WorldWideScience

Sample records for technologies energetiques durables

  1. The guide to sustainable energy technologies for schools; Un guide pour les technologies energetiques durables dans les ecoles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    There are significant attractions for municipalities to opt for sustainable solutions which involve energy efficient technologies and measures. This is the challenging background which led to the production the Guide to Sustainable Energy Technologies for Schools. This guide is a decision-making tool intended for European municipalities and school managers. Its aim is to: assist them in choosing between the energy technologies that will be used in school building or retrofitting projects and provide them with a framework for measuring and comparing different aspects of energy performance that can be used to convince decision-makers to select sustainable energy technologies and measures. The guide is composed of three parts: an illustrative list of sustainable energy technologies, an introduction to energy performance indicators and fifteen case studies describing practical sustainable energy solutions applied to schools in seven European countries. (A.L.B.)

  2. Quebec energy development in a sustainable development context; Le developpement energetique du Quebec dans un contexte de developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    Laplatte, Benjamin; Bourque, Francis; Granger, Francois P.

    2010-09-15

    Quebec is a net importer of oil and it is clear that the reduction of its dependence with regards to hydrocarbons must be a main preoccupation. Moreover, the energy consumption per habitant of Quebec is higher than that of the majority of the other developed countries. This analysis looks at the choice on offer to the society of the province of Quebec, in terms of energy resources and technologies of today and tomorrow, in a context of sustainable development. [French] Le Quebec est un importateur net de petrole et il est clair que la reduction de sa dependance a l'egard des hydrocarbures doit etre une preoccupation de premier plan. De plus, la consommation energetique par habitant du Quebec est plus elevee que celle de la majorite des autres pays developpes. La presente analyse adresse les choix qui s'offrent a la societe quebecoise, en matiere de ressources et de technologies de l'energie d'aujourd'hui et de demain, dans un contexte de developpement durable.

  3. The engineer, sustainable development craftsman at the center of the global energy challenge!; L'ingenieur, artisan du developpement durable au centre du defi energetique mondial!

    Energy Technology Data Exchange (ETDEWEB)

    Laplatte, Benjamin; Bourque, Francis; Granger, Francois P.; Dery, Gaston; Berube, Martin

    2010-09-15

    By its omnipresence in society, the energy question is at the heart of sustainable development issues. The engineer, as a central actor of human society development, is therefore tightly linked to the energy issue and he must actively contribute to resolve it by integrating to his practices the principles of sustainable development and by applying the solutions that arises. Part of these elements include as the main ones, listening to the consideration of citizens, becoming aware of the environment importance and reducing costs at all levels. The engineer is a social actor that cannot be ignored in the resolution of these issues. [French] Par son omnipresence dans la societe, la question energetique est au coeur des enjeux du developpement durable. L'ingenieur, etant un acteur central du developpement des societes humaines, est donc inextricablement lie a la question energetique qu'il doit contribuer activement a resoudre en integrant a sa pratique les principes du developpement durable et en appliquant les solutions qui en decoulent. Parmi ces elements, l'ecoute des considerations citoyennes, la prise de conscience de l'importance de l'environnement et la reduction des couts a tous les niveaux sont des elements centraux. L'ingenieur est un acteur social incontournable pour la resolution de ces enjeux.

  4. Mobility energy label: An indicator for a sustainable city; Les etiquettes energetiques de mobilite: Un indicateur pour la ville durable

    Energy Technology Data Exchange (ETDEWEB)

    Flety, Yann; Antoni, Jean-Philippe; Vuidel, Gilles; de Sede-Marceau, Marie-Helene

    2010-09-15

    Perspectives of energy consumption reduction linked to global warming are bringing a desire for actions relating to the mastering and the improvement of energy efficiency. In this context, from the French example of greater Besancon (Communaute d'Agglomeration du Grand Besancon (CAGB)), the research presented here wants to define an energy indicator useful to planners called 'Territory energy label': to measure how the urban area is situated energy wise in terms of the daily mobility of its inhabitants, the behaviour of whom is looked at in a prescriptive manner. [French] Les perspectives de reduction des consommations energetiques en lien avec le rechauffement climatique se traduisent par une volonte d'actions en matiere de maitrise et d'amelioration de l'efficacite energetique. Dans ce contexte, a partir de l'exemple francais de la Communaute d'Agglomeration du Grand Besancon (CAGB), la recherche presentee vise a definir un indicateur energetique utile aux amenageurs intitule 'etiquette energetique Territoriale' : il s'agit de mesurer comment 'se situent energetiquement' les differents espaces que regroupent une meme aire urbaine du point de vu des mobilites quotidiennes de ses habitants, dont le comportement est apprehende de maniere normative.

  5. Mars Technologies Spawn Durable Wind Turbines

    Science.gov (United States)

    Bubenheim, David L.

    2013-01-01

    Sometimes referred to as regenerative life support systems, the concept includes an enclosed self-sufficient habitat that can independently support life for years on end. Such a system aims not only to produce its own food and water but to purify air and convert waste into useful byproducts. In the early 1990s, NASA was planning for an extended stay on Mars, and Bubenheim and his Ames colleagues were concentrating efforts on creating a complete ecological system to sustain human crewmembers during their time on the Red Planet. The main barrier to developing such a system, he says, is energy. Mars has no power plants, and a regenerative system requires equipment that runs on electricity to do everything from regulating humidity in the atmosphere to monitoring the quality of recycled water. The Ames group started looking at how to best make power on a planet that is millions of miles away from Earth and turned to a hybrid concept combining wind and solar power technologies. The reason was that Mars experiences frequent dust storms that can block nearly all sunlight. When theres a dust storm and the wind is blowing, the wind system could be the dominant power source. When the wind is not blowing and the sun is out, photovoltaics could be the dominant source, says Bubenheim.To develop and test the wind power technology, Ames turned to a remote, harsh environment here on Earth: the South Pole. The South Pole was a really good analog for Mars, says Bubenheim. The technology features for going to Mars were the same technology features needed to make something work at the South Pole.Around the same time that NASA started investigating energy technologies for the Red Planet, the National Science Foundation (NSF) was working on a redesign of their station at the South Pole. To power its operations, NSF used fuel that it flew to the remote location, but the Foundation recognized the benefits of also using onsite renewable energy technologies. In the winter they have small

  6. Mars Technologies Spawn Durable Wind Turbines

    Science.gov (United States)

    2014-01-01

    To develop and test wind power technology for use on Mars, Ames Research Center turned to Northern Power Systems (NPS), based in Barre, Vermont. Ames awarded NPS an SBIR contract so the company could enhance their turbine’s function. Today, over 200 NASA-derived Northern Power 100s are in operation on Earth and have reduced carbon emissions by 50,000 tons annually.

  7. No. 3425 National Assembly. No. 56 Senate, report on the contributions of the science and the technology to the sustainable development Tome 1: the climatic changes and the energy transition: over the crisis; No. 3425 Assemblee Nationale. No. 56 Senat, rapport sur 'les apports de la science et de la technologie au developpement durable' Tome 1: 'changement climatique et transition energetique: depasser la crise'

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-15

    Energy crisis can be avoided by the use of anticipation policies. After an examination of the technologies, concerning the energy production and more particularly the electricity, the energy conservation, the new transport modes and the new houses architecture, the authors noted that these policies exist, but need time to implement. In this framework this report aims to defines the situation and bring some recommendations and answers to implement a real policy. (A.L.B.)

  8. Proceedings of the meeting 'towards a sustainable energy policy'; Comptes rendus de la rencontre 'vers une politique energetique durable'

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-05-01

    This document is a report of the debates and talks given at the 7. meeting of the national debate on energies. It comprises 5 papers. The first paper is a pedagogical session with three scientists (R. Balian, G. Megie, P.R. Bauquis) who answer some general questions about energy consumptions and climatic changes. The second paper is the opening talk of Ms N. Fontaine, representative minister of the industry who recalls the principles, challenges and goals of the future French energy policy (greenhouse effect, oil and gas prices, research, technology and regulation, public information, financial help, diversification of energy sources, nuclear debate). The third paper is the opinion of Ms C. Haignere, representative minister of research and new technologies, about the French energy policy and the development of nuclear fusion. The fourth paper is a debate about the proposals made during the previous six meetings (habits and energy conservation, energy choices, development of renewable energies, nuclear energy), the debate ends with the answer to some questions from the audience. The last paper is the closing talk of T. Saifi, secretary of state for the sustainable development. (J.S.)

  9. Development of Quebec's energy in a sustainable development context : summary; Le developpement energetique du Quebec dans un contexte de developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    Vaillancourt, K.; Lemieux, D.; Lambert, N.; Lachance, J.G. [Eco Ressources Consultants, Montreal, PQ (Canada); Bourque, F.; Benoit, P.A. [Reseau des ingenieurs du Quebec, Montreal, PQ (Canada)

    2009-04-30

    As a net energy importer, issues of energy security are becoming increasingly important in Quebec. Since Quebec's energy policy is largely based on the development of hydropower, its energy development has already been consistent with sustainable development. Industry remains the largest energy consumer in Quebec, followed by the transportation sector, and the residential, commercial and agricultural sectors. Total energy consumption in the province is expected to increase by 1.2 per cent annually between 2001-2016. Although competitive electricity prices in Quebec have contributed to strengthening the provincial economy, it has been argued that the low price of electricity does not promote energy efficiency nor the development of alternative energy sources. Quebec imports all of its crude oil and natural gas. Energy production in the province is currently confined to electricity generation and refining of petroleum products at 3 main refineries. In 2005, the installed electrical capacity was 92.2 per cent hydropower, 5.3 per cent thermal power, 1.5 per cent nuclear power, and 0.9 per cent wind power. The vast majority of this installed capacity (78 per cent) is owned by Hydro-Quebec. Wind capacity is expected to reach 3,500 MW by 2017, representing about 8 per cent of Quebec's total electrical capacity. Guidelines have been identified in Quebec's energy strategy for 2006-2015 to promote energy efficiency and innovation of new energy technologies covering all markets and all forms of energy, including geothermal energy, solar energy and ethanol produced from forest residues, agricultural wastes and municipal wastes. The government's overall goal is to generate both energy savings and a reduction in annual greenhouse gas emissions.

  10. Developpement energetique par modelisation et intelligence territoriale: Un outil de prise de decision participative pour le developpement durable des projets eoliens

    Science.gov (United States)

    Vazquez Rascon, Maria de Lourdes

    enabled the testing of TIMED in an ex-post experience of a wind farm in operation since 2006. In this test, II people participated representing four stakeholder' categories: the private sector, the public sector, experts and civil society. This test allowed us to analyze the current situation in which wind projects are currently developed in Quebec. The concerns of some stakeholders regarding situations that are not considered in the current context were explored through a third goal. This third objective allowed us to make simulations taking into account the assumptions of strategic levels. Examples of the strategic level are the communication tools used to approach the host community and the park property type. Finally, the fourth objective, a SWOT analysis with the participation of eight experts, allowed us to verify the extent to which TIMED approach succeeded in constructing four fields for participatory decision-making: physical, intellectual, emotional and procedural. From these facts, 116 strengths, 28 weaknesses, 32 constraints and 54 opportunities were identified. Contributions, applications, limitations and extensions of this research are based on giving a participatory decision-making methodology taking into account socio-cultural, environmental and economic variables; making reflection sessions on a wind farm in operation; acquiring MCDA knowledge for participants involved in testing the proposed methodology; taking into account the physical, intellectual, emotional and procedural spaces to al1iculate a participatory decision; using the proposed methodology in renewable energy sources other than wind; the need to an interdisciplinary team for the methodology application; access to quality data; access to information technologies; the right to public participation; the neutrality of experts; the relationships between experts and non-experts; cultural constraints; improvement of designed indicators; the implementation of a Web platform for participatory

  11. Technology of combined chemical-mechanical fabrication of durable coatings

    Science.gov (United States)

    Smolentsev, V. P.; Ivanov, V. V.; Portnykh, A. I.

    2018-03-01

    The article presents the scientific fundamentals of methodology for calculating the modes and structuring the technological processes of combined chemical-mechanical fabrication of durable coatings. It is shown that they are based on classical patterns, describing the processes of simultaneous chemical and mechanical impact. The paper demonstrates the possibility of structuring a technological process, taking into account the systematic approach to impact management and strengthening the reciprocal positive influence of each impact upon the combined process. The combined processes have been planned for fabricating the model types of chemical-mechanical coatings of durable products in machine construction. The planning methodology is underpinned by a scientific hypothesis of a single source of impact management through energy potential of process components themselves, or by means of external energy supply through mechanical impact. The control of it is fairly thoroughly studied in the case of pulsed external strikes of hard pellets, similar to processes of vibroimpact hardening, thoroughly studied and mastered in many scientific schools of Russia.

  12. Progressive Damage Modeling of Durable Bonded Joint Technology

    Science.gov (United States)

    Leone, Frank A.; Davila, Carlos G.; Lin, Shih-Yung; Smeltzer, Stan; Girolamo, Donato; Ghose, Sayata; Guzman, Juan C.; McCarville, Duglas A.

    2013-01-01

    The development of durable bonded joint technology for assembling composite structures for launch vehicles is being pursued for the U.S. Space Launch System. The present work is related to the development and application of progressive damage modeling techniques to bonded joint technology applicable to a wide range of sandwich structures for a Heavy Lift Launch Vehicle. The joint designs studied in this work include a conventional composite splice joint and a NASA-patented Durable Redundant Joint. Both designs involve a honeycomb sandwich with carbon/epoxy facesheets joined with adhesively bonded doublers. Progressive damage modeling allows for the prediction of the initiation and evolution of damage. For structures that include multiple materials, the number of potential failure mechanisms that must be considered increases the complexity of the analyses. Potential failure mechanisms include fiber fracture, matrix cracking, delamination, core crushing, adhesive failure, and their interactions. The joints were modeled using Abaqus parametric finite element models, in which damage was modeled with user-written subroutines. Each ply was meshed discretely, and layers of cohesive elements were used to account for delaminations and to model the adhesive layers. Good correlation with experimental results was achieved both in terms of load-displacement history and predicted failure mechanisms.

  13. Technologies for a sustainable development; Technologies pour un developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The European Event on Technology (EET), a recurrent annual event since 1992, is a major meeting opportunity for researchers and engineers as well as private and public decision-makers, on technologies, their evolution and their industrial and social implications. In less than a decade, sustainable development has become both an economic and a political priority. It was urgent and legitimate that those who are the mainsprings should take hold of the subject and give it technological content, estimate its costs and define clear timetables. The debates consist of: plenary sessions on environmental, social and economic stakes of sustainable development and the challenges for, and commitment of engineers, managers and politicians with respect to these goals; and workshops, which provide an overview of recently acquired or upcoming technologies developed by sector: energy, transports, new information technologies, new industrial manufacturing technologies (materials, products, services), waste management, global environment monitoring, water management, bio-technologies, and innovation management. This document brings together the different talks given by the participants. Among these, the following ones fall into the energy and environment scope: energy efficiency of buildings: towards energy autonomy; superconductors enable in new millennium for electric power industry; advanced gas micro-turbine-driven generator technology; environmental and technical challenges of an offshore wind farm; future nuclear energy systems; modelling combustion in engines: progress and prospects for reducing emissions; on-board computers: reduction in consumption and emissions of engine-transmission units for vehicles; polymer-lithium batteries: perspectives for zero-emission traction; hybrid vehicles and energy/environmental optimization: paths and opportunities; fuel cells and zero-emission: perspectives and developments; global change: causes, modeling and economic issues; the GMES

  14. The internationalization of the technological activities in the energy industries; L'internationalisation des activites technologiques dans les industries energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, B [Institut d' Economie et de Politique de l' Energie - IEPE-CNRS/ Universite Pierre Mendes-France, 38 - Grenoble (France); Jacquier-Roux, V [Institut de Recherche Economique sur la Production et le Developpement -IREPD, 38 - Grenoble (France)

    2001-06-01

    This analysis of the technological internationalization factors is defined in five chapters. The first chapter deals with the evolutionist representation of the internationalization process of the technological activities of the firms. The chapter two is an historical synthesis from 1985 to 2000, of the industrial dynamics and of the technological strategies of the petroleum and electric power industries. The chapter three details the empirical method used to verify the hypothesis. Chapter four exposes the data analysis results of the patents of the sampled firms. The last chapter is devoted to the results interpretation. (A.L.B.)

  15. Lightweight, Durable Army Antennas Using Carbon Nanotube Technology

    Science.gov (United States)

    2013-01-01

    may be adjusted by collecting the sheet on a revolving substrate conveyor belt (e.g., Teflon belt ), as shown in figure 15 (12). SEM images of the... designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an official endorsement or approval of the use...CNT) materials to produce lightweight, flexible, and durable alternatives to existing and future Army antenna designs is explored through fabrication

  16. French memorandum for revitalizing European energy policy with a view to sustainable development; Memorandum de la France pour une relance de la politique energetique europeenne dans une perspective de developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-01-15

    During the European Council at Hampton Court (October 2005), the European Heads of State or Government expressed the desire to see Europe's energy policy revitalized, given the new and increasingly tough challenges facing Europe and the world today, in particular concerning energy security on the one hand, and the need to combat climate change on the other. These guidelines were confirmed and clarified by the European Council on 15 and 16 December 2005, which particularly 'stressed the importance of an integrated approach to climate change, energy and competitiveness objectives, and underlined the fact that strategies to invest in cleaner and more sustainable energy, both within the EU and more widely, can support a range of policy objectives, including energy security, competitiveness, employment, air quality and reduced greenhouse gas emissions'. To make a contribution to the debate around these strategic questions ongoing in many arenas, and pending the publication of new documents announced by the Commission and the Presidency of the Council concerning European energy policy, France wishes to make known its point of view and propose areas for action in order to promote solutions to encourage the creation of safer and more sustainable energy systems both within the EU and with our partners, which would be accessible to all. This involves: - guaranteeing that the energy we produce, import and consume for our economic and social development remains available and economically accessible to all, both today and in the future; - progressing towards sustainable use of energy in that it must take account of environmental impacts and the depletion of fossil resources; - developing employment by promoting energy efficiency, renewable energies and other low greenhouse gas emitting technologies. After a reminder of the context and stakes (part 1), suggestions are made with regard to policies (part 2) and means, concerning the various types of consumption on

  17. Design and technology parameters influence on durability for heat exchangers tube to tubesheet joints

    Science.gov (United States)

    Ripeanu, R. G.

    2017-02-01

    The main failures of heat exchangers are: corrosion of tubes and jacket, tubes blockage and failures of tube to tubesheet joints also by corrosion. The most critical zone is tube to tubesheet joints. Depending on types of tube to tubesheet joints, in order to better respect conditions of tension and compression, this paper analyses the tubesheet holes shapes, smooth and with a grove, on corrosion behavior. In the case of welding tubes with tubesheet, welding parameters modify corrosion behavior. Were realized welded joints by three welding regimes and tested at corrosion in two media, tap water and industrial water. Were tested also samples made of smooth tubes, finned tubes and tubes coated with a passive product as applied by a heat exchanger manufacturer. For all samples, the roughness parameters were measured, before and after the corrosion tests. The obtained corrosion rates show that stress values and their distribution along the joint modify the corrosion behavior. The optimum welding parameters were established in order to increase the joint durability. The paper has shown that passive product used is not proper chosen and the technology of obtaining rolled thread pipes diminishes tubes’ durability by increasing the corrosion rate.

  18. The internationalization of the technological activities in the energy industries; L'internationalisation des activites technologiques dans les industries energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, B. [Institut d' Economie et de Politique de l' Energie - IEPE-CNRS/ Universite Pierre Mendes-France, 38 - Grenoble (France); Jacquier-Roux, V. [Institut de Recherche Economique sur la Production et le Developpement -IREPD, 38 - Grenoble (France)

    2001-06-01

    This analysis of the technological internationalization factors is defined in five chapters. The first chapter deals with the evolutionist representation of the internationalization process of the technological activities of the firms. The chapter two is an historical synthesis from 1985 to 2000, of the industrial dynamics and of the technological strategies of the petroleum and electric power industries. The chapter three details the empirical method used to verify the hypothesis. Chapter four exposes the data analysis results of the patents of the sampled firms. The last chapter is devoted to the results interpretation. (A.L.B.)

  19. Energy perspectives of France by 2020-2050. Technological evolutions; Perspectives energetiques de la France a l'horizon 2020-2050. Evolutions technologiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-09-15

    The different technologies in phase of research and development and concerning the energy production or storage, are examined and presented in function of their probability of emergence at the industrial level: the projects which are going to appear in planed time on the market, the projects based on known technologies which should appear but at non predicted date and the possible projects but based on a new technology. The different type of energy, from the fossil fuels to the renewable energies are concerned. (A.L.B.)

  20. Energy perspectives of France by 2020-2050. Technological evolutions; Perspectives energetiques de la France a l'horizon 2020-2050. Evolutions technologiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-09-15

    The different technologies in phase of research and development and concerning the energy production or storage, are examined and presented in function of their probability of emergence at the industrial level: the projects which are going to appear in planed time on the market, the projects based on known technologies which should appear but at non predicted date and the possible projects but based on a new technology. The different type of energy, from the fossil fuels to the renewable energies are concerned. (A.L.B.)

  1. The quest for durable lesions in catheter ablation of atrial fibrillation - technological advances in radiofrequency catheters and balloon devices.

    Science.gov (United States)

    Maurer, Tilman; Kuck, Karl-Heinz

    2017-08-01

    Atrial fibrillation is the most common cardiac arrhythmia and represents a growing clinical, social and economic challenge. Catheter ablation for symptomatic atrial fibrillation has evolved from an experimental procedure into a widespread therapy and offers a safe and effective treatment option. A prerequisite for durable PVI are transmural and contiguous circumferential lesions around the pulmonary veins. However, electrical reconnection of initially isolated pulmonary veins remains a primary concern and is a dominant factor for arrhythmia recurrence during long-term follow up. Areas covered: This article discusses the physiology of lesion formation using radiofrequency-, cryo- or laser- energy for pulmonary vein isolation and provides a detailed review of recent technological advancements in the field of radiofrequency catheters and balloon devices. Finally, future directions and upcoming developments for the interventional treatment of atrial fibrillation are discussed. Expert commentary: Durable conduction block across deployed myocardial lesions is mandatory not only for PVI but for any other cardiac ablation strategy as well. A major improvement urgently expected is the intraprocedural real-time distinction of durable lesions from interposed gaps with only transiently impaired electrical conduction. Furthermore, a simplification of ablation tools used for PVI is required to reduce the high technical complexity of the procedure.

  2. Development of advanced pump impeller fabrication technology using direct nano- ceramic dispersion casting for long time erosion durability

    International Nuclear Information System (INIS)

    Rhee, Chang Kyu; Lee, Min Ku; Park, Jin Ju

    2008-09-01

    Many components of pump impeller of nuclear power plants is generally made of stainless steel and Al-bronze with superior corrosion resistance to sea water. However, they should be replaced by one- to five-year period because of material damage by a very big cavitation impact load, even though their designed durability is twenty years. Especially, in case of Young-Gwang nuclear power plant located at the west sea, damage of components of pump impeller is so critical due to the additional damage by solid particle erosion and hence their replacement period is very short as several months compared to other nuclear power plants. In addition, it is very difficult to maintain and repair the components of pump impeller since there is no database on the exact durability and damage mechanism. Therefore, in this study, fabrication technology of new advanced materials modified by dispersion of nano-carbide and -oxide ceramics into the matrix is developed first. Secondly, technology to estimate the dynamic damage by solid particle erosion is established and hence applied to the prediction of the service life of the components of pump impeller

  3. Optimisation structurelle des systemes energetiques

    Science.gov (United States)

    Saloux, Etienne

    The development of renewable energies is growing over the last decade to face environmental issues due to the world fossil fuel consumption increase. These energies are highly involved in houses and commercial buildings and numerous systems have been proposed to meet their energy demand. Therefore, improving both efficiency and use of systems, i.e. improving energy management, appears essential to limit the ecological footprint of humanity on the planet. However, system integration yields a very complex problem to be solved due to the large number of units and theirs technology, size, working conditions and interconnections. This situation highlights the lack of systematic analysis for comparing integrated system performance and for correctly pointing out their potential. As a result, the objective of this thesis is to develop and to present such a method, in other words the structural optimization of energy systems. It will be helpful to choose the optimal equipment by identifying all the possibilities of system arrangements and for comparing their performance. Combinations have then been subjected to environmental (climate), structural (available area) and economical constrains while assessment criteria have considered both energy, economic and ecological aspects. For that reason, as well as energy and economic analyses, the exergy concept has also been applied to the equipment. Nevertheless, the high degree of complexity of integrated systems and the tedious numerical calculations make the resolution by using standard software very difficult. It is clear that the whole optimization project would be considerable and the aim is to develop models and optimization tools. First of all, an exhaustive review of energy equipment including photovoltaic panels, solar collectors, heat pumps and thermal energy storage systems, has been performed. Afterwards, energy and exergy models have been developed and tested for two specific energy scenarios: a) a solar assisted heat

  4. An influence of technological contraflexure of crane bridges on its durability

    Directory of Open Access Journals (Sweden)

    Artur BLUM

    2010-01-01

    Full Text Available Standard requirements till 1996 year during bridge crane manufacturing demanded a positive technological contraflexure. As a result of this process were implemented technological compressive stress into tensile zone from inertial and operational loads and tensile stress into compressive zone. This way there were redistributed resultant stress which have increased fatigue strength of exploited crane bridges. Actually valid standard PN-ISO 7363 has removed this obligatory requirement. Its use depends of crane buyer demands. Reduction of initial positive deflection can be seen after few years of crane operations. It is a case of girders permanent deflections increment. Article presents method of technological prestressing of bridge girders with its practical application to obtain positive contrafexure.

  5. Concrete durability

    OpenAIRE

    Gaspar Tébar, Demetrio

    1991-01-01

    The evidence that the concrete is not a material for ever was noticed from the beginning of its industrial use. In the present work, the author describes the studies carried out during the last century and the early ages of the present one, mainly devoted to the study of the durability in sea water. At the present days, and in spite of the numerous papers published from then, the study of the concrete durability continues focusing the research priorities and economical resources of rese...

  6. Assessment of Durable SiC JFET Technology for +600 C to -125 C Integrated Circuit Operation

    Science.gov (United States)

    Neudeck, P. G.; Krasowski, M. J.; Prokop, N. F.

    2011-01-01

    Electrical characteristics and circuit design considerations for prototype 6H-SiC JFET integrated circuits (ICs) operating over the broad temperature range of -125 C to +600 C are described. Strategic implementation of circuits with transistors and resistors in the same 6H-SiC n-channel layer enabled ICs with nearly temperature-independent functionality to be achieved. The frequency performance of the circuits declined at temperatures increasingly below or above room temperature, roughly corresponding to the change in 6H-SiC n-channel resistance arising from incomplete carrier ionization at low temperature and decreased electron mobility at high temperature. In addition to very broad temperature functionality, these simple digital and analog demonstration integrated circuits successfully operated with little change in functional characteristics over the course of thousands of hours at 500 C before experiencing interconnect-related failures. With appropriate further development, these initial results establish a new technology foundation for realizing durable 500 C ICs for combustion engine sensing and control, deep-well drilling, and other harsh-environment applications.

  7. A microencapsulation process of liquid mercury by sulfur polymer stabilization/solidification technology. Part II: Durability of materials

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Delgado, A.; Guerrero, A.; Lopez, F. A.; Perez, C.; Alguacil, F. J.

    2012-11-01

    Under the European LIFE Program a microencapsulation process was developed for liquid mercury using Sulfur Polymer Stabilization/Solidification (SPSS) technology, obtaining a stable concrete-like sulfur matrix that allows the immobilization of mercury for long-term storage. The process description and characterization of the materials obtained were detailed in Part I. The present document, Part II, reports the results of different tests carried out to determine the durability of Hg-S concrete samples with very high mercury content (up to 30 % w/w). Different UNE and RILEM standard test methods were applied, such as capillary water absorption, low pressure water permeability, alkali/acid resistance, salt mist aging, freeze-thaw resistance and fire performance. The samples exhibited no capillarity and their resistance in both alkaline and acid media was very high. They also showed good resistance to very aggressive environments such as spray salt mist, freeze-thaw and dry-wet. The fire hazard of samples at low heat output was negligible. (Author)

  8. Estimation of the energy needs; Estimation des besoins energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Ailleret, [Electricite de France (EDF), Dir. General des Etudes de Recherches, 75 - Paris (France)

    1955-07-01

    The present report draws up the balance on the present and estimable energy consumption for the next twenty years. The present energy comes mainly of the consumption of coal, oil products and essentially hydraulic electric energy. the market development comes essentially of the development the industrial activity and of new applications tributary of the cost and the distribution of the electric energy. To this effect, the atomic energy offers good industrial perspectives in complement of the energy present resources in order to answer the new needs. (M.B.) [French] Le present rapport dresse le bilan sur la consommation energetique actuelle et previsionnelle pour les vingt prochaines annees. L'energie actuelle provient principalement consommation de charbon, de produits petroliers et d'energie electrique essentiellement hydraulique. l'evolution du marche provient essentielement du developpement l'activite industriel et de nouvelles applications tributaire du cout et de la distribution de l'energie electrique. A cet effet, l'energie atomique offre de bonne perspectives industrielles en complement des sources actuelles energetiques afin de repondre aux nouveaux besoins. (M.B.)

  9. Experimental Durability Testing of 4H SiC JFET Integrated Circuit Technology at 727 C

    Science.gov (United States)

    Spry, David; Neudeck, Phil; Chen, Liangyu; Chang, Carl; Lukco, Dorothy; Beheim, Glenn M

    2016-01-01

    We have reported SiC integrated circuits (IC's) with two levels of metal interconnect that have demonstrated prolonged operation for thousands of hours at their intended peak ambient operational temperature of 500 C [1, 2]. However, it is recognized that testing of semiconductor microelectronics at temperatures above their designed operating envelope is vital to qualification. Towards this end, we previously reported operation of a 4H-SiC JFET IC ring oscillator on an initial fast thermal ramp test through 727 C [3]. However, this thermal ramp was not ended until a peak temperature of 880 C (well beyond failure) was attained. Further experiments are necessary to better understand failure mechanisms and upper temperature limit of this extreme-temperature capable 4H-SiC IC technology. Here we report on additional experimental testing of custom-packaged 4H-SiC JFET IC devices at temperatures above 500 C. In one test, the temperature was ramped and then held at 727 C, and the devices were periodically measured until electrical failure was observed. A 4H-SiC JFET on this chip electrically functioned with little change for around 25 hours at 727 C before rapid increases in device resistance caused failure. In a second test, devices from our next generation 4H-SiC JFET ICs were ramped up and then held at 700 C (which is below the maximum deposition temperature of the dielectrics). Three ring oscillators functioned for 8 hours at this temperature before degradation. In a third experiment, an alternative die attach of gold paste and package lid was used, and logic circuit operation was demonstrated for 143.5 hours at 700 C.

  10. Les reseaux de politique publique comme facteur d'influence du choix des instruments de politique energetique canadienne a des fins environnementales de 1993 a nos jours

    Science.gov (United States)

    Fathy El Dessouky, Naglaa

    Au cours de la derniere decennie, les modes de la gouvernance ont pris place dans un contexte totalement different de celui qu'ils avaient auparavant. Les gouvernements modernes se rendent compte qu'ils perdent de plus en plus leur capacite a elaborer et a gerer les changements d'une maniere autonome. Ainsi, les fonctions et les activites traditionnellement accomplies exclusivement par le gouvernement engagent de nos jours une gamme d'acteurs etatiques et non etatiques. A l'encontre du concept traditionnel de l'Etat controleur, la gouvernance contemporaine est ainsi devenue moins une question d'offre de service et davantage une gestion indirecte des reseaux de politique publique. Dans cette entreprise, les gouvernements contemporains, cherchant plus d'information, de soutien et de legitimite en matiere de formulation des decisions, ont besoin d'etablir des relations avec les divers groupes d'interet qui, a leur tour, voulaient plus de promotion et de protection en faveur de leurs interets a travers leur implication au processus de l'elaboration et de la mise en oeuvre des politiques publiques. Ainsi, l'approche des reseaux de politique publique represente aujourd'hui un courant considerable au sein du champ d'analyse des politiques publiques. Toutefois, les preoccupations des chercheurs pour cette approche, dans le domaine des politiques energetiques a des fins environnementales, semblent recentes, et les etudes realisees sont encore trop peu nombreuses. Au Canada, au debut des annees 1990, le gouvernement ainsi que plusieurs groupes d'interets, des differents secteurs energetique, industriel et environnemental, ont commence a intensifier leurs efforts pour s'attaquer au probleme du changement climatique d'origine energetique, genere surtout par le secteur de l'industrie. Au cours de la derniere decennie, la question touchant plutot le sujet du developpement energetique durable represente le plus important domaine des politiques publiques ayant surgi recemment dans

  11. Decoration and durability

    DEFF Research Database (Denmark)

    Riisberg, Vibeke; Munch, Anders V.

    2015-01-01

    Throughout the scales of design there has been an exploding interest in the ornament that seems to be fuelled by different kinds of digital technology and media from CAD to digital printing in both 2D and 3D. In architecture and industrial design, it is discussed as a “return of ornament” because...... from fashion and tableware to archi- tecture and link ornamentation to the aesthetics of durability....

  12. A microencapsulation process of liquid mercury by sulfur polymer stabilization/solidification technology. Part II: Durability of materials

    Directory of Open Access Journals (Sweden)

    López-Delgado, A.

    2012-02-01

    Full Text Available Under the European LIFE Program a microencapsulation process was developed for liquid mercury using Sulfur Polymer Stabilization/Solidification (SPSS technology, obtaining a stable concrete-like sulfur matrix that allows the immobilization of mercury for long-term storage. The process description and characterization of the materials obtained were detailed in Part I. The present document, Part II, reports the results of different tests carried out to determine the durability of Hg-S concrete samples with very high mercury content (up to 30 % w/w. Different UNE and RILEM standard test methods were applied, such as capillary water absorption, low pressure water permeability, alkali/acid resistance, salt mist aging, freeze-thaw resistance and fire performance. The samples exhibited no capillarity and their resistance in both alkaline and acid media was very high. They also showed good resistance to very aggressive environments such as spray salt mist, freeze-thaw and dry-wet. The fire hazard of samples at low heat output was negligible.

    Dentro del Programa Europeo LIFE, se ha desarrollado un proceso de microencapsulación de mercurio liquido, utilizando la tecnología de estabilización/solidificación con azufre polimérico (SPSS. Como resultado se ha obtenido un material estable tipo concreto que permite la inmovilización de mercurio y su almacenamiento a largo plazo. La descripción del proceso y la caracterización de los materiales obtenidos, denominados concretos Hg-S, se detallan en la Parte I. El presente trabajo, Parte II, incluye los resultados de los diferentes ensayos realizados para determinar la durabilidad de las muestras de concreto Hg-S con un contenido de mercurio de hasta el 30 %. Se han utilizado diferentes métodos de ensayo estándar, UNE y RILEM, para determinar propiedades como la absorción de agua por capilaridad, la permeabilidad de agua a baja presión, la resistencia a álcali y ácido, el comportamiento en

  13. Concrete durability

    Directory of Open Access Journals (Sweden)

    Gaspar Tébar, Demetrio

    1991-03-01

    Full Text Available The evidence that the concrete is not a material for ever was noticed from the beginning of its industrial use. In the present work, the author describes the studies carried out during the last century and the early ages of the present one, mainly devoted to the study of the durability in sea water. At the present days, and in spite of the numerous papers published from then, the study of the concrete durability continues focusing the research priorities and economical resources of researchers and industries related with this material. Moreover, the new laboratory techniques are allowing to understand old problems and even to open again the discussion on reaction mechanisms which were believed to be completely understood. The article finalizes with a brief description of the numerous studies carried out at the Institute Eduardo Torroja on concrete durability, mainly those related with the resistance against gypsum attack (so abundant in our country land and against sea water attack.

    La realidad de que el hormigón no es un material eterno y es susceptible de sufrir ataques por agentes químicos, fue constatada desde el comienzo mismo de su uso industrial. En el presente trabajo el autor enumera los estudios realizados el siglo pasado y a comienzos del presente sobre la durabilidad del hormigón en agua de mar. En la actualidad y a pesar de los numerosos trabajos desarrollados desde entonces, el estudio de la durabilidad del hormigón sigue centrando la atención prioritaria y los recursos económicos de los investigadores e industrias relacionadas con este material. Además las nuevas técnicas de estudio están permitiendo comprender antiguos problemas e incluso reabrir la discusión sobre mecanismos de reacción que se creían completamente explicados. Finaliza el artículo con una descripción somera de los múltiples trabajos realizados en el Instituto Eduardo Torreja sobre la materia, en especial los estudios realizados sobre

  14. Which sustainable energy policy in France?; Quelle politique energetique durable en France?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Concurrently to the National Debate on the energies, a real debate has been proposed by seven associations of the environment protection and improvement. This debate, international, wonders on the energy choices in France. Presentations of the interveners and working documents are provided on the following topics: energy choices for the economic development, renewable energies, the possibilities and the development of the solar energy in France, the economic interest of the cogeneration, quick overview of the wind energy in France, energy production data, the transport and the greenhouse effect, the sustainable development and the energy policy and the local governments. (A.L.B.)

  15. Decoration and Durability

    DEFF Research Database (Denmark)

    Riisberg, Vibeke; Munch, Anders V.

    2015-01-01

    Throughout the scales of design there has been an exploding interest in the ornament that seems to be fuelled by different kinds of digital technology and media from CAD to digital printing in both 2D and 3D. In architecture and industrial design it is discussed as a Return of ornament, because...... appropriate or not. This leads us to suggest an array of parameters that points out different situations and meanings of ornamentation: Product categories, Durability of materials, Styles, Aesthetic experience, Emotional attachment and Historical references. We discuss these parameters in cases from fashion...

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

    Science.gov (United States)

    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

  17. Presentation of the 10. European Event on Technology: technologies for a sustainable development; Presentation des 10. Entretiens Europeens de la Technologie: technologies pour un developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-11-01

    The European Event on Technology (EET), is a major meeting on technologies, their evolution and their industrial and social implications. In less than a decade, sustainable development has become both an economic and a political priority. It was urgent and legitimate that those who are the mainsprings should take hold of the subject and give it technological content, estimate its costs and define clear timetables. The debates consist of: plenary sessions on environmental, social and economic stakes of sustainable development and the challenges for, and commitment of engineers, managers and politicians with respect to these goals; and workshops, which provide an overview on recently acquired or upcoming technologies developed by sector. These proceedings present several technologies of interest for the energy and environment sectors: Energy efficiency of buildings: towards energy autonomy; superconductors enable in new millennium for electric power industry; advanced gas micro-turbine-driven generator technology; environmental and technical challenges of an offshore wind farm; future nuclear energy system; transports and propulsion systems: modelling combustion in engines: progress and prospects for reducing emissions; on-board computers: reduction in consumption and emissions of engine-transmission units for vehicles; polymer-lithium batteries: perspectives for zero-emission traction; hybrid vehicles and energy/environmental optimization: paths and opportunities; fuel cells and zero-emission: perspectives and developments; urban goods transport: towards a drop in congestion and nuisance; new hybrid propulsion for buses: energy/environmental optimization; Tram-train: city-suburbs concept without transshipment; safety: computerization in controlling nuclear power plant processes (EPR architecture); refractory materials: a key factor for the increase in aero-turbo-engines output; the contribution of waste processing to the production of greenhouse gases; waste as a

  18. Concrete aggregate durability study.

    Science.gov (United States)

    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...

  19. Optimisation multi-objectif des systemes energetiques

    Science.gov (United States)

    Dipama, Jean

    The increasing demand of energy and the environmental concerns related to greenhouse gas emissions lead to more and more private or public utilities to turn to nuclear energy as an alternative for the future. Nuclear power plants are then called to experience large expansion in the coming years. Improved technologies will then be put in place to support the development of these plants. This thesis considers the optimization of the thermodynamic cycle of the secondary loop of Gentilly-2 nuclear power plant in terms of output power and thermal efficiency. In this thesis, investigations are carried out to determine the optimal operating conditions of steam power cycles by the judicious use of the combination of steam extraction at the different stages of the turbines. Whether it is the case of superheating or regeneration, we are confronted in all cases to an optimization problem involving two conflicting objectives, as increasing the efficiency imply the decrease of mechanical work and vice versa. Solving this kind of problem does not lead to unique solution, but to a set of solutions that are tradeoffs between the conflicting objectives. To search all of these solutions, called Pareto optimal solutions, the use of an appropriate optimization algorithm is required. Before starting the optimization of the secondary loop, we developed a thermodynamic model of the secondary loop which includes models for the main thermal components (e.g., turbine, moisture separator-superheater, condenser, feedwater heater and deaerator). This model is used to calculate the thermodynamic state of the steam and water at the different points of the installation. The thermodynamic model has been developed with Matlab and validated by comparing its predictions with the operating data provided by the engineers of the power plant. The optimizer developed in VBA (Visual Basic for Applications) uses an optimization algorithm based on the principle of genetic algorithms, a stochastic

  20. Emissions Performance and In-Use Durability of Retrofit After-Treatment Technologies (SAE Paper 2014-01-2347)

    Science.gov (United States)

    In-use testing of diesel emissoin control technologies is an integral component of EPA's verification program. EPA identified and recovered a variety of retrofit devices, installed on heavy-duty vehicles for test.

  1. The influencing factors of energy poverty in rural Cameroon; Les determinants de la pauvrete energetique en milieu rural au Cameroun

    Energy Technology Data Exchange (ETDEWEB)

    Kamdem, Maxime; Edzengte, Joseph

    2010-09-15

    The objective of this study is to assess the influencing factors of energy poverty in rural Cameroon. The method used is in two stages: the first stage is a statistical analysis that has allowed to determine the level of energy poverty in rural areas, which is 7.5%. The second stage assesses the influencing factors of this poverty type. The results show that the revenue impacts on energy poverty, as well as the size of the household, in which the arrival of an additional person increases by 1.16% the chances that the household will suffer from energy poverty. [French] L'objectif de cette etude est d'evaluer les determinants de la pauvrete energetique en milieu rural au Cameroun. La methode mise en oeuvre procede en deux etapes : la premiere est une analyse statistique qui a permis de determiner le seuil de pauvrete energetique en milieu rural, qui se situe a 7,5%. La deuxieme etape evalue les determinants de ce type de pauvrete. Les resultats indiquent que le revenu explique la pauvrete energetique, de meme que la taille du menage dont l'arrivee d'une personne supplementaire accroit de 1,16% les chances de ce menage d'etre pauvre sur le plan energetique.

  2. Experimental Durability Testing of 4H SiC JFET Integrated Circuit Technology at 727 Degrees Centigrade

    Science.gov (United States)

    Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Chang, Carl W.; Lukco, Dorothy; Beheim, Glenn M.

    2016-01-01

    We have reported SiC integrated circuits (ICs) with two levels of metal interconnect that have demonstrated prolonged operation for thousands of hours at their intended peak ambient operational temperature of 500 degrees Centigrade. However, it is recognized that testing of semiconductor microelectronics at temperatures above their designed operating envelope is vital to qualification. Towards this end, we previously reported operation of a 4H-SiC JFET IC ring oscillator on an initial fast thermal ramp test through 727 degrees Centigrade. However, this thermal ramp was not ended until a peak temperature of 880 degrees Centigrade (well beyond failure) was attained. Further experiments are necessary to better understand failure mechanisms and upper temperature limit of this extreme-temperature capable 4H-SiC IC technology.Here we report on additional experimental testing of custom-packaged 4H-SiC JFET IC devices at temperatures above 500 degrees Centigrade. In one test, the temperature was ramped and then held at 727 degrees Centigrade, and the devices were periodically measured until electrical failure was observed. A 4H-SiC JFET on this chip electrically functioned with little change for around 25 hours at 727 degrees Centigrade before rapid increases in device resistance caused failure. In a second test, devices from our next generation 4H-SiC JFET ICs were ramped up and then held at 700 degrees Centigrade (which is below the maximum deposition temperature of the dielectrics). Three ring oscillators functioned for 8 hours at this temperature before degradation. In a third experiment, an alternative die attach of gold paste and package lid was used, and logic circuit operation was demonstrated for 143.5 hours at 700 degrees Centigrade.

  3. ICP experiments more durable pavements

    International Nuclear Information System (INIS)

    Carta Petrolera

    1994-01-01

    A new asphalts technology that will make more durable the pavement in the highways and roads of the cities of Colombia investigates the Colombian Institute of the Petroleum ICP. The project that will have important incidence in the solution of one of the main problems in the roads of cities like Bogota, is only one of the 35 investigation programs and application of new technologies that with relationship to the sector of the hydrocarbons and its influence branches the ICP advances. The investigation looks for to elevate the current average of useful life of the pavements, with that it would be reached a standard that has the developed countries in this field

  4. A sustainable local energy policy. Into a renewable millennium; Politique energetique locale durable: vers un millenaire renouvelable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    Renewable energy sources only contribute to a marginal extent to the energy balance of most European towns and cities. Many of them, however, have set ambitious targets for 2010 and have developed programmes to this end. During the seminar organised by Energie-Cites in Verona, around 200 people representing towns and cities from over 20 countries were able to present and exchange experience in all areas related to renewable energy: on practical projects and on their impact on local development, urban planning and employment. It is in towns and cities that energy consumption is the highest and that heat networks working on biomass and buildings equipped with thermal and photovoltaic solar collectors are to be found. Renewable energy has been increasingly gaining ground in urban areas over the last few years for the following reasons: cities are responsible for 80% of total energy consumption and therefore concentrate most of energy needs; the existence of heat networks in densely-populated areas is an incentive to use resources such as biomass or geothermal energy for producing heat or in CHP units; biogas from sewage plants or resulting from the biological treatment of waste is also an urban product; thermal solar systems can often be installed on roof tops to satisfy part of the needs in terms of hot water or space heating and the same applies to photovoltaic solar energy; even wind energy can be promoted, either directly or through green buying procedures. Sustainable urban development depends on the implementation of a sustainable local energy policy based on the involvement of local authorities in improving energy efficiency and developing the use of renewable energy sources in municipal energy supplies. Local development, employment, social integration, the quality of the air - all being major sources of concern for local decision-makers - are stimulated by the promotion of renewable energy sources. Cities are, on account of their size, capable of defining local promotional policies. Many of them, via their technical departments, municipal energy companies, local energy agencies, promotional resources etc. have the operational means to take action. These proceedings comprise: a presentation of three examples of municipal practice, two round tables about some communities 100% supplied with renewable energy, and about the liberalization of energy markets and the development of renewable energy, and 8 working groups about: renewable energy sources, local development, employment and social issues, renewable energy sources and urban planning, financing renewable energy policies, programmes for promoting renewable energy sources at local level, solar thermal, biomass and biogas, wind energy, and photovoltaic. (J.S.)

  5. Durability of critical infrastructures

    OpenAIRE

    Raluca Pascu; Ramiro Sofronie

    2011-01-01

    The paper deals with those infrastructures by which world society, under the pressure ofdemographic explosion, self-survives. The main threatening comes not from terrorist attacks, but fromthe great natural catastrophes and global climate change. It’s not for the first time in history when suchmeasures of self-protection are built up. First objective of this paper is to present the background fordurability analysis. Then, with the aid of these mathematical tools the absolute durability of thr...

  6. COMPARAISON ENERGETIQUE ET EXERGETIQUE DE SYSTEMES DE DESSALEMENT

    OpenAIRE

    Byrne , Paul; Diaby , Ahmadou ,; Sarray , Yemna; Ghoubali , Redouane; Loulergue , Patrick; Balannec , Béatrice; Maré , Thierry; Sow , Ousmane

    2016-01-01

    International audience; Dans certaines zones du monde, l'eau potable n'est pas une ressource abondante et est produite par des systèmes de dessalement. Par ailleurs, les ressources en énergie doivent être rationalisées. Les performances des systèmes de dessalement sont difficiles à comparer car les technologies peuvent être très différentes et faire appel à des procédés thermiques, électriques ou mécaniques, membranaires ou non. L'exergie correspond à l'énergie mécanique potentiellement produ...

  7. Durability Evaluation of Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Akihiko; Ogata, Masafumi; Nakauchi, Masahiko; Asahara, Tetsuo; Herai, Toshiki; Nishikawa, Yoichi

    2006-06-01

    It is one of the most essential things to verify the durability of devices and components of JR-Maglev system to realize the system into the future inauguration. Since the load requirements were insufficient in terms of the durability under vibrations under mere running tests carried out on Yamanashi Maglev Test Line hereinafter referred to YMTL, we have developed supplemental method with bench tests. Superconducting magnets hereinafter referred to SCM as used in the experimental running for the last seven years on the YMTL were brought to Kunitachi Technical Research Institute; we conducted tests to evaluate the durability of SCM up to a period of the service life in commercial use. The test results have indicated that no irregularity in each part of SCM proving that SCM are sufficiently durable for the practical application.

  8. Durability Evaluation of Superconducting Magnets

    International Nuclear Information System (INIS)

    Inoue, Akihiko; Ogata, Masafumi; Nakauchi, Masahiko; Asahara, Tetsuo; Herai, Toshiki; Nishikawa, Yoichi

    2006-01-01

    It is one of the most essential things to verify the durability of devices and components of JR-Maglev system to realize the system into the future inauguration. Since the load requirements were insufficient in terms of the durability under vibrations under mere running tests carried out on Yamanashi Maglev Test Line hereinafter referred to YMTL, we have developed supplemental method with bench tests. Superconducting magnets hereinafter referred to SCM as used in the experimental running for the last seven years on the YMTL were brought to Kunitachi Technical Research Institute; we conducted tests to evaluate the durability of SCM up to a period of the service life in commercial use. The test results have indicated that no irregularity in each part of SCM proving that SCM are sufficiently durable for the practical application

  9. DURABILITY TESTING OF FLUIDIZED BED STEAM REFORMER (FBSR) WASTE FORMS

    International Nuclear Information System (INIS)

    Jantzen, C

    2006-01-01

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of high sodium aqueous radioactive wastes. The addition of clay and a catalyst as co-reactants converts high sodium aqueous low activity wastes (LAW) such as those existing at the Hanford and Idaho DOE sites to a granular ''mineralized'' waste form that may be made into a monolith form if necessary. Simulant Hanford and Idaho high sodium wastes were processed in a pilot scale FBSR at Science Applications International Corporation (SAIC) Science and Technology Applications Research (STAR) facility in Idaho Falls, ID. Granular mineral waste forms were made from (1) a basic Hanford Envelope A low-activity waste (LAW) simulant and (2) an acidic INL simulant commonly referred to as sodium-bearing waste (SBW). The FBSR waste forms were characterized and the durability tested via ASTM C1285 (Product Consistency Test), the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP), and the Single Pass Flow Through (SPFT) test. The durability of the FBSR waste form products was tested in order to compare the measured durability to previous FBSR waste form testing on Hanford Envelope C waste forms that were made by THOR Treatment Technologies (TTT) and to compare the FBSR durability to vitreous LAW waste forms, specifically the Hanford low activity waste (LAW) glass known as the Low-activity Reference Material (LRM). The durability of the FBSR waste form is comparable to that of the LRM glass for the test responses studied

  10. Barriers to Systemic, Effective, and Sustainable Technology Use in High School Classrooms / Obstacles à l’utilisation systémique, efficace et durable de la technologie dans les salles de classe des écoles secondaires

    Directory of Open Access Journals (Sweden)

    Jason Scott Daniels

    2014-01-01

    Full Text Available The purpose of the Technology and High School Success (THSS initiative was to encourage innovative strategies focused on improving provincial high school completion rates, using technology and student-centered learning to engage student interest. The primary purpose of this paper is to report on barriers that impede systemic, effective and sustainable technology integration within schools. Even with teacher and administrative support and commitment for THSS, evaluative research indicated minimal change in system capacity as a result of the initiative. Three primary barriers to program sustainability were: 1 schools and school districts did not leverage the opportunity to revisit their existing vision(s, 2 schools and school districts did not use data to make changes, and 3 limited access to technology. Le but de l’initiative « Technology and High School Success (THSS » était d'encourager des stratégies novatrices visant à améliorer le taux d’achèvement des études secondaires dans la province de l’Alberta en utilisant la technologie et un apprentissage centré sur l'élève afin de susciter l'intérêt des élèves. L'objectif principal de cet article est de rendre compte des obstacles entravant l'intégration systémique, efficace et durable de la technologie dans les écoles. La recherche évaluative a révélé des changements minimes dans la capacité systémique à la suite de l'initiative, et ce, malgré l’appui et l’engagement des enseignants et des administrateurs envers le THSS. Les trois obstacles principaux à la viabilité du programme sont les suivants: 1 les écoles et les districts scolaires n'ont pas profité de l’occasion pour revoir leur(s vision(s, 2 les écoles et les districts scolaires n'ont pas utilisé les données pour effectuer des changements, et 3 l'accès limité à la technologie.

  11. Analysis of the energy efficiency of the transport system in Algeria; Analyse de l'efficacite energetique du systeme de transport en Algerie

    Energy Technology Data Exchange (ETDEWEB)

    Hamdani, Sid Ahmed

    2010-09-15

    The objective of this communication is analyze the energy efficiency of the transport system in Algeria and to show the areas of possible rationalization in this sector. Our approach is to analyze the existing configuration of the sector and its impact on energy consumption, by developing a sectional model Bottom Up, where the transport park has been modified by the means used. We have shown that the potential to improve the transport system energy efficiency is important and have recommended some options aimed at the sector organisation and aimed at increasing the relative part of transport systems to make it more energy efficient. [French] L'objectif de cette communication est d'analyser l'efficacite energetique du systeme de transport algerien et de montrer les gisements de rationalisation possibles dans ce secteur. Notre approche consiste a analyser la configuration existante du secteur et son impact sur la consommation d'energie, en elaborant un modele sectoriel Bottom Up, ou le parc de transport a ete desagrege par moyen utilise. Nous avons montre que le potentiel d'amelioration de la performance energetique du systeme de transport est important et avons recommande quelques options ciblant l'organisation du secteur et visant a augmenter la part relative de moyens de transport plus efficace energetiquement.

  12. Temperature induced effects on the durability of MR fluids

    International Nuclear Information System (INIS)

    Wiehe, A; Maas, J; Kieburg, C

    2013-01-01

    Although commercial MR fluids exist for quite some time now and the feasibility as well as the advantages of the MR technology have been demonstrated for several applications by a variety of MR actuator prototypes, a sustainable market break-through of brake and clutch applications utilizing the shear mode is still missing. Essential impediments are the marginal knowledge about the durability of the MR technology. To overcome this situation, a long-term measurement system was developed for the durability analysis of MR fluid formulations within a technical relevant scale with respect to the volume of MR fluid and the transmitted torque. The focus of the presented series of measurements is given to the analysis of temperature induced effects on the durability. In this context four different failure indicators can be distinguished, namely an apparent negative viscosity, deviations in torque data obtained from different measurements as well as a pressure increase and a drop in the on-state torque. The measurement data of the present durability experiments indicate a significant dependency of the attainable energy intake density on the temperature. The aim of such durability tests is to establish a reliable data base for the industry to estimate the life-time of MR devices.

