WorldWideScience

Sample records for challenges long-term materials

  1. Protection and structural materials for fusion reactors: Main challenges, long term materials development needs, differences and commonalities with fission

    International Nuclear Information System (INIS)

    Developing plasma-facing and structural materials with Low nuclear Activation (LA), high heat and radiation resistance, is a challenge that the materials community has to address to enable reliable development and safe operation of fusion reactors in the future. This requires scientific innovation, new knowledge, and the exploration of a range of new materials. To address this challenge, the EU fusion programme has set up a Fusion Materials Topical Group to strengthen coordination of long-term fusion materials development for DEMO, and to undertake physically based modelling of radiation induced microstructure and degradation of mechanical properties required to guide the experimental developments. In this paper we describe main radiation effects induced by the intense flux of 14 MeV neutrons in the reference structural materials (i) for Tritium-Breeding Blanket (TBB) modules, LA Ferritic/Martensitic Steel EUROFER, Oxide Dispersion (ODS) EUROFER and ODS ferritic steels, and, (ii) for the divertor, W and W-alloys. Specific issues concerning the peculiar microstructure induced by the impact of α particles on the surface of tungsten, foreseen as a reference protection material, will also be discussed. Modelling radiation effects in EUROFER under fusion reactor relevant conditions is the first priority for the programme, in order to inter-correlate the data obtained with various neutron spectra, contribute to the definition of the irradiation matrix in the future intense source of 14 MeV neutrons, IFMIF, and bring comprehensive understanding and extrapolation capabilities towards the very large range of DEMO operating conditions. Formulating and developing predictive modelling tools is therefore a task of prime significance. Particular care has been taken (i) to focus the modelling effort on the scale where physics can be mastered, i.e. on the scale of the chemical bond, which is triggered by electronic correlation in the case of Fe-Cr system and body cubic centred

  2. Long-term alteration of cementitious materials

    International Nuclear Information System (INIS)

    Long-term alteration of cementitious materials in the geological condition has been discussed for the safety assessment of radioactive waste disposal. This paper describes the status of understanding long-term chemical alteration of cement, by reviewing some of our investigations on this issue in which we developed a thermodynamic incongruent C-S-H dissolution/precipitation model and a reactive transport calculation code. Alteration of C-S-H gel in a saline groundwater and the change of chemical barrier performance of cementitious materials due to the alteration are also discussed. Some key issues to be discussed further are given and suggested for the future studies on the long-term alteration of cementitious materials in the repository environment. (author)

  3. Long-Term Soft Denture Lining Materials

    Directory of Open Access Journals (Sweden)

    Grzegorz Chladek

    2014-08-01

    Full Text Available Long-term soft denture lining (LTSDL materials are used to alleviate the trauma associated with wearing complete dentures. Despite their established clinical efficacy, the use of LTSDLs has been limited due to the unfavorable effects of the oral environment on some of their mechanical and performance characteristics. The unresolved issue of LTSDL colonization by Candida albicans is particularly problematic. Silicone-based LTSDL (SLTSDL materials, which are characterized by more stable hardness, sorption and solubility than acrylic-based LTSDLs (ALTSDLs, are currently the most commonly used LTSDLs. However, SLTSDLs are more prone to debonding from the denture base. Moreover, due to their limitations, the available methods for determining bond strength do not fully reflect the actual stability of these materials under clinical conditions. SLTSDL materials exhibit favorable viscoelastic properties compared with ALTSDLs. Furthermore, all of the lining materials exhibit an aging solution-specific tendency toward discoloration, and the available cleansers are not fully effective and can alter the mechanical properties of LTSDLs. Future studies are needed to improve the microbiological resistance of LTSDLs, as well as some of their performance characteristics.

  4. Esophageal replacement in children: Challenges and long-term outcomes

    Science.gov (United States)

    Soccorso, Giampiero; Parikh, Dakshesh H.

    2016-01-01

    Replacement of a nonexistent or damaged esophagus continues to pose a significant challenge to pediatric surgeons. Various esophageal replacement grafts and techniques have not produced consistently good outcomes to emulate normal esophagus. Therefore, many techniques are still being practiced and recommended with no clear consensus. We present a concise literature review of the currently used techniques and with discussions on the advantages and anticipated morbidity. There are no randomized controlled pediatric studies to compare different types of esophageal replacements. Management and graft choice are based on geographical and personal predilections rather than on any discernible objective data. The biggest series with long-term outcome are reported for gastric transposition and colonic replacement. Comparison of different studies shows no significant difference in early (graft necrosis and anastomotic leaks) or late complications (strictures, poor feeding, gastro-esophageal reflux, tortuosity of the graft, and Barrett's esophagus). The biggest series seem to have lower complications than small series reflecting the decennials experience in their respective centers. Long-term follow-up is recommended following esophageal replacement for the development of late strictures, excessive tortuosity, and Barrett's changes within the graft. Once child overcomes initial morbidity and establishes oral feeding, long-term consequences and complications of pediatric esophageal replacement should be monitored and managed in adult life. PMID:27365900

  5. Implementing geological disposal. A long-term governance challenge

    International Nuclear Information System (INIS)

    necessarily have to lead to a rejection of the proposed project. In this presentation I would like to draw on these two cases to make a related argument about the need to consider long-term governance processes, reaching beyond the remits of classical site selection procedures. Rather than considering siting as the end point of a participatory process, it should be seen as a starting point. For that purpose, I will make use of the notion of hosting to emphasize the relationship between the repository and its host community. A relationship that demands a re-figuration of the geography and temporality of geological disposal. Hosting a geological disposal facility brings with it specific challenges, involving both social and technical adjustments, as well as reconfigurations of the boundary between them (Landstroem and Bergmans 2014).

  6. Implementing geological disposal. A long-term governance challenge

    Energy Technology Data Exchange (ETDEWEB)

    Bergmans, Anne [Antwerp Univ. (Belgium). Faculty of Political and Social Sciences and Faculty of Law

    2015-07-01

    necessarily have to lead to a rejection of the proposed project. In this presentation I would like to draw on these two cases to make a related argument about the need to consider long-term governance processes, reaching beyond the remits of classical site selection procedures. Rather than considering siting as the end point of a participatory process, it should be seen as a starting point. For that purpose, I will make use of the notion of hosting to emphasize the relationship between the repository and its host community. A relationship that demands a re-figuration of the geography and temporality of geological disposal. Hosting a geological disposal facility brings with it specific challenges, involving both social and technical adjustments, as well as reconfigurations of the boundary between them (Landstroem and Bergmans 2014).

  7. The Precise Orbit and the Challenge of Long Term Stability

    Science.gov (United States)

    Lemoine, Frank G.; Cerri, Luca; Otten, Michiel; Bertiger, William; Zelensky, Nikita; Willis, Pascal

    2012-01-01

    the future remains a source of error. Other sources of omission error include the geocenter for which no consensus model is as of yet applied. Although progress has been made in nonconservative force modeling through the use of detailed satellite-specific models, radiation pressure modeling, and atmospheric density modeling remain a potential source of orbit error. The longer term influence of variations in the solar and terrestrial radiation fields over annual and solar cycles remains principally untested. Also the long term variation in optical and thermal properties of the space vehicle surfaces would contribute to biases in the orbital frame if ignored. We review the status of altimetric precision orbit determination as exemplified by the recent computations undertaken by the different analysis centers for ERS, Envisat, TOPEX/Poseidon, Jason, Cryosat2 and HY2A, and we provide a perspective on the challenges for future missions such as the Jason-3, SENTINEL-3 and SWOT.

  8. Application of aging methods to estimate long term performance of secondary materials for road construction

    NARCIS (Netherlands)

    Akbarnejad, S.; Houben, L.J.M.; Molenaar, A.A.A.

    2012-01-01

    Long term performance of secondary materials is becoming a challenging aspect in road construction since due to their benefits they are being used on a large scale, but on the other hand their future behaviors are difficult to estimate. In this study, aging is proposed as a means of exploring the lo

  9. The challenges facing the long term interim storage

    International Nuclear Information System (INIS)

    In France electricity generation by means of commercial nuclear power plants has come to a point where it contributes to the national demand at a level of 80%. The safety performance of the production system has also reached a high level of both maturity and reliability taking advantage of the cumulative effect of a 30 years long learning experience and ever more stringent safety requirements. The policy to reprocess spent fuel has been overriding but no final decision has yet been made regarding the ultimate disposition of the waste streams. Although studies on deep geological disposal are ongoing, France is also looking at whether and under which conditions a long-term interim storage may provide an effective flexibility to the fuel cycle back-end. We discuss thereafter the needs and the paramount objectives of this latter R and D program. Results are being framed as potential guiding criteria for decision makers and various stakeholders. In first part, we propose a general analysis which emphasises that a long term interim storage is more than a classical nuclear facility because it explicitly requires long-lasting control and creates a burden for Society during many generations. Then, in second part, we offer an overview of the technical results from the R and D program as they stand at the time of writing. As an answer to the Government request, a strong emphasis has been put on this research for three years. Conclusion is an attempt to outline the societal context in which future decisions will have to be made. (author)

  10. Long term assurance of supply of raw materials

    International Nuclear Information System (INIS)

    The working group discussed the long-term assurance of uranium supply. A number of key questions is presented along with the answers given by representatives of 10 countries and by EC commission. Emphasis is laid on market stability and on the difficulties in adopting to sudden changes in the supply and demand situation

  11. Methodology of long term behaviour study of containment materials

    International Nuclear Information System (INIS)

    Here is the presentation of the papers shown in the colloquium on environment and ceramics; the Atomic Energy Commissariat (Cea) have been working for fifteen years on the long term behaviour of fission products glasses on very long periods, about several millions years. The method of studies is detailed. 2 refs

  12. Long-term Socioeconomic Challenges for Russia and Demand for New Technology

    OpenAIRE

    Alexander Apokin; Dmitry Belousov; Vladimir Salnikov(Laboratoire de Mathématiques Nicolas Oresme, Université de Caen Basse-Normandie, CS 14032, Bd. Maréchal Juin, BP 5186, 14032 Caen Cedex, France); Igor Frolov

    2015-01-01

    The primary long-term socio-economic challenges facing Russia – both global and country-specific in nature — drive demand for a range of technologies. We explore several groups of challenges, namely urbanization, demographic, socio-economic, the consequences of ageing, geopolitical, restricted access to key technological competences, climate change and its ecological consequences, as well as technological challenges largely associated with risks in ICT and biotech deve...

  13. Long-Term Technetium Interactions With Reducing Cementitious Materials

    International Nuclear Information System (INIS)

    Technetium is among the key risk drivers at the Saltstone Facility. The way that it is immobilized in this cementitious waste form is by converting its highly mobile Tc(VII) form to a much less mobile Tc(IV) form through reduction by the cement's blast furnace slag. This report includes a review of published data and experimental results dealing with Tc leaching from Portland cement waste forms. The objectives for the literature study were to document previous reports of Tc interactions with slag-containing cementitious materials. The objectives for the laboratory study were to measure Tc-saltstone Kd values under reducing conditions. From the literature it was concluded: (1) Spectroscopic evidence showed that when Tc(IV) in a slag-cement was exposed to an oxidizing environment, it will convert to the more mobile Tc(VII) species within a short time frame, 2.5 years. (2) SRS saltstone will reduce Tc(VII) in the absence of NaS or sodium dithionite in a reducing atmosphere. (3) Only trace concentrations of atmospheric oxygen (30 to 60 ppm O2; Eh 120 mV) at the high pH levels of cementitious systems is required to maintain Tc as Tc(VII). (4) Experimental conditions must be responsible for wide variability of measured Kd values, such that they are either very low, ∼1 mL/g, or they are very high ∼1000 mL/g, suggesting that Tc(VII) or Tc(IV) dominate the systems. Much of this variability appears to be the result of experimental conditions, especially direct controls of oxygen contact with the sample. (5) A field study conducted at SRS in the 1980s indicated that a slag-saltstone immobilized Tc for 2.5 years. Below background concentrations of Tc leached out of the slag-containing saltstone, whereas Tc leached out of the slag-free saltstone at the rate of nitrate loss. One possible explanation for the immobilization of Tc in this study was that the slag-saltstone maintained reducing conditions within the core of the 55-gallon sample, whereas in the small-scale lab

  14. 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).

  15. Structural cardboard: feasibility study of cardboard as a long-term structural material in architecture

    OpenAIRE

    Sekulic, Branko

    2013-01-01

    This study aims to evaluate the feasibility of cardboard as a long-term structural material in architecture. Recent experiments with cardboard in architecture are based on assemble of structural elements with existing cardboard products, which are afterwards put to load tests. Obtained results are usually in lack of coherence, making difficult to have precise prediction of structural behavior on a long-term basis. On the other hand, information that comes from packaging industry d...

  16. Long-term accessibility of e-books: challenges, obstacles, responsibilities

    Directory of Open Access Journals (Sweden)

    Maja Krtalić

    2015-07-01

    Full Text Available The traditional life cycle of books has gone through many changes in the digital environment - enough to start questioning the effects of such changes on the process of creating, publishing, distributing, reading and preserving books. This paper focuses on issues concerning the preservation and archiving of published authors’ works in the digital environment for the purpose of their long-term accessibility. The aim of this paper is to give an overview of relevant legal, technical, societal and organisational issues from which challenges, obstacles and responsibilities in ensuring long-term accessibility of e-books arise. Issues related to authorship, editions, changes in content, copyright and digital rights management, selection criteria for preservation, and preservation responsibility will be discussed, specifically focusing on libraries’ and publishers’ roles in this process. The paper is based on a literature review and content analysis aiming to answer two basic research questions: What specific characteristics of e-books influence their preservation possibilities? Who is responsible for long-term accessibility of e-books?

  17. Long Term Behavior of Composite Material Polyester-Wood Reinforced Glass Fiber

    Directory of Open Access Journals (Sweden)

    E.T. Olodo

    2013-06-01

    Full Text Available If the industry generally considers composite materials as potentially interesting, the lack of durability makes their often limited employment. Indeed, the design of composite structures often requires taking account of the long-term behaviour under various types of complex solicitations. This study is based on the development of a methodology for modeling the long term behavior under constant load for multilayer composite structures subjected to complex solicitations. This study is on the evaluation of the long-term behaviour of tri-layers glass/polyester-wood composite material. The objective is the evaluation of the long term strength of this material by the Goldenblat-Kopnov criterion. The studied model is an orthotropic tri layer plate of sandwich type with upper and lower flanges (skins are in composite material glass/polyester KACT-B and the intermediate layer (soul is pine wood. The character of loading of the plate is reflected in the model by the functions &sigmaik(&xi, &sigmamn(&xi which can be of different natures. For example, to load in the long term by constant constraints in time (the weight own element for example, we will have: &sigmaik = const &sigmamn = const. The results of the calculations show that, for this type of material, the conditions of strength to the dangerous points of the plate are met.

  18. Environmental bonds and the challenge of long-term carbon sequestration.

    Science.gov (United States)

    Gerard, David; Wilson, Elizabeth J

    2009-02-01

    The potential to capture carbon from industrial sources and dispose of it for the long-term, known as carbon capture and sequestration (CCS), is widely recognized as an important option to reduce atmospheric carbon dioxide emissions. Specifically, CCS has the potential to provide emissions cuts sufficient to stabilize greenhouse gas levels, while still allowing for the continued use of fossil fuels. In addition, CCS is both technologically-feasible and commercially viable compared with alternatives with the same emissions profile. Although the concept appears to be solid from a technical perspective, initial public perceptions of the technology are uncertain. Moreover, little attention has been paid to developing an understanding of the social and political institutional infrastructure necessary to implement CCS projects. In this paper we explore a particularly dicey issue--how to ensure adequate long-term monitoring and maintenance of the carbon sequestration sites. Bonding mechanisms have been suggested as a potential mechanism to reduce these problems (where bonding refers to financial instruments used to ensure regulatory or contractual commitments). Such mechanisms have been successfully applied in a number of settings (e.g., to ensure court appearances, completion of construction projects, and payment of taxes). The paper examines the use of bonding to address environmental problems and looks at its possible application to nascent CCS projects. We also present evidence on the use of bonding for other projects involving deep underground injection of materials for the purpose of long-term storage or disposal. PMID:18619728

  19. A United States perspective on long-term management of areas contaminated with radioactive materials.

    Science.gov (United States)

    Jones, C Rick

    2004-01-01

    The US has far-reaching and extensive experience in the long-term management of areas contaminated with radioactive materials. This experience base includes the Department of Energy's continued follow-up with Hiroshima and Nagasaki from the 1940s at the Radiological Effects Research Foundation in Hiroshima, Japan, the long-term management of the Marshall Islands Programme, the clean-up of the US nuclear weapons complex and the ongoing management of accident sites such as in Palomares, Spain. This paper discusses the lessons learnt and best practices gained from this far-reaching and extensive experience in the long-term management of areas contaminated with radioactive materials. PMID:15238660

  20. Long Term Stewardship Challenges at the St. Louis District FUSRAP Sites

    Energy Technology Data Exchange (ETDEWEB)

    Dell' Orco, L.; Chambers, D.

    2002-02-27

    Non-Federally owned radioactively contaminated sites in St. Louis, Missouri are currently being remediated by the St. Louis District Corps of Engineers under the Formerly Utilized Sites Remedial Action Program (FUSRAP). When FUSRAP remediation is complete, inaccessible soils which have levels of contamination greater than unrestricted use standards, will remain. The purpose of this paper is to document the initial challenges facing the project team during its development of the Long Term Stewardship plan for the management of these soils. These soils are located under buildings, roads, railroads and bridges. The Long Term Stewardship plan for the majority of the sites is being developed simultaneously with the remedy selection process. A living document, it will ultimately document the remedial action end state and location of inaccessible soils and implement the plan for ensuring these soils are not a threat to human health and the environment. Although these soils are protective in their current configuration, at some point in time, when activities such as maintenance, utility or property improvement occur, the soils will become accessible and need to be addressed by the federal government. Up until that point in time they will need to be effectively managed to ensure they remain protective. The St. Louis District is in the process of collaboratively developing this plan with its regulators, affected stakeholders and interested parties.

  1. 9975 Shipping Package Performance Of Alternate Materials For Long-Term Storage Application

    International Nuclear Information System (INIS)

    The Model 9975 shipping package specifies the materials of construction for its various components. With the loss of availability of material for two components (cane fiberboard overpack and Viton(regsign) GLT O-rings), alternate materials of construction were identified and approved for use for transport (softwood fiberboard and Viton(regsign) GLT-S O-rings). As these shipping packages are part of a long-term storage configuration at the Savannah River Site, additional testing is in progress to verify satisfactory long-term performance of the alternate materials under storage conditions. The test results to date can be compared to comparable results on the original materials of construction to draw preliminary conclusions on the performance of the replacement materials.

  2. A United States perspective on long term management of areas contaminated with radioactive materials

    International Nuclear Information System (INIS)

    Full text: The United States has far-reaching experience in the long-term management of areas contaminated with radioactive materials. The events resulting from the atmospheric testing of nuclear weapons in the Marshall Islands, follow-up from Hiroshima and Nagasaki, accidents, and the environmental cleanup of our weapons complex have resulted in an extensive body of lessons learned and best practices. The lack of trust created in the affected population, regardless of cause of the spread of radioactive material, creates the working environment for long-term management of the situation. The extent of advanced planning for such an event will define and bound your ultimate success in reaching a conclusion acceptable to the affected parties. The two key issues to be addressed in the long-term management of areas contaminated with radioactive materials are the two 'T's' - technical and trust. The technical issues to be resolved include: access to the affected area; infrastructure to support operations; local and imported staffing; health care for the affected population; and payment to name a few. In addressing the issue of trust it is critical to establish open, honest and inclusive communications and decision making with the affected population and stakeholders, with clear roles and responsibilities defined. Actions must be sensitive to local cultural issues and agreements reached with affected populations prior to actions being taken. Establishment of an alternative views resolution process helps build trust and allow actions to taken. Government to government relations and agreements must be established with an acceptance and understanding of the long term investment in time and resources needed. Planning ahead for such an eventuality and putting in place procedures, agreements and resources needed to address the technical and trust issues associated with the long-term management of areas contaminated with radioactive materials enhances success. (author)

  3. Long term integrity of spent fuel and construction materials for dry storage facilities

    International Nuclear Information System (INIS)

    In Japan, two dry storage facilities at reactor sites have already been operating since 1995 and 2002, respectively. Additionally, a large scale dry storage facility away from reactor sites is under safety examination for license near the coast and desired to start its operation in 2010. Its final storage capacity is 5,000tU. It is therefore necessary to obtain and evaluate the related data on integrity of spent fuels loaded into and construction materials of casks during long term dry storage. The objectives are: - Spent fuel rod: To evaluate hydrogen migration along axial fuel direction on irradiated claddings stored for twenty years in air; To evaluate pellet oxidation behaviour for high burn-up UO2 fuels; - Construction materials for dry storage facilities: To evaluate long term reliability of welded stainless steel canister under stress corrosion cracking (SCC) environment; To evaluate long term integrity of concrete cask under carbonation and salt attack environment; To evaluate integrity of sealability of metal gasket under long term storage and short term accidental impact force.

  4. Characterization of pollucite as a material for the long term storage of cesium-137

    International Nuclear Information System (INIS)

    Storage of nuclear waste requires materials which are thermodynamically stable. Pollucite (Cs2O . Al2O3 . 4SiO2) may be an acceptable material for the long-term storage of the purified 137CsCl. Pollucite is made at near theoretical yields when CsCl (or any cesium salt) reacts at about 9700K with a montmorillonite-containing clay. Pollucite dissolves in deionized water at rates which are less than 2 x 10-9 kg/(m2 . s) based on cesium. Microstructural analyses show that cesium reacts with the montmorillonite clay to form ill-defined pollucite crystals which contain low concentrations of the impurities found in the clay. Although further work needs to be done, pollucite is considered to be an excellent material for the long-term storage of 137Cs

  5. Characterization of pollucite as a material for long-term storage of cesium-137

    International Nuclear Information System (INIS)

    Pollucite (Cs2O.Al2O3.4SiO2) may be an acceptable material for the long-term storage of purified 137CsCl. Pollucite is made at near theoretical yields when CsCl (or any cesium salt) reacts at approx. = 9700K with a montmorillonite-containing clay. Pollucite dissolves in deionized water at rates -7 kg/(m2 d) based on cesium. Microstructural analyses showed that cesium reacts with montmorillonite clay to form ill-defined pollucite crystals containing low concentrations of the impurities found in the clay. Although further work needs to be done, pollucite is considered to be an excellent materials for the long-term storage of 137Cs

  6. China’s Rapidly Aging Population Creates Policy Challenges In Shaping A Viable Long-Term Care System

    OpenAIRE

    Feng, Zhanlian; Liu, Chang; Guan, Xinping; Mor, Vincent

    2012-01-01

    In China, formal long-term care services for the large aging population have increased to meet escalating demands as demographic shifts and socioeconomic changes have eroded traditional elder care. We analyze China’s evolving long-term care landscape and trace major government policies and private-sector initiatives shaping it. Although home and community-based services remain spotty, institutional care is booming with little regulatory oversight. Chinese policy makers face mounting challenge...

  7. Grand Challenges for Biological and Environmental Research: A Long-Term Vision

    Energy Technology Data Exchange (ETDEWEB)

    Arkin, A.; Baliga, N.; Braam, J.; Church, G.; Collins, J; ; Cottingham, R.; Ecker, J.; Gerstein, M.; Gilna, P.; Greenberg, J.; Handelsman, J.; Hubbard, S.; Joachimiak, A.; Liao, J.; Looger, L.; Meyerowitz, E.; Mjolness, E.; Petsko, G.; Sayler, G.; Simpson, M.; Stacey, G.; Sussman, M.; Tiedje, J.; Bader, D.; Cessi, P.; Collins, W.; Denning, S.; Dickinson, R.; Easterling, D.; Edmonds, J.; Feddema, J.; Field, C.; Fridlind, A.; Fung, I.; Held, I.; Jackson, R.; Janetos, A.; Large, W.; Leinen, M.; Leung, R.; Long, S.; Mace, G.; Masiello, C.; Meehl, G.; Ort, D.; Otto-Bliesner, B.; Penner, J.; Prather, M.; Randall, D.; Rasch, P.; Schneider, E.; Shugart, H.; Thornton, P.; Washington, W.; Wildung, R.; Wiscombe, W.; Zak, D.; Zhang, M.; Bielicki, J.; Buford, M.; Cleland, E.; Dale, V.; Duke, C.; Ehleringer, J.; Hecht, A.; Kammen, D.; Marland, G.; Pataki, D.; Riley, M. Robertson, P.; Hubbard, S.

    2010-12-01

    outcomes and behaviors of complex biological and environmental systems, leading to robust solutions for DOE missions and strategic goals. In March 2010, the Biological and Environmental Research Advisory Committee held the Grand Challenges for Biological and Environmental Research: A Long-Term Vision workshop to identify scientific opportunities and grand challenges for BER science in the coming decades and to develop an overall strategy for drafting a long-term vision for BER. Key workshop goals included: (1) Identifying the greatest scientific challenges in biology, climate, and the environment that DOE will face over a 20-year time horizon. (2) Describing how BER should be positioned to address those challenges. (3) Determining the new and innovative tools needed to advance BER science. (4) Suggesting how the workforce of the future should be trained in integrative system science. This report lays out grand research challenges for BER - in biological systems, climate, energy sustainability, computing, and education and workforce training - that can put society on a path to achieve the scientific evidence and predictive understanding needed to inform decision making and planning to address future energy needs, climate change, water availability, and land use.

  8. Long-term behaviour of high-temperature steels and other high-temperature materials

    International Nuclear Information System (INIS)

    This volume includes 17 lectures with the following topics: 1) Latest results of current creep rupture tests of the working group 'Creep-Resistant Steels on Creep-Resistant Cast-Steel Grades'. 2) Creep-resistant cast steel GS-17 CrMoV 5 11 - contribution to the behaviour of simulated heat-affected-zone structures. 3) Metallographic follow-up check-ups of samples from welded joints of the steel X 20 CrMoV 12 1 after subjection to creep stress. 4) Long-term toughness behaviour of steels containing 3 to 3.5% NiCrMoV. 5) Creep-fatigue behaviour of a steel containing 1% CrMoNiV in the long-term range. 6) Long-term creep behaviour of the alloy S-590 up to 200,000 h. Creep equations for gas turbine materials. 8) Behaviour of heat-resisting steels and nickel base alloys subjected to varying creep stress. 9) Assessment of the creep behaviour of welded joints differently produced of materials of the type Alloy 800. 10) Investigations on monocrystalline superalloys for turbine blades. 11) Structure investigation on high-temperature nickel base alloys with consideration to previous impacts. 12) The influence of the grain boundary segregation of phosphorus on the tensile strength and the H-induced stress crack corrosion of Ni-20% Cr. 13) Mechanical behaviour of nickel base alloys for screw connections of steam turbines. 14) Investigations into the residual durability of creep-resistant bolts subjected to long-term operating stress. 15) Crack growth of intercrystalline cracks of the steel X 6 CrNi 18 11 subjected to creep stress. 16) Evaluation of fracture mechanics parameters for the description of creep crack growth. 17) Calculations of the deformation behaviour of pipe bends with finite elements in the creep range. (orig./MM)

  9. Porous materials based on cenospheres for immobilization and long-term isolation of liquid radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    A.G. Anshits; T.A. Vereshchagina; O.M. Sharonova; N.N. Anshits; N.G. Vasilieva; M.V. Burdin; I.D. Zykova; S.V. Podoinitsyn [Institute of Chemistry and Chemical Technology (Russian Federation)

    2003-07-01

    Cenospheres, or hollow silica-alumina microspheres, is one of the valuable components within coal combustion fly ash. One of the promising areas of cenosphere application is conditioning liquid radioactive waste (LRW) to reduce waste volumes and to transform waste into a solid form suitable for transport and/or storage and/or long-term disposal. It was found that chemical composition of cenosphere material is similar to the composition of a granite rock in the Earth lithosphere. Due to this property in combination with the high mechanical strength, spherical design, thermal and chemical stability, cenospheres are considered to be the suitable material for LRW long-term isolation in the form of stable mineral-like silicaalumina ceramics (feldspars, pyroxene, polucite, and nepheline). Two types of engineering forms for the cenosphere material have been developed, such as molded block porous material (porous matrices) and microspherical porous material, which can be activated by impregnation with additives trapping radionuclides (Cs-137, Sr-90). Different glass crystalline materials based on the cenospheres for immobilization and longterm isolation of liquid radioactive waste will be presented in the report including porous matrices of 40-90% open-cell porosity, microspherical porous glasses and specific sorbents. Variants to use these materials for conditioning LRW and reducing their volume by a factor of 1500 are discussed. 14 refs., 4 figs., 1 tab.

  10. High-temperature MEMS Heater Platforms: Long-term Performance of Metal and Semiconductor Heater Materials

    Directory of Open Access Journals (Sweden)

    Theodor Doll

    2006-04-01

    Full Text Available Micromachined thermal heater platforms offer low electrical power consumptionand high modulation speed, i.e. properties which are advantageous for realizing non-dispersive infrared (NDIR gas- and liquid monitoring systems. In this paper, we report oninvestigations on silicon-on-insulator (SOI based infrared (IR emitter devices heated byemploying different kinds of metallic and semiconductor heater materials. Our resultsclearly reveal the superior high-temperature performance of semiconductor over metallicheater materials. Long-term stable emitter operation in the vicinity of 1300 K could beattained using heavily antimony-doped tin dioxide (SnO2:Sb heater elements.

  11. Challenges in long-term operation of nuclear power plants - Implications for regulatory bodies

    International Nuclear Information System (INIS)

    Nuclear power reactors have become a major source of electricity supply in many countries in the past half a century. Based on this experience, many operators have sought and have received authorisation for long-term operation, whereby plant operation continues beyond the period considered in the design of the plant. Acceptance of a nuclear power plant for extended service should be based on assurance of the fitness of the plant and the operator for safe and reliable operation over the entire period considered for long-term operation. This assurance may be obtained by establishment of appropriate regulatory requirements, specification of goals and safety levels and regulatory assessment and oversight of the operator's programme for long-term operation. The operators and regulators should ensure that operating experience continues to be evaluated during long-term operation to ensure that any relevant lessons are effectively applied. Other considerations for assurance of safe operation are effective management of ageing, possible need for safety improvements, application of lessons learnt from operating experience, evaluation of environmental impacts, adequate staff resources and performance, review of security at the plant, action in response to emerging issues, and openness and transparency in the transition to long-term operation. Even though most of these considerations are addressed under the regulatory framework that applies to the initial operating period, additional regulatory activities in these areas may be necessary for long-term operation. Although there can be significant differences in regulatory approaches used by different countries for evaluating acceptability of long-term operation, there is general agreement on the purposes and goals of the regulatory reviews. An authorisation of long-term operation could involve a licence renewal or a periodic safety review or an approach that melds elements of both. This report presents guidance that is intended

  12. The impact of materials selection on long-term activation in fusion power plants

    International Nuclear Information System (INIS)

    Neutron-induced transmutation of materials in a D-T fusion power plant will give rise to the potential for long-term activation. To ensure that the attractive safety and environmental characteristics of fusion power are not degraded, careful design choices are necessary. An aim of optimising power plant design must be to minimise both the level of activation and the total volume of active material that might ultimately be categorised as waste requiring disposal. Materials selection is central to this optimisation. In this paper we assess the influence of materials choices for a power plant on the waste volume and the potential to clear (i.e. remove from regulatory control) and recycle material. Although the use of low activation materials in regions of high neutron flux is an important part of the strategy to minimise the level of activation, different choices may result from a strategy aimed at minimising the volume of active waste

  13. Long-term radiation effects on commercial cable-insulating materials irradiated at CERN

    International Nuclear Information System (INIS)

    Long-term irradiation damage tests have been carried out on a variety of flexible cable-insulating materials offered to CERN by different European cable manufacturers. Tensile test specimens were exposed for a maximum of three years in high-level radiation areas of the Super Proton Synchrotron (SPS) and for comparison at high dose rates in a nuclear reactor. The degradation of mechanical properties after irradiation in air depends not only on the total absorbed dose, but also on the dose rate for most of these polymer compounds. These dose-rate effects vary between material types and for different compounds. The results presented here illustrate the difference in radiation damage between short-term and long-term irradiation conditions in a typical service application for the various materials tested. They also allow safety factors to be estimated for the extrapolation of the limiting exposure in service from accelerated material tests in the range of dose rates covered. A discussion of the available models of the dose-rate effects results in a conservative estimate for extrapolation to low dose rates from measured values at intermediate dose rates of the order of 0.1 Gy/s. Based on short-term irradiation tests only, the safety factors to be applied depend on the end-point criterion used, and may vary between 1 and 10 for the range of dose rates and materials considered here. (orig.)

