a complete durability assessment of the PMC materials. At Langley Research Center, a durability assessment of promising new polyimide-based PMCs is underway. This durability program has focused on designing a set of critical laboratory experiments that will determine fundamental material properties under combined thermal-mechanical loading at cryogenic temperatures. The test program provides measurements of lamina and laminate properties, including strength, stiffness, and fracture toughness. The performance of the PMC materials is monitored as a function of exposure conditions and aging time. Residual properties after exposure are measured at cryogenic temperatures and provide quantitative values of residual strength and stiffness. Primary degradation mechanisms and the associated damage modes are measured with both destructive and nondestructive techniques. In addition to mechanical properties, a range of physical properties, such as weight, glass transition, and crack density, are measured and correlated with the test conditions. This paper will report on the progress of this research program and present critical results and illustrative examples of current findings.

3D visualization of membrane failures in fuel cells

NASA Astrophysics Data System (ADS)

Singh, Yadvinder; Orfino, Francesco P.; Dutta, Monica; Kjeang, Erik

2017-03-01

Durability issues in fuel cells, due to chemical and mechanical degradation, are potential impediments in their commercialization. Hydrogen leak development across degraded fuel cell membranes is deemed a lifetime-limiting failure mode and potential safety issue that requires thorough characterization for devising effective mitigation strategies. The scope and depth of failure analysis has, however, been limited by the 2D nature of conventional imaging. In the present work, X-ray computed tomography is introduced as a novel, non-destructive technique for 3D failure analysis. Its capability to acquire true 3D images of membrane damage is demonstrated for the very first time. This approach has enabled unique and in-depth analysis resulting in novel findings regarding the membrane degradation mechanism; these are: significant, exclusive membrane fracture development independent of catalyst layers, localized thinning at crack sites, and demonstration of the critical impact of cracks on fuel cell durability. Evidence of crack initiation within the membrane is demonstrated, and a possible new failure mode different from typical mechanical crack development is identified. X-ray computed tomography is hereby established as a breakthrough approach for comprehensive 3D characterization and reliable failure analysis of fuel cell membranes, and could readily be extended to electrolyzers and flow batteries having similar structure.

Ultra High Voltage Propellant Isolators and Insulators for JIMO Ion Thrusters

NASA Technical Reports Server (NTRS)

Banks, Bruce A.; Gaier, James R.; Hung, Ching-Cheh; Walters, Patty A.; Sechkar, Ed; Panko, Scott; Kamiotis, Christina A.

2004-01-01

Within NASA's Project Prometheus, high specific impulse ion thrusters for electric propulsion of spacecraft for the proposed Jupiter Icy Moon Orbiter (JIMO) mission to three of Jupiter's moons: Callisto, Ganymede and Europa will require high voltage operation to meet mission propulsion. The anticipated approx.6,500 volt net ion energy will require electrical insulation and propellant isolation which must exceed that used successfully by the NASA Solar Electric Propulsion Technology Readiness (NSTAR) Deep Space 1 mission thruster by a factor of approx.6. Xenon propellant isolator prototypes that operate at near one atmosphere and prototypes that operate at low pressures (<100 Torr) have been designed and are being tested for suitability to the JIMO mission requirements. Propellant isolators must be durable to Paschen breakdown, sputter contamination, high temperature, and high voltage while operating for factors longer duration than for the Deep Space 1 Mission. Insulators used to mount the thrusters as well as those needed to support the ion optics have also been designed and are under evaluation. Isolator and insulator concepts, design issues, design guidelines, fabrication considerations and performance issues are presented. The objective of the investigation was to identify candidate isolators and insulators that are sufficiently robust to perform durably and reliably during the proposed JIMO mission.

Critical Science Issues for Direct Drive Inertial Fusion Energy

NASA Astrophysics Data System (ADS)

Dahlburg, Jill P.; Gardner, John H.; Schmitt, Andrew J.; Obenschain, S. P.

1998-09-01

There are several topics that require resolution prior to the construction of an Inertial Fusion Energy [IFE] laboratory Engineering Test Facility [ETF]: a pellet that produces high gain; a pellet fabrication system that cost-effectively and rapidly manufactures these pellets; a sufficiently uniform and durable high repetition-rate laser pellet driver; a practical target injection system that provides accurate pellet aiming; and, a target chamber that will survive the debris and radiation of repeated high-gain pellet implosions. In this summary we describe the science issues and opportunities that are involved in the design of a successful high gain direct drive Inertial Confinement Fusion [ICF] pellet.

Lifecycle Verification of Tank Liner Polymers

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

Anovitz, Lawrence; Smith, Barton

2014-03-01

This report describes a method that was developed for the purpose of assessing the durability of thermoplastic liners used in a Type IV hydrogen storage tank during the tank s expected service life. In the method, a thermoplastic liner specimen is cycled between the maximum and minimum expected working temperatures while it is differentially pressurized with high-pressure hydrogen gas. The number of thermal cycling intervals corresponds to those expected within the tank s design lifetime. At prescribed intervals, hydrogen permeation measurements are done in situ to assess the ability of the liner specimen to maintain its hydrogen barrier properties andmore » to model its permeability over the tank lifetime. Finally, the model is used to assess whether the steady-state leakage rate in the tank could potentially exceed the leakage specification for hydrogen fuel cell passenger vehicles. A durability assessment was performed on a specimen of high-density polyethylene (HDPE) that is in current use as a tank liner. Hydrogen permeation measurements were performed on several additional tank liner polymers as well as novel polymers proposed for use as storage tank liners and hydrogen barrier materials. The following technical barriers from the Fuel Cell Technologies Program MYRDD were addressed by the project: D. Durability of on-board storage systems lifetime of at least 1500 cycles G. Materials of construction vessel containment that is resistant to hydrogen permeation M. Lack of Tank Performance Data and Understanding of Failure Mechanisms And the following technical targets1 for on-board hydrogen storage systems R&D were likewise addressed: Operational cycle life (1/4 tank to full) FY 2017: 1500 cycles; Ultimate: 1500 cycles Environmental health & safety Permeation and leakage: Meets or exceeds applicable standards Loss of useable H2: FY 2017: 0.05 g/h/kg H2; Ultimate: 0.05 g/h/kg H2« less

Prediction of fracture toughness and durability of adhesively bonded composite joints with undesirable bonding conditions

NASA Astrophysics Data System (ADS)

Musaramthota, Vishal

Advanced composite materials have enabled the conventional aircraft structures to reduce weight, improve fuel efficiency and offer superior mechanical properties. In the past, materials such as aluminum, steel or titanium have been used to manufacture aircraft structures for support of heavy loads. Within the last decade or so, demand for advanced composite materials have been emerging that offer significant advantages over the traditional metallic materials. Of particular interest in the recent years, there has been an upsurge in scientific significance in the usage of adhesively bonded composite joints (ABCJ's). ABCJ's negate the introduction of stress risers that are associated with riveting or other classical techniques. In today's aircraft transportation market, there is a push to increase structural efficiency by promoting adhesive bonding to primary joining of aircraft structures. This research is focused on the issues associated with the durability and related failures in bonded composite joints that continue to be a critical hindrance to the universal acceptance of ABCJ's. Of particular interest are the short term strength, contamination and long term durability of ABCJ's. One of the factors that influence bond performance is contamination and in this study the influence of contamination on composite-adhesive bond quality was investigated through the development of a repeatable and scalable surface contamination procedure. Results showed an increase in the contaminant coverage area decreases the overall bond strength significantly. A direct correlation between the contaminant coverage area and the fracture toughness of the bonded joint was established. Another factor that influences bond performance during an aircraft's service life is its long term strength upon exposure to harsh environmental conditions or when subjected to severe mechanical loading. A test procedure was successfully developed in order to evaluate durability of ABCJ's comprising severe environmental conditioning, fatiguing in ambient air and a combination of both. The bonds produced were durable enough to sustain the tests cases mentioned above when conditioned for 8 weeks and did not experience any loss in strength. Specimens that were aged for 80 weeks showed a degradation of 10% in their fracture toughness when compared to their baseline datasets. The effect of various exposure times needs to be further evaluated to establish the relationship of durability that is associated with the fracture toughness of ABCJ's.

Construction Guide to Next-Generation High-Performance Walls in Climate Zones 3-5 - Part 2: 2x4 Walls

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

Kochkin, V.; Wiehagen, J.

2017-06-01

Part 2 of this Construction Guide to High-Performance Walls in Climate Zones 3-5 provides straightforward and cost-effective strategies to construct durable, energy-efficient walls. It addresses walls constructed with 2x4 wood frame studs, wood structural panel (WSP) sheathing as wall bracing and added backing for foam sheathing, a layer of rigid foam sheathing insulation up to 1.5 inches thick over the WSP, and a cladding system installed over the foam sheathing in low-rise residential buildings up to three stories high. Walls with 2x6 framing are addressed in Part 1 of the Guide.

Construction Guide to Next-Generation High-Performance Walls in Climate Zones 3-5 - Part 2: 2x4 Walls

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

Kochkin, V.; Wiehagen, J.

Part 2 of this Construction Guide to High-Performance Walls in Climate Zones 3-5 provides straightforward and cost-effective strategies to construct durable, energy-efficient walls. It addresses walls constructed with 2x4 wood frame studs, wood structural panel (WSP) sheathing as wall bracing and added backing for foam sheathing, a layer of rigid foam sheathing insulation up to 1.5 inches thick over the WSP, and a cladding system installed over the foam sheathing in low-rise residential buildings up to three stories high. Walls with 2x6 framing are addressed in Part 1 of the Guide.

Transferable Durability: Enhancing decay resistance of non-durable species with extractives from durable wood species

Treesearch

G.T. Kirker; A.B. Blodgett; S. Lebow; C.A. Clausen

2013-01-01

Extractive content and composition is a vital component of naturally durable woods; however, variability in extractives can limit their usefulness in the field. Two extractive-free, non-durable wood species were pressure treated with ethanol-toluene extractives from 8 durable wood species. Extracted Southern pine, Paulownia and unextracted Southern pine blocks were...

Recyclable automobiles. (Latest citations from Engineered Materials abstracts). Published Search

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

NONE

The bibliography contains citations concerning the technology and characteristics of non-metal, recyclable components used in automobiles. Existing polymer, plastic, and composite technology and materials are discussed. The citations also examine design and development of new recyclable materials that are durable. Design features and constraints are included. Some citations address future trends leading to the 100 percent recyclable automobile. (Contains a minimum of 77 citations and includes a subject term index and title list.)

Recyclable automobiles. (Latest citations from Engineered Materials abstracts). Published Search

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

NONE

The bibliography contains citations concerning the technology and characteristics of non-metal, recyclable components used in automobiles. Existing polymer, plastic, and composite technology and materials are discussed. The citations also examine design and development of new recyclable materials that are durable. Design features and constraints are included. Some citations address future trends leading to the 100 percent recyclable automobile. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

Recyclable automobiles. (Latest citations from Engineered Materials Abstracts). Published Search

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

Not Available

The bibliography contains citations concerning the technology and characteristics of non-metal, recyclable components used in automobiles. Existing polymer, plastic, and composite technology and materials are discussed. The citations also examine design and development of new recyclable materials that are durable. Design features and constraints are included. Some citations address future trends leading to the 100 percent recyclable automobile. (Contains a minimum of 58 citations and includes a subject term index and title list.)

Advanced composites characterization with x-ray technologies

NASA Astrophysics Data System (ADS)

Baaklini, George Y.

1993-12-01

Recognizing the critical need to advance new composites for the aeronautics and aerospace industries, we are focussing on advanced test methods that are vital to successful modeling and manufacturing of future generations of high temperature and durable composite materials. These newly developed composites are necessary to reduce propulsion cost and weight, to improve performance and reliability, and to address longer-term national strategic thrusts for sustaining global preeminence in high speed air transport and in high performance military aircraft.

The National Nanotechnology Initiative: Overview, Reauthorization, and Appropriations Issues

DTIC Science & Technology

2013-08-09

new organs to replace damaged or diseased ones;10 • contact lenses, skin patches, and glucose-sensing tattoos that monitor diabetics’ blood sugar...collection on a device the size of a sugar cube;16 • inexpensive, flexible, durable, low-voltage “electronic skin ” sensors that allow robots and...Toward Nanoparticle-Based Electronic Skin ,” ACS Applied Materials and Interfaces, vol. 5, no. 12 (2013), pp. pp 5531-5541. 18 U.S. Department of

Durability of a novel durable bait for control of subterranean termites (Isoptera: Rhinotermitidae): results of five-year field aging studies.

PubMed

Eger, J E; Hamm, R L; Demark, J J; Chin-Heady, E; Tolley, M P; Benson, E P; Zungoli, P A; Smith, M S; Spomer, N A

2014-06-01

A durable termite bait containing 0.5% noviflumuron was evaluated for physical durability, retention of active ingredient, consumption by termites, and toxicity to termites over 5 yr in field studies at locations in Indiana, Mississippi, and South Carolina. Plots in Indiana and Mississippi included both natural rainfall and irrigated plots, while plots in South Carolina received only natural rainfall. Samples collected every 3 mo for the first 4 yr were evaluated for consumption with a 7 d no-choice bioassay using Reticulitermes flavipes (Kollar). Consumption and toxicity of 5 yr samples were evaluated in similar bioassays conducted for 42 d. Durable baits received from field sites had some cracking, and a small amount of external flaking, but no major deterioration based on visual observation. There were no significant differences in noviflumuron concentration over the 5-yr period and no trend toward reduced concentrations of noviflumuron over time. Consumption of aged durable baits over 4 yr was variable, but termites usually consumed more aged durable bait than fresh durable bait and the differences were frequently significant. There were some exceptions, but termites consumed significantly more fresh durable bait than aged durable bait in only 4% of observations. When 5 yr samples were evaluated, consumption was lowest for fresh durable bait and termites consumed significantly more aged durable bait from irrigated plots in Indiana and from both natural and irrigated plots in Mississippi than fresh durable bait. Survival of termites fed blank durable bait was significantly higher than that for termites fed any of the baits containing noviflumuron and there were no significant differences in survival among the noviflumuron durable baits. Our results suggest that the bait would be durable for at least 5 yr and possibly longer under most environmental conditions.

Manufacturing of Low Cost, Durable Membrane Electrode Assemblies Engineered for Rapid Conditioning

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

Busby, Colin

Over the past 20 years significant progress in membrane-electrode assembly (MEA) technology development for polymer electrolyte fuel cells (PEMFCs) has resulted in the PEMFC technology approaching a commercial reality for transportation applications. However, there remain two primary technical challenges to be addressed in the MEA. First and foremost is meeting the automotive cost targets: Producing a fuel cell stack cost competitive with today’s internal combustion engine. In addition to the material cost, MEA (and other components) and stack assembly production methods must be amenable for use in low cost, high speed, automotive assembly line. One impediment to this latter goalmore » is that stack components must currently go through a long and tedious conditioning procedure before they produce optimal power. This so-called “break-in” can take many hours, and can involve quite complex voltage, temperature and/or pressure steps. These break-in procedures must be simplified and the time required reduced if fuel cells are to become a viable automotive engine. The second challenge is to achieve the durability targets in real-world automotive duty cycle operations. Significant improvements in cost, break-in time, and durability for the key component of fuel cell stacks, MEAs were achieved in this project. Advanced modeling was used to guide design of the new MEA to maximize performance and durability. A new, innovative process and manufacturing approach utilizing direct in-line coating using scalable, cost-competitive, continuous high volume 3-layer rolled-good manufacturing processes was developed and validated by single cell and short stack testing. In addition, the direct coating methods employed were shown to reduce the cost for sacrificial films. Furthermore, Gore has demonstrated a 10 µm reinforced membrane that is used in the new low-cost process and can meet automotive power density and durability targets. Across a wide range of operating conditions, the direct-coated MEA outperformed the commercial baseline MEA, and did so through a process that delivers MEAs at $92.35/m2 at a volume of 500,000 systems per year, according to Strategic Analysis (SA) estimates.« less

Physiochemical Characterization of Briquettes Made from Different Feedstocks

PubMed Central

Karunanithy, C.; Wang, Y.; Muthukumarappan, K.; Pugalendhi, S.

2012-01-01

Densification of biomass can address handling, transportation, and storage problems and also lend itself to an automated loading and unloading of transport vehicles and storage systems. The purpose of this study is to compare the physicochemical properties of briquettes made from different feedstocks. Feedstocks such as corn stover, switchgrass, prairie cord grass, sawdust, pigeon pea grass, and cotton stalk were densified using a briquetting system. Physical characterization includes particle size distribution, geometrical mean diameter (GMD), densities (bulk and true), porosity, and glass transition temperature. The compositional analysis of control and briquettes was also performed. Statistical analyses confirmed the existence of significant differences in these physical properties and chemical composition of control and briquettes. Correlation analysis confirms the contribution of lignin to bulk density and durability. Among the feedstocks tested, cotton stalk had the highest bulk density of 964 kg/m3 which is an elevenfold increase compared to control cotton stalk. Corn stover and pigeon pea grass had the highest (96.6%) and lowest (61%) durability. PMID:22792471

Development of a Prototype Water Pump for Future Space Suit Applications

NASA Technical Reports Server (NTRS)

Hartman, David; Hodgson, Edward; Dionne, Steven; Gervais, Edward, III; Trevino, Luis

2009-01-01

NASA's next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew's liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

Development of a Prototype Water Pump for Future Space Suit Applications

NASA Technical Reports Server (NTRS)

Hartman, David; Hodgson, Edward; Gervais, Edward, III; Trevino, Luis

2008-01-01

NASA s next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew s liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

Design, manufacture and testing of an FBG-instrumented composite wing

NASA Astrophysics Data System (ADS)

Abouzeida, E.; Quinones, V.; Gowayed, Y.; Soobramaney, P.; Flowers, G.; Black, R. J.; Costa, J. M.; Faridian, F.; Moslehi, B.

2014-02-01

In this work, our research team investigated the efficacy of using optical static and dynamic strain sensing with embedded Fiber Bragg Gratings (FBGs) in structural health monitoring (SHM) of a model composite airplane wing. A one-fourth scale model of a T38 airplane wing was designed and manufactured using fabric reinforced polymer matrix composites with FBG sensors embedded under the top layer of the composite. The accuracy and durability of the sensors were evaluated at the coupon and structural levels utilizing static and dynamic testing. Strain measurements using embedded FBGs with an optical interrogator were found to be in agreement with values measured using other strain measuring devices and with results obtained using finite element analysis (ANSYS®). Preferred locations for the FBG sensors were identified in accordance with contour maps of internal strain distributions resulting from critical load cases. Manufacturing techniques used to address handling, survivability and durability of the embedded sensors during and post manufacturing of the composites were evaluated and optimized.

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.

From Famine to Feast: Developing Early-Phase Combination Immunotherapy Trials Wisely.

PubMed

Day, Daphne; Monjazeb, Arta M; Sharon, Elad; Ivy, S Percy; Rubin, Eric H; Rosner, Gary L; Butler, Marcus O

2017-09-01

Not until the turn of this century has immunotherapy become a fundamental component of cancer treatment. While monotherapy with immune modulators, such as immune checkpoint inhibitors, provides a subset of patients with durable clinical benefit and possible cure, combination therapy offers the potential for antitumor activity in a greater number of patients. The field of immunology has provided us with a plethora of potential molecules and pathways to target. This abundance makes it impractical to empirically test all possible combinations efficiently. We recommend that potential immunotherapy combinations be chosen based on sound rationale and available data to address the mechanisms of primary and acquired immune resistance. Novel trial designs may increase the proportion of patients receiving potentially efficacious treatments and, at the same time, better define the balance of clinical activity and safety. We believe that implementing a strategic approach in the early development of immunotherapy combinations will expedite the delivery of more effective therapies with improved safety and durable outcomes. ©2017 American Association for Cancer Research.

Challenges to the Transition of IPMC Artificial Muscle Actuators to Practical Application

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph; Leary, Sean; Oguro, Keisuke; Tadokoro, Satoshi; Harrison, Joycelyn; Smith, Joseph; Su, Ji

1999-01-01

Ion-exchange membrane metallic composites (IPMC), which were first reported in 1992, are one of the electroactive materials (EAP) with potential applications as artificial muscle actuators. The recent introduction of perfluorocarboxylate-gold composite with tetra-n-butylammonium and Lithium cations instead of sodium made the most significant improvement of the material electroactivity. Under less than 3 volts, IPMC with the new constituents is capable of bending beyond a complete loop. Taking into account the fact that IMPC materials do not induce a significant force, the authors are extensively seeking applications for these bending EAP. Some of the applications that were demonstrated include dust-wiper, catheter guide, miniature motor, robotic-gripper, micro-manipulator, etc. Generally, space applications are the most demanding in terms of operating conditions, robustness and durability, and the co-authors of this paper are jointly addressing the associated challenges. Specifically, a dust-wiper is being developed for the Nanorover's infrared camera window of the MUSES-CN mission. This joint NASA and the Japanese space agency mission, is scheduled to be launch from Kagoshima, Japan, in January 2002, to explore the surface of a small near-Earth asteroid. Several issues that are critical to the operation of IPMC are addressed including the operation in vacuum, low temperatures, and the effect of the electromechanical characteristic of the IPMC on its actuation capability. Highly efficient IPMC materials, mechanical modeling, unique elements and protective coating were introduced by the authors and are making a high probability the success of the IPMC actuated dust-wiper.

Patient and healthcare perspectives on the importance and efficacy of addressing spiritual issues within an interdisciplinary bone marrow transplant clinic: a qualitative study

PubMed Central

Sinclair, Shane; McConnell, Shelagh; Raffin Bouchal, Shelley; Ager, Naree; Booker, Reanne; Enns, Bert; Fung, Tak

2015-01-01

Objectives The purpose of this study was to use a qualitative approach to better understand the importance and efficacy of addressing spiritual issues within an interdisciplinary bone marrow transplant clinic from the perspectives of patients and healthcare providers. Setting Participants were recruited from the bone marrow transplant clinic of a large urban outpatient cancer care centre in western Canada. Participants: Focus groups were conducted with patients (n=7) and healthcare providers (n=9) to explore the importance of addressing spiritual issues across the treatment trajectory and to identify factors associated with effectively addressing these needs. Results Data were analysed using the qualitative approach of latent content analysis. Addressing spiritual issues was understood by patients and healthcare providers, as a core, yet under addressed, component of comprehensive care. Both sets of participants felt that addressing basic spiritual issues was the responsibility of all members of the interdisciplinary team, while recognising the need for specialised and embedded support from a spiritual care professional. While healthcare providers felt that the impact of the illness and treatment had a negative effect on patients’ spiritual well-being, patients felt the opposite. Skills, challenges, key time points and clinical indicators associated with addressing spiritual issues were identified. Conclusions Despite a number of conceptual and clinical challenges associated with addressing spiritual issues patients and their healthcare providers emphasised the importance of an integrated approach whereby basic spiritual issues are addressed by members of the interdisciplinary team and by an embedded spiritual care professional, who in addition also provides specialised support. The identification of clinical issues associated with addressing spiritual needs provides healthcare providers with clinical guidance on how to better integrate this aspect of care into their clinical practice, while also identifying acute incidences when a more targeted and specialised approach may be of benefit. PMID:26614623

Efficacy and safety of a biodegradable polymer sirolimus-eluting stent in primary percutaneous coronary intervention: a randomized controlled trial

PubMed Central

Li, Qiang; Tong, Zichuan; Wang, Lefeng; Zhang, Jianjun; Ge, Yonggui; Wang, Hongshi; Li, Weiming; Xu, Li; Ni, Zhuhua

2013-01-01

Introduction With long-term follow-up, whether biodegradable polymer drug-eluting stents (DES) is efficient and safe in primary percutaneous coronary intervention (PCI) remains a controversial issue. This study aims to assess the long-term efficacy and safety of DES in PCI for ST-segment elevation myocardial infarction (STEMI). Material and methods A prospective, randomized single-blind study with 3-year follow-up was performed to compare biodegradable polymer DES with durable polymer DES in 332 STEMI patients treated with primary PCI. The primary end point was major adverse cardiac events (MACE) at 3 years after the procedure, defined as the composite of cardiac death, recurrent infarction, and target vessel revascularization. The secondary end points included in-segment late luminal loss (LLL) and binary restenosis at 9 months and cumulative stent thrombosis (ST) event rates up to 3 years. Results The rate of the primary end points and the secondary end points including major adverse cardiac events, in-segment late luminal loss, binary restenosis, and cumulative thrombotic event rates were comparable between biodegradable polymer DES and durable polymer DES in these 332 STEMI patients treated with primary PCI at 3 years. Conclusions Biodegradable polymer DES has similar efficacy and safety profiles at 3 years compared with durable polymer DES in STEMI patients treated with primary PCI. PMID:24482648

31 CFR 240.17 - Powers of attorney.

Code of Federal Regulations, 2010 CFR

2010-07-01

... incompetent. (e) Springing durable special powers of attorney. A springing durable special power of attorney... principal's subsequent incompetence. As with a durable special power of attorney, a springing durable... than those specified in paragraph (b) of this section may be negotiated under a springing durable...

31 CFR 240.17 - Powers of attorney.

Code of Federal Regulations, 2014 CFR

2014-07-01

... incompetent. (e) Springing durable special powers of attorney. A springing durable special power of attorney... principal's subsequent incompetence. As with a durable special power of attorney, a springing durable... than those specified in paragraph (b) of this section may be negotiated under a springing durable...

Feasibility of Energy Harvesting Using a Piezoelectric Tire

NASA Astrophysics Data System (ADS)

Malotte, Christopher

While the piezoelectric effect has been around for some time, it has only recently caught interest as a potential sustainable energy harvesting device. Piezoelectric energy harvesting has been developed for shoes and panels, but has yet to be integrated into a marketable bicycle tire. For this thesis, the development and feasibility of a piezoelectric tire was done. This includes the development of a circuit that incorporates piezoceramic elements, energy harvesting circuitry, and an energy storage device. A single phase circuit was designed using an ac-dc diode rectifier. An electrolytic capacitor was used as the energy storage device. A financial feasibility was also done to determine targets for manufacturing cost and sales price. These models take into account market trends for high performance tires, economies of scale, and the possibility of government subsidies. This research will help understand the potential for the marketability of a piezoelectric energy harvesting tire that can create electricity for remote use. This study found that there are many obstacles that must be addressed before a piezoelectric tire can be marketed to the general public. The power output of this device is minuscule compared to an alkaline battery. In order for this device to approach the power output of an alkaline battery the weight of the device would also become an issue. Additionally this device is very costly compared to the average bicycle tire. Lastly, this device is extreme fragile and easily broken. In order for this device to become marketable the issues of power output, cost, weight, and durability must all be successfully overcome.

High voltage requirements and issues for the 1990's. [for spacecraft power supplies

NASA Technical Reports Server (NTRS)

Dunbar, W. G.; Faymon, K. A.

1984-01-01

The development of high-power high-voltage space systems will require advances in power generation and processing. The systems must be reliable, adaptable, and durable for space mission success. The issues, which must be resolved in order to produce a high power system, are weight and volume reduction of components and modules and the creation of a reliable high repetition pulse power processor. Capacitor energy density must be increased by twice the present capacity and packaging must be reduced by a factor of 10 to 20 times. The packaging must also protect the system from interaction with the natural space environment and the induced environment, produced from spacecraft systems and environment interaction.

[Ethical issues in the practice of advance directives, living wills, and self-determination in end of life care].

PubMed

Fang, Hui-Feng; Jhing, Huei-Yu; Lin, Chia-Chin

2009-02-01

The Hospice-Palliative Care Act, enacted in Taiwan in 2000, was designed to respect the end of life medical wishes of patients with incurable illnesses, safeguard the rights of these patients, and provide clinical guidelines for healthcare workers responsible to provide end of life care. Self-determination is a core element of human dignity. Advance directive documents include a living will, and durable power of attorney for healthcare. This article reviews current issues and ethical dilemmas with regard to advance directives. Patients, family members, and clinicians may require better education on the Hospice-Palliative Care Act in order to respect more appropriately patient end of life medical care wishes.

Addressing Lesbian, Gay, Bisexual, Transgender, and Queer (LGBTQ) Issues in Teacher Education: Teacher Candidates' Perceptions

ERIC Educational Resources Information Center

Kitchen, Julian; Bellini, Christine

2012-01-01

Homophobic harassment and bullying are persistent issues in Canadian schools despite recent initiatives to improve school climate. Among the reasons is that educators feel reluctant or ill-prepared to address these issues. The purpose of this paper is to examine how teacher education can help make schools safer by addressing LGBTQ issues and…

Genetic Issues in Mental Retardation, 1996-1997.