  13. Durability of air lime mortar

    DEFF Research Database (Denmark)

    Nielsen, Anders

    2016-01-01

    This contribution deals with the physical and chemical reasons why pure air lime mortars used in masonry of burned bricks exposed to outdoor climate have shown to be durable from the Middle Ages to our days. This sounds strange in modern times where pure air lime mortars are regarded as weak...... materials, which are omitted from standards for new masonry buildings, where use of hydraulic binders is prescribed. The reasons for the durability seam to be two: 1. The old mortars have high lime contents. 2. The carbonation process creates a pore structure with a fine pored outer layer and coarser pores...

  14. The durability and mechanical strenght properties of bamboo in ...

    African Journals Online (AJOL)

    The durability and mechanical strenght properties of bamboo in reinforced concrete. GA Alade, FA Olutoge, AA Alade. Abstract. No Abstract. Journal of Applied Science, Engineering and Technology Vol. 4(2) 2004: 35-40. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  15. Durability of building joint sealants

    Science.gov (United States)

    Christopher C. White; Kar Tean Tan; Donald L. Hunston; R. Sam Williams

    2009-01-01

    Predicting the service life of building joint sealants exposed to service environments in less than real time has been a need of the sealant community for many decades. Despite extensive research efforts to design laboratory accelerated tests to duplicate the failure modes occurring in field exposures, little success has been achieved using conventional durability...

  16. Compositional threshold for Nuclear Waste Glass Durability

    International Nuclear Information System (INIS)

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

    2013-01-01

    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

  17. Durability of fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Hansen, Kurt Kielsgaard

    1996-01-01

    The planned research will indicate, whether fibre reinforced concrete has better or worse durability than normal concrete. Durability specimens will be measured on cracked as well as uncracked specimens. Also the pore structure in the concrete will be characterized.Keywords: Fibre reinforced...... concrete, durability, pore structure, mechanical load...

  18. Durable and Robust Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Knibbe, Ruth; Hauch, Anne

    project had as one of its’ overarching goals to improve durability and robustness of the Danish solid oxide fuel cells. The project focus was on cells and cell components suitable for SOFC operation in the temperature range 600 – 750 °C. The cells developed and/or studied in this project are intended......The solid oxide fuel cell (SOFC) is an attractive technology for the generation of electricity with high efficiency and low emissions. Risø DTU (now DTU Energy Conversion) works closely together with Topsoe Fuel Cell A/S in their effort to bring competitive SOFC systems to the market. This 2-year...... for use within the CHP (Combined Heat and Power) market segment with stationary power plants in the range 1 – 250 kWe in mind. Lowered operation temperature is considered a good way to improve the stack durability since corrosion of the interconnect plates in a stack is lifetime limiting at T > 750 °C...

  19. The hydrogen: a clean and durable energy; L'hydrogene: une energie propre et durable

    Energy Technology Data Exchange (ETDEWEB)

    Alleau, Th. [Association Francaise de l' Hydrogene (France); Nejat Veziroglu, T. [Clean Energy Research Institute, University of Miami (United States); Lequeux, G. [Commission europeenne, DG de la Recherche, Bruxelles (Belgium)

    2000-07-01

    All the scientific experts agree, the hydrogen will be the energy vector of the future. During this conference day on the hydrogen, the authors recalled the actual economic context of the energy policy with the importance of the environmental policy and the decrease of the fossil fuels. The research programs and the attitudes of the France and the other countries facing the hydrogen are also discussed, showing the great interest for this clean and durable energy. They underline the importance of an appropriate government policy, necessary to develop the technology of the hydrogen production, storage and use. (A.L.B.)

  20. Durability of building materials and components

    CERN Document Server

    Delgado, JMPQ

    2013-01-01

    Durability of Building Materials and Components provides a collection of recent research works to contribute to the systematization and dissemination of knowledge related to the long-term performance and durability of construction and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of durability, service life prediction methodologies, the durability approach for historical and old buildings, asset and maintenance management and on the durability of materials, systems and components. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

  1. Chemical durability of silicoborate glasses

    International Nuclear Information System (INIS)

    Nieto, M.I.; Rodriguez, M.A.; Rubio, J.; Fernandez, A.; Oteo, J.L.

    1987-01-01

    A general view of the durability in silicoborate glasses is presented with more emphasis on the etching factors (chemical composition, lattice structure, pH...) the techniques used for this study and the experimental results. Likewise, the research presently developed in this area at the Instituto de Ceramica y Vidrio, CSIC, is related to the applications. Future research in this field is also mentioned. (author) 15 figs

  2. Durable solid oxide electrolysis cells and stacks

    Energy Technology Data Exchange (ETDEWEB)

    Ming Chen

    2010-08-15

    The purpose of this project was to make a substantial contribution to development of a cost competitive electrolysis technology based on solid oxide cells. The strategy was to address what had been identified as the key issues in previous research projects. Accordingly five lines of work were carried out in the here reported project: 1) Cell and stack element testing and post test characterization to identify major degradation mechanisms under electrolysis operation. 2) Development of interconnects and coatings to allow stable electrolysis operation at approx850 deg. C or above. 3) Development of seals with reduced Si emission. 4) Development of durable SOEC cathodes. 5) Modeling. Good progress has been made on several of the planned activities. The outcome and most important achievements of the current project are listed for the five lines of the work. (LN)

  3. Cement replacement materials. Properties, durability, sustainability

    International Nuclear Information System (INIS)

    Ramezanianpour, Ali Akbar

    2014-01-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  4. Energy security, sustainable development, which place for the Nuclear in the world?; Securite energetique, developpement durable, quelle place pour le nucleaire dans le monde?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Facing the increase of the energy consumption and the necessity of the greenhouse gases emission decrease, the authors define the role of the nuclear energy in a policy of a sustainable development. They recall the leadership part of the France in the nuclear research and development and the channel of the nuclear production. The second part of the paper proposes sheets of countries energy policy and nuclear program situation: USA, Europe, Russian, China and India. (A.L.B.)

  5. Estimating Durability of Reinforced Concrete

    Science.gov (United States)

    Varlamov, A. A.; Shapovalov, E. L.; Gavrilov, V. B.

    2017-11-01

    In this article we propose to use the methods of fracture mechanics to evaluate concrete durability. To evaluate concrete crack resistance characteristics of concrete directly in the structure in order to implement the methods of fracture mechanics, we have developed special methods. Various experimental studies have been carried out to determine the crack resistance characteristics and the concrete modulus of elasticity during its operating. A comparison was carried out for the results obtained with the use of the proposed methods and those obtained with the standard methods for determining the concrete crack resistance characteristics.

  6. Durability Improvements Through Degradation Mechanism Studies

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baker, Andrew M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lujan, Roger W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Langlois, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahluwalia, Rajesh [Argonne National Lab. (ANL), Argonne, IL (United States); Papadia, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Weber, Adam Z. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kusoglu, Ahmet [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shi, Shouwnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); More, K. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Grot, Steve [Ion Power, New Castle, DE (United States)

    2015-08-03

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. By investigating cell component degradation modes and defining the fundamental degradation mechanisms of components and component interactions, new materials can be designed to improve durability. To achieve a deeper understanding of PEM fuel cell durability and component degradation mechanisms, we utilize a multi-institutional and multi-disciplinary team with significant experience investigating these phenomena.

  7. Hygrothermal Behavior, Building Pathology and Durability

    CERN Document Server

    Delgado, JMPQ

    2013-01-01

    The main purpose of this book, Hygrothermal, Building Pathology and Durability, is to provide a collection of recent research works to contribute to the systematization and dissemination of knowledge related to construction pathology, hygrothermal behaviour of buildings, durability and diagnostic techniques and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of building physics and hygrothermal behaviour, durability approach for historical and old buildings and building pathology vs. durability. The book is divided in several chapters that are a resume of the current state of knowledge for benefit of professional colleagues, scientists, students, practitioners, lecturers and other interested parties to network.

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

    OpenAIRE

    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,...

  9. Durability of Self Compacting Concrete

    International Nuclear Information System (INIS)

    Benmarce, A.; Boudjehem, H.; Bendjhaiche, R.

    2011-01-01

    Self compacting concrete (SCC) seem to be a very promising materials for construction thanks to their properties in a fresh state. Studying of the influence of the parameters of specific designed mixes to their mechanical, physical and chemical characteristics in a state hardened is an important stage so that it can be useful for new-to-the-field researchers and designers (worldwide) beginning studies and work involving self compacting concrete. The objective of this research is to study the durability of self compacting concrete. The durability of concrete depends very much on the porosity; the latter determines the intensity of interactions with aggressive agents. The pores inside of concrete facilitate the process of damage, which began generally on the surface. We are interested to measure the porosity of concrete on five SCC with different compositions (w/c, additives) and vibrated concrete to highlight the influence of the latter on the porosity, thereafter on the compressive strength and the transfer properties (oxygen permeability, chloride ion diffusion, capillary absorption). (author)

  10. Durability as integral characteristic of concrete

    Science.gov (United States)

    Suleymanova, L. A.; Pogorelova, I. A.; Suleymanov, K. A.; Kirilenko, S. V.; Marushko, M. V.

    2018-03-01

    The carried-out research provides insight into the internal bonds energy in material as the basis of its durability, deformability, integrity and resistance to different factors (combined effects of external loadings and (or) environment), into the limits of technical possibilities, durability and physical reality of the process of concrete deterioration, which allows designing reliable and cost-effective ferroconcrete constructions for different purposes.

  11. Reliability and durability in solar energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Godolphin, D.

    1982-10-01

    The reliability and durability in solar energy systems for residential buildings is discussed. It is concluded that although strides have been made in design and manufacturing over the past years, the reliability and durability of the equipment depends on the proper installation. (MJF)

  12. Ceramics: Durability and radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C.; Lutze, W. [Univ. of New Mexico, Albuquerque, NM (United States); Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-05-01

    At present, there are three seriously considered options for the disposition of excess weapons plutonium: (1) incorporation, partial burn-up and direct disposal of MOX-fuel; (2) vitrification with defense waste and disposal as glass {open_quotes}logs{close_quotes}; (3) deep borehole disposal. The first two options provide a safeguard due to the high activity of fission products in the irradiated fuel and the defense waste. The latter option has only been examined in a preliminary manner, and the exact form of the plutonium has not been identified. In this paper, we review the potential for the immobilization of plutonium in highly durable crystalline ceramics apatite, pyrochlore, zirconolite, monazite and zircon. Based on available data, we propose zircon as the preferred crystalline ceramic for the permanent disposition of excess weapons plutonium.

  13. Durability of aircraft composite materials

    Science.gov (United States)

    Dextern, H. B.

    1982-01-01

    Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

  14. Optimal Monetary Policy with Durable Consumption Goods and Factor Demand Linkages

    DEFF Research Database (Denmark)

    Petrella, Ivan; Santoro, Emiliano

    of production in both sectors, according to an input-output matrix calibrated on the US economy. As shown in a number of recent contributions, this roundabout technology allows us to reconcile standard two-sector New Keynesian models with the empirical evidence showing co-movement between durable and non......-durable spending in response to a monetary policy shock. A main result of our monetary policy analysis is that strategic complementarities generated by factor demand linkages amplify social welfare loss. As the degree of interconnection between sectors increases, the cost of misperceiving the correct production......This paper deals with the implications of factor demand linkages for monetary policy design. We develop a dynamic general equilibrium model with two sectors that produce durable and non-durable goods, respectively. Part of the output produced in each sector is used as an intermediate input...

  15. Integrated durability process in product development

    International Nuclear Information System (INIS)

    Pompetzki, M.; Saadetian, H.

    2002-01-01

    This presentation describes the integrated durability process in product development. Each of the major components of the integrated process are described along with a number of examples of how integrated durability assessment has been used in the ground vehicle industry. The durability process starts with the acquisition of loading information, either physically through loads measurement or virtually through multibody dynamics. The loading information is then processed and characterized for further analysis. Durability assessment was historically test based and completed through field or laboratory evaluation. Today, it is common that both the test and CAE environments are used together in durability assessment. Test based durability assessment is used for final design sign-off but is also critically important for correlating CAE models, in order to investigate design alternatives. There is also a major initiative today to integrate the individual components into a process, by linking applications and providing a framework to communicate information as well as manage all the data involved in the entire process. Although a single process is presented, the details of the process can vary significantly for different products and applications. Recent applications that highlight different parts of the durability process are given. As well as an example of how integration of software tools between different disciplines (MBD, FE and fatigue) not only simplifies the process, but also significantly improves it. (author)

  16. Highly Dispersed Alloy Catalyst for Durability

    Energy Technology Data Exchange (ETDEWEB)

    Murthi, Vivek S.; Izzo, Elise; Bi, Wu; Guerrero, Sandra; Protsailo, Lesia

    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 with 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.

  17. Durability of PEM Fuel Cell Membranes

    Science.gov (United States)

    Huang, Xinyu; Reifsnider, Ken

    Durability is still a critical limiting factor for the commercialization of polymer electrolyte membrane (PEM) fuel cells, a leading energy conversion technology for powering future hydrogen fueled automobiles, backup power systems (e.g., for base transceiver station of cellular networks), portable electronic devices, etc. Ionic conducting polymer (ionomer) electrolyte membranes are the critical enabling materials for the PEM fuel cells. They are also widely used as the central functional elements in hydrogen generation (e.g., electrolyzers), membrane cell for chlor-alkali production, etc. A perfluorosulfonic acid (PFSA) polymer with the trade name Nafion® developed by DuPont™ is the most widely used PEM in chlor-alkali cells and PEM fuel cells. Similar PFSA membranes have been developed by Dow Chemical, Asahi Glass, and lately Solvay Solexis. Frequently, such membranes serve the dual function of reactant separation and selective ionic conduction between two otherwise separate compartments. For some applications, the compromise of the "separation" function via the degradation and mechanical failure of the electrolyte membrane can be the life-limiting factor; this is particularly the case for PEM in hydrogen/oxygen fuel cells.

  18. Increase of cyclic durability of pressure vessels

    International Nuclear Information System (INIS)

    Vorona, V.A.; Zvezdin, Yu.I.

    1980-01-01

    The durability of multilayer pressure vessels under cyclic loading is compared with single-layer vessels. The relative conditional durability is calculated taking into account the assumption on the consequent destruction of layers and viewing a vessel wall as an indefinite plate. It is established that the durability is mainly determined by the number of layers and to a lesser degree depends on the relative size of the defect for the given layer thickness. The advantage of the multilayer vessels is the possibility of selecting layer materials so that to exclude the effect of agressive corrosion media on the strength [ru

  19. Durability Properties of Palm Oil Fuel Ash Self Compacting Concrete

    Directory of Open Access Journals (Sweden)

    T. Ofuyatan

    2015-02-01

    Full Text Available Self Compacting Concrete (SCC is a new innovation in technology that can flow readily into place under its own self weight and fill corner areas of reinforcement structures without the need to vibrate and without segregation of its constitute. The problem of durability of concrete structures due to inadequate compaction by skilled workers has become a source of concern globally. The shortage of skilled manpower, noise and vibration of equipment on construction sites has led to the development of self compacting concrete. This paper presents an experimental study on the durability properties of Self Compacting Concrete with partial placement of Palm Oil Fuel Ash (POFA. Twelve POFA self-compacting concretes of various strength grades were designed at varying percentages of 0, 5, 10, 15, 20, 25 and 30%. The concrete with no placement of ash served as control. Conplast SP432MS was used as superplasticiser in the mix. The experiments are carried out by adopting a water-powder ratio of 0.36. Workability of the fresh concrete is determined by using tests such as: slump flow, T50, V-funnel and L-Box tests. The durability of concrete is tested by acid resistance, sulphate attack and saturated water absorption at the age of 14, 28, 56 and 90 days.

  20. Quick test for durability factor estimation.

    Science.gov (United States)

    2010-03-01

    The Missouri Department of Transportation (MoDOT) is considering the use of the AASHTO T 161 Durability Factor (DF) as an endresult : performance specification criterion for evaluation of paving concrete. However, the test method duration can exceed ...

  1. International Conference on Durability of Critical Infrastructure

    CERN Document Server

    Cherepetskaya, Elena; Pospichal, Vaclav

    2017-01-01

    This book presents the proceedings of the International Conference on Durability of Critical Infrastructure. Monitoring and Testing held in Satov, Czech Republic from 6 to 9 December 2016. It discusses the developments in the theoretical and practical aspects in the fields of Safety, Sustainability and Durability of the Critical Infrastructure. The contributions are dealing with monitoring and testing of structural and composite materials with a new methods for their using for protection and prevention of the selected objects.

  2. Mechanistic Enhancement of SOFC Cathode Durability

    Energy Technology Data Exchange (ETDEWEB)

    Wachsman, Eric [Univ. of Maryland, College Park, MD (United States)

    2016-02-01

    Durability of solid oxide fuel cells (SOFC) under “real world” conditions is an issue for commercial deployment. In particular cathode exposure to moisture, CO2, Cr vapor (from interconnects and BOP), and particulates results in long-term performance degradation issues. Here, we have conducted a multi-faceted fundamental investigation of the effect of these contaminants on cathode performance degradation mechanisms in order to establish cathode composition/structures and operational conditions to enhance cathode durability.

  3. The world Bank's support for concentrated solar power stations;L'initiative de la banque mondiale en faveur d'une montee en puissance des centrales solaires a concentration (CSP). Utilisation du Fonds des Technologies Propres en faveur d'une approche cooperative pour faire face aux defis du changement climatique et aux defis energetiques des pays du Moyen-Orient et d'Afrique du Nord (MENA)

    Energy Technology Data Exchange (ETDEWEB)

    Pariente-David, S.; Walters, J.; Govindarajalu, Ch.; Coma Cunill, R. [Banque mondiale, Washington, DC (United States)

    2009-11-15

    The Clean Technology Fund (CTF) was set up in 2008 to provide funding, especially subsidies, on an industrial scale for projects that experiment with, deploy or transfer low-carbon technology, which can potentially reduce greenhouse gas emissions significantly in the long run. The CTF helps multilateral development banks providing the funds needed, and giving a boost to experiments with low-carbon techniques, while waiting for the conclusion of the negotiations conducted by the United Nations on climate change. The World Bank manages this temporary fund. The article presents the use of CTF as a catalyzer to lower costs, to create a viable market and to attract important financing for the development of concentrating solar plants in Middle East and North-Africa countries

  4. Problems and energy choices in Burkina Faso[Energie ; Economie domestique ; Bois de feu ; Produits petroliers ; Legislation fonciere ; Electricite]; Burkina : Problemes et choix energetiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-01-15

    This document is about the evaluation of the energy sector in Burkina Faso. It reports about the main issues of energy: poverty of the households, the lack of fund to finance the sector, desertification...The main resources of energy are firewood, fuel and electricity. The energy needs of Burkina Faso are related to the cooking of food, with liquid fuels intended for the railway transport and fuels used in industry and for the production of electricity. With regard to the transport sector, there is currently no possibility of substitution for the fuel, except the use of ethanol diluted in the gasoline. At the industrial level, agro-industrial, bagasse and the other residues constitute right now the independent source of energy for the production of industrial heat as well as for that of electricity. For the public network of electricity supply, the production rests exclusively on diesel power stations. Regarding the immense needs for its populations in energy, Burkina has only very limited resources. The biomass used for domestic needs cannot continuously ensure the households with the necessary energy supply for food cooking. As for the agro-industrial residues, they cannot reduce the industrial consumption of fuels. There are also hydraulic resources whose conscientious exploitation could contribute to decrease the fuel consumption in terms of electricity. In sum, it would be necessary to improve the regulation as regards firewood supply, to promote the use of improved hearths with wood, to plan the fuel supplies and to assist the SONABEL in the electric production capacities reinforcement of its fuel-based power stations. [French] Ce document traite de l evaluation du secteur de l energie au Burkina. Il fait etat des principaux problemes energetiques : pauvrete des menages, manque de financement dans le secteur, desertification... Les principales ressources energetiques sont le bois de feu, les produits petroliers et l electricite. Les besoins energetiques du

  5. Increased durability concrete for generation of pillars power lines

    Directory of Open Access Journals (Sweden)

    Yakovlev Grigory

    2016-01-01

    Full Text Available In this researches multilayered carbon nanotubes of production of the French corporation “Arkema” were used. It has followed features: diameter of 10-15 nanometers and up to 15 microns long. Multilayered carbon nanotubes were used for increasing of physics and technology properties of cement concrete. It was established that at introduction of multilayered carbon nanotubes in amount of 0.006% of the mass led concrete durability increases by 28%, resistance to frost from F200 to F400, tightness to water from W8 to W14.

  6. A generalized definition for waste form durability

    International Nuclear Information System (INIS)

    Fanning, T. H.; Bauer, T. H.; Morris, E. E.; Wigeland, R. A.

    2002-01-01

    When evaluating waste form performance, the term ''durability'' often appears in casual discourse, but in the technical literature, the focus is often on waste form ''degradation'' in terms of mass lost per unit area per unit time. Waste form degradation plays a key role in developing models of the long-term performance in a repository environment, but other factors also influence waste form performance. These include waste form geometry; density, porosity, and cracking; the presence of cladding; in-package chemistry feedback; etc. The paper proposes a formal definition of waste form ''durability'' which accounts for these effects. Examples from simple systems as well as from complex models used in the Total System Performance Assessment of Yucca Mountain are provided. The application of ''durability'' in the selection of bounding models is also discussed

  7. Durability analysis of gneiss using wear resistance

    Directory of Open Access Journals (Sweden)

    José Luiz Ernandes Dias Filho

    2014-01-01

    Full Text Available This paper presents a study conducted in gneiss in Santo Antonio de Pádua, RJ, BR, including durability analysis of the rock using slake durability test. Rocks in the region of Pádua are mostly used for ornamental purposes. A lab equipment was developed to evaluate the influence of rotation in the test, allowing for the speed variation of 7 RPM to 238 RPM. This study could be implemented in a wide variety of rock materials, targeting them according to their lifetime in the project. With variation of the wear levels, increasing weight loss was observed until the inertia moment in which the sample holds to the machine wall. The results indicate an increase in linear mass loss. These procedures allow a more precise analysis of durability than can be applied in different different regions of the world.

  8. Pyramiding for Resistance Durability: Theory and Practice.

    Science.gov (United States)

    Mundt, Chris

    2018-04-12

    Durable disease resistance is a key component of global food security, and combining resistance genes into "pyramids" is an important way to increase durability of resistance. The mechanisms by which pyramids impact durability are not well known. The traditional view of resistance pyramids considers the use of major resistance gene (R-gene) combinations deployed against pathogens that are primarily asexual. Interestingly, published examples of the successful use of pyramids in the traditional sense are rare. In contrast, most published descriptions of durable pyramids in practice are for cereal rusts, and tend to indicate an association between durability and cultivars combining major R-genes with incompletely expressed, adult plant resistance genes. Pyramids have been investigated experimentally for a diversity of pathogens, and many reduce disease levels below that of the single best gene. Resistance gene combinations have been identified through phenotypic reactions, molecular markers, and challenge against effector genes. As resistance genes do not express equally in all genetic backgrounds, however, a combination of genetic information and phenotypic analyses provide the ideal scenario for testing of putative pyramids. Not all resistance genes contribute equally to pyramids, and approaches have been suggested to identify the best genes and combinations of genes for inclusion. Combining multiple resistance genes into a single plant genotype quickly is a challenge that is being addressed through alternative breeding approaches, as well as through genomics tools such as resistance gene cassettes and gene editing. Experimental and modeling tests of pyramid durability are in their infancy, but have promise to help direct future studies of pyramids. Several areas for further work on resistance gene pyramids are suggested.

  9. Revisiting the role of durable polymers in cardiovascular devices.

    Science.gov (United States)

    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.

  10. Probabilistic Durability Analysis in Advanced Engineering Design

    Directory of Open Access Journals (Sweden)

    A. Kudzys

    2000-01-01

    Full Text Available Expedience of probabilistic durability concepts and approaches in advanced engineering design of building materials, structural members and systems is considered. Target margin values of structural safety and serviceability indices are analyzed and their draft values are presented. Analytical methods of the cumulative coefficient of correlation and the limit transient action effect for calculation of reliability indices are given. Analysis can be used for probabilistic durability assessment of carrying and enclosure metal, reinforced concrete, wood, plastic, masonry both homogeneous and sandwich or composite structures and some kinds of equipments. Analysis models can be applied in other engineering fields.

  11. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    1997-01-01

    (capillary water uptake) is used, involving an in-situ method and a laboratory method. Three different concrete qualities as well as steel fibres (ZP) and polypropylene fibres (PP) are used. Results of the durability tests on cracked FRC-beams are compared to results for uncracked FRC-beams and beams without......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to il-point bending until a predefined crack width is reached, using a newly developed test setup. As environmental load, exposure to water...

  12. Research of Tool Durability in Surface Plastic Deformation Processing by Burnishing of Steel Without Metalworking Fluids

    Science.gov (United States)

    Grigoriev, S. N.; Bobrovskij, N. M.; Melnikov, P. A.; Bobrovskij, I. N.

    2017-05-01

    Modern vector of development of machining technologies aimed at the transition to environmentally safe technologies - “green” technologies. The concept of “green technology” includes a set of signs of knowledge intended for practical use (“technology”). One of the ways to improve the quality of production is the use of surface plastic deformation (SPD) processing methods. The advantage of the SPD is a capability to combine effects of finishing and strengthening treatment. The SPD processing can replace operations: fine turning, grinding or polishing. The SPD is a forceful contact impact of indentor on workpiece’s surface in condition of their relative motion. It is difficult to implement the core technology of the SPD (burnishing, roller burnishing, etc.) while maintaining core technological advantages without the use of lubricating and cooling technology (metalworking fluids, MWF). The “green” SPD technology was developed by the authors for dry processing and has not such shortcomings. When processing with SPD without use of MWF requirements for tool’s durability is most significant, especially in the conditions of mass production. It is important to determine the period of durability of tool at the design stage of the technological process with the purpose of wastage preventing. This paper represents the results of durability research of natural and synthetic diamonds (polycrystalline diamond - ASPK) as well as precision of polycrystalline superabrasive tools made of dense boron nitride (DBN) during SPD processing without application of MWF.

  13. Durability of commercial aircraft and helicopter composite structures

    International Nuclear Information System (INIS)

    Dexter, H.B.

    1982-01-01

    The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified

  14. Durability of commercial aircraft and helicopter composite structures

    Science.gov (United States)

    Dexter, H. B.

    1982-01-01

    The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified.

  15. The prospective buyer of consumer durables

    NARCIS (Netherlands)

    Jonge, Leendert de; Oppedijk van Veen, Walle Melis

    1982-01-01

    In this book, an empirical investigation is reported wich aims at the specification of models of individual households’ purchase behaviour for particular consumer durable goods, such as private passenger cars and television sets. In particular, the focus is on models wich can be used for predicting

  16. Durable Glass For Thousands Of Years

    International Nuclear Information System (INIS)

    Jantzen, C.

    2009-01-01

    The durability of natural glasses on geological time scales and ancient glasses for thousands of years is well documented. The necessity to predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to various thermodynamic and kinetic approaches. Advances in the measurement of medium range order (MRO) in glasses has led to the understanding that the molecular structure of a glass, and thus the glass composition, controls the glass durability by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. During the early stages of glass dissolution, a 'gel' layer resembling a membrane forms through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer ages into clay or zeolite minerals by Ostwald ripening. Zeolite mineral assemblages (higher pH and Al 3+ rich glasses) may cause the dissolution rate to increase which is undesirable for long-term performance of glass in the environment. Thermodynamic and structural approaches to the prediction of glass durability are compared versus Ostwald ripening.

  17. Advantage from Funding Durable Centers Leasing

    Directory of Open Access Journals (Sweden)

    Alina Zając

    2009-09-01

    Full Text Available In present market conditions huge number of businessmen has problems from gain over from banks capital on purchase of durable centers not only, but also on develop - ment and operating activity Individual can use with different forms funding investment, it which is between different leasing.

  18. Enhancing composite durability : using thermal treatments

    Science.gov (United States)

    Jerrold E. Winandy; W. Ramsay Smith

    2007-01-01

    The use of thermal treatments to enhance the moisture resistance and aboveground durability of solid wood materials has been studied for years. Much work was done at the Forest Products Laboratory in the last 15 years on the fundamental process of both short-and long-term exposure to heat on wood materials and its interaction with various treatment chemicals. This work...

  19. 40 CFR 610.33 - Durability tests.

    Science.gov (United States)

    2010-07-01

    ....33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY... problems, deterioration in spark plug life, increase in carburetor or combustion chamber deposits, or..., then a durability run may be made as described in subpart E, in which fuel economy and exhaust...

  20. DURABLE GLASS FOR THOUSANDS OF YEARS

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.

    2009-12-04

    The durability of natural glasses on geological time scales and ancient glasses for thousands of years is well documented. The necessity to predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to various thermodynamic and kinetic approaches. Advances in the measurement of medium range order (MRO) in glasses has led to the understanding that the molecular structure of a glass, and thus the glass composition, controls the glass durability by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. During the early stages of glass dissolution, a 'gel' layer resembling a membrane forms through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer ages into clay or zeolite minerals by Ostwald ripening. Zeolite mineral assemblages (higher pH and Al{sup 3+} rich glasses) may cause the dissolution rate to increase which is undesirable for long-term performance of glass in the environment. Thermodynamic and structural approaches to the prediction of glass durability are compared versus Ostwald ripening.

  1. Durability of wood-plastic composite lumber

    Science.gov (United States)

    Rebecca E. Ibach

    2010-01-01

    Wood-plastic composite (WPC) lumber has been marketed as a low-maintenance, high-durability product. Retail sales in the United States were slightly less than $1 billion in 2008. Applications include docking, railing, windows, doors, fencing, siding, moldings, landscape timbers, car interior parts, and furniture. The majority of these products are used outdoors and...

  2. DURABILITY OF FLEXIBLE PAVEMENTS: A CASE STUDY OF ...

    African Journals Online (AJOL)

    user

    years, ranking, predominant factors affecting pavement durability and the estimate of durability. In this regard .... subgrade soil into the base course and provide the drainage of ..... [3] Oguara T. M. “A management model for road infrastructure ...

  3. Carbon nanocages: a new support material for Pt catalyst with remarkably high durability.

    Science.gov (United States)

    Wang, Xiao Xia; Tan, Zhe Hua; Zeng, Min; Wang, Jian Nong

    2014-03-24

    Low durability is the major challenge hindering the large-scale implementation of proton exchange membrane fuel cell (PEMFC) technology, and corrosion of carbon support materials of current catalysts is the main cause. Here, we describe the finding of remarkably high durability with the use of a novel support material. This material is based on hollow carbon nanocages developed with a high degree of graphitization and concurrent nitrogen doping for oxidation resistance enhancement, uniform deposition of fine Pt particles, and strong Pt-support interaction. Accelerated degradation testing shows that such designed catalyst possesses a superior electrochemical activity and long-term stability for both hydrogen oxidation and oxygen reduction relative to industry benchmarks of current catalysts. Further testing under conditions of practical fuel cell operation reveals almost no degradation over long-term cycling. Such a catalyst of high activity, particularly, high durability, opens the door for the next-generation PEMFC for "real world" application.

  4. Studies of The Durability of Belt Conveyor Idlers with Working Loads Taken into Account

    Science.gov (United States)

    Król, Robert

    2017-12-01

    The results of laboratory and operational studies conducted in the Machinery Systems Division of Wroclaw University of Technology in recent years have became the basis for selecting proper belt conveyor roller designs optimized for specific strength and operational criteria. The usefulness of the results for assessing the energy intensity of idlers, estimating their durability and determining modernization policies has been confirmed. Methods of estimating the durability of carrying idlers on the basis of the identified output stream distributions are presented. Results of studies carried out using an analytical method and a laboratory method are reported. It has been shown that the operational durability of a roller is determined by its design, the roller set parameters (the spacing and the angle of bevel) and the operating conditions having a bearing on the irregularity of the transported output stream.

  5. THE STUDY ON THE DURABILITY OF SUBMERGED STRUCTURE DISPLACEMENT DUE TO CONCRETE FAILURE

    Directory of Open Access Journals (Sweden)

    M. Mohd

    2016-09-01

    Full Text Available Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures.

  6. Durability of ink jet prints

    International Nuclear Information System (INIS)

    Dobric, E; Mirkovic, I Bolanca; Bolanca, Z

    2010-01-01

    The aim of this paper is the result presentation of some optical properties research for ink jet prints after: exposing the prints to the mixed daylight and artificial light, exposing of prints to the sun-light through the glass window, and exposing of prints to outdoor conditions during the summer months. The prints obtained by piezoelectric and thermal ink jet technologies were used in the researches. The dye-based inks and the pigmented inks based on water and the low solvent inks were used. The results of these researches, except the scientific contribution in the domain of understanding and explaining the environmental conditions on the gamut size, i.e. the range of color tonality, colorimetric stability and print quality, can be used by the ink and paper manufacturers in new formulations, offer data for the printer producers for further production and evaluation of the position of their products.

  7. The influence of humidity on strengths and durability of light guides fibers

    International Nuclear Information System (INIS)

    Karimov, S.N.; Kuksenko, V.S.; Sultonov, U.; Abdumanonov, A.; Shamsidinov, M.I.

    1993-01-01

    Humidity influence on durability and light water durability fibres is studied are studied in this article. Humidity energy under influence of process destruction decreases activity, durability and durability decreases is shown

  8. Sustainable development - billions of watts under the seas - Marine current turbines play simple - Technological waves; Developpement durable - Des milliards de watts sous les mers - Les hydroliennes jouent la simplicite - Vagues technologiques

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Th.

    2011-10-27

    The author evokes the opportunities of power generation by the development of sea current or tidal stream turbines. Some developments are already tested by Norwegian, French, Danish, British and American companies. Some specific turbines are briefly presented. In order to reduce the cost of the electricity production from sea currents, manufacturers are using simple and robust technologies, and exploit the experience gained on wind turbines. Some designs and prototypes are evoked for the production of electricity by sea waves (Pelamis and Oyster projects). Principles, strengths and production projects are briefly indicated. The challenge of maintenance in sea environment is outlined for these projects

  9. Monetary Policy with Sectoral Linkages and Durable Goods

    DEFF Research Database (Denmark)

    Petrella, Ivan; Rossi, Raffaele; Santoro, Emiliano

    We study the normative implications of a New Keynesian model featuring intersectoral trade of intermediate goods between two sectors that produce durables and non-durables. The interplay between durability and sectoral production linkages fundamentally alters the intersectoral stabilization trade....... Aggregating durable and non-durable inflation depending on the relative degrees of sectoral price stickiness may induce a severe bias. Input materials attenuate the response of sectoral inflations to movements in the real marginal costs, so that the effective slopes of the sectoral supply schedules...

  10. The chemical durability of alkali aluminosilicate glasses

    International Nuclear Information System (INIS)

    Tait, J.C.; Mandolesi, D.L.

    1983-09-01

    The aqueous durabilities of a series of glasses based on the sodium aluminosilicate system (Na 2 O-Al 2 O 3 -SiO 2 ) have been studied. The effects of molecular substitution of K 2 O or CaO for Na 2 O, and B 2 O 3 for Al 2 O 3 have been investigated. The temperature dependence of leaching in the Na 2 O-B 2 O 3 -Al 2 O 3 -SiO 2 system was studied with glasses containing 2 wt percent simulated UO 2 fuel recycle waste. The results confirm that aluminosilicate glasses are more durable than their borosilicate counterparts. The leaching results are explained in terms of glass structure and bonding, and a general leaching mechanism for aluminosilicate glasses is presented

  11. Durable terrestrial bedrock predicts submarine canyon formation

    Science.gov (United States)

    Smith, Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

    2017-01-01

    Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

  12. Mankiw's Puzzle on Consumer Durables: A Misspecification

    OpenAIRE

    Tam Bang Vu

    2005-01-01

    Mankiw (1982) shows that consumer durables expenditures should follow a linear ARMA(1,1) process, but the data analyzed supports an AR(1) process instead; thus, a puzzle. In this paper, we employ a more general utility function than Mankiw's quadratic one. Further, the disturbance and depreciation rate are respecified, respectively, as multiplicative and stochastic. The analytical consequence is a nonlinear ARMA(infinity,1) process, which implies that the linear ARMA(1,1) is a misspecificatio...

  13. OPTIONS D'INTENSIFICATION DURABLE DES CULTURES ...

    African Journals Online (AJOL)

    (Received 14 August, 2001 ; accepted 10 May, 2002) RÉSUMÉ Pour intensifier de manière durable les cultures vivrières dans les zones de terres de barre dégradées au sud du Togo, plusieurs options ont été évaluées avec les paysans. Grâce à des entretiens collectifs de type participatif, sept différents groupes ...

  14. Durability 2007. Injection grout investigations. Background description

    International Nuclear Information System (INIS)

    Orantie, K.; Kuosa, H.

    2008-12-01

    The aim of this project was to evaluate the durability risks of injection grouts. The investigations were done with respect to the application conditions, materials and service life requirements at the ONKALO underground research facility. The study encompassed injection grout mixtures made of ultrafine cement with and without silica fume. Some of the mixtures hade a low pH and thus a high silica fume content. The project includes a background description on durability literature, laboratory testing programme, detailed analysis of results and recommendations for selecting of ideal grout mixtures. The background description was made for the experimental study of low-pH and reference rock injection grouts as regards pore- and microstructure, strength, shrinkage/swelling and thus versatile durability properties. A summary of test methods is presented as well as examples, i.e. literature information or former test results, of expected range of results from the tests. Also background information about how the test results correlate to other material properties and mix designs is presented. Besides the report provides basic information on the pore structure of cement based materials. Also the correlation between the pore structure of cement based materials and permeability is shortly discussed. The test methods included in the background description are compressive strength, measurement of bulk drying, autogenous and chemical shrinkage and swelling, hydraulic conductivity / permeability, capillary water uptake test, mercury intrusion porosimetry (MIP) and thin section analysis. Three main mixtures with water-binder ratio of 0.8, 1.0 and 1.4 and silica fume content of 0, 15 and 40% were studied in the laboratory. Besides two extra mixtures were studied to provide additional information about the effect of varying water-dry-material ratio and silica fume content on durability. The evaluation of water tightness based on water permeability coefficient and micro cracking was

  15. Intermediate Ethanol Blends Catalyst Durability Program

    Energy Technology Data Exchange (ETDEWEB)

    West, Brian H; Sluder, Scott; Knoll, Keith; Orban, John; Feng, Jingyu

    2012-02-01

    In the summer of 2007, the U.S. Department of Energy (DOE) initiated a test program to evaluate the potential impacts of intermediate ethanol blends (also known as mid-level blends) on legacy vehicles and other engines. The purpose of the test program was to develop information important to assessing the viability of using intermediate blends as a contributor to meeting national goals for the use of renewable fuels. Through a wide range of experimental activities, DOE is evaluating the effects of E15 and E20 - gasoline blended with 15% and 20% ethanol - on tailpipe and evaporative emissions, catalyst and engine durability, vehicle driveability, engine operability, and vehicle and engine materials. This report provides the results of the catalyst durability study, a substantial part of the overall test program. Results from additional projects will be reported separately. The principal purpose of the catalyst durability study was to investigate the effects of adding up to 20% ethanol to gasoline on the durability of catalysts and other aspects of the emissions control systems of vehicles. Section 1 provides further information about the purpose and context of the study. Section 2 describes the experimental approach for the test program, including vehicle selection, aging and emissions test cycle, fuel selection, and data handling and analysis. Section 3 summarizes the effects of the ethanol blends on emissions and fuel economy of the test vehicles. Section 4 summarizes notable unscheduled maintenance and testing issues experienced during the program. The appendixes provide additional detail about the statistical models used in the analysis, detailed statistical analyses, and detailed vehicle specifications.

  16. Amenagements sportifs et developpement durable : Des enjeux ...

    African Journals Online (AJOL)

    ... contredite » éprouvée par (Jeu, 1977), comme l'apanage d'une double hybridation culturelle des pays en développement. Derrière l'apparence de la dislocation des héritages, doit émerger une définition nouvelle sur les rapports que les sports devraient entretenir avec l'environnement pour un développement durable.

  17. Durability of heavyweight concrete containing barite

    International Nuclear Information System (INIS)

    Binici, Hanifi

    2010-01-01

    The supplementary waste barite aggregates deposit in Osmaniye, southern Turkey, has been estimated at around 500 000 000 tons based on 2007 records. The aim of the present study is to investigate the durability of concrete incorporating waste barite as coarse and river sand (RS), granule blast furnace slag (GBFS), granule basaltic pumice (GBP) and ≤ 4 mm granule barite (B) as fine aggregates. The properties of the fresh concrete determined included the air content, slump, slump loss and setting time. They also included the compressive strength, flexural and splitting tensile strengths and Young's modulus of elasticity, resistance to abrasion and sulphate resistance of hardened concrete. Besides these, control mortars were prepared with crushed limestone aggregates. The influence of waste barite as coarse aggregates and RS, GBFS, GBP and B as fine aggregates on the durability of the concretes was evaluated. The mass attenuation coefficients were calculated at photon energies of 1 keV to 100 GeV using XCOM and the obtained results were compared with the measurements at 0.66 and 1.25 MeV. The results showed the possibility of using these waste barite aggregates in the production of heavy concretes. In several cases, some of these properties have been improved. Durability of the concrete made with these waste aggregates was improved. Thus, these materials should be preferably used as aggregates in heavyweight concrete production. (orig.)

  18. Creep Behavior and Durability of Cracked CMC

    Science.gov (United States)

    Bhatt, R. T.; Fox, Dennis; Smith, Craig

    2015-01-01

    To understand failure mechanisms and durability of cracked Ceramic matrix composites (CMCs), Melt Infiltration (MI) SiCSiC composites with Sylramic-iBN fibers and full Chemical vapour infiltration SiCSiC composites with Sylramic-ion bombarded BN (iBN) and Hi-Nicalon -S fibers were pre-cracked between 150 to 200 megapascal and then creep and Sustained Peak Low Cycle Fatigue (SPLCF) tested at 13150 C at stress levels from 35 to 103 megapascal for up to 200 hours under furnace and burner rig conditions. In addition creep testing was also conducted on pre-cracked full Chemical vapour infiltration SiCSiC composites at 14500 C between 35 and 103 megapascal for up to 200 hours under furnace conditions. If the specimens survived the 200 hour durability tests, then they were tensile tested at room temperature to determine their residual tensile properties. The failed specimens were examined by Scanning electron microscope (SEM) to determine the failure modes and mechanisms. The influence of crack healing matrix, fiber types, crack density, testing modes and interface oxidation on durability of cracked Ceramic matrix composites (CMCs) will be discussed.

  19. Durability evaluation of reversible solid oxide cells

    Science.gov (United States)

    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.

  20. Effects of Irradiation on Albite's Chemical Durability.

    Science.gov (United States)

    Hsiao, Yi-Hsuan; La Plante, Erika Callagon; Krishnan, N M Anoop; Le Pape, Yann; Neithalath, Narayanan; Bauchy, Mathieu; Sant, Gaurav

    2017-10-19

    Albite (NaAlSi 3 O 8 ), a framework silicate of the plagioclase feldspar family and a common constituent of felsic rocks, is often present in the siliceous mineral aggregates that compose concrete. When exposed to radiation (e.g., in the form of neutrons) in nuclear power plants, the crystal structure of albite can undergo significant alterations. These alterations may degrade its chemical durability. Indeed, careful examinations of Ar + -implanted albite carried out using Fourier transform infrared spectroscopy (FTIR) and molecular dynamics simulations show that albite's crystal structure, upon irradiation, undergoes progressive disordering, resulting in an expansion in its molar volume (i.e., a reduction of density) and a reduction in the connectivity of its atomic network. This loss of network connectivity (i.e., rigidity) results in an enhancement of the aqueous dissolution rate of albite-measured using vertical scanning interferometry (VSI) in alkaline environments-by a factor of 20. This enhancement in the dissolution rate (i.e., reduction in chemical durability) of albite following irradiation has significant impacts on the durability of felsic rocks and of concrete containing them upon their exposure to radiation in nuclear power plant (NPP) environments.

  1. Effect Of Climatic Conditions On Durability

    Directory of Open Access Journals (Sweden)

    Ibrahem M. Al Kiki

    2013-04-01

    Full Text Available Durability is one of the most important subjects in the soil stabilization. Since there is no specifications concerned the durability of lime stabilized soils, several factors were selected to show their effects on the durability, namely: wetting, drying, freezing, thawing and slaking.The effect of each one of the above factors as well as the combined effect of two or more factors, were studied on the volume change and soil strength and weight loss of soil samples stabilized with optimum lime content except the slaking test at which soil samples stabilized with different lime content.Tests results showed that the higher the lime content the lower the slaking effect, also its found the soil strength decreased when the period of immersion or freezing increased. The strength of the lime stabilized soils decreased when subjected to the cycles of wetting and drying or to the cycles freezing and thawing. However, the  combined effect of wetting, drying, freezing and thawing has a pronounced effect on reduction of the lime stabilized clayey soil. The worst condition recorded when lime stabilized soil undergo to freezing then drying then wetting which should be avoided in the field

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  4. Energy Research in Switzerland in 1997; Energieforschung 1997. Ueberblicksberichte/Recherche energetique 1997. Rapports de synthese

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-15

    This comprehensive annual report for the Swiss Federal Office of Energy (SFOE) contains the overview-reports for the year 1997 that were made by the heads of the following Swiss energy research programmes: Research co-ordination, efficient use of energy in buildings, solar architecture, electricity, ambient heat and heat-pumps, solar energy, photovoltaics, biomass, geothermal energy, small hydropower, wind energy, solar chemistry and hydrogen, combustion technologies, heat storage, nuclear energy and nuclear safety, nuclear fusion, fuel cells and accumulators, traffic and the fundamentals of energy economics. In the following, just a few of the large number of topics covered are mentioned. Under the topic of efficient energy use in buildings, a new optimisation tool and a work done on highly-insulated walls are mentioned along with new developments in building technology and simulation. In the solar architecture area, both the direct and indirect use of solar energy for heating and lighting are covered. Electrical topics include efficient electricity use, drives, high-temperature superconductors, transport, energy management, power-electronics, EDP projects and saving energy in trains. In the ambient heat and heat-pump area, projects on the modelling and the regeneration of heat probes are noted, as are projects concerning refrigerants, combined heat and power technologies and Stirling engines. Work done in co-operation with the IEA Heat Pump Program is noted. In the solar energy area, software aids for the calculation of solar gain and the testing of solar collectors are commented on and experience gained with various installations is noted. The photovoltaics section reports on work done on solar cells, building integration and systems technology as well as various studies and projects. The report on the biomass program reports on pollution aspects of firing, project aids, small ready-to-use biogas installations, and motor fuels from biomass. Among the projects

  5. Final Report - MEA and Stack Durability for PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yandrasits, Michael A.

    2008-02-15

    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.

  6. Build together the problem, obligatory passage for the conception of acceptable energy solutions?; Construire ensemble le probleme, passage oblige pour la conception de solutions energetiques acceptables?

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, Marie-Jose; Le Floch, Sophie

    2010-09-15

    Social acceptance is a condition in performing energy projects. This notion is however complex: just like 'build', it is based on several factors and is changing. We would like to show that its construction requires that some time be spend at a stage often neglected, that of the formulation of the problem. So that the 'awareness' would be aimed not only to the public, but also to the decision makers and promoters, so that everyone has a good knowledge of the concerns of the others, and of their limits. To this end, the 'participation' could take several forms, complementary to the 'public' one generally accepted. [French] L'acceptabilite sociale est une condition de realisation de projets energetiques. Cette notion est toutefois complexe : comme 'construit', elle se fonde sur plusieurs facteurs et est evolutive. Nous voudrions montrer que sa construction exige qu'un temps soit consacre a une etape souvent negligee, celle de la formulation du probleme. Ainsi, la 'sensibilisation' serait destinee non seulement au grand public, mais aussi aux decideurs et promoteurs, afin que tous aient une bonne connaissance des preoccupations des uns et des autres, comme de leurs contraintes. A cette fin, la 'participation' pourrait prendre plusieurs formes, complementaires a celle 'publique' generalement adoptee.

  7. Local energy policies: Planning devices and coaching tools - Example of the French case; Politiques energetiques locales: Dispositifs de planification et outils d'accompagnement - Exemple du cas francais

    Energy Technology Data Exchange (ETDEWEB)

    Chanard, Camille; de Sede-Marceau, Marie-Helene

    2010-09-15

    Collectivities traditionally have multiple responsibilities linked to energy. They act directly on the energy chain (production-distribution-consumption) through their heritage, but also on the tripych space-environment-society, in particular through their planning choices. Hence, all the public policies are concerned by the energy theme. However, collectivities seem to suffer from an information deficit, both on planning devices that can be mobilized and on the territory features. This article proposes to realise an overview tour of the coaching tools that can be used by the French territories collectivities to build efficient energy policies. [French] Les collectivites ont traditionnellement des responsabilites multiples en lien avec l'energie. Elles agissent directement sur la chaine energetique (production-distribution-consommation) a travers leur patrimoine, mais aussi sur le triptyque espace-environnement-societe, en particulier a travers leurs choix d'amenagement. Ainsi, toutes les politiques publiques sont concernees par la thematique ' energie '. Cependant, les collectivites semblent souffrir d'un deficit d'information, tant sur les dispositifs de planification pouvant etre mobilises que sur les caracteristiques du territoire. Cet article propose de realiser un tour d'horizon de l'ensemble des outils d'accompagnements pouvant etre mobilises par les collectivites territoriales francaises pour construire des politiques energetiques efficaces.

  8. Energy Research in Switzerland in 2001; Energieforschung 2001. Ueberblicksberichte/Recherche energetique 2001. Rapports de synthese

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-15

    This comprehensive annual report for the Swiss Federal Office of Energy (SFOE) contains the overview-reports that were made by the heads of the following Swiss energy research programmes for the year 2000: Efficient use of energy in buildings, traffic, vehicles and accumulators, electricity, ambient heat and combined heat and power generation, fuel cells, combustion technologies, solar heat and storage, photovoltaics, solar chemistry and hydrogen, biomass, geothermal energy, wind energy, small hydropower, nuclear safety and nuclear waste disposal, regulatory nuclear safety research, nuclear fusion and energy economy basics. In the following, just a selection of the large number of topics covered are mentioned. Under the topic of efficient energy use in buildings, an emphasis was placed on highly efficient insulation systems, so-called passive dwellings, environmental issues, the use of solar energy, insulation using grass and hemp fibre as well as a market analysis for the IEA sustainable housing project. In the solar area, experience gained with solar buildings, air-collectors and the optimisation of solar energy and daylight use are noted. In the building technologies area, highly glazed buildings were also looked at, as were airing and ventilation topics. Various instruments in the building technical services area are noted. A number of pilot and demonstration projects are listed. Traffic topics reported on include a review of statistics on mobility, lightweight body technologies, drive systems and on-board electrification, fuel cell drive technologies, supercaps and accumulators, as well as various pilot and demonstration projects. Electrical topics include distribution and tariffs, high-temperature superconductors, energy efficiency in computer applications, drives, electrical machines and a heat-pump based tumbler. In the ambient heat and heat-pump area, projects concerning refurbishment, two-stage systems, small ammonia heat-pumps, carbon dioxide

  9. Microcracking and durability of high strength concretes

    International Nuclear Information System (INIS)

    Yssorche, M.P.

    1995-07-01

    Durability of 28 days compressive strength concrete of 20 to 120 MPa has been studied. The ability of concrete to transport aggressive agents has been determined for four properties: the air permeability, the chloride diffusivity, the water absorption and the carbonation. A chloride migration test for high and very high strength concrete (HSC and VHSC) has been built. The relationship between transport properties and the compressive strength after one and 28 days of humid curing has always the same shape: transport decreases when strength increases. However, transport properties often vary in the ordinary concrete field. Beyond, the domain is much more limited. The relationship between transport properties and strength valid for ordinary concrete can not be simply extrapolated for HSC and VHSC. To determine the part of microcracking of HSC and VHSC, concrete behaviour stored in two mediums has been studied: the ones shaming the storing condition of concrete in auto-desiccation, the others reproducing the storing conditions of concrete in desiccation. Auto-desiccation (measuring relative humidity at balance) and desiccation (measuring mass losses) have been showed. Microcracks and shrinkage strains have been measured. It has been showed that auto-desiccation microcracks proving in HSC or VHSC don't question the durability. Microcracks, as for permeability, do not develop between 28 days and one year. On the contrary, desiccation microcracks observed in HSC and VHSC, increase with transport properties between 28 days and 1.5 year. Thus, a bulk concrete is always more durable than a cover concrete. At last, the good influence of increase of curing of 1 to 28 days on the transport of all concretes has been emphasized. (author)

  10. Durable fear memories require PSD-95

    Science.gov (United States)

    Fitzgerald, Paul J.; Pinard, Courtney R.; Camp, Marguerite C.; Feyder, Michael; Sah, Anupam; Bergstrom, Hadley; Graybeal, Carolyn; Liu, Yan; Schlüter, Oliver; Grant, Seth G.N.; Singewald, Nicolas; Xu, Weifeng; Holmes, Andrew

    2014-01-01

    Traumatic fear memories are highly durable but also dynamic, undergoing repeated reactivation and rehearsal over time. While overly persistent fear memories underlie anxiety disorders such as posttraumatic stress disorder, the key neural and molecular mechanisms underlying fear memory durability remain unclear. Post-synaptic density 95 (PSD-95) is a synaptic protein regulating glutamate receptor anchoring, synaptic stability and certain types of memory. Employing a loss-of-function mutant mouse lacking the guanylate kinase domain of PSD-95 (PSD-95GK), we analyzed the contribution of PSD-95 to fear memory formation and retrieval, and sought to identify the neural basis of PSD-95-mediated memory maintenance using ex vivo immediate-early gene mapping, in vivo neuronal recordings and viral-mediated knockdown approaches. We show that PSD-95 is dispensable for the formation and expression of recent fear memories, but essential for the formation of precise and flexible fear memories and for the maintenance of memories at remote time points. The failure of PSD-95GK mice to retrieve remote cued fear memories was associated with hypoactivation of the infralimbic cortex (IL) (not anterior cingulate (ACC) or prelimbic cortex), reduced IL single-unit firing and bursting, and attenuated IL gamma and theta oscillations. Adeno-associated PSD-95 virus-mediated knockdown in the IL, not ACC, was sufficient to impair recent fear extinction and remote fear memory, and remodel IL dendritic spines. Collectively, these data identify PSD-95 in the IL as a critical mechanism supporting the durability of fear memories over time. These preclinical findings have implications for developing novel approaches to treating trauma-based anxiety disorders that target the weakening of overly persistent fear memories. PMID:25510511

  11. The globalization of energy activities: what are the issues?; La mondialisation des activites energetiques: quels enjeux?