  14. Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

    International Nuclear Information System (INIS)

    The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria. - Highlights: • Long-term exposure of waterproof materials to radon and soil bacteria. • Changes in mechanical properties shown. • Major changes in diffusion coefficient of radon found for PVC

  15. LONG-TERM CORROSION TESTING OF CANDIDATE MATERIALS FOR HIGH-LEVEL RADIOACTIVE WASTE CONTAINMENT

    International Nuclear Information System (INIS)

    Preliminary results are presented from the long-term corrosion test program of candidate materials for the high-level radioactive waste packages that would be emplaced in the potential repository at Yucca Mountain, Nevada. The present waste package design is based on a multi-barrier concept having an inner container of a corrosion resistant material and an outer container of a corrosion allowance material. Test specimens have been exposed to simulated bounding environments that may credibly develop in the vicinity of the waste packages. Corrosion rates have been calculated for weight loss and crevice specimens, and U-bend specimens have been examined for evidence of stress corrosion cracking (SCC). Galvanic testing has been started recently and initial results are forthcoming. Pitting characterization of test specimens will be conducted in the coming year. This test program is expected to continue for a minimum of five years so that long-term corrosion data can be determined to support corrosion model development, performance assessment, and waste package design

  16. Effect of Clickers "versus" Online Homework on Students' Long-Term Retention of General Chemistry Course Material

    Science.gov (United States)

    Gebru, Misganaw T.; Phelps, Amy J.; Wulfsberg, Gary

    2012-01-01

    This study reports the effects of student response systems (clickers) "versus" online homework on students' long-term retention of General Chemistry I course material. Long-term content retention was measured by a comprehensive yearlong American Chemical Society (ACS) GC97 exam administered seven months after students had completed the General…

  17. Integrated care for childhood epilepsy: ongoing challenges and lessons for other long-term conditions

    OpenAIRE

    Bali, A; Cross, H.; Lakhanpaul, M.; Hargreaves, D.; Cowman, J; Power, M; Dunkley, C.

    2016-01-01

    Epilepsy care has been identified as a major global issue – and there are many recognised concerns in the UK for children and young people with the condition. A proposed new model could help to increase multi-sector integration, facilitate better outcomes, and offer lessons for improving care of other long-term conditions.

  18. Inventory extension considerations for long-term storage at the nuclear materials storage facility

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory is in the process of modifying its nuclear materials storage facility to a long-term storage configuration. In support of this effort, we examined technical and administrative means to extend periods between physical inventories. Both the frequency and sample size during a physical inventory could significantly impact required sizing of the non-destructive assay (NDA) laboratory as well as material handling capabilities. Several options are being considered, including (1) treating each storage location as a separate vault, (2) minimizing the number of items returned for quantitative analysis by optimizing the use of in situ confirmatory measurements, and (3) utilizing advanced monitoring technologies. Careful consideration of these parameters should allow us to achieve and demonstrate safe and secure storage while minimizing the impact on facility operations and without having to increase the size of the NDA laboratory beyond that required for anticipated shipping and receiving activities

  19. Long-term environmental effects and flight service evaluation of composite materials

    Science.gov (United States)

    Dexter, H. Benson

    1987-01-01

    Results of a NASA-Langley sponsored research program to establish the long term effects of realistic flight environments and ground based exposure on advanced composite materials are presented. The effects of moisture, ultraviolet radiation, aircraft fuels and fluids, sustained stress, and fatigue loading are reported. Residual strength and stiffness as a function of exposure time and exposure location are reported for seven different material systems after 10 years of worldwide outdoor exposure. Flight service results of over 300 composite components installed on rotorcraft and transport aircraft are included. Over 4 million total component flight hours were accumulated on various aircraft since initiation of flight service in 1973. Service performance, maintenance characteristics, and residual strength of numerous composite components installed on commercial and military aircraft are reported as a function of flight hours and years in service. Residual strength test results of graphite/epoxy spoilers with 10 years of worldwide service and over 28,000 flight hours are reported.

  20. Composition and long-term safety of salt deposits as candidate sites for toxic material dumping

    International Nuclear Information System (INIS)

    For the evaluation of the long-term safety of toxic material dumps in salt bodies, it is necessary to understand also the potential processes in the rock and to evaluate their effects on the dump. The scientific fundamentals are observations on the geological situation as well as the mineralogical and chemical composition of the rock in which the dump is planned to be constructed. Knowledge on the existing geological, mineralogical and physico-chemical conditions of formation and transformation of evaporite allow a quantitative interpretation of mineral reactions and material transfers, which have taken place in the geological past. This working principle is independent of location. It is exemplarily applied to the Gorleben salt dome. (orig./DG)

  1. A review of the LICON methodology for predicting the long term creep rupture strength of materials

    International Nuclear Information System (INIS)

    In the late 1990s, an advanced iso-thermal extrapolation approach referred to as the LICON methodology was developed in a European Brite Euram project to predict the long term creep rupture behaviour of new generation steels. This methodology relies on multiaxial loading conditions to accelerate the onset of long time creep damage formation into the short time rupture regime. The LICON method therefore enables the prediction of long time uniaxial creep rupture strengths using the results from several short duration multiaxial creep crack initiation tests in conjunction with the outcome of a mechanical analysis for the adopted multiaxial specimen geometry. This paper briefly reviews the latest findings concerning application of the LICON method for different types of materials. Successful applications of the method for long time creep rupture strength predictions of advanced martensitic 9%Cr pipe steels (i.e. P91, E911 and P92), a low alloy ferritic steel (i.e. 1CrMoV) and a dissimilar metal weld (1CrMoV/Inconel 617/Inconel 625) have been successfully achieved during the last 15 years. These evaluations have well proven the applicability of the LICON concept for different types of engineering materials while at the same time emphasising the need for i) consideration of appropriate mechanical analysis tools for the assessment of the multiaxial geometry used for creep crack initiation tests dependent on the type of material/structure under investigation and ii) consideration of the complex multiaxial stress state developing within the constituent parts of weldments, even within a uniaxial testpiece. - Highlights: • LICON is an approach for predicting long term uniaxial creep strength from short duration multi-axial creep tests. • Recommendations are summarised for application of the LICON method for different material-conditions. • Successful application of the method for 9% and 1%Cr steels and a dissimilar metal weld has been reviewed

  2. Long-term accessibility of e-books: challenges, obstacles, responsibilities

    OpenAIRE

    Maja Krtalić; Damir Hasenay

    2015-01-01

    The traditional life cycle of books has gone through many changes in the digital environment - enough to start questioning the effects of such changes on the process of creating, publishing, distributing, reading and preserving books. This paper focuses on issues concerning the preservation and archiving of published authors’ works in the digital environment for the purpose of their long-term accessibility. The aim of this paper is to give an overview of relevant legal, technical, societal an...

  3. Regulating the long-term safety of geological disposal of radioactive waste: practical issues and challenges

    International Nuclear Information System (INIS)

    Regulating the long-term safety of geological disposal of radioactive waste is a key part of making progress on the radioactive waste management issue. A survey of member countries has shown that differences exist both in the protection criteria being applied and in the methods for demonstrating compliance, reflecting historical and cultural differences between countries which in turn result in a diversity of decision-making approaches and frameworks. At the same time, however, these differences in criteria are unlikely to result in significant differences in long-term protection, as all the standards being proposed are well below levels at which actual effects of radiological exposure can be observed and a range of complementary requirements is foreseen. In order to enable experts from a wide range of backgrounds to debate the various aspects of these findings, the NEA organised an international workshop in November 2006 in Paris, France. Discussions focused on diversity in regulatory processes; the basis and tools for assuring long-term protection; ethical responsibilities of one generation to later generations and how these can be discharged; and adapting regulatory processes to the long time frames involved in implementing geological disposal. These proceedings include a summary of the viewpoints expressed as well as the 22 papers presented at the workshop. (author)

  4. The challenge of long-term participatory repository governance. Lessons learned for high level radioactive waste and spent fuel

    International Nuclear Information System (INIS)

    Voluntaristic siting procedures for deep geological repositories are becoming increasingly common; they reconfigure the relationship of repositories and society in ways that have implications for the long-term governance of these facilities. This paper identifies three challenges emerging in relation to this question: principles of monitoring, repository content, and facility closure. This paper discusses them in a comparison with similar challenges being addressed in Belgian partnerships founded to facilitate the siting and design of a low- and intermediate level short lived waste repository. The empirical exploration confirms the importance of securing stakeholder engagement throughout the repository lifecycle, for which there is a need to develop knowledge about how to encourage long-term democratic governance systems.

  5. Long-term stability of earthen materials in contact with acidic tailings solutions

    International Nuclear Information System (INIS)

    The objectives of the studies documented in this report were to use experimental and geochemical computer modeling tools to assess the long-term environmental impact of leachate movement from acidic uranium mill tailings. Liner failure (i.e., an increase in the permeability of the liner material) was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 years. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The high clay materials tested appear suitable for lining tailings impoundment ponds. The decreases in permeability are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. In conclusion the same mineralogical changes and contaminant reactions predicted by geochemical modeling and observed in laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 4 year history of acid attack

  6. Long-term strength data of the material 1.4876

    International Nuclear Information System (INIS)

    By multilinear regression analyses the main influencing parameters and their quantitative effect on the creep strength of the material 1.4876 could be shown. It could be explained by these analyses why the mean values of the creep strength in the evaluation presented for materials according to the specifications of the VdTUeV material performance sheets 412 and 434 did not show the clear differentiation which has been supposed up to now. On account of the extended level of knowledge changed limited values of the chemical composition, the heat treatment and the grain size were indicated in the specification proposals A 800 HT and A 800 NT which differentiate between the material application in the creep range at temperatures of ≥7000C (A 800 HT) and ≤7000C (A 800 NT). As a special case of the proposal A 800 NT the specification proposal A 800 DE is given for HTR steam generation pipes following the THTR specifications. The long-term characteristic values of strength and their ranges were determined as a basis of the design values for all specification proposals. (orig.)

  7. Long-term performance of passive materials for removal of ozone from indoor air.

    Science.gov (United States)

    Cros, C J; Morrison, G C; Siegel, J A; Corsi, R L

    2012-02-01

    The health effects associated with exposure to ozone range from respiratory irritation to increased mortality. In this paper, we explore the use of three green building materials and an activated carbon (AC) mat that remove ozone from indoor air. We studied the effects of long-term exposure of these materials to real environments on ozone removal capability and pre- and post-ozonation emissions. A field study was completed over a 6-month period, and laboratory testing was intermittently conducted on material samples retrieved from the field. The results show sustained ozone removal for all materials except recycled carpet, with greatest ozone deposition velocity for AC mat (2.5-3.8 m/h) and perlite-based ceiling tile (2.2-3.2 m/h). Carbonyl emission rates were low for AC across all field sites. Painted gypsum wallboard and perlite-based ceiling tile had similar overall emission rates over the 6-month period, while carpet had large initial emission rates of undesirable by-products that decayed rapidly but remained high compared with other materials. This study confirms that AC mats and perlite-based ceiling tile are viable surfaces for inclusion in buildings to remove ozone without generating undesirable by-products. PRACTICAL IMPLICATIONS The use of passive removal materials for ozone control could decrease the need for, or even render unnecessary, active but energy consuming control solutions. In buildings where ozone should be controlled (high outdoor ozone concentrations, sensitive populations), materials specifically designed or selected for removing ozone could be implemented, as long as ozone removal is not associated with large emissions of harmful by-products. We find that activated carbon mats and perlite-based ceiling tiles can provide substantial, long-lasting, ozone control. PMID:21777291

  8. Long-term metallurgical stability and materials integrity of high temperature plants

    International Nuclear Information System (INIS)

    In the pressure vessels for high temperature use, the technique of accurately forecasting the creep characteristics of the structural materials being used over the period of using plants is demanded. For ensuring the soundness by evaluating the long term, high temperature stability of individual material characteristics, attention should be paid to creep strength and deformation at high temperature and high pressure, creep fatigue due to the superposition of cyclic thermal stress, the properties of welded parts and the characteristics affected by the environment of use. In this report, the way of thinking about the evaluation of these characteristics is described. Three stages of creep deformation are explained. The time until creep fracture is dependent on stress and temperature. The strength balance between crystal grains and grain boundaries is discussed. The evaluation of creep fatigue taking the relaxation of thermal stress into account is explained. In parent metal, heat-affected zone and weld metal, the plasticity and creep properties are not uniform. The evaluation of welded parts is discussed. The compatibility of vessel materials with used pressure media and the confirmation that corrosion and embrittlement do not occur at grain boundaries are indispensable. Also the effect of the impurities in media should be grasped. (K.I.)

  9. Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

    Science.gov (United States)

    Navratilova Rovenska, Katerina; Jiranek, Martin; Kokes, Pavel; Wasserbauer, Richard; Kacmarikova, Veronika

    2014-01-01

    The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria.

  10. Challenges Associated With Managing Suicide Risk in Long-Term Care Facilities

    Science.gov (United States)

    O'Riley, Alisa; Nadorff, Michael R.; Conwell, Yeates; Edelstein, Barry

    2016-01-01

    Little information about suicidal ideation and behavior in long-term care (LTC) facilities is available. Nonetheless, the implementation of the Minimum Data Set 3.0 requires that LTC facilities screen their residents for suicide risk and have protocols in place to effectively manage residents’ responses. In this article, the authors briefly discuss the risk factors of suicide in the elderly and the problems that suicidal ideation and behavior pose in the LTC environment. The authors explain issues that arise when trying to manage suicide risk in the elderly LTC population with general, traditional approaches. These inherent issues make it difficult to develop an effective protocol for managing suicide risk in LTC facilities, leading the authors to propose their own framework for assessing and managing suicide risk in the LTC setting.

  11. Investigations on materials for small Stirling refrigerators in long-term operation

    International Nuclear Information System (INIS)

    Work is being carried out world-wide on the development of refrigerators with low power requirements for the cooling of high-temperature superconductors and other cryoelectronic components. Due to its good efficiency factor, the well-known Stirling principle is particularly suitable for this purpose, but the increasing contamination of the working gases needed for the process which is caused by outgassing and the permeability to gas of the epoxide resins and other materials generally used makes it prone to interference over long periods of operation. For the first time, DURAN glass has been taken as a regenerator material and tested with successful results over a long period of operation in a small Stirling refrigerator designed and constructed for this purpose. A commercial double-membrane compressor which was also to be tested in long-term operation was converted into a dynamic pressure source and used as a refrigerator component. With this refrigerator, it was possible to maintain a temperature of 34 K over a continous period of operation of 77 days. Parallel to this, mass spectrometric permeation measurements were carried out on a compressor membrane made of VITON in which the water vapour of the atmosphere dominated. (orig.)

  12. Long-term high temperature fatigue properties of new structural materials for nuclear reactors

    International Nuclear Information System (INIS)

    This study aims to evaluate fatigue strength properties at long-term high temperature of 316FR steels developed for structural materials applied to high temperature components in the 21st Century such as Demonstration FBR, and to obtain design indicators on high temperature strength properties arranged on chemical composition and grain size on a base of 316FR stainless steels. As results obtained by the study, it could be found that as a result of systematic examinations on temperatures and strain rate dependence on symmetric triangular strain waveform of 316FR steels between 500 to 600degC, temperature of fatigue life, and strain rate dependence can be integrally evaluated by a parameter analysis method developed by authors and life prediction at ultra low strain rate of less than 10-6/s and its experimental verification could be carried out. And, it was also found that as a result of evaluation of creep fatigue life and creep rupture properties on materials prepared by controlling main elements such as carbon, nitrogen, manganese, chromium, and performing grain refining through thermomechanical treatment under aiming to further upgrade creep fatigue life properties of 316FR steels, it was clarified to enable to carry out about three times of life extension by combined effects of low carbon (0.002 wt-%) and grain refining (7 in grain number). (G.K.)

  13. Long-term research challenges in wind energy – a research agenda by the European Academy of Wind Energy

    DEFF Research Database (Denmark)

    van Kuik, G. A. M.; Peinke, Joachim; Nijssen, R.;

    2016-01-01

    eawe document takes a longer-term perspective, addressing the scientific knowledge base that is required to develop wind energy beyond the applications of today and tomorrow. In other words, this long-term research agenda is driven by problems and curiosity, addressing basic research and fundamental...... knowledge in 11 research areas, ranging from physics and design to environmental and societal aspects. Because of the very nature of this initiative, this document does not intend to be permanent or complete. It shows the vision of the experts of the eawe, but other views may be possible. We sincerely hope......The European Academy of Wind Energy (eawe), representing universities and institutes with a significant wind energy programme in 14 countries, has discussed the long-term research challenges in wind energy. In contrast to research agendas addressing short- to medium-term research activities, this...

  14. Long Term Behaviour of Cementitious Materials in the Korean Repository Environment

    International Nuclear Information System (INIS)

    The safe management of radioactive waste is a national task required for sustainable generation of nuclear power and for energy self-reliance in Korea. After the selection of the final candidate site for low- and intermediate-level waste (LILW) disposal in Korea, a construction and operation license was issued for the Wolsong LILW Disposal Center (WLDC) for the first stage of disposal. Underground silo type disposal has been determined for the initial phase. The engineered barrier system of the disposal silo consists of waste packages, disposal containers, backfills, and a concrete lining. Main objective of our study in this IAEA-CRP is to investigate closure concepts and cementitious backfill materials for the closure of silos. For this purpose, characterisation of cementitious materials, development of silo closure concept, and evaluation of long-term behaviour of cementitious materials, including concrete degradation in repository environment, have been carried out. The overall implementation plan for the CRP comprises performance testing for the physic-chemical properties of cementitious materials, degradation modelling of concrete structures, comparisons of performance for silo closure options, radionuclide transport modelling (considering concrete degradation in repository conditions), and the implementation of an input parameter database and quality assurance for safety/performance assessment. In particular, the concrete degradation modelling study has been focused on the corrosion of reinforcement steel induced by chloride attack, which was of primary concern in the safety assessment of the WLDC. A series of electrochemical experiments were conducted to investigate the effect of dissolved oxygen, pH, and Cl on the corrosion rate of reinforcing steel in a concrete structure saturated with groundwater. Laboratory-scale experiments and a thermodynamic modelling were performed to understand the porosity change of cement pastes, which were prepared using

  15. Modelling Long-Term Evolution of Cementitious Materials Used in Waste Disposal

    International Nuclear Information System (INIS)

    This report summarizes the latest developments at SCK-CEN in modelling long-term evolution of cementitious materials used as engineered barriers in waste disposal. In a first section chemical degradation of concrete during leaching with rain and soil water types is discussed. The geochemical evolution of concrete thus obtained forms the basis for all further modelling. Next we show how the leaching model is coupled with a reactive transport module to determine leaching of cement minerals under diffusive or advective boundary conditions. The module also contains a simplified microstructural model from which hydraulic and transport properties of concrete may be calculated dynamically. This coupled model is simplified, i.e. abstracted prior to being applied to large-scale concrete structures typical of a near-surface repository. Both the original and simplified models are then used to calculate the evolution of hydraulic, transport, and chemical properties of concrete. Characteristic degradation states of concrete are further linked to distribution ratios that describe sorption onto hardened cement via a linear and reversible sorption process. As concrete degrades and pH drops the distribution ratios are continuously updated. We have thus integrated all major chemical and physical concrete degradation processes into one simulator for a particular scale of interest. Two simulators are used: one that can operate at relatively small spatial scales using all process details and another one which simulates concrete degradation at the scale of the repository but with a simplified cement model representation. (author)

  16. Diagnostic chelation challenge with DMSA: a biomarker of long-term mercury exposure?

    OpenAIRE

    Frumkin, H; Manning, C C; Williams, P. L.; Sanders, A; Taylor, B.B.; Pierce, M; Elon, L; Hertzberg, V S

    2001-01-01

    Chelation challenge testing has been used to assess the body burden of various metals. The best-known example is EDTA challenge in lead-exposed individuals. This study assessed diagnostic chelation challenge with dimercaptosuccinic acid (DMSA) as a measure of mercury body burden among mercury-exposed workers. Former employees at a chloralkali plant, for whom detailed exposure histories were available (n = 119), and unexposed controls (n = 101) completed 24-hr urine collections before and afte...

  17. Long term test of buffer material. Final Report on the pilot parcels

    International Nuclear Information System (INIS)

    The 'Long Term Test of Buffer Material' (LOT) series at the Aespoe HRL aims at checking models and hypotheses for a bentonite buffer material under conditions similar to those in a KBS3 repository. The test series comprises seven test parcels, which are exposed to repository conditions for 1, 5 and 20 years. This report concerns the two completed pilot tests (1-year tests) with respect to construction, field data and laboratory results. Four research groups were engaged in this part of the project working on physical properties - mineralogy, cation diffusion, bacteria and copper corrosion, respectively. The experimental layout was to place parcels containing heater, central copper tube, pre-compacted bentonite blocks and instruments in vertical boreholes in crystalline rock. The heaters were used for simulating the decay power from spent nuclear fuel at standard KBS3 conditions (S1 parcel, 90 deg C) and to give adverse conditions (A1 parcel, 130 deg C). The latter was used in order to accelerate possible processes. Temperature, total pressure, water pressure and water content were measured during the heating period. The two pilot tests were terminated after approximately 12 months of heating, and the parcels were extracted by overlapping core drilling outside the original borehole. The entire 4.5 m long S1-parcel with approximately 20 cm rock cover was successfully lifted in one piece from the rock, whereas the central part of the A1 parcel was lost during drilling. The upper and lower parts were however retrieved. Reference and exposed bentonite material were analysed with respect to physical properties (triaxial, beam and oedometer tests), and to mineralogical properties (XRD, CEC, ICP-AES and SEM analyses) according to a defined test program. Some precipitation, mainly gypsum, was found in the warmest part of the parcels, and the only unpredicted change was minor uptake of Cu into the clay matrix. An overarching conclusion is that no degrading processes, with

  18. Long term test of buffer material. Final Report on the pilot parcels

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Sanden, Torbjoern; Johannesson, Lars-Erik [Clay Technology AB, Lund (Sweden); Eriksen, Trygve E; Jansson, Mats; Wold, Susanna [Royal Inst. of Tech., Stockholm (Sweden); Pedersen, Karsten; Motamedi, Mehrdad [Goeteborg Univ. (Sweden); Rosborg, Bo [Studsvik Material AB, Nykoeping (Sweden)

    2000-12-01

    The 'Long Term Test of Buffer Material' (LOT) series at the Aespoe HRL aims at checking models and hypotheses for a bentonite buffer material under conditions similar to those in a KBS3 repository. The test series comprises seven test parcels, which are exposed to repository conditions for 1, 5 and 20 years. This report concerns the two completed pilot tests (1-year tests) with respect to construction, field data and laboratory results. Four research groups were engaged in this part of the project working on physical properties - mineralogy, cation diffusion, bacteria and copper corrosion, respectively. The experimental layout was to place parcels containing heater, central copper tube, pre-compacted bentonite blocks and instruments in vertical boreholes in crystalline rock. The heaters were used for simulating the decay power from spent nuclear fuel at standard KBS3 conditions (S1 parcel, 90 deg C) and to give adverse conditions (A1 parcel, 130 deg C). The latter was used in order to accelerate possible processes. Temperature, total pressure, water pressure and water content were measured during the heating period. The two pilot tests were terminated after approximately 12 months of heating, and the parcels were extracted by overlapping core drilling outside the original borehole. The entire 4.5 m long S1-parcel with approximately 20 cm rock cover was successfully lifted in one piece from the rock, whereas the central part of the A1 parcel was lost during drilling. The upper and lower parts were however retrieved. Reference and exposed bentonite material were analysed with respect to physical properties (triaxial, beam and oedometer tests), and to mineralogical properties (XRD, CEC, ICP-AES and SEM analyses) according to a defined test program. Some precipitation, mainly gypsum, was found in the warmest part of the parcels, and the only unpredicted change was minor uptake of Cu into the clay matrix. An overarching conclusion is that no degrading

  19. HDR Opportunities and Challenges Beyond the Long-Term Flow Test

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, David

    1992-03-24

    The long term flow test (LTFT) of the worlds largest, deepest, and hottest hot dry rock (HDR) reservoir currently underway at Fenton Hill, NM, is expected to demonstrate that thermal energy can be mined from hot rock within the earth on a sustainable basis with minimal water consumption. This test will simulate the operations of a commercial facility in some ways, but it will not show that energy from HDR can be produced at a variety of locations with different geological settings. Since the Fenton Hill system was designed as a research facility rather than strictly for production purposes, it will also not demonstrate economic viability, although it may well give indications of system modifications needed for economic HDR operations. A second production site must be constructed, ideally under the direction of the private geothermal community, to begin the process of proving that the vast HDR resources can be accessed on a worldwide scale. This facility should be designed and engineered to produce and market energy at competitive prices. At the same time, a wide variety of techniques to advance the state-of-the-art of HDR technology must be pursued to develop this infant technology rapidly to its maximum potential. A number of design and operational techniques have been conceived which may lead to improved economics in HDR systems. After careful technical and economic scrutiny, those showing merit should be vigorously pursued. Finally, research and development work in areas such as reservoir interrogation, and system modeling must be accelerated to increase the competitiveness and geographical applications of HDR and the geothermal industry in general. This paper addresses the above issues in detail and outlines possible paths to future prosperity for the commercial geothermal industry.

  20. Getting out of the house: the challenges mothers face when their children have long-term care needs.

    Science.gov (United States)

    Yantzi, Nicole M; Rosenberg, Mark W; McKeever, Patricia

    2007-01-01

    In most industrialised countries, the care needs of those who are sick, disabled and frail are increasingly met in peoples' homes. One of the implications of this shift in the site of care is that individuals with long-term care needs and their family care providers experience social and spatial isolation. Many are housebound and most face considerable challenges in getting out of the house. This paper illuminates these challenges as they are experienced by mothers of children with long-term care needs, and the resulting isolation and disconnection that they experience. Eleven semistructured interviews were conducted in two regions of Ontario, Canada. Grounded theory informed the analysis of the mothers' accounts of their experiences of getting out of the house. The present findings are derived from a larger investigation of the meanings and experiences of the home as a place of caring for families with children who have long-term care needs. Secondary analysis of the data found that three main challenges restricted the mothers' abilities to leave their houses. Mothers experienced difficulties getting out of the house when they attempted to leave with the child, and when the child was left with an alternative care provider. Physical challenges were associated with the work and planning required in moving the child's equipment and supplies, meticulous planning of the outing within the daily schedule, and navigating barriers in the built and natural environments. Social challenges reflected the lack of people within the mothers' social network of family and friends who have the knowledge and expertise to care for the child. Service challenges resulted from the gaps between the policies and practices of paid respite, and the conditions that must be satisfied in order for mothers to be able and/or willing to leave the house. The authors also examined the reasons why some of the mothers worked from home, and the strategies that they used to get out of the house for

  1. Characterization of representative materials in support of safe, long term storage of surplus plutonium in DOE-STD-3013 containers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul H [Los Alamos National Laboratory; Narlesky, Joshua E [Los Alamos National Laboratory; Worl, Laura A [Los Alamos National Laboratory; Gillispie, Obie W [Los Alamos National Laboratory

    2010-01-01

    The Surveillance and Monitoring Program (SMP) is a joint LANL/SRS effort funded by DOE/EM to provide the technical basis for the safe, long-term storage (up to 50 years) of over 6 metric tons of plutonium stored in over 5000 DOE-STD-3013 containers at various facilities around the DOE complex. The majority of this material is plutonium that is surplus to the nuclear weapons program, and much of it is destined for conversion to mixed oxide fuel for use in US nuclear power plants. The form of the plutonium ranges from relatively pure metal and oxide to very impure oxide. The performance of the 3013 containers has been shown to depend on moisture content and on the levels, types and chemical forms of the impurities. The oxide materials that present the greatest challenge to the storage container are those that contain chloride salts. The chlorides (NaCl, KCl, CaCl{sub 2}, and MgCl{sub 2}) range from less than half of the impurities present to nearly all the impurities. Other common impurities include oxides and other compounds of calcium, magnesium, iron, and nickel. Over the past 15 years the program has collected a large body of experimental data on over 60 samples of plutonium chosen to represent the broader population of materials in storage. This paper will summarize the characterization data, including the origin and process history, particle size, surface area, density, calorimetry, chemical analysis, moisture analysis, prompt gamma, gas generation and corrosion behavior.

  2. Characterization of Representative Materials in Support of Safe, Long Term Storage of Surplus Plutonium in DOE-STD-3013 Containers

    Energy Technology Data Exchange (ETDEWEB)

    Narlesky, Joshua E. [Los Alamos National Laboratory; Stroud, Mary Ann [Los Alamos National Laboratory; Smith, Paul Herrick [Los Alamos National Laboratory; Wayne, David M. [Los Alamos National Laboratory; Mason, Richard E. [MET-1: ACTINIDE PROCESSING SUPPORT; Worl, Laura A. [Los Alamos National Laboratory

    2013-02-15

    The Surveillance and Monitoring Program is a joint Los Alamos National Laboratory/Savannah River Site effort funded by the Department of Energy-Environmental Management to provide the technical basis for the safe, long-term storage (up to 50 years) of over 6 metric tons of plutonium stored in over 5,000 DOE-STD-3013 containers at various facilities around the DOE complex. The majority of this material is plutonium that is surplus to the nuclear weapons program, and much of it is destined for conversion to mixed oxide fuel for use in US nuclear power plants. The form of the plutonium ranges from relatively pure metal and oxide to very impure oxide. The performance of the 3013 containers has been shown to depend on moisture content and on the levels, types and chemical forms of the impurities. The oxide materials that present the greatest challenge to the storage container are those that contain chloride salts. Other common impurities include oxides and other compounds of calcium, magnesium, iron, and nickel. Over the past 15 years the program has collected a large body of experimental data on 54 samples of plutonium, with 53 chosen to represent the broader population of materials in storage. This paper summarizes the characterization data, moisture analysis, particle size, surface area, density, wattage, actinide composition, trace element impurity analysis, and shelf life surveillance data and includes origin and process history information. Limited characterization data on fourteen nonrepresentative samples is also presented.

  3. What comes after active remediation: Long term challenges at uranium mining and milling sites

    International Nuclear Information System (INIS)

    Remediation plans for uranium mining and milling sites often tacitly assume that a certain amount of maintenance has to be carried out for almost unlimited time spans. The paper highlights the relevant issues and attempts to outline the conceptual, management and technical problems and challenges of maintaining institutional control over possibly hundreds or even thousands of years. (author)

  4. Nursing Assistants for Long-Term Care. Performance-Based Instructional Materials.

    Science.gov (United States)

    Indiana Univ., Bloomington. Vocational Education Services.

    This guide is intended to assist students enrolled in programs to train nursing assistants for employment in an Indiana long-term health care facility. The first part discusses human development (growth, aging, and dying); communication with residents; sexuality; legal, ethical, and professional responsibilities of nursing assistants in long-term…

  5. Nuclear Waste Disposal and Strategies for Predicting Long-Term Performance of Material

    International Nuclear Information System (INIS)

    Ceramics have been an important part of the nuclear community for many years. On December 2, 1942, an historic event occurred under the West Stands of Stagg Field, at the University of Chicago. Man initiated his first self-sustaining nuclear chain reaction and controlled it. The impact of this event on civilization is considered by many as monumental and compared by some to other significant events in history, such as the invention of the steam engine and the manufacturing of the first automobile. Making this event possible and the successful operation of this first man-made nuclear reactor, was the use of forty tons of UO2. The use of natural or enriched UO2 is still used today as a nuclear fuel in many nuclear power plants operating world-wide. Other ceramic materials, such as 238Pu, are used for other important purposes, such as ceramic fuels for space exploration to provide electrical power to operate instruments on board spacecrafts. Radioisotopic Thermoelectric Generators (RTGs) are used to supply electrical power and consist of a nuclear heat source and converter to transform heat energy from radioactive decay into electrical power, thus providing reliable and relatively uniform power over the very long lifetime of a mission. These sources have been used in the Galileo spacecraft orbiting Jupiter and for scientific investigations of Saturn with the Cassini spacecraft. Still another very important series of applications using the unique properties of ceramics in the nuclear field, are as immobilization matrices for management of some of the most hazardous wastes known to man. For example, in long-term management of radioactive and hazardous wastes, glass matrices are currently in production immobilizing high-level radioactive materials, and cementious forms have also been produced to incorporate low level wastes. Also, as part of nuclear disarmament activities, assemblages of crystalline phases are being developed for immobilizing weapons grade plutonium, to

  6. Nuclear Waste Disposal and Strategies for Predicting Long-Term Performance of Material

    Energy Technology Data Exchange (ETDEWEB)

    Wicks, G G

    2001-03-28

    Ceramics have been an important part of the nuclear community for many years. On December 2, 1942, an historic event occurred under the West Stands of Stagg Field, at the University of Chicago. Man initiated his first self-sustaining nuclear chain reaction and controlled it. The impact of this event on civilization is considered by many as monumental and compared by some to other significant events in history, such as the invention of the steam engine and the manufacturing of the first automobile. Making this event possible and the successful operation of this first man-made nuclear reactor, was the use of forty tons of UO2. The use of natural or enriched UO2 is still used today as a nuclear fuel in many nuclear power plants operating world-wide. Other ceramic materials, such as 238Pu, are used for other important purposes, such as ceramic fuels for space exploration to provide electrical power to operate instruments on board spacecrafts. Radioisotopic Thermoelectric Generators (RTGs) are used to supply electrical power and consist of a nuclear heat source and converter to transform heat energy from radioactive decay into electrical power, thus providing reliable and relatively uniform power over the very long lifetime of a mission. These sources have been used in the Galileo spacecraft orbiting Jupiter and for scientific investigations of Saturn with the Cassini spacecraft. Still another very important series of applications using the unique properties of ceramics in the nuclear field, are as immobilization matrices for management of some of the most hazardous wastes known to man. For example, in long-term management of radioactive and hazardous wastes, glass matrices are currently in production immobilizing high-level radioactive materials, and cementious forms have also been produced to incorporate low level wastes. Also, as part of nuclear disarmament activities, assemblages of crystalline phases are being developed for immobilizing weapons grade plutonium, to

  7. Factors challenging our ability to detect long-term trends in ocean chlorophyll

    Directory of Open Access Journals (Sweden)

    C. Beaulieu

    2012-11-01

    Full Text Available Global climate change is expected to affect the ocean's biological productivity. The most comprehensive information available about the global distribution of contemporary ocean primary productivity is derived from satellite data. Large spatial patchiness and interannual to multidecadal variability in chlorophyll a concentration challenges efforts to distinguish a global, secular trend given satellite records which are limited in duration and continuity. The longest ocean color satellite record comes from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, which failed in December 2010. The Moderate Resolution Imaging Spectroradiometer (MODIS ocean color sensors are beyond their originally planned operational lifetime. Successful retrieval of a quality signal from the current Visible Infrared Imager Radiometer Suite (VIIRS instrument, or successful launch of the Ocean Land Colour Instrument (OLCI in 2013 will hopefully extend the ocean color time series and increase the potential for detecting trends in ocean productivity in the future. Alternatively, a potential discontinuity in the time series of ocean chlorophyll a, introduced by a change of instrument without overlap and opportunity for cross-calibration, would make trend detection even more challenging. In this paper, we demonstrate that there are a few regions with statistically significant trends over the ten years of SeaWiFS data, but at a global scale the trend is not large enough to be distinguished from noise. We quantify the degree to which red noise (autocorrelation especially challenges trend detection in these observational time series. We further demonstrate how discontinuities in the time series at various points would affect our ability to detect trends in ocean chlorophyll a. We highlight the importance of maintaining continuous, climate-quality satellite data records for climate-change detection and attribution studies.

