WorldWideScience

Sample records for amenagement durables prevention

  1. Opinion presented on the behalf of sustainable development and land planning commission on the finance bill for 2012. Volume 1: Ecology, sustainable development and planning: protection of the environment and risk prevention; Avis presente au nom de la Commission du Developpement Durable et de l'Amenagement du Territoire sur la loi de finances pour 2012 (n. 3775),Tome 1 Ecologie, Developpement et Amenagement Durables: protection de l'environnement et prevention des risques

    Energy Technology Data Exchange (ETDEWEB)

    Priou, Ch.

    2011-07-01

    This author first reports the examination of credits asked for 2012 for a 'risk prevention' program. This program comprises prevention and struggle regarding natural and hydraulic hazards, prevention and struggle regarding technological and pollution hazards, and health and environment policies. Then, he reports the examination of credits asked for 2012 for a 'Meteo-France' program. He discusses the program structure and the asked credits, the Meteo-France budget situation, and the new objectives. He does the same for a 'geographic and cartographic information' program for which he discusses the program structure and the asked credits, the strategic orientations, and the progress status in the building up of a large scale referential

  2. Report realized in the name of the finances, economy and the plan commission on the project of financing law for 2009 (n. 1127), annex n. 13 ecology, sustainable development and management risks prevention planing of the ecology, the energy, the sustainable development and the territory management policies; Rapport fait au nom de la commission des finances, de l'economie generale et du plan sur le projet de loi de finances pour 2009 (n. 1127), annexe n. 13 ecologie, developpement et amenagement durables prevention des risques conduite et pilotage des politiques de l'ecologie, de l'energie, du developpement durable et de l'amenagement du territoire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This document presents the law project n. 1127 for 2009, concerning the risks prevention in the framework of the ecology and the sustainable development and management. The first part details the program of risks prevention (technological, pollutions, natural and hydraulic risks, nuclear safety and radioprotection, the mine site rehabilitation). The second part develops the ecology, energy sustainable development and territory management, policies. (A.L.B.)

  3. Report on the behalf of the Finance, General Economy and Budgetary Control Commission on the Finance bill for 2011 (n. 2824), appendix N. 13: ecology, sustainable development and land planning, hazard prevention, management and steering of ecology, energy, sustainable development, land planning and sea policies; Rapport fait au nom de la Commission des Finances, de L'economie Generale et du Controle Budgetaire sur le projet de loi de finances pour 2011 (n. 2824), annexe N. 13 ecologie, developpement et amenagement durables prevention des risques conduite et pilotage des politiques de l'ecologie, de l'energie, du developpement durable et de la mer

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This report comments the grants awarded to two programmes, the first one concerning the prevention of hazards, and the second concerning the management and steering of ecology, energy, sustainable development, land planning and sea policies. These two programmes are emblematic of the French government's action and ambition in the field of sustainable development and ecology. For the first one, the report comments the evolution of grants, their objectives and performance indicators. Then it addresses its various aspects: prevention of technological hazards and pollutions, prevention of natural and hydraulic hazards, nuclear safety, after-mine management. For the second programme, the report gives an assessment of the ministry reorganization, and comments the means requested for 2011

  4. Notice presented in the name of the economical affairs, the environment and the territory commission, on the financial law project for 2009 (n. 1127), part 2 ecology, sustainable development and management. volume 1 environment and energy; Avis presente au nom de la commission des affaires economiques, de l'environnement et du territoire sur le projet de loi de finances pour 2009 (n. 1127), tome 2 ecologie, developpement et amenagement durables. volume 1 environnement et energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This law document concerns the evaluation and analysis of the demanded credits for 2009 (the increase of the credits in the risks prevention, the energy supply in the framework of the climatic change) and the supply of the energy in a context of the environmental quality (the renewable energies development, the electric power production and consumption, the nuclear energy future). (A.L.B.)

  5. 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

  6. Designing concrete for durability

    Directory of Open Access Journals (Sweden)

    Boyd, A. J.

    2001-12-01

    Full Text Available Some of the factors affecting the durability of modern concrete structures are discussed, with an emphasis on the problems caused by modern portland cements. This is followed by a description of some concrete durability issues of current interest, such as plastic shrinkage, seawater attack, and sulfate attack. The strategies for testing for durability are also discussed. It is concluded that, to produce durable concretes, a holistic approach to concrete construction must be adopted.

    Se discuten algunos de los factores que influyen en la durabilidad de las estructuras de hormigón modernas, haciendo énfasis en los problemas causados por el cemento Portland. A esto sigue una descripción de algunas cuestiones de interés general de la durabilidad del hormigón tales como la retracción plástica, el ataque por agua de mar y el ataque por sulfatos. Se discuten también las estrategias de los ensayos de durabilidad. Se concluye que para producir hormigones durables se debe adoptar un enfoque holístico de la construcción con hormigón.

  7. Durable superoleophobic polypropylene surfaces.

    Science.gov (United States)

    Brown, Philip S; Bhushan, Bharat

    2016-08-01

    Polypropylene (PP) is a popular plastic material used in consumer packaging. It would be desirable if such plastic containers were liquid repellent and not so easily fouled by their contents. Existing examples of superoleophobic surfaces typically rely on poorly adhered coatings or delicate surface structures, resulting in poor mechanical durability. Here, we report a facile method for creating superoleophobic PP surfaces via incorporation of nanoparticles (NPs) into the polymer surface. A solvent-NP-PP mixture was spin coated at high temperature to achieve the necessary roughness. Such surfaces were further functionalized with fluorosilane to result in a durable, super-repellent surface. They were also found to exhibit some repellency towards shampoos. This method of incorporating NPs into polymer surfaces could also prove useful in improving the anti-bacterial, mechanical and liquid-repellent properties of plastic devices.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. PMID:27354730

  8. Chemical durability of zircon

    Science.gov (United States)

    Trocellier, Patrick; Delmas, Robert

    2001-07-01

    Zircon (ZrSiO 4) exhibits a strong structural affinity for uranium and thorium together with a very high chemical durability. This makes it a potential crystalline host matrix to immobilize actinides issued from separation of nuclear wastes. Irradiation induces amorphization of the crystalline structure (the metamictization process) and thus may decrease the chemical durability of the material. Leaching tests have been conducted on natural zircons from Brazil and Madagascar at 96°C for a period of 1 month, using deionized water. Leachates have been analysed by inductively coupled plasma mass spectrometry (ICP-MS) and UV-visible spectrophotometry. Zircon solid surfaces have been investigated by coupling scanning electron microscopy and X-ray microanalysis (SEM-EDX) with nuclear microprobe analysis ( μPIXE, μRBS and μERDA). From the mass balance between leachates and hydrated surfaces, the probable mechanisms of zircon aqueous alteration are presented and discussed.

  9. Low Cost, Durable Seal

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, George; Parsons, Jason; Friedman, Jake

    2010-12-17

    Seal durability is critical to achieving the 2010 DOE operational life goals for both stationary and transportation PEM fuel cell stacks. The seal material must be chemically and mechanically stable in an environment consisting of aggressive operating temperatures, humidified gases, and acidic membranes. The seal must also be producible at low cost. Currentlyused seal materials do not meet all these requirements. This project developed and demonstrated a high consistency hydrocarbon rubber seal material that was able to meet the DOE technical and cost targets. Significant emphasis was placed on characterization of the material and full scale molding demonstrations.

  10. Durability of critical infrastructures

    Directory of Open Access Journals (Sweden)

    Raluca Pascu

    2011-08-01

    Full Text Available 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 three linearmodels, typical for critical infrastructures, are successively calculated. In order to enhance the durabilityof critical infrastructures the solution based on redundancies is chosen. Five types of connection theredundancies for each of the three models are considered. Three topological schemes for connecting theredundancies are adopted: locally, by twining and globally. Absolute values of durability in all fifteenmodels with redundancies are further calculated. Then, the relative performances of enhanced durabilityin the same fifteen models, compared with the three original models, considered as references, areanalysed. The relative costs of the same fifteen models and in similar topologic conditions are furtheranalysed. By dividing the performance with cost the relative profitableness of each model is obtained.Finally, the three initial models, each reshaped with redundancies in three selective modes, arecompared from the perspective of their relative profitableness. The outcomes of this paper are original.They are of practical interests in planning the maintenance programs and checking the plausibility ofproposed interventions according to the clause 7.4 of ISO 13822:2001

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

    Science.gov (United States)

    Wolfe, Jesse D.

    2010-11-23

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

  12. Concrete durability with antigraffiti protection

    OpenAIRE

    Neto, Elsa; Souto, Ana; Camões, Aires; Begonha, Arlindo; Cachim, Paulo

    2014-01-01

    The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti. Durability of concrete depends on the composition and characteristics of the surface, whereby it is essential to study the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes i...

  13. Improving durability through probabilistic design

    OpenAIRE

    Ferreira, Rui Miguel

    2006-01-01

    In order to obtain a more controlled durability and long-term performance of concrete structures in chloride containing environment special care is needed in the design phase of reinforced concrete structures. The recent development of probability-based procedures has proven to give a more realistic basis for both durability design and condition assessment of reinforced concrete structures. Although there is still a lack of relevant data, this approach has been successfully applied to several...

  14. The durability of Synroc

    International Nuclear Information System (INIS)

    Polished specimens of well characterised Synroc ( a polyphase titanate ceramic designed to immobilise high-level nuclear waste) containing 10 wt% simulated (PW-4b-D) waste were subjected to MCC-2 type dissolution tests at 150deg C in doubly deionised water (surface area to volume ratio 0.01 ± 0.0005 mm-1) for periods of up to 532 d. Scanning electron microscopy (SEM) of the polished surfaces and transverse sections confirmed that Synroc is highly durable and suffers little corrosion even after 532 d in doubly deionised water at 150deg C (corrosion of the least resistant major phase, perovskite, was < 0.2 μm deep, i.e. less than half the size of a grain). Many of the features observed by SEM and a large percentage of the elements released into leachants result from the dissolution of minor phases which constitute < 5 wt% of Synroc and contain a small proportion of the waste. Analysis of leachates showed that the percentages of the initial amounts of Al, Ba, Ca, Ce, Cs, Mo, Nd and Sr lost from a representative sample exposed to doubly deionised water at 150deg C for a total of 337 d were 0.10, 0.017, 0.068, 0.045, 0.028, 0.093, 0.026 and 0.064, respectively. The mechanisms of Synroc dissolution are complex. Further studies on the effect of pH and Eh on dissolution mechanisms and rates are needed. (orig.)

  15. Prevention

    DEFF Research Database (Denmark)

    Halken, S; Høst, A

    2001-01-01

    populations. These theories remain to be documented in proper, controlled and prospective studies. Breastfeeding and the late introduction of solid foods (>4 months) is associated with a reduced risk of food allergy, atopic dermatitis, and recurrent wheezing and asthma in early childhood. In all infants......, breastfeeding should be encouraged for 4-6 months. In high-risk infants a documented extensively hydrolysed formula is recommended if exclusive breastfeeding is not possible for the first 4 months of life. There is no evidence for preventive dietary intervention neither during pregnancy nor lactation...

  16. Compositional threshold for Nuclear Waste Glass Durability

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A. [Pacific Northwest National Lab., Richland, WA (United States); Farooqi, Rahmatullah [Pohang Univ. of Science and Technology, (Korea, Republic of); Hrma, Pavel R. [Pacific Northwest National Lab., Richland, WA (United States), Pohang Univ. of Science and Technology, (Korea, Republic of)

    2013-04-24

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

  17. 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.

  18. CODSTRAN: Composite durability structural analysis

    Science.gov (United States)

    Chamis, C. C.; Smith, G. T.

    1978-01-01

    CODSTRAN (COmposite Durability STRuctural ANalysis) is an integrated computer program being developed for the prediction of defect growth and fracture of composite structures subjected to service loads and environments. CODSTRAN is briefly described with respect to organization, capabilities and present status. Application of CODSTRAN current capability to a flat composite laminate with a center slit which was subjected to axial tension loading predicted defect growth which is in good agreement with C-scan ultrasonic test records.

  19. Durability of expanded polystyrene mortars

    OpenAIRE

    Ferrándiz Mas, Verónica; García Alcocel, Eva María

    2013-01-01

    The influence of the addition of various types and various concentrations of expanded polystyrene foam (both commercial and recycled) on the durability of Portland cement mortars is studied. In particular, the microstructure is studied utilizing the following methods: capillary absorption of water, mercury intrusion porosimetry, impedance spectroscopy and open porosity. In addition, the effects of heat cycles and freeze–thaw cycles on compressive strength are examined. Scanning electron micro...

  20. Monitoring the durability of marine concrete structures

    OpenAIRE

    Tzoura, Effrosyni; Basheer, Muhammed; Nanukuttan, Sreejith; McPolin, Daniel; McCarter, John; Grattan, Kenneth; Sun, Tong; Srinivasan, Sudarsan

    2016-01-01

    New techniques based on embedded sensors have been developed for monitoring reinforced concrete structures for assessing their durability, which can be used instead of the conventional non-destructive test techniques. The continuous monitoring of concrete for its durability with various types of sensors allows not only early assessment of the potential durability of structures, but also a prediction of their service life. Effrosyni Tzoura and Muhammed Basheer of University of Leeds, Sreejith ...

  1. 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.

  2. 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.

  3. Steam pipelines' effort and durability

    Directory of Open Access Journals (Sweden)

    J. Okrajni

    2007-06-01

    Full Text Available Purpose: The main problem addressed in the paper is the description of an effort and durability of steam pipelines under the conditions of mechanical and thermal interactions.Design/methodology/approach: The FEM modelling has been used to determine the stress and strain fields in the pipelines and to describe their behaviour under mechanical and thermal loading.Findings: An appropriate model description has been developed. So far, experimental verification of the usefulness of the model description to determine the stress and strain patterns in particular object and for chosen operation conditions has been made. The analysis made has shown that the most probable cause of cracks occurrence on the analyzed chosen pipeline’ inner surfaces are thermal deformations and constraints of their dislocations.Research limitations/implications: The developed description should be useful in problems of behaviour predictions of high temperature components and their durability assessment under different mechanical and thermal loadings in industry practical applications.Originality/value: The method, which more precise description of power industry components behaviour makes possible have been shown in the work. The work is addressed to researchers interested in problems of component behaviour prediction under different loadings that we can meet in the operation practice and to power industry engineering maintenance staff.

  4. Nuclear power and durable development

    International Nuclear Information System (INIS)

    This paper highlights the role that the nuclear power can play in a durable development of society. From a comparative analysis of different energy sources capable to fulfil the national energy demand it turns out that for Romania the optimal alternative is nuclear power. The nuclear power proved its attributes and characteristics in ensuring durable development by: 1. the technological maturation of the CANDU system as demonstrated by the good functioning of Cernavoda NPP Unit 1; 2. optimal utilization of the uranium national resources as well as the mining industry; 3. uranium processing and nuclear fuel and heavy water manufacturing as entailed by an educational infrastructure, research and industrial development; 4. low environmental impact; 5. high professional skill of the nuclear personnel. In addition, the low cost of the energy produced by the nuclear sector, as well as the social effects, namely, a 100% utilization of industrial infrastructure and national research capacity, urges the decision makers to develop the Cernavoda NPP, to increase the weight of nuclear energy in the energy production of the country

  5. 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,...

  6. DURABILITY OF HARDENED FLY ASH PASTE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The mechanical properties and durability ( mainly frost-resistance and carbonation resistance ) of fly ash-CaO-CaSO4 .2H2O hardened paste are studied. The relationship among durability of harden ed fly ash paste, the quantity and distribution of hydrates and the initial p aste texture of hardened fly ash paste is presented.

  7. 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.

  8. Hygrothermal behavior, building pathology and durability

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto de Freitas V.; Delgado, J.M.P.Q. (eds.) [Porto Univ. (Portugal). Building Physics Lab.

    2013-03-01

    Includes a set of new developments in the field of building physics and hygrothermal behavior. Presents a new durability approach for historical and old buildings. Reviews the current state of knowledge. 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.

  9. ETUDE PREALABLE A L'AMENAGEMENT DE LA RESERVE FORESTIERE DE MBALMAYO (CAMEROUN) : PRATIQUES ET MODES D'ACCES DES POPULATIONS LOCALES

    OpenAIRE

    Peltier, Régis; Temgoua, Lucie Félicité

    2008-01-01

    La protection de l'environnement est devenue un enjeu planétaire durant les années 1980. Le discours international sur la gestion durable des forêts tropicales prône la nécessité d'impliquer les populations locales dans la gestion des ressources forestières et fauniques. Au Cameroun, La loi forestière de 1994 offre aux populations locales de nouvelles possibilités de développement à travers une gestion décentralisée. Tout récemment, le Ministère des Forêts et de la Faune a prévu le transfert ...

  10. 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.

  11. Compositional threshold for nuclear waste glass durability

    Energy Technology Data Exchange (ETDEWEB)

    Farooqi, Rahmatullah; Hrma, Pavel [Pohang Univ. of Science and Technology, Pohang (Korea, Republic of)

    2013-07-01

    The issue of major concern with the waste form, such as glass, is its chemical durability, I. e., the resistance to corrosion by aqueous media. A number of standard durability tests have been established for waste glasses, among which the product consistency test was selected as a criterion of HLW glass acceptability for the repository subsequently, a large PCT database has been collected containing over 1000 glasses. Such a database allows the development of models that relate PCT releases to glass is a strong function of composition, these models are used to formulate acceptable glasses in which the waste loading is maximized. Within the composition space of glasses, a distinct threshold appears to exist that separates 'good' glasses, I. e. these which are sufficiently durable, from 'bad' glasses of a low durability. According to Populate al., transition region between durable and less durable glasses lies around 2a m{sup -2} as determined by the 7-day PCT normalized B release. 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. Our study is focused on the corrosion behavior of SiO{sub 2} - B{sub 2}O{sub 3} - Na{sub 2}O - Al{sub 2}O{sub 3} - Colleagues composition region. In particular, we try to identify the durability threshold separating durable from nondurable glasses in the composition space. So far we have explored the elemental releases of Na and B measured with the 7-day PCT.

  12. Durable Dust Repellent Coating for Metals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Durable Dust Repellent Coating (DDRC) consists of nano-phase silica, titania, or other oxide coatings to repel dust in a vacuum environment over a wide range of...

  13. Local spillovers and durable adoption: Evidence from durable consumptions in rural China

    OpenAIRE

    Rong, Zhao; Feng, Yao

    2012-01-01

    Purpose – The effects of social learning and network externalities in the diffusion of a new product imply that there should be local spillovers from existing owners to new adopters in a closely-related community. Using the 1999 durable consumption survey data in rural China, this paper examines the importance of local spillovers in the diffusion of two major durable goods, washing machine and refrigerator. Design/methodology/approach – Based on an October 1999 survey of rural durable good...

  14. 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.

  15. L’examen méthodique d’un geste de métier pour une prévention durable des TMS : une intervention en clinique de l’activité Methodological examination of job-related body movements for the sustainable prevention of msds: a clinical intervention on the activity El examen metódico de un gesto de oficio por une prevención durable des LMS : une interpretación en clínica de la actividad

    Directory of Open Access Journals (Sweden)

    Pascal Simonet

    2009-11-01

    Full Text Available L’intervention sur laquelle s’appuie cet article a été initiée par un service de médecine préventive qui souhaite étendre ses actions de prévention durable des TMS. Elle a été conduite selon les principes méthodologiques de la clinique de l’activité dans la perspective d’ouvrir les corps porteurs de douleurs déclarées sur un autre destin que celui de la réalisation de la pathologie. Les observations prolongées et répétées des activités concrètes de travail transforment les sujets observés en observateurs de leur activité. Le cadre des autoconfrontations simples et croisées a pour fonction de soutenir les efforts d’élaboration des professionnels à partir de dialogues entre eux. Les controverses professionnelles qui trouvent parfois à s’y réaliser enrichissent les connaissances et l’expertise de chacun dans le métier. Cet article souhaite interroger les ressorts méthodologiques de la prévention des TMS en posant, notamment, la question du protagoniste de la prévention ou encore celle, associée, de la place du collectif de métier comme ressource potentiellement durable d’une démarche préventive. Dans une telle perspective, les efforts de l’intervenant portent sur les méthodes à engager pour conduire les professionnels à se confronter, dans des cadres appropriés, à d’autres réalisations gestuelles au sein d’un collectif envisagé comme instrument psychologique de développement de leur activité.1The intervention on which this article is based was initiated by a preventive medical department wanting to extend its actions on the sustainable prevention of MSDs. The intervention was based on the activity clinic’s methodological principles from the perspective of people with reported pain having a fate other than that of pathology. Prolonged and repeated observations of the actual work activities change the observed subjects into observers of their activity. The purpose of the context of

  16. To the question of reliability and durability ballastless deck of bridge

    Directory of Open Access Journals (Sweden)

    V.V. Prystynskaya

    2012-12-01

    Full Text Available The principal causes of operational defects in bridge ballastless deck plates are considered in the article. The drawbacks of these plates construction that prevent from achieving a higher level of bridge framework reliability and durability have been analysed.

  17. Durability of polymer composite materials

    Science.gov (United States)

    Liu, Liu

    The purpose of this research is to examine structural durability of advanced composite materials under critical loading conditions, e.g., combined thermal and mechanical loading and shear fatigue loading. A thermal buckling model of a burnt column, either axially restrained or under an axial applied force was developed. It was predicted that for a column exposed to the high heat flux under simultaneous constant compressive load, the response of the column is the same as that of an imperfection column; the instability of the burnt column happens. Based on the simplified theoretical prediction, the post-fire compressive behavior of fiberglass reinforced vinyl-ester composite columns, which have been exposed to high heat flux for a certain time was investigated experimentally, the post-fire compressive strength, modulus and failure mode were determined. The integrity of the same column under constant compressive mechanical loading combined with heat flux exposure was examined using a specially designed mechanical loading fixture that mounted directly below a cone calorimeter. All specimens in the experiments exhibited compressive instability. The experimental results show a thermal bending moment exists and has a significant influence on the structural behavior, which verified the thermal buckling model. The trend of response between the deflection of the column and exposure time is similar to that predicted by the model. A new apparatus was developed to study the monotonic shear and cyclic-shear behavior of sandwich structures. Proof-of-concept experiments were performed using PVC foam core polymeric sandwich materials. Shear failure occurred by the extension of cracks parallel to the face-sheet/core interface, the shear modulus degraded with the growth of fatigue damage. Finite element analysis was conducted to determine stress distribution in the proposed specimen geometry used in the new technique. Details for a novel apparatus used for the fatigue testing of thin

  18. Durability Assessment of Gamma Tial

    Science.gov (United States)

    Draper, Susan L.; Lerch, Bradley A.; Pereira, J. Michael; Miyoshi, Kazuhisa; Arya, Vinod K.; Zhuang, Wyman

    2004-01-01

    Gamma TiAl was evaluated as a candidate alloy for low-pressure turbine blades in aeroengines. The durability of g-TiAl was studied by examining the effects of impact or fretting on its fatigue strength. Cast-to-size Ti-48Al-2Cr-2Nb was studied in impact testing with different size projectiles at various impact energies as the reference alloy and subsequently fatigue tested. Impacting degraded the residual fatigue life. However, under the ballistic impact conditions studied, it was concluded that the impacts expected in an aeroengine would not result in catastrophic damage, nor would the damage be severe enough to result in a fatigue failure under the anticipated design loads. In addition, other gamma alloys were investigated including another cast-to-size alloy, several cast and machined specimens, and a forged alloy. Within this Ti-48-2-2 family of alloys aluminum content was also varied. The cracking patterns as a result of impacting were documented and correlated with impact variables. The cracking type and severity was reasonably predicted using finite element models. Mean stress affects were also studied on impact-damaged fatigue samples. The fatigue strength was accurately predicted based on the flaw size using a threshold-based, fracture mechanics approach. To study the effects of wear due to potential applications in a blade-disk dovetail arrangement, the machined Ti-47-2-2 alloy was fretted against In-718 using pin-on-disk experiments. Wear mechanisms were documented and compared to those of Ti-6Al-4V. A few fatigue samples were also fretted and subsequently fatigue tested. It was found that under the conditions studied, the fretting was not severe enough to affect the fatigue strength of g-TiAl.

  19. Credit frictions and the comovement between durable and non-durable consumption

    NARCIS (Netherlands)

    V. Sterk

    2010-01-01

    Frictions in lending between households have been proposed as a solution to the difficulties new-Keynesian models have in predicting a decline in both durable and non-durable consumption following a monetary tightening. By revisiting a standard new-Keynesian framework with collateral constraints, it

  20. A Review: Durability of Fired Clay Brick Masonry Wall due to Salt Attack

    Directory of Open Access Journals (Sweden)

    B.H. Abu Bakar

    2009-12-01

    Full Text Available This paper offers a review on durability of fired clay brick masonry wall due to salt attack. Durability of brick normally affected when an external masonry walls are exposed to aggressive environment. Masonry structures, when subjected to salt attack or exposed to aggressive environment during their service life may suffer degradation due to the formation of crystallization pressure as a result of the evaporation of soluble salt in clay masonry structures. The crystallization pressures produce normally higher than tensile stress of clay brick and sufficient to damage the masonry structures. The mechanism of salt attack must be prevented and addressed thoroughly in order to maintain the integrity and service life of masonry wall. Therefore, the summary of durability, factors, mechanism and main sources of salt attack on fired clay brick masonry walls are discussed.

  1. Description of Concrete Durability Damage Process

    Institute of Scientific and Technical Information of China (English)

    CHEN Yueshun; WEI Jun; ZHAO Xiaolong

    2006-01-01

    Based on the damage mechanics, the concrete damage grade of relative stable environment in measurable spatial is constructed in this paper, and the concrete damage evolving model and corresponding failure rule is constructed based on the damage grade fore-defined. Therefore, the concrete health status and the residual life-span can be assessed according to the measured damage grade. It is propitious to drive the development of concrete durability assessment and life-span forecast. Its feasibility of concrcte damage process description and health assessment is validated with the example in this paper, in which the damage state is described with the ultrasound velocity attenuation, and the freeze-thaw process is regarded as the concrete durability degradation influencing factor to reflect the concrete durability degradation process.

  2. Durability of phosphate-selective CHEMFETs

    NARCIS (Netherlands)

    Wroblewski, Wojciech; Wojciechowski, Kamil; Dybko, Artur; Brzozka, Zbigniew; Egberink, Richard J.M.; Snellink-Ruel, Bianca H.M.; Reinhoudt, David N.

    2001-01-01

    Lipophilic uranyl salophenes derivatives I and II were used as ionophores in membranes of phosphate-selective CHEMFETs. High selectivity for H2PO4− over other anions was obtained for these sensors. The influence of the ionophore structure on the sensor durability was investigated. CHEMFETs based on

  3. Accelerated Testing of Solar Collector Durability

    DEFF Research Database (Denmark)

    Svendsen, Sv Aa Højgaard

    1996-01-01

    A climatic simulator has been build to test the reliability and durability of solar collectors. In the climatic simulator the collector is expåosed to extreme climatic conditions and temperature variations in an accelerated way and during this process the function of the collector is tested...... and the microclimate in the collector box is measured....

  4. 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.

  5. 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.

  6. Selection procedures for durable resistance in wheat.

    NARCIS (Netherlands)

    Beek, M.A.

    1988-01-01

    A wheat breeding programme for durable resistance to all locally important pathogens: leaf rust, stem rust, powdery mildew, Septoria nodorum, Septoria tritici, Cochliobolus sativus, Fusarium graminearum, Common Root Rot, Barley Yellow Dwarf Virus and Soil Borne Mosaic Virus was conducted in Brazil.

  7. Prognosing the durability of polymer sealings

    Directory of Open Access Journals (Sweden)

    W. Okularczyk

    2006-04-01

    Full Text Available Purpose: The paper describes the phenomena connected with the sealing for water hydraulic systems.Design/methodology/approach: For the durability tests two types of sealings, made of three polymeric materials recommended for use in water hydraulics systems have been used. In all investigation arrangements the same guide elements have been used. The tests have been performed maintaining water pressure on the sealing at a level of p = 8±1 MPa and the average speed of the piston rod of v ≈ 0.35 m/sec. Water temperature during investigations was regulated within the range of Tmin = 291 K and Tmax = 305 K. The leakage was distributed to the measurement hoses with the internal diameter of 5mm. For the investigations, the working piston rod with ø 45 f7 with the following parameters has been used: Material: chromium-nickel steel AISI 431 (Cr=16.7%, Ni=2.08% covered with hard chromium plating of ≥ 20 μm, micro-cracks number ≤ 5 000/mm2, Ra = 0.07 μm.Findings: Weibull method, thanks to its multifunctionality, helps to select elements for certain applications (required long failure-free mileages → high characteristic durability – sealings series 30413. Equipment which works sporadically → low characteristic durability but e.g. lower weight and sizes of sealing element – sealing series 30412.Practical implications: Within the confines of the given research concerning an optimal choice of piston rod sealing for water hydraulic systems, large dependence of the sealing durability on the properly chosen guide elements of the piston rod has been found. In extreme cases the durability changed even a few times.Originality/value: The Weibull method has been applied for assessment of durability and reliability of mechanical parts. A computer program has been used to compare two types of piston rod seals used in water hydraulic power systems. Durability limits have been estimated even though discontinued measurement data were used.

  8. Quantitative risk assessment of durable glass fibers.

    Science.gov (United States)

    Fayerweather, William E; Eastes, Walter; Cereghini, Francesco; Hadley, John G

    2002-06-01

    This article presents a quantitative risk assessment for the theoretical lifetime cancer risk from the manufacture and use of relatively durable synthetic glass fibers. More specifically, we estimate levels of exposure to respirable fibers or fiberlike structures of E-glass and C-glass that, assuming a working lifetime exposure, pose a theoretical lifetime cancer risk of not more than 1 per 100,000. For comparability with other risk assessments we define these levels as nonsignificant exposures. Nonsignificant exposure levels are estimated from (a) the Institute of Occupational Medicine (IOM) chronic rat inhalation bioassay of durable E-glass microfibers, and (b) the Research Consulting Company (RCC) chronic inhalation bioassay of durable refractory ceramic fibers (RCF). Best estimates of nonsignificant E-glass exposure exceed 0.05-0.13 fibers (or shards) per cubic centimeter (cm3) when calculated from the multistage nonthreshold model. Best estimates of nonsignificant C-glass exposure exceed 0.27-0.6 fibers/cm3. Estimates of nonsignificant exposure increase markedly for E- and C-glass when non-linear models are applied and rapidly exceed 1 fiber/cm3. Controlling durable fiber exposures to an 8-h time-weighted average of 0.05 fibers/cm3 will assure that the additional theoretical lifetime risk from working lifetime exposures to these durable fibers or shards is kept below the 1 per 100,000 level. Measured airborne exposures to respirable, durable glass fibers (or shards) in glass fiber manufacturing and fabrication operations were compared with the nonsignificant exposure estimates described. Sampling results for B-sized respirable E-glass fibers at facilities that manufacture or fabricate small-diameter continuous-filament products, from those that manufacture respirable E-glass shards from PERG (process to efficiently recycle glass), from milled fiber operations, and from respirable C-glass shards from Flakeglass operations indicate very low median exposures of 0

  9. Optical durability testing of candidate solar mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Kennedy, C.; King, D.; Terwilliger, K.

    2000-03-24

    Durability testing of a variety of candidate solar reflector materials at outdoor test sites and in laboratory accelerated weathering chambers is the main activity within the Advanced Materials task of the Concentrated Solar Power (CSP) Program. Outdoor exposure testing (OET) at up to eight outdoor, worldwide exposure sites has been underway for several years. This includes collaboration under the auspices of the International Energy Agency (IEA) Solar Power and Chemical Energy Systems (SolarPACES) agreement. Outdoor sites are fully instrumented in terms of monitoring meteorological conditions and solar irradiance. Candidate materials are optically characterized prior to being subjected to exposure in real and simulated weathering environments. Optical durability is quantified by periodically re-measuring hemispherical and specular reflectance as a function of exposure time. By closely monitoring the site- and time-dependent environmental stress conditions experienced by the material samples, site-dependent loss of performance may be quantified. In addition, accelerated exposure testing (AET) of these materials in parallel under laboratory-controlled conditions may permit correlating the outdoor results with AET, and subsequently predicting service lifetimes. Test results to date for a large number of candidate solar reflector materials are presented in this report. Acronyms are defined. Based upon OET and AET results to date, conclusions can be drawn about the optical durability of the candidate reflector materials. The optical durability of thin glass, thick glass, and two metallized polymers can be characterized as excellent. The all-polymeric construction, several of the aluminized reflectors, and a metallized polymer can be characterized as having intermediate durability and require further improvement, testing and evaluation, or both.

  10. 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...... are not properly accounted for by conventional measures of core inflation...

  11. Estimation of cyclic durability for turbine rotors

    International Nuclear Information System (INIS)

    The paper deals with data on the effect of asymetry and cycle form on low-cycle fatigue and injurability of and 15kh1m1f rotor steels at high temperatures. It is shown that the sum of injuries from the effect of cyclic and static loads may vary within the limits of-1.2. The steels were analyzed for strength effect on their deformation kinetics and durability. It is noted that the low-cycle fatigue curves in the ''complete deformation scale-cycle number'' coordinates do not depend on the strength level, and therefore it is concluded possible to use these curves for estimating the turbine rotor material durability

  12. Prediction of glass durability as a function of environmental conditions

    International Nuclear Information System (INIS)

    The author reports on thermodynamic model of glass durability applied to natural, ancient, and nuclear waste glasses. The durabilities of over 150 different natural and man-made glasses, including actual ancient Roman and Islamic glasses (Jalame ca. 350 A. D., Nishapur 10-11th century A. D., and Gorgon 9-11th century A.D.), have been compared. Glass durability had been shown to be a function of the thermodynamic hydration free energy. Δ Ghyd, which can be calculated from glass composition and solution pH. Using this approach, the durability of the most durable nuclear waste glasses examined was ≅106 years by comparison with the durability of the natural basalts of ≅106 years. The least durable waste glass formulations were comparable in durability to the most durable simulated medieval window glasses of ≅103 years. In this manner, the durability of nuclear waste glasses has been interpolated to be ≅106 years and no less than 103 years. Hydration thermodynamics are shown to be applicable to the dissolution of glass in various natural environments. Groundwater-glass interactions relative to geologic disposal of nuclear waste, hydration rind dating of obsidians, and/or other archeological studies can be modeled, e.g. the relative durabilities of six simulated medieval window glasses have been correctly predicted for both laboratory (one month) and burial (5 year) experiments

  13. 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.

  14. 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

  15. UV-Shifted Durable Silver Coating for Astronomical Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, N.L.; Wolfe, J.

    2000-06-01

    Silver has the highest reflectance of all of the metals, but it tarnishes in the presence of sulfides, chlorides, and oxides in the atmosphere. Also, the silver reflectance is very low at wavelengths below 400 nm making aluminum more desirable mirror coating for the UV region. They have found a way to prevent silver tarnishing by sandwiching the silver layer between two thin layers of NiCrN{sub x}, and to extend the metal's high reflectance down to 200 nm by depositing the (thin) Ag layer on top of Al. Thus, the uv is transmitted through the thin Ag layer below 400 nm wavelength, and is reflected from the Al layer underneath. This UV-shifted durable coating provides a valuable alternative to the aluminum coating for telescope mirror coatings where high throughput and durability are important considerations. The throughput for a telescope with, say, six reflections from silver coatings is (0.97){sup 6} = 83% compared to (0.92){sup 6} = 60% for aluminum coatings, or 28% less. The use of silver coatings allows more photons to be collected by primary mirror. Aluminum also has a reflectance dip at 850 nm caused by inter-band transitions which is eliminated by placing the thin Ag layer on top. This paper describes a non-tarnishing silver coating having high reflectance down into the UV region. The average specular reflectance is 70%-97% in the near-UV, 95%-99% in the visible region, and {ge} 99% in the infrared region covering the total wavelength range 200 nm to 10,000 nm. Figure 1 compares the reflectance of the UVHR-LLNL silver coating to bare silver and aluminum over-coated with magnesium fluoride over the wavelength range 300 nm to 2000 nm.

  16. Microcracking and durability of high strength concretes

    International Nuclear Information System (INIS)

    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)

  17. (Durability of building materials and components)

    Energy Technology Data Exchange (ETDEWEB)

    Naus, D.J.

    1990-11-27

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

  18. Pour une agriculture mondiale, productive et durable

    OpenAIRE

    Gautier, Henri

    2015-01-01

    Ancien directeur du département Agriculture et développement durable de la Banque mondiale, Michel Petit nous livre un essai directement inspiré de son expérience au service des agricultures du monde. La critique du productivisme, en particulier de son impact sur les ressources naturelles, peut-elle faire l’impasse sur le rôle déterminant de la productivité agricole dans les processus de développement économique ? Dans la lignée des travaux de Théodore Schultz, prix Nobel d’économie en 1979 p...

  19. Prognosing the durability of polymer sealings

    OpenAIRE

    W. Okularczyk; Kwiatkowski, D.

    2006-01-01

    Purpose: The paper describes the phenomena connected with the sealing for water hydraulic systems.Design/methodology/approach: For the durability tests two types of sealings, made of three polymeric materials recommended for use in water hydraulics systems have been used. In all investigation arrangements the same guide elements have been used. The tests have been performed maintaining water pressure on the sealing at a level of p = 8±1 MPa and the average speed of the piston rod of v ≈ 0.35 ...

  20. 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.

  1. Durable, Low-Surface-Energy Treatments

    Science.gov (United States)

    Willis, Paul B.; Mcelroy, Paul M.; Hickey, Gregory S.

    1992-01-01

    Chemical treatment for creation of durable, low-surface-energy coatings for glass, ceramics and other protonated surfaces easily applied, and creates very thin semipermanent film with extremely low surface tension. Exhibits excellent stability; surfaces retreated if coating becomes damaged or eroded. Uses include water-repellent surfaces, oil-repellent surfaces, antimigration barriers, corrosion barriers, mold-release agents, and self-cleaning surfaces. Film resists wetting by water, alcohols, hydrocarbon solvents, and silicone oil. Has moderate resistance to abrasion, such as rubbing with cloths, and compression molding to polymers and composite materials.

  2. Durable and Robust Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Knibbe, Ruth; Hauch, Anne;

    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...... 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...

  3. The Durability of Epoxy Resin Coating

    Institute of Scientific and Technical Information of China (English)

    ZHAO Fujun; BA Hengjing; GAO Xiaojian

    2008-01-01

    The durability of epoxy resin coating was studied under environments with relative humidity(RH) of 98%-100%, at 55 ℃ for 900 h, at 65℃ for 700 h and at 75 ℃ for 400 h, respectively. Peel strength test, dynamical mechanical thermal analysis (DMTA), infrared spectroscopy (IR) and energy dispersive X-ray spectroscopy (EDX) were employed for measurements. Peel strength indicated the development of adhesive property of the coating, DMTA indicated the development of physical property, IR revealed the development of chemical structure, and EDX showed surface element change of the coating. All these results show a good time-temperature equivalence characteristic between humidity aging time and temperature.

  4. Product Durability, Solid Waste Management and Market Structure

    OpenAIRE

    Runkel, Marco

    1999-01-01

    For a durable consumption good which turns into waste after consumption, the socially optimal durability increases with an increase in the marginal environmental damage. In a laissez-faire equilibrium under perfect competition, producers fail to provide an efficient product design, i.e. durability is inefficiently small, whereas the amount of solid waste is inefficiently large. The market failure is corrected simply by Pigouvian taxation which also can be interpreted as an extension of the pr...

  5. 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.

  6. 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...

  7. CHP Fuel Cell Durability Demonstration - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Petrecky, James; Ashley, Christopher J

    2014-07-21

    Plug Power has managed a demonstration project that has tested multiple units of its high-temperature, PEM fuel cell system in micro-combined heat and power (μ-CHP) applications in California. The specific objective of the demonstration project was to substantiate the durability of GenSys Blue, and, thereby, verify its technology and commercial readiness for the marketplace. In the demonstration project, Plug Power, in partnership with the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine (UCI), and Sempra, will execute two major tasks: • Task 1: Internal durability/reliability fleet testing. Six GenSys Blue units will be built and will undergo an internal test regimen to estimate failure rates. This task was modified to include 3 GenSys Blue units installed in a lab at UCI. • Task 2: External customer testing. Combined heat and power units will be installed and tested in real-world residential and/or light commercial end user locations in California.

  8. Experimental Investigation on Contribution of CFRP Attachment to Durability of Reinforced Concrete Structure Subjected to Chloride Attack

    Institute of Scientific and Technical Information of China (English)

    Chen Fengshan; Zhao Guofan; Pan Deqiang

    2006-01-01

    The function of externally-bonded carbon fiber reinforced polymer (CFRP) in preventing chloride from entering into concrete is verified by experiment. The results show that externally-bonded CFRP can be considered as a part of corrosion prevention system of strengthened concrete structures subjected to chloride ingress, and the contribution of CFRP should be considered in evaluation of durability of reinforced concrete structures with externally-bonded CFRP. With the effective shielding function of CFRP considered, an equation for residual lifetime prediction of concrete structures with externally-bonded CFRP is derived from Ficks dispersion law. CFRP has two functions for coastal concrete structures, including strengthening and increasing durability as part of corrosion prevention system.

  9. Further steps towards a quantitative approach to durability design

    NARCIS (Netherlands)

    Lounis, Z.; Lacasse, M.A.; Siemes, A.J.M.; Moser, K.