    Energy Technology Data Exchange (ETDEWEB)

    Percebois, J. [Montpellier I Univ., (France)

    2001-03-01

    Globalization in many sectors such as information, research and development, finance, technology, etc. led to the implementation of transnational networks to facilitate decision-making. The result is that governments are left to regulation functions. This globalization also led to a larger gap between North and South. Developing countries represent 80 per cent of world population, yet only produce less than 33 per cent of gross domestic product (GDP). In the energy sector, developing countries have limited access to energy and use it less efficiently, since they do not master the latest technologies. States must retain their power to regulate this sector to ensure competition takes place in a fair environment within specified guidelines. Licenses must be issued through bidding or auctioned off, but in every case the State must ensure that commitments are met. It must also ensure that pricing is fair. Access for third parties to the power distribution system must be adequate, especially when the company operates in a monopoly environment. The State ends up managing a new category of risks (called major risks) that the private sector is not willing to consider, for example global warming or the management of nuclear waste. Confidence in market mechanisms is limited. Energy exchanges and others represent an economic growth factor and a potential guarantee for world peace. Who is responsible for the social costs associated with economic growth, and what are the solutions? A major issue left to decision-makers is the sharing of wealth within humankind and nations, and the State has a vital role to play. 5 refs., 5 tabs.

  12. Durability Testing of Idlers for Belt Conveyors

    Directory of Open Access Journals (Sweden)

    Andrzej Pytlik

    2013-01-01

    On the basis of the durability tests carried out on both of these idlers it can be concluded that the applied research methodology describes the test conditions of idlers, in a manner as close as possible to their actual operational conditions, which were subject to a variety of factors for a total time of 116 hours, they included: dust, water, loads and variable rotational speed. This methodology allowed us to determine, even at the stage of laboratory tests, the suitability of a particular idler to certain operational conditions.

  13. Advanced Face Gear Surface Durability Evaluations

    Science.gov (United States)

    Lewicki, David G.; Heath, Gregory F.

    2016-01-01

    The surface durability life of helical face gears and isotropic super-finished (ISF) face gears was investigated. Experimental fatigue tests were performed at the NASA Glenn Research Center. Endurance tests were performed on 10 sets of helical face gears in mesh with tapered involute helical pinions, and 10 sets of ISF-enhanced straight face gears in mesh with tapered involute spur pinions. The results were compared to previous tests on straight face gears. The life of the ISF configuration was slightly less than that of previous tests on straight face gears. The life of the ISF configuration was slightly greater than that of the helical configuration.

  14. DURABILITY OF ASPHALT CONCRETE MIXTURES USING DOLOMITE AGGREGATES

    Directory of Open Access Journals (Sweden)

    Imad Al-Shalout

    2015-12-01

    Full Text Available This study deals with the durability of asphalt concrete, including the effects of different gradations, compaction temperatures and immersion time on the durability potential of mixtures. The specific objectives of this study are: to investigate the effect of compaction temperature on the mechanical properties of asphalt concrete mixtures; investigate the effect of bitumen content and different aggregate gradations on the durability potential of bituminous mixtures.

  15. Durability of capital goods: taxes and market structure

    Energy Technology Data Exchange (ETDEWEB)

    Raviv, A [Carnegie-Mellon Univ., Pittsburgh; Zemel, E

    1977-04-01

    This paper examines the durability of capital goods produced under different market structures when tax considerations are included. Since investment tax credit and depreciation allowances are realized by the owner of the durable good, the durability of products produced by an industry which sells its output differs from that of an industry which rents. For each of these two commercial forms, both monopolistic and competitive market structure are considered. Potential gains from different forms of regulation are discussed.

  16. The household decision making process in replacement of durable goods

    OpenAIRE

    Marell Molander, Agneta

    1998-01-01

    As durables are essential in many households, the level of ownership is high and, due to the high degree of penetration, a vast proportion of the current sales are replacement purchases. Even though a lot of research attention has been paid to decision making and decision processes many models are oriented towards non-durable goods and although a majority of purchases of many durable goods are replacements, few studies seem to make a distinction between a replacement purchase decision and a d...

  17. Intrahousehold Bargaining and the Demand for Consumer Durables in Brazil

    OpenAIRE

    Polato e Fava, Ana Claudia; Arends-Kuenning, Mary P.

    2013-01-01

    In Brazil, wives do most of the household work. About sixty percent of them also work outside the household, working a total of about 10 hours more per week than men. Because of this unequal distribution of household work, husbands and wives might have different priorities regarding the purchase of durable goods. Although both husbands and wives enjoy entertainment durable goods, wives might have a relative preference for household-production durable goods such as washing machines over entert...

  18. Energy Research in Switzerland in 1999; Energieforschung 1999. Ueberblicksberichte/Recherche energetique 1999. Rapports de synthese

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-15

    This comprehensive annual report for the Swiss Federal Office of Energy (SFOE) contains the overview-reports that were made by the heads of the following Swiss energy research programmes for the year 1999: Efficient use of energy in buildings and hot-water systems, solar architecture, electricity, ambient heat and heat-pumps, solar energy, photovoltaics, biomass, geothermal energy, small hydropower, wind energy, solar chemistry and hydrogen, combustion technologies, heat storage, nuclear energy and nuclear safety, nuclear fusion, fuel cells, accumulators and traffic. In the following, just a selection of the large number of topics covered are mentioned. Under the topic of efficient energy use in buildings, an environmental optimisation tool and an eco-inventory are mentioned and work done on the use of grass-fibres for insulation is noted along with new developments in highly efficient insulation systems, refurbishment of windows, thermo-active building components, as well as ventilation and heating systems. The efficient use of energy in hot-water preparation is discussed in a further report. In the solar architecture area, the validation of simulation programs and the trial of refurbishment concepts making indirect use of solar energy for heating, lighting and power generation are covered. Electrical topics include distribution and islanding, flywheel energy storage, high-temperature superconductors, power consumption of personal computers and household electronics, drives and compressors as well as saving energy in railway coaches. In the ambient heat and heat-pump area, projects on the modelling of heat probes are noted, as are those concerning intermediate injection, small ammonia heat-pumps, optimisation of combined heat and power plants, low-temperature heating, commercial cooling and disposal of used refrigerants. In the solar energy area, further work on software aids for the calculation of solar gain and developments in coatings for solar collectors are

  19. Energy Research in Switzerland in 2009; Energieforschung 2009. Ueberblicksberichte/Recherche energetique 2009. Rapports de synthese

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-06-15

    This very comprehensive annual report for the Swiss Federal Office of Energy (SFOE) contains the overview-reports for the year 2009 that were made by the heads of the following program-groups covered by Swiss energy research: Efficient energy use, renewable energy, nuclear energy and the energy-economy-society area. Under the comprehensive topic of efficient energy use, building concepts compatible with the '2000-Watt Society', Minergie-P 'passive' housing, calculation and dynamic simulation tools, sustainable building projects and developments in the building insulation area are mentioned along with refurbishment topics, the use of solar-thermal energy and electrical efficiency. In the traffic area, lightweight vehicles, drive systems - including hybrid systems - are reported on, as are electric scooters, vehicle-to-grid power storage and inter-modal transport systems. In the accumulators area, various new systems are looked at. With respect to electrical technology, work on electricity storage, conversion and high-temperature superconductors are reported on. Alternative power generation and storage systems are reviewed. Developments in the information and communications area are noted. 'Smart metering', standby losses and lift drives are reported on, as are household appliances and lighting systems. In the electricity area, the interaction of electricity grid and communication systems as well as future energy networks are reported on. In the heat pump and combined heat and power generation area, improving thermodynamic processes, integral system optimisation and high-efficiency systems as well as environment-friendly refrigerants and magnetic heat-pumps are discussed. Combustion topics reviewed include how research basics can be improved, numerical simulation methods, large diesel engines, catalytic reactions, the use of biogenic fuels and exhaust gas treatment. The 'Power Station 2020' and carbon capture and storage program reports on combined heat and power

  20. Energy Research in Switzerland in 2009; Energieforschung 2009. Ueberblicksberichte/Recherche energetique 2009. Rapports de synthese

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-06-15

    This very comprehensive annual report for the Swiss Federal Office of Energy (SFOE) contains the overview-reports for the year 2009 that were made by the heads of the following program-groups covered by Swiss energy research: Efficient energy use, renewable energy, nuclear energy and the energy-economy-society area. Under the comprehensive topic of efficient energy use, building concepts compatible with the '2000-Watt Society', Minergie-P 'passive' housing, calculation and dynamic simulation tools, sustainable building projects and developments in the building insulation area are mentioned along with refurbishment topics, the use of solar-thermal energy and electrical efficiency. In the traffic area, lightweight vehicles, drive systems - including hybrid systems - are reported on, as are electric scooters, vehicle-to-grid power storage and inter-modal transport systems. In the accumulators area, various new systems are looked at. With respect to electrical technology, work on electricity storage, conversion and high-temperature superconductors are reported on. Alternative power generation and storage systems are reviewed. Developments in the information and communications area are noted. 'Smart metering', standby losses and lift drives are reported on, as are household appliances and lighting systems. In the electricity area, the interaction of electricity grid and communication systems as well as future energy networks are reported on. In the heat pump and combined heat and power generation area, improving thermodynamic processes, integral system optimisation and high-efficiency systems as well as environment-friendly refrigerants and magnetic heat-pumps are discussed. Combustion topics reviewed include how research basics can be improved, numerical simulation methods, large diesel engines, catalytic reactions, the use of biogenic fuels and exhaust gas treatment. The 'Power Station 2020' and carbon capture and storage

  1. Pricing for a Durable-Goods Monopolist Under Rapid Sequential Innovation

    OpenAIRE

    Laura J. Kornish

    2001-01-01

    A durable-goods monopolist who will be introducing new and improved versions of his product must decide how to price his products, keeping in mind the relative attractiveness of the current and future products. Dhebar (1994) has shown that if technology is changing too quickly and the producer cannot credibly commit to future prices and quality, then no equilibrium strategy exists. That is, there is no credible strategy for the future product that the producer can commit to in the first perio...

  2. Evaluation of models of waste glass durability

    International Nuclear Information System (INIS)

    Ellison, A.

    1995-01-01

    The main variable under the control of the waste glass producer is the composition of the glass; thus a need exists to establish functional relationships between the composition of a waste glass and measures of processability, product consistency, and durability. Many years of research show that the structure and properties of a glass depend on its composition, so it seems reasonable to assume that there also is relationship between the composition of a waste glass and its resistance to attack by an aqueous solution. Several models have been developed to describe this dependence, and an evaluation their predictive capabilities is the subject of this paper. The objective is to determine whether any of these models describe the ''correct'' functional relationship between composition and corrosion rate. A more thorough treatment of the relationships between glass composition and durability has been presented elsewhere, and the reader is encouraged to consult it for a more detailed discussion. The models examined in this study are the free energy of hydration model, developed at the Savannah River Laboratory, the structural bond strength model, developed at the Vitreous State Laboratory at the Catholic University of America, and the Composition Variation Study, developed at Pacific Northwest Laboratory

  3. Durability of cement and geopolimer composites

    Science.gov (United States)

    Błaszczyński, T.; Król, M.

    2017-10-01

    Concrete structures are constantly moving in the direction of improving the durability. This main feature depends on many factors, which are the composition of concrete mix, the usage of additives and admixtures and the place, where material will work and carry the load. The introduction of new geopolymer binders for geopolymer structures adds a new aspect that is type of used activator. This substance with strongly alkaline reaction is divided because of the physical state, the alkaline degree and above all the chemical composition. Taking into account, that at present the geopolymer binders are made essentially from waste materials or by products from the combustion of coal or iron ore smelting, unambiguous determination of the effect of the activator on the properties of the geopolymer material requires a number of trials, researches and observation. This paper shows the influence of the most alkaline activators on the basic parameters of the durability of geopolymer binders. In this study there were used a highly alkaline hydroxides, water glasses and granules, which are waste materials in a variety of processes taking place in a chemical plants. As the substrate of geopolymer binders there were used fly ash which came from coal and high calcium ash from the burning of lignite.

  4. Durability of composites in a marine environment

    CERN Document Server

    Rajapakse, Yapa

    2014-01-01

    Composites are widely used in marine applications. There is considerable experience of glass reinforced resins in boats and ships but these are usually not highly loaded. However, for new areas such as offshore and ocean energy there is a need for highly loaded structures to survive harsh conditions for 20 years or more. High performance composites are therefore being proposed. This book provides an overview of the state of the art in predicting the long term durability of composite marine structures. The following points are covered: •       Modelling water diffusion •       Damage induced by water •       Accelerated testing •       Including durability in design •       In-service experience. This is essential reading for all those involved with composites in the marine industry, from initial design and calculation through to manufacture and service exploitation. It also provides information unavailable elsewhere on the mechanisms involved in degradation and how to t...

  5. Durability of coconut shell powder (CSP) concrete

    Science.gov (United States)

    Leman, A. S.; Shahidan, S.; Senin, M. S.; Shamsuddin, S. M.; Anak Guntor, N. A.; Zuki, S. S. Mohd; Khalid, F. S.; Azhar, A. T. S.; Razak, N. H. S.

    2017-11-01

    The rising cost of construction in developing countries like Malaysia has led concrete experts to explore alternative materials such as coconut shells which are renewable and possess high potential to be used as construction material. Coconut shell powder in varying percentages of1%, 3% and 5% was used as filler material in concrete grade 30 and evaluated after a curing period of 7 days and 28days respectively. Compressive strength, water absorption and carbonation tests were conducted to evaluate the strength and durability of CSP concrete in comparison with normal concrete. The test results revealed that 1%, 3% and 5% of CSP concrete achieved a compressive strength of 47.65 MPa, 45.6 MPa and 40.55% respectively. The rate of water absorption of CSP concrete was recorded as 3.21%, 2.47%, and 2.73% for 1%, 3% and 5% of CSP concrete respectively. Although CSP contained a carbon composition of 47%, the carbonation test showed that CSP no signs of carbon were detected inside the concrete. To conclude, CSP offers great prospects as it demonstrated relatively high durability as a construction material.

  6. Durability of thin-walled concrete structures

    International Nuclear Information System (INIS)

    Salomon, M.; Gallias, J.L.

    1991-01-01

    The aim of the present document is to draw up a survey of knowledge of the problems of ageing of reinforced concrete shell structure atmospheric coolers. The exposure conditions are particularly favourable to the induction and development of degradation which, because of the thinness of the reinforced concrete can compromise the stability and the durability of coolers. The study will be axed on the link between the specific characteristics of coolers from the point of view of operation, design and environment, also the durability of reinforced concrete. The set of factors exerting their influence on the reinforced concrete of the shell structure (condensates, rain water, temperature and humidity gradients, dynamic loads, weathering, etc.) is particularly complex. The principal degradation reactions involved are classified according to the chemical and physical action on concrete and on the reinforcement. Particular emphasis is placed on the analysis of degradation processes and the influence of the characteristics of the materials and of the medium. The aim is to determine the mechanisms which present the greatest risk for coolers. The interaction between the degradation to concrete and the change in mechanical characteristics is also studied [fr

  7. Durability of high performance concrete in seawater

    International Nuclear Information System (INIS)

    Amjad Hussain Memon; Salihuddin Radin Sumadi; Rabitah Handan

    2000-01-01

    This paper presents a report on the effects of blended cements on the durability of high performance concrete (HPC) in seawater. In this research the effect of seawater was investigated. The specimens were initially subjected to water curing for seven days inside the laboratory at room temperature, followed by seawater curing exposed to tidal zone until testing. In this study three levels of cement replacement (0%, 30% and 70%) were used. The combined use of chemical and mineral admixtures has resulted in a new generation of concrete called HPC. The HPC has been identified as one of the most important advanced materials necessary in the effort to build a nation's infrastructure. HPC opens new opportunities in the utilization of the industrial by-products (mineral admixtures) in the construction industry. As a matter of fact permeability is considered as one of the fundamental properties governing the durability of concrete in the marine environment. Results of this investigation indicated that the oxygen permeability values for the blended cement concretes at the age of one year are reduced by a factor of about 2 as compared to OPC control mix concrete. Therefore both blended cement concretes are expected to withstand in the seawater exposed to tidal zone without serious deterioration. (Author)

  8. The city and the energy security; La ville et la securite energetique

    Energy Technology Data Exchange (ETDEWEB)

    Roques, F.; Volkov, E.; Gantes, P.; Peek, P.; Vallar, Ch.; Telegina, E.; Fache, D.; Dreiski, P.; Pouffary, St.; Plate, N.; Kopsov, A.Y.; Benque, J.P.; Allegre, M.; Gsell, K.; Sanchez, M.; Hadhri, M.; Rouyer, J.L.; Rogeaux, B.; Clauwaert, A.; Garin, P.; Mernier, A.; Ruban, L.; Alario, E.; Allegre, M.; Asiani, F.; Banon, G.; Barelli, P.; Benque, J.P.; Bertoglio, S.; Blot, Y.; Bogolyubov, S.; Bonnaure, A.; Cabana, Y.; Casanova, L.; Chegodaev, A.; Cisse, S.; Clauwaert, A.; Colombier, A.M.; Collard, P.; Coma, O.; Combe, M.; Corbiere-Medecin, A.; Courdy, J.C.; Coursimault, E.; D' Addio, J.C.; Dastarac, H.; Daugreilh, J.P.; Surville, H. de; Doz, M.; Dreiski, P.; Efimouchkine, S.; Fache, D.; Ferrari, B.; Forkasiewicz, J.; Gantes, P.; Garin, P.; Gouirand, P.; Gsell, K.; Guibbolini, P.; Guillot, V.; Hadhri, M.; Ionescu, S.; Kostyuk, V.; Lecach, J.; Lorieux, L.; Luca, L.; Mangeard, Ph.; Matchabelli, V.; Mernier, A.; Murgeanu, R.; Nastase, A.; Nigoul, C.; D' Oleon, M.; Ollivier, J.; Oulianovsky, Y.; Pages, D.; Pataki, Z.; Peek, P.; Perdigon, M.F.; Piacenza, M.; Plate, N.; Poirier, J.; Pouffary, St.; Prez, Ch.; Prufer, Y.; Rogeaux, B.; Roques, F.; Rouyer, J.L.; Ruban, L.; Sanchez, M.; Sayamov, Y.; Semenescu, O.; Skorov, G.; Telegina, E.; Theiler, Ch.; Thomas, D.; Valais, M.; Vallar, Ch.; Volkov, E.; Von Scholz, H.; Waechter, M.; Zaboussov, V.; Zakharova, N.; Zoubkov, Y

    2006-07-01

    The answers to the world energy crisis should not be limited to the management of geopolitical factors (Iran, Nigeria, Venezuela etc.) and to the control of the offer (inciting OPEC countries to optimize their production). They involve also a change of the demand and of the consumers' behaviour. The comments caused by the recent rise of oil prices have shown that this idea, considered as marginal by policy-makers, has started to make its way. The analyses limited to macro-economical units (states, international organization), always forget that cities are the main places of energy consumption. Recent events, like the repetitive saturation of power grids at the origin of spectacular blackouts (Moscow, California, Switzerland, Italy), have led the local authorities to take into consideration part of the problem. They effectively have at their disposition some important leviers which allow them to act both on the offer and on the behaviours. It is evident that in domains like transports, urban renovation or waste treatment, the local authorities have to play a significant role by implementing policies that maximize the energy efficiency and minimize the costs at the same time. The debates which took place during this forum were based on the experiences and realizations presented by experts of several big cities, in particular of Moscow, Madrid and Nuremberg. Some remarkable examples were presented, in particular in the domain of energy auditing, mastery of energy consumptions and production of alternative resources. The usual topics were also approached: energy overview, main trends of the present day energy policy of Russia, new opportunities of new technologies, geo-energy evolutions, Russia-European Union dialogue. (J.S.)

  9. Swiss energy research programme on solar heat and storage for 2008-2011; Programme de recherche energetique. Chaleur solaire et stockage pour la periode 2008-2011

    Energy Technology Data Exchange (ETDEWEB)

    Hadorn, J.-C.

    2009-07-15

    This report published by the Swiss Federal Office of Energy (SFOE) takes a look at the research programme on solar heat and heat storage for the years 2008 - 2011. This document presents some aspects of the solar thermal market in 2007, summarizes the main solar thermal technologies for buildings and sketches the main topics of the 'Solar Heat and Heat Storage' research programme. Research and development issues looked at focus mainly on the heating and cooling of buildings. The research and development issues for solar thermal technologies during the period 2008-2011 include improved performance and durability of solar collectors and components, new coatings for solar collectors based on nano-materials as well as simplified and standardised systems for solar heating and cooling. Building Integration and integration in existing heating systems and long-term work with a focus on new materials for storing heat for use in residential buildings are discussed. Also, calculation methods and simulation tools are examined. Pilot and demonstration projects are reviewed.

  10. Influence Of Density On The Durabilities Of Three Ghanaian Timbers ...

    African Journals Online (AJOL)

    Review of factors influencing wood durability shows although density varies depending on trunk position, its role appears controversial for many timber species. Thus, for the first time, the influence of density on the durability of three Ghanaian timbers (Nauclea diderrichii (de Wild.) Merr., Nesogordonia papaverifera (A. Chev ...

  11. Adhesives for Achieving Durable Bonds with Acetylated Wood

    Science.gov (United States)

    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...

  12. Chemical durability of glasses containing radioactive fission product waste

    International Nuclear Information System (INIS)

    Mendel, J.E.; Ross, W.A.

    1974-04-01

    Measurements made to determine the chemical durability of glasses for disposal of radioactive waste are discussed. The term glass covers materials varying from true glass with only minute quantities of crystallites, such as insoluble RuO 2 , to quasi glass-ceramics which are mostly crystalline. Chemical durability requirements and Soxhlet extractor leach tests are discussed

  13. Effect of Unprofessional Supervision on Durability of Buildings.

    Science.gov (United States)

    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.

  14. Durability of Silicate Glasses: An Historical Approach

    International Nuclear Information System (INIS)

    Farges, Francois; Etcheverry, Marie-Pierre; Haddi, Amine; Trocellier, Patrick; Curti, Enzo; Brown, Gordon E. Jr.

    2007-01-01

    We present a short review of current theories of glass weathering, including glass dissolution, and hydrolysis of nuclear waste glasses, and leaching of historical glasses from an XAFS perspective. The results of various laboratory leaching experiments at different timescales (30 days to 12 years) are compared with results for historical glasses that were weathered by atmospheric gases and soil waters over 500 to 3000 years. Good agreement is found between laboratory experiments and slowly leached historical glasses, with a strong enrichment of metals at the water/gel interface. Depending on the nature of the transition elements originally dissolved in the melt, increasing elemental distributions are expected to increase with time for a given glass durability context

  15. Glass Durability Modeling, Activated Complex Theory (ACT)

    International Nuclear Information System (INIS)

    CAROL, JANTZEN

    2005-01-01

    The most important requirement for high-level waste glass acceptance for disposal in a geological repository is the chemical durability, expressed as a glass dissolution rate. During the early stages of glass dissolution in near static conditions that represent a repository disposal environment, a gel layer resembling a membrane forms on the glass surface through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer has been found to age into either clay mineral assemblages or zeolite mineral assemblages. The formation of one phase preferentially over the other has been experimentally related to changes in the pH of the leachant and related to the relative amounts of Al +3 and Fe +3 in a glass. The formation of clay mineral assemblages on the leached glass surface layers ,lower pH and Fe +3 rich glasses, causes the dissolution rate to slow to a long-term steady state rate. The formation of zeolite mineral assemblages ,higher pH and Al +3 rich glasses, on leached glass surface layers causes the dissolution rate to increase and return to the initial high forward rate. The return to the forward dissolution rate is undesirable for long-term performance of glass in a disposal environment. An investigation into the role of glass stoichiometry, in terms of the quasi-crystalline mineral species in a glass, has shown that the chemistry and structure in the parent glass appear to control the activated surface complexes that form in the leached layers, and these mineral complexes ,some Fe +3 rich and some Al +3 rich, play a role in whether or not clays or zeolites are the dominant species formed on the leached glass surface. The chemistry and structure, in terms of Q distributions of the parent glass, are well represented by the atomic ratios of the glass forming components. Thus, glass dissolution modeling using simple

  16. Durability of Silicate Glasses: An Historical Approach

    Energy Technology Data Exchange (ETDEWEB)

    Farges, Francois; /Museum Natl. Hist. Natur. /Stanford U., Geo. Environ. Sci.; Etcheverry, Marie-Pierre; /Marne la Vallee U.; Haddi, Amine; /Marne la Valle U.; Trocellier,; /Saclay; Curti, Enzo; /PSI, Villigen; Brown, Gordon E., Jr.; /SLAC, SSRL

    2007-01-02

    We present a short review of current theories of glass weathering, including glass dissolution, and hydrolysis of nuclear waste glasses, and leaching of historical glasses from an XAFS perspective. The results of various laboratory leaching experiments at different timescales (30 days to 12 years) are compared with results for historical glasses that were weathered by atmospheric gases and soil waters over 500 to 3000 years. Good agreement is found between laboratory experiments and slowly leached historical glasses, with a strong enrichment of metals at the water/gel interface. Depending on the nature of the transition elements originally dissolved in the melt, increasing elemental distributions are expected to increase with time for a given glass durability context.

  17. Lightweight, durable lead-acid batteries

    Science.gov (United States)

    Lara-Curzio, Edgar; An, Ke; Kiggans, Jr., James O; Dudney, Nancy J; Contescu, Cristian I; Baker, Frederick S; Armstrong, Beth L

    2013-05-21

    A lightweight, durable lead-acid battery is disclosed. Alternative electrode materials and configurations are used to reduce weight, to increase material utilization and to extend service life. The electrode can include a current collector having a buffer layer in contact with the current collector and an electrochemically active material in contact with the buffer layer. In one form, the buffer layer includes a carbide, and the current collector includes carbon fibers having the buffer layer. The buffer layer can include a carbide and/or a noble metal selected from of gold, silver, tantalum, platinum, palladium and rhodium. When the electrode is to be used in a lead-acid battery, the electrochemically active material is selected from metallic lead (for a negative electrode) or lead peroxide (for a positive electrode).

  18. Durable bistable auxetics made of rigid solids

    Science.gov (United States)

    Shang, Xiao; Liu, Lu; Rafsanjani, Ahmad; Pasini, Damiano

    2018-02-01

    Bistable Auxetic Metamaterials (BAMs) are a class of monolithic perforated periodic structures with negative Poisson's ratio. Under tension, a BAM can expand and reach a second state of equilibrium through a globally large shape transformation that is ensured by the flexibility of its elastomeric base material. However, if made from a rigid polymer, or metal, BAM ceases to function due to the inevitable rupture of its ligaments. The goal of this work is to extend the unique functionality of the original kirigami architecture of BAM to a rigid solid base material. We use experiments and numerical simulations to assess performance, bistability and durability of rigid BAMs at 10,000 cycles. Geometric maps are presented to elucidate the role of the main descriptors of BAM architecture. The proposed design enables the realization of BAM from a large palette of materials, including elastic-perfectly plastic materials and potentially brittle materials.

  19. Durable fiber reinforced self-compacting concrete

    International Nuclear Information System (INIS)

    Corinaldesi, V.; Moriconi, G.

    2004-01-01

    In order to produce thin precast elements, a self-compacting concrete was prepared. When manufacturing these elements, homogenously dispersed steel fibers instead of ordinary steel-reinforcing mesh were added to the concrete mixture at a dosage of 10% by mass of cement. An adequate concrete strength class was achieved with a water to cement ratio of 0.40. Compression and flexure tests were carried out to assess the safety of these thin concrete elements. Moreover, serviceability aspects were taken into consideration. Firstly, drying shrinkage tests were carried out in order to evaluate the contribution of steel fibers in counteracting the high concrete strains due to a low aggregate-cement ratio. Secondly, the resistance to freezing and thawing cycles was investigated on concrete specimens in some cases superficially treated with a hydrophobic agent. Lastly, both carbonation and chloride penetration tests were carried out to assess durability behavior of this concrete mixture

  20. Sustainability and durability analysis of reinforced concrete structures

    Science.gov (United States)

    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.

  1. Durability of an inorganic polymer concrete coating

    Science.gov (United States)

    Wasserman, Kenneth

    The objective of the research program reported in this thesis is to evaluate the durability of an inorganic polymer composite coating exposed to freeze/thaw cycling and wet-dry cycling. Freeze/thaw cycling is performed following ASTM D6944-09 Standard Practice for Resistance of Cured Coatings to Thermal Cycling and wet/dry cycling is performed following guidelines set forth in a thesis written by Ronald Garon at Rutgers University. For both sets of experiments, four coating mixture proportions were evaluated. The variables were: silica/alumina ratio, mixing protocol using high shear and normal shear mixing, curing temperatures of 70 and 120 degrees Fahrenheit and use of nano size constituent materials. The mix with highest silica/alumina ratio was designated as Mix 1 and mixes with lower ratios were designated as Mix 2 and Mix 3. Mix 4 had nano silica particles. Four prisms were used for each variable including control that had no coating. The performance of the coating was evaluated using adhesion strength measured using: ASTM D7234 Test Method for Pull-Off Strength of Coatings on Concrete Using Portable Adhesion Testers. Tests were performed after every five consecutive cycles of thermal conditioning and six consecutive cycles of wet-dry exposure. Results from the thermal cycling and wet-dry testing demonstrate that all coating formulations are durable. The minimum adhesion strength was 300 psi even though a relatively weak base concrete surface was chosen for the study. The weak surface was chosen to simulate aged concrete surfaces present in actual field conditions. Due to the inherent nature of the test procedure the variation in test results is high. However, based on the test results, high shear mixer and high temperature curing are not recommended. As expected nano size constituent materials provide better performance.

  2. 75 FR 51245 - Agency Information Collection Activities; Proposed Collection; Comment Request; Durable Nursery...

    Science.gov (United States)

    2010-08-19

    ... CONSUMER PRODUCT SAFETY COMMISSION [Docket No. CPSC-2010-0088] Agency Information Collection Activities; Proposed Collection; Comment Request; Durable Nursery Products Exposure Survey AGENCY: Consumer... efforts on durable infant and toddler products. The draft Durable Nursery Products Exposure Survey...

  3. FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Harris, C.E.

    1994-09-01

    International technical experts in durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The symposium focused on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure, criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and advanced approaches to resist corrosion and environmentally assisted fatigue. Separate abstracts have been indexed for articles from this report.

  4. Energy diagnosis; Diagnostic energetique

    Energy Technology Data Exchange (ETDEWEB)

    Vivien, P. [Centre Technique des Industries Mecaniques (CETIM), Franche-Comte (France)

    1996-12-31

    Through a partnership with regional authorities and the French Energy Conservation Agency (ADEME), the CETIM (Technical Agency for Mechanical Industries) is proposing energy audits in industrial plants with the aim to increase the plant performances, reduce energy costs and work out environmental issues. Concrete improvement solutions are proposed with profitability calculations. The audit procedure is presented. The most efficient solutions generally involve energy tariff rate shifts, heating regulation, power cut-off, reactive energy compensation and lighting management

  5. Energy efficiency; Efficacite energetique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    This road-map proposes by the Group Total aims to inform the public on the energy efficiency. It presents the energy efficiency and intensity around the world with a particular focus on Europe, the energy efficiency in industry and Total commitment. (A.L.B.)

  6. Conception et validation d'un modele d'analyse et de suivi pour une politique energetique durable et acceptable de l'energie eolienne: Une etude comparative France-Quebec

    Science.gov (United States)

    Feurtey, Evariste

    In this research, we built a conceptual model of a sustainable and acceptable wind power policy that we tried to validate through the case study of France and Quebec in the wind energy sector. Our qualitative and comparative approach helps us to illustrate the interaction of institutional variables studied, including the national context of emergence, the balance of power between pressure groups, the supranational and exogenous influences, level of political commitment, policy and regulatory instruments, social acceptance and energy policy mechanisms. The research confirms that the neo-corporatism is present in France as in Quebec. With the unfavorable energy context (low cost of electricity tariff, lack of electricity demand, and an already low zero carbon electric mix), it is an important factor explaining : 1) the 20 years delay accumulated by France and Quebec in the development of wind projects or industrial sector; 2) the 10% limited penetration scale given to wind energy. We also demonstrate that the political commitment to develop wind energy fluctuates with the government majority, the energy context or the influence of pressure groups. This manifests itself in a lack of continuity of policies and tariff instruments used. In both national case studies, the results also show that balanced policies and regulations ensure sustainable development of wind energy only if they allow a sufficient market size. The search results also illustrates that the conceptual division made between acceptance of wind sector, acceptance of ownership, local acceptance is very instructive. Social controversies, though multifactorial, are connected to both a critique of the development model too industrial and private, territorial dilemmas (closed environment), energy context (electric surplus in Quebec), or related to strategic planning system and centralized decision. An important issue for a more acceptable wind policy in the future will come to a greater plurality of ownership, variety of wind projects scale, diversity of financial support mechanisms. This transformation to a more territorial policy that require renewables also calls for decentralization and ecological modernization of institutions. Sustainable and acceptable energy policy requires obtaining a stabilized consensus on the long-term energy mix, which should be done by a comprehensive energy and public debate upstream the development of energy policy. Keywords: energy policy, social acceptance, wind energy, environmental assessment, components, interactions.

  7. Towards a durability test for washing-machines.

    Science.gov (United States)

    Stamminger, Rainer; Tecchio, Paolo; Ardente, Fulvio; Mathieux, Fabrice; Niestrath, Phoebe

    2018-04-01

    Durability plays a key role in enhancing resource conservation and contributing to waste minimization. The washing-machine product group represents a relevant case study for the development of a durability test and as a potential trigger to systematically address durability in the design of products. We developed a procedure to test the durability performance of washing-machines as a main objective of this research. The research method consisted of an analysis of available durability standards and procedures to test products and components, followed by an analysis of relevant references related to frequent failures. Finally, we defined the criteria and the conditions for a repeatable, relatively fast and relevant endurance test. The durability test considered the whole product tested under conditions of stress. A series of spinning cycles with fixed imbalanced loads was run on two washing-machines to observe failures and performance changes during the test. Even though no hard failures occurred, results clearly showed that not all washing-machines can sustain such a test without abrasion or performance deterioration. However, the attempt to reproduce the stress induced on a washing-machine by carrying out a high number of pure spinning cycles with fixed loads did not allow equal testing conditions: the actions of the control procedure regarding imbalanced loads differ from machine to machine. The outcomes of this research can be used as grounds to develop standardised durability tests and to, hence, contribute to the development of future product policy measures.

  8. Testing the durability of concrete with neutron radiography

    International Nuclear Information System (INIS)

    Beer, F.C. de; Le Roux, J.J.; Kearsley, E.P.

    2005-01-01

    The ability of concrete to withstand the penetration of liquid and oxygen can be described as the durability of concrete. The durability of concrete, can in turn, be quantified by certain characteristics of the concrete such as the porosity, sorptivity and permeability. The quantification of neutron radiography images of concrete structures and, therefore, the determination of concrete characteristics validate conventional measurements. This study compares the neutron radiography capability to obtain quantitative data for porosity and sorptivity in concrete to laboratory or conventional measurements. The effects that water to cement ratio and curing time have on the durability of concrete are investigated

  9. Influence of chloride admixtures on cement matrix durability

    International Nuclear Information System (INIS)

    Sheikh, I.A.; Zamorani, E.; Serrini, G.

    1989-01-01

    The influence of various inorganic salts, as chloride admixtures to Portland cement, on the mechanical properties and the durability of the matrix has been studied. The salts used in this study are chromium, nickel and cadmium chlorides. Improved compressive strength values are obtained which have been correlated to the stable metal hydroxide formation in high pH environment. Under static water conditions at 50 0 C, hydrolyzed chloride ions exhibit adverse effects on the matrix durability through rapid release of calcium as calcium chloride in the initial period of leaching. On the contrary, enhanced matrix durability is obtained on long term leaching in the case of cement containing chromium chloride

  10. Factors influencing chemical durability of nuclear waste glasses

    International Nuclear Information System (INIS)

    Feng, Xiangdong; Bates, J.K.

    1993-01-01

    A short summary is given of our studies on the major factors that affect the chemical durability of nuclear waste glasses. These factors include glass composition, solution composition, SA/V (ratio of glass surface area to the volume of solution), radiation, and colloidal formation. These investigations have enabled us to gain a better understanding of the chemical durability of nuclear waste glasses and to accumulate.a data base for modeling the long-term durability of waste glass, which will be used in the risk assessment of nuclear waste disposal. This knowledge gained also enhances our ability to formulate optimal waste glass compositions

  11. ACCELERATED METHODS FOR ESTIMATING THE DURABILITY OF PLAIN BEARINGS

    Directory of Open Access Journals (Sweden)

    Myron Czerniec

    2014-09-01

    Full Text Available The paper presents methods for determining the durability of slide bearings. The developed methods enhance the calculation process by even 100000 times, compared to the accurate solution obtained with the generalized cumulative model of wear. The paper determines the accuracy of results for estimating the durability of bearings depending on the size of blocks of constant conditions of contact interaction between the shaft with small out-of-roundedness and the bush with a circular contour. The paper gives an approximate dependence for determining accurate durability using either a more accurate or an additional method.

  12. The Sit-and-Wait Hypothesis in Bacterial Pathogens: A Theoretical Study of Durability and Virulence

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2017-11-01

    Full Text Available The intriguing sit-and-wait hypothesis predicts that bacterial durability in the external environment is positively correlated with their virulence. Since its first proposal in 1987, the hypothesis has been spurring debates in terms of its validity in the field of bacterial virulence. As a special case of the vector-borne transmission versus virulence tradeoff, where vector is now replaced by environmental longevity, there are only sporadic studies over the last three decades showing that environmental durability is possibly linked with virulence. However, no systematic study of these works is currently available and epidemiological analysis has not been updated for the sit-and-wait hypothesis since the publication of Walther and Ewald’s (2004 review. In this article, we put experimental evidence, epidemiological data and theoretical analysis together to support the sit-and-wait hypothesis. According to the epidemiological data in terms of gain and loss of virulence (+/- and durability (+/- phenotypes, we classify bacteria into four groups, which are: sit-and-wait pathogens (++, vector-borne pathogens (+-, obligate-intracellular bacteria (--, and free-living bacteria (-+. After that, we dive into the abundant bacterial proteomic data with the assistance of bioinformatics techniques in order to investigate the two factors at molecular level thanks to the fast development of high-throughput sequencing technology. Sequences of durability-related genes sourced from Gene Ontology and UniProt databases and virulence factors collected from Virulence Factor Database are used to search 20 corresponding bacterial proteomes in batch mode for homologous sequences via the HMMER software package. Statistical analysis only identified a modest, and not statistically significant correlation between mortality and survival time for eight non-vector-borne bacteria with sit-and-wait potentials. Meanwhile, through between-group comparisons, bacteria with higher

  13. Durability and performance optimization of cathode materials for fuel cells

    Science.gov (United States)

    Colon-Mercado, Hector Rafael

    The primary objective of this dissertation is to develop an accelerated durability test (ADT) for the evaluation of cathode materials for fuel cells. The work has been divided in two main categories, namely high temperature fuel cells with emphasis on the Molten Carbonate Fuel Cell (MCFC) cathode current collector corrosion problems and low temperature fuel cells in particular Polymer Electrolyte Fuel Cell (PEMFC) cathode catalyst corrosion. The high operating temperature of MCFC has given it benefits over other fuel cells. These include higher efficiencies (>50%), faster electrode kinetics, etc. At 650°C, the theoretical open circuit voltage is established, providing low electrode overpotentials without requiring any noble metal catalysts and permitting high electrochemical efficiency. The waste heat is generated at sufficiently high temperatures to make it useful as a co-product. However, in order to commercialize the MCFC, a lifetime of 40,000 hours of operation must be achieved. The major limiting factor in the MCFC is the corrosion of cathode materials, which include cathode electrode and cathode current collector. In the first part of this dissertation the corrosion characteristics of bare, heat-treated and cobalt coated titanium alloys were studied using an ADT and compared with that of state of the art current collector material, SS 316. PEMFCs are the best choice for a wide range of portable, stationary and automotive applications because of their high power density and relatively low-temperature operation. However, a major impediment in the commercialization of the fuel cell technology is the cost involved due to the large amount of platinum electrocatalyst used in the cathode catalyst. In an effort to increase the power and decrease the cathode cost in polymer electrolyte fuel cell (PEMFC) systems, Pt-alloy catalysts were developed to increase its activity and stability. Extensive research has been conducted in the area of new alloy development and

  14. L'impact de l'obsolescence perçue des biens durables sur la décision de remplacement et la destinée de l'objet remplacé

    OpenAIRE

    Guillard , Valérie; Le Nagard , Emmanuelle

    2018-01-01

    This research aims to understand, define and measure the perceived obsolescence of durable goods. A qualitative study of 10 people followed by three quantitative studies of 765 people made it possible to i) define the obsolescence of a durable good owned by a consumer as his/her perception that there is a better product on the market; (ii) to measure its technological, social, ecological, market and technological dimensions and (iii) to understand its antecedents and its consequence on the in...

  15. Research report for fiscal 1995 on analysis and evaluation of demonstration tests for establishment of residential photovoltaic power generation load leveling technology. Evaluation on durability of device installed with inverter to protect grid connection; 1995 nendo kenkyu hokokusho. Jutaku you taiyoko hatsuden fuka heijunka gijutsu tou kakuritsu jissho shiken ni kansuru kaiseki hyoka - Inbata tsuki keito renkei hogo sochi no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Discussions and evaluations have been performed on the safety and durability of the device installed with inverter to protect grid connection being an important device in the photovoltaic power generation system. In discussing the durability test items, electrical property changes were observed on AC overvoltage, AC undervoltage, frequency rise, and frequency fall, as the continuation from the previous fiscal year, in order to evaluate temperature rise in different parts due to lapse of operation time and the effects of thermal stress in each component on the stress of the entire product. Furthermore, verification of single operation detecting function, tests on sudden input power change, sudden grid voltage change, and measurement of conductive high frequency terminal voltage were conducted in addition to the above observations. In discussing the durability test methods, repetition of operation and shutdown during the rated operation was adopted in place of the simulated operation using variation in the insolation having been discussed in the previous year. As a result of the tests, no noticeable changes were recognized from the evaluation result after a lapse of 5,000 hours from the start of the operation, as compared to those after the aging operation. (NEDO)

  16. High gain durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Colson, Thomas E.; Gonsalves, Peter R.; Abrams, Ze' ev R.

    2017-06-27

    Disclosed herein are polysilsesquioxane-based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In one embodiment, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, thermal radical initiator, photo radical initiators, crosslinkers, Si--OH condensation catalyst and nano-fillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  17. Teeth: Among Nature's Most Durable Biocomposites

    Science.gov (United States)

    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.

  18. Surface chemistry and durability of borosilicate glass

    International Nuclear Information System (INIS)

    Carroll, S.A.; Bourcier, W.L.; Phillips, B.L.

    1994-01-01

    Important glass-water interactions are poorly understood for borosilicate glass radioactive waste forms. Preliminary results show that glass durability is dependent on reactions occurring at the glass-solution interface. CSG glass (18.2 wt. % Na 2 O, 5.97 wt. % CaO, 11.68 wt. % Al 2 O 3 , 8.43 wt. % B 2 O 3 , and 55.73 wt. % SiO 2 ) dissolution and net surface H + and OH - adsorption are minimal at near neutral pH. In the acid and alkaline pH regions, CSG glass dissolution rates are proportional to [H + ] adsorbed 2 and [OH - ] adsorbed 0.8 , respectively. In contrast, silica gel dissolution and net H + and OH - adsorption are minimal and independent of pH in acid to neutral solutions. In the alkaline pH region, silica gel dissolution is proportional to [OH - ] adsorbed 0.9 adsorbed . Although Na adsorption is significant for CSG glass and silica gel in the alkaline pH regions, it is not clear if it enhances dissolution, or is an artifact of depolymerization of the framework bonds

  19. Increase of operational reliability and durability of square sectoral working bodies of flexible screw conveyors

    Directory of Open Access Journals (Sweden)

    O.L. Lyashuk

    2017-12-01

    Full Text Available The construction of the device for guiding screw sectional working bodies of increased operational reliability and durability and the method of determination of the force of guiding the design parameters are given. Two main methods of manufacturing screw mechanisms of machines of various service purposes were investigated and it was established that twisted screws, in terms of their strength and performance, considerably exceed rolling stock. The design of the device for manufacturing screw working bodies of conveyors by means of cutting by periodic and continuous methods, as the most reliable in operation, is developed. The specifics of their work are due to various operations of technological processes, as well as physical and mechanical properties of goods, determine the nomenclature and design parameters of screw mechanisms (SM. In studying the processes of forming screw spirals, the basic precision characteristics of the methods of drilling and rolling are established. A comparative study of two main methods in terms of their operational and durable capabilities has been carried out. An important factor determining the reliability and durability of a screw is the difference in the thickness of the inner and outer edges.

  20. A highly durable fuel cell electrocatalyst based on double-polymer-coated carbon nanotubes.

    Science.gov (United States)

    Berber, Mohamed R; Hafez, Inas H; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2015-11-23

    Driven by the demand for the commercialization of fuel cell (FC) technology, we describe the design and fabrication of a highly durable FC electrocatalyst based on double-polymer-coated carbon nanotubes for use in polymer electrolyte membrane fuel cells. The fabricated electrocatalyst is composed of Pt-deposited polybenzimidazole-coated carbon nanotubes, which are further coated with Nafion. By using this electrocatalyst, a high FC performance with a power density of 375 mW/cm(2) (at 70 ˚C, 50% relative humidity using air (cathode)/H2(anode)) was obtained, and a remarkable durability of 500,000 accelerated potential cycles was recorded with only a 5% loss of the initial FC potential and 20% loss of the maximum power density, which were far superior properties compared to those of the membrane electrode assembly prepared using carbon black in place of the carbon nanotubes. The present study indicates that the prepared highly durable fuel cell electrocatalyst is a promising material for the next generation of PEMFCs.

  1. Effect of Soorh Metakaolin on Concrete Compressive Strength and Durability

    Directory of Open Access Journals (Sweden)

    A. Saand

    2017-12-01

    Full Text Available Concrete durability is a key aspect for forecasting the expected life time of concrete structures. In this paper, the effect of compressive strength and durability of concrete containing metakaolin developed from a local natural material (Soorh of Thatta Distict of Sindh, Pakistan is investigated. Soorh is calcined by an electric furnace at 8000C for 2 hours to produce metakaolin. One mix of ordinary concrete and five mixes of metakaolin concrete were prepared, where cement is replaced by developed metakaolin from 5% to 25% by weight, with 5% increment step. The concrete durability was tested for water penetration, carbonation depth and corrosion resistance. The obtained outcomes demonstrated that, 15% replacement level of local developed metakaolin presents considerable improvements in concrete properties. Moreover, a considerable linear relationship was established between compressive strength and concrete durability indicators like water penetration, carbonation depth and corrosion resistance.

  2. Thermodynamic model of natural, medieval and nuclear waste glass durability

    International Nuclear Information System (INIS)

    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 from the Hanford Reservation (10 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

  3. Development of a CB Resistant Durable, Flexible Hydration System

    National Research Council Canada - National Science Library

    Hall, Peyton W; Zeller, Frank T; Bulluck, John W; Dingus, Michael L

    2002-01-01

    A durable, flexible hydration system resistant to contamination by contact with VX, GD, and HD chemical agents, as well as damage by the decontaminants sodium hypochlorite and DS-2 is being developed for aviator use...

  4. Nanocomposites for Improved Physical Durability of Porous PVDF Membranes

    Science.gov (United States)

    Lai, Chi Yan; Groth, Andrew; Gray, Stephen; Duke, Mikel

    2014-01-01

    Current commercial polymer membranes have shown high performance and durability in water treatment, converting poor quality waters to higher quality suitable for drinking, agriculture and recycling. However, to extend the treatment into more challenging water sources containing abrasive particles, micro and ultrafiltration membranes with enhanced physical durability are highly desirable. This review summarises the current limits of the existing polymeric membranes to treat harsh water sources, followed by the development of nanocomposite poly(vinylidene fluoride) (PVDF) membranes for improved physical durability. Various types of nanofillers including nanoparticles, carbon nanotubes (CNT) and nanoclays were evaluated for their effect on flux, fouling resistance, mechanical strength and abrasion resistance on PVDF membranes. The mechanisms of abrasive wear and how the more durable materials provide resistance was also explored. PMID:24957121

  5. Durability studies on the high calcium flyash based GPC

    African Journals Online (AJOL)

    Keywords: Geopolymer concrete, high calcium flyash, durability, corrosion resistance, polarisation test. ... Reddy, et al (2011) reported that excellent resistance to chloride .... being the metal on the higher electro potential range, to the negative ...

  6. Durability of Bricks Coated with Red mud Based Geopolymer Paste

    Science.gov (United States)

    Singh, Smita; Basavanagowda, S. N.; Aswath, M. U.; Ranganath, R. V.

    2016-09-01

    The present study is undertaken to assess the durability of concrete blocks coated with red mud - fly ash based geopolymer paste. Concrete blocks of size 200 x 200 x 100mm were coated with geopolymer paste synthesized by varying the percentages of red mud and fly ash. Uncoated concrete blocks were also tested for the durability for comparison. In thermal resistance test, the blocks were subjected to 600°C for an hour whereas in acid resistance test, they were kept in 5% sulphuric acid solution for 4 weeks. The specimens were thereafter studied for surface degradation, strength loss and weight loss. Pastes with red mud percentage greater than 50% developed lot of shrinkage cracks. The blocks coated with 30% and 50% red mud paste showed better durability than the other blocks. The use of blocks coated with red mud - fly ash geopolymer paste improves the aesthetics, eliminates the use of plaster and improves the durability of the structure.

  7. The Overjustification Effect in Retarded Children: Durability and Generalizability.

    Science.gov (United States)

    Ogilvie, Lee; Prior, Margot

    1982-01-01

    Generalizability and durability of the overjustification effect (on decline in intrinsic motivation due to the lack of rewards in behavior modification programs) were examined in 35 normal preschool children and 17 mental age-matched retarded children. (Author/SW)

  8. Durability of filament-wound composite flywheel rotors

    Science.gov (United States)

    Koyanagi, Jun

    2012-02-01

    This paper predicts the durability of two types of flywheels, one assumes to fail in the radial direction and the other assumes to fail in the circumferential direction. The flywheel failing in the radial direction is a conventional filament-wound composite flywheel and the one failing in the circumferential direction is a tailor-made type. The durability of the former is predicted by Micromechanics of Failure (MMF) (Ha et al. in J. Compos. Mater. 42:1873-1875, 2008), employing time-dependent matrix strength, and that of the latter is predicted by Simultaneous Fiber Failure (SFF) (Koyanagi et al. in J. Compos. Mater. 43:1901-1914, 2009), employing identical time-dependent matrix strength. The predicted durability of the latter is much greater than that of the former, depending on the interface strength. This study suggests that a relatively weak interface is necessary for high-durability composite flywheel fabrication.

  9. Research notes : durability of composite repairs on bridges.

    Science.gov (United States)

    2009-08-01

    The research showed that conditions that allow moisture to get under the carbon fiber reinforced polymer composites (CFRP) combined with freeze-thaw were detrimental to durability. In addition, the results showed that the American Concrete Institute ...

  10. The Dynamic Pricing of Next Generation Consumer Durables

    OpenAIRE

    Barry L. Bayus

    1992-01-01

    Learning curve effects, aspects of consumer demand models (e.g., reservation price distributions, intertemporal utility maximizing behavior), and competitive activity are reasons which have been offered to explain why prices of new durables decline over time. This paper presents an alternative rationale based on the buying behavior for products with overlapping replacement cycles (i.e., next generation products). A model for consumer sales of a new durable is developed by incorporating the re...

  11. Durability of compressed soil-cement bricks

    Directory of Open Access Journals (Sweden)

    Acosta Valle, A.

    2001-06-01

    Full Text Available This papers shows the evaluation process of the durability of compressed soil-cement bricks. A great number of tests were made to determine the behavior of bricks when they are compression loaded and under the influence of moisture. Two different types of soils were used to produce the bricks, a lime-clay soil and a sand one. The sand soil is very resistant. The other one has a limited use. An experimental design was used to test the bricks. It is a rotational and quadratic method with a hexagonal figure which contains replicas at the central point. This method ensures the reliability of test results. Otherwise, it would reduce the amount of specimens necessary for the tests. The optimun moisture content is obtained by using a press machine. It is more rational than the standard Proctor compactation test, because it applies the same type and amount of energy used to produce the bricks. The obtained results show the behavior differences between the two compressed soil-cement bricks subjected to the compression test, water absorption and wetting and drying tests. The durability tests results are very important in the possible use of the bricks produced.

    En el trabajo se evalúa la durabilidad de elementos aglomerados de suelo estabilizado. Se realiza un amplio número de ensayos encaminados a determinar el comportamiento frente a la acción de las cargas y la humedad de dos suelos con características diferentes: uno limo-arcilloso y el otro arenoso. Este último presenta resultados muy favorables en ambas direcciones. El otro, con un posible uso más limitado. Se emplea un método de diseño experimental del tipo rotacional cuadrático en hexágono, con réplicas en el punto central, el que garantiza la confiabilidad de los resultados de los ensayos, a la vez que disminuye la cantidad de especímenes a ensayar. Se determina la humedad óptima a utilizar en las diferentes dosificaciones empleando la máquina compactadora, que resulta m

  12. Importance of microscopy in durability studies of solidified and stabilized contaminated soils

    Science.gov (United States)

    Klich, I.; Wilding, L.P.; Drees, L.R.; Landa, E.R.

    1999-01-01

    Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or achieved in a laboratory warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analyses alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical

  13. Erectile Function Durability Following Permanent Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Taira, Al V.; Merrick, Gregory S.; Galbreath, Robert W.; Butler, Wayne M.; Wallner, Kent E.; Kurko, Brian S.; Anderson, Richard; Lief, Jonathan H.

    2009-01-01

    Purpose: To evaluate long-term changes in erectile function following prostate brachytherapy. Methods and Materials: This study included 226 patients with prostate cancer and preimplant erectile function assessed by the International Index of Erectile Function-6 (IIEF-6) who underwent brachytherapy in two prospective randomized trials between February 2001 and January 2003. Median follow-up was 6.4 years. Pre- and postbrachytherapy potency was defined as IIEF-6 ≥ 13 without pharmacologic or mechanical support. The relationship among clinical, treatment, and dosimetric parameters and erectile function was examined. Results: The 7-year actuarial rate of potency preservation was 55.6% with median postimplant IIEF of 22 in potent patients. Potent patients were statistically younger (p = 0.014), had a higher preimplant IIEF (p < 0.001), were less likely to be diabetic (p = 0.002), and were more likely to report nocturnal erections (p = 0.008). Potency preservation in men with baseline IIEF scores of 29-30, 24-28, 18-23, and 13-17 were 75.5% vs. 73.6%, 51.7% vs. 44.8%, 48.0% vs. 40.0%, and 23.5% vs. 23.5% in 2004 vs. 2008. In multivariate Cox regression analysis, preimplant IIEF, hypertension, diabetes, prostate size, and brachytherapy dose to proximal penis strongly predicted for potency preservation. Impact of proximal penile dose was most pronounced for men with IIEF of 18-23 and aged 60-69. A significant minority of men who developed postimplant impotence ultimately regained erectile function. Conclusion: Potency preservation and median IIEF scores following brachytherapy are durable. Thoughtful dose sparing of proximal penile structures and early penile rehabilitation may further improve these results.