  8. Factors challenging our ability to detect long-term trends in ocean chlorophyll

    Directory of Open Access Journals (Sweden)

    C. Beaulieu

    2013-04-01

    Full Text Available Global climate change is expected to affect the ocean's biological productivity. The most comprehensive information available about the global distribution of contemporary ocean primary productivity is derived from satellite data. Large spatial patchiness and interannual to multidecadal variability in chlorophyll a concentration challenges efforts to distinguish a global, secular trend given satellite records which are limited in duration and continuity. The longest ocean color satellite record comes from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, which failed in December 2010. The Moderate Resolution Imaging Spectroradiometer (MODIS ocean color sensors are beyond their originally planned operational lifetime. Successful retrieval of a quality signal from the current Visible Infrared Imager Radiometer Suite (VIIRS instrument, or successful launch of the Ocean and Land Colour Instrument (OLCI expected in 2014 will hopefully extend the ocean color time series and increase the potential for detecting trends in ocean productivity in the future. Alternatively, a potential discontinuity in the time series of ocean chlorophyll a, introduced by a change of instrument without overlap and opportunity for cross-calibration, would make trend detection even more challenging. In this paper, we demonstrate that there are a few regions with statistically significant trends over the ten years of SeaWiFS data, but at a global scale the trend is not large enough to be distinguished from noise. We quantify the degree to which red noise (autocorrelation especially challenges trend detection in these observational time series. We further demonstrate how discontinuities in the time series at various points would affect our ability to detect trends in ocean chlorophyll a. We highlight the importance of maintaining continuous, climate-quality satellite data records for climate-change detection and attribution studies.

  9. Engineering challenges to the long term operation of the international space station

    Science.gov (United States)

    Kelly, Thomas; Albert, Thomas; Levin, George M.

    2001-03-01

    The U.S. Congress has maintained an intense interest in the ISS program since its inception. In the Appropriations Act of 1997, the Senate of the United States included language directing National Aeronautics and Space Administration (NASA) to have the National Research Council (NRC) under take a study that evaluates the engineering challenges posed by extravehicular activity (EVA) requirements, United States and non-United States space launch requirements, the potential need to upgrade or replace equipment and components after Assembly Complete, and the requirement to decommission and disassemble the facility. NASA and the NRC decided the focus should be on the anticipated challenges in the continuous operation and maintenance of the ISS after assembly of the on-orbit facility has been completed. This would encompass the operational years, from late 2004 (if the current schedule holds) to 2020 - 2025. This executive summary overviews the results of this NRC study. it focuses on the U.S. operation of the ISS after assembly Complete, including cooperative efforts by the United States and Russia. The paper summaries the primary findings and recommendations in each of the areas considered during this two-year NRC study.

  10. Challenges in long-term mechanical circulatory support and biological replacement of the failing heart.

    Science.gov (United States)

    Lala, Anuradha; Joyce, Emer; Groarke, John D; Mehra, Mandeep R

    2014-01-01

    The burden of advanced heart failure is reaching epidemic proportions. Generally considered for cardiac transplantation, patients often cannot receive this therapy because of their advanced age, comorbidity or the scarcity of donors. Most transplants are concentrated in North America and Europe, with the average center performing fewer than 20 annual transplants. A search for nonbiological means of cardiac support has led to the advent of mechanical circulatory support (MCS), a concept now entrenched as a bridge to transplantation or, for those ineligible for transplantation, as lifetime therapy. In this review we discuss contemporary challenges posed by the changing epidemiology of cardiac transplant and MCS and outline the basis for an understanding of the future of this important therapeutic stance.   PMID:24451651

  11. Long term storage of virus templated fluorescent materials for sensing applications

    Science.gov (United States)

    Seetharam, Raviraja N.; Szuchmacher Blum, Amy; Soto, Carissa M.; Whitley, Jessica L.; Sapsford, Kim E.; Chatterji, Anju; Lin, Tianwei; Johnson, John E.; Guerra, Charles; Satir, Peter; Ratna, Banahalli R.

    2008-03-01

    Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications.

  12. Long term storage of virus templated fluorescent materials for sensing applications

    International Nuclear Information System (INIS)

    Wild type, mutant, and chemically modified Cowpea mosaic viruses (CPMV) were studied for long term preservation in the presence and absence of cryoprotectants. Viral complexes were reconstituted and tested via fluorescence spectroscopy and a UV/vis-based RNase assay for structural integrity. When viruses lyophilized in the absence of cryoprotectant were rehydrated and RNase treated, UV absorption increased, indicating that the capsids were damaged. The addition of trehalose during lyophilization protected capsid integrity for at least 7 weeks. Measurements of the fluorescence peak maximum of CPMV lyophilized with trehalose and reconstituted also indicate that the virus remained intact. Microarray binding assays indicated that CPMV particles chemically modified for use as a fluorescent tracer were intact and retained binding specificity after lyophilization in the presence of trehalose. Thus, we demonstrate that functionalized CPMV nanostructures can be stored for the long term, enabling their use in practical sensing applications

  13. Targeting thrombin long-term after an acute coronary syndrome: Opportunities and challenges.

    Science.gov (United States)

    De Caterina, Raffaele; Goto, Shinya

    2016-06-01

    Patients after an acute coronary syndrome (ACS) are at increased risk of recurrent thrombotic events, justifying the search for additional antithrombotic treatments. The pathophysiology of ACS involves arterial thrombus formation, in turn occurring because of a combination of platelet activation and fibrin formation, with thrombin playing a key role in both. Antiplatelet therapy, targeting the thromboxane pathway and the ADP P2Y12 receptor has been widely accepted for secondary prevention after an ACS. Now, data from recent clinical trials in such patients also encourage the pursuit of inhibiting thrombin formation or thrombin-mediated platelet activation in addition to antiplatelet therapy. This "triple pathway inhibition", including inhibition of thrombin activity or thrombin receptor(s), is currently an option in pure ACS, but already a must in the setting of ACS accompanied by atrial fibrillation (AF), where anticoagulants have been shown to be much more effective than antiplatelet agents in preventing stroke. We here discuss the challenges of managing combined thrombin activity or receptor inhibition and antiplatelet therapy in all such patients. Translating this into practice still requires further studies and patient tailoring to fully exploit its potential. PMID:26994821

  14. Clay minerals in aqueous alteration of meteorites as analogue materials for the long term disposal of nuclear waste

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Introduction: The long term disposal of nuclear waste provides a big challenge for material science. The material waste has to be stored safely for at least 105 years. The nuclides are embedded as particles in silica glass, which is conditioned in steel containers, which again are emplaced in a clay-rich environment. Since it is difficult to estimate the long-term stability of materials in such a time frame, certain types of meteorites are used as an analogue material. Precursor materials of meteorites formed 4.56 Gy ago in the protoplanetary disk, a disk of gas and dust particles around the young sun. One of the first components to be formed was the chondrules. These spherical, silicate-rich objects formed by the quenching of silicate droplets in the protoplanetary disk. Chondrules mainly consist of silicates like olivine and pyroxene, metal and sulfide grains. These phases are often embedded in a silicate-rich glass, the mesostasis. Chondrules and other components accreted together with finer particles to form larger parent bodies, planetesimals. On some of these bodies, accreted ices melted as result of the heat created by the decay of short-lived nuclides. In the following aqueous alteration phase circulating fluids altered the materials on these bodies to varying degrees. This probably lasted more than 1 my, so meteoritic materials allow to study alteration and corrosion in a much longer time frame than possible in laboratory. Abundant larger metal grains (up to several 100 μm in size) can help to estimate corrosion processes of the steel containment. These components are embedded in a phyllosilicate-rich matrix, similar to the clay material in which the waste packages are emplaced. CR chondrites are a group of meteorites that show alteration over the whole range from type 3 (pristine, unaltered material) to 1 (completely hydrated), thus allowing the investigation of all steps in corrosion of the materials

  15. Frictional contact problems for electro-viscoelastic materials with long-term memory, damage, and adhesion

    Directory of Open Access Journals (Sweden)

    Tedjani Hadj Ammar

    2014-10-01

    Full Text Available We consider a quasistatic contact problem between two electro-viscoelastic bodies with long-term memory and damage. The contact is frictional and is modelled with a version of normal compliance condition and the associated Coulomb's law of friction in which the adhesion of contact surfaces is taken into account. We derive a variational formulation for the model and prove an existence and uniqueness result of the weak solution. The proof is based on arguments of evolutionary variational inequalities, a classical existence and uniqueness result on parabolic inequalities, and Banach fixed point theorem.

  16. Emerging trends in the finance and delivery of long-term care: public and private opportunities and challenges.

    Science.gov (United States)

    Cohen, M A

    1998-02-01

    A number of key trends are emerging in long-term care related to financing, new models of service delivery, and shifts in consumer expectations and preferences. Taken together, changes occurring in these areas point to a rapidly transforming long-term care landscape. Financing responsibility is shifting away from the federal government to states, individuals, and their families; providers are integrating and managing acute and long-term care services and adding new services to the continuum of care; and consumers are thinking more seriously about how to plan and pay for their future care needs, as well as how to independently navigate the long-term care system. PMID:9499656

  17. Long term Integrity of Spent Fuel and Construction Materials and Behaviour of Components for Dry Storage Facilities

    International Nuclear Information System (INIS)

    In Japan, two dry storage facilities at TEPCO and JAPCO sites have been in operation since 1995 and 2002 respectively. The TEPCO dry storage facility was damaged by a Tsunami attack on 11th March 2011. The casks stored in the facility have since been moved to an onsite temporary cask custody area; after confirmation of the integrity of casks. On the other hand, the Tsunami did not attack the dry storage facility at the JAPCO site. The integrity of the storage building and the casks were maintained. In addition, an off-site centralized dry storage facility has been constructed at Mutsu City. Operation of the storage facility is pending a safety re-examination against new safety regulations. Its final storage capacity will be 5000 t(U) and the storage period is up to 50 years. To support storage operations, it is therefore necessary to obtain and evaluate data on the integrity of spent fuels and cask construction materials during long term dry storage. Objectives: Construction materials for dry storage facilities: • To evaluate long-term reliability of welded stainless steel canisters under stress corrosion cracking (SCC) environment, including the critical salt density deposited on the canister to initiate SCC, monitoring, prevention, and the mitigation method of SCC; • To detect and analyze the cover gas leak from canisters; • To evaluate integrity of sealability of metal gasket under long term storage; • To evaluate influence of the vibration on sealing performance of the ageing gasket

  18. Long-term behaviour of high-temperature steels and other high-temperature materials. Langzeitverhalten warmfester Staehle und Hochtemperaturwerkstoffe

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    This volume includes 17 lectures with the following topics: (1) Latest results of current creep rupture tests of the working group 'Creep-Resistant Steels on Creep-Resistant Cast-Steel Grades'. (2) Creep-resistant cast steel GS-17 CrMoV 5 11 - contribution to the behaviour of simulated heat-affected-zone structures. (3) Metallographic follow-up check-ups of samples from welded joints of the steel X 20 CrMoV 12 1 after subjection to creep stress. (4) Long-term toughness behaviour of steels containing 3 to 3.5% NiCrMoV. (5) Creep-fatigue behaviour of a steel containing 1% CrMoNiV in the long-term range. (6) Long-term creep behaviour of the alloy S-590 up to 200,000 h. Creep equations for gas turbine materials. (8) Behaviour of heat-resisting steels and nickel base alloys subjected to varying creep stress. (9) Assessment of the creep behaviour of welded joints differently produced of materials of the type Alloy 800. (10) Investigations on monocrystalline superalloys for turbine blades. (11) Structure investigation on high-temperature nickel base alloys with consideration to previous impacts. (12) The influence of the grain boundary segregation of phosphorus on the tensile strength and the H-induced stress crack corrosion of Ni-20% Cr. (13) Mechanical behaviour of nickel base alloys for screw connections of steam turbines. (14) Investigations into the residual durability of creep-resistant bolts subjected to long-term operating stress. (15) Crack growth of intercrystalline cracks of the steel X 6 CrNi 18 11 subjected to creep stress. (16) Evaluation of fracture mechanics parameters for the description of creep crack growth. (17) Calculations of the deformation behaviour of pipe bends with finite elements in the creep range. (orig./MM).

  19. Effect of ageing under gamma radiations on the long term behaviour of bitumen material

    International Nuclear Information System (INIS)

    The referential scenario considered for bituminized waste drums is an intermediate storage likely to be followed by a deep geological disposal. Under geological disposal conditions, when site will be re-saturated with water and containers will be corroded, the main phenomenon likely to alter bituminized waste is linked to the presence of water. During intermediate storage conditions, drums will be submitted to the effect of irradiation, and for the external part of the wasteform to the effect of oxidation by surrounding air. The combined effect of air and radiation may increase bitumen oxidation. In further disposal conditions, alteration phenomena of drums will concern aged drums. The aim of these studies dealing with ageing, is to characterise the effect of alteration factors such as irradiation and radio-oxidation on the potential release of radionuclides from bituminized waste in disposal conditions. Radio-oxidation depends on: - the diffusion of O2 in the matrix (diffusion coefficient, solubility), -the intensity of radiation (dose rate), -the time of exposure to radiations. Low dose rates of radiation, near realistic dose rates are here investigated in order to characterise the effect of ageing phenomena on the long term behaviour of bitumen properties. Results concern Infra-red characterization of oxidized bitumen, gases evolution and diffusion of water. The evolution of the thickness of the oxidized layer with the dose and the dose rate for bitumen sample can be deduced from profiles of oxidised compounds concentration obtained with FTIR (Fourier transformed Infrared Spectroscopy). (authors)

  20. 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

  1. A long-term laboratory test on staining susceptibility of esthetic composite resin materials

    NARCIS (Netherlands)

    S. Ardu; V. Braut; D. Gutemberg; I. Krejci; D. Dietschi; A.J. Feilzer

    2010-01-01

    Objective: To evaluate the color stability of composite resin types designed for esthetic anterior restorations when continuously exposed to various staining agents. Method and Materials: Thirty-six disk-shaped specimens were made of each of 12 composite materials (1 microfilled and 11 hybrid compos

  2. Long-term development directions of PVD/CVD coatings deposited onto sintered tool materials

    Directory of Open Access Journals (Sweden)

    A.D. Dobrzańska-Danikiewicz

    2011-06-01

    Full Text Available Purpose: The purpose of this article is to evaluate strategic development perspectives of physical/ chemical vapour deposition of monolayer, multilayer and gradient coatings onto sintered tool materials with cemented carbides, cermets and tool ceramics substrates. The coating type was adopted as the criterion for technology division, thus obtaining eight technology groups for carried out research.Design/methodology/approach: In the framework of foresight-materials science research: a group of matrices characterising technology strategic position was created, materials science experiments using high-class specialised equipment were conducted and technology roadmaps were prepared.Findings: High potential and attractiveness were shown of the analysed technologies against the environment, as well as a promising improvement of mechanical and functional properties as a result of covering with the PVD/CVD coatings.Research limitations/implications: Research pertaining to covering sintered tool materials with the PVD/CVD coatings is part of a bigger research project aimed at selecting, researching and characterizing priority innovative material surface engineering technologies.Practical implications: The presented results of experimental materials science research prove the significant positive impact of covering with the PVD/CVD coatings on the structure and mechanical properties of sintered tool materials, which leads to the justification of their including into the set of priority innovative technologies recommended for application in industrial practice.Originality/value: The advantage of the article are results of comparative analysis of sintered tools materials with different types of coatings deposited in the PVD/CVD processes together with the recommended strategies of conduct, strategic development tracks and roadmaps of these technologies.

  3. Long-term ageing tests on glazing materials for solar collectors; Langzeit-Alterungsuntersuchung an Abdeckungsmaterialien fuer thermische Sonnenkollektoren

    Energy Technology Data Exchange (ETDEWEB)

    Ruesch, F.; Brunold, S.; Haeuselmann, T.; Frank, E.; Frei, U.

    2008-02-15

    This report made by the Swiss Institute for Solar Technology at the University of Applied Sciences in Rapperswil, Switzerland, for Swiss Federal Office of Energy (SFOE) takes a look at the results of a project that investigated the long-term behaviour of glazing materials for solar collectors. The locations tested and their associated meteorological data are presented and the tests made concerning the optical characteristics of several different types of glazing are discussed. Soiling and degradation are also looked at. An overview of the solar transmission of the various materials is presented. Details on the various materials such as glass, polymethyl metacrylate (PMMA), polycarbonate (PC), fluorised plastics, unsaturated polyester (UP), polyvinyl chloride (PVC) and polyethylene terephthalate (PET) are presented.

  4. Investigations into the Effects of Long-Term Seawater Exposure on Graphite/Epoxy Composite Materials

    OpenAIRE

    Sloan, Forrest E.

    1991-01-01

    The investigations documented here were intended to determine whether graphite-fiber-reinforced plastics can survive the highly aggressive seawater environment when used as structural materials in advanced ocean engineering designs. Two general effects of seawater exposure were identified as potentially life-limiting phenomena. The first effect is a weakening of the fiber-to-matrix bond caused by exposure of the interface to moisture. The second effect is the establishment of an electrolyte (...

  5. External insulation with cellular plastic materials:thermal properties, long term stability and fire properties

    OpenAIRE

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

    External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems. This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time s...

  6. Evaluation and prediction of long-term environmental effects on non metallic materials

    Science.gov (United States)

    Papazian, H.

    1985-01-01

    Predictive modeling of environmental conditions on nonmetallic materials was studied. The in-flight data of the atomic oxygen reaction with carbon and osmium, the laboratory and in-flight data of the atomic oxygen reaction with polymeric films and the effect of electron irradiation on the rates of oxidation are discussed. No information is found that can be used to model such effects on composites. The effects of the space environment on thermal control coatings and its effect on the space station are examined.

  7. Evaluation and prediction of long term space environmental effects on non-metallic materials

    Science.gov (United States)

    Shepic, J. A.

    1980-01-01

    The effects of prolonged spacecraft materials were determined and the results compared with predicted behavior. The adhesion and dielectric properties of poly-thermaleze and therm-amid magnet wire insulation were studied. The tensile properties of Lexan, polyurethane, polyethelyne, lucite, and nylon were studied well as the flexure and tensile characteristic of Adlock 851, a phenolic laminate. The volume resistivity of Cho-seal, a conductive elastomer was also a examined. Tables show the time exposed at thermal vacuum, and the high, low, and average MPA and KSI.

  8. Study on applying technology of utilizing long-term materials for corrosion facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Chul; Park, Young Kyu; Baek, Soo Gon; Lee, Jong Sub [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Park, Yong Soo [Yonsei University, Seoul (Korea, Republic of); Hwang, Won Suk [Inha University (Korea, Republic of); Song, Rhyo Seong [Hankuk Aviation, University (Korea, Republic of)

    1996-12-31

    Nowadays, as the pollution in seawater is escalating rapidly because of fast industrialization, corrosion rate and repairing frequency of seawater facilities in power plant are increasing. In addition, new construction is restricted with narrow limits due to the deterioration of social condition, asking for extension of facility life and repairing frequency. The objectives of this study are to select the appropriate new high corrosion resistance materials and apply them in the field, to make the corrosion data base in accordance with their usage conditions and to predict the remaining life and optimum repairing period by predicting the life of facilities. (author). 77 refs., 54 figs.

  9. Long term behaviour of composite materials. Application for the qualification of pressure vessels

    International Nuclear Information System (INIS)

    The behaviour of carbon fibre reinforced epoxy pressure vessels and the prevision of their operational lifetime in different conditions in use have been studied. We have tried to foresee the behaviour of complex laminate structures from the mechanical properties of unidirectional laminates. A simple degradation model was initially developed to predict first ply failure and the burst pressure of the vessels. The results obtained from this model were then compared with the experimental values by testing a series of small spherical composite vessels. The damage was detected by the acoustic emission technique. Afterwards, the effects of the time, temperature, stress and moisture content on the mechanical behaviour of the material were examined. Based on the classical time-temperature superposition principle, dynamic test results have been used to analyse the durability of the material. The rheological model with parabolic elements obtained by a transposition of the Cole-Cole dielectric model was used for the evaluation of the linear viscoelastic properties of material. However, the concept of linearity is only applicable at low applied stresses. At high levels of stress the behaviour of composite materials can become highly nonlinear and the applicability of linear principles is questionable. A quadratic non-linear model was developed. The creep functions obtained by the linear and non-linear analysis were then introduced into the degradation model mentioned above the predict the lifetime of the vessel. The degradation model proposed was a useful tool allowing a rapid evaluation of the vessel performance and the improvement in the design of vessels. Nevertheless, because of its simplicity, it had limitations. For the case of spherical vessels with polar opening, the model proved inadequate; the local discontinuities, such as that of a fill tube was not considered. An exact application of the initial model required the effects of the stress concentration around the tube

  10. Long-term behaviour of heat-resistant steels and high-temperature materials

    International Nuclear Information System (INIS)

    This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, 14 MoV 6 3, 10 Cr Mo 910 and GS-17 Cr Mo V 5 11 (K. Niel et al.); Determining the creep crack behaviour of heat resistant steels with samples of different geometry (K. Maile, R. Tscheuschner). (orig.,/MM)

  11. Long term testing of materials for tube shielding, stage 2; Laangtidsprovning av tubskyddsmaterial, etapp 2

    Energy Technology Data Exchange (ETDEWEB)

    Norling, Rikard; Hjoernhede, Anders; Mattsson, Mattias

    2012-02-15

    Circulating Fluidized Bed (CFB) boilers are commonly used for combustion of biomass and are used to some extent for Waste-to-Energy (WtE) plants as well. The superheaters of the latter are for obvious reasons more prone to suffer from high temperature corrosion caused by the corrosive species in the fuel, mainly chlorides. Frequently the final (hottest) superheater is positioned in the loop seal, where the circulating bed material is returned to the furnace after being separated from the flue gas by a cyclone. The environment in the loop seal is relatively free of chlorides, since these primarily follow the flue gas into the convection pass. Hence, higher steam temperature can be allowed without excessive damage to the final superheater. On the other hand the superheaters, which are located in the convection pass, are more exposed to the corrosive species of the flue gas. Further, they are eroded by particles entrained in the gas flow. Particles and condensing gaseous species are to a large extent deposited on the superheaters, which limits the heat transfer and promotes corrosion. The deposits are regularly removed e.g. by soot blowers. The pressurized steam from soot blowers causes additional erosion damage to that caused by entrained particles. It shall be noted that the actual damage is caused by a combined mechanism of erosion and corrosion denoted erosion-corrosion, which usually results in dramatically accelerated wear. To avoid excessive erosion damage on the superheater tubes the first tube row of each bundle is protected by tube shielding. In its simplest form the shields are made from a steel sheet that has been bent into a semi-circular half-cylinder shell. These shields are attached onto the wind-side of the tubes by hangers. A typical material for tube shielding is the austenitic high temperature resistant stainless steel 253MA. Life of tube shielding depends on numerous factors such as boiler design, superheater location, fuel and operating

  12. Nuclear Materials Diversion Safety and the Long-term Future of Nuclear Energy

    International Nuclear Information System (INIS)

    Primarily due to irresponsible cold war politics of nuclear weapon countries nuclear proliferation situation is little short of getting out of control. In addition to five nominal nuclear weapon countries there are at present at least three more nuclear weapon countries and several countries with nuclear weapon potential. Non-proliferation treaty (NPT), signed in 1970, has been recognized by most non-nuclear weapon countries as unjust and ineffective. After the initial, deliberate, nuclear weapon developments of five nominal nuclear weapon countries, subsequent paths to nuclear weapons have been preceded by nominal peaceful use of nuclear energy. Uranium enrichment installations as well as reprocessing installations in non-nuclear weapon countries are the weakest spots of fuel cycle for diversion of nuclear materials either by governments or by illicit groups. An energy scenario, which would, by the end of century, replace the large part of fossil fuels use through extension of present nuclear practices, would mean very large increase in a number of such installations, with corresponding increase of the probability of diversion of nuclear materials. Such future is not acceptable from the point of view of proliferation safety. Recent events make it clear, that it cannot be accepted from the requirements of nuclear terrorism safety either. Nuclear community should put it clearly to their respective governments that the time has come to put general interest before the supposed national interest, by placing all enrichment and reprocessing installations under full international control. Such internationalization has a chance to be accepted by non-nuclear weapon countries, only in case should it apply to nuclear weapon countries as well, without exception. Recent terrorist acts, however horrible they were, are child,s play compared with possible acts of nuclear terrorism. Nuclear energy can be made proliferation safe and diversion of nuclear materials safe, and provide

  13. The long-term effects of the micrometeoroid and orbital debris environments on materials used in space

    International Nuclear Information System (INIS)

    The long-term effects of the orbital debris and micrometeoroid environments on materials that are current candidates for use on space vehicles are discussed. In addition, the limits of laboratory testing to determine these effects are defined and the need for space-based data is delineated. The impact effects discussed are divided into primary and secondary surfaces. Primary surfaces are those that are subject to erosion, pitting, the degradation and delamination of optical coatings, perforation of atomic oxygen erosion barriers, vapor coating of optics and the production of secondary ejecta particles. Secondary surfaces are those that are affected by the result of the perforation of primary surfaces, for example, vapor deposition on electronic components and other sensitive equipment, and the production of fragments with damage potential to internal pressurized elements. The material properties and applications that are required to prevent or lessen the effects described, are defined

  14. Irradiation Experiment to Determine Effect of Long Term Low Dose Irradiation on FBTR Grid Plate Material

    International Nuclear Information System (INIS)

    The performance of the FBTR 316 SS grid plate which experiences a cumulative neutron dose of a few dpa at a temperature of about 350ºC over its life time is one of the factors that could limit life of FBTR. While adequate data are available on austenitic stainless steels subjected to low doses, damage induced is a function of a number of parameters, some of which are unique to a reactor. An accelerated irradiation test was performed to characterize the mechanical property changes of 316 SS grid plate material subjected to neutron doses in the range ~1.0 - 2.5 dpa. The results show an increase in strength from un-irradiated values and a reduction in uniform elongation. Based on an extrapolation of this data, the limiting value of 10% on uniform elongation is estimated to be reached after 6.5 EFPY, at a dose of 4.4 dpa. Further irradiation experiments are planned to validate this extrapolation. (author)

  15. Atomic oxygen ground-based accelerated tests of spacecraft materials and structures for long-term LEO missions

    Science.gov (United States)

    Chernik, Vladimir; Novikov, Lev; Smirnova, Tatyana; Shumov, Andrey

    Spacecraft materials are degradated during long-term low earth orbit (LEO) flight. The Internation Space Station (ISS) is planed to be prolonged the term of action up to 20-25 years. To specify so long life one requires a validation of spacecraft material behaviour conservation for the period. The LEO environment includes atomic oxygen (AO) destructive incident flow. The appropriate AO fluence is proposed to be as high as 10E22-10E23 atom O/sq cm. The simulative ground-based test is evident to be acceptable if its duration is not too long usually under several hundreds of hours. In that case the rate of the test acceleration exceeds 100-200. One way to accelerate test is to increase oxygen particles energy. We test materials under oxygen plasma beam, formed by a magnetoplasmadynamic accelerator, with the oxygen particle energy of 20 -30 eV. In this way we determine an AO effective fluence by a kapton equivalent technique. The beam varies from LEO incident flow by energy, flux and rates of the oxygen dissociation / ionization/ excitation. To evaluate the test adequacy we measured and compared with LEO data erosion yields of a number of polymer materials, applied on spacecraft external surfaces. There were: polyimide (kapton), polyamide (nylon), polyethylene, polyvinyl fluoride (tedlar), polysteren, polymethyl methacrylate, epoxy, polyethylene terephthalate (mylar), graphite. Their relative erosion yields, measured and normalized by polyimide in this way, practically coincide with the data of flight experiments on the ISS. The results ground to use our plasma mode for accelerated tests of spacecraft material durability for long-term LEO flights. We tested quite a number of polymer-based materials and structures usable on ISS and another LEO spacecrafts. The effective AO fluencies ran up to 3,5 10E22 atom O/sq cm corresponding to the ISS flight duration about 20 years. We studied material behaviors like mass and thickness losses, erosion yield, surface morphology

  16. Results of the "Komplast" experiment on the long-term exposure of materials specimens on the ISS surface

    Science.gov (United States)

    Shumov, Andrey; Novikov, Lev

    The "Komplast" materials experiment was designed by the Khrunichev State Research and Production Space Center together with Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University and other Russian scientific institutes, and has been carried out since 1998. The aim of the experiment is to study the complex effects of space factors on specimens of various materials. Eight “Komplast” panels fitted with material specimens equipped UV-sensors and temperature sensors were located on the International Space Station (ISS) Functional Cargo Block (FGB) module exterior surface. The panels were sent into orbit with the FGB when it launched on November 20, 1998. Two of these panels were subsequently returned to Earth by Space Shuttle Discovery after 12 years of LEO exposure. The uniqueness of the "Komplast" experiment determined by long duration of open space exposure, which is much longer than in other similar experiments. For example LDEF: 1984-1990, МЕЕР (Space Station «Mir»): 1996-1997, MISSE-1, -2 (ISS): 1,5-2 years. In this work reveals laboratory research results of some materials specimens, which had been exposed on “Komplast” panels. A distinctive feature of this research was additional irradiation of specimens by atomic oxygen and electrons with energies of ~ 1-8 MeV in laboratory. In the interpretation of the experiment results was taken into account the specimens exposure temperature conditions on the ISS exterior surface and the conditions of their sunlit, defined by the above-mentioned sensors readings. Lot of attention was paid to the investigation of rubber materials specimens. The deformation, mechanical and relaxation characteristics were defined for the specimens. Also were investigations the seals-ability of model rubber seals after the long-term outer exposure. It was determined conservation volumetric deformation and relaxation characteristics of the exposed specimens and the localization of structural changes in the thin

  17. Influence of halogen irradiance on short- and long-term wear resistance of resin-based composite materials.

    LENUS (Irish Health Repository)

    Bhamra, Gurcharn S

    2009-02-01

    The Oregon Health Science University (OHSU) four-chamber oral wear simulator was used to examine the impact of halogen irradiance on the short- and long-term wear behavior of four-methacrylate resin-based composites (RBCs). The hypothesis proposed was that exacerbated wear would occur following the long-term wear of RBCs irradiated under non-optimized irradiance conditions.

  18. Materials Assessment of Insulating Foam in the 9977 Shipping Package for Long-Term Storage - Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, A. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-01

    The 9977 shipping package is being evaluated for long-term storage applications in the K-Area Complex (KAC) with specific focus on the packaging foam material. A rigid closed cell polyurethane foam, LAST-A-FOAM® FR-3716, produced by General Plastics Manufacturing Company is sprayed and expands to fill the void between the inner container and the outer shell of the package. The foam is sealed in this annular space and is not accessible. During shipping and storage, the foam experiences higher than ambient temperatures from the heat generated by nuclear material within the package creating the potential for degradation of the foam. A series of experiments is underway to determine the extent of foam degradation. Foam samples of three densities have been aging at elevated temperatures 160 °F, 160 °F + 50% relative humidity (RH), 185 °F, 215 °F, and 250 °F since 2014. Samples were periodically removed and tested. After approximately 80 weeks, samples conditioned at 160 °F, 160 °F + 50% RH, and 185 °F have retained initial property values while samples conditioned at 215 °F have reduced intumescence. Samples conditioned at 250 °F have shown the most degradation, loss of volume, mass, absorbed energy under compression, intumescence, and increased flammability. Based on the initial data, temperatures up to 185 °F have not yet shown an adverse effect on the foam properties and it is recommended that exposure of FR-3716 foam to temperatures in excess of 250 °F be avoided or minimized. Testing will continue beyond the 96 week mark. This will provide additional data to help define the long-term behavior for the lower temperature conditions. Additional testing will be pursued in an attempt to identify transition points (threshold times and temperatures) at the higher temperatures of interest, as well as possible benefits of aging within the relatively oxygen-free environment the foam experiences inside the 9977 shipping package.