    1998-01-01

    Abstract This paper presents further steps in the development of reliability-based approaches for the durability design and service life prediction of building components which integrate the requirements of safety, serviceability and durability. In general, the load and resistance should be modelled

  10. 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.

  11. Thermal fatigue durability for advanced propulsion materials

    Science.gov (United States)

    Halford, Gary R.

    1989-01-01

    A review is presented of thermal and thermomechanical fatigue (TMF) crack initiation life prediction and cyclic constitutive modeling efforts sponsored recently by the NASA Lewis Research Center in support of advanced aeronautical propulsion research. A brief description is provided of the more significant material durability models that were created to describe TMF fatigue resistance of both isotropic and anisotropic superalloys, with and without oxidation resistant coatings. The two most significant crack initiation models are the cyclic damage accumulation model and the total strain version of strainrange partitioning. Unified viscoplastic cyclic constitutive models are also described. A troika of industry, university, and government research organizations contributed to the generation of these analytic models. Based upon current capabilities and established requirements, an attempt is made to project which TMF research activities most likely will impact future generation propulsion systems.

  12. Cement replacement materials. Properties, durability, sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanianpour, Ali Akbar [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Concrete Technology Center

    2014-04-01

    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.

  13. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    and the pore structure.Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached. A test arrangement is developed. The surface crack pattern is characterized using video-scanning and digital image analysis. As environmental load, exposure to 1) a concentrated...... chloride solution or 2) water (capillary suction) is used. Penetration of chlorides will be characterized qualitatively (Color-test) as well as quantitatively (Rapid Chloride Test from Germann).Additional durability tests (freeze-thaw, water vapour diffusion, chloride permeability) and studies of pore...... structure are made on specimens drilled or sawed from beams after unloading (mechanical load). The pore structure of the concretes will be studied by microscopy, sorption and suction curves. The test programme involves three different concrete qualities (water-cement ratios). Both steel fibres (ZP...

  14. 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).

  15. Durability of Prunus africana: Evidence of Biocidal and Lipophilic Properties Responsible for Natural Durability

    International Nuclear Information System (INIS)

    Analysis of the prunus africana sapwood and heartwood extracts was studied with the aim of understanding the reasons for it's natural durability. Soxhlet extraction of wood powder using different solvents was done. The extracts were tested against the fungi coriolus versicolor, Poria placenta and Aureobasidium pullulans at concentrations of 50, 100, 500 and 1000 ppm. Soxhlet extraction of wood blocks using the same solvents was also carried out and the wood blocks finally tested against fungi and termites. The results showed high exhibition rate against fungi at low extract concentrations. Extracted wood blocks showed low resistance against termites while the un-extracted ones were resistant. Analysis of the products present in hexane, dichloromethane, acetone, toluene/ethanol and water extracts by HPLC indicates presence of phenols and lipophilic compounds, which could be associated with the preceding results. Inhibition against fungi increased with extract concentration and decreased with time. In some instances at high concentration, fungal growth started after the control Petri-dish was fully colonized. Inspite of the fungal and termiticidal properties of certain products contained in the extracts, these properties do not entirely explain the reasons for the high durability. Chemical synthesis with formulations based on the natural components present in the extracts of such durable wood could be interesting as potential additives in fungicides and insecticides. Such formulations based on natural compounds could environmentally friendly

  16. Encapsulation of TRISO particle fuel in durable soda-lime-silicate glasses

    International Nuclear Information System (INIS)

    Tri-Structural Isotropic (TRISO) coated particle-fuel is a key component in designs for future high temperature nuclear reactors. This study investigated the suitability of three soda lime silicate glass compositions, for the encapsulation of simulant TRISO particle fuel. A cold press and sinter (CPS) methodology was employed to produce TRISO particle–glass composites. Composites produced were determined to have an aqueous durability, fracture toughness and Vickers’ hardness comparable to glasses currently employed for the disposal of high level nuclear wastes. Sintering at 700 °C for 30 min was found to remove all interconnected porosity from the composite bodies and oxidation of the outer pyrolytic carbon layer during sintering was prevented by processing under a 5% H2/N2 atmosphere. However, the outer pyrolytic carbon layer was not effectively wetted by the encapsulating glass matrix. The aqueous durability of the TRISO particle–glass composites was investigated using PCT and MCC-1 tests combined with geochemical modelling. It was found that durability was dependent on silicate and calcium solution saturation. This study provides significant advancements in the preparation of TRISO particle encapsulant waste forms. The potential for the use of non-borosilicate sintered glass composites for TRISO particle encapsulation has been confirmed, although further refinements are required

  17. Covercrete with hybrid functions - A novel approach to durable reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Tang, L.; Zhang, E.Q. [Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Fu, Y. [KTH Royal Institute of Technology, SE-106 91 Stockholm (Sweden); Schouenborg, B.; Lindqvist, J.E. [CBI Swedish Cement and Concrete Research Institute, c/o SP, Box 857, SE-501 15 Boraas (Sweden)

    2012-12-15

    Due to the corrosion of steel in reinforced concrete structures, the concrete with low water-cement ratio (w/c), high cement content, and large cover thickness is conventionally used for prolonging the passivation period of steel. Obviously, this conventional approach to durable concrete structures is at the sacrifice of more CO{sub 2} emission and natural resources through consuming higher amount of cement and more constituent materials, which is against sustainability. By placing an economically affordable conductive mesh made of carbon fiber or conductive polymer fiber in the near surface zone of concrete acting as anode we can build up a cathodic prevention system with intermittent low current density supplied by, e.g., the solar cells. In such a way, the aggressive negative ions such as Cl{sup -}, CO{sub 3}{sup 2-}, and SO{sub 4}{sup 2-} can be stopped near the cathodic (steel) zone. Thus the reinforcement steel is prevented from corrosion even in the concrete with relatively high w/c and small cover thickness. This conductive mesh functions not only as electrode, but also as surface reinforcement to prevent concrete surface from cracking. Therefore, this new type of covercrete has hybrid functions. This paper presents the theoretical analysis of feasibility of this approach and discusses the potential durability problems and possible solutions to the potential problems. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Preventing medical device recalls

    CERN Document Server

    Raheja, Dev

    2014-01-01

    Introduction to Medical Device RequirementsIntroductionThe ChallengesSources of ErrorsUnderstanding the Science of Safety     Overview of FDA Quality System Regulation     Overview of Risk Management Standard ISO 14971     Overview of FDA Device Approval Process     Overview of Regulatory Requirements for Clinical TrialsSummaryReferencesPreventing Recalls during Specification WritingIntroductionConduct Requirements Analysis to Identify Missing RequirementsSpecifications for Safety, Durability, and

  19. 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.

  20. Influence of chloride admixtures on cement matrix durability

    International Nuclear Information System (INIS)

    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 500C, 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

  1. Bill asserting the national commitment for the environment (declared urgency), text from the commission of economy, sustainable development and town and country planning; Projet de Loi portant engagement national pour l'environnement (urgence declaree), Texte de la Commission de L'Economie, du Developpement Durable et de L'Amenagement du Territoire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-15

    The bill asserting the French national commitment for the environment (also named 'Grenelle 2') is considered as the juridical tool-box of the French environmental policy. It confirms, strengthens, and concretizes the objectives defined by the Grenelle 1 law. The main dispositions of the bill concern the following domains: settlement and urbanism with the improvement of the energy efficiency, energy conservation and life-cycle of buildings; transports with the development of sustainable transportation systems; energy with the creation of regional climate, air and energy schemes with the aim of developing renewable energies (with some restrictions concerning wind power) and reducing CO{sub 2} emissions; biodiversity with the creation of ecological pathways between protected areas for the migration of flora and fauna species; environment and waste management with the reinforcement of measures for the abatement of environmental pollutant effects. Among the numerous dispositions involving more than 20 codes (urbanism, environment, buildings etc..) one concerns the progressive implementation of a 'carbon price' index taking into account the greenhouse gas emission costs during the whole life cycle of a product, another one concerns the monitoring of indoor air quality in public buildings. This document is the text of the bill as prepared by the Commission of economy, sustainable development and town and country planning. (J.S.)

  2. Information report, on behalf of the delegation to the national and sustainable development, about the management of household wastes in the French territory; Rapport d'information, au nom de la delegation a l'amenagement et au developpement durable du territoire, sur la gestion des dechets menagers sur le territoire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-11-01

    The French law from July 13, 1992, relative to the elimination of wastes and to the waste management facilities, was based on four goals: reduction of waste production at the source, transport, valorization by recycling or energy recovery, and disposal of ultimate wastes only. This report makes a status of the situation of wastes management in France, ten years after the enforcement of the 1992 law: persistence of the society problem of wastes, mitigated results (collection, processing, delays, insufficient valorization), present day and future national development stakes (saturated storage and processing facilities, public psychological reserve, environmental conflicts), financing, new proposals (restoring public confidence, transforming harmful effects into richnesses thanks to financial incentives). Some additional information is given in appendixes which make the second part of this report (origin and processing of household wastes, storage facilities with a capacity greater than 20000 t/year, list of incineration facilities in operation, transport of municipal wastes). (J.S.)

  3. Information report realized for the Senate delegation to the territory management and sustainable development on the local energies; Rapport d'information fait au nom de la delegation du Senat a l'amenagement et au developpement durable du territoire sur les energies locales

    Energy Technology Data Exchange (ETDEWEB)

    Belot, C.; Juilhard, J.M

    2006-06-15

    This report deals with the renewable energies and the local development called the territory intelligence in action. Taking into account the place of the electricity in the french energy accounting and the part of the nuclear in its production, the local authorities have to act in the heat domain, which is the first energy need in France, far in front of the specific electricity (those which cannot be replace by other type of energy). But 80% of the heat is today covered by fossil energies. No actions to change this situation will be done without a real implication of the local government. The authors preconize an ambitious objective: cover 50% of the heat needs from renewable energies in the next generat This objective must rely on a program called ''alternative energies''. In this framework the authors provide recommendations on the implementation of the renewable energies as an essential challenge for the local authorities. (A.L.B.)

  4. Opinion presented on behalf of the Economical Affairs Commission on the finance bill for 2010 (n. 1946) - Volume II: Sustainable ecology, development and planning. Industry and energy; Avis presente au nom de la Commission des Affaires Economiques sur le projet de loi de finances pour 2010 (n.1946), tome 2 ecologie, developpement et amenagement durables industrie et energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-10-15

    This report of the French National Assembly first presents the different programmes and actions related to energy and industry for which credits are foreseen in the French finance bill for 2010: development of firms and employment, energy policy, after-mining policy, struggle against climate change, management of ecology, energy, sustainable development, and sea policies, research in the field of energy and sustainable development and planning. The author then outlines the importance of the creation of conditions for a green growth in order to cope with an unprecedented crisis which ruins industrial employment. This implies the support of strategic sectors (energy-efficient building, evolution towards green chemistry, photovoltaic solar energy, renewable heat, innovating vehicles), the implementation of new priorities (smart grids, management of raw materials), and the emergence of ecological technologies promoted by the new tools of a climate policy (carbon tax introduction, improvement of carbon markets). It also implies an industrial output for research by means of a networking of actors (development of competitiveness poles, participation to European partnerships), and a reinforcement of the industrial horizon in the research policy (patenting, start-up development, support to innovating small and middle-sized companies, implementation of a true French capital-risk sector)

  5. Opinion presented on behalf of the Foreign Affairs Commission on the Finance bill for 2011 (n. 2824), volume 5 Ecology, Sustainable Development and Land Planning; Avis presente au nom de la Commission des Affaires Etrangeres sur le projet de loi de finances pour 2011 (n. 2824), tome 5 ecologie, developpement et amenagement durables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This report first gives an overview of the action of the French diplomacy for the protection of the environment. It comments the participation to international and European negotiations, evokes the negotiations within the Union for the Mediterranean, and outlines the quality of the French administrative arrangement (relationship between the Ministry of Foreign Affairs and the Ministry of Ecology, increasing importance of a network of correspondents, support to NGOs, and role of the ADEME). Then, the author reports the ongoing works of the European Union on energy and climate (carbon tax, carbon emission reductions, cooperation with Russia, challenges of energy efficiency improvement in Russia) and comments what comes next the Copenhagen Conference. In the last part, the author highlights the forthcoming challenges which may lead either to success or failure: the Nagoya Conference and the issue of biodiversity management in high seas

  6. Opinion presented on behalf of the Economic Affairs Commission on the Finance bill for 2011 (n. 2824), volume 2 Ecology, Sustainable Development and Land Planning, industry and energy; Avis presente au nom de la Commission des Affaires Economiques sur le projet de loi de finances pour 2011 (n. 2824), tome 2 ecologie, developpement et amenagement durables industrie et energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    In her introduction, the author gives a description of the difficult context and situation faced by the industrial sector in France, notably because of the growing activity of emerging countries like China, India or Brazil, but also because of the weakness of research industrial valorization and of the innovation policy (losing the manufacturing capacity leads to losing the capacity for innovation). Then, after a critic of the current policy (reform of the professional tax, a boosting plan with limited results), she comments the contents of public programmes concerning firm and job development, energy, the steering of ecology, energy, sustainable development and sea policies, research in energy and sustainable development and land planning. She comments ways and tools aimed at supporting industrial jobs through innovation: the FSI (strategic investment fund), the competitiveness poles, specific aids to small and medium sized enterprises, tax credit related to research activities. She addresses the energy sector, questioning the French supremacy in the nuclear energy and the increase of electricity price, and criticizing the management of the development of renewable energies (high expenses for no industrial development)

  7. Durability of tannin-boron-treated timber

    Directory of Open Access Journals (Sweden)

    Gianluca Tondi

    2012-11-01

    Full Text Available Tannin-boron wood preservatives were investigated for their resistance against outdoor agents. This work focused on the analysis of the causes that affect the durability of the tannin-hexamine-treated samples. In particular, dimensional stability, resistance to leaching, and resistance to biological agents were investigated. The combined effect of deterioration agents was evaluated by subjecting the treated samples to simulated and natural weathering tests. The study of the appearance and of the color components (L*, a*, and b* according to CIELAB space of the exposed samples was monitored to assess the efficacy of the tannin-boron formulations for outdoor applications. Significant resistance against the action of water (EN 84, ENV 1250-2 and insects (EN 47 has been demonstrated in specific tests. Conversely, the continuous stress due to artificial and natural weathering deteriorates the color and the visible features of the treated specimens. The combined effect of moisture modifications, solar exposition, and leaching cycles damages the structure of the tannin-based polymeric network and subsequently it negatively affects its preservation properties.

  8. Optical enhancing durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Varadarajan, Aravamuthan; Movassat, Meisam

    2016-07-05

    Disclosed herein are polysilsesquioxane based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In embodiments, 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 the 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, Si--OH condensation catalyst and/or nanofillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes including flow coating and roll coating, 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.

  9. 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.

    2016-07-26

    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.

  10. 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.

  11. Durability of Alkali Activated Blast Furnace Slag

    Science.gov (United States)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  12. INFLUENCE OF TEMPERATURE, HUMIDITY AND ULTRAVIOLET IRRADIATION ON DURABILITY AND DURABILITY OF MODIFIED WOOD

    Directory of Open Access Journals (Sweden)

    V. P. Yartsev

    2011-02-01

    Full Text Available Problem statement. A technological mode of wood modification with the use of various sub-stances (kerosene, paraffin, Emukril M, emulsion 252 is described. The influence of type of mod-ifier on mechanical and hydrophysical properties of wood is discussed.Results and conclusions. The effect of elevated temperature on expansion and compression of modified wood is investigated, and the values of coefficients of linear thermal expansion are de-termined. The analysis of the results of the influence of climatic factors (water and UV radiation, repeated freezing/thawing on properties of modified wood is performed. The durability of mod-ified wood is studied.

  13. 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.)

  14. Biological durability of wood modified by citric acid

    Directory of Open Access Journals (Sweden)

    Bogoslav Šefc

    2008-07-01

    Full Text Available This paper presents the results of measurement of durability of beech wood (Fagus sylvatica modified by Citric Acid (CA against brown rot fungus Poria placenta according to EN 113. Modification was performedby impregnation with 7.0% CA and 6.5% sodium-hypophosphite (SHP water solution and 10-hour curing at 140 °C. The influence of thermal treatment on durability was also researched. Weight percentage gain (WPG caused by modification, moisture content (MC and mass loss of wood (dm after fungal nutrition were measured. WPG of modified beech wood was 6.1% and that of thermally treated wood was -0.3%. The results showed increased durability of modified wood to be 8.3 times greater than nonmodified, while thermal treatment did not give significant durability improvement. These results indicate modification by CA as a promising alternative, but further research on optimisation of modification parameters is needed to achieve improvement of wood properties.

  15. Durability of styrene-butadiene latex modified concrete

    Energy Technology Data Exchange (ETDEWEB)

    Shaker, F.A.; El-Dieb, A.S.; Reda, M.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Structural Engineering

    1997-05-01

    The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties. This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability aspects of Styrene-Butadiene latex modified concrete (LMC) compared to those of conventional concrete. Also, the main microstructural characteristics of LMC were studied using a Scanning Electron Microscope (SEM). The SEM investigation of the LMC showed major differences in its microstructure compared to that of the conventional concrete. The LMC proved to be superior in its durability compared to the durability of conventional concrete especially its water tightness (measured by water penetration, absorption, and sorptivity tests), abrasion, corrosion, and sulphate resistance.

  16. High-durability phase-shift film with variable transmittance

    Science.gov (United States)

    Nozawa, Osamu; Shishido, Hiroaki; Kajiwara, Takenori

    2015-10-01

    In order to maintain the lithographic margin and to have sufficient image resolution, attenuated phase shift masks are widely used as a resolution enhancement technique. To improve the radiation durability of the phase shift film, we have developed low oxidation MoSi shifters, such as A6L2, as one option for improving radiation durability. But to provide the best radiation durability, we have developed a new approach eliminating the molybdenum from the phase shift film and introduced a Silicon-Nitride (Si-N) based attenuated phase shift film. Traditionally the transmittance of the phase shift layer is usually around 6%. In the case of a pure Si3N4 film, the transmittance with 180 degree phase shift is around 18%. But, by controlling film structure with a combination of Si-N the transmittance can be tuned to the customers desired transmission value for high durability Mo free attenuated phase shift films.

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

    International Nuclear Information System (INIS)

    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 (106 years old). The thermodynamic hydration energy is shown to be related to the bond energetics of the glass. 69 references, 2 figures, 1 table

  18. Durability of optically variable devices on bank notes

    Science.gov (United States)

    Bartz, William J.

    2002-04-01

    Currency producers are facing dual marketplace demands to increase bank note circulation life and to employ increasingly effective security features against counterfeiting. Diffractive optically variable devices such as foil patches, stripes and windowed thread have become popular security features used for bank notes throughout the world, but historically have suffered in their ability to match the durability of the bank note substrate itself. A study to find a durable, diffractive OVD led to the development of a windowed-thread feature designed to pass stringent durability criteria for laundry, chemical soak and other performance tests. Diffractive-film production methods, demetallization techniques, thread construction and applied coatings were key factors in achieving this durability.

  19. Durability of Concrete under Multi-damage Action

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiao-long; WEI Jun; LIU Zhan-ke

    2004-01-01

    Several different experiments,including freezing-thawing,freezing-thawing+drying-wetting,and drying-wetting,in salt solution and in water respectively,were designed to determine the durability of concrete.The durability damage features of concrete in the above experiments were studied.It is demonstrated that the damage extent of concrete under freezing-thawing and freezing-thawing+drying-wetting in salt solution is larger than that in water.Thus,freezing-thawing and freezing-thawing+drying-wetting in salt solution are stricter and more effective methods to evaluate the durability of concrete in salt-existing environment in cold regions.The damage extent of concrete under freezing-thawing+drying-wetting shows an ultra-superposition effect.The order of concrete durability deterioration degree in these experiments is determined.It shows that effects of multi-damage factors are greater than those of single-damage factor.

  20. Durability Study on High Calcium Fly Ash Based Geopolymer Concrete

    OpenAIRE

    Ganesan Lavanya; Josephraj Jegan

    2015-01-01

    This study presents an investigation into the durability of geopolymer concrete prepared using high calcium fly ash along with alkaline activators when exposed to 2% solution of sulfuric acid and 5% magnesium sulphate for up to 45 days. The durability was also assessed by measuring water absorption and sorptivity. Ordinary Portland cement concrete was also prepared as control concrete. The grades chosen for the investigation were M20, M40, and M60. The alkaline solution used for present study...

  1. Durability of hydrophobic coatings for superhydrophobic aluminum oxide

    Science.gov (United States)

    Jenner, Elliot; Barbier, Charlotte; D'Urso, Brian

    2013-10-01

    Robust and easily produced superhydrophobic surfaces are of great interest for mechanical applications, including drag reduction and MEMS. We produce novel superhydrophobic surfaces with several different coatings and tested the durability of each of these coatings with respect to long term immersion in water in order to determine the most long-lasting surface preparation. A pair of combinations of spin on polymers, surface features, and adhesion promoters was found that provide long term durability.

  2. Evolutionary Model of a Anonymous Consumer Durable Market

    OpenAIRE

    Joachim Kaldasch

    2013-01-01

    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. Describing the aggregate sales as the sum of first, multiple and replacement purchase the product life...

  3. 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

  4. Assessment of cement durability in repository environment

    International Nuclear Information System (INIS)

    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

  5. Opinion on the behalf of the Sustainable Development and Land Planning Commission on the Finance bill for 2011 (n. 2824), volume 7: research and university education, research in the fields of sustainable development; Avis presente Au nom de la Commission du Developpement Durable et de L'amenagement du Territoire sur le projet de loi de finances pour 2011 (n. 2824), tome 7 recherche et enseignement superieur recherche dans les domaines du developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    While presenting two programmes which respectively concern the management of surroundings and resources, and the fields of energy and of sustainable development and land planning, and commenting their financial means, their objectives and performance indicators, this report shows that these programmes are facing insufficient grants. Then, it shows that the different public operators (research laboratories, centres and institutions, public agencies) are weakened by decreasing allocations. Three examples are then studied to show the difficulties of these institutions which have to perform fundamental missions with limited means: IFREMER (in the case of oyster control), INRA (for the development of the biotechnology sector) and IRSN (for the safety of nuclear waste storage)

  6. New approaches to building pathology and durability

    CERN Document Server

    2016-01-01

    This book presents a collection of recent research works intended to assist in the effective management of service loss. It develops and evaluates methodologies for the assessment of defects and failures, and proposes methodologies for preventing and mitigating building defects. As such, the book will appeal to a broad readership of scientists, practitioners, students and lecturers.

  7. Durable temperature sensor for extreme environments

    International Nuclear Information System (INIS)

    A number of pyrometallurgical processes are operated without continuous measurement of the process temperature. In most cases this is due to the coupling of extremely high temperatures with chemically corrosive environments. Since the classical thermocouple must operate at these conditions, its life is usually very short and normally only serves for batch measurements. In recent years the evolution of infrared pyrometers has led to an increasing use of these instruments to monitor process temperatures. They are not however without drawbacks. They require a clear line of sight and their lenses must be clean. Moreover, the dusty nature of such environments can lead to changing emissivities and faulty readings. In an effort to overcome these deficiencies and provide continuous and accurate readings of temperature we developed and tested a novel temperature-sensing device that is durable and long lasting. This new sensor is based on heat pipe technology, which involves the evaporation and condensation of a working fluid within the pipe. The leading portion (i.e. evaporator) of the probe is inserted into the process chamber while the other portion (i.e. condenser) of the probe protrudes on the outside of the chamber. By virtue of the superconducting nature of the probe, the overall operating temperature of the probe can be regulated by controlling the cooling of the condenser (typically with air). Since the probe can be made to operate within a temperature range that is safe for the materials of construction of the probe, its life can be in the order of months. A calibration of the operating temperature of the probe with actual process temperature is used to provide continuous process temperature. As the process temperature changes so does the heat pipe temperature. Numerous tests on lab scale probes have shown this unit to be viable. Moreover, a series of plant trials at Cominco in the copper drossing furnace, the Kivcet smelter, and a zinc roaster have yielded

  8. Natural and agglomerated stone durability assessment according to technical standards

    Directory of Open Access Journals (Sweden)

    Ivana Šimková

    2010-01-01

    Full Text Available The assessment of rock behaviour and durability plays an important role in the use of rocks and similar materials for all building purposes. Durability is a complex term, therefore the paper deals with the terminology and aspects related to the evaluation and prediction possibilities of stone durability. Technical standards offer some laboratory procedures suitable for stone durability assessment. The paper presents the results of the application of some standard laboratory methods on select types of natural and agglomerated stones, from the physical properties determination and durability assessment point of view. On the basis of defined criteria of physical properties, such as the value of open porosity, uniaxial compressive strength and water absorption, was predicted the behaviour of selected stones against ageing and weathering. Results of the realised laboratory weathering tests such as the determination of resistance to frost and salt crystallisation, determination of resistance to ageing by SO2 action in the presence of humidity, and determination of resistance to thermal shock, confirmed and verified rock behaviour conditional on stone genesis, mineral composition and structural characteristics.

  9. Biological Durability of Oil Heat Treated Alder Wood

    Directory of Open Access Journals (Sweden)

    Robert Lacić

    2014-06-01

    Full Text Available The article presents preliminary results of the biological durability of oil heat treated (OHT alder wood (Alnus glutinosa against pure cultures of rot fungi (Postia placenta and Trametes versicolor in lab conditions. The modification was performed by heating of specimens immersed in soya oil. There were four heating regimes of different duration (6 and 10 hours at final temperature of 180 and 200 ºC. The increase in mass (MI caused by modification and mass loss of wood caused by fungal decay (ML were determined. In addition, the natural durability of alder wood was determined and compared to the natural durability of beech wood as the reference wood species. After modification of alder wood at 200 °C, MI was lower than after treatment at 180 °C. MI was also lower after 10 hours of treatment than after 6 hours of treatment. The results showed significantly increased biological durability of modified alder wood against both tested fungi. The effect of OHT on increasing the biological durability of alder wood was higher against the fungus P. placenta. It seems that the fungus T. versicolor favours the remained oil after modification causing higher mass loss. The results showed that alder wood, thermally modified in soya oil by testing regimens, is not suitable for applications in use classes 3-5.

  10. More Durable Tracks for Heavy Vehicles

    Science.gov (United States)

    Collins, Earl R., Jr.

    1987-01-01

    Tie bars instead of threaded fasteners make track throwing less likely. Proposed undercarriage for tank or bulldozer has flanged edges to prevent rocks and other road debris from getting caught in track drive and damaging or casting off track. Improved track has no threaded fasteners to be loosened by road shock and vibration. Continuous chain of floating guide bars articulated at web junctions. Pins replace bolted connections. Guide bars and flanges on vehicle keep out stones.

  11. Properties and durability of metakaolin blended cements

    Directory of Open Access Journals (Sweden)

    Ezzat, El-Sayed

    2010-09-01

    Full Text Available This paper evaluates the optimal calcination temperature and replacement ratio to ensure high metakaolin (MK pozzolanicity in blended cement. The MK used was prepared by firing two types of local at temperatures ranging from 700 to 850 ºC. Dry blends of ordinary Portland cement (OPC and varying proportions of MK were mixed with the amount of water required to ensure optimal consistency of the resulting pastes. The specimens were cured at 100% RH for 24 h and then immersed in water for 3, 7, 28, 90 or 180 days. At each test time, the degree of hydration and compressive strength of the hardened cement pastes were measured The findings showed that the most suitable calcination temperature to obtain metakaolin is 700 ºC, while the optimal replacement ratio ranges from 25 to 30%. DTA was used to determine the phases comprising the hydration products forming at the ages studied. Pure OPC and OPC-MK specimens were immersed in 3% NaCl and 5% MgSO4 solutions for 30, 90 and 180 days to measure their durability. The OPC-MK pastes immersed in the 3% NaCl solution were observed to be highly resistant to chloride attack.

    El presente trabajo evalúa el comportamiento puzolánico de metacaolín (MK, producto de la calcinación a distintas temperaturas de dos tipos de caolín local de composiciones químicas diferentes, al incorporarse al cemento en diferentes proporciones. Se preparó un cemento adicionado mediante la mezcla en seco de cemento Portland ordinario (OPC y metacaolín (MK, a los que se añadió la cantidad óptima de agua para obtener una pasta de la consistencia deseada. Las probetas se curaron a una HR del 100% durante 24 horas, sumergiéndose posteriormente en agua durante 3, 7, 28, 90 o 180 días. A cada tiempo de ensayo se controló el grado de hidratación de las pastas endurecidas y se comprobó la resistencia a la compresión de las probetas cúbicas a las edades de curado establecidas. Los resultados obtenidos indican que la

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

    International Nuclear Information System (INIS)

    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)

  13. Durability of monopolar Teflon-coated electromyographic needles.

    Science.gov (United States)

    Mikolich, L M; Waylonis, G W

    1977-10-01

    The results of a two-year study on durability and cause of failure of electromyographic monopolar electrodes are reported. The electrodes were obtained from the regular stock of three different manufacturing sources. Durability is defined on the basis of the number of patients that could be examined before failure. The range was 3 to 110 with the averages 19.7, 33.8, and 62.5 for the three different manufacturers. Common causes of electrode failure included: Teflon retraction, 40.6%; tip dullness or burrs, 34.8%; structural failure of wire or pin, 13.1%; electrical artifacts, 9.7%; and bending of needle shank, 5.7%. Variations in manufactures' tip contour and bevel correlated with tip durability. PMID:907451

  14. Durability/life of fiber composites in hygrothermomechanical environments

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1982-01-01

    Statistical analysis and multiple regression were used to determine and quantify the significant hygrothermomechanical variables which influence the tensile durability/life (cycle loading, fatigue) of boron-fiber/epoxy-matrix (B/E) and high-modulus-fiber/epoxy-matrix (HMS/E) composites. The use of the multiple regression analysis reduced the variables from fifteen, assumed initially, to six or less with a probability of greater than 0.999. The reduced variables were used to derive predictive models for compression and intralaminar shear durability/life of B/E and HMS/E composites assuming isoparametric fatigue behavior. The predictive models were subsequently generalized to predict the durability/life of graphite/fiber-r generalized model is of simple form, predicts conservative values compared with measured data and should be adequate for use in preliminary designs. Previously announced in STAR as N82-14287

  15. Effects of slag fineness on durability of mortars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS)replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects,exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Consequently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.

  16. The phenomenon of durability variable dies for aluminum extrusion profiles

    Directory of Open Access Journals (Sweden)

    J. Borowski

    2016-04-01

    Full Text Available Extrusion dies are usually regenerated several times (min 4 times. The phenomenon of extended life after each regenerative nitriding process has not been explained. In this work, the regeneration process of dies used in the extrusion of aluminium profiles has been presented. In the article, it was sought to explain the cause of increased die durability after the third or fourth nitriding. Also in this work is presented an analysis of the influence of the parameters of gas nitriding with the ZeroFlow method on hardness of dies. Results were verified under industrial conditions at extrusion company, comparing the durability of the dies nitrided with the ZeroFlow method with so-far-used dies nitrided in the commercial way. An increase of the dies durability was achieved after a single ZeroFlow nitriding.

  17. Preventing stroke

    Science.gov (United States)

    Stroke - prevention; CVA - prevention; cerebral vascular accident - prevention; TIA - prevention, transient ischemic attack - prevention ... A stroke occurs when the blood supply is cut off to any part of the brain. A stroke is ...

  18. Antisuperbug Cotton Fabric with Excellent Laundering Durability.

    Science.gov (United States)

    Yu, Ming; Wang, Ziqiang; Lv, Min; Hao, Rongzhang; Zhao, Rongtao; Qi, Lihua; Liu, Shima; Yu, Chuhong; Zhang, Bowu; Fan, Chunhai; Li, Jingye

    2016-08-10

    Multidrug-resistant superbugs are currently a severe threat to public health. Here, we report a novel kind of antisuperbug material prepared by irradiation induced graft polymerization of 1-butyl-3-vinyl imidazole chloride onto cotton fabric. The reduction of superbugs on this fabric is higher than 99.9%. Attributed to the strong covalent bonding between the graft chains and the cellulose macromolecules, the antisuperbug performance did not decrease even after 150 equiv of domestic laundering cycles. Covalent bonding also prevented the release of the antibacterial groups during application and guarantees the safety of the material, which was proved by animal skin irritation and acute oral toxicity tests. PMID:27464074

  19. Long time durability tests of fabric inlet stratification pipes

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    The long time durability of seven different two layer fabric inlet stratification pipes for enhancing thermal stratification in hot water stores is investigated experimentally. Accelerated durability tests are carried out with the inlet stratification pipes both in a domestic hot water tank...... and that this destroys the capability of building up thermal stratification for the fabric inlet stratification pipe. The results also show that although dirt, algae etc. are deposited in the fabric pipes in the space heating tank, the capability of the fabric inlet stratifiers to build up thermal stratification...

  20. 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.

  1. Durable phosphate-selective electrodes based on uranyl salophenes

    NARCIS (Netherlands)

    Wroblewski, Wojciech; Wojciechowski, Kamil; Dybko, Artur; Brzozka, Zbigniew; Egberink, Richard J.M.; Snellink-Ruel, Bianca H.M.; Reinhoudt, David N.

    2001-01-01

    Lipophilic uranyl salophenes derivatives were used as ionophores in durable phosphate-selective electrodes. The influence of the ionophore structure and membrane composition (polarity of plasticizer, the amount of incorporated ionic sites) on the electrode selectivity and long-term stability were st

  2. Durability Quality Research of Concrete Containing Solar PV Cells

    Directory of Open Access Journals (Sweden)

    Chao Sao-Jeng

    2015-01-01

    Full Text Available In this article we demonstrated the study results of durability quality of concrete containing waste solar PV cells. The study used alkali activator to improve the activity of alkali-activated materials in solar PV cells so as to replace Portland cement as binder in concrete. By using sodium hydroxide as an alkali-activator, a high-pH environment is generated to excite the binding characteristics of alkali-activated materials in solar PV cells, and thus develops better durability of the mixes. The conclusions were made on effect of this cement replacement. As a result, we identified the durability for those of 16 concrete specimens predefined and made to consider various possible control factors. The conclusions also depicted that all experiments but the drying shrinkage may be helpful with the suitable use of control factors as far as concerning the recycled solar PV cells for mixing in concrete. In other words, the durability quality of concrete may be partially unacceptable of containing solar PV cells.

  3. 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

  4. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, D.N.

    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 sodium-se

  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 components...

  6. DURABILITY AND BREAKAGE OF FEED PELLETS DURING REPEATED ELEVATOR HANDLING

    Science.gov (United States)

    Pelleting of animal feeds is important for improved feeding efficiency and for convenience of handling. Pellet quality impacts the feeding benefits for the animals and pellet integrity during handling. To determine the effect of repeated handling on feed pellet breakage and durability, a 22.6-t (100...

  7. 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.

  8. The Search for Durable Exterior Clear Coatings for Wood

    Directory of Open Access Journals (Sweden)

    Philip D. Evans

    2015-11-01

    Full Text Available The goal of a durable exterior clear coating has eluded generations of coatings technologists, despite long-standing desire amongst the public for such a coating. The journey towards this goal initially focused on modifications to coating formulation, but took a completely different direction when it was found that a UV-transparent silicone clear coating on wood modified with chromic acid met consumer expectations of coating durability. This finding sparked world-wide interest in wood pre-treatments as a way of enhancing the durability of clear coatings. This interest initially focused on transition metal compounds, but has now shifted in the direction of organic and inorganic photostabilizers or even more drastic pre-treatments. Pre-treatments that dimensionally stabilize wood, protect it from microbial degradation and photostabilize lignin, when combined with flexible, photostable, coatings provide the next way-stop on the journey towards achieving the goal of durable exterior clear coatings for wood. This paper reviews this journey, drawing upon our research and that of other groups who have focused on this elusive goal.

  9. Low viscosity automatic transmission fluids with enhanced friction durability

    Institute of Scientific and Technical Information of China (English)

    Kenji Yatsunami; Samuel H. Tersigni; TANG Hong- zhi; Lee D. Saathoff; Christopher S. Cleveland; Mark Jones

    2009-01-01

    This study focused on the development of a new low viscosity automatic transmission fluid (ATF) with enhanced friction durability to meet the needs of new step type automatic transmissions. Recent high fuel prices encourage increased efficiency in the driveline, including the transmission. Reduction in fluid viscosity and wider use of slip control in torque con-verter clutches are two ways to practically improve fuel efficiency. Increased torque and more shifting is seen with a variety of new transmission hardware platforms, such as wet starting clutches, dual clutches and seven - or eight - speed ATs.This suggests the need for enhanced levels of friction durability from the ATF. The new challenge from this hardware for the ATF formulator lies in the need to simultaneously meet the wear, friction durability and torque capacity requirements at low viscosity in a cost- effective manner. This report introduced a new low viscosity fluid that represents a different commercial ATF formulation style. The new chemistry employs a low viscosity for increased fuel economy, while easily doubling the friction durability of current conven-tional ATFs and offering higher torque and better EP.

  10. Ancient analogues concerning stability and durability of cementitious wasteform

    International Nuclear Information System (INIS)

    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

  11. Structural Properties and Mechanical Durability of Extruded Fish Feed

    DEFF Research Database (Denmark)

    Haubjerg, Anders Fjeldbo; Veje, Christian; Jørgensen, Bo Nørregaard;

    2015-01-01

    This article investigates the possible correlation between mechanical properties of fish feed pellets and their mechanical durability. Mechanical properties were obtained by texture profile analysis (TPA) and stress relaxation test (SRT) of different types of fish feed. The results were correlate...

  12. 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.

  13. 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. PMID:26792021

  14. The Effects of Sensitization and Habituation in Durable Goods Markets

    NARCIS (Netherlands)

    G. Liberali (Guilherme); T.S. Gruca (Thomas); W.M. Nique (Walter)

    2011-01-01

    textabstractWe develop a model to study the impact of changes in price sensitivity on the firm as it introduces multiple generations of a durable product where unit costs are a convex function of quality. We incorporate the psychological processes of sensitization and habituation into a model of dis

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-01-06

    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.

  17. Frost Durability and Strength of Concrete Prepared with Crushed Sand of Different Characteristics

    OpenAIRE

    Zhou, Ming-kai; Liu, Zhan-ao; Chen, Xiao

    2016-01-01

    The influences of fines content, methylene blue (MB) value, and lithology of crushed sand (CS) on frost durability and strength of concrete were investigated, and the frost durability and strength of crushed sand concrete (CSC) and river sand concrete (RSC) were compared. The results show that inclusion of fines improves CSC compressive strength and reduces frost durability of C30 CSC when fines content reaches 10%, whereas it has little negative influence on frost durability of C60 CSC. Incr...

  18. A novel durable intelligent fiber reinforced polymer anchor with embedded optical fiber Bragg grating sensors

    Institute of Scientific and Technical Information of China (English)

    HUANG MingHua; ZHOU Zhi; YUE Shuai; HE JianPing; OU JinPing

    2012-01-01

    Anchors are the key members of the geotechnical anchorage engineering,it is urgent to monitor their behavior in service for preventing the potential risks.This paper proposes a novel durable intelligent fiber reinforced polymer (FRP) anchor to understand the behavior of the anchor in the field application.Series of optical fiber Bmgg grating (FBG) sensors were embedded into the central axis along the anchor to sense itself axial strain variations.An evolution model of axial strain was also developed to evaluate the behavior along the anchor.A demonstration test was carried out to test its self-sensing properties in the laboratory.The experimental results indicated that the embedded FBG sensors monitored the behavior,e.g.axial strain/interfacial damage evolutions along the anchor and displacement/applied load at the pulling end effectively,without influence from the interfacial compression and slip effects.

  19. A study on management of corporate cash in consumer durable sector

    Directory of Open Access Journals (Sweden)

    Somnath Das

    2015-02-01

    Full Text Available Cash plays essential role in modern business and economy and it is the life blood of all businesses. Therefore, cash management is the art of managing a company’s short-term resources for its ongoing activities, mobilizing funds and optimizing liquidity. Inefficient cash management may lead the company to bankruptcy. In this paper, we highlight different perspectives in which we can control the corporate cash including Cash Conversion Cycle, Cash Holding and Creditworthiness. The term Cash Conversion Cycle can be considered as a length of time between purchase of raw-materials and collection of cash from debtors. Cash holding is one of the most important financial decisions that the manager of the concerned organization has to make for the organizations. In this paper, we try to interlink among different items to control cash so that bankruptcy could be prevented and profitability would be improved by investigating on five companies from Consumer Durable sector.

  20. 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

  1. Investigation on natural durability and sorption properties of Italian Chestnut (Castanea sativa Mill.) from coppice stands

    NARCIS (Netherlands)

    Militz, H.; Busetto, D.; Hapla, F.

    2003-01-01

    Castanea sativa Mill. from coppice stands in Italy were evaluated. Fungi trials with different white rot, brown rot and soft rot fungi showed, that the heartwood of chestnut can be classified following EN 350 in durability class 2 as ¿durable¿. However, the durability within the tested material (bet

  2. Improved Durability of Electrocatalyst Based on Coating of Carbon Black with Polybenzimidazole and their Application in Polymer Electrolyte Fuel Cells.