ERIC Educational Resources Information Center

Genetic Issues in Mental Retardation, 1996

1996-01-01

This document consists of the first six issues of a newsletter, which discusses current knowledge about and concerns related to genetics and mental retardation. The second issue addresses the problem of genetic discrimination. The third issue considers genetic testing, screening, and counseling. The fourth issue addresses genetic privacy issues.…

A Look Inside Argonne's Center for Nanoscale Materials

ScienceCinema

Divan, Ralu; Rosenthal, Dan; Rose, Volker; Wai Hla

2018-05-23

At a very small, or "nano" scale, materials behave differently. The study of nanomaterials is much more than miniaturization - scientists are discovering how changes in size change a material's properties. From sunscreen to computer memory, the applications of nanoscale materials research are all around us. Researchers at Argonne's Center for Nanoscale Materials are creating new materials, methods and technologies to address some of the world's greatest challenges in energy security, lightweight but durable materials, high-efficiency lighting, information storage, environmental stewardship and advanced medical devices.

Ceramic Matrix Composites (CMC) Life Prediction Development - 2003

NASA Technical Reports Server (NTRS)

Levine, Stanley R.; Calomino, Anthony M.; Verrilli, Michael J.; Thomas, David J.; Halbig, Michael C.; Opila, Elizabeth J.; Ellis, John R.

2003-01-01

Accurate life prediction is critical to successful use of ceramic matrix composites (CMCs). The tools to accomplish this are immature and not oriented toward the behavior of carbon fiber reinforced silicon carbide (C/SiC), the primary system of interest for many reusable and single mission launch vehicle propulsion and airframe applications. This paper describes an approach and progress made to satisfy the need to develop an integrated life prediction system that addresses mechanical durability and environmental degradation of C/SiC.

The prospect of gene therapy for prostate cancer: update on theory and status.

PubMed

Koeneman, K S; Hsieh, J T

2001-09-01

Molecularly based novel therapeutic agents are needed to address the problem of locally recurrent, or metastatic, advanced hormone-refractory prostate cancer. Recent basic science advances in mechanisms of gene expression, vector delivery, and targeting have rendered clinically relevant gene therapy to the prostatic fossa and distant sites feasible in the near future. Current research and clinical investigative efforts involving methods for more effective vector delivery and targeting, with enhanced gene expression to selected (specific) sites, are reviewed. These areas of research involve tissue-specific promoters, transgene exploration, vector design and delivery, and selective vector targeting. The 'vectorology' involved mainly addresses selective tissue homing with ligands, mechanisms of innate immune system evasion for durable transgene expression, and the possibility of repeat administration.

Sliding mode observer for proton exchange membrane fuel cell: automotive application

NASA Astrophysics Data System (ADS)

Piffard, Maxime; Gerard, Mathias; Fonseca, Ramon Da; Massioni, Paolo; Bideaux, Eric

2018-06-01

This work proposes a state observer as a tool to manage cost and durability issues for PEMFC (Proton Exchange Membrane Fuel Cell) in automotive applications. Based on a dead-end anode architecture, the observer estimates the nitrogen build-up in the anode side, as well as relative humidities in the channels. These estimated parameters can then be used at fuel cell management level to enhance the durability of the stack. This observer is based on transport equations through the membrane and it reconstructs the behavior of the water and nitrogen inside the channels without the need of additional humidity sensors to correct the estimate. The convergence of the output variables is proved with Lyapunov theory for dynamic operating conditions. The validation is made with a high-fidelity model running a WLTC (Worldwide harmonized Light vehicles Test Cycle). This observer provides the average values of nitrogen and relative humidities with sufficient precision to be used in a global real-time control scheme.

Fatigue Damage of Collagenous Tissues: Experiment, Modeling and Simulation Studies

PubMed Central

Martin, Caitlin; Sun, Wei

2017-01-01

Mechanical fatigue damage is a critical issue for soft tissues and tissue-derived materials, particularly for musculoskeletal and cardiovascular applications; yet, our understanding of the fatigue damage process is incomplete. Soft tissue fatigue experiments are often difficult and time-consuming to perform, which has hindered progress in this area. However, the recent development of soft-tissue fatigue-damage constitutive models has enabled simulation-based fatigue analyses of tissues under various conditions. Computational simulations facilitate highly controlled and quantitative analyses to study the distinct effects of various loading conditions and design features on tissue durability; thus, they are advantageous over complex fatigue experiments. Although significant work to calibrate the constitutive models from fatigue experiments and to validate predictability remains, further development in these areas will add to our knowledge of soft-tissue fatigue damage and will facilitate the design of durable treatments and devices. In this review, the experimental, modeling, and simulation efforts to study collagenous tissue fatigue damage are summarized and critically assessed. PMID:25955007

Prevention and management of incontinence-associated dermatitis using a barrier cream.

PubMed

Holroyd, Sharon; Graham, Katriona

2014-12-01

Incontinence-associated dermatitis (IAD) is a common skin disorder affecting patients with urinary and/or faecal incontinence. Maintaining the skin's integrity is a challenge, particularly in the elderly and individuals with medical or surgical comorbidities. It is widely reported that the issue is complex and recognition is inconsistent, with symptoms often being confused with those of pressure ulcers. This article explores the causes of IAD, looking at the structure of healthy skin and the pathology that occurs during skin breakdown. It identifies risk factors and prevention and management strategies, including the use of barrier creams. The article then presents the results of a large product evaluation that took place with Cavilon Durable Barrier Cream (3M). The barrier cream was shown to be more effective in treating and managing patients with IAD than the previous product that patients had been using. A case study is also included to demonstrate the efficacy of the newest version of Cavilon Durable Barrier Cream.

The Role of Biomass Composition and Steam Treatment on Durability of Pellets

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

Tang, Yong; Chandra, Richard P.; Sokhansanj, Shahab

Steam treatment has been reported to improve the durability of wood pellet likely by changing the physical and chemical structures of wood particles, but published literature is inconclusive about which structure change is the major reason for enhanced durability. Here, in this paper, steam treatment was combined either with alkaline or with SO 2 to study. The solids obtained after steam treatments along with a control sample were dried and each was compacted into pellets. The pellets were then tested for durability. Steam treatment alone dominated improvements in durability. The pellet durability increased with the amount of xylose, but xylosemore » performed better in the pellet from raw poplar than did in the pellet from treated poplar. Water-soluble components contributed a maximum 4% of the durability of poplar pellets. The addition of lignin and sugars to substrates after steam treatment did not improve durability significantly. The surface modification that took place as a result of size reduction during steam treatment was the major reason, contributing about 50% of the durability of the pellet from steam-treated poplar. The acidity of steam treatment slightly affected the relative contributions of these structure changes on the durability. Lastly, the new knowledge helps tailor the chemical and/or mechanical pretreatment involved in pelleting biomass to durable pellets.« less

The Role of Biomass Composition and Steam Treatment on Durability of Pellets

DOE PAGES

Tang, Yong; Chandra, Richard P.; Sokhansanj, Shahab; ...

2018-03-03

Steam treatment has been reported to improve the durability of wood pellet likely by changing the physical and chemical structures of wood particles, but published literature is inconclusive about which structure change is the major reason for enhanced durability. Here, in this paper, steam treatment was combined either with alkaline or with SO 2 to study. The solids obtained after steam treatments along with a control sample were dried and each was compacted into pellets. The pellets were then tested for durability. Steam treatment alone dominated improvements in durability. The pellet durability increased with the amount of xylose, but xylosemore » performed better in the pellet from raw poplar than did in the pellet from treated poplar. Water-soluble components contributed a maximum 4% of the durability of poplar pellets. The addition of lignin and sugars to substrates after steam treatment did not improve durability significantly. The surface modification that took place as a result of size reduction during steam treatment was the major reason, contributing about 50% of the durability of the pellet from steam-treated poplar. The acidity of steam treatment slightly affected the relative contributions of these structure changes on the durability. Lastly, the new knowledge helps tailor the chemical and/or mechanical pretreatment involved in pelleting biomass to durable pellets.« less

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

NASA Technical Reports Server (NTRS)

Glass, David E.

2008-01-01

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this paper is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

Putting copper into action: copper-impregnated products with potent biocidal activities.

PubMed

Borkow, Gadi; Gabbay, Jeffrey

2004-11-01

Copper ions, either alone or in copper complexes, have been used for centuries to disinfect liquids, solids, and human tissue. Today copper is used as a water purifier, algaecide, fungicide, nematocide, molluscicide, and antibacterial and antifouling agent. Copper also displays potent antiviral activity. We hypothesized that introducing copper into clothing, bedding, and other articles would provide them with biocidal properties. A durable platform technology has been developed that introduces copper into cotton fibers, latex, and other polymeric materials. This study demonstrates the broad-spectrum antimicrobial (antibacterial, antiviral, antifungal) and antimite activities of copper-impregnated fibers and polyester products. This technology enabled the production of antiviral gloves and filters (which deactivate HIV-1 and other viruses), antibacterial self-sterilizing fabrics (which kill antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci), antifungal socks (which alleviate symptoms of athlete's foot), and anti-dust mite mattress covers (which reduce mite-related allergies). These products did not have skin-sensitizing properties, as determined by guine pig maximization and rabbit skin irritation tests. Our study demonstrates the potential use of copper in new applications. These applications address medical issues of the greatest importance, such as viral transmissions; nosocomial, or healthcare-associated, infections; and the spread of antibiotic-resistant bacteria.

Synergistic effect of Nitrogen-doped hierarchical porous carbon/graphene with enhanced catalytic performance for oxygen reduction reaction

NASA Astrophysics Data System (ADS)

Kong, Dewang; Yuan, Wenjing; Li, Cun; Song, Jiming; Xie, Anjian; Shen, Yuhua

2017-01-01

Developing efficient and economical catalysts for the oxygen reduction reaction (ORR) is important to promote the commercialization of fuel cells. Here, we report a simple and environmentally friendly method to prepare nitrogen (N) -doped hierarchical porous carbon (HPC)/reduced graphene oxide (RGO) composites by reusing waste biomass (pomelo peel) coupled with graphene oxide (GO). This method is green, low-cost and without using any acid or alkali activator. The typical sample (N-HPC/RGO-1) contains 5.96 at.% nitrogen and larger BET surface area (1194 m2/g). Electrochemical measurements show that N-HPC/RGO-1 exhibits not only a relatively positive onset potential and high current density, but also considerable methanol tolerance and long-term durability in alkaline media as well as in acidic media. The electron transfer number is close to 4, which means that it is mostly via a four-electron pathway toward ORR. The excellent catalytic performance of N-HPC/RGO-1 is due to the synergistic effect of the inherent interwoven network structure of HPC, the good electrical conductivity of RGO, and the heteroatom doping for the composite. More importantly, this work demonstrates a good example for turning discarded rubbish into valuable functional products and addresses the disposal issue of waste biomass simultaneously for environment clean.

Fusion energy with lasers, direct drive targets, and dry wall chambers

NASA Astrophysics Data System (ADS)

Sethian, J. D.; Friedman, M.; Lehmberg, R. H.; Myers, M.; Obenschain, S. P.; Giuliani, J.; Kepple, P.; Schmitt, A. J.; Colombant, D.; Gardner, J.; Hegeler, F.; Wolford, M.; Swanekamp, S. B.; Weidenheimer, D.; Welch, D.; Rose, D.; Payne, S.; Bibeau, C.; Baraymian, A.; Beach, R.; Schaffers, K.; Freitas, B.; Skulina, K.; Meier, W.; Latkowski, J.; Perkins, L. J.; Goodin, D.; Petzoldt, R.; Stephens, E.; Najmabadi, F.; Tillack, M.; Raffray, R.; Dragojlovic, Z.; Haynes, D.; Peterson, R.; Kulcinski, G.; Hoffer, J.; Geller, D.; Schroen, D.; Streit, J.; Olson, C.; Tanaka, T.; Renk, T.; Rochau, G.; Snead, L.; Ghoneim, N.; Lucas, G.

2003-12-01

A coordinated, focused effort is underway to develop Laser Inertial Fusion Energy. The key components are developed in concert with one another and the science and engineering issues are addressed concurrently. Recent advances include: target designs have been evaluated that show it could be possible to achieve the high gains (>100) needed for a practical fusion system.These designs feature a low-density CH foam that is wicked with solid DT and over-coated with a thin high-Z layer. These results have been verified with three independent one-dimensional codes, and are now being evaluated with two- and three-dimensional codes. Two types of lasers are under development: Krypton Fluoride (KrF) gas lasers and Diode Pumped Solid State Lasers (DPSSL). Both have recently achieved repetitive 'first light', and both have made progress in meeting the fusion energy requirements for durability, efficiency, and cost. This paper also presents the advances in development of chamber operating windows (target survival plus no wall erosion), final optics (aluminium at grazing incidence has high reflectivity and exceeds the required laser damage threshold), target fabrication (demonstration of smooth DT ice layers grown over foams, batch production of foam shells, and appropriate high-Z overcoats), and target injection (new facility for target injection and tracking studies).

4onse: four times open & non-conventional technology for sensing the environment

NASA Astrophysics Data System (ADS)

Cannata, Massimiliano; Ratnayake, Rangageewa; Antonovic, Milan; Strigaro, Daniele; Cardoso, Mirko; Hoffmann, Marcus

2017-04-01

The availability of complete, quality and dense monitoring hydro-meteorological data is essential to address a number of practical issues including, but not limited to, flood-water and urban drainage management, climate change impact assessment, early warning and risk management, now-casting and weather predictions. Thanks to the recent technological advances such as Internet Of Things, Big Data and Ubiquitous Internet, non-conventional monitoring systems based on open technologies and low cost sensors may represent a great opportunity either as a complement of authoritative monitoring network or as a vital source of information wherever existing monitoring networks are in decline or completely missing. Nevertheless, scientific literature on such a kind of open and non-conventional monitoring systems is still limited and often relates to prototype engineering and testing in rather limited case studies. For this reason the 4onse project aims at integrating existing open technologies in the field of Free & Open Source Software, Open Hardware, Open Data, and Open Standards and evaluate this kind of system in a real case (about 30 stations) for a medium period of 2 years to better scientifically understand strengths, criticalities and applicabilities in terms of data quality; system durability; management costs; performances; sustainability. The ultimate objective is to contribute in non-conventional monitoring systems adoption based on four open technologies.

Evaluation of Temporary Wound Dressings for Adherence, Durability and Autografting on Sulfur Mustard-Induced Lesions in Weanling Swine

DTIC Science & Technology

2000-12-01

interpretation of the May 7, 1996 meeting with Carl Olson, Tim Hayes, Tom Dreier, Dave Stitcher , and Frances Reid. This procedure of decontamination and proof...with Carl Olson, Tim Hayes, Tom Dreier, Dave Stitcher , and Frances Reid. TASK 33 DECONTAMINATION PROCEDURE AND PROOF OF DECONTAMINATION Decontamination...two of you, Mr. Stitcher and Dr. Estep to share our results and resolve any safety issues. Thanks, and M-3 have a good weekend! John S. Graham John S

Review of a solution-processed vertical organic transistor as a solid-state vacuum tube

NASA Astrophysics Data System (ADS)

Lin, Hung-Cheng; Zan, Hsiao-Wen; Chao, Yu-Chiang; Chang, Ming-Yu; Meng, Hsin-Fei

2015-05-01

In this paper, we investigate the key issues in raising the on/off current ratio and increasing the output current. A 1 V operated inverter composed of an enhancement-mode space-charge-limited transistor (SCLT) and a depletion-mode SCLT is demonstrated using the self-assembled monolayer modulation process. With a bulk-conduction mechanism, good bias-stress reliability, and good bending durability are obtained. Finally, key scaling-up processes, including nanoimprinting and blade-coated nanospheres, are demonstrated.

CCR 20th Anniversary Commentary: Autologous T Cells—The Ultimate Personalized Drug for the Immunotherapy of Human Cancer

PubMed Central

Rosenberg, Steven A.

2015-01-01

Summary The article by Rosenberg and colleagues, which was published in the July 1, 2011, issue of Clinical Cancer Research, demonstrated the power of the adoptive transfer of autologous antitumor T cells to mediate the complete, durable, and likely curative regression of cancer in patients with heavily pretreated metastatic melanoma. It also provided a stimulus to the development of cell transfer approaches for other cancer types using both natural and genetically engineered lymphocytes. PMID:26672082

A Case Study on Science Teacher Leadership to Address Diversity and Equity through Professional Development

ERIC Educational Resources Information Center

Doraiswamy, Nithya

2015-01-01

This qualitative case study focused on the multifaceted issue of exploring science teacher leaders understanding and addressing of issues of diversity and equity with peers through professional development. The purpose of the study was to highlight the opportunities and barriers to the addressing of issues of diversity and equity through the work…

Aggregate Freezing-Thawing Performance Using the Iowa Pore Index : final report.

DOT National Transportation Integrated Search

2016-10-01

In cold climates, the use of non-durable aggregate leads to premature pavement deterioration due to damage caused by freezing-thawing cycles. Differentiating durable and non-durable aggregates is a crucial yet challenging task. The frost durability o...

State-of-the-Art Report About Durability of Post-Tensioned Bridge Substructures

DOT National Transportation Integrated Search

1999-10-01

Durability design requires an understanding of the factors influencing durability and the measures necessary to improve durability of concrete structures. The objectives of this report are to: 1. Survey the condition of bridge substructures in Texas;...

Durability assessment of soft elastomeric capacitor skin for SHM of wind turbine blades

NASA Astrophysics Data System (ADS)

Downey, Austin; Pisello, Anna Laura; Fortunati, Elena; Fabiani, Claudia; Luzi, Francesca; Torre, Luigi; Ubertini, Filippo; Laflamme, Simon

2018-03-01

Renewable energy production has become a key research driver during the last decade. Wind energy represents a ready technology for large-scale implementation in locations all around the world. While important research is conducted to optimize wind energy production efficiency, a critical issue consists of monitoring the structural integrity and functionality of these large structures during their operational life cycle. This paper investigates the durability of a soft elastomeric capacitor strain sensing membrane, designed for structural health monitoring of wind turbines, when exposed to aggressive environmental conditions. The sensor is a capacitor made of three thin layers of an SEBS polymer in a sandwich configuration. The inner layer is doped with titania and acts as the dielectric, while the external layers are filled with carbon black and work as the conductive plates. Here, a variety of samples, not limited to the sensor configuration but also including its dielectric layer, were fabricated and tested within an accelerated weathering chamber (QUV) by simulating thermal, humidity, and UV radiation cycles. A variety of other tests were performed in order to characterize their mechanical, thermal, and electrical performance in addition to their solar reflectance. These tests were carried out before and after the QUV exposures of 1, 7, 15, and 30 days. The tests showed that titania inclusions improved the sensor durability against weathering. These findings contribute to better understanding the field behavior of these skin sensors, while future developments will concern the analysis of the sensing properties of the skin after aging.

Sensitivity study on durability variables of marine concrete structures

NASA Astrophysics Data System (ADS)

Zhou, Xin'gang; Li, Kefei

2013-06-01

In order to study the influence of parameters on durability of marine concrete structures, the parameter's sensitivity analysis was studied in this paper. With the Fick's 2nd law of diffusion and the deterministic sensitivity analysis method (DSA), the sensitivity factors of apparent surface chloride content, apparent chloride diffusion coefficient and its time dependent attenuation factor were analyzed. The results of the analysis show that the impact of design variables on concrete durability was different. The values of sensitivity factor of chloride diffusion coefficient and its time dependent attenuation factor were higher than others. Relative less error in chloride diffusion coefficient and its time dependent attenuation coefficient induces a bigger error in concrete durability design and life prediction. According to probability sensitivity analysis (PSA), the influence of mean value and variance of concrete durability design variables on the durability failure probability was studied. The results of the study provide quantitative measures of the importance of concrete durability design and life prediction variables. It was concluded that the chloride diffusion coefficient and its time dependent attenuation factor have more influence on the reliability of marine concrete structural durability. In durability design and life prediction of marine concrete structures, it was very important to reduce the measure and statistic error of durability design variables.

Metallic State FeS Anchored (Fe)/Fe3O4/N-Doped Graphitic Carbon with Porous Spongelike Structure as Durable Catalysts for Enhancing Bioelectricity Generation.

PubMed

Xu, Xin; Dai, Ying; Yu, Jia; Hao, Liang; Duan, Yaqiang; Sun, Ye; Zhang, Yanhong; Lin, Yuhui; Zou, Jinlong

2017-03-29

The critical issues in practical application of microbial fuel cells (MFCs) for wastewater treatment are the high cost and poor activity and durability of precious metal catalysts. To alleviate the activity loss and kinetic barriers for oxygen reduction reaction (ORR) on cathode, (Fe)/Fe 3 O 4 /FeS/N-doped graphitic carbon ((Fe)/Fe 3 O 4 /FeS/NGC) is prepared as ORR catalyst through a one-step method using waste pomelo skins as carbon source. Various characterization techniques and electrochemical analyses are conducted to illustrate the correlation between structural characteristics and catalytic activity. MFCs with Fe/Fe 3 O 4 /FeS/NGC (900 °C) cathode produces the maximum power density of 930 ± 10 mW m -2 (Pt/C of 489 mW m -2 ) and maintains a good long-term durability, which only declines 18% after 90 day operation. Coulombic efficiency (22.2%) obtained by Fe/Fe 3 O 4 /FeS/NGC (900 °C) cathode is significantly higher than that of Pt/C (17.3%). Metallic state FeS anchored in porous NGC skeleton can boost electron transport through the interconnected channels in spongelike structure to improve catalytic activity. Charge delocalization of C atoms can be strengthened by N atoms incorporation into carbon skeleton, which correspondingly contributes to the O 2 chemisorptions and O-O bond weakening during ORR. Energetically existed active components (Fe and N species) are more efficient than Pt to trap and consume electrons in catalyzing ORR in wastewater containing Pt-poisoning substances (bacterial metabolites). (Fe)/Fe 3 O 4 /FeS/NGC catalysts with the advantages of durable power outputs and environmental-friendly raw material can cover the shortages of Pt/C and provide an outlook for further applications of these catalysts.

Design features to enhance external hip protector adherence in the nursing home setting.

PubMed

Honkanen, Lisa A; Dehner, Melissa L; Lachs, Mark S

2006-11-01

To determine the preferences for external hip protector (EHP) design features of both certified nursing assistants (CNAs) and nursing home laundry personnel, and to test the durability of favored model features. Cross-sectional descriptive study of CNAs' and laundry personnels' preferences and a prospective experimental study of EHP fastener durability under institutional laundry conditions. Three urban nursing homes and a hospital-based laundry service. Twenty-seven CNAs, 4 laundry service supervisors. Five focus groups with CNAs and a survey of laundry supervisors were conducted to elicit preferences of EHP design features with an emphasis on convenience and durability. A laundry test of 20 EHPs was conducted to compare these design features. There was wide agreement among CNAs and laundry personnel that EHPs with soft pads in garments of light neutral colors, and cotton-blend fabrics were most preferred. CNAs preferred sewn-in pads to removeable ones, but laundry personnel had no consensus on this issue. For dependent residents, wraparound (front opening) garments using Velcro were preferred by CNAs, whereas laundry supervisors preferred snap closures. When EHP underwent repeated washing in the laundry test, Velcro and snaps were functionally comparable at 52 cycles. Garments constructed of heavyweight cotton blends, polyester, or cotton with spandex maintained elasticity at 52 weeks, whereas the lightweight cotton blend stretched significantly. Based on CNAs' preferences, laundry personnels' input, and a laundry test, EHP design features that could enhance both caregiver efficiency and resident comfort include soft pads sewn into a light-colored (but non-white) heavier weight cotton-blend garment, with the availability of both a pull-up style and a wraparound style using Velcro fasteners. Snaps did not demonstrate superior durability in the laundry test, but further comparison with Velcro under clinical conditions is indicated. Education and inclusion of CNAs in EHP decision making are important ways to improve EHP adherence.

Investigation of Dynamic Force/Vibration Transmission Characteristics of Four-Square Type Gear Durability Test Machines

NASA Technical Reports Server (NTRS)

Kahraman, Ahmet

2002-01-01

In this study, design requirements for a dynamically viable, four-square type gear test machine are investigated. Variations of four-square type gear test machines have been in use for durability and dynamics testing of both parallel- and cross-axis gear set. The basic layout of these machines is illustrated. The test rig is formed by two gear pairs, of the same reduction ratio, a test gear pair and a reaction gear pair, connected to each other through shafts of certain torsional flexibility to form an efficient, closed-loop system. A desired level of constant torque is input to the circuit through mechanical (a split coupling with a torque arm) or hydraulic (a hydraulic actuator) means. The system is then driven at any desired speed by a small DC motor. The main task in hand is the isolation of the test gear pair from the reaction gear pair under dynamic conditions. Any disturbances originated at the reaction gear mesh might potentially travel to the test gearbox, altering the dynamic loading conditions of the test gear mesh, and hence, influencing the outcome of the durability or dynamics test. Therefore, a proper design of connecting structures becomes a major priority. Also, equally important is the issue of how close the operating speed of the machine is to the resonant frequencies of the gear meshes. This study focuses on a detailed analysis of the current NASA Glenn Research Center gear pitting test machine for evaluation of its resonance and vibration isolation characteristics. A number of these machines as the one illustrated has been used over last 30 years to establish an extensive database regarding the influence of the gear materials, processes surface treatments and lubricants on gear durability. This study is intended to guide an optimum design of next generation test machines for the most desirable dynamic characteristics.

Teeth: Among Nature's Most Durable Biocomposites

NASA Astrophysics Data System (ADS)

Lawn, Brian R.; Lee, James J.-W.; Chai, Herzl

2010-08-01

This paper addresses the durability of natural teeth from a materials perspective. Teeth are depicted as smart biocomposites, highly resistant to cumulative deformation and fracture. Favorable morphological features of teeth at both macroscopic and microscopic levels contribute to an innate damage tolerance. Damage modes are activated readily within the brittle enamel coat but are contained from spreading catastrophically into the vulnerable tooth interior in sustained occlusal loading. Although tooth enamel contains a multitude of microstructural defects that can act as sources of fracture, substantial overloads are required to drive any developing cracks to ultimate failure—nature's strategy is to contain damage rather than avoid it. Tests on model glass-shell systems simulating the basic elements of the tooth enamel/dentin layer structure help to identify important damage modes. Fracture and deformation mechanics provide a basis for analyzing critical conditions for each mode, in terms of characteristic tooth dimensions and materials properties. Comparative tests on extracted human and animal teeth confirm the validity of the model test approach and point to new research directions. Implications in biomechanics, especially as they relate to dentistry and anthropology, are outlined.

Measure Guideline: Guide to Attic Air Sealing

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

Lstiburek, J.

2014-09-01

The Guide to Attic Air Sealing was completed in 2010 and although not in the standard Measure Guideline format, is intended to be a Measure Guideline on Attic Air Sealing. The guide was reviewed during two industry stakeholders meetings held on December 18th, 2009 and January 15th, 2010, and modified based on the comments received. Please do not make comments on the Building America format of this document. The purpose of the Guide to Attic Air Sealing is to provide information and recommendations for the preparation work necessary prior to adding attic insulation. Even though the purpose of this guidemore » is to save energy - health, safety and durability should not be compromised by energy efficiency. Accordingly, combustion safety and ventilation for indoor air quality are addressed first. Durability and attic ventilation then follow. Finally, to maximize energy savings, air sealing is completed prior to insulating. The guide is intended for home remodelers, builders, insulation contractors, mechanical contractors, general contractors who have previously done remodeling and homeowners as a guide to the work that needs to be done.« less

Hollow Fibers Networked with Perovskite Nanoparticles for H2 Production from Heavy Oil

NASA Astrophysics Data System (ADS)

Jeon, Yukwon; Park, Dae-Hwan; Park, Joo-Il; Yoon, Seong-Ho; Mochida, Isao; Choy, Jin-Ho; Shul, Yong-Gun

2013-10-01

Design of catalytic materials has been highlighted to build ultraclean use of heavy oil including liquid-to-gas technology to directly convert heavy hydrocarbons into H2-rich gas fuels. If the H2 is produced from such heavy oil through high-active and durable catalysts in reforming process that is being constructed in hydrogen infrastructure, it will be addressed into renewable energy systems. Herein, the three different hollow fiber catalysts networked with perovskite nanoparticles, LaCr0.8Ru0.2O3, LaCr0.8Ru0.1Ni0.1O3, and LaCr0.8Ni0.2O3 were prepared by using activated carbon fiber as a sacrificial template for H2 production from heavy gas oil reforming. The most important findings were arrived at: (i) catalysts had hollow fibrous architectures with well-crystallized structures, (ii) hollow fibers had a high specific surface area with a particle size of ~50 nm, and (iii) the Ru substituted ones showed high efficiency for H2 production with substantial durability under high concentrations of S, N, and aromatic compounds.

Hollow fibers networked with perovskite nanoparticles for H2 production from heavy oil.