  19. Long-Term Fracture Resistance of Simulated Immature Teeth Filled with Various Calcium Silicate-Based Materials

    Science.gov (United States)

    Dincol, M. Emir; Ozel, Emre; Yilmaz, Bulent; Aktoren, Oya

    2016-01-01

    Objective. The aim of this in vitro study was to evaluate the long-term fracture resistance of simulated human immature permanent teeth filled with BioAggregate™ (BA), mineral trioxide aggregate (MTA), and EndoSequence® Root Repair Material (ERRM). Material and Methods. 40 teeth, simulated to average root length of 13 ± 1 mm (Cvek's stage 3), were included in the study. The teeth were randomly divided into four groups: Group 1: DiaRoot® BA, Group 2: MTA-Plus™ (MTA-P), Group 3: MTA-Angelus (MTA-A), and Group 4: ERRM. The root canal filling materials were applied according to the manufacturers' instructions. After 24 months of incubation, the roots of the teeth were embedded in acrylic blocks and subjected to fracture testing. The resultant data were analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. Results. Mean (±SD) failure loads (MPa) were 20.46 ± 2.53 for BA, 18.88 ± 5.13 for MTA-P, 14.12 ± 1.99 for MTA-A, and 17.65 ± 4.28 for ERRM groups. BA group exhibited the highest and MTA-A group showed the lowest resistance to fracture. Significant differences in fracture resistance were found between the groups of BA and MTA-A (p MTA-P and MTA-A (p MTA-A (p < 0.05). Conclusion. Within the limitations of this study, data suggests that BA-filled immature teeth demonstrate higher fracture resistance than other groups at 24 months appearing to be the most promising material tested. PMID:27382564

  20. Long-Term Fracture Resistance of Simulated Immature Teeth Filled with Various Calcium Silicate-Based Materials

    Directory of Open Access Journals (Sweden)

    Yeliz Guven

    2016-01-01

    Full Text Available Objective. The aim of this in vitro study was to evaluate the long-term fracture resistance of simulated human immature permanent teeth filled with BioAggregate™ (BA, mineral trioxide aggregate (MTA, and EndoSequence® Root Repair Material (ERRM. Material and Methods. 40 teeth, simulated to average root length of 13±1 mm (Cvek’s stage 3, were included in the study. The teeth were randomly divided into four groups: Group 1: DiaRoot® BA, Group 2: MTA-Plus™ (MTA-P, Group 3: MTA-Angelus (MTA-A, and Group 4: ERRM. The root canal filling materials were applied according to the manufacturers’ instructions. After 24 months of incubation, the roots of the teeth were embedded in acrylic blocks and subjected to fracture testing. The resultant data were analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. Results. Mean (±SD failure loads (MPa were 20.46±2.53 for BA, 18.88±5.13 for MTA-P, 14.12±1.99 for MTA-A, and 17.65±4.28 for ERRM groups. BA group exhibited the highest and MTA-A group showed the lowest resistance to fracture. Significant differences in fracture resistance were found between the groups of BA and MTA-A (p<0.001, MTA-P and MTA-A (p<0.05, and ERRM and MTA-A (p<0.05. Conclusion. Within the limitations of this study, data suggests that BA-filled immature teeth demonstrate higher fracture resistance than other groups at 24 months appearing to be the most promising material tested.

  1. The Behaviours of Cementitious Materials in Long Term Storage and Disposal of Radioactive Waste. Results of a Coordinated Research Project

    International Nuclear Information System (INIS)

    Radioactive waste with widely varying characteristics is generated from the operation and maintenance of nuclear power plants, nuclear fuel cycle facilities, research laboratories and medical facilities. This waste must be treated and conditioned, as necessary, to provide waste forms acceptable for safe storage and disposal. Many countries use cementitious materials (concrete, mortar, etc.) as a containment matrix for immobilization, as well as for engineered structures of disposal facilities. Radionuclide release is dependent on the physicochemical properties of the waste forms and packages, and on environmental conditions. In the use of cement, the diffusion process and metallic corrosion can induce radionuclide release. The advantage of cementitious materials is the added stability and mechanical support during storage and disposal of waste. Long interim storage is becoming an important issue in countries where it is difficult to implement low level waste and intermediate level waste disposal facilities, and in countries where cement is used in the packaging of waste that is not suitable for shallow land disposal. This coordinated research project (CRP), involving 24 research organizations from 21 Member States, investigated the behaviour and performance of cementitious materials used in an overall waste conditioning system based on the use of cement - including waste packaging (containers), waste immobilization (waste form) and waste backfilling - during long term storage and disposal. It also considered the interactions and interdependencies of these individual elements (containers, waste, form, backfill) to understand the processes that may result in degradation of their physical and chemical properties. The main research outcomes of the CRP are summarized in this report under four topical sections: (i) conventional cementitious systems; (ii) novel cementitious materials and technologies; (iii) testing and waste acceptance criteria; and (iv) modelling long

  2. The challenge of the growth of the asian gas market in the long term. Opportunities and restrictions

    International Nuclear Information System (INIS)

    The Asian gas market is expected to quickly resume its ground at the spectacular rate of the 90's, expanding to new purchasers and new exporters, including the countries of the Middle East and the CIS in search of outlets for their gas resources. The aim of this article is to identify the broad tendencies in the development of this market over the next 20 years. To meet potential demand (600 Mtoe in the year 2020 as opposed to 210 Mtoe at present) the base of reserves to be exploited must expand beyond South Eastern Asia. The procedures for commercialization must gradually open to include trade via land-based infrastructures, alongside conventional LNG business. If al gas projects, LNG chains or gas pipelines are faced with significant restriction (scale of capital to be mobilized, outlets to be guaranteed, price risk, country risk), the gas-pipe-line projects, the only ones which are capable of establishing a link between the richest basins and the most important potential markets would be feasible only in the long-term future. In any case, the major petroleum and gas companies are essential to the concrete realisation of the projects. (authors)

  3. Introduction: Long term prediction

    International Nuclear Information System (INIS)

    Making a decision upon the right choice of a material appropriate to a given application should be based on taking into account several parameters as follows: cost, standards, regulations, safety, recycling, chemical properties, supplying, transformation, forming, assembly, mechanical and physical properties as well as the behaviour in practical conditions. Data taken from a private communication (J.H.Davidson) are reproduced presenting the life time range of materials from a couple of minutes to half a million hours corresponding to applications from missile technology up to high-temperature nuclear reactors or steam turbines. In the case of deep storage of nuclear waste the time required is completely different from these values since we have to ensure the integrity of the storage system for several thousand years. The vitrified nuclear wastes should be stored in metallic canisters made of iron and carbon steels, stainless steels, copper and copper alloys, nickel alloys or titanium alloys. Some of these materials are passivating metals, i.e. they develop a thin protective film, 2 or 3 nm thick - the so-called passive films. These films prevent general corrosion of the metal in a large range of chemical condition of the environment. In some specific condition, localized corrosion such as the phenomenon of pitting, occurs. Consequently, it is absolutely necessary to determine these chemical condition and their stability in time to understand the behavior of a given material. In other words the corrosion system is constituted by the complex material/surface/medium. For high level nuclear wastes the main features for resolving problem are concerned with: geological disposal; deep storage in clay; waste metallic canister; backfill mixture (clay-gypsum) or concrete; long term behavior; data needed for modelling and for predicting; choice of appropriate solution among several metallic candidates. The analysis of the complex material/surface/medium is of great importance

  4. 10 CFR 40.28 - General license for custody and long-term care of uranium or thorium byproduct materials disposal...

    Science.gov (United States)

    2010-01-01

    ... long-term care of uranium or thorium byproduct materials disposal sites. (a) A general license is... in this part for uranium or thorium mill tailings sites closed under title II of the Uranium Mill... this general license is to ensure that uranium and thorium mill tailings disposal sites will be...

  5. Influence of long-term thermal aging on the microstructural evolution of nuclear reactor pressure vessel materials: An atom probe study

    International Nuclear Information System (INIS)

    Atom probe field ion microscopy (APFIM) investigations of the microstructure of unaged (as-fabricated) and long-term thermally aged (∼ 100,000 h at 280 C) surveillance materials from commercial reactor pressure vessel steels were performed. This combination of materials and conditions permitted the investigation of potential thermal-aging effects. This microstructural study focused on the quantification of the compositions of the matrix and carbides. The APFIM results indicate that there was no significant microstructural evolution after a long-term thermal exposure in weld, plate, or forging materials. The matrix depletion of copper that was observed in weld materials was consistent with the copper concentration in the matrix after the stress-relief heat treatment. The compositions of cementite carbides aged for 100,000 h were compared with the Thermocalc trademark prediction. The APFIM comparisons of materials under these conditions are consistent with the measured change in mechanical properties such as the Charpy transition temperature

  6. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    International Nuclear Information System (INIS)

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below ∼140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses may

  7. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Sanden, Torbjoern; Faelth, Billy (Clay Technology AB, Lund (Sweden)); Jansson, Mats; Eriksen, Trygve E.; Svaerdstroem, Kjell (KTH Royal Inst. of Technology, Stockholm (Sweden)); Rosborg, Bo (Studsvik AB, Nykoeping (Sweden); Rosborg Consulting, Nykoeping (Sweden)); Muurinen, Arto (VTT, Espoo (Finland))

    2011-02-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses

  8. Offshore Brazil: forcing the path to the future managing supply chain challenges to ensure long-term growth

    Energy Technology Data Exchange (ETDEWEB)

    Hillegeist, Paul H.; Pickard, Matt [Quest Offshore Resources, Inc., Sugar Land, TX (United States)

    2008-07-01

    Over the last 10 years, worldwide demand for energy has seen a significant increase. This accelerated growth has placed a tremendous strain on the offshore oil and gas E and P industry, as operators strive to find and develop new accumulations to help meet rising global energy demand, while overcoming many substantial challenges. Whether those challenges come from limited manufacturing and construction supply or limited human capital, these issues will need to be addressed in order for the industry to continue to push forward at a record pace. Additionally, the industry will have to rely heavily on new and emerging technologies, some of which are largely unproven. Nowhere is this dedication to technological achievement more evident than in the deep waters offshore Brazil. Recent discoveries have placed an added degree of focus on the technologies that will be needed to help develop these fields in a commercially viable manner. Given Brazil's track record for innovation and accomplishment, the region is poised to present a number of industry-wide advancements over the next 10 to 15 years as Brazil continues to be a trend setter for worldwide energy security. A thorough understanding of these issues, as well as the potential solutions to overcoming them, is critical to companies wishing to participate in the highly rewarding Brazilian offshore sector. This presentation will strive to detail the underlying factors that drive industry activity, including burgeoning commercial opportunities for service and supply companies, as well as addressing the technologies currently in progress that will help move the industry into ultra-deep water exploration and development. (author)

  9. Challenge to Overcome the Concern of SCC in Canister During Long-Term Storage of Spent Fuel

    International Nuclear Information System (INIS)

    In order to put the concrete cask in practical use in Japan (an island country), stress corrosion cracking (SCC) of canister must be coped with. It is required to take measures for one or two of the three factors, i.e. welding residual stress, material, and environment, to cope with the SCC that may result in loss of the containment function of the canister. Prevention of loss of containment due to SCC of a canister was evaluated either by a method of comparing the amount of salt on the canister surface during storage with the minimum amount of salt to initiate rust and SCC or by a method of comparing the wetting time of the canister surface under salty-air field environment with the lifetime of the SCC fracture of the canister material. Although the use of highly corrosion-resistance stainless steel is one solution, it brings about a cost rise of the concrete cask storage. In order to suppress the cost rise, it should be evaluated whether the measure against SCC of the normal stainless steel is possible by reducing welding residual stress. In addition, technology should be developed to reduce salt particles in the air flowing into the storage facility and concrete cask. (author)

  10. Building long-term constituencies for space exploration: The challenge of raising public awareness and engagement in the United States and in Europe

    Science.gov (United States)

    Ehrenfreund, P.; Peter, N.; Billings, L.

    2010-08-01

    Space exploration is a multifaceted endeavor and will be a "grand challenge" of the 21st century. It has already become an element of the political agenda of a growing number of countries worldwide. However, the public is largely unaware of space exploration activities and in particular does not perceive any personal benefit. In order to achieve highly ambitious space exploration goals to explore robotically and with humans the inner solar system, space agencies must improve and expand their efforts to inform and raise the awareness of the public about what they are doing, and why. Therefore adopting new techniques aiming at informing and engaging the public using participatory ways, new communication techniques to reach, in particular, the younger generation will be a prerequisite for a sustainable long-term exploration program: as they will enable it and carry most of the associated financial burden. This paper presents an environmental analysis of space exploration in the United States and Europe and investigates the current branding stature of the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). We discuss how improved market research and new branding methods can increase public space awareness and improve the image of NASA and ESA. We propose a new participatory approach to engage the public as major stakeholder (along governments, the industrial space sector and the science community) that may provide sufficient resources for and sustainability of a long-term space exploration program.

  11. Long term behaviour of material erosion and deposition on the vessel wall and remote areas of TEXTOR

    International Nuclear Information System (INIS)

    Long term erosion/deposition at the plasma facing surfaces as well as the carbon transport to the remote areas are discussed. The erosion of the liner wall and the deposition at the inner walls of the pump ducts were quantified. A small net deposition of carbon was found also at the liner, but only in the vicinity of the toroidal belt limiter. A deposition of polymer like deuterium rich carbon films (D/C ∼ 0.7) took place in remote areas. Despite the minute deposition rate of ∼0.02 gC/h these deposits might be decisive in view of tritium retention in next step fusion devices

  12. Summary report of the screening process to determine reasonable alternatives for long-term storage and disposition of weapons-usable fissile materials

    International Nuclear Information System (INIS)

    Significant quantities of weapons-usable fissile materials (primarily plutonium and highly enriched uranium) have become surplus to national defense needs both in the US and Russia. These stocks of fissile materials pose significant dangers to national and international security. The dangers exist not only in the potential proliferation of nuclear weapons but also in the potential for environmental, safety and health consequences if surplus fissile materials are not properly managed. As announced in the Notice of Intent (NOI) to prepare a Programmatic Environmental Impact Statement (PEIS), the Department of Energy is currently conducting an evaluation process for disposition of surplus weapons-usable fissile materials determined surplus to National Security needs, and long-term storage of national security and programmatic inventories, and surplus weapons-usable fissile materials that are not able to go directly from interim storage to disposition. An extensive set of long-term storage and disposition options was compiled. Five broad long-term storage options were identified; thirty-seven options were considered for plutonium disposition; nine options were considered for HEU disposition; and eight options were identified for Uranium-233 disposition. Section 2 discusses the criteria used in the screening process. Section 3 describes the options considered, and Section 4 provides a detailed summary discussions of the screening results

  13. Summary report of the screening process to determine reasonable alternatives for long-term storage and disposition of weapons-usable fissile materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-29

    Significant quantities of weapons-usable fissile materials (primarily plutonium and highly enriched uranium) have become surplus to national defense needs both in the US and Russia. These stocks of fissile materials pose significant dangers to national and international security. The dangers exist not only in the potential proliferation of nuclear weapons but also in the potential for environmental, safety and health consequences if surplus fissile materials are not properly managed. As announced in the Notice of Intent (NOI) to prepare a Programmatic Environmental Impact Statement (PEIS), the Department of Energy is currently conducting an evaluation process for disposition of surplus weapons-usable fissile materials determined surplus to National Security needs, and long-term storage of national security and programmatic inventories, and surplus weapons-usable fissile materials that are not able to go directly from interim storage to disposition. An extensive set of long-term storage and disposition options was compiled. Five broad long-term storage options were identified; thirty-seven options were considered for plutonium disposition; nine options were considered for HEU disposition; and eight options were identified for Uranium-233 disposition. Section 2 discusses the criteria used in the screening process. Section 3 describes the options considered, and Section 4 provides a detailed summary discussions of the screening results.

  14. Long-term collections

    CERN Multimedia

    Collectes à long terme

    2007-01-01

    The Committee of the Long Term Collections (CLT) asks for your attention for the following message from a young Peruvian scientist, following the earthquake which devastated part of her country a month ago.

  15. Long Term Preservation of Digital Information.

    Science.gov (United States)

    Lorie, Raymond A.

    The preservation of digital data for the long term presents a variety of challenges from technical to social and organizational. The technical challenge is to ensure that the information, generated today, can survive long term changes in storage media, devices, and data formats. This paper presents a novel approach to the problem. It distinguishes…

  16. Material properties and structure of thick-walled elements made of steel 7CrMoVTiB10-10 after long-term annealing

    OpenAIRE

    A. Zieliński; J. Dobrzański

    2012-01-01

    Purpose: Condition assessment of material and welded joints with regard to required utility properties of low-alloy steel for operation at elevated temperature.Design/methodology/approach: The structural and mechanical testing of parent material and welded joint at room and elevated temperature after annealing at 550°C and 600°C for 30,000 h was carried out.Findings: The effect of temperature and duration of long-term annealing on mechanical properties, hardness and structure of tested materi...

  17. Long-Term Collections

    CERN Multimedia

    Comité des collectes à long terme

    2011-01-01

    It is the time of the year when our fireman colleagues go around the laboratory for their traditional calendars sale. A part of the money of the sales will be donated in favour of the long-term collections. We hope that you will welcome them warmly.

  18. Long term morphological modelling

    DEFF Research Database (Denmark)

    Kristensen, Sten Esbjørn; Deigaard, Rolf; Taaning, Martin;

    2010-01-01

    A morphological modelling concept for long term nearshore morphology is proposed and examples of its application are presented and discussed. The model concept combines parameterised representations of the cross-shore morphology, with a 2DH area model for waves, currents and sediment transport in...

  19. Long-term creep-fatigue life property of Mod.9Cr-1Mo steel for steam generator material in FBR

    International Nuclear Information System (INIS)

    Extensive research is being executed to establish creep-fatigue life evaluation methodology for Mod.9Cr-1Mo steel which is the principal candidate material of steam generators in Demonstration Fast Breeder Reactor. Previous studies showed that the features of the creep-fatigue life property of the steel are small life reduction by tensile strain hold and significant reduction in compressive hold tests due to oxidation effect. Most of the experiments, however, were conducted under relatively short-term hold conditions and the failure life properties under long-term hold conditions have not yet been clarified. In order to investigate the oxidation and long-term strain hold effects on the creep-fatigue life property, the crack propagation tests in vacuum and air conditions, and the long-term creep-fatigue tests, up to 10 hours hold time per cycle, were performed. As a result, it was found that the significant life reduction occurred by introducing the tensile strain hold longer than 1 hour because of increase of the grain boundary damage due to cavity nucleation, and that the life reduction in compressive hold was caused by acceleration of the crack propagation rate due to accumulation of the tensile strain in center of the specimen. (author)

  20. Challenges of nurse delivery of psychological interventions for long-term conditions in primary care: a qualitative exploration of the case of chronic fatigue syndrome/myalgic encephalitis

    Directory of Open Access Journals (Sweden)

    Peters Sarah

    2011-12-01

    Full Text Available Abstract Background The evidence base for a range of psychosocial and behavioural interventions in managing and supporting patients with long-term conditions (LTCs is now well-established. With increasing numbers of such patients being managed in primary care, and a shortage of specialists in psychology and behavioural management to deliver interventions, therapeutic interventions are increasingly being delivered by general nurses with limited training in psychological interventions. It is unknown what issues this raises for the nurses or their patients. The purpose of the study was to examine the challenges faced by non-specialist nurses when delivering psychological interventions for an LTC (chronic fatigue syndrome/myalgic encephalomyelitis [CFS/ME] within a primary care setting. Methods A qualitative study nested within a randomised controlled trial [ISRCTN 74156610] explored the experiences and acceptability of two different psychological interventions (pragmatic rehabilitation and supportive listening from the perspectives of nurses, their supervisors, and patients. Semi structured in-depth interviews were conducted with three nurse therapists, three supervisors, and 46 patients. An iterative approach was used to develop conceptual categories from the dataset. Results Analyses identified four sets of challenges that were common to both interventions: (i being a novice therapist, (ii engaging patients in the therapeutic model, (iii dealing with emotions, and (iv the complexity of primary care. Each challenge had the potential to cause tension between therapist and patient. A number of strategies were developed by participants to manage the tensions. Conclusions Tensions existed for nurses when attempting to deliver psychological interventions for patients with CFS/ME in this primary care trial. Such tensions should be addressed before implementing psychological interventions within routine clinical practice. Similar tensions may be found

  1. 10 CFR 40.27 - General license for custody and long-term care of residual radioactive material disposal sites.

    Science.gov (United States)

    2010-01-01

    ... lease any subsurface mineral rights associated with land on which residual radioactive materials are... radioactive material disposal sites. 40.27 Section 40.27 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... residual radioactive material disposal sites. (a) A general license is issued for the custody of and...

  2. Long-term studies on the leachability of cemented and non-cemented iodine-129 loaded sorption material

    International Nuclear Information System (INIS)

    Leaching tests on the load AC 6120 iodine sorption material (12 wt.% Ag) in water and salt brines were performed over a rather long period of time to allow better judgement of the behavior of radioactive waste disposed of in a salt dome. The utilization of capacity of the loaded iodine sorption material from the Karlsruhe reprocessing plant (WAK) was 95% related to the amount of silver added. The result of the stationary leaching tests has been a leaching rate of the material not embedded in cement of < 0.1%, whereas the leaching rate of the iodine sorption material embedded in cement has been < 0.01% of the total iodine-129 inventory. After addition of carbon steel to the sorption material embedded in cement the same leaching rates were measured as for material not embedded in cement. The addition of stainless steel exerted but little influence on the leaching rate. (orig.)

  3. Long-term effect of water chemistry on the swelling pressure of a bentonite-based material

    OpenAIRE

    Wang, Qiong; Cui, Yu-Jun; Tang, Anh Minh; Delage, Pierre; Gatmiri, Behrouz; Ye, Wei-Min

    2014-01-01

    Compacted bentonite-based materials have been proposed as possible sealing and backfill materials in geological repositories for the high-level radioactive waste disposal in several countries. During the long time lifespan of a repository, as the chemical composition of pore water can change, the swelling and sealing capacity of the material may also change. From a point of view of storage safety assessment, it is important to evaluate this possible change of swelling capacity. In this study,...

  4. Consideration Of The Change Of Material Emission Signatures Due To Long-term Emissions For Enhancing Voc Source Identification

    DEFF Research Database (Denmark)

    Han, K. H.; Zhang, J. S.; Knudsen, H. N.; Wargocki, Pawel; Guo, B.

    2011-01-01

    The objectives of this study were to characterize the changes of VOC material emission profiles over time and develop a method to account for such changes in order to enhance a source identification technique that is based on the measurements of mixed air samples and the emission signatures of...... individual building materials determined by PTRMS. Source models, including powerlaw model, doubleexponential decay model and mechanistic diffusion model, were employed to track the change of individual material emission signatures by PTRMS over a ninemonth period. Samples of nine typical building materials...

  5. Radiolysis of Salts and Long-Term Storage Issues for Both Pure and Impure PuO{sub 2} Materials in Plutonium Storage Containers

    Energy Technology Data Exchange (ETDEWEB)

    Lav Tandon

    2000-05-01

    The Material Identification and Surveillance (MIS) project sponsored a literature search on the effects of radiation on salts, with focus on alkali chlorides. The goal of the survey was to provide a basis for estimating the magnitude of {alpha} radiation effects on alkali chlorides that can accompany plutonium oxide (PuO{sub 2}) into storage. Chloride radiolysis can yield potentially corrosive gases in plutonium storage containers that can adversely affect long-term stability. This literature search was primarily done to provide a tutorial on this topic, especially for personnel with nonradiation chemistry backgrounds.

  6. A radiation barrier alloy for long-term storage of special nuclear materials: Definition and preliminary assessment

    International Nuclear Information System (INIS)

    The radiation barrier alloy (RBA) concept is a method for introducing radioactive, chemical, and physical barriers for storing weapons-grade plutonium, and yet still allowing for accurate material control and accountability, as well as for retrieving the material by the host nation if desired. The radioactive and chemical barriers are achieved by fabricating the plutonium in the form of a plutonium-beryllium compound (PuBe13), which results in neutron emission resulting from (α,n) reactions within the compound and multiplication from (n,fission) processes in the plutonium. Preliminary physics analyses have been completed, as well as a general review of fabrication techniques and availability of the required materials. These studies revealed that dose levels in excess of 500 rem/h at a 1-m distance from the surface of the RBA assembly can be obtained. However, essential for achieving these dose levels is operation at a high level of neutron multiplication (keff ∼ 0.9). Criticality concerns, even under flooded conditions, can be eliminated through the use of a thermal-neutron-absorbing material (e.g., cadmium) either as a cladding material or a container material surrounding the RBA assembly. Fabrication techniques for the Pu-Be compound are well demonstrated and fully compatible with the RBA assembly fabrication. Data from disassembly of Pu-Be sources indicate that the compound is stable and no significant physical degradation occurs over a 40-yr time frame. There is no reason to believe that any additional problems exist for longer time frames, given that the components are designed for the appropriate lifetimes (i.e., adequately account for gas production). The materials required for RBA implementation are available in the required quantities, and cost of these materials is not prohibitive

  7. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term Irradiation at Elevated Temperature: Critical Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Jiao, Zhijie; Allen, Todd; Yang, Yong

    2013-12-20

    The in-service degradation of reactor core materials is related to underlying changes in the irradiated microstructure. During reactor operation, structural components and cladding experience displacement of atoms by collisions with neutrons at temperatures at which the radiation-induced defects are mobile, leading to microstructure evolution under irradiation that can degrade material properties. At the doses and temperatures relevant to fast reactor operation, the microstructure evolves by microchemistry changes due to radiation-induced segregation, dislocation loop formation and growth, radiation induced precipitation, destabilization of the existing precipitate structure, as well as the possibility for void formation and growth. These processes do not occur independently; rather, their evolution is highly interlinked. Radiation-induced segregation of Cr and existing chromium carbide coverage in irradiated alloy T91 track each other closely. The radiation-induced precipitation of Ni-Si precipitates and RIS of Ni and Si in alloys T91 and HCM12A are likely related. Neither the evolution of these processes nor their coupling is understood under the conditions required for materials performance in fast reactors (temperature range 300-600°C and doses to 200 dpa and beyond). Further, predictive modeling is not yet possible, as models for microstructure evolution must be developed along with experiments to characterize these key processes and provide tools for extrapolation. To extend the range of operation of nuclear fuel cladding and structural materials in advanced nuclear energy and transmutation systems to that required for the fast reactor, the irradiation-induced evolution of the microstructure, microchemistry, and the associated mechanical properties at relevant temperatures and doses must be understood. This project builds upon joint work at the proposing institutions, under a NERI-C program that is scheduled to end in September, to understand the effects of

  8. Long-term benthic infaunal monitoring at a deep-ocean dredged material disposal site off Northern California

    Science.gov (United States)

    Blake, James A.; Maciolek, Nancy J.; Ota, Allan Y.; Williams, Isabelle P.

    2009-09-01

    One hundred and thirty-five benthic infaunal samples were collected from the San Francisco Deep-Ocean Disposal Site (SF-DODS) over a 10-year period from January 1996 to September 2004. Each sample was 0.1 m 2, cut to a depth of 10 cm, and sieved through a 300-μm mesh. A total of 810 species of benthic invertebrates were identified; the majority of taxa (65.4%) new to science. The fauna represents a rich lower slope infaunal assemblage that rivals similarly studied locations in the western North Atlantic. No regional impact or degradation of benthic infauna due to dredged material disposal was detected. All reference stations and stations on the site boundary maintained high species richness and diversity during the monitoring period. Exceptions included an occasional sample with anomalously high numbers of one or two species that reduced the diversity and/or equitability. Within SF-DODS species richness and diversity were often reduced. Stations within the disposal site were recolonized by the same taxa that normally occurred in adjacent reference areas. Initial colonizers of fresh dredged material included spionid and paraonid polychaetes that were typical dominants at the site. At least one polychaete species, Ophelina sp. 1, sometimes colonized dredged materials containing coarse sand. One sample at Station 13, located in the middle of SF-DODS (September 2002), contained 57 species of benthic invertebrates, suggesting that colonization of fresh dredged material is rapid. It seems unlikely that larval dispersal and settlement account for this rapid recolonization; therefore it is postulated that adult organisms from adjacent areas move to the disturbed sites via boundary layer currents. The steep continental slope adjacent to SF-DODS is subject to turbidity flows and the resident fauna are likely pre-adapted to rapidly colonize disturbed sediments. Larval dispersal, especially by spionid polychaetes such as Prionospio delta, may also be important in colonizing

  9. Estimation of the radionuclide inventory in LWR spent fuel assembly structural materials for long-term safety analysis

    Directory of Open Access Journals (Sweden)

    Caruso Stefano

    2016-01-01

    Full Text Available The radionuclide inventory of materials irradiated in a reactor depends on the initial material composition, irradiation history and on the magnitude and spectrum of the neutron flux. The material composition of a fuel assembly structure includes various alloys of Zircaloy, Inconel and stainless steel. The existing impurities in these materials are very important for accurate determination of the activation of all nuclides with a view to assessing the radiological consequences of their geological disposal. In fact, the safety assessments of geological repositories require the average and maximum (in the sense of very conservative inventories of the very long-lived nuclides as input. The purpose of the present work is to describe the methodology applied for determining the activation of these nuclides in fuel assembly structural materials by means of coupled depletion/activation calculations and also to crosscheck the results obtained from two approaches. UO2 and MOX PWR fuels have been simulated using SCALE/TRITON, simultaneously irradiating the fuel region in POWER mode and the cladding region in FLUX mode and aiming to produce binary macro cross-section libraries by applying accurate local neutron spectra in the cladding region as a function of irradiation history that are suitable for activation calculations. The developed activation libraries have been re-employed in a second run using the ORIGEN-S program for a dedicated activation calculation. The axial variation of the neutron flux along the fuel assembly length has also been considered. The SCALE calculations were performed using a 238-group cross-section library, according to the ENDF/B-VII. The results obtained with the ORIGEN-S activation calculations are compared with the results obtained from TRITON via direct irradiation of the cladding, as allowed by the FLUX mode. It is shown that an agreement on the total calculated activities can be found within 55% for MOX and within 22% for

  10. Collectes à long terme

    CERN Document Server

    Collectes à long terme

    2014-01-01

    En cette fin d’année 2014 qui approche à grands pas, le Comité des Collectes à Long Terme remercie chaleureusement ses fidèles donatrices et donateurs réguliers pour leurs contributions à nos actions en faveur des plus démunis de notre planète. C’est très important, pour notre Comité, de pouvoir compter sur l’appui assidu que vous nous apportez. Depuis plus de 40 ans maintenant, le modèle des CLT est basé principalement sur des actions à long terme (soit une aide pendant 4-5 ans par projet, mais plus parfois selon les circonstances), et sa planification demande une grande régularité de ses soutiens financiers. Grand MERCI à vous ! D’autres dons nous parviennent au cours de l’année, et ils sont aussi les bienvenus. En particulier, nous tenons à remercier...

  11. Test Methodology Development for Experimental Structural Assessment of ASC Planar Spring Material for Long-Term Durability

    Science.gov (United States)

    Yun, Gunjin; Abdullah, A. B. M.; Binienda, Wieslaw; Krause, David L.; Kalluri, Sreeramesh

    2014-01-01

    A vibration-based testing methodology has been developed that will assess fatigue behavior of the metallic material of construction for the Advanced Stirling Convertor displacer (planar) spring component. To minimize the testing duration, the test setup is designed for base-excitation of a multiplespecimen arrangement, driven in a high-frequency resonant mode; this allows completion of fatigue testing in an accelerated period. A high performance electro-dynamic exciter (shaker) is used to generate harmonic oscillation of cantilever beam specimens, which are clasped on the shaker armature with specially-designed clamp fixtures. The shaker operates in closed-loop control with dynamic specimen response feedback provided by a scanning laser vibrometer. A test coordinator function synchronizes the shaker controller and the laser vibrometer to complete the closed-loop scheme. The test coordinator also monitors structural health of the test specimens throughout the test period, recognizing any change in specimen dynamic behavior. As this may be due to fatigue crack initiation, the test coordinator terminates test progression and then acquires test data in an orderly manner. Design of the specimen and fixture geometry was completed by finite element analysis such that peak stress does not occur at the clamping fixture attachment points. Experimental stress evaluation was conducted to verify the specimen stress predictions. A successful application of the experimental methodology was demonstrated by validation tests with carbon steel specimens subjected to fully-reversed bending stress; high-cycle fatigue failures were induced in such specimens using higher-than-prototypical stresses

  12. The coupling of coal and nuclear energy for the long-term supply of energy and raw materials

    International Nuclear Information System (INIS)

    In view of the limited world reserves of fossil fuels and the increase in demand to be expected because of the continued growth of the world population, coal and nuclear energy will have to make an increasing contribution to the energy supply. Their contribution will range from electricity generation to the heat sector and to the raw materials market via various gases obtained from them. The further development towards this field of tasks will lead first via the gasification of coal. It will be carried out autothermally in the first stage of development. The gas produced is suitable for realising considerable improvements in efficiency as compared to coal-fired power stations of present-day design since it will permit the generation of electricity via combined gas turbine/steam turbine processes. Efforts are being made to take further the processes based on this technology by introducing a sodium circuit in addition to the coal gasification, which will make it possible to keep the plants required for coal gasification small. In later stages, this technology will also be suitable for producing a considerable improvement in the diversion of heat at high temperatures from high-temperature reactor nuclear power stations for several purposes. (author)

  13. Improving the long-term stability of PBDTTPD polymer solar cells through material purification aimed at removing organic impurities

    KAUST Repository

    Mateker, William R.