  14. Bonding Durability of Four Adhesive Systems

    Directory of Open Access Journals (Sweden)

    Leila Atash Biz Yeganeh

    2016-04-01

    Full Text Available Objectives: This study aimed to compare the durability of four adhesive systems by assessing their microtensile bond strength (MTBS and microleakage during six months of water storage.Materials and Methods: A total of 128 human third molars were used. The adhesives tested were Scotch Bond Multipurpose (SBMP, Single Bond (SB, Clearfil-SE bond (CSEB, and All-Bond SE (ABSE. After sample preparation for MTBS testing, the microspecimens were subjected to microtensile tester after one day and six months of water storage. For microleakage evaluation, facial and lingual class V cavities were prepared and restored with composite. After thermocycling, microleakage was evaluated. Bond strength values were subjected to one-way ANOVA and Tamhane’s test, and the microleakage data were analyzed by the Kruskal-Wallis, Dunn, Mann Whitney and Wilcoxon tests (P<0.05.Results: Single Bond yielded the highest and ABSE yielded the lowest bond strength at one day and six months. Short-term bond strength of SBMP and CSEB was similar. After six months, a significant decrease in bond strength was observed in ABSE and SBMP groups. At one day, ABSE showed the highest microleakage at the occlusal margin; however, at the gingival margin, there was no significant difference among groups. Long-term microleakage of all groups at the occlusal margins was similar, whilst gingival margins of SBMP and SB showed significantly higher microleakage.Conclusion: The highest MTBS and favorable sealability were obtained by Clearfil SE bond. Water storage had no effect on microleakage of self-etch adhesives at the gingival margin or MTBS of CSEB and SB. 

  15. Assessment of cement durability in repository environment

    International Nuclear Information System (INIS)

    Ferreira, E.G.A.; Vicente, R.; Isiko, V.L.K.; Miyamoto, H.; Marumo, J.T.; Gobbo, L.A.

    2015-01-01

    The present research aimed at investigating the durability of cement paste under nuclear waste repository conditions using accelerated tests. Cement paste samples are examined after being exposed to the environmental conditions that are expected to prevail in the repository environment and the results are compared with those obtained with unexposed specimens or specimens exposed to reference conditions. The following exposure conditions were selected: a) Immersion in salt solution, distilled water, or kept in dry storage; b) Room temperature (20 C. degrees) or high temperature (60 C. degrees); c) Immersion time of 30 days or 60 days (not for dry storage); d) Irradiation to a dose of (400 kGy) or background radiation (0 kGy). After exposure to the stressing conditions, the effects of each factor on the cement paste samples were observed by changes in their characteristics. Compressive strength tests were performed on all samples and some of them were investigated in terms of changes in mineralogy by X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). With the results obtained so far it was possible to point out the following conclusions. First, after a period of immersion in water, cement paste samples further hydrated and presented higher mechanical resistance, as expected. Secondly, dry storage did not allow a complete hydration as a consequence of pore water evaporation. High temperatures intensified this process and led to the ettringite decomposition to meta-ettringite. Thirdly, higher temperature accelerated hydration kinetics and promoted higher mechanical resistance in samples kept under immersion. Fourthly, the irradiation dose applied was unable to change the mineralogy of cement paste samples and fifthly, no statistically significant differences were observed between 30 or 60 days exposure time, for the test conditions

  16. Soft energy paths toward a durable peace

    CERN Document Server

    Lovins, Amory B

    1977-01-01

    Introduction ; energy strategy : the road not taken ? ; methods of exploring the energy future ; energy quality ; scale ; capital costs of hard technologies ; capital costs of transitional and soft technologies ; comparative capital costs and the role of electrification ; sociopolitics ; values ; rebottling the nuclear genie

  17. Durability of solid oxide electrolysis cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

    2007-05-15

    In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

  18. Research on Durability of Big Recycled Aggregate Self-Compacting Concrete Beam

    Science.gov (United States)

    Gao, Shuai; Liu, Xuliang; Li, Jing; Li, Juan; Wang, Chang; Zheng, Jinkai

    2018-03-01

    Deflection and crack width are the most important durability indexes, which play a pivotal role in the popularization and application of the Big Recycled Aggregate Self-Compacting Concrete technology. In this research, comparative study on the Big Recycled Aggregate Self-Compacting Concrete Beam and ordinary concrete beam were conducted by measuring the deflection and crack width index. The results show that both kind of concrete beams have almost equal mid-span deflection value and are slightly different in the maximum crack width. It indicates that the Big Recycled Aggregate Self-Compacting Concrete Beam will be a good substitute for ordinary concrete beam in some less critical structure projects.

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

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

    2016-01-01

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

  20. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  1. New MEA Materials for Improved DMFC Performance, Durability and Cost

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, James H. [University of North Florida; Campbell, Joseph L. [University of North Florida; Cox, Philip [University of North Florida; Harrington, William J. [University of North Florida

    2013-09-16

    Abstract Project Title: New MEA Materials for Improved DMFC Performance, Durability and Cost The University of North Florida (UNF)--with project partners the University of Florida, Northeastern University, and Johnson Matthey--has recently completed the Department of Energy (DOE) project entitled “New MEA Materials for Improved DMFC Performance, Durability and Cost”. The primary objective of the project was to advance portable fuel cell MEA technology towards the commercial targets as laid out in the DOE R&D roadmap by developing a passive water recovery MEA (membrane electrode assembly). Developers at the University of North Florida identified water management components as an insurmountable barrier to achieving the required system size and weight necessary to achieve the energy density requirements of small portable power applications. UNF developed an innovative “passive water recovery” MEA for direct methanol fuel cells (DMFC) which provides a path to system simplification and optimization. The passive water recovery MEA incorporates a hydrophobic, porous, barrier layer within the cathode electrode, so that capillary pressure forces the water produced at the cathode through holes in the membrane and back to the anode. By directly transferring the water from the cathode to the anode, the balance of plant is very much simplified and the need for heavy, bulky water recovery components is eliminated. At the heart of the passive water recovery MEA is the UNF DM-1 membrane that utilizes a hydrocarbon structure to optimize performance in a DMFC system. The membrane has inherent performance advantages, such as a low methanol crossover (high overall efficiency), while maintaining a high proton conductivity (good electrochemical efficiency) when compared to perfluorinated sulfonic acid membranes such as Nafion. Critically, the membrane provides an extremely low electro-osmotic drag coefficient of approximately one water molecule per proton (versus the 2-3 for

  2. Quality of durable cookies enriched with rape bee pollen

    Directory of Open Access Journals (Sweden)

    Miriam Solgajová

    2014-03-01

    Full Text Available The objective of this study was to enrich durable cookies with different additions of rape (Brassica napus var. napus bee pollen to increase nutritional properties of cookie samples and to improve technological and sensorial properties as well. Bee pollen is an important raw material due to its nutritional and functional properties. Cookie samples were prepared by substituting wheat flour with rape bee pollen in the amount of 16 % (1 g of bee pollen per cookie and 32 % (2 g of bee pollen per cookie using bee pollen from two localities Lenártovce and Nové Zámky. In baked samples beside sensory properties also chemical parameters and technological parameters of cookies were evaluated. It was found out that with the gradual addition of rape bee pollen the amount of ash content increased and the highest ash content was analysed in variants II and IV (0.71 and 0.77 % using 32 % addition of rape bee pollen. In terms of reducing sugars, addition of bee pollen caused that the content of reducing sugars in the products increased slightly. The highest reducing sugar content was determined in variant II. (24.59 %. On the other hand amount of crude protein the most considerably raised by addition of 2 g of pollen per cookie. The highest content of crude protein was analysed in variants II and IV (8.72 and 9.00 %. From the results of a linear models in which the dependent variables were the ash, crude protein and moisture it was determined the significant effect (p <0.05 only of the pollen addition. In the case of the model with the dependent variable reducing sugars it was found out significant effect (p<0.0001 of pollen addition and locality and their interactions. With the gradual addition of bee pollen values of technological parameters such as diameter and weight of cookies increased and thickness of products decreased. Based on sensory scores using a 9-point Hedonic scale the best sensorial acceptability (7.4 was found in variant I (1 g of bee

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

    Science.gov (United States)

    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

  4. A structural bond strength model for glass durability

    International Nuclear Information System (INIS)

    Feng, Xiangdong; Metzger, T.B.

    1996-01-01

    A glass durability model, structural bond strength (SBS) model was developed to correlate glass durability with its composition. This model assumes that the strengths of the bonds between cations and oxygens and the structural roles of the individual elements in the glass arc the predominant factors controlling the composition dependence of the chemical durability of glasses. The structural roles of oxides in glass are classified as network formers, network breakers, and intermediates. The structural roles of the oxides depend upon glass composition and the redox state of oxides. Al 2 O 3 , ZrO 2 , Fe 2 O 3 , and B 2 O 3 are assigned as network formers only when there are sufficient alkalis to bind with these oxides. CaO can also improve durability by sharing non-bridging oxygen with alkalis, relieving SiO 2 from alkalis. The percolation phenomenon in glass is also taken into account. The SBS model is applied to correlate the 7-day product consistency test durability of 42 low-level waste glasses with their composition with an R 2 of 0.87, which is better than 0.81 obtained with an eight-coefficient empirical first-order mixture model on the same data set

  5. Experimental Study on Color Durability of Color Asphalt Pavement

    Science.gov (United States)

    Ning, Shi; Huan, Su

    2017-06-01

    Aiming at the poor Color durability and the lack of research on Color asphalt pavement, spraying an anti-tire trace seal resin emulsion on the surface, a Color durable asphalt pavement was proposed. After long-term rolling and long-term aging test, the Color durability was evaluated by RGB function in Photoshop and trace residue rate formula. Test results proved that the Evaluation method was simple and effective. After long-term rolling, the Color of the road surface tends to a constant value. Spraying the emulsion on the road surface can resist tire traces. After long-term aging test, the resistance to tire traces was increased by 26.6% compared with the conventional type, while the former was 44.1% higher than the latter without long-term aging. The Color durable asphalt pavement can effectively improve the ability of Color asphalt pavement to resist tire traces, and significantly improve the Color durability of Color asphalt pavement.

  6. Bases for extrapolating materials durability in fuel storage pools

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.

    1994-12-01

    A major body of evidence indicates that zirconium alloys have the most consistent and reliable durability in wet storage, justifying projections of safe wet storage greater than 50 y. Aluminum alloys have the widest range of durabilities in wet storage; systematic control and monitoring of water chemistry have resulted in low corrosion rates for more than two decades on some fuels and components. However, cladding failures have occurred in a few months when important parameters were not controlled. Stainless steel is extremely durable when stress, metallurgical and water chemistry factors are controlled. LWR SS cladding has survived for 25 y in wet storage. However, sensitized, stressed SS fuels and components have seriously degraded in fuel storage pools (FSPs) at ∼ 30 C. Satisfactory durability of fuel assembly and FSP component materials in extended wet storage requires investments in water quality management and surveillance, including chemical and biological factors. The key aspect of the study is to provide storage facility operators and other decision makers a basis to judge the durability of a given fuel type in wet storage as a prelude to basing other fuel management plans (e.g. dry storage) if wet storage will not be satisfactory through the expected period of interim storage

  7. Research report for fiscal 1996 on analysis and evaluation of demonstration tests for establishment of residential photovoltaic power generation load leveling technology. Evaluation on durability of device installed with inverter to protect grid connection; 1996 nendo kenkyu hokokusho. Jutaku you taiyoko hatsuden fuka heijunka gijutsu tou kakuritsu jissho shiken ni kansuru kaiseki hyoka - Inbata tsuki keito renkei hogo sochi no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Discussions and evaluations have been performed on the safety and durability of the device installed with inverter to protect grid connection being an important device in the photovoltaic power generation system. This paper summarizes the achievements in fiscal 1996. The current fiscal year performed data collection and long-term continuous operation according to the durability test program for the device installed with inverter to protect grid connection, as the continuation from the previous fiscal year. In the electrical characteristics, although no large changes have been found in AC overvoltage and AC undervoltage, instability was observed in the detection level. With regard to temperatures in different components, the temperature rise has become nearly the same as in the maximum output continuous operation as a result of the repetition of the operation and shutdown, whereas the influence on the electrical and thermal stresses have increased. Particularly, when temperature rise in the AC side noise filter was given observation, the measurement of conductive high-frequency terminal voltage showed a value higher by several ten dB than in the previous fiscal year. The current fiscal year has gone farther to starting the measurement of noise electric field intensity as the base of electromagnetic interference. (NEDO)

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

    Science.gov (United States)

    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

  9. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  10. Effect of manufactured sand on the durability characteristics of concrete

    Directory of Open Access Journals (Sweden)

    S. S. SARAVANAN

    2016-12-01

    Full Text Available Concrete is the most sought after material due to increase in construction activities and infrastructural developments. Availability of natural sand is decreasing thereby increase in the cost of construction. In the present work undertaken, an attempt has been made to give an alternative to natural sand. Optimization of replacement of natural sand with manufactured sand in concrete, durability studies such as water absorption, rapid chloride permeability test, sorptivity, acid resistance, alkaline resistance, impact resistance and abrasion resistance of M40 and M50 grades of concrete have been studied with manufactured sand as fine aggregate and compared the results with the conventional sand concrete. The results shows that there is an increase in the durability properties up to 70 % level of replacements of sand with manufactured sand as fine aggregate and for 100 % use of manufactured sand also gives the better durability than the conventional sand concrete.

  11. Review of durability of cementitious engineered barriers in repository environments

    International Nuclear Information System (INIS)

    Parrott, L.J.; Lawrence, C.D.

    1992-01-01

    This report is concerned with the durability of cementitious engineered barriers in a repository for low and intermediate level nuclear waste. Following the introduction the second section of the review identifies the environmental conditions associated with a deep, hard rock repository for ILW and LLW that are relevant to the durability of cementitious barriers. Section three examines the microstructure and macrostructure of cementitious materials and considers the physical and chemical processes of radionuclide immobilization. Potential repository applications and compositions of cementitious materials are reviewed in Section four. The main analysis of durability is dealt with in Section five. The different types of cementitious barrier are considered separately and their most probable modes of degradation are analysed. Concluding remarks that highlight critical technical matters are given in Section six. (author)

  12. Durability reliability analysis for corroding concrete structures under uncertainty

    Science.gov (United States)

    Zhang, Hao

    2018-02-01

    This paper presents a durability reliability analysis of reinforced concrete structures subject to the action of marine chloride. The focus is to provide insight into the role of epistemic uncertainties on durability reliability. The corrosion model involves a number of variables whose probabilistic characteristics cannot be fully determined due to the limited availability of supporting data. All sources of uncertainty, both aleatory and epistemic, should be included in the reliability analysis. Two methods are available to formulate the epistemic uncertainty: the imprecise probability-based method and the purely probabilistic method in which the epistemic uncertainties are modeled as random variables. The paper illustrates how the epistemic uncertainties are modeled and propagated in the two methods, and shows how epistemic uncertainties govern the durability reliability.

  13. Durability and damage tolerance of Large Composite Primary Aircraft Structure (LCPAS)

    Science.gov (United States)

    Mccarty, John E.; Roeseler, William G.

    1984-01-01

    Analysis and testing addressing the key technology areas of durability and damage tolerance were completed for wing surface panels. The wing of a fuel-efficient, 200-passenger commercial transport airplane for 1990 delivery was sized using graphite-epoxy materials. Coupons of various layups used in the wing sizing were tested in tension, compression, and spectrum fatigue with typical fastener penetrations. The compression strength after barely visible impact damage was determined from coupon and structural element tests. One current material system and one toughened system were evaluated by coupon testing. The results of the coupon and element tests were used to design three distinctly different compression panels meeting the strength, stiffness, and damage-tolerance requirements of the upper wing panels. These three concepts were tested with various amounts of damage ranging from barely visible impact to through-penetration. The results of this program provide the key technology data required to assess the durability and damage-tolerance capability or advanced composites for use in commercial aircraft wing panel structure.

  14. Fabrication and Testing of Durable Redundant and Fluted-Core Joints for Composite Sandwich Structures

    Science.gov (United States)

    Lin, Shih-Yung; Splinter, Scott C.; Tarkenton, Chris; Paddock, David A.; Smeltzer, Stanley S.; Ghose, Sayata; Guzman, Juan C.; Stukus, Donald J.; McCarville, Douglas A.

    2013-01-01

    The development of durable bonded joint technology for assembling composite structures is an essential component of future space technologies. While NASA is working toward providing an entirely new capability for human space exploration beyond low Earth orbit, the objective of this project is to design, fabricate, analyze, and test a NASA patented durable redundant joint (DRJ) and a NASA/Boeing co-designed fluted-core joint (FCJ). The potential applications include a wide range of sandwich structures for NASA's future launch vehicles. Three types of joints were studied -- splice joint (SJ, as baseline), DRJ, and FCJ. Tests included tension, after-impact tension, and compression. Teflon strips were used at the joint area to increase failure strength by shifting stress concentration to a less sensitive area. Test results were compared to those of pristine coupons fabricated utilizing the same methods. Tensile test results indicated that the DRJ design was stiffer, stronger, and more impact resistant than other designs. The drawbacks of the DRJ design were extra mass and complex fabrication processes. The FCJ was lighter than the DRJ but less impact resistant. With barely visible but detectable impact damages, all three joints showed no sign of tensile strength reduction. No compression test was conducted on any impact-damaged sample due to limited scope and resource. Failure modes and damage propagation were also studied to support progressive damage modeling of the SJ and the DRJ.

  15. The Network of Excellence 'Knowledge-based Multicomponent Materials for Durable and Safe Performance'

    International Nuclear Information System (INIS)

    Moreno, Arnaldo

    2008-01-01

    The Network of Excellence 'Knowledge-based Multicomponent Materials for Durable and Safe Performance' (KMM-NoE) consists of 36 institutional partners from 10 countries representing leading European research institutes and university departments (25), small and medium enterprises, SMEs (5) and large industry (7) in the field of knowledge-based multicomponent materials (KMM), more specifically in intermetallics, metal-ceramic composites, functionally graded materials and thin layers. The main goal of the KMM-NoE (currently funded by the European Commission) is to mobilise and concentrate the fragmented scientific potential in the KMM field to create a durable and efficient organism capable of developing leading-edge research while spreading the accumulated knowledge outside the Network and enhancing the technological skills of the related industries. The long-term strategic goal of the KMM-NoE is to establish a self-supporting pan-European institution in the field of knowledge-based multicomponent materials--KMM Virtual Institute (KMM-VIN). It will combine industry oriented research with educational and training activities. The KMM Virtual Institute will be founded on three main pillars: KMM European Competence Centre, KMM Integrated Post-Graduate School, KMM Mobility Programme. The KMM-NoE is coordinated by the Institute of Fundamental Technological Research (IPPT) of the Polish Academy of Sciences, Warsaw, Poland

  16. UV Ink-Jet printability and durability of stone and foil

    Directory of Open Access Journals (Sweden)

    Tadeja Muck

    2014-07-01

    Full Text Available he use of ultraviolet (UV printing technology has impacted printing industry in last years due to its applicability on many different »absorptive« as well as »non-absorptive« printing materials. The printability of building materials and recycled foils is relatively unknown. For primary building materials like stones, functionality can be explored with the use of UV printing technology; increased visual, informative effect or even “creative printing” of buildings. Also several aspects of recycled foils reusability as a printing material could be find (printed packaging material or also like secondary building materials. In the present study, printability of the stone and recycled foil and durability of UV prints was explored by means of macroscopically and microscopically characterization. Results indicate that higher print quality can be achieved on polished stone and on coated foil, which surfaces have higher smoothness. Durability of UV prints at freezing is higher at unpolished stone and coated foil that is at materials with the higher surface energy.

  17. The Network of Excellence ``Knowledge-based Multicomponent Materials for Durable and Safe Performance''

    Science.gov (United States)

    Moreno, Arnaldo

    2008-02-01

    The Network of Excellence "Knowledge-based Multicomponent Materials for Durable and Safe Performance" (KMM-NoE) consists of 36 institutional partners from 10 countries representing leading European research institutes and university departments (25), small and medium enterprises, SMEs (5) and large industry (7) in the field of knowledge-based multicomponent materials (KMM), more specifically in intermetallics, metal-ceramic composites, functionally graded materials and thin layers. The main goal of the KMM-NoE (currently funded by the European Commission) is to mobilise and concentrate the fragmented scientific potential in the KMM field to create a durable and efficient organism capable of developing leading-edge research while spreading the accumulated knowledge outside the Network and enhancing the technological skills of the related industries. The long-term strategic goal of the KMM-NoE is to establish a self-supporting pan-European institution in the field of knowledge-based multicomponent materials—KMM Virtual Institute (KMM-VIN). It will combine industry oriented research with educational and training activities. The KMM Virtual Institute will be founded on three main pillars: KMM European Competence Centre, KMM Integrated Post-Graduate School, KMM Mobility Programme. The KMM-NoE is coordinated by the Institute of Fundamental Technological Research (IPPT) of the Polish Academy of Sciences, Warsaw, Poland.

  18. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Jha, M.C.; Berggren, M.H.

    1989-05-02

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  19. Durability evaluation method on rebar corrosion of reinforced concrete

    International Nuclear Information System (INIS)

    Kitsutaka, Yoshinori

    2013-01-01

    In this paper, method on the durability evaluation in nuclear power plant concrete structures was investigated. In view of the importance of evaluating the degree of deterioration of reinforced concrete structures, relationships should be formulated among the number of years elapsed, t, the amount of action of a deteriorative factor, F, the degree of material deterioration, D, and the performance of the structure, P. Evaluation by PDFt diagrams combining these relationships may be effective. A detailed procedure of durability evaluation for a reinforced concrete structure using PDFt concept is presented for the deterioration of rebar corrosion caused by neutralization and penetration of salinity by referring to the recent papers. (author)

  20. Highly durable and low permeable concrete for LLW facilities

    International Nuclear Information System (INIS)

    Yanagibashi, Kunio; Saito, Toshio; Odagawa, Masaro.

    1997-01-01

    Concrete used for LLW facilities is required to be highly durable. The authors evaluated concrete containing glycol ether derivatives and silica fume as admixtures. Compressive strength, diffusion coefficient of water, depth of accelerated carbonation, drying shrinkage, depth of chlorides penetration and resistance to freezing and thawing were investigated using concrete specimens. Compressive strength, depth of accelerated carbonation, diffusion coefficient of 137 Cs were investigated using mortar specimens before and after irradiation of gamma rays. Results showed that using glycol ether derivatives and silica fume was effective in improving the durability. (author)

  1. Glycogen with short average chain length enhances bacterial durability

    Science.gov (United States)

    Wang, Liang; Wise, Michael J.

    2011-09-01

    Glycogen is conventionally viewed as an energy reserve that can be rapidly mobilized for ATP production in higher organisms. However, several studies have noted that glycogen with short average chain length in some bacteria is degraded very slowly. In addition, slow utilization of glycogen is correlated with bacterial viability, that is, the slower the glycogen breakdown rate, the longer the bacterial survival time in the external environment under starvation conditions. We call that a durable energy storage mechanism (DESM). In this review, evidence from microbiology, biochemistry, and molecular biology will be assembled to support the hypothesis of glycogen as a durable energy storage compound. One method for testing the DESM hypothesis is proposed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Busby, Colin [W. L. Gore & Associates Inc., Newark, DE (United States)

    2017-05-23

    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 goal 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

  3. Unconventional gases: a North-American energy revolution not without consequences for Europe; Les gaz non conventionnels: une revolution energetique nord-americaine non sans consequences pour l'Europe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This paper gives a definition of the different existing unconventional gases (coal-bed methane, tight gases, shale gases), and outlines that, although these gases as well as the techniques to extract them have been well known for a long time, it is the combination of two of these techniques (hydraulic fracturing or fracking, and horizontal drilling) which enables the current technological development and the exploitation of these gases. It also outlines that the current situation in terms of natural resources favours such a development. It evokes projects in the United States, China, India, Europe, and more particularly in France, stressing that environmental issues and population density in Europe are obstacles to perform these drillings. The author questions the production cost issue and explains how these developments, notably in the USA, may change completely the world energetic landscape, and therefore entail a review of the European energy agenda. He explores the possible consequences of a durable decrease of gas prices

  4. Unconventional gases: a North-American energy revolution not without consequences for Europe; Les gaz non conventionnels: une revolution energetique nord-americaine non sans consequences pour l'Europe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This paper gives a definition of the different existing unconventional gases (coal-bed methane, tight gases, shale gases), and outlines that, although these gases as well as the techniques to extract them have been well known for a long time, it is the combination of two of these techniques (hydraulic fracturing or fracking, and horizontal drilling) which enables the current technological development and the exploitation of these gases. It also outlines that the current situation in terms of natural resources favours such a development. It evokes projects in the United States, China, India, Europe, and more particularly in France, stressing that environmental issues and population density in Europe are obstacles to perform these drillings. The author questions the production cost issue and explains how these developments, notably in the USA, may change completely the world energetic landscape, and therefore entail a review of the European energy agenda. He explores the possible consequences of a durable decrease of gas prices

  5. Fiscal 1999 research and development of technologies for practical application of photovoltaic power generation systems. Research and development of photovoltaic power utilizing system and peripheral technologies (Research and development of novel type solar cell module integratable with building materials - Highly durable roof module); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Taiyoko hatsuden riyo system shuhen gijutsu no kenkyu kaihatsu (shinkenzai ittaigata taiyo denchi module no kenkyu kaihatsu - kotaikyusei yane module)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    A thin-film solar array, a large roof panel, and an interconnecting power conditioner are integrated into one and single structural member for the development of a residential photovoltaic power system in which a unit AC (alternating current) output is collected from each panel. In fiscal 1999, in the study of highly durable materials for solar cell modules and of their structure, a thin film compound solar cell module was enlarged to 82cm times 71cm, evaluated for performance, and installed on the third test house. In the study of collecting AC power from the solar cell module, a compact power conditioner for a roof panel which had been in test operation on the roof of the laboratory since 1998 was checked for practical performance, improved, and evaluated for system generation efficiency. In the study of a highly durable roof module structure, problems pertaining to heat radiation from the rear side steel sheet, the burning of the junction box, etc., were solved, and the module passed a verification test under the Building Standard Law. In the validation of the roof module for which power generation performance and meteorological conditions had already been continuously measured for 19 months, it was found that the roof module suffered no troubles such as water leak or deformation. (NEDO)

  6. Relationship between wheelchair durability and wheelchair type and years of test.

    Science.gov (United States)

    Wang, Hongwu; Liu, Hsin-Yi; Pearlman, Jon; Cooper, Rosemarie; Jefferds, Alexandra; Connor, Sam; Cooper, Rory A

    2010-01-01

    To investigate the relationship between the durability of wheelchairs according to American National Standard for Wheechairs/Rehabilitation Engineering and Assistive Technology Society of North America (ANSI/RESNA) Wheelchair Standards and wheelchair type as well as year of test. A retrospective study design with a sample of 246 wheelchairs that were tested in accordance with the ANSI/RESNA standards from 1992 to 2008 including four types of wheelchairs: manual wheelchair (MWC), electrical powered wheelchair (EPW), scooters and pushrim-activated power-assisted wheelchair (PAPAW). Unconditional binary logic regression analysis was chosen to evaluate the relationship between test results and test year as well as wheelchair type. Rehabilitation Engineering Research Center. Wheelchair durability test result (fatigue test: pass or fail) There was no significant correlation between the year when tested and equivalent cycles. A significant relation was found between test results and wheelchair type (Wald score = 10.845, degree of freedom = 3, p = 0.013) with scooters having a significantly higher pass ratio than MWC (OR = 15.629, 95% CI = 2.026-120.579). EPW also had significantly higher pass ratio than MWC (OR = 1.953, 95% CI = 1.049-3.636). No significant difference on pass ratio was found between PAPAW and MWC. No significant improvements in wheelchair test results during the time frame from 1992 to 2008 were discovered. Wheelchair standard tests should be conducted to assure minimum quality of the wheelchairs and for improving the design of wheelchairs. Although the ANSI/RESNA wheelchair durability test procedures have remained consistent, it does not appear that the introduction of new materials, designs and the availability of test data have improved wheelchair fatigue life.

  7. Highly durable, coking and sulfur tolerant, fuel-flexible protonic ceramic fuel cells.

    Science.gov (United States)

    Duan, Chuancheng; Kee, Robert J; Zhu, Huayang; Karakaya, Canan; Chen, Yachao; Ricote, Sandrine; Jarry, Angelique; Crumlin, Ethan J; Hook, David; Braun, Robert; Sullivan, Neal P; O'Hayre, Ryan

    2018-05-01

    Protonic ceramic fuel cells, like their higher-temperature solid-oxide fuel cell counterparts, can directly use both hydrogen and hydrocarbon fuels to produce electricity at potentially more than 50 per cent efficiency 1,2 . Most previous direct-hydrocarbon fuel cell research has focused on solid-oxide fuel cells based on oxygen-ion-conducting electrolytes, but carbon deposition (coking) and sulfur poisoning typically occur when such fuel cells are directly operated on hydrocarbon- and/or sulfur-containing fuels, resulting in severe performance degradation over time 3-6 . Despite studies suggesting good performance and anti-coking resistance in hydrocarbon-fuelled protonic ceramic fuel cells 2,7,8 , there have been no systematic studies of long-term durability. Here we present results from long-term testing of protonic ceramic fuel cells using a total of 11 different fuels (hydrogen, methane, domestic natural gas (with and without hydrogen sulfide), propane, n-butane, i-butane, iso-octane, methanol, ethanol and ammonia) at temperatures between 500 and 600 degrees Celsius. Several cells have been tested for over 6,000 hours, and we demonstrate excellent performance and exceptional durability (less than 1.5 per cent degradation per 1,000 hours in most cases) across all fuels without any modifications in the cell composition or architecture. Large fluctuations in temperature are tolerated, and coking is not observed even after thousands of hours of continuous operation. Finally, sulfur, a notorious poison for both low-temperature and high-temperature fuel cells, does not seem to affect the performance of protonic ceramic fuel cells when supplied at levels consistent with commercial fuels. The fuel flexibility and long-term durability demonstrated by the protonic ceramic fuel cell devices highlight the promise of this technology and its potential for commercial application.

  8. Durable and Sustainable Road Constructions for Developing Countries

    NARCIS (Netherlands)

    Molenaar, A.A.A.

    2013-01-01

    This paper discusses the possibilities to build durable and sustainable pavement structures in developing countries. Attention will be paid to geometric design aspects which have a significant effect on pavement life. Following this attention will be paid to the importance of controlling wheel loads

  9. Effect of Acidic Water on Strength, Durability and Corrosion of ...

    African Journals Online (AJOL)

    In this study, specimens of 108 cubes (150 mm x 150 mm x 150 mm), 36 cylinders (300 mm x 150 mm), and 72 cylinders (102 mm x 51 mm) were cast and cured in percentages of NaCl added water to find the workability, strength, durability and corrosion resistance characteristics concrete. The effect of corrosion of steel in ...

  10. Durability studies on the high calcium flyash based GPC ...

    African Journals Online (AJOL)

    Three different grades namely GM20, GM30 and GM40 are designed and common durability related properties like water absorption, acid resitance and corrosion resistance by constant voltage polarization test are determined using relevant concrete specimens and compared with similar grades of conventional concrete.

  11. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, David

    1995-01-01

    The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a

  12. Enhancing durability of wood-based composites with nanotechnology

    Science.gov (United States)

    Carol Clausen

    2012-01-01

    Wood protection systems are needed for engineered composite products that are susceptible to moisture and biodeterioration. Protection systems using nano-materials are being developed to enhance the durability of wood-based composites through improved resistance to biodeterioration, reduced environmental impact from chemical leaching, and improved resistance to...

  13. 40 CFR 86.1822-01 - Durability data vehicle selection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Durability data vehicle selection. 86... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light...

  14. Application of Kingview and PLC in friction durability test system

    Science.gov (United States)

    Gao, Yinhan; Cui, Jing; Yang, Kaiyu; Ke, Hui; Song, Bing

    2013-01-01

    Using PLC and Kingview software, a friction durability test system is designed. The overall program, hardware configuration, software structure and monitoring interface are described in detail. PLC ensures the stability of data acquisition, and the KingView software makes the HMI easy to manipulate. The practical application shows that the proposed system is cheap, economical and highly reliable.

  15. Comparative durability of timber bridges in the USA

    Science.gov (United States)

    James P. Wacker; Brian K. Brashaw

    2017-01-01

    As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was...

  16. Measuring Happiness: From Fluctuating Happiness to Authentic–Durable Happiness

    Science.gov (United States)

    Dambrun, Michaël; Ricard, Matthieu; Després, Gérard; Drelon, Emilie; Gibelin, Eva; Gibelin, Marion; Loubeyre, Mélanie; Py, Delphine; Delpy, Aurore; Garibbo, Céline; Bray, Elise; Lac, Gérard; Michaux, Odile

    2012-01-01

    On the basis of the theoretical distinction between self-centeredness and selflessness (Dambrun and Ricard, 2011), the main goal of this research was to develop two new scales assessing distinct dimensions of happiness. By trying to maximize pleasures and to avoid displeasures, we propose that a self-centered functioning induces a fluctuating happiness in which phases of pleasure and displeasure alternate repeatedly (i.e., Fluctuating Happiness). In contrast, a selfless psychological functioning postulates the existence of a state of durable plenitude that is less dependent upon circumstances but rather is related to a person’s inner resources and abilities to deal with whatever comes his way in life (i.e., Authentic–Durable Happiness). Using various samples (n = 735), we developed a 10-item Scale measuring Subjective Fluctuating Happiness (SFHS) and a 13-item scale assessing Subjective Authentic–Durable Happiness (SA–DHS). Results indicated high internal consistencies, satisfactory test–retest validities, and adequate convergent and discriminant validities with various constructs including a biological marker of stress (salivary cortisol). Consistent with our theoretical framework, while self-enhancement values were related only to fluctuating happiness, self-transcendence values were related only to authentic–durable happiness. Support for the distinction between contentment and inner-peace, two related markers of authentic happiness, also was found. PMID:22347202

  17. Durability of adhesive glass-metal connections for structural applications

    NARCIS (Netherlands)

    Van Lancker, B.; Dispersyn, J.; De Corte, W.; Belis, J.

    2016-01-01

    The use of adhesive bonds for structural glass-metal connections in the building envelope has increased in recent years. Despite the multiple advantages compared to more traditional bolted connections, long-term behaviour and durability of the adhesives have to be investigated accurately. Because,

  18. Review: Durability and degradation issues of PEM fuel cell components

    NARCIS (Netherlands)

    Bruijn, de F.A.; Dam, V.A.T.; Janssen, G.J.M.

    2008-01-01

    Besides cost reduction, durability is the most important issue to be solved before commercialisation of PEM Fuel Cells can be successful. For a fuel cell operating under constant load conditions, at a relative humidity close to 100% and at a temperature of maximum 75 °C, using optimal stack and flow

  19. Durable Tactile Glove for Human or Robot Hand

    Science.gov (United States)

    Butzer, Melissa; Diftler, Myron A.; Huber, Eric

    2010-01-01

    A glove containing force sensors has been built as a prototype of tactile sensor arrays to be worn on human hands and anthropomorphic robot hands. The force sensors of this glove are mounted inside, in protective pockets; as a result of this and other design features, the present glove is more durable than earlier models.

  20. Recent advances in the mechanical durability of superhydrophobic materials.

    Science.gov (United States)

    Milionis, Athanasios; Loth, Eric; Bayer, Ilker S

    2016-03-01

    Large majority of superhydrophobic surfaces have very limited mechanical wear robustness and long-term durability. This problem has restricted their utilization in commercial or industrial applications and resulted in extensive research efforts on improving resistance against various types of wear damage. In this review, advances and developments since 2011 in this field will be covered. As such, we summarize progress on fabrication, design and understanding of mechanically durable superhydrophobic surfaces. This includes an overview of recently published diagnostic techniques for probing and demonstrating tribo-mechanical durability against wear and abrasion as well as other effects such as solid/liquid spray or jet impact and underwater resistance. The review is organized in terms of various types of mechanical wear ranging from substrate adhesion, tangential surface abrasion, and dynamic impact to ultrasonic processing underwater. In each of these categories, we highlight the most successful approaches to produce robust surfaces that can maintain their non-wetting state after the wear or abrasive action. Finally, various recommendations for improvement of mechanical wear durability and its quantitative evaluation are discussed along with potential future directions towards more systematic testing methods which will also be acceptable for industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Durability Issues and Status of PBI-Based Fuel Cells

    DEFF Research Database (Denmark)

    Jakobsen, Mark Tonny Dalsgaard; Jensen, Jens Oluf; Cleemann, Lars Nilausen

    2016-01-01

    This chapter briefly reviews durability and stability issues with key materials and components for HT-PEMFCs, including the polymer membrane, the doping acid, the electrocatalyst, the catalyst support and bipolar plates. Degradation mechanisms and their dependence on fuel cell operating condition...

  2. Framework for a procedure for design for durability

    NARCIS (Netherlands)

    Siemes, A.J.M.

    1996-01-01

    The design for durability of structures and building components is in general based on implicit requirements with respect to the quality and dimensions of the composing building materials and components. These requirements are based on long term experience. This approach has disadvantages. It is

  3. Développement durable de l'agriculture urbaine

    International Development Research Centre (IDRC) Digital Library (Canada)

    La gestion concertée et durable des filières maraîchères urbaines, Paule Moustier, Michel ..... avec des eaux usées, le plus souvent non traitées : dans quelle mesure cette agriculture peut-elle ...... Le contrôle des performances zootechniques

  4. Ancient analogues concerning stability and durability of cementitious wasteform

    International Nuclear Information System (INIS)

    Jiang, W.; Roy, D.M.

    1994-01-01

    The history of cementitious materials goes back to ancient times. The Greeks and Romans used calcined limestone and later developed pozzolanic cement by grinding together lime and volcanic ash called open-quotes pozzolanclose quotes which was first found near Port Pozzuoli, Italy. The ancient Chinese used lime-pozzolanic mixes to build the Great Wall. The ancient Egyptians used calcined impure gypsum to build the Great Pyramid of Cheops. The extraordinary stability and durability of these materials has impressed us, when so much dramatically damaged infrastructure restored by using modern portland cement now requires rebuilding. Stability and durability of cementitious materials have attracted intensive research interest and contractors' concerns, as does immobilization of radioactive and hazardous industrial waste in cementitious materials. Nuclear waste pollution of the environment and an acceptable solution for waste management and disposal constitute among the most important public concerns. The analogy of ancient cementitious materials to modern Portland cement could give us some clues to study their stability and durability. This present study examines selected results of studies of ancient building materials from France, Italy, China, and Egypt, combined with knowledge obtained from the behavior of modern portland cement to evaluate the potential for stability and durability of such materials in nuclear waste forms

  5. Utilization of Durability Criterion to Develop Automotive Components

    DEFF Research Database (Denmark)

    Ricardo, Luiz Carlos Hernandes

    2010-01-01

    Today the automotive companies must reduce the time to development of new products with improvement in performance, durability and low cost reductions where possible. To achieve this goal the carmakers need to improve the design criterion of car systems like body, chassis and suspension component...

  6. FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, part 2

    Energy Technology Data Exchange (ETDEWEB)

    Harris, C.E.

    1994-09-01

    The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance. Separate articles from this report have been indexed into the database.

  7. FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, part 2

    Science.gov (United States)

    Harris, Charles E. (Editor)

    1994-01-01

    The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance.

  8. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Berggren, M.H.; Jha, M.C.

    1989-10-01

    AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.

  9. Multi-factor Effects on the Durability of Recycle Aggregate Concrete

    Science.gov (United States)

    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%.

  10. Durability of fibre reinforced concrete structures exposed to combined mechanical and environmental load

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Hansen, Kurt Kielsgaard

    1999-01-01

    The main conclusions from a research project on durability of cracked fibre reinforced concrete structures exposed to chlorides, water or freeze-thaw are presented. The effect of fibres and cracks on the durability of concrete is studied.......The main conclusions from a research project on durability of cracked fibre reinforced concrete structures exposed to chlorides, water or freeze-thaw are presented. The effect of fibres and cracks on the durability of concrete is studied....

  11. 30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

    Science.gov (United States)

    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...

  12. 30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

    Science.gov (United States)

    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...

  13. Design of concrete structures for durability. Example: Chloride penetration in the lining of a bored tunnel

    NARCIS (Netherlands)

    Siemes, A.J.M.

    1998-01-01

    The present design method for durability of concrete is based on a set of rules that give no objective in-sight in the service life to expect from the concrete structure. An objective comparison between different durability measures is therefor not possible. Especially if the lack of durability can

  14. Design procedure for formulating and assessing the durability of particulate grouts

    International Nuclear Information System (INIS)

    Okonkwo, I.O.; Altschaeff, A.G.

    1989-01-01

    The current disposal plans for low-level wastes call for stabilizing or encapsulating and storing of these wastes in steel drums which in turn are buried in shallow trenches. Complete sealing is accomplished with grout, a liquid injection comprising principally of cement and fly ash, etc. Upon solidification, the grout forms a rigid mass around the drum, thereby eliminating access of groundwater into or out of the waste barrier, or leaching of radionuclides. Since the primary mechanism for the likely introduction of hazardous and/or radioactive elements into the biosphere in this situation, is through physical or chemical deterioration of the waste barrier, it is necessary that the effect of adverse environments on the durability of the grouts be examined and incorporated in barrier design. Currently, procedures for formulating grout mixes to assure a given impermeability or durability of the grout over its service period is lacking, and so are the techniques for monitoring the in-service performance of waste barrier systems. This paper depicts a serious limitation in waste barrier system technology, for it is time that optimization in design be possible. To allow this, a method is needed that creates the grout formulation specification for an optimization of behavior parameters in the resulting product. These considerations suggest a strong need for improvement in the grout formulation specification to allow a focus upon behavior properties desired by the engineer in the creation of optimum performance. This paper addresses these problems

  15. Review of research on the hygrothermal environmental durability of structural adhesively bonded joints

    Directory of Open Access Journals (Sweden)

    Xiao HAN

    2017-06-01

    Full Text Available In recent years, structural adhesive bonding technology has been widely used in many industrial fields, with many advantages over traditional mechanical connection methods, such as riveting, welding and bolt connection. Due to the adhesive characteristics of polymer materials, the environmental durability of adhesive joint becomes the key problems in engineering structure connection feasibility and long-term service reliability. On the basis of the review of the research of the hot-humid environmental durability of structural adhesive joints, the effects of temperature, moisture and coupled condition on the structural mechanical behaviour are discussed, introducing the published research progress and results both at home and abroad. The prospects are provided: the future research work can be combined with a variety of observation scales of environmental aging test and numerical simulation method, delve into sub hygroscopic, creep, thermal expansion and hygroscopic expansion aging behavior, such as the environment of model prediction method simulation in more than a variety of mechanical performance degradation behavior of coupling conditions, and provide more reliable theoretical modeling and experimental data for engineering design and application of cementing structure.

  16. Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

    Science.gov (United States)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

    2017-09-01

    The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

  17. A durability study of a paracorporeal pulsatile electro-mechanical pneumatic biventricular assist device.

    Science.gov (United States)

    Choi, Hyuk; Lee, Heung-Man; Nam, Kyoung Won; Choi, Jaesoon; Lee, Jung-Joo; Kim, Ho Chul; Song, Seung Joon; Ahn, Chi Bum; Son, Ho Sung; Lim, Choon Hak; Son, Kuk Hui; Park, Yong Doo; Jeong, Gi Seok; Sun, Kyung

    2011-06-01

    In 2002, the paracorporeal pulsatile electro-mechanical pneumatic ventricular assist device (VAD) began to be developed by the Korea Artificial Organ Center at Korea University under a Health & Medical Technology Research and Development program which finished in 2008. In vitro durability testing was conducted on the paracorporeal pulsatile pneumatic VAD to determine device durability and to evaluate device failures. The 1- and 2-year reliability of the paracorporeal pulsatile pneumatic VAD was shown to be 91.2% and 54.9%, respectively, with an 80% confidence level. Failure modes were analyzed using fault tree analysis, with customized software continuously acquiring data during the test period. After this period, 21 in vivo animal tests were done, with 14 cases of left atrium to left ventricle (LV) inflow cannulation (36Fr)/outflow grafting to descending aorta, and seven cases of apex cannulation of LV to descending aorta (12 mm). The longest postoperative day (182 days) in Korea was recently recorded in in vivo animal testing (bovine, 90 kg, male, 3.5-4.0 L/min flow rate, and 55 bpm). © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  18. Energy Tax and Competition in Energy Efficiency. The Case of Consumer Durables

    International Nuclear Information System (INIS)

    Conrad, K.

    2000-01-01

    The purpose of this paper is to analyze the role of an energy tax on technical improvements and on prices of consumer durables induced by strategic competition in energy efficiency. If the gasoline tax is raised this does in principle not affect the producers of cars because the motorist pays for it in terms of a higher cost of using the car. This, however, affects the unit sales of car producers because of substitution towards other modes of transportation. A second element of reaction to energy price variation is an indirect one and relates to the effect of energy prices on technology. Competition forces car producers to develop more energy efficient cars in order to reduce the cost of using a car. This indirect effect can partly offset the direct effect of higher energy prices on demand if it is profitable for the automobile industry to engineer more energy efficient equipment. We will analyze the impact of an energy tax on energy efficiency and on the price of a durable good. This will be done within the framework of a duopoly competing in prices and in the energy efficiency of its products. The government chooses a welfare maximizing energy tax as an incentive to innovate. Then we will analyze a strategic two-stage decision process in which the duopolists first decide about energy efficiency and then compete in prices. 18 refs

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

    Science.gov (United States)

    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.

  20. Mechanically durable underwater superoleophobic surfaces based on hydrophilic bulk metals for oil/water separation

    Science.gov (United States)

    Yu, Huadong; Lian, Zhongxu; Xu, Jinkai; Wan, Yanling; Wang, Zuobin; Li, Yiquan; Yu, Zhanjiang; Weng, Zhankun

    2018-04-01

    Despite the success of previous methods for fabricating underwater superoleophobic surfaces, most of the surfaces based on soft materials are prone to collapse and deformation due to their mechanically fragile nature, and they fail to perform their designed functions after the surface materials are damaged in water. In this work, the nanosecond laser-induced oxide coatings on hydrophilic bulk metals are reported which overcomes the limitation and shows the robust underwater superoleophobicity to a mechanical challenge encountered by surfaces deployed in water environment. The results show that the surface materials have the advantage that the underwater superoleophobicity is still preserved after the surfaces are scratched by knife or sandpaper and even completely destroyed because of the hydrophilic property of damaged materials in water. It is important that the results provide a guide for the design of durable underwater superoleophobic surfaces, and the development of superoleophobic materials in many potential applications such as the oil-repellent and the oil/water separation. Additionally, the nanosecond laser technology is simple, cost-effective and suitable for the large-area and mass fabrication of mechanically durable underwater superoleophobic metal materials.

  1. An artificial tendon with durable muscle interface.

    Science.gov (United States)

    Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia

    2010-02-01

    A coupling mechanism that can permanently fix a forcefully contracting muscle to a bone anchor or any totally inert prosthesis would meet a serious need in orthopaedics. Our group developed the OrthoCoupler device to satisfy these demands. The objective of this study was to test OrthoCoupler's performance in vitro and in vivo in the goat semitendinosus tendon model. For in vitro evaluation, 40 samples were fatigue-tested, cycling at 10 load levels, n = 4 each. For in vivo evaluation, the semitendinosus tendon was removed bilaterally in eight goats. Left sides were reattached with an OrthoCoupler, and right sides were reattached using the Krackow stitch with #5 braided polyester sutures. Specimens were harvested 60 days postsurgery and assigned for biomechanics and histology. Fatigue strength of the devices in vitro was several times the contractile force of the semitendinosus muscle. The in vivo devices were built equivalent to two of the in vitro devices, providing an additional safety factor. In strength testing at necropsy, suture controls pulled out at 120.5 +/- 68.3 N, whereas each OrthoCoupler was still holding after the muscle tore, remotely, at 298 +/- 111.3 N (mean +/- SD) (p < 0.0003). Muscle tear strength was reached with the fiber-muscle composite produced in healing still soundly intact. This technology may be of value for orthopaedic challenges in oncology, revision arthroplasty, tendon transfer, and sports-injury reconstruction. (c) 2009 Orthopaedic Research Society.

  2. Evolutionary model of an anonymous consumer durable market

    Science.gov (United States)

    Kaldasch, Joachim

    2011-07-01

    An analytic model is presented that considers the evolution of a market of durable goods. The model suggests that after introduction goods spread always according to a Bass diffusion. However, this phase will be followed by a diffusion process for durable consumer goods governed by a variation-selection-reproduction mechanism and the growth dynamics can be described by a replicator equation. The theory suggests that products play the role of species in biological evolutionary models. It implies that the evolution of man-made products can be arranged into an evolutionary tree. The model suggests that each product can be characterized by its product fitness. The fitness space contains elements of both sites of the market, supply and demand. The unit sales of products with a higher product fitness compared to the mean fitness increase. Durables with a constant fitness advantage replace other goods according to a logistic law. The model predicts in particular that the mean price exhibits an exponential decrease over a long time period for durable goods. The evolutionary diffusion process is directly related to this price decline and is governed by Gompertz equation. Therefore it is denoted as Gompertz diffusion. Describing the aggregate sales as the sum of first, multiple and replacement purchase the product life cycle can be derived. Replacement purchase causes periodic variations of the sales determined by the finite lifetime of the good (Juglar cycles). The model suggests that both, Bass- and Gompertz diffusion may contribute to the product life cycle of a consumer durable. The theory contains the standard equilibrium view of a market as a special case. It depends on the time scale, whether an equilibrium or evolutionary description is more appropriate. The evolutionary framework is used to derive also the size, growth rate and price distribution of manufacturing business units. It predicts that the size distribution of the business units (products) is lognormal

  3. Research report for fiscal 1997 on analysis and evaluation of demonstration tests for establishment of residential photovoltaic power generation load leveling technology. Evaluation on durability of device installed with inverter to protect grid connection; 1997 nendo kenkyu hokokusho. Jutaku you taiyoko hatsuden fuka heijunka gijutsu tou kakuritsu jissho shiken ni kansuru kaiseki hyoka - Inbata tsuki keito renkei hogo sochi no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Tests and discussions have been performed on the safety and durability of the device installed with inverter to protect grid connection, being an important device in the photovoltaic power generation system. The particularly important requirements demanded in the device were specified as maintenance of electric power quality, coordination with the protection system in the grid side, and assurance of safety of personnel and facilities. The current fiscal year has performed operation corresponding to that in the actual field for 20 years in total, and the evaluation tests on electrical characteristics and electric power quality. This paper summarizes the achievements in four years including the results available up to the previous fiscal year. Although no large change has been identified in the electrical characteristics, variance has been found in the detection time of overvoltage in the grid side. With regard to the electric power quality, the value has exceeded 89 dB as the determining condition for the certification test in the conduction interfering waves of 5 kHz to 10 kHz. In addition, it was confirmed that the conductive high-frequency noise terminal voltage in the grid side after the repetition of operations and shutdowns tends to increase according to the operation lapse time. (NEDO)

  4. Technical advances and energy substitutions in the transportation sector; Progres techniques et substitutions energetiques dans le secteur des transports

    Energy Technology Data Exchange (ETDEWEB)

    Tromenschlager-Philippe, F.

    2002-11-01

    Alternative motorization technologies have been proposed in order to achieve energy diversification and a reduction in pollutant emissions. Fuel cell vehicles are, among others, at the centre of research carried out by car manufacturers and oil companies. The use of fuel cell vehicles could contribute, first to a less stringent long-term energy dependence of oil importing countries and, second, to pollutant reduction in the transport sector. First of all, we propose the definition of 'innovation' and its treatment in the frame of mainstream economic theories. Then we proceed to a retrospective analysis of diesel motorization of the car market. In the second part of our work, we conduct a survey among French households aiming to obtain up-to-date information about their degree of acceptance of fuel cell technology. We are concerned about highlighting the determining factors of fuel cell vehicle adoption by consumers. For this, we set up a discrete choice model linking the individual decision to the whole group of technical or socio-economical factors and characteristics. Finally, we develop patterns of fuel cell equipment of passenger cars which differ according to type of vehicle and possible purchase assistance. These patterns lead us to the analysis of long-term fuel cell vehicle development on the French car market. (authors)

  5. Energy choices under environmental controversy: the French biofuels case; Controverse environnemental et choix de filieres energetiques: les biocarburants en France

    Energy Technology Data Exchange (ETDEWEB)

    Fallot, A.

    2003-07-01

    In France, the persistence of biofuels at an experimental or pre-industrial stage, hangs on measures that were taken on the account of environmental policy in the energy sector. Our recent and thorough case study has resulted in the statement that biofuels do not offer the prospects for enough profitability to any economic agent - neither biomass providers nor energeticists - that would justify the investments necessary to reach large scale production. A real biofuel 'file' is not viable in a context where fossil energies dominate, nor in a context where the complete taking into account of environmental variables would have defeated the ''technological lock-in'' that nowadays excludes no-carbon technologies. We look for an explanation of the continuing public support to biofuels in the present peculiar context, where new measures of environmental policy are being decided in the energy sector without any agreement on the importance of environmental and other long term issues. For that matter, we propose a simple option value model, where both issues of irreversibility and uncertainty are tackled. (author)

  6. Durability properties of high volume fly ash self compacting concretes

    Energy Technology Data Exchange (ETDEWEB)

    P. Dinakar; K.G. Babu; Manu Santhanam [Indian Institute of Technology, Chennai (India). Building Technology Division

    2008-11-15

    This paper presents an experimental study on the durability properties of self compacting concretes (SCCs) with high volume replacements of fly ash. Eight fly ash self compacting concretes of various strength grades were designed at desired fly ash percentages of 0, 10, 30, 50, 70 and 85%, in comparison with five different mixtures of normal vibrated concretes (NCs) at equivalent strength grades. The durability properties were studied through the measurement of permeable voids, water absorption, acid attack and chloride permeation. The results indicated that the SCCs showed higher permeable voids and water absorption than the vibrated normal concretes of the same strength grades. However, in acid attack and chloride diffusion studies the high volume fly ash SCCs had significantly lower weight losses and chloride ion diffusion.

  7. Moisture Durability with Vapor-Permeable Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    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 different climate zones. This report describes the research project, key research questions, and the procedures utilized to analyse the problems.

  8. Moisture Durability with Vapor-Permeable Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    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 different climate zones. This report describes the research project, key research questions, and theprocedures utilized to analyse the problems.