PubMed

Jeon, Yukwon; Park, Dae-Hwan; Park, Joo-Il; Yoon, Seong-Ho; Mochida, Isao; Choy, Jin-Ho; Shul, Yong-Gun

2013-10-09

Design of catalytic materials has been highlighted to build ultraclean use of heavy oil including liquid-to-gas technology to directly convert heavy hydrocarbons into H2-rich gas fuels. If the H2 is produced from such heavy oil through high-active and durable catalysts in reforming process that is being constructed in hydrogen infrastructure, it will be addressed into renewable energy systems. Herein, the three different hollow fiber catalysts networked with perovskite nanoparticles, LaCr(0.8)Ru(0.2)O3, LaCr(0.8)Ru(0.1)Ni(0.1)O3, and LaCr(0.8)Ni(0.2)O3 were prepared by using activated carbon fiber as a sacrificial template for H2 production from heavy gas oil reforming. The most important findings were arrived at: (i) catalysts had hollow fibrous architectures with well-crystallized structures, (ii) hollow fibers had a high specific surface area with a particle size of ≈50 nm, and (iii) the Ru substituted ones showed high efficiency for H2 production with substantial durability under high concentrations of S, N, and aromatic compounds.

The state of human dimensions capacity for natural resource management: needs, knowledge, and resources

USGS Publications Warehouse

Sexton, Natalie R.; Leong, Kirsten M.; Milley, Brad J.; Clarke, Melinda M.; Teel, Tara L.; Chase, Mark A.; Dietsch, Alia M.

2013-01-01

The social sciences have become increasingly important in understanding natural resource management contexts and audiences, and are essential in design and delivery of effective and durable management strategies. Yet many agencies and organizations do not have the necessary resource management. We draw on the textbook definition of HD: how and why people value natural resources, what benefits people seek and derive from those resources, and how people affect and are affected by those resources and their management (Decker, Brown, and Seimer 2001). Clearly articulating how HD information can be used and integrated into natural resource management planning and decision-making is an important challenge faced by the HD field. To address this challenge, we formed a collaborative team to explore the issue of HD capacity-building for natural resource organizations and to advance the HD field. We define HD capacity as activities, efforts, and resources that enhance the ability of HD researchers and practitioners and natural managers and decision-makers to understand and address the social aspects of conservation.Specifically, we sought to examine current barriers to integration of HD into natural resource management, knowledge needed to improve HD capacity, and existing HD tools, resources, and training opportunities. We conducted a needs assessment of HD experts and practitioners, developed a framework for considering HD activities that can contribute both directly and indirectly throughout any phase of an adaptive management cycle, and held a workshop to review preliminary findings and gather additional input through breakout group discussions. This paper provides highlights from our collaborative initiative to help frame and inform future HD capacity-building efforts and natural resource organizations and also provides a list of existing human dimensions tools and resources.

Addressing Personal Issues in Supervision: Impact of Counselors' Experience Level on Various Aspects of the Supervisory Relationship.

ERIC Educational Resources Information Center

Sumerel, Marie B.; Borders, L. Dianne

1996-01-01

In this study, entry-level and advanced counselors (N=40) rated videotaped supervision sessions in which either the counselor's personal issues or skills deficits were addressed. The study's goal was to determine the impact that addressing counselors' personal issues in supervision has on relationship, quality of the session, postsession mood, and…

Guidance for Catastrophic Emergency Situations Involving Asbestos

EPA Pesticide Factsheets

This document addresses the types of asbestos issues that may arise during catastrophic events and how EPA has addressed such issues. It replaces the Guidelines for Catastrophic Emergency Situations Involving Asbestos which was issued in 1992.

Industry and water security: overarching conclusions.

PubMed

Stigson, B

2001-01-01

Fresh water is key to sustainable development. World Business Council for Sustainable Development members are addressing fresh water use "within the corporate fenceline". However, to address water issues "outside the corporate fenceline" will require creative new public-private partnerships. Government's role is to provide sound framework conditions that will encourage businesses to invest time, staff and resources to address vital fresh water issues. Industry is committed to best practice within its internal operations and is ready to enter into partnerships to address broader fresh water issues.

40 CFR 610.33 - Durability tests.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Durability tests. 610.33 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria § 610.33 Durability tests. The Administrator may determine that a device under evaluation will require durability testing in...

40 CFR 610.33 - Durability tests.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Durability tests. 610.33 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria § 610.33 Durability tests. The Administrator may determine that a device under evaluation will require durability testing in...

40 CFR 610.33 - Durability tests.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Durability tests. 610.33 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria § 610.33 Durability tests. The Administrator may determine that a device under evaluation will require durability testing in...

40 CFR 610.33 - Durability tests.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Durability tests. 610.33 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria § 610.33 Durability tests. The Administrator may determine that a device under evaluation will require durability testing in...

40 CFR 610.33 - Durability tests.

Code of Federal Regulations, 2013 CFR

2013-07-01

... applied. After identification of a potential failure mode, durability tests may be conducted to... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Durability tests. 610.33 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria § 610.33 Durability...

Atomic oxygen effects on materials

NASA Technical Reports Server (NTRS)

Banks, Bruce A.; Rutledge, Sharon K.; Brady, Joyce A.; Merrow, James E.

1989-01-01

Understanding of the basic processes of atomic oxygen interaction is currently at a very elementary level. However, measurement of erosion yields, surface morphology, and optical properties for low fluences have brought about much progress in the past decade. Understanding the mechanisms and those factors that are important for proper simulation of low Earth orbit is at a much lower level of understanding. The ability to use laboratory simulations with confidence to quantifiably address the functional performance and durability of materials in low Earth orbit will be necessary to assure long-term survivability to the natural space environment.

Radiation-resistant composite for biological shield of personnel

NASA Astrophysics Data System (ADS)

Barabash, D. E.; Barabash, A. D.; Potapov, Yu B.; Panfilov, D. V.; Perekalskiy, O. E.

2017-10-01

This article presents the results of theoretical and practical justification for the use of polymer concrete based on nonisocyanate polyurethanes in biological shield structures. We have identified the impact of ratio: polymer - radiation-resistant filling compound on the durability and protection properties of polymer concrete. The article expounds regression dependence of the change of basic properties of the aforementioned polymer concrete on the absorbed radiation dose rate. Synergy effect in attenuation of radioactivity release in case of conjoint use of hydrogenous polymer base and radiation-resistant powder is also addressed herein.

Self-Powered High-Resolution and Pressure-Sensitive Triboelectric Sensor Matrix for Real-Time Tactile Mapping.

PubMed

Wang, Xiandi; Zhang, Hanlu; Dong, Lin; Han, Xun; Du, Weiming; Zhai, Junyi; Pan, Caofeng; Wang, Zhong Lin

2016-04-20

A triboelectric sensor matrix (TESM) can accurately track and map 2D tactile sensing. A self-powered, high-resolution, pressure-sensitive, flexible and durable TESM with 16 × 16 pixels is fabricated for the fast detection of single-point and multi-point touching. Using cross-locating technology, a cross-type TESM with 32 × 20 pixels is developed for more rapid tactile mapping, which significantly reduces the addressing lines from m × n to m + n. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Handbook on Teaching Social Issues. NCSS Bulletin 93.

ERIC Educational Resources Information Center

Evans, Ronald W., Ed.; Saxe, David Warren, Ed.

This handbook explores the issues-centered curriculum for social studies teaching and how student performance reflects an intellectual capacity to address public issues. The book is divided into 11 parts with essays to address specific aspects of the approach. The foreword, written by Shirley Engle, establishes a context for issues-based…

40 CFR 86.094-26 - Mileage and service accumulation; emission requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-duty vehicles. It prescribes mileage and service accumulation requirements for durability data vehicles... Durability Program of § 86.094-13(d), and for emission data vehicles regardless of the durability program employed. Service accumulation requirements for durability data vehicles run under the Alternative Service...

76 FR 43808 - Designation of Biobased Items for Federal Procurement

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-22

... thermal shipping containers, including durable and non-durable thermal shipping containers as... able to utilize this Web site as one tool to determine the availability of qualifying biobased products... containers and the subcategories are (1) durable thermal shipping containers, and (2) non-durable thermal...

REDUCTION OF CONSTRAINTS FOR COUPLED OPERATIONS

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

Raszewski, F.; Edwards, T.

2009-12-15

The homogeneity constraint was implemented in the Defense Waste Processing Facility (DWPF) Product Composition Control System (PCCS) to help ensure that the current durability models would be applicable to the glass compositions being processed during DWPF operations. While the homogeneity constraint is typically an issue at lower waste loadings (WLs), it may impact the operating windows for DWPF operations, where the glass forming systems may be limited to lower waste loadings based on fissile or heat load limits. In the sludge batch 1b (SB1b) variability study, application of the homogeneity constraint at the measurement acceptability region (MAR) limit eliminated muchmore » of the potential operating window for DWPF. As a result, Edwards and Brown developed criteria that allowed DWPF to relax the homogeneity constraint from the MAR to the property acceptance region (PAR) criterion, which opened up the operating window for DWPF operations. These criteria are defined as: (1) use the alumina constraint as currently implemented in PCCS (Al{sub 2}O{sub 3} {ge} 3 wt%) and add a sum of alkali constraint with an upper limit of 19.3 wt% ({Sigma}M{sub 2}O < 19.3 wt%), or (2) adjust the lower limit on the Al{sub 2}O{sub 3} constraint to 4 wt% (Al{sub 2}O{sub 3} {ge} 4 wt%). Herman et al. previously demonstrated that these criteria could be used to replace the homogeneity constraint for future sludge-only batches. The compositional region encompassing coupled operations flowsheets could not be bounded as these flowsheets were unknown at the time. With the initiation of coupled operations at DWPF in 2008, the need to revisit the homogeneity constraint was realized. This constraint was specifically addressed through the variability study for SB5 where it was shown that the homogeneity constraint could be ignored if the alumina and alkali constraints were imposed. Additional benefit could be gained if the homogeneity constraint could be replaced by the Al{sub 2}O{sub 3} and sum of alkali constraint for future coupled operations processing based on projections from Revision 14 of the High Level Waste (HLW) System Plan. As with the first phase of testing for sludge-only operations, replacement of the homogeneity constraint with the alumina and sum of alkali constraints will ensure acceptable product durability over the compositional region evaluated. Although these study glasses only provide limited data in a large compositional region, the approach and results are consistent with previous studies that challenged the homogeneity constraint for sludge-only operations. That is, minimal benefit is gained by imposing the homogeneity constraint if the other PCCS constraints are satisfied. The normalized boron releases of all of the glasses are well below the Environmental Assessment (EA) glass results, regardless of thermal history. Although one of the glasses had a normalized boron release of approximately 10 g/L and was not predictable, the glass is still considered acceptable. This particular glass has a low Al{sub 2}O{sub 3} concentration, which may have attributed to the anomalous behavior. Given that poor durability has been previously observed in other glasses with low Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} concentrations, including the sludge-only reduction of constraints study, further investigations appear to be warranted. Based on the results of this study, it is recommended that the homogeneity constraint (in its entirety with the associated low frit/high frit constraints) be eliminated for coupled operations as defined by Revision 14 of the HLW System Plan with up to 2 wt% TiO{sub 2}. The use of the alumina and sum of alkali constraints should be continued along with the variability study to determine the predictability of the current durability models and/or that the glasses are acceptable with respect to durability. The use of a variability study for each batch is consistent with the glass product control program and it will help to assess new streams or compositional changes. It is also recommended that the influence of alumina and alkali on durability be studied in greater detail. Limited data suggests that there may be a need to adjust the lower Al{sub 2}O{sub 3} limit and/or the upper alkali limit in order to prevent the fabrication of unacceptable glasses. An in-depth evaluation of all previous data as well as any new data would help to better define an alumina and alkali combination that would avoid potential phase separation and ensure glass durability.« less

Post-human and scientific research: how engineering carried out the project.

PubMed

Ghilardi, Giampaolo; Accoto, Dino

2014-01-01

We start with a definition of robot in order to understand which are legitimate robotics' objectives. Then it is provided an outline of new robot generations and their industrial and biomedical applications. We consider the consequences of this new kind of technology on the notion of intelligence, stressing how the exteroceptive sensor systems provide a new bottom up approach to the AI debate. We consider three challenges Robotics have to face nowadays. First materials and components, which are built with technologies top-down, set huge limits in terms of weight, speed, safety and cost, not to mention reliability and durability. Second the methodological aspects: the challenge concerns the management of complexity. How to achieve intelligent and adaptive behaviours out of the control system of the robot, which must remain intrinsically simple? A third issue we address is the cultural one: the unreasonable expectations of the general public often provoked by a misunderstanding of the notion of intelligence itself. We consider then what makes human specifically human from a broader philosophic point of view, pointing out how the will is strangely absent in the AI debate. We show three advantages connected with this different perspective instead of the classical one intellect centered. First, while intellect is not used only by man, will is. Second, desire involves intellect while the reciprocal is not necessarily true. Third, looking at robotics and more specifically to cybernetics the key concept of these fields are control and governance, whereas both of them are specifically relate to the domain of will rather than intellect. We look then into the concept of participation as essential to the understanding of the notion of will, to overcome some roboethics' issues related to the adoption of the still dominant rationalistic paradigm.

Investigating the BSA protein adsorption and bacterial adhesion of Al-alloy surfaces after creating a hierarchical (micro/nano) superhydrophobic structure.

PubMed

Moazzam, Parisa; Razmjou, Amir; Golabi, Mohsen; Shokri, Dariush; Landarani-Isfahani, Amir

2016-09-01

Bacterial adhesion and subsequent biofilm formation on metals such as aluminum (Al) alloys lead to serious issues in biomedical and industrial fields from both an economical and health perspective. Here, we showed that a careful manipulation of Al surface characteristics via a facile two-steps superhydrophobic modification can provide not only biocompatibility and an ability to control protein adsorption and bacterial adhesion, but also address the issue of apparent long-term toxicity of Al-alloys. To find out the roles of surface characteristics, surface modification and protein adsorption on microbial adhesion and biofilm formation, the surfaces were systematically characterized by SEM, EDX, XPS, AFM, FTIR, water contact angle (WCA) goniometry, surface free energy (SFE) measurement, MTT, Bradford, Lowry and microtiter plate assays and also flow-cytometry and potentiostat analyses. Results showed that WCA and SFE changed from 70° to 163° and 36.3 to 0.13 mN m(-1) , respectively. The stable and durable modification led to a substantial reduction in static/dynamic BSA adsorption. The effect of such a treatment on the biofilm formation was analyzed by using three different bacteria of Pseudomonas aeruginosa, Staphylococcus epidermidis, and Staphylococcus aureus. The microtiter plate assay and flow cytometry analysis showed that the modification not only could substantially reduce the bacterial adhesion but this biofouling resistance is independent of bacterium type. An excellent cell viability after exposure of HeLa cells to waters incubated with the modified samples was observed. Finally, the corrosion rate reduced sharply from 856.6 to 0.119 MPY after superhydrophobic modifications, which is an excellent stable corrosion inhibition property. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2220-2233, 2016. © 2016 Wiley Periodicals, Inc.

Planning the Safety of Atrial Fibrillation Ablation Registry Initiative (SAFARI) as a Collaborative Pan-Stakeholder Critical Path Registry Model: a Cardiac Safety Research Consortium "Incubator" Think Tank.

PubMed

Al-Khatib, Sana M; Calkins, Hugh; Eloff, Benjamin C; Packer, Douglas L; Ellenbogen, Kenneth A; Hammill, Stephen C; Natale, Andrea; Page, Richard L; Prystowsky, Eric; Jackman, Warren M; Stevenson, William G; Waldo, Albert L; Wilber, David; Kowey, Peter; Yaross, Marcia S; Mark, Daniel B; Reiffel, James; Finkle, John K; Marinac-Dabic, Danica; Pinnow, Ellen; Sager, Phillip; Sedrakyan, Art; Canos, Daniel; Gross, Thomas; Berliner, Elise; Krucoff, Mitchell W

2010-01-01

Atrial fibrillation (AF) is a major public health problem in the United States that is associated with increased mortality and morbidity. Of the therapeutic modalities available to treat AF, the use of percutaneous catheter ablation of AF is expanding rapidly. Randomized clinical trials examining the efficacy and safety of AF ablation are currently underway; however, such trials can only partially determine the safety and durability of the effect of the procedure in routine clinical practice, in more complex patients, and over a broader range of techniques and operator experience. These limitations of randomized trials of AF ablation, particularly with regard to safety issues, could be addressed using a synergistically structured national registry, which is the intention of the SAFARI. To facilitate discussions about objectives, challenges, and steps for such a registry, the Cardiac Safety Research Consortium and the Duke Clinical Research Institute, Durham, NC, in collaboration with the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, organized a Think Tank meeting of experts in the field. Other participants included the National Heart, Lung and Blood Institute, the Centers for Medicare and Medicaid Services, the Agency for Healthcare Research and Quality, the Society of Thoracic Surgeons, the AdvaMed AF working group, and additional industry representatives. The meeting took place on April 27 to 28, 2009, at the US Food and Drug Administration headquarters in Silver Spring, MD. This article summarizes the issues and directions presented and discussed at the meeting. Copyright 2010 Mosby, Inc. All rights reserved.

Inclusion of ethical issues in dementia guidelines: a thematic text analysis.

PubMed

Knüppel, Hannes; Mertz, Marcel; Schmidhuber, Martina; Neitzke, Gerald; Strech, Daniel

2013-08-01

Clinical practice guidelines (CPGs) aim to improve professionalism in health care. However, current CPG development manuals fail to address how to include ethical issues in a systematic and transparent manner. The objective of this study was to assess the representation of ethical issues in general CPGs on dementia care. To identify national CPGs on dementia care, five databases of guidelines were searched and national psychiatric associations were contacted in August 2011 and in June 2013. A framework for the assessment of the identified CPGs' ethical content was developed on the basis of a prior systematic review of ethical issues in dementia care. Thematic text analysis and a 4-point rating score were employed to assess how ethical issues were addressed in the identified CPGs. Twelve national CPGs were included. Thirty-one ethical issues in dementia care were identified by the prior systematic review. The proportion of these 31 ethical issues that were explicitly addressed by each CPG ranged from 22% to 77%, with a median of 49.5%. National guidelines differed substantially with respect to (a) which ethical issues were represented, (b) whether ethical recommendations were included, (c) whether justifications or citations were provided to support recommendations, and (d) to what extent the ethical issues were explained. Ethical issues were inconsistently addressed in national dementia guidelines, with some guidelines including most and some including few ethical issues. Guidelines should address ethical issues and how to deal with them to help the medical profession understand how to approach care of patients with dementia, and for patients, their relatives, and the general public, all of whom might seek information and advice in national guidelines. There is a need for further research to specify how detailed ethical issues and their respective recommendations can and should be addressed in dementia guidelines. Please see later in the article for the Editors' Summary.

Inclusion of Ethical Issues in Dementia Guidelines: A Thematic Text Analysis

PubMed Central

Knüppel, Hannes; Schmidhuber, Martina; Neitzke, Gerald

2013-01-01

Background Clinical practice guidelines (CPGs) aim to improve professionalism in health care. However, current CPG development manuals fail to address how to include ethical issues in a systematic and transparent manner. The objective of this study was to assess the representation of ethical issues in general CPGs on dementia care. Methods and Findings To identify national CPGs on dementia care, five databases of guidelines were searched and national psychiatric associations were contacted in August 2011 and in June 2013. A framework for the assessment of the identified CPGs' ethical content was developed on the basis of a prior systematic review of ethical issues in dementia care. Thematic text analysis and a 4-point rating score were employed to assess how ethical issues were addressed in the identified CPGs. Twelve national CPGs were included. Thirty-one ethical issues in dementia care were identified by the prior systematic review. The proportion of these 31 ethical issues that were explicitly addressed by each CPG ranged from 22% to 77%, with a median of 49.5%. National guidelines differed substantially with respect to (a) which ethical issues were represented, (b) whether ethical recommendations were included, (c) whether justifications or citations were provided to support recommendations, and (d) to what extent the ethical issues were explained. Conclusions Ethical issues were inconsistently addressed in national dementia guidelines, with some guidelines including most and some including few ethical issues. Guidelines should address ethical issues and how to deal with them to help the medical profession understand how to approach care of patients with dementia, and for patients, their relatives, and the general public, all of whom might seek information and advice in national guidelines. There is a need for further research to specify how detailed ethical issues and their respective recommendations can and should be addressed in dementia guidelines. Please see later in the article for the Editors' Summary PMID:23966839

31 CFR 240.17 - Powers of attorney.

Code of Federal Regulations, 2013 CFR

2013-07-01

... following a determination that the named payee is incompetent. (e) Springing durable special powers of attorney. A springing durable special power of attorney is similar to a durable power of attorney except... special power of attorney, a springing durable special power of attorney is created by the principal's use...

31 CFR 240.17 - Powers of attorney.

Code of Federal Regulations, 2011 CFR

2011-07-01

... following a determination that the named payee is incompetent. (e) Springing durable special powers of attorney. A springing durable special power of attorney is similar to a durable power of attorney except... special power of attorney, a springing durable special power of attorney is created by the principal's use...

Identifying veterinary students' capacity for moral behavior concerning animal ethics issues.

PubMed

Verrinder, Joy M; Phillips, Clive J C

2014-01-01

Veterinarians face unique animal ethics challenges as practitioners and policy advisors to government and industry. Changing societal attitudes, cultural diversity, and the often conflicting needs and interests of patients and clients contribute to moral distress. Yet little has been done to identify veterinarians' capacity to address these animal ethics issues. In this study, first-year and final-year veterinary students in an Australian university were surveyed to explore moral sensitivity, moral motivation, and moral character and their relationship with moral reasoning. The majority of students were concerned about animal ethics issues and had experienced moral distress in relation to the treatment of animals. Most believed that veterinarians should address the wider social issues of animal protection and that veterinary medicine should require a commitment to animals' interests over owners'/caregivers' interests. There was less agreement that the veterinary profession was sufficiently involved in addressing animal ethics issues. The principal motivators for studying veterinary medicine were, in declining importance, enjoyment in working with animals, helping sick and injured animals, and improving the way animals are treated. However, most students had taken little or no action to address animal ethics issues. These results suggest that both first- and fifth-year veterinary students are sensitive to animal ethics issues and are motivated to prioritize the interests of animals but have little experience in taking action to address these issues. Further research is needed to determine ways to identify and assess these moral behavior components in veterinary education to develop veterinarians' capacity to address animal ethics issues.

Multi-factor Effects on the Durability of Recycle Aggregate Concrete

NASA Astrophysics Data System (ADS)

Ma, Huan; Cui, Yu-Li; Zhu, Wen-Yu; Xie, Xian-Jie

2016-05-01

Recycled Aggregate Concrete (RAC) was prepared with different recycled aggregate replacement ratio, 0, 30%, 70% and 100% respectively. The performances of RAC were examined by the freeze-thaw cycle, carbonization and sulfate attack to assess the durability. Results show that test sequence has different effects on the durability of RAC; the durability is poorer when carbonation experiment was carried out firstly, and then other experiment was carried out again; the durability is better when recycled aggregate replacement ratio is 70%.

Using Lean methodologies to streamline processing of requests for durable medical equipment and supplies for children with complex conditions.

PubMed

Fields, Elise; Neogi, Smriti; Schoettker, Pamela J; Lail, Jennifer

2017-12-12

An improvement team from the Complex Care Center at our large pediatric medical center participated in a 60-day initiative to use Lean methodologies to standardize their processes, eliminate waste and improve the timely and reliable provision of durable medical equipment and supplies. The team used value stream mapping to identify processes needing improvement. Improvement activities addressed the initial processing of a request, provider signature on the form, returning the form to the sender, and uploading the completed documents to the electronic medical record. Data on lead time (time between receiving a request and sending the completed request to the Health Information Management department) and process time (amount of time the staff worked on the request) were collected via manual pre- and post-time studies. Following implementation of interventions, the median lead time for processing durable medical equipment and supply requests decreased from 50 days to 3 days (p < 0.0001). Median processing time decreased from 14min to 9min (p < 0.0001). The decrease in processing time realized annual cost savings of approximately $11,000. Collaborative leadership and multidisciplinary training in Lean methods allowed the CCC staff to incorporate common sense, standardize practices, and adapt their work environment to improve the timely and reliable provision of equipment and supplies that are essential for their patients. The application of Lean methodologies to processing requests for DME and supplies could also result in a natural spread to other paperwork and requests, thus avoiding delays and potential risk for clinical instability or deterioration. Copyright © 2017 Elsevier Inc. All rights reserved.

Drag reduction using metallic engineered surfaces with highly ordered hierarchical topographies: nanostructures on micro-riblets

NASA Astrophysics Data System (ADS)

Kim, Taekyung; Shin, Ryung; Jung, Myungki; Lee, Jinhyung; Park, Changsu; Kang, Shinill

2016-03-01

Durable drag-reduction surfaces have recently received much attention, due to energy-saving and power-consumption issues associated with harsh environment applications, such as those experienced by piping infrastructure, ships, aviation, underwater vehicles, and high-speed ground vehicles. In this study, a durable, metallic surface with highly ordered hierarchical structures was used to enhance drag-reduction properties, by combining two passive drag-reduction strategies: an air-layer effect induced by nanostructures and secondary vortex generation by micro-riblet structures. The nanostructures and micro-riblet structures were designed to increase slip length. The top-down fabrication method used to form the metallic hierarchical structures combined laser interference lithography, photolithography, thermal reflow, nanoimprinting, and pulse-reverse-current electrochemical deposition. The surfaces were formed from nickel, which has high hardness and corrosion resistance, making it suitable for use in harsh environments. The drag-reduction properties of various metal surfaces were investigated based on the surface structure: a bare surface, a nanostructured surface, a micro-riblet surface, and a hierarchically structured surface of nanostructures on micro-riblets.

Flash-induced nanowelding of silver nanowire networks for transparent stretchable electrochromic devices.

PubMed

Lee, Chihak; Oh, Youngsu; Yoon, In Seon; Kim, Sun Hong; Ju, Byeong-Kwon; Hong, Jae-Min

2018-02-09

Electrochromic devices (ECDs) are emerging as a novel technology for various applications like commercialized smart window glasses, and auto-dimming rear-view mirrors. Recently, the development of low-power, lightweight, flexible, and stretchable devices has been accelerated to meet the growing demand in the new wearable devices market. Silver nanowires (AgNWs) can become new primary transparent conducting electrode (TCE) materials to replace indium tin oxide (ITO) for ECDs. However, issues such as substrate adhesion, delamination, and higher resistance still exist with AgNWs. Herein, we report a high-performance stretchable flash-induced AgNW-network-based TCE on surface-treated polydimethylsiloxane (PDMS) substrates. A Xe flash light method was used to create nanowelded networks of AgNWs. Surface silane treatments increased the adhesion and durability of the films as well. Finally, ECDs were fabricated under the optimal conditions and examined under strained conditions to demonstrate the resistance and mechanical behaviours of the devices. Results showed a flexible and durable film maintaining a high level of conductivity and reversible resistance behaviour, beyond those currently achievable with standard ITO/PET flexible TCEs.

Development and Testing of Ceramic Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Miller, Robert A.

2004-01-01

Ceramic thermal barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. Durability of the coating systems remains a critical issue with the ever-increasing temperature requirements. Thermal conductivity increase and coating degradation due to sintering and phase changes are known to be detrimental to coating performance. There is a need to characterize the coating behavior and temperature limits, in order to potentially take full advantage of the current coating capability, and also accurately assess the benefit gained from advanced coating development. In this study, thermal conductivity behavior and cyclic durability of plasma-sprayed ZrO2-8wt%Y2O3 thermal barrier coatings were evaluated under laser heat-flux simulated high temperature, large thermal gradient and thermal cycling conditions. The coating degradation and failure processes were assessed by real-time monitoring of the coating thermal conductivity under the test conditions. The ceramic coating crack propagation driving forces and resulting failure modes will be discussed in light of high temperature mechanical fatigue and fracture testing results.

42 CFR 414.229 - Other durable medical equipment-capped rental items.

Code of Federal Regulations, 2011 CFR

2011-10-01

... AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PAYMENT FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for Durable Medical Equipment and Prosthetic and Orthotic Devices § 414.229 Other durable medical... 42 Public Health 3 2011-10-01 2011-10-01 false Other durable medical equipment-capped rental items...

42 CFR 414.229 - Other durable medical equipment-capped rental items.

Code of Federal Regulations, 2010 CFR

2010-10-01

... AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PAYMENT FOR PART B MEDICAL AND OTHER HEALTH SERVICES Payment for Durable Medical Equipment and Prosthetic and Orthotic Devices § 414.229 Other durable medical... 42 Public Health 3 2010-10-01 2010-10-01 false Other durable medical equipment-capped rental items...

30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement in...