    2013-01-01

    While bulk heterojunction (BHJ) solar cells fabricated from high M n PBDTTPD achieve power conversion efficiencies (PCE) as high as 7.3%, the short-circuit current density (JSC) of these devices can drop by 20% after seven days of storage in the dark and under inert conditions. This degradation is characterized by the appearance of S-shape features in the reverse bias region of current-voltage (J-V) curves that increase in amplitude over time. Conversely, BHJ solar cells fabricated from low Mn PBDTTPD do not develop S-shaped J-V curves. However, S-shapes identical to those observed in high Mn PBDTTPD solar cells can be induced in low M n devices through intentional contamination with the TPD monomer. Furthermore, when high Mn PBDTTPD is purified via size exclusion chromatography (SEC) to reduce the content of low molecular weight species, the JSC of polymer devices is significantly more stable over time. After 111 days of storage in the dark under inert conditions, the J-V curves do not develop S-shapes and the JSC degrades by only 6%. The S-shape degradation feature, symptomatic of low device lifetimes, appears to be linked to the presence of low molecular weight contaminants, which may be trapped within samples of high Mn polymer that have not been purified by SEC. Although these impurities do not affect initial device PCE, they significantly reduce device lifetime, and solar cell stability is improved by increasing the purity of the polymer materials. © 2013 The Royal Society of Chemistry.

  14. Long term morphological modelling

    DEFF Research Database (Denmark)

    Kristensen, Sten Esbjørn; Deigaard, Rolf; Taaning, Martin; Fredsøe, Jørgen; Drønen, Nils; Hjelmager Jensen, Jacob

    2010-01-01

    concept often used in one-line modelling of cross-shore shifting of an otherwise constant shape cross-shore profile is applied for the case of a groyne and a detached breakwater. In the case of alongshore bar/nourishment migration an alternative parameterization is adopted. All examples are presented......A morphological modelling concept for long term nearshore morphology is proposed and examples of its application are presented and discussed. The model concept combines parameterised representations of the cross-shore morphology, with a 2DH area model for waves, currents and sediment transport in...... the surf zone. Two parameterization schemes are tested for two different morphological phenomena: 1) Shoreline changes due to the presence of coastal structures and 2) alongshore migration of a nearshore nourishment and a bar by-passing a harbour. In the case of the shoreline evolution calculations, a...

  15. Building Capacity for a Long-Term, in-Situ, National-Scale Phenology Monitoring Network: Successes, Challenges and Lessons Learned

    Science.gov (United States)

    Weltzin, J. F.; Browning, D. M.

    2014-12-01

    The USA National Phenology Network (USA-NPN; www.usanpn.org) is a national-scale science and monitoring initiative focused on phenology - the study of seasonal life-cycle events such as leafing, flowering, reproduction, and migration - as a tool to understand the response of biodiversity to environmental variation and change. USA-NPN provides a hierarchical, national monitoring framework that enables other organizations to leverage the capacity of the Network for their own applications - minimizing investment and duplication of effort - while promoting interoperability. Network participants can leverage: (1) Standardized monitoring protocols that have been broadly vetted, tested and published; (2) A centralized National Phenology Database (NPDb) for maintaining, archiving and replicating data, with standard metadata, terms-of-use, web-services, and documentation of QA/QC, plus tools for discovery, visualization and download of raw data and derived data products; and/or (3) A national in-situ, multi-taxa phenological monitoring system, Nature's Notebook, which enables participants to observe and record phenology of plants and animals - based on the protocols and information management system (IMS) described above - via either web or mobile applications. The protocols, NPDb and IMS, and Nature's Notebook represent a hierarchy of opportunities for involvement by a broad range of interested stakeholders, from individuals to agencies. For example, some organizations have adopted (e.g., the National Ecological Observatory Network or NEON) -- or are considering adopting (e.g., the Long-Term Agroecosystems Network or LTAR) -- the USA-NPN standardized protocols, but will develop their own database and IMS with web services to promote sharing of data with the NPDb. Other organizations (e.g., the Inventory and Monitoring Programs of the National Wildlife Refuge System and the National Park Service) have elected to use Nature's Notebook to support their phenological monitoring

  16. A study on long term stability of bentonite. The preliminary study on the bentonite stability in the groundwater influenced by cementitious material

    International Nuclear Information System (INIS)

    In the geological disposal concept of radioactive wastes, a kind of clay with sorption ability and low permeability, called bentonite, is envisaged as an engineered barrier system in the geological repository. Also, the cementitious material is envisaged as the backfill material in the vaults and the structure material of the vaults. The groundwater in contact with the cementitious material will promote hyperalkaline conditions in the repository environment and these conditions will affect the performance of the bentonite. Therefore, it is necessary to investigate the interaction between the cementitious material and the bentonite for the evaluation of long term stability of the disposal system. In this study, for the identification and the investigation of the secondary minerals, the batch immersion experiments of the powder bentonite were carried out using synthetic cement leachates (pH=7, 12.5, 14) at 200degC. As the results, it was confirmed that Na as exchangeable cations in the bentonite can exchange relatively easily with Ca in the solution from the experiment results. And the ratio of cation exchange was estimated to be about 25% based on the amount of exchangeable cations Ca2+ between layers. Furthermore, it was concretely shown that the generation of analcime might be affected by the Na concentration from results of the solution analyses and a stability analysis of analcime using the chemical equilibrium model, in addition to the pH in the solution. (author)

  17. Wyoming bentonites. Evidence from the geological record to evaluate the suitability of bentonite as a buffer material during the long-term underground containment of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Smellie, J. [Conterra AB (Sweden)

    2001-12-01

    In the Swedish programme for the deep, geological disposal of radioactive wastes, bentonite is planned to be used as a barrier material to reduce groundwater flow and minimise radionuclide migration into the geosphere. One of the possible threats to long-term bentonite stability is the gradual incursion of saline water into the repository confines which may reduce the swelling capacity of the bentonite, even to the extent of eliminating the positive effects of mixing bentonite into backfill materials. Important information may be obtained from the study of analogous processes in nature (i.e. natural analogue or natural system studies) where bentonite, during its formation, has been in long-term contact with reducing waters of brackish to saline character. Type bentonites include those mined from the Clay Spur bed at the top of the Cretaceous Mowry Formation in NE Wyoming and demarcated for potential use as a barrier material (e.g. MX-80 sodium bentonite) in the Swedish radioactive waste programme. This bentonite forms part of the Mowry Shale which was deposited in a southern embayment of the late Albian Western Interior Cretaceous sea (Mowry Sea). The question is whether these bentonite deposits show evidence of post-deposition alteration caused by the sea water in which they were deposited, and/or, have they been altered subsequently by contact with waters of increasing salinity? Bentonites are the product of pyroclastic fall deposits thought to be generated by the type of explosive, subaerial volcanic activity characteristic of Plinian eruptive systems. In Wyoming the overall composition of the original ash varied from dacite to rhyolite, or latite to trachyte. The ash clouds were carried to high altitudes and eastwards by the prevailing westerly winds before falling over the shallow Mowry Sea and forming thin but widespread and continuous horizons on sea floor muds and sands. Whilst bentonites were principally wind-transported, there is evidence of some water

  18. Wyoming bentonites. Evidence from the geological record to evaluate the suitability of bentonite as a buffer material during the long-term underground containment of radioactive wastes

    International Nuclear Information System (INIS)

    In the Swedish programme for the deep, geological disposal of radioactive wastes, bentonite is planned to be used as a barrier material to reduce groundwater flow and minimise radionuclide migration into the geosphere. One of the possible threats to long-term bentonite stability is the gradual incursion of saline water into the repository confines which may reduce the swelling capacity of the bentonite, even to the extent of eliminating the positive effects of mixing bentonite into backfill materials. Important information may be obtained from the study of analogous processes in nature (i.e. natural analogue or natural system studies) where bentonite, during its formation, has been in long-term contact with reducing waters of brackish to saline character. Type bentonites include those mined from the Clay Spur bed at the top of the Cretaceous Mowry Formation in NE Wyoming and demarcated for potential use as a barrier material (e.g. MX-80 sodium bentonite) in the Swedish radioactive waste programme. This bentonite forms part of the Mowry Shale which was deposited in a southern embayment of the late Albian Western Interior Cretaceous sea (Mowry Sea). The question is whether these bentonite deposits show evidence of post-deposition alteration caused by the sea water in which they were deposited, and/or, have they been altered subsequently by contact with waters of increasing salinity? Bentonites are the product of pyroclastic fall deposits thought to be generated by the type of explosive, subaerial volcanic activity characteristic of Plinian eruptive systems. In Wyoming the overall composition of the original ash varied from dacite to rhyolite, or latite to trachyte. The ash clouds were carried to high altitudes and eastwards by the prevailing westerly winds before falling over the shallow Mowry Sea and forming thin but widespread and continuous horizons on sea floor muds and sands. Whilst bentonites were principally wind-transported, there is evidence of some water

  19. LONG TERM COLLECTIONS

    CERN Multimedia

    STAFF ASSOCIATION

    2010-01-01

    ACKNOWLEDGMENTS The Long-Term Collections (CLT) committee would like to warmly thank its faithful donors who, year after year, support our actions all over the world. Without you, all this would not be possible. We would like to thank, in particular, the CERN Firemen’s Association who donated 5000 CHF in the spring thanks to the sale of their traditional calendar, and the generosity of the CERN community. A huge thank you to the firemen for their devotion to our cause. And thank you to all those who have opened their door, their heart, and their purses! Similarly, we warmly thank the CERN Yoga Club once again for its wonderful donation of 2000 CHF we recently received. We would also like to tell you that all our projects are running well. Just to remind you, we are currently supporting the activities of the «Réflexe-Partage» Association in Mali; the training centre of «Education et Développement» in Abomey, Benin; and the orphanage and ...

  20. Long-Term Care Challenges in an Ageing Society: The Role of ICT and Migrants Results from a Study on England, Germany, Italy and Spain

    OpenAIRE

    KLUZER Stefano; Redecker, Christine; CENTENO MEDIAVILLA Isabel Clara

    2010-01-01

    This report synthesizes and discusses the findings of a series of studies on the use of ICT to support caregivers providing Long-Term Care at home, with particular attention to migrant caregivers. The use of Information Communication Technologies (ICT) for health and social care is playing an increasingly important role in the context of the demographic changes. As, on the one hand, people are getting older and the need for care is increasing, and, on the other hand, the number of formal ...

  1. The challenges of long-term ecological research in springs in the northern and southern Alps: indicator groups, habitat diversity, and medium-term change

    Directory of Open Access Journals (Sweden)

    Sofia WIEDENBRUG

    2011-09-01

    Full Text Available After extensive exploratory investigations into crenic habitats at the beginning of the 1990s, a number of springs were selected and long-term ecological research programmes independently initiated in the Berchtesgaden National Park (north-eastern Alps, Bavaria and the Adamello-Brenta Nature Park (south-eastern Alps, Trentino. Following more than a decade of standardized work, this paper presents a selection of results from both sides of the Alps, with a focus on zoobenthos in Bavaria and on pro- and eukaryotic algae in Trentino. In order to test the assumption that permanent springs are particularly suitable habitats for long-term ecological research, the following topics are addressed: (1 taxonomic diversity and relationships between diversity and spring typology; (2 transverse gradients in crenic habitats, hygrophilous terrestrial invertebrates and xerotolerant algae; (3 possibilities of documenting changes in species composition over decadal time scales ("medium-term" based on emergence traps, benthos, and benthic algae. The data obtained show that: (1 crenic habitats support particularly high biological diversity (but a thorough documentation of insect diversity is impossible without emergence studies; (2 helocrenes are the most species-rich habitats, for both invertebrates and diatoms; (3 dynamic (unstable and occasionally-impacted springs show identifiable signs of medium-term change, whilst particularly complex and stable crenic habitats seem to be controlled by internal processes. Our results suggest that: (1 the meiofauna is likely to react directly to environmental change, while emergers and the hygrophilous terrestrial fauna are indirectly affected, and (2 diatoms react both to direct effects of environmental change, e.g. discharge and hydrochemistry, and to indirect effects on the surroundings of the spring. Based on our results, long-term research strategies are discussed. For long-term studies, we propose a focus on meiofauna and

  2. Effects of testing on subsequent re-encoding and long-term forgetting of action-relevant materials: On the influence of recall type.

    Science.gov (United States)

    Kubik, Veit; Nilsson, Lars-Göran; Olofsson, Jonas K; Jönsson, Fredrik U

    2015-10-01

    Testing one's memory of previously studied information reduces the rate of forgetting, compared to restudy. However, little is known about how this direct testing effect applies to action phrases (e.g., "wash the car") - a learning material relevant to everyday memory. As action phrases consist of two different components, a verb (e.g., "wash") and a noun (e.g., "car"), testing can either be implemented as noun-cued recall of verbs or verb-cued recall of nouns, which may differently affect later memory performance. In the present study, we investigated the effect of testing for these two recall types, using verbally encoded action phrases as learning materials. Results showed that repeated study-test practice, compared to repeated study-restudy practice, decreased the forgetting rate across 1 week to a similar degree for both noun-cued and verb-cued recall types. However, noun-cued recall of verbs initiated more new subsequent learning during the first restudy, compared to verb-cued recall of nouns. The study provides evidence that testing has benefits on both subsequent restudy and long-term retention of action-relevant materials, but that these benefits are differently expressed with testing via noun-cued versus verb-cued recall. PMID:26243692

  3. Characterisation and migration properties of silicone materials during typical long-term commercial and household use applications: a combined case study.

    Science.gov (United States)

    Helling, R; Seifried, P; Fritzsche, D; Simat, T J

    2012-01-01

    In consequent continuation of previous described studies, pre-characterised silicone materials were assessed for chemical and physical parameters during long-term usage. In a particular case study silicone moulds were used in a commercial pizza bakery on a daily basis up to 1700 times. Migration behaviour, uptake of fat, the amount of volatiles and extractables, as well as physical properties (elongation, tensile strength) were monitored for the whole period. The main question was whether a significant degradation or even breakdown of the silicone elastomer could take place yielding enhanced migration of dimethyl siloxanes. Oligomeric dimethyl siloxanes are reaction side-products of the polymerisation process and despite their origin as so-called non-intentionally added substances (NIAS) were found to be the by far most dominating constituents of the overall migration. Furthermore, the influence of long-term thermal stress on the functionality of the elastomer was proven. Migration into food was determined by (1)H-NMR and was found to decrease during the experiment from values between 11 and 18 mg kg(-1) to levels below the limit of detection (LOD migrating siloxanes beside the initial amount in the new, unused moulds could be observed. The loss of extractable siloxanes of the used compared with the new moulds was compensated by an uptake of fat and other lipophilic food constituents. The release of volatile organic compounds (VOC) decreased from 0.44% for the new moulds to 0.14% for the longest used ones (about 1700 individual uses; the corresponding summarised baking time was approximately 400 h at 180°C). GC-MS analysis of evaporating volatile compounds showed only cyclic oligomers for the new moulds but exclusively incorporated food components for the heavily used moulds. The physical properties of the silicone moulds remained almost constant during the experiment; no limitations in function due to the repeated thermal stress were observed. Similar results

  4. Alteration and long-term behaviour of different types of innovative materials for long-lived radionuclides confinement; Alteration et comportement a long terme de differentes classes de materiaux innovants pour le confinement des radionucleides a vie longue

    Energy Technology Data Exchange (ETDEWEB)

    Leturcq, G

    1998-09-29

    The present work is an experimental study on alteration mechanisms of synthetic and natural materials: aluminosilicate glasses, glass ceramics and Ti, Zr or P based ceramics. It is a part of CEA's study program on the immobilization of long- lived radionuclides and deals with chemical processes which control dissolution of amorphous and crystallized solids. The different aluminosilicate glasses studied are altered according to a process of hydrolysis of the bonds between the glass network formers; the activation energy of this reaction is about 60 kJ/mol. Alteration rates of all the glasses decrease by four orders of magnitude when the reaction progress increases. Kinetic laws based on the deviation from the thermodynamic equilibrium between leachate and the fresh solid cannot explain these great decreases. Alteration layers in the reactional interface seem to control the alteration kinetics by providing a passivation process. The chemical durability of the glass ceramics (zirconolite and titanite) improves by a factor of ten in regard to the primary glasses which were obtained by thermal treatment. Zirconium-titanate ceramics are altered only slightly by water. The altered mass corresponds to a few atomic layers only. Steady stases are quickly observed. On the basis of thermodynamic calculations, they are not correlated with saturation between the leachate and primary zirconium-titanate phases. Alteration here also ceases due to the development of a passivating layer. Models aiming at studying the chemical durability of zirconium-titanate ceramics under conditions more representative of a clayey site of geological storage were carried out. The results of the interactions of these ceramics with clays, at 708 deg.C, show clearly that there is no modification of the process of alteration, compared to the simpler pure water systems. Thus, perovskite and zirconolite do not deteriorate under these conditions. (author)

  5. Long-term environmental stewardship.

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Michael David

    2010-08-01

    The purpose of this Supplemental Information Source Document is to effectively describe Long-Term Environmental Stewardship (LTES) at Sandia National Laboratories/New Mexico (SNL/NM). More specifically, this document describes the LTES and Long-Term Stewardship (LTS) Programs, distinguishes between the LTES and LTS Programs, and summarizes the current status of the Environmental Restoration (ER) Project.

  6. PEBS: an international challenge for improve understanding of the natural barriers to isolate long-term radioactive waste; PEBS: un reto internacional para mejorar el conocimiento de las barreras naturales para aislar residuos radiactivos a largo plazo

    Energy Technology Data Exchange (ETDEWEB)

    Gaus, I.

    2015-07-01

    The radioactive materials have a wide range of applications ranging from nuclear reactors to the use of isotopes in industries, medicine or research centres. These technologies generate waste whose disposal systems are becoming more sophisticated, to the point of using artificial barriers able to isolate them from contact with other materials, precipitation, surface water and groundwater subsurface. In this context, the European project long term Performance of the engineered Barrier Systems (PeBS), funded by the seventh framework (Fp7) Euratom and has counted with the participation of ENRESA, reviewed the evolution of the performance of sealing and barrier systems of artificial barriers in relevant time scales through the development of a comprehensive method that includes experiments, models, and a consideration of the potential impacts of long-term security functions. (Author)

  7. Temporary Protected Status after 25 Years: Addressing the Challenge of Long-Term “Temporary” Residents and Strengthening a Centerpiece of US Humanitarian Protection

    Directory of Open Access Journals (Sweden)

    Claire Bergeron

    2014-04-01

    Full Text Available Since 1990, the United States has offered hundreds of thousands of non-citizens who are unable to return to their countries of origin because of war or a natural disaster a vital form of humanitarian protection: temporary protected status (TPS. While a grant of TPS does not place a non-citizen on a path to permanent residence, TPS recipients receive protection against deportation and temporary permission to live and work in the United States. Nearly 25 years after the statutory creation of TPS, however, the use of the program has been the subject of some debate, largely because of concerns over whether TPS grants are truly “temporary.”This paper examines the legal parameters of TPS and traces the program's legislative history, exploring congressional intent behind its creation. While acknowledging that extended designations of TPS are often the result of long-running international crises, the paper argues that extended TPS designations are problematic for two reasons. First, they run contrary to congressional intent, which was to create a temporary safe haven for individuals unable to return home due to emergency situations. Second, continued grants of TPS status effectively lock TPS beneficiaries into a "legal limbo," rendering them unable to fully integrate into life in the United States.This paper considers several administrative and legislative "fixes" to align the TPS program with the goal of providing temporary protection to certain individuals that do not meet the refugee definition, while also ensuring that long-term immigrants in the United States are fully able to integrate into the fabric of the country. It considers:Amending the US definition of a “refugee” to enable more would-be TPS beneficiaries to qualify for asylum;Creating a new form of subsidiary protection for individuals who cannot return home but do not meet the refugee definition;Permitting TPS holders who have resided in the United States for a certain number of

  8. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term and Elevated Temperature Irradiation: Modeling and Experimental Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, Brian; Morgan, Dane; Kaoumi, Djamel; Motta, Arthur

    2013-12-01

    irradiation. This project will focus on modeling microstructural and microchemical evolution of irradiated alloys by performing detailed modeling of such microstructure evolution processes coupled with well-designed in situ experiments that can provide validation and benchmarking to the computer codes. The broad scientific and technical objectives of this proposal are to evaluate the microstructure and microchemical evolution in advanced ferritic/martensitic and oxide dispersion strengthened (ODS) alloys for cladding and duct reactor materials under long-term and elevated temperature irradiation, leading to improved ability to model structural materials performance and lifetime. Specifically, we propose four research thrusts, namely Thrust 1: Identify the formation mechanism and evolution for dislocation loops with Burgers vector of a<100> and determine whether the defect microstructure (predominately dislocation loop/dislocation density) saturates at high dose. Thrust 2: Identify whether a threshold irradiation temperature or dose exists for the nucleation of growing voids that mark the beginning of irradiation-induced swelling, and begin to probe the limits of thermal stability of the tempered Martensitic structure under irradiation. Thrust 3: Evaluate the stability of nanometer sized Y- Ti-O based oxide dispersion strengthened (ODS) particles at high fluence/temperature. Thrust 4: Evaluate the extent to which precipitates form and/or dissolve as a function of irradiation temperature and dose, and how these changes are driven by radiation induced segregation and microchemical evolutions and determined by the initial microstructure.

  9. Assessment of advanced materials development in the European Fusion long-term Technology Programme. Report to the FTSC-P by the Advanced Materials Working Group

    International Nuclear Information System (INIS)

    In view of the transition to the next, fifth, framework program, and the resources available, the European Commission (EC) requested to launch an assessment for the Advanced Materials area, as part of the European Fusion Technology Programme. A working group chaired by the Materials Field Coordinator assessed the current status of the programme with the view to prepare its future focusing on one class of materials, as expressed by the FTSC-P. Two classes of materials: SiC/SiC ceramic composites and low activation alloys on the basis of V, Ti and Cr are presently in the Advanced Materials area. They are all in very early stages of development with a view to their application in fusion power reactors. All have adverse properties that could exclude their use. SiC/SiC ceramic composites have by far the highest potential operating temperature, contributing greatly to the efficiency of fusion power reactors. At the same time it is also the development with the highest development loss risk. This class of materials needs an integrated approach of design, manufacturing and materials development different from alloy development. The alloys with vanadium and titanium as base element have limited application windows due to their inherent properties. If the development of RAFM steels continues as foreseen, the development of V and Ti alloys is not justifiable in the frame of the advanced materials programme. The oxide dispersion strengthened variant of RAFM steels might reach similar temperature limits: about 900K. Chromium based alloys hold the promise of higher operating temperatures, but the knowledge and experience in fusion applications is limited. Investigating the potential of chromium alloys is considered worthwhile. The alloys have comparable activation hazards and early recycling potential, with properly controlled compositions. Recycling of the SiC/SiC class of materials needs further investigation. The working group concludes that at this stage no contender can be

  10. Raw materials potential and long-term raw materials supply in the pit-and-quarry sector: The Niedersachsen experience; Rohstoffpotential sowie Rohstoffsicherung fuer Steine-Erden-Rohstoffe - Erfahrungen in Niedersachsen

    Energy Technology Data Exchange (ETDEWEB)

    Langer, A. [Niedersaechsisches Landesamt fuer Bodenforschung, Hannover (Germany)

    1998-11-01

    The contribution outlines the potential of nometallic minerals in Niedersachsen, e.g. gravel and sand, raw materials for brick and gypsum production, and oil shales. Measures taken to ensure long-term supply and the experience gained in this sector are presented. (orig.) [Deutsch] Der Beitrag beschaeftigt sich mit dem Potential an Steine-Erden-Rohstoffen in Niedersachsen, wie u.a. Kiese und Sande, Rohstoffe der Ziegelindustrie, Rohstoffe fuer die Gipsindustrie und Oelschiefervorkommen. Zudem werden die Massnahmen und die Erfahrungen bei der Rohstoffsicherung geschildert.

  11. Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Dueck, Ann; Birgersson, Martin; Nilsson, Ulf; Hernan-Haakansson, Tania (Clay Technology AB, Lund (Sweden)); Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden); Goeteborg Univ., Dept. of Cell and Molecular Biology, Goeteborg (Sweden)); Nilsson, Sara; Eriksen, Trygve E. (School of Chemical Science and Engineering, Nuclear chemistry, Royal Inst. of Tech., Stockholm (Sweden)); Rosborg, Bo (Rosborg Consulting, Nykoeping (Sweden))

    2009-11-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical

  12. Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

    International Nuclear Information System (INIS)

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below ∼140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical properties

  13. Evaluation of long-term interaction between cement and bentonite for geological disposal (2) XAFS analysis of calcium silicate hydrate precipitates at cementitious and bentonite material interface

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Numerical analyses of the long-term alteration of the engineered barriers used for the disposal of TRU waste predicted precipitation of C-S-H minerals at the interface between the cementitious materials and the bentonite-based buffer. When the C-S-H precipitates at this interface, the diffusion coefficient in the engineered barriers will decrease, resulting in reduced mass transport, which feeds back to reduce the rate of subsequent alteration. The C-S-H predicted to form at the cement-bentonite interface could not be identified directly using conventional analytical tools, including XRD, due to its low crystallinity. The authors propose that XAFS analysis, which provides spectra sensitive to the valency and coordination of the element of interest regardless of its crystallinity, would be capable of characterizing the C-S-H. The presence of the C-S-H precipitated as a secondary mineral has already been confirmed by applying chemical and XAFS analyses to bentonite specimens collected from the compacted bentonite-cement interface. However, because of the limitations on the width of specimens that can be collected by cutting from block samples, i.e. approximately 1 mm, detailed concentration profiles could not be obtained for this secondary C-S-H. In this study, XAFS spectra of thin specimens were measured using an X-ray detector in order to obtain detailed concentration profiles for the C-S-H formed at the interface between the cementitious material and the bentonite-based buffer. The X-ray detector used in the XAFS analysis consists of 1024 photodiodes arranged in line with a 0.025 mm pitch (photodiode array; PDA). Ca-K-edge XAFS measurements were conducted at the Photon Factory of the KEK. The synchrotron was operated in top-up mode with 450 mA during the measurements. Specimens were taken from a contact sample of compacted bentonite (Kunigel V1; dry density of 1.6 g/cm3) and hardened OPC (w/c = 0.6) immersed in

  14. Beyond the novelty effect: The role of in-game challenges, rewards and choices for long-term motivation to improve obesity-related health behaviours in adolescents

    OpenAIRE

    Anne Martin; Janet Hanley; Rajeeb Rashid

    2015-01-01

    Background: The prevalence of adolescent obesity is high in the UK. Engaging adolescent boys and girls in health behaviour related to the prevention of obesity proves to be challenging. Mobile and wireless technology shows promise for increasing knowledge and motivation to increase physical activity and healthy eating by capturing the interest of many adolescents. However, solutions for overcoming the novelty effect to enable habit formation and thus long-lasting behaviour change needs to be ...

  15. Designing Spacecraft and Mission Operations Plans to Meet Flight Crew Radiation Dose Requirements: Why is this an "Epic Challenge" for Long-Term Manned Interplanetary Flight

    Science.gov (United States)

    Koontz, Steven

    2012-01-01

    Outline of presentation: (1) Radiation Shielding Concepts and Performance - Galactic Cosmic Rays (GCRs) (1a) Some general considerations (1b) Galactic Cosmic Rays (2)GCR Shielding I: What material should I use and how much do I need? (2a) GCR shielding materials design and verification (2b) Spacecraft materials point dose cosmic ray shielding performance - hydrogen content and atomic number (2c) Accelerator point dose materials testing (2d) Material ranking and selection guidelines (2e) Development directions and return on investment (point dose metric) (2f) Secondary particle showers in the human body (2f-1) limited return of investment for low-Z, high-hydrogen content materials (3) GCR shielding II: How much will it cost? (3a) Spacecraft design and verification for mission radiation dose to the crew (3b) Habitat volume, shielding areal density, total weight, and launch cost for two habitat volumes (3c) It's All about the Money - Historical NASA budgets and budget limits (4) So, what can I do about all this? (4a) Program Design Architecture Trade Space (4b) The Vehicle Design Trade Space (4c) Some Near Term Recommendations

  16. Beyond the novelty effect: The role of in-game challenges, rewards and choices for long-term motivation to improve obesity-related health behaviours in adolescents

    Directory of Open Access Journals (Sweden)

    Anne Martin

    2015-10-01

    Full Text Available Background: The prevalence of adolescent obesity is high in the UK. Engaging adolescent boys and girls in health behaviour related to the prevention of obesity proves to be challenging. Mobile and wireless technology shows promise for increasing knowledge and motivation to increase physical activity and healthy eating by capturing the interest of many adolescents. However, solutions for overcoming the novelty effect to enable habit formation and thus long-lasting behaviour change needs to be explored. Aim: This study aimed to explore Scottish adolescents’ perception of the usability and acceptability of a serious mobile game, wearable activity sensors and a smart phone eDiary application (app for promoting physical activity and healthy eating. Methods: The game, sensors and app are being developed following the COM-B model of the Behaviour Change Wheel. The technology is interlinked in that physical activity tracked by the wearable activity sensors and healthy eating captured by using the eDiary app are central to recover the player’s energy levels in the serious game. The player replenishes their in-game energy to progress in the game and to boost abilities. Applying a user-centred approach for developing the technology, 11 adolescents aged 13-16 years (6 boys, 5 girls participated in semi-structured focus groups. This was the first of three pre-pilot study iterations. Mock-up versions of the serious mobile game, wearable activity sensors and the prototype of the eDiary app were presented. Focus groups were audio-recorded, transcribed and thematically analysed. Results: All adolescents responded positively to the general idea of the game and all were keen to play the actual game once developed. Adolescents understood the importance and novelty of the link between player’s real-life health behaviours and in-game activities for improving obesity-related health behaviour. It became evident that the adolescents would only be motivated to be

  17. Long term e-archiving

    OpenAIRE

    Dobratz, Susanne

    2002-01-01

    Conclusions of the breakout session "Long term e-archiving". Looking at the motto of this workshop “Gaining independence with e-Print archives and OAI” it suggests first of all that using e-Print publishing methods especially in the sense of a scholarly non-profit publishing independently from any commercial publishing house offers a unique chance to scientists.

  18. The Uneasy Case for Favoring Long-Term Shareholders

    OpenAIRE

    Jesse M. Fried

    2015-01-01

    This paper challenges a persistent and pervasive view in corporate law and corporate governance: that a firm’s managers should favor long-term shareholders over short-term shareholders, and maximize long-term shareholders’ returns rather than the short-term stock price. Underlying this view is a strongly-held intuition that taking steps to increase long-term shareholder returns will generate a larger economic pie over time. But this intuition, I show, is flawed. Long-term shareholders, like s...