  9. The contribution of economic theory to the energy debates; L'apport de la theorie economique aux debats energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Percebois, J

    1999-11-01

    This paper proposes a brief overview of the contributions of the micro- and macro-economic theory to the answer of the following four main questions: 1 - how will change the world energy demand with respect to the economic activity and what will be the determining factors of this demand, globally and per energy source? What are the respective roles of energy prices and technological innovations? How will change the petroleum price and what will be the share of economical and political weight in this change? 2 - how passing on this price to the end-user taking into consideration the national preferences? Is there an optimum price when the energy producing, transporting and distributing company is a monopoly? 3 - what is the optimal structure of a network industry? 4 - how to integrate the local and global externalities characteristic of the energy sector in the economical calculus? (J.S.)

  10. The contribution of economic theory to the energy debates; L'apport de la theorie economique aux debats energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Percebois, J.

    1999-11-01

    This paper proposes a brief overview of the contributions of the micro- and macro-economic theory to the answer of the following four main questions: 1 - how will change the world energy demand with respect to the economic activity and what will be the determining factors of this demand, globally and per energy source? What are the respective roles of energy prices and technological innovations? How will change the petroleum price and what will be the share of economical and political weight in this change? 2 - how passing on this price to the end-user taking into consideration the national preferences? Is there an optimum price when the energy producing, transporting and distributing company is a monopoly? 3 - what is the optimal structure of a network industry? 4 - how to integrate the local and global externalities characteristic of the energy sector in the economical calculus? (J.S.)

  11. Product development capability and marketing strategy for new durable products

    OpenAIRE

    Banerjee, Sumitro; Soberman, David A.

    2013-01-01

    Our objective is to understand how a firm’s product development capability (PDC) affects the launch strategy for a durable product that is sequentially improved over time in a market where consumers have heterogeneous valuations for quality. We show that the launch strategy of firms is affected by the degree to which consumers think ahead. However, only the strategy of firms with high PDC is affected by the observability of quality. When consumers are myopic and quality is observable, both hi...

  12. Durability of fired clay bricks containing granite powder

    OpenAIRE

    Xavier, G. C.; Saboya, F.; Maia, P. C.; Alexandre, J.

    2012-01-01

    Over the past few decades, hundreds of papers have been published on the benefits of including rock powder as a raw material in fired clay brick manufacture. Very little has been written, however, about the durability and long-term behaviour of the final product. As a rule, the ceramic bricks used in construction in developing countries are fired at low temperatures, which detracts from their mechanical performance. This is particularly visible in harsh environmental conditions, where weather...

  13. Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

    Science.gov (United States)

    Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

    1988-01-01

    Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

  14. Des effets durables : Asie | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    6 juin 2014 ... Le Projet hippocampe devient un important protagoniste de la conservation de la faune marine. En savoir plus. L'Initiative pour les micronutriments : des solutions durables à la faim inapparente · L'information améliore les conditions de vie dans les Philippines · De l'eau potable dans les foyers grâce à un ...

  15. Durability of light steel framing in residential applications

    OpenAIRE

    Lawson, RM; Popo-Ola, S.O.; Way, A.; Heatley, T; Pedreschi, Remo

    2010-01-01

    This paper presents a summary and analysis of research findings on the durability of galvanised cold-formed steel sections used in housing in order to deduce their design life. These cold-formed sections are produced from pre-galvanised strip steel. It reviews reports and publications from research projects carried out by Corus and the Steel Construction Institute on zinc-coated, cold-formed steel products. New data have also been gathered from measurements on houses and similar buildings tha...

  16. THE CONCEPT OF COMPETITIVE ADVANTAGES. LOGIC, SOURCES AND DURABILITY

    OpenAIRE

    Cegliński, Paweł

    2017-01-01

    Purpose: The main purpose of this article is to present theoretical assumptions of the concept of competitive advantages and main problems connected with the same. Most of all, the article outlines issues, which are presently discussed in the field of management sciences, including sources of competitive advantages, causal ambiguity and character of durability of competitive advantages in the contemporary turbulent business environment. In the author’s opinion, the issues have a great signifi...

  17. AGRICULTURE DURABLE De nouvelles pratiques sont source de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    17 nov. 2010 ... Depuis 1970, les travaux de recherche soutenus par le CRDI ont permis à des agriculteurs et à des collectivités de pays en développement d'adopter des pratiques agricoles durables. Le résultant? Une productivité accrue, un recul de la pauvreté, une plus grande sécurité alimentaire et un environnement ...

  18. Durable-Goods Monopolists, Network Effects and Penetration Pricing

    OpenAIRE

    Cyrus C.Y. Chu; Hung-Ken Chien

    2005-01-01

    We study the pricing problem of a durable-goods monopolist. With network effects, consumption externalities among heterogeneous groups of consumers generate a discontinuous demand function. Consequently, the lessor has to offer a low price in order to reach the mass market, whereas the seller has the option to build a customer base by setting a lower initial price and raise the price later in the mass market, which explains the practice of introductory pricing. Contrary to the existing litera...

  19. Energy and durable development: the place of the renewable energies

    International Nuclear Information System (INIS)

    2001-01-01

    The 29 may 2000, took place at the UNESCO, a colloquium on the place of the renewable energies facing the economic development. This document presents the opening presentation of A. Antolini and L. Jospin and the colloquium papers and debates in the following four domains: the energy challenges of the durable development, the renewable energies sources facing the european directive, the thermal renewable energies (solar, geothermics and biomass) and the greenhouse effect, the world market of the renewable energies. (A.L.B.)

  20. The influence of adherent surface preparation on bond durability

    International Nuclear Information System (INIS)

    Rider, A.N.; Arnott, D.R.; Olsson-Jacques, C.L.

    1999-01-01

    Full text: One of the major factors limiting the use of adhesive bonding is the problem associated with the production of adhesive joints that can maintain their initial strength over long periods of time in hostile environments. It is well known that the adherent surface preparation method is critical to the formation of a durable adhesive bond. Work presented in this paper focuses on the critical aspects of the surface preparation of aluminium employed for the manufacture of aluminium-epoxy joints. The surface preparation procedure examined is currently employed by the RAAF for repairs requiring metal to adhesive bonding. The influence of each step in the surface preparation on the ultimate bond durability performance of the adhesive joint is examined by a combination of methods. Double cantilever wedge style adhesive joints are loaded in mode 1 opening and then exposed to a humid environment. X-ray photoelectron spectroscopy (XPS) and contact angle measurements of the aluminium adherent before bonding provides information about the adherent surface chemistry. XPS is also employed to analyse the surfaces of the bonded specimens post failure to establish the locus of fracture. This approach provides important information regarding the properties influencing bond durability as well as the bond failure mechanisms. A two step bond degradation model was developed to qualitatively describe the observed bond durability performance and fracture data. The first step involves controlled moisture ingress by stress induced microporosity of the adhesive in the interfacial region. The second step determines the locus of fracture through the relative dominance of one of three competitive processes, viz: oxide degradation, polymer desorption, or polymer degradation. A key element of the model is the control exercised over the interfacial microporosity by the combined interaction of stress and the relative densities of strong and weak linkages at the metal to adhesive interface

  1. Durability-Based Design Criteria for a Quasi-Isotropic Carbon-Fiber-Reinforced Thermoplastic Automotive Composite

    Energy Technology Data Exchange (ETDEWEB)

    Naus, Dan J [ORNL; Corum, James [ORNL; Klett, Lynn B [ORNL; Davenport, Mike [ORNL; Battiste, Rick [ORNL; Simpson, Jr., William A [ORNL

    2006-04-01

    This report provides recommended durability-based design properties and criteria for a quais-isotropic carbon-fiber thermoplastic composite for possible automotive structural applications. The composite consisted of a PolyPhenylene Sulfide (PPS) thermoplastic matrix (Fortron's PPS - Ticona 0214B1 powder) reinforced with 16 plies of carbon-fiber unidirectional tape, [0?/90?/+45?/-45?]2S. The carbon fiber was Hexcel AS-4C and was present in a fiber volume of 53% (60%, by weight). The overall goal of the project, which is sponsored by the U.S. Department of Energy's Office of Freedom Car and Vehicle Technologies and is closely coordinated with the Advanced Composites Consortium, is to develop durability-driven design data and criteria to assure the long-term integrity of carbon-fiber-based composite systems for automotive structural applications. This document is in two parts. Part 1 provides design data and correlations, while Part 2 provides the underlying experimental data and models. The durability issues addressed include the effects of short-time, cyclic, and sustained loadings; temperature; fluid environments; and low-energy impacts (e.g., tool drops and kickups of roadway debris) on deformation, strength, and stiffness. Guidance for design analysis, time-independent and time-dependent allowable stresses, rules for cyclic loadings, and damage-tolerance design guidance are provided.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  4. Freeze-Thaw Durability of Air-Entrained Concrete

    Directory of Open Access Journals (Sweden)

    Huai-Shuai Shang

    2013-01-01

    Full Text Available One of the most damaging actions affecting concrete is the abrupt temperature change (freeze-thaw cycles. The types of deterioration of concrete structures by cyclic freeze-thaw can be largely classified into surface scaling (characterized by the weight loss and internal crack growth (characterized by the loss of dynamic modulus of elasticity. The present study explored the durability of concrete made with air-entraining agent subjected to 0, 100, 200, 300, and 400 cycles of freeze-thaw. The experimental study of C20, C25, C30, C40, and C50 air-entrained concrete specimens was completed according to “the test method of long-term and durability on ordinary concrete” GB/T 50082-2009. The dynamic modulus of elasticity and weight loss of specimens were measured after different cycles of freeze-thaw. The influence of freeze-thaw cycles on the relative dynamic modulus of elasticity and weight loss was analyzed. The findings showed that the dynamic modulus of elasticity and weight decreased as the freeze-thaw cycles were repeated. They revealed that the C30, C40, and C50 air-entrained concrete was still durable after 300 cycles of freeze-thaw according to the experimental results.

  5. Novel Arrangements for High Performance and Durable Dielectric Elastomer Actuation

    Directory of Open Access Journals (Sweden)

    Runan Zhang

    2016-07-01

    Full Text Available This paper advances the design of Rod Pre-strained Dielectric Elastomer Actuators (RP-DEAs in their capability to generate comparatively large static actuation forces with increased lifetime via optimized electrode arrangements. RP-DEAs utilize thin stiff rods to constrain the expansion of the elastomer and maintain the in-plane pre-strain in the rod longitudinal direction. The aim is to study both the force output and the durability of the RP-DEA. Initial design of the RP-DEA had poor durability, however, it generated significantly larger force compared with the conventional DEA due to the effects of pre-strain and rod constraints. The durability study identifies the in-electro-active-region (in-AR lead contact and the non-uniform deformation of the structure as causes of pre-mature failure of the RP-DEA. An optimized AR configuration is proposed to avoid actuating undesired areas in the structure. The results show that with the optimized AR, the RP-DEA can be effectively stabilized and survive operation at least four times longer than with a conventional electrode arrangement. Finally, a Finite Element simulation was also performed to demonstrate that such AR design and optimization can be guided by analyzing the DEA structure in the state of pre-activation.

  6. Self-curing concrete types; water retention and durability

    Directory of Open Access Journals (Sweden)

    Magda I. Mousa

    2015-09-01

    This study was carried out to compare among concretes without or with silica fume (SF along with chemical type of shrinkage reducing admixture, polyethylene-glycol (Ch, and leca as self-curing agents for water retention even at elevated temperature (50 °C and their durability. The cement content of 400 kg/m3, silica fume of 15% by weight of cement, polyethylene-glycol of 2% by weight of cement, pre-saturated lightweight aggregate (leca 15% by volume of sand and water with Ch/binder ratio of 0.4 were selected in this study. Some of the physical and mechanical properties were determined periodically up to 28 days in case of exposure to air curing in temperature of (25 °C and (50 °C while up to 6 months of exposure to 5% of carbon dioxide and wet/dry cycles in 8% of sodium chloride for durability study. The concrete mass loss and the volumetric water absorption were measured, to evaluate the water retention of the investigated concretes. Silica fume concrete either without or with Ch gave the best results under all curing regimes; significant water retention and good durability properties.

  7. Use of recycled fine aggregate in concretes with durable requirements.

    Science.gov (United States)

    Zega, Claudio Javier; Di Maio, Angel Antonio

    2011-11-01

    The use of construction waste materials as aggregates for concrete production is highly attractive compared to the use of non-renewable natural resources, promoting environmental protection and allowing the development of a new raw material. Several countries have recommendations for the use of recycled coarse aggregate in structural concrete, whereas the use of the fine fraction is limited because it may produce significant changes in some properties of concrete. However, during the last decade the use of recycled fine aggregates (RFA) has achieved a great international interest, mainly because of economic implications related to the shortage of natural sands suitable for the production of concrete, besides to allow an integral use of this type of waste. In this study, the durable behaviour of structural concretes made with different percentage of RFA (0%, 20%, and 30%) is evaluated. Different properties related to the durability of concretes such as absorption, sorptivity, water penetration under pressure, and carbonation are determined. In addition, the results of compressive strength, static modulus of elasticity and drying shrinkage are presented. The obtained results indicate that the recycled concretes have a suitable resistant and durable behaviour, according to the limits indicated by different international codes for structural concrete. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Freeze-thaw durability of air-entrained concrete.

    Science.gov (United States)

    Shang, Huai-Shuai; Yi, Ting-Hua

    2013-01-01

    One of the most damaging actions affecting concrete is the abrupt temperature change (freeze-thaw cycles). The types of deterioration of concrete structures by cyclic freeze-thaw can be largely classified into surface scaling (characterized by the weight loss) and internal crack growth (characterized by the loss of dynamic modulus of elasticity). The present study explored the durability of concrete made with air-entraining agent subjected to 0, 100, 200, 300, and 400 cycles of freeze-thaw. The experimental study of C20, C25, C30, C40, and C50 air-entrained concrete specimens was completed according to "the test method of long-term and durability on ordinary concrete" GB/T 50082-2009. The dynamic modulus of elasticity and weight loss of specimens were measured after different cycles of freeze-thaw. The influence of freeze-thaw cycles on the relative dynamic modulus of elasticity and weight loss was analyzed. The findings showed that the dynamic modulus of elasticity and weight decreased as the freeze-thaw cycles were repeated. They revealed that the C30, C40, and C50 air-entrained concrete was still durable after 300 cycles of freeze-thaw according to the experimental results.

  9. Durable transparent carbon nanotube films for flexible device components

    International Nuclear Information System (INIS)

    Sierros, K.A.; Hecht, D.S.; Banerjee, D.A.; Morris, N.J.; Hu, L.; Irvin, G.C.; Lee, R.S.; Cairns, D.R.

    2010-01-01

    This paper describes a durable carbon nanotube (CNT) film for flexible devices and its mechanical properties. Films as thin as 10 nm thick have properties approaching those of existing electrodes based on indium tin oxide (ITO) but with significantly improved mechanical properties. In uniaxial tension, strains as high as 25% are required for permanent damage and at lower strains resistance changes are slight and consistent with elastic deformation of the individual CNTs. A simple model confirms that changes in electrical resistance are described by a Poisson's ratio of 0.22. These films are also durable to cyclic loading, and even at peak strains of 10% no significant damage occurs after 250 cycles. The scratch resistance is also high as measured by nanoscratch, and for a 50 μm tip a load of 140 mN is required to cause initial failure. This is more than 5 times higher than is required to cause cracking in ITO. The robustness of the transparent conductive coating leads to significant improvement in device performance. In touch screen devices fabricated using CNT no failure occurs after a million actuations while for devices based on ITO electrodes 400,000 cycles are needed to cause failure. These durable electrodes hold the key to developing robust, large-area, lightweight, optoelectronic devices such as lighting, displays, electronic-paper, and printable solar cells. Such devices could hold the key to producing inexpensive green energy, providing reliable solid-state lighting, and significantly reducing our dependence on paper.

  10. Preliminary results of durability testing with borosilicate glass compositions

    International Nuclear Information System (INIS)

    Adel-Hadadi, M.; Adiga, R.; Barkatt, Aa.

    1987-01-01

    This is a report on the first year of research conducted at the Vitreous State Laboratory of the Catholic University of America in support of the West Valley Demonstration Project. One objective is the vitrification of liquid waste generated by previous nuclear fuel reprocessing. This work has been directed principally at the problem of glass composition optimization. This has necessitated the development of a coordinated program of glass production, durability measurements, and processability assessment. A small-scale continuous melter has been constructed for melting uranium and thorium containing glasses and for studying glass processing characteristics. Glass viscosities have been measured over a range of temperatures. A large number of glasses have also been produced in small crucible melts. Glass durability has been assessed using four types of leach tests: MCC-3, MCC-1, IAEA/ISO, and pulsed-flow tests. Extensive data from these tests are reported. The data have led to the design of very durable glasses (comparable to the Savannah River Laboratory Defense Waste Reference Glass) which have the requisite waste loading and processing characteristics. 14 refs., 4 figs., 77 tabs

  11. Reliability algorithms applied to reinforced concrete structures durability assessment

    Directory of Open Access Journals (Sweden)

    C. G. Nogueira

    Full Text Available This paper addresses the analysis of probabilistic corrosion time initiation in reinforced concrete structures exposed to ions chloride penetration. Structural durability is an important criterion which must be evaluated in every type of structure, especially when these structures are constructed in aggressive atmospheres. Considering reinforced concrete members, chloride diffusion process is widely used to evaluate the durability. Therefore, at modelling this phenomenon, corrosion of reinforcements can be better estimated and prevented. These processes begin when a threshold level of chlorides concentration is reached at the steel bars of reinforcements. Despite the robustness of several models proposed in the literature, deterministic approaches fail to predict accurately the corrosion time initiation due to the inherently randomness observed in this process. In this regard, the durability can be more realistically represented using probabilistic approaches. A probabilistic analysis of ions chloride penetration is presented in this paper. The ions chloride penetration is simulated using the Fick's second law of diffusion. This law represents the chloride diffusion process, considering time dependent effects. The probability of failure is calculated using Monte Carlo simulation and the First Order Reliability Method (FORM with a direct coupling approach. Some examples are considered in order to study these phenomena and a simplified method is proposed to determine optimal values for concrete cover.

  12. Enhanced Performance of Recycled Aggregate Concrete with Atomic Polymer Technology

    Science.gov (United States)

    2012-06-01

    The atomic polymer technology in form of mesoporous inorganic polymer (MIP) can effectively improve material durability and performance of concrete by dramatically increase inter/intragranular bond strength of concrete at nano-scale. The strategy of ...

  13. Effect of Humidity in Air on Performance and Long-Term Durability of SOFCs

    DEFF Research Database (Denmark)

    Hagen, Anke; Neufeld, Kai; Liu, Yi-Lin

    2010-01-01

    Anode-supported solid oxide fuel cells (SOFCs) based on Ni–yttria-stabilized zirconia (YSZ) anodes, YSZ electrolytes, and lanthanum strontium manganite (LSM)–YSZ cathodes were studied with respect to durability in humid air (~4%) typically over 1500 h. Operating temperature and current density were...... varied between 750 and 850°C and 0.25–0.75 A/cm2, respectively. The introduction of humidity affected the cell voltage under polarization of the cell, and this effect was (at least partly) reversible upon switching off the humidity. Generally, the studied cells were operated in humid air under...... technologically relevant conditions over more than 1500 h. Improvements at the cathode/electrolyte interface made it possible to obtain highly stable cells, which can be operated under high current density and at 750°C in humid air, conditions that cause significant cell voltage degradation in dry air on cells...

  14. Effect of Humidity in Air on Performance and Long-Term Durability of SOFCs

    DEFF Research Database (Denmark)

    Hagen, Anke; Chen, Ming; Neufeld, Kai

    2009-01-01

    Anode supported SOFCs based on Ni-YSZ anodes, YSZ electrolytes, and LSM-YSZ cathodes were studied with respect to durability in humid air (~4%) over typically 1500 hours. Operating temperature and current density were varied between 750 and 850 oC and 0.25-0.75 A/cm2, respectively. It was found...... that the introduction of humidity affected the cell voltage under polarization of the cell and that this effect was (at least partly) reversible upon switching off the humidity, probably related to a segregation of impurities towards the three phase boundary in the presence of humidity. Generally, the studied cells...... were successfully operated in humid air under technologically relevant conditions. Improvements at the cathode/electrolyte interface made it possible to obtain highly stable cells, which can be operated under high current density and at 750 oC in humid air - conditions that are known to cause...

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

    Science.gov (United States)

    McKenzie, Clifford; Parness, Aaron

    2012-01-01

    The Durable Reconnaissance and Observation Platform (DROP) is a prototype robotic platform with the ability to climb concrete surfaces up to 85deg at a rate of 25cm/s, make rapid horizontal to vertical transitions, carry an audio/visual reconnaissance payload, and survive impacts from 3 meters. DROP is manufactured using a combination of selective laser sintering (SLS) and shape deposition manufacturing (SDM) techniques. The platform uses a two-wheel, two-motor design that delivers high mobility with low complexity. DROP extends microspine climbing technology from linear to rotary applications, providing improved transition ability, increased speeds, and simpler body mechanics while maintaining microspines ability to opportunistically grip rough surfaces. Various aspects of prototype design and performance are discussed, including the climbing mechanism, body design, and impact survival.

  16. A durability analysis of the Cascad facility based on feedback obtained after 10 years of operation

    International Nuclear Information System (INIS)

    Samoel, R.; Canas, D.; Henry, H.; Battesti, P.

    1999-01-01

    The CASCAD facility at the nuclear research centre in Cadarache is a dry storage facility for spent fuel that has been placed in a vault. Feedback on its design and performance after 10 years of operation was obtained in order to identify the factors limiting its life time. This assessment corresponds to a durability analysis based on a combination of dependability methods. This is a critical analysis identifying the risks involving failure of the components when they are subjected to internal and external disturbances (aging, technology obsolescence, etc.). The measures to be implemented to extend the life time of the facility are subsequently enumerated. A proposed synthesis or 'logic diagram' of the analysis is also presented. (authors)

  17. Evaluation of gamma ray durability and its application of shielded RF tags

    International Nuclear Information System (INIS)

    Teraura, Nobuyuki; Ito, Kunio; Kobayashi, Daisuke; Sakurai, Kouichi

    2015-01-01

    In this study, the RF (Radio Frequency) tag with radiation shield is developed and its gamma ray durability is evaluated. RFID (RF Identification) is a radio-wave-based identification technology that can be used for various items. RF tags find use in many applications, including item tracing, access control, etc. RF tags can be classified as active RF tags, which have inbuilt voltaic cells, and passive RF tags without these cells. Passive RF tags, known for their low price and durability, are used in various fields. For instance, they are used for equipment maintenance in factories and thermal power plants. Several frequencies are used for RF tags. Further, RF tagging on the UHF (Ultra High Frequency) frequencies allows a communication range of approximately 10 m, and thus, remote reading is possible. When used in radiation environments such as in nuclear power plants, remote reading can contribute to the reduction of radiation exposure. However, because semiconductors are the primary elements used in the manufacture of RF tags, they can be damaged by radiation, and operational errors can occur. Therefore, this technology has not been used in environments affected by relatively high radiation levels. Therefore, in nuclear power plants, the use of RF tags is limited in areas of low radiation levels. In our study, we develop and manufacture a new RF tag with a radiation shield cover that provides error correction functionality. It is expected that radiation shielded RF tags will improve the radiation-proof feature, and its application range will be expanded. Using the radiation-proof RF tag, we have conducted radiation durability tests. These tests are of two types: one using low energy gamma ray, and the other using high-energy gamma ray. Experimental results are then analyzed. The number of applications for radiation shielded RF tags is considerably increasing, because it can be used in various radiation environments other than nuclear power plants as well, such as

  18. Energy and durable development: the place of the renewable energies; Energie et developpement durable: la place des energies renouvelables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The 29 may 2000, took place at the UNESCO, a colloquium on the place of the renewable energies facing the economic development. This document presents the opening presentation of A. Antolini and L. Jospin and the colloquium papers and debates in the following four domains: the energy challenges of the durable development, the renewable energies sources facing the european directive, the thermal renewable energies (solar, geothermics and biomass) and the greenhouse effect, the world market of the renewable energies. (A.L.B.)

  19. Couches minces electrochromiques d'oxyde de tungstene dense et poreux pour des applications de controle energetique

    Science.gov (United States)

    Camirand, Hubert

    Nanotechnology has modified the landscape of energy generation, energy storage and energy saving devices. Architectural fenestration can extensively benefit from green nanotechnologies. Amongst them, active fenestration or "smart" windows are able to modify their coloration state upon the application of a small electrical voltage, when based on electrochromic materials. In fact, the amount of visible and near-infrared light that can penetrate through the window can be altered. Therefore, their implementation can allow for a significant reduction in energy consumption in buildings. Furthermore, the capability of optimizing indoor comfort is user-controlled, thus an additional degree of freedom is given by electrochromic-based technology. It is worth mentioning that such devices can be largely advantageous in countries with variable seasons, such as here in Canada. As a matter of fact, the large temperature difference between the hot and cold season influences the requirement of impeding or enabling visible and thermal radiation to pass through. This master's thesis is entirely devoted to tungsten trioxide (WO 3), which is the most widely studied electrochromic material. In the present case, WO3 thin films are synthesized by radiofrequency magnetron sputtering. By varying the deposition pressure and power, the porosity content/packing density of the films is modified. This work's main topic is the characterization of electrochromic samples by in situ spectroscopic ellipsometry simultaneously with the application of an electrical voltage in an aqueous electrolytic medium made of sulfuric acid (H2SO 4). The methodology developed here allows for an in-depth study of electro-active materials. To corroborate this, optical properties of WO3 are obtained for a wide range of coloration levels, and these are subsequently used to model the resulting coloration of electrochromic multilayer systems. However, the interface between the dense and porous films affects the coloration

  20. Polylactic Acid-Based Polymer Blends for Durable Applications

    Science.gov (United States)

    Finniss, Adam

    There has been considerable scientific interest in both research and commercial communities as of late in the area of biologically based or sourced plastics. As the consumption of petroleum rises and concerns about climate change increase, this field is likely to grow even larger. One bioplastic that has received a great deal of attention is polylactic acid (PLA). In the past, this material was used mainly in medical or specialty applications, but advancements in manufacturing have led to a desire to use PLA more widely, especially in durable applications. Unfortunately, PLA has several drawbacks that hinder more widespread usage of the material as a durable item: it has low ductility and impact strength in bulk applications, along with poor stability in the face of heat, humidity or liquid media. To combat these deficiencies, a number of techniques were investigated. Samples were annealed to create crystalline domains that would improve mechanical properties and reduce diffusion, blended with graphene to create barriers to diffusion throughout the material, or compounded with a polycarbonate (PC) polymer phase to protect the PLA phase and to enhance the mechanical properties of the blend. If a material containing biologically sourced components with good mechanical properties can be created, it would be desirable for durable uses such as electronics components or as an automotive grade resin. Crystallization experiments were carried out in a differential scanning calorimeter to determine the effects of heat treatment and additives on the rather slow crystallization kinetics of PLA polymer. It was determined that the blending in of the PC phase did not significantly alter the kinetics or mechanism of crystal growth. The addition of graphene to any PC/PLA formulation served as a nucleating agent which speeded up the crystallization kinetics markedly, in some cases by several orders of magnitude. Results obtained from these experiments were internally consistent

  1. Durability of Low Platinum Fuel Cells Operating at High Power Density

    Energy Technology Data Exchange (ETDEWEB)

    Polevaya, Olga [Nuvera Fuel Cells Inc.; Blanchet, Scott [Nuvera Fuel Cells Inc.; Ahluwalia, Rajesh [Argonne National Lab; Borup, Rod [Los-Alamos National Lab; Mukundan, Rangachary [Los-Alamos National Lab

    2014-03-19

    Understanding and improving the durability of cost-competitive fuel cell stacks is imperative to successful deployment of the technology. Stacks will need to operate well beyond today’s state-of-the-art rated power density with very low platinum loading in order to achieve the cost targets set forth by DOE ($15/kW) and ultimately be competitive with incumbent technologies. An accelerated cost-reduction path presented by Nuvera focused on substantially increasing power density to address non-PGM material costs as well as platinum. The study developed a practical understanding of the degradation mechanisms impacting durability of fuel cells with low platinum loading (≤0.2mg/cm2) operating at high power density (≥1.0W/cm2) and worked out approaches for improving the durability of low-loaded, high-power stack designs. Of specific interest is the impact of combining low platinum loading with high power density operation, as this offers the best chance of achieving long-term cost targets. A design-of-experiments approach was utilized to reveal and quantify the sensitivity of durability-critical material properties to high current density at two levels of platinum loading (the more conventional 0.45 mgPt.cm–1 and the much lower 0.2 mgPt.cm–2) across several cell architectures. We studied the relevance of selected component accelerated stress tests (AST) to fuel cell operation in power producing mode. New stress tests (NST) were designed to investigate the sensitivity to the addition of electrical current on the ASTs, along with combined humidity and load cycles and, eventually, relate to the combined city/highway drive cycle. Changes in the cathode electrochemical surface area (ECSA) and average oxygen partial pressure on the catalyst layer with aging under AST and NST protocols were compared based on the number of completed cycles. Studies showed elevated sensitivity of Pt growth to the potential limits and the initial particle size distribution. The ECSA loss

  2. Advanced Stirling Convertor Durability Testing: Plans and Interim Results

    Science.gov (United States)

    Meer, David W.; Oriti, Salvatore M.

    2012-01-01

    The U.S. Department of Energy (DOE), Lockheed Martin Corporation (LM), and NASA Glenn Research Center (GRC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. In support of this program, GRC has been involved in testing Stirling convertors, including the Advanced Stirling Convertor (ASC), for use in the ASRG. This testing includes electromagnetic interference/compatibility (EMI/EMC), structural dynamics, advanced materials, organics, and unattended extended operation. The purpose of the durability tests is to experimentally demonstrate the margins in the ASC design. Due to the high value of the hardware, previous ASC tests focused on establishing baseline performance of the convertors within the nominal operating conditions. The durability tests present the first planned extension of the operating conditions into regions beyond those intended to meet the product spec, where the possibility exists of lateral contact, overstroke, or over-temperature events. These tests are not intended to cause damage that would shorten the life of the convertors, so they can transition into extended operation at the conclusion of the tests. This paper describes the four tests included in the durability test sequence: 1) start/stop cycling, 2) exposure to constant acceleration in the lateral and axial directions, 3) random vibration at increased piston amplitude to induce contact events, and 4) overstroke testing to simulate potential failures during processing or during the mission life where contact events could occur. The paper also summarizes the analysis and simulation used to predict the results of each of these tests.

  3. Evaluation of the Mechanical Durability of the Egyptian Machine Readable Booklet Passport

    Directory of Open Access Journals (Sweden)

    Ahmed Mahmoud Yosri

    2013-12-01

    Full Text Available In 2008 the first Egyptian booklet Machine Readable Passport/ MRP has been issued and its security and informative standard quality levels were proved in a research published in 2011. Here the durability profiles of the Egyptian MRP have been evaluated. Seven mechanical durability tests were applied on the Egyptian MRP. Such tests are specified in the International Civil Aviation Organization / ICAO standard requirements documents. These seven very severe durability tests resulted in that the Egyptian MRP has achieved better & higher results than the values detected in ICAO-Doc N0232: Durability of Machine Readable Passports - Version: 3.2. Hence, this research had proved the complete conformance between the Egyptian MRP mechanical durability profiles to the international requirements. The Egyptian booklet MRP doesn’t need any obligatory modification concerning its mechanical durability profiles.

  4. State of the art of durability-performance evaluation of hardened cement based on phase compositions

    International Nuclear Information System (INIS)

    Kurashige, Isao; Imoto, Harutake; Yamamoto, Takeshi; Hironaga, Michihiko

    2006-01-01

    Upgrading durability-performance evaluation technique for concrete is urgently demanded in connection to its application to radio-active waste repository which needs ultra long-term durability. Common concrete structures also require an advanced method for minimizing the life-cycle cost. The purpose of this research is to investigate current problems and future tasks on durability-performance evaluation of hardened cement from the view point of phase composition. Although the phase composition of hardened cement has not fully been reflected to durability-performance evaluation, it influences concrete durability as well as its pore structure. This report reviews state of the art of the factors affecting phase composition, analytical and experimental evaluation techniques for phase composition, and durability-performance evaluation methods of hardened cement based on phase composition. (author)

  5. Flexible, durable proton energy degraders for the GE PETtrace

    DEFF Research Database (Denmark)

    Engle, J. W.; Gagnon, K.; Severin, Gregory

    2012-01-01

    In order to limit the formation of radioisotopic impurities during proton bombardments of solid targets, two methods of introducing degrader foils into the beam upstream of the target were tested. The first design uses a 445 μm thick fixed degrader machined from a single piece of aluminum....... The second design permits introduction of foils made of any material and was tested with foils as thick as 635 μm (also aluminium). In both cases, the foils are cooled with by water flowing through an annular channel outside the radius of the beam. Both designs proved durable and tolerated proton beam...

  6. Deformable and durable phantoms with controlled density of scatterers

    Energy Technology Data Exchange (ETDEWEB)

    Bisaillon, Charles-Etienne; Lamouche, Guy; Dufour, Marc; Monchalin, Jean-Pierre [Industrial Materials Institute, National Research Council Canada, 75 de Mortagne, Boucherville, Quebec J4B 6Y4 (Canada); Maciejko, Romain [Optoelectronics Laboratory, Engineering Physics, Ecole Polytechnique de Montreal, PO Box 6079, Station ' Centre-ville' Montreal, Quebec H3C 3A7 (Canada)], E-mail: charles-etienne.bisaillon@cnrc-nrc.gc.ca, E-mail: guy.lamouche@cnrc-nrc.gc.ca, E-mail: marc.dufour@cnrc-nrc.gc.ca, E-mail: jean-pierre.monchalin@cnrc-nrc.gc.ca, E-mail: romain.maciejko@polytml.ca

    2008-07-07

    We have developed deformable and durable optical tissue phantoms with a simple and well-defined microstructure including a novel combination of scatterers and a matrix material. These were developed for speckle and elastography investigations in optical coherence tomography, but should prove useful in many other fields. We present in detail the fabrication process which involves embedding silica microspheres in a silicone matrix. We also characterize the resulting phantoms with scanning electron microscopy and optical measurements. To our knowledge, no such phantoms were proposed in the literature before. Our technique has a wide range of applicability and could also be adapted to fabricate phantoms with various optical and mechanical properties. (note)

  7. SEM investigation of incandescent lamp mantle structure on durability

    International Nuclear Information System (INIS)

    Gerneke, D.; Lang, C.

    2002-01-01

    Full text: The incandescent mantle as used on pressure and non-pressure liquid fuel lamps has been in use for over 100 years. What remains unexplained is the way in which the resistance to mechanical shock and the decline in tensile strength with usage is experienced. It has been suggested that to improve durability it is necessary to continuously burn a new mantle for the first two to three hours. The known factors in mantle durability and mechanical strength are chemical composition and fabric weave. This study was undertaken to investigate the effects of burning time and temperature on thorium oxide mantles. The operating temperature of mantles on a range of kerosene pressure lamps was measured and found to be between 800 and 1100 deg C. Heat treatments of thorium based Coleman mantles were carried out in a laboratory furnace within these ranges of temperatures for periods ranging from 2 minutes to 2 hours. The mantles were then viewed in a LEO S440 analytical SEM. Results at 800 deg C show a distinct change in surface morphology with increasing exposure time. At the shorter times (2-5 minutes) the surface was relatively smooth. With increased time periods (15 - 120 minutes) the surface was observed to have a large lumpy structure. At 1100 deg C the difference in surface morphology was not apparent between the shortest and longest times. The surface appears much smoother and no lumpy structure was observed. This suggests that when a mantle is operated at the higher temperature of 1100 deg C the structure of the Thorium oxide is quickly transformed into the known stronger amorphous form. This is taken as the observed smooth structure seen in the SEM images of the 1100 deg C samples. Thus the mantle is expected to be more resistant to mechanical shock and have increased durability. Practical field test results confirm these observations. The mantle on a lamp that is operating efficiently, burns brightly, will far outlast a mantle on an inefficient lamp which bums

  8. Water-thinnable polymers for durable coatings for different materials

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Piotr, E-mail: piotr.jankowski@ichp.pl; Kijowska, Dorota, E-mail: piotr.jankowski@ichp.pl [Industrial Chemistry Research Institute, Department of Polyesters, Epoxides and Polyurethanes, 8 Rydygiera Str., 01-793 Warszawa (Poland)

    2014-05-15

    The methods of obtaining water-thinnable polymers - water-thinnable unsaturated polyester resins (WTUPR) - by polycondensation were elaborate and optimized. As hydrophilic monomers different types of sulfonate monomers were used. The monomers, with sulfonate groups and other reactive groups, were obtained by sulfonation of organic compounds with satisfactory yield. All products were analyzed by {sup 1}H NMR and {sup 13}C NMR spectra. WTUPR were used as polymeric binders for coatings applications. Coatings with relatively high pendulum hardness, good properties and durability, useful for practical applications, were obtained. Typical existing equipment for the production of unsaturated polyester resins can be applied for the industrial preparation of WTUPR.

  9. Durable zinc oxide-containing sorbents for coal gas desulfurization

    Science.gov (United States)

    Siriwardane, Ranjani V.

    1996-01-01

    Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.

  10. Flexible, durable proton energy degraders for the GE PETtrace

    Energy Technology Data Exchange (ETDEWEB)

    Engle, J. W.; Gagnon, K.; Severin, G. W.; Valdovinos, H. F.; Nickles, R. J.; Barnhart, T. E. [Chemistry Division - Isotopes, Inorganics and Actinides, Los Alamos National Laboratory, Los Alamos, NM (United States); Department of Radiation Oncology, University of Washington, Seattle, WA (United States); Hevesy Laboratory, Danish Technical University, Risoe (Denmark); Department of Medical Physics, University of Wisconsin, WI, Madison (United States)

    2012-12-19

    In order to limit the formation of radioisotopic impurities during proton bombardments of solid targets, two methods of introducing degrader foils into the beam upstream of the target were tested. The first design uses a 445 {mu}m thick fixed degrader machined from a single piece of aluminum. The second design permits introduction of foils made of any material and was tested with foils as thick as 635 {mu}m (also aluminium). In both cases, the foils are cooled with by water flowing through an annular channel outside the radius of the beam. Both designs proved durable and tolerated proton beam currents in excess of 80 {mu}A.

  11. Electrostimulated recovery of welded joint durability: experiment and model

    International Nuclear Information System (INIS)

    Semakin, E.V.; Chirakadze, D.Z.; Tsellermaer, V.Ya.; Gromov, V.E.; Sosnin, O.V.

    1997-01-01

    The possibility to increase the durability of welded joints operating under conditions of low cycle fatigue is shown to be brought about using electric current pulses. Experimental method of recovery of operational capability is demonstrated on welded joints of tool steels R6M5 and 40Kh/ The onset of critical stage of fatigue in the welded joint was determined by ultrasonic testing. Then the specimens were treated with 20 Hz electric pulses with amplitude of 250 MA/M 2 for 100 μs. Such treatment resulted in an increase of time to fracture. The phenomenological model of the process is proposed

  12. Tiling as a Durable Abstraction for Parallelism and Data Locality

    Energy Technology Data Exchange (ETDEWEB)

    Unat, Didem [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chan, Cy P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhang, Weiqun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bell, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shalf, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-11-18

    Tiling is a useful loop transformation for expressing parallelism and data locality. Automated tiling transformations that preserve data-locality are increasingly important due to hardware trends towards massive parallelism and the increasing costs of data movement relative to the cost of computing. We propose TiDA as a durable tiling abstraction that centralizes parameterized tiling information within array data types with minimal changes to the source code. The data layout information can be used by the compiler and runtime to automatically manage parallelism, optimize data locality, and schedule tasks intelligently. In this study, we present the design features and early interface of TiDA along with some preliminary results.

  13. FY 2000 report on the results of the development of transportation use and residential/commercial use high efficiency energy system technology. R and D of polymer electrolyte cells (Research on ion exchange membranes for commercialization of highly durable cells); 2000 nendo unyu minsei you kokoritsu energy system gijutsu kaihatsu seika hokokusho. Kotai kobunshigata nenryo denchi no kenkyu kaihatsu (Kotaikyusei denchi jitsuyoka no tame no ion kokanmaku ni kansuru kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    As to ion exchange membranes for fuel cells, the R and D were made with the aim of clarifying the characteristics of the membrane required to realize highly durable modules and of demonstrating durability of membrane, and the FY 2000 results were reported. Concerning the low ion exchange capacity thin membrane, the following were confirmed: in perfluorosulfonic acid with ion exchange capacity of 0.84-1.0, the lower the ion exchange capacity is, the greater characteristics of mechanical strength are improved; the optimization of membrane thickness makes the design which satisfies cell characteristics and mechanical strength characteristics possible. In the durability test by medium-/long-term continued operation using each of small unit cell and large unit cell, the results of the stable operation of 5,000 hours using S1102 and S1201Q membranes were obtained. About effects of methanol, changes were observed in creep characteristics and piercing strength in the test on the environmental cycle at -40 degrees C to 80 degrees C. The membrane of low ion exchange capacity kept high elastic modulus even after the treatment at 120 degrees C, which indicated its usability for the higher temperature operation. (NEDO)

  14. The Effectiveness of Materials Different with Regard to Increasing the Durability

    Directory of Open Access Journals (Sweden)

    Erofeev Vladimir

    2016-01-01

    Full Text Available The article considers contemporary materials and structures for construction of buildings. The article conducts an economic study of the problem of durability. It addresses the issue of increasing longevity, affecting the term of service to building structures and the efficiency of their operation. Revealed the main factors affecting the durability. It identifies measures its realisation. The method of calculation of economic efficiency of improving the durability of building constructions.

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

    Science.gov (United States)

    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

  16. Enhancing the Durability of Calcareous Stone Monuments of Ancient Egypt Using CaCO3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohammad A. Aldoasri

    2017-08-01

    Full Text Available The unwanted changes in valuable historic calcareous stone monuments due to exposure to many physical and chemical effects may lead to its deterioration. The growing interest in the field of conservation of stone monuments encourages the development of consolidation and water-repellent materials. The aim of this study is to evaluate the effectiveness of CaCO3 nanoparticles as a consolidation and protection material for calcareous stone monuments, when those nanoparticles used are dispersed in acrylic copolymer; polyethylmethacrylate (EMA/methylacrylate (MA (70/30, respectively. Samples were subjected to artificial aging by relative humidity/temperature to show the optimum conditions of durability and the effectiveness of the nano-mixture in improving the physical and mechanical properties of the stone material. The synthesis process of CaCO3 nanoparticles/polymer nanocomposite has been prepared by in situ emulsion polymerization system. The prepared nanocomposites with 0.15 g CaCO3 nanoparticles showed obvious transparency features and represent nanocomposites coating technology with hydrophobic, consolidating and good protection properties. Some tests were performed in order to estimate the superficial consolidating and protective effect of the treatment. The obtained nanocomposites have been characterized by TEM, while the surface morphology before and after treatment and homogeneous distribution of used consolidation materials on stone surface were examined by SEM. Improvement of stone mechanical properties was evaluated by compressive strength tests. Change in water-interaction properties was evaluated by water absorption capillarity measurements, and colorimetric measurements were used to evaluate the optical appearance. Taken together, the results indicate that CaCO3/polymer nanocomposite is a completely compatible, efficient material for the consolidation of artistic and architectural limestone monuments capable of enhancing the

  17. Performance and durability tests of smart icephobic coatings to reduce ice adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Janjua, Zaid A.; Turnbull, Barbara [Faculty of Engineering, University of Nottingham (United Kingdom); Choy, Kwang-Leong; Pandis, Christos [Institute for Materials Discovery, University College London (UCL) (United Kingdom); Liu, Junpeng; Hou, Xianghui; Choi, Kwing-So [Faculty of Engineering, University of Nottingham (United Kingdom)

    2017-06-15

    Highlights: • Repeated ice adhesion and removal occurs on nanocoatings. • Icephobicity of nanocoatings reduces with each test cycle. • Adhesion strength linked to contact angle hysteresis in Gaussian fit. • Icephobicity not linked to hydrophobicity. - Abstract: The accretion of ice can cause damage in applications ranging from power lines and shipping decks, to wind turbines and rail infrastructure. In particular on aircraft, it can change aerodynamic characteristics, greatly affecting the flight safety. Commercial aircraft are therefore required to be equipped with de-icing devices, such as heating mats over the wings. The application of icephobic coatings near the leading edge of a wing can in theory reduce the high power requirements of heating mats, which melt ice that forms there. Such coatings are effective in preventing the accretion of runback ice, formed from airborne supercooled droplets, or the water that the heating mats generate as it is sheared back over the wing's upper surface. However, the durability and the practicality of applying them over a large wing surface have been prohibitive factors in deploying this technology so far. Here, we evaluated the ice adhesion strength of four non-conductive coatings and seven thermally conductive coatings by shearing ice samples from coated plates by spinning them in a centrifuge device. The durability of the coating performance was also assessed by repeating the tests, each time regrowing ice samples on the previously-used coatings. Contact angle parameters of each coating were tested for each test to determine influence on ice adhesion strength. The results indicate that contact angle hysteresis is a crucial parameter in determining icephobicity of a coating and hydrophobicity is not necessarily linked to icephobicity.

  18. Complexing agents and pH influence on chemical durability of type I moulded glass containers.

    Science.gov (United States)

    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.

  19. Durability of metals from archaeological objects, metal meteorites, and native metals

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.; Francis, B.

    1980-01-01

    Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects

  20. Controlling cation segregation in perovskite-based electrodes for high electro-catalytic activity and durability.

    Science.gov (United States)

    Li, Yifeng; Zhang, Wenqiang; Zheng, Yun; Chen, Jing; Yu, Bo; Chen, Yan; Liu, Meilin

    2017-10-16

    Solid oxide cell (SOC) based energy conversion systems have the potential to become the cleanest and most efficient systems for reversible conversion between electricity and chemical fuels due to their high efficiency, low emission, and excellent fuel flexibility. Broad implementation of this technology is however hindered by the lack of high-performance electrode materials. While many perovskite-based materials have shown remarkable promise as electrodes for SOCs, cation enrichment or segregation near the surface or interfaces is often observed, which greatly impacts not only electrode kinetics but also their durability and operational lifespan. Since the chemical and structural variations associated with surface enrichment or segregation are typically confined to the nanoscale, advanced experimental and computational tools are required to probe the detailed composition, structure, and nanostructure of these near-surface regions in real time with high spatial and temporal resolutions. In this review article, an overview of the recent progress made in this area is presented, highlighting the thermodynamic driving forces, kinetics, and various configurations of surface enrichment and segregation in several widely studied perovskite-based material systems. A profound understanding of the correlation between the surface nanostructure and the electro-catalytic activity and stability of the electrodes is then emphasized, which is vital to achieving the rational design of more efficient SOC electrode materials with excellent durability. Furthermore, the methodology and mechanistic understanding of the surface processes are applicable to other materials systems in a wide range of applications, including thermo-chemical photo-assisted splitting of H 2 O/CO 2 and metal-air batteries.

  1. Engine rotor health monitoring: an experimental approach to fault detection and durability assessment

    Science.gov (United States)

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

    2015-03-01

    Efforts to update and improve turbine engine components in meeting flights safety and durability requirements are commitments that engine manufacturers try to continuously fulfill. Most of their concerns and developments energies focus on the rotating components as rotor disks. These components typically undergo rigorous operating conditions and are subject to high centrifugal loadings which subject them to various failure mechanisms. Thus, developing highly advanced health monitoring technology to screen their efficacy and performance is very essential to their prolonged service life and operational success. Nondestructive evaluation techniques are among the many screening methods that presently are being used to pre-detect hidden flaws and mini cracks prior to any appalling events occurrence. Most of these methods or procedures are confined to evaluating material's discontinuities and other defects that have mature to a point where failure is eminent. Hence, development of more robust techniques to pre-predict faults prior to any catastrophic events in these components is highly vital. This paper is focused on presenting research activities covering the ongoing research efforts at NASA Glenn Research Center (GRC) rotor dynamics laboratory in support of developing a fault detection system for key critical turbine engine components. Data obtained from spin test experiments of a rotor disk that relates to investigating behavior of blade tip clearance, tip timing and shaft displacement based on measured data acquired from sensor devices such as eddy current, capacitive and microwave are presented. Additional results linking test data with finite element modeling to characterize the structural durability of a cracked rotor as it relays to the experimental tests and findings is also presented. An obvious difference in the vibration response is shown between the notched and the baseline no notch rotor disk indicating the presence of some type of irregularity.

  2. Durability of metals from archaeological objects, metal meteorites, and native metals

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Francis, B.

    1980-01-01

    Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects.

  3. Durable, High Thermal Conductivity Melt Infiltrated Ceramic Composites for Turbine Engine Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Durable, creep-resistant ceramic composites are necessary to meet the increased operating temperatures targeted for advanced turbine engines. Higher operating...

  4. THE PROBLEM OF ESTIMATING THE DURABILITY OF THE REINFORCED CONCRETE BRIDGES

    Directory of Open Access Journals (Sweden)

    O. I. Lantukh-Liashchenko

    2007-10-01

    Full Text Available This paper presents an assessment and prediction of service life for reinforced concrete bridges. The deterministic and probabilistic approach prediction models of durability are proposed.

  5. Examining the durability of incidentally learned trust from gaze cues.

    Science.gov (United States)

    Strachan, James W A; Tipper, Steven P

    2017-10-01

    In everyday interactions we find our attention follows the eye gaze of faces around us. As this cueing is so powerful and difficult to inhibit, gaze can therefore be used to facilitate or disrupt visual processing of the environment, and when we experience this we infer information about the trustworthiness of the cueing face. However, to date no studies have investigated how long these impressions last. To explore this we used a gaze-cueing paradigm where faces consistently demonstrated either valid or invalid cueing behaviours. Previous experiments show that valid faces are subsequently rated as more trustworthy than invalid faces. We replicate this effect (Experiment 1) and then include a brief interference task in Experiment 2 between gaze cueing and trustworthiness rating, which weakens but does not completely eliminate the effect. In Experiment 3, we explore whether greater familiarity with the faces improves the durability of trust learning and find that the effect is more resilient with familiar faces. Finally, in Experiment 4, we push this further and show that evidence of trust learning can be seen up to an hour after cueing has ended. Taken together, our results suggest that incidentally learned trust can be durable, especially for faces that deceive.

  6. The morphology of durability issues in PEM fuel cells

    International Nuclear Information System (INIS)

    Kundu, S.; Fowler, M.; Simon, L.; Grot, S.

    2004-01-01

    'Full text:' The work presented here examines durability issues in PEM fuel cell materials by examining material morphology and linking morphological features to performance. Scanning electron microscope (SEM) techniques have been able to identify a variety of features on the catalyst layer, each with their own implication to the overall performance and durability of the membrane electrode assembly (MEA). These features include cracking, delamination of the catalyst layer, catalyst clustering, electrolyte clustering, and thickness variations. Links between several of these features and catalyst dispersion conditions was also examined, showing that how the material was manufactured influences the type of morphological features present. The SEM has also been used with accelerated aging techniques to closely examine aging of the gas diffusion layer (GDL). It can be shown that over time the GDL will loose its hydrophobic character and hence become more susceptible to flooding in a fuel cell. The impact of morphological changes were determined using fuel cell models and experimental work. The ultimate aim of this work is to provide material developers with the tools and knowledge necessary to design better materials and therefore bring fuel cells closer to commercialization. (author)

  7. Operational durability of a giant ER valve for Braille display

    Science.gov (United States)

    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.

  8. Durability testing with West Valley borosilicate glass composition- Phase II

    International Nuclear Information System (INIS)

    Macedo, P.B.; Finger, S.M.; Barkatt, A.A.; Pegg, I.L.; Feng, X.; Freeborn, W.P.

    1988-06-01

    This report presents the research performed by the Catholic University of America Vitreous State Laboratory (VSL) during FY 1987 in support of the West Valley Demonstration Project (WVDP) nuclear waste vitrification process. A principal objective of this work is the optimization of the glass composition be used for the vitrification of the liquid high-level waste generated at West Valley during nuclear fuel reprocessing. This report discusses (1) the experimental investigations to optimize the reference glass composition (the current leading candidates are WVCM-50 and ATM-10) for the WVDP vitrification process; (2) the systematic experimental investigation performed to determine the effects of compositional variations in WVCM-50 and WV-205 reference glasses on their viscosity and durability (including initial results of long-term leach tests of WVCM-50 under repository conditions); (3) the development of short-time and predictive leach tests; (4) the development of a process model for the West Valley vitrification process which predicts the range of glass compositions which may be encountered during normal operations and the effects of deviations in process control parameters; and (5) the development of product models for predicting the durability and viscosity of nuclear waste glasses

  9. Determination of Stone-Mastic Asphalt Concrete Durability

    Science.gov (United States)

    Yastremsky, D. A.; Abaidullina, T. N.; Chepur, P. V.

    2018-05-01

    The paper is focused on determination of durability of the stone-mastic asphalt (SMA) concrete, containing various stabilizing additives: "Armidon" (authors’ development) and "Viatop". At the first stage of experiments, the APA method was used to determine the rutting in the SMA containing these additives. Strength test for only top layers of asphalt concrete surface is insufficient for the calculation of the pavement fatigue resistance limits. Due to this fact, a comprehensive approach was employed which incorporates the interaction of the surface and subgrade natural soil. To analyze the road surface stress-strain state and to determine the durability margin, a numerical model was used (describes the processes of fatigue life). The model was developed basing on the finite element method (FEM) in the ANSYS program. Conducted studies and numerical calculations allowed obtaining the minimum and maximum stress values in the structure affected zones and in the zones of plastic deformations occurrence in artificial and natural bases. It allows predicting deformation processes during repeated wheel loads caused by moving vehicles. In course of studies, the results of static stresses in the pavement were also obtained.

  10. Fabrication of silver nanoparticle sponge leather with durable antibacterial property.

    Science.gov (United States)

    Liu, Gongyan; Haiqi, Gao; Li, Kaijun; Xiang, Jun; Lan, Tianxiang; Zhang, Zongcai

    2018-03-15

    Leather product with durable antibacterial property is of great interest both from industry and consumer's point of view. To fabricate such functional leather, gallic acid modified silver nanoparticles (GA@AgNPs) were first in situ synthesized with a core-shell structure and an average size of 15.3nm. Due to its hydrophilic gallic acid surface, the GA@AgNPs possessed excellent stability and dispersibility in wide pH range from 3 to 12 and also showed effective antibacterial activity with a minimum inhibitory concentration (MIC) of around 10μgmL -1 . Then, such GA@AgNPs were used as retanning agent to be successfully filled into leather matrix during the leather manufacturing process. Moreover, taking the advantage of its high surface density of carboxyl groups, these GA@AgNPs could be further chemically cross-linked onto collagen fibers by chrome tanning agent. After retanning, the resultant leather was given a "AgNPs sponge" feature with high payload of silver nanoparticles against laundry, exhibiting high and durable antibacterial activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Highly efficient and durable TiN nanofiber electrocatalyst supports.