Highly Dispersed Alloy Catalyst for Durability

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

Vivek S. Murthi; Izzo, Elise; Bi, Wu

2013-01-08

Achieving DOE's stated 5000-hr durability goal for light-duty vehicles by 2015 will require MEAs with characteristics that are beyond the current state of the art. Significant effort was placed on developing advanced durable cathode catalysts to arrive at the best possible electrode for high performance and durability, as well as developing manufacturing processes that yield significant cost benefit. Accordingly, the overall goal of this project was to develop and construct advanced MEAs that will improve performance and durability while reducing the cost of PEMFC stacks. The project, led by UTC Power, focused on developing new catalysts/supports and integrating them withmore » existing materials (membranes and gas diffusion layers (GDLs)) using state-of-the-art fabrication methods capable of meeting the durability requirements essential for automotive applications. Specifically, the project work aimed to lower platinum group metals (PGM) loading while increasing performance and durability. Appropriate catalysts and MEA configuration were down-selected that protects the membrane, and the layers were tailored to optimize the movements of reactants and product water through the cell to maximize performance while maintaining durability.« less

Main issues of pile foundation at waterfront development and its prevention method

NASA Astrophysics Data System (ADS)

Manap, N.; Tan, K. Y.; Syahrom, N.

2017-12-01

Pile foundation is widely used in construction and building marine structures. This is because pile foundation is an important structure and should have long-term durability. However, in waterfront development, a lot of issues from the seawater should be considered distinctively because it consists of many problems that can affect the building structure especially the foundation of the building. Thus, a research should be conducted to identify issues of pile foundation at waterfront development and determine its prevention methods. The research was carried out through interviews with the developers and contractors from the projects of Lexis Hibiscus at Port Dickson, Negeri Sembilan and Redevelopment for Deep-Water Facilities at Quay 6 in Pasir Gudang, Johor, Malaysia. The objectives of this research are to identify issues of pile foundation and to determine the prevention methods of pile foundation issues at waterfront development. All respondents agreed that the main issues of pile foundations at waterfront development are the wave and tide condition. The prevention methods of the issue faced at waterfront development that are most frequently used for the pile foundation are coating system and concrete cover. This research is beneficial to all developers and contractors to ensure pile foundations at waterfront development can be protected by using the prevention methods.

Controls concepts for next generation reuseable rocket engines

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Merrill, Walter C.; Musgrave, Jefferey L.; Ray, Asok

1995-01-01

Three primary issues will drive the design and control used in next generation reuseable rocket engines. In addition to steady-state and dynamic performance, the requirements for increased durability, reliability and operability (with faults) will dictate which new controls and design technologies and features will be brought to bear. An array of concepts which have been brought forward will be tested against the measures of cost and benefit as reflected in the above 'ilities'. This paper examines some of the new concepts and looks for metrics to judge their value.

Carbon Fiber Reinforced Ceramic Composites for Propulsion Applications

NASA Technical Reports Server (NTRS)

Shivakumar, Kunigal; Argade, Shyam

2003-01-01

This report presents a critical review of the processing techniques for fabricating continuous fiber-reinforced CMCs for possible applications at elevated temperatures. Some of the issues affecting durability of the composite materials such as fiber coatings and cracking of the matrix because of shrinkage in PIP-process are also examined. An assessment of the potential inexpensive processes is also provided. Finally three potential routes of manufacturing C/SiC composites using a technology that NC A&T developed for carbon/carbon composites are outlined. Challenges that will be encountered are also listed.

Controls concepts for next generation reuseable rocket engines

NASA Astrophysics Data System (ADS)

Lorenzo, Carl F.; Merrill, Walter C.; Musgrave, Jefferey L.; Ray, Asok

1995-04-01

Three primary issues will drive the design and control used in next generation reuseable rocket engines. In addition to steady-state and dynamic performance, the requirements for increased durability, reliability and operability (with faults) will dictate which new controls and design technologies and features will be brought to bear. An array of concepts which have been brought forward will be tested against the measures of cost and benefit as reflected in the above 'ilities'. This paper examines some of the new concepts and looks for metrics to judge their value.

CCR 20th Anniversary Commentary: Autologous T Cells-The Ultimate Personalized Drug for the Immunotherapy of Human Cancer.

PubMed

Rosenberg, Steven A

2015-12-15

The article by Rosenberg and colleagues, which was published in the July 1, 2011, issue of Clinical Cancer Research, demonstrated the power of the adoptive transfer of autologous antitumor T cells to mediate the complete, durable, and likely curative regression of cancer in patients with heavily pretreated metastatic melanoma. It also provided a stimulus to the development of cell transfer approaches for other cancer types using both natural and genetically engineered lymphocytes. ©2015 American Association for Cancer Research.

Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency

DTIC Science & Technology

2010-06-01

cell ( PEMFC ), and the phosphoric acid fuel cell (PAFC). 2.3.1 Solid Oxide Fuel Cells (SOFC) The first type of fuel cell considered is the SOFC. This...durability issues for use within a given application. 2.3.2 Polymer Electrolyte Membrane Fuel Cells ( PEMFC ) The PEMFC operates by passing hydrogen that has...cells. Some advantages of PEMFC operating at such low temperatures is that the fuel cell doesn’t require as meticulous of a support system infrastructure

Compositional threshold for Nuclear Waste Glass Durability

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

Kruger, Albert A.; Farooqi, Rahmatullah; Hrma, Pavel R.

2013-04-24

Within the composition space of glasses, a distinct threshold appears to exist that separates "good" glasses, i.e., those which are sufficiently durable, from "bad" glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region.

Microbial Community Analysis of Naturally Durable Wood in an Above Ground Field Test

Treesearch

G.T. Kirker; S.V. Diehl; P.K. Lebow

2014-01-01

This paper presents preliminary results of an above ground field test wherein eight naturally durable wood species were exposed concurrently at two sites in North America. Surface samples were taken at regular intervals from non-durable controls and compared to their more durable counterparts. Terminal Restriction Fragment Length Polymorphism was performed to...

Combined hydrophobicity and mechanical durability through surface nanoengineering

DOE PAGES

Elliott, Paul R.; Stagon, Stephen P.; Huang, Hanchen; ...

2015-04-08

This paper reports combined hydrophobicity and mechanical durability through the nanoscale engineering of surfaces in the form of nanorod-polymer composites. Specifically, the hydrophobicity derives from nanoscale features of mechanically hard ZnO nanorods and the mechanical durability derives from the composite structure of a hard ZnO nanorod core and soft polymer shell. Experimental characterization correlates the morphology of the nanoengineered surfaces with the combined hydrophobicity and mechanical durability, and reveals the responsible mechanisms. Such surfaces may find use in applications, such as boat hulls, that benefit from hydrophobicity and require mechanical durability.

Study Acoustic Emissions from Composites

NASA Technical Reports Server (NTRS)

Walker, James L.; Workman, Gary L.

1997-01-01

The nondestructive evaluation (NDE) of future propulsion systems utilizing advanced composite structures for the storage of cryogenic fuels, such as liquid hydrogen or oxygen, presents many challenges. Economic justification for these structures requires, light weight, reusable components with an infrastructure allowing periodic evaluation of structural integrity after enduring demanding stresses during operation. A major focus has been placed on the use of acoustic emission NDE to detect propagating defects, in service, necessitating an extensive study into characterizing the nature of acoustic signal propagation at very low temperatures and developing the methodology of applying AE sensors to monitor cryogenic components. This work addresses the question of sensor performance in the cryogenic environment. Problems involving sensor mounting, spectral response and durability are addressed. The results of this work provides a common point of measure from which sensor selection can be made when testing composite components at cryogenic temperatures.

2D Electrostatic Actuation of Microshutter Arrays

NASA Technical Reports Server (NTRS)

Burns, Devin E.; Oh, Lance H.; Li, Mary J.; Kelly, Daniel P.; Kutyrev, Alexander S.; Moseley, Samuel H.

2015-01-01

Electrostatically actuated microshutter arrays consisting of rotational microshutters (shutters that rotate about a torsion bar) were designed and fabricated through the use of models and experiments. Design iterations focused on minimizing the torsional stiffness of the microshutters, while maintaining their structural integrity. Mechanical and electromechanical test systems were constructed to measure the static and dynamic behavior of the microshutters. The torsional stiffness was reduced by a factor of four over initial designs without sacrificing durability. Analysis of the resonant behavior of the microshutters demonstrates that the first resonant mode is a torsional mode occurring around 3000 Hz. At low vacuum pressures, this resonant mode can be used to significantly reduce the drive voltage necessary for actuation requiring as little as 25V. 2D electrostatic latching and addressing was demonstrated using both a resonant and pulsed addressing scheme.

2D Electrostatic Actuation of Microshutter Arrays

NASA Technical Reports Server (NTRS)

Burns, Devin E.; Oh, Lance H.; Li, Mary J.; Jones, Justin S.; Kelly, Daniel P.; Zheng, Yun; Kutyrev, Alexander S.; Moseley, Samuel H.

2015-01-01

An electrostatically actuated microshutter array consisting of rotational microshutters (shutters that rotate about a torsion bar) were designed and fabricated through the use of models and experiments. Design iterations focused on minimizing the torsional stiffness of the microshutters, while maintaining their structural integrity. Mechanical and electromechanical test systems were constructed to measure the static and dynamic behavior of the microshutters. The torsional stiffness was reduced by a factor of four over initial designs without sacrificing durability. Analysis of the resonant behavior of the microshutter arrays demonstrates that the first resonant mode is a torsional mode occurring around 3000 Hz. At low vacuum pressures, this resonant mode can be used to significantly reduce the drive voltage necessary for actuation requiring as little as 25V. 2D electrostatic latching and addressing was demonstrated using both a resonant and pulsed addressing scheme.

Mechanisms of degradation of the hybrid layer in adhesive dentistry and therapeutic agents to improve bond durability--A literature review.

PubMed

Frassetto, Andrea; Breschi, Lorenzo; Turco, Gianluca; Marchesi, Giulio; Di Lenarda, Roberto; Tay, Franklin R; Pashley, David H; Cadenaro, Milena

2016-02-01

Success in adhesive dentistry means long lasting restorations. However, there is substantial evidence that this ideal objective is not always achieved. Current research in this field aims at increasing the durability of resin-dentin bonds. The objective of this paper is to examine the fundamental processes responsible for the aging mechanisms involved in the degradation of resin-bonded interfaces and the potential approaches to prevent and counteract this degradation. PubMed searches on the hybrid layer degradation were carried out. Keywords were chosen to assess hybrid layer degradation for providing up-dated information on the basis of scientific coherence with the research objective. Approaches to prevent and counteract this degradation were also reviewed. 148 peer-review articles in the English language between 1982 and 2015 were reviewed. Literature shows that resin-dentin bond degradation is a complex process, involving the hydrolysis of both the resin and the collagen fibril phases contained within the hybrid layer. Collagen fibers become vulnerable to mechanical and hydraulic fatigue, as well as degradation by host-derived proteases with collagenolytic activity (matrix metalloproteinases and cysteine cathepsins). Inhibition of the collagenolytic activity and the use of cross-linking agents are the two main strategies to increase the resistance of the hybrid layer to enzymatic degradation. This review analyzes the issues regarding the durability of the adhesive interface, and the techniques to create stable resin-dentin bonds able to resist the collagenolytic hydrolysis that are currently studied. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Chitin Nanofibers Extracted from Crab Shells in Broadband Visible Antireflection Coatings with Controlling Layer-by-Layer Deposition and the Application for Durable Antifog Surfaces.

PubMed

Manabe, Kengo; Tanaka, Chie; Moriyama, Yukari; Tenjimbayashi, Mizuki; Nakamura, Chiaki; Tokura, Yuki; Matsubayashi, Takeshi; Kyung, Kyu-Hong; Shiratori, Seimei

2016-11-23

Reflection from various surfaces of many optical systems, such as photovoltaics and displays, is a critical issue for their performance, and antireflection coatings play a pivotal role in a wide variety of optical technologies, reducing light reflectance loss and hence maximizing light transmission. With the current movement toward optically transparent polymeric media and coatings for antireflection technology, the need for economical and environmentally friendly materials and methods without dependence on shape or size has clearly been apparent. Herein, we demonstrate novel antireflection coatings composed of chitin nanofibers (CHINFs), extracted from crab shell as a biomass material through an aqueous-based layer-by-layer self-assembly process to control the porosity. Increasing the number of air spaces inside the membrane led low refractive index, and precise control of refractive index derived from the stacking of the CHINFs achieved the highest transmittance with investigating the surface structure and the refractive index depending on the solution pH. At a wavelength of 550 nm, the transmittance of the coatings was 96.4%, which was 4.8% higher than that of a glass substrate, and their refractive index was 1.30. Further critical properties of the films were the durability and the antifogging performance derived from the mechanical stability and hydrophilicity of CHINFs, respectively. The present study may contribute to a development of systematically designed nanofibrous films which are suitable for optical applications operating at a broadband visible wavelength with durability and antifog surfaces.

Experimental study on durability improvement of fly ash concrete with durability improving admixture.

PubMed

Quan, Hong-zhu; Kasami, Hideo

2014-01-01

In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%-20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized.

Durable silver mirror with ultra-violet thru far infra-red reflection

DOEpatents

Wolfe, Jesse D.

2010-11-23

A durable highly reflective silver mirror characterized by high reflectance in a broad spectral range of about 300 nm in the UV to the far infrared (.about.10000 nm), as well as exceptional environmental durability. A high absorptivity metal underlayer is used which prevents the formation of a galvanic cell with a silver layer while increasing the reflectance of the silver layer. Environmentally durable overcoat layers are provided to enhance mechanical and chemical durability and protect the silver layer from corrosion and tarnishing, for use in a wide variety of surroundings or climates, including harsh or extreme environments.

Mod-0A Wind Turbine in Block Island, Rhode Island

NASA Image and Video Library

1979-06-21

A Mod-0A 200-kilowatt wind turbine designed by National Aeronautics and Space Administration (NASA) Lewis Research Center and constructed in Block Island, Rhode Island. The wind turbine program was a joint program between NASA and the Energy Research and Development Administration (ERDA) during the 1970s to develop less expensive forms of energy. NASA Lewis was assigned the responsibility of developing large horizontal-axis wind turbines. The program included a series of increasingly powerful wind turbines, designated: Mod-0A, Mod-1, WTS-4, and Mod-5. The program’s first device was a Mod-0 100-kilowatt wind turbine test bed at NASA’s Plum Brook Station. This Mod-0A 200-kilowatt turbine, completed in 1977, was the program’s second-generation device. It included a 125-foot diameter blade atop a 100-foot tall tower. This early wind turbine was designed determine its operating problems, integrate with the local utilities, and assess the attitude of the local community. There were additional Mod-0A turbines built in Culebra, Puerto Rico; Clayton, New Mexico; and Oahu, Hawaii. The Mod-0A turbines suffered durability issues with the rotor blade and initially appeared unreliable. NASA engineers addressed the problems, and the turbines proved to be reliable and efficient devices that operated for a number of years. The information gained from these early models was vital to the design and improvement of the later generations.

Kaolinite-supported nanoscale zero-valent iron for removal of Pb2+ from aqueous solution: reactivity, characterization and mechanism.

PubMed

Zhang, Xin; Lin, Shen; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

2011-05-01

The use of nanoscale zero-valent iron (nZVI) to remediate contaminated groundwater is limited due to its lack of durability and mechanical strength. To address this issue, 20% (w/w) nZVI was loaded onto kaolinite as a support material (K-nZVI). More than 96% of Pb(2+) was removed from aqueous solution using K-nZVI at an initial condition of 500 mg/L Pb(2+) within 30 min under the conditions of 10 g/L of K-nZVI, pH 5.10 and a temperature of 30 °C. To understand the mechanism of removal of Pb(2+), various techniques were implemented to characterize K-nZVI. Scanning electron microscopy (SEM) indicated that K-nZVI had a suitable dispersive state with a lower aggregation, where the mean specific surface area and average particle size as determined by the BET-N(2) method and X-ray diffraction (XRD), were 26.11 m(2)/g and 44.3 nm, respectively. The results obtained from XRD, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) indicated that a small number of iron oxides formed on the surface of K-nZVI, suggesting that free Pb(2+) was adsorbed onto K-nZVI and subsequently reduced to Pb(0). Copyright © 2011 Elsevier Ltd. All rights reserved.

Macroporous Double-Network Hydrogel for High-Efficiency Solar Steam Generation Under 1 sun Illumination.

PubMed

Yin, Xiangyu; Zhang, Yue; Guo, Qiuquan; Cai, Xiaobing; Xiao, Junfeng; Ding, Zhifeng; Yang, Jun

2018-04-04

Solar steam generation is one of the most promising solar-energy-harvesting technologies to address the issue of water shortage. Despite intensive efforts to develop high-efficiency solar steam generation devices, challenges remain in terms of the relatively low solar thermal efficiency, complicated fabrications, high cost, and difficulty in scaling up. Herein, a double-network hydrogel with a porous structure (p-PEGDA-PANi) is demonstrated for the first time as a flexible, recyclable, and efficient photothermal platform for low-cost and scalable solar steam generation. As a novel photothermal platform, the p-PEGDA-PANi involves all necessary properties of efficient broadband solar absorption, exceptional hydrophilicity, low heat conductivity, and porous structure for high-efficiency solar steam generation. As a result, the hydrogel-based solar steam generator exhibits a maximum solar thermal efficiency of 91.5% with an evaporation rate of 1.40 kg m -2 h -1 under 1 sun illumination, which is comparable to state-of-the-art solar steam generation devices. Furthermore, the good durability and environmental stability of the p-PEGDA-PANi hydrogel enables a convenient recycling and reusing process toward real-life applications. The present research not only provides a novel photothermal platform for solar energy harvest but also opens a new avenue for the application of the hydrogel materials in solar steam generation.

Moving to Aqueous Binder: A Valid Approach to Achieving High‐Rate Capability and Long‐Term Durability for Sodium‐Ion Battery

PubMed Central

Zhao, Jing; Yang, Xu; Yao, Ye; Gao, Yu; Sui, Yongming; Zou, Bo; Ehrenberg, Helmut; Chen, Gang

2018-01-01

Abstract Polyanionic Na3V2(PO4)2F3 with a NASICON‐type structure is heralded as a promising cathode material for sodium‐ion batteries due to its fast ionic conduction, high working voltage, and favorable structural stability. However, a number of challenging issues remain regarding its rate capability and cycle life, which must be addressed to enable greater application compatibility. Here, a facile and effective approach that can be used to overcome these disadvantages by introducing an aqueous carboxymethyl cellulose (CMC) binder is reported. The resulting conductive network serves to accelerate the diffusion of Na+ ions across the interface as well as in the bulk. The strong binding force of the CMC and stable solid permeable interface protect the electrode from degradation, leading to an excellent capacity of 75 mA h g−1 at an ultrahigh rate of 70 C (1 C = 128 mA g−1) and a long lifespan of 3500 cycles at 30 C while sustaining 79% of the initial capacity value. A full cell based on this electrode material delivers an impressive energy density as high as 216 W h kg−1, indicating the potential for application of this straightforward and cost‐effective route for the future development of advanced battery technologies. PMID:29721423

What Is the Purpose of the Theses Addressing the Issue of Program Evaluation in Turkey? (The Case of Curriculum and Instruction: 1997-2015)

ERIC Educational Resources Information Center

Alkin-Sahin, Senar; Tunca, Nihal

2016-01-01

In the current study, the aim is to investigate the theses addressing the issue of program evaluation in the field of Curriculum and Instruction (C&I) in 1997-2015. The study employed the survey model. The universe of the study consists of totally 87 theses addressing the issue of program evaluation in the field of C&I in 1997-2015. As the…

Importance of Addressing Sexuality in Certified Rehabilitation Counselor Practice

ERIC Educational Resources Information Center

Kazukauskas, Kelly A.; Lam, Chow S.

2009-01-01

This study investigated Certified Rehabilitation Counselors' (CRCs) beliefs about the importance of addressing sexuality issues during rehabilitation. A modified version of the Family Life Sex Education Goals Questionnaire (FLSEGQ) was completed by 199 CRCs to determine which issues CRCs believe are most important to address. Six sexuality-related…

Opportunity Foregone: Education in Brazil.

ERIC Educational Resources Information Center

Birdsall, Nancy, Ed.; Sabot, Richard H., Ed.

The studies presented in this volume help readers to understand the constraints faced in addressing the key problems within the Brazilian education system. Steps to address the issues and benefits to be gained by addressing those issues are discussed. Forty-two authors reiterate that the success of Brazil's education reform will have an important…

Durable solar mirror films

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

O'Neill, Mark B.; Henderson, Andrew J.; Hebrink, Timothy J.

The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.

Durable solar mirror films

DOEpatents

O'Neill, Mark B.; Henderson, Andrew J.; Hebrink, Timothy J.; Katare, Rajesh K.; Jing, Naiyong; North, Diane; Peterson, Eric M.

2017-02-14

The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.

Prediction of glass durability as a function of environmental conditions

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

Jantzen, C M

1988-01-01

A thermodynamic model of glass durability is applied to natural, ancient, and nuclear waste glasses. The durabilities of over 150 different natural and man-made glasses, including actual ancient Roman and Islamic glasses (Jalame ca. 350 AD, Nishapur 10-11th century AD and Gorgon 9-11th century AD), are compared. Glass durability is a function of the thermodynamic hydration free energy, ..delta..G/sub hyd/, which can be calculated from glass composition and solution pH. The durability of the most durable nuclear waste glasses examined was /approximately/10/sup 6/ years. The least durable waste glass formulations were comparable in durability to the most durable simulated medievalmore » window glasses of /approximately/10/sup 3/ years. In this manner, the durability of nuclear waste glasses has been interpolated to be /approximately/10/sup 6/ years and no less than 10/sup 3/ years. Hydration thermodynamics have been shown to be applicable to the dissolution of glass in various natural environments. Groundwater-glass interactions relative to geologic disposal of nuclear waste, hydration rind dating of obsidians, andor other archeological studies can be modeled, e.g., the relative durabilities of six simulated medieval window glasses have been correctly predicted for both laboratory (one month) and burial (5 years) experiments. Effects of solution pH on glass dissolution has been determined experimentally for the 150 different glasses and can be predicted theoretically by hydration thermodynamics. The effects of solution redox on dissolution of glass matrix elements such as SI and B have shown to be minimal. The combined effects of solution pH and Eh have been described and unified by construction of thermodynamically calculated Pourbaix (pH-Eh) diagrams for glass dissolution. The Pourbaix diagrams have been quantified to describe glass dissolution as a function of environmental conditions by use of the data derived from hydration thermodynamics. 56 refs., 7 figs.« less

The Distance Education Evolution: Issues and Case Studies

ERIC Educational Resources Information Center

Monolescu, Dominique; Schifter, Catherine; Greenwood, Linda

2004-01-01

"The Distance Education Evolution: Case Studies" addresses issues regarding the development and design of online courses, and the implementation and evaluation of an online learning program. Several chapters include design strategies for online courses that range from the specific to the universal. Many authors address pedagogical issues from both…

Development of Mechanics in Support of Rocket Technology in Ukraine

NASA Astrophysics Data System (ADS)

Prisnyakov, Vladimir

2003-06-01

The paper analyzes the advances of mechanics made in Ukraine in resolving various problems of space and rocket technology such as dynamics and strength of rockets and rocket engines, rockets of different purpose, electric rocket engines, and nonstationary processes in various systems of rockets accompanied by phase transitions of working media. Achievements in research on the effect of vibrations and gravitational fields on the behavior of space-rocket systems are also addressed. Results obtained in investigating the reliability and structural strength durability conditions for nuclear installations, solid- and liquid-propellant engines, and heat pipes are presented

Residual-strength tests of L-1011 vertical fin components after 10 and 20 years of simulated flight service

NASA Technical Reports Server (NTRS)

Lopez, O. F.

1984-01-01

Part of the NASA/ACEE Program was to determine the effect of long-term durability testing on the residual strength of graphite-epoxy cover panel and spar components of the Lockheed L-1011 aircraft vertical stabilizer. The results of these residual strength tests are presented herein. The structural behavior and failure mode of both cover panel and spar components were addressed, and the test results obtained were compared with the static test results generated by Lockheed. The effect of damage on one of the spar specimens was described.

Paraesophageal Hernia Repair: Techniques for Success.

PubMed

Cohn, Tyler D; Soper, Nathaniel J

2017-01-01

With the introduction of laparoscopy, the outcomes of patients undergoing paraesophageal hernia repair have improved dramatically. When the fundamentals of a proper repair are followed, patients can expect to have improvement in gastroesophageal reflux symptoms, including heartburn, regurgitation, chest pain, dysphagia, and dyspnea. Adhering to these principles will alleviate patients' symptoms and avoid reoperation. This article describes the approach to paraesophageal hernia repair, including patient evaluation, operative technique, and postoperative management. Esophageal lengthening and crural reinforcement with mesh are addressed as well. Adhering to the basic techniques outlined in this article should lead to successful and durable patient outcomes following a paraesophageal hernia repair.

Durability, value, and reliability of selected electric powered wheelchairs.

PubMed

Fass, Megan V; Cooper, Rory A; Fitzgerald, Shirley G; Schmeler, Mark; Boninger, Michael L; Algood, S David; Ammer, William A; Rentschler, Andrew J; Duncan, John

2004-05-01

To compare the durability, value, and reliability of selected electric powered wheelchairs (EPWs), purchased in 1998. Engineering standards tests of quality and performance. A rehabilitation engineering center. Fifteen EPWs: 3 each of the Jazzy, Quickie, Lancer, Arrow, and Chairman models. Not applicable. Wheelchairs were evaluated for durability (lifespan), value (durability, cost), and reliability (rate of repairs) using 2-drum and curb-drop machines in accordance with the standards of the American National Standards Institute and Rehabilitation Engineering and Assistive Technology Society of North America. The 5 brands differed significantly (P

Development of a high-temperature durable catalyst for use in catalytic combustors for advanced automotive gas turbine engines

NASA Astrophysics Data System (ADS)

Tong, H.; Snow, G. C.; Chu, E. K.; Chang, R. L. S.; Angwin, M. J.; Pessagno, S. L.

1981-09-01

Durable catalytic reactors for advanced gas turbine engines were developed. Objectives were: to evaluate furnace aging as a cost effective catalytic reactor screening test, measure reactor degradation as a function of furnace aging, demonstrate 1,000 hours of combustion durability, and define a catalytic reactor system with a high probability of successful integration into an automotive gas turbine engine. Fourteen different catalytic reactor concepts were evaluated, leading to the selection of one for a durability combustion test with diesel fuel for combustion conditions. Eight additional catalytic reactors were evaluated and one of these was successfully combustion tested on propane fuel. This durability reactor used graded cell honeycombs and a combination of noble metal and metal oxide catalysts. The reactor was catalytically active and structurally sound at the end of the durability test.

Development of a high-temperature durable catalyst for use in catalytic combustors for advanced automotive gas turbine engines

NASA Technical Reports Server (NTRS)

Tong, H.; Snow, G. C.; Chu, E. K.; Chang, R. L. S.; Angwin, M. J.; Pessagno, S. L.

1981-01-01

Durable catalytic reactors for advanced gas turbine engines were developed. Objectives were: to evaluate furnace aging as a cost effective catalytic reactor screening test, measure reactor degradation as a function of furnace aging, demonstrate 1,000 hours of combustion durability, and define a catalytic reactor system with a high probability of successful integration into an automotive gas turbine engine. Fourteen different catalytic reactor concepts were evaluated, leading to the selection of one for a durability combustion test with diesel fuel for combustion conditions. Eight additional catalytic reactors were evaluated and one of these was successfully combustion tested on propane fuel. This durability reactor used graded cell honeycombs and a combination of noble metal and metal oxide catalysts. The reactor was catalytically active and structurally sound at the end of the durability test.

Sustainability and durability analysis of reinforced concrete structures

NASA Astrophysics Data System (ADS)

Horáková, A.; Broukalová, I.; Kohoutková, A.; Vašková, J.

2017-09-01

The article describes an assessment of reinforced concrete structures in terms of durability and sustainable development. There is a short summary of findings from the literature on evaluation methods for environmental impacts and also about corrosive influences acting on the reinforced concrete structure, about factors influencing the durability of these structures and mathematical models describing the corrosion impacts. Variant design of reinforced concrete structure and assessment of these variants in terms of durability and sustainability was performed. The analysed structure was a concrete ceiling structure of a parking house for cars. The variants differ in strength class of concrete and thickness of concrete slab. It was found that in terms of durability and sustainable development it is significantly preferable to use higher class of concrete. There are significant differences in results of concrete structures durability for different mathematical models of corrosive influences.

Fundamental Impact of Humidity on SOFC Cathode ORR

DOE PAGES

Huang, Y. L.; Pellegrinelli, C.; Wachsman, E. D.