    Science.gov (United States)

    Fujigaya, Tsuyohiko; Hirata, Shinsuke; Berber, Mohamed R; Nakashima, Naotoshi

    2016-06-15

    Improvement of durability of the electrocatalyst has been the key issue to be solved for the practical application of polymer electrolyte membrane fuel cells. One of the promising strategies to improve the durability is to enhance the oxidation stability of the carbon-supporting materials. In this report, we describe in detail the mechanism of the stability improvement of carbon blacks (CBs; Vulcan and Ketjen) by coating with polybenzimidazole (PBI). Nitrogen adsorption experiments reveal that the PBI coating of CBs results in the capping of the gates of the CB-micropores by the PBI. Since the surface of the micropores inside the CBs are inherently highly oxidized, the capping of such pores effectively prevents the penetration of the electrolyte into the pore and works to avoid the further oxidation of interior of the micropore, which is proved by cyclic voltammogram measurements. Above mechanism agrees very well with the dramatic enhancement of the durability of the membrane electrode assembly fabricated using Pt on the PBI-coated CBs as an electrocatalyst compared to the conventional Pt/CB (PBI-non coated) catalyst.

  3. Durable and water-floatable ionic polymer actuator with hydrophobic and asymmetrically laser-scribed reduced graphene oxide paper electrodes.

    Science.gov (United States)

    Kim, Jaehwan; Jeon, Jin-Han; Kim, Hyun-Jun; Lim, Hyuneui; Oh, Il-Kwon

    2014-03-25

    Ionic polymer actuators driven by electrical stimuli have been widely investigated for use in practical applications such as bioinspired robots, sensors, and biomedical devices. However, conventional ionic polymer-metal composite actuators have a serious drawback of poor durability under long-term actuation in open air, mainly because of the leakage of the inner electrolyte and hydrated cations through cracks in the metallic electrodes. Here, we developed a highly durable and water-floatable ionic polymer artificial muscle by employing hydrophobic and asymmetrically laser-scribed reduced graphene oxide paper electrodes (HLrGOP). The highly conductive, flexible, and cost-effective HLrGOP electrodes have asymmetrically smooth hydrophobic outer and rough inner surfaces, resulting in liquid-impermeable and water-floatable functionalities and strong bonding between an ionic polymer and the electrodes. More interestingly, the HLrGOP electrode, which has a unique functionality to prevent the leakage of the vaporized or liquid electrolyte and mobile ions during electrical stimuli, greatly contributes to an exceptionally durable ionic polymer-graphene composite actuator that is a prerequisite for practical applications in active biomedical devices, biomimetic robots, touch-feedback haptic systems, and flexible soft electronics. PMID:24548279

  4. Biodegradable polymer brush as nanocoupled interface for improving the durability of polymer coating on metal surface.

    Science.gov (United States)

    Bedair, Tarek M; Cho, Youngjin; Joung, Yoon Ki; Han, Dong Keun

    2014-10-01

    Metal-based drug-eluting stents (DESs) have severe drawbacks such as peeling-off and cracking of the coated polymer. To prevent the fracture of polymer-coated layer and improve the durability of DES, poly(l-lactide) (PLLA) brushes were synthesized onto cobalt-chromium (Co-Cr or CC) surface through atom transfer radical polymerization (ATRP) of 2-hydroxyethylmethacrylate (HEMA) followed by surface-initiated ring opening polymerization (SI-ROP) of l-lactide. The polymer brushes were then characterized by attenuated total reflection-Fourier transform infrared (ATR-FTIR), water contact angle, ellipsometry, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All of the unmodified and modified Co-Cr surfaces were coated with a matrix of poly(d,l-lactide) (PDLLA) and sirolimus (SRL). The in vitro drug release profile was measured for 70 days. The PLLA-modified Co-Cr showed a biphasic release pattern in the initial burst followed by a slow release. On the other hand, the unmodified Co-Cr showed fast drug release and detachment of the coated polymer layer due to the instability of the polymer layer on Co-Cr surface. In comparison, the PLLA-modified Co-Cr preserved a uniform coating without detachment even after 6 weeks of degradation test. The platelet morphology and low density of platelet adhered on the modified layer and the SRL-in-PDLLA coated Co-Cr surfaces demonstrated that these samples would be blood compatible. Therefore, the introduction of PLLA brush onto Co-Cr surface is proved to dramatically improve the durability of the coating layer, and it is a promising strategy to prevent the coating defects found in DESs.

  5. 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

  6. Quality differentiation of durable goods in secondary markets

    Directory of Open Access Journals (Sweden)

    Richard Saito

    2003-06-01

    Full Text Available This paper presents a framework to study how changes in exogenous parameters, such as quality levels of new and used durables, affect the composition of durable good stocks. Our model extends the previous literature by including the endogeneity of prices and qualities. Our results could be applied to evaluate policies for controlling the externality level associated with the use and quality of durable goods in the long-term. We studied the characterization of the demand under a special situation: the consumer can choose the operation and/or maintenance level in the period the durable goods are new, which determines the quality levels for the subsequent periods. Comparative statics is performed to analyze the effects of exogenous variable change on the composition of durable stocks, and thus its impact on the externality level associated with each quality level. Contrary to most expectations, we provide an example in which the regulator imposes stricter quality standards for new durables to decrease negative externality associated with the use of durables. In this example, the comparative static results show that policies focusing only on new durable externality control may turn out to increase total externality, since stocks of older vintages may increase.Este trabalho apresenta uma estrutura para analisar as mudanças de parâmetros exógenos, tais como níveis de qualidade de bens duráveis novos e usados sobre a composição de estoques de bens duráveis. O modelo amplia a literatura anterior ao incluir a endogeneidade de preço e qualidade. Os resultados podem ser aplicados para avaliar políticas destinadas a controlar o nível de externalidade associado ao uso e à qualidade de bens duráveis a longo prazo. Para analisar o impacto desses programas regulamentares, é importante estudar as mudanças associadas na composição de estoques de bens duráveis. O artigo avalia a caracterização da demanda sob uma situação especial: o

  7. Study on durability of concrete in coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Jin, Z.; Sun, W.; Guan, X. [Henan Polytechnic University, Jiaozuo (China). Dept. of Resource and Material

    2004-12-01

    There are sulfate and chloride ions corrosion and carbonation of concrete in coal mine. Based on taking test of accelerated carbonation, corrosion of 3.5% weight of NaCl solution and 5% weight of Na{sub 2}SO{sub 4} solution of coal mine concretes, durability of concretes which include spray concrete of C20, high performance concretes of C30 and C50 and effect of fly ash on durability have been studied. Results suggest that the coal mineral high performance concretes show good resistance capacities of carbonation, and sulfate and chloride corrosion to meet the coal mine construction. Moreover, fly ash improves resistance capacity of high performance concrete (HPC) to chloride and sulfate but decreases the resistance capacity of C30's to carbonation and average dynamic modulus. 9 refs., 4 figs., 1 tab.

  8. High Performance and Durable Low PGM Cathode Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Jun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shao, Yuyan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cheng, Yingwen [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Borup, Rodney L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rockward, Tommy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brosha, Eric Lanich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-17

    There is a strong need to decrease the amount of Pt electrocatalyst used in fuel cells and increase its durability for transportation application. Conventional strategies include Pt nanocrystals and Pt alloy with well-controlled structures, durable carbon support, non-carbon support, etc. We have developed the so-called “metal-metal oxide-carbon” triple junction concept to stabilize Pt and protect carbon from corrosion. It also improved the activity of Pt. The good performance was not achieved in fuel cell test mainly because of the transport issue due to the use of 2D graphene. In this project, our main goal is to demonstrate the concept in fuel cell device test using 3D porous graphene as support so that the transport issue could be addressed.

  9. Cement mixtures containing copper tailings as an additive: durability properties

    Directory of Open Access Journals (Sweden)

    Obinna Onuaguluchi

    2012-12-01

    Full Text Available The effects of copper tailings as an additive, on some durability properties of cement mixtures were investigated. In each mixture, copper tailings addition levels by mass were 0%, 5% and 10%. Compared to the control samples, copper tailings blended pastes showed superior performance against autoclave expansion while insignificant decreases in sulfate resistance of mortars were observed. Copper tailings increased the water absorption and total permeable voids of concretes slightly. However, the compressive and flexural strengths of blended concretes were higher than those of the control samples. Similarly, improved resistance to acid attack and chloride penetration as the copper tailings content of concretes increased were also observed. Results further showed that the ASTM C 1202 rapid chloride permeability test may not be a valid indicator of chloride migration in mixtures containing conductive copper tailings. These results suggest that copper tailings can potentially enhance the durability properties of cement based materials.

  10. Moisture Durability with Vapor-Permeable Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Lepage, R.; Lstiburek, J.

    2013-10-01

    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.

  11. Mechanical durability and combustion characteristics of pellets from biomass blends.

    Science.gov (United States)

    Gil, M V; Oulego, P; Casal, M D; Pevida, C; Pis, J J; Rubiera, F

    2010-11-01

    Biofuel pellets were prepared from biomass (pine, chestnut and eucalyptus sawdust, cellulose residue, coffee husks and grape waste) and from blends of biomass with two coals (bituminous and semianthracite). Their mechanical properties and combustion behaviour were studied by means of an abrasion index and thermogravimetric analysis (TGA), respectively, in order to select the best raw materials available in the area of study for pellet production. Chestnut and pine sawdust pellets exhibited the highest durability, whereas grape waste and coffee husks pellets were the least durable. Blends of pine sawdust with 10-30% chestnut sawdust were the best for pellet production. Blends of cellulose residue and coals (raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends. PMID:20605093

  12. MATHEMATICAL MODELING FOR DURABILITY CHARACTERISTICS OF FLY ASH CONCRETE

    Directory of Open Access Journals (Sweden)

    JINO JOHN

    2012-01-01

    Full Text Available This paper presents the results obtained from the mathematical modeling for the durability characteristics of fly ash concrete. A mathematical model is employed to predict the saturated water absorption, permeability, sorpitivity and acid resistance of the concrete containing fly ash as a replacement of cement at a range of 0%, 10%, 20%, 30%, 40% and 50 %. This model is valid for mixes with cement quantity 208 to 416 kg/m3, water cement ratio 0.38 to 0.76, flyash 0 to 208 kg/m3 and cement/ total aggregate ratio varying from 0.11 to 0.22. Fly ash content and water cement ratio are the main parameters which influence the durability characteristics. The predicted mathematical model for saturated water absorption, permeability, sorpitivity and acid resistance produced accurate results for the respective ages when compared with the experimental results.

  13. DURABILITY OF MIXED MORTAR LINING CONTAINING DREGS-GRITS

    Directory of Open Access Journals (Sweden)

    B. P. Zanella

    2014-01-01

    Full Text Available The improper disposal of industrial waste and exploitation of natural resources has resulted in the scarcity of river sand and environmental degradation, such as river erosions and pollution. This study aimed to assess the durability of mixed mortar lining walls and ceilings, containing 0 (default, 10 and 20% of dregs-grits compounds-waste of the pulp industry-in substitution with river sand. This was done with tests that simulated both natural and artificial conditions: Direct solar incidence (testing ultraviolet radiation, attack by spraying solution (salt spray test, natural warming of the walls and ceilings incidence by indirect solar (thermal degradation and residential fires (thermogravimetric test, in compliance with both national and/or international standards. The grout containing dregs-grits compounds showed similarity to standard (0% for testing thermal degradability, thermogravimetric and ultraviolet radiation, but shows significantly less durability when exposed to salty environments.

  14. Durability Challenges for Next Generation of Gas Turbine Engine Materials

    Science.gov (United States)

    Misra, Ajay K.

    2012-01-01

    Aggressive fuel burn and carbon dioxide emission reduction goals for future gas turbine engines will require higher overall pressure ratio, and a significant increase in turbine inlet temperature. These goals can be achieved by increasing temperature capability of turbine engine hot section materials and decreasing weight of fan section of the engine. NASA is currently developing several advanced hot section materials for increasing temperature capability of future gas turbine engines. The materials of interest include ceramic matrix composites with 1482 - 1648 C temperature capability, advanced disk alloys with 815 C capability, and low conductivity thermal barrier coatings with erosion resistance. The presentation will provide an overview of durability challenges with emphasis on the environmental factors affecting durability for the next generation of gas turbine engine materials. The environmental factors include gaseous atmosphere in gas turbine engines, molten salt and glass deposits from airborne contaminants, impact from foreign object damage, and erosion from ingestion of small particles.

  15. Durability of concrete structures strengthened with FRP laminates

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the fast freeze-thaw cycling test, the alkaline immersion test, the water immersion test and the wet-thermal exposure test, the influence of aggressive environments on mechanical behavior of FRP was studied. CFRP specimens subjected to aggressive environments showed good durability with no significant degradation in tensile strength and modulus; however, GFRP specimens exhibited a little decrease in mechanical property after aggressive environments exposure. Based on the fast freeze-thaw cycling test and the wet-thermal exposure test, the influence of aggressive environments on the bond behavior between FRP and concrete, mechanical behavior of concrete beams and columns strengthened with FRP laminates was studied. The results showed that the bond strength had a significant decrease compared with those specimens kept at room temperature, and the specimens strengthened with FRP exhibited good durability.

  16. 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.

  17. 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.

  18. Study on durability of concrete in coal mine

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-shun; JIN Zu-quan; SUN Wei; GUAN Xue-mao

    2004-01-01

    There are sulfate and chloride ions corrosion and carbonation to concrete in coal mine. Based on taking test of accelerated carbonation, corrosion of 3.5% weight of NaCl solution and 5% weight of Na2SO4 solution of coal mine concretes, durability of concretes which include spray concrete of C20, high performance concretes of C30 and C50and effect of fly ash on durability have been studied. Results suggest that the coal mineral high performance concretes show good resistance capacities of carbonation, sulfate and chloride corrosion to meet the coal mine construction. And the higher the strength grade is,the better the resistance capacity of corrosion of carbonation is, chloride and sulfate.Moreover, fly ash improves resistance capacity of high performance concrete(HPC) to chloride and sulfate but decreases the resistance capacity of C30's to carbonation and average dynamic modulus.

  19. Durable strategies to deploy plant resistance in agricultural landscapes

    OpenAIRE

    Fabre, Frédéric; Rousseau, Elsa; Mailleret, Ludovic; Moury, Benoit

    2012-01-01

    The deployment of resistant crops often leads to the emergence of resistance-breaking pathogens that suppress the yield benefit provided by the resistance. Here, we theoretically explored how farmers’ main leverages (resistant cultivar choice, resistance deployment strategy, landscape planning and cultural practices) can be best combined to achieve resistance durability while minimizing yield losses as a result of plant viruses. Assuming a gene-for-gene type of interaction, virus epidemics ar...

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

    OpenAIRE

    T. Ofuyatan; F. Olutoge; A. Olowofoyeku

    2015-01-01

    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 developmen...

  1. The durability of beneficial health effects associated with expressive writing

    OpenAIRE

    Sloan, Denise M.; Feinstein, Brian A.; Marx, Brian P.

    2009-01-01

    This study examined the durability of benefits associated with expressive writing. Sixty-eight college undergraduates completed measures of physical and psychological health at the beginning of their first year and were then randomized to either an expressive writing or a control writing condition. Changes in physical health, psychological health (i.e., depression, stress, and anxiety), and academic performance were assessed two, four, and six months later. Findings indicated that participant...

  2. Freeze-Thaw Durability of Air-Entrained Concrete

    OpenAIRE

    Huai-Shuai Shang; Ting-Hua Yi

    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. T...

  3. Improvement of durable properties of surgical textiles using plasma treatment

    OpenAIRE

    Alay, S.; Goktepe, F.; Souto, A. Pedro; Carneiro, Noémia; F. Fernandes; Dias, Paula

    2007-01-01

    Nowadays one of the important plasmas used in textile industry is Corona discharge, which is applied in air at atmospheric pressure. Corona offers many advantages such as low production costs mainly due to effective energy utilization and minimum waste materials. In this study, the main focus is to use Corona plasma to produce reusable surgical fabrics with durable properties and using chemical agents at low concentrations. Therefore a new more economic production process of surgical fabri...

  4. What Drives Replacement of Durable Goods at the Micro Level?

    OpenAIRE

    Viviana Fernández

    2002-01-01

    Technological innovations have contributed over the years to an increasing stock of durable goods - those products that are not immediately consumed but provide a stream of services over a long period of time. Indeed, virtually every household in a modern economy owns a refrigerator, a personal computer and an automobile. Given the inter-temporal nature of replacement decisions, the existing literature has resorted to the technique of dynamic programming, and most recently to the theory of st...

  5. DURABLE DEVELOPMENT OF TOURISM AND ITS IMPACT ON THE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    TONEA ELENA

    2012-05-01

    Full Text Available Tourism is a factor in the degradation and pollution of the environment and of the touristic potential, either by tourist direct pressure on the landscape, flora and fauna or other touristic objectives which can be partially or wholly deteriorated. This can happen due to a misconception about capitalizing and equipping some areas or touristic objectives. That is why promoting some forms of durable development is necessary, as they are based on ecosystems and on the touristic environmental capacity.

  6. Durable Goods: An Explanation for Their Slow Adjustment

    OpenAIRE

    1991-01-01

    Aggregate expenditure on durable goods responds too slowly to wealth and other aggregate innovations to be consistent with the simplest frictionless version of PIH (permanent income hypothesis). In this paper I present a model of aggregate expenditure on durab1es that builds up from the lumpy nature of microeconomic purchases, and provide evidence supporting its contribution to the resolution of the ?slowness? puzzle. The paper also contains several new results on the problem of dynamic aggre...

  7. Durable Effects of Cognitive Restructuring on Conditioned Fear

    OpenAIRE

    Shurick, Ashley A.; Hamilton, Jeffrey R.; Harris, Lasana T.; Roy, Amy K.; Gross, James J.; Phelps, Elizabeth A.

    2012-01-01

    Studies of cognitive reappraisal have demonstrated that reinterpreting a stimulus can alter emotional responding, yet few studies have examined the durable effects associated with reinterpretation-based emotion regulation strategies. Evidence for the enduring effects of emotion regulation may be found in clinical studies that use cognitive restructuring (CR) techniques in cognitive–behavioral therapy (CBT) to alleviate anxiety. These techniques are based on cognitive theories of anxiety that ...

  8. Cement mixtures containing copper tailings as an additive: durability properties

    OpenAIRE

    Obinna Onuaguluchi; Özgur Eren

    2012-01-01

    The effects of copper tailings as an additive, on some durability properties of cement mixtures were investigated. In each mixture, copper tailings addition levels by mass were 0%, 5% and 10%. Compared to the control samples, copper tailings blended pastes showed superior performance against autoclave expansion while insignificant decreases in sulfate resistance of mortars were observed. Copper tailings increased the water absorption and total permeable voids of concretes slightly. However, t...

  9. 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. PMID:21775123

  10. Durable transparent carbon nanotube films for flexible device components

    International Nuclear Information System (INIS)

    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.

  11. 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.

  12. Study on Micro-Structure and Durability of Fiber Concrete

    Directory of Open Access Journals (Sweden)

    Huijun Wu

    2013-01-01

    Full Text Available In this study, we compare micro-structure characteristics of alkali-resistant glass fiber reinforced concrete, polypropylene fiber reinforced concrete, basalt fiber reinforced concrete and common concrete. Moreover, they were tested and analyzed micro-structure characteristics of fiber reinforced concretes by mercury injection, mainly analyzed the size of pore distribution, studied the influence on improving pore structure. In addition, the internal structure of fiber reinforced concrete was researched by scanning electron microscope analysis. Then the influence of fiber on the internal structure was described. Durability of the fiber reinforced concrete was tested. Durability mainly contains the frost-resistance and permeability. The permeability experiment has water-penetration and chloride penetration test study then characterize the permeability of fiber reinforced concrete through the seepage height and chloride ions diffusion coefficient. Through the result of freeze-thaw cycle 100 times we can analyze the frost resistance of fiber reinforced concrete. Finally, some fiber concrete durability is analyzed and compared.

  13. Influences of a New Admixture MX on Concrete Durability

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; DONG Rongzhen; ZHU Hongbo; ZHANG Li; ZHONG Kaihong; HE Xingyang; LI Zongjin

    2005-01-01

    The performance of concrete with a new admixture MX was studied by using the freeze-thaw cycle, permeability and chemical attack test. The experimental results show that MX improves the durability of concrete. Within the optimum proportion ranges from 0.1%to 1%,the compressive strength of concrete after freeze-thaw is increased by 20%-50%,and Young's modulus can be increased by 3.76-5.64 times.The strength and weight loss of concrete with 0.4%MX are respectively decreased by 28% and 60% after hydrochloric acid attack.The strength and weight loss of concrete with 0.4% MX are decreased by 5%-20% after sulfuric acid and sodium sulfate attack.The permeability of concrete with 1% MX at 28 days can be decreased by more than 30%. The investigation of the negative temperature property of MX and analysis on concrete composition and microstructure by MIP reveal that the heat conduction is resisted and the freezing procedure of solution in concrete pore is retarded due to the adding of MX. Moreover,the pore structure of concrete with MX is improved, thus improving the durability. Based on this study, a resistance model of MX to block the heat and mass transference was proposed, and the mechanism of durability improvement of concrete with MX was explained.

  14. Durability of organobentonite-amended liner for decelerating chloroform transport.

    Science.gov (United States)

    He, Shichong; Zhu, Lizhong

    2016-04-01

    Chloroform is added to landfill for suppressing methane generation, which however may transport through landfill liners and lead to contamination of groundwater. To decelerate chloroform transport, the enhanced sorption ability of clay liners following organobentonite addition was tested. In this study, we used batch sorption to evaluate sorption capacity of chloroform to organobentonite, followed by column tests and model simulations for assessing durability of different liners. Results show that adding 10% CTMAB-bentonite (organobentonite synthesized using cetyltrimethylammonium bromide) increased the duration of a bentonite liner by 88.5%. CTMAB-bentonite consistently showed the highest sorption capacity (Qm) among six typical organobentonites under various environmental conditions. The removal rate of chloroform by CTMAB-bentonite was 3.6-23 times higher than that by natural soils. According to the results derived by model simulation, a 70-cm 10% CTMAB-bentonite liner exhibited much better durability than a 100-cm compact clay liner (CCL) and natural bentonite liner evidenced by the delayed and lower peak of eluent concentration. A minimum thickness of 65.8 cm of the 10% CTMAB-bentonite liner could completely sorb the chloroform in a 100-m-high landfill. The 10% CTMAB-bentonite liner exhibiting much better durability has the promise for reducing environmental risk of chloroform in landfill. PMID:26874063

  15. 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.

  16. 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.

  17. 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.)

  18. Rape prevention

    Science.gov (United States)

    Date rape - prevention; Sexual assault - prevention ... Centers for Disease Control and Prevention. Sexual assault and abuse and STDs. In: 2015 sexually transmitted diseases treatment guidelines 2015. Updated June 4, 2015. www.cdc.gov/ ...

  19. 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

  20. Durability associated efficacy of long-lasting insecticidal nets after five years of household use

    Directory of Open Access Journals (Sweden)

    Msangi Shandala

    2011-08-01

    Full Text Available Abstract Background Long-lasting insecticidal nets (LLINs have been strongly advocated for use to prevent malaria in sub-Saharan Africa and have significantly reduced human-vector contact. PermaNet® 2.0 is among the five LLINs brands which have been given full approval by the WHO Pesticide Evaluation Scheme (WHOPES. The LLINs are expected to protect the malaria endemic communities, but a number of factors within the community can affect their durability and efficacy. This study evaluated the durability, efficacy and retention of PermaNet® 2.0 after five years of use in a Tanzanian community. Method Two to three day- old non blood-fed female mosquitoes from an insectary susceptible colony (An. gambiae s.s, this colony was established at TPRI from Kisumu, Kenya in 1992 and wild mosquito populations (An. arabiensis and Culex quinquefasciatus were used in cone bioassay tests to assess the efficacy of mosquito nets. Findings The knockdown effect was recorded after three minutes of exposure, and mortality was recorded after 24 hours post-exposure. Mortality of An. gambiae s.s from insectary colony was 100% while An. arabiensis and Cx.quinquefasciatus wild populations had reduced mortality. Insecticide content of the new (the bed net of the same brand but never used before and used PermaNet® 2.0 was determined using High Performance Liquid Chromatography (HPLC. Conclusion The results of this study suggest that, in order to achieve maximum protection against malaria, public health education focusing on bed net use and maintenance should be incorporated into the mass distribution of nets in communities.

  1. 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

  2. Enhancement of durability of glass fiber-reinforced cement with PVA

    Institute of Scientific and Technical Information of China (English)

    钱晓倩; 詹树林

    2002-01-01

    The main thrust of this research was to determine the effectiveness of polyvinyl alcohol (PVA) powder in enhancing the durability of short GFRC materials. Accelerated aging of the materials was achieved through low-pressure steam curing in a moist chamber. The strength and ductility of GFRC were measured by the direct tension test, which showed that incorporation of PVA powder into GFRC could improve its mechanical behaviour and turn it from brittle to ductile. To investigate the mechanism of the tensile strength enhancement, the fiber-matrix interface was examined by polarizing optical microscopy and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX). It was found that PVA powder tended to migrate to the fiber-matrix interfacial zone and thus prevented the accumulation of calcium hydroxide in this area. PVA film around the fiber resulted in a more ductile interfacial microstructure and better bonding between fiber and matrix, which should be responsible for enhancing the tensile property and preventing the aging of GFRC. Furthermore, PVA powder reduced the microhardness and brittleness at the interface.

  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. Durability Studies of Fly Ash Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Salmabanu Luhar

    2015-08-01

    Full Text Available A detailed study on the durability of geopolymer concrete has been done. Geopolymer concrete is an environment friendly concrete which has lower carbon footprint as compared to that of conventional concrete. In this study, cement has been replaced by fly ash and the properties such as compressive strength, sulphur resistance, acid resistance, water absorption, sorptivity and chloride attack have been studied. Class F fly ash has been used and geopolymer concrete was heat cured for 24 hours under 75◦C. It was observed that use of geopolymer in concrete not only reduces its greenhouse footprint but, also increases its strength and resistivity to harmful acids.

  5. Direct alcohol fuel cells materials, performance, durability and applications

    CERN Document Server

    Corti, Horacio R

    2013-01-01

    Direct Alcohol Fuel Cells: Materials, Performance, Durability and Applications begins with an introductory overview of direct alcohol fuel cells (DAFC); it focuses on the main goals and challenges in the areas of materials development, performance, and commercialization. The preparation and the properties of the anodic catalysts used for the oxidation of methanol, higher alcohols, and alcohol tolerant cathodes are then described. The membranes used as proton conductors in DAFC are examined, as well as alkaline membranes, focusing on the electrical conductivity and alcohol permeability. The use

  6. Durable, Low-cost, Improved Fuel Cell Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chris Roger; David Mountz; Wensheng He; Tao Zhang

    2011-03-17

    The development of low cost, durable membranes and membranes electrode assemblies (MEAs) that operate under reduced relative humidity (RH) conditions remain a critical challenge for the successful introduction of fuel cells into mass markets. It was the goal of the team lead by Arkema, Inc. to address these shortages. Thus, this project addresses the following technical barriers from the fuel cells section of the Hydrogen Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan: (A) Durability (B) Cost Arkema’s approach consisted of using blends of polyvinylidenefluoride (PVDF) and proprietary sulfonated polyelectrolytes. In the traditional approach to polyelectrolytes for proton exchange membranes (PEM), all the required properties are “packaged” in one macromolecule. The properties of interest include proton conductivity, mechanical properties, durability, and water/gas transport. This is the case, for example, for perfluorosulfonic acid-containing (PFSA) membranes. However, the cost of these materials is high, largely due to the complexity and the number of steps involved in their synthesis. In addition, they suffer other shortcomings such as mediocre mechanical properties and insufficient durability for some applications. The strength and originality of Arkema’s approach lies in the decoupling of ion conductivity from the other requirements. Kynar® PVDF provides an exceptional combination of properties that make it ideally suited for a membrane matrix (Kynar® is a registered trademark of Arkema Inc.). It exhibits outstanding chemical resistance in highly oxidative and acidic environments. In work with a prior grant, a membrane known as M41 was developed by Arkema. M41 had many of the properties needed for a high performance PEM, but had a significant deficiency in conductivity at low RH. In the first phase of this work, the processing parameters of M41 were explored as a means to increase its proton

  7. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-02-01

    Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate material types, field-induced failure mechanisms, and factors of influence (if possible) of polymeric encapsulation. These results will ultimately be weighed against those of future qualification and accelerated life test procedures.

  8. PEM Fuel Cell Freeze Durability and Cold Start Project

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, T.; O' Neill, Jonathan

    2008-01-02

    UTC has taken advantage of the unique water management opportunities inherent in micro-porous bipolar-plates to improve the cold-start performance of its polymer electrolyte fuel cells (PEFC). Diagnostic experiments were used to determine the limiting factors in micro-porous plate PEFC freeze performance and the causes of any performance decay. Alternative cell materials were evaluated for their freeze performance. Freeze-thaw cycling was also performed to determine micro-porous plate PEFC survivability. Data from these experiments has formed the basis for continuing development of advanced materials capable of supporting DOE's cold-start and durability objectives.

  9. 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.

  10. NOTE: Deformable and durable phantoms with controlled density of scatterers

    Science.gov (United States)

    Bisaillon, Charles-Etienne; Lamouche, Guy; Maciejko, Romain; Dufour, Marc; Monchalin, Jean-Pierre

    2008-07-01

    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.

  11. 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 conditions...... are summarized as well. To date, lifetimes of this type of fuel cells of up to 18,000 h with degradation rates of around 5 μV/h at temperatures of 150–160 °C have been demonstrated using hydrogen and air under constant moderate load. However, the degradation rate increases by a factor 10 when the cell is exposed...

  12. 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...

  13. PREDICTING THE DURABILITY OF EXTRUDED FOAM POLYSTYRENE IN ROAD STRUCTURES

    Directory of Open Access Journals (Sweden)

    V. P. Yartsev

    Full Text Available Statement of the problem. It is possible to improve working conditions of road pavement and to use it more efficiently by regulating water-thermal conditions of the subgrade thereby reducing humidity in the design period and mitigating its seasonal changes.Results and conclusions. It is suggested to use extruded foam polystyrene as a heating layer. The thermal fluctuation approach was applied to failure and deformation processes. Physical constants for the analytical description of these processes at varying temperatures and stresses are calculated. The technique for determining acting stresses and temperatures was described. The prediction of the durability of extruded foam polystyrene in road structure is presented

  14. Methods for Using Durable Adhesively Bonded Joints for Sandwich Structures

    Science.gov (United States)

    Smeltzer, Stanley S., III (Inventor); Lundgren, Eric C. (Inventor)

    2016-01-01

    Systems, methods, and apparatus for increasing durability of adhesively bonded joints in a sandwich structure. Such systems, methods, and apparatus includes an first face sheet and an second face sheet as well as an insert structure, the insert structure having a first insert face sheet, a second insert face sheet, and an insert core material. In addition, sandwich core material is arranged between the first face sheet and the second face sheet. A primary bondline may be coupled to the face sheet(s) and the splice. Further, systems, methods, and apparatus of the present disclosure advantageously reduce the load, provide a redundant path, reduce structural fatigue, and/or increase fatigue life.

  15. Durable innovative solar optical materials: the international challenge

    Energy Technology Data Exchange (ETDEWEB)

    Lampert, C.M.

    1982-01-01

    A variety of optical coatings are discussed in the context of solar energy utilization. Well known coatings such as heat mirrors, selective absorbers, and reflective films are covered briefly. Emphasis is placed on the materials limitations and design choices for various lesser known optical coatings and materials. Physical and optical properties are detailed for protective antireflection films, fluorescent concentrator materials, holographic films, cold mirrors, radiative cooling surfaces, and optical switching films including electrochromic, thermochromic, photochromic, and liquid crystal types. For many of these materials research is only now being considered, and various design and durability issues must be addressed.

  16. Durability Analysis of Subway Station in Chloride Environment

    Directory of Open Access Journals (Sweden)

    Yang LuFeng

    2013-02-01

    Full Text Available In this study, a finite element model for chloride ions transport in saturated concrete was proposed based on the Fick’s second law of diffusion. The governing partial differential equation was solved numerically in space as a boundary-value problem and in time as an initial-value problem by means of the finite element formulations. The maximum allowable value of chloride diffusion coefficient within different locations of subway station with service life of 100a was achieved and suggestions for durability analysis of subway station in chloride environment were also proposed.

  17. Experimental investigation of the variability of concrete durability properties

    International Nuclear Information System (INIS)

    One of the main objectives of the APPLET project was to quantify the variability of concrete properties to allow for a probabilistic performance-based approach regarding the service lifetime prediction of concrete structures. The characterization of concrete variability was the subject of an experimental program which included a significant number of tests allowing the characterization of durability indicators or performance tests. Two construction sites were selected from which concrete specimens were periodically taken and tested by the different project partners. The obtained results (mechanical behavior, chloride migration, accelerated carbonation, gas permeability, desorption isotherms, porosity) are discussed and a statistical analysis was performed to characterize these results through appropriate probability density functions. (authors)

  18. Properties of Leakage Corrosion of Concrete and Its Durability

    Institute of Scientific and Technical Information of China (English)

    GE Xueliang; FANG Kunhe; ZENG Li; CHEN Xia

    2008-01-01

    The properties and mechanism of concrete under water leakage corrosion were studied in terms of the dissolution of calcium oxide and silicon oxide from concrete and the variation of pH value of permeate water.The experimental results show that the amount of calcium oxide and silicon oxide dissolved from per cubic meter of concrete gradually decrease with penetration time and ultimately stabilize at a certain value.The pH value of permeate water descend along with penetration time.The durability of concrete under leakage corrosion was analyzed by a formula fitted on the dissolved amount of calcium oxide.

  19. Highly-Durable Carbon Electrode for Electrochemical Capacitors

    Directory of Open Access Journals (Sweden)

    Soshi Shiraishi

    2013-01-01

    Full Text Available The electric double layer capacitor (EDLC is anelectrochemical capacitor storing electric energy bycharging the electric double layer on the microporesof a nanoporous carbon electrode such as activatedcarbon. The EDLC has a fast charge-dischargeproperty and excellent cycle life, but its energydensity is lower than other electrochemical energystorage devices such as the rechargeable battery.The energy density of the EDLC can be improvedby increasing the double layer capacitance and themaximum charging voltage. In this review, the authordescribes the activated carbon electrodes for use ina durable EDLC for high voltage charging.

  20. Durable Catalysts for High Temperature Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Durability of proton exchange membrane fuel cells (PEMFCs) is recognized as one of the most important issues to be addressed before the commercialization. The failure mechanisms are not well understood, however, degradation of carbon supported noble metal catalysts is identified as a major failure...... significant attention in recent years because of its potential advantages such as high CO tolerance, easy cooling, better heat utilization and possible integration with fuel processing units. However, the high temperature obviously aggravates the carbon corrosion and catalyst degradation. Based on thermally...

  1. Durability of cracked fibre reinforced concrete structures exposed to chlorides

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Ekman, Tom; Hansen, Kurt Kielsgaard

    1999-01-01

    is used as environmental load. The chloride penetration is characterized both qualitatively (UV-test) and quantitatively (chloride profile) and by microscopy. The test programme involves three different concrete qualities. Both steel fibres and polypropylene fibres are used in the concrete beams as well......Durability studies are carried out by subjecting FRC-beams to combined mechanical and environmental load. Mechanical load is obtained by exposing beams to 4-point bending until a predefined crack width is reached, using a newly developed test setup. Exposure to a concentrated chloride solution...... as main reinforcement. The effect of the cracks, the fibres and the concrete quality on the chloride penetration is studied....

  2. Are Consumers Affected by Durable Goods Makers' Financial Distress? The Case of Auto Manufacturers

    OpenAIRE

    Ali Hortaçsu; Gregor Matvos; Chad Syverson; Sriram Venkataraman

    2010-01-01

    The financial decisions of durable goods makers can impose spillovers on their consumers. Namely, durable goods provide a consumption stream that frequently depends on services provided by the manufacturer (e.g., warranties, parts, and maintenance). Manufacturer bankruptcy, or even the possibility thereof, threatens this service provision and can substantially reduce the value of its products to their current owners. We test this hypothesis in one of the largest durable goods markets, automob...

  3. Sensoric assessment of the durable meat product depending on the production technology.

    OpenAIRE

    TÁBOR, Rudolf

    2011-01-01

    This diploma thesis deals with sensoric analysis of the selected types of durable meat products depending on the production technology. By sensoric assessment and subsequent statistic analysis, this diploma thesis pursues to compare fermented durable meat products, made without added starting cultures, with fermented durable meat products, made with added starting cultures, and to determine which of these kinds of products are preferred by the evaluators as well as the consumers. The theoreti...

  4. Local spillovers and learning from neighbors: Evidence from durable adoptions in rural China

    OpenAIRE

    Feng, Yao

    2011-01-01

    Using the 1999 durable consumption survey data in rural China, we examine the importance of local spillovers in the diffusion of three major durable goods, i.e., color television set, washing machine, and refrigerator. We find that, with control for many family characteristics, a household is more likely to buy its first durable good in villages where a large share of households already own one. Further evidence suggests that theses patterns are unlikely to be explained by unobserved local ch...

  5. Durable, High Thermal Conductivity Melt Infiltrated Ceramic Composites for Turbine Engine Applications Project

    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...

  6. 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.

  7. NATURAL DURABILITY AND PHENOLIC CONTENT IN DRIED SCOTS PINE HEARTWOOD

    Directory of Open Access Journals (Sweden)

    Margot Sehlstedt-Persson

    2010-04-01

    Full Text Available The durability of Scots pine heartwood has previously been shown to be affected by the industrial drying process of sawn lumber. The durability of heartwood from boards dried at temperatures between 20°C-110°C was studied by measuring the mass loss in a decay test with a brown rot fungus (Coniophora puteana, and the concentration of total phenolics was measured according to the Folin-Ciocalteu (FC assay. The relation between mass loss and phenolics in dried heartwood showed a weaker negative correlation at lower levels of phenolics as compared to the strong relationship found in a study on heartwood from standing Scots pine trees. Mass loss in dried heartwood showed a weak negative correlation to density. Heating of extractives-rich green sawdust under moist conditions resulted in a reduction of phenolics with temperature up to 180 oC and with increasing time. The concentration of phenolics in heated, green sawdust was higher in extractives-rich pine heartwood than in heartwood with a normal extractives content.

  8. Towards a durable management of genetic resistances to Leptosphaeria maculans

    Directory of Open Access Journals (Sweden)

    Pinochet Xavier

    2003-05-01

    Full Text Available Blackeg is the major disease of winter oilseed rape in France. For an efficient control of the disease several tools could be combined, but mainly plant breeding has been used to increase winter oilseed rape resistance to blackleg. A useful step was reached in the nineties, using a specific resistance gene (Rlm1. After being widely used this resistance was broken down by an increase of the virulent sub-populations of the fungus. Such a situation worried the different actors and raised the question of the promotion of a durable management of genetic resistances to Leptosphaeria. After a synthetic presentation of the state of the art in the fields of genetics of resistance, of Leptosphaeria populations and on agronomic practices able to control the pathogen, the promotion of a durable management of resistances is discussed. This target needs to precise the strategy, to improve methodologies to characterise genotypes, to promote proper agronomic practices, to follow Leptosphaeria population behaviour and to motivate economic actors.

  9. Durability Study on High Calcium Fly Ash Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Ganesan Lavanya

    2015-01-01

    Full Text Available This study presents an investigation into the durability of geopolymer concrete prepared using high calcium fly ash along with alkaline activators when exposed to 2% solution of sulfuric acid and 5% magnesium sulphate for up to 45 days. The durability was also assessed by measuring water absorption and sorptivity. Ordinary Portland cement concrete was also prepared as control concrete. The grades chosen for the investigation were M20, M40, and M60. The alkaline solution used for present study is the combination of sodium silicate and sodium hydroxide solution with the ratio of 2.50. The molarity of sodium hydroxide was fixed as 12. The test specimens were 150×150×150 mm cubes, 100×200 mm cylinders, and 100×50 mm discs cured at ambient temperature. Surface deterioration, density, and strength over a period of 14, 28, and 45 days were observed. The results of geopolymer and ordinary Portland cement concrete were compared and discussed. After 45 days of exposure to the magnesium sulfate solution, the reduction in strength was up to 12% for geopolymer concrete and up to 25% for ordinary Portland cement concrete. After the same period of exposure to the sulphuric acid solution, the compressive strength decrease was up to 20% for geopolymer concrete and up to 28% for ordinary Portland cement concrete.

  10. Enhanced durability of desulfurization sorbents for fluidized-bed applications

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, R.P.; Gangwal, S.K.

    1991-06-01

    Advanced integrated gasification combined cycle (IGCC) power systems require the development of high-temperature desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier down to very low levels. The objective of this investigation was to identify and demonstrate methods for enhancing the long-term chemical reactivity and mechanical strength of zinc ferrite, a leading regenerable sorbent, for fluidized-bed applications. Fluidized sorbent beds offer significant potential in IGCC systems because of their ability to control the highly exothermic regeneration involved. However, fluidized beds require a durable, attrition-resistant sorbent in the 100--300 {mu}m size range. A bench-scale high-temperature, high- pressure (HTHP) fluidized-bed reactor (7.6-cm I.D.) system capable of operating up to 24 atm and 800{degree}C was designed, built and tested. A total of 175 sulfidation-regeneration cycles were carried out using KRW-type coal gas with various zinc ferrite formulations. A number of sorbent manufacturing techniques including spray drying, impregnation, crushing and screening, and granulation were investigated. While fluidizable sorbents prepared by crushing durable pellets and screening had acceptable sulfur capacity, they underwent excessive attrition during multicycle testing. The sorbent formulations prepared by a proprietary technique were found to have excellent attrition resistance and acceptable chemical reactivity during multicycle testing. However, zinc ferrite was found to be limited to 550{degree}C, beyond which excessive sorbent weakening due to chemical transformations, e.g., iron oxide reduction, was observed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yandrasits, Michael A.