  19. Nuclear Energy, Long Term Requirements

    International Nuclear Information System (INIS)

    There are serious warnings about depletion of oil and gas and even more serious warnings about dangers of climate change caused by emission of carbon dioxide. Should developed countries be called to replace CO2 emitting energy sources as soon as possible, and the time available may not be longer then few decades, can nuclear energy answer the call and what are the requirements? Assuming optimistic contribution of renewable energy sources, can nuclear energy expand to several times present level in order to replace large part of fossil fuels use? Paper considers intermediate and long-term requirements. Future of nuclear power depends on satisfactory answers on several questions. First group of questions are those important for near and intermediate future. They deal with economics and safety of nuclear power stations in the first place. On the same time scale a generally accepted concept for radioactive waste disposal is also required. All these issues are in the focus of present research and development. Safer and more economical reactors are targets of international efforts in Generation IV and INPRO projects, but aiming further ahead these innovative projects are also addressing issues such as waste reduction and proliferation resistance. However, even assuming successful technical development of these projects, and there is no reason to doubt it, long term and large-scale nuclear power use is thereby not yet secured. If nuclear power is to play an essential role in the long-term future energy production and in reduction of CO2 emission, than several additional questions must be replied. These questions will deal with long-term nuclear fuel sufficiency, with necessary contribution of nuclear power in sectors of transport and industrial processes and with nuclear proliferation safety. This last issue is more political then technical, thus sometimes neglected by nuclear engineers, yet it will have essential role for the long-term prospects of nuclear power. The

  20. Comparing long term energy scenarios

    International Nuclear Information System (INIS)

    Major projection studies by international organizations and senior analysts have been compared with reference to individual key parameters (population, energy demand/supply, resources, technology, emissions and global warming) to understand trends and implications of the different scenarios. Then, looking at the long term (i.e., 2050 and beyond), parameters and trends have been compared together to understand and quantify whether and when possible crisis or market turbulence might occur due to shortage of resources or environmental problems

  1. Challenges and reforms in Long-Term Care policy in Spain - See more at: http://www.gigapp.org/index.php/component/jresearch/?view=publication&task=show&id=1808#sthash.QjsbaT7Q.dpuf

    Directory of Open Access Journals (Sweden)

    Moreno-Fuentes, Francisco Javier

    2015-02-01

    Full Text Available The NorSpaR project aims to analyse the main public policy initiatives by which Norway and Spain cope with the new social and economic challenges derived from the so-called New Social Risks (NSR. Although both countries present significant differences in their institutional settings (such as Spanish EU membership, or its belonging to diverse welfare regimes types (Norway is generally included in the Nordic regime, while Spain is part of the Mediterranean one, both countries share a common interest in addressing the aforementioned challenges while maintaining social cohesion. In the last decade, governments in both countries have tried to respond to those challenges by reforming their labour markets, adapting their unemployment schemes, as well as their gender, family and long-term care policies. The analysis covered in this project includes three areas of public policy addressing NSR. First, dependency is one of the most daunting challenges for post-industrial societies experiencing population ageing and with an increasing number of frail people in need of care. This situation is forcing governments to rethink their long-term care policies. Second, family and gender public programs need to respond to the growing difficulties of families in reconciling professional and family life. Third, in the transition to a post-industrial order, and in a context of mass unemployment, social protection systems have a renewed prominence. Along with the so-called passive policies offering financial support to the unemployed, active labour market policies are geared to put people back into work. In our analysis we try to find answers to the following questions: What are the challenges that each of these policies have been trying to address in recent years? How have these policies evolved? What kinds of reforms have been implemented, and which ones have been neglected? Have the policy goals and targets of welfare programs been modified in any significant way

  2. The Long Term Agroecosystem Research Network - Shared research strategy

    Science.gov (United States)

    Agriculture faces tremendous challenges in meeting multiple societal goals, including a safe and plentiful food supply; climate change adaptation and mitigation; supplying sources of bioenergy; improving water, air, and soil quality; and maintaining biodiversity. The Long Term Agroecosystem Research...

  3. Titanium for long-term tritium storage

    Energy Technology Data Exchange (ETDEWEB)

    Heung, L.K.

    1994-12-01

    Due to the reduction of nuclear weapon stockpile, there will be an excess of tritium returned from the field. The excess tritium needs to be stored for future use, which might be several years away. A safe and cost effective means for long term storage of tritium is needed. Storing tritium in a solid metal tritide is preferred to storing tritium as a gas, because a metal tritide can store tritium in a compact form and the stored tritium will not be released until heat is applied to increase its temperature to several hundred degrees centigrade. Storing tritium as a tritide is safer and more cost effective than as a gas. Several candidate metal hydride materials have been evaluated for long term tritium storage. They include uranium, La-Ni-Al alloys, zirconium and titanium. The criteria used include material cost, radioactivity, stability to air, storage capacity, storage pressure, loading and unloading conditions, and helium retention. Titanium has the best combination of properties and is recommended for long term tritium storage.

  4. Materials for Space: It's Challenging!

    Science.gov (United States)

    Johnson, Sylvia M.

    2016-01-01

    Space environments place tremendous demands on materials that must perform with exceptional reliability to realize the goals of human or robotic space exploration missions. Materials are subjected to extremes of temperature, pressure, radiation and mechanical loads during all phases of use, including takeoff and ascent, exposure to space or entry into an atmosphere, and operation in a planetary atmosphere. Space materials must be robust and enable the formation of lightweight structures or components that perform the required functions; materials that perform multiple functions are of particular interest. This talk will review the unique challenges for materials in space and some of the specific material capabilities that will be needed for future exploration missions. A description of needs and trends in thermal protection materials and systems will complete the talk.

  5. Long-Term Care Policy: Singapore's Experience.

    Science.gov (United States)

    Chin, Chee Wei Winston; Phua, Kai-Hong

    2016-01-01

    Singapore, like many developed countries, is facing the challenge of a rapidly aging population and the increasing need to provide long-term care (LTC) services for elderly in the community. The Singapore government's philosophy on care for the elderly is that the family should be the first line of support, and it has relied on voluntary welfare organizations (VWOs) or charities for the bulk of LTC service provision. For LTC financing, it has emphasized the principles of co-payment and targeting of state support to the low-income population through means-tested government subsidies. It has also instituted ElderShield, a national severe disability insurance scheme. This paper discusses some of the challenges facing LTC policy in Singapore, particularly the presence of perverse financial incentives for hospitalization, the pitfalls of over-reliance on VWOs, and the challenges facing informal family caregivers. It discusses the role of private LTC insurance in LTC financing, bearing in mind demand- and supply-side failures that have plagued the private LTC insurance market. It suggests the need for more standardized needs assessment and portable LTC benefits, with reference to the Japanese Long-Term Care Insurance program, and also discusses the need to provide more support to informal family caregivers. PMID:26808468

  6. Long term stability of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Kundur, P.; Gao, B. [Powertech Labs. Inc., Surrey, BC (Canada)

    1994-12-31

    Power system long term stability is still a developing subject. In this paper we provide our perspectives and experiences related to long term stability. The paper begins with the description of the nature of the long term stability problem, followed by the discussion of issues related to the modeling and solution techniques of tools for long term stability analysis. Cases studies are presented to illustrate the voltage stability aspect and plant dynamics aspect of long term stability. (author) 20 refs., 11 figs.

  7. Long-term governance for sustainability

    International Nuclear Information System (INIS)

    Meritxell Martell spoke of the long-term aspects of radioactive waste management. She pointed out that decision-making processes need to be framed within the context of sustainability, which means that a balance should be sought between scientific considerations, economic aspects and structural conditions. Focusing on structural aspects, Working Group 3 of COWAM-Spain came to the conclusion that the activity of the regulator is a key factor of long-term management. Another finding is that from a sustainability perspective multi-level governance is more effective for coping with the challenges of radioactive waste management than one tier of government-making decisions. The working group also felt that the current Local Information Committees need to evolve towards more institutionalized and legitimized mechanisms for long-term involvement. Ms. Martell introduced a study comparing the efficiency of economic instruments to advance sustainable development in nuclear communities vs. municipalities in mining areas. The study found that funds transferred to nuclear zones had become a means to facilitate local acceptance of nuclear facilities rather than a means to promote socio-economic development. Another finding is that economic instruments are not sufficient guarantees of sustainable development by themselves; additional preconditions include leadership, vision and entrepreneur-ship on the part of community leaders, private or public investments, among others. Finally, Ms. Martell summarised the challenges faced by the Spanish radioactive waste management programme, which include the need for strategic thinking, designing the future in a participatory fashion, and working with local and regional governments and citizens to devise mechanisms for social learning, economic development and environmental protection. (author)

  8. Long Term R&D for Safeguards

    International Nuclear Information System (INIS)

    Within the Office of Defense Nuclear Non-proliferation Research and Development (DNN R&D), the Nuclear Weapons and Material Security Team conducts research to develop advanced detection and source technologies for the purposes of detecting and characterizing special nuclear materials (SNM); international safeguards and radiological source replacement; nuclear arms control treaty monitoring and verification; and supporting interdiction and nuclear security efforts across NNSA. Our safeguards-specific goal is to develop and demonstrate new technologies and capabilities to cooperatively quantify and track SNM in the nuclear fuel cycle and detect any diversion of these materials for illicit purposes. Our goals and objectives align with a technology goal of the International Atomic Energy's Long Term Strategy for 2012-2023 ''to improve the Department's technical capabilities by making use of scientific and technological innovation, and to enhance its readiness to safeguard new nuclear technology and support new verification missions.'' Toward that end, we work closely with the US Department of Energy's Next Generation Safeguards Initiative and the US Support Programme to meet their specific long term needs. In this talk we will give a brief overview of current research efforts and specifically describe several helium-3 replacement technologies, advanced spent nuclear fuel characterization methods, and upcoming tags and seals technologies. We will present additional research into cross cutting enabling technologies such as advancements in detector materials, electronics, and sources, and basic physics measurements that support long term safeguards R&D. (author)

  9. Long Term Durability of Glass Reinforced Composites

    OpenAIRE

    Cain, Jason James

    2008-01-01

    This dissertation discusses topics related to the performance and long-term durability of glass-reinforced composites. The first portion of this dissertation describes work to assess the effect that post-curing has on widely used E-glass/vinyl-ester composites (E-glass/Derakane 510-A and E-glass/Derakane 8084). It is shown that post-curing can have significant positive effects on the initial material properties of glass-reinforced vinyl ester composites. Furthermore, the post-cure of 82Â...

  10. Influenza in long-term care facilities: preventable, detectable, treatable.

    Science.gov (United States)

    Mossad, Sherif B

    2009-09-01

    Influenza in long-term care facilities is an ever more challenging problem. Vaccination of residents and health care workers is the most important preventive measure. Although vaccine efficacy has been questioned, the preponderance of data favors vaccination. Antiviral resistance complicates postexposure chemoprophylaxis and treatment. Factors that limit the choice of antiviral agents in this patient population include limited vaccine supplies and impaired dexterity and confusion in long-term care residents. PMID:19726556

  11. What Does Long-Term Care Include?

    Medline Plus

    Full Text Available Video: "What Does Long-Term Care Include?" Long-term care involves a variety of services designed to meet a person's health or personal care needs during a short or long period of ...

  12. Model-based prediction of long-term leaching of contaminants from secondary materials in road constructions and noise protection dams.

    Science.gov (United States)

    Beyer, Christof; Konrad, Wilfried; Rügner, Hermann; Bauer, Sebastian; Liedl, Rudolf; Grathwohl, Peter

    2009-02-01

    In this study, contaminant leaching from three different secondary materials (demolition waste, municipal solid waste incineration ash, and blast furnace slag) to groundwater is assessed by numerical modeling. Reactive transport simulations for a noise protection dam and a road dam (a typical German autobahn), in which secondary materials are reused as base layers, were performed to predict the breakthrough of a conservative tracer (i.e., a salt) and sorbing contaminants (e.g., PAHs like naphthalene and phenanthrene or heavy metals) at the groundwater table. The dam constructions have a composite architecture with soil covers in inclined layers and distinct contrasts in the unsaturated hydraulic properties of the used materials. Capillary barrier effects result in strong spatial variabilities of flow and transport velocities. Contaminant breakthrough curves at the groundwater table show significant tailing due to slow sorption kinetics and a wide distribution of travel times. While conservative tracer breakthrough depends primarily on subsoil hydraulic properties, equilibrium distribution coefficients and sorption kinetics represent additional controlling factors for contaminant spreading. Hence, the three secondary materials show pronounced differences in the temporal development of leached contaminant concentrations with consequences for breakthrough times and peak concentrations at the groundwater table. Significant concentration reductions due to dispersion occur only if the source concentrations decrease significantly prior to the arrival of the contaminant at the groundwater table. Biodegradation causes significant reduction of breakthrough concentrations only if flow velocities are low. PMID:18707860

  13. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Salafranca, Jesús, E-mail: fjsl@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Clemente, Isabel, E-mail: isabelclemente1984@gmail.com [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Isella, Francesca, E-mail: Francesca.Isella@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy); Nerín, Cristina, E-mail: cnerin@unizar.es [Aragón Institute of Engineering Research (I3A), EINA, Department of Analytical Chemistry, University of Zaragoza, María de Luna 3 (Torres Quevedo Bldg.), 50018 Zaragoza (Spain); Bosetti, Osvaldo, E-mail: Osvaldo.Bosetti@goglio.it [Goglio S.p.A. Packaging Division, Via dell' Industria 7, 21020 Daverio (Italy)

    2015-06-09

    Highlights: • 13 different food-use multilayers unirradiated and gamma-irradiated were studied. • 60–80 compounds/sample were identified by SPME–GC–MS even after 8-month storage. • Volatile profile of air- and N{sub 2}-filled bags greatly differed after irradiation. • Principal component analysis classified the samples into 4 groups. • Migration from irradiated materials to vapor phase was much lower than EU limits. - Abstract: The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction–gas chromatography–mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60–80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011.

  14. Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

    International Nuclear Information System (INIS)

    Highlights: • 13 different food-use multilayers unirradiated and gamma-irradiated were studied. • 60–80 compounds/sample were identified by SPME–GC–MS even after 8-month storage. • Volatile profile of air- and N2-filled bags greatly differed after irradiation. • Principal component analysis classified the samples into 4 groups. • Migration from irradiated materials to vapor phase was much lower than EU limits. - Abstract: The profile of volatile compounds released from 13 different multilayer polymeric materials for food use, before and after their exposure to gamma radiation, has been assessed by solid-phase microextraction–gas chromatography–mass spectrometry. Thermosealed bags of different materials were filled with either air or nitrogen to evaluate the oxygen influence. One-third of the samples were analyzed without irradiation, whereas the rest were irradiated at 15 and 25 kGy. Half of the samples were processed just after preparation and the other half was stored for 8 months at room temperature prior to analysis. Very significant differences between unirradiated and irradiated bags were found. About 60–80 compounds were released and identified per sample. A huge peak of 1,3-ditertbutylbenzene was present in most of the irradiated samples. An outstanding reproducibility in all the variables evaluated (chromatograms, oxygen percentage, volume of bags) was noticed. Independently of filling gas, the results of unirradiated materials were almost identical. In contrast, the chromatographic profile and the odor of irradiated bags filled with nitrogen were completely different to those filled with air. Principal component analysis was performed and 86.9% of the accumulated variance was explained with the first two components. The migration of compounds from irradiated materials to the vapor phase was much lower than the limits established in the Commission Regulation (EU) No 10/2011

  15. Research Opportunities in Corrosion Science for Long-Term Prediction of Materials Performance: A Report of the DOE Workshop on “Corrosion Issues of Relevance to the Yucca Mountain Waste Repository”.

    Energy Technology Data Exchange (ETDEWEB)

    Payer, Joe H. [Case Western Reserve Univ., Cleveland, OH (United States); Scully, John R. [Univ. of Virginia, Charlottesville, VA (United States)

    2003-07-29

    The report summarizes the findings of a U.S. Department of Energy workshop on “Corrosion Issues of Relevance to the Yucca Mountain Waste Repository”. The workshop held on July 29-30, 2003 in Bethesda, MD and was co-sponsored by the Office of Basic Energy Sciences and Office of Civilian Radioactive Waste Management. The workshop focus was corrosion science relevant to long-term prediction of materials performance in hostile environments and with special focus on relevance to the permanent disposal of nuclear waste at the Yucca Mountain Repository. The culmination of the workshop is this report that identifies both generic and Yucca-Mountain-Project specific research opportunities in basic and applied topic areas. The research opportunities would be realized well after the U.S. Nuclear Regulatory Commission’s initial construction-authorization licensing process. At the workshop, twenty-three invited scientists deliberated on basic and applied science opportunities in corrosion science relevant to long-term prediction of damage accumulation by corrosive processes that affect materials performance.

  16. Long-term biosignals visualization and processing

    OpenAIRE

    Gomes, Ricardo Rafael Baptista

    2011-01-01

    Long-term biosignals acquisitions are an important source of information about the patients’state and its evolution. However, long-term biosignals monitoring involves managing extremely large datasets, which makes signal visualization and processing a complex task. To overcome these problems, a new data structure to manage long-term biosignals was developed. Based on this new data structure, dedicated tools for long-term biosignals visualization and processing were implemented. A mul...

  17. Experimental study on long-term stability of bentonite. Influence of hyperalkaline pore water generated by the chemical reaction of cementitious material and saline groundwater

    International Nuclear Information System (INIS)

    The engineered barrier system (EBS) in the geological disposal of TRU waste is composed of bentonite and cementitious materials. The montmorillonite component of bentonite is, however, not chemically compatible with the high pH leachates derived from cementitious materials and may alter to a more stable secondary mineral assemblage. Previous research for TRU waste disposal has focused on the alteration behavior of bentonite in leachates from cementitious materials exposed to fresh groundwater. If the EBS is located in the coastal region, then the leachates will instead be derived from the interaction of cementitious materials and saline groundwater. This has important implications for the alteration of bentonite because the likely difference in the chemical composition of the leachate will influence the dissolution rate of montmorillonite and the composition of the secondary mineral assemblage. At present, these processes are not well understood. The focus of the present study was to examine the alteration of bentonite in high pH saline groundwaters. Two solutions were used in batch immersion experiments of bentonite. The first solution was prepared using a mixture of NaOH and NaCl (NN), and the second solution was prepared using synthetic Region 1 water (high K and Na content) and synthetic seawater (SR). Analysis showed that bentonite altered to analcime in the NN solution and to analcime and phillipsite-K in the SR solution. Moreover, the generation of calcium silicate hydrate and calcium aluminosilicate hydrate were extrapolated in the SR solution based on the concentrations of dissolved species. These alteration products were in accord with Oda et al.(2005), who summarized the possible relationships between the secondary mineral assemblage of bentonite under high pH conditions and the influence of solution composition. (author)

  18. Timber beams subjected to long - term loading

    Science.gov (United States)

    Sógel, K.

    2010-09-01

    Wood is a significant structural material, which is often used for timber bearing structures. Elements of timber structures must especially satisfy safety requirements, which are expressed by the ultimate limit states in the established standards. The structure must also satisfy the serviceability limit states. Local and global deformations make it impossible for the structure to serve the purpose it was designed for. It is important to take the deflections and their possible increase into account in the design to provide a structure which can be used during the whole period of service. Based on earlier examinations, it is known that a timber element over the course of long-term loading shows creep behavior. The structure of wood is able to adapt to the conditions of the surrounding environment. The properties of wood are especially affected by the relative humidity of the air and then by the type, intensity and duration of the loading. The most important factors affecting the serviceability of timber structures are volume changes caused by humidity and additional deflections caused by the effects of long-term loading. These phenomena emphasize the importance of serviceability limit states for timber structures. The paper deals with a long-term experimental investigation of timber girders that are currently often used. The aim was to obtain the deflection curves and mark the time dependence and the final deflections. The paper will also define the approximations for simulating the time-dependent deflections and obtain the creep coefficients for calculating the final deflections of the girders investigated.

  19. Long term energy and materials strategies for reduction of industrial CO2 emissions. A case study for the iron and steel industry

    International Nuclear Information System (INIS)

    Greenhouse gas emissions emerged in the last decade as a key environmental problem on the political agenda. The most important greenhouse gas is carbon dioxide (CO2). This gas results from the combustion of fossil fuels (natural gas, oil and coal). As a consequence, greenhouse gas emission reduction is closely related to energy policies. Even a stabilization of the atmospheric CO2 concentrations at a level of 750 ppm (parts per million), more than twice the current level, implies a reduction of global emissions by 50% in the next century. The world population will simultaneously double and the capita energy consumption will increase. As a consequence, the Western industrialized countries will have to reduce their per capita emissions by more than a factor four. Such a policy goal will significantly affect the future industrial production structure. Approximately 4% of the global CO2 emissions can be attributed to the production of iron and steel. This sector is the most important industrial source of CO2. The case study for the iron and steel industry will be discussed in this paper in order to illustrate the impact of significant CO2 emission mitigation on the industry. The goal is to show the consequences of CO2 policies for R and D planning and investment decisions. The notion that the iron and steel industry will be affected by CO2 policies is not new; a number of studies have addressed this issue before. These studies have compared steel production technologies and emission reduction options within the iron and steel production sector. In this paper, the emission reduction in the iron and steel industry is analyzed within the framework of the changing (inter-)national energy and materials system configuration. This includes all production, conversion and consumption processes. The impact of CO2 policies on the optimal choice of steel production technologies and on the competitiveness of steel compared to other materials will be discussed. This paper focuses on

  20. Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic short stack fixture, Part II: Sealing glass stability, microstructure and interfacial reactions

    Science.gov (United States)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.; Choi, Jung-Pyung

    2014-03-01

    A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing methods under realistic conditions. Part II of the work examined the sealing glass stability, microstructure development, interfacial reaction, and volatility issues of a 3-cell stack with LSM-based cells. After 6000 h of testing, the refractory sealing glass YSO7 showed desirable chemical compatibility with YSZ electrolyte in that no discernable interfacial reaction was identified. In addition, no glass penetration into the thin electrolyte was observed. At the aluminized AISI441 interface, the protective alumina coating appeared to be corroded by the sealing glass. Air side interactions appeared to be more severe than fuel side interactions. Metal species such as Cr, Mn, and Fe were detected in the glass, but were limited to the vicinity of the interface. No alkaline earth chromates were found at the air side. Volatility was also studied in a similar glass and weight loss in a wet reducing environment was determined. Using the steady-state volatility data, the life time weight loss of refractory sealing glass YSO77 was estimated to be less than 0.1 wt%.

  1. Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic short stack fixture, Part II: sealing glass stability, microstructure and interfacial reactions.

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Y. S.; Stevenson, Jeffry W.; Choi, Jung-Pyung

    2014-03-15

    A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing methods under realistic conditions. Part I of the work addressed the stack fixture, seal system and cell performance of a 3-cell short stack tested at 800oC for 6000h. Commercial NiO-YSZ anode-supported thin YSZ electrolyte cells with LSM cathodes were used for assessment and were tested in constant current mode with dilute (~50% H2) fuel versus air. Part II of the work examined the sealing glass stability, microstructure development, interfacial reactions, and volatility issues. Part III of the work investigated the stability of Ce-(Mn,Co) spinel coating, AISI441 metallic interconnect, alumina coating, and cell degradation. After 6000h of testing, the refractory sealing glass YSO77 (Ba-Sr-Y-B-Si) showed desirable chemical compatibility with YSZ electrolyte in that no discernable interfacial reaction was identified, consistent with thermodynamic calculations. In addition, no glass penetration into the thin electrolyte was observed. At the aluminized AISI441 interface, the protective alumina coating appeared to be corroded by the sealing glass. Air side interactions appeared to be more severe than fuel side interactions. Metal species such as Cr, Mn, and Fe were detected in the glass, but were limited to the vicinity of the interface. No alkaline earth chromates were found at the air side. Volatility was also studied in a similar glass and weight loss in a wet reducing environment was determined. Using the steady-state volatility data, the life time (40,000h) weight loss of refractory sealing glass YSO77 was estimated to be less than 0.1 wt%.

  2. Managing Records for the Long Term - 12363

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) is responsible for managing vast amounts of information documenting historical and current operations. This information is critical to the operations of the DOE Office of Legacy Management. Managing legacy records and information is challenging in terms of accessibility and changing technology. The Office of Legacy Management is meeting these challenges by making records and information management an organizational priority. The Office of Legacy Management mission is to manage DOE post-closure responsibilities at former Cold War weapons sites to ensure the future protection of human health and the environment. These responsibilities include environmental stewardship and long-term preservation and management of operational and environmental cleanup records associated with each site. A primary organizational goal for the Office of Legacy Management is to 'Preserve, Protect, and Share Records and Information'. Managing records for long-term preservation is an important responsibility. Adequate and dedicated resources and management support are required to perform this responsibility successfully. Records tell the story of an organization and may be required to defend an organization in court, provide historical information, identify lessons learned, or provide valuable information for researchers. Loss of records or the inability to retrieve records because of poor records management processes can have serious consequences and even lead to an organisation's downfall. Organizations must invest time and resources to establish a good records management program because of its significance to the organization as a whole. The Office of Legacy Management will continue to research and apply innovative ways of doing business to ensure that the organization stays at the forefront of effective records and information management. DOE is committed to preserving records that document our nation's Cold War legacy, and the Office of Legacy

  3. Standard practice for prediction of the long-term behavior of materials, including waste forms, used in engineered barrier systems (EBS) for geological disposal of high-level radioactive waste

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice describes test methods and data analyses used to develop models for the prediction of the long-term behavior of materials, such as engineered barrier system (EBS) materials and waste forms, used in the geologic disposal of spent nuclear fuel (SNF) and other high-level nuclear waste in a geologic repository. The alteration behavior of waste form and EBS materials is important because it affects the retention of radionuclides by the disposal system. The waste form and EBS materials provide a barrier to release either directly (as in the case of waste forms in which the radionuclides are initially immobilized), or indirectly (as in the case of containment materials that restrict the ingress of groundwater or the egress of radionuclides that are released as the waste forms and EBS materials degrade). 1.1.1 Steps involved in making such predictions include problem definition, testing, modeling, and model confirmation. 1.1.2 The predictions are based on models derived from theoretical considerat...

  4. Materials Challenges for Automotive PEM Fuel Cells

    Science.gov (United States)

    Gasteiger, Hubert

    2004-03-01

    Over the past few years, significant R efforts aimed at meeting the challenging cost and performance targets required for the use of Polymer Electrolyte Membrane (PEM) fuel cells in automotive applications. Besides engineering advances in bipolar plate materials and design, the optimization of membrane-electrode assemblies (MEAs) was an important enabler in reducing the cost and performance gaps towards commercial viability for the automotive market. On the one hand, platinum loadings were reduced from several mgPt/cm2MEA [1] to values of 0.5-0.6 mgPt/cm2MEA in current applications and loadings as low as 0.25 mgPt/cm2MEA have been demonstrated on the research level [2]. On the other hand, implementation of thin membranes (20-30 micrometer) [3, 4] as well as improvements in diffusion medium materials, essentially doubled the achievable power density of MEAs to ca. 0.9 W/cm2MEA (at 0.65 V) [5], thereby not only reducing the size of a PEMFC fuel cell system, but also reducing its overall materials cost (controlled to a large extent by membrane and Pt-catalyst cost). While this demonstrated a clear path towards automotive applications, a renewed focus of R efforts is now required to develop materials and fundamental materials understanding to assure long-term durability of PEM fuel cells. This presentation therefore will discuss the state-of-the-art knowledge of catalyst, catalyst-support, and membrane degradation mechanisms. In the area of Pt-catalysts, experience with phosphoric acid fuel cells (PAFCs) has shown that platinum sintering leads to long-term performance losses [6]. While this is less critical at the lower PEMFC operating temperatures (200C), very little is known about the dependence of Pt-sintering on temperature, cell voltage, and catalyst type (i.e., Pt versus Pt-alloys) and will be discussed here. Similarly, carbon-support corrosion can contribute significantly to voltage degradation in PAFCs [7], and even in the PEMFC environment more corrosion

  5. Long-term stability of bentonite. A literature review

    International Nuclear Information System (INIS)

    The long-term thermodynamic stability of the bentonite buffer in the evolving chemical, thermal and hydrological conditions at Olkiluoto has been evaluated by reviewing the relevant experimental data and natural occurrences of bentonite that could serve as analogues for the long-term bentonite stability in the expected repository conditions, especially focussing on mineral transformations due, among others, to thermal effects including cementation. Natural occurrences with stable smectite have been reviewed and compared with Olkiluoto groundwater compositions at present and during the expected hydrogeochemical evolution of the repository. Alteration of the bentonite buffer is expected to be insignificant for natural groundwater conditions at present and for the evolving groundwater conditions at the expected thermal boundary conditions caused by the heat induced from the fuel canisters (+ and SiO2 and elevated pH due to degradation and dissolution processes. These may alter the conditions in the repository that may favour alteration and cementation processes. The amounts of foreign materials to be used in the repository will be updated along with the progress of the construction. Also the information on their impact on the barriers needs to be evaluated in more detail, including the degradation rate, mobility or dilution of the foreign materials in the repository environment. The exchangeable cation composition of the buffer bentonite is expected to equilibrate with the surrounding groundwater during and after saturation. This process is expected to lead towards Ca-dominant exchangeable cation composition within the montmorillonite interlayer spaces in the buffer. In general it seems that the transformation towards Ca-dominated composition would favour the long-term stability of the buffer as Ca-dominated smectite (compared to Na-dominated type) has larger water retention capacity and anion incorporation to the interlayer space of montmorillonite is more extensive

  6. Towards Long-Term Preservation Policy in Electronic Archive

    OpenAIRE

    Abd El Karim Bjaja

    2005-01-01

    A Study about long-term preservation policy in electronic archives, it deals the important of the electronic government, then the challenges of preservation in electronic archives, and the media which use in preservation, and puts a policy for managing the electronic archives.

  7. Long-term predictions using natural analogues

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-09-01

    One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3}-10{sup 5} years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., {open_quotes}natural analogues{close_quotes}) provide perhaps the only means of partial {open_quotes}validation,{close_quotes} as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (10{sup 3}-10{sup 8} years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the {open_quotes}validation{close_quotes} of performance assessments.

  8. Optimization of cask capacity for long term spent fuel storage

    International Nuclear Information System (INIS)

    Full text: Long term storage of spent fuel is a priority topic within the Member States of the IAEA. Long term spent fuel storage was previously addressed in an IAEA Co-ordinated Research Project /1/, which recognized the growing challenge of extending the life of storage facilities. Dry cask storage of spent fuel is playing a steadily increasing role in this regard. Storage practices should comply with IAEA safety requirements 'International Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources' /2/, including maintaining doses as low as reasonably (taking economic/social/etc aspects. into account) achievable [i.e., the ALARA principle]. Within the framework of the IAEA Subprogramme of Spent Fuel Management, a new project was conceived, focusing on issues associated with the optimisation of cask/container loading (capacity) with respect to long term storage and the related integrity of fuel, see IAEA /3. Optimization is a part of the design process in which the combination of application objectives, regulatory limits and design margins are innovatively addressed and judiciously balanced in the final design. A primary result of a successful design optimization is a cask of superior assembly and burnup/age capacity that minimizes the total number of required cask loadings. An equally important and parallel benefit is that this process also results in reduced radiation exposure, thereby contributing significantly to maintaining doses as low as reasonably achievable (ALARA objectives). In this sense, both cask designers and regulators have the common ultimate goal of improving cask performance, and thus facilitating optimization. An initial Consultants Meeting held in November 2002 identified and discussed principal issues regarding the optimization of cask/container assembly capacity and burnup/age capability in the design of systems for long term spent fuel storage and the related integrity of fuel. Working

  9. Financing Purchase of long-term Property

    OpenAIRE

    Pastyřík, Jaroslav

    2012-01-01

    Bachelor’s thesis is focused on issues of financing a purchase of long-term property in specific company. Particular variations of purchase and financing of fixed assets are described in the teoretical part of the thesis, presentation of the specific company and long-term property that is purchased and variations of financing are described in the practical part of the thesis. The aim of the thesis is to assess possible recources of financing purchase of long-term property in the specific comp...

  10. Stirling engine - Approach for long-term durability assessment

    Science.gov (United States)

    Tong, Michael T.; Bartolotta, Paul A.; Halford, Gary R.; Freed, Alan D.

    1992-01-01

    The approach employed by NASA Lewis for the long-term durability assessment of the Stirling engine hot-section components is summarized. The approach consists of: preliminary structural assessment; development of a viscoplastic constitutive model to accurately determine material behavior under high-temperature thermomechanical loads; an experimental program to characterize material constants for the viscoplastic constitutive model; finite-element thermal analysis and structural analysis using a viscoplastic constitutive model to obtain stress/strain/temperature at the critical location of the hot-section components for life assessment; and development of a life prediction model applicable for long-term durability assessment at high temperatures. The approach should aid in the provision of long-term structural durability and reliability of Stirling engines.

  11. Equitable long term care for the elderly immigrants

    OpenAIRE

    2012-01-01

    Background: The recent studies conducted among the health professionals representing long term care have shown that working with the elderly immigrants involves a range of challenges. One of the typical challenges is to adjust care service to the individual needs so that it maintains the patient’s integrity and dignity. The Norwegian health care system is built on the principles of equal access, equal quality and equal health outcomes. At the same time, it requires that health care takes into...

  12. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  13. Long-Term Care Ombudsman Program

    Science.gov (United States)

    ... Strategic Plan Federal Initiatives Career Opportunities Contact Us Administration on Aging (AoA) Long-Term Care Ombudsman Program ( ... Section Q Fact Sheet Back to top Funding History Older Americans Act Title VII Chapter 2 (Ombudsman ...

  14. Long-Term Ownership by Industrial Foundations

    DEFF Research Database (Denmark)

    Børsting, Christa Winther; Kuhn, Johan Moritz; Poulsen, Thomas;

    2016-01-01

    Short-termism has become a serious concern for businesses and policy makers and this has inspired a search for governance arrangement to promote long term decision making. In this paper we study a particularly long-term ownership structure, which is fairly common in Northern Europe, particularly in...... Denmark. Industrial foundations are independent legal entities without owners or members typically with the dual objective of preserving the company and using excess profits for charity. We use a unique Danish data set to examine the governance of foundation-owned companies. We show that they are long......-term in several respects. Foundations hold on to their shares for longer. Foundation-owned companies replace managers less frequently. They have more conservative capital structures with less leverage. Their companies survive longer. Their business decisions appear to be more long term. This paper...