2015-12-17

Although solid oxide fuel cells (SOFC) have demonstrated excellent performance, the durability of SOFCs under real working conditions is still an issue for commercial deployment. In particular cathode exposure to atmospheric air contaminants, such as humidity, can result in long-term performance degradation issues. Therefore, a fundamental understanding of the interaction between water molecules and cathodes is essential to resolve this issue and further enhance cathode durability. In order to study the effects of humidity on the oxygen reduction reaction (ORR), we used in-situ 18O isotope exchange techniques to probe the exchange of water with two of themost common SOFC cathodemore » materials, (La 0.8Sr 0.2) 0.95MnO 3±δ (LSM) and La 0.6Sr 0.4Co 0.2Fe 0.8O 3-δ (LSCF). In this experiment, heavy water, D 2O (with a mass/charge ratio of m/z = 20), is used to avoid the overlapping of H 2O and the 18O 2 cracking fraction, which both provide a peak at m/z = 18. A series of temperature programmed isotope exchange measurements were performed to comprehensively study the interaction of water with the cathode surface as a function of temperature, oxygen partial pressure, and water vapor concentration. The results suggest that water and O 2 share the same surface exchange sites, leading to competitive adsorption. Our findings show that water prefers to exchange with LSCF at lower temperatures, around 300–450°C. For LSM, O 2 is more favorable than water to be adsorbed on the surface and the presence of O 2 limits water exchange. The experimental data are summarized in a Temperature-PO 2 diagram to help visualize how the exchange of water on each material depends on the operating conditions.« less

Afterschool: A Strategy for Addressing and Preventing Middle School Bullying. MetLife Foundation Afterschool Alert. Issue Brief No. 51

ERIC Educational Resources Information Center

Afterschool Alliance, 2011

2011-01-01

The Afterschool Alliance, in partnership with MetLife Foundation, is proud to present the second in a series of four issue briefs examining critical issues facing middle school youth and the vital role afterschool programs play in addressing these issues. This brief focuses on bullying awareness and prevention. Bullying is a dangerous behavior…

Security and health research databases: the stakeholders and questions to be addressed.

PubMed

Stewart, Sara

2006-01-01

Health research database security issues abound. Issues include subject confidentiality, data ownership, data integrity and data accessibility. There are also various stakeholders in database security. Each of these stakeholders has a different set of concerns and responsibilities when dealing with security issues. There is an obvious need for training in security issues, so that these issues may be addressed and health research will move on without added obstacles based on misunderstanding security methods and technologies.

Using Bonding Enamel-Coated Steel Fixtures to Produce More Durable Brick/Masonry Structures

DTIC Science & Technology

2010-02-01

Initial tests with enameled metal straps cracked all the test cylinders and straps would not pull out BUILDING STRONG® New Strong Durable Ties...BUILDING STRONG® Using Bonding Enamel -Coated Steel Fixtures to Produce More Durable Brick/Masonry Structures Principal Investigator: Steven C...COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Using Bonding Enamel -Coated Steel Fixtures to Produce More Durable Brick/Masonry

Bitumen performance and chemistry in solvent refined bitumen blends

NASA Astrophysics Data System (ADS)

Holleran, Glynn; Holleran, Irina; Wilson, Douglas J.

2017-09-01

In years gone past most oil companies in Australia and New Zealand (NZ) developed experts that bridged the divide between refining and paving. This was supported by laboratories in Australia and sometimes Asia. This is no longer the case and many refineries have ceased bitumen production or closed. With the market moving towards imports and control to supply companies disconnects on bitumen passing a national specification and performance on the road. This reduces both durability and increases costs. This has been addressed by development in NZ of a performance specification for hot mix asphalt binders (including modified) and work being done on sealing grades. This paper discusses the development of the HMA specification with respect to crude sources and the development of methodologies to assess imported binders for suitability in all applications including emulsion. The conclusion is that bitumen quality may be maintained by use of these methodologies that include, chromatographic analysis, measurement of thermodynamic internal stability (Heithaus), aging, and Dynamic Shear Rheometry testing and mix performance testing in the laboratory. This forms a regime capable of use in any context and this leads to better durability of surfaces and extended service life.

A simple way to an ultra-robust superhydrophobic fabric with mechanical stability, UV durability, and UV shielding property.

PubMed

Ren, Guina; Song, Yuanming; Li, Xiangming; Wang, Bo; Zhou, Yanli; Wang, Yuyan; Ge, Bo; Zhu, Xiaotao

2018-07-15

Development of an ultra-robust superhydrophobic fabric with mechanical stability, UV durability, and UV shielding by a simple method is highly desirable, yet it remains a challenge that current technologies have been unable to fully address. Herein, the original fabric is immersed into the solution containing ZnO nanoparticle and PDMS (polydimethylsiloxane), and the fiber surfaces are uniformly covered by a ZnO-PDMS layer after thermal treatment at 110 °C for 30 min. Droplets of water and corrosive liquids including strong acid, strong alkali, and saturated salt solution display sphere shape on the ZnO-PDMS coated fabric surface. The stable binding of ZnO-PDMS layer onto the fibers allows for the fabric coating with robust superhydrophobicity, and the coated fabric still displays superhydrophobicity after hand twisting, knife scratching, finger touching, and even cycles of sandpaper abrasion. The ZnO-PDMS coated fabric can also keep its superhydrophobic property when exposed to long term UV illumination, demonstrating its UV resistance. Moreover, the uniformly distribution of ZnO nanoparticles on fibers allows the ZnO-PDMS coated fabric to display UV shielding property. Copyright © 2018 Elsevier Inc. All rights reserved.

Cold Climate Foundation Retrofit Experimental Hygrothermal Performance: Cloquet Residential Research Facility Laboratory Results

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

Goldberg, Louise F.; Harmon, Anna C.

2015-04-01

Thermal and moisture problems in existing basements create a unique challenge because the exterior face of the wall is not easily or inexpensively accessible. This approach addresses thermal and moisture management from the interior face of the wall without disturbing the exterior soil and landscaping. the interior and exterior environments. This approach has the potential for improving durability, comfort, and indoor air quality. This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes.more » NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.« less

Hollow Fibers Networked with Perovskite Nanoparticles for H2 Production from Heavy Oil

PubMed Central

Jeon, Yukwon; Park, Dae-Hwan; Park, Joo-Il; Yoon, Seong-Ho; Mochida, Isao; Choy, Jin-Ho; Shul, Yong-Gun

2013-01-01

Design of catalytic materials has been highlighted to build ultraclean use of heavy oil including liquid-to-gas technology to directly convert heavy hydrocarbons into H2–rich gas fuels. If the H2 is produced from such heavy oil through high-active and durable catalysts in reforming process that is being constructed in hydrogen infrastructure, it will be addressed into renewable energy systems. Herein, the three different hollow fiber catalysts networked with perovskite nanoparticles, LaCr0.8Ru0.2O3, LaCr0.8Ru0.1Ni0.1O3, and LaCr0.8Ni0.2O3 were prepared by using activated carbon fiber as a sacrificial template for H2 production from heavy gas oil reforming. The most important findings were arrived at: (i) catalysts had hollow fibrous architectures with well-crystallized structures, (ii) hollow fibers had a high specific surface area with a particle size of ≈50 nm, and (iii) the Ru substituted ones showed high efficiency for H2 production with substantial durability under high concentrations of S, N, and aromatic compounds. PMID:24104596

D.R.O.P: The Durable Reconnaissance and Observation Platform

NASA Technical Reports Server (NTRS)

McKenzie, Clifford; Parness, Aaron

2011-01-01

Robots can provide a remote presence in areas that are either inaccessible or too dangerous for humans. However, robots are often limited by their ability to adapt to the terrain or resist environmental factors. The Durable Reconnaissance and Observation Platform (DROP) is a lightweight robot that addresses these challenges with the capability to survive falls from significant heights, carry a useable payload, and traverse a variety of surfaces, including climbing vertical surfaces like wood, stone, and concrete. DROP is manufactured using a combination of rapid prototyping and shape deposition manufacturing. It uses microspine technology to create a new wheel-like design for vertical climbing. To date, DROP has successfully engaged several vertical surfaces, hanging statically without assistance, and traversed horizontal surfaces at approximately 30 cm/s. Unassisted vertical climbing is capable on surfaces up to 85deg at a rate of approximately 25cm*s(sup -1). DROP can also survive falls from up to 3 meters and has the ability to be thrown off of and onto rooftops. Future efforts will focus on improving the microspine wheels, selecting more resilient materials, customizing the controls, and performing more rigorous and quantifiable testing.

Determining the dissolution rates of actinide glasses: A time and temperature Product Consistency Test study

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

Daniel, W.E.; Best, D.R.

1995-12-01

Vitrification has been identified as one potential option for the e materials such as Americium (Am), Curium (Cm), Neptunium (Np), and Plutonium (Pu). A process is being developed at the Savannah River Site to safely vitrify all of the highly radioactive Am/Cm material and a portion of the fissile (Pu) actinide materials stored on site. Vitrification of the Am/Cm will allow the material to be transported and easily stored at the Oak Ridge National Laboratory. The Am/Cm glass has been specifically designed to be (1) highly durable in aqueous environments and (2) selectively attacked by nitric acid to allow recoverymore » of the valuable Am and Cm isotopes. A similar glass composition will allow for safe storage of surplus plutonium. This paper will address the composition, relative durability, and dissolution rate characteristics of the actinide glass, Loeffler Target, that will be used in the Americium/Curium Vitrification Project at Westinghouse Savannah River Company near Aiken, South Carolina. The first part discusses the tests performed on the Loeffler Target Glass concerning instantaneous dissolution rates. The second part presents information concerning pseudo-activation energy for the one week glass dissolution process.« less

Concrete aggregate durability study.

DOT National Transportation Integrated Search

2009-06-01

There are many factors that affect the durability of Portland cement concrete (PCC), including the mix design and the : materials used, the quality of construction, and the environment. Durability is not an intrinsic property of the concrete, but : i...

Research notes : inlaid durable pavement markings : year one.

DOT National Transportation Integrated Search

2004-12-01

Durable pavement markings are becoming more prevalent on primary highways statewide, increasing the safety of the traveling public and the ODOT maintenance personnel responsible for maintaining the striping. Several durable products are now being use...

Your Medicare Coverage: Durable Medical Equipment (DME) Coverage

MedlinePlus

... test, item, or service covered? Go Durable medical equipment (DME) coverage How often is it covered? Medicare ... B (Medical Insurance) covers medically necessary durable medical equipment (DME) that your doctor prescribes for use in ...

Comparison of enamel bond fatigue durability between universal adhesives and two-step self-etch adhesives: Effect of phosphoric acid pre-etching.

PubMed

Suda, Shunichi; Tsujimoto, Akimasa; Barkmeier, Wayne W; Nojiri, Kie; Nagura, Yuko; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

2018-03-30

The effect of phosphoric acid pre-etching on enamel bond fatigue durability of universal adhesives and two-step self-etch adhesives was investigated. Four universal adhesives and three two-step self-etch adhesives were used. The initial shear bond strengths and shear fatigue strengths to enamel with and without phosphoric acid pre-etching using the adhesives were determined. SEM observations were also conducted. Phosphoric acid pre-etching of enamel was found to increase the bond fatigue durability of universal adhesives, but its effect on two-step self-etch adhesives was material-dependent. In addition, some universal adhesives with phosphoric acid pre-etching showed similar bond fatigue durability to the two-step self-etch adhesives, although the bond fatigue durability of universal adhesives in self-etch mode was lower than that of the two-step self-etch adhesives. Phosphoric acid pre-etching enhances enamel bond fatigue durability of universal adhesives, but the effect of phosphoric acid pre-etching on the bond fatigue durability of two-step self-etch adhesives was material-dependent.

Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

PubMed Central

Quan, Hong-zhu; Kasami, Hideo

2014-01-01

In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%–20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized. PMID:25013870

Brush Seal Performance and Durability Issues Based on T-700 Engine Test Results

NASA Technical Reports Server (NTRS)

Hendricks, R. C.

1994-01-01

The integrity and performance of brush seals have been established. Severe bench and engine tests have shown high initial wear or run-in rates, material smearing at the interface, and bristle and rub-runner wear, but the brush seals did not fail. Short-duration (46 hr) experimental T-700 engine testing of the compressor discharge seal established over 1-percent engine performance gain (brush versus labyrinth). Long-term gains were established only as leakage comparisons, with the brush at least 20 percent better at controlling leakage. Long-term materials issues, such as wear and ultimately seal life, remain to be resolved. Future needs are cited for materials and analysis tools that account for heat generation, thermomechanical behavior, and tribological pairing to enable original equipment manufacturers to design high-temperature, high-surface-speed seals with confidence.

Dilemmas and challenges for the shelter sector: lessons learned from the Sphere revision process.

PubMed

Saunders, Graham

2004-06-01

Key dilemmas and challenges for those involved in the shelter sector are described, based on issues that emerged from the extensive global consultative process undertaken to inform the revision of the Sphere handbook. The range of perspectives on the major themes is presented, with suggestions as to how these issues could be progressed. Themes include the poor definition of the sector and the lack of a consistent approach among the leading shelter actors; the absence of a common terminology; the conflict between "temporary" versus "durable" solutions; the disconnect between technical advisers and the field; the need for greater recognition of local coping strategies and the local context; the involvement of recipients and host governments in policy development; the need for better "how-to" guidance; and the limited incorporation of the emerging themes of livelihoods etc. to date.

Advanced Systems for Preprocessing and Characterizing Coal-Biomass Mixtures as Next-Generation Fuels and Feedstocks

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

Karmis, Michael; Luttrell, Gerald; Ripepi, Nino

The research activities presented in this report are intended to address the most critical technical challenges pertaining to coal-biomass briquette feedstocks. Several detailed investigations were conducted using a variety of coal and biomass feedstocks on the topics of (1) coal-biomass briquette production and characterization, (2) gasification of coal-biomass mixtures and briquettes, (3) combustion of coal-biomass mixtures and briquettes, and (4) conceptual engineering design and economic feasibility of briquette production. The briquette production studies indicate that strong and durable co-firing feedstocks can be produced by co-briquetting coal and biomass resources commonly available in the United States. It is demonstrated that binderlessmore » coal-biomass briquettes produced at optimized conditions exhibit very high strength and durability, which indicates that such briquettes would remain competent in the presence of forces encountered in handling, storage and transportation. The gasification studies conducted demonstrate that coal-biomass mixtures and briquettes are exceptional gasification feedstocks, particularly with regard to the synergistic effects realized during devolatilization of the blended materials. The mixture combustion studies indicate that coal-biomass mixtures are exceptional combustion feedstocks, while the briquette combustion study indicates that the use of blended briquettes reduces NO x, CO 2, and CO emissions, and requires the least amount of changes in the operating conditions of an existing coal-fired power plant. Similar results were obtained for the physical durability of the pilot-scale briquettes compared to the bench-scale tests. Finally, the conceptual engineering and feasibility analysis study for a commercial-scale briquetting production facility provides preliminary flowsheet and cost simulations to evaluate the various feedstocks, equipment selection and operating parameters.« less

Estimating Price Elasticity using Market-Level Appliance Data

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

Fujita, K. Sydny

This report provides and update to and expansion upon our 2008 LBNL report “An Analysis of the Price Elasticity of Demand for Appliances,” in which we estimated an average relative price elasticity of -0.34 for major household appliances (Dale and Fujita 2008). Consumer responsiveness to price change is a key component of energy efficiency policy analysis; these policies influence consumer purchases through price both explicitly and implicitly. However, few studies address appliance demand elasticity in the U.S. market and public data sources are generally insufficient for rigorous estimation. Therefore, analysts have relied on a small set of outdated papers focusedmore » on limited appliance types, assuming long-term elasticities estimated for other durables (e.g., vehicles) decades ago are applicable to current and future appliance purchasing behavior. We aim to partially rectify this problem in the context of appliance efficiency standards by revisiting our previous analysis, utilizing data released over the last ten years and identifying additional estimates of durable goods price elasticities in the literature. Reviewing the literature, we find the following ranges of market-level price elasticities: -0.14 to -0.42 for appliances; -0.30 to -1.28 for automobiles; -0.47 to -2.55 for other durable goods. Brand price elasticities are substantially higher for these product groups, with most estimates -2.0 or more elastic. Using market-level shipments, sales value, and efficiency level data for 1989-2009, we run various iterations of a log-log regression model, arriving at a recommended range of short run appliance price elasticity between -0.4 and -0.5, with a default value of -0.45.« less

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.

Ethics: The Role of Adult and Vocational Education. Trends and Issues Alert No. 24.

ERIC Educational Resources Information Center

Wonacott, Michael E.

Ethics and social responsibility are the subject of both curriculum materials and research in adult and vocational education. State academic standards and curriculum frameworks address citizenship and personal and social responsibility. Ethical and legal issues for specific occupations are addressed in curricula issued by states, professional…

Addressing Career Issues Online: Perceptions of Counselor Education Professionals

ERIC Educational Resources Information Center

Lewis, Jacqueline; Coursol, Diane

2007-01-01

The Internet is the latest arena in which counseling services are available for a variety of issues. This study surveyed counselor education professionals about their perceptions regarding the use of online counseling to address various mental health issues including career counseling. It also examined their perceptions about 3 formats of online…

Measuring Up: Assessment Issues for Teachers, Counselors, and Administrators.

ERIC Educational Resources Information Center

Wall, Janet E., Ed.; Walz, Garry R., Ed.

This book attempts to promote improved understanding of assessment concepts by addressing the broad expanse of issues facing educators as they go about their duties and fulfill their responsibilities in schools and classrooms. The chapters in the book address some of the "hot button" issues related to testing and assessment in our nation's…

Evaluation of inlaid durable pavement markings in an Oregon snow zone.

DOT National Transportation Integrated Search

2006-04-01

The Oregon Department of Transportation (ODOT) evaluated the use of inlaid durable pavement markings within a snow zone. Three different durable pavement marking products were installed and evaluated: Dura-Stripe, a methyl methacrylate; Permaline...

Durability of Waste Glass Flax Fiber Reinforced Mortar

NASA Astrophysics Data System (ADS)

Aly, M.; Hashmi, M. S. J.; Olabi, A. G.; Messeiry, M.

2011-01-01

The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performance of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.

Durable superhydrophobic and superamphiphobic polymeric surfaces and their applications: A review.

PubMed

Ellinas, Kosmas; Tserepi, Angeliki; Gogolides, Evangelos

2017-12-01

Wetting control is essential for many applications, such as self-cleaning, anti-icing, anti-fogging, antibacterial action as well as anti-reflection and friction control. While significant effort has been devoted to fabricate superhydrophobic/superamphiphobic surfaces (repellent to water and other low surface tension liquids), very few polymeric superhydrophobic/superamphiphobic surfaces can be considered as durable against various externally imposed stresses (e.g. application of heating, pressure, mechanical forces, chemical, etc.). Therefore, durability tests are extremely important for applications especially when such surfaces are made of "soft" materials. Here, we review the most recent and promising efforts reported towards the realization of durable, superhydrophobic/superamphiphobic, polymeric surfaces emphasizing the durability tests performed, and some important applications. We compare and put in context the scattered durability tests reported in the literature, and present conclusions, perspectives and challenges in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling the Rate-Dependent Durability of Reduced-Ag SAC Interconnects for Area Array Packages Under Torsion Loads

NASA Astrophysics Data System (ADS)

Srinivas, Vikram; Menon, Sandeep; Osterman, Michael; Pecht, Michael G.

2013-08-01

Solder durability models frequently focus on the applied strain range; however, the rate of applied loading, or strain rate, is also important. In this study, an approach to incorporate strain rate dependency into durability estimation for solder interconnects is examined. Failure data were collected for SAC105 solder ball grid arrays assembled with SAC305 solder that were subjected to displacement-controlled torsion loads. Strain-rate-dependent (Johnson-Cook model) and strain-rate-independent elastic-plastic properties were used to model the solders in finite-element simulation. Test data were then used to extract damage model constants for the reduced-Ag SAC solder. A generalized Coffin-Manson damage model was used to estimate the durability. The mechanical fatigue durability curve for reduced-silver SAC solder was generated and compared with durability curves for SAC305 and Sn-Pb from the literature.

Maintenance and Durability of the Concrete External Layer of Curtain Walls in Prefabricated Technological Poznan Large Panel System

NASA Astrophysics Data System (ADS)

Jasiczak, Józef; Girus, Krzysztof

2017-10-01

The issue of usability and durability of large-panel building constructed several decades ago is a subject of an in-depth analysis of many domestic and foreign investments. When considering the durability of specific large-panel system, one should consider, among others, the process of making external walls. The long-term and direct impact of weather conditions on the external layer of curtain walls is significant for the durability of large-panel buildings. For the needs of the presented paper, in 2016, the survey of cracks and a series of other tests of large-panel façade, residential building constructed in 1986, in Poland, in the PLP process system - Rataje was executed. Several hundred large-size, triple-layer curtain-wall slab with a 6-cm, concrete exterior cladding layer anchored using pins and hangers with the load-bearing layer, a 9-cm insulation layer made of mineral wool, and a 21-cm structural layer were surveyed. Significant deviations in thicknesses of particular wall layers were proven. Other significant damages and defects of external layers were found. At the second stage, many tests, both nondestructive and destructive, were conducted. They involved determining mechanical properties of an external layer. The concrete thickness was measured using with a type N Schmidt sclerometer and core samples were taken from this layer in order to mark concrete’s compressive strength. The range of carbonation (by phenolphthalein method) and the actual location and condition of reinforcement were estimated using a ferromagnetic device to determine the condition of the external layer. The diagnosis conducted in such a manner was the verification of necessary repair of the walls and their thermal efficiency improvement while ensuring safe conditions of their operation and modern functional and utility requirements. It should be also emphasized that the method of diagnosing the external walls presented in this paper may be popularized when evaluating such facilities both in Poland and other countries of the Central Europe (Germany, Czechia, Slovakia, Lithuania, Bulgaria, and Ukraine).

Study of Acoustic Emissions from Composites

NASA Technical Reports Server (NTRS)

Walker, James L.; Workman, Gary L.

1997-01-01

The nondestructive evaluation (NDE) of future propulsion systems utilizing advanced composite structures for the storage of cryogenic fuels, such as liquid hydrogen or oxygen, presents many challenges. Economic justification for these structures requires light weight, reusable components with an infrastructure allowing periodic evaluation of structural integrity after enduring demanding stresses during operation. A major focus has been placed on the use of acoustic emission NDE to detect propagating defects, in service, necessitating an extensive study into characterizing the nature of acoustic signal propagation at very low temperatures and developing the methodology of applying AE sensors to monitor cryogenic components. This work addresses the question of sensor performance in the cryogenic environment. Problems involving sensor mounting, spectral response and durability are addressed. The results of this work provides a common point of measure from which sensor selection can be made when testing composite components at cryogenic temperatures.

Transport, energy and environment

DOT National Transportation Integrated Search

1996-12-01

The conference addressed economic and broader policy issues as well as technological perspectives. Further, focus was primarily on medium to long term aspects. The conference was primarily devoted to Euorpean issues, but papers were also addressing g...

Measuring students' attitudes toward college education's role in addressing social issues.

PubMed

Weber, James E; Weber, Paula S; Craven, Barney L

2008-06-01

As service-learning projects have spread throughout academia, efforts to assess the service-learning experience have assumed a greater importance. The BERSI scale (Business Education's Role in addressing Social Issues) was developed as a measure of business students' attitudes toward social issues being addressed as part of a business education. As such, it was intended to be useful in assessing attitudinal outcomes of service learning. In order for the BERSI to be useful for nonbusiness students, the scale would need to be reconceptualized and revalidated. This study modified the BERSI items with a focus on college students in general rather than business students, making the resulting scale, College Education's Role in addressing Social Issues (CERSI), potentially helpful to service-learning researchers in a broader setting. The CERSI scale was then validated using standard techniques and normative data were reported.

Policy issues in space analogues

NASA Astrophysics Data System (ADS)

Auger, Robin N.; Facktor, Debra D.

Space mission planning is increasingly focusing on destinations beyond Earth orbit. Advancements in technology will inevitably be required to enable long-duration human spaceflight missions, and breakthroughs in the policy arena will also be needed to achieve success in such missions. By exploring how policy issues have been addressed in analogous extreme environments, policymakers can develop a framework for addressing these issues as they apply to long-term human spaceflight. Policy issues that need to be addressed include: crew selection, training, organization, and activities, medical testing, illness, injury, and death; communication; legal accountability and liability; mission safety and risk management; and environmental contamination. This paper outlines the approach of a study underway by The George Washington University and ANSER to examine how these policy issues have been addressed in several analogues and how the experiences of these analogues can help formulate policies for long-duration human spaceflight missions. Analogues being studied include Antarctic bases, submarine voyages, undersea stations, Biosphere 2, and the U.S. Skylab and Russian Mir space stations.

40 CFR 610.52 - Maintenance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DEVICES Test Procedures and Evaluation Criteria Durability Test Procedures § 610.52 Maintenance. (a) Maintenance during the durability evaluation can best be considered in three separate categories: (1) Normal... durability evaluation in this program will probably have considerable mileage accumulation and unknown...

U.S.-China Military Contacts: Issues for Congress

DTIC Science & Technology

2008-02-01

Military Contacts: Issues for Congress 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Congressional Research Service,The Library of Congress,101...Independence Ave, SE,Washington,DC,20540-7500 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR

U.S.-China Military Contacts: Issues for Congress

DTIC Science & Technology

2007-12-12

Military Contacts: Issues for Congress 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Congressional Research Center,The Library of Congress,101...Independence Ave, SE,Washington,DC,20540-7500 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR

Multi-User Performance Issues in Wireless Impulse Radio Networks

DTIC Science & Technology

2004-01-01

Performance Issues in Wireless Impulse Radio Networks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT...NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) North Carolina State University,Department of...Electrical and Computer Engineering,Raleigh,NC,27695 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10

2014 Australian Association for Research in Education Presidential Address: Educational Research and the Tree of Knowledge in a Post Human Digital Age

ERIC Educational Resources Information Center

Moss, Julianne

2016-01-01

The 2014, 41st Australian Association for Research in Education (AARE) presidential address is both inspired and guided by the discursive genres of presidential addresses and the role of the president in a member association such as AARE. In the address, typically the president speaks to the members on an issue or issues that are to shape or…

Consumption of a durable termite bait matrix by subterranean termites (Isoptera: Rhinotermitidae) and resulting insecticidal activity.

PubMed

Hamm, Ronda L; DeMark, Joseph J; Chin-Heady, Eva; Tolley, Mike P

2013-04-01

A novel durable termite bait was developed to enable continuous bait availability and lengthen the monitoring interval to 1 year. Laboratory studies were conducted to determine the palatability and insecticidal activity of this bait to Reticulitermes flavipes (Kollar), R. virginicus (Banks), R. hesperus Banks, Coptotermes formosanus Shiraki and Heterotermes aureus (Synder). Consumption of the blank durable bait matrix was significantly higher than consumption of a blank preferred textured cellulose matrix (PTC) by R. virginicus, R. flavipes and C. formosanus. R. flavipes, R. hesperus and H. aureus consumed significantly more durable bait than PTC when both contained the active ingredient noviflumuron. All bait treatments resulted in significant mortality relative to the untreated controls. Survivorship of R. virginicus, C. formosanus and H. aureus was 2% or less and not significantly different between the durable bait and PTC treatments containing noviflumuron. The durable bait matrix lagged behind the PTC matrix in mortality over time for all species tested except H. aureus. The durable bait was highly palatable and effective in inducing mortality to R. flavipes, R. virginicus, R. hesperus, C. formosanus and H. aureus in the laboratory. This unique bait matrix will be available to termites continuously and allows for an annual monitoring interval. The durability of this bait matrix is unprecedented, allowing for bait to remain active for years and thus providing continuous structural protection. © 2012 Society of Chemical Industry.

Addressing HIV/AIDS Education: A Look at Teacher Preparedness in Ghana

ERIC Educational Resources Information Center

Weiler, Jim Martin; Martin-Weiler, Cassandra J.

2012-01-01

Our research shows that social science university trained Ghanaian student/teachers do have the knowledge, confidence, and willingness to address HIV/AIDS issues in their teaching, yet they do not. The reason, we argue, is that teachers have little incentive to address contentious issues in the classroom. Questionnaires were administered to 382…

Temperature influence on water transport in hardened cement pastes

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

Drouet, Emeline; Poyet, Stéphane, E-mail: stephane.poyet@cea.fr; Torrenti, Jean-Michel

2015-10-15

Describing water transport in concrete is an important issue for the durability assessment of radioactive waste management reinforced concrete structures. Due to the waste thermal output such structures would be submitted to moderate temperatures (up to 80 °C). We have then studied the influence of temperature on water transport within hardened cement pastes of four different formulations. Using a simplified approach (describing only the permeation of liquid water) we characterized the properties needed to describe water transport (up to 80 °C) using dedicated experiments. For each hardened cement paste the results are presented and discussed.