    Science.gov (United States)

    Kim, Hyun; Cho, Min Kyung; Kwon, Jeong An; Jeong, Yeon Hun; Lee, Kyung Jin; Kim, Na Young; Kim, Min Jung; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Nam, Suk Woo; Lim, Dong-Hee; Cho, EunAe; Lee, Kwan-Young; Kim, Jin Young

    2015-11-28

    To date, carbon-based materials including various carbon nanostructured materials have been extensively used as an electrocatalyst support for proton exchange membrane fuel cell (PEMFC) applications due to their practical nature. However, carbon dissolution or corrosion caused by high electrode potential in the presence of O2 and/or water has been identified as one of the main failure modes for the device operation. Here, we report the first TiN nanofiber (TNF)-based nonwoven structured materials to be constructed via electrospinning and subsequent two-step thermal treatment processes as a support for the PEMFC catalyst. Pt catalyst nanoparticles (NPs) deposited on the TNFs (Pt/TNFs) were electrochemically characterized with respect to oxygen reduction reaction (ORR) activity and durability in an acidic medium. From the electrochemical tests, the TNF-supported Pt catalyst was better and more stable in terms of its catalytic performance compared to a commercially available carbon-supported Pt catalyst. For example, the initial oxygen reduction performance was comparable for both cases, while the Pt/TNF showed much higher durability from an accelerated degradation test (ADT) configuration. It is understood that the improved catalytic roles of TNFs on the supported Pt NPs for ORR are due to the high electrical conductivity arising from the extended connectivity, high inertness to the electrochemical environment and strong catalyst-support interactions.

  12. Durability of conventional concretes containing black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2011-01-01

    In this study, black rice husk ash (BRHA) from a rice mill in Thailand was ground and used as a partial cement replacement. The durability of conventional concretes with high water-binder ratios was investigated including drying shrinkage, autogenous shrinkage, depth of carbonation, and weight loss of concretes exposed to hydrochloric (HCl) and sulfuric (H(2)SO(4)) acid attacks. Two different replacement percentages of cement by BRHA, 20% and 40%, and three different water-binder ratios (0.6, 0.7 and 0.8) were used. The ratios of paste volume to void content of the compacted aggregate (γ) were 1.2, 1.4, and 1.6. As a result, when increasing the percentage replacement of BRHA, the drying shrinkage and depth of carbonation reaction of concretes increased. However, the BRHA provides a positive effect on the autogenous shrinkage and weight loss of concretes exposed to hydrochloric and sulfuric acid attacks. In addition, the resistance to acid attack was directly varied with the (SiO(2) + Al(2)O(3) + Fe(2)O(3))/CaO ratio. Results show that ground BRHA can be applied as a pozzolanic material and also improve the durability of concrete. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Fatigue behaviour analysis for the durability prequalification of strengthening mortars

    International Nuclear Information System (INIS)

    Bocca, P; Grazzini, A; Masera, D

    2011-01-01

    An innovative laboratory procedure used as a preliminary design stage for the pre-qualification of strengthening mortars applied to historical masonry buildings is described. In the analysis of the behaviour of masonry structures and their constituent materials, increasing importance has been assumed by the study of the long-term evolution of deformation and mechanical characteristics, which may be affected by both loading and environmental conditions. Through static and fatigue tests on mixed specimens historical brick-reinforced mortar it has been possible to investigate the durability of strengthening materials, in order to select, from a range of alternatives, the most suitable for the historical masonry. Cyclic fatigue stress has been applied to accelerate the static creep and to forecast the corresponding creep behaviour of the historical brick-strengthening mortar system under static long-time loading. This methodology has proved useful in avoiding the errors associated with materials that are not mechanically compatible and guarantees the durability of strengthening work. The experimental procedure has been used effectively in the biggest restoration building site in Europe, the Royal Palace of Venaria, and it is in progress of carrying out at the Special Natural Reserve of the Sacro Monte di Varallo, in Piedmont (Italy).

  14. Neural network analysis of nuclear waste glass composition vs durability

    International Nuclear Information System (INIS)

    Seibel, C.K.

    1994-01-01

    The relationship between the chemical composition of oxide glasses and their physical properties is poorly understood, but it is becoming more important as vitrification (transformation into glass) of high-level nuclear waste becomes the favored method for long-term storage. The vitrified waste will be stored deep in geologic repositories where it must remain intact for at least 10,000 years. A strong resistance to groundwater exposure; i.c. a slow rate of glass dissolution, is of great importance. This project deals specifically with glass samples developed and tested for the nuclear fuel reprocessing facility near West Valley, New York. This facility needs to dispose of approximately 2.2 million liters of high-level radioactive liquid waste currently stored in stainless steel tanks. A self-organizing, artificial neural network was used to analyze the trends in the glass dissolution data for the effects of composition and the resulting durability of borosilicate glasses in an aqueous environment. This durability data can be used to systematically optimize the properties of the complex nuclear glasses and slow the dissolution rate of radionuclides into the environment

  15. Recyclable magnetite-silver heterodimer nanocomposites with durable antibacterial performance

    Directory of Open Access Journals (Sweden)

    Chunyan Yong

    2018-03-01

    Full Text Available There is a significant need for magnetite-silver nanocomposites that exhibit durable and recyclable antimicrobial activity. In this study, magnetic iron oxide nanoparticles (Fe3O4 NPs coated with ethylenediamine-modified chitosan/polyacrylic acid copolymeric layer (Fe3O4@ECS/PAA were fabricated. Subsequently, directly deposited silver (Ag NPs procedure was carried out to form the antibacterial heterodimers of Fe3O4@ECS/PAA-Ag NPs. The composition and morphology of the resultant nanostructures were confirmed by FT-IR, XRD, TEM and TGA. The overall length of the heterodimers was approximately 45 nm, in which the mean diameter of Fe3O4@ECS/PAA NPs reached up to 35 nm, and that of Ag NPs was around 15 nm. The mass fraction of silver NPs in the nanocomposites was about 63.1%. The obtained Fe3O4@ECS/PAA NPs exhibited good colloidal stability, and excellent response to additional magnetic field, making the NPs easy to recover after antibacterial tests. In particular, the Fe3O4@ECS/PAA-Ag NPs retained nearly 100% biocidal efficiency (106–107 CFU/mg nanoparticles for both Gram-negative bacteria E. coli and Gram-positive bacteria S. aureus throughout ten cycles without washing with any solvents or water, exhibiting potent and durable antibacterial activity.

  16. Durable concrete for a waste repository - Measurement of ionic ingress

    International Nuclear Information System (INIS)

    Feldman, R.F.; Beaudoin, J.J.; Philipose, K.E.

    1990-01-01

    A waste repository for the below ground disposal of low level radioactive waste is planned at Chalk River Nuclear Laboratories. It relies greatly on the durability of concrete for the required 500 year service life. A research program to design durable concrete and predict its service life is in progress. The degradation of the concrete depends to a large extent on the rate of ingress of corrosive agents. Penetration of chloride and sulfate ions are particularly relevant. Twenty mix formulations were developed to create various types and qualities of concrete, and to study their behavior in different site environmental conditions. A total of 1,000 concrete specimens are being exposed at 20C and 45C to 25 different combinations of the corrosive agents including CO 2 . Procedures to measure the ionic profiles and to determine the factors controlling diffusion of the ions in the various concretes have been developed. Results of selected concrete systems exposed to chloride and sulfate solutions for 1 year are presented and discussed in terms of pore structure and permeability parameters of the concrete

  17. Durable superhydrophobic carbon soot coatings for sensor applications

    Science.gov (United States)

    Esmeryan, K. D.; Radeva, E. I.; Avramov, I. D.

    2016-01-01

    A novel approach for the fabrication of durable superhydrophobic (SH) carbon soot coatings used in quartz crystal microbalance (QCM) based gas or liquid sensors is reported. The method uses modification of the carbon soot through polymerization of hexamethyldisiloxane (HMDSO) by means of glow discharge RF plasma. The surface characterization shows a fractal-like network of carbon nanoparticles with diameter of ~50 nm. These particles form islands and cavities in the nanometer range, between which the plasma polymerized hexamethyldisiloxane (PPHMDSO) embeds and binds to the carbon chains and QCM surface. Such modified surface structure retains the hydrophobic nature of the soot and enhances its robustness upon water droplet interactions. Moreover, it significantly reduces the insertion loss and dynamic resistance of the QCM compared to the commonly used carbon soot/epoxy resin approach. Furthermore, the PPHMDSO/carbon soot coating demonstrates durability and no aging after more than 40 probing cycles in water based liquid environments. In addition, the surface layer keeps its superhydrophobicity even upon thermal annealing up to 540 °C. These experiments reveal an opportunity for the development of soot based SH QCMs with improved electrical characteristics, as required for high-resolution gas or liquid measurements.

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

    Science.gov (United States)

    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

  19. Effects of aqueous environment on long-term durability of phosphate-bonded ceramic waste forms

    International Nuclear Information System (INIS)

    Singh, D.; Wagh, A.S.; Jeong, S.Y.

    1996-01-01

    Over the last few years, Argonne National Laboratory has been developing room-temperature-setting chemically-bonded phosphate ceramics for solidifying and stabilizing low-level mixed wastes. This technology is crucial for stabilizing waste streams that contain volatile species and off-gas secondary waste streams generated by high-temperature treatment of such wastes. Magnesium phosphate ceramic has been developed to treat mixed wastes such as ash, salts, and cement sludges. Waste forms of surrogate waste streams were fabricated by acid-base reactions between the mixtures of magnesium oxide powders and the wastes, and phosphoric acid or acid phosphate solutions. Dense and hard ceramic waste forms are produced in this process. The principal advantage of this technology is that the contaminants are immobilized by both chemical stabilization and subsequent microencapsulation of the reaction products. This paper reports the results of durability studies conducted on waste forms made with ash waste streams spiked with hazardous and radioactive surrogates. Standard leaching tests such as ANS 16.1 and TCLP were conducted on the final waste forms. Fates of the contaminants in the final waste forms were established by electron microscopy. In addition, stability of the waste forms in aqueous environments was evaluated with long-term water-immersion tests

  20. A zwitterionic macro-crosslinker for durable non-fouling coatings.

    Science.gov (United States)

    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.

  1. Performance based durability design of a bored tunnel with concrete lining

    NARCIS (Netherlands)

    Vries, H. de; Siemes, A.J.M.

    2002-01-01

    Design for durability is gradually changing from a deem-to-satisfy approach to a performance based approach. The conventional building codes give in principle only construction rules. If these rules are fulfilled, it is assumed that the structure will have an adequate durability. But specifications

  2. The durability of waveguide fibers at cyclic change of loading, temperature and humidity

    International Nuclear Information System (INIS)

    Karimov, S.N.; Sultonov, U.; Shamsidinov, M.I.

    1992-01-01

    Present article is devoted to durability of waveguide fibers at cyclic change of loading, temperature and humidity. The mounting scheme and loading of sample is presented. The dependence of glass fiber durability on number of thermal cycles at various humidity rates was considered. The dependence of number of cycles on maximal loading at cyclic temperature change was studied.

  3. Durability of Dukovany shallow land repository engineered barriers. Appendix 7: Czech Republic

    International Nuclear Information System (INIS)

    Vokal, A.; Nachmilner, L.; Wasserbauer, R.; Dohnalek, J.

    2001-01-01

    The main aim of this project was to explore the durability of engineering barriers used at Dukovany shallow land repository as a support of safety assessments. This appendix summarises the principal results focused on durability of asphaltopropyleneconcrete (APC) hydroisolation and steel reinforced concrete construction

  4. Durability of sealants exposed to outdoor weathering and hot compression cycles

    Science.gov (United States)

    Gregory T. Schueneman; Steven Lacher; Christopher G. Hunt; Christopher C. White; Donald L. Hunston

    2011-01-01

    Sealants play an important role in weatherproofing structures by filling gaps and preventing air and water intrusion. When incorrectly selected or improperly applied, they may fail quickly, compromising durability of the structure. To ensure reliability and prevent the need for costly repairs to structures, it is necessary to measure durability and predict life...

  5. Chemical durability of simulated nuclear glasses containing water

    International Nuclear Information System (INIS)

    Li, H.; Tomozawa, M.

    1995-04-01

    The chemical durability of simulated nuclear waste glasses having different water contents was studied. Results from the product consistency test (PCT) showed that glass dissolution increased with water content in the glass. This trend was not observed during MCC-1 testing. This difference was attributed to the differences in reactions between glass and water. In the PCT, the glass network dissolution controlled the elemental releases, and water in the glass accelerated the reaction rate. On the other hand, alkali ion exchange with hydronium played an important role in the MCC-1. For the latter, the amount of water introduced into a leached layer from ion-exchange was found to be much greater than that of initially incorporated water in the glass. Hence, the initial water content has no effect on glass dissolution as measured by the MCC-1 test

  6. Application of the Durability Reinforcement Technique on the Frame Structure

    International Nuclear Information System (INIS)

    Kwon, Sung Hun; Yoo, Hong Hee

    2009-01-01

    In this paper, the technique to reinforce the durability performance of structure using the sensitivity information for the frame structure is applied. The fatigue life calculation for the frame structure is performed from the quasi-static and transient analysis and the characteristics of two methods are compared for the fatigue analysis. Then the reinforcement technique is applied. First, some design variables related to the locations of fatigue failure is selected. Then sensitivities of fatigue life at fracture points with respect to the variation of design variables are calculated and the vector composed of gaps between the target life and initial life cycles is calculated. If the number of fatigue fracture points is same as the number of design variables, the variations of the design variables are calculated from the linear algebraic equation. If not, the variations of the design variables are calculated from the optimization formulation with the constraints

  7. Durability Tests of Ball Valve Prototype with Flowmeter Operation

    Science.gov (United States)

    Rogula, J.; Romanik, G.

    2018-02-01

    The results of the investigation of the prototypical ball valve are presented in this article. The innovation of the tested valve is a ball with a built-in measuring orifice. The valve has been subjected to durability tests. Leakage under three temperatures: ambient, -30°C and +100°C was analyzed. Sealing elements of the valve were tested for roughness and deviation of shape before and after the cycles of operation. Ball valve operation means cycles of open/close. It was planned to perform 1000 cycles at each temperature condition accordingly. Tests of the valve were performed under gas pressure equal to 10 MPa. The research was carried out under the Operational Program "Intelligent Development" (POIR 01.01.01-00-0013 / 15 "Development of devices for measurement of media flow on industrial trunk-lines".

  8. Durability of Cement Composites Reinforced with Sisal Fiber

    Science.gov (United States)

    Wei, Jianqiang

    This dissertation focuses mainly on investigating the aging mechanisms and degradation kinetics of sisal fiber, as well as the approaches to mitigate its degradation in the matrix of cement composites. In contrast to previous works reported in the literature, a novel approach is proposed in this study to directly determine the fiber's degradation rate by separately studying the composition changes, mechanical and physical properties of the embedded sisal fibers. Cement hydration is presented to be a crucial factor in understanding fiber degradation behavior. The degradation mechanisms of natural fiber consist of mineralization of cell walls, alkali hydrolysis of lignin and hemicellulose, as well as the cellulose decomposition which includes stripping of cellulose microfibrils and alkaline hydrolysis of amorphous regions in cellulose chains. Two mineralization mechanisms, CH-mineralization and self-mineralization, are proposed. The degradation kinetics of sisal fiber in the cement matrix are also analyzed and a model to predict the degradation rate of cellulose for natural fiber embedded in cement is outlined. The results indicate that the time needed to completely degrade the cellulose in the matrix with cement replacement by 30wt.% metakaolin is 13 times longer than that in pure cement. A novel and scientific method is presented to determine accelerated aging conditions, and to evaluating sisal fiber's degradation rate and durability of natural fiber-reinforced cement composites. Among the static aggressive environments, the most effective approach for accelerating the degradation of natural fiber in cement composites is to soak the samples or change the humidity at 70 °C and higher temperature. However, the dynamic wetting and drying cycling treatment has a more accelerating effect on the alkali hydrolysis of fiber's amorphous components evidenced by the highest crystallinity indices, minimum content of holocellulose, and lowest tensile strength. Based on the

  9. Dynamics of a durable commodity market involving trade at disequilibrium

    Science.gov (United States)

    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.

  10. The efficacy and durability of radon remedial measures

    International Nuclear Information System (INIS)

    Cliff, K.D.; Naismith, S.P.; Scivyer, C.; Stephen, R.

    1994-01-01

    In the UK, over 16,000 homes, from an estimated 100,000, with annual average radon concentrations exceeding the UK Action Level of 200 Bq.m -3 have been discovered. Some 600 householders who have taken action have sought confirmatory measurements from NRPB. Results for 345 such homes are discussed. A number of remedied homes are being remeasured annually to determine the durability of the remedies: results for the first year follow-up measurements are given. In a separate exercise, homes having the highest radon levels known in the UK have been enrolled in a research programme of the Building Research Establishment. The results for 53 homes in which BRE surveyed, designed and supervised remedial work are presented. (author)

  11. Low power consumption and high temperature durability for radiation sensor

    International Nuclear Information System (INIS)

    Matsumoto, Yoshinori; Ueno, Hiroto

    2015-01-01

    Low power consumption and high temperature operation are important in an environmental monitoring system. The power consumption of 3 mW is achieved for the radiation sensor using low voltage operational amplifier and comparator in the signal processing circuit. The leakage reverse current of photodiode causes the charge amplifier saturation over 50degC. High temperature durability was improved by optimizing the circuit configuration and the values of feedback resistance and capacitance in the charge amplifier. The pulse response of the radiation sensor was measured up to 55degC. The custom detection circuit was designed by 0.6 μm CMOS process at 5-V supply voltage. The operation temperature was improved up to 65degC. (author)

  12. Quantify and improve PEM fuel cell durability. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Grahl-Madsen, L.; Odgaard, M.; Munksgaard Nielsen, R. (IRD Fuel Cell A/S, Svendborg (Denmark)); Li, Q.; Jensen, Jens Oluf (Technical Univ. of Denmark, Dept. of Chemistry, Kgs. Lyngby (Denmark)); Andersen, Shuang Ma; Speder, J.; Skou, E. (Syddansk Univ. (SDU), Odense (Denmark))

    2010-07-01

    The aim of the present project is to systematically quantify and improve the durability of the PEM FC including the following three PEM FC variants: LT PEM FC, DMFC, and HT PEM FC. Different factors influencing dissolution properties of noble metal catalyst platinum and platinum-ruthenium alloy has been studied. The dissolution was found to increase by increasing the CV cycle upper potential limit, number of potential cycles, solution acidity, oxygen partial pressure, involvement of chloride, and temperature. Ruthenium was found to deteriorate ten (10) times faster than platinum catalyst; and carbon supported catalyst (Pt: 20%, Ru: up to 100%) deteriorate ten (10) times faster than non-supported catalyst (Pt: 2%, Ru: 30%) at the same condition. Loss of sulphonic acid groups and fluoride from perfluorinated sulfonic acid membrane was confirmed by different techniques, which locally leads to loss of acidity, and consequently enhances dissolution of noble metal catalyst. Degradation of Nafion ionomer in the electrode was enhanced by noble metal catalyst and the thermal decomposition properties has synergetic effect with carbon degradation. Hydrophobicity of GDL and electrode on GDL were found to degrade e.g. radical attack, oxidation, and physical wear out. The very top micro surface structure turned out to be responsible for wetting property after chemical ageing. Optimal catalyst and ionomer ratio is also reflected in contact angle value, which can be understood in terms of catalyst/carbon - ionomer affinity and layered structure. Long-term tested and 'virgin' LT PEM MEAs have been characterised with respect to SEM, TEM, EDS, and XRD. Both failed and well-functioning MEAs have been characterised. The Post Mortem analysis has shown and quantified degradation mechanisms like catalyst growth and carbon corrosion. Furthermore, the effect of fuel starvation was shown by pronounced Ru-catalyst band within the membrane. The catalyst coarsening observed after

  13. Durability of Mortar Made with Fine Glass Powdered Particles

    Directory of Open Access Journals (Sweden)

    Rosemary Bom Conselho Sales

    2017-01-01

    Full Text Available Different studies investigate the use of waste glass in Portland cement compounds, either as aggregates or as supplementary cementitious materials. Nevertheless, it seems that there is no consensus about the influence of particle color and size on the behavior of the compounds. This study addresses the influence of cement replacement by 10 and 20% of the colorless and amber soda-lime glass particles sized around 9.5 μm on the performance of Portland cement mortars. Results revealed that the partial replacement of cement could contribute to the production of durable mortars in relation to the inhibition of the alkali-aggregate reaction. This effect was more marked with 20% replacement using amber glass. Samples containing glass microparticles were more resistant to corrosion, in particular those made of colorless glass. The use of colorless and amber glass microparticles promoted a reduction in wear resistance.

  14. Durability properties for adhesively bonded structural aerospace applications

    International Nuclear Information System (INIS)

    Shaffer, D.K.; Davis, G.D.; McNamara, D.K.; Shah, T.K.; Desai, A.

    1992-01-01

    This paper reports on the importance of good bond durability of adhesively joined aerospace components which has been recognized for many years. Military and civilian aircraft are exposed to harsh environments in addition to severe thermal and stress cycles during their service lives. Moisture is responsible for the majority of bond failures in the field. The presence of surface contaminants (e.g., fluoride, silicones) and the non-neutral pH of poor rinse water are common causes of adhesion problems in production environments. Honeycomb panels, stringer skins, doubler plates and core cowl assemblies are bonded joint structures that are subject to environmental- or contaminant-induced debonding. The identification and characterization of the causes of such bond failures leads to improved production quality, yield and cost reduction

  15. A relational approach to durable poverty, inequality and power.

    Science.gov (United States)

    Mosse, David

    2010-01-01

    The article argues for what can be called a 'relational' approach to poverty: one that first views persistent poverty as the consequence of historically developed economic and political relations, and second, that emphasises poverty and inequality as an effect of social categorisation and identity, drawing in particular on the experience of adivasis ("tribals") and dalits ("untouchables") subordinated in Indian society. The approach follows Charles Tilly's Durable Inequality in combining Marxian ideas of exploitation and dispossession with Weberian notions of social closure. The article then draws on the work of Steven Lukes, Pierre Bourdieu and Arjun Appadurai to argue for the need to incorporate a multidimensional conception of power; including not only power as the direct assertion of will but also 'agenda-setting power' that sets the terms in which poverty becomes (or fails to become) politicised, and closely related to power as political representation. This sets the basis for discussion of the politics of poverty and exclusion.

  16. Some Durability Aspects of Ambient Cured Bottom Ash Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Saravanakumar R.

    2017-09-01

    Full Text Available The present study examines some durability aspects of ambient cured bottom ash geopolymer concrete (BA GPC due to accelerated corrosion, sorptivity, and water absorption. The bottom ash geopolymer concrete was prepared with sodium based alkaline activators under ambient curing temperatures. The sodium hydroxide used concentration was 8M. The performance of BA GPC was compared with conventional concrete. The test results indicate that BA GPC developes a strong passive layer against chloride ion diffusion and provides better protection against corrosion. Both the initial and final rates of water absorption of BA GPC were about two times less than those of conventional concrete. The BA GPC significantly enhanced performance over equivalent grade conventional concrete (CC.

  17. Carbonation-Related Microstructural Changesin Long-Term Durability Concrete

    Directory of Open Access Journals (Sweden)

    Cláudio A. Rigo da Silva

    2002-09-01

    Full Text Available This paper discusses the effects of carbonation on the microstructure of Portland cement concrete for long-term durability applications. A class C40 concrete (characteristic compression strength between 40 MPa and 44 MPa on the 28th day, according to Brazilian standard NBR 8953 was chosen for the experimental study of the carbonation effects, from which test samples were molded for accelerated test under a 100%-CO2 atmosphere after physical and mechanical characterization. It was observed that carbonation provoked a reduction of 5% to 12% of the concrete open porosity accessible to water. Flexural strength values obtained after the carbonation tests revealed a decrease of 12% and 25% in relation to the values obtained before tests on the 28th and 91st days, respectively.

  18. Durability of PEDOT: PSS-pentacene Schottky diode

    International Nuclear Information System (INIS)

    Kang, K S; Lim, H K; Cho, K Y; Han, K J; Kim, Jaehwan

    2008-01-01

    The durability and failure cause of a polymer Schottky diode made with PEDOT : PSS-pentacene were investigated. A polymer Schottky diode was fabricated by dissolving pentacene in N-methylpyrrolidone (NMP) and mixing with PEDOT : PSS. Pentacene solution having a maximum concentration of approximately 9.7 mmoles was prepared by simply stirring the solution at room temperature for 36 h. As the pentacene concentration increased, the absorption of the broad UV regime increased dramatically. However, absorption peaks of pentacene at 301 and 260 nm were not observed for the PEDOT : PSS-pentacene. A three-layered polymer Schottky diode was fabricated and its current-voltage (I-V) characteristic was evaluated. The current was reduced by 7% in the first 50 min and then stabilized during biased electrical field sweeps. After 500 and 800 min, catastrophic failure occurred. FESEM images revealed that the electrode damage caused catastrophic failure of the Schottky diode. (fast track communication)

  19. Influence of Some Nuclear Waste on The Durability and Mechanical Properties of Borosilicate glass

    International Nuclear Information System (INIS)

    El-Alaily, N.A.

    2003-01-01

    Various glass systems have been shown to be suitable for producing waste glass forms that are thermally and mechanically stable and exhibit good chemical durability. In this study borosilicate glass containing sodium oxide and aluminum oxide was prepared as a host for high level nuclear waste. The glass durability when the samples were immersed either in distilled water or ground water at 70 degree was studied. The density, porosity and mechanical properties were also investigated. The effects of exposing the samples immersed in groundwater to gamma rays in the glass durability and all other mentioned properties were also studied. The results showed that immersing the glass in ground water causing a decrease in the glass durability. The exposure of the glass immersed in ground water to the gamma rays increases the durability of the glass. The mechanical properties of the prepared glass were good. Although these properties decrease for the corroded glass but they were still good

  20. Processing and Characterization of Thousand-Hour 500 C Durable 4H-SiC JFET Integrated Circuits

    Science.gov (United States)

    Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.; Krasowski, Michael J.; Prokop, Norman F.

    2016-01-01

    This work reports fabrication and testing of integrated circuits (ICs) with two levels of interconnect that consistently achieve greater than 1000 hours of stable electrical operation at 500 C in air ambient. These ICs are based on 4H-SiC junction field effect transistor (JFET) technology that integrates hafnium ohmic contacts with TaSi2 interconnects and SiO2 and Si3N4 dielectric layers over 1-m scale vertical topology. Following initial burn-in, important circuit parameters remain stable for more than 1000 hours of 500 C operational testing. These results advance the technology foundation for realizing long-term durable 500 C ICs with increased functional capability for sensing and control combustion engine, planetary, deep-well drilling, and other harsh-environment applications.

  1. Moisture Durability Assessment of Selected Well-insulated Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Pallin, Simon B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boudreaux, Philip R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kehrer, Manfred [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    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. 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.

  2. Performance and durability testing of parabolic trough receivers

    Science.gov (United States)

    Lei, Dongqiang; Fu, Xuqiang; Zhao, Dongming; Yuan, Guofeng; Wang, Zhifeng; Guo, Minghuan

    2017-06-01

    The paper describes the key performance and durability testing facilities of the parabolic trough receiver developed by Institute of Electrical Engineering, Chinese Academy of Sciences. The indoor heat loss test can be applied at 4-7 different temperature levels within 200-550 on receivers. The optical efficiency test bench consists of 12 metal halide lamps as the solar simulator and a 5 m length half-elliptical cylinder reflector with flat end reflectors. 3 ultra-precision temperature sensors are used in receiver each end to get the temperature difference. The residual gas analysis test bench is applied to analyze and predict the vacuum lifetime of the receiver. It can test the variations of composition and partial pressure of residual gases with temperature and time in the receiver annulus space by a high sensitivity quadrupole mass spectrometer gas analyzer. A coating accelerated ageing test bench, which is also used to test the thermal cycle, has been developed. This test bench uses the absorber tube of the recevier as the resistance heater to heat up the whole receiver. The coating lifetime can be predicted by the Arrhenius parameters. For the cycling test, the compressed air is used to directly cool the inner surface of the absorber tube. The thermal cycling test is performed with temperature cycles from 150 °C to 450 °C for 160 cycles. The maximum thermal cycling frequency is 8 cycles per day. The mechanical fatigue test bench is used to test the bellows and the glass-to-metal seals durability at the same time. Both bellows are expanded and compressed to 6.5 mm in turn with 10,000 cycles. A new rotating test bench was also developed to test the thermal efficiency of the receiver.

  3. Robotic mitral valve operations by experienced surgeons are cost-neutral and durable at 1 year.

    Science.gov (United States)

    Coyan, Garrett; Wei, Lawrence M; Althouse, Andrew; Roberts, Harold G; Schauble, Drew; Murashita, Takashi; Cook, Chris C; Rankin, J Scott; Badhwar, Vinay

    2018-04-12

    Robotic mitral valve surgery has potential advantages in patient satisfaction and 30-day outcome. Cost concerns and repair durability limit wider adoption of robotic technology. This study examined detailed cost differences between robotic and sternotomy techniques in relation to outcomes and durability following robotic mitral program initiation. Between April 2013 and October 2015, 30-day and 1-year outcomes of 328 consecutive patients undergoing robotic or sternotomy mitral valve repair or replacement by experienced surgeons were examined. Multivariable logistic regression informed propensity matching to derive a cohort of 182 patients. Echocardiographic follow-up was completed at 1 year in all robotic patients. Detailed activity-based cost accounting was applied to include direct, semidirect, and indirect costs with special respect to robotic depreciation, maintenance, and supplies. A quantitative analysis of all hospital costs was applied directly to each patient encounter for comparative financial analyses. Mean predicted risk of mortality was similar in both the robotic (n = 91) and sternotomy (n = 91) groups (0.9% vs 0.8%; P > .431). The total costs of robotic mitral operations were similar to those of sternotomy ($27,662 vs $28,241; P = .273). Early direct costs were higher in the robotic group. There was a marked increase in late indirect cost with the sternotomy cohort related to increased length of stay, transfusion requirements, and readmission rates. Robotic repair technique was associated with no echocardiographic recurrence greater than trace to only mild regurgitation at 1 year. Experienced mitral surgeons can initiate a robotic program in a cost-neutral manner that maintains clinical outcome integrity as well as repair durability. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  4. Effect of glass composition on waste form durability: A critical review

    International Nuclear Information System (INIS)

    Ellison, A.J.G.; Mazer, J.J.; Ebert, W.L.

    1994-11-01

    This report reviews literature concerning the relationship between the composition and durability of silicate glasses, particularly glasses proposed for immobilization of radioactive waste. Standard procedures used to perform durability tests are reviewed. It is shown that tests in which a low-surface area sample is brought into contact with a very large volume of solution provide the most accurate measure of the intrinsic durability of a glass composition, whereas high-surface area/low-solution volume tests are a better measure of the response of a glass to changes in solution chemistry induced by a buildup of glass corrosion products. The structural chemistry of silicate and borosilicate glasses is reviewed to identify those components with the strongest cation-anion bonds. A number of examples are discussed in which two or more cations engage in mutual bonding interactions that result in minima or maxima in the rheologic and thermodynamic properties of the glasses at or near particular optimal compositions. It is shown that in simple glass-forming systems such interactions generally enhance the durability of glasses. Moreover, it is shown that experimental results obtained for simple systems can be used to account for durability rankings of much more complex waste glass compositions. Models that purport to predict the rate of corrosion of glasses in short-term durability tests are evaluated using a database of short-term durability test results for a large set of glass compositions. The predictions of these models correlate with the measured durabilities of the glasses when considered in large groupings, but no model evaluated in this review provides accurate estimates of durability for individual glass compositions. Use of these models in long-term durability models is discussed. 230 refs

  5. The Strategy of New Product Introduction in Durable Goods with Secondary Market: Application of the Optimization Method to Supply Chain Problem

    Directory of Open Access Journals (Sweden)

    Pei Zhao

    2014-01-01

    Full Text Available The aim of this paper is to address how the secondary market affects the strategy of the manufacturer’s new product introduction by using the optimization method. To do so, we develop a two-period model in which a monopolistic manufacturer sells its new durable products directly to end consumers in both periods, while an entrant operates a reverse channel selling used products in the secondary market. We assume that the manufacturer launches a higher quality product in the second period for the technological innovation. We find that the secondary market can actually increase the manufacturer’s profitability and drives the new product introduction in the second period. We also derive the effect of the durability and the degree of quality improvement on the pricing of supply chain partners.

  6. Durability and service life design of concrete structures. Experiences and the way to prove in The Netherlands

    NARCIS (Netherlands)

    Siemes, A.J.M.; Vrouwenvelder, A.C.W.M.

    2002-01-01

    After the introduction of reinforced concrete it was believed that the material was extremely durable. Soon it was found however, that reinforced concrete could have serious durability problems and that special care should be taken to avoid them. Durability became an issue.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Dimitrios C. Papageorgopoulos

    2012-12-01

    Full Text Available 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.

  9. Photovoltaic technologies

    International Nuclear Information System (INIS)

    Bagnall, Darren M.; Boreland, Matt

    2008-01-01

    Photovoltaics is already a billion dollar industry. It is experiencing rapid growth as concerns over fuel supplies and carbon emissions mean that governments and individuals are increasingly prepared to ignore its current high costs. It will become truly mainstream when its costs are comparable to other energy sources. At the moment, it is around four times too expensive for competitive commercial production. Three generations of photovoltaics have been envisaged that will take solar power into the mainstream. Currently, photovoltaic production is 90% first-generation and is based on silicon wafers. These devices are reliable and durable, but half of the cost is the silicon wafer and efficiencies are limited to around 20%. A second generation of solar cells would use cheap semiconductor thin films deposited on low-cost substrates to produce devices of slightly lower efficiency. A number of thin-film device technologies account for around 5-6% of the current market. As second-generation technology reduces the cost of active material, the substrate will eventually be the cost limit and higher efficiency will be needed to maintain the cost-reduction trend. Third-generation devices will use new technologies to produce high-efficiency devices. Advances in nanotechnology, photonics, optical metamaterials, plasmonics and semiconducting polymer sciences offer the prospect of cost-competitive photovoltaics. It is reasonable to expect that cost reductions, a move to second-generation technologies and the implementation of new technologies and third-generation concepts can lead to fully cost-competitive solar energy in 10-15 years. (author)

  10. Durability of cemented waste in repository and under simulated conditions

    International Nuclear Information System (INIS)

    Dragolici, F.; Nicu, M.; Lungu, L.; Turcanu, C.; Rotarescu, Gh.

    2000-01-01

    The Romanian Radioactive Waste National Repository for low level and intermediate level radioactive waste was built in Baita - Bihor county, in an extinct uranium exploitation. The site is at 840 m above sea level and the host rock is crystalline with a low porosity, a good chemical homogeneity and impermeability, keeping these qualities over a considerable horizontal and vertical spans. To obtain the experimental data necessary for the waste form and package characterization together with the back-filling material behaviour in the repository environment, a medium term research programme (1996 - 2010) was implemented. The purpose of this experimental programme is to obtain a part of the data base necessary for the approach of medium and long term assessment of the safety and performance of Baita - Bihor Repository. The programme will provide: a deeper knowledge of the chemical species and reaction mechanisms, the structure, properties and performances of the final products. For safety reasons the behaviour of waste package, which is a main barrier, must be properly known in terms of long term durability in real repository conditions. Characterization of the behaviour includes many interactions between the waste package itself and the surrounding near field conditions such as mineralogy, hydrogeology and groundwater chemistry. To obtain a more deeper knowledge of the species and physical-chemical reactions participating in the matrix formation, as well as their future behaviour during the disposal period, a thorough XRD study started in 1998. For Romanian Radioactive Waste National Repository (DNDR) Baita - Bihor the following steps are planned for the conditioned waste matrix characterization in simulated and real conditions: - preparation and characterization of normal reference matrices based on different cement formulations; - preparation of reference simulated sludge cemented matrices containing iron hydroxide and iron phosphate; - selection of real and

  11. Durability of fired clay bricks containing granite powder

    Directory of Open Access Journals (Sweden)

    Xavier, G. C.

    2012-06-01

    Full Text Available Over the past few decades, hundreds of papers have been published on the benefits of including rock powder as a raw material in fired clay brick manufacture. Very little has been written, however, about the durability and long-term behaviour of the final product. As a rule, the ceramic bricks used in construction in developing countries are fired at low temperatures, which detracts from their mechanical performance. This is particularly visible in harsh environmental conditions, where weathering causes severe deterioration. The present paper describes the impact of weathering on clay bricks containing from 0 to 10% granite powder, an industrial by-product. The specimens were fired at 500, 700 or 900 ºC and subsequently exposed to natural environmental conditions or accelerated laboratory weathering. Their physical and mechanical properties were evaluated to determine the effect of the composition of raw materials on fired clay product durability.

    En las últimas décadas se han publicado cientos de artículos sobre las ventajas de incluir polvo de roca como materia prima en la fabricación de los ladrillos cerámicos. Sin embargo, la durabilidad y el comportamiento a largo plazo del producto final han sido objeto de pocas investigaciones. Por lo general, los ladrillos cerámicos empleados en la construcción en los países en vías de desarrollo se cuecen a temperaturas bajas, lo que impide el desarrollo de sus propiedades mecánicas. Esto queda especialmente patente cuando las condiciones ambientales son severas, en cuyo caso la meteorización puede provocar un deterioro importante. En este artículo se describe el efecto de la meteorización en ladrillos cerámicos que incorporaban entre un 0 y un 10% de polvo de granito, que es un derivado industrial. Las probetas se cocieron a 500, 700 o 900 °C y luego se sometieron a condiciones ambientales naturales o a un proceso de laboratorio de meteorización acelerada. Se evaluaron sus

  12. Mine d’or et développement durable

    Directory of Open Access Journals (Sweden)

    Mouhamadou Lamine Diallo

    2009-03-01

    Full Text Available La relance des activités extractives au Sénégal oriental a commencé avec le projet minier de Sabodala. A l’image de sa région (Tambacounda, le village de Sabodala est une localité enclavée, caractérisée par la domination des activités traditionnelles (agriculture, orpaillage. La pauvreté y est perceptible à travers le manque d’emplois des jeunes, la rareté des infrastructures socio-économiques et des voies de communications. Ainsi, l’installation d’une industrie minière moderne suscite beaucoup d’espoirs auprès des populations villageoises, d’autant plus que l’Etat et la société adjudicataire du projet (Mineral Deposit Limited - MDL placent cette entreprise sous les auspices des principes du développement durable. Mais entre les intentions affichées et les réalités du terrain, l’écart est grand : à l’échelle locale, la mine produit des effets très ambivalents, difficiles à interpréter via les grilles d’analyse du développement durable.The revival of mining activities in western Senegal began with Sabodala mining project. Similarly to its region (Tambacounda, Sabodala is a remote village where traditional activities such as agriculture and gold digging are mainly practised. Poverty is perceived through joblessness among young people, the absence of social and economical infrastructures and the lack of thoroughfare. Therefore, the setting up of a new mining industry gives rise to hope within villagers and specially the government along with the allocated companies namely Mineral Deposits Limited (Mineral Deposit Limited - MDL, that are claiming sustainable development principles. However the gap between these demands and the results in the field induces to wonder whether it’s possible to establish a linkage between mining project and development at the local scale.

  13. High temperature PEM fuel cells - Degradation and durability

    Energy Technology Data Exchange (ETDEWEB)

    Araya, S.S.

    2012-12-15

    This work analyses the degradation issues of a High Temperature Proton Exchange Membrane Fuel Cell (HT-PEMFC). It is based on the assumption that given the current challenges for storage and distribution of hydrogen, it is more practical to use liquid alcohols as energy carriers for fuel cells. Among these, methanol is very attractive, as it can be obtained from a variety of renewable sources and has a relatively low reforming temperature for the production of hydrogen rich gaseous mixture. The effects on HT-PEMFC of the different constituents of this gaseous mixture, known as a reformate gas, are investigated in the current work. For this, an experimental set up, in which all these constituents can be fed to the anode side of a fuel cell for testing, is put in place. It includes mass flow controllers for the gaseous species, and a vapor delivery system for the vapor mixture of the unconverted reforming reactants. Electrochemical Impedance Spectroscopy (EIS) is used to characterize the effects of these impurities. The effects of CO were tested up to 2% by volume along with other impurities. All the reformate impurities, including ethanol-water vapor mixture, cause loss in the performance of the fuel cell. In general, CO{sub 2} dilutes the reactants, if tested alone at high operating temperatures (180 C), but tends to exacerbate the effects of CO if they are tested together. On the other hand, CO and methanol-water vapor mixture degrade the fuel cell proportionally to the amounts in which they are tested. In this dissertation some of the mechanisms with which the impurities affect the fuel cell are discussed and interdependence among the effects is also studied. This showed that the combined effect of reformate impurities is more than the arithmetic sum of the individual effects of reformate constituents. The results of the thesis help to understand better the issues of degradation and durability in fuel cells, which can help to make them more durable and

  14. Comparative Dose Accuracy of Durable and Patch Insulin Infusion Pumps

    Science.gov (United States)

    Jahn, Luis G.; Capurro, Jorge J.; Levy, Brian L.

    2013-01-01

    Background: As all major insulin pump manufacturers comply with the international infusion pump standard EN 60601-2-24:1998, there may be a general assumption that all pumps are equal in insulin-delivery accuracy. This research investigates single-dose and averaged-dose accuracy of incremental basal deliveries for one patch model and three durable models of insulin pumps. Method: For each pump model, discrete single doses delivered during 0.5 U/h basal rate infusion over a 20 h period were measured using a time-stamped microgravimetric system. Dose accuracy was analyzed by comparing single doses and time-averaged doses to specific accuracy thresholds (±5% to ±30%). Results: The percentage of single doses delivered outside accuracy thresholds of ±5%, ±10%, and ±20% were as follows: Animas OneTouch® Ping® (43.2%, 14.3%, and 1.8%, respectively), Roche Accu-Chek® Combo (50.6%, 24.4%, and 5.5%), Medtronic Paradigm® RevelTM/VeoTM (54.2%, 26.7%, and 6.6%), and Insulet OmniPod® (79.1%, 60.5%, and 34.9%). For 30 min, 1 h, and 2 h averaging windows, the percentage of doses delivered outside a ±15% accuracy were as follows: OneTouch Ping (1.0%, 0.4%, and 0%, respectively), Accu-Chek Combo (4.2%, 3.5%, and 3.1%), Paradigm Revel/Veo (3.9%, 3.1%, and 2.2%), and OmniPod (33.9%, 19.9%, and 10.3%). Conclusions: This technical evaluation demonstrates significant differences in single-dose and averaged-dose accuracy among the insulin pumps tested. Differences in dose accuracy were most evident between the patch pump model and the group of durable pump models. Of the pumps studied, the Animas OneTouch Ping demonstrated the best single-dose and averaged-dose accuracy. Further research on the clinical relevance of these findings is warranted. PMID:23911184

  15. Transport durable et développement économique

    Directory of Open Access Journals (Sweden)

    Corinne Meunier

    2006-12-01

    Full Text Available Le transport génère des externalités négatives – notamment environnementales – largement reconnues et dénoncées. Aussi, la référence à la durabilité désormais incontournable dans de nombreux domaines de l’action publique, s’étend inévitablement au transport via la notion de transport durable. C’est notamment en matière de fret que les enjeux de durabilité semblent les plus importants : le taux de croissance du transport des marchandises est en effet plus élevé que celui des passagers et le déséquilibre des parts modales s’y creuse davantage, en défaveur des modes les moins polluants. Dans le transport de fret, c’est la politique européenne des transports qui exerce aujourd'hui une influence déterminante à la fois sur la conduite de la politique française (à toutes les échelles et sur les comportements de la quasi-totalité des acteurs et des opérateurs qui interviennent dans le domaine des transports en France. C’est donc sur le segment des flux de marchandises que notre papier traitera de la traduction européenne des principes fondateurs de la notion de transport durable.Transportation generates negative externalities (especially environmental ones widely known and denounced. Thereby, the reference to sustainability, now incontrovertible in many areas of the public action, reaches transportation via the concept of sustainable transportation. The most important need in sustainability is on freight transportation : carriage growth rate is higher than passenger transportation, and the unevenness between the modal parts is in favour of the most polluting. On freight transportation, the European Union policy exercises a determining opinion, both on the French public policies (at every scale and on most of the actors stepping in the transportation domain in France. The topic of this paper is on the segment of carriage flux and on the European translation of the founding principles of sustainable

  16. Durability of crystalline phase in concrete microstructure modified by the mineral powders: evaluation by nanoindentation tests

    Directory of Open Access Journals (Sweden)

    Rajczakowska Magdalena

    2016-03-01

    Full Text Available This paper presents the nanoindentation investigation of the evolution of concrete microstructure modified by the Internal Crystallization Technology mineral powders. The samples under study were retrieved from a fragment of a circular concrete lining of the vertical mine shaft at a depth of approximately 1,000 m. Due to the aggressive environment and exposure to contaminated water, the internal surface of the structure was deteriorated, decreasing its strength significantly. The mineral powders were applied directly on the surface lining. The specimens were investigated one month, three months and one year after the application of the aforementioned substance in order to verify the time dependence of the strengthening processes and durability of the crystalline phase. The microstructural changes of concrete were assessed with the use of nanoindentation technique. The testing procedure involved including the previously cut specimens in the epoxy resin and grinding and polishing in order to reduce the surface roughness. As a result of the nanoindentation tests the hardness as well as Young’s modulus of the material were evaluated. The results were then compared and statistically analyzed. As a consequence, the disintegration time of the crystalline network in the pores of concrete was identified.

  17. Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Gedvilas, L. M.; To, B.; Kennedy, C. E.; Kurtz, S. R.

    2010-08-01

    Concentrating photovoltaic (CPV) technology has recently gained interest based on their expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems use Fresnel lenses made of poly(methyl methacrylate)(PMMA) to obtain a high optical flux density. The optical and mechanical durability of such components, however, are not well established relative to the desired service life of 30 years. Specific reliability issues may include: reduced optical transmittance, discoloration, hazing, surface erosion, embrittlement, crack growth, physical aging, shape setting (warpage), and soiling. The initial results for contemporary lens- and material-specimens aged cumulatively to 6 months are presented. The study here uses an environmental chamber equipped with a xenon-arc lamp to age specimens at least 8x the nominal field rate. A broad range in the affected characteristics (including optical transmittance, yellowness index, mass loss, and contact angle) has been observed to date, depending on the formulation of PMMA used. The most affected specimens are further examined in terms of their visual appearance, surface roughness (examined via atomic force microscopy), and molecular structure (via Fourier transform infrared spectroscopy).

  18. Final Report - Durable Catalysts for Fuel Cell Protection during Transient Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Atanasoski, Radoslav [3M Company, St. Paul, MN (United States); van der Vliet, Dennis [3M Company, St. Paul, MN (United States); Cullen, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atanasoska, Ljiljana [3M Company, St. Paul, MN (United States)

    2015-01-26

    The objective of this project was to develop catalysts that will enable proton exchange membranes (PEM) fuel cell systems to weather the damaging conditions in the fuel cell at voltages beyond the thermodynamic stability of water during the transient periods of start-up/shut-down and fuel starvation. Such catalysts are required to make it possible for the fuel cell to satisfy the 2015 DOE targets for performance and durability. The project addressed a key issue of importance for successful transition of PEM fuel cell technology from development to pre-commercial phase. This issue is the failure of the catalyst and the other thermodynamically unstable membrane electrode assembly (MEA) components during start-up/shut-down and local fuel starvation at the anode, commonly referred to as transient conditions. During these periods the electrodes can reach potentials higher than the usual 1.23V upper limit during normal operation. The most logical way to minimize the damage from such transient events is to minimize the potential seen by the electrodes. At lower positive potentials, increased stability of the catalysts themselves and reduced degradation of the other MEA components is expected.

  19. Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

    International Nuclear Information System (INIS)

    Chong, Eui-seok; Hwang, Gi Byoung; Nho, Chu Won; Kwon, Bo Mi; Lee, Jung Eun; Seo, SungChul; Bae, Gwi-Nam; Jung, Jae Hee

    2013-01-01

    Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

  20. Exploring demand reduction through design, durability and 'usership' of fashion clothes.

    Science.gov (United States)

    Fletcher, Kate

    2017-06-13

    Global planetary boundaries confer limits to production and consumption of material goods. They also confer an obligation to experiment, as individuals and collectively as society, with less-materially-intensive, but no less exuberant, ways of living. This paper takes up this mantle and explores materials demand reduction through a focus on design, fashion garments and the universal, everyday activity of wearing clothes. It takes as its starting point the design of longer-lasting products, a widely favoured strategy for increasing materials efficiency and reducing materials demand in many sectors, including fashion. Drawing on scholarship in the field of design for sustainability and ethnographic research conducted in 16 locations in nine countries about already-existing practices of intensive use and maintenance of clothing, this paper critiques the effectiveness of durability strategies to reduce the amount of materials used. It argues for an update in the familiar preference within sustainability debates for the 'techno-fix' to explore instead resourceful use of materials as emerging from human actions and relationships with material goods. It suggests that, while facilitated by design, technology and engineering, opportunities to reduce materials demand begin in individual and collective practices, which, in turn, have dynamic implications for use of materials.This article is part of the themed issue 'Material demand reduction'. © 2017 The Author(s).

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

    Science.gov (United States)

    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.

  2. Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Eui-seok; Hwang, Gi Byoung [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Nho, Chu Won [Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do 210-340 (Korea, Republic of); Kwon, Bo Mi [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Jung Eun [Biosafety Research Team, National Institute of Environmental Research, Kyungseo-Dong, Seo-Gu, Incheon 404-170 (Korea, Republic of); Seo, SungChul [Department of Environmental Health, College of Medicine, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Bae, Gwi-Nam, E-mail: gnbae@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Jung, Jae Hee, E-mail: jaehee@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2013-02-01

    Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

  3. Preparation of durable hydrophobic cellulose fabric from water glass and mixed organosilanes

    Science.gov (United States)

    Shang, Song-Min; Li, Zhengxiong; Xing, Yanjun; Xin, John H.; Tao, Xiao-Ming

    2010-12-01

    Durable superhydrophobic cellulose fabric was prepared from water glass and n-octadecyltriethoxysilane (ODTES) with 3-glycidyloxypropyltrimethoxysilane (GPTMS) as crosslinker by sol-gel method. The result showed that the addition of GPTMS could result in a better fixation of silica coating from water glass on cellulose fabric. The silanization of hydrolyzed ODTES at different temperatures and times was studied and optimized. The results showed that silanization time was more important than temperature in forming durable hydrophobic surface. The durability of superhydrophobicity treatment was analyzed by XPS. As a result, the superhydrophobic cotton treated under the optimal condition still remained hydrophobic properties after 50 washing cycles.

  4. Determinants of Long-Term Durable Glycemic Control in New-Onset Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Kyoung Jin Kim

    2017-08-01

    Full Text Available BackgroundLong-term durable glycemic control is a difficult goal in the management of type 2 diabetes mellitus (T2DM. We evaluated the factors associated with durable glycemic control in a real clinical setting.MethodsWe retrospectively reviewed the medical records of 194 new-onset, drug-naïve patients with T2DM who were diagnosed between January 2011 and March 2013, and were followed up for >2 years. Glycemic durability was defined as the maintenance of optimal glycemic control (glycosylated hemoglobin [HbA1c] <7.0% for 2 years without substitution or adding other glucose-lowering agents. Clinical factors and glycemic markers associated with glycemic durability were compared between two groups: a durability group and a non-durability group.ResultsPatients in the durability group had a higher baseline body mass index (26.1 kg/m2 vs. 24.9 kg/m2 and lower HbA1c (8.6% vs. 9.7% than the non-durability group. The initial choice of glucose-lowering agents was similar in both groups, except for insulin and sulfonylureas, which were more frequently prescribed in the non-durability group. In multiple logistic regression analyses, higher levels of education, physical activity, and homeostasis model assessment of β-cell function (HOMA-β were associated with glycemic durability. Notably, lower HbA1c (<7.0% at baseline and first follow-up were significantly associated with glycemic durability (adjusted odds ratio [OR], 7.48; 95% confidence interval [CI], 2.51 to 22.3 (adjusted OR, 9.27; 95% CI, 1.62 to 53.1, respectively, after adjusting for confounding variables including the types of glucose-lowering agents.ConclusionEarly achievement of HbA1c level within the glycemic target was a determinant of long-term glycemic durability in new-onset T2DM, as were higher levels of education, physical activity, and HOMA-β.

  5. Price freezes, durables and residential electricity demand - Evidence from the Greater Buenos Aires

    Energy Technology Data Exchange (ETDEWEB)

    Casarin, Ariel; Delfino, Maria Eugenia

    2010-09-15

    This paper examines the determinants of residential electricity demand in the Greater Buenos Aires between 1997 and 2006. During the second half of this period, residential tariffs remained nominally fixed, while an income boom boosted up the sales of durables. This study differs from previous works in that it explicitly considers the impact of the stock of air-conditioners on residential demand. The paper reports short- and long-run elasticities and examines the contribution of prices and durables to recent demand growth. Simulations illustrate the impact of prices and durables on future demand.

  6. Superhydrophobic durable coating based on UV-photoreactive silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nahum, T.; Dodiuk, H.; Dotan, A.; Kenig, S. [Department of Plastics Engineering, Shenkar College of Engineering and Design, 12 Anna Frank Street, Ramat Gan 52526 (Israel); Lellouche, J. P. [Department of Chemistry, Nanomaterials Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramar-Gan, 52900 (Israel)

    2015-05-22

    Superhydrophobic surfaces with contact angle (CA) >150 and sliding angle (SA) <10 have been aroused curiosity over the years due to their various applications. Superhydrophobicity can be obtained tailoring the chemistry and the roughness of the surface, mimicking the Lotus flower. Most superhydrophobic surfaces based on secondary bonding lose their roughness in harsh conditions and are unsuitable for practical applications. Photoreactive SiO{sub 2} nanoparticles (NPs) based on benzophenone (BP) can be a very effective tool for formation of reactive species that function as a molecular bridge by covalent bonding between the NP and any polymer matrix with C-C and C-H bonds. The present work focused on thermoset radiation curing urethane acrylate. Upon UV irradiation reactive excited nπ* triplet benzophenone species are formed and react through hydrogen abstraction to form ketyl radicals which interact with a radicals from the UV irradiated polymer matrix to yield covalent bonding. Roughness was achieved by dipping the substrate in SiO{sub 2}@BPs NPs dispersion followed by irradiation. Fluoroalkylsilane was used to obtain hydrophobic top layer. AFM nano manipulation was used to verify the immobilization of NPs. Evaluation of durability was made using air flow at 300 km/hr. Preliminary results indicate the formation of super hydrophobic surfaces (CA>150 and SA<10) with improved stability.