  15. Long-term outcome of meniscectomy

    DEFF Research Database (Denmark)

    Roos, Ewa M.; Ostenberg, A; Roos, H; Ekdahl, C; Lohmander, L S

    2001-01-01

    To describe the long-term influence of meniscectomy on pain, functional limitations, and muscular performance. To assess the effects of radiographic osteoarthritis (OA), gender and age on these outcomes in patients with meniscectomy....

  16. Long Term Care Minimum Data Set (MDS)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Long-Term Care Minimum Data Set (MDS) is a standardized, primary screening and assessment tool of health status that forms the foundation of the comprehensive...

  17. Long-term Treatment in Bipolar Disorder

    OpenAIRE

    Meliha Zengin Eroglu; Nurgul Ozpoyraz

    2010-01-01

    Although the importance of long-term prophylactic treatment is certain in bipolar disorder, there is stil debate on how to which patients and evaluate the treatment response. Efficacious long-term treatment can reduce morbidity and mortality significantly and improve quality of life of bipolar patients. The concept of ideal response should also be defined very clearly in order to discuss the difficulties of measuring the effectiveness of the prophylactic treatment. The aims of this paper are ...

  18. Sleep facilitates long-term face adaptation

    OpenAIRE

    Ditye, T.; A.H Javadi; Carbon, C.C.; Walsh, V

    2013-01-01

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted imag...

  19. Long-term e-arhiv

    OpenAIRE

    Petkovšek , Bojan

    2011-01-01

    With expansion of e-business and consequently with creating original electronic documents, legally compliant long-term digital preservation has become a commitment for organizations that do business electronically. Accepted legislation that equalizes the legal validity of electronic documents with their paper original, regulates the operating and preservation of documents, recommendations, existing standards and service and equipment providers for ensuring long-term digital preservation, enab...

  20. Databases Strengthen Long-Term Care Partnerships

    OpenAIRE

    Ann D Bagchi Jung Y Kim

    2008-01-01

    The Community Partnerships for Older Adults program provided grants to eight community partnerships to develop and implement creative strategies for improving awareness about long-term care and supportive services systems. This brief examines three partnerships—Aging Atlanta, El Paso Successful Aging Through Long-Term Strategic Alliances, and the San Francisco Partnership for Community-Based Care and Support—with different levels of information technology expertise that designed databases...

  1. Databases Strengthen Long-Term Care Partnerships.

    OpenAIRE

    Ann Bagchi; Jung Kim

    2008-01-01

    The Community Partnerships for Older Adults program provided grants to eight community partnerships to develop and implement creative strategies for improving awareness about long-term care and supportive services systems. This brief examines three partnerships—Aging Atlanta, El Paso Successful Aging Through Long-Term Strategic Alliances, and the San Francisco Partnership for Community-Based Care and Support—with different levels of information technology expertise that designed databases...

  2. Manganese in long term paediatric parenteral nutrition.

    OpenAIRE

    Reynolds, A. P.; Kiely, E; Meadows, N

    1994-01-01

    The current practice of providing manganese supplementation to neonates on long term parenteral nutrition is leading to a high incidence of hypermanganesaemia. Magnetic resonance imaging (MRI) studies in adults on long term manganese parenteral nutrition have shown changes in TI weighted MRI images and similar findings in a neonate receiving trace element supplementation are reported here. Whole blood manganese concentration in the infant was 1740 nmol/l (or 8.3 times upper reference limit). ...

  3. CO2 and CH4 fluxes along a latitudinal transect in Northern Alaska using eddy covariance technique in challenging conditions: first results of a long term experiment in the Arctic tundra

    Science.gov (United States)

    Moreaux, V.; Oechel, W. C.; Losacco, S.; McEwing, R.; Murphy, P.; Zona, D.

    2013-12-01

    the first year of a new long-term study that includes the results of the upgrading of 5 sites in Northern Alaska across a latitudinal transect (Barrow, Atqasuk, and Ivotuk) and across a moisture gradient (Barrow) in the Arctic. These sites are equipped with different eddy covariance systems to follow CO2 and CH4 fluxes, combined with a full data set of meteorological and soil measurements. The study summarizes a full analysis of energy balance, CO2 and CH4 fluxes correlated to changes in meteorological and soil conditions on the 5 sites of the transect. Based on the results available, CH4 fluxes averaged approximatively 8 mgC m-2 d-1 in the north (Barrow) to 13 mgC m-2 d-1 in the south (Ivotuk). In between these two sites, a daily value of about 20 mgC m-2 d-1 in the wetter, vegetated drained lake basin was observed. Surprisingly, from our preliminary data investigation, the southernmost and warmer site (Ivotuk) did not present the highest CH4 emission, which instead was the highest in the 200 km north site (Atqasuk) with a mean daily value of 25 mgC m-2 d-1. The importance of fall season CH4 emissions will also be presented and their importance relative to summertime emissions.

  4. Wastewater treatment by soil infiltration: Long-term phosphorus removal

    Science.gov (United States)

    Eveborn, David; Kong, Deguo; Gustafsson, Jon Petter

    2012-10-01

    Phosphorus (P) leaching from on-site wastewater treatment systems may contribute to eutrophication. In developed countries the most common on-site treatment technique is septic systems with soil infiltration. However, the current knowledge about long term P removal in soil treatment systems is not well developed and the data used for estimation of P losses from such systems are unreliable. In this study we sampled four filter beds from community-scale soil treatment systems with an age of between 14 and 22 years to determine the long-term P removal and to investigate the chemical mechanisms behind the observed removal. For one site the long-term P removal was calculated using a mass balance approach. After analysis of the accumulated P, it was estimated that on average 12% of the long-term P load had been removed by the bed material. This indicates a low overall capacity of soil treatment systems to remove phosphorus. Batch experiments and chemical speciation modelling indicated that calcium phosphate precipitation was not an important long-term P removal mechanism, with the possible exception of one of the sites. More likely, the P removal was induced by AlPO4 precipitation and/or sorption to poorly ordered aluminium compounds, as evidenced by strong relationships between oxalate-extractable Al and P.

  5. Long term assurance of supply of heavy water

    International Nuclear Information System (INIS)

    The answer of Switzerland and Great Britain to a number of questions concerning the long-term assurance of the supply of heavy water are presented. The original problems are seen in the wider context of raw materials supply and its assurance in general. Non-proliferation aspects are touched

  6. Long-term follow-up study and long-term care of childhood cancer survivors

    Directory of Open Access Journals (Sweden)

    Hyeon Jin Park

    2010-04-01

    Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.

  7. Forecasting long-term energy demand of Croatian transport sector

    International Nuclear Information System (INIS)

    The transport sector in Croatia represents one of the largest consumers of energy today, with a share of almost one third of the country's final energy demand. Considering this fact, it is very challenging to assess future trends influencing that demand. In this paper, long-term energy demand predictions for the Croatian transport sector are presented. Special emphasis is given to different influencing mechanisms, both legal and financial. The energy demand predictions presented in this paper are based on an end-use simulation model developed and tested with Croatia as a case study. The model incorporates the detailed modal structure of the Croatian transport sector, including road, rail, air, public and water transport modes. Four long-term energy demand scenarios were analysed till the year 2050; frozen efficiency, implementation of EU legislation, electrification and modal split. Based on that analysis, significant savings can be achieved through energy efficiency improvements, electrification of personal vehicles fleet as well as gradual modal split. Comparing the frozen efficiency scenario and electrification scenario for the year 2050, it can be concluded that energy consumption, with the heavy electrification of personal vehicles fleet, can be cut by half. - Highlights: • A bottom-up model was created and used to forecast long term energy demand of Croatian transport sector. • Four different long term energy demand scenarios were created using the model. If comparing the two most extreme scenarios, energy savings can go up to 59% in the year 2050

  8. Long-term home care scheduling

    DEFF Research Database (Denmark)

    Gamst, Mette; Jensen, Thomas Sejr

    In several countries, home care is provided for certain citizens living at home. The long-term home care scheduling problem is to generate work plans spanning several days such that a high quality of service is maintained and the overall cost is kept as low as possible. A solution to the problem...... provides detailed information on visits and visit times for each employee on each of the covered days. We propose a branch-and-price algorithm for the long-term home care scheduling problem. The pricing problem generates one-day plans for an employee, and the master problem merges the plans with respect...

  9. Long-term effects of forced migration

    OpenAIRE

    Markus Jäntti; Matti Sarvimäki; Roope Uusitalo

    2009-01-01

    We study the long-term effects of human displacement using individual level panel data on forced migrants and comparable non-migrants. After World War II, Finland ceded a tenth of its territory to the Soviet Union and resettled the entire population living in these areas in the remaining parts of the country. We find that displacement increased the long-term income of men, but had no effect on that of women. We attribute a large part of the effect to faster transition from traditional (rural)...

  10. Long-Term Effects of Forced Migration

    OpenAIRE

    Sarvimäki, Matti; Uusitalo, Roope; Jäntti, Markus

    2009-01-01

    We study the long-term effects of human displacement using individual-level panel data on forced migrants and comparable non-migrants. After World War II, Finland ceded a tenth of its territory to the Soviet Union and resettled the entire population living in these areas in the remaining parts of the country. We find that displacement increased the long-term income of men, but had no effect on that of women. We attribute a large part of the effect to faster transition from traditional (rural)...

  11. Long-term effects of forced migration

    OpenAIRE

    Sarvimäki, Matti; Uusitalo, Roope; Jäntti, Markus

    2009-01-01

    We study the long-term effects of human displacement using individual-level panel data on forced migrants and comparable non-migrants. After World War II, Finland ceded a tenth of its territory to the Soviet Union and resettled the entire population living in these areas in the remaining parts of the country. We find that displacement increased the long-term income of men, but had no effect on that of women. We attribute a large part of the effect to faster transition from traditional (rural)...

  12. Long-term consequences of adolescent fertility: The Colombian case

    OpenAIRE

    B. Piedad Urdinola; Carlos Ospino

    2015-01-01

    Background: Estimating the long-term effects of adolescent motherhood is challenging for all developing countries, including Colombia, where this rate has been steadily increasing for 24 years, despite the reduction in the overall fertility rate. We propose a replicable methodology by applying a pseudo panel that evaluates the consequences of adolescent motherhood on outcomes previously neglected in the literature, such as job quality, marriage instability, partner's job class, presence of ph...

  13. The uranium industry: long term planning for short term competition

    International Nuclear Information System (INIS)

    Today, uranium producers face new challenges in terms of both production (new regulatory, environmental and social constraints) and market conditions (new sources of uranium supply, very low prices and tough competition). In such a context, long-term planning is not just a prerequisite to survive in the nuclear fuel cycle industry. In fact, it also contributes to sustaining nuclear electricity generation facing fierce competition from other energy sources in increasingly deregulated markets. (authors)

  14. Beyond Quarterly Earnings: Preparing the Business Community for Long-term Climate Risks

    Science.gov (United States)

    Carlson, C.; Goldman, G. T.

    2014-12-01

    The business community stands to be highly impacted by climate change. In both short and long-term timescales, climate change presents material and financial risks to companies in diverse economic sectors. How the private sector accounts for long-term risks while making short-term decisions about operations is a complex challenge. Companies are accountable to shareholders and must report performance to them on a quarterly basis. At the same time, company investors are exposed to long-term climate-related risks and face losses if companies fail to prepare for climate impacts. The US Securities and Exchange Commission (SEC) obligates publicly traded companies to discuss risks that might materially affect their business and since 2010, the agency recommends that companies consider and discuss any significant risks to their business from climate change. Some companies have complied with this guidance and comprehensively analyze potential climate change impacts, yet others fail to consider climate change at all. Such omissions leave companies without plans for addressing future risks and expose investors and the public to potential catastrophic events from climate change impacts. Climate risk projections can inform companies about the vulnerability of their facilities, supply chains, transportation pathways, and other assets. Such projections can help put climate-related risks in terms of material costs for companies and their investors. Focusing on the vulnerability of coastal facilities, we will use climate change impact projections to demonstrate the economic impacts of climate change faced by the private sector. These risks are then compared to company disclosures to the SEC to assess the degree to which companies have considered their vulnerability to climate change. Finally, we will discuss ways that companies can better assess and manage long-term climate risks.

  15. Long term property prediction of polyethylene nanocomposites

    Science.gov (United States)

    Shaito, Ali Al-Abed

    properties of the nanocomposites was analyzed by examining tensile and creep-recovery behavior of the films at temperatures in the range of 25 to -100°C. Within the measured temperature range, the materials showed a nonlinear temperature dependent response. The time-temperature superposition principle was successfully used to predict the long term behavior of LLDPE nanocomposites.

  16. Long-term sealing of openings in salt formations

    International Nuclear Information System (INIS)

    Radioactive wastes can be disposed of in deep salt formations. Rock salt is a suitable geologic medium because of its unique characteristics. Open boreholes, shafts and drifts are created to provide physical access to the repository. Long-term seals must be emplaced in those potential pathways to prevent radioactive release to the biosphere. The sealing materials must be mechanically and, most important, geochemically stable within the host rock. Salt bricks made of compressed salt-powder are understood to be the first choice long-term sealing material. Seals built from salt bricks will be ductile. The permeability of the salt bricks is assumed to be in the order of 2*10-15 m2. Large sealing systems are built by combining the individual bricks with mortar. Raw materials for mortar are fine-grained halite powder and ground saliferous clay. The permeability of the mortar decreases with its salt content to approx. 2*10-14 m2. Moistened saliferous clay may show temporary swelling. Sealing experiments will be carried out in the Asse salt mine. Long-term seals will be built into holes of 1 m diameter. The contact and merging of the brick-wall with the surrounding rock salt will be investigated in long-term tests. Within the in situ sealing program a number of geophysical methods are applied. Acoustic emission measurements are used to study the effects of high pressure gas injection and a geoelectrical observation program is aiming to estimate the permeability in and around the long-term seal. High frequency electromagnetic methods contribute to the knowledge of the petrophysical rock properties. 11 refs., 12 figs

  17. Long-Term Monitoring Research Needs: A DOE Perspective

    Science.gov (United States)

    Moore, B.; Davis, C. B.

    2002-05-01

    The U.S. Department of Energy's Office of Environmental Management is responsible for dealing with the nation's legacy of Cold War radioactive and hazardous waste and contamination. Major efforts are underway to deal with this legacy; these are expected to last up to decades and cost up to billions of dollars at some sites. At all sites, however, active remediation must eventually cease; if hazards then remain, the site must enter into a long-term stewardship mode. In this talk we discuss aspects of long-term monitoring pertinent to DOE sites, focusing on challenges to be faced, specific goals or targets to be met, and research needs to be addressed in order to enable DOE to meet its long-term stewardship obligations. DOE LTM research needs fall into three major categories: doing what we can do now much more efficiently; doing things we cannot do now; and proving the validity of our monitoring programs. Given the enormity of the DOE obligations, it will be highly desirable to develop much more efficient monitoring paradigms. Doing so will demand developing autonomous, remote monitoring networks of in situ sensors capable of replacing (or at least supplementing to a large extent) conventional groundwater and soil gas sampling and analysis programs. The challenges involved range from basic science (e.g., inventing in situ sensors for TCE that do not demand routine maintenance) to engineering (attaining superior reliability in data reporting in remote networks) to ergonomics (developing decent ways of selecting and presenting the "right" information from the monitoring network) to regulatory affairs (presenting convincing evidence that the more efficient systems actually provide superior monitoring). We explore these challenges in some detail, focusing on the "long" in long-term monitoring as it applies to DOE sites. Monitoring system performance validation and, ultimately, regulator and stakeholder acceptance of site closure and long-term stewardship plans depend

  18. Long-Term Outcome of Idiopathic Macrocephaly

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-11-01

    Full Text Available The neuroradiological, developmental, and psychological, long-term sequelae of 41 infants (30 boys, 11 girls diagnosed with macrocephaly (an occipito-facial head circumference [OFC] >95th centile at a family health service visit between 1985 and 1986 were studied at the Royal Alexandra Hospital for Children and other centers in Sydney, Australia.

  19. Long-Term Stability of Social Participation

    Science.gov (United States)

    Hyyppa, Markku T.; Maki, Juhani; Alanen, Erkki; Impivaara, Olli; Aromaa, Arpo

    2008-01-01

    The long-term stability of social participation was investigated in a representative urban population of 415 men and 579 women who had taken part in the nationwide Mini-Finland Health Survey in the years 1978-1980 and were re-examined 20 years later. Stability was assessed by means of the following tracking coefficients: kappa, proportion of…

  20. Long-term effects of ionizing radiation

    International Nuclear Information System (INIS)

    This paper approaches the long-term effects of ionizing radiation considering the common thought that killing of cells is the basis for deterministic effects and that the subtle changes in genetic information are important in the development of radiation-induced cancer, or genetic effects if these changes are induced in germ cells

  1. Long-term fixed income market structure

    Science.gov (United States)

    Grilli, Luca

    2004-02-01

    Long-term fixed income market securities present a strong positive correlation in daily returns. By using a metrical approach and considering “modified” time series, I show how it is possible to show a more complex structure which depends strictly on the maturity date.

  2. Long term prospects for double beta decay

    OpenAIRE

    Zuber, K.

    2010-01-01

    In rather general terms the long term perspective of double beta decay is discussed. All important experimental parameters are investigated as well as the status of nuclear matrix element issues. The link with other neutrino physics results and options to disentangle the underlying physics process are presented.

  3. Hot functional test chemistry - long term experience

    Energy Technology Data Exchange (ETDEWEB)

    Vonkova, K.; Kysela, J., E-mail: von@ujv.cz [Nuclear Research Inst. Rez plc, Husinec-Rez (Czech Republic); Marcinsky, M. [ENEL-SE, NPP Mochovce, Mochovce (Slovakia); Martykan, M. [CEZ-ETE, NPP Temelin, Temelin (Czech Republic)

    2010-07-01

    Primary circuit materials undergo general corrosion in high temperature, deoxygenated, neutral or mildly alkaline solutions to form thin oxide films. These oxide layers (films) serve as protective film and mitigate the further corrosion of primary materials. Inner chromium-rich oxide layer has low cation diffusion coefficients and thus control iron and nickel transport from the metal surface to the outer layer and their dissolution into the coolant. Much less corrosion products are generated by the compact, integral and stable oxide (passivation) layer. For the latest Czech and Slovak stations commissioned (Temelin and Mochovce) a modified Hot Functional Test (HFT) chemistry was developed in the NRI Rez. Chromium rich surface layer formatted due to modified HTF chemistry ensures lower corrosion rates and radiation field formation and thus also mitigates crud formation during operation. This procedure was also designed to prepare the commissioned unit for the further proper water chemistry practise. Mochovce 1 (SK) was the first station commissioned using these recommendations in 1998. Mochovce 2 (1999) and Temelin 1 and 2 (CZ - 2000 and 2002) were subsequently commissioned using these guidelines too. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. Samples from Mochovce indicated that duplex oxide layers up to 20 μm thick were produced, which were mainly magnetite substituted with nickel and chromium (e.g. 60-65% Fe, 18-28% Cr, 9-12% Ni, <1% Mn and 1-2% Si on a stainless steel primary circuit sample). Long term operation experience from both nuclear power plants are discussed in this paper. Radiation field, occupational radiation exposure and corrosion layers evolution during the first c. ten years of operation are

  4. Hot functional test chemistry - long term experience

    International Nuclear Information System (INIS)

    Primary circuit materials undergo general corrosion in high temperature, deoxygenated, neutral or mildly alkaline solutions to form thin oxide films. These oxide layers (films) serve as protective film and mitigate the further corrosion of primary materials. Inner chromium-rich oxide layer has low cation diffusion coefficients and thus control iron and nickel transport from the metal surface to the outer layer and their dissolution into the coolant. Much less corrosion products are generated by the compact, integral and stable oxide (passivation) layer. For the latest Czech and Slovak stations commissioned (Temelin and Mochovce) a modified Hot Functional Test (HFT) chemistry was developed in the NRI Rez. Chromium rich surface layer formatted due to modified HTF chemistry ensures lower corrosion rates and radiation field formation and thus also mitigates crud formation during operation. This procedure was also designed to prepare the commissioned unit for the further proper water chemistry practise. Mochovce 1 (SK) was the first station commissioned using these recommendations in 1998. Mochovce 2 (1999) and Temelin 1 and 2 (CZ - 2000 and 2002) were subsequently commissioned using these guidelines too. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. Samples from Mochovce indicated that duplex oxide layers up to 20 μm thick were produced, which were mainly magnetite substituted with nickel and chromium (e.g. 60-65% Fe, 18-28% Cr, 9-12% Ni, <1% Mn and 1-2% Si on a stainless steel primary circuit sample). Long term operation experience from both nuclear power plants are discussed in this paper. Radiation field, occupational radiation exposure and corrosion layers evolution during the first c. ten years of operation are

  5. Architecture analysis for European Long-Term Archiving EO systems

    Science.gov (United States)

    Garcia Gil, I.; Perez Moreno, R.; Perez Navarro, O.; Leone, R.

    2012-04-01

    Over the last ten years there has been a strongly increased need for access to historical Earth Observation (EO) data series, mainly for long term science and environmental monitoring applications. As the contents of EO space data archives increases from a few years duration to a period of decades their scientific values increases dramatically. The main objective of this Long Term Data Preservation(LTDP) initiative is to guarantee the long term preservation of the data from all EO ESA and Third Parties ESA managed missions, while also ensuring their accessibility and usability, as part of a joint and cooperative approach in Europe aimed at preserving the EO European data from member states' missions. To allow the maximum value to be extracted from the data, it is well recognized that there is a need to preserve this data without time limitations, while keeping all archived data accessible and exploitable. This will be even more of a challenge in the coming years, as the large number of upcoming Earth Observation missions will lead to a major increase in the available volume of EO data The LTDP Impact Analysis and Architecture Definition project (for simplicity known as LTDP-IMPACTS) aims to define and consolidate the architecture of European Long-Term Archiving EO systems, especially in the context of ESA PDGS. To do this, we shall perform a complete assessment of the impacts of implementing the guidelines from the LTDP initiative. This assessment will be over all timescales, short, middle and long-term, and must take into account all systems involved, from the point of view of "System of System" (SoS), and their data flows, data sets and their related operational policies for LTDP implementation The LTDP guidelines, and the standards adopted as a result, will have various impacts on the legacy and future long term archiving systems, the systems used to access them, and on the overall operational concept. This will particularly apply to the ESA PDGS environment

  6. Northern European long term climate archives

    Energy Technology Data Exchange (ETDEWEB)

    Hohl, Veronica [Stockholm Univ. (Sweden)

    2005-01-01

    The Swedish Nuclear Fuel and Waste Management Company is responsible for the management and disposal of Sweden's radioactive waste. It is intended to deposit the spent nuclear fuel in a deep geological repository. This repository shall keep the radiotoxic material separated from humans and the environment for extended periods, from decades to millennia and possibly to geological timescales. During this time perspective climate induced changes such as shore-level displacement and evolution of permafrost and ice sheets are expected to occur which may affect the repository. The possible occurrence, extent and duration of these long-term changes, are therefore of interest when considering the assessment of repository performance and safety. The main climate parameters determining both surface and subsurface conditions are temperature and precipitation. As a result of the last advance of the Weichselian ice sheet only few geological archives exist, which contain information on past climatic conditions in Sweden before c 16,000 years BP. The purpose of this literature review is to compile and evaluate available information from Scandinavian, Northern and Central European geological archives, which record climatic conditions during the Weichselian time period. The compilation provides paleotemperature data sets, which may be used to explore the possible evolution of periglacial permafrost in Sweden. This report is a synopsis of 22 publications detailing climatic and environmental changes during the Weichselian time period in Northwestern Europe based on quantified paleotemperature records. Some of the data is presented as temperature curves which were digitised specifically for this report. The time range covered by the different publications varies considerably. Only few authors dealt with the whole Weichselian period and the majority cover only a few thousand years. This however is not considered to influence the reliability of the archives. The reason for the

  7. Northern European long term climate archives

    International Nuclear Information System (INIS)

    The Swedish Nuclear Fuel and Waste Management Company is responsible for the management and disposal of Sweden's radioactive waste. It is intended to deposit the spent nuclear fuel in a deep geological repository. This repository shall keep the radiotoxic material separated from humans and the environment for extended periods, from decades to millennia and possibly to geological timescales. During this time perspective climate induced changes such as shore-level displacement and evolution of permafrost and ice sheets are expected to occur which may affect the repository. The possible occurrence, extent and duration of these long-term changes, are therefore of interest when considering the assessment of repository performance and safety. The main climate parameters determining both surface and subsurface conditions are temperature and precipitation. As a result of the last advance of the Weichselian ice sheet only few geological archives exist, which contain information on past climatic conditions in Sweden before c 16,000 years BP. The purpose of this literature review is to compile and evaluate available information from Scandinavian, Northern and Central European geological archives, which record climatic conditions during the Weichselian time period. The compilation provides paleotemperature data sets, which may be used to explore the possible evolution of periglacial permafrost in Sweden. This report is a synopsis of 22 publications detailing climatic and environmental changes during the Weichselian time period in Northwestern Europe based on quantified paleotemperature records. Some of the data is presented as temperature curves which were digitised specifically for this report. The time range covered by the different publications varies considerably. Only few authors dealt with the whole Weichselian period and the majority cover only a few thousand years. This however is not considered to influence the reliability of the archives. The reason for the varying

  8. Long-term outcome of sports injuries: results after inpatient treatment

    OpenAIRE

    Dekker, R.; Sluis, CK; Groothoff, JW; Eisma, WH; Ten Duis, HJ

    2003-01-01

    Objective: To investigate whether sports injuries result in long-term disabilities and handicaps and to establish variables with a prognostic value for the occurrence of these long-term consequences. Materials and methods: All patients older than 17 years of age and admitted to the University Hospital Groningen because of a sports injury were entered in the study. By filling in a questionnaire 1 - 4 years after the injury an inventory was made of the long-term consequences. Main outcome measu...

  9. Long-Term Problems of Nuclear Energy, October 1976

    International Nuclear Information System (INIS)

    The Text was written by Enelbert Broda in Oktober 1976. In this report, the physicist and chemist Engelbert Broda discusses various areas of peaceful uses of nuclear energy and concludes that the negative aspects outweigh the positive and that the use of nuclear energy has to be rejected in the long term. In 16 chapters the biggest and most dangerous problems are discussed. Include the unresolved question of disposal, problems of reprocessing and transport of fissile materials, the proliferation of nuclear weapons technology, risks of terrorism, dismantling and decontamination of old nuclear power plants, the toxicity of fissile material, as well as the general unprofitable use of nuclear power plants. As a long-term alternative the author suggests an intensification of the exploitation of solar energy, as well as a deliberate restriction of the rising demand for energy.(roessner)

  10. Long-Term Problems of Nuclear Energy, December 1976

    International Nuclear Information System (INIS)

    The Text was written by Enelbert Broda in Oktober 1976. In this report, the physicist and chemist Engelbert Broda discusses various areas of peaceful uses of nuclear energy and concludes that the negative aspects outweigh the positive and that the use of nuclear energy has to be rejected in the long term. In 16 chapters the biggest and most dangerous problems are discussed. Include the unresolved question of disposal, problems of reprocessing and transport of fissile materials, the proliferation of nuclear weapons technology, risks of terrorism, dismantling and decontamination of old nuclear power plants, the toxicity of fissile material, as well as the general unprofitable use of nuclear power plants. As a long-term alternative the author suggests an intensification of the exploitation of solar energy, as well as a deliberate restriction of the rising demand for energy.(roessner)

  11. Biocompatibility of Ti-alloys for long-term implantation.

    Science.gov (United States)

    Abdel-Hady Gepreel, Mohamed; Niinomi, Mitsuo

    2013-04-01

    The design of new low-cost Ti-alloys with high biocompatibility for implant applications, using ubiquitous alloying elements in order to establish the strategic method for suppressing utilization of rare metals, is a challenge. To meet the demands of longer human life and implantation in younger patients, the development of novel metallic alloys for biomedical applications is aiming at providing structural materials with excellent chemical, mechanical and biological biocompatibility. It is, therefore, likely that the next generation of structural materials for replacing hard human tissue would be of those Ti-alloys that do not contain any of the cytotoxic elements, elements suspected of causing neurological disorders or elements that have allergic effect. Among the other mechanical properties, the low Young's modulus alloys have been given a special attention recently, in order to avoid the occurrence of stress shielding after implantation. Therefore, many Ti-alloys were developed consisting of biocompatible elements such as Ti, Zr, Nb, Mo, and Ta, and showed excellent mechanical properties including low Young's modulus. However, a recent attention was directed towards the development of low cost-alloys that have a minimum amount of the high melting point and high cost rare-earth elements such as Ta, Nb, Mo, and W. This comes with substituting these metals with the common low cost, low melting point and biocompatible metals such as Fe, Mn, Sn, and Si, while keeping excellent mechanical properties without deterioration. Therefore, the investigation of mechanical and biological biocompatibility of those low-cost Ti-alloys is highly recommended now lead towards commercial alloys with excellent biocompatibility for long-term implantation. PMID:23507261

  12. Long-term Treatment in Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Meliha Zengin Eroglu

    2010-08-01

    Full Text Available Although the importance of long-term prophylactic treatment is certain in bipolar disorder, there is stil debate on how to which patients and evaluate the treatment response. Efficacious long-term treatment can reduce morbidity and mortality significantly and improve quality of life of bipolar patients. The concept of ideal response should also be defined very clearly in order to discuss the difficulties of measuring the effectiveness of the prophylactic treatment. The aims of this paper are to determine whether our currently methods and criteria are valid, reliable and sensitive evaluating the efficacy of the treatment response and to briefly inform the clinicians about the drugs used in pharmacologic prophylaxis in accordance with relevant data.

  13. [Taiwan long-term care insurance and the evolution of long-term care in Japan].

    Science.gov (United States)

    Huang, Hui-Wen; Liu, Shu-Hui; Pai, Yu-Chu

    2010-08-01

    The proportion of elderly (65 years of age and older) in Taiwan has exceeded 10% since 2008. With more elderly, the number of patients suffering from dementia and disabilities has also been rapidly increasing. Japan also has been facing increasing demand for long-term care due to an aging society. Prior to 2000, social welfare programs in Japan, working to cope with changing needs, typically provided insufficient services, and geriatric patients were hospitalized unnecessarily, wasting medical resources and causing undue patient hardship. In response, Japan launched its long-term care insurance program in April 2000. Under the program, city, town and village-based organizations should take responsibility for providing care to the elderly in their place of residence. The program significantly improved previous financial shortfalls and long-term care supply and demand has been met by existing social welfare organization resources. In Taiwan, the provision of long-term care by county / city authorities has proven inconsistent, with performance deemed poor after its first decade of long-term care operations. Service was found to be affected by differences in available resources and insufficient long-term care administration. The cultures of Taiwan and Japan are similar. The authors visited the Japan Long-Term Care Insurance Institute in August 2009. Main issues involved in the implementation and evolution of the Japan long-term Care Insurance are reported on in this paper. We hope such may be useful information to those working to develop long-term care programs in Taiwan. PMID:20661859

  14. Long-term outcomes of 23-gauge transconjunctival sutureless vitrectomy

    OpenAIRE

    ÇITIRIK, Mehmet; BATMAN, Coşar; BİÇER, Tolga; Akinci, Arsen

    2011-01-01

    To assess the long-term efficacy and safety of 23-gauge transconjunctival sutureless pars plana vitrectomy in the management of vitreoretinal diseases. Materials and methods: In this study, 53 eyes of patients who underwent 23-gauge transconjunctival sutureless pars plana vitrectomy were included. A complete ophthalmological examination was performed preoperatively and at day 1, week 1, and months 1, 3, 6, and 12 after the surgery. Results: The mean age of the patients was 56.3 years (rang...

  15. Lyophilization as a method for pathogens long term preservation

    OpenAIRE

    Milošević Mirjana B.; Medić-Pap Slađana S.; Ignjatov Maja V.; Petrović Dragana N.

    2007-01-01

    Lyophilization (freeze-drying) is one of the most suitable methods used for a long term preservation of pathogens. The aim of this paper was the application of lyophilization for storage of three significant plant pathogens: Fusarium graminearum, Helminthosporium gramineum, and Pseudomonas syringae pv. gylicinea, respectively. The plant material was collected continuously (during a four year period 2002-2006), depending on a plant development stage, from different localities in Vojvodina. Pat...