Caterpillar C7 and GEP 6.5L (T) Fuel System Durability Using 25% ATJ Fuel Blend

DTIC Science & Technology

2015-02-01

loss. Its most likely that this degradation was caused by some sort of engine controller or sensor issue that existed on the engine being evaluated...Some investigation was conducted into the engine controller/harness/ sensors , but ultimately it was determined that the time and cost to fully...Abs./cm) E168 FTNG 0.0 5.0 13.7 18.4 31.6 59.5 100.7 Nitration (Abs./cm) E168 FTNG 0.0 10.3 16.7 19.5 31.5 45.3 48.6 Soot Soot 0.2

The Full Scope of Family Physicians' Work Is Not Reflected by Current Procedural Terminology Codes.

PubMed

Young, Richard A; Burge, Sandy; Kumar, Kaparaboyna Ashok; Wilson, Jocelyn

2017-01-01

The purpose of this study was to characterize the content of family physician (FP) clinic encounters, and to count the number of visits in which the FPs addressed issues not explicitly reportable by 99211 to 99215 and 99354 Current Procedural Terminology (CPT) codes with current reimbursement methods and based on examples provided in the CPT manual. The data collection instrument was modeled on the National Ambulatory Medical Care Survey. Trained assistants directly observed every other FP-patient encounter and recorded every patient concern, issue addressed by the physician (including care barriers related to health care systems and social determinants), and treatment ordered in clinics affiliated with 10 residencies of the Residency Research Network of Texas. A visit was deemed to include physician work that was not explicitly reportable if the number or nature of issues addressed exceeded the definitions or examples for 99205/99215 or 99214 + 99354 or a preventive service code, included the physician addressing health care system or social determinant issues, or included the care of a family member. In 982 physician-patient encounters, patients raised 517 different reasons for visit (total, 5278; mean, 5.4 per visit; range, 1 to 16) and the FPs addressed 509 different issues (total issues, 3587; mean, 3.7 per visit; range, 1 to 10). FPs managed 425 different medications, 18 supplements, and 11 devices. A mean of 3.9 chronic medications were continued per visit (range, 0 to 21) and 4.6 total medications were managed (range, 0 to 22). In 592 (60.3%) of the visits the FPs did work that was not explicitly reportable with available CPT codes: 582 (59.3%) addressed more numerous issues than explicitly reportable, 64 (6.5%) addressed system barriers, and 13 (1.3%) addressed concerns for other family members. FPs perform cognitive work in a majority of their patient encounters that are not explicitly reportable, either by being higher than the CPT example number of diagnoses per code or the type of problems addressed, which has implications for the care of complex multi-morbid patients and the growth of the primary care workforce. To address these limitations, either the CPT codes and their associated rules should be updated to reflect the realities of family physicians' practices or new billing and coding approaches should be developed. © Copyright 2017 by the American Board of Family Medicine.

Enhancement of crack healing efficiency and performance of SAP in biocrete

NASA Astrophysics Data System (ADS)

Giriselvam, M. G.; Poornima, V.; Venkatasubramani, R.; Sreevidya, V.

2018-02-01

Concrete usage in Construction becomes more common in this speedy world. Despite its benefits, concrete often exhibits crack which appear due to stresses. Larger cracks cause Structural integrity problems and smaller cracks may result in durability issues. A novel environmental friendly strategy to restore or remediate cracks formed in the structures is bio-mineralization of calcium carbonate using microbes such as Bacillus Subtilis (used in this study), as manual repair and maintenance is costly. In this Paper, an idea of using Super Absorbent Polymer in Bacterial Concrete was analysed which increases the strength and durability properties of concrete and also which acts as a protection to bacteria, where Self-Healing nature is viewed. In the span of 90 days, the results of Bacterial concrete cured under normal water providing nutrients inside with SAP shows healing up to 74 % and without SAP displays 49 % and when it is cured under nutrient medium, Bacterial Concrete having SAP displays healing up to 66 %, whereas without SAP it displays 57.4% of healing. During the observation it is discernible that the crack width ranging from 0.10 mm near 0.45 mm show better self-healing capacity. XRD analysis displays the presence of Calcium carbonate precipitation in cracks.

The vexing problem of thrombosis in long-term mechanical circulatory support.

PubMed

Mehra, Mandeep R; Stewart, Garrick C; Uber, Patricia A

2014-01-01

Durable left ventricular assist devices (LVADs) have not only enhanced longevity but also conferred sustained improvements in quality of life, symptom control, and functional capacity in patients with medically refractory advanced heart failure. Problems with device-related infection, bleeding, neurologic events, right-sided heart failure, and device malfunction have dominated the clinical care of patients living on mechanical support. Even as adoption of durable LVADs accelerated globally, we began to encounter a growing dilemma of pump malfunction caused by thrombosis. In early 2011, clinicians began to notice a spike in the incidence of pump thrombosis with the HeartMate II (Thoratec Corp, Pleasanton, CA) LVAD. By 2012, the problem of thrombosis in LVADs began to consume most of the scientific direction as centers and collaborative groups began to dissect this nascent phenomenon. In this perspective, we describe the magnitude and implications of pump thrombosis, discuss secular and management trends in this unique population, attempt to dissect the problem at its root, offer guidance on surveillance and therapeutic principles, and outline issues that deserve our immediate and collaborative attention. © 2014 International Society for Heart and Lung Transplantation Published by International Society for the Heart and Lung Transplantation All rights reserved.

High Performance Electroactive Polymer Actuators Based on Sulfonated Block Copolymers Comprising Ionic Liquids

NASA Astrophysics Data System (ADS)

Kim, Onnuri; Park, Moon Jeong

2015-03-01

Electroactive polymer (EAP) actuators that show reversible deformation under external electric stimulus have attracted great attention toward a range of biomimetic applications such as microsensors and artificial muscles. Key challenges to advance the technologies can be placed on the achievement of fast response time, low driving voltage, and durable operation in air. In present study, we are motivated to solve these issues by employing self-assembled block copolymers containing ionic liquids (ILs) as polymer layers in the actuator based on knowledge of factors affecting electromechanical properties of actuators. By controlling the block architecture and molecular weight of block copolymers, bending strain and durability were controlled in a straightforward manner. It has also been revealed that the type of IL makes impact on the EAP actuator performance by determining ion migration dynamics. Our actuators demonstrated large bending strains (up to 4%) under low voltages of 1-3V, which far exceeds the best performance of other EAP actuators reported in the literature. To underpin the molecular-level understanding of actuation mechanisms underlying the improved performance, we carried out in situ spectroscopy and in situ scattering experiments under actuation.

Thermo-Mechanical Compatibility of Viscoelastic Mortars for Stone Repair

PubMed Central

Demoulin, Thibault; Scherer, George W.; Girardet, Fred; Flatt, Robert J.

2016-01-01

The magnitude of the thermal stresses that originate in an acrylic-based repair material used for the reprofiling of natural sandstone is analyzed. This kind of artificial stone was developed in the late 1970s for its peculiar property of reversibility in an organic solvent. However, it displays a high thermal expansion coefficient, which can be a matter of concern for the durability either of the repair or of the underlying original stone. To evaluate this risk we propose an analytical solution that considers the viscoelasticity of the repair layer. The temperature profile used in the numerical evaluation has been measured in a church where artificial stone has been used in a recent restoration campaign. The viscoelasticity of the artificial stone has been characterized by stress relaxation experiments. The numerical analysis shows that the relaxation time of the repair mortar, originating from a low Tg, allows relief of most of the thermal stresses. It explains the good durability of this particular repair material, as observed by the practitioners, and provides a solid scientific basis for considering that the problem of thermal expansion mismatch is not an issue for this type of stone under any possible conditions of natural exposure. PMID:28787857

Semiconductor nanostructures for artificial photosynthesis

NASA Astrophysics Data System (ADS)

Yang, Peidong

2012-02-01

Nanowires, with their unique capability to bridge the nanoscopic and macroscopic worlds, have already been demonstrated as important materials for different energy conversion. One emerging and exciting direction is their application for solar to fuel conversion. The generation of fuels by the direct conversion of solar energy in a fully integrated system is an attractive goal, but no such system has been demonstrated that shows the required efficiency, is sufficiently durable, or can be manufactured at reasonable cost. One of the most critical issues in solar water splitting is the development of a suitable photoanode with high efficiency and long-term durability in an aqueous environment. Semiconductor nanowires represent an important class of nanostructure building block for direct solar-to-fuel application because of their high surface area, tunable bandgap and efficient charge transport and collection. Nanowires can be readily designed and synthesized to deterministically incorporate heterojunctions with improved light absorption, charge separation and vectorial transport. Meanwhile, it is also possible to selectively decorate different oxidation or reduction catalysts onto specific segments of the nanowires to mimic the compartmentalized reactions in natural photosynthesis. In this talk, I will highlight several recent examples in this lab using semiconductor nanowires and their heterostructures for the purpose of direct solar water splitting.

Addressing Physical and Emotional Issues in Children's Literature

ERIC Educational Resources Information Center

Johnson, Jonathon

2010-01-01

The purpose of this paper is to examine how physical and mental disabilities are addressed in children's literature. Many authors are able to integrate the issues into their work in a way that enhances the story and benefits the reader. As young readers learn about the issues and struggles faced by children with mental and physical disabilities,…

Student Teachers as Advocates for Student-Led Research-Informed Socioscientific Activism

ERIC Educational Resources Information Center

Bencze, J. Lawrence; Sperling, Erin R.

2012-01-01

Progress has been made in addressing socioscientific issues, such as debates about merits of nuclear power, by encouraging school students to consider complex issues and take positions about them. We contend, however, that they also need to learn to take research-informed actions to address issues. In the study reported here, we concluded--based…

The Democratic Imperative to Address Sexual Equality Rights in Schools

ERIC Educational Resources Information Center

Gereluk, Dianne

2013-01-01

Issues of sexual orientation elicit ethical debates in schools and society. In jurisdictions where a legal right has not yet been established, one argument commonly rests on whether schools ought to address issues of same-sex relationships and marriage on the basis of civil equality, or whether such controversial issues ought to remain in the…

Space Station Engineering Design Issues

NASA Technical Reports Server (NTRS)

Mcruer, Duane T.; Boehm, Barry W.; Debra, Daniel B.; Green, C. Cordell; Henry, Richard C.; Maycock, Paul D.; Mcelroy, John H.; Pierce, Chester M.; Stafford, Thomas P.; Young, Laurence R.

1989-01-01

Space Station Freedom topics addressed include: general design issues; issues related to utilization and operations; issues related to systems requirements and design; and management issues relevant to design.

Unanticipated Effects of New Drug Availability on Antiretroviral Durability: Implications for Comparative Effectiveness Research

PubMed Central

Eaton, Ellen F.; Tamhane, Ashutosh R.; Burkholder, Greer A.; Willig, James H.; Saag, Michael S.; Mugavero, Michael J.

2016-01-01

Background. Durability of antiretroviral (ARV) therapy is associated with improved human immunodeficiency virus (HIV) outcomes. Data on ARV regimen durability in recent years and clinical settings are lacking. Methods. This retrospective follow-up study included treatment-naive HIV-infected patients initiating ARV therapy between January 2007 and December 2012 in a university-affiliated HIV clinic in the Southeastern United States. Outcome of interest was durability (time to discontinuation) of the initial regimen. Durability was evaluated using Kaplan-Meier survival analyses. Cox proportional hazard analyses was used to evaluate the association among durability and sociodemographic, clinical, and regimen-level factors. Results. Overall, 546 patients were analyzed. Median durability of all regimens was 39.5 months (95% confidence interval, 34.1–44.4). Commonly prescribed regimens were emtricitabine and tenofovir with efavirenz (51%; median duration = 40.1 months) and with raltegravir (14%; 47.8 months). Overall, 67% of patients had an undetectable viral load at the time of regimen cessation. Discontinuation was less likely with an integrase strand transfer inhibitor (adjusted hazards ratio [aHR] = 0.35, P = .001) or protease inhibitor-based regimen (aHR = 0.45, P = .006) and more likely with a higher pill burden (aHR = 2.25, P = .003) and a later treatment era (aHR = 1.64, P < .001). Conclusions. Initial ARV regimen longevity declined in recent years contemporaneous with the availability of several new ARV drugs and combinations. Reduced durability mostly results from a preference for newly approved regimens rather than indicating failing therapy, as indicated by viral suppression observed in a majority of patients (67%) prior to regimen cessation. Durability is influenced by extrinsic factors including new drug availability and provider preference. Medication durability must be interpreted carefully in the context of a dynamic treatment landscape. PMID:27419181

Moisture Durability Assessment of Selected Well-insulated Wall Assemblies

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

Pallin, Simon B.; Boudreaux, Philip R.; Kehrer, Manfred

2015-12-01

This report presents the results from studying the hygrothermal performance of two well-insulated wall assemblies, both complying with and exceeding international building codes (IECC 2015 2014, IRC 2015). The hygrothermal performance of walls is affected by a large number of influential parameters (e.g., outdoor and indoor climates, workmanship, material properties). This study was based on a probabilistic risk assessment in which a number of these influential parameters were simulated with their natural variability. The purpose of this approach was to generate simulation results based on laboratory chamber measurements that represent a variety of performances and thus better mimic realistic conditions.more » In total, laboratory measurements and 6,000 simulations were completed for five different US climate zones. A mold growth indicator (MGI) was used to estimate the risk of mold which potentially can cause moisture durability problems in the selected wall assemblies. Analyzing the possible impact on the indoor climate due to mold was not part of this study. The following conclusions can be reached from analyzing the simulation results. In a hot-humid climate, a higher R-value increases the importance of the airtightness because interior wall materials are at lower temperatures. In a cold climate, indoor humidity levels increase with increased airtightness. Air leakage must be considered in a hygrothermal risk assessment, since air efficiently brings moisture into buildings from either the interior or exterior environment. The sensitivity analysis of this study identifies mitigation strategies. Again, it is important to remark that MGI is an indicator of mold, not an indicator of indoor air quality and that mold is the most conservative indicator for moisture durability issues.« less

Complexing agents and pH influence on chemical durability of type I moulded glass containers.

PubMed

Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

2017-06-16

Among the factors that affect the glass surface chemical durability, pH and complexing agents presence in aqueous solution have the main role (1). Glass surface attack can be also related to the delamination issue with glass particles appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed (2,3). The present study emphasizes the possible synergy between a few complexing agents with pH on the borosilicate glass chemical durability. Hydrolytic attack was performed in small volume 23 ml type I glass containers autoclaved according to EP or USP for 1 hour at 121°C, in order to enhance the chemical attack due to time, temperature and the unfavourable surface/volume ratio. 0,048 M or 0.024 M (moles/liter) solutions of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid) and sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ± 0,05 units at fixed values 5,5-6,6-7-7,4-8-9 by LiOH diluted solution. Since silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by ICPAES. The work was completed by the analysis of the silicon release in the worst attack conditions, of moulded glass, soda lime type II and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by SEM was finally performed to check for the surface status after the worst chemical attack condition by citric acid. Copyright © 2017, Parenteral Drug Association.

Durability assessment of coarse aggregates for HMA in Maine.

DOT National Transportation Integrated Search

2012-12-01

In this study, Micro-Deval and L.A. Abrasion were used to evaluate the durability of 72 individual : coarse aggregates used for HMA in Maine. Aggregates used in hot-mix asphalt (HMA) must be : durable and resistant to abrasion and degradation. Materi...

40 CFR 86.094-13 - Light-duty exhaust durability programs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements. (5) In-use verification. The Standard Self-Approval Durability Program includes no requirement... selection methods, durability data vehicle compliance requirements, in-use verification requirements... Accumulation Carryover. Light-duty Trucks Tier 1 & Tier 0 Standard Self-Approval Carryover. Alternative Service...

Chemical Durability Improvement and Static Fatigue of Glasses.

DTIC Science & Technology

1982-08-01

Afl-Alla 837 RENSSELAER POLYIECmfJ!C INST TRtOY NY DEPT OF MATERIAL--ETC F/6 ii/ CHEMICAL DURABILITY IMPROVEMENT AND STATIC FATIGUE OF GLASSESW AUC2...82 M TOMOZAWA NOGGIN 7A-C-0315 UNC LASS IF IED N ENEEEEEE FINAL TECHNICAL REPORT For the period April 1, 1978 "u March 31, 198200 CHEMICAL DURABILITY...REPORT A PERIOD COVERED Chemical Durability Improvement and Static Final Technical Report Fatiue o GlasesApril 1, 1978"’,March 31, 1982 S. PERFORMING ORG

Durability of high performance concrete in magnesium brine

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

Tumidajski, P.J.; Chan, G.W.

1996-04-01

The durability of six concretes exposed to magnesium brine was monitored for 24 months. These concretes incorporated ground granulated blast furnace slag, silica fume, and fly ash. The Young`s moduli, chloride penetrations, and median pore diameters were measured. There was a cyclic nature to these properties due to the complicated interaction of hydration with magnesium, chloride and sulfate attack. Mineral admixtures, in combination with a long initial cure, provided the most durable concrete. Concrete with 65% slag had the best overall durability to the brines tested.

Genetic Markers Predict Primary Non-Response and Durable Response To Anti-TNF Biologic Therapies in Crohn's Disease.

PubMed

Barber, Grant E; Yajnik, Vijay; Khalili, Hamed; Giallourakis, Cosmas; Garber, John; Xavier, Ramnik; Ananthakrishnan, Ashwin N

2016-12-01

One-fifth of patients with Crohn's disease (CD) are primary non-responders to anti-tumor necrosis factor (anti-TNF) therapy, and an estimated 10-15% will fail therapy annually. Little is known about the genetics of response to anti-TNF therapy. The aim of our study was to identify genetic factors associated with primary non-response (PNR) and loss of response to anti-TNFs in CD. From a prospective registry, we characterized the response of 427 CD patients to their first anti-TNF therapy. Patients were designated as achieving primary response, durable response, and non-durable response based on clinical, endoscopic, and radiologic criteria. Genotyping was performed on the Illumina Immunochip. Separate genetic scores based on presence of predictive genetic alleles were calculated for PNR and durable response and performance of clinical and genetics models were compared. From 359 patients, 36 were adjudged to have PNR (10%), 200 had durable response, and 74 had non-durable response. PNRs had longer disease duration and were more likely to be smokers. Fifteen risk alleles were associated with PNR. Patients with PNR had a significantly higher genetic risk score (GRS) (P =8 × 10 -12 ). A combined clinical-genetic model more accurately predicted PNR when compared with a clinical only model (0.93 vs. 0.70, P <0.001). Sixteen distinct single nucleotide polymorphisms predicted durable response with a higher GRS (P =7 × 10 -13 ). The GRSs for PNR and durable response were not mutually correlated, suggesting distinct mechanisms. Genetic risk alleles can predict primary non-response and durable response to anti-TNF therapy in CD.

Exploring factors influencing farmers' willingness to pay (WTP) for a planned adaptation programme to address climatic issues in agricultural sectors.

PubMed

Ahmed, Adeel; Masud, Muhammad Mehedi; Al-Amin, Abul Quasem; Yahaya, Siti Rohani Binti; Rahman, Mahfuzur; Akhtar, Rulia

2015-06-01

This study empirically estimates farmers' willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in Pakistan's agricultural sectors. The contingent valuation method (CVM) was employed to determine a monetary valuation of farmers' preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues. The survey was conducted by distributing structured questionnaires among Pakistani farmers. The study found that 67 % of respondents were willing to pay for a planned adaptation programme. However, several socioeconomic and motivational factors exert greater influence on their willingness to pay (WTP). This paper specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support attempts by policy makers to design an efficient adaptation framework for mitigating and adapting to the adverse impacts of climate change.

A Case Study on Science Teacher Leadership to Address Diversity and Equity Through Professional Development

NASA Astrophysics Data System (ADS)

Doraiswamy, Nithya

This qualitative case study focused on the multifaceted issue of exploring science teacher leaders understanding and addressing of issues of diversity and equity with peers through professional development. The purpose of the study was to highlight the opportunities and barriers to the addressing of issues of diversity and equity through the work of a community of teachers leaders in science professional development. To frame this study, the researcher drew from the interdisciplinary field of multicultural education, transformative learning, and teacher leadership. In drawing out the connections from these vast bodies of literature, the study speaks to the need of both, creating teacher leaders in science education who are capable of meeting the twin demands of excellence and equity, and also attending to the challenges in the professional learning continuums of teachers leaders and their peers towards addressing issues of diversity and equity in science education.

75 FR 51245 - Agency Information Collection Activities; Proposed Collection; Comment Request; Durable Nursery...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-19

... perceptions regarding such products. The survey will gather information on the characteristics and usage... Activities; Proposed Collection; Comment Request; Durable Nursery Products Exposure Survey AGENCY: Consumer... draft survey regarding ownership and use characteristics of durable infant or toddler products. DATES...

A rule-based expert system applied to moisture durability of building envelopes

DOE PAGES

Boudreaux, Philip R.; Pallin, Simon B.; Accawi, Gina K.; ...

2018-01-09

The moisture durability of an envelope component such as a wall or roof is difficult to predict. Moisture durability depends on all the construction materials used, as well as the climate, orientation, air tightness, and indoor conditions. Modern building codes require more insulation and tighter construction but provide little guidance about how to ensure these energy-efficient assemblies remain moisture durable. Furthermore, as new products and materials are introduced, builders are increasingly uncertain about the long-term durability of their building envelope designs. Oak Ridge National Laboratory and the US Department of Energy’s Building America Program are applying a rule-based expert systemmore » methodology in a web tool to help designers determine whether a given wall design is likely to be moisture durable and provide expert guidance on moisture risk management specific to a wall design and climate. Finally, the expert system is populated with knowledge from both expert judgment and probabilistic hygrothermal simulation results.« less

Durable superhydrophobic paper enabled by surface sizing of starch-based composite films

NASA Astrophysics Data System (ADS)

Chen, Gang; Zhu, Penghui; Kuang, Yudi; Liu, Yu; Lin, Donghan; Peng, Congxing; Wen, Zhicheng; Fang, Zhiqiang

2017-07-01

Superhydrophobic paper with remarkable durability is of considerable interest for its practical applications. In this study, a scalable, inexpensive, and universal surface sizing technique was implemented to prepare superhydrophobic paper with enhanced durability. A thin layer of starch-based composite, acting as a bio-binder, was first coated onto the paper surface by a sophisticated manufacturing technique called surface sizing, immediately followed by a spray coating of hexamethyl disilazane treated silica nanoparticles (HMDS-SiNPs) dispersed in ethanol on the surface of the wet starch-coated sheet, and the dual layers dried at the same time. Consequently, durable superhydrophobic paper with bi-layer structure was obtained after air drying. The as-prepared superhydrophobic paper not only exhibited a self-cleaning behavior, but also presented an enhanced durability against scratching, bending/deformation, as well as moisture. The universal surface sizing of starch-based composites may pave the way for the up-scaled and cost-effective production of durable superhydrophobic paper.

A rule-based expert system applied to moisture durability of building envelopes

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

Boudreaux, Philip R.; Pallin, Simon B.; Accawi, Gina K.

The moisture durability of an envelope component such as a wall or roof is difficult to predict. Moisture durability depends on all the construction materials used, as well as the climate, orientation, air tightness, and indoor conditions. Modern building codes require more insulation and tighter construction but provide little guidance about how to ensure these energy-efficient assemblies remain moisture durable. Furthermore, as new products and materials are introduced, builders are increasingly uncertain about the long-term durability of their building envelope designs. Oak Ridge National Laboratory and the US Department of Energy’s Building America Program are applying a rule-based expert systemmore » methodology in a web tool to help designers determine whether a given wall design is likely to be moisture durable and provide expert guidance on moisture risk management specific to a wall design and climate. Finally, the expert system is populated with knowledge from both expert judgment and probabilistic hygrothermal simulation results.« less

Durability of waste glass flax fiber reinforced mortar

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

Aly, M.; Hashmi, M. S. J.; Olabi, A. G.

2011-01-17

The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performancemore » of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.« less

A Nationwide Study of Pharmacists' Perception of the Impact of Medicare Part D on the Pharmacist-Patient Relationship.

PubMed

Spooner, Joshua J; Spotts, Harlan; Khan, Shamima

2017-10-01

Medicare Part D was implemented in 2006, introducing change to the community pharmacy marketplace, with profound disruption to independent pharmacy operations across the United States. To understand pharmacist perceptions about Part D and their perceived obligation to address Part D issues on behalf of their beneficiaries. A nationwide, cross-sectional survey of pharmacists was conducted between April and July 2013. The 43-item online survey collected information about demographics, implications of Part D on community pharmacy and patients, and beliefs about ideal pharmacy practice. Pharmacists reported more responsibility to address prior authorization issues (55.3% strongly agree or agree) than dispensing preferred medications (43.5%) or addressing patient copayment issues (38.1%). Predictors of the perceived responsibility to assist patients varied and included practice site, pharmacist age, pharmacy prescription volume, and pharmacy financial performance. Financial concerns continue to be the most significant issue following Part D implementation. The degree to which pharmacists feel responsible for addressing patient Part D concerns is variable and dependent on a variety of factors. Pharmacists who felt a personal responsibility to address patient copayment issues reported a better pharmacy financial performance, a larger increase in prescription volume, and a better pharmacist-patient relationship since Part D implementation. Nationwide, Part D financial concerns remain significant. Pharmacists can assist patients with managing cost issues, which can help alleviate pharmacy financial concerns. Many pharmacists practicing at independent locations do not feel responsible for addressing patient cost concerns, which may inadvertently impart a negative financial effect upon their pharmacy.

Issues in Peer Review of the Scientific Basis for Regulatory Decisions.

ERIC Educational Resources Information Center

American Chemical Society, Washington, DC.

This document is intended to provide a discussion of the issues that need to be addressed in the development of peer review guidelines, the options for addressing the issues, and a range of views about such options. The document focuses on peer review with regard to regulatory decisions and contains major sections which deal with: (1) what should…

Addressing Individual Difficulties in Reading: Issues Relating to Reading Recovery and Pause, Prompt, Praise

ERIC Educational Resources Information Center

Wearmouth, Janice

2004-01-01

Recently the DfES has issued guidance on ways to address the needs of students who experience difficulties in literacy through Wave Three provision in the National Literacy Strategy (DfES, 2002). This guidance raises the issue of what kind of programmes might be initiated in mainstream schools that will improve what is available generally for…

Secondary Education Systemic Issues: Addressing Possible Contributors to a Leak in the Science Education Pipeline and Potential Solutions

ERIC Educational Resources Information Center

Young, Hollie

2005-01-01

To maintain the legacy of cutting edge scientific innovation in the United States our country must address the many pressing issues facing science education today. One of the most important issues relating to science education is the under-representation of African Americans and Hispanics in the science, technology, and engineering workforce.…

A New Approach: Making Ethical Decisions regarding Adult Learner Issues.

ERIC Educational Resources Information Center

Missey, Jeanne T.

Many new student affairs professionals have had little or no experience in applying such codes to different learners. How to address issues where codes are insufficient and how to make student affairs professionals sensitive to the moral and ethical issues of adult learners are addressed in this paper. It is not meant as a guide, but as a tool for…

32 CFR Appendix C to Part 22 - Administrative Requirements and Issues To Be Addressed in Award Terms and Conditions

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 1 2013-07-01 2013-07-01 false Administrative Requirements and Issues To Be Addressed in Award Terms and Conditions C Appendix C to Part 22 National Defense Department of Defense... AND ADMINISTRATION Pt. 22, App. C Appendix C to Part 22—Administrative Requirements and Issues To Be...

Encouraging the Spiritual Development of Counseling Students and Supervisees Using Fowler's Stages of Faith Development.

ERIC Educational Resources Information Center

Erwin, Terry McVannel

The impact of faith on individuals has been described in research for many years, yet counseling programs often do not address issues of spirituality. Little has been documented about how to integrate spirituality and religious issues into counseling programs and practices. In an attempt to address the need for more discussion on issues of…

THE ROLE OF RISK ASSESSMENT IN ADDRESSING HAZARDOUS WASTE ISSUES

EPA Science Inventory

Risk assessment plays many important roles in addressing hazardous waste issues. In addition to providing a scientific framework and common health metric to evaluate risks. Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or "Superfund") risk assessm...

40 CFR 86.1825-08 - Durability demonstration procedures for refueling emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...), or (e) of this section. (c) Whole vehicle refueling durability demonstration. The following procedures must be used when conducting a whole vehicle durability demonstration: (1) Mileage accumulation... available fuels, including the Tier 2 requirement to include alcohol fuel; (3) Vibration of components; (4...

40 CFR 86.1825-08 - Durability demonstration procedures for refueling emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...), or (e) of this section. (c) Whole vehicle refueling durability demonstration. The following procedures must be used when conducting a whole vehicle durability demonstration: (1) Mileage accumulation... available fuels, including the Tier 2 requirement to include alcohol fuel; (3) Vibration of components; (4...

40 CFR 86.1825-08 - Durability demonstration procedures for refueling emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (c) Whole vehicle refueling durability demonstration. The following procedures must be used when conducting a whole vehicle durability demonstration: (1) Mileage accumulation must be conducted using the SRC... Tier 2 requirement to include alcohol fuel; (3) Vibration of components; (4) Deterioration of hoses...