    2008-02-15

    Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets. The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain

  12. 40 CFR 86.1823-08 - Durability demonstration procedures for exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... guidelines of the high mileage IUVP program (ref: 40 CFR 86.1845-04). (3) Manufacturers may use previously...) Emission component durability. . For guidance see 40 CFR 86.1823-01(e). (h) Application of the durability... diesel fueled vehicles or vehicles which do not use a catalyst as the principle after-treatment...

  13. Durable Late Blight Resistance in Potato Through Dynamic Varieties Obtained by Cisgenesis

    NARCIS (Netherlands)

    Haverkort, A.J.; Boonekamp, P.M.; Hutten, R.; Jacobsen, E.; Lotz, L.A.P.; Kessel, G.J.T.; Vossen, J.H.; Visser, R.G.F.

    2016-01-01

    From 2006 through 2015, a research project on Durable Resistance in potato against Phytophthora (DuRPh) was carried out at Wageningen University and Research Centre. Its objective was to develop a proof of principle for durable resistance against late blight by cisgenesis. This public-funded proj

  14. Durable and self-healing superamphiphobic coatings repellent even to hot liquids.

    Science.gov (United States)

    Li, Bucheng; Zhang, Junping

    2016-02-14

    Durable and self-healing superamphiphobic coatings with high repellency to both cool and hot liquids are successfully prepared on various substrates by the combination of rodlike palygorskite and organosilanes via spray-coating. The coatings feature high mechanical, environmental and chemical durability, and are self-healing. PMID:26758697

  15. The interest rate and capital durability, and the importance of methodological pluralism

    NARCIS (Netherlands)

    R. van Arkel; K. Vermeylen

    2013-01-01

    Champions of sustainable growth often call for more durable production technologies with less capital depreciation. As investment in more durable capital is encouraged by lower interest rates, we investigate whether policy makers can steer the economy towards a path with low interest rates in order

  16. Report on the behalf of the finance, general economy and budget control commission on the finance bill for 2012: Appendix 14: ecology, sustainable development and planning. Energy; Rapport fait au nom de la Commission des Finances, de l'Economie Generale et du Controle Budgetaire sur le projet de loi de finances pour 2012 (n. 3775), Annexe n.14 ecologie, developpement et amenagement durables. Energie

    Energy Technology Data Exchange (ETDEWEB)

    Carrez, G.

    2011-07-01

    The author first addresses aspect of the finance bill concerning past decisions and the past energy production context and policy: the after-mining management, measure in favour of Lorraine, an electricity cost which misses out the plant dismantling financing. Then, he addresses the policy in favour of renewable energies: renewal of hydroelectric concessions, tax support for energy sobriety. He comments the on-going audit of AREVA and EDF, and notably addresses the EPR construction issue (in Finland) and the purchase of UraMin by AREVA

  17. The durability of beneficial health effects associated with expressive writing.

    Science.gov (United States)

    Sloan, Denise M; Feinstein, Brian A; Marx, Brian P

    2009-10-01

    This study examined the durability of benefits associated with expressive writing. Sixty-eight college undergraduates completed measures of physical and psychological health at the beginning of their first year and were then randomized to either an expressive writing or a control writing condition. Changes in physical health, psychological health (i.e., depression, stress, and anxiety), and academic performance were assessed two, four, and six months later. Findings indicated that participants assigned to the expressive writing condition reported less depression symptom severity at the two-month follow-up assessment relative to participants assigned to the control condition. However, these symptom reductions were not observed at any of the subsequent follow-up assessments. No significant changes were reported for physical health complaints, stress symptoms,anxiety symptoms, or academic performance. These findings suggest that,among first-year college students, expressive writing may provide some shortterm relief for certain symptoms. PMID:19333797

  18. Durable solid oxide electrolysis cells for hydrogen production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang;

    2014-01-01

    Solid oxide cell (SOC) for electrolysis application has attracted great interest in recent years due to its high power-to-gas efficiency and capability of co-electrolysis of H2O and CO2 for syngas (H2 + CO) production. The demonstration of durable solid oxide electrolysis cell operation for fuel...... production is required for promoting commercialization of the SOEC technology. In this work, we report a recent 4400 hours test of a state-of-the-art Ni-YSZ electrode supported SOEC cell. The cell consists of a Ni-YSZ (YSZ: yttria stabilized zirconia) support and active fuel electrode, an YSZ electrolyte...... that except for the first 250 hours fast initial degradation, for the rest of the testing period, the cell showed rather stable performance with an moderate degradation rate of around 25 mV/1000 h. The electrochemical impedance spectra show that both serial resistance and polarization resistance of the cell...

  19. 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)LSC and LC. The electrochemical performance of the LSC-infiltrated CGO cathode was found to depend on the infiltrate firing temperature and is suggested to originate...... from a complex interplay between the formation, percolation, and surface area of electronically conducting and catalytically active phases. Simplified models that predict the Rp of LSC-infiltrated CGO were applied and showed that the performance is not only characterized by the nanoscale size...

  20. Contact and Bending Durability Calculation for Spiral-Bevel Gears

    Science.gov (United States)

    Vijayakar, Sandeep

    2016-01-01

    The objective of this project is to extend the capabilities of the gear contact analysis solver Calyx, and associated packages Transmission3D, HypoidFaceMilled, HypoidFaceHobbed. A calculation process for the surface durability was implemented using the Dowson-Higginson correlation for fluid film thickness. Comparisons to failure data from NASA's Spiral Bevel Gear Fatigue rig were carried out. A bending fatigue calculation has been implemented that allows the use of the stress-life calculation at each individual fillet point. The gears in the NASA test rig did not exhibit any bending fatigue failure, so the bending fatigue calculations are presented in this report by using significantly lowered strength numbers.

  1. 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

  2. Entrepreneuriat social et développement durable : Quelles perspectives

    OpenAIRE

    Boutillier, Sophie

    2008-01-01

    La crise économique des années 1970 a provoqué dans les pays industrialisés et en développement des bouleversements économiques, sociaux, technologiques et politiques très importants. Le modèle économique de l'après guerre est face à ses limites. La reconstruction est achevée. Les besoins solvables que l'entreprise fordiste pouvait offrir sont saturés. La solution proposée combine quatre éléments interdépendants : l'entrepreneuriat, le micro crédit, le développement durable et le recul de l'E...

  3. Durability Study of SOFCs Under Cycling Current Load Conditions

    DEFF Research Database (Denmark)

    Hagen, Anke; Hendriksen, Peter Vang; Frandsen, Henrik Lund;

    2009-01-01

    In fuel cell applications, the cells must be able to withstand varying operating conditions. Anode supported solid oxide fuel cells were tested under cycling current load in order to determine the durability and possibly identify degradation mechanisms. At 750 °C and a cycling between zero and 0.......75 A cm-2, the cell voltage degradation rate was similar to tests with the corresponding high constant current density. However, by analyzing the impedance spectra it was found that anode degradation was becoming more important when going from constant to cycling conditions. Running the cycling load tests...... at 850 °C, the cells degraded similarly as under the corresponding constant current load whereas, in some cases, cells failed mechanically after a few hundred hours. These cells did not experience severe additional degradation due to the cycling of the current density until the point of failure...

  4. Durability properties for adhesively bonded structural aerospace applications

    International Nuclear Information System (INIS)

    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

  5. Evaluation of the durability of composite tidal turbine blades.

    Science.gov (United States)

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

    2013-02-28

    The long-term reliability of tidal turbines is critical if these structures are to be cost effective. Optimized design requires a combination of material durability models and structural analyses. Composites are a natural choice for turbine blades, but there are few data available to predict material behaviour under coupled environmental and cycling loading. The present study addresses this problem, by introducing a multi-level framework for turbine blade qualification. At the material scale, static and cyclic tests have been performed, both in air and in sea water. The influence of ageing in sea water on fatigue performance is then quantified, and much lower fatigue lives are measured after ageing. At a higher level, flume tank tests have been performed on three-blade tidal turbines. Strain gauging of blades has provided data to compare with numerical models. PMID:23319705

  6. Les villes du Golfe sont-elles des villes durables ?

    OpenAIRE

    Lavergne, Marc

    2010-01-01

    Conférence oc-organisée par l'IRMC de Tunis, le SYfacte de Sfax et le CEDEJ du Caire/Khartoum; Le développement urbain durable est souvent envisagé sous l'angle de leur modèle urbanistique, ou de l'adéquation entre les ressources dont elles disposent et leurs objectifs ou perspectives de croissance (ressources en biens publics tels que l'eau, l'espace disponible, ressources financières et base économique...). Cela semble s'appliquer particulièrement aux villes du Golfe, bâties littéralement s...

  7. 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.

  8. 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

    2015-11-01

    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.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

  9. 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.

  10. Développement durable, gouvernance et démocratie

    OpenAIRE

    Pinson, Gilles

    2006-01-01

    Les termes de développement durable et de gouvernance sont aujourd'hui fréquemment associés. Tout se passe comme si l'on considérait désormais qu'une bonne prise en charge des problèmes d'environnement et de développement économique ne passait plus uniquement par le recours à des systèmes technologiques éco-compatibles ou à des modèles économiques soucieux de la préservation des ressources naturelles et des équilibres sociaux, mais aussi par la mise en place de systèmes organisationnels, de s...

  11. Durability and Micro-structure of Reactive Powder Concrete

    Institute of Scientific and Technical Information of China (English)

    LIU Juanhong; SONG Shaomin; WANG Lin

    2009-01-01

    Durability of traditional reactive powder concrete(RPC)with rich cement and high volume of fly-ash reactive powder concrete(FRPC)were studied.The X-diffraction and scanning electron microscope(SEM)measurement was imployed to analyze the microstructure.The results show that both types of RPC have higher compressive strength,less volume shrinkage ratio and better carbonation-,chloride-,freezing-resistances than the conventional concrete.The results of X-diffraction indicate that they basically have C-S-H as the main composition without Ca(OH)_2 crystal and ettringite.SEM results show that hydration products of FRPC is mainlyⅢ-C-S-H which is piled up closely like densely arranged stone body and it has very compacted structure,in addition,Ca/Si ratio of C-S-H gel is lower than 1.5.

  12. 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.

  13. Investigation into digital print hard copy quality, longevity and durability

    Energy Technology Data Exchange (ETDEWEB)

    Kazlauciunas, Algy; Zhang Mingyu [Department of Colour Science, School of Chemistry, University of Leeds LS2 9JT (United Kingdom); Ball, Jeff, E-mail: ccdak@leeds.ac.u [Nazdar Limited, Heaton Mersey, Stockport, Cheshire SK4 3EG (United Kingdom)

    2010-06-01

    The main purpose of the research project was to investigate whether deskjet ink jet printing could produce A-4 size images on a par with conventional silver halide continuous tone photographic media prints. To this end, equivalent images were produced using both dye-based and pigment-based deskjet ink jet prints. To assist the research project, a multi-cultured array of observers were enlisted to give individual responses to a range of specific questions appertaining to the image characteristics of the A-4 size images produced. In addition, in order to assess the image stability and print durability of both the conventional silver halide prints and the ink jet prints, a range of laboratory tests were undertaken in the areas of light fastness, water fastness and both dry and wet rub fastness.

  14. 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

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

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. Freezing and Thawing Durability of Very High Strength Concrete

    Directory of Open Access Journals (Sweden)

    Sameer Hamoush

    2011-01-01

    Full Text Available Problem statement: The newly developed Very High Strength Concrete (VHSC, having compressive strengths of 29 ksi and flexural strengths of 6 ksi, represents a breakthrough in concrete technology. Study to further enhance the properties of this new concrete is continuing. Approach: The objective of this study is to investigate the effect of exposing Very High Strength Concrete (VHSC specimens to rapid freeze/thaw cycles. Twenty one specimens were tested according to the Standards of the American Society for Testing and Materials ASTM C215, ASTM C666 and ASTM C78. Results: One hundred freeze/thaw cycles were performed on the VHSC specimens. Change in specimen’s dimensions and material’s properties were recorded at zero, forty, seventy and one hundred cycles. Dimensions and properties considered were: dimension of cross section, length, weight, Dynamic Moduli, Poisson’s Ratio, durability factor and Modulus of Rupture. Conclusion/Recommendations: The test results indicated that VHSC is good freeze-thaw resistance (durability factor > 85% and can avoid freeze/thaw damage. Freeze- thaw cycling did not significantly affect VHSC specimens’ cross sectional dimensions, length, or Poisson’s Ratio. However, there was a decrease in the specimens’ weight with the increase in number of freeze/thaw cycles, but the decrease was very slim indicating little or no deterioration has occur. Moreover, the fine voids exist in VHSC greatly lower the freezing point of any trapped water, making the material less susceptible to Freeze- Thaw damage.

  18. Use of fiber-reinforced composites to improve the durability of bridge elements

    Science.gov (United States)

    Garon, Ronald; Balaguru, P. N.; Cao, Yong; Lee, K. Wayne

    2000-04-01

    Fiber composites made of carbon fibers and organic polymers are being used to strengthen plain, reinforced, and prestressed concrete structures. The composites are becoming more popular as compared to traditional strengthening with steel plates and jackets because they do not corrode and also have a very high strength to weight ratio. Organic polymers have been used as protective coatings for more than thirty years. The impermeable membrane of the polymer seals the concrete surface of the structures preventing the ingress of salts. Their main drawback is their inability to release vapor pressure buildup that causes damage in the concrete and delamination of the bonded fiber reinforced plastic. As a result of this and other weaknesses in the organic polymers, a new generation of breathable coating materials is being developed. These compositions range from epoxy modified portland cement coatings to completely inorganic silicate systems. The durability of five of the most promising compositions was evaluated under freeze-thaw, wet-dry, and scaling conditions. The silicate matrix was also used to bond carbon tows and fabrics to unreinforced concrete members. These beams were tested after exposure to wet-dry and scaling conditions. The results indicate that the inorganic matrix can be effectively used for repairs. The carbon tows can be used to replace the existing corroded reinforcing bars. The possibility of embedding optical fibers with the carbon fibers to monitor the field performance is being studied.

  19. Durable superhydrophilic/phobic surfaces based on green patina with corrosion resistance.

    Science.gov (United States)

    Cho, Handong; Lee, Jeongwon; Lee, Sangmin; Hwang, Woonbong

    2015-03-14

    Special wetting surfaces with superhydrophilicity or superhydrophobicity have attracted great interest because of their potential for practical applications. However, since the special wetting surface may be used in a severe environment, including polluted air and seawater, it is necessary to develop a durable special wetting surface with excellent corrosion-resistance. Here, we report a new strategy for robust superhydrophilic or superhydrophobic green patina surfaces on copper substrates with superior corrosion resistance and adhesion strength, which have great potential for treating marine pollution. The as-prepared surfaces exhibited superhydrophilicity with underwater superoleophobicity or superoleophilicity with under-oil superhydrophobicity, which allowed them to selectively separate oil and water with high efficiency. More importantly, the surface displayed not only good mechanical stability but also chemical stability in corrosive liquids owing to the intrinsic properties of the patina and hydrophobic coating. Furthermore, the surface can be utilized as coating material for the decoration of building exteriors and prevention from surface fouling. We believe that our proposed method would make it possible to develop engineering materials that require robust anti-fouling, anti-frost, and anti-corrosion properties in marine environments.

  20. Assessing the durability of concrete regarding ASR[ACI SP-234-15

    Energy Technology Data Exchange (ETDEWEB)

    Stark, J.; Giebson, C. [Bauhaus Univ., Weimar (Germany). F.A. Finger-Inst. for Building Materials Sciences

    2006-07-01

    Damages on concrete structures caused by alkali-aggregate reaction (AAR) were discussed. In Germany, the first damage caused by the alkali-silica reaction (ASR) occurred on a bridge that was built in 1964 and which had to be demolished in 1968 due to the loss of structural stability. As a result of intensive research into the cause of damage, the first Alkali-Guideline was published in 1974 by the German Committee for Reinforced Concrete. The guideline made it possible to classify alkali-reactive aggregates which contained opaline sandstone and flint. In order to prevent deleterious ASR, the guidelines proposed clear measures for moisture, external alkali supply and cement content. The guidelines were revised many times over the past decades to include other rock type aggregates that also posed problems. The guideline is going to be revised one more time to include testing methods that assess the influence of an external alkali supply, such as de-icing solutions, for pavement concretes. The cyclic climate storage was used and proved as an appropriate method. It was concluded that the new mortar bar test and cyclic climate storage represent more opportunities to assess the durability of concretes regarding ASR due to alkali-reactive slow/late aggregates. 17 refs., 2 tabs., 11 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, A.J.G.; Mazer, J.J.; Ebert, W.L. [Argonne National Lab., IL (United States). Chemical Technology Div.

    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.

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

    International Nuclear Information System (INIS)

    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

  3. Impact of Sn/F Pre-Treatments on the Durability of Protective Coatings against Dentine Erosion/Abrasion.

    Directory of Open Access Journals (Sweden)

    Carolina Ganss

    Full Text Available For preventing erosive wear in dentine, coating with adhesives has been suggested as an alternative to fluoridation. However, clinical studies have revealed limited efficacy. As there is first evidence that Sn(2+ increases bond strength of the adhesive Clearfil SE (Kuraray, the aim of the present study was to investigate whether pre-treatment with different Sn(2+/F(- solutions improves the durability of Clearfil SE coatings. Dentine samples (eight groups, n=16/group were freed of smear layer (0.5% citric acid, 10 s, treated (15 s either with no solution (control, aminefluoride (AmF, 500 ppm F(-, pH 4.5, SnCl2 (800/1600 ppm Sn(2+; pH 1.5, SnCl2/AmF (500 ppm F(-, 800 ppm Sn(2+, pH 1.5/3.0/4.5, or Elmex Erosion Protection Rinse (EP, 500 ppm F-, 800 ppm Sn(2+, pH 4.5; GABA International, then rinsed with water (15 s and individually covered with Clearfil SE. Subsequently the specimens were subjected to an erosion/abrasion protocol consisting of 1320 cycles of immersion in 0.5% citric acid (5 °C/55 °C; 2 min and automated brushing (15 s, 200 g, NaF-toothpaste, RDA 80. As the coatings proved stable up to 1320 cycles, 60 modified cycles (brushing time 30 min/cycle were added. Wear was measured profilometrically. After SnCl2/AmF, pH 4.5 or EP pre-treatment all except one coating survived. In the other groups, almost all coatings were lost and there was no significant difference to the control group. Pre-treatment with a Sn(2+/F(- solution at pH 4.5 seems able to improve the durability of adhesive coatings, rendering these an attractive option in preventing erosive wear in dentine.

  4. A la recherche du développement socialement durable: concepts fondamentaux et principes de base

    Directory of Open Access Journals (Sweden)

    Jérôme Ballet

    2004-06-01

    Full Text Available Le développement est considéré comme durable lorsqu’il permet aux générations actuelles de satisfaire à leurs besoins sans compromettre la capacité des générations futures à satisfaire les leurs. Il faut pour cela que les générations futures détiennent au moins autant de ressources, sous la forme de capital ou de potentialités diverses, que la génération actuelle. Lorsqu’on considère la dimension sociale du développement durable, se pose alors la question du transfert des acquis ou potentialités d’une génération à l’autre. Ces potentialités prennent de multiples formes: capital humain (éducation, santé, capital social (liens sociaux, capacité à utiliser les potentialités disponibles, etc. Plus généralement, la durabilité sociale du développement demande d’aborder les conditions d’une transmission équitable des "capacités à faire et à être" (plus simplement "capabilités" d’une génération à l’autre. On attend donc d’un développement socialement durable qu’il protège les potentialités, renforce les capacités d’une génération donnée, et facilite leur transfert à la génération suivante. Cela implique d’examiner ce qui empêche la constitution de potentialités (trappes à pauvreté, l’amélioration des capacités (exclusion sociale et vulnérabilité et la transmission inter-générationnelle (inégalités. Dès lors, dans le cadre d’une éthique de la responsabilité, des principes de précaution sociale adéquats pourraient guider l’élaboration des politiques publiques.Sustainable development allows the current generation to satisfy its needs without compromising the capacity of future generations to satisfy theirs. This implies that future generations should have in hand at least as many resources, in terms of capital or various potentialities, than the current generation. The social dimension of sustainable development raises the issue of transmitting social assets

  5. Durability of particulate grouts: For isolation of low-level radioactive wastes

    International Nuclear Information System (INIS)

    Over the years particulate grouts have been used for isolating low-concerns that over time and following exposure to adverse environmental conditions, durability of the grouts may become grossly affected and contamination of groundwater system may result. To address some of these problems, a detailed laboratory study was conducted to characterize the fabric and performance of particulate grouts. Before and after exposure to several wet-dry and freeze-thaw cycles, pore size distribution measurements via mercury intrusion porosimetry, unconfined compressive strength, permeability and pulse velocity tests were performed on the studied grouts. Prediction equations were developed for assessing grout durability. Formulation factors: water/solid ratio; mix composition, and interaction between these were found to have significant statistical effect on both wet-dry and freeze-thaw durability of the studied grouts. Fly ash in excess of 30% by weight of total solids present, was found to lower durability considerably. Addition of 7 grams of fiber to the high fly ash grout mix improved durability. Silica fume caused considerable reduction in pore sizes and initial grain in strength, but appear to lower durability particularly under wet-dry conditions. Latex, showed a potential for use as an additive for formulating durable grout mixes. Statistically based design procedures were developed to aid the waste management practitioner to select a range of formulation factors that will assure a desired magnitude of behavior over a specified service period

  6. Preventative Maintenance.

    Science.gov (United States)

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  7. Poison Prevention

    Science.gov (United States)

    ... Prevention Listen Español Text Size Email Print Share Poison Prevention Page Content Article Body Post the Poison Help number 1-800-222-1222 on the ... or empty container of a toxic substance, call Poison Help immediately. More than a million American children ...

  8. Preventing Falls

    Science.gov (United States)

    ... from osteoporosis. Lower-body strength exercises and balance exercises can help you prevent falls and avoid the disability that may result from falling. Here are some fall prevention tips from Go4Life : l Have your eyes and hearing tested often. Always wear your glasses when you ...

  9. Preventing Suicide

    Science.gov (United States)

    ... Center for Injury Prevention and Control, Division of Violence Prevention Page maintained by: Office of the Associate Director for Communication, Digital Media Branch, Division of Public Affairs Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...

  10. Unanticipated Effects of New Drug Availability on Antiretroviral Durability: Implications for Comparative Effectiveness Research

    Science.gov (United States)

    Eaton, Ellen F.; Tamhane, Ashutosh R.; Burkholder, Greer A.; Willig, James H.; Saag, Michael S.; Mugavero, Michael J.

    2016-01-01

    Background. Durability of antiretroviral (ARV) therapy is associated with improved human immunodeficiency virus (HIV) outcomes. Data on ARV regimen durability in recent years and clinical settings are lacking. Methods. This retrospective follow-up study included treatment-naive HIV-infected patients initiating ARV therapy between January 2007 and December 2012 in a university-affiliated HIV clinic in the Southeastern United States. Outcome of interest was durability (time to discontinuation) of the initial regimen. Durability was evaluated using Kaplan-Meier survival analyses. Cox proportional hazard analyses was used to evaluate the association among durability and sociodemographic, clinical, and regimen-level factors. Results. Overall, 546 patients were analyzed. Median durability of all regimens was 39.5 months (95% confidence interval, 34.1–44.4). Commonly prescribed regimens were emtricitabine and tenofovir with efavirenz (51%; median duration = 40.1 months) and with raltegravir (14%; 47.8 months). Overall, 67% of patients had an undetectable viral load at the time of regimen cessation. Discontinuation was less likely with an integrase strand transfer inhibitor (adjusted hazards ratio [aHR] = 0.35, P = .001) or protease inhibitor-based regimen (aHR = 0.45, P = .006) and more likely with a higher pill burden (aHR = 2.25, P = .003) and a later treatment era (aHR = 1.64, P drugs and combinations. Reduced durability mostly results from a preference for newly approved regimens rather than indicating failing therapy, as indicated by viral suppression observed in a majority of patients (67%) prior to regimen cessation. Durability is influenced by extrinsic factors including new drug availability and provider preference. Medication durability must be interpreted carefully in the context of a dynamic treatment landscape.

  11. Flexible, Mechanically Durable Aerogel Composites for Oil Capture and Recovery.

    Science.gov (United States)

    Karatum, Osman; Steiner, Stephen A; Griffin, Justin S; Shi, Wenbo; Plata, Desiree L

    2016-01-13

    More than 30 years separate the two largest oil spills in North American history (the Ixtoc I and Macondo well blowouts), yet the responses to both disasters were nearly identical in spite of advanced material innovation during the same time period. Novel, mechanically durable sorbents could enable (a) sorbent use in the open ocean, (b) automated deployment to minimize workforce exposure to toxic chemicals, and (c) mechanical recovery of spilled oils. Here, we explore the use of two mechanically durable, low-density (0.1-0.2 g cm(-3)), highly porous (85-99% porosity), hydrophobic (water contact angles >120°), flexible aerogel composite blankets as sorbent materials for automated oil capture and recovery: Cabot Thermal Wrap (TW) and Aspen Aerogels Spaceloft (SL). Uptake of crude oils (Iraq and Sweet Bryan Mound oils) was 8.0 ± 0.1 and 6.5 ± 0.3 g g(-1) for SL and 14.0 ± 0.1 and 12.2 ± 0.1 g g(-1) for TW, respectively, nearly twice as high as similar polyurethane- and polypropylene-based devices. Compound-specific uptake experiments and discrimination against water uptake suggested an adsorption-influenced sorption mechanism. Consistent with that mechanism, chemical extraction oil recoveries were 95 ± 2 (SL) and 90 ± 2% (TW), but this is an undesirable extraction route in decentralized oil cleanup efforts. In contrast, mechanical extraction routes are favorable, and a modest compression force (38 N) yielded 44.7 ± 0.5% initially to 42.0 ± 0.4% over 10 reuse cycles for SL and initially 55.0 ± 0.1% for TW, degrading to 30.0 ± 0.2% by the end of 10 cycles. The mechanical integrity of SL deteriorated substantially (800 ± 200 to 80 ± 30 kPa), whereas TW was more robust (380 ± 80 to 700 ± 100 kPa) over 10 uptake-and-compression extraction cycles.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Analysis Approach to Durability Based on Material Initial Fatigue Quality and S-N Curve

    Institute of Scientific and Technical Information of China (English)

    Yang Moucun; Nie Hong

    2007-01-01

    Based on probabilistic fracture mechanics approach, a new concept of material initial fatigue quality (MIFQ) is developed. Then,the relation between S-N curve and crack propagation curve is studied. From the study, a new durability analysis method is presented. In this method, S-N curve is used to determine crack growth rate under constant amplitude.loading and evaluate the effects of different factors on durability and then the structural durability is analyzed. The tests and analyses indicate that this method has lower dependence on testing, and higher accuracy, reliability and generality and is convenient for application.

  17. Activity and Durability of Iridium Nanoparticles in the Oxygen Evolution Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Alia, Shaun M.; Rasimick, Brian; Ngo, Chilan; Neyerlin, Kenneth C.; Kocha, Shyam S.; Pylypenko, Svitlana; Xu, Hui; Pivovar, Bryan S.

    2016-07-15

    Unsupported iridium (Ir) nanoparticles, that serve as standard oxygen evolution reaction (OER) catalysts in acidic electrolyzers, were investigated for electrochemical performance and durability in rotating disk electrode (RDE) half-cells. Fixed potential holds and potential cycling were applied to probe the durability of Ir nanoparticles, and performance losses were found to be driven by particle growth (coarsening) at moderate potential (1.4 to 1.6 V) and Ir dissolution at higher potential (>/=1.8 V). Several different commercially available samples were evaluated and standardized conditions for performance comparison are reported. The electrocatalyst RDE results have also been compared to results obtained for performance and durability in electrolysis cells.

  18. 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.

  19. 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...... field where published data are scarce. Durability and constantly high and good physical properties are some of the most important properties of the materials used in the building industry. Thermal durability, i.e. the ability of a material to retain its original physical-mechanical properties during...

  20. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2012-03-01

    Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple and optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interface(s), while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced failure modes for a variety of popular PV encapsulation materials. An existing CPV module (with no PV cells present) was modified to accommodate encapsulation specimens. The module (where nominal concentration of solar flux is 500x for the domed-Fresnel design) has been mounted on a tracker in Golden, CO (elevation 1.79 km). Initial results are reported here for 18 months cumulative exposure, including the hottest and coldest months of the past year. Characteristics observed at intervals during that time include: visual appearance, direct and hemispherical transmittance, and mass. Degradation may be assessed from subsequent analysis (including yellowness index and cut-on frequency) relative to the ambient conditions present during field exposure. The fluorescence signature observed of all the silicone specimens is examined here, including possible factors of causation -- the platinum catalyst used in the addition cured materials as well as the primer used to promote adhesion to the quartz substrate and superstrate.

  1. Durability Tests of a Fiber Optic Corrosion Sensor

    Directory of Open Access Journals (Sweden)

    Christopher K.Y. Leung

    2012-03-01

    Full Text Available Steel corrosion is a major cause of degradation in reinforced concrete structures, and there is a need to develop cost-effective methods to detect the initiation of corrosion in such structures. This paper presents a low cost, easy to use fiber optic corrosion sensor for practical application. Thin iron film is deposited on the end surface of a cleaved optical fiber by sputtering. When light is sent into the fiber, most of it is reflected by the coating. If the surrounding environment is corrosive, the film is corroded and the intensity of the reflected signal drops significantly. In previous work, the sensing principle was verified by various experiments in laboratory and a packaging method was introduced. In this paper, the method of multiplexing several sensors by optical time domain reflectometer (OTDR and optical splitter is introduced, together with the interpretation of OTDR results. The practical applicability of the proposed sensors is demonstrated in a three-year field trial with the sensors installed in an aggressive marine environment. The durability of the sensor against chemical degradation and physical degradation is also verified by accelerated life test and freeze-thaw cycling test, respectively.

  2. Durability tests of a fiber optic corrosion sensor.

    Science.gov (United States)

    Wan, Kai Tai; Leung, Christopher K Y

    2012-01-01

    Steel corrosion is a major cause of degradation in reinforced concrete structures, and there is a need to develop cost-effective methods to detect the initiation of corrosion in such structures. This paper presents a low cost, easy to use fiber optic corrosion sensor for practical application. Thin iron film is deposited on the end surface of a cleaved optical fiber by sputtering. When light is sent into the fiber, most of it is reflected by the coating. If the surrounding environment is corrosive, the film is corroded and the intensity of the reflected signal drops significantly. In previous work, the sensing principle was verified by various experiments in laboratory and a packaging method was introduced. In this paper, the method of multiplexing several sensors by optical time domain reflectometer (OTDR) and optical splitter is introduced, together with the interpretation of OTDR results. The practical applicability of the proposed sensors is demonstrated in a three-year field trial with the sensors installed in an aggressive marine environment. The durability of the sensor against chemical degradation and physical degradation is also verified by accelerated life test and freeze-thaw cycling test, respectively. PMID:22737030

  3. Durability of the accretion disk of millisecond pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Michel, F.C.; Dessler, A.J.

    1985-05-01

    Pulsars with pulsation periods in the millisecond range are thought to be neutron stars that have acquired an extraordinarily short spin period through the accretion of stellar material spiraling down onto the neutron star from a nearby companion. Nearly all the angular momentum and most of the mass of the companion star is transferred to the neutron star. During this process, wherein the neutron star consumes its companion, it is required that a disk of stellar material be formed around the neutron star. In conventional models it is supposed that the disk is somehow lost when the accretion phase is finished, so that only the rapidly spinning neutron star remains. However, it is possible that, after the accretion phase, a residual disk remains in stable orbit around the neutron star. The end result of such an accretion process is an object that looks much like a miniature (about 100 kilometers), heavy version of Saturn: a central object (the neutron star) surrounded by a durable disk. 10 references.

  4. Durability of the accretion disk of millisecond pulsars.

    Science.gov (United States)

    Michel, F C; Dessler, A J

    1985-05-24

    Pulsars with pulsation periods in the millisecond range are thought to be neutron stars that have acquired an extraordinarily short spin period through the accretion of stellar material spiraling down onto the neutron star from a nearby companion. Nearly all the angular momentum and most of the mass of the companion star is transferred to the neutron star. During this process, wherein the neutron star consumes its companion, it is required that a disk of stellar material be formed around the neutron star. In conventional models it is supposed that the disk is somehow lost when the accretion phase is finished, so that only the rapidly spinning neutron star remains. However, it is possible that, after the accretion phase, a residual disk remains in stable orbit around the neutron star. The end result of such an accretion process is an object that looks much like a miniature (about 100 kilometers), heavy version of Saturn: a central object (the neutron star) surrounded by a durable disk. PMID:17797665

  5. Durable strategies to deploy plant resistance in agricultural landscapes.

    Science.gov (United States)

    Fabre, Frédéric; Rousseau, Elsa; Mailleret, Ludovic; Moury, Benoit

    2012-03-01

    The deployment of resistant crops often leads to the emergence of resistance-breaking pathogens that suppress the yield benefit provided by the resistance. Here, we theoretically explored how farmers' main leverages (resistant cultivar choice, resistance deployment strategy, landscape planning and cultural practices) can be best combined to achieve resistance durability while minimizing yield losses as a result of plant viruses. Assuming a gene-for-gene type of interaction, virus epidemics are modelled in a landscape composed of a mosaic of resistant and susceptible fields, subjected to seasonality, and a reservoir hosting viruses year-round. The model links the genetic and the epidemiological processes, shaping at nested scales the demogenetic dynamics of viruses. The choice of the resistance gene (characterized by the equilibrium frequency of the resistance-breaking virus at mutation-selection balance in a susceptible plant) is the most influential leverage of action. Our results showed that optimal strategies of resistance deployment range from 'mixture' (where susceptible and resistant cultivars coexist) to 'pure' strategies (with only resistant cultivar) depending on the resistance characteristics and the epidemiological context (epidemic incidence and landscape connectivity). We demonstrate and discuss gaps concerning virus epidemiology across the agro-ecological interface that must be filled to achieve sustainable disease management. PMID:22260272

  6. Durability Tests of a Fiber Optic Corrosion Sensor

    Science.gov (United States)

    Wan, Kai Tai; Leung, Christopher K.Y.

    2012-01-01

    Steel corrosion is a major cause of degradation in reinforced concrete structures, and there is a need to develop cost-effective methods to detect the initiation of corrosion in such structures. This paper presents a low cost, easy to use fiber optic corrosion sensor for practical application. Thin iron film is deposited on the end surface of a cleaved optical fiber by sputtering. When light is sent into the fiber, most of it is reflected by the coating. If the surrounding environment is corrosive, the film is corroded and the intensity of the reflected signal drops significantly. In previous work, the sensing principle was verified by various experiments in laboratory and a packaging method was introduced. In this paper, the method of multiplexing several sensors by optical time domain reflectometer (OTDR) and optical splitter is introduced, together with the interpretation of OTDR results. The practical applicability of the proposed sensors is demonstrated in a three-year field trial with the sensors installed in an aggressive marine environment. The durability of the sensor against chemical degradation and physical degradation is also verified by accelerated life test and freeze-thaw cycling test, respectively. PMID:22737030

  7. Durability of geomembrane exposed to jet fuel A-1

    Energy Technology Data Exchange (ETDEWEB)

    Rimal, S.; Rowe, R.K.; Hansen, S. [Queen' s Univ., Kingston, ON (Canada). GeoEngineering Centre]|[Royal Military Coll. of Canada, Kingston, ON (Canada)

    2004-07-01

    A geosynthetic clay liner (GCL) has been installed at a former Canadian Distant Early Warning Line (DEW Line) site off the southeast coast of Baffin Island, in the Canadian Arctic. The liner was installed in an area of hydrocarbon contaminated soil to limit the migration of hydrocarbons to nearby water prior to future site remediation. This study examined the antioxidant depletion and the compatibility of both untreated and fluorinated high density polyethylene (HDPE) geomembranes with jet fuel A-1. The objective was to determine the durability and long term performance of the HDPE geomembrane. Geomembrane swatches were immersed in jet fuel and placed inside a fumehood at -23 degrees C. They were examined for changes in oxidative induction time, crystallinity, tensile properties and dimensions. Immersion in jet fuel appears to accelerate the antioxidant depletion rate compared to that observed in municipal solid waste leachate. The untreated geomembrane had a higher rate of antioxidant depletion than the fluorinated geomembrane, suggesting that fluorination is beneficial. Tensile tests show that immersion in jet fuel decreases the yield stress while increasing the strain at yield. The results indicate that there is no significant permeation by jet fuel or diffusion at lower temperatures for the short term, but additional studies are needed to confirm long term behaviour. 27 refs., 1 tab., 6 figs.

  8. 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.

  9. 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.

  10. 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

  11. Method Evaluating the Durability of Aircraft Piston Engines

    Directory of Open Access Journals (Sweden)

    Luca PIANCASTELLI

    2012-12-01

    Full Text Available A significant issue in aircraft engines is quantifying residual life to overhaul. The algorithm described in this paper calculates with a good level of reliability the residual life of a petrol piston engine. The method was tested on small, latest-generation, naturally-aspirated aircraft and racing piston engines, and has been effective in several experiments. This method is implemented directly on the electronic control system of the engine with very few lines of C-code. The method can also be used in many industrial engines. This innovative method assumes that only two main factors (power level and wear affect engine durability or time between overhauls. These two factors are considered as separate and combined with worst case criteria. The wear is assumed to follow a logarithmic law and a formula similar to the Miner’s law for material fatigue is used, making it possible to calculate the power-level curve with knowledge of only two points. The wear-curve is also related to elapsed engine cycles. The algorithm is very simple and can be implemented with just a few lines of software code accessing data collected from existing sensors. The system is currently used to evaluate actual residual life of racing engines.

  12. Electro-active paper for a durable biomimetic actuator

    Science.gov (United States)

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

    2009-02-01

    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

  13. [The problem of durable resistance of plants to different pests].

    Science.gov (United States)

    Odintsova, I G; Radchenko, E E; Tyryshkin, L G

    2002-01-01

    Different hypotheses concerning durable plant resistance against different pest were tested: 1) resistance is weak and polygenetically controlled; 2) resistance depends on "residual effect" of oligogenes that were overcome by pests. Contrast pair of plants and pests were used in experiments: wheat, barley--facultative parasite Bipolaris sorokiniana Shoem., wheat--obligate parasite Puccinia recondita Rob. ex Desm., sorghum--greenbug Schizaphis graminum Rond. Differential interaction between parasite and host plant resulted in their increased compatibility under long reproduction of parasite on resistant varieties were regarded as criteria of quick overcoming of resistance. The results did not support any hypothesis. The rate of adaptation of B. sorokiniana to the resistant varieties of wheat and barley did not depend on the level of resistance expression (weak, moderate or strong) and genetic control (oligogenic, polygenic or cytoplasmatic). It was shown by hybridological analysis that "residual effect" of oligogenes of sorghum resistance against greenbug depended on small resistance genes, that can be independent or weakly connected with marker oligogene. These data allows to doubt in phenomenon of "residual effect" of oligogenes. It was shown that non specific pathogenicity of parasitic fungi increased during their reproductions on sensitive varieties of plants. Thus, cultivation of sensitive varieties causes damage of crop culture non only because of their own losses, but also by increasing the infection of moderately resistant varieties.

  14. Research on the Durability of the Splints of Lower Limbs

    Directory of Open Access Journals (Sweden)

    Oleg Ardatov

    2012-12-01

    Full Text Available The paper presents research on the durability of the splint of the ankle joint and suggests a solution to the raised problem of the fatigue behaviour of the splint of the ankle joint. With the help of computer aided modelling and SolidWorks software, the model of the splint of the ankle joint has been created. The article analyses social problems, ankle joint biomechanics and describes modelling methods and results of the fatigue test.The results of research show instructions on the use and adaptation of the splints of the ankle joint made of high density polyethylene and polypropylene. The models produced from high density polyethylene were rather endurant (3 •107 cycles of load compared to those made of polypropylene (1,6 •107 cycles of load. Thus, the use of polyethylene splints should be extended at bigger loads. Polypropylene splints can be used in cases under smaller load (the weight of a splint user should not exceed 70 kg thus increasing the thickness of the material.Article in Lithuanian

  15. Research on the Durability of the Splints of Lower Limbs

    Directory of Open Access Journals (Sweden)

    Oleg Ardatov

    2013-02-01

    Full Text Available The paper presents research on the durability of the splint of the ankle joint and suggests a solution to the raised problem of the fatigue behaviour of the splint of the ankle joint. With the help of computer aided modelling and SolidWorks software, the model of the splint of the ankle joint has been created. The article analyses social problems, ankle joint biomechanics and describes modelling methods and results of the fatigue test. The results of research show instructions on the use and adaptation of the splints of the ankle joint made of high density polyethylene and polypropylene. The models produced from high density polyethylene were rather endurant (3 •107 cycles of load compared to those made of polypropylene (1,6 •107 cycles of load. Thus, the use of polyethylene splints should be extended at bigger loads. Polypropylene splints can be used in cases under smaller load (the weight of a splint user should not exceed 70 kg thus increasing the thickness of the material.Article in Lithuanian

  16. 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

  17. Preventive analgesia

    DEFF Research Database (Denmark)

    Dahl, Jørgen B; Kehlet, Henrik

    2011-01-01

    This paper will discuss the concepts of pre-emptive and preventive analgesia in acute and persistent postsurgical pain, based on the most recent experimental and clinical literature, with a special focus on injury-induced central sensitization and the development from acute to chronic pain. Recent...... findings: The nature of central sensitization during acute and chronic postsurgical pain share common features, and there may be interactions between acute and persistent postoperative pain. The term ‘pre-emptive analgesia’ should be abandoned and replaced by the term ‘preventive analgesia’. Recent studies...... of preventive analgesia for persistent postoperative pain are promising. However, clinicians must be aware of the demands for improved design of their clinical studies in order to get more conclusive answers regarding the different avenues for intervention. Summary: The concept of preventive...