  7. Durable Airtightness in Single-Family Dwellings: Field Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Wanyu R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-06-01

    Durability of building envelope is important to new homes that are increasingly built with improved levels of airtightness. It is also important to weatherized homes such that energy savings from retrofit measures, such as air sealing, are persistent. We presented a comparison of air leakage measurements collected in November 2013 through March 2014, with two sets of prior data collected between 2001-2003 from 17 new homes located near Atlanta, GA, and 17 homes near Boise, ID that were weatherized in 2007-2008. The purpose of the comparison is to determine if there are changes to the airtightness of building envelopes over time. The air leakage increased in all but one of the new homes, with a mean increase of about 25%. The weatherized homes also showed an increase in the mean air leakage (12%). We performed a regression analysis to describe the relationship between prior and current measurements in terms of normalized leakage (NL). The best estimate of the aging factor predicts a 15% increase in NL over ten years. Further analysis using ResDB data (LBNL’s Residential Diagnostic Database) showed the expected changes in air leakage if aging were modeled. These results imply that we should examine the causes of increased leakage and methods to avoid them. This increase in leakage with time should be accounted for in long-term population-wide energy savings estimates, such as those used in ratings or energy savings programs.

  8. Durability and Performance of High Performance Infiltration Cathodes

    DEFF Research Database (Denmark)

    Samson, Alfred Junio; Søgaard, Martin; Hjalmarsson, Per

    2013-01-01

    The performance and durability of solid oxide fuel cell (SOFC) cathodes consisting of a porous Ce0.9Gd0.1O1.95 (CGO) infiltrated with nitrates corresponding to the nominal compositions La0.6Sr0.4Co1.05O3-δ (LSC), LaCoO3-δ (LC), and Co3O4 are discussed. At 600°C, the polarization resistance, Rp......, varied as: LSC (0.062Ωcm2)cathode was found to depend on the infiltrate firing temperature and is suggested to originate...... of the infiltrate but also from a better surface exchange property. A 450h test of an LSC-infiltrated CGO cathode showed an Rp with final degradation rate of only 11mΩcm2kh-1. An SOFC with an LSC-infiltrated CGO cathode tested for 1,500h at 700°C and 0.5Acm-2 (60% fuel, 20% air utilization) revealed no measurable...

  9. Space environment durability of beta cloth in LDEF thermal blankets

    Science.gov (United States)

    Linton, Roger C.; Whitaker, Ann F.; Finckenor, Miria M.

    1993-01-01

    Beta cloth performance for use on long-term space vehicles such as Space Station Freedom (S.S. Freedom) requires resistance to the degrading effects of the space environment. The major issues are retention of thermal insulating properties through maintaining optical properties, preserving mechanical integrity, and generating minimal particulates for contamination-sensitive spacecraft surfaces and payloads. The longest in-flight test of beta cloth's durability was on the Long Duration Exposure Facility (LDEF), where it was exposed to the space environment for 68 months. The LDEF contained 57 experiments which further defined the space environment and its effects on spacecraft materials. It was deployed into low-Earth orbit (LEO) in Apr. 1984 and retrieved Jan. 1990 by the space shuttle. Among the 10,000 plus material constituents and samples onboard were thermal control blankets of multilayer insulation with a beta cloth outer cover and Velcro attachments. These blankets were exposed to hard vacuum, thermal cycling, charged particles, meteoroid/debris impacts, ultraviolet (UV) radiation, and atomic oxygen (AO). Of these space environmental exposure elements, AO appears to have had the greatest effect on the beta cloth. The beta cloth analyzed in this report came from the MSFC Experiment S1005 (Transverse Flat-Plate Heat Pipe) tray oriented approximately 22 deg from the leading edge vector of the LDEF satellite. The location of the tray on LDEF and the placement of the beta cloth thermal blankets are shown. The specific space environment exposure conditions for this material are listed.

  10. Environmental Degradation and Durability of Epoxy-Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    Raman P. Singh

    2010-01-01

    Full Text Available This experimental investigation reports on the durability of epoxy-clay nanocomposites upon exposure to multiple environments. Nanocomposites are fabricated by mixing the clay particles using various combinations of mechanical mixing, high-shear dispersion, and ultrasonication. Clay morphology is characterized using X-ray diffraction and transmission electron microscopy. Specimens of both neat epoxy and the epoxy-clay nanocomposite are subjected to two environmental conditions: combined UV radiation and condensation on 3-hour repeat cycle and constant temperature-humidity, for a total exposure duration of 4770 hours. The presence of nanoscale clay inhibits moisture uptake, as demonstrated by exposure to constant temperature-humidity. Nonetheless, both materials lose mass under exposure to combined UV radiation and condensation due to the erosion of epoxy by a synergistic process. Surprisingly, the epoxy-clay specimens exhibit greater mass loss, as compared to neat epoxy. Mechanical testing shows that either environment does not significant affect the flexure modulus of either material. On the other hand, both materials undergo degradation in flexural strength when exposed to either environment. However, the epoxy-clay nanocomposite retains 37% more flexure strength than the neat epoxy after 4072 hours of exposure.

  11. Comparative study of durability test methods for pellets and briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Temmerman, Michaeel; Rabier, Fabienne [Centre wallon de Recherches agronomiques (CRA-W), 146, chaussee de Namur, B-5030, Gembloux (Belgium); Jensen, Peter Daugbjerg [Forest and Landscape, The Royal Veterinary and Agricultural University, Rolighedsvej 23, DK-1958 Frederiksberg C (Denmark); Hartmann, Hans; Boehm, Thorsten [Technologie- und Foerderzentrum fuer Nachwachsende Rohstoffe-TFZ, Schulgasse 18, D-94315 Straubing (Germany)

    2006-11-15

    Different methods for the determination of the mechanical durability (DU) of pellets and briquettes were compared by international round robin tests including different laboratories. The DUs of five briquette and 26 pellet types were determined. For briquettes, different rotation numbers of a prototype tumbler and a calculated DU index are compared. For pellets testing, the study compares two standard methods, a tumbling device according to ASAE S 269.4, the Lignotester according to ONORM M 7135 and a second tumbling method with a prototype tumbler. For the tested methods, the repeatability, the reproducibility and the required minimum number of replications to achieve given accuracy levels were calculated. Additionally, this study evaluates the relation between DU and particle density. The results show for both pellets and briquettes, that the measured DU values and their variability are influenced by the applied method. Moreover, the variability of the results depend on the biofuel itself. For briquettes of DU above 90%, five replications lead to an accuracy of 2%, while 39 replications are needed to achieve an accuracy of 10%, when briquettes of DU below 90% are tested. For pellets, the tumbling device described by the ASAE standard allows to reach acceptable accuracy levels (1%) with a limited number of replications. Finally, for the tested pellets and briquettes no relation between DU and particle density was found. (author)

  12. PEMFC for aeronautic applications: A review on the durability aspects

    Science.gov (United States)

    Dyantyi, Noluntu; Parsons, Adrian; Sita, Cordellia; Pasupathi, Sivakumar

    2017-11-01

    Proton exchange membrane fuel cells (PEMFC) not only offer more efficient electrical energy conversion, relative to on-ground/backup turbines but generate by-products useful in aircraft such as heat for ice prevention, deoxygenated air for fire retardation and drinkable water for use on-board. Consequently, several projects (e.g. DLR-H2 Antares and RAPID2000) have successfully tested PEMFC-powered auxiliary unit (APU) for manned/unmanned aircraft. Despite the progress from flying PEMFC-powered small aircraft with 20 kW power output as high as 1 000 m at 100 km/h to 33 kW at 2 558 m, 176 km/h [1, 2, 3], durability and reliability remain key challenges. This review reports on the inadequate understanding of behaviour of PEMFC under aeronautic conditions and the lack of predictive methods conducive for aircraft that provide real-time information on the State of Health of PEMFCs. -To minimize performance loss due to high altitude and inclination by adjusting cathode stoichiometric ratio. -To improve quality of oxygen-depleted air by controlling operating temperature and stoichiometric ratio. -Need to devise real time prediction methods conducive for determining PEMFC SoH in aircraft.

  13. Electro-active paper for a durable biomimetic actuator

    International Nuclear Information System (INIS)

    Yun, Sung-Ryul; Yun, Gyu Young; Kim, Jung Hwan; Chen, Yi; Kim, Jaehwan

    2009-01-01

    Cellulose electro-active paper (EAPap), known as a smart material, has merits in terms of low voltage operation, light weight, dryness, low power consumption, biodegradability, abundance and low price. Since EAPap requires low power consumption, a remotely driven actuator has been proposed using microwave power transmission. This concept is attractive for many biomimetic systems such as crawling micro-insect robots, flying objects like dragon flies and smart wallpapers. However, the actuation performance of EAPap is sensitive to humidity and degrades with time. Thus, in this paper, a durable EAPap is studied. The fabrication of EAPap is explained and the actuation performance is shown with applied electric field, frequency, humidity level and time. The fabrication process includes dissolving cellulose fibers, eliminating solvent and Li ions with a mixture of deionized water and isopropyl alcohol, washing with water, drying and coating with gold. The morphology of the fabricated EAPap is analyzed by taking scanning electron microscope images and x-ray diffractograms. The actuation performance is tested in terms of bending displacement with frequency, time and humidity level

  14. Durable development of tourism in Pitesti and Arges county

    Directory of Open Access Journals (Sweden)

    Bianca DABU

    2010-05-01

    Full Text Available Durable development is one of the main concerns of the contemporary period.The complex relationship between tourism, development and natural environment is anexample of the changes that have taken place in this filed of tourism considered animportant polluter of the natural environment. Tourism is the key element of durabledevelopment having an important impact on the economy, being considered a source ofeconomic growth. Romania has to find its way through the differences given by the needof development, the regulations imposed by the EU and the concerns related to the nextgenerations’ future. Tourism is an important component of the tertiary sector, aconsequence and interface branch of the national economy, and an industry withoutsmoke that has an important contribution to the creation of the world gross product. Anobjective of the National Development Plan adopted in December 2005, component ofthe National Economy Development Strategy is the capitalization of the tourist andcultural potential and the growth of these fields’ contribution to the regions’development, emphasizing the development of the infrastructure, diversifying andpromoting the internal touristy offer, the increase of competitiveness

  15. Superhydrophobic durable coating based on UV-photoreactive silica nanoparticles

    International Nuclear Information System (INIS)

    Nahum, T.; Dodiuk, H.; Dotan, A.; Kenig, S.; Lellouche, J. P.

    2015-01-01

    Superhydrophobic surfaces with contact angle (CA) >150 and sliding angle (SA) <10 have been aroused curiosity over the years due to their various applications. Superhydrophobicity can be obtained tailoring the chemistry and the roughness of the surface, mimicking the Lotus flower. Most superhydrophobic surfaces based on secondary bonding lose their roughness in harsh conditions and are unsuitable for practical applications. Photoreactive SiO 2 nanoparticles (NPs) based on benzophenone (BP) can be a very effective tool for formation of reactive species that function as a molecular bridge by covalent bonding between the NP and any polymer matrix with C-C and C-H bonds. The present work focused on thermoset radiation curing urethane acrylate. Upon UV irradiation reactive excited nπ* triplet benzophenone species are formed and react through hydrogen abstraction to form ketyl radicals which interact with a radicals from the UV irradiated polymer matrix to yield covalent bonding. Roughness was achieved by dipping the substrate in SiO 2 @BPs NPs dispersion followed by irradiation. Fluoroalkylsilane was used to obtain hydrophobic top layer. AFM nano manipulation was used to verify the immobilization of NPs. Evaluation of durability was made using air flow at 300 km/hr. Preliminary results indicate the formation of super hydrophobic surfaces (CA>150 and SA<10) with improved stability

  16. Durability of incinerator ash waste encapsulated in modified sulfur cement

    International Nuclear Information System (INIS)

    Kalb, P.D.; Heiser, J.H. III; Pietrzak, R.; Colombo, P.

    1991-01-01

    Waste form stability under anticipated disposal conditions is an important consideration for ensuring continued isolation of contaminants from the accessible environment. Modified sulfur cement is a relatively new material and has only recently been applied as a binder for encapsulation of mixed wastes. Little data are available concerning its long-term durability. Therefore, a series of property evaluation tests for both binder and waste-binder combinations have been conducted to examine potential waste form performance under storage and disposal conditions. These tests include compressive strength, biodegradation, radiation stability, water immersion, thermal cycling, and leaching. Waste form compressive strength increased with ash waste loadings to 30.5 MPa at a maximum incinerator ash loading of 43 wt %. Biodegradation testing resulted in no visible microbial growth of either bacteria or fungi. Initial radiation stability testing did not reveal statistically significant deterioration in structural integrity. Results of 90 day water immersion tests were dependent on the type of ash tested. There were no statistically significant changes in compressive strength detected after completion of thermal cycle testing. Radionuclides from ash waste encapsulated in modified sulfur cement leached between 5 and 8 orders of magnitude slower than the leach index criterion established by the Nuclear Regulatory Commission (NRC) for low-level radioactive waste. Modified sulfur cement waste forms containing up to 43 wt % incinerator fly ash passed EPA Toxicity Characteristic Leaching Procedure (TCLP) criteria for lead and cadmium leachability. 11 refs., 2 figs., 5 tabs

  17. The durability of examination gloves used on intensive care units.

    Science.gov (United States)

    Hübner, Nils-Olaf; Goerdt, Anna-Maria; Mannerow, Axel; Pohrt, Ute; Heidecke, Claus-Dieter; Kramer, Axel; Partecke, Lars Ivo

    2013-05-20

    The use of examination gloves is part of the standard precautions to prevent medical staff from transmission of infectious agents between patients. Gloves also protect the staff from infectious agents originating from patients. Adequate protection, however, depends on intact gloves. The risk of perforation of examination gloves is thought to correlate with duration of wearing, yet, only very few prospective studies have been performed on this issue. A total number of 1500 consecutively used pairs of examination gloves of two different brands and materials (latex and nitrile) were collected over a period of two months on two ICU's. Used gloves were examined for micro perforations using the "water-proof-test" according to EN 455-1. Cox-regression for both glove types was used to estimate optimal changing intervals. Only 26% of gloves were worn longer than 15 min. The total perforation rate was 10.3% with significant differences and deterioration of integrity of gloves between brands (pgloves show marked differences in their durability that cannot be predicted based on the technical data routinely provided by the manufacturer. Based on the increase of micro perforations over time and the wearing behavior, recommendations for maximum wearing time of gloves should be given. Changing of gloves after 15 min could be a good compromise between feasibility and safety. HCWs should be aware of the benefits and limitations of medical gloves. To improve personal hygiene hand disinfection should be further encouraged.

  18. Durability of recycled aggregate concrete using pozzolanic materials.

    Science.gov (United States)

    Ann, K Y; Moon, H Y; Kim, Y B; Ryou, J

    2008-01-01

    In this study, pulverized fuel ash (PFA) and ground granulated blast furnace slag (GGBS) were used to compensate for the loss of strength and durability of concrete containing recycled aggregate. As a result, 30% PFA and 65% GGBS concretes increased the compressive strength to the level of control specimens cast with natural granite gravel, but the tensile strength was still lowered at 28 days. Replacement with PFA and GGBS was effective in raising the resistance to chloride ion penetrability into the concrete body, measured by a rapid chloride ion penetration test based on ASTM C 1202-91. It was found that the corrosion rate of 30% PFA and 65% GGBS concretes was kept at a lower level after corrosion initiation, compared to the control specimens, presumably due to the restriction of oxygen and water access. However, it was less effective in increasing the chloride threshold level for steel corrosion. Hence, it is expected that the corrosion time for 30% PFA and 65% GGBS concrete containing recycled aggregate mostly equates to the corrosion-free life of control specimens.

  19. Environmental Degradation and Durability of Epoxy-Clay Nanocomposites

    International Nuclear Information System (INIS)

    Singh, R.P.; Zunjarrao, S.C.; Pandey, G.; Khait, M.; Korach, C.S.

    2010-01-01

    This experimental investigation reports on the durability of epoxy-clay nanocomposites upon exposure to multiple environments. Nanocomposites are fabricated by mixing the clay particles using various combinations of mechanical mixing, high-shear dispersion, and ultrasonication. Clay morphology is characterized using X-ray diffraction and transmission electron microscopy. Specimens of both neat epoxy and the epoxy-clay nanocomposite are subjected to two environmental conditions: combined UV radiation and condensation on 3-hour repeat cycle and constant temperature-humidity, for a total exposure duration of 4770 hours. The presence of nanoscale clay inhibits moisture uptake, as demonstrated by exposure to constant temperature-humidity. Nonetheless, both materials lose mass under exposure to combined UV radiation and condensation due to the erosion of epoxy by a synergistic process. Surprisingly, the epoxy-clay specimens exhibit greater mass loss, as compared to neat epoxy. Mechanical testing shows that either environment does not significant affect the flexure modulus of either material. On the other hand, both materials undergo degradation in flexural strength when exposed to either environment. However, the epoxy-clay nanocomposite retains 37% more flexure strength than the neat epoxy after 4072 hours of exposure.

  20. Transparent superwetting nanofilms with enhanced durability at model physiological condition

    Science.gov (United States)

    Hwangbo, Sunghee; Heo, Jiwoong; Lin, Xiangde; Choi, Moonhyun; Hong, Jinkee

    2016-01-01

    There have been many studies on superwetting surfaces owing to the variety of their potential applications. There are some drawbacks to developing these films for biomedical applications, such as the fragility of the microscopic roughness feature that is vital to ensure superwettability. But, there are still only a few studies that have shown an enhanced durability of nanoscale superwetting films at certain extreme environment. In this study, we fabricated intrinsically stable superwetting films using the organosilicate based layer-by-layer (LbL) self-assembly method in order to control nano-sized roughness of the multilayer structures. In order to develop mechanically and chemically robust surfaces, we successfully introduced polymeric silsesquioxane as a building block for LbL assembly with desired fashion. Even in the case that the superhydrophobic outer layers were damaged, the films maintained their superhydrophobicity because of the hydrophobic nature of their inner layers. As a result, we successfully fabricated superwetting nano-films and evaluated their robustness and stability. PMID:26764164

  1. Durability of Gamma Irradiated Polymer Impregnated Blended Cement Pastes

    International Nuclear Information System (INIS)

    Khattab, M.M.; Abdel-Rahman, H.A.; Younes, M.M.

    2010-01-01

    This study is focusing on durability and performance of the neat blended cement paste as well as those of the polymer-impregnated paste towards seawater and various concentrations of magnesium sulfate solutions up to 6 months of curing. The neat blended cement paste is prepared by a partial substitution of ordinary Portland cement with 5% of active rice husk ash (RHA). These samples were cured under tap water for 7 days. Similar samples were impregnated with unsaturated polyester resin (UPE) and subjected to various doses of gamma rays ranging from 10 to 50 kGy. The results showed that the irradiated impregnated specimens gave higher values of compressive strength than the neat blended cement paste specimens. On immersing the neat blended cement specimens and polymer impregnated specimens especially that irradiated at 30 kGy in seawater and different concentrations of magnesium sulfate solutions up to 6 months of curing, the results showed that the polymer impregnated blended cement (OPC-RHA-UPE) paste have a good resistance towards aggressive media as compared to the neat blended cement (OPC-RHA) paste. The results also indicated that the sea water has a greater corrosive effect than the magnesium sulfate solutions. These results were confirmed by scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP)

  2. A durable and dependable solution for RTR spent fuel management

    International Nuclear Information System (INIS)

    Thomasson, J.

    1999-01-01

    RTR Operators need efficient and cost-effective services for the management of their spent fuel and this, for the full lifetime of their facility. Thanks to the integration of transport, reprocessing and conditioning services, COGEMA provides a cogent solution, with the utmost respect for safety and preservation of the environment, for the short, medium and long terms. As demonstrated in this paper, this option offers the only durable and dependable solution for the RTR spent fuel management, leading to a conditioning for the final residues directly suitable for final disposal. The main advantage of such an option is obviously the significant reduction in terms of volume and radiotoxicity of the ultimate waste when compared to direct disposal of spent fuels. The efficiency of such a solution has been proven, some RTR operators having already trusted COGEMA for the management of their aluminide fuel. With its commitment in R and D activities for the development of a high performance and reprocessable LEU fuels, COGEMA will be able to propose a solution for all types of fuels, HEU and LEU

  3. Integrated Monitoring System for Durability Assessment of Concrete Bridges

    Directory of Open Access Journals (Sweden)

    Cristian-Claudiu Comisu

    2005-01-01

    Full Text Available An ageing and deteriorating bridge stock presents the bridge owners with the growing challenge of maintaining the structures at a satisfactory level of safety, performance and aesthetic appearance within the allocated budgets. This task calls for optimized bridge management based on efficient methods of selecting technical and economical optimal maintenance and rehabilitation strategies. One of the crucial points in the assessment of the current condition and future development and performance. Selecting the optimal maintenance and rehabilitation strategy within the actual budget is a key point in bridge management for which an accurate assessment of performance and deterioration rate is necessary. For this assessment, the use of integrated monitoring system has several advantages compared to the traditional approach of scattered visual inspections combined with occasional on site testing with portable equipment and laboratory testing of collected samples. For this reason, attention is more focusing on the development of permanent integrated monitoring system for durability assessment of concrete bridges. It is estimated that with the implementation of such integrated monitoring systems, it should be possible to reduce the operating costs of inspections and maintenance by 25% and the operator of the structures will be able to take protective actions before damaging processes start. This paper indentifies the main bridge owner requirements to integrated monitoring systems and outlines how monitoring systems may be used for performance and deterioration rate assessment to establish a better basis for selecting the optimal maintenance and rehabilitation strategy.

  4. The effect of compositional parameters on the TCLP and PCT durability of environmental glasses

    International Nuclear Information System (INIS)

    Resce, J.L.; Overcamp, T.J.

    1995-01-01

    The relationship between glass composition and the chemical durability of environmental waste glass is very important for both the development of glass formulations and the prediction of glass durability for process control. The development of such a model is extremely difficult for several reasons. Firstly, chemical durability is dependent upon the type of leach test employed; the leach tests themselves being only crude approximations of actual environmental conditions or long term behavior. Secondly, devitrification or crystallinity can also play a major role in durability, but is much more difficult to quantify. Lastly, the development of any one model for all glass types is impractical because of the wide variety of wastestreams, the heterogeneity of the wastestreams, and the large variety of components within each wastestream. Several ongoing efforts have been directed toward this goal, but as yet, no model has been proven acceptable

  5. Next Generation , Lightweight, Durable Boot Materials to Provide Active & Passive Thermal Protection, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this NASA Phase I SBIR program is to leverage lightweight, durable materials developed by NanoSonic for use within extra vehicular activity (EVA)...

  6. Recent Advances in Durability and Damage Tolerance Methodology at NASA Langley Research Center

    Science.gov (United States)

    Ransom, J. B.; Glaessgen, E. H.; Raju, I. S.; Harris, C. E.

    2007-01-01

    Durability and damage tolerance (D&DT) issues are critical to the development of lighter, safer and more efficient aerospace vehicles. Durability is largely an economic life-cycle design consideration whereas damage tolerance directly addresses the structural airworthiness (safety) of the vehicle. Both D&DT methodologies must address the deleterious effects of changes in material properties and the initiation and growth of damage that may occur during the vehicle s service lifetime. The result of unanticipated D&DT response is often manifested in the form of catastrophic and potentially fatal accidents. As such, durability and damage tolerance requirements must be rigorously addressed for commercial transport aircraft and NASA spacecraft systems. This paper presents an overview of the recent and planned future research in durability and damage tolerance analytical and experimental methods for both metallic and composite aerospace structures at NASA Langley Research Center (LaRC).

  7. Sports, genre et developpement durable : l'heritage d'une ...

    African Journals Online (AJOL)

    Sports, genre et developpement durable : l'heritage d'une distribution ... to new populations in situation of confrontation with the difference that Goffman (1975) ... and women (gender), maintain the sports field and behind the appearance of a ...

  8. Experimental research on durability of recycled aggregate concrete under freeze- thaw cycles

    Science.gov (United States)

    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.

  9. Durability assessment of recycled concrete aggregates for use in new concrete.

    Science.gov (United States)

    2012-06-01

    The primary goal of this research project was to investigate the long-term durability of concrete incorporating : recycled concrete aggregate (RCA) through accelerated laboratory testing. Overall it was found that modifications to : standard aggregat...

  10. 40 CFR 86.094-13 - Light-duty exhaust durability programs.

    Science.gov (United States)

    2010-07-01

    ... conformity for the affected engine families void ab initio. (e) Alternative Service Accumulation Durability... shall propose sample sizes, recruitment procedures, testing procedures, optional provisions for the...) of this section, the manufacturer shall provide reliability data that shows to the Administrator's...

  11. Neonatal GLP1R activation limits adult adiposity by durably altering hypothalamic architecture

    Directory of Open Access Journals (Sweden)

    Andrea V. Rozo

    2017-07-01

    Conclusion: These observations suggest that the acute activation of GLP1R in neonates durably alters hypothalamic architecture to limit adult weight gain and adiposity, identifying GLP1R as a therapeutic target for obesity prevention.

  12. Durability and Reliability of Large Diameter HDPE Pipe for Water Main Applications (Web Report 4485)

    Science.gov (United States)

    Research validates HDPE as a suitable material for use in municipal piping systems, and more research may help users maximize their understanding of its durability and reliability. Overall, corrosion resistance, hydraulic efficiency, flexibility, abrasion resistance, toughness, f...

  13. Rapid Manufacturing of Durable, Cost-Effective Ceramic Matrix Composites for High Temperature Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Hypersonic vehicles require durable and cost-effective hot structures that do not impose weight penalties such as those associated with the use of non-structural...

  14. Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 3

    International Nuclear Information System (INIS)

    Ulm, Franz-Josef

    2000-01-01

    OAK-B135 Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 3(NOTE: Part II A item 1 indicates ''PAPER'', but a report is attached electronically)

  15. Evaluation of curing compound application time on concrete surface durability : [brief].

    Science.gov (United States)

    2015-05-01

    Roadways that are both durable and aesthetically pleasing are primary goals of Wisconsin : Department of Transportation (WisDOT) paving projects. Recently, Portland Cement Concrete : (PCC) pavement projects constructed by WisDOT have experienced incr...

  16. Concrete pavement mixture design and analysis (MDA) : assessment of air void system requirements for durable concrete.

    Science.gov (United States)

    2012-06-01

    Concrete will suffer frost damage when saturated and subjected to freezing temperatures. Frost-durable concrete can be produced if a : specialized surfactant, also known as an air-entraining admixture (AEA), is added during mixing to stabilize micros...

  17. Effect of wet curing duration on durability parameters of hydraulic cement concretes.

    Science.gov (United States)

    2010-01-01

    Hydraulic cement concrete slabs were cast and stored outdoors in Charlottesville, Virginia, to study the impact of wet curing duration on durability parameters. Concrete mixtures were produced using portland cement, portland cement with slag cement, ...

  18. Durability of saw-cut joints in plain cement concrete pavements.

    Science.gov (United States)

    2011-01-01

    The objective of this project was to evaluate factors influencing the durability of the joints in portland cement concrete : pavement in the state of Indiana. Specifically this work evaluated the absorption of water, the absorption of deicing solutio...

  19. METHODS OF THE APPROXIMATE ESTIMATIONS OF FATIGUE DURABILITY OF COMPOSITE AIRFRAME COMPONENT TYPICAL ELEMENTS

    Directory of Open Access Journals (Sweden)

    V. E. Strizhius

    2015-01-01

    Full Text Available Methods of the approximate estimations of fatigue durability of composite airframe component typical elements which can be recommended for application at the stage of outline designing of the airplane are generated and presented.

  20. Durable crystalline Si photovoltaic modules based on silicone-sheet encapsulants

    Science.gov (United States)

    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.

  1. Effects of radiation and environmental factors on the durability of materials in spent fuel storage and disposal

    International Nuclear Information System (INIS)

    2002-12-01

    This is the second report that addresses results from the Coordinated Research Project (CRP) on Irradiation Enhanced Degradation of Materials in Spent Fuel Storage Facilities. This second report addresses results of topical studies that are relevant to issues important to materials behaviour in wet storage technology, but also involves topics on materials behaviour in dry storage and repository environments, including effects of radiation. The material is in seven separate papers contributed by the participants in the CRP and contains details of research studies started within the framework of the CRP and in several cases completed well after the CRP was finished. The seven contributions fall into three broad subject areas: Effects of temperature and radiation on aqueous and moist air corrosion of stainless steels; Studies of materials behaviour in wet and dry storage; Effects of gamma radiation on the durability of candidate canister materials for repository applications: carbon steel, titanium, and copper. Each of the papers has been indexed separately

  2. Short-term mechanical circulatory support as a bridge to durable left ventricular assist device implantation in refractory cardiogenic shock: a systematic review and meta-analysis.

    Science.gov (United States)

    den Uil, Corstiaan A; Akin, Sakir; Jewbali, Lucia S; Dos Reis Miranda, Dinis; Brugts, Jasper J; Constantinescu, Alina A; Kappetein, Arie Pieter; Caliskan, Kadir

    2017-07-01

    Short-term mechanical circulatory support (MCS) is increasingly used as a bridge to decision in patients with refractory cardiogenic shock. Subsequently, these patients might be bridged to durable MCS either as a bridge to candidacy/transplantation, or as destination therapy. The aim of this study was to review support duration and clinical outcome of short-term MCS in cardiogenic shock, and to analyse application of this technology as a bridge to long-term cardiac support (left ventricular assist device, LVAD) from 2006 till June 2016. Using Cochrane Register of Trials, Embase and Medline, a systematic review was performed on patients with cardiogenic shock from acute myocardial infarction, end-stage cardiomyopathy, or acute myocarditis, receiving short-term MCS. Studies on periprocedural, post-cardiotomy and cardiopulmonary resuscitation support were excluded. Thirty-nine studies, mainly registries of heterogeneous patient populations (n = 4151 patients), were identified. Depending on the device used (intra-aortic balloon pump, TandemHeart, Impella 2.5, Impella 5.0, CentriMag and peripheral veno-arterial extracorporeal membrane oxygenation), mean support duration was (range) 1.6-25 days and the mean proportion of short-term MCS patients discharged was (range) 45-66%. The mean proportion of bridge to durable LVAD was (range) 3-30%. Bridge to durable LVAD was most frequently performed in patients with end-stage cardiomyopathy (22 [12-35]%). We conclude that temporary MCS can be used to bridge patients with cardiogenic shock towards durable LVAD. Clinicians are encouraged to share their results in a large multicentre registry in order to investigate optimal device selection and best duration of support. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. An experimental survey on combined effects of fibers and nanosilica on the mechanical, rheological, and durability properties of self-compacting concrete

    International Nuclear Information System (INIS)

    Beigi, Morteza H.; Berenjian, Javad; Lotfi Omran, Omid; Sadeghi Nik, Aref; Nikbin, Iman M.

    2013-01-01

    Highlights: • We investigate combine effects of fibers and nanosilica on SCC. • The mechanical, rheological, and durability properties were tested and compared. • Microstructural properties of concrete were assessed using AFM and XRD techniques. • Nanosilica and fibers can improve the mechanical properties and durability of SCC. - Graphical abstract: - Abstract: Previous studies have shown that application of fibers in concrete enhances scratching, flexural and tensile strength. Self-Compacting Concrete (SCC) is a highly flowable and coherent concrete able to self-compact under its own weight. On the other hand, nanosilica particles and artificial pozzolans possessing high efficiency in concrete technology can improve structural properties of cement-based materials. Previous studies have suggested self-compacting and fiber-reinforced concretes for more stable and efficient buildings. Therefore, the present study aimed to evaluate the effects of nanosilica and different concrete reinforcing fibers including steel, polypropylene and glass on the performance of concrete. In this study mechanical (compressive, splitting tensile and flexural strength, toughness and modulus of elasticity), rheological (L-Box, slump flow, T50) and durability (resist chloride ion penetration (RCPT) and water absorption) properties are assessed. In addition, microstructural properties of concrete were assessed using Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD) techniques. Totally, 40 concrete mixes , labeled as A, B, C and D, with nanosilica contents of 0, 2, 4 and 6 weight percent (wt.%) of cement, respectively and three types of reinforcing fibers (steel: 0.2, 0.3 and 0.5 volume percent (v%) and polypropylene: 0.1, 0.15 and 0.2 v% and glass: 0.15, 0.2 and 0.3 v%) were evaluated. The results of the study showed that the presence of both nanosilica and reinforcing fibers in optimal percentages, can improve the mechanical properties and durability of self

  4. Will It Every Fly? Modeling the Takeoff of Really New Consumer Durables

    OpenAIRE

    Peter N. Golder; Gerard J. Tellis

    1997-01-01

    A consistent pattern observed for really new household consumer durables is a takeoff or dramatic increase in sales early in their history. The takeoff tends to appear as an elbow-shaped discontinuity in the sales curve showing an average sales increase of over 400%. In contrast, most marketing textbooks as well as diffusion models generally depict the growth of new consumer durables as a smooth sales curve. Our discussions with managers indicate that they have little idea about the takeoff a...

  5. Highly Sensitive, Transparent, and Durable Pressure Sensors Based on Sea-Urchin Shaped Metal Nanoparticles.

    Science.gov (United States)

    Lee, Donghwa; Lee, Hyungjin; Jeong, Youngjun; Ahn, Yumi; Nam, Geonik; Lee, Youngu

    2016-11-01

    Highly sensitive, transparent, and durable pressure sensors are fabricated using sea-urchin-shaped metal nanoparticles and insulating polyurethane elastomer. The pressure sensors exhibit outstanding sensitivity (2.46 kPa -1 ), superior optical transmittance (84.8% at 550 nm), fast response/relaxation time (30 ms), and excellent operational durability. In addition, the pressure sensors successfully detect minute movements of human muscles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Old materials and techniques to improve the durability of earth buildings

    OpenAIRE

    Camões, Aires; Eires, R.; Jalali, Said

    2012-01-01

    Quite a big part of the world’s heritage is still made by earth constructions. The durability of the existent heritage, as well as the new earth buildings is particularly conditioned by erosion caused by water action, especially in countries with high rainfall index. With this research one intends to value the ancient knowledge in order to allow higher durability. Analysing the old building techniques to protect the earth material from the water action it is possible to understand how ear...

  7. THE RELEVANCE OF ELECTRONIC COMMERCE FOR DURABLE DEVELOPMENT. CHALLENGES FOR ROMANIA

    OpenAIRE

    Assist. Ph.D Student Maruntelu Irina

    2009-01-01

    This article aims to approach the topic of the electronic commerce considering the context of the durable development, without exclusively limiting to the economic dimension of sustainable development. This paper aims to offer a vision on the e-commerce based on an optimistic approach of the reconciliation between economic growth and durable development, but moderate by the current realities (digital divide between countries/regions, economic crisis etc). Furthermore, by identifying some of t...

  8. Advanced Durability Analysis. Volume 2. Analytical Predictions, Test Results and Analytical Correlations

    Science.gov (United States)

    1989-02-27

    Deteministic Crack Growth ApprMach ( CApm -DCG-) Ndaft)/dt m 101Ca )I SUVICE TINE Wh Two-stit btei’uinistic-stochastic Crack Groth Approach (WHO-CG) Figure...physical description of the state of damage for a durability- critical component and a logical basis for estimating structural maintenance/repair require...The stress level for each stress region is important for crack growth predictions. Therefore, the stress analysis for durability- critical components

  9. Fostering a durable relationship between a waste management facility and its host community

    International Nuclear Information System (INIS)

    2007-01-01

    Any long-term radioactive waste management project is likely to last decades to centuries. It requires a physical site and will impact in a variety of ways on the surrounding community over that whole period. The societal durability of an agreed solution is essential to success. This report identifies a number of design elements (including functional, cultural and physical features) that favour a durable relationship between the facility and its host community by improving prospects for quality of life across generations

  10. Durability testing of the high-capacity GA-4/GA-9 trailer

    International Nuclear Information System (INIS)

    Zimmer, A.; Lyon, T.

    1995-01-01

    GA designed trailers to transport the GA-4 and GA-9 LWT from-reactor spent nuclear fuel shipping casks. GA designed and fabricated the GA-9 trailer to ANSI N14.30 requirements and is now performing a durability test at the AlliedSignal Automotive Proving Grounds. The trailer, simulated cask and tractor. The test program objective is to evaluate and improve, as necessary, the trailer's durability, reliability and performance

  11. Experimental research on the durability cutting tools for cutting-off steel profiles

    Directory of Open Access Journals (Sweden)

    Cristea Alexandru

    2017-01-01

    Full Text Available The production lines used for manufacturing U-shaped profiles are very complex and they must have high productivity. One of the most important stages of the fabrication process is the cutting-off. This paper presents the experimental research and analysis of the durability of the cutting tools used for cutting-off U-shaped metal steel profiles. The results of this work can be used to predict the durability of the cutting tools.

  12. Evolution of Durable High-Strength Flowable Mortar Reinforced with Hybrid Fibers

    OpenAIRE

    Dawood, Eethar Thanon; Ramli, Mahyuddin

    2012-01-01

    The production and use of durable materials in construction are considered as one of the most challenging things for the professional engineers. Therefore, this research was conducted to investigate the mechanical properties and the durability by using of different percentages of steel fiber with high-strength flowable mortar (HSFM) and also the use of the hybridization of steel fibers, palm fibers, and synthetic fiber (Barchip). Different experimental tests (compressive strength, splitting t...

  13. The effect of a finite time horizon in the durable good monopoly problem with atomic consumers

    OpenAIRE

    Berbeglia, Gerardo; Sloan, Peter; Vetta, Adrian

    2014-01-01

    A durable good is a long-lasting good that can be consumed repeatedly over time, and a duropolist is a monopolist in the market of a durable good. In 1972, Ronald Coase conjectured that a duropolist who lacks commitment power cannot sell the good above the competitive price if the time between periods approaches zero. Coase's counterintuitive conjecture was later proven by Gul et al. (1986) under an infinite time horizon model with non-atomic consumers. Remarkably, the situation changes drama...

  14. Moving towards a virtual durability of vehicles; Auf dem Weg zur virtuellen Festigkeit im Fahrzeugbau

    Energy Technology Data Exchange (ETDEWEB)

    Heuler, P.; Birk, O.; Beste, A. [Audi AG, Ingolstadt (Germany). Abt. I/EG-32

    2001-04-01

    The dualism of experimental and virtual durability assessment is addressed. The possibilities and limitations of the virtual concepts are discussed with regard to the different steps of the durability assessment. It is outlined from a user's point of view where the use of these concepts is presently seen. It is important to rate the potentials of each step ranging from the definition of load requirements to the life time calculation. (orig.)

  15. Report on achievements in fiscal 1998. Development of technologies to put photovoltaic power generation systems into practical use - Development of solar beam power generation and utilization systems and ancillary technologies (Research and development of building material integrated solar cell modules - high-durability roof modules); 1998 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Taiyoko hatsuden riyo system shuhen gijutsu no kenkyu kaihatsu (shinkenzai ittaigata taiyo denchi module no kenkyu kaihatsu (kotaikyusei yane module))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    With the target set on a system with a roof array efficiency of 8.5%, and a system cost of 170 yen/W, development is being made on a large roof panel and its construction technology, which is capable of AC output by integrating into a large roof panel the compound thin film solar cells having glass/CdS/CdTe/rear air chamber/rear metal, and the inverter. In the cell constituting materials and the structure design, sealants were evaluated, the painting process was developed, and two kinds of structures were prepared. The frameless type has a lamination structure, and a prototype module of 886 times 664 mm was fabricated, and the frame type has a double sealing structure, and a prototype module 600 times 900 mm was fabricated. Prototype modules that can be fixed on a rail type fixing stand were fabricated and constructed, having demonstrated sufficient workability. In addition, a prototype small inverter with system coordination protection was operated actually, and the initial stage malfunctions were corrected. Two demonstration buildings were built, and the whole process was performed from assembly and transportation of the modules and to the installation thereof at the construction site. (NEDO)

  16. Enhanced washing durability of hydrophobic coating on cellulose fabric using polycarboxylic acids

    International Nuclear Information System (INIS)

    Huang Wenqi; Xing Yanjun; Yu Yunyi; Shang Songmin; Dai Jinjin

    2011-01-01

    Nine polycarboxylic acids were used to improve washing durability of hydrophobic cellulose fabric finished by sol-gel method. By simultaneous forming ester-bridge between cellulose and silica layer by ester bond, polycarboxylic acids could anchor silica coating onto cellulose fabric to strengthen the adhesion of organic-inorganic hybrid coating. The wettability of treated fabrics was characterized by water contact angle, spray test and hydrostatic pressure test. The results showed that all investigated polycarboxylic acids could improve the durability. The polycarboxylic acid with proper distance between terminal carboxylic acid groups and number of carboxylic acid groups showed the highest durability. 1,2,3,4-butanetetracarboxylic acid (BTCA) led to the best durability of hydrophobic cellulose fabric with water contact angle of 137.6 o (recovery percentage of 94.2%) after 30 washing times. The effect of BTCA on durability was characterized by scanning electron microscopy. This study demonstrated that the surface treatment using polycarboxylic acids and mixed organosilanes is a promising alternative for achieving durable hydrophobic fabrics.

  17. Application of the cementitious grouts on stability and durability of semi flexible bituminous mixtures

    Science.gov (United States)

    Karami, Muhammad

    2017-11-01

    This paper describes the results of laboratory test for a high durability semi flexible bituminous mixtures (SFBM). The SFBM consists of an open asphalt structure where a high strength mortar is penetrated into the air voids of the bituminous mixtures. The SFBM combines the cement concrete's strength and the asphalt material flexibility. The objective of this study is to involve in the determination of stability and durability of SFBM by located the position of the specimen on an exposed area for 7, 90, 180 and 240 days. The performance of the SFBM was assessed using Marshall and wheel tracking apparatus. Total 18 specimens were prepared and examined for both of test. The Marshall specimens were cylindrical with dimension of 10.16 cm in diameter and 6.35 cm in high. For wheel tracking test, the specimens consisted of slabs with dimension of 30 cm in length, 30 cm in width and 5 cm in height. The results indicated that the first durability index and second durability index increased significantly. For Marshall test, the first and second durability index increased about 0.9% per day and 52.3%, respectively. However, for wheel tracking test, the first and second durability index increased about 1.9% per day and 119%, respectively.

  18. Organic Solvent-Free Fabrication of Durable and Multifunctional Superhydrophobic Paper from Waterborne Fluorinated Cellulose Nanofiber Building Blocks.

    Science.gov (United States)

    Baidya, Avijit; Ganayee, Mohd Azhardin; Jakka Ravindran, Swathy; Tam, Kam Chiu; Das, Sarit Kumar; Ras, Robin H A; Pradeep, Thalappil

    2017-11-28

    In view of a great demand for paper-based technologies, nonwettable fibrous substrates with excellent durability have drawn much attention in recent years. In this context, the use of cellulose nanofibers (CNFs), the smallest unit of cellulosic substrates (5-20 nm wide and 500 nm to several microns in length), to design waterproof paper can be an economical and smart approach. In this study, an eco-friendly and facile methodology to develop a multifunctional waterproof paper via the fabrication of fluoroalkyl functionalized CNFs in the aqueous medium is presented. This strategy avoids the need for organic solvents, thereby minimizing cost as well as reducing safety and environmental concerns. Besides, it widens the applicability of such materials as nanocellulose-based aqueous coatings on hard and soft substrates including paper, in large areas. Water droplets showed a contact angle of 160° (±2°) over these surfaces and rolled off easily. While native CNFs are extremely hydrophilic and can be dispersed in water easily, these waterborne fluorinated CNFs allow the fabrication of a superhydrophobic film that does not redisperse upon submersion in water. Incorporated chemical functionalities provide excellent durability toward mechanochemical damages of relevance to daily use such as knife scratch, sand abrasion, spillage of organic solvents, etc. Mechanical flexibility of the chemically modified CNF composed paper remains intact despite its enhanced mechanical strength, without additives. Superhydrophobicity induced excellent microbial resistance of the waterproof paper which expands its utility in various paper-based technologies. This includes waterproof electronics, currency, books, etc., where the integrity of the fibers, as demonstrated here, is a much-needed criterion.

  19. Durability of Selected Membrane Materials when Exposed to Chlorine Gas

    Energy Technology Data Exchange (ETDEWEB)

    Eikeland, Marianne Soerflaten

    2001-03-01

    This thesis is focusing on the durability of selected membrane materials when exposed to chlorine gas in the temperature range 30-100{sup o}C. Studies of the changes of membrane separation properties and the mechanisms promoting these changes have been studied. The selected membrane materials were poly(dimethylsioxane) (PDMS), Fluorel, fluorosilicone, and blends of PDMS and Fluorel. The thesis is organised in seven chapters. The first chapter gives an introduction to the background of the work. The second chapter presents the theory for gas separation using dense rubbery membranes. The properties of the selected membrane materials are presented in chapter three. The fourth chapter describes degradation mechanisms for polymeric materials in general and for the selected membrane materials in particular. Presentation of the experimental work is given in chapter five, while the results with discussions are presented in chapter six. The conclusions and recommendations for further studies are given in chapter seven. Five appendixes are attached: Appendix A describes the calculations of permeability and solubility coefficients and the accuracy of the experimental measurements. Appendix B summarises the measured values in tables and Appendix C describes the analytical methods. Appendix D gives the properties of the gases used in the experiments. Appendix E is the article ''Durability of Poly(dimethylsiloxane) when Exposed to Chlorine Gas'', submitted to the Journal of Applied Polymer Science. Highly crosslinked PDMS was found to have an initial high permeability for chlorine gas and a high Cl{sub 2}/O{sub 2} selectivity. However when exposed to chlorine gas the permeability decreased significantly. Crosslinking of the PDMS polymer chain and chlorination of the polymer gave a denser polymer structure and thus lower permeability. Fluorel showed very low permeabilities and selectivities for the gases in question and was thus not interesting for this

  20. Evaluation of durability of SSCs injected with seawater

    International Nuclear Information System (INIS)

    2012-01-01

    At the units 1 to 4 in the Fukushima Daiichi Nuclear Power Plant, seawater was injected into reactor pressure vessels and spent fuel pools in order to cool down nuclear fuel is after the disaster of the 2011 off the Pacific Coast of Tohoku Earthquake and Tsunami. Therefore, for fuel cladding tubes exposed to seawater and piping items to pour seawater into a nuclear reactor, it was necessary to evaluate structural integrity under the seawater environment. And then, JNES carried out the safety research of 'Evaluation of Durability of SSCs injected with Seawater' in FY2011. The contents and the results obtained from the search are as follows; (1) For the pipes and nuclear reactor containment vessels, corrosion tests under high temperature seawater at 50degC and 80degC were carried out for the carbon steel that corrosion resistance was less. The data of relationship between a dipping time upto 1,500h and a corrosion rate were obtained as parameters at chloride ion (CI - ) content and the temperature of the seawater. As the results, the corrosion rate was almost 0.1 mm/y for the carbon steel SGV480. No significant influence of CT - content and the temperature of the seawater was confirmed. (2) Corrosion tests were carried out to obtain the relations of time and corrosion under different CI - content conditions for the simulated fuel rod specimens in seawater at 90degC for durations upto 1,200h. As the results, very little corrosion was observed on Zry-2 cladding tube. Brown rust was slightly appeared on the nut made of stainless steel and the lower tie plate made of cast stainless steel. Thinning and corrosion pit were not observed. (author)

  1. Study on durability for thermal cycle of planar SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Motoo; Nakata, Kei-ichi; Wakayama, Sin-ichi [Tonen Corp., Saitama (Japan)] [and others

    1996-12-31

    TONEN CORPORATION has developed planar type SOFC since 1986. We demonstrated the output of 1.3 kW in 1991 and 5.1 kW in 1995. Simultaneously we have studied how to raise electric efficiency and reliability utilizing hydrogen and propane as fuel. Durability for thermal cycle is one of the most important problems of planar SOFC to make it more practical. The planar type SOFC is made up of separator, zirconia electrolyte and glass sealant. The thermal expansion of these components are expected to be the same value, however, they still possess small differences. In this situation, a thermal cycle causes a thermal stress due to the difference of the cell components and is often followed by a rupture in cell components, therefore, the analysis of the thermal stress should give us much useful information. The thermal cycle process consists of a heating up and cooling down procedure. Zirconia electrolyte is not bonded to the separator under the condition of the initial heating up procedure, and glass sealant becomes soft or melts and glass seals spaces between the zirconia and separator. The glass sealant becomes harder with the cooling down procedure. Moreover, zirconia is tightly bonded with separator below a temperature which is defined as a constraint temperature and thermal stress also occurs. This indicates that the heating up process relaxes the thermal stress and the cooling down increases it. In this paper, we simulated dependence of the stress on the sealing configuration, thermal expansion of sealant and constraint temperature of sealant glass. Furthermore, we presented SOFC electrical properties after a thermal cycle.

  2. Durability of two water repelents applied to granite

    Directory of Open Access Journals (Sweden)

    Rivas, T.

    1998-06-01

    Full Text Available The durability of two water-repellents for granitic stonework was determined. Weathered and sound samples of granites widely used in building construction and restoration in Galicia (NW Spain were treated with water repellents of known efficacy, and then subjected to two artificial weathering tests: prolonged exposure to UV light, and sodium sulphate crystallization cycles. In both tests, but especially in the salt crystallization cycles, both treatments rapidly lost their water-repellency. Furthermore, the hydrophobic layer of water repellent impeded salt mobility, favouring fissuration parallel to the treated surface, which was eventually shed in the form of a plaque.

    Se presentan los resultados de la durabilidad de dos tratamientos de hidrofugación aplicados a rocas graníticas ampliamente utilizados en la construcción de edificios en Galicia (Noroeste de España. Tras la evaluación de la eficacia de dichos tratamientos, cuyos resultados se presentaron en un trabajo anterior, se someten las muestras tratadas a dos ensayos diferentes de envejecimiento acelerado: ciclos de exposición a la luz ultravioleta y ciclos de cristalización de sulfato de sodio. Los productos hidrofugantes muestran una escasa resistencia a ambos ensayos, sobre todo a los ciclos de cristalización de sulfato de sodio; esta débil durabilidad se manifiesta en una rápida pérdida de sus propiedades hidrofugantes. Así mismo, se observa que la presencia de la capa hidrófoba en la piedra funciona como una barrera frente a la movilidad de sales, lo que ocasiona el total desprendimiento de aquella y un fuerte deterioro del material rocoso.

  3. Durability of building stones against artificial salt crystallization

    Science.gov (United States)

    Min, K.; Park, J.; Han, D.

    2005-12-01

    Salts have been known as the most powerful weathering agents, especially when combined with frost action. Salt crystallization test along with freezing-thawing test and acid immersion test was carried out to assess the durability of building stones against weathering. Granite, limestone, marble and basalt were sampled from different quarries in south Korea for this study. One cycle of artificial salt crystallization test was composed of immersion of cored rock specimens in oversaturated solutions of CaCl2, KCl, NaCl and Na2SO4, respectively for 15 hours and successive drying in an oven of 105°C for 3 hours and cooling at room temperature. Tests were performed up to 30 cycles, and specific gravity and ultrasonic velocity were measured after experiencing every 10 cycles and uniaxial compressive strength was measured only after 30 cycles. During the repeated Na2SO4 salt crystallization, some rock samples were gradually deformed excessively and burst after 20 to 30 cycles of test. The variation patterns of physical properties during the salt crystallization tests are too variable to generalize the effect of salt weathering on physical properties but limestone, marble and basalt samples showed relatively greater change of physical properties than granite samples. The recrystallized salts were well observed in the cracks of rock samples through the scanning electron microscope. In the all salt crystallization tests, apparent specific gravities for all tested samples increased generally but not so significantly due to recrystallization of salts. It can be inferred that filling the pores with salt crystals cause the increase of ultrasonic velocity during the early stage of salt crystallization and then in later stages the repeated cycles of salt crystallization result in development of cracks leading decrease of ultrasonic velocity for some rock samples.

  4. Rock as a construction material: durability, deterioration and conservation

    Directory of Open Access Journals (Sweden)

    Esbert, Rosa M.ª

    1991-03-01

    Full Text Available The different aspects related to the deterioration and conservation of stone, used as a construction material, are reviewed in this article. The petrographical characteristics and physical properties which control the durability of stone material are stated. The importance of the voids and the properties more directly linked to the up-taking and transfer of humidity through the stone are pointed out. Regarding to the deterioration processes, the role of water, soluble salts and atmospheric pollutants upon the different alteration mechanisms of the building stones is emphasized. Finally, the steps related to the stone conservation, and the methods and products more currently employed to that aim are revised.

    Se compendian los distintos aspectos relacionados con el deterioro y la conservación de la piedra utilizada como material de edificación. Se revisan las características petrográficas y propiedades físicas que controlan la durabilidad de los materiales pétreos, resaltando la importancia de los espacios vacíos y de aquellas propiedades más directamente relacionadas con la captación y transferencia de humedad por el interior de la piedra. En cuanto a los procesos de deterioro se destaca el papel del agua, de las sales solubles y de los contaminantes atmosféricos en los diversos mecanismos de alteración desarrollados en la piedra de edificación. Finalmente se plantean las diversas fases relacionadas con la conservación de la piedra, y se revisan los métodos y productos más empleados en la actualidad para tal fin.