40 CFR 86.1820-01 - Durability group determination.

Code of Federal Regulations, 2011 CFR

2011-07-01

... into durability groups based on the criteria listed above (such as non-catalyst control system... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Durability group determination. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...

40 CFR 86.1820-01 - Durability group determination.

Code of Federal Regulations, 2014 CFR

2014-07-01

... into durability groups based on the criteria listed above (such as non-catalyst control system... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Durability group determination. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General...

40 CFR 86.1820-01 - Durability group determination.

Code of Federal Regulations, 2010 CFR

2010-07-01

... into durability groups based on the criteria listed above (such as non-catalyst control system... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Durability group determination. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...

40 CFR 86.1820-01 - Durability group determination.

Code of Federal Regulations, 2013 CFR

2013-07-01

... into durability groups based on the criteria listed above (such as non-catalyst control system... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Durability group determination. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...

40 CFR 86.1820-01 - Durability group determination.

Code of Federal Regulations, 2012 CFR

2012-07-01

... into durability groups based on the criteria listed above (such as non-catalyst control system... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Durability group determination. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED...

40 CFR 86.094-13 - Light-duty exhaust durability programs.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and Heavy-Duty Engines, and for 1985 and Later Model Year New Gasoline Fueled, Natural Gas-Fueled... selection methods, durability data vehicle compliance requirements, in-use verification requirements... provisions of § 86.094-25. (3) Vehicle/component selection method. Durability data vehicles shall be selected...

40 CFR 94.219 - Durability data engine selection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Durability data engine selection. 94... (CONTINUED) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Certification Provisions § 94.219 Durability data engine selection. (a) For Category 1 and Category 2 engines, the manufacturer shall select...

A review of manufacturing metrology for improved reliability of silicon photovoltaic modules

NASA Astrophysics Data System (ADS)

Davis, Kristopher O.; Walters, Joseph; Schneller, Eric; Seigneur, Hubert; Brooker, R. Paul; Scardera, Giuseppe; Rodgers, Marianne P.; Mohajeri, Nahid; Shiradkar, Narendra; Dhere, Neelkanth G.; Wohlgemuth, John; Rudack, Andrew C.; Schoenfeld, Winston V.

2014-10-01

In this work, the use of manufacturing metrology across the supply chain to improve crystalline silicon (c-Si) photovoltaic (PV) module reliability and durability is addressed. Additionally, an overview and summary of a recent extensive literature survey of relevant measurement techniques aimed at reducing or eliminating the probability of field failures is presented. An assessment of potential gaps is also given, wherein the PV community could benefit from new research and demonstration efforts. This review is divided into three primary areas representing different parts of the c-Si PV supply chain: (1) feedstock production, crystallization and wafering; (2) cell manufacturing; and (3) module manufacturing.

Ceramic Matrix Composites (CMC) Life Prediction Development

NASA Technical Reports Server (NTRS)

Levine, Stanley R.; Verrilli, Michael J.; Thomas, David J.; Halbig, Michael C.; Calomino, Anthony M.; Ellis, John R.; Opila, Elizabeth J.

1990-01-01

Advanced launch systems will very likely incorporate fiber reinforced ceramic matrix composites (CMC) in critical propulsion and airframe components. The use of CMC will save weight, increase operating margin, safety and performance, and improve reuse capability. For reusable and single mission use, accurate life prediction is critical to success. The tools to accomplish this are immature and not oriented toward the behavior of carbon fiber reinforced silicon carbide (C/SiC), the primary system of interest for many applications. This paper describes an approach and progress made to satisfy the need to develop an integrated life prediction system that addresses mechanical durability and environmental degradation.

Grading technologies for the manufacture of innovative cutting blades

NASA Astrophysics Data System (ADS)

Rostek, Tim; Homberg, Werner

2018-05-01

Cutting blades for harvesting applications are used in a variety of agricultural machines. These parts are in contact with highly abrasive lawn clippings and often wear out within hours which results in high expensive re-sharpening maintenance. This paper relates to manufacturing techniques enhancing the durability of cutting blades based on a structural analysis of the prevailing wear mechanisms containing chipping and abrasive wear. Each mechanism results in specific demands on the cutting edge's mechanical characteristics. The design of evaluation methods respectively is one issue of the paper. This is basis for approaches to improve the cutting edge performance on purpose. On option to improve abrasive wear resistance and, thus, service life is the application of locally graded steel materials as semi-finished products for self-sharpening cutting blades. These materials comprise a layered structure consisting of a hard, wear resistant layer and a relatively softer layer which is lesser wear resistant. As the cutting blade is subjected to wear conditions, the less wear resistant layer wears faster than the relatively more wear resistant harder layer revealing a durable cross section of the cutting edge and, thus, cutting performance. Anyways, chipping is another key issue on the cutting edge's lifetime. Here, the cutting edges cross section by means of geometry and grind respectively as well as its mechanical properties matter. FEM analysis reveal innovative options to optimize the cross section of the blade as well as thermomechanical strengthening add further strength to reduce chipping. This paper contains a comprehensive strategy to improve cutting blades with use of innovative manufacturing technologies which apply application-specific graded mechanical characteristics and, thus, significantly improved performance characteristics.

42 CFR 402.1 - Basis and scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

...)(A) and 1842(j)(2)—Any durable medical equipment supplier that knowingly and willfully charges for a... nonparticipating durable medical equipment supplier that knowingly and willfully, in violation of section 1834(a....) (9) Section 1834(j)(2)(A)(iii)—Any supplier of durable medical equipment, including a supplier of...

42 CFR 402.1 - Basis and scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

...)(A) and 1842(j)(2)—Any durable medical equipment supplier that knowingly and willfully charges for a... nonparticipating durable medical equipment supplier that knowingly and willfully, in violation of section 1834(a....) (9) Section 1834(j)(2)(A)(iii)—Any supplier of durable medical equipment, including a supplier of...

77 FR 36292 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Cooperative...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-18

... Production Act of 1993--Cooperative Research Group on Particle Sensor Performance and Durability Notice is... Research Group on Particle Sensor Performance and Durability (``PSPD'') has filed written notifications... the performance and durability of various particle sensor technologies on a diesel engine platform...

Fifty-Year Durability Evaluation of Posts Treated with Industrial Wood Preservatives

Treesearch

Stan T. Lebow; Patricia Lebow; Bessie Woodward; Grant T. Kirker; Rachel Arango

2015-01-01

Long-term durability data are needed to improve service life estimates for treated wood products used as critical structural supports in industrial applications. This article reports the durability of longleaf pine (Pinus palustris) posts pressure treated with ammoniacal copper arsenate (ACA), chromated copper arsenate (CCA), creosote, or...

Effect of Unprofessional Supervision on Durability of Buildings.

PubMed

Yahaghi, Javad

2018-02-01

The durability of buildings which depends on the nature of the supervisory system used in their construction is an important feature of the construction industry. This article tries to draw the readers' attention to the effect of untrained and unprofessional building supervisors and their unethical performance on the durability of buildings.

Laboratory Evaluations of Durability of Southern Pine Pressure Treated With Extractives From Durable Wood Species

Treesearch

Grant T. Kirker; Amy Blodgett; Patricia Lebow

2015-01-01

Extracts from sawdust of four naturally durable wood species [Alaskan yellow cedar, AYC, Cupressus nootkanansis D. Don 1824; eastern red cedar, ERC, Juniperus virginiana L.; honey mesquite, HM, Prosopis glandulosa Torr.; and black locust, BL, Robinia pseudoacacia L.] were used to treat...

A zwitterionic macro-crosslinker for durable non-fouling coatings.

PubMed

Wang, Wei; Lu, Yang; Xie, Jinbing; Zhu, Hui; Cao, Zhiqiang

2016-03-28

A novel zwitterionic macro-crosslinker was developed and applied to fabricate durable non-fouling coatings on a polyurethane substrate. The zwitterionic macro-crosslinker coating exhibited superior durability over the traditional brush polymer coating and was able to retain its non-fouling property even after weeks of shearing in flowing liquid.

Experimental research on durability of recycled aggregate concrete under freeze- thaw cycles

NASA Astrophysics Data System (ADS)

Cheng, Yanqiu; Shang, Xiaoyu; Zhang, Youjia

2017-07-01

The freeze-thaw durability of recycled aggregate concrete has significance for the concrete buildings in the cold region. In this paper, the rapid freezing and thawing cycles experience on recycle aggregate concrete was conducted to study on the effects of recycle aggregate amount, water-binder ratio and fly ash on freeze-thaw durability of recycle aggregate concrete. The results indicates that recycle aggregate amount makes the significant influence on the freeze-thaw durability. With the increase of recycled aggregates amount, the freeze-thaw resistance for recycled aggregate concrete decreases. Recycled aggregate concrete with lower water cement ratio demonstrates better performance of freeze-thaw durability. It is advised that the amount of fly ash is less than 30% for admixture of recycled aggregates in the cold region.

Comparison of transcatheter aortic valve and surgical bioprosthetic valve durability: a fatigue simulation study

PubMed Central

Martin, Caitlin; Sun, Wei

2015-01-01

Transcatheter aortic valve (TAV) intervention is now the standard-of-care treatment for inoperable patients and a viable alternative treatment option for high-risk patients with symptomatic aortic stenosis. While the procedure is associated with lower operative risk and shorter recovery times than traditional surgical aortic valve (SAV) replacement, TAV intervention is still not considered for lower-risk patients due in part to concerns about device durability. It is well known that bioprosthetic SAVs have limited durability, and TAVs are generally assumed to have even worse durability, yet there is little long-term data to confirm this suspicion. In this study, TAV and SAV leaflet fatigue due to cyclic loading was investigated through finite element analysis by implementing a computational soft tissue fatigue damage model to describe the behavior of the pericardial leaflets. Under identical loading conditions and with identical leaflet tissue properties, the TAV leaflets sustained higher stresses, strains, and fatigue damage compared to the SAV leaflets. The simulation results suggest that the durability of TAVs may be significantly reduced compared to SAVs to about 7.8 years. The developed computational framework may be useful in optimizing TAV design parameters to improve leaflet durability, and assessing the effects of underexpanded, elliptical, or non-uniformly expanded stent deployment on TAV durability. PMID:26294354

Friction Durability of Extremely Thin Diamond-Like Carbon Films at High Temperature

PubMed Central

Miyake, Shojiro; Suzuki, Shota; Miyake, Masatoshi

2017-01-01

To clarify the friction durability, both during and after the high-temperature heating of nanometer-thick diamond-like carbon (DLC) films, deposited using filtered cathodic vacuum arc (FCVA) and plasma chemical vapor deposition (P-CVD) methods, the dependence of the friction coefficient on the load and sliding cycles of the DLC films, were evaluated. Cluster-I consisted of a low friction area in which the DLC film was effective, while cluster-II consisted of a high friction area in which the lubricating effect of the DLC film was lost. The friction durability of the films was evaluated by statistical cluster analysis. Extremely thin FCVA-DLC films exhibited an excellent wear resistance at room temperature, but their friction durability was decreased at high temperatures. In contrast, the durability of the P-CVD-DLC films was increased at high temperatures when compared with that observed at room temperature. This inverse dependence on temperature corresponded to the nano-friction results obtained by atomic force microscopy. The decrease in the friction durability of the FCVA-DLC films at high temperatures, was caused by a complex effect of temperature and friction. The tribochemical reaction produced by the P-CVD-DLC films reduced their friction coefficient, increasing their durability at high temperatures. PMID:28772520

Friction Durability of Extremely Thin Diamond-Like Carbon Films at High Temperature.

PubMed

Miyake, Shojiro; Suzuki, Shota; Miyake, Masatoshi

2017-02-10

To clarify the friction durability, both during and after the high-temperature heating of nanometer-thick diamond-like carbon (DLC) films, deposited using filtered cathodic vacuum arc (FCVA) and plasma chemical vapor deposition (P-CVD) methods, the dependence of the friction coefficient on the load and sliding cycles of the DLC films, were evaluated. Cluster-I consisted of a low friction area in which the DLC film was effective, while cluster-II consisted of a high friction area in which the lubricating effect of the DLC film was lost. The friction durability of the films was evaluated by statistical cluster analysis. Extremely thin FCVA-DLC films exhibited an excellent wear resistance at room temperature, but their friction durability was decreased at high temperatures. In contrast, the durability of the P-CVD-DLC films was increased at high temperatures when compared with that observed at room temperature. This inverse dependence on temperature corresponded to the nano-friction results obtained by atomic force microscopy. The decrease in the friction durability of the FCVA-DLC films at high temperatures, was caused by a complex effect of temperature and friction. The tribochemical reaction produced by the P-CVD-DLC films reduced their friction coefficient, increasing their durability at high temperatures.

Hope for the future: intensifying spirituality in the workplace.

PubMed

Batcheller, Joyce; Davis, James; Yoder-Wise, Patricia S

2013-01-01

Healthy workplaces address various issues. Work focused on ergonomics addresses physical issues, satisfaction surveys reveal psychosocial issues; and other approaches address spirituality issues. Spirituality in the workplace contributes to holistic care and to the worth of the individual. Incorporating the concept of spirituality, in its broad sense, into the workplace enriches leadership practice and contributes to a holistic work environment. Spirituality is core to the servant leader approach to leadership and beneficial to other approaches. Followers benefit from a holistic approach to leadership; and some specific practices can exhibit the belief an organization holds related to the worth of the individual. Incorporating spirituality into an organization reflects the same values nursing holds for person-centered care, a view of integration of physical, psychological, and spiritual needs.

49 CFR 192.933 - What actions must be taken to address integrity issues?

Code of Federal Regulations, 2011 CFR

2011-10-01

... Transmission Pipeline Integrity Management § 192.933 What actions must be taken to address integrity issues? (a... any indication of metal loss, cracking or a stress riser. (iii) An indication or anomaly that in the...

49 CFR 192.933 - What actions must be taken to address integrity issues?

Code of Federal Regulations, 2013 CFR

2013-10-01

... Transmission Pipeline Integrity Management § 192.933 What actions must be taken to address integrity issues? (a... any indication of metal loss, cracking or a stress riser. (iii) An indication or anomaly that in the...

49 CFR 192.933 - What actions must be taken to address integrity issues?

Code of Federal Regulations, 2012 CFR

2012-10-01

... Transmission Pipeline Integrity Management § 192.933 What actions must be taken to address integrity issues? (a... any indication of metal loss, cracking or a stress riser. (iii) An indication or anomaly that in the...

ITS National Architecture -- Rural Issues Workshop

DOT National Transportation Integrated Search

1995-06-15

THE PURPOSE OF THE WORKSHOP IS TO BRING TOGETHER A DIVERSITY OF PEOPLE INTERESTED IN HOW THE NATIONAL ITS ARCHITECTURE IS ADDRESSING ISSUES THAT IMPACT IMPLEMENTATION OF ITS IN RURAL AREAS (AND TO WHAT DEGREE IT ADDRESSES THEM). : THE TWO-DAY AGEN...

The Dangers of Art "Appreciation."

ERIC Educational Resources Information Center

Irvine, Hope

1991-01-01

Addresses the issue of the fame of Leonardo da Vinci's "Mona Lisa." Describes several kitsch objects that have been created about the painting. Maintains that students need to address this issue otherwise such exploitation will depreciate the value of the art work. (KM)

Sink or Swim: The Marine Corps Capacity to Conduct a Marine Expeditionary Brigade Amphibious Assault using Expeditionary Maneuver Warfare

DTIC Science & Technology

2010-03-01

Expeditionary Maneuver Warfare? This study addresses the equipment issues surrounding the Marine expeditionary brigade ’s’ ability to conduct an amphibious...addresses the equipment issues surrounding the expeditionary brigade’s ability to conduct an amphibious assault under expeditionary maneuver warfare in...1 Issues and Elements of the Modern-Day MEB Assault .................................................................. 2 The Marine Corps

Focus on Infants & Toddlers (Ages 0-3): A Quarterly Newsletter for the Education Community, 1999-2000.

ERIC Educational Resources Information Center

Barry, Virginia M., Ed.; Cantor, Patricia, Ed.

2000-01-01

These four quarterly newsletter issues address various topics of interest to child caregivers. Each issue focuses on a theme and includes articles on that theme, along with regular news or vice president's columns. The Fall 1999 issue addresses family play and seeks to encourage families to regard play as a way of relaxing and finding contentment…

Beneficial Role of Copper in the Enhancement of Durability of Ordered Intermetallic PtFeCu Catalyst for Electrocatalytic Oxygen Reduction.

PubMed

Arumugam, Balamurugan; Tamaki, Takanori; Yamaguchi, Takeo

2015-08-05

Design of Pt alloy catalysts with enhanced activity and durability is a key challenge for polymer electrolyte membrane fuel cells. In the present work, we compare the durability of the ordered intermetallic face-centered tetragonal (fct) PtFeCu catalyst for the oxygen reduction reaction (ORR) relative to its counterpart bimetallic catalysts, i.e., the ordered intermetallic fct-PtFe catalyst and the commercial catalyst from Tanaka Kikinzoku Kogyo, TKK-PtC. Although both fct catalysts initially exhibited an ordered structure and mass activity approximately 2.5 times higher than that of TKK-Pt/C, the presence of Cu at the ordered intermetallic fct-PtFeCu catalyst led to a significant enhancement in durability compared to that of the ordered intermetallic fct-PtFe catalyst. The ordered intermetallic fct-PtFeCu catalyst retained more than 70% of its mass activity and electrochemically active surface area (ECSA) over 10 000 durability cycles carried out at 60 °C. In contrast, the ordered intermetallic fct-PtFe catalyst maintained only about 40% of its activity. The temperature of the durability experiment is also shown to be important: the catalyst was more severely degraded at 60 °C than at room temperature. To obtain insight into the observed enhancement in durability of fct-PtFeCu catalyst, a postmortem analysis of the ordered intermetallic fct-PtFeCu catalyst was carried out using scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDX) line scan. The STEM-EDX line scans of the ordered intermetallic fct-PtFeCu catalyst over 10 000 durability cycles showed a smaller degree of Fe and Cu dissolution from the catalyst. Conversely, large dissolution of Fe was identified in the ordered intermetallic fct-PtFe catalyst, indicating a lesser retention of Fe that causes the destruction of ordered structure and gives rise to poor durability. The enhancement in the durability of the ordered intermetallic fct-PtFeCu catalyst is ascribed to the synergistic effects of Cu presence and the ordered structure of catalyst.

Heteropoly acid functionalized fluoroelastomer with outstanding chemical durability and performance for vehicular fuel cells

DOE PAGES

Motz, Andrew R.; Kuo, Mei-Chen; Horan, James L.; ...

2018-03-23

To further facilitate commercialization of automotive fuel cells, durability concerns need to be addressed. Currently the addition of a mechanical support in the membrane is able to adequately solve issues of mechanical degradation, but chemical degradation via oxygenated radical attack remains an unsolved challenge. Typical mitigation strategies use cerium or manganese species to serve as radical scavengers, but these ions are able to migrate in the membrane and even leach out of the system. The approach used in this paper is to covalently link and immobilize a heteropoly acid (HPA), more specifically 11-silicotungstic acid (HSiW11), a lacunary HPA of themore » Keggin structure to a fluoroelastomer, serving as both a radical decomposition catalyst and the proton conducting acid. This dual functionality allows for both high content of radical scavenging species and high ion-exchange capacity. An efficient three step, high yield (77%), commercially viable synthesis for this polymer is reported. The synthesis route for making this new heteropoly acid functionalized polymer is confirmed using infrared spectroscopy (IR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). The material exhibits clustering of the HSiW11 moieties, resulting in a poorly connected proton conducting phase when dry, but excellent conductivity is achieved at elevated humidities (0.298 S cm -1 at 80 °C and 95% RH). The proton conductivity shows an enhancement above 60 °C due to a softening of the polymer, as shown by DSC. Under an aggressive chemical accelerated stress test (AST), 90 °C, 30% RH, zero current, and pure O 2, the PolyHPA losses only 0.05 V of open circuit voltage (OCV) after 500 h, greatly out performing any other material reported in the literature. For comparison, the Nafion® N211 fuel cell drops below 0.8 V after only 76 h under the same conditions. Finally, in fuel cell testing the PolyHPAs have outstanding chemical stability and also possess very low in situ high frequency resistance (HFR) leading to high performance (1.14 W cm -2 at 2 A cm -2), compared to 1.11 W cm -2 for the Nafion® N211 fuel cell at the same current. At 75 wt% HSiW11 loading, the fuel cell HFR showed a 22% decrease over N211.« less

Heteropoly acid functionalized fluoroelastomer with outstanding chemical durability and performance for vehicular fuel cells

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

Motz, Andrew R.; Kuo, Mei-Chen; Horan, James L.

To further facilitate commercialization of automotive fuel cells, durability concerns need to be addressed. Currently the addition of a mechanical support in the membrane is able to adequately solve issues of mechanical degradation, but chemical degradation via oxygenated radical attack remains an unsolved challenge. Typical mitigation strategies use cerium or manganese species to serve as radical scavengers, but these ions are able to migrate in the membrane and even leach out of the system. The approach used in this paper is to covalently link and immobilize a heteropoly acid (HPA), more specifically 11-silicotungstic acid (HSiW11), a lacunary HPA of themore » Keggin structure to a fluoroelastomer, serving as both a radical decomposition catalyst and the proton conducting acid. This dual functionality allows for both high content of radical scavenging species and high ion-exchange capacity. An efficient three step, high yield (77%), commercially viable synthesis for this polymer is reported. The synthesis route for making this new heteropoly acid functionalized polymer is confirmed using infrared spectroscopy (IR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). The material exhibits clustering of the HSiW11 moieties, resulting in a poorly connected proton conducting phase when dry, but excellent conductivity is achieved at elevated humidities (0.298 S cm -1 at 80 °C and 95% RH). The proton conductivity shows an enhancement above 60 °C due to a softening of the polymer, as shown by DSC. Under an aggressive chemical accelerated stress test (AST), 90 °C, 30% RH, zero current, and pure O 2, the PolyHPA losses only 0.05 V of open circuit voltage (OCV) after 500 h, greatly out performing any other material reported in the literature. For comparison, the Nafion® N211 fuel cell drops below 0.8 V after only 76 h under the same conditions. Finally, in fuel cell testing the PolyHPAs have outstanding chemical stability and also possess very low in situ high frequency resistance (HFR) leading to high performance (1.14 W cm -2 at 2 A cm -2), compared to 1.11 W cm -2 for the Nafion® N211 fuel cell at the same current. At 75 wt% HSiW11 loading, the fuel cell HFR showed a 22% decrease over N211.« less

NIH Research Addresses Aging Issues and Disparities in Oral Health | NIH MedlinePlus the Magazine

MedlinePlus

... JavaScript on. Feature: Oral Health and Aging NIH Research Addresses Aging Issues and Disparities in Oral Health ... NIH Why is it important to have a research focus on older adults? One reason is that ...

Effective Organizational Structures and Processes: Addressing Issues of Change

ERIC Educational Resources Information Center

Andrade, Maureen Snow

2016-01-01

This chapter describes organizational structures and processes at the institutional and project levels for the development and support of distance learning initiatives. It addresses environmental and stakeholder issues and explores principles and strategies of effective leadership for change creation and management.

Addressing Social Issues.

ERIC Educational Resources Information Center

Schoebel, Susan

1991-01-01

Maintains that advertising can help people become more aware of social responsibilities. Describes a successful nationwide newspaper advertising competition for college students in which ads address social issues such as literacy, drugs, teen suicide, and teen pregnancy. Notes how the ads have helped grassroots programs throughout the United…

Addressing Measurement Issues Related to Bullying Involvement

ERIC Educational Resources Information Center

Casper, Deborah M.; Meter, Diana J.; Card, Noel A.

2015-01-01

In this article, we address measurement issues related to select aspects of bullying involvement with the goal of moving psychometrically sound measurement practices toward applied bullying research. We first provide a nontechnical introduction to psychometric considerations in measuring bullying involvement, highlighting the importance of…

Medication education and consultation at a senior dining program for independently living seniors.

PubMed

Schmiedt, Dean; Ellingson, Jody

2010-08-01

To determine if pharmacist involvement within a senior dining program benefits diners by addressing their medication-related questions, using educational sessions, and providing individual consultations. Catholic Charities Senior Dining sites in central Minnesota. Pharmacists went to three senior dining sites, providing educational sessions and individual consultations to independently living senior diners. Pharmacists developed a program, in a nontraditional setting, that used educational sessions and individual consultations to assist seniors with their medication-related questions. The number of diner questions, significant issues raised, issues addressed, and level of diner satisfaction. Pharmacists made 36 visits from January to December 2009. During those visits they presented educational talks to 3,089 diners, and 12.4% of all diners spoke individually with pharmacists. Pharmacists addressed 581 questions or concerns from 384 diners. Significant issues were noted in 25.8% of individual consultations (144 questions). The most common significant issues included: adverse drug reactions (59), indications without treatment (27), and drug interactions (23). Nonopioid analgesics, antilipemics, and antihypertensive medications were most commonly involved in significant issues. Satisfaction surveys were strongly positive, with 97% indicating pharmacists had addressed their medication-related concern; only 3% did not reply. Almost half (42.7%) of satisfaction surveys indicated the diner would change something as a result of meeting with the pharmacist. Pharmacist availability in a nontraditional setting can assist seniors with addressing potentially significant medication-related issues. Independently living seniors will seek out information from a pharmacist in a convenient setting.

Experimentally Observed Electrical Durability of 4H-SiC JFET ICs Operating from 500 C to 700 C

NASA Technical Reports Server (NTRS)

Neudeck, Philip G.; Spry, David J.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.

2016-01-01

This ECSCRM 2016 submission presents further electrical testing and microscopic post-failure studies aimed at more comprehensive understanding of the durability limits of this extreme temperature IC technology. The results summarized represent an unprecedented combination of T 500 C semiconductor IC durability and functionality.

Coating WPC's using co-extrusion to improve durability

Treesearch

Nicole M. Stark; Laurent M. Matuana

2007-01-01

Wood-plastic composites (WPCs) have been gaining market share in the residential construction industry as lumber for decking, roof tiles, and siding. The durability of these materials in exterior environments is just beginning to be understood. Current research suggests that controlling moisture absorption by the composite is key to improving durability. Methods to...

Outdoor durability of wood-polymer composites

Treesearch

N. M. Stark; D. J. Gardner

2008-01-01

Wood-plastic composite (WPC) lumber is promoted as a low-maintenance, high-durability product (Clemons, 2002). However, after a decade of exterior use in the construction industry, questions have arisen regarding durability. These questions are based on documented evidence of failures in the field of WPC decking products due to such impacts as polymer degradation (...

Adhesives for Achieving Durable Bonds with Acetylated Wood

Treesearch

Charles Frihart; Rishawn Brandon; James Beecher; Rebecca Ibach

2017-01-01

Acetylation of wood imparts moisture durability, decay resistance, and dimensional stability to wood; however, making durable adhesive bonds with acetylated wood can be more difficult than with unmodified wood. The usual explanation is that the acetylated surface has fewer hydroxyl groups, resulting in a harder-to-wet surface and in fewer hydrogen bonds between wood...

Toward understanding molecular mechanisms of durable and non-durable resistance to stripe rust in wheat

USDA-ARS?s Scientific Manuscript database

Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici, continues causing severe damage worldwide. Durable resistance is a key for sustainable control of the disease. High-temperature adult-plant (HTAP) resistance, which expresses when weather becomes warm and plants grow old, has bee...

40 CFR 86.094-26 - Mileage and service accumulation; emission requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.094-26 Mileage... the durability data obtained up to that point out to the durability useful life or to replace the... vehicles and durability data vehicles obtained pursuant to the provisions of this section will be used in...

40 CFR 86.094-26 - Mileage and service accumulation; emission requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Gas-Fueled, Liquefied Petroleum Gas-Fueled and Methanol-Fueled Heavy-Duty Vehicles § 86.094-26 Mileage... the durability data obtained up to that point out to the durability useful life or to replace the... vehicles and durability data vehicles obtained pursuant to the provisions of this section will be used in...

Durable soy-based adhesive dispersions

Treesearch

James M. Wescott; Amy Traska; Charles R. Frihart; Linda Lorenz

2005-01-01

An important aspect of any adhesive bond is that the bond maintains its integrity during its end use. Epoxies form highly durable bonds with many substrates but are usually not considered capable of forming completely durable bonds with wood by standard accelerated tests. However, epoxies are sold for wood boat construction, and some data have indicated that epoxies...

Sliding durability of candidate seal fiber materials in hydrogen from 25 to 900 C

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher; Steinetz, Bruce M.