  18. Tuberculosis Prevention

    Science.gov (United States)

    ... Skip Content Marketing Share this: Main Content Area Tuberculosis (TB) Prevention TB is an airborne disease and ... patients. Many people who are infected with Mycobacterium tuberculosis ( Mtb ) do not get sick or spread the ...

  19. HIV Prevention

    Centers for Disease Control (CDC) Podcasts

    2012-02-01

    Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, talks about steps people can take to protect their health from HIV.  Created: 2/1/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 2/1/2012.

  20. Dual-layered-coated mechanically-durable superomniphobic surfaces with anti-smudge properties.

    Science.gov (United States)

    Muthiah, Palanikkumaran; Bhushan, Bharat; Yun, Kyungsung; Kondo, Hirofumi

    2013-11-01

    Bio-inspired surfaces that exhibit high contact angle and low contact angle hysteresis for various liquids and demonstrate mechanical durability and anti-smudge properties are of interest for various applications. The fabrication of such surfaces has often involved complex or expensive processes, required techniques that may not be suitable for various substrates and particles, may require surface post-treatment, or may lack durability. Dual layered coatings of roughness-induced superomniphobic surfaces that demonstrate good mechanical durability were fabricated on glass substrates using hydrophobic SiO2 nanoparticles and low surface energy fluorobinders using dip coating and spray coating techniques. The particle-to-binder ratio was optimized for contact angles of interest. The mechanical durability of these coatings was examined under mechanical rubbing action. The anti-smudge properties were examined by wiping an artificially contaminated coating using oil-impregnated microfiber cloth.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ulm, Franz-Josef

    2000-03-31

    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)

  2. Durable Silver Mirror Coating Via Ion Assisted, Electron Beam Evaporation For Large Aperture Optics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the Phase I research, Surface Optics Corporation (SOC) demonstrated a durable silver mirror coating based an ion assisted, thermal evaporation process. The...

  3. Farmers' participation and breeding for durable disease resistance in the Andean region

    NARCIS (Netherlands)

    Danial, D.L.; Parlevliet, J.E.; Almekinders, C.J.M.; Thiele, G.

    2007-01-01

    In the Andean region, the Preduza project and its partners combined breeding for durable disease resistance using locally adapted cultivars and farmer participatory methods. The approach taken resembles participatory variety selection (PVS). Farmers participated in the selection of advanced material

  4. Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

    Science.gov (United States)

    Tesler, Alexander B.; Kim, Philseok; Kolle, Stefan; Howell, Caitlin; Ahanotu, Onye; Aizenberg, Joanna

    2015-10-01

    Formation of unwanted deposits on steels during their interaction with liquids is an inherent problem that often leads to corrosion, biofouling and results in reduction in durability and function. Here we report a new route to form anti-fouling steel surfaces by electrodeposition of nanoporous tungsten oxide (TO) films. TO-modified steels are as mechanically durable as bare steel and highly tolerant to compressive and tensile stresses due to chemical bonding to the substrate and island-like morphology. When inherently superhydrophilic TO coatings are converted to superhydrophobic, they remain non-wetting even after impingement with yttria-stabilized-zirconia particles, or exposure to ultraviolet light and extreme temperatures. Upon lubrication, these surfaces display omniphobicity against highly contaminating media retaining hitherto unseen mechanical durability. To illustrate the applicability of such a durable coating in biofouling conditions, we modified naval construction steels and surgical instruments and demonstrated significantly reduced marine algal film adhesion, Escherichia coli attachment and blood staining.

  5. The Durability and Fragility of Knowledge Infrastructures: Lessons Learned from Astronomy

    CERN Document Server

    Borgman, Christine L; Sands, Ashley E; Golshan, Milena S

    2016-01-01

    Infrastructures are not inherently durable or fragile, yet all are fragile over the long term. Durability requires care and maintenance of individual components and the links between them. Astronomy is an ideal domain in which to study knowledge infrastructures, due to its long history, transparency, and accumulation of observational data over a period of centuries. Research reported here draws upon a long-term study of scientific data practices to ask questions about the durability and fragility of infrastructures for data in astronomy. Methods include interviews, ethnography, and document analysis. As astronomy has become a digital science, the community has invested in shared instruments, data standards, digital archives, metadata and discovery services, and other relatively durable infrastructure components. Several features of data practices in astronomy contribute to the fragility of that infrastructure. These include different archiving practices between ground- and space-based missions, between sky su...

  6. Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel.

    Science.gov (United States)

    Tesler, Alexander B; Kim, Philseok; Kolle, Stefan; Howell, Caitlin; Ahanotu, Onye; Aizenberg, Joanna

    2015-10-20

    Formation of unwanted deposits on steels during their interaction with liquids is an inherent problem that often leads to corrosion, biofouling and results in reduction in durability and function. Here we report a new route to form anti-fouling steel surfaces by electrodeposition of nanoporous tungsten oxide (TO) films. TO-modified steels are as mechanically durable as bare steel and highly tolerant to compressive and tensile stresses due to chemical bonding to the substrate and island-like morphology. When inherently superhydrophilic TO coatings are converted to superhydrophobic, they remain non-wetting even after impingement with yttria-stabilized-zirconia particles, or exposure to ultraviolet light and extreme temperatures. Upon lubrication, these surfaces display omniphobicity against highly contaminating media retaining hitherto unseen mechanical durability. To illustrate the applicability of such a durable coating in biofouling conditions, we modified naval construction steels and surgical instruments and demonstrated significantly reduced marine algal film adhesion, Escherichia coli attachment and blood staining.

  7. 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).

  8. 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...

  9. Next Generation , Lightweight, Durable Boot Materials to Provide Active & Passive Thermal Protection Project

    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)...

  10. Durable Pulmonary Vein Isolation: The Holy Grail of Atrial Fibrillation Ablation

    Directory of Open Access Journals (Sweden)

    Duy Thai Nguyen; William H. Sauer

    2010-10-01

    Full Text Available The inability to achieve durable pulmonary vein isolation remains a major limitation to catheter ablation for the treatment of atrial fibrillation (AF. In this review, we discuss the research performed over the past decade investigating methods to improve lesion permanence for the goal of durable pulmonary vein isolation (PVI. Investigations evaluating procedural techniques, adjunctive pharmacologic therapy, and newer energy sources designed to improve ablation lesion permanence are discussed.

  11. Do Migrant Remittances Affect Household Purchases of Physical Investments and Durable Goods? Evidence for Kenya

    OpenAIRE

    Farai Jena

    2015-01-01

    This paper investigates the impact of remittances on household decisions to purchase physical investments and durable goods in Kenya using household survey data. Remittances are found to be endogenous in the durable goods case and their effects are estimated using bivariate and IV probit models. In the physical investments case, remittances are found to be exogenous and remittance effects are estimated using univariate probit models. The evidence obtained is supportive of remittances having a...

  12. Fostering a durable relationship between a waste management facility and its host community

    International Nuclear Information System (INIS)

    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

  13. Effect of Fly Ash on Durability of High Performance Concrete Composites

    OpenAIRE

    Peng Zhang; Qingfu Li

    2013-01-01

    A parametric experimental study has been conducted to investigate the effect of fly ash on the durability of the concrete composites. Four different fly ash contents (10, 15, 20 and 25% respectively) were used. The durability of concrete composites includes water impermeability, dry shrinkage property, the carbonation resistance and the freeze-thaw resistance. The results indicate that the addition of fly ash has greatly improved the water impermeability and restricted the dry shrinkage of co...

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

    OpenAIRE

    LEBENTAL, Bérengère; Chainais, Pierre; CHENEVIER, Pascale; Chevalier, Nicolas; Delevoye, Eric; Fabbri, Jean-Marc; Nicoletti, Sergio; Renaux, Philippe; Ghis, Anne

    2011-01-01

    International audience Structural health monitoring of porous materials such as concrete is becoming a major component in our resource-limited economy, as it conditions durable exploitation of existing facilities. Durability in porous materials depends on nanoscale features which need to be monitored in situ with nanometric resolution. To address this problem, we put forward an approach based on the development of a new nanosensor, namely a capacitive micrometric ultrasonic transducer whos...

  15. Lime-based repair mortars with water-repellent admixtures: laboratory durability assessment

    OpenAIRE

    Nunes, C.; Slížková, Z. (Zuzana)

    2015-01-01

    Conservation of architectural structures using lime binders is currently an important research topic aiming compatibility, durability and sustainability. In this study, lime (L) and lime-metakaolin (LM) mortars were prepared with the addition of water-repellent admixtures: linseed oil, stand oil and a silane based water-repellent. Experimental results demonstrate that oil imparts higher hydrophobicity to both L and LM mixtures. Durability was assessed through freeze-thaw and NaCl crystal...

  16. Laboratory aging of asphalt mixtures : simulation of reclaimed asphalt and application as test method for durability

    OpenAIRE

    Mollenhauer, Konrad; MOUILLET, Virginie; PIERARD, Nathalie; TUSAR, Marjan; Gabet, Thomas

    2012-01-01

    Surface asphalt courses reach their end of service life after a time span between 10 and 30 years, depending on their durability. Afterwards, the surface layer is usually milled and reused in asphalt mixtures as reclaimed asphalt. In order to enable the analysis of durability and recyclability of a new asphalt mixture, four laboratory aging procedures were designed and comparatively applied on twoasphalt mixes. Besides aging of loose asphalt mix in heating cabinets at varied temperatures and ...

  17. Influence of the mineral admixture on the durability of medium-strenght self compacting concrete

    OpenAIRE

    Bermejo Núñez, Ester B.; Gálvez Ruíz, Jaime; Fernández Cánovas, Manuel; Moragues Terrades, Amparo

    2010-01-01

    Self-compacting concrete (SCC) is an innovative concrete that does not require vibration for placing and compacting. SCC, developed in Japan in the 1980s, provides a present-day and attractive challenge for many researchers, as the long list of papers on the topic corroborates. Nevertheless, the durability of SCC, especially medium strength SCC, provides the researcher with opportunities for study in depth. This paper deals with the durability of SCC: two SCC mixtures, with 30 MPa com...

  18. Various durability aspects of calcined Kaolin-blended Portland cement pastes and concretes

    OpenAIRE

    SAILLIO, Mickael; BAROGHEL BOUNY, Véronique; PRADELLE, Sylvain

    2015-01-01

    The use of calcined clay, in the form of metakaolin (MK), as a pozzolanic constituent for concrete has received considerable attention in recent years, due to the lower CO2 emission of this supplementary cementitious material compared to the production of a classic portland cement. Furthermore, concretes incorporating MK show some improve durability properties. In this paper, the durability of concretes and cement pastes with MK as partial replacement of cement (10 and 25%) has been investiga...

  19. Various durability aspects of cement pastes and concretes with supplementary cementitious materials

    OpenAIRE

    SAILLIO, Mickael; BAROGHEL BOUNY, Véronique; PRADELLE, Sylvain

    2016-01-01

    The use of supplementary cementitious materials (SCMs) as a constituent for concrete receives considerable attention, due to the lower CO2 emission of these materials compared to the production of classic Portland cement. Furthermore, concretes incorporating SCMs show some improved durability properties. SCMs are mainly pozzolanic materials (Fly Ash or Metakaolin) or alkali-activated materials such as ground granulated blast slag (GGBS). In this paper, the durability of concretes and cement p...

  20. Commitment Power in a Non-Stationary Durable-Good Market

    OpenAIRE

    Usategui Díaz de Otalora, José María

    2001-01-01

    This paper derives and evaluates the decisions of a durable good monopolist in a context where demand for the services of the durable good changes over time. It shows that, if the size of the market decreases over time, social welfare may be higher when the monopolist has commitment ability than when she has not. Moreover, the equilibrium under a monopolist seller with commitment power may Pareto-dominate the equilibrium under a monopolist seller without commitment ability. The work also prov...

  1. Durable Pulmonary Vein Isolation: The Holy Grail of Atrial Fibrillation Ablation

    Directory of Open Access Journals (Sweden)

    Darrat Y; Morales G; Shah J; Di Biase L; Natale A; Elayi CS

    2014-04-01

    Full Text Available The inability to achieve durable pulmonary vein isolation (PVI remains a major limitation to catheter ablation for the treatment of atrial fibrillation (AF, potentially resulting in AF recurrence. In this review, we discuss the research performed investigating methods to improve lesion permanence for the goal of durable PVI. Investigations evaluating procedural techniques, various catheters utilized, adjunctive pharmacologic therapy, and novel energy sources designed to improve ablation lesion permanence are discussed.

  2. 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...

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

    DEFF Research Database (Denmark)

    Petrella, Ivan; Santoro, Emiliano

    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 of pro...... is crucial, as this does not only influence the user cost of durables through the conventional demand channel, but also affects in opposite directions the real marginal cost of production in either sector through the intermediate input channel.......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......-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...

  4. 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

  5. Durability aspects of polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Sethuraman, Vijay Anand

    In order for the successful adoption of proton exchange membrane (PEM) fuel cell technology, it is imperative that durability is understood, quantified and improved. A number of mechanisms are known to contribute to PEMFC membrane electrode assembly (MEA) performance degradation. In this dissertation, we show, via experiments, some of the various processes that degrade the proton exchange membrane in a PEM fuel cell; and catalyst poisoning due to hydrogen sulfide (H2S) and siloxane. The effect of humidity on the chemical stability of two types of membranes, [i.e., perfluorosulfonic acid type (PFSA, NafionRTM 112) and biphenyl sulfone hydrocarbon type, (BPSH-35)] was studied by subjecting the MEAs to open-circuit voltage (OCV) decay and potential cycling tests at elevated temperatures and low inlet gas relative humidities. The BPSH-35 membranes showed poor chemical stability in ex situ Fenton tests compared to that of NafionRTM membranes. However, under fuel cell conditions, BPSH-35 MEAs outperformed NafionRTM 112 MEAs in both the OCV decay and potential cycling tests. For both membranes, (i) at a given temperature, membrane degradation was more pronounced at lower humidities and (ii) at a given relative humidity operation, increasing the cell temperature accelerated membrane degradation. Mechanical stability of these two types of membranes was also studied using relative humidity (RH) cycling. Hydrogen peroxide (H2O2) formation rates in a proton exchange membrane (PEM) fuel cell were estimated by studying the oxygen reduction reaction (ORR) on a rotating ring disc electrode (RRDE). Fuel cell conditions were replicated by depositing a film of Pt/Vulcan XC-72 catalyst onto the disk and by varying the temperature, dissolved O2 concentration and the acidity levels in HClO4. The HClO4 acidity was correlated to ionomer water activity and hence fuel cell humidity. H 2O2 formation rates showed a linear dependence on oxygen concentration and square dependence on water

  6. Performance and Durability Evaluation of Bamboo Reinforced Cement Concrete Beams

    Directory of Open Access Journals (Sweden)

    Ankit Singh Mehra

    2016-04-01

    Full Text Available A big part of population in India is still homeless due to raising unaffordability of housing structures. People sleeping on roadsides and living in slums is a common sight in Indian cities. To overcome this problem India today needs millions of houses for their growing population, making concrete as the most widely to be used material in the country. Concrete has found to have excellent compressive strength but poor in tensile strength, to take care of the tensile stresses steel is commonly used as reinforcing material in concrete. Production of steel is a very costly business and its use in concrete as reinforcing material increases the cost of construction by many folds. Also production of steel emits a large amount of green house gases causing considerable deterioration of the environment. The above mentioned socio-economic and environmental factors creates a necessity for finding an appropriate environment friendly and cheap material that can successfully substitute steel as reinforcement in concrete elements of a low cost dwelling for the poor and homeless people of the country. It is here that engineered bamboo can be of great value to Civil Engineers owning to its several net worthy features. Production of every tone of bamboo consumes about a tone of atmospheric CO2 in addition to releasing fresh O2. From structural point of view bamboo has been used as a structural material from the earlier times as it possesses excellent flexure and tensile strength as well as high strength to weight ratio. All this necessitates examining bamboo-reinforced cement concrete in detail for its appropriateness as a structural material for construction of a low cost dwelling unit. The study focuses on evaluating the mechanical and durability properties of cement-concrete beams both singly and doubly reinforced with bamboo splints.

  7. Durable resistance to Puccinia triticina by accumulation of resistance genes

    Directory of Open Access Journals (Sweden)

    Bošković Jelena

    2009-01-01

    Full Text Available The individual use of single race-specific resistance genes with major phenotypic effects has rarely provided lasting resistance. However, breeding and combining or pyramiding of resistance genes into individual cultivars has had considerable success, particularly in situations in which the pathogen does not reproduce sexually, as in the case of wheat leaf rust pathogen. In European-Mediterranean region perfomed international investigations of wheat leaf rust proved that breeding of new lines of wheat resistant to Puccinia triticina Eriks. for differentiation of pathogen population, as well as for sources of durable resistance is necessary. Breeding of such resistant lines has proved necessary due to the unsatisfatory survey results of these regions on standard isogenic Lr lines. It has become clear that these regions needed new, more efficient differential resistance genes, as well as sources of resistance. In the beginning, after extensive screening tests of several International Rust Nurseries, 18 donors of resistance had been selected as crosses with recurrent parents' varieties Princ and Starke. These hybrid lines had been comparatively tested with twenty six Lr single gene lines using twenty especially virulent cultures of P. triticina in order to check the presence of these known Lr genes in our hybrid lines. Considerable influence of recurrent parent to the number of resistant genes in used donors was demonstrated. On the other hand, considerable influence of the pathogen culture was established to the number of resistance genes in used donors. In order to enhance resistance and pyramiding genes in these hybrids, the most interesting selected eight lines have been crossed with only effective isogenic ones, containing the strong genes Lr9, Lr19 and Lr24. On the basis of different segregation rations of all crossing combinations it was proved that no one of resistant donors contained the applied strong resistant genes. It means that our

  8. Factors determining the durability of steam superheater chambers

    Directory of Open Access Journals (Sweden)

    J. Lisok

    2008-11-01

    Full Text Available Purpose: The paper presents the results of calculations of effort for the material of selected superheater chambers’constructional systems in unsteady operation conditions.Design/methodology/approach: In model tests, the influence was analysed of internal pressure andtemperature gradient in the chamber wall on the distribution and value of stress . In the calculations, the processof hot start-up of a boiler was simulated, which was accompanied by short thermal shock induced by rapid coolingof the chamber inner wall.Findings: The random nature of thermal shock, which in the industrial practice may occur in any row and to anynumber of coil pipes, determines the value of maximal stress and the area of its occurrence. It has a significantinfluence on the possibility of forecasting the durability of chambers in working conditions.Research limitations/implications: The research has evidenced a link between the method of forcingthermal shock and the value of maximal stress in the area of bridges.Practical implications: The research has demonstrated the existence of connection between the way of forcingthermal shock and the stress value which, depending on the variant of cooling the chamber, ranges between150-370 MPa. These results are very important to the industry connected with the structure of pipelines.Originality/value: It was found that the primary reason for the superheater chamber damage, leading to crackformation, are thermal shocks. A link has been shown between the method of forcing the thermal shock and thevalue of maximal stress in the zone of bridges.

  9. 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.

  10. Evaluation of pressure and durability of a low-cost wheelchair cushion designed for developing countries.

    Science.gov (United States)

    Guimaraes, Evandro; Mann, William C

    2003-06-01

    Pressure sores are a medical problem for wheelchair users worldwide. In developing countries this problem is more critical because of lack of access to specialized technologies and medical assessment. Seat cushions to relieve pressure represent one of best ways to prevent pressure sores for people with spinal cord injury, amputation, cerebral palsy, and other disabilities that require use of wheelchairs for long periods of time. The purpose of this study was to evaluate the performance of a low cost cushion, called the Tuball, designed for low-income communities in developing countries. The Tuball is made from bicycle inner tubes and plastic balls. Its durability and pressure-relieving characteristics were compared with the ROHOTM cushion and the foam cushions now used in Brazil. A sample of 30 participants tested the three cushions: 15 persons with paraplegia and 15 matched able-bodied persons evaluated the capacity of the cushions to distribute pressure. This study also addressed the use of samples of persons without disabilities to test wheelchair cushions.The Tuball cushion provided significantly better pressure distribution than the foam cushion. A t-test was used to compare disabled persons and non-disabled persons as samples in testing cushions. No difference between pressure distribution between non-disabled and disabled participants was found in testing the ROHO cushion or the foam cushion. However, both capacities of pressure distribution and HICPR varied between non-disabled and disabled participants for the Tuball cushion. To determine the useful life of the Tuball cushion, a fatigue test was conducted to simulate sitting and transfer. Both the Tuball and ROHO cushions withstood the equivalent of at least 1 year of use, whereas the foam cushion broke down. PMID:12799609

  11. Highly Durable and Active PtFe Nanocatalyst for Electrochemical Oxygen Reduction Reaction.

    Science.gov (United States)

    Chung, Dong Young; Jun, Samuel Woojoo; Yoon, Gabin; Kwon, Soon Gu; Shin, Dong Yun; Seo, Pilseon; Yoo, Ji Mun; Shin, Heejong; Chung, Young-Hoon; Kim, Hyunjoong; Mun, Bongjin Simon; Lee, Kug-Seung; Lee, Nam-Suk; Yoo, Sung Jong; Lim, Dong-Hee; Kang, Kisuk; Sung, Yung-Eun; Hyeon, Taeghwan

    2015-12-16

    Demand on the practical synthetic approach to the high performance electrocatalyst is rapidly increasing for fuel cell commercialization. Here we present a synthesis of highly durable and active intermetallic ordered face-centered tetragonal (fct)-PtFe nanoparticles (NPs) coated with a "dual purpose" N-doped carbon shell. Ordered fct-PtFe NPs with the size of only a few nanometers are obtained by thermal annealing of polydopamine-coated PtFe NPs, and the N-doped carbon shell that is in situ formed from dopamine coating could effectively prevent the coalescence of NPs. This carbon shell also protects the NPs from detachment and agglomeration as well as dissolution throughout the harsh fuel cell operating conditions. By controlling the thickness of the shell below 1 nm, we achieved excellent protection of the NPs as well as high catalytic activity, as the thin carbon shell is highly permeable for the reactant molecules. Our ordered fct-PtFe/C nanocatalyst coated with an N-doped carbon shell shows 11.4 times-higher mass activity and 10.5 times-higher specific activity than commercial Pt/C catalyst. Moreover, we accomplished the long-term stability in membrane electrode assembly (MEA) for 100 h without significant activity loss. From in situ XANES, EDS, and first-principles calculations, we confirmed that an ordered fct-PtFe structure is critical for the long-term stability of our nanocatalyst. This strategy utilizing an N-doped carbon shell for obtaining a small ordered-fct PtFe nanocatalyst as well as protecting the catalyst during fuel cell cycling is expected to open a new simple and effective route for the commercialization of fuel cells. PMID:26670103

  12. Durability of Peace Education Effects in the Shadow of Conflict

    Science.gov (United States)

    Rosen, Yigal; Salomon, Gavriel

    2011-01-01

    Value-oriented instructional programs, such as anti-racism, may often face societal barriers. A case in point are peace education programs in conflictual contexts. Close analysis of peace education programs in regions of conflict and tension suggest that they face formidable barriers that would appear to prevent the attainment of their goals of…

  13. Prevent Pneumonia

    Centers for Disease Control (CDC) Podcasts

    2015-08-06

    CDC’s Matthew Westercamp explains what pneumonia is, its symptoms, and how to prevent it.  Created: 8/6/2015 by National Center for Immunization and Respiratory Diseases (NCIRD), Division of Bacterial Diseases (DBD), Respiratory Diseases Branch (RDB).   Date Released: 8/6/2015.

  14. Bullying Prevention

    Science.gov (United States)

    Kemp, Patrice

    2016-01-01

    The focus of the milestone project is to focus on bridging the gap of bullying and classroom instruction methods. There has to be a defined expectations and level of accountability that has to be defined when supporting and implementing a plan linked to bullying prevention. All individuals involved in the student's learning have to be aware of…

  15. 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)

  16. 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

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

    Science.gov (United States)

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

    2015-02-25

    The durability of superhydrophobic surface is a major problem to restrict industrial application of superhydrophobic materials from laboratory research, which can be attributed to a more general issue of mechanical stability for superhydrophobic coatings. Therefore, in order to handle this issue, we have fabricated a mechanically stable drag-reducing coating composed of elastic polydimethylsiloxane (PDMS) and hydrophobic copper particles on model ships, which can resist mechanical abrasion and has displayed a durable drag-reducing effect. In comparison with normal Au superhydrophobic coatings, the as-prepared PDMS/copper coatings showed durable drag reduction performance with a similar drag-reducing rate before (26%) and after (24%) mechanical abrasion. The mechanism for the enhanced mechanical stability and maintained drag reduction of the superhydrophobic surfaces was investigated through characterizations of surface morphology, surface wettability, and water adhesive force evaluation before and after abrasion. This is the first demonstration to realize the application of durable drag reduction by improving the mechanical stability of superhydrophobic coatings. We do believe that superhydrophobic surfaces with good resistance to mechanical abrasion or scratching may draw wide attention and gain significant applications with durable drag-reducing properties. PMID:25644454

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

    Science.gov (United States)

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

    2015-02-25

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

  19. First-order model for durability of Hanford waste glasses as a function of composition

    International Nuclear Information System (INIS)

    This paper discusses two standard chemical durability tests, the static leach test (MCC-1) and product consistency test (PCT), which were conducted on simulated borosilicate glasses that encompass the expected range of compositions to be produced in the Hanford Waste Vitrification Plant. A first-order empirical model was fitted to the data from each test method. The results indicate that glass durability is increased by addition of Al2O3, moderately increased by addition of ZrO2 and SiO2, and decreased by addition of Li2O, Na2O, B2O3, and MgO. Additions of CaO and Fe2O3 reduce MCC-1 durability and produce a moderately positive (CaO) or indifferent (Fe2O3) effect on PCT durability. The first-order models show a statistically significant lack-of-fit, which is attributed to the effects of multiple chemical reactions occurring during glass-water interaction. Liquid-liquid immiscibility is suspected to be responsible for extremely low durability of some glasses

  20. A review of the gas diffusion layer in proton exchange membrane fuel cells: Durability and degradation

    International Nuclear Information System (INIS)

    Highlights: • This paper focuses on the evaluation of the durability characteristics of GDL. • GDL degradation can be categorized into mechanical and chemical degradation. • Standardized test protocols need to be established to evaluate GDL durability. - Abstract: For successful commercialization of a proton exchange membrane fuel cell, the durability requirement must be satisfied. The degradation of a proton exchange membrane fuel cell has been extensively studied, and a number of review papers investigating the durability issue have already been published. However, the gas diffusion layer has rarely been examined, even though it might be a key factor for managing mass transport and two-phase flow while mechanically supporting a membrane-electrode assembly and a bipolar plate. This paper reviews the published works on the durability of the gas diffusion layer of the proton exchange membrane fuel cell. The degradation of the gas diffusion layer can be divided into mechanical degradation, including the compression force effect, freeze/thaw cycle effect, dissolution effect, and erosion effect, and chemical degradation, which consists of the carbon corrosion effect. Following these categories, the methods of accelerated stress tests, the degradation mechanisms, and the influential factors are investigated along with various measurements of gas diffusion layer properties and cell performances

  1. Durability of low-pH injection grout. A literature survey

    International Nuclear Information System (INIS)

    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.)

  2. Physico-chemical durability criteria of oils and linked bio-based polymers

    Directory of Open Access Journals (Sweden)

    Irshad Ambreen

    2015-01-01

    Full Text Available The oxidative stability or durability is an important indicator of performance that depends on the composition of the sample. The fatty oil or polymer degradation processes have generally been established as being free radical mechanism yielding primary oxidation products. We propose to explain in detail all the analytical methods and tools used for the determination of the initial physico-chemical properties of oils and the properties in ageing conditions. Chemical titrations for acid or peroxide value, Rancimat method or thermogravimetric measurements are discussed. Accelerated ageing tools for thermal or photochemical exposures are also shown. After the assessment of oil durability, the development of new bio-based polymer with vegetable oil is tackled because of its industrial interest. It is essential to understand the long term behavior of oils and biopolymers and to assess exactly the durability which is useful to produce life cycle analysis of materials. At last we underline the advantages of a new Fourier transform infrared (FTIR instrumentation with in-situ irradiation and gas cell to give a screening of the durability of various oils or polymers. Main durability criteria of oils and biopolymers are linked to the production of volatile organic compounds and the resistance to the oxidation process.

  3. The Study on the Durability of Submerged Structure Displacement due to Concrete Failure

    Science.gov (United States)

    Mohd, M.; Zainon, O.; Rasib, A. W.; Majid, Z.

    2016-09-01

    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.

  4. Mechanism and Durability of Repair Systems in Polymer-Modified Cement Mortars

    Directory of Open Access Journals (Sweden)

    Ru Wang

    2015-01-01

    Full Text Available This paper investigated the mechanism and durability of repair systems made of ordinary cement-based repair mortar and three kinds of polymer-modified repair mortars with old concrete, SBR dispersion, SAE dispersion, and SAE powder. By comparing the bonding properties of mortars before and after erosion, it was found that polymers could effectively improve the durability of the repair system and SAE powder had the best improvement. Micromorphology study of the repair mortar and the interface of repair mortar with old concrete through SEM showed that the polymer film formed from SAE powder whatever in the mortar or at the interface was dense and tough, the film formed from SAE dispersion was loose and weak, while the film formed from SBR dispersion was in between them, which explained the difference in the tensile bond strength and the durability of the repair systems.

  5. Prediction of the Residual Strength for Durability Failure of Concrete Structure in Acidic Environments

    Institute of Scientific and Technical Information of China (English)

    LI Beixing; CAI Laohu; WANG Kai; ZHANG Yaming

    2016-01-01

    According to the results of accelerated tests of acidiifcation corrosion depth and compressive strength of concretes subjected to sulfuric acid environments, the acidiifcation depth laws of concretes were predicted based on the grey system theory. Thus, the remaining compressive strength was calculated when the acidiifcation depth reached the protection layer thickness of concrete structures, which indicates that the limit state of durability failure can be deifned based on strength degradation, and the calculation process was illustrated by an example. The calculated results show that the remaining compressive strength values in the durability failure limit state for the concrete structures exposed to pH=2 and 3 sulfuric acid water environments and wet-dry cyclic sulfuric acid environment with pH=2 are 74%, 72%, and 80% of initial strength, respectively. The method provides references for the durability evaluation of concrete structure design under the acidic environments.

  6. Recent results on the effect of gamma radiation on the durability and microstructure of DWPF glass

    International Nuclear Information System (INIS)

    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 1010 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

  7. 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.

  8. The selection of private brand durable goods: factors affecting the Choice

    Directory of Open Access Journals (Sweden)

    Carmen Pérez Cabañero

    2010-12-01

    Full Text Available Distributors have extended their brand policy to durable good categories such as household appliances and electronic devices, what has been proved to be worthy, although it has received a lot of criticism. Possibly, the higher familiarity of the consumer with private brands, the favourable change of attitude towards them, the availability of technology and, why not, the actual international economic crisis which affects to the domestic economies can be factors which explain this success. The few researches trying to explain the reasons of acceptance of these brands in durable goods have taken us to analyze whether factors determining the purchase of private brands in typical study categories such as food and cosmetics can be applied to durable goods. Preliminary results indicate that it is not possible.

  9. Chemical durability of soda-lime-aluminosilicate glass for radioactive waste vitrification

    International Nuclear Information System (INIS)

    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 Al2O3 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

  10. Long-term Durability of Cement-based Materials with Very Low w/b

    Institute of Scientific and Technical Information of China (English)

    XIE Youjun; LIU Yunhua; LONG Guangeheng

    2008-01-01

    To investigate the durability, especially the long-term stability of cement-based materials with very low w/b, the air permeability test, carbonation test, capillary absorption rate test and dilation Dotential test were adopted under long-term heat treatment condition. Microstructure of these materials is also analyzed by scannmg electronic microscopy (SEM) and mercury intrusion porosimeter (MIP) in order to further unveil its mechanism and interrelation between microstructure and its properties. The results indicate that in the area investigated, cement-based material with w/b 0.17, like RPC, possesses low porosity and excellent durability. Moreover, its porosity will further decrease under long-term heat treatment compared with normal heat treatment. Its long-term durability is much superior to that of other cement-based materials with w/b 0.25 or 0.35 as high strength concrete (HSC).

  11. Durability of reinforced concrete beams strengthened with fiber reinforced polymers under varying environmental conditions

    International Nuclear Information System (INIS)

    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.

  12. Predicting the long-term durability of hemp-lime renders in inland and coastal areas using Mediterranean, Tropical and Semi-arid climatic simulations.

    Science.gov (United States)

    Arizzi, Anna; Viles, Heather; Martín-Sanchez, Inés; Cultrone, Giuseppe

    2016-01-15

    Hemp-based composites are eco-friendly building materials as they improve energy efficiency in buildings and entail low waste production and pollutant emissions during their manufacturing process. Nevertheless, the organic nature of hemp enhances the bio-receptivity of the material, with likely negative consequences for its long-term performance in the building. The main purpose of this study was to study the response at macro- and micro-scale of hemp-lime renders subjected to weathering simulations in an environmental cabinet (one year was condensed in twelve days), so as to predict their long-term durability in coastal and inland areas with Mediterranean, Tropical and Semi-arid climates, also in relation with the lime type used. The simulated climatic conditions caused almost unnoticeable mass, volume and colour changes in hemp-lime renders. No efflorescence or physical breakdown was detected in samples subjected to NaCl, because the salt mainly precipitates on the surface of samples and is washed away by the rain. Although there was no visible microbial colonisation, alkaliphilic fungi (mainly Penicillium and Aspergillus) and bacteria (mainly Bacillus and Micrococcus) were isolated in all samples. Microbial growth and diversification were higher under Tropical climate, due to heavier rainfall. The influence of the bacterial activity on the hardening of samples has also been discussed here and related with the formation and stabilisation of vaterite in hemp-lime mixes. This study has demonstrated that hemp-lime renders show good durability towards a wide range of environmental conditions and factors. However, it might be useful to take some specific preventive and maintenance measures to reduce the bio-receptivity of this material, thus ensuring a longer durability on site.

  13. Durable resistance to crop pathogens: an epidemiological framework to predict risk under uncertainty.

    Directory of Open Access Journals (Sweden)

    Giovanni Lo Iacono

    Full Text Available Increasing the durability of crop resistance to plant pathogens is one of the key goals of virulence management. Despite the recognition of the importance of demographic and environmental stochasticity on the dynamics of an epidemic, their effects on the evolution of the pathogen and durability of resistance has not received attention. We formulated a stochastic epidemiological model, based on the Kramer-Moyal expansion of the Master Equation, to investigate how random fluctuations affect the dynamics of an epidemic and how these effects feed through to the evolution of the pathogen and durability of resistance. We focused on two hypotheses: firstly, a previous deterministic model has suggested that the effect of cropping ratio (the proportion of land area occupied by the resistant crop on the durability of crop resistance is negligible. Increasing the cropping ratio increases the area of uninfected host, but the resistance is more rapidly broken; these two effects counteract each other. We tested the hypothesis that similar counteracting effects would occur when we take account of demographic stochasticity, but found that the durability does depend on the cropping ratio. Secondly, we tested whether a superimposed external source of stochasticity (for example due to environmental variation or to intermittent fungicide application interacts with the intrinsic demographic fluctuations and how such interaction affects the durability of resistance. We show that in the pathosystem considered here, in general large stochastic fluctuations in epidemics enhance extinction of the pathogen. This is more likely to occur at large cropping ratios and for particular frequencies of the periodic external perturbation (stochastic resonance. The results suggest possible disease control practises by exploiting the natural sources of stochasticity.

  14. An Evaluation of the Durability of Polymer Concrete Bonds to Aluminum Bridge Decks

    OpenAIRE

    Zhang, Huiying

    1999-01-01

    The objective of this study is to evaluate the bond durability of an epoxy-based polymer concrete wearing surface bonded to aluminum bridge decks. In the bridge design, an aluminum alloy bridge deck is used with a polymer concrete wearing surface. A modified mixed mode flexure fracture test was developed to assess the bond durability of specimens aged in the following environmental conditionings: 30°C [86°F], 98% RH; 45°C [113°F], 98% RH; 60°C [140°F], 98% RH; freezing and thawing; sal...

  15. Characterization and durability testing of a glass-bonded ceramic waste form

    International Nuclear Information System (INIS)

    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

  16. Energy efficient one-pot synthesis of durable superhydrophobic coating through nylon micro-rods

    Science.gov (United States)

    Simovich, T.; Wu, A. H.; Lamb, R. N.

    2014-03-01

    A durable and superhydrophobic coating was fabricated at room temperature through encapsulating nylon micro-rods in a hydrophobic silica shell. This was achieved through the precipitation of miniemulsified nylon under high shear to generate micro-rods with high aspect ratio in the presence of methyltrimethoxysilane. The resultant coating structure resembles a network of highly entangled micro-rods that give rise to both surface roughness and hydrophobicity, resulting in contact angles greater than 155°. The embedded nylon polymer within the micro-rods imparts significant mechanical durability to the surface, resulting in a coating hardness of 2H using the pencil hardness test.

  17. Atomic Oxygen Durability Evaluation of Protected Polymers Using Thermal Energy Plasma Systems

    Science.gov (United States)

    Banks, Bruce A.; Rutledge, Sharon K.; Degroh, Kim K.; Stidham, Curtis R.; Gebauer, Linda; Lamoreaux, Cynthia M.

    1995-01-01

    The durability evaluation of protected polymers intended for use in low Earth orbit (LEO) has necessitated the use of large-area, high-fluence, atomic oxygen exposure systems. Two thermal energy atomic oxygen exposure systems which are frequently used for such evaluations are radio frequency (RF) plasma ashers and electron cyclotron resonance plasma sources. Plasma source testing practices such as ample preparation, effective fluence prediction, atomic oxygen flux determination, erosion measurement, operational considerations, and erosion yield measurements are presented. Issues which influence the prediction of in-space durability based on ground laboratory thermal energy plasma system testing are also addressed.

  18. Examples of feedback, experimental and theoretical approaches for concrete durability assessment

    Directory of Open Access Journals (Sweden)

    Toutlemonde F.

    2011-04-01

    Full Text Available This paper presents some experimental data obtained from UHPFRC (Ultra-High Performance Fibre-Reinforced Concrete being exposed for 10 years in a cooling tower and a high slag content concrete being exposed for 30 years in a marine environment. Experimental data are then used for assessing concrete durability through a theoretical approach, namely performance-based analysis. The results from the application of this approach are consistent with the penetration depth of aggressive agents measured from core samples. Finally a simulation method currently being developed by EDF is presented, which has great relevance to durability assessment.

  19. 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.

  20. Recommended Minimum Test Requirements and Test Methods for Assessing Durability of Random-Glass-Fiber Composites

    Energy Technology Data Exchange (ETDEWEB)

    Battiste, R.L.; Corum, J.M.; Ren, W.; Ruggles, M.B.

    1999-06-01

    This report provides recommended minimum test requirements are suggested test methods for establishing the durability properties and characteristics of candidate random-glass-fiber polymeric composites for automotive structural applications. The recommendations and suggestions are based on experience and results developed at Oak Ridge National Laboratory (ORNL) under a US Department of Energy Advanced Automotive Materials project entitled ''Durability of Lightweight Composite Structures,'' which is closely coordinated with the Automotive Composites Consortium. The report is intended as an aid to suppliers offering new structural composites for automotive applications and to testing organizations that are called on to characterize the composites.

  1. Advances in studies on concrete durability and countermeasures against freezing-thawing effects

    Institute of Scientific and Technical Information of China (English)

    WuJian Yan; FuJun Niu; XianJun Zhang; Jing Luo; GuoAn Yin

    2014-01-01

    This-paper-is-a-meta-analysis-of-recent-domestic-and-foreign-research-on-freezing-thawing-effects-on-concrete-durability.-The-main-theories-on-the-mechanisms-of-freeze-thaw-damage-to-concrete-are-introduced:-the-hydrostatic-pressure-theory,-the-osmotic-pressure-theory,-the-critical-water-saturation-degree-theory,-the-dual-mechanism-theory,-and-the-mi-cro-ice-crystal-lens-model-theory.-The-influence-laws-of-freezing-thawing-on-the-mechanical-properties-of-concrete-are-summarized,-and-countermeasures-to-improve-concrete-durability-in-freezing-thawing-circumstances-are-presented.-This-work-provides-valuable-references-for-future-engineering-constructions-in-cold-regions.