  5. Thermal durability of modified Synroc material as reactor fuel matrix

    International Nuclear Information System (INIS)

    Kikuchi, Akira; Kanazawa, Hiroyuki; Togashi, Yoshihiro; Matumoto, Seiichiro; Nishino, Yasuharu; Ohwada, Isao; Nakata, Masahito; Amano, Hidetoshi; Mitamura, Hisayoshi

    1994-08-01

    A Synroc, a polyphase titanate ceramics composed of three mineral phases (perovskite, hollandite and zirconolite), has an excellent performance of immobilization of high level nuclear waste. A working group in the Department of Hot Laboratories paid special attention to this merit and started a development study on a LWR fuel named 'Waste Disposal Possible (WDP) Fuel', which has the two functions of a reactor fuel and a waste form. The present paper mainly describes thermal durability of a modified Synroc material, which is essentially important for applying the material to a fuel matrix. The two kinds of Synroc specimens, designated 'SM' as modified and 'SB' as a reference, were prepared by hot-pressing and annealed at 1200degC to 1500degC for 30 min in air. Unexpected and peculiar spherical voids were observed in the specimen SM at 1400degC and 1500degC, which caused the specimen swelling. The formation of the voids depends significantly on the existence of spherical precipitates seen in the as-fabricated specimen including latent micropores with high pressure. On the other hand, the heat treatment at 1500degC formed additional new phases, designated 'Phase A' for the specimen SB and 'Phase X' for SM. Phase A is a decomposition product of hollandite and Phase X a reaction product of Phase A and perovskite in the spherical voids. Furthermore, additional information and thermal properties examined are presented in Appendix 1 and Appendix 2, respectively. It was recognized that the modified Synroc specimen SM had excellent thermal properties. (author)

  6. Durable diamond-like carbon templates for UV nanoimprint lithography

    International Nuclear Information System (INIS)

    Tao, L; Ramachandran, S; Nelson, C T; Overzet, L J; Goeckner, M; Lee, G; Hu, W; Lin, M; Willson, C G; Wu, W

    2008-01-01

    The interaction between resist and template during the separation process after nanoimprint lithography (NIL) can cause the formation of defects and damage to the templates and resist patterns. To alleviate these problems, fluorinated self-assembled monolayers (F-SAMs, i.e. tridecafluoro-1,1,2,2,tetrahydrooctyl trichlorosilane or FDTS) have been employed as template release coatings. However, we find that the FDTS coating undergoes irreversible degradation after only 10 cycles of UV nanoimprint processes with SU-8 resist. The degradation includes a 28% reduction in surface F atoms and significant increases in the surface roughness. In this paper, diamond-like carbon (DLC) films were investigated as an alternative material not only for coating but also for direct fabrication of nanoimprint templates. DLC films deposited on quartz templates in a plasma enhanced chemical vapor deposition system are shown to have better chemical and physical stability than FDTS. After the same 10 cycles of UV nanoimprints, the surface composition as well as the roughness of DLC films were found to be unchanged. The adhesion energy between the DLC surface and SU-8 is found to be smaller than that of FDTS despite the slightly higher total surface energy of DLC. DLC templates with 40 nm features were fabricated using e-beam lithography followed by Cr lift-off and reactive ion etching. UV nanoimprinting using the directly patterned DLC templates in SU-8 resist demonstrates good pattern transfer fidelity and easy template-resist separation. These results indicate that DLC is a promising material for fabricating durable templates for UV nanoimprint lithography

  7. Durability of polymer/metal interfaces under cyclic loading

    Science.gov (United States)

    Du, Tianbao

    Fatigue crack growth along metal/epoxy interface was examined in an aqueous environment and under mixed-mode conditions. A stress corrosion cracking mechanism was identified in this process. The fatigue crack growth rate in an aqueous environment was increased by several orders of magnitude and the fatigue threshold decreased by a factor of 10. The loss of adhesion in the aqueous environment was induced by the hydration of the surface oxide which resulted in a hydroxide with poor adhesion to the substrate metal. Self-assembled monolayer of long chain alkyl phosphonic acid and amino phosphonic acid were synthesized to enhance the adhesion and improve the durability of Al/epoxy interfacial bonding system. The same approach was taken to promote adhesion between copper and epoxy, where a two-component coupling system of 11-mercapto-1-undercanol and 3-aminopropyltriethoxysilane provided the most significant improvement in the copper/epoxy adhesion. The mixed-mode was applied by a piezoelectric actuator. Subcritical crack growth was observed along the epoxy/aluminum interface and the growth rate was found to depend on the magnitude of the applied electric field. Kinetics of the crack growth was correlated with the piezoelectric driving force. The resulting crack growth behavior was compared with the results from the conventional mechanical testing technique. Large differences were found between these two methods. Using this newly developed technique, effects of loading mode and frequency were studied. The fatigue resistance was found to increase with the mode II component and was expressed as a function of the KII/K I ratio. A strong frequency effect was observed for the subcritical crack growth along the Al/Epoxy interface, their fatigue resistance increased with the testing frequency.

  8. Assessment of the Durability of Cementitious Materials in Repository Environment

    International Nuclear Information System (INIS)

    Vicente, R.; Marumo, J.T.; Miyamoto, H.; Isiki, V.L.K.; Ferreira, E.G.

    2013-01-01

    The Radioactive Waste Management Laboratory of the Energy and Nuclear Research Institute is developing the concept of a borehole repository for disused sealed radioactive sources drilled in a deep granite batholite. In this concept, the annular space between the well steel casing and the geological formation is backfilled with cement paste. The hardened cement paste functions as an additional barrier against the escape of radionuclides from the repository and their migration to the environment. It also functions as an obstacle to the flow of groundwater between different layers of the geological setting crossed by the borehole. The long term behavior of hydrated cement compounds is yet incompletely known and therefore more research is needed to increase the confidence on the performance of the material under the repository conditions as required. For the repository to achieve the required performance, the cement paste must be durable. However, in a deep repository, the cementitious materials is exposed to the deleterious action of high temperatures and pressures, the radiation field created by the radioactive sources and aggressive ion species that may be present in groundwater. Furthermore, it is necessary to consider that the cement paste is unstable in the long term because its microstructure and mineralogy change with time as the cement gel components recrystallize and react chemically with materials of the repository environment. In principle, the lifetime of this material could be determined based on the study of its long-term behavior, which, in turn, could be estimated from the extrapolation of short-term results, by accelerating, under controlled laboratory conditions, the composition changes and the loss of mechanical strength and cohesion induced by any detrimental component of the repository environment. Loss of mechanical strength, dimensional variations, changes in chemical-mineralogical composition, and leaching of hydrate compounds are all possible

  9. Enhanced performance and durability of low catalyst loading PEM water electrolyser based on a short-side chain perfluorosulfonic ionomer

    International Nuclear Information System (INIS)

    Siracusano, Stefania; Baglio, Vincenzo; Van Dijk, Nicholas; Merlo, Luca; Aricò, Antonino Salvatore

    2017-01-01

    Graphical abstract: Tripling current density (>3 A·cm"−"2) with respect to the state of the art of commercial PEM electrolyser can be achieved also in the presence of a significant reduction, about 4-fold, of the total noble metal loading (0.5 mg·cm"−"2) while achieving high efficiency (>80%) and proper durability. - Highlights: • Current density >3 A·cm"−"2 is achieved in electrolysis cells with efficiency >80%. • A 4-fold reduction of noble metal loading is demonstrated in electrolysis cells. • Degradation rate <5 μV/h is achieved in a 1000 h durability test at 1 A·cm"−"2. • Degradation associated to a change in Lewis acidity characteristics is observed. - Abstract: Water electrolysis supplied by renewable energy is the foremost technology for producing “green” hydrogen for fuel cell vehicles. In addition, the ability to rapidly follow an intermittent load makes electrolysis an ideal solution for grid-balancing caused by differences in supply and demand for energy generation and consumption. Membrane-electrode assemblies (MEAs) designed for polymer electrolyte membrane (PEM) water electrolysis, based on a novel short-side chain (SSC) perfluorosulfonic acid (PFSA) membrane, Aquivion®, with various cathode and anode noble metal loadings, were investigated in terms of both performance and durability. Utilizing a nanosized Ir_0_._7Ru_0_._3O_x solid solution anode catalyst and a supported Pt/C cathode catalyst, in combination with the Aquivion® membrane, gave excellent electrolysis performances exceeding 3.2 A·cm"−"2 at 1.8 V terminal cell voltage (∼80% efficiency) at 90 °C in the presence of a total catalyst loading of 1.6 mg⋅cm"−"2. A very small loss of efficiency, corresponding to 30 mV voltage increase, was recorded at 3 A⋅cm"−"2 using a total noble metal catalyst loading of less than 0.5 mg·cm"−"2 (compared to the industry standard of 2 mg·cm"−"2). Steady-state durability tests, carried out for 1000 h at 1 A

  10. Energy policy and challenges: which part for the nuclear energy; Politique et defis energetiques: quel role pour l'energie nucleaire?

    Energy Technology Data Exchange (ETDEWEB)

    Bouchard, J

    2004-07-01

    This document provides many data and charts on the energy domain: energy consumption, energy demand, the reserves, the climatic changes, the renewable energies, the energy cost, the radioactive wastes management, the new nuclear technology. (A.L.B.)

  11. Biological durability of wood in relation to end-use - Part 1. Towards a European standard for laboratory testing of the biological durability of wood

    NARCIS (Netherlands)

    Acker, Van J.; Stevens, M.; Carey, J.; Sierra-Alvarez, R.; Militz, H.; Bayon, Le I.; Kleist, G.; Peek, R.D.

    2003-01-01

    The determination of biological durability of wood is an issue requiring sufficient reliability regarding end-use related prediction of performance. Five test institutes joined efforts to check standard test methods and to improve methodology and data interpretation for assessment of natural

  12. Structural Technology and Analysis Program (STAP) Delivery Order 0004: Durability Patch

    National Research Council Canada - National Science Library

    Ikegami, Roy

    2001-01-01

    .... This type of damage can result in costly inspections and repair. The repairs often do not last long because the repaired structure continues to respond in a resonant fashion to the environment...

  13. Towards high-energy and durable lithium-ion batteries via atomic layer deposition: elegantly atomic-scale material design and surface modification

    International Nuclear Information System (INIS)

    Meng, Xiangbo

    2015-01-01

    Targeted at fueling future transportation and sustaining smart grids, lithium-ion batteries (LIBs) are undergoing intensive investigation for improved durability and energy density. Atomic layer deposition (ALD), enabling uniform and conformal nanofilms, has recently made possible many new advances for superior LIBs. The progress was summarized by Liu and Sun in their latest review [1], offering many insightful views, covering the design of nanostructured battery components (i.e., electrodes and solid electrolytes), and nanoscale modification of electrode/electrolyte interfaces. This work well informs peers of interesting research conducted and it will also further help boost the applications of ALD in next-generation LIBs and other advanced battery technologies. (viewpoint)

  14. Income and Wealth Distribution in a Neoclassical Two-Sector Heterogeneous-Households Growth Model with Elastic Labor Supply and Consumer Durable Goods

    Directory of Open Access Journals (Sweden)

    Wei-Bin ZHANG

    2017-06-01

    Full Text Available This paper proposes a two-sector two-group growth model with elastic labor supply and consumer durable goods. We study dynamics of wealth and income distribution in a competitive economy with capital accumulation as the main engine of economic growth. The model is built on the Uzawa two-sector model. It is also influenced by the neoclassical growth theory and the post-Keynesian theory of growth and distribution. We plot the motion of the economic system and determine the economic equilibrium. We carry out comparative dynamic analysis with regard to the propensity to save and improvements in human capital and technology.

  15. Durability studies on the high calcium flyash based GPC ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 9, No 4 (2017) >. Log in or Register to get access to full text downloads.

  16. Durable PROX catalyst based on gold nanoparticles and hydrophobic silica

    KAUST Repository

    Laveille, Paco; Guillois, Kevin; Tuel, Alain; Petit, Corine; Basset, Jean-Marie; Caps, Valerie

    2016-01-01

    3 nm gold nanoparticles (Au NP) obtained by direct chemical reduction of AuPPh3Cl in the presence of methyl-terminated silica exhibit superior durability for low temperature CO oxidation in the presence of hydrogen (PROX). The activity of hydrophobic Au/SiO2-R972 indeed appears much more stable with time-on-stream than those of the OH-terminated, hydrophilic Au/TiO2 and Au/Al2O3 catalysts, with similar Au NP size. This enhanced stability is attributed to the peculiar catalyst surface of Au/SiO2-R972. Not only may the support hydrophobicity concentrate and facilitate reactant adsorption and product desorption over Au NP, but methyl-terminated SiO2-R972 likely also inhibits carbonatation of the Au/support interface. Hence, at a temperature at which H2/H2O “cleaning” of the carbonate-contaminated Au/Al2O3 and Au/TiO2 surface is inefficient (< 100°C), passivated Au/SiO2-R972 displays much more stable PROX activity. Besides, the virtual absence of surface hydroxyl groups, which provide sites for water formation in H2/O2 atmospheres, can also account for the improved PROX selectivity (>85%) observed over Au/SiO2-R972. This new example, of CO oxidation activity of gold nanoparticles dispersed over a hydrophobic, “inert” support, clearly emphasizes the role of hydrogen as a promoter for the gold-catalyzed oxidation of CO at low temperature. Unlike support-mediated oxygen activation, hydrogen-only mediated oxygen activation takes full advantage of the hydrophobic surface, which is much more resistant against CO2 and thus remains free of poisonous carbonate species, as compared with hydroxyl-terminated catalysts. Hence, although the absence of surface hydroxyl groups prevents the hydrophobic Au/SiO2-R972 catalyst to reach the state-of-the-art activities initially displayed by Au/TiO2 and Au/Al2O3, it brings long-term stability with time-on-stream and superior selectivity, which opens up promising perspectives in the development of viable PROX catalysts based on gold.

  17. Durable PROX catalyst based on gold nanoparticles and hydrophobic silica

    KAUST Repository

    Laveille, Paco

    2016-01-20

    3 nm gold nanoparticles (Au NP) obtained by direct chemical reduction of AuPPh3Cl in the presence of methyl-terminated silica exhibit superior durability for low temperature CO oxidation in the presence of hydrogen (PROX). The activity of hydrophobic Au/SiO2-R972 indeed appears much more stable with time-on-stream than those of the OH-terminated, hydrophilic Au/TiO2 and Au/Al2O3 catalysts, with similar Au NP size. This enhanced stability is attributed to the peculiar catalyst surface of Au/SiO2-R972. Not only may the support hydrophobicity concentrate and facilitate reactant adsorption and product desorption over Au NP, but methyl-terminated SiO2-R972 likely also inhibits carbonatation of the Au/support interface. Hence, at a temperature at which H2/H2O “cleaning” of the carbonate-contaminated Au/Al2O3 and Au/TiO2 surface is inefficient (< 100°C), passivated Au/SiO2-R972 displays much more stable PROX activity. Besides, the virtual absence of surface hydroxyl groups, which provide sites for water formation in H2/O2 atmospheres, can also account for the improved PROX selectivity (>85%) observed over Au/SiO2-R972. This new example, of CO oxidation activity of gold nanoparticles dispersed over a hydrophobic, “inert” support, clearly emphasizes the role of hydrogen as a promoter for the gold-catalyzed oxidation of CO at low temperature. Unlike support-mediated oxygen activation, hydrogen-only mediated oxygen activation takes full advantage of the hydrophobic surface, which is much more resistant against CO2 and thus remains free of poisonous carbonate species, as compared with hydroxyl-terminated catalysts. Hence, although the absence of surface hydroxyl groups prevents the hydrophobic Au/SiO2-R972 catalyst to reach the state-of-the-art activities initially displayed by Au/TiO2 and Au/Al2O3, it brings long-term stability with time-on-stream and superior selectivity, which opens up promising perspectives in the development of viable PROX catalysts based on gold.

  18. Properties and durability of metakaolin blended cements: mortar and concrete

    Directory of Open Access Journals (Sweden)

    Abbas, Rafik

    2010-12-01

    Full Text Available This article explores the effect of metakaolin, a pozzolan, on concrete performance. Compressive and splitting tensile strength were found for specimens cured for up to 360 and 90 days, respectively. Changes were recorded in the compressive strength of specimens exposed to salt (chloride and sulfatechloride solutions, and chloride penetration and binding capacity were measured. The findings were compared to the results for concrete prepared with ordinary Portland (OPC and moderate heat of hydration (Type II cement. MK was found to have a very positive effect on 28-day concrete strength, due to microstructure improvement of the hydrated cement. Replacing cement with metakaolin effectively raised concrete resistance to chloride attack. Concrete containing metakaolin proved to be substantially more durable in sulfate-chloride environment.

    En este trabajo se estudia el efecto del metacaolín sobre las prestaciones del hormigón. Las probetas curadas a 360 y 90 días se sometieron a ensayos de resistencia a compresión y de tracción indirecta respectivamente. Se hizo un seguimiento de la resistencia a la compresión de los materiales ante el ataque de sales (soluciones de cloruro y de sulfato-cloruro y, se midió la penetración de cloruros y la capacidad de los hormigones de inmovilizar estos iones. Los resultados se compararon con los obtenidos con hormigones elaborados con cemento pórtland ordinario (OPC y, con cemento de calor de hidratación moderado (tipo II. El MK resultó influir muy positivamente en la resistencia del hormigón a 28 días debido a la mejora de la microestructura del cemento hidratado. La sustitución de cemento por metacaolín aumentó la resistencia del hormigón al ataque de cloruros. El hormigón con metacaolín demostró ser más duradero en entornos de sulfato-cloruro que los hormigones elaborados con OPC o con cemento de tipo II. Los perfiles de concentración de cloruros a distintas profundidades y la

  19. Performance Evaluation and Durability Studies of Adhesive Bonds

    Science.gov (United States)

    Ranade, Shantanu Rajendra

    In this thesis, four test approaches were developed to characterize the adhesion performance and durability of adhesive bonds for specific applications in areas spanning from structural adhesive joints to popular confectionaries such as chewing gum. In the first chapter, a double cantilever beam (DCB) specimen geometry is proposed for combinatorial fracture studies of structural adhesive bonds. This specimen geometry enabled the characterization of fracture energy vs. bondline thickness trends through fewer tests than those required during a conventional "one at a time" characterization approach, potentially offering a significant reduction in characterization times. The second chapter investigates the adhesive fracture resistance and crack path selection in adhesive joints containing patterns of discreet localized weak interfaces created using physical vapor deposition of copper. In a DCB specimen tested under mode-I conditions, fracture energy within the patterned regions scaled according to a simple rule of mixture, while reverse R-curve and R-curve type trends were observed in the regions surrounding weak interface patterns. Under mixed mode conditions such that bonding surface with patterns is subjected to axial tension, fracture energy did not show R-curve type trends while it was observed that a crack could be made to avoid exceptionally weak interfaces when loaded such that bonding surface with defects is subjected to axial compression. In the third chapter, an adaptation of the probe tack test is proposed to characterize the adhesion behavior of gum cuds. This test method allowed the introduction of substrates with well-defined surface energies and topologies to study their effects on gum cud adhesion. This approach and reported insights could potentially be useful in developing chewing gum formulations that facilitate easy removal of improperly discarded gum cuds from adhering surfaces. In the fourth chapter we highlight a procedure to obtain insights

  20. Engineered Nanostructured MEA Technology for Low Temperature Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yimin

    2009-07-16

    The objective of this project is to develop a novel catalyst support technology based on unique engineered nanostructures for low temperature fuel cells which: (1) Achieves high catalyst activity and performance; (2) Improves catalyst durability over current technologies; and (3) Reduces catalyst cost. This project is directed at the development of durable catalysts supported by novel support that improves the catalyst utilization and hence reduce the catalyst loading. This project will develop a solid fundamental knowledge base necessary for the synthetic effort while at the same time demonstrating the catalyst advantages in Direct Methanol Fuel Cells (DMFCs).

  1. Eco-imposition du capital, emploi et développement industriel durable

    Directory of Open Access Journals (Sweden)

    Bernard Dupont

    2010-09-01

    Full Text Available En remplaçant la part des cotisations sociales à la charge de l’employeur par un éco-impôt sur le capital polluant, l’Etat peut inciter les entreprises à investir dans les trajectoires technologiques de la durabilité. Cet article expose un modèle macroéconomique à trois facteurs qui montre comment la fixation conjointe et combinée du taux de cotisations sociales et du taux d'éco-impôt peut assurer la stabilité globale des prix, garantir la neutralité budgétaire et conserver en l’état la compétitivité prix. Contrôlée par le ministère du développement durable, la déformation de la fonction de production provoquée par une fiscalité directe favorable au capital non polluant et au travail augmente le volume de l’emploi et améliore la qualité environnementale sans détériorer la compétitivité ni déséquilibrer les comptes sociaux.Replacing the welfare cost by an eco-taxation based on polluting capital can incite companies to invest in the technological trajectories for sustainability. This paper proposes a macroeconomic three factors model in which the jointed and combined determination of welfare cost and eco-taxation rates can maintain the global price stability, guarantees the budget balance of fiscal transfers and keeps the state of the competitiveness price as it was before. Controlled by the ministry of sustainable development, the deformation of the function of production, caused by a direct tax system favorable to the non-polluting capital and to the labour, increases the employment and improves the environmental quality without negative effects on competitiveness and social accounts.

  2. Stent Coating Integrity of Durable and Biodegradable Coated Drug Eluting Stents.

    Science.gov (United States)

    Yazdani, Saami K; Sheehy, Alexander; Pacetti, Stephen; Rittlemeyer, Brandon; Kolodgie, Frank D; Virmani, Renu

    2016-10-01

    Coatings consisting of a polymer and drug are widely used in drug-eluting stents (DES) and are essential in providing programmable drug release kinetics. Among other factors, stent coating technologies can influence blood compatibility, affect acute and sub-acute healing, and potentially trigger a chronic inflammatory response. The aim of this study was to investigate the short-term (7 and 28 days) and long-term (90 and 180 days) coating integrity of the Xience Prime Everolimus-Eluting Stent (EES), Resolute Zotarolimus-Eluting Stent (ZES), Taxus Paclitaxel-Eluting Stent (PES), and Nobori Biolimus A9-Eluting Stent (BES) in a rabbit ilio-femoral stent model. Stented arteries (n = 48) were harvested and the tissue surrounding the implanted stents digested away with an enzymatic solution. Results demonstrated that the majority of struts of EES were without any coating defects with a few struts showing minor defects. Similarly, for the ZES, most of the struts were without coating defects at all time points except at 180 days. The majority of PES demonstrated mostly webbing and uneven coating. In the BES group, the majority of strut coating showed polymer cracking. Overall, the EES and ZES had fewer coating defects than the PES and BES. Coating defects, however increase over time for the ZES, whereas the percent of coating irregularities remained constant for the EES. These results provide, for the first time, a comparison of the long-term durability of these drug-eluting stent coatings in vivo. © 2016, Wiley Periodicals, Inc.

  3. A durable, non power consumptive, simple seal for rotary blood pumps.

    Science.gov (United States)

    Mitamura, Y; Sekine, K; Asakawa, M; Yozu, R; Kawada, S; Okamoto, E

    2001-01-01

    One of the key technologic requirements for rotary blood pumps is the sealing of the motor shaft. A mechanical seal, a journal bearing, magnetic coupling, and magnetic suspension have been developed, but they have drawbacks such as wear, thrombus formation, and power consumption. A magnetic fluid seal was developed for an axial flow pump. A magnetic fluid seal is durable, simple, and non power consumptive. Long-term experiments and finite element modeling (FEM) analyses confirmed these advantages. The seal body was composed of a Ned-Fe magnet and two pole pieces; the seal was formed by injecting ferrofluid into the gap (50 microm) between the pole pieces and the motor shaft. To contain the ferrofluid in the seal and to minimize the possibility of ferrofluid making contact with blood, a shield with a small cavity was attached to the pole piece. While submerged in blood, the sealing pressure of the seal was measured and found to be 188 mm Hg with ferrofluid LS-40 (saturated magnetization, 24.3 kA/m) at a motor speed of 10,000 rpm and 225 mm Hg under static conditions. The magnetic fluid seals performed perfectly at a pressure of 100 mm Hg for 594 + days in a static condition, and 51, 39+, and 34+ days at a motor speed of 8,000 rpm. FEM analyses indicated a theoretical sealing pressure of 260 mm Hg. The state of the magnetic fluid in the seal in water was observed with a microscope. Neither splashing of magnetic fluid nor mixing of the magnetic fluid and water was observed. The specially designed magnetic fluid seal for keeping liquids out is useful for axial flow blood pumps. The magnetic fluid seal was incorporated into an intracardiac axial flow pump.

  4. Study of belite calcium sulfo-aluminate cement potential for zinc conditioning: From hydration to durability

    International Nuclear Information System (INIS)

    Berger, St.

    2009-12-01

    Calcium silicate cements are widely used for low- and intermediate-level radioactive waste conditioning. However, wastes produced by nuclear activities are very diverse and some of their components may chemically react with cement phases. For instance, ashes resulting from the incineration of technological wastes including neoprene and polyvinylchloride may contain substantial amounts of soluble zinc chloride. This compound is known to strongly delay or inhibit Portland cement setting. One approach to limit adverse cement-waste interactions is to select a binder showing a better compatibility with the waste while keeping cement matrix advantages (low cost, simple process, hydration with water provided by the waste...). This work thus investigates the potential of calcium sulfo-aluminate cement for zinc Zn(II) immobilization. Four aspects were considered: hydration (kinetics and products formed), properties of hydrated binders, mechanisms of zinc retention and durability of the cement pastes (based on leaching experiments and modelling). The influence of three main parameters was assessed: the gypsum content of the cement, the concentration of ZnCl 2 and the thermal evolution at early age. It follows that materials based on a calcium sulfo-aluminate cement containing 20% gypsum are interesting candidates for zinc Zn(II) stabilization/solidification: there is no delay in hydration, mineralogy of the hydrated phases is slightly dependent on thermal history, mechanical strength is high, dimensional changes are limited and zinc Zn(II) is well immobilized, even if the cement paste is leached by pure water during a long period (90 d). (author)

  5. Quantitative Resistance to Plant Pathogens in Pyramiding Strategies for Durable Crop Protection

    Directory of Open Access Journals (Sweden)

    Marie-Laure Pilet-Nayel

    2017-10-01

    Full Text Available Quantitative resistance has gained interest in plant breeding for pathogen control in low-input cropping systems. Although quantitative resistance frequently has only a partial effect and is difficult to select, it is considered more durable than major resistance (R genes. With the exponential development of molecular markers over the past 20 years, resistance QTL have been more accurately detected and better integrated into breeding strategies for resistant varieties with increased potential for durability. This review summarizes current knowledge on the genetic inheritance, molecular basis, and durability of quantitative resistance. Based on this knowledge, we discuss how strategies that combine major R genes and QTL in crops can maintain the effectiveness of plant resistance to pathogens. Combining resistance QTL with complementary modes of action appears to be an interesting strategy for breeding effective and potentially durable resistance. Combining quantitative resistance with major R genes has proven to be a valuable approach for extending the effectiveness of major genes. In the plant genomics era, improved tools and methods are becoming available to better integrate quantitative resistance into breeding strategies. Nevertheless, optimal combinations of resistance loci will still have to be identified to preserve resistance effectiveness over time for durable crop protection.

  6. Beta cloth durability assessment for Space Station Freedom (SSF) Multi-Layer Insulation (MLI) blanket covers

    International Nuclear Information System (INIS)

    Koontz, S.L.; Jacobs, S.; Le, J.

    1993-03-01

    MLI blankets for the Space Station Freedom (SSF) must comply with general program requirements and recommendations for long life and durability in the low-Earth orbit (LEO) environment. Atomic oxygen and solar ultraviolet/vacuum ultraviolet are the most important factors in the SSF natural environment which affect materials life. Two types of Beta cloth (Teflon coated woven glass fabric), which had been proposed as MLI blanket covers, were tested for long-term durability in the LEO environment. General resistance to atomic oxygen attack and permeation were evaluated in the high velocity atomic oxygen beam system at Los Alamos National Laboratories. Long-term exposure to the LEO environment was simulated in the laboratory using a radio frequency oxygen plasma asher. The plasma asher treated Beta cloth specimens were tested for thermo-optical properties and mechanical durability. Space exposure data from the Long Duration Exposure Facility and the Intelsat Solar Array Coupon were also used in the durability assessment. Beta cloth fabricated to Rockwell specification MBO 135-027 (Chemglas 250) was shown to have acceptable durability for general use as an MLI blanket cover material in the LEO environment while Sheldahl G414500 should be used only in locations which are protected from direct Ram atomic oxygen

  7. Bio-inspired polymeric patterns with enhanced wear durability for microsystem applications

    International Nuclear Information System (INIS)

    Singh, R. Arvind; Siyuan, L.; Satyanarayana, N.; Kustandi, T.S.; Sinha, Sujeet K.

    2011-01-01

    At micro/nano-scale, friction force dominates at the interface between bodies moving in relative motion and severely affects their smooth operation. This effect limits the performance of microsystem devices such as micro-electro-mechanical systems (MEMS). In addition, friction force also leads to material removal or wear and thereby reduces the durability i.e. the useful operating life of the devices. In this work, we fabricated bio-inspired polymeric patterns for tribological applications. Inspired by the surface features on lotus leaves namely, the protuberances and wax, SU-8 polymeric films spin-coated on silicon wafers were topographically and chemically modified. For topographical modification, micro-scale patterns were fabricated using nanoimprint lithography and for chemical modification, the micro-patterns were coated with perfluoropolyether nanolubricant. Tribological investigation of the bio-inspired patterns revealed that the friction coefficients reduced significantly and the wear durability increased by several orders. In order to enhance the wear durability much further, the micro-patterns were exposed to argon/oxygen plasma and were subsequently coated with the perfluoropolyether nanolubricant. Bio-inspired patterns with enhanced wear durability, such as the ones investigated in the current work, have potential tribological applications in MEMS/Bio-MEMS actuator-based devices. Highlights: →Bio-inspired polymeric patterns for tribological applications in microsystems. →Novel surface modification for the patterns to enhance tribological properties. →Patterns show low friction properties and extremely high wear durability.

  8. Durability of low-pH injection grout. A literature survey

    International Nuclear Information System (INIS)

    Holt, E.

    2008-01-01

    This publication provides an overview of the durability of injection grouts. It is intended for use during planning and construction at the ONKALO underground research facility. The review has been done with respect to the application conditions, materials and service life requirements expressed by Posiva Oy. The publication describes all types of cement-based material durability, with an emphasis on the key issues of shrinkage cracking, leaching and sulphate attack. The second part of the report provides information on how durability expectations have changed with the history of injection grout development. The report gives information specific to low-pH injection grouts containing high amounts of silica fume performance and how their durability is expected to differ from traditional normal cement-based mixtures. The final part of the report provides suggestions for future research needs for ensuring the service life of injection grouts. The key finding from this study is that the low-pH grout material is not expected to have worse durability performance compared to the standard injection grout. Combining high amounts of silica fume with the cement to produce low-pH grout should result in a material having lower permeability and thus greater resistance to leaching and chemical attack. Further laboratory testing is needed to quantitatively verify these findings and to provide inputs for future service life modeling. (orig.)

  9. Durability of glasses from the Hg-doped Integrated DWPF Melter System (IDMS) campaign

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1992-01-01

    The Integrated DWPF Melter System (IDMS) for the vitrification of high-level radioactive wastes is designed and constructed to be a 1/9th scale prototype of the full scale Defense Waste Processing Facility (DWPF) melter. The IDMS facility is the first engineering scale melter system capable of processing mercury, and flowsheet levels of halides and noble metals. In order to determine the effects of mercury on the feed preparation process, the off-gas chemistry, glass melting behavior, and glass durability, a three-run mercury (Hg) campaign was conducted. The glasses produced during the Hg campaign were composed of Batch 1 sludge, simulated precipitate hydrolysis aqueous product (PHA) from the Precipitate Hydrolysis Experimental Facility (PHEF), and Frit 202. The glasses were produced using the DWPF process/product models for glass durability, viscosity, and liquidus. The durability model indicated that the glasses would all be more durable than the glass qualified in the DWPF Environmental Assessment (EA). The glass quality was verified by performing the Product Consistency Test (PCT) which was designed for glass durability testing in the DWPF

  10. Durable superhydrophobic paper enabled by surface sizing of starch-based composite films

    Science.gov (United States)

    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.

  11. Investigation of the Durability of a Diaphragm for a Total Artificial Heart.

    Science.gov (United States)

    Gräf, Felix; Rossbroich, Ralf; Finocchiaro, Thomas; Steinseifer, Ulrich

    2016-10-01

    One of the most critical components regarding the durability of the ReinHeart total artificial heart (TAH) is its biocompatible diaphragm, which separates the drive unit from the ventricles. Hence, a durability tester was designed to investigate its required 5-year lifetime. The aim of this study was to prove the validity of accelerated testing of the polyurethane diaphragm. The durability tester allows simultaneous testing of 12 diaphragms and mimics physiological conditions. To accelerate the time of testing, it operates with an increased speed at a frequency of 8 Hz. To prove the correctness of this acceleration, a servo-hydraulic testing machine was used to study the effect of different frequencies and their corresponding loads. Thereby the viscoelastic behavior of the polyurethane was investigated. Additionally, high-speed video measurements were performed. The force against frequency and the high-speed video measurements showed constant behavior. In the range of 1-10 Hz, the maximum resulting forces varied by 3%, and the diaphragm movement was identical. Frequencies below 10 Hz allow a valid statement of the diaphragm's mechanical durability. Viscoelasticity of the polyurethane in the considered frequency-range is negligible. The accelerated durability test is applicable to polyurethane diaphragms, and the results are applicable to TAH use. The reliability of the diaphragm for a lifetime of 5 years was found to be 80% with a confidence of 62%. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  12. L’INFLUENCE DE L’ELECTROSTIMULATION SUR LES TRANSFORMATIONS POST-MORTEM DES RESERVES ENERGETIQUES DU MUSCLE DE BŒUF

    Directory of Open Access Journals (Sweden)

    Felicia Dima

    2010-10-01

    Full Text Available The experimental results show that electrical stimulation has a positive effect on the biochemical changes and technological properties of beef meat. Given the beneficial changes reported in the literature, we used a portable device for electrical stimulation of the beef carcasses that can be used in small size slaughterhouses.

  13. Fabrication of durable fluorine-free superhydrophobic polyethersulfone (PES) composite coating enhanced by assembled MMT-SiO2 nanoparticles

    Science.gov (United States)

    Zhang, Xiguang; Wang, Huaiyuan; Liu, Zhanjian; Zhu, Yixing; Wu, Shiqi; Wang, Chijia; Zhu, Yanji

    2017-02-01

    A durable fluorine-free polyethersulfone (PES) superhydrophobic composite coating with excellent wear-resistant and anti-corrosion properties has been successfully fabricated by combining sol-gel and spray technology. The robust micro/nano-structures of the prepared surface were established by introducing binary montmorillonite-silica (MMT-SiO2) assembled composite particles, which were formed by in-situ growth of SiO2 on MMT surfaces via sol-gel. Combined with the low surface energy of amino silicon oil (APDMS), the fluorine-free superhydrophoic PES coating was obtained with high water contact angle 156.1 ± 1.1° and low sliding angle 4.8 ± 0.7°. The anti-wear of the final PES/APDMS/MMT-SiO2 superhydrophobic coating can reach up to 60,100 cycles, which is outdistancing the pure PES coating (6800 cycles) and the PES/MMT/SiO2 coating prepared by simple physical mixture (18,200 cycles). The enhanced wear resistance property can be mainly attributed to the lubrication performance of APDMS and stable interface bonding force between the MMT surface and SiO2. Simultaneously, potentiodynamic polarization curves and electrochemical impedance spectroscopy exhibited the outstanding anti-corrosion property of PES/APDMS/MMT-SiO2 composite coating, with low corrosion current (1.6 × 10-10 A/cm2) and high protection efficiency (99.999%) even after 30 d immersion process. These test results show that this durable superhydrophobic PES composite coating can be hopefully to provide the possibility of industrial application.

  14. Production and remediation of low sludge simulated Purex waste glasses, 2: Effects of sludge oxide additions on glass durability

    International Nuclear Information System (INIS)

    Ramsey, W.G.

    1993-01-01

    Glass produced during the Purex 4 campaigns of the Integrated DWPF Melter System (IDMS) and the 774 Research Melter contained a lower fraction of sludge components than targeted by the Product Composition Control System (PCCS). Purex 4 glass was more durable than the benchmark (EA) glass, but was less durable than most other simulated SRS high-level waste glasses. Further, the measured durability of Purex 4 glass was not as well correlated with the durability predicted from the DWPF process control algorithm, probably because the algorithm was developed to predict the durability of SRS high-level waste glasses with higher sludge content than Purex 4. A melter run, designated Purex 4 Remediation, was performed using the 774 Research Melter to determine if the initial PCCS target composition determined for Purex 4 would produce acceptable glass whose durability could be accurately modeled by the DWPF glass durability algorithm. Reagent grade oxides and carbonates were added to Purex 4 melter feed stock to simulate a higher sludge loading. Each canister of glass produced was sampled and the glass durability was determined by the Product Consistency Test method. This document details the durability data and subsequent analysis

  15. Chemical durability of soda-lime-aluminosilicate glass for radioactive waste vitrification

    International Nuclear Information System (INIS)

    Eppler, F.H.; Yim, M.S.

    1998-01-01

    Vitrification has been identified as one of the most viable waste treatment alternatives for nuclear waste disposal. Currently, the most popular glass compositions being selected for vitrification are the borosilicate family of glasses. Another popular type that has been around in glass industry is the soda-lime-silicate variety, which has often been characterized as the least durable and a poor candidate for radioactive waste vitrification. By replacing the boron constituent with a cheaper substitute, such as silica, the cost of vitrification processing can be reduced. At the same time, addition of network intermediates such as Al 2 O 3 to the glass composition increases the environmental durability of the glass. The objective of this study is to examine the ability of the soda-lime-aluminosilicate glass as an alternative vitrification tool for the disposal of radioactive waste and to investigate the sensitivity of product chemical durability to variations in composition

  16. Durability Properties of Self Compacting Concrete containing Fly ash, Lime powder and Metakaolin

    Directory of Open Access Journals (Sweden)

    Rizwan Ahmad Khan

    2016-01-01

    Full Text Available This paper investigates the durability properties of Self-compacting concrete (SCC, with different amounts of fly ash (FA, lime powder (LP and metakaolin (MK. A total of 6 mixes were prepared that have a constant water-binder ratio (w/b of 0.41 and superplasticizer dosage of 1% by weight of cement. In addition to compressive strength, the durability properties of SCC mixes were determined by means of Initial surface absorption test (ISAT and Capillary suction test. The test results indicated that the durability properties of the mixes appeared to be very dependent on the type and amount of the mineral admixture used; the mixes containing MK were found to have considerably higher permeability resistance. Good co-relation between strength and absorption were achieved.

  17. Recent results on the effect of gamma radiation on the durability and microstructure of DWPF glass

    International Nuclear Information System (INIS)

    Bibler, N.E.; Tosten, M.H.; Beam, D.C.

    1989-01-01

    The effect of gamma radiation on the durability and microstructure of a simulated nuclear waste glass from the Savannah River Site has been carefully investigated. Three large pieces of glass were irradiated with a Co-60 source to three doses up to a maximum dose of 3.1 x 10 10 rad. Internal samples of the large pieces of irradiated and unirradiated glass were leached in deionized water to investigate durability changes and were examined by transmission electron microscopy (TEM) to investigate microstructure changes. Leach tests were performed in triplicate at 90 degree C with crushed glass samples in deionized water. A statistical analysis of the results indicated to the 95% confidence level that the radiation did not affect the glass durability. Careful examination by TEM indicated no effect of gamma radiation on the microstructure of the glass although severe damage could be induced by the electron beam from the microscope. 19 refs., 2 figs., 3 tabs

  18. Mixed hydrocarbon/fluoropolymer membrane/ionomer MEAs for durability studies

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo [Los Alamos National Laboratory; Kim, Yu Seung [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Wilson, Mahlon S [Los Alamos National Laboratory; Welch, Cynthia [Los Alamos National Laboratory; Fenton, James [FLORIDA SOLAR ENERGY CENTER

    2010-01-01

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the fuel cell components to increase the system reliability. The aim of this work is to separate ionomer degradation from membrane degradation via mixed membrane/ionomer MEA experiments. The challenges of mixed MEA fabrication due to the incompatibility of the membrane and the electrode are addressed. OCV accelerated testing experiment (AST) were performed. Development of in situ diagnostics and unique experiments to characterize the performance and properties of the ionomer in the electrode as a function of time is reported. These measurements, along with extensive ex situ and post-mortem characterization, can delineate the degradation mechanisms in order to develop more durable fuel cells and fuel cell components.

  19. Highly Durable Platinum Single-Atom Alloy Catalyst for Electrochemical Reactions

    DEFF Research Database (Denmark)

    Kim, Jiwhan; Roh, Chi-Woo; Sahoo, Suman Kalyan

    2018-01-01

    Single atomic Pt catalyst can offer efficient utilization of the expensive platinum and provide unique selectivity because it lacks ensemble sites. However, designing such a catalyst with high Pt loading and good durability is very challenging. Here, single atomic Pt catalyst supported on antimony...... functional theory calculations show that replacing Sb sites with Pt atoms in the bulk phase or at the surface of SbSn or ATO is energetically favorable. The Pt1/ATO shows superior activity and durability for formic acid oxidation reaction, compared to a commercial Pt/C catalyst. The single atomic Pt...... structure is retained even after a harsh durability test, which is performed by repeating cyclic voltammetry in the range of 0.05–1.4 V for 1800 cycles. A full cell is fabricated for direct formic acid fuel cell using the Pt1/ATO as an anode catalyst, and an order of magnitude higher cell power is obtained...

  20. Study on the durability of concrete using granulated blast furnace slag as fine aggregate

    Science.gov (United States)

    Shi, Dongsheng; Liu, Qiang; Xue, Xinxin; He, Peiyuan

    2018-03-01

    In order to assessing the durability of concrete using granulated blastfurnace slag (GBS) as fine aggregate and compare it with natural river sand concrete, three different size of specimen were produced by using the same mix proportion with 3 different water cement ratios and 3 replacement ratios, and using it to measure the three aspects on the durability of concrete including freeze-thaw performance, dry-shrinkage performance and anti-chloride-permeability performance. In this paper. The test results show that using GBS as fine aggregate can slightly improve anti-chloride-permeability performance and dry-shrinkage performance of concrete in the condition of low water cement ratio, on the other hand, using GBS or natural river sand as fine aggregate has almost similar durability of concrete.

  1. Facile Fabrication of Durable Copper-Based Superhydrophobic Surfaces via Electrodeposition.

    Science.gov (United States)

    Jain, R; Pitchumani, R

    2018-03-13

    Superhydrophobic surfaces have myriad industrial applications, yet their practical utilization has been limited by their poor mechanical durability and longevity. We present a low-cost, facile process to develop superhydrophobic copper-based coatings via an electrodeposition route, that addresses this limitation. Through electrodeposition, a stable, multiscale, cauliflower shaped fractal morphology was obtained and upon modification by stearic acid, the prepared coatings show extreme water repellency with contact angle of 162 ± 2° and roll-off angle of about 3°. Systematic studies are presented on coatings fabricated under different processing conditions to demonstrate good durability, mechanical and underwater stability, corrosion resistance, and self-cleaning effect. The study also presents an approach for rejuvenation of slippery superhydrophobic nature (roll-off angle <10°) on the surfaces after long-term water immersion. The presented process can be scaled to larger, durable coatings with controllable wettability for diverse applications.

  2. Durability of reinforced concrete beams strengthened with fiber reinforced polymers under varying environmental conditions

    International Nuclear Information System (INIS)

    El-Sadani, R.A.M.G

    2008-01-01

    Fiber reinforced polymers (FRP) materials were adopted by the aerospace and marine industries, not only for their lightweight and high strength characteristics but also due to their tough and durable nature . As the engineering community has become more familiar with the performance advantages of these materials, new applications have been investigated and implemented. Researches and design guidelines concluded that externally bonded FRP to concrete elements could efficiently increase the capacity of RC elements. Long-term exposure to harsh environments deteriorates concrete and the need for repair and rehabilitation is evident. In order to accept these FRP materials, they must be evaluated for durability in harsh environments. An experimental program was conducted at the materials laboratory- faculty of engineering-Ain Shams university to study the durability of RC beams strengthened with FRP sheets and to compare them with un strengthened beams.The effect of gamma rays on FRP materials and concrete specimens bonded to FRP sheets were also investigated.

  3. Electricity and energy policy: french specificities and challenges in the european framework; Electricite et politique energetique: specificites francaises et enjeux dans le cadre europeen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-15

    In the today context of the electric power european market deregulation and the increase of the energy prices, the energy policy must change. The increase of the energy prices makes wonder the question of the competitiveness of the french economy: what type of supplies and which technological orientations will allow to reduce the constraints. After a presentation of the today electric power french market and the recently modifications bond to the deregulation, this note aims to describe the evolutions, since the first petroleum crisis, of the place given to the electric power in the energy policy, as the technological choices explaining the today structure he electricity production, characterized by the major part of the nuclear. Then the energy policy in matter of the electric power is discussed in the european context, to present the choices impacts facing the european objectives of energy security, environment and market liberalization. (A.L.B.)

  4. Deliverable D4.2. Design variables for durability

    NARCIS (Netherlands)

    Visser, J.H.M.

    2015-01-01

    On January 1st 2012, the European project SUS-CON has been started: “SUStainable, innovative and energy efficient CONcrete, based on the integration of all waste materials” (grant agreement no: 285463). The SUS-CON project aims at developing new technology routes to integrate waste materials in the

  5. Improving Reliability and Durability of Efficient and Clean Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Prabhakar [Univ. of Connecticut, Storrs, CT (United States)

    2010-08-01

    Overall objective of the research program was to develop an in-depth understanding of the degradation processes in advanced electrochemical energy conversion systems. It was also the objective of the research program to transfer the technology to participating industries for implementation in manufacturing of cost effective and reliable integrated systems.

  6. Assessing the representativeness of durability tests for wood pellets by DEM Simulation - Comparing conditions in a durability test with transfer chutes

    Science.gov (United States)

    Mahajan, Aditya; Dafnomilis, Ioannis; Hancock, Victoria; Lodewijks, Gabriel; Schott, Dingena

    2017-06-01

    Dust generation when handling wood pellets is related to the durability of the product, in other words the wear rate of particles subject to forces. During transport, storage and handling wood pellets undergo different forces when interacting with different pieces of equipment. This paper assesses the representativeness of the tumbling can test in relation to transfer chutes, by comparing forces acting on wood pellets in durability tests and in transfer chutes using DEM. The study also incorporates effects such as shape and size variations. The results showed that the tumbling can test underestimates compressive and tangential forces. Since the tested material is subject to milder conditions than in reality, it can be concluded that this test is not representative for the conditions in the supply chain of wood pellets.

  7. Influence of ceria on the thermally durability of Pt/Rh automotive catalyst

    International Nuclear Information System (INIS)

    Muraki, H.; Zhang, G.

    1998-01-01

    Full text: The use of cerium oxide as an oxygen storage component in automotive three-way catalysts has been well established. More recently the requirement of the three-way catalysts against the increase of the severity in emission standards has focused attention on the development of more active, durable catalysts. The thermally durability of Pt/Rh catalyst can be achieved by the utilization of thermally stable ceria as well as optimization of washcoat composition and structure in order to control the extent of interaction between PGM and ceria. In the present paper, we describe the influence of newly developed washcoat components and PGM interaction with ceria on catalytic performance. First, to clear that the interaction between PGM and ceria contributes to catalytic performance, several kinds of catalysts which have the varied interactions between PGM and ceria were prepared using engineered washcoat techniques and evaluated in the model gas reactor. It was obvious that the difference in performance among them after aging derived from a diversity of interactions between Pt, Rh, and ceria. Second, for the purpose of determining the thermally durability of the developed Pt/Rh catalyst, the catalysts including the current catalyst were aged under three different temperatures and evaluated on engine dynamometer. Result of engine dynamometer evaluation revealed that significant improvement in the thermal durability can be achieved by optimizing the PGM-ceria interaction. In conclusion, we recognize that a thermal durability of a three-way catalyst can be improved by the stabilization of proper PGM-ceria interaction after aging as well as the utilization of thermally durable ceria material

  8. Weathering durability of commercial polymeric coatings tested by positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Chen, H.; Peng, Q.; Huang, Y.Y.; Zhang, R.; Li, Y.; Zhang, J.; Wu, Y.C.; Richardson, J.R.; Sandreczki, T.C.; Jean, Y.C.

    2003-01-01

    A series of commercial coatings were prepared according to the industrial specifications and were exposed to Florida natural weathering and controlled UVA irradiation. The Doppler broadening energy spectra (DBES) of positron annihilation were measured as a function of incident positron energy at different periods of weathering. A significant decrease in the S parameter was observed and it was used as an indicator to test coating durability in micro-scale. Application to weathering durability of commercial polymeric coatings under natural weathering and controlled UVA irradiation is investigated by using the S parameter from the DBES

  9. Characterization and durability testing of a glass-bonded ceramic waste form

    International Nuclear Information System (INIS)

    Johnson, S. G.

    1998-01-01

    Argonne National Laboratory is developing a glass bonded ceramic waste form for encapsulating the fission products and transuranics from the conditioning of metallic reactor fuel. This waste form is currently being scaled to the multi-kilogram size for encapsulation of actual high level waste. This paper will present characterization and durability testing of the ceramic waste form. An emphasis on results from application of glass durability tests such as the Product Consistency Test and characterization methods such as X-ray diffraction and scanning electron microscopy. The information presented is based on a suite of tests utilized for assessing product quality during scale-up and parametric testing

  10. The effects of moisture and temperature variations on the long term durability of polymer concrete

    DEFF Research Database (Denmark)

    Barbosa, Ricardo; Hansen, Kurt Kielsgaard; Grelk, Bent

    2013-01-01

    The use of polymer concrete to precast products in construction presents normally many advantages compared to traditional concrete. Higher strength, lower permeability, shorter curing periods, better chemical resistances and a better durability is normally predicated, however this is a research...... and after exposure to different thermal conditions is very important. In this paper, an experimental study concerning the influence of temperature and moisture in cyclic conditions on the durability of polymer concrete based on an unsaturated polyester resin is described and the results are presented...

  11. The influence of fly ash as substitute of cement in the durability of concrete

    OpenAIRE

    Molina Bas, Omar I.; Moragues Terrades, Amparo; Gálvez Ruíz, Jaime; Guerrero Bustos, Ana

    2008-01-01

    Limitation of transport capacity through the concrete is one of the key points in the improvement of the material’s durability. The use of fly ash as an admixture to concrete is widely extended; a general consensus has been established due to the pore size reduction produced by the ashes. Nevertheless, the importance of the micro-structural and composition changes in mechanical and durable properties is not well defined. In the present study the use of fly ash has been considered as substitut...

  12. Fused Microknot Optical Resonators in Folded Photonic Tapers for in-Liquid Durable Sensing

    Directory of Open Access Journals (Sweden)

    Alexandra Logvinova

    2018-04-01

    Full Text Available Optical microknot fibers (OMFs serve as localized devices, where photonic resonances (PRs enable self-interfering elements sensitive to their environment. However, typical fragility and drifting of the knot severely limit the performance and durability of microknots as sensors in aqueous settings. Herein we present the fabrication, electrical fusing, preparation, and persistent detection of volatile liquids in multiple wetting–dewetting cycles of volatile compounds and quantify the persistent phase shifts with a simple model relating to the ambient liquid, enabling durable in-liquid sensing employing OMF PRs.

  13. Composition models for the viscosity and chemical durability of West Valley related nuclear waste glasses

    International Nuclear Information System (INIS)

    Feng, X.; Saad, E.E.; Freeborn, W.P.; Macedo, P.B.; Pegg, I.L.; Sassoon, R.E.; Barkatt, A.; Finger, S.M.

    1988-01-01

    There are two important criteria that must be satisfied by a nuclear waste glass durability and processability. The chemical composition of the glass must be such that it does not dissolve or erode appreciably faster than the decay of the radioactive materials embedded in it. The second criterion, processability, means that the glass must melt with ease, must be easily pourable, and must not crystallize appreciably. This paper summarizes the development of simple models for predicting the durability and viscosity of nuclear waste glasses from their composition

  14. Chemical durability and degradation mechanisms of HT9 based alloy waste forms with variable Zr content

    Energy Technology Data Exchange (ETDEWEB)

    Olson, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-30

    In Corrosion studies were undertaken on alloy waste forms that can result from advanced electrometallurgical processing techniques to better classify their durability and degradation mechanisms. The waste forms were based on the RAW3-(URe) composition, consisting primarily of HT9 steel and other elemental additions to simulate nuclear fuel reprocessing byproducts. The solution conditions of the corrosion studies were taken from an electrochemical testing protocol, and meant to simulate conditions in a repository. The alloys durability was examined in alkaline and acidic brines.

  15. Durability aspects of high-performance concretes for a waste repository. Appendix 3: Canada

    International Nuclear Information System (INIS)

    Philipose, K.E.

    2001-01-01

    The IRUS facility for the disposal of low level radioactive waste at the Chalk River Nuclear Laboratories in Ontario, Canada relies on the durability of concrete for the required 500 years of service life. A research programme based on laboratory testing to design a durable concrete and assess its long-term behaviour was initiated in 1988. This appendix discusses the methodology to assess the long-term behaviour of concrete, and some initial observations. Longevity predictions for concrete formulations based on diffusion testing are also presented

  16. Estimation of metallic structure durability for a known law of stress variation

    Science.gov (United States)

    Mironov, V. I.; Lukashuk, O. A.; Ogorelkov, D. A.

    2017-12-01

    Overload of machines working in transient operational modes leads to such stresses in their bearing metallic structures that considerably exceed the endurance limit. The estimation of fatigue damages based on linear summation offers a more accurate prediction in terms of machine durability. The paper presents an alternative approach to the estimation of the factors of the cyclic degradation of a material. Free damped vibrations of the bridge girder of an overhead crane, which follow a known logarithmical decrement, are studied. It is shown that taking into account cyclic degradation substantially decreases the durability estimated for a product.

  17. Influence of the leaching mode on the durability of a glass for fission product containment

    International Nuclear Information System (INIS)

    Nogues, J.L.; Terki, A.

    1984-06-01

    The chemical durability of a glass containing wastes from light water reactor (LWR) has been studied with three different lixiviation modes: ''static'' leach test, ''soxhlet'' test and ''continuous flow'' test. After a description of these tests, the leaching mode influence on the glass durability is reported as obtained from weight loss measurements, analyses of the leaching solutions and surface analyses of the samples. Finally, the corrosion mechanisms of this type of glass are approached and a phenomenological explanation of attack from an aqueous solution is proposed [fr

  18. Durability and degradation of HT9 based alloy waste forms with variable Ni and Cr content

    Energy Technology Data Exchange (ETDEWEB)

    Olson, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-31

    Short-term electrochemical and long-term hybrid electrochemical corrosion tests were performed on alloy waste forms in reference aqueous solutions that bound postulated repository conditions. The alloy waste forms investigated represent candidate formulations that can be produced with advanced electrochemical treatment of used nuclear fuel. The studies helped to better understand the alloy waste form durability with differing concentrations of nickel and chromium, species that can be added to alloy waste forms to potentially increase their durability and decrease radionuclide release into the environment.

  19. Durability Issues of High Temperature Proton Exchange Membrane Fuel Cells Based on Acid Doped Polybenzimidazole Membranes

    DEFF Research Database (Denmark)

    . As a critical concern, issues of long term durability of PBI based fuel cells are addressed in this talk, including oxidative degradation of the polymer, mechanical failures of the membrane, acid leaching out, corrosion of carbon support and sintering of catalysts particles. Excellent polymer durability has...... or ionically cross-linking and structure modification With load, thermal or startup-shutdown cycling, the performance loss was found to be much bigger, about 300 µV per cycle or 40 µV per operating hour, due to the increased acid loss and catalyst support corrosion, particularly under open circuit voltage...... operation. Further efforts are outlined to the future work....

  20. Durability Testing of Additively Manufactured High Power Microwave Structures

    Science.gov (United States)

    2017-10-29

    D. Hoffman, B. Singh and J. Thomas, Handbook of vacuum science and technology . San Diego, CA: Academic Press, 1998. [17] M. Cuneo, "The effect of...the higher He diffusion rate through rubber o-rings, its lower pumping speed within the cryopump and possibly saturation of the charcoal arrays...Third Edition, CRC Press (Boca Raton, FL, USA, 2016). [3] J. C. Whitaker, “Power Vacuum Tubes Handbook ”, Second Edition, CRC Press (New York, NY, USA