1992-01-01

Sliding durability studies of candidate ceramic fibers were conducted in hydrogen to support the high temperature seal development program at NASA LeRC. Pin-on-disk tests were used to measure the friction and durability of a tow or bundle of ceramic fibers in sliding against a superalloy disk. This procedure was used previously to test candidate fibers in an air environment. The fibers based upon mullite (Al2O3-SiO2) chemistry (Nextel 550, 440, and 312) exhibited better durability in hydrogen than in air. HPZ, a complex silicon carboxynitride fiber which showed good durabilty in air, however, showed a significant loss of durability in hot hydrogen. These results are consistent with recent thermodynamic and experimental studies of ceramic compatibility with hydrogen at elevated temperatures. These research results indicate that only oxide fibers display good durability in both air and hydrogen environments. Also, simple, low cost testing in air can provide an adequate data base for initial seal material screening and selection, especially for oxide fiber candidates. The findings of this research provide critical input to the seal design team.

Physicians’ perspectives on cancer survivors’ work integration issues

PubMed Central

Morrison, Tricia; Thomas, Roanne; Guitard, Paulette

2015-01-01

Abstract Objective To explore physicians’ perspectives on supporting cancer survivors’ work integration (WI) issues. Design Using vignette methodology, 10 physicians were individually interviewed. Interviews were audiorecorded, transcribed, and subsequently analyzed. Setting Ontario. Participants A total of 10 physicians participated: 5 oncologists and 5 FPs. Methods An inductive interpretive description approach was used to identify themes across the entire data set. Main findings Physicians primarily focused on patients’ medical needs and did not spontaneously address WI issues with them. Instead, it was their patients who raised WI issues, most often owing to insurance requirements. Physicians readily completed insurance forms to aid patients’ well-being, but they did not believe their guidance was empirically sound based upon their limited WI training; rather, they recognized other health professionals, such as occupational therapists, as being better equipped to address cancer survivors’ WI issues. Despite this recognition, referrals for WI support were not routinely facilitated owing to a lack of resources or knowledge. Conclusion Owing to a lack of training and time, as well as the belief that WI issues are not part of their mandate of care, physicians perceive themselves as ill-equipped to address cancer survivors’ WI issues. These findings underscore the need for enhanced awareness of cancer survivors’ WI issues and the need for accessible support services offered by duly trained health care professionals, such as occupational therapists, ideally working in a multidisciplinary team to holistically address cancer survivors’ unique needs. PMID:25756147

Building America Best Practices Series Volume 11. Builders Challenge Guide to 40% Whole-House Energy Savings in the Marine Climate

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

Baechler, Michael C.; Gilbride, Theresa L.; Hefty, Marye G.

2010-09-01

This best practices guide is the eleventh in a series of guides for builders produced by the U.S. Department of Energy’s Building America Program. This guide book is a resource to help builders design and construct homes that are among the most energy-efficient available, while addressing issues such as building durability, indoor air quality, and occupant health, safety, and comfort. With the measures described in this guide, builders in the marine climate (portions of Washington, Oregon, and California) can achieve homes that have whole house energy savings of 40% over the Building America benchmark (a home built to mid-1990s buildingmore » practices roughly equivalent to the 1993 Model Energy Code) with no added overall costs for consumers. These best practices are based on the results of research and demonstration projects conducted by Building America’s research teams. The guide includes information for managers, designers, marketers, site supervisors, and subcontractors, as well as case studies of builders who are successfully building homes that cut energy use by 40% in the marine climate. This document is available on the web at www.buildingamerica.gov. This report was originally cleared 06-29-2010. This version is Rev 1 cleared in Nov 2010. The only change is the reference to the Energy Star Windows critieria shown on pg 8.25 was updated to match the criteria - Version 5.0, 04/07/2009, effective 01/04/2010.« less

Setting high-impact clinical research priorities for the Society for Vascular Surgery.

PubMed

Kraiss, Larry W; Conte, Michael S; Geary, Randolph L; Kibbe, Melina; Ozaki, C Keith

2013-02-01

With the overall goal of enhancing the effectiveness and efficiency of vascular care, the Society for Vascular Surgery (SVS) recently completed a process by which it identified its top clinical research priorities to address critical gaps in knowledge guiding practitioners in prevention and treatment of vascular disease. After a survey of the SVS membership, a panel of SVS committee members and opinion leaders considered 53 distinct research questions through a structured process that resulted in identification of nine clinical issues that were felt to merit immediate attention by vascular investigators and external funding agencies. These are, in order of priority: (1) define optimal management of asymptomatic carotid stenosis, (2) compare the effectiveness of medical vs invasive treatment (open or endovascular) of vasculogenic claudication, (3) compare effectiveness of open vs endovascular infrainguinal revascularization as initial treatment of critical limb ischemia, (4) develop and compare the effectiveness of clinical strategies to reduce cardiovascular and other perioperative complications (eg, wound) after vascular intervention, (5) compare the effectiveness of strategies to enhance arteriovenous fistula maturation and durability, (6) develop best practices for management of chronic venous ulcer, (7) define optimal adjunctive medical therapy to enhance the success of lower extremity revascularization, (8) identify and evaluate medical therapy to prevent abdominal aortic aneurysm growth, and (9) evaluate ultrasound vs computed tomographic angiography surveillance after endovascular aneurysm repair. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Construction of a Mod-0A Wind Turbine in Clayton, New Mexico

NASA Image and Video Library

1977-11-21

TA Mod-0A 200-kilowatt wind turbine designed by National Aeronautics and Space Administration (NASA) Lewis Research Center and constructed in Clayton, New Mexico. The wind turbine program was a joint effort by NASA and the Energy Research and Development Administration (ERDA) during the 1970s to develop less expensive forms of energy. NASA Lewis was assigned the responsibility of developing large horizontal-axis wind turbines. The program included a series of increasingly powerful wind turbines, designated: Mod-0A, Mod-1, WTS-4, and Mod-5. The program’s first device was a Mod-0 100-kilowatt wind turbine test bed built at NASA’s Plum Brook Station. This Mod-0A 200-kilowatt turbine built in Clayton in 1977 was the program’s second device. It included a 125-foot long blade atop a 100-foot tall tower. The Mod-0A was designed to determine the turbine’s operating problems, integrate the system with the local utilities, and assess the attitude of the local community. There were additional Mod-0A turbines built in Culebra, Puerto Rico; Block Island, Rhode Island; and Oahu, Hawaii. The Mod-0A turbines were initially unreliable and suffered issues with the durability of the rotor blade. Lewis engineers addressed the problems, and the wind turbines proved to be reliable and efficient devices that operated for a number of years. The information gained from these early models was vital to the design and improvement of the later generations.

Making ultrafine and highly-dispersive multimetallic nanoparticles in three-dimensional graphene with supercritical fluid as excellent electrocatalyst for oxygen reduction reaction

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

Zhou, Yazhou; Yen, Clive H.; Hu, Yun Hang

2016-01-01

Three-dimensional (3D) graphene showed an advanced support for designing porous electrode materials due to its high specific surface area, large pore volume, and excellent electronic property. However, the electrochemical properties of reported porous electrode materials still need to be improved further. The current challenge is how to deposit desirable nanoparticles (NPs) with controllable structure, loading and composition in 3D graphene while maintaining the high dispersion. Herein, we demonstrate a modified supercritical fluid (SCF) technique to address this issue by controlling the SCF system. Using this superior method, a series of Pt-based/3D graphene materials with the ultrafine-sized, highly dispersive and controllablemore » composition multimetallic NPs were successfully synthesized. Specifically, the resultant Pt40Fe60/3D graphene showed a significant enhancement in electrocatalytic performance for the oxygen reduction reaction (ORR), including a factor of 14.2 enhancement in mass activity (1.70 A mgPt 1), a factor of 11.9 enhancement in specific activity (1.55 mA cm 2), and higher durability compared with that of Pt/C catalyst. After careful comparison, the Pt40Fe60/3D graphene catalyst shows the higher ORR activity than most of the reported similar 3D graphene-based catalysts. The successful synthesis of such attractive materials by this method also paves the way to develop 3D graphene in widespread applications.« less

Critical review of lasers in benign prostatic hyperplasia (BPH).

PubMed

Gravas, Stavros; Bachmann, Alexander; Reich, Oliver; Roehrborn, Claus G; Gilling, Peter J; De La Rosette, Jean

2011-04-01

• Laser treatment of benign prostatic hyperplasia has challenged transurethral resection of the prostate (TURP) due to advances in laser technology, better understanding of tissue-laser interactions and growing clinical experience. • Various lasers have been introduced including neodymium: yttrium aluminium garnet (YAG), holmium (Ho):YAG, potassium titanyl phosphate:YAG, thulium(Tm) and diode laser. Based on the different wave-length dependent laser-prostatic tissue interactions, the main techniques are coagulation, vaporization, resection and enucleation. • The present review aims to help urologists to distinguish and to critically evaluate the role of different laser methods in the treatment by using an evidence-based approach. It also details further evidence for use in specific patient groups (in retention, on anticoagulation) and addresses the issues of cost and learning curve. • Coagulation-based techniques have been abandoned; holmium ablation/resection of the prostate has been superseded by the enucleation technique Ho-laser enucleation of the prostate (HoLEP). The short-term efficacy of the emerging laser treatments such as diode and Tm prostatectomy has been suggested by low quality studies. HoLEP and photoselective vaporization of the prostate (PVP) represent valid clinical alternatives to TURP. HoLEP is the most rigorously analysed laser technique with durable efficacy for any prostate size and low early and late morbidity. PVP has grown in acceptance and popularity but long-term results from high quality studies are pending. © 2010 THE AUTHORS; BJU INTERNATIONAL © 2010 BJU INTERNATIONAL.

Next-Generation in Situ Hybridization Chain Reaction: Higher Gain, Lower Cost, Greater Durability

PubMed Central

2014-01-01

Hybridization chain reaction (HCR) provides multiplexed, isothermal, enzyme-free, molecular signal amplification in diverse settings. Within intact vertebrate embryos, where signal-to-background is at a premium, HCR in situ amplification enables simultaneous mapping of multiple target mRNAs, addressing a longstanding challenge in the biological sciences. With this approach, RNA probes complementary to mRNA targets trigger chain reactions in which metastable fluorophore-labeled RNA hairpins self-assemble into tethered fluorescent amplification polymers. The properties of HCR lead to straightforward multiplexing, deep sample penetration, high signal-to-background, and sharp subcellular signal localization within fixed whole-mount zebrafish embryos, a standard model system for the study of vertebrate development. However, RNA reagents are expensive and vulnerable to enzymatic degradation. Moreover, the stringent hybridization conditions used to destabilize nonspecific hairpin binding also reduce the energetic driving force for HCR polymerization, creating a trade-off between minimization of background and maximization of signal. Here, we eliminate this trade-off by demonstrating that low background levels can be achieved using permissive in situ amplification conditions (0% formamide, room temperature) and engineer next-generation DNA HCR amplifiers that maximize the free energy benefit per polymerization step while preserving the kinetic trapping property that underlies conditional polymerization, dramatically increasing signal gain, reducing reagent cost, and improving reagent durability. PMID:24712299

A testing platform for durability studies of polymers and fiber-reinforced polymer composites under concurrent hygrothermo-mechanical stimuli.

PubMed

Gomez, Antonio; Pires, Robert; Yambao, Alyssa; La Saponara, Valeria

2014-12-11

The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus.

A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli

PubMed Central

Gomez, Antonio; Pires, Robert; Yambao, Alyssa; La Saponara, Valeria

2014-01-01

The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus. PMID:25548950

Taking Control: The Efficacy and Durability of a Peer-Led Uncertainty Management Intervention for People Recently Diagnosed With HIV.

PubMed

Brashers, Dale E; Basinger, Erin D; Rintamaki, Lance S; Caughlin, John P; Para, Michael

2017-01-01

HIV creates substantial uncertainty for people infected with the virus, which subsequently affects a host of psychosocial outcomes critical to successful management of the disease. This study assessed the efficacy and durability of a theoretically driven, one-on-one peer support intervention designed to facilitate uncertainty management and enhance psychosocial functioning for patients newly diagnosed with HIV. Using a pretest-posttest control group design, 98 participants received information and training in specific communication strategies (e.g., disclosing to friends and family, eliciting social support, talking to health care providers, using the Internet to gather information, and building social networks through AIDS service organizations). Participants in the experimental group attended six 1-hour sessions, whereas control participants received standard of care for 12 months (after which they received the intervention). Over time, participants in the intervention fared significantly better regarding (a) illness uncertainty, (b) depression, and (c) satisfaction with social support than did those in the control group. Given the utility and cost-effectiveness of this intervention and the uncertainty of a multitude of medical diagnoses and disease experiences, further work is indicated to determine how this program could be expanded to other illnesses and to address related factors, such as treatment adherence and clinical outcomes.

Modeling and experimental performance of an intermediate temperature reversible solid oxide cell for high-efficiency, distributed-scale electrical energy storage

NASA Astrophysics Data System (ADS)

Wendel, Christopher H.; Gao, Zhan; Barnett, Scott A.; Braun, Robert J.

2015-06-01

Electrical energy storage is expected to be a critical component of the future world energy system, performing load-leveling operations to enable increased penetration of renewable and distributed generation. Reversible solid oxide cells, operating sequentially between power-producing fuel cell mode and fuel-producing electrolysis mode, have the capability to provide highly efficient, scalable electricity storage. However, challenges ranging from cell performance and durability to system integration must be addressed before widespread adoption. One central challenge of the system design is establishing effective thermal management in the two distinct operating modes. This work leverages an operating strategy to use carbonaceous reactant species and operate at intermediate stack temperature (650 °C) to promote exothermic fuel-synthesis reactions that thermally self-sustain the electrolysis process. We present performance of a doped lanthanum-gallate (LSGM) electrolyte solid oxide cell that shows high efficiency in both operating modes at 650 °C. A physically based electrochemical model is calibrated to represent the cell performance and used to simulate roundtrip operation for conditions unique to these reversible systems. Design decisions related to system operation are evaluated using the cell model including current density, fuel and oxidant reactant compositions, and flow configuration. The analysis reveals tradeoffs between electrical efficiency, thermal management, energy density, and durability.

Improving Fatigue Performance of AHSS Welds

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

Feng, Zhili; Yu, Xinghua; Erdman, III, Donald L.

Reported herein is technical progress on a U.S. Department of Energy CRADA project with industry cost-share aimed at developing the technical basis and demonstrate the viability of innovative in-situ weld residual stresses mitigation technology that can substantially improve the weld fatigue performance and durability of auto-body structures. The developed technology would be costeffective and practical in high-volume vehicle production environment. Enhancing weld fatigue performance would address a critical technology gap that impedes the widespread use of advanced high-strength steels (AHSS) and other lightweight materials for auto body structure light-weighting. This means that the automotive industry can take full advantage ofmore » the AHSS in strength, durability and crashworthiness without the concern of the relatively weak weld fatigue performance. The project comprises both technological innovations in weld residual stress mitigation and due-diligence residual stress measurement and fatigue performance evaluation. Two approaches were investigated. The first one was the use of low temperature phase transformation (LTPT) weld filler wire, and the second focused on novel thermo-mechanical stress management technique. Both technical approaches have resulted in considerable improvement in fatigue lives of welded joints made of high-strength steels. Synchrotron diffraction measurement confirmed the reduction of high tensile weld residual stresses by the two weld residual stress mitigation techniques.« less

Thermodynamic model of natural, medieval and nuclear waste glass durability

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

Jantzen, C.M.; Plodinec, M.J.

1983-01-01

A thermodynamic model of glass durability based on hydration of structural units has been applied to natural glass, medieval window glasses, and glasses containing nuclear waste. The relative durability predicted from the calculated thermodynamics correlates directly with the experimentally observed release of structural silicon in the leaching solution in short-term laboratory tests. By choosing natural glasses and ancient glasses whose long-term performance is known, and which bracket the durability of waste glasses, the long-term stability of nuclear waste glasses can be interpolated among these materials. The current Savannah River defense waste glass formulation is as durable as natural basalt frommore » the Hanford Reservation (10/sup 6/ years old). The thermodynamic hydration energy is shown to be related to the bond energetics of the glass. 69 references, 2 figures, 1 table.« less

Durable crystalline Si photovoltaic modules based on silicone-sheet encapsulants

NASA Astrophysics Data System (ADS)

Hara, Kohjiro; Ohwada, Hiroto; Furihata, Tomoyoshi; Masuda, Atsushi

2018-02-01

Crystalline Si photovoltaic (PV) modules were fabricated with sheets of poly(dimethylsiloxane) (silicone) as an encapsulant. The long-term durability of the silicone-encapsulated PV modules was experimentally investigated. The silicone-based modules enhanced the long-term durability against potential-induced degradation (PID) and a damp-heat (DH) condition at 85 °C with 85% relative humidity (RH). In addition, we designed and fabricated substrate-type Si PV modules based on the silicone encapsulant and an Al-alloy plate as the substratum, which demonstrated high impact resistance and high incombustible performance. The high chemical stability, high volume resistivity, rubber-like elasticity, and incombustibility of the silicone encapsulant resulted in the high durability of the modules. Our results indicate that silicone is an attractive encapsulation material, as it improves the long-term durability of crystalline Si PV modules.

Materials research for high-speed civil transport and generic hypersonics: Composites durability

NASA Technical Reports Server (NTRS)

Allen-Lilly, Heather; Cregger, Eric; Hoffman, Daniel; Mccool, Jim

1995-01-01

This report covers a portion of an ongoing investigation of the durability of composites for the High Speed Civil Transport (HSCT) program. Candidate HSCT composites need to possess the high-temperature capability required for supersonic flight. This program was designed to initiate the design, analysis, fabrication, and testing of equipment intended for use in validating the long-term durability of materials for the HSCT. This equipment includes thermally actuated compression and tension fixtures, hydraulic-actuated reversible load fixtures, and thermal chambers. This equipment can be used for the durability evaluation of both composite and adhesive materials. Thermally actuated fixtures are recommended for fatigue cycling when long-term thermomechanical fatigue (TMF) data are required on coupon-sized tension or compression specimens. Long term durability testing plans for polymer matrix composite specimens are included.

Durability of Flexible Ureteroscopes: A Prospective Evaluation of Longevity, the Factors that Affect it, and Damage Mechanisms.

PubMed

Legemate, Jaap D; Kamphuis, Guido M; Freund, Jan Erik; Baard, Joyce; Zanetti, Stefano P; Catellani, Michele; Oussoren, Harry W; de la Rosette, Jean J

2018-03-10

Flexible ureteroscopy is an established treatment modality for evaluating and treating abnormalities in the upper urinary tract. Reusable ureteroscope (USC) durability is a significant concern. To evaluate the durability of the latest generation of digital and fiber optic reusable flexible USCs and the factors affecting it. Six new flexible USCs from Olympus and Karl Storz were included. The primary endpoint for each USC was its first repair. Data on patient and treatment characteristics, accessory device use, ureteroscopy time, image quality, USC handling, disinfection cycles, type of damage, and deflection loss were collected prospectively. Ureteroscopy. USC durability was measured as the total number of uses and ureteroscopy time before repair. USC handling and image quality were scored. After every procedure, maximal ventral and dorsal USC deflection were documented on digital images. A total of 198 procedures were performed. The median number of procedures was 27 (IQR 16-48; 14h) for the six USCs overall, 27 (IQR 20-56; 14h) for the digital USCs, and 24 (range 10-37; 14h) for the fiber optic USCs. Image quality remained high throughout the study for all six USCs. USC handling and the range of deflection remained good under incremental use. Damage to the distal part of the shaft and shaft coating was the most frequent reason for repair, and was related to intraoperative manual forcing. A limitation of this study is its single-center design. The durability of the latest reusable flexible USCs in the current study was limited to 27 uses (14h). Damage to the flexible shaft was the most important limitation to the durability of the USCs evaluated. Prevention of intraoperative manual forcing of flexible USCs maximizes their overall durability. Current flexible ureteroscopes proved to be durable. Shaft vulnerability was the most important limiting factor affecting durability. Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.

The emergence and effectiveness of global health networks: findings and future research.

PubMed

Shiffman, Jeremy; Schmitz, Hans Peter; Berlan, David; Smith, Stephanie L; Quissell, Kathryn; Gneiting, Uwe; Pelletier, David

2016-04-01

Global health issues vary in the amount of attention and resources they receive. One reason is that the networks of individuals and organizations that address these issues differ in their effectiveness. This article presents key findings from a research project on the emergence and effectiveness of global health networks addressing tobacco use, alcohol harm, maternal mortality, neonatal mortality, tuberculosis and pneumonia. Although networks are only one of many factors influencing priority, they do matter, particularly for shaping the way the problem and solutions are understood, and convincing governments, international organizations and other global actors to address the issue. Their national-level effects vary by issue and are more difficult to ascertain. Networks are most likely to produce effects when (1) their members construct a compelling framing of the issue, one that includes a shared understanding of the problem, a consensus on solutions and convincing reasons to act and (2) they build a political coalition that includes individuals and organizations beyond their traditional base in the health sector, a task that demands engagement in the politics of the issue, not just its technical aspects. Maintaining a focused frame and sustaining a broad coalition are often in tension: effective networks find ways to balance the two challenges. The emergence and effectiveness of a network are shaped both by its members' decisions and by contextual factors, including historical influences (e.g. prior failed attempts to address the problem), features of the policy environment (e.g. global development goals) and characteristics of the issue the network addresses (e.g. its mortality burden). Their proliferation raises the issue of their legitimacy. Reasons to consider them legitimate include their members' expertise and the attention they bring to neglected issues. Reasons to question their legitimacy include their largely elite composition and the fragmentation they bring to global health governance. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2016; all rights reserved.

The emergence and effectiveness of global health networks: findings and future research

PubMed Central

Shiffman, Jeremy; Peter Schmitz, Hans; Berlan, David; Smith, Stephanie L; Quissell, Kathryn; Gneiting, Uwe; Pelletier, David

2016-01-01

Global health issues vary in the amount of attention and resources they receive. One reason is that the networks of individuals and organizations that address these issues differ in their effectiveness. This article presents key findings from a research project on the emergence and effectiveness of global health networks addressing tobacco use, alcohol harm, maternal mortality, neonatal mortality, tuberculosis and pneumonia. Although networks are only one of many factors influencing priority, they do matter, particularly for shaping the way the problem and solutions are understood, and convincing governments, international organizations and other global actors to address the issue. Their national-level effects vary by issue and are more difficult to ascertain. Networks are most likely to produce effects when (1) their members construct a compelling framing of the issue, one that includes a shared understanding of the problem, a consensus on solutions and convincing reasons to act and (2) they build a political coalition that includes individuals and organizations beyond their traditional base in the health sector, a task that demands engagement in the politics of the issue, not just its technical aspects. Maintaining a focused frame and sustaining a broad coalition are often in tension: effective networks find ways to balance the two challenges. The emergence and effectiveness of a network are shaped both by its members’ decisions and by contextual factors, including historical influences (e.g. prior failed attempts to address the problem), features of the policy environment (e.g. global development goals) and characteristics of the issue the network addresses (e.g. its mortality burden). Their proliferation raises the issue of their legitimacy. Reasons to consider them legitimate include their members’ expertise and the attention they bring to neglected issues. Reasons to question their legitimacy include their largely elite composition and the fragmentation they bring to global health governance. PMID:27067141

Sustainable design guidelines to support the Washington State ferries terminal design manual : stormwater and material issues.

DOT National Transportation Integrated Search

2011-08-01

In an effort to assist the developers of the terminal design manual in potentially addressing : sustainable design issues, the overall goal is to produce Sustainable Design Guidelines that : will specifically address the unique needs and requirements...

Privacy Questions from Practicing School Nurses

ERIC Educational Resources Information Center

Bergren, Martha Dewey

2004-01-01

This Question and Answer (Q&A) article addresses practice issues related to school health records and school nursing documentation that were posed by school nurses in the field. Specifically, the questions addressed concern the following: education records, medication privacy issues, sharing of sensitive health information, privacy of…

New Haven Conn. Group Awarded EPA Grant to Help Air and Water Issues

EPA Pesticide Factsheets

A Connecticut organization working to address water and air pollution issues in New Haven was one of three groups in New England to receive an EPA grant award of $30,000 each, to help communities directly address local environmental concerns.

Space station operations task force. Panel 4 report: Management integration

NASA Technical Reports Server (NTRS)

1987-01-01

The Management Integration Panel of the Space Station Operations Task Force was chartered to provide a structure and ground rules for integrating the efforts of the other three panels and to address a number of cross cutting issues that affect all areas of space station operations. Issues addressed include operations concept implementation, alternatives development and integration process, strategic policy issues and options, and program management emphasis areas.

Homelessness and the Public's Health: Legal Responses.

PubMed

Hodge, James G; DiPietro, Barbara; Horton-Newell, Amy E

2017-03-01

This commentary addresses public health issues underlying homelessness and related law, policy, and advocacy options. After framing public health issues for affected individuals and the community, legal and policy approaches and related barriers are assessed. Major topics include deficits in housing availability, the role of state-based Medicaid programs, criminalization of homelessness, and the use of emergency declarations seeking to address particular issues related to homelessness in select states and localities.

Laboratory challenges conducting international clinical research in resource-limited settings.

PubMed

Fitzgibbon, Joseph E; Wallis, Carole L

2014-01-01

There are many challenges to performing clinical research in resource-limited settings. Here, we discuss several of the most common laboratory issues that must be addressed. These include issues relating to organization and personnel, laboratory facilities and equipment, standard operating procedures, external quality assurance, shipping, laboratory capacity, and data management. Although much progress has been made, innovative ways of addressing some of these issues are still very much needed.

Addressing Social Issues in the Classroom and Beyond: The Pedagogical Efforts of Pioneers in the Field. Research in Curriculum and Instruction

ERIC Educational Resources Information Center

Totten, Samuel, Ed.; Pedersen, Jon, Ed.

2007-01-01

Addressing Social Issues in the Classroom and Beyond: The Pedagogical Efforts of Pioneers in the Field is comprised of essays that delineate the genesis and evolution of the thought and work of pioneers in the field of social issues and education. The authors (many of whom, themselves, are noted professors of education and who have done…

Bounded agency in humanitarian settings: a qualitative study of adherence to antiretroviral therapy among refugees situated in Kenya and Malaysia.

PubMed

Mendelsohn, Joshua B; Rhodes, Tim; Spiegel, Paul; Schilperoord, Marian; Burton, John Wagacha; Balasundaram, Susheela; Wong, Chunting; Ross, David A

2014-11-01

HIV-positive refugees confront a variety of challenges in accessing and adhering to antiretroviral therapy (ART) and attaining durable viral suppression; however, there is little understanding of what these challenges are, how they are navigated, or how they may differ across humanitarian settings. We sought to document and examine accounts of the threats, barriers and facilitators experienced in relation to HIV treatment and care and to conduct comparisons across settings. We conducted semi-structured interviews among a purposive sample of 14 refugees attending a public, urban HIV clinic in Kuala Lumpur, Malaysia (July-September 2010), and 12 refugees attending a camp-based HIV clinic in Kakuma, Kenya (February-March 2011). We used framework methods and between-case comparison to analyze and interpret the data, identifying social and environmental factors that influenced adherence. The multiple issues that threatened adherence to antiretroviral therapy or precipitated actual adherence lapses clustered into three themes: "migration", "insecurity", and "resilience". The migration theme included issues related to crossing borders and integrating into treatment systems upon arrival in a host country. Challenges related to crossing borders were reported in both settings, but threats pertaining to integration into, and navigation of, a new health system were exclusive to the Malaysian setting. The insecurity theme included food insecurity, which was most commonly reported in the Kenyan setting; health systems insecurity, reported in both settings; and emotional insecurity, which was most common in the Kenyan setting. Resilient processes were reported in both settings. We drew on the concept of "bounded agency" to argue that, despite evidence of personal and community resilience, these processes were sometimes insufficient for overcoming social and environmental barriers to adherence. In general, interventions might aim to bolster individuals' range of action with targeted support that bolsters resilient processes. Specific interventions are needed to address locally-based food and health system insecurities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Drug-eluting stents and acute myocardial infarction: A lethal combination or friends?

PubMed Central

Otsuki, Shuji; Sabaté, Manel

2014-01-01

Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction (STEMI). First generation drug-eluting stents (DES), (sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI. PMID:25276295

The Artilect Debate

NASA Astrophysics Data System (ADS)

de Garis, Hugo; Halioris, Sam

Twenty-first-century technologies will allow the creation of massively intelligent machines, many trillions of times as smart, fast, and durable as humans. Issues concerning industrial, consumer, and military applications of mobile autonomous robots, cyborgs, and computer-based AI systems could divisively split humanity into ideological camps regarding whether "artilects" (artificial intellects) should be built or not. The artilect debate, unlike any before it, could dominate the 21st-century political landscape, and has the potential to cause conflict on a global scale. Research is needed to inform policy and individual decisions; and healthy debate should be initiated now to prepare institutions and individuals alike for the impact of AI.