  2. Recent Development of Durable and Self-Healing Surfaces with Special Wettability.

    Science.gov (United States)

    Chen, Kunlin; Wu, Yi; Zhou, Shuxue; Wu, Limin

    2016-03-01

    Artificial special wetting surfaces have drawn much interest due to their important applications in many fields. Nevertheless, tremendous challenges still remain for the fabrication of wetting surfaces with durable and self-healing properties. Here, recent progress of durable, self-healing wetting surfaces is highlighted by discussing the fabrications of several typical wetting surfaces including superhydrophobic surfaces, superamphiphobic surfaces, underwater superoleophobic surfaces, and high hydrophilic antifouling surfaces based on expertise and related research experience. To conclude, some perspectives on the future research and development of these special wetting surfaces are presented. PMID:26833559

  3. Durability and static strength of microcrystalline titanium VT1-0 obtained by equal-channel angular pressing

    Science.gov (United States)

    Betekhtin, V. I.; Dvorak, J.; Kadomtsev, A. G.; Kardashev, B. K.; Narykova, M. V.; Raab, G. K.; Sklenička, V.; Faizova, S. N.

    2015-01-01

    The influence of deformation by equal-channel angular pressing (ECAP) on the durability of titanium (VT1-0 grade) tensile tested under creep conditions has been studied for the first time. It is established that the ECAP-induced transition of titanium to a microcrystalline state leads to a decrease in the durability, while the characteristics of static strength are improved.

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

    Science.gov (United States)

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

    1976-01-01

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

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

    Science.gov (United States)

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

    2013-08-01

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

  6. Asphalt durability and self-healing modelling with discrete particles approach

    NARCIS (Netherlands)

    Magnanimo, V.; Huerne, ter H.L.; Luding, S.; Scarpas, A.; Kringos, N.; Al-Qadi, I.; Loizos, A.

    2012-01-01

    Asphalt is an important road paving material, where besides an acceptable price, durability, surface conditions (like roughening and evenness), age-, weather- and traffic-induced failures and degradation are relevant aspects. In the professional road engineering branch empirical models are used to d

  7. FORECASTING OF DURABILITY OF ASPHALT PAVEMENT ON THE BASIS OF LEVELS OF THEIR VIBRATION LOADING

    Directory of Open Access Journals (Sweden)

    V. A. Osinovskaya

    2015-01-01

    Full Text Available The problem of low durability of flexible pavement is one of the most important problems of road economy. For example, the actual service life of asphalt pavement in Russia about 3 … 5 years. The bad condition of highways is an obstacle for the development of the national economy and leads to a significant annual economic losses.At present, this problem has no exact solution. Even at the seeming good road conditions of Europe and America the problem of low durability is no less important in these countries. And this problem becomes more and more actual every year.Our scientific researches allowed to make a hypothesis that the projected of pavements are not have the necessary durability yet not of a stage of designing because in strength calculations did not take into account the vibration of road constructions.Very actual the vibration loading becomes today as is now significantly changed the nature of loading of pavements. As a result the deflections of a pavements are reduced, but the increased vibration of pavements accelerated processes of destruction and significantly reduced durability.The theory of vibration destruction developed by the author allows to adjust the vibration, to form the vibration resistance pavements, and also to forecast a residual life of pavements that will more effectively develop repair actions.

  8. Bond strength durability of a resin composite on a reinforced ceramic using various repair systems

    NARCIS (Netherlands)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Amaral, Regina; Leite, Fabiola; Bottino, Marco Antonio

    2009-01-01

    Objectives. This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems. Methods. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha(R)) (N=30) were randomly divided into three groups according to the repair method: PR-

  9. The stratified significance of a historic facade as a basis for a more durable conservation approach

    NARCIS (Netherlands)

    Van Roy, N.; Van Balen, K.; Verstrynge, E.; Naldini, S.

    2015-01-01

    In heritage conservation, a gap is often observed between the theory of conservation as a durable process that aims at the preservation of a historic building and the practice of restoration as a single intervention that aims at a fast and convincing result. This paper describes the proposed approac

  10. Does Adhesive Resin Application Contribute to Resin Bond Durability on Etched and Silanized Feldspathic Ceramic?

    NARCIS (Netherlands)

    Passos, Sheila Pestana; Valandro, Luiz Felipe; Amaral, Regina; Ozcan, Mutlu; Bottino, Marco Antonio; Kimpara, Estevao Tomomitsu

    2008-01-01

    Purpose: To assess the effect of adhesive application and aging on the bond durability of resin cement to etched and silanized feldspathic ceramic. Materials and Methods: Twenty blocks (6.4 x 6.4 x 4.8 mm) of feldspathic ceramic (Vita VM7) were produced. The ceramic surfaces were conditioned with 10

  11. The design of durable Na+-selective CHEMFETs based on polysiloxane membranes

    NARCIS (Netherlands)

    Brunink, Jos A.J.; Lugtenberg, Ronny J.W.; Brzozka, Zbigniew; Engbersen, Johan F.J.; Reinhoudt, David N.

    1994-01-01

    The design of durable sodium-selective CHEMFETs based on the covalent attachment of a sodium-selective ionophore and tetraphenylborate anions to a polysiloxane membrane matrix is described. Simulations of the membrane potential of such CHEMFETs using an extended version of the model developed previo

  12. Highly durable superhydrophobic coatings with gradient density by movable spray method

    Science.gov (United States)

    Tenjimbayashi, Mizuki; Shiratori, Seimei

    2014-09-01

    Superhydrophobic surface is expected to be applied in anti-fouling, anti-icing, and anti-bacterial. However, practical use is interrupted by low mechanical strength, time-consuming process, and limited coating substrate. Here highly durable superhydrophobic coatings were prepared by simple and novel spraying method, which sprays with changing the "spray distance between substrate and spray" (SD), named "movable spray method." We prepared the solution that changes wettability and durability with spraying distance by mixing SiO2 nanoparticles and ethyl alpha cyanoacrylate polymer (EAC). Then, we evaluated the chemical components and surface morphologies of each spraying distance coatings (0 ˜ 50 cm) by XPS, SEM, and laser scanning microscope. It revealed that surface roughness and SiO2/EAC ratio increased as the SD increases. Thus, durable superhydrophobic coatings were designed by spraying with increasing SD gradually. Glow discharge-optical emission spectrometry analysis revealed that designed coatings showed the gradual increase of SiO2/EAC ratio. As a result, coatings prepared on glass, wood, or aluminum substrates maintained their superhydrophobicity up to the abrasion at 40 kPa. This movable spray method is simple coating by the wet process and prepares robust hydrophobic coating on complex shape and large area substrates. The gradient functional surface was found to have mechanical durability and superhydrophobicity, and wide area applications will be expected.

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

    NARCIS (Netherlands)

    Siemes, T.; Polder, R.; Vries, H. de

    1998-01-01

    To design concrete structures for durability, all relevant performances that the structure has to fulfill and that can be influenced by degradations have to be defined. The probability that a given performance must be delivered within a design service life should also be considered. One of the conse

  14. Calculations of durability of thin-walled shells with account of hydrogenation and aggressive environmental effect

    International Nuclear Information System (INIS)

    A nomogram ascertaining the dependence between the time of fracture and thickness of shell walls for different values of embrittlement indices is presented. Using the nomogram offered it proved possible to define safe radii of the shells under conditions of hydrogenation and corrosive medium influence, as well as to calculate the durability of the shell.6 refs., 1 fig., 1 tab

  15. 76 FR 20822 - Proposed Information Collection (Living Will and Durable Power of Attorney for Health Care...

    Science.gov (United States)

    2011-04-13

    ... AFFAIRS Proposed Information Collection (Living Will and Durable Power of Attorney for Health Care) Activity: Comment Request AGENCY: Veterans Health Administration, Department of Veterans Affairs. ACTION... Power of Attorney for Health Care, VA Form 10-0137. OMB Control Number: 2900-0556. Type of...

  16. Feed Pellet and Corn Durability and Breakage During Repeated Elevator Handling

    Science.gov (United States)

    Pelleting of animal feeds is important for improved feeding efficiency and for convenience of handling. Pellet quality impacts the feeding benefits for the animals and pellet integrity during handling. To determine the effect of repeated handling on feed pellet breakage and durability, a 22.6-t (100...

  17. Characterization and modelling of self healing of bituminous materials towards durable asphalt pavement

    NARCIS (Netherlands)

    Qiu, J.; Van de Ven, M.F.C.; Schlangen, H.E.J.G.; Wu, S.; Molenaar, A.A.A.

    2012-01-01

    The traffic volume and the number of heavy vehicles are growing enormously nowadays. There is a need for designing a durable asphalt pavement with innovative technologies. Pavement structures and materials with self healing and self repairing capability are believed to be very useful in such a syste

  18. Laboratory evaluation of durability of open-graded friction course Mixtures

    Directory of Open Access Journals (Sweden)

    N. A. Qureshi

    2015-06-01

    Full Text Available Open-graded friction courses (OGFC are special purpose thin surface mixtures of hot mix asphalt (HMA pavement that is increasingly being used around the world. Owing to its safety aspects, OGFC is being regularly used as final riding surface on interstate and high speed expressways by different highway agencies in United States, including Alabama Department of Transportation. OGFC pavements in Alabama are facing premature failure due to different reasons. Loss of durability and functionality causes failure of OGFC pavements. Thus, research is needed to improve the durability of OGFC and enhance its beneficial properties. This research proposes methods to improve the durability of OGFC mixtures through laboratory performance testing. Aggregate gradation and layer thickness significantly affected the durability of the OGFC surfaces in general, especially the layer thickness. The Hamburg test indicated a 50-60% higher resistance to moisture damage of OGFC pavement with increase in thickness from 19 mm to 38 mm. The Cantabro stone loss of OGFC pavements is reduced 10- 50% with increase in thickness from 19 mm to 38 mm. The permeability tests results indicated 12-100% increase in permeability with increase in thickness of OGFC pavement from 19 mm to 38 mm. Indirect tensile strength tests indicated 50-300% increase in strength with increase in thickness of OGFC pavement from 19 mm to 38 mm.

  19. Skid resistance and durability of coated and uncoated concrete floors in dairy cattle buildings

    OpenAIRE

    Georg, Heiko

    2011-01-01

    Passageways in cattle buildings should provide durable and non-slippery surface to allow cattle an unrestrained locomotion and expression of behaviour. In order to evaluate walking areas fo cattle buildings and their grip or skid resistance, measures with Skid Resistance Tester to obtain SRT-values were performed on sevreal dairy farms in Germany.

  20. Durability of polymer matrix composites for automotive structural applications: A state-of-the-art review

    Energy Technology Data Exchange (ETDEWEB)

    Corum, J.M.; Simpson, W.A. Jr.; Sun, C.T.; Talreja, R.; Weitsman, Y.J.

    1995-07-01

    A key unanswered question that must be addressed before polymeric composites will be widely used in automotive structural components is their known durability. Major durability issues are the effects that cyclic loadings, creep, automotive fluid environments, and low-energy impacts have on dimensional stability, strength, and stiffness throughout the required life of a composite component. This report reviews the current state of understanding in each of these areas. It also discusses the limited information that exists on one of the prime candidate materials for automotive structural applications--an isocyanurate reinforced with a continuous strand, swirl mat. Because of the key role that nondestructive evaluations must play in understanding damage development and progression, a chapter is included on ultrasonic techniques. A final chapter then gives conclusions and recommendations for research needed to resolve the various durability issues. These recommendations will help provide a sound basis for program planning for the Durability of Lightweight Composite Structures Project sponsored by the US Department of Energy in cooperation with the Automotive Composites Consortium of Chrysler, Ford, and General Motors.

  1. Studies on durable resistance of rice to blast in different latitudes

    Institute of Scientific and Technical Information of China (English)

    LIUErming; PENGShaoqiu; HUANGFeiyuan; XIAOFanghua

    1996-01-01

    It has been an important problem on resistant breeding that cultivar's resistance of rice to blast disease eaused by Magnaporthe grisea(Hebert)Barr. is easily broken down. In order to find out resources with durable, resistance to blast, the study was carried put during 1990-1994.

  2. The long-term durability of plication of the anterior rectus sheath assessed by ultrasonography

    NARCIS (Netherlands)

    van Uchelen, J H; Kon, M; Werker, P M

    2001-01-01

    The purpose of this study was to assess the long-term durability of a standard vertical plication of the anterior rectus sheath. For this purpose, 70 women who had undergone this procedure as part of an abdominoplasty were sent a questionnaire, their records were studied, and they were invited back

  3. Influence of surface topography on the surface durability of steam oxidised sintered iron

    Directory of Open Access Journals (Sweden)

    José Daniel Biasoli de Mello

    2005-06-01

    Full Text Available Durability of surfaces has been reported as the main factor affecting tribological behavior of steam oxidised sintered iron. The presence of surface pores and their negative influence on load bearing capacity, suggest that surface topography might play an important role on the durability of the oxide layer. In this paper, the influence of compaction pressure and powder grade on surface topography, and as a consequence, its effect on the tribological behavior of steam oxidised sintered iron has been analysed. Specimens prepared from atomised iron powders with different sizes were compacted using 4 different pressures, sintered, and then subjected to steam treatment. Tribological characterisation was carried out in a reciprocating sliding wear test. Although the processing parameters affected the surface topography to a considerable extent, the main influence may be attributed to powder grade. A strong influence of surface topography on the durability distance, evaluated in terms of the evolution of contact resistance with total sliding distance, has been highlighted. Surfaces which were smoother and had high load-carrying capacity were always associated with a higher durability distance.

  4. Durability of polymeric materials in space : Application of scanning thermal microscopy

    NARCIS (Netherlands)

    Fischer, H.R.; Semprimoschnig, C.O.A.

    2009-01-01

    In this work, a new method, the scanning thermal microscopy method, is applied to study the durability of polymeric materials for space applications. The method was applied to study ground-tested as well as space-retrieved materials. Space-grade silicones, high-temperature polyimides, and the well-k

  5. Moisture sorption, biological durability, and mechanical performance of WPC containing modified wood and polylactates

    Directory of Open Access Journals (Sweden)

    B. Kristoffer Segerholm

    2012-11-01

    Full Text Available Biological durability is an important feature for wood-plastic composites (WPC intended for outdoor applications. One route to achieving WPC products with increased biological durability is to use wood preservative agents in the formulation of the WPC. Another option could be to use a chemically modified wood component that already exhibits increased resistance to biological degradation. There is also a need to use biobased thermoplastics made from renewable resources, which would decrease the dependency on petrochemically-produced thermoplastics in the future. The objective of this study was to examine moisture sorption properties, biological durability, and mechanical performance of injection-molded WPC samples based on acetylated or thermally modified wood components and a polylactate matrix. The biological durability was evaluated in a terrestrial microcosm (TMC test according to ENV 807, followed by mechanical evaluation in a center point bending test. The moisture sorption properties were investigated via both water soaking and exposure in a high-humidity climate. Low or negligible mass losses were observed in the TMC test for all WPC samples. However, the mechanical evaluation after exposure in the TMC test showed 35-40% losses in both strength and stiffness for the WPC containing an unmodified wood component.

  6. Durable cisgenic resistance to Phytophthora infestans in potato and perspectives for applications in Africa

    NARCIS (Netherlands)

    Gheysen, G.; Heremans, B.; Droogenbroeck, van B.; Custers, R.; Vossen, J.H.; Visser, R.G.F.; Jacobsen, E.; Hutten, R.C.B.; Haverkort, A.J.

    2015-01-01

    Late blight caused by Phytophthora infestans is a major constraint in potato production. A promising strategy to combat late blight in potato is to combine different resistance genes to achieve durable resistance. Resistance genes from wild relatives can be introduced by breeding or by transformatio

  7. Effect of Curing Conditions on the Durability of Ultra-high Performance Concrete under Flexural Load

    Institute of Scientific and Technical Information of China (English)

    GU Chunping; SUN Wei; GUO Liping; WANG Qiannan

    2016-01-01

    We experimentally investigated the effect of curing conditions on the durability of UHPC under flexural load. Moreover, the mechanisms of the effect of curing conditions were revealed from the microstructural point of view with environmental scanning electron microscopy (ESEM) and X-ray computerized tomography (X-ray CT). The experimental results show that the flexural load has negative inlfuence on the durability of UHPC, but UHPC still exhibits excellent durability under lfexural load. Besides, the curing conditions do show inlfuences on the durability of UHPC. Compared with standard and steam curing, oven curing led to a lower chloride resistance and freeze-thaw performance of UHPC. The microstructure of UHPC paste was detected with ESEM. It is revealed that, compared with standard and steam cured UHPC, the lower reaction degree and internal microcracks are the causes for the lower chloride resistance of oven cured UHPC. The defects distribution in UHPC before and after freeze-thaw action was investigated with X-ray CT. The number of defects in oven cured UHPC increases the fastest during the freeze-thaw action due to its more defective microstructure.

  8. 75 FR 7550 - Requirements for Consumer Registration of Durable Infant or Toddler Products; Correction

    Science.gov (United States)

    2010-02-22

    ... Register of December 29, 2009 (74 FR 68668). The document issued a final rule under section 104(d) of the... . SUPPLEMENTARY INFORMATION: In FR Doc. E9-30485 appearing on page 68668 in the Federal Register of Tuesday... COMMISSION 16 CFR Part 1130 Requirements for Consumer Registration of Durable Infant or Toddler...

  9. 77 FR 9522 - Requirements for Consumer Registration of Durable Infant or Toddler Products

    Science.gov (United States)

    2012-02-17

    .... 75 FR 7550. Since December 29, 2010, registration forms have been required for all durable infant or..., and the date of manufacture on each such product. 74 FR 68668. The rule specified formatting and text... amend the rule in order to clarify or correct certain aspects of the rule. 76 FR 48053. Through...

  10. Modeling of asphalt durability and self-healing with discrete particles method

    NARCIS (Netherlands)

    Magnanimo, V.; Huerne, ter H.L.; Luding, S.; Beuving, E.; Dewez, P.; Malkoc, G.; Southern, M.

    2012-01-01

    Asphalt is an important road paving material. Besides an acceptable price, durability, surface conditions (like roughening and evenness), age-, weather- and traffic-induced failures and degradation are relevant aspects. In the professional road-engineering branch empirical models are used to describ

  11. Experimental Investigation on the Durability of Glass Fiber-Reinforced Polymer Composites Containing Nanocomposite

    Directory of Open Access Journals (Sweden)

    Weiwen Li

    2013-01-01

    Full Text Available Nanoclay layers incorporated into polymer/clay nanocomposites can inhibit the harmful penetration of water and chemicals into the material, and thus the durability of glass fiber-reinforced polymer (GFRP composites should be enhanced by using polymer/clay nanocomposite as the matrix material. In this study, 1.5 wt% vinyl ester (VE/organoclay and 2 wt% epoxy (EP/organoclay nanocomposites were prepared by an in situ polymerization method. The dispersion states of clay in the nanocomposites were studied by performing XRD analysis. GFRP composites were then fabricated with the prepared 1.5 wt% VE/clay and 2.0 wt% EP/clay nanocomposites to investigate the effects of a nanocomposite matrix on the durability of GFRP composites. The durability of the two kinds of GFRP composites was characterized by monitoring tensile properties following degradation of GFRP specimens aged in water and alkaline solution at 60°C, and SEM was employed to study fracture behaviors of aged GFRP composites under tension. The results show that tensile properties of the two types of GFRP composites with and without clay degrade significantly with aging time. However, the GFRP composites with nanoclay show a lower degradation rate compared with those without nanoclay, supporting the aforementioned hypothesis. And the modification of EP/GFRP enhanced the durability more effectively.

  12. Design and fabrication of durable owner-built wind turbine blades

    Science.gov (United States)

    Queeney, R. A.

    To find the configuration of materials that will produce lightweight, durable wind tubine blades, a composite material blade consisting of an aluminum tubing spar, a foam insulating filler and a glass reinforced plastic skin was analyzed. Various tensile and creep tests were conducted on model blades, and a computer analysis determined the best configuration for the blade.

  13. Durability of Solid Oxide Electrolysis Cell and Interconnects for Steam Electrolysis

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin;

    2013-01-01

    Durability of a solid oxide electrolysis cell tested at -1.5A / cm2 for high temperature steam electrolysis was investigated in the present work under stack relevant conditions. Detailed electrochemical and microstructural analyses were carried out. The results show that both the hydrogen...

  14. 42 CFR 410.38 - Durable medical equipment: Scope and conditions.

    Science.gov (United States)

    2010-10-01

    ... supporting documentation, including pertinent parts of the beneficiary's medical record (for example, history... 42 Public Health 2 2010-10-01 2010-10-01 false Durable medical equipment: Scope and conditions... HUMAN SERVICES MEDICARE PROGRAM SUPPLEMENTARY MEDICAL INSURANCE (SMI) BENEFITS Medical and Other...

  15. Multi-functional and durable nanofiber-fabric layered composite for protective application

    Science.gov (United States)

    A multifunctional and durable nanofiber-fabric-layered composite (NFLC) material was prepared by depositing electrospun Ag/PAN hybrid nanofibers onto a Nylon/cotton 50: 50 fabric substrate. The NFLCs showed excellent aerosol barrier efficiency and good air/moisture permeability. In addition, they sh...

  16. Long-term elastic durability of polymer matrix composite materials after repeated steam sterilization.

    Science.gov (United States)

    Chong, Alexander C M; Fischer, Gustav; Dart, Bradley R; Wooley, Paul H

    2015-11-01

    We compared the durability of 3 different selected composite materials that underwent repeated steam sterilization with the durability of traditional metal materials. Composite materials Tepex, CFR-PPS (carbon-fiber-reinforced polyphenylene sulfide), and HTN-53 (Zytel HTN53G50HSLR NC010) were evaluated for durability and water retention after repeated steam sterilization. These composites were compared with stainless steel and aluminum. The structural properties of these materials were measured (short-beam load-to-failure and cyclic compression loading tests) before, during, and after repeated steam sterilization. The relative radiographic density of these materials was also compared. There was no significant difference in the moisture retention of these composite materials before and after repeated sterilization. The composite materials were significantly more radiolucent than the metals. For all the composite materials, load to failure deteriorated after repeated sterilization. The cyclic compression loading tests showed HTN-53 had the poorest performance, with complete failure after 400 cycles of repeated sterilization. CFR-PPS performed slightly better, with 33% failure at final testing. Tepex had no failures at final testing. Although HTN-53 has shown promise in other orthopedic applications, its performance after repeated sterilization was relatively poor. Tepex showed the most potential for durability after repeated sterilization. Further study is needed to identify specific applications for these materials in the orthopedic industry. PMID:26566557

  17. FUNDAMENTAL STUDIES OF THE DURABILITY OF MATERIALS FOR INTERCONNECTS IN SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, J.; Laney, S.; Jackson, W.; Pettit, F.; Meier, J.; Dhanaraj, N.; Beuth, J.

    2005-01-28

    This task involves theoretical analysis of possible alternative metallic interconnect schemes including: Ni and dispersion-strengthened Ni, low CTE alloys based on Fe-Ni (Invar), coatings to suppress evaporation, and incorporation of high conductivity paths. The most promising systems are being evaluated experimentally with regard to durability and oxide conductivity.

  18. Durability assessment of concrete sheet piling in the 'De Betuweroute' railway line

    NARCIS (Netherlands)

    Peelen, W.H.A.; Polder, R.B.

    2004-01-01

    Assessment of the durability of prestressed concrete sheet piles under the interference of CP gas pipeline system current, established that due to their low magnitude, these currents do not compromise the required 100-year service life of the structures. The sophisticated numerical modelling tools b

  19. 40 CFR 86.1825-08 - Durability demonstration procedures for refueling emissions.

    Science.gov (United States)

    2010-07-01

    ... must be conducted using the SRC or a road cycle approved under the provisions of § 86.1823(e)(1). (2...: (1) Cycling of canister loading due to diurnal and refueling events; (2) Use of various commercially... paragraph. (h) Emission component durability. . For guidance see 40 CFR 86.1845-01 (e). (i) If...

  20. Load cycle durability of a graphitized carbon black-supported platinum catalyst in polymer electrolyte fuel cell cathodes

    Science.gov (United States)

    Takei, Chikara; Kakinuma, Katsuyoshi; Kawashima, Kazuhito; Tashiro, Keisuke; Watanabe, Masahiro; Uchida, Makoto

    2016-08-01

    We focus on Pt degradation occurring during fuel cell vehicle (FCV) combined drive cycles involving load and open circuit voltage (OCV) just after startup and during idling. Load cycle durability is evaluated as a function of OCV/load holding time, load rate and relative humidity (RH) with a graphitized carbon black-supported platinum catalyst (Pt/GCB) in the cathode. The degradation of Pt/GCB is suppressed for shorter OCV holding times, lower load rates and lower RH. Scanning ion microscopy (SIM) images of membrane cross-sections indicate that the amount of Pt deposited in the membrane decreases during drive cycles involving load with short OCV holding times. Investigations of the Pt distribution in the cathode catalyst layer (CL) by using scanning TEM-EDX show that the dissolution of Pt is suppressed on the membrane side in the CL. The Pt dissolution is accelerated by the high Pt oxidation due to the long OCV holding time. A load cycle with both long OCV holding time and low load inhibits the Pt2+ migration into the membrane but accelerates the Pt particle growth due to electrochemical Ostwald ripening; meanwhile, a load cycle with long OCV holding time at lower RH prevents both the Pt dissolution and particle growth.

  1. Thermal Conductivity and Erosion Durability of Composite Two-Phase Air Plasma Sprayed Thermal Barrier Coatings

    Science.gov (United States)

    Schmitt, Michael P.; Rai, Amarendra K.; Zhu, Dongming; Dorfman, Mitchell R.; Wolfe, Douglas E.

    2015-01-01

    To enhance efficiency of gas turbines, new thermal barrier coatings (TBCs) must be designed which improve upon the thermal stability limit of 7 wt% yttria stabilized zirconia (7YSZ), approximately 1200 C. This tenant has led to the development of new TBC materials and microstructures capable of improved high temperature performance. This study focused on increasing the erosion durability of cubic zirconia based TBCs, traditionally less durable than the metastable t' zirconia based TBCs. Composite TBC microstructures composed of a low thermal conductivity/high temperature stable cubic Low-k matrix phase and a durable t' Low-k secondary phase were deposited via APS. Monolithic coatings composed of cubic Low-k and t' Low-k were also deposited, in addition to a 7YSZ benchmark. The thermal conductivity and erosion durability were then measured and it was found that both of the Low-k materials have significantly reduced thermal conductivities, with monolithic t' Low-k and cubic Low-k improving upon 7YSZ by approximately 13 and approximately 25%, respectively. The 40 wt% t' Low-k composite (40 wt% t' Low-k - 60 wt% cubic Low-k) showed a approximately 22% reduction in thermal conductivity over 7YSZ, indicating even at high levels, the t' Low-k secondary phase had a minimal impact on thermal in the composite coating. It was observed that a mere 20 wt% t' Low-k phase addition can reduce the erosion of a cubic Low-k matrix phase composite coating by over 37%. Various mixing rules were then investigated to assess this non-linear composite behavior and suggestions were made to further improve erosion durability.

  2. Performance and durability of high emittance heat receiver surfaces for solar dynamic power systems

    Science.gov (United States)

    Degroh, Kim K.; Roig, David M.; Burke, Christopher A.; Shah, Dilipkumar R.

    1994-01-01

    Haynes 188, a cobalt-based superalloy, will be used to make thermal energy storage (TES) containment canisters for a 2 kW solar dynamic ground test demonstrator (SD GTD). Haynes 188 containment canisters with a high thermal emittance (epsilon) are desired for radiating heat away from local hot spots, improving the heating distribution, which will in turn improve canister service life. In addition to needing a high emittance, the surface needs to be durable in an elevated temperature, high vacuum environment for an extended time period. Thirty-five Haynes 188 samples were exposed to 14 different types of surface modification techniques for emittance and vacuum heat treatment (VHT) durability enhancement evaluation. Optical properties were obtained for the modified surfaces. Emittance enhanced samples were exposed to VHT for up to 2692 hours at 827 C and less than or equal to 10(exp -6) torr with integral thermal cycling. Optical properties were taken intermittently during exposure, and after final VHT exposure. The various surface modification treatments increased the emittance of pristine Haynes 188 from 0.11 up to 0.86. Seven different surface modification techniques were found to provide surfaces which met the SD GTD receiver VHT durability requirement. Of the 7 surface treatments, 2 were found to display excellent VHT durability: an alumina based (AB) coating and a zirconia based coating. The alumina based coating was chosen for the epsilon enhancement surface modification technique for the SD GTD receiver. Details of the performance and vacuum heat treatment durability of this coating and other Haynes 188 emittance surface modification techniques are discussed. Technology from this program will lead to successful demonstration of solar dynamic power for space applications, and has potential for application in other systems requiring high emittance surfaces.

  3. Preventive maintenance

    International Nuclear Information System (INIS)

    The information contained in this paper should be used in conjunction with the maintenance instructions provided by the manufacturer of each valve. When there is any question or conflict between the procedure described and the manufacturer's, the author suggests determining the best method for the applications. A good long range preventative maintenance program for valves will eliminate costly repairs or replacement of valves long before their time. A little flush, lube, and what was once called elbow grease will also go a long way in reducing your downtime and maintenance budget. This paper will discuss one of the most misunderstood theories concerning valve maintenance, i.e., that periodic maintenance of valves includes the injection of sealants. Sealants are injected into valves as a secondary seal for most valves. Under normal conditions, valves do not require sealant injection. Solid fillers in sealants tend to plug the system making it virtually impossible to inject either sealant or a lubricant, requiring the injection of flush or cleaners to dislodge the solids. Topics covered in this paper will range from general maintenance requirements to valve flushing, cleaning and lubrication

  4. 泉州湾跨海大桥海工混凝土耐久性解决方案%Research of Durability Design and Life Prediction for the Quanzhou Bay Bridge Marine Concrete Structure

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    分析了泉州湾跨海大桥混凝土结构所处的腐蚀环境特点,提出了桥梁海工混凝土耐久性解决方案。研究表明,采用低渗透高抗裂海工混凝土,提出合理的混凝土保护层最小厚度、裂缝宽度允许值,同时根据不同混凝土结构采取必要的附加防腐蚀措施,加强施工过程中混凝土质量、保护层厚度以及裂缝控制等系列措施确保桥梁混凝土的耐久性。%This paper analyzed the environmental corrosion characteristics of Quanzhou Bay Bridge concrete struc-ture and proposed solutions of the durability of bridge marine concrete.Results show that using low permeability and highly crack-resistant marine concrete,presenting proper minimum thickness of concrete cover and allowable crack width and adopting necessary additional corrosion protecting measures can improve the durability of concrete effective-ly.Meanwhile,strengthening the regulatory measures of the quality of concrete,thickness of concrete cover and crack prevention can ensure the durability of bridge concrete.

  5. Investigating the Variable Durability of Malta's Lower Globigerina Limestone to Soluble-Salt Damage.

    Science.gov (United States)

    Zammit, Tano; Cassar, JoAnn

    2014-05-01

    Investigating the Variable Durability of Malta's Lower Globigerina Limestone to Soluble-Salt Damage. Tano Zammit, JoAnn Cassar Department of the Built Heritage, Faculty for the Built Environment. University of Malta. The millenary use of Lower Globigerina Limestone (LGL) as a building stone in the Maltese Islands, and its export to other Mediterranean countries in the past, is confirmation of its validity. Notwithstanding the diminishing economic importance of this once principal resource of the local building industry, the ever growing need for conservation of Malta's rich patrimony of archaeological/historical buildings and structures built of this stone, emphasise the need for on-going research particularly that investigating its variable durability. The research under discussion here forms part of a wider research programme on the characterisation of this locally very important resource. In this investigation the durability of the LGL is considered in terms of two main climatic features, namely a temperate Mediterranean climate involving i) a salt-laden marine environment together with ii) relatively short spans of heavy precipitations alternating with longer periods of virtual drought. It is virtually impossible to all but the quarry owners to identify 'good' from 'bad' quality stone simply through the visual observation, as LGL is a fine-grained, white to yellow, homogenous limestone. On the other hand, it is empirically known that LGL is a moderately weak limestone, characterized by the predominance of the mineral calcite (86 - 99%) and by a high total porosity (up to 40%) of which, over 85%, is microporosity below 5µm. In theory, these physical properties should render such stone-type particularly susceptible to deterioration involving a) mechanisms of capillary salt-laden moisture accumulation and movement together with, b) thermodynamic changes of soluble-salts during dissolution and crystallization cycles. The adopted research methodology investigating

  6. Durability and inflammogenic impact of carbon nanotubes compared with asbestos fibres

    Directory of Open Access Journals (Sweden)

    Clark Steve

    2011-05-01

    Full Text Available Abstract Background It has been suggested that carbon nanotubes might conform to the fibre pathogenicity paradigm that explains the toxicities of asbestos and other fibres on a continuum based on length, aspect ratio and biopersistence. Some types of carbon nanotubes satisfy the first two aspects of the fibre paradigm but only recently has their biopersistence begun to be investigated. Biopersistence is complex and requires in vivo testing and analysis. However durability, the chemical mimicking of the process of fibre dissolution using in vitro treatment, is closely related to biopersistence and more readily determined. Here, we describe an experimental process to determine the durability of four types of carbon nanotubes in simulated biological fluid (Gambles solution, and their subsequent pathogenicity in vivo using a mouse model sensitive to inflammogenic effects of fibres. The in vitro and in vivo results were compared with well-characterised glass wool and asbestos fibre controls. Results After incubation for up to 24 weeks in Gambles solution, our control fibres were recovered at percentages consistent with their known in vitro durabilities and/or in vivo persistence, and three out of the four types of carbon nanotubes tested (single-walled (CNTSW and multi-walled (CNTTANG2, CNTSPIN showed no, or minimal, loss of mass or change in fibre length or morphology when examined by electron microscopy. However, the fourth type [multi-walled (CNTLONG1] lost 30% of its original mass within the first three weeks of incubation, after which there was no further loss. Electron microscopy of CNTLONG1 samples incubated for 10 weeks confirmed that the proportion of long fibres had decreased compared to samples briefly exposed to the Gambles solution. This loss of mass and fibre shortening was accompanied by a loss of pathogenicity when injected into the peritoneal cavities of C57Bl/6 mice compared to fibres incubated briefly. CNTSW did not elicit an

  7. Approches de gestion durable et démocratique des forêts dans le monde

    OpenAIRE

    Gareau, Priscilla

    2005-01-01

    La déforestation, la dégradation des écosystèmes forestiers et les moyens privilégiés pour y remédier, classés sous le terme générique de gestion durable des forêts, sont devenus des sujets importants dans l’agenda politique international depuis les vingt dernières années.  Malgré les piétinements au niveau politique, diverses approches de gestion durable et démocratique des forêts ont été expérimentées à travers le monde.  Cet article recense les événements politiques majeurs menant aux pour...

  8. Laundering durable antibacterial cotton fabrics grafted with pomegranate-shaped polymer wrapped in silver nanoparticle aggregations

    Science.gov (United States)

    Liu, Hanzhou; Lv, Ming; Deng, Bo; Li, Jingye; Yu, Ming; Huang, Qing; Fan, Chunhai

    2014-08-01

    To improve the laundering durability of the silver functionalized antibacterial cotton fabrics, a radiation-induced coincident reduction and graft polymerization is reported herein where a pomegranate-shaped silver nanoparticle aggregations up to 500 nm can be formed due to the coordination forces between amino group and silver and the wrapping procedure originated from the coincident growth of the silver nanoparticles and polymer graft chains. This pomegranate-shaped silver NPAs functionalized cotton fabric exhibits outstanding antibacterial activities and also excellent laundering durability, where it can inactivate higher than 90% of both E. coli and S. aureus even after 50 accelerated laundering cycles, which is equivalent to 250 commercial or domestic laundering cycles.

  9. Durability of symmetrically and asymmetrically porous polybenzimidazole membranes for high temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Jheng, Li-Cheng; Chang, Wesley Jen-Yang; Hsu, Steve Lien-Chung; Cheng, Po-Yang

    2016-08-01

    Two types of porous polybenzimidazole (PBI) membranes with symmetric and asymmetric morphologies were fabricated by the template-leaching method and characterized by scanning electron microscope (SEM). Their physicochemical properties were compared in terms of acid-doping level, proton conductivity, mechanical strength, and oxidative stability. The durability of fuel cell operation is one of the most challenging for the PBI based membrane electrode assembly (MEA) used in high-temperature proton exchange membrane fuel cells (HT-PEMFCs). In the present work, we carried out a long-term steady-state fuel cell test to compare the effect of membrane structure on the cell voltage degradation. It has also been demonstrated that the asymmetrically porous PBI could bring some notable improvements on the durability of fuel cell operation, the fuel crossover problem, and the phosphoric acid leakage.

  10. Fatigue Durability Analysis of Collecting Rapping System in Electrostatic Precipitators under Impact Loading

    Directory of Open Access Journals (Sweden)

    Ali Akbar Lotfi Neyestanak

    2014-01-01

    Full Text Available Due to the importance of collecting rapping system in electrostatic precipitators (ESP and controlling the relevant damage under impact loading, fatigue durability of this system is analyzed in the present study based on the numerical and experimental results considering fatigue damage growth and vibration acceleration in the collecting system because of the successive impact of rapping hammers. By microscopic examination of the fracture surface of rapping hammer, beach marks obviously show typical fatigue failure in the rapping hammer arm. In addition, the microscopic examination of the cross section of the collecting plates indicates the corrosion voids which cause crack and eventually fatigue failure. The finite element method is applied to determine both the stress and concentration positions of dynamic stress on the rapping system under impact loading. The paper results can be utilized in system optimization and new material selection for the system by evaluating rapping system durability.

  11. The synthesis and chemical durability of Nd-doped single-phase zirconolite solid solutions

    Science.gov (United States)

    Cai, Xin; Teng, Yuancheng; Wu, Lang; Zhang, Kuibao; Huang, Yi

    2016-10-01

    Nd-doped single-phase zirconolite solid solutions was synthesized by solid-state reaction and following two steps of acid treatment. The phase composition, microstructure, and chemical durability of the zirconolite solid solutions were investigated. About 15 at% Nd was successfully stabilized into the zirconolite. The element mapping images of Ca, Zr, Nd and Ti show that all the elements are almost distributed homogeneously in the zirconolite waste forms. Product Consistency Test (PCT) was conducted under different pH values (pH = 5, 7 and 9) to evaluate the chemical durability of the Nd-doped zirconolite waste forms. The normalized element release rate of Ca (LRCa) in pH = 5 medium is higher than that of pH = 7 and 9, while the LRNd value remains almost unchanged under different pH values. The LRNd value is as low as 10-5 g m-2 d-1 after 42 days.

  12. New tests for characterizing the durability of a ceramic catalytic converter package

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, K.P.; Helfinstine, J.D.; Gulati, S.T. [Corning, Inc., NY (United States)

    1996-09-01

    New test methods were developed to characterize the high temperature durability of intumescent mats that are used to mount ceramic catalyst supports in stainless steel cans. The key attribute of these tests is the use of an electric resistance heating method to maintain a temperature gradient through the thickness of the mat when a cyclic or constant shear stress is applied to the mat interface. These tests are simple to perform and do not require expensive equipment or highly skilled operators. Using these new test methods, the durability of ceramic preconverters mounted with 4,070 gm/m{sup 2} intumescent mat was studied. The results of these tests indicate that a preconverter package with 4070 gm/m{sup 2} intumescent mat can perform satisfactorily in the close-coupled application where temperatures exceed 900 C. The mat performance can be quantified in terms of applied stress and test temperature by utilizing the experimental methods described in the present study.

  13. Quels impacts des TIC sur le développement durable ?

    Directory of Open Access Journals (Sweden)

    Benoît Dumolin

    2015-07-01

    Full Text Available La première partie de l’étude examine quels sont les impacts des TIC sur le développement durable. A l’inverse d’une approche sectorielle, l’objectif du développement durable s’inscrit à l’intersection des sphères sociétale, économique, environnementale et de la gouvernance. La dimension transversale des TIC rend l’analyse des interactions entre ces quatre piliers difficile d’autant plus que l’influence du numérique sur l’économie ou sur l’organisation sociale est complexe à mesurer. Les effe...

  14. Performance and Durability of Solid Oxide Electrolysis Cells for Syngas Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hjalmarsson, Per;

    2012-01-01

    was examined at 800°C and electrolysis current density of -1 or -1.5 A/cm2 with 60% reactant (H2O+CO2) utilization. The cell voltage degradation showed a strong dependence on the electrolysis current density, with an overall cell voltage degradation rate of 0.24 mV/h at -1 A/cm2 and of 0.82 mV/h at -1.5 A/cm2......Performance and durability of Ni/YSZ based solid oxide electrolysis cells (SOECs) for co-electrolysis of H2O and CO2 at high current density were investigated. The cells consist of a Ni/YSZ support, a Ni/YSZ fuel electrode, a YSZ electrolyte, and a LSM-YSZ oxygen electrode. The cell durability...

  15. Study on durability and reliability of strut type suspension noise based on experimental methods

    International Nuclear Information System (INIS)

    When cars are released from the factory, strut noises are very small and therefore it is difficult to perceive them. As the use time and travel distance increase, however, strut noises get larger so as to cause users much uneasiness. The noises generated at the field include engine noises and flow noises and therefore it is difficult to clearly discern the noises generated from struts. This study developed a test method which can reproduce field strut noises in the lab. Using the newly developed noise evaluation test, this study analyzed the effects that insulator performance degradation and failure can have on car noises. The study also confirmed that the insulator durability test by the simple back-and-forth motion cannot completely reflect the state of the parts failure in the field. Based on this, the study also confirmed that field noises can be reproduced through a durability test that considers heat aging

  16. Pricing strategy in the context of durable goods monopoly with discrete demand

    Directory of Open Access Journals (Sweden)

    Nunes Paulo Maçãs

    2015-01-01

    Full Text Available Considering a model of discrete demand with two consumers, this article shows that irrespective of the difference between the willingness to pay of consumers with high and low incomes, if interest rates are low, a durable goods monopolist has an advantage in discriminating prices over time. If the difference in willingness to pay is limited and interest rates high, the monopolist has an advantage in setting a price equal to the low-income consumer’s willingness to pay. Finally, in the case of great difference in willingness to pay and high interest rates, the monopolist has an advantage in setting a price equal to the high-income consumer’s willingness to pay, and not selling the durable good to the low-income consumer. The results show that the Coase conjecture can fail if the difference in willingness to pay is great, and interest rates are high.

  17. Durability of doped zinc oxide/silver/doped zinc oxide low emissivity coatings in humid environment

    Energy Technology Data Exchange (ETDEWEB)

    Ando, E. [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama 221-8755 (Japan)], E-mail: eiichi-ando@agc.co.jp; Miyazaki, M. [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama 221-8755 (Japan)

    2008-05-30

    The relationship between internal stress of doped zinc oxide films and durability of doped zinc oxide/silver/doped zinc oxide low emissivity (low-e) coatings in humid environment was investigated. Aluminum, titanium, tin, chromium, silicon, gallium, magnesium, boron, barium, and calcium were chosen as a doping element in sputtering targets. Ratios of dopant/zinc in the oxide targets were 4/96-5/95 at.%. Films were formed by radio frequency sputtering. Doping of barium and calcium to the zinc oxide film led to a large increase in the internal stress. Doping of the other elements resulted in decreasing the internal stress. It was concluded that durability of the low-e coatings in humid environment closely correlated with the internal stress of the oxide layers.

  18. Durability and Strength Properties on High Performance Self Compacting Concrete with GGBS and Silica Fumes

    Directory of Open Access Journals (Sweden)

    J. M.Srishaila

    2014-06-01

    Full Text Available This study on the experimental investigation on strength aspects like compressive strength, flexural strength and split tensile strength, and durability aspects like rapid chloride penetration test(RCPT of high performance self-compacting concrete with different mineral admixtures . Initials tests like slump test, L-box test, U-box test and T50 test will be carried out. The methodology adopted here is Ground granulated blast furnace slag (GGBS which is replaced partially by cement at 10%, 20% and 30% and silica fumes(SF by 3%, 6%, 9% in combination with Portland cement and the performance is measured and compared. The influence of mineral admixtures on the workability, mechanical strength and durability aspects of self-compacting concrete are studied. The mix proportion is obtained as per the guidelines given by European Federation of producers and contractors of special products for structure.

  19. Long term chemical durability studies of vitrified waste products containing sulphate bearing high level radioactive waste

    International Nuclear Information System (INIS)

    Evaluation of the term durability of the vitrified waste product (VWP) is of paramount importance for ascertaining safe containment of radionuclide immobilized in the matrix, because leaching is the principle mechanism through which radionuclide can migrate to human environment. Sodium released out from the glass was taken as the index element to examine the leach rate as a function of time. Average leach rate of VWPs based on barium borosilicate glass matrix immobilizing sulphate bearing HLW is 2.32'10-6 g.cm-2, day-1 after a period of 710 days at 373 deg K using demineralised water as leachant indicating adequate leach resistance of the conditioned product. The paper presented here describes the outcome of the work carried out for studying long term chemical durability of the vitrified waste period. (author)

  20. Methods for Enhancing the Thermal Durability of High-Temperature Thermoelectric Materials

    Science.gov (United States)

    Skomedal, Gunstein; Kristiansen, Nils R.; Engvoll, Marianne; Middleton, Hugh

    2014-06-01

    Thermoelectric materials, for example skutterudites and magnesium silicides, are being investigated as promising materials for medium-to-high-temperature waste heat recovery in transport and in industry. A crucial aspect of the success of a thermoelectric material is its stability over time when exposed to rapid heating and cooling. In this work different aspects of the degradation of these thermoelectric materials at high temperature were examined. Initial thermal durability was studied, and several candidate coatings were evaluated to enhance durability by protecting the materials from oxidation and sublimation during thermal cycles in air for up to 500 h and up to 873 K. The samples were characterized by SEM and EDS. The results showed it is possible to reduce degradation of the thermoelectric material without compromising overall thermoelectric efficiency.

  1. WOOD-WATER RELATIONSHIPS AND BIOLOGICAL DURABILITY OF HEAT-TREATED TAURUS FIR WOOD

    Directory of Open Access Journals (Sweden)

    Bekir Cihad BAL

    2015-09-01

    Full Text Available In this study, Taurus Fir (Abies cilicica wood was treated with hot air at temperatures of 160, 190 and 220°C for 2h durations. After heat treatment, some physical properties and wood-water relationships were evaluated, such as mass loss, density, tangential swelling, radial swelling, volumetric swelling, swelling anisotropy, and fiber saturation point. In addition, the biological durability of Taurus Fir wood was tested in the laboratory with the soil contact test, and determined weight loss. The relationships between mass loss and some of the tested properties were determined using regression analysis. The results showed that heat treatment at 220°C had significant effects on the physical properties and the biological durability of Taurus Fir wood. Further, it was determined that there was a linear-negative correlation between weight loss and mass loss.

  2. Gouvernance territoriale durable via les PME : L’exemple de la région Aquitaine

    OpenAIRE

    Anne Musson

    2011-01-01

    A partir d’une enquête auprès de 18 PME aquitaines, nous analysons la représentation qu’elles se font du développement durable, de leurs territoires et de leurs relations avec les collectivités locales. Grâce à une analyse textuelle, nous montrons que l’hypothèse d’un développement durable local impulsé par les PME semble à ce jour réaliste. En maximisant le bien-être de la population, une politique volontariste de la part des collectivités locales constituerait alors le socle d’une attractiv...

  3. Design, durability and low cost processing technology for composite fan exit guide vanes

    Science.gov (United States)

    Blecherman, S. S.

    1980-01-01

    A program was conducted to design, fabricate and test a durable, low cost, lightweight composite fan exit guide vane for high bypass ratio gas turbine engine application. Eight candidate material/design combinations were evaluated by NASTRAN finite element analysis. Four of these candidate systems were selected for composite vane fabrication by two vendors. A core and shell vane design was chosen in which the unidirectional graphite core fiber was the same for all candidates. The shell material, fiber orientation and ply configuration were varied. Material tests were performed on raw material and composite specimens to establish specification requirements. Composite vanes were nondestructively inspected and subsequently fatigue tested in both dry and 'wet' conditions. The program provided relevant data with respect to design analysis, materials properties, inspection standards, improved durability, weight benefits and part price of the composite fan exit guide vane.

  4. Application of microorganisms in concrete: a promising sustainable strategy to improve concrete durability.

    Science.gov (United States)

    Wang, Jianyun; Ersan, Yusuf Cagatay; Boon, Nico; De Belie, Nele

    2016-04-01

    The beneficial effect of microbially induced carbonate precipitation on building materials has been gradually disclosed in the last decade. After the first applications of on historical stones, promising results were obtained with the respect of improved durability. An extensive study then followed on the application of this environmentally friendly and compatible material on a currently widely used construction material, concrete. This review is focused on the discussion of the impact of the two main applications, bacterial surface treatment and bacteria based crack repair, on concrete durability. Special attention was paid to the choice of suitable bacteria and the metabolic pathway aiming at their functionality in concrete environment. Interactions between bacterial cells and cementitious matrix were also elaborated. Furthermore, recommendations to improve the effectiveness of bacterial treatment are provided. Limitations of current studies, updated applications and future application perspectives are shortly outlined.

  5. Durability-Based Design Criteria for a Chopped-Glass-Fiber Automotive Structural Composite

    Energy Technology Data Exchange (ETDEWEB)

    Battiste, R.L.; Corum, J.M.; Ren, W.; Ruggles, M.B.

    1999-11-01

    This report provides recommended durability-based design criteria for a chopped-glass-fiber reinforced polymeric composite for automotive structural applications. The criteria closely follow the framework of an earlier criteria document for a continuous-strand-mat (CSM) glass-fiber reference composite. Together these design criteria demonstrate a framework that can be adapted for future random-glass-fiber composites for automotive structural applications.

  6. Effect of fillers Granulated slag on the durability of HPC in marine environment

    OpenAIRE

    Tebbal Nadia; El abidine Rahmouni Zine; Djendi Zoubir

    2014-01-01

    The combined effect of fillers of silica fume and blast furnace slag on the durability of high performance concretes was studied .The storage media are: seawater and tap water as reference. This work focuses on the effect of the incorporation of different amounts of milk more silica fume on the mechanical strength of concretes with limestone cements and its influence on sustainability with respect to marine. The results show that the addition of quantity 10%slag and 5% silica fume offers the ...

  7. STUDY ON DURABILITY PROPERTIES OF RECYCLED AGGREGATE CONCRETE INCORPORATED WITH S ILICA FUME AND MINERAL QUARTZ

    OpenAIRE

    Anand K . Darji *; Dr. Indrajit N Patel,; Mrs. Jagruti Shah

    2015-01-01

    Disposal of construction waste is now new challenge for the construction industry in this era. This is peak time to use Construction waste as recycled aggregate (RA) in concrete manufacturing for sustainable development. Recycled aggregate concrete (RAC ) is the future to save environment from the waste. Supplementary Cementing Materials (SCMs) are widely used these days to improve the durability of c oncrete. Silica fume has gai...

  8. Improvement of the durability of concrete with recycled aggregates in chloride exposed environment

    OpenAIRE

    Vázquez Ramonich, Enric; Barra Bizinotto, Marilda; Aponte Hernández, Diego Fernando; Jiménez Fernández, Cristian Gonzalo; Valls del Barrio, Susanna

    2014-01-01

    Recycled aggregates concrete (RAC) becomes an important participant in recycled materials, although there are still questionable issues about some of its properties. Durability of RAC and its relationship with recycled concrete aggregate (RCA) is often discussed, especially in relation with chloride penetration and diffusion properties. An extensive experimental campaign was performed in order to evaluate the effect of RCA content in the retention and diffusion of chlorides in RAC. The influe...

  9. Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Technology (Revised) (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Carloni, J. D.; Pankow, J. W.; Gjersing, E. L.; To, B.; Packard, C. E.; Kennedy, C. E.; Kurtz, S. R.

    2012-01-01

    Concentrating photovoltaic (CPV) technology recently gained interest based on its expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems employ Fresnel lenses composed of poly(methyl methacrylate) (PMMA) to obtain a high optical flux density on the cell. The optical and mechanical durability of these lenses, however, is not well established relative to the desired surface life of 30 years. Our research aims to quantify the expected lifetime of PMMA in key market locations (FL, AZ, and CO).

  10. Impact of power converter current ripple on the durability of a fuel cell stack

    OpenAIRE

    WAHDAME, B; GIRARDOT, L; Hissel, D.; Harel, F.; Francois, X.; Candusso, D.; PERA, MC; DUMERCY, L

    2008-01-01

    The durability and performance of Polymer Electrolyte Membrane Fuel Cell (PEMFC) have a major impact on the most important challenges facing fuel cell commercialization including final cost, mass production, system integration, functionality and reliability. This work is supported by French Government via an ANR' project (PAN'H) named SPACT80. The global objective is to develop and validate the use of a fuel cell based power system for heavy-duty vehicles (dedicated to railway applications or...

  11. An Auction for Medicare Durable Medical Equipment: Evidence from an Industry Mock Auction

    OpenAIRE

    Peter Cramton; Ulrich Gall; Pacharasut Sujarittanonta

    2012-01-01

    On 1 April 2011, 110 stakeholders in the Medicare Durable Medical Equipment (DME) industry came to the University of Maryland to discuss how the CMS’ current competitive bidding program could be improved. The participants included Medicare providers, government leaders, and auction experts. A major part of the event was the conduct of a mock auction based on the auction design proposed in Cramton (2011a). This design addresses the fatal flaws in the CMS design (Letter from experts 2010, 2011)...

  12. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity

    OpenAIRE

    Martins, Karen A O; Christopher L Cooper; Stronsky, Sabrina M.; Sarah L.W. Norris; Steven A Kwilas; Jesse T. Steffens; Benko, Jacqueline G.; van Tongeren, Sean A.; Sina Bavari

    2016-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection fro...

  13. THE IMPACT OF PSYCHOLOGICAL FACTORS ON THE PURCHASE BEHAVIOR OF YOUNG BUYERS OF DURABLE GOODS

    OpenAIRE

    Dominika Woźny

    2015-01-01

    The determinants of consumer purchase behavior have been for years the object of the study of researchers who dealt with the analysis of the consumption process and the behavior of buyers. Among numerous classification proposals for the determinants, the most common are the economic, social and psychological stimuli. The article is an attempt to identify the impact of psychological determinants on consumer purchase behavior, with a particular consideration of young buyers of durable goods. P...

  14. Durability and compressive strength of blast furnace slag-based cement grout for special geotechnical applications

    OpenAIRE

    Ortega Álvarez, José Marcos; Pastor Navarro, José Luis; Albaladejo Ruiz, Arturo; Sánchez Martín, Isidro; Climent, Miguel-Ángel

    2014-01-01

    Special foundations, most prominently micropiles and soil anchors, are frequently used in construction today. In Spain, the grout for these special technical applications is generally prepared with portland cement, although the codes and standards in place stipulate only the minimum compressive strength required, with no mention of cement type. Those texts also establish a range of acceptable water:cement ratios. In the present study, durability and compressive strength in cement grout prepar...

  15. A Model for duopoly competition in the durable household goods market

    OpenAIRE

    İnal, Arzu Gülay; Inal, Arzu Gulay

    2003-01-01

    In this study, a model for duopoly competition in the durable household goods market is presented. The aim is to investigate the various scenarios and policies on a representative dynamic model. System dynamics is used as the methodology, since it is an adaptive tool that allows for feedback mechanisms. The proposed model consists of six modules: (1) diffusion module, (2) price module, (3) advertising module, (4) word of mouth (WOM) module, (5) cost module, and (6) delivery delay module. Diff...

  16. Competition in Durable Goods Markets: The Strategic Consequences of Leasing and Selling

    OpenAIRE

    Preyas S. Desai; Devavrat Purohit

    1999-01-01

    In marketing durable goods, manufacturers use varying degrees of leasing and selling to consumers, e.g., cars, photo-copiers, personal computers, airplanes, etc. The question that this raises is whether the distinction between leases and sales is simply one of price, or whether the proportion of leases and sales effects a firm's ability to compete in the market. In this paper we use two approaches to argue that leasing and selling create strategic consequences that extend beyond prices. First...

  17. The development of a durability procedure for pallets with structural panel decking

    OpenAIRE

    Cao, Jiqiang

    1993-01-01

    The Pallet Design System (PDS) is a widely accepted engineering procedure for comparing the performance of competing pallet designs. As part of a new version of the PDS, the objective of this study was to develop a durability model for pallets with structural panel decking. An accelerated rough material handling test system, "the VPI unit-load material handling FasTrack" , was developed to simulate pallets used in the unit-load material handling environments. 100 pallets representing 14...

  18. Efficiency of Sodium Polyacrylate to Improve Durability of Concrete under Adverse Curing Condition

    OpenAIRE

    Tanvir Manzur; Shohana Iffat; Munaz Ahmed Noor

    2015-01-01

    The conventional external curing process requires supply of large amount of water in addition to mixing water as well as strict quality control protocol. However, in a developing country like Bangladesh, many local contractors do not have awareness and required knowledge on importance of curing which often results in weaker concrete with durability issues. Moreover, at times it is difficult to maintain proper external curing process due to nonavailability of water and skilled laborer. Interna...

  19. A study on the effects of seawater on the durable life of concrete structures(II)

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Byung Hwan; Jang, Bong Suk; Jang, Seung Yeop; Jeon, Se Jin; Yu, Yeong; Park, Dae Gyun; Hyeong, Sang Soo [Seoul National Univ., Seoul (Korea, Republic of)

    1999-02-15

    Recently, large scale concrete structures such as nuclear power plants and offshore structures are actively being built in this country. These structures are subject to heavy attack due to seawater environment. A reasonable consideration for corrosion has not been paid to the structures in the past decades due to insufficient research data and guidelines. The durability is emerging as one of the most important factors. In the design and construction of concrete structures. The purpose of the present study is, therefore, to explore the corrosion mechanism and penetration mechanism of chloride ion, and to establish the evaluation procedure of durability life of concrete structures. In this study, the chloride ion concentration of seawater around our country have been analyzed and the deterioration mechanism of concrete structures have been also analyzed. The penetration mechanism of seawater into the concrete has been also studied. To this end, a comprehensive experimental program has been setup. The major test variables include the type of cement and the type of mineral admixture. The strength test as well as corrosion test have been conducted to explore the effects of chloride ion penetration on the properties of concrete. The corrosion mechanism and the penetration of chloride ion into concrete structures have been studied. These results will allow the estimation of durable life of concrete structures in nuclear power plants. The experimental results and the developed theory in the present study can be efficiently used to analyze the chloride ion penetration and to estimate the durability of concrete structures In nuclear power plants. The present study may also provide strong basis to evaluate the remaining service life of concrete structures in nuclear power plants.

  20. Development of Self-Consolidating Hybrid Fiber Reinforced Concrete and Assessment of Its Durability Performance

    OpenAIRE

    Jen, Gabriel

    2014-01-01

    Conventional concrete used for construction has neither the inherent ductility nor durability to meet the requirements of modern infrastructure construction. With ageing highway and bridge infrastructure requiring a significant expenditure of capital, it is prudent to explore utilization of so-called high performance materials that have the potential to outperform and outlast their conventional counterparts. This research program is built around the concept of creating a sustainable material ...

  1. Moisture-Cure Polyurethane Wood Adhesives: Wood/Adhesive Interactions and Weather Durability

    OpenAIRE

    Ren, Dakai

    2010-01-01

    This project addresses two main subjects of moisture-cure polyurethane (PUR) wood adhesives: wood/PUR interactions and structure-property behavior emphasizing on weather durability. For these purposes, one simplified model PUR (MPUR) and three more commercially significant PURs (CPURs) with different hard segment contents were prepared. Separately, an early side project involved the synthesis of a 13C and 15N double-labeled polymeric methylenebis(phenylisocyanate) (pMDI) resin; this was use...

  2. Hanford enhanced waste glass characterization. Influence of composition on chemical durability

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-06-01

    This report provides a review of the complete high-level waste (HLW) and low-activity waste (LAW) data sets for the glasses recently fabricated at Pacific Northwest National Laboratory and characterized at Savannah River National Laboratory (SRNL). The review is from the perspective of relating the chemical durability performance to the compositions of these study glasses, since the characterization work at SRNL focused on chemical analysis and ASTM Product Consistency Test (PCT) performance.

  3. Structural durability assessment of welded offshore K-nodes by different local design concepts

    Directory of Open Access Journals (Sweden)

    C.M. Sonsino

    2009-07-01

    Full Text Available The structural durability design of complex welded structures should not rely only on one single design method but should apply different methods for assuring the reliability of the assessment. In this context the application of the structural stress concept, notch stress concept and crack propagation concept are discussed through the example of K-nodes used in energetic offshore constructions like oil platforms or windpower plants, presenting the state of the art.

  4. Durability-Based Design Criteria for a Chopped-Glass-Fiber Automotive Structural Composite; TOPICAL

    International Nuclear Information System (INIS)

    This report provides recommended durability-based design criteria for a chopped-glass-fiber reinforced polymeric composite for automotive structural applications. The criteria closely follow the framework of an earlier criteria document for a continuous-strand-mat (CSM) glass-fiber reference composite. Together these design criteria demonstrate a framework that can be adapted for future random-glass-fiber composites for automotive structural applications

  5. Durability-Based Design Properties of Reference Crossply Carbon-Fiber Composite

    Energy Technology Data Exchange (ETDEWEB)

    Corum, J.M.

    2001-04-16

    This report provides recommended durability-based design properties and criteria for a crossply carbon-fiber composite for possible automotive structural applications. Although the composite utilized aerospace-grade carbon-fiber reinforcement, it was made by a rapid-molding process suitable for high-volume automotive use. The material is the first in a planned progression of candidate composites to be characterized as part of an Oak Ridge National Laboratory project entitled Durability of Carbon-Fiber Composites. The overall goal of the project, which is sponsored by the U.S. Department of Energy's Office of Advanced Automotive 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. The composite addressed in this report is a ({+-}45{degree})3S crossply consisting of continuous Thornel T300 fibers in a Baydur 420 IMR urethane matrix. This composite is highly anisotropic with two dominant fiber orientations--0/90{degree} and {+-}45{degree}. Properties and models were developed for both orientations. 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.

  6. Real-SOFC - A Joint European Effort to Improve SOFC Durability

    OpenAIRE

    Steinberger-Wilckens, Robert; Bucheli, Olivier; De Haart, L.G.J.; Hagen, Anke; Kiviaho, Jari; Larsen, Jørgen G.; Pyke, Stephen; Rietveld, B. G.; Sfeir, Josef; Tietz, Frank

    2009-01-01

    The Integrated Project Real-SOFC joined 26 partners from throughout Europe active in SOFC technology. The project was funded by the European Commission within the 6th Framework Programme and aimed at improving the durability of planar SOFC stacks to degradation rates of well below 1% per 1 000 hours of operation. This is an essential requirement in gaining access to the market for stationary applications. The underlying idea was to improve materials and materials processing on the basis of ex...

  7. Exploring the Relationship Between the Markets for New and Used Durable Goods: The Case of Automobiles

    OpenAIRE

    Devavrat Purohit

    1992-01-01

    Given that durable products are long-lived, there exists the possibility of secondary markets for used products as well as the potential for product obsolescence. This is an important issue in markets where technology changes rapidly, because the introduction of new versions of a product can make earlier versions obsolete. More generally, prices of older versions in the secondary market adjust in response to changes incorporated in new versions of the product. Thus, another method of evaluati...

  8. A Model of Promotion-Free Retail Pricing of Durable Products

    OpenAIRE

    Subramanian Balachander

    2007-01-01

    An important decision facing retailers is the level of price promotions or "sales" to have in their retail prices. In this paper, we consider the use of promotion-free (PF) retail pricing by stores selling durable products, where PF pricing means that the retailer does not use or advertise price promotions. Interestingly, we find, contrary to the previous literature, that a store using a PF strategy does not advertise prices, and yet may charge below shoppers' reservation prices. Further, we ...

  9. Optimal Policy Instruments for Externality-Producing Durable Goods under Time Inconsistency

    OpenAIRE

    Heutel, Garth

    2010-01-01

    Empirical evidence suggests that individual choices often display behavioral anomalies, like time-inconsistent preferences. For example, a household's preferences at the time of purchase of energy-intensive durable goods like cars and appliances may differ from its preferences later on, "underweighting" future operating costs. The standard solution to market failures caused by externalities—Pigouvian pricing—is suboptimal under time inconsistency. I investigate how public policies aimed at ex...

  10. Turnover of Used Durables in a Stationary Equilibrium: Are Older Goods Traded More?

    OpenAIRE

    Dmitriy Stolyarov

    2002-01-01

    This paper develops a dynamic model with transaction costs to determine the equilibrium resale pattern in a market for a durable good. The key result is that the probability of resale is nonmonotonic in the age of the good. Trade volume is relatively low in the very beginning and in the middle of a good's life. This result helps explain observed variations of resale rates across vintages for the U.S. market of used cars.

  11. Effects of Climate Variations and Global Warming on the Durability of RC Structures Subjected to Carbonation

    OpenAIRE

    De Larrard, Thomas; Bastidas-Arteaga, Emilio; Duprat, F.; Schoefs, Franck

    2014-01-01

    International audience Carbonation affects the performance, serviceability and safety of reinforced concrete (RC) structures when they are placed in environments with important CO2 concentrations. Since the kinetics of carbonation depends on parameters that could be affected by climate change (temperature, atmospheric CO2 pressure and relative humidity), this study aims at quantifying the effect of climate change on the durability of RC structures subjected to carbonation risks. This work ...

  12. Obtaining of coffee varieties with durable resistance to illnesses, using the genetic diversity as improvement strategy

    International Nuclear Information System (INIS)

    With the purpose of producing improved coffee varieties with resistance to the leaf rust (Hemileia vastatrix), the national federation of coffee growers of Colombia initiated in 1970 a research program, whose first results achieved in 1982 were the abstention of the Colombia coffee variety. The use of genetic variability as a strategy in plant breeding for a durable resistance is discussed. In addition, the breeding outline is described and the main features of the developed materials are presented

  13. Durability-Based Design Criteria for a Quasi-Isotropic Carbon-Fiber Automotive Composite

    Energy Technology Data Exchange (ETDEWEB)

    Corum, J.M.

    2002-04-17

    This report provides recommended durability-based design properties and criteria for a quasi-isotropic carbon-fiber composite for possible automotive structural applications. The composite, which was made by a rapid molding process suitable for high-volume automotive applications, consisted of continuous Thornel T300 fibers (6K tow) in a Baydur 420 IMR urethane matrix. The reinforcement was in the form of four {+-}45{sup o} stitch-bonded mats in the following layup: [0/90{sup o}/{+-}45{sup o}]{sub S}. This material is the second in a progression of three candidate thermoset composites to be characterized and modeled as part of an Oak Ridge National Laboratory project entitled Durability of Carbon-Fiber Composites. The overall goal of the project, which is sponsored by the U.S. Department of Energy's Office of Advanced Automotive Technologies and is closely coordinated with the industry Automotive Composites Consortium, is to develop durability-driven design data and criteria to assure the long-term integrity of carbon-fiber-based composite systems for large automotive structural components. This document is in two parts. Part I provides the design criteria, and Part 2 provides the underlying experimental data and models. The durability issues addressed include the effects on deformation, strength, and stiffness of cyclic and sustained loads, operating temperature, automotive fluid environments, and low-energy impacts (e.g., tool drops and kickups of roadway debris). Guidance is provided for design analysis, time-dependent allowable stresses, rules for cyclic loadings, and damage tolerance design guidance, including the effects of holes. Chapter 6 provides a brief summary of the design criteria.

  14. The durability of Božanov sandstone – simulation of Prague winter climatic conditions

    OpenAIRE

    Kateřina Kovářová

    2011-01-01

    Sandstones were often used mainly as building material in Prague. Weathering processes lead to deterioration of these dimension stones and to changes in their durability. The range of the deterioration depends on petrography, including internal structure, mineral and matrix composition, and also changes initiated. The stone’s properties are negatively influenced especially during the winter frost period, and the presence of salt can exacerbate this process. The national standardized testing m...

  15. Management coordinations on steel industry in the context of durable development

    OpenAIRE

    O. Pandia; I. Sărăcin; F. Văduva; I. Oncioiu; M. Ștefan; G. Dobrotă

    2016-01-01

    The durable development imposes the respect of economic, social and environment-protection requests. The objective of this paper is the emphasis of applying a rational management at the level of all the siderurgical operators in order for a healthy economic growth to be assured, correlated with the environment protection. In this sense, the study is based on the analysis of a data set which relates to the growth rhythm of the gross domestic product (GDP), raw steel production and the consume ...

  16. Durability of Chopped FiberReinforced Polymeric Composites for use in Experimental Automotive Fuel Cells

    OpenAIRE

    Fazio, James A

    2003-01-01

    Recent interest in utilizing hydrogen fuel cell technology for automotive applications has lead to concerns regarding the durability of fiber reinforced polymer (FRP) composite materials. Automotive fuel cell power train systems must prove themselves as a reliable alternative to the combustion engines and automatic transmissions. The use of polymer composites in fuel cells to serve as manifolds is promising because of their high strength to weight ratio, and they do not corrode like metals ...

  17. Hydration, microstructure, transport properties and durability of self-compacting concrete

    OpenAIRE

    De Schutter, Geert

    2009-01-01

    Because of the different mix design in comparison with traditional concrete and the abscence of vibration, different characteritics can be expected for self-compacting concrete (SCC). The degradation mechanisms of a cementitious material are greatly influenced by the permeability of the material for potentially aggressive substances. As the pore structure is different for SCC in comparison with traditional vibrated concrete, some changes in durability can be noticed. This paper is first gi...

  18. Comparative investigation of durability of chairs made of beach and Paulownia tomentosa

    OpenAIRE

    Skakić Dušan; Džinčić Igor

    2008-01-01

    The result of parallel investigation of chair durability, which has been made in two different wood species (beach and Paulwonia tomentosa) has been presented in this paper. Static and dynamic loads has highest values in seating furniture, and that is the reason why chair has been chosen to bee representative for testing new species, which could be used in furniture production in Serbia. A shown results indicates on possibility that this species can be used only for production furniture which...

  19. Computational Evaluation of Amorphous Carbon Coating for Durable Silicon Anodes for Lithium-Ion Batteries

    OpenAIRE

    Jeongwoon Hwang; Jisoon Ihm; Kwang-Ryeol Lee; Seungchul Kim

    2015-01-01

    We investigate the structural, mechanical, and electronic properties of graphite-like amorphous carbon coating on bulky silicon to examine whether it can improve the durability of the silicon anodes of lithium-ion batteries using molecular dynamics simulations and ab-initio electronic structure calculations. Structural models of carbon coating are constructed using molecular dynamics simulations of atomic carbon deposition with low incident energies (1–16 eV). As the incident energy decrease...

  20. Influence of global warming on durability of corroding RC structures: A probabilistic approach

    OpenAIRE

    Bastidas-Arteaga, Emilio; Schoefs, Franck; Stewart, Mark G.; Wang, Xiaoming

    2013-01-01

    International audience Chloride ingress and carbonation cause corrosion of reinforced concrete (RC) structures affecting its operational life. Experimental evidence indicates that these deterioration processes are highly influenced by CO2 emissions and climatic conditions in the surrounding environment - i.e., temperature, humidity, etc. Since studies on global warming announce changes in climate, the impact of changing climate on RC durability should also be considered. This paper links R...

  1. Ageing and durability of concrete in lab and in field conditions: investigation of chloride penetration

    OpenAIRE

    BAROGHEL BOUNY, Véronique; DIERKENS, Michaël; WANG, X; SOIVE, A; SAILLIO, Mickael; THIERY, Mickaël; THAUVIN, B

    2013-01-01

    Long-term studies under various natural exposure conditions are still needed in order to understand and quantify ageing and durability of concrete structures, in particular in the case of mixtures which incorporate supplementary cementitious materials (e.g. fly ash). With this purpose, a large-scale and long-term experimental program was initiated a lot of years ago by the LPC network within the framework of the French national project 'BHP 2000'. From then, further researches have been carri...

  2. On the Durability of Sealable Circular Concrete Structures under Chloride Environment

    OpenAIRE

    Changwen Mi; Kaikai Shao; Xiaobao Li

    2015-01-01

    Reinforcement corrosion resulting from chloride attack is one major mechanism that compromises concrete durability. Numerical methods were commonly used for tackling Fick’s diffusion equations. In this paper, we developed a Crank-Nicolson based finite difference scheme suitable for circular concrete structures. Both a time-dependent surface chloride model and diffusivity were considered. The impact of an ideal sealer on chloride redistribution was further investigated. Results suggested that ...

  3. Durability assessment of concrete bridge deck considering waterproof membrane and epoxy-coated reinforcement

    OpenAIRE

    Petr Konečný; Petr Lehner

    2016-01-01

    The effect of waterproof membrane and steel reinforcement protection on the concrete bridge deck is modeled. The attention is paid to the durability prediction related to steel reinforcement corrosion initiation based on the chloride penetration. Thus 2-D finite element chloride ingress model is applied. The transient finite element model serves to solve Fick's second diffusion law using the computer tool compatible with the Matlab environment. The model focuses on the transport of chloride i...

  4. The durability of public goods changes the dynamics and nature of social dilemmas.

    Directory of Open Access Journals (Sweden)

    Sam P Brown

    Full Text Available An implicit assumption underpins basic models of the evolution of cooperation, mutualism and altruism: The benefits (or pay-offs of cooperation and defection are defined by the current frequency or distribution of cooperators. In social dilemmas involving durable public goods (group resources that can persist in the environment-ubiquitous from microbes to humans this assumption is violated. Here, we examine the consequences of relaxing this assumption, allowing pay-offs to depend on both current and past numbers of cooperators. We explicitly trace the dynamic of a public good created by cooperators, and define pay-offs in terms of the current public good. By raising the importance of cooperative history in determining the current fate of cooperators, durable public goods cause novel dynamics (e.g., transient increases in cooperation in Prisoner's Dilemmas, oscillations in Snowdrift Games, or shifts in invasion thresholds in Stag-hunt Games, while changes in durability can transform one game into another, by moving invasion thresholds for cooperation or conditions for coexistence with defectors. This enlarged view challenges our understanding of social cheats. For instance, groups of cooperators can do worse than groups of defectors, if they inherit fewer public goods, while a rise in defectors no longer entails a loss of social benefits, at least not in the present moment (as highlighted by concerns over environmental lags. Wherever durable public goods have yet to reach a steady state (for instance due to external perturbations, the history of cooperation will define the ongoing dynamics of cooperators.

  5. Decisions to Replace Consumer Durables Goods: An Econometric Application of Wiener and Renewal Processes

    OpenAIRE

    Viviana Fernandez

    2000-01-01

    Current sales of most consumer durable goods are accounted for by replacements. However, only in recent years has the economic literature provided a more rigorous analysis of replacement purchases by incorporating elements of dynamic programming and of the theory of stochastic processes. This paper is an empirical study of household replacement decisions modeled as an optimal stopping rule. Using data from the ‘Residential Energy Consumption Survey’ (RECS) of the U.S. Department of Energy, we...

  6. Steel fibre reinforced self-compacting concrete for lightweight and durable pedestrian bridges : creep behaviour

    OpenAIRE

    Mendes, Pedro J. D.; Barros, Joaquim A. O.; Gonçalves, Delfina; Sena-Cruz, José

    2012-01-01

    In recent years, pedestrian bridges built from composites materials have notably increased. This growth is related to the durability problems of traditional materials, as well as the need for fastest construction times. In this context, fiber reinforced concrete (FRC) becomes an important material in this type of structures, since the ductility, high post-cracking tensile strength, high compressive stiffness and strength of FRC can be combined with the benefits derived from the use of FRP pro...

  7. The Durability and Performance of Short Fibers for a Newly Developed Alkali-Activated Binder

    Directory of Open Access Journals (Sweden)

    Henrik Funke

    2016-03-01

    Full Text Available This study reports the development of a fiber-reinforced alkali-activated binder (FRAAB with an emphasis on the performance and the durability of the fibers in the alkaline alkali-activated binder (AAB-matrix. For the development of the matrix, the reactive components granulated slag and coal fly ash were used, which were alkali-activated with a mixture of sodium hydroxide (2–10 mol/L and an aqueous sodium silicate solution (SiO2/Na2O molar ratio: 2.1 at ambient temperature. For the reinforcement of the matrix integral fibers of alkali-resistant glass (AR-glass, E-glass, basalt, and carbon with a fiber volume content of 0.5% were used. By the integration of these short fibers, the three-point bending tensile strength of the AAB increased strikingly from 4.6 MPa (no fibers up to 5.7 MPa (carbon after one day. As a result of the investigations of the alkali resistance, the AR-glass and the carbon fibers showed the highest durability of all fibers in the FRAAB-matrix. In contrast to that, the weight loss of E-glass and basalt fibers was significant under the alkaline condition. According to these results, only the AR-glass and the carbon fibers reveal sufficient durability in the alkaline AAB-matrix.

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

    Science.gov (United States)

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

    2011-09-30

    Structural health monitoring of porous materials such as concrete is becoming a major component in our resource-limited economy, as it conditions durable exploitation of existing facilities. Durability in porous materials depends on nanoscale features which need to be monitored in situ with nanometric resolution. To address this problem, we put forward an approach based on the development of a new nanosensor, namely a capacitive micrometric ultrasonic transducer whose vibrating membrane is made of aligned single-walled carbon nanotubes (SWNT). Such sensors are meant to be embedded in large numbers within a porous material in order to provide information on its durability by monitoring in situ neighboring individual micropores. In the present paper, we report on the feasibility of the key building block of the proposed sensor: we have fabricated well-aligned, ultra-thin, dense SWNT membranes that show above-nanometer amplitudes of vibration over a large range of frequencies spanning from 100 kHz to 5 MHz. PMID:21891837

  9. On the durable critic load in creep buckling of viscoelastic laminated plates and circular cylindrical shells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the first order shear deformation theory and classic buckling theory, the paper investigates the creep buckling behavior of viscoelastic laminated plates and laminated circular cylindrical shells. The analysis and elaboration of both instantaneous elastic critic load and durable critic load are emphasized. The buckling load in phase domain is obtained from governing equations by applying Laplace transform, and the instantaneous elastic critic load and durable critic load are determined according to the extreme value theorem for inverse Laplace transform. It is shown that viscoelastic approach and quasi-elastic approach yield identical solutions for these two types of critic load respectively. A transverse disturbance model is developed to give the same mechanics significance of durable critic load as that of elastic critic load. Two types of critic loads of boron/epoxy composite laminated plates and circular cylindrical shells are discussed in detail individually, and the influencing factors to induce creep buckling are revealed by examining the viscoelasticity incorporated in transverse shear deformation and in-plane flexibility.

  10. On the problems of stability and durability of field-emission current sources for electrovacuum devices

    Science.gov (United States)

    Yakunin, Alexander N.; Aban'shin, Nikolay P.; Akchurin, Garif G.; Akchurin, Georgy G.; Avetisyan, Yuri A.

    2016-03-01

    The results of the practical implementation of the concept of field-emission current source with high average current density of 0.1-0.3 A-cm-2 are shown. The durability of cathode samples at a level of 6000 hours is achieved under conditions of technical vacuum. A phenomenological model is suggested that describes the tunneling of both equilibrium and nonequilibrium electrons in a vacuum from the zone of concentration of electrostatic field. Conditions are discussed as the resulting increase in the emission current due to the connection mechanism of the photoelectric effect is thermodynamically favorable, that is not accompanied by an undesirable increase in the temperature of the local emission zone. It is shown that to ensure stability and durability of the cathode is also important to limit the concentration of equilibrium carriers using composite structures «DLC film on Mo substrate." This helps to reduce the criticality of the CVC. A possible alternative is to use a restrictive resistance in the cathode. However, this increases the heat losses and thus decreases assembly efficiency. The results of experimental studies of the structure showing the saturation of photoemission current component with an increase in operating voltage. This fact suggests the existence of an effective mechanism for control of emission at constant operating voltage. This is fundamentally important for the stabilization of field emission cathode, providing a reliability and durability. The single-photon processes and the small thickness DLC films (15-20 nm) provide high-speed process of control.

  11. The Association Between Household Consumer Durable Assets and Maternal Health-Seeking Behavior in Ghana.

    Science.gov (United States)

    Ansong, Eric

    2015-01-01

    This article examined the association between household consumer durable assets and maternal health-seeking behavior. Several studies have suggested a relationship between households' socioeconomic status (SES) and health outcomes. However, SES is a multidimensional concept that encompasses variables, such as wealth, education, and income. By grouping these variables together as one construct, prior studies have not provided enough insight into possible independent associations with health outcomes. This study used data from the 2008 Ghana Demographic and Health Survey of 2,065 women aged between 15 and 49 years to examine the association between household consumer durables (a component of SES) and maternal health-seeking behavior in Ghana. Results from a set of generalized linear models indicated that household consumer durable assets were positively associated with four measures of maternal health-seeking behaviors, namely, seeking prenatal care from skilled health personnel, delivery by skilled birth attendant, place of delivery, and the number of antenatal visits. Also, households with more assets whose residents lived in urban areas were more likely to use skilled health personnel before and during delivery, and at an approved health facility, compared those who lived in rural areas. Implications for health interventions and policies that focus on the most vulnerable households are discussed.

  12. Mechanical and Durability Properties of Concrete Made with Used Foundry Sand as Fine Aggregate

    Directory of Open Access Journals (Sweden)

    G. Ganesh Prabhu

    2015-01-01

    Full Text Available In recent years, the construction industry has been faced with a decline in the availability of natural sand due to the growth of the industry. On the other hand, the metal casting industries are being forced to find ways to safely dispose of waste foundry sand (FS. With the aim of resolving both of these issues, an investigation was carried out on the reuse of waste FS as an alternative material to natural sand in concrete production, satisfied with relevant international standards. The physical and chemical properties of the FS were addressed. The influence of FS on the behaviour of concrete was evaluated through strength and durability properties. The test results revealed that compared to the concrete mixtures with a substitution rate of 30%, the control mixture had a strength value that was only 6.3% higher, and this enhancement is not particularly high. In a similar manner, the durability properties of the concrete mixtures containing FS up to 30% were relatively close to those of control mixture. From the test results, it is suggested that FS with a substitution rate of up to 30% can be effectively used in concrete production without affecting the strength and durability properties of the concrete.

  13. Improving Housing Durability in Deprived Settlements of Lagos Megacity through Ingenuous Use of Sustainable Indigenous Materials

    Directory of Open Access Journals (Sweden)

    Anthony C.O. Iweka

    2011-05-01

    Full Text Available The challenge of housing delivery in many developing nations is exacerbated by the predominance of deprived settlements, according to recent publications of the United Nations Settlement Programme (UN-Habitat. In Nigeria, 30% of its urban population is currently living in Lagos megacity. The Lagos megacity region plays host to more than 200 officially recognized slum settlements. Going by the United Nations’ adopted definition, these settlements harbour households that suffer from lack of access to one or more housing deprivation measures such as durable housing, improved water, improved sanitation, sufficient living space and security of tenure. Nine major slum communities in this fast-growing megacity are presently benefiting from a massive World Bank assisted seven-year upgrading exercise that commenced in 2006. However, there is perplexity because emphasis is ostensibly on infrastructure, particularly roads. There is apparent neglect of the housing durability element. This paper argues that the approach adopted in this exercise is not exhaustive, and could in fact, portend danger for the future. The study discusses how the durability component of housing deprivation can be addressed through actions and policies that encourage ingenuous use of indigenous building materials.

  14. Large faceted Pd nanocrystals supported small Pt nanoparticles as highly durable electrocatalysts for oxygen reduction

    Science.gov (United States)

    Zhang, Geng; Lu, Wangting; Cao, Longsheng; Qin, Xiaoping; Ding, Fei; Tang, Shun; Shao, Zhi-Gang; Yi, Baolian

    2016-09-01

    The reduction of Pt content together with the improvement of the durability of the catalyst for oxygen reduction reaction (ORR) is required to the large-scale commercialization of proton exchange membrane fuel cells. In this work, a novel ORR catalyst consisting of large Pd nanocrystal as the core with small Pt nanoparticles supported on the Pd core is prepared by a facile one-step synthesis method. The Pd substrate is presented in the form of well-defined cuboctahedrons and icosahedrons. The type of metal precursors and Pt/Pd molar ratio are important factors to obtain this Pd-supporting-Pt structure. The Pd2-s-Pt1 catalyst with a nominal Pt/Pd atomic ratio at 1/2 shows improved ORR activity: its mass specific activity and area specific activity is 2.5 and 3.5 times that of commercial Pt/C, respectively. More importantly, the Pd2-s-Pt1 catalyst demonstrates outstanding durability against potential cycling which can be ascribed to the slow dissolution of Pd core and the structure transformation from Pd@Pt to hollow PdPt alloyed nanocages. This exciting result provides a new pathway to the design of ORR catalyst with excellent durability.

  15. Organic monolith frits encased in polyether ether ketone tubing with improved durability for liquid chromatography.

    Science.gov (United States)

    Park, Sin Young; Cheong, Won Jo

    2015-09-01

    This study introduces a preparation method for polymer-encased monolith frits with improved durability for liquid chromatography columns. The inner surface of the polyether ether ketone tubing is pretreated with sulfuric acid in the presence of catalysts (vanadium oxide and sodium sulfate). The tubing was rinsed with water and acetone, flushed with nitrogen, and treated with glycidyl methacrylate. After washing, the monolith reaction mixture composed of lauryl methacrylate, ethylene glycol dimethacrylate, initiator, and porogenic solvent was filled in the tubing and subjected to in situ polymerization. The tubing was cut into thin slices and used as frits for microcolumns. To check their durability, the frit slices were placed in a vial and a heavy impact was applied on the vial by a vortex mixer for various periods. The frits made in the presence of catalysts were found to be more durable than those made without catalysts. Furthermore, when the monolith-incorporated tubing was used as a chromatography column, the column prepared in the presence of catalysts resulted in a better separation efficiency. The separation performance of the columns installed with the polyether ether ketone encased monolith frits was comparable to that of the columns installed with the commercial stainless-steel screen frits. PMID:26097071

  16. Durability predictions from rate of diffusion testing of normal portland cement, fly ash, and slag concrete

    International Nuclear Information System (INIS)

    A waste repository for the belowground disposal of low-level radioactive waste, labelled IRUS (Intrusion Resistant Underground Structure), is planned at the Chalk River Laboratories. It relies greatly on the durability of concrete for a minimum of 500 years of service life. A research program based on laboratory testing to design a durable concrete and predict its useful engineered service life is in progress. The durability of concrete depends on its resistance to deterioration from both internal and external causes. Since the rate of degradation depends to a major extent on the rate of ingress of aggressive ions into concrete, laboratory testing is in progress to establish the diffusion rates of chlorides and sulphate ions. A total of 1000 concrete specimens and 500 paste specimens are being exposed at 22 degrees and 45 degrees C to twenty-five different combinations of corrosive agents, including CO2. Procedures to measure the ionic penetration profile and to determine the factors controlling diffusion of ions in the various concretes have been developed. The paper presents the initial results from the research program and the longevity predictions to qualify concretes for the IRUS waste repository, based on 16 months of diffusion testing on laboratory specimens

  17. Durability improvement assessment in different high strength bacterial structural concrete grades against different types of acids

    Indian Academy of Sciences (India)

    Ramin Andalib; M Zaimi Abd Majid; A Keyvanfar; Amirreza Talaiekhozan; Mohd Warid Hussin; A Shafaghat; Rosli Mohd Zin; Chew Tin Lee; Mohammad Ali Fulazzaky; Hasrul Haidar Ismail

    2014-12-01

    This paper provides an insight into a new biotechnological method based on calcite precipitation for achieving high strength bio-concrete durability. It is very clear that mineral precipitation has the potential to enhance construction material resistance towards degradation procedures. The appropriate microbial cell concentration (30 * 105 cells/ml) was introduced onto different structural concrete grades (40, 45 and 50 MPa) by mixing water. In order to study the durability of structural concrete against aggressive agents, specimens were immersed in different types of acids solution (5% H2SO4 and HCl) to compare their effects on 60th, 90th and 120th day. In general, sulphuric acid and hydrochloric acid are known to be the most aggressive natural threats from industrial waters which can penetrate concrete to transfer the soluble calcium salts away from the cement matrix. The experimental results demonstrated that bio-concrete has less weight and strength losses when compared to the ordinary Portland cement concrete without microorganism. It was also found that maximum compressive strength and weight loss occurred during H2SO4 acid immersion as compared to HCl immersion. The density and uniformity of bio-concrete were examined using ultrasonic pulse velocity (UPV) test. Microstructure chemical analysis was also quantified by energy dispersive spectrometer (EDS) to justify the durability improvement in bacterial concrete. It was observed that less sulphur and chloride were noticed in bacterial concrete against H2SO4 and HCl, respectively in comparison to the ordinary Portland cement concrete due to calcite deposition.

  18. An investigation into the durability of screen-printed conductive tracks on textiles

    Science.gov (United States)

    Paul, Gordon; Torah, Russel; Yang, Kai; Beeby, Steve; Tudor, John

    2014-02-01

    This paper examines the durability of screen-printed conductive tracks on textiles. These tracks are composed of a silver polymer paste as a conductive layer, which is fully encapsulated with polyurethane. The polyurethane materials and layer structures used to encapsulate the textile are varied and each structure is tested in a cyclic mandrel machine to simulate the effects of normal wear and tear. These results are compared to a MATLAB model of the strain in the conductive track, relating the predicted strain on the conductive layer to the measured resistance change. From these results, a batch of structures with high durability are fabricated and these are machine washed. It was found that 97.1% of the conductive tracks remained conductive after ten domestic machine washes with a 1 kg load at 40 °C and 1000 rpm spin speed. This compares with 8.9% which remained conductive before optimization. This optimization process has therefore led to over ten times improvement in durability for screen-printed conductive tracks on textiles.

  19. Durability Index Performance of High Strength Concretes Made Based on Different Standard Portland Cements

    Directory of Open Access Journals (Sweden)

    Stephen O. Ekolu

    2012-01-01

    Full Text Available A consortium of three durability index test methods consisting of oxygen permeability, sorptivity and chloride conductivity were used to evaluate the potential influence of four (4 common SANS 10197 cements on strength and durability of concrete. Twenty four (24 concrete mixtures of water-cement ratios (w/c's = 0.4, 0.5, 0.65 were cast using the cement types CEM I 42.5N, CEM II/A-M (V-L 42.5N, CEM IV/B 32.5R and CEM II/A-V 52.5N. The concretes investigated fall in the range of normal strength, medium strength and high strength concretes. It was found that the marked differences in oxygen permeability and sorptivity results observed at normal and medium strengths tended to vanish at high concrete strengths. Also, the durability effects attributed to use of different cement types appear to diminish at high strengths. Cements of low strength and/or that contained no extenders (CEM 32.5R, CEM I 42.5N showed greater sensitivity to sorptivity, relative to other cement types. Results also show that while concrete resistance to chlorides generally improves with increase in strength, adequately high chloride resistance may not be achieved based on high strength alone, and appropriate incorporation of extenders may be necessary.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lebental, B [Universite Paris-Est, IFSTTAR, 58 boulevard Lefebvre, 75732 Paris Cedex 15 (France); Chainais, P [INRIA Lille-Nord Europe (SEQUEL), 40 avenue Halley, 59650 Villeneuve d' Ascq (France); Chenevier, P [SPEC, IRAMIS, CEA/Saclay, Gif-sur-Yvette (France); Chevalier, N; Delevoye, E; Fabbri, J-M; Nicoletti, S; Renaux, P; Ghis, A, E-mail: berengere.lebental@ifsttar.fr [CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2011-09-30

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

  1. Durability of carbon fiber reinforced shape memory polymer composites in space

    Science.gov (United States)

    Jang, Joon Hyeok; Hong, Seok Bin; Ahn, Yong San; Kim, Jin-Gyun; Nam, Yong-Youn; Lee, Geun Ho; Yu, Woong-Ryeol

    2016-04-01

    Shape memory polymer (SMP) is one of smart polymers which exhibit shape memory effect upon external stimuli. Recently, shape memory polymer composites (SMPCs) have been considered for space structure instead of shape memory alloys due to their deformability, lightweight and large recovery ratio, requiring characterization of their mechanical properties against harsh space environment and further prediction of the durability of SMPCs in space. As such, the durability of carbon fiber reinforced shape memory polymer composites (CF-SMPCs) was investigated using accelerated testing method based on short-term testing of CF-SMPCs in harsh condition. CF-SMPCs were prepared using woven carbon fabrics and a thermoset SMP via vacuum assisted resin transfer molding process. Bending tests with constant strain rate of CF-SMPCs were conducted using universal tensile machine (UTM) and Storage modulus test were conducted using dynamic mechanical thermal analysis (DMTA). Using the results, a master curve based on time-temperature superposition principle was then constructed, through which the mechanical properties of CF-SMPCs at harsh temperature were predicted. CF-SMPCs would be exposed to simulated space environments under ultra-violet radiations at various temperatures. The mechanical properties including flexural and tensile strength and shape memory properties of SMPCs would be measured using UTM before and after such exposures for comparison. Finally, the durability of SMPCs in space would be assessed by developing a degradation model of SMPC.

  2. Pt35Cu65 nanoarchitecture: a highly durable and effective electrocatalyst towards methanol oxidation

    International Nuclear Information System (INIS)

    Aiming at electro-catalytic performance enhancement and reduction of catalyst cost, PtxCu1−x (Pt35Cu65, Pt53Cu47, and Pt68Cu32) nanoarchitecture samples with controllable atomic composition, similar morphology and particle-size have been prepared by using a one-pot chemical route. The as-prepared PtxCu1−x nanoarchitectures are confirmed as consisting of the integration of initial small alloy nanoparticles (NPs), resulting in an interconnected nanoporous structure. The electrochemical experiments indicate that these PtxCu1−x nanocatalysts exhibit atomic composition dependent catalytic activity, although the surfaces of all the catalysts were characterized to be featured with a Pt enrichment structure. With optimal atomic composition, the Pt35Cu65 catalyst possesses enhanced electro-catalytic activities towards methanol oxidation in comparison with other PtxCu1−x samples and pure Pt catalyst with similar morphology. Furthermore, the integrated Pt35Cu65 nanoarchitecture displays good durability during the long term electrochemical scanning through as many as 1500 cycles. The comparable catalytic performance of Pt35Cu65 catalyst could be attributed to the interconnected initial small NPs, formation of open porous structure, durable nanoarchitecture, and synergetic effect of the alloyed atoms. The structural evolution from metastable small alloy NPs to integrated stable nanoarchitectures may provide new opportunities to design and prepare novel composite materials with durable structure and effective catalytic properties. (paper)

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

    Science.gov (United States)

    Lee, Kang N.

    2000-01-01

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

  4. Study on durability of natural fibre concrete composites using mechanical strength and microstructural properties

    Indian Academy of Sciences (India)

    M Sivaraja; Kandasamy; N Velmani; M Sudhakaran Pillai

    2010-12-01

    Investigations to overcome the brittle response and limiting post-yield energy absorption of concrete led to the development of fibre reinforced concrete using discrete fibres within the concrete mass. Out of the commonly used fibres, easily available low cost natural fibres are renewable source materials. Though these fibres are ecologically advantageous, they have some limitations such as lower durability and lesser strength. But recent research provides several treatment processes to enhance the durability of natural fibres. In this paper, the durability of natural fibres such as coconut coir and sugarcane bagasse has been reported by conducting an experimental investigation. This investigation includes two parts. The first part focuses on the determination of mechanical strength properties such as compressive, tensile, modulus of rupture and flexural properties of natural fibre reinforced concrete specimens once every 3 months for a period for 2 years under alternate wetting and drying conditions. Gain or loss in strength of composite concrete at 9 intervals were computed and are reported here. The second part covers the microstructural properties of fresh natural fibres in as received condition and natural fibres reacted with concrete under accelerated curing conditions for two years. SEM and EDAC test results are discussed.

  5. Primer on Durability of Nuclear Power Plant Reinforced Concrete Structures - A Review of Pertinent Factors

    Energy Technology Data Exchange (ETDEWEB)

    Naus, Dan J [ORNL

    2007-02-01

    The objective of this study was to provide a primer on the environmental effects that can affect the durability of nuclear power plant concrete structures. As concrete ages, changes in its properties will occur as a result of continuing microstructural changes (i.e., slow hydration, crystallization of amorphous constituents, and reactions between cement paste and aggregates), as well as environmental influences. These changes do not have to be detrimental to the point that concrete will not be able to meet its performance requirements. Concrete, however, can suffer undesirable changes with time because of improper specifications, a violation of specifications, or adverse performance of its cement paste matrix or aggregate constituents under either physical or chemical attack. Contained in this report is a discussion on concrete durability and the relationship between durability and performance, a review of the historical perspective related to concrete and longevity, a description of the basic materials that comprise reinforced concrete, and information on the environmental factors that can affect the performance of nuclear power plant concrete structures. Commentary is provided on the importance of an aging management program.

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

    Science.gov (United States)

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

    2011-09-30

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

  7. Fatigue Life of Haynes 188 Superalloy in Direct Connect Combustor Durability Rig

    Science.gov (United States)

    Gabb, TIm; Gayda, John; Webster, Henry; Ribeiro, Greg

    2007-01-01

    The Direct Connect Combustor Durability Rig (DCR) will provide NASA a flexible and efficient test bed to demonstrate the durability of actively cooled scramjet engine structure, static and dynamic sealing technologies, and thermal management techniques. The DCR shall be hydrogen fueled and cooled, and test hydrogen coolded structural panels at Mach 5 and 7. Actively cooled Haynes 188 superalloy DCR structural panels exposed to the combustion environment shall have electrodischarge machined (EDM) internal cooling holes with flowing liquid hydrogen. Hydrogen combustion could therefore produce severe thermal conditions that could challenge low cycle fatigue durability of this material. The objective of this study was to assess low cycle fatigue capability of Haynes 188 for DCR application. Tests were performed at 25 and 650 C, in hydrogen and helium environments, using specimens with low stress ground (LSG) and electro-discharge machined (EDM) surface finish. Initial fatigue tests in helium and hydrogen indicate the low cycle fatigue life capability of Haynes 188 in hydrogen appears quite satisfactory for the DCR application. Fatigue capability did not decrease with increasing test temperature. Fatigue capability also did not decrease with EDM surface finish. Failure evaluations indicate retention of ductility in all conditions. Additional tests are planned to reconfirm these positive trends.

  8. Manufacturing Metrology for c-Si Photovoltaic Module Reliability and Durability, Part I: Feedstock, Crystallization and Wafering

    Energy Technology Data Exchange (ETDEWEB)

    Seigneur, Hubert; Mohajeri, Nahid; Brooker, R. Paul; Davis, Kristopher O.; Schneller, Eric J.; Dhere, Neelkanth G.; Rodgers, Marianne P.; Wohlgemuth, John; Shiradkar, Narendra S.; Scardera, Giuseppe; Rudack, Andrew C.; Schoenfeld, Winston V.

    2016-06-01

    This article is the first in a three-part series of manufacturing metrology for c-Si photovoltaic (PV) module reliability and durability. Here in Part 1 we focus on the three primary process steps for making silicon substrates for PV cells: (1) feedstock production; (2) ingot and brick production; and (3) wafer production. Each of these steps can affect the final reliability/durability of PV modules in the field with manufacturing metrology potentially playing a significant role. This article provides a comprehensive overview of historical and current processes in each of these three steps, followed by a discussion of associated reliability challenges and metrology strategies that can be employed for increased reliability and durability in resultant modules. Gaps in the current state of understanding in connective metrology data during processing to reliability/durability in the field are then identified along with suggested improvements that should be considered by the PV community.

  9. The prediction of the freeze/thaw durability of coarse aggregate in concrete by mercury intrusion porosimetry

    Science.gov (United States)

    Lindgren, M. N.

    1980-10-01

    Aggregates from fifty-two Indiana highway cores were tested as were five rock samples supplied by the Portland Cement Association. The Expected Durability Factor values were determined from the pore size distributions, and an average value was assigned to each pavement associated with the cores. These values were then compared with the field performance of the pavement to ascertain the borderline between EDF values for durable and for nondurable aggregates. A good correlation between the field performance and the average EDF values was found. A pavement will be durable if its coarse aggregate has an EDF value greater than 50 for 90% or more of the aggregate. This criterion applies to stone and gravel aggregates with a maximum size of 1-1/2 to 2-1/2 inches. The pavement will be durable for at lest thirty years.

  10. Effect of W/C Ratio on Durability and Porosity in Cement Mortar with Constant Cement Amount

    Directory of Open Access Journals (Sweden)

    Yun-Yong Kim

    2014-01-01

    Full Text Available Water is often added to concrete placing for easy workability and finishability in construction site. The additional mixing water can help easy mixing and workability but causes increased porosity, which yields degradation of durability and structural performances. In this paper, cement mortar samples with 0.45 of W/C (water to cement ratio are prepared for control case and durability performances are evaluated with additional water from 0.45 to 0.60 of W/C. Several durability tests including strength, chloride diffusion, air permeability, saturation, and moisture diffusion are performed, and they are analyzed with changed porosity. The changing ratios and patterns of durability performance are evaluated considering pore size distribution, total porosity, and additional water content.

  11. Oxide film microstructure: the link between surface preparation processes and strength/durability of adhesively bonded aluminum. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hsia, K. Jimmy; Pearlstein, Arne J.; Scheeline, Alexander; Shang, Jian Ku

    2000-11-30

    Strength and durability of adhesive bonding of aluminum alloys structures are intrinsically determined by the surface microstructures and interfacial failure micromechanisms. The current project presents a multidisciplinary approach to addressing critical issues controlling the strength and durability of adhesive bonds of aluminum alloys. Three main thrust areas have been pursued: surface treatment technology development to achieve desirable surface microstructures; relationship between surface structure and properties of adhesive bonds; and failure mechanisms of adhesively bonded components.

  12. A multi-timescale modeling methodology for PEMFC performance and durability in a virtual fuel cell car

    OpenAIRE

    Mayur, Manik; Strahl, Stephan; Husar, Attila; Bessler, Wolfgang G.

    2015-01-01

    The durability of polymer electrolyte membrane fuel cells (PEMFC) is governed by a nonlinear cou-pling between system demand, component behavior, and physicochemical degradation mechanisms, occurring on timescales from the sub-second to the thousand-hour. We present a simulation methodol-ogy for assessing performance and durability of a PEMFC under automotive driving cycles. The simu-lation framework consists of (a) a fuel cell car model converting velocity to cell power demand, (b) a 2D mult...

  13. Application of the Resistivity in Quality Control of Concrete Durability for the Hong Kong–Zhuhai–Macao Bridge

    OpenAIRE

    Xiong, Jianbo; Dong, Guihong; Wang, Shengnian; Chai, Rui

    2014-01-01

    Engineering uses the chloride ion diffusion coefficient as the durability of concrete quality control indicators under the marine environment, due to the chloride ion diffusion coefficient and the electrical resistivity of concrete parameters are reflected in the concrete pore structure, and resistivity testing is convenient, fast advantages, the resistivity alternative chloride ion diffusion coefficient for the durability of concrete quality control has practical significance. In this paper,...

  14. Improving the durability of methanol oxidation reaction electro-catalysts through the modification of carbon architectures

    Science.gov (United States)

    Wood, Kevin N.

    Carbon materials represent one of the largest areas of studied research today, having integrated applications stretching from energy production and storage to medical use and far beyond. One of these many intriguing applications is fuel cells, which offers the promise of clean electricity through a direct electrochemical energy conversion process. Unfortunately, at the present time the cost per watt-hour produced by fuel cells is more expensive than conventional methods of energy production/storage (i.e. combustion engines, batteries, etc.). Under the umbrella of fuel cell systems, methanol is a promising fuel source because of its high energy density and convenience of direct liquid fuel operation. In this field, recent advancements are bringing direct methanol fuel cells (DMFCs) closer to commercial viability. However, just as in other fuel cell systems, further improvements are greatly needed, particularly in the area of catalyst durability. This need for improved durability has led to increased research activity focused on improving catalyst stability and utilization. This thesis explores one of the most promising areas of enhancing catalyst-support interactions; namely, modification of carbon support architectures. Through the use of heteroatom modifiers, such as nitrogen, fuel cell support systems can be enhanced in such a way as to improve metal nucleation and growth, catalyst durability and catalytic activity. To this end, this thesis employs advanced characterization techniques to study the changes in catalyst particle morphology before and after nitrogen modification of the support structure. These results clearly show the beneficial effects of nitrogen moieties on carbon structures and help elucidate the effects of nitrogen on the stability of supported catalytic nanoparticles systems. Similarly, the novel concept of post-modifying commercially available supported catalysts with nitrogen ion implantation gives further insight into the behavior of

  15. Method for the Accelerated Testing of the Durability of a Construction Binder using the Arrhenius Approach

    Directory of Open Access Journals (Sweden)

    Fridrichová Marcela

    2016-03-01

    Full Text Available The single most reliable indicator of a material’s durability is its performance in long-term tests, which cannot always be carried out due to a limited time budget. The second option is to perform some kind of accelerated durability tests. The aim of the work described in this article was to develop a method for the accelerated durability testing of binders. It was decided that the Arrhenius equation approach and the theory of chemical reaction kinetics would be applied in this case. The degradation process has been simplified to a single quantifiable parameter, which became compressive strength. A model hydraulic binder based on fluidised bed combustion ash (FBC ash was chosen as the test subject for the development of the method. The model binder and its hydration products were tested by high-temperature X-ray diffraction analysis. The main hydration product of this binder was ettringite. Due to the thermodynamic instability of this mineral, it was possible to verify the proposed method via long term testing. In order to accelerate the chemical reactions in the binder, four combinations of two temperatures (65 and 85°C and two different relative humidities (14 and 100% were used. The upper temperature limit was chosen because of the results of the high-temperature x-ray testing of the ettringite’s decomposition. The calculation formulae for the accelerated durability tests were derived on the basis of data regarding the decrease in compressive strength under the conditions imposed by the four above-mentioned combinations. The mineralogical composition of the binder after degradation was also described. The final degradation product was gypsum under dry conditions and monosulphate under wet conditions. The validity of the method and formula was subsequently verified by means of long-term testing. A very good correspondence between the calculated and real values was achieved. The deviation of these values did not exceed 5 %. The designed

  16. Prevent Back Pain

    Science.gov (United States)

    ... Prevent Back Pain Print This Topic En español Prevent Back Pain Browse Sections The Basics Overview Am ... at Risk? 3 of 5 sections Take Action: Prevent Injuries Focus on good posture. Good posture can ...

  17. Lung Cancer Prevention

    Science.gov (United States)

    ... Treatment Lung Cancer Prevention Lung Cancer Screening Research Lung Cancer Prevention (PDQ®)–Patient Version What is prevention? Go ... to keep cancer from starting. General Information About Lung Cancer Key Points Lung cancer is a disease in ...

  18. Child Maltreatment Prevention

    Science.gov (United States)

    ... Resources Featured Topic: Opportunities for Action Featured Topic: Bullying Research Featured Topic: Prevent Gang Membership Featured Topic: School Violence Data & Statistics Risk & Protective Factors Prevention Prevention Tools & Resources Featured Topic: Electronic Aggression Funded ...

  19. Introduction of revision of Code for design of concrete structures part Ⅲ:Durability design of concrete structures%《混凝土结构设计规范》修订简介(三)——混凝土结构的耐久性设计

    Institute of Scientific and Technical Information of China (English)

    金伟良; 邸小坛; 徐有邻

    2011-01-01

    The importance, ultimate principle and qualitative design method for the durability design of concrete structures were emphasized.According to the revised standard, the environmental category of durability, the requirements to durability of concrete material performance, the technical measures for preventing material degradation, the method for extending the design working life, the inspection and maintenance requirements of period of use were introduced.It could help designer understand and carry out the durability design of the revised standard.%强调了混凝土结构耐久性设计的重要性、基本原理及定性设计方法.根据修订规范介绍了:耐久性环境类别;对混凝土材料的耐久性能要求;防止材料劣化的技术措施;延长设计使用年限的方法;使用期的检测、维护要求.可以帮助设计人员理解和执行修订规范的耐久性设计.

  20. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Preventing Pressure Sores Preventing Pressure Sores Transition from Hospital to Home Transition from Hospital to Home Spasticity, Physical Therapy-Lokomat Spasticity, Physical ...

  1. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Injury 101 The Basics of Spinal Cord Injury Rehabilitation The Basics of Spinal Cord Injury Rehabilitation Preventing Pressure Sores Preventing Pressure Sores Transition from ...

  2. 铁路旅客站房耐久性混凝土试验研究%Research on Durable Concrete of Railway Station Building

    Institute of Scientific and Technical Information of China (English)

    牛俊勇

    2012-01-01

    结合郑西客运专线西安北站房工程,对高性能混凝土耐久性进行了试验研究。研究证明,通过对原材料的优选和对配合比的优化,采用优质高效外加剂和矿物掺合科,降低了用水量,减少了水泥用量,提高了混凝土的抗氯离子渗透、抗裂和抗冻性能,并采取了限制原材料碱含量和氯离子含量等措施来预防混凝土发生碱骨料反应和钢筋锈蚀,从而确保了混凝土的耐久性。%Combining the Zheng-Xi' an passenger line Xi' an North station building engineering, the durability of the high performance concrete are studied. Study proves, through the selection of raw materials and the design of the optimization, using high quality and highly efficient and mineral admixtures mixing with families, water consumption and the dosage of cement is reduced, the resistance of concrete chloride permeability, crack and the frost resistance are improved, and a limit of raw materials and alkali content of chlorine ion in concrete measures are taken to prevent alkali aggregate reaction and rust corrosion, to ensure the durability of concrete passenger special line.

  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. 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

  5. Report on the behalf of sustainable development and land planning commission of a bill aiming at prohibiting the exploration and exploitation on non conventional hydrocarbons, at abrogating exclusive search permits for non conventional hydrocarbon mines, and to ensure more transparency in the mining code; Rapport fait au nom de la Commission du Developpement Durable et de l'Amenagement du Territoire sur la proposition de loi, visant a interdire l'exploration et l'exploitation des hydrocarbures non conventionnels, a abroger les permis exclusifs de recherche de mines d'hydrocarbures non conventionnels et a assurer plus de transparence dans le code minier (n. 3690)

    Energy Technology Data Exchange (ETDEWEB)

    Chanteguet, J.P.

    2011-07-01

    In the first part of this report, the author (from the opposition party) outlines the opacity of the attribution procedure defined in the mining code for search permits, the lack of recognition of the citizen mobilization, and the inefficient and inapplicable character of the law of 2001 on the search for non conventional hydrocarbon mining sites. In the second part, the author outlines the need for an environment-friendly energy strategy, while recalling the necessity of protection of the environment when exploiting subsoils, the necessity of implementing an energy transition, and the necessity to reform the mining law. The discussion of the commission about the bill articles is reported

  6. Development of Carriers for Polymer Inclusion Membranes (PIMs) Applied to Radioactive Wastewater Treatment. Improvement in Durability

    International Nuclear Information System (INIS)

    Polymer inclusion membrane (PIM), which is prepared with cellulose triacetate (CTA) as a polymer matrix, 2-nitrophenyl n-octyl ether (NPOE) as a liquid plasticizer, and an adequate carrier, is the most promising method to apply a liquid membrane system to a practical process. Here, NPOE simultaneously acts as an organic solvent similar to that used in the liquid membrane. One of possible applications of PIMs is the treatment of low level radioactive wastewater. For the environmental safety, the large volume of the wastes must be concentrated into the smallest possible volume before the storage. We have presented that the up-hill transport of cerium ion, which is used as a model substance for actinoids, is feasible using PIM prepared with octyl(phenyl)-N,N-diisobutyl carbamoylmethylphosphine oxide (CMPO) or N,N,N',N'-tetraoctyl-3-oxapentane diamide (TODGA), which are the well known extractants for actinoids, as a carrier. In this study, we systematically designed and synthesized new carriers for cerium ion and evaluated the cerium transport performance and durability of the PIMs made with the carriers comparing with those with CMPO and TODGA. The cerium transport performance of one of the PIMs was nearly equal to that of the PIM with TODGA, and the durabilities of some of the PIMs were superior to that of the PIM with CMPO. The durabilities of the PIMs were different between the carries used for the PIMs. The cause was discussed relating to the microstructures of the PIMs with the effects of the carriers and NPOE. (author)

  7. Adaptive evolution and environmental durability jointly structure phylodynamic patterns in avian influenza viruses.

    Directory of Open Access Journals (Sweden)

    Benjamin Roche

    2014-08-01

    Full Text Available Avian influenza viruses (AIVs have been pivotal to the origination of human pandemic strains. Despite their scientific and public health significance, however, there remains much to be understood about the ecology and evolution of AIVs in wild birds, where major pools of genetic diversity are generated and maintained. Here, we present comparative phylodynamic analyses of human and AIVs in North America, demonstrating (i significantly higher standing genetic diversity and (ii phylogenetic trees with a weaker signature of immune escape in AIVs than in human viruses. To explain these differences, we performed statistical analyses to quantify the relative contribution of several potential explanations. We found that HA genetic diversity in avian viruses is determined by a combination of factors, predominantly subtype-specific differences in host immune selective pressure and the ecology of transmission (in particular, the durability of subtypes in aquatic environments. Extending this analysis using a computational model demonstrated that virus durability may lead to long-term, indirect chains of transmission that, when coupled with a short host lifespan, can generate and maintain the observed high levels of genetic diversity. Further evidence in support of this novel finding was found by demonstrating an association between subtype-specific environmental durability and predicted phylogenetic signatures: genetic diversity, variation in phylogenetic tree branch lengths, and tree height. The conclusion that environmental transmission plays an important role in the evolutionary biology of avian influenza viruses-a manifestation of the "storage effect"-highlights the potentially unpredictable impact of wildlife reservoirs for future human pandemics and the need for improved understanding of the natural ecology of these viruses.

  8. La politique de la ville : une trajectoire de développement urbain durable ?

    Directory of Open Access Journals (Sweden)

    Mélanie Goffi

    2005-11-01

    Full Text Available La politique de la ville en France valorise une approche stratégique multiforme des difficultés urbaines, dans une démarche de participation des habitants. La similitude de ses objectifs avec ceux du développement durable est frappante. Il apparaît dès lors pertinent d’engager notre réflexion sur la politique de la ville comme une stratégie de développement durable des quartiers en difficultés. Nous proposons ainsi à travers cet article un essai de définition du quartier en développement durable, tant dans son concept que dans sa mise en œuvre, en nous basant d’une part sur l’analyse de la démarche de participation dans la politique de renouvellement urbain en France, et d’autre part sur la représentation du territoire comme un écosystème.French urban policy is aimed at implementing a transversal understanding of urban problematics using a participative approach. In that sense its objectives are very much interconnected with those of sustainable development. We can therefore consider urban governance policies as strategies supposely focused on the sustainable development of deprived neighborhoods. Through this article, we intend to define what the sustainable development means at the scale of a neighborhood i.e. what are its objectives and how to implement it. We firstly analyse the participatory process in the French urban policy. Second, we engage our reflexion on the ecosystemic understanding of a sustainably developing neighbourhood.  

  9. A study on the effectiveness of a preventive equipment against the fault due to magpies in overhead distribution line

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.M.; Lee, B.S.; Lee, J.B. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    This study examines the applicability of a preventive equipment (liquid grass) to the field. The preventive equipment mass produced already is to prevent the fault due to birds-magpies, and is known for the excellent performance within magpies' living quarters. To assess the practicality of the production, it was mounted on the poles on which the magpie can build a nest with ease, thus the durability, emitting effect of a foul odor and evading temper of magpies were assessed. (author). 16 refs., 8 figs., 6 tabs.

  10. Photovoltaic module performance and durability following long-term field exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ellibee, D.E.; Hansen, B.R.; King, D.L.; Kratochvil, J.A.; Quintana, M.A.

    1998-09-08

    Our investigations of both new and field-aged photovoltaic modules have indicated that, in general, today's commercially available modules area highly reliable product. However, by using new test procedures, subtle failure mechanisms have also been identified that must be addressed in order to achieve 30-year module lifetimes. This paper summarizes diagnostic test procedures, results, and implications of in-depth investigations of the performance and durability characteristics of commercial modules after long-term field exposure. A collaborative effort with U.S. module manufacturers aimed at achieving 30-year module lifetimes is also described.

  11. Genetic base of durable resistance to Puccinia triticina of two Serbian varieties

    OpenAIRE

    Prijić Željana; Jerković Zoran

    2010-01-01

    The durable resistant varieties were developed more than 15 years ago. The basis of the resistance was investigated at seedling stage according to reaction type (RT) at air temperatures 20-25°C. The F2 generations of varieties Anastasia or Selekta x Lr 1, Lr 2a, Lr 3, Lr 13, Lr 14a, Lr 16 or Lr 26 were tested with isolates producing low RT on first two mentioned Lr lines. The presence of these single resistant genes in the varieties was excluded by presence of susceptible plants in F2 progeni...

  12. Tracing formation and durability of calcite in a Punic-Roman cistern mortar (Pantelleria Island, Italy).

    Science.gov (United States)

    Dietzel, Martin; Schön, Frerich; Heinrichs, Jens; Deditius, Artur P; Leis, Albrecht

    2016-01-01

    Ancient hydraulic lime mortar preserves chemical and isotopic signatures that provide important information about historical processing and its durability. The distribution and isotopic composition of calcite in a mortar of a well-preserved Punic-Roman cistern at Pantelleria Island (Italy) was used to trace the formation conditions, durability, and individual processing periods of the cistern mortar. The analyses of stable carbon and oxygen isotopes of calcite revealed four individual horizons, D, E, B-1 and B-2, of mortar from the top to the bottom of the cistern floor. Volcanic and ceramic aggregates were used for the production of the mortar of horizons E/D and B-1/B-2, respectively. All horizons comprise hydraulic lime mortar characterized by a mean cementation index of 1.5 ± 1, and a constant binder to aggregate ratio of 0.31 ± 0.01. This suggests standardized and highly effective processing of the cistern. The high durability of calcite formed during carbonation of slaked lime within the matrix of the ancient mortar, and thus the excellent resistance of the hydraulic lime mortar against water, was documented by (i) a distinct positive correlation of δ(18)Ocalcite and δ(13)Ccalcite; typical for carbonation through a mortar horizon, (ii) a characteristic evolution of δ(18)Ocalcite and δ(13)Ccalcite through each of the four mortar horizons; lighter follow heavier isotopic values from upper to lower part of the cistern floor, and (iii) δ(18)Ocalcite varying from -10 to -5 ‰ Vienna Pee Dee belemnite (VPDB). The range of δ(18)Ocalcite values rule out recrystallization and/or neoformation of calcite through chemical attack of water stored in cistern. The combined studies of the chemical composition of the binder and the isotopic composition of the calcite in an ancient mortar provide powerful tools for elucidating the ancient techniques and processing periods. This approach helps to evaluate the durability of primary calcite and demonstrates the

  13. Evaluating the Impact of Dwell Time on Solder Interconnect Durability Under Bending Loads

    Science.gov (United States)

    Menon, Sandeep; Osterman, Michael; Pecht, Michael

    2015-11-01

    With the increasing portability and miniaturization of modern-day electronics, the mechanical robustness of these systems has become more of a concern. Existing standards for conducting mechanical durability tests of electronic assemblies include bend, shock/drop, vibration, and torsion. Although these standards provide insights into both cyclic fatigue and overstress damage incurred in solder interconnects (widely regarded as the primary mode of failure in electronic assemblies), they fail to address the impact of time- dependent (creep) behavior due to sustained mechanical loads on solder interconnect durability. It has been seen in previous studies that solder durability under thermal cycling loads is inversely proportional to the dwell time or hold time at either temperature extreme of the imposed temperature cycle. Fatigue life models, which include dwell time, have been developed for solder interconnects subject to temperature cycling. However, the fatigue life models that have been developed in the literature for solder interconnects under mechanical loads fail to address the influence of the duration of loading. In this study, solder interconnect test vehicles were subjected to cyclic mechanical bending with various dwell times in order to understand the impact of the duration of mechanical loads on solder interconnect durability. The solder interconnects examined in this study were formed with 2512 resistor packages using various solder compositions [tin-lead (Sn-Pb) and 96.5Sn-3Ag-0.5Cu (SAC305)]. To evaluate the impact of dwell time, the boards were tested with 0 s, 60 s, and 300 s of dwell time at both extremes of the loading profile. It was observed that an increase in the dwell time of the loading profile resulted in a decrease in the characteristic life of the solder interconnects. The decrease in fatigue life was attributed to increased creep damage as identified using finite-element simulations. An energy partitioning approach was then used to

  14. Theory of VVER-1000 fuel rearrangement optimization taking into account both fuel cladding durability and burnup

    International Nuclear Information System (INIS)

    Using the VVER-1000 fuel element (FE) cladding failure estimation method based on creep energy theory (CET-method), it is shown that practically FE cladding rupture life at normal operation conditions can be controlled by an optimal assignment of fuel assembly (FA) rearrangement algorithm. The probabilistic FA rearrangement efficiency criterion based on Monte Carlo Sampling takes into account robust operation conditions and gives results corresponding to the deterministic ones in principle, though the robust efficiency estimation is more conservative. It is proved that CET-method allows us to create an automated complex controlling FE cladding durability in VVER-1000.

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Evaluation of the durability of 3D printed keys produced by computational processing of image data

    Science.gov (United States)

    Straub, Jeremy; Kerlin, Scott

    2016-05-01

    Possession of a working 3D printed key can, for most practical purposes, convince observers that an illicit attempt to gain premises access is authorized. This paper seeks to assess three things. First, work has been performed to determine how easily the data for making models of keys can be obtained through manual measurement. It then presents work done to create a model of the key and determine how easy key modeling could be (particularly after a first key of a given key `blank' has been made). Finally, it seeks to assess the durability of the keys produced using 3D printing.

  17. Electronic Durability of Flexible Transparent Films from Type-Specific Single-Wall Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Harris, J; Iyer, S; Bernhardt, A; Huh, JY; Hudson, S; Fagan, J; Hobbie, E.

    2011-12-11

    The coupling between mechanical flexibility and electronic performance is evaluated for thin films of metallic and semiconducting single-wall carbon nanotubes (SWCNTs) deposited on compliant supports. Percolated networks of type-purified SWCNTs are assembled as thin conducting coatings on elastic polymer substrates, and the sheet resistance is measured as a function of compression and cyclic strain through impedance spectroscopy. The wrinkling topography, microstructure and transparency of the films are independently characterized using optical microscopy, electron microscopy, and optical absorption spectroscopy. Thin films made from metallic SWCNTs show better durability as flexible transparent conductive coatings, which we attribute to a combination of superior mechanical performance and higher interfacial conductivity.

  18. On the Durability of Sealable Circular Concrete Structures under Chloride Environment

    Directory of Open Access Journals (Sweden)

    Changwen Mi

    2015-01-01

    Full Text Available Reinforcement corrosion resulting from chloride attack is one major mechanism that compromises concrete durability. Numerical methods were commonly used for tackling Fick’s diffusion equations. In this paper, we developed a Crank-Nicolson based finite difference scheme suitable for circular concrete structures. Both a time-dependent surface chloride model and diffusivity were considered. The impact of an ideal sealer on chloride redistribution was further investigated. Results suggested that the chloride threshold depth in a concrete structure is greatly affected by the radius of curvature, environment severity, and diffusivity. For sealable concrete structures, both the sealer application timing and location are of great importance.

  19. L’innovation de la communication dans le développement durable des ressources humaines

    OpenAIRE

    Jean-Luc PENOT

    2011-01-01

    L’innovation de la communication dans le développement durable des ressources humaines développe une analyse des pratiques de la communication. Partant du constat que nous ne parlons pas forcément de la même chose quand nous parlons de communication il s’agit de présenter les concepts à partir d’un axe central: l’information n’est pas de la communication. Si la communication a un grand rôle dans l’évolution des organisations, elle ne peut pas tout. En rappelant les fondements de la communicat...

  20. Simulation of durability the evaluation of relief-dot Braille images

    Directory of Open Access Journals (Sweden)

    Svitlana Havenko

    2016-07-01

    Full Text Available The paper presents a model of factors that influence on the quality of relief-dot Braille inscriptions in their intensive use by blind people. It was constructed matrix of depending and distancing by using a directed graph. It allowed establish a hierarchy between studied criteria’s of impact the on durability of relief prints. It was developed a basic structure of digital system of assessment the conformity of Braille symbols to applicable international standards and definition of operational stability.