  16. Update Knowledge Base for Long-term Core Cooling Reliability

    International Nuclear Information System (INIS)

    This revision of the Knowledge Base for Emergency Core Cooling System Recirculation Reliability (NEA/CSNI/R (95)11) describes the current status (late 2012) of the knowledge base on emergency core cooling system (ECCS) and containment spray system (CSS) suction strainer performance and long-term cooling in operating power reactors. New reactors, such as the AP1000, EPR and APR1400 that are under construction in some Organization for Economic Co-operation and Development (OECD) member countries, are not addressed in detail in this revision. The containment sump (also known as the emergency or recirculation sump in pressurized water reactors (PWRs) and pressurized heavy water reactors (PHWRs) or the suppression pools or wet wells in boiling water reactors (BWRs)) and associated ECCS strainers are parts of the ECCS in both reactor types. All nuclear power plants (NPPs) are required to have an ECCS that is capable of mitigating a design basis accident (DBA). The containment sump collects reactor coolant, ECCS injection water, and containment spray solutions, if applicable, after a loss-of-coolant accident (LOCA). The sump serves as the water source to support long-term recirculation for residual heat removal, emergency core cooling, and containment atmosphere clean-up. This water source, the related pump suction inlets, and the piping between the source and inlets are important safety-related components. In addition, if fibrous material is deposited at the fuel element spacers, core cooling can be endangered. The performance of ECCS/CSS strainers was recognized many years ago as an important regulatory and safety issue. One of the primary concerns is the potential for debris generated by a jet of high-pressure coolant during a LOCA to clog the strainer and obstruct core cooling. The issue was considered resolved for all reactor types in the mid-1990s and the OECD/NEA/CSNI published report NEA/CSNI/R(95)11 in 1996 to document the state of knowledge of ECCS performance

  17. Long term complications in juvenile diabetes mellitus

    OpenAIRE

    Nordwall, Maria

    2006-01-01

    Background/aim. The incidence of microvascular complications has been reported to be unchanged the last decades. However, in randomized clinical trials it has been shown that improved metabolic control can reduce the development of long term complications. It has been debated whether it is possible to achieve the same results in an unselected population. In a previous study we found a decreased incidence of overt nephropathy, but unchanged incidence of severe laser treated retinopathy in a po...

  18. Clinical review: Long-term noninvasive ventilation

    OpenAIRE

    Robert, Dominique; Argaud, Laurent

    2007-01-01

    Noninvasive positive ventilation has undergone a remarkable evolution over the past decades and is assuming an important role in the management of both acute and chronic respiratory failure. Long-term ventilatory support should be considered a standard of care to treat selected patients following an intensive care unit (ICU) stay. In this setting, appropriate use of noninvasive ventilation can be expected to improve patient outcomes, reduce ICU admission, enhance patient comfort, and increase...

  19. Have long-term inflation expectations declined?

    OpenAIRE

    Nechio, Fernanda

    2015-01-01

    Based on surveys of professional forecasters, expectations for price inflation 5 to 10 years ahead have edged down over the past few years. This decline seems to be primarily driven by revised expectations from forecasters who overestimated inflation in the aftermath of the Great Recession. Currently, the median survey-based expectation for long-term inflation is close to its pre-recession level and appears well anchored at the Fed’s 2% longer-run inflation objective.

  20. Long term prognosis of reactive salmonella arthritis

    OpenAIRE

    Leirisalo-Repo, M; Helenius, P; Hannu, T; Lehtinen, A; Kreula, J; Taavitsainen, M; Koskimies, S

    1997-01-01

    OBJECTIVES—Reactive joint complications triggered by salmonella gastroenteritis are increasingly reported, but the outcome and long term prognosis of the patients is incompletely known. This study looked at the prognosis of salmonella arthritis in patients hospitalised in 1970-1986.
METHODS—Hospital records from two hospitals in southern Finland were screened for patients with the discharge diagnosis of salmonellosis or reactive, postinfectious arthritis or Reiter's disease. For the patients ...

  1. Long-term consequences of anorexia nervosa.

    Science.gov (United States)

    Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Katulski, Krzysztof

    2013-07-01

    Anorexia nervosa (AN) is a psychiatric disorder that occurs mainly in female adolescents and young women. The obsessive fear of weight gain, critically limited food intake and neuroendocrine aberrations characteristic of AN have both short- and long-term consequences for the reproductive, cardiovascular, gastrointestinal and skeletal systems. Neuroendocrine changes include impairment of gonadotropin releasing-hormone (GnRH) pulsatile secretion and changes in neuropeptide activity at the hypothalamic level, which cause profound hypoestrogenism. AN is related to a decrease in bone mass density, which can lead to osteopenia and osteoporosis and a significant increase in fracture risk in later life. Rates of birth complications and low birth weight may be higher in women with previous AN. The condition is associated with fertility problems, unplanned pregnancies and generally negative attitudes to pregnancy. During pregnancy, women with the condition have higher rates of hyperemesis gravidarum, anaemia and obstetric complications, as well as impaired weight gain and compromised intrauterine foetal growth. It is reported that 80% of AN patients are affected by a cardiac complications such as sinus bradycardia, a prolonged QT interval on electrocardiography, arrythmias, myocardial mass modification and hypotension. A decrease in bone mineral density (BMD) is one of the most important medical consequences of AN. Reduced BMD may subsequently lead to a three- to seven-fold increased risk of spontaneous fractures. Untreated AN is associated with a significant increase in the risk of death. Better detection and sophisticated therapy should prevent the long-term consequences of this disorder. The aims of treatment are not only recovery but also prophylaxis and relief of the long-term effects of this disorder. Further investigations of the long-term disease risk are needed. PMID:23706279

  2. Long Term Evolution of Plasma Wakefields

    OpenAIRE

    Sahai, Aakash A.; Katsouleas, T. C.; Tsung, F. S.; Mori, W. B.

    2014-01-01

    We study the long-term evolution (LTE) of plasma wakefields over multiple plasma-electron periods and few plasma-ion periods, much less than a recombination time. The evolution and relaxation of such a wakefield-perturbed plasma over these timescales has important implications for the upper limits of repetition-rates in plasma colliders. Intense fields in relativistic lasers (or intense beams) create plasma wakefields (modes around {\\omega}pe) by transferring energy to the plasma electrons. C...

  3. Long term evolution 4G and beyond

    CERN Document Server

    Yacoub, Michel; Figueiredo, Fabrício; Tronco, Tania

    2016-01-01

    This book focus on Long Term Evolution (LTE) and beyond. The chapters describe different aspects of research and development in LTE, LTE-Advanced (4G systems) and LTE-450 MHz such as telecommunications regulatory framework, voice over LTE, link adaptation, power control, interference mitigation mechanisms, performance evaluation for different types of antennas, cognitive mesh network, integration of LTE network and satellite, test environment, power amplifiers and so on. It is useful for researchers in the field of mobile communications.

  4. Energy: solutions for the long term

    International Nuclear Information System (INIS)

    'Power towers' operated by sunlight, vertical-axis, windmills capable of generating electricity, breeder reactors producing more uranium than they consume, and power plants fuelled by nuclear fusion - these are some of the exotic energy sources to be created as long term alternatives under the U.S. Government's plan for energy and research development. International co-operation, which has already begun, could permit other nations to share with America the fruits of this investment in the future

  5. Long-term course of opioid addiction.

    Science.gov (United States)

    Hser, Yih-Ing; Evans, Elizabeth; Grella, Christine; Ling, Walter; Anglin, Douglas

    2015-01-01

    Opioid addiction is associated with excess mortality, morbidities, and other adverse conditions. Guided by a life-course framework, we review the literature on the long-term course of opioid addiction in terms of use trajectories, transitions, and turning points, as well as other factors that facilitate recovery from addiction. Most long-term follow-up studies are based on heroin addicts recruited from treatment settings (mostly methadone maintenance treatment), many of whom are referred by the criminal justice system. Cumulative evidence indicates that opioid addiction is a chronic disorder with frequent relapses. Longer treatment retention is associated with a greater likelihood of abstinence, whereas incarceration is negatively related to subsequent abstinence. Over the long term, the mortality rate of opioid addicts (overdose being the most common cause) is about 6 to 20 times greater than that of the general population; among those who remain alive, the prevalence of stable abstinence from opioid use is low (less than 30% after 10-30 years of observation), and many continue to use alcohol and other drugs after ceasing to use opioids. Histories of sexual or physical abuse and comorbid mental disorders are associated with the persistence of opioid use, whereas family and social support, as well as employment, facilitates recovery. Maintaining opioid abstinence for at least five years substantially increases the likelihood of future stable abstinence. Recent advances in pharmacological treatment options (buprenorphine and naltrexone) include depot formulations offering longer duration of medication; their impact on the long-term course of opioid addiction remains to be assessed. PMID:25747921

  6. Long term nuclear programme for Australia

    International Nuclear Information System (INIS)

    While it is difficult at this time to foreshadow a long term nuclear programme for Australia, the essential ingredients of the decision-making back-ground have been set out. The first involvement in the nuclear scene appears to be an entry as a uranium supplier in the late 1970s, though no indigenous use of uranium as a fuel is foreseen until after 1990. (J.R.)

  7. Managing soils for long-term productivity

    OpenAIRE

    Syers, J. K.

    1997-01-01

    Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated. Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that soi...

  8. Timber joints under long-term loading

    DEFF Research Database (Denmark)

    Feldborg, T.; Johansen, M.

    This report describes tests and results from stiffness and strength testing of splice joints under long-term loading. During two years of loading the spicimens were exposed to cyclically changing relative humidity. After the loading period the specimens were short-term tested. The connectors were...... integral nail-plates and nailed steel and plywood gussets. The report is intended for designers and researchers in timber engineering....

  9. Long-term reductions in tinnitus severity

    OpenAIRE

    Folmer Robert L

    2002-01-01

    Abstract Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to their initial appointment at the Or...

  10. Long-term reductions in tinnitus severity

    OpenAIRE

    Folmer, Robert L.

    2002-01-01

    Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to their initial appointment at the Oregon Heal...

  11. Procrastination on Long-Term Projects

    OpenAIRE

    O'Donoghue, Ted; Rabin, Matthew

    2002-01-01

    Previous papers on time-inconsistent procrastination assume projects are completed once begun. We develop a model in which a person chooses whether and when to complete each stage of a long-term project. In addition to procrastination in starting a project, a naive person might undertake costly effort to begin a project but then never complete it. When the costs of completing different stages are more unequal, procrastination is more likely, and it is when later stages are more costly that ...

  12. Long-Term Trends in World Politics

    Directory of Open Access Journals (Sweden)

    George Modelski

    2015-08-01

    Full Text Available A revisit, and an extension, of the paper “From Leadership to Organization: The Evolution of Global Politics,” originally presented at the University of Zurich in 1993. Three long-term processes: the evolution of global politics (or political globalization; the rise and decline of world powers (the long cycle of global politics; and the emergence of the world system, have been reviewed and updated.

  13. Long-term orbital lifetime predictions

    Science.gov (United States)

    Dreher, P. E.; Lyons, A. T.

    1990-10-01

    Long-term orbital lifetime predictions are analyzed. Predictions were made for three satellites: the Solar Max Mission (SMM), the Long Duration Exposure Facility (LDEF), and the Pegasus Boiler Plate (BP). A technique is discussed for determining an appropriate ballistic coefficient to use in the lifetime prediction. The orbital decay rate should be monitored regularly. Ballistic coefficient updates should be done whenever there is a significant change in the actual decay rate or in the solar activity prediction.

  14. [Long-term survival after severe trauma].

    Science.gov (United States)

    Mutschler, W; Mutschler, M; Graw, M; Lefering, R

    2016-07-01

    Long-term survival after severe trauma is rarely addressed in German trauma journals although knowledge of life expectancy and identification of factors contributing to increased mortality are important for lifetime care management, development of service models, and targeting health promotion and prevention interventions. As reliable data in Germany are lacking, we compiled data mainly from the USA and Australia to describe life expectancy, risk factors, and predictors of outcome in patients experiencing traumatic spinal cord injury, traumatic brain injury, and polytrauma. Two years after trauma, life expectancy in all three categories was significantly lower than that of the general population. It depends strongly on severity of disability, age, and gender and is quantifiable. Whereas improvements in medical care have led to a marked decline in short-term mortality, surprisingly long-term survival in severe trauma has not changed over the past 30 years. Therefore, there is need to intensify long-term trauma patient care and to find new strategies to limit primary damage. PMID:27342106

  15. Perceived problems, challenges and needs in the area: Long term needs of nuclear data of innovative materials for fission energy systems

    International Nuclear Information System (INIS)

    Improved nuclear data are essential to support new initiatives such as the international project on innovative nuclear reactors and fuel cycles (e.g. INPRO of the IAEA) that aim to support the safe, sustainable, economic and proliferation-resistant use of nuclear technology to meet the global energy needs (7 billion population now and growing) of the 21st century. The detailed pursuit of development of Generation IV nuclear energy systems that offer advantages in the areas of economics, safety, reliability and sustainability require significantly improved nuclear data. Design and safe operation of long burnup innovative reactor systems also need improved data and covariances for a larger number of fission products and minor actinides

  16. Long-term surveillance plan for the Mexican Hat disposal site, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    This plan describes the long-term surveillance activities for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Mexican Hat, Utah. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This long-term surveillance plan (LTSP) was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive material (RRM). This LTSPC documents the land ownership interests and details how the long-term care of the disposal site will be accomplished

  17. Long-term surveillance plan for the Mexican Hat disposal site, Mexican Hat, Utah

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This plan describes the long-term surveillance activities for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Mexican Hat, Utah. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This long-term surveillance plan (LTSP) was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive material (RRM). This LTSPC documents the land ownership interests and details how the long-term care of the disposal site will be accomplished.

  18. Materials in Sweden for future production of fuel pellets. A review of possible materials in short- and medium long-term; Raavaror foer framtida tillverkning av braenslepellets i Sverige. En kartlaeggning av taenkbara alternativa raavaror paa kort och medellaang sikt

    Energy Technology Data Exchange (ETDEWEB)

    Martinsson, Lars [Swedish National Testing and Research Inst., Boraas (Sweden)

    2003-07-01

    The use of fuel pellets, mainly produced from sawdust and shavings from the Swedish sawmill industry, has increased during the 1990s among small-scale users such as private houses as well as large-scale users such as thermal power stations. During the last years this increase has continued for small-scale use. Due to a significant increase of the pellet prices the last couple of years the increase for the large-scale users seems to have stopped. It is reasonable to believe that these higher prices depend mostly on lack of raw materials for the fuel pellet production. The greater part of sawdust from Swedish saw mills is used in the pellet industry, the board industry or as an internal fuel. It is reasonable to assume a small increase of present raw material available for pellet production without a further decrease in the use for the board industry. Another sawmill by-product, dry chips, may increase in importance as a fuel pellet raw material and give a small contribution while the green chips should be for use in the pulp industry only. If the use of fuel pellets should increase there is a need for new raw materials. In the short-term, thinning material and cull tree could be alternatives that could give pellets with similar characteristics as present fuel pellets. For large-scale consumers with greater ability to handle problems concerning ash, such as sintering and fouling, as well as particle and gaseous emissions a further choice of raw materials could be possible, such as bark, peat and logging residues. In the longer term energy crops could be used as well as lignin, derived from energy effective pulp industry and from possible large-scale production of ethanol from woody biomass. Nearly all of the different raw materials studied in this review have higher amounts of substances not desirable in combustion such as potassium, chlorine and nitrogen. However, pelletizing gives an unique opportunity to mix different raw materials and possible additives in order

  19. On the very long term delayed behavior of concrete

    International Nuclear Information System (INIS)

    The prediction of very long-term deformation of prestressed concrete structures is a major challenge considering the service life of these structures. It is therefore necessary to correctly model the delayed behavior of these structures. Using a review of laboratory tests and observations of the delayed behavior of structures (bridges and nuclear power plants), the main conclusions of this work are the following ones. First, very long term creep in laboratory or of real structures seems to be non asymptotic. In the actual Eurocode-2, creep is calculated by means of an asymptotic hyperbolic function while in the recent Model Code 2010 creep is expressed as a combination of an asymptotic and a logarithmic functions. In the latter case the logarithmic function corresponds to basic creep while drying creep is asymptotic. Secondly, using a long test (3 years) in a laboratory is not enough to assess the long term behaviour of a massive structure. We need physical relations for creep in codes in order to predict the delayed behavior of massive structures. Thirdly, the biaxial creep of nuclear power plant could be modelled but using data of the structure itself. This would allow to predict the delayed behavior of these structures. Further work is needed to improve the prediction in the design phase

  20. Long term creep strength of silver alloyed copper

    International Nuclear Information System (INIS)

    The long term creep strength of silver alloyed copper has been estimated using literature creep data for materials with less than 0.1% Ag. The available data was very limited, and it was necessary to test the differences between various data sets and extrapolation methods. Assuming constant stress level and constant or changing temperature, the creep behaviour has been assessed using mainly Larson-Miller and theta-projection approaches. The calculations indicate that the different extrapolation methods and data sources can yield strongly different life estimates. With the available incomplete data the theta projection method may give the conservative life predictions, whereas the Larson-Miller approach grossly overestimates creep life. It is recommended that supplementary data is acquired to better assess the long term creep properties of canisters in repository conditions

  1. Optimization of cask capacity for long term spent fuel storage

    International Nuclear Information System (INIS)

    Within the framework of the IAEA Subprogramme of Spent Fuel Management, a new project was conceived, focusing on issues associated with the optimization of cask/container loading (capacity) with respect to long term storage and the related integrity of fuel. An initial Consultants Meeting held in November 2002 identified and discussed principal issues regarding the optimization of cask/container assembly capacity and burnup/age capability in the design of systems for long term spent fuel storage and the related integrity of fuel. Based on resulting working materials, a Technical Meeting was held in March 2003 to obtain country-specific views from both regulators and implementers on this topic. Discussions focused on the following issues relevant to cask loading optimization: fuel integrity, retrievability, zoning, burnup credit, damaged fuel, computer code verification, life of cask components, cask maintenance, performance confirmation, and records management. Follow-on actions and meetings will be pursued to develop a TECDOC on this subject. (author)

  2. Critical challenges for EUV resist materials

    Energy Technology Data Exchange (ETDEWEB)

    Naulleau, Patrick P.; Anderson, Christopher N.; Baclea-an, Lorie-Mae; Denham, Paul; George, Simi; Goldberg, Kenneth A.; Jones, Gideon; McClinton, Brittany; Miyakawa, Ryan; Rekawa, Seno; Smith, Nathan

    2011-02-28

    Although Extreme ultraviolet lithography (EUVL) is now well into the commercialization phase, critical challenges remain in the development of EUV resist materials. The major issue for the 22-nm half-pitch node remains simultaneously meeting resolution, line-edge roughness (LER), and sensitivity requirements. Although several materials have met the resolution requirements, LER and sensitivity remain a challenge. As we move beyond the 22-nm node, however, even resolution remains a significant challenge. Chemically amplified resists have yet to demonstrate the required resolution at any speed or LER for 16-nm half pitch and below. Going to non-chemically amplified resists, however, 16-nm resolution has been achieved with a LER of 2 nm but a sensitivity of only 70 mJ/cm{sup 2}.

  3. Technical aspects of ageing for long-term operation

    International Nuclear Information System (INIS)

    The aspects of plant ageing management gained increasing attention over the last ten years. Numerous technical studies have been performed to study the impact of ageing mechanisms on the safe and reliable operation of nuclear power plants. National research activities have been initiated or are in progress to provide the technical basis for decision making processes. The long-term operation of nuclear power plants is influenced by economic considerations, the socio-economic environment including public acceptance, developments in research and the regulatory framework, the availability of technical infrastructure to maintain and service the systems, structures and components as well as qualified personnel. This document restricts itself to the technical aspects of the basis for long-term operation. Its objective is the characterisation of technical key items. Regulatory aspects are being discussed within CNRA. The light water reactor (LWR) nuclear power plants in operation are generically of pressurised water reactor (PWR) or boiling water reactor (BWR) type. The design principles of the nuclear steam supply system (NSSS) are proven in long-term operation as well as the principles being applied to the balance of plant (BOP), although a rather large variety of technical solutions do exist. The steps in the developments were tremendous in the 60's and 70's up to a power output of 1200 MWe followed by a period of further optimisation in the 80's and 90's, which raised it close to 1500 MWe. The NPPs in operation can be grouped into different generations of design in order to characterise similarities in technical principles and manufacturing standards. In the area of civil and mechanical structures and components there has been continuous development to optimise the design, the materials used as well as the manufacturing technology. The majority of these structures and components is still in use. In principle there are no major obstacles to further use of these

  4. LTE (4G) – Long Term Evolution

    OpenAIRE

    Juhala, Arttu

    2014-01-01

    Tässä opinnäytetyössä käsitellään matkapuhelinverkko teknologian neljättä sukupolvea ja tarkemmin Long Term Evolutionia eli LTE:tä. Tutustutaan 4G LTE – matkapuhelinverkon historiaan, teknologian kehitykseen ja rakenteeseen. Lisäksi esitellään tarkemmin tekniikoita, joita LTE käyttää. Työssä on tehty pienimuotoinen mittausesimerkki pakettidatan siirrosta signaali analysaattorilla, sekä testattu käytännössä operaattorin tarjoamaa rajatonta 4G liittymää Tampereen keskustassa. Lopuksi työssä ver...

  5. Long-term effects of class size

    OpenAIRE

    Fredriksson, Peter; Öckert, Björn; Oosterbeek, Hessel

    2012-01-01

    This paper evaluates the long-term effects of class size in primary school. We use rich administrative data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are not only beneficial for cognitive test scores at age 13 but also for non-cognitive scores at that age, for cognitive test scores at ages 16 and 18, and for completed education and wages at age 27 to 42. The estimated effect on...

  6. Long-Term Effects of Class Size

    OpenAIRE

    Fredriksson, Peter; Öckert, Björn; Oosterbeek, Hessel

    2011-01-01

    This paper evaluates the long-term effects of class size in primary school. We use rich administrative data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are not only beneficial for cognitive test scores at age 13 but also for non-cognitive scores at that age, for cognitive test scores at ages 16 and 18, and for completed education and wages at age 27 to 42. The estimated effect on...

  7. Long-term effects of class size

    OpenAIRE

    Fredriksson, Peter; Öckert, Björn; Oosterbeek, Hessel

    2011-01-01

    This paper evaluates the long-term effects of class size in primary school. We use rich administrative data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are not only beneficial for cognitive test scores at age 13 but also for non-cognitive scores at that age, for cognitive test scores at ages 16 and 18, and for completed education and wages at age 27 to 42. The estimated effect on...

  8. Long-term effects of class size

    OpenAIRE

    Fredriksson, Peter; Öckert, Björn; Oosterbeek, Hessel

    2012-01-01

    This paper evaluates the long-term effects of class size in primary school. We use rich data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are beneficial for cognitive and non-cognitive ability at age 13, and improve achievement at age 16. Most importantly, we find that smaller classes have positive effects on completed education, wages, and earnings at age 27 to 42. The estimated ...

  9. Declining Long-Term Employment in Japan

    OpenAIRE

    KAWAGUCHI Daiji; UENO Yuko

    2011-01-01

    This paper documents the secular decline of years of job tenure in Japan based on micro data from two representative government surveys, namely the household-based Employment Status Survey (ESS) and the establishment-based Basic Survey of Wage Structure (BSWS). Workers born in 1970 have experienced about 20 percent fewer years of job tenure than those born in 1945, based on an analysis of ESS data. The decline of the long-term employment relationship is uniformly observed across firm sizes an...

  10. The long-term stability of becquerelite

    International Nuclear Information System (INIS)

    Uranium-series disequilibria data, in conjunction with petrographic analyses, indicate that the uranyl oxide hydrate becquerelite can persist for hundreds of thousands of years, possibly longer. Becquerelite probably forms continuously as ground water compositions permit and is resistant to U leaching by ground water. On the time scale of interest for the geologic disposal of spent UO2 nuclear fuel, becquerelite is a long-lived sink for uranium in oxidizing, U and Ca-bearing ground waters. Such long-term stability also supports recent solubility experiments that indicate natural becquerelite has a lower solubility product than that determined for synthetic becquerelites

  11. Long Term Archiving and CCSDS Standards

    Science.gov (United States)

    Boucon, Danièle

    This article presents some conceptual and implementation CCSDS -Consultative Committee for Space Data Systemsstandards for long term archiving. It focuses on the most recent one, the Producer Archive Interface Specification (PAIS) standard. This standard, currently available as a draft on the CCSDS web site, will be published by the beginning of 2014. It will enable the Producer to share with the Archive a sufficiently precise and unambiguous formal definition of the Digital Objects to be produced and transferred, by means of a model. It will also enable a precise definition of the packaging of these objects in the form of Submission Information Packages (SIPs), including the order in which they should be transferred.

  12. The long term stability of lidar calibrations

    DEFF Research Database (Denmark)

    Courtney, Michael; Gayle Nygaard, Nicolai

    Wind lidars are now used extensively for wind resource measurements. One of the requirements for the data to be accepted in support of project financing (so-called ‘banka-bility’) is to demonstrate the long-term stability of lidar cali-brations. Calibration results for six Leosphere WindCube li-dars......-ters pertaining in the different calibration periods. This is supported by sliding-window analyses of one lidar at one location where the same order of variation is observed as between pre-service and post-service calibrations....

  13. Long term youth unemployment or disposable workforce?

    OpenAIRE

    Bruno Contini; Elisa Grand

    2010-01-01

    This paper explores a process which I denote as “young workforce disposal” (YWD). YWD reflects the fact that many young people enter the labor market as dependent employees, at some later time they are dismissed and (presumably) move into never-ending unemployment. Long term unemployment may last two, three, four years, but, in the end, it should lead to re-entry in working activities. If it does not, i.e. if we observe young men separating from their jobs for whatever reason, and, for as lon...

  14. Human Behaviour in Long-Term Missions

    Science.gov (United States)

    1997-01-01

    In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

  15. Long-term plant availability of actinides

    International Nuclear Information System (INIS)

    Environmental releases of actinide elements raise issues about which data are very limited. Quantitative information is required to assess the long-term behavior of actinides and their potential hazards resulting from the transport through food chains leading to man. Of special interest is the effect of time on the changes in the availability of actinide elements for uptake by plants from soil. This study provides valuable information on the effects of weathering and aging on the uptake of actinides from soil by range and crop plants grown under realistic field conditions

  16. Long-term motor cortex stimulation for phantom limb pain.

    Science.gov (United States)

    Pereira, Erlick A C; Moore, Tom; Moir, Liz; Aziz, Tipu Z

    2015-04-01

    We present the long-term course of motor cortex stimulation to relieve a case of severe burning phantom arm pain after brachial plexus injury and amputation. During 16-year follow-up the device continued to provide efficacious analgesia. However, several adjustments of stimulation parameters were required, as were multiple pulse generator changes, antibiotics for infection and one electrode revision due to lead migration. Steady increases in stimulation parameters over time were required. One of the longest follow-ups of motor cortex stimulation is described; the case illustrates challenges and pitfalls in neuromodulation for chronic pain, demonstrating strategies for maintaining analgesia and overcoming tolerance. PMID:25340991

  17. Nuclear material management: challenges and prospects

    International Nuclear Information System (INIS)

    The articles in this dossier were derived from the papers of the yearly S.F.E.N. convention, which took place in Paris, 12-13 March 2008. They deal with the new challenges and prospects in the field of nuclear material management, throughout the nuclear whole fuel cycle, namely: the institutional frame of nuclear materials management, the recycling, the uranium market, the enrichment market, the different scenarios for the management of civil nuclear materials, the technical possibilities of spent fuels utilization, the option of thorium, the convention on the physical protection of nuclear materials and installations, the characterisation of nuclear materials by nondestructive nuclear measurements, the proliferation from civil installations, the use of plutonium ( from military origin) and the international agreements. (N.C.)

  18. Long-term environmental behaviour of radionuclides

    International Nuclear Information System (INIS)

    The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: i) redistribution in the soil-plant system, ii) modelling, iii) countermeasures, iv) runoff v) spatial variations, and vi) dose assessment. The long term behaviour of the radionuclides 137Cs, 90Sr and 239-240Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

  19. Long term testing of PSI-membranes

    Energy Technology Data Exchange (ETDEWEB)

    Huslage, J.; Brack, H.P.; Geiger, F.; Buechi, F.N.; Tsukada, A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.

  20. Sleep facilitates long-term face adaptation.

    Science.gov (United States)

    Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

    2013-10-22

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation--which are usually not considered to play a relevant role in mnemonic processes--with learning and memory, and at the same time reveal a new function of sleep in cognition. PMID:23986109

  1. Long-term environmental behaviour of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Brechignac, F.; Moberg, L.; Suomela, M

    2000-04-01

    The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: (i) redistribution in the soil-plant system, (ii) modelling, (iii) countermeasures, (iv) runoff (v) spatial variations, and (vi) dose assessment. The long term behaviour of the radionuclides {sup 137}Cs, {sup 90}Sr and {sup 239-240}Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

  2. Long term changes in the polar vortices

    Science.gov (United States)

    Braathen, Geir O.

    2015-04-01

    As the amount of halogens in the stratosphere is slowly declining and the ozone layer slowly recovers it is of interest to see how the meteorological conditions in the vortex develop over the long term since such changes might alter the foreseen ozone recovery. In conjunction with the publication of the WMO Antarctic and Arctic Ozone Bulletins, WMO has acquired the ERA Interim global reanalysis data set for several meteorological parameters. This data set goes from 1979 - present. These long time series of data can be used for several useful studies of the long term development of the polar vortices. Several "environmental indicators" for vortex change have been calculated, and a climatology, as well as trends, for these parameters will be presented. These indicators can act as yardsticks and will be useful for understanding past and future changes in the polar vortices and how these changes affect polar ozone depletion. Examples of indicators are: vortex mean temperature, vortex minimum temperature, vortex mean PV, vortex "importance" (PV*area), vortex break-up time, mean and maximum wind speed. Data for both the north and south polar vortices have been analysed at several isentropic levels from 350 to 850 K. A possible link between changes in PV and sudden stratospheric warmings will be investigated, and the results presented.

  3. Structural materials challenges for fusion power systems

    International Nuclear Information System (INIS)

    Full text: Structural materials in a fusion power system must function in an extraordinarily demanding environment that includes various combinations of high temperatures, reactive chemicals, time-dependent thermal and mechanical stresses, and intense damaging radiation. The fusion neutron environment produces displacement damage equivalent to displacing every atom in the material about 150 times during its expected service life, and changes in chemical composition by transmutation reactions, which includes creation of reactive and insoluble gases. Fundamental materials challenges that must be resolved to effectively harness fusion power include (1) understanding the relationships between material strength, ductility and resistance to cracking, (2) development of materials with extraordinary phase stability, high-temperature strength and resistance to radiation damage, (3) establishment of the means to control corrosion of materials exposed to aggressive environments, (4) development of technologies for large-scale fabrication and joining, and (5) design of structural materials that provide for an economically attractive fusion power system while simultaneously achieving safety and environmental acceptability goals. The most effective approach to solve these challenges is a science-based effort that couples development of physics-based, predictive models of materials behavior with key experiments to validate the models. The U.S. Fusion Materials Sciences program is engaged in an integrated effort of theory, modeling and experiments to develop structural materials that will enable fusion to reach its safety, environmental and economic competitiveness goals. In this presentation, an overview of recent progress on reduced activation ferritic/martensitic steels, nanocomposited ferritic alloys, and silicon carbide fiber reinforced composites for fusion applications will be given

  4. Long-term storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    This report presents the results of a study on the storage of spent nuclear fuel, with particular reference to the options which would be available for long-term storage. Two reference programmes of nuclear power generation in the UK are defined and these are used as a basis for the projection of arisings of spent fuel and the storage capacity which might be needed. The characteristics of spent fuel which are relevant to long-term storage include the dimensions, materials and physical construction of the elements, their radioactive inventory and the associated decay heating as a function of time after removal from the reactor. Information on the behaviour of spent fuel in storage ponds is reviewed with particular reference to the corrosion of the cladding. The review indicates that, for long-term storage, both Magnox and AGR fuel would need to be packaged because of the high rate of cladding corrosion and the resulting radiological problems. The position on PWR fuel is less certain. Experience of dry storage is less extensive but it appears that the rate of corrosion of cladding is much lower than in water. Unit costs are discussed. Consideration is given to the radiological impact of fuel storage. (author)

  5. Weld overlay repairs from conception to long-term qualification

    International Nuclear Information System (INIS)

    Weld overlay repairs serve several design functions. These include: structurally reinforcing the flawed location to restore code margins to failure, providing an IGSCC-resistant barrier to crack growth, and imposing a favorable residual stress distribution in the inner portion of the flawed component to inhibit further flaw initiation and growth. The qualification programs confirm that these design functions are maintained with long-term service. A regulatory barrier to long-term operation with weld overlays was the need periodically to inspect overlays and thereby demonstrate continued integrity. Although IGSCC flaws have generally been detected by ultrasonic methods, the repair of these flaws by weld overlay made continued monitoring of the repaired flaw by conventional ultrasonic techniques difficult. Recent developments in ultrasonic examination equipment and techniques, including surface preparation criteria, have enhanced the inspectability of weld overlay repairs and the underlying base material. The original acceptance of weld overlay repairs by the USNRC was for limited service (one or two fuel cycles of operation). However, more recent regulatory guidance, including the recently issued NUREG-0313, Revision 2, recognizes the above technical advances, and provides criteria for acceptance of weld overlays as long-term repairs. Several US utilities have been successful to date in obtaining USNRC approval for extended operation with weld overlays. Some overlays at these plants are currently entering their fourth successful fuel cycle of operation. (author)

  6. Non-intrusive long-term monitoring approaches

    International Nuclear Information System (INIS)

    In order to promote internatinal confidence that the US and Russia are disarming per their commitments under Article 6 of the Non-Proliferation Treaty, an international verification regime may be applied to US and Russian excess fissile materials. Initially, it is envisioned that this verification regime would be applied at storage facilities; however, it should be anticipated that the verification regime would continue throughout any material disposition activities, should such activities be pursued. once the materials are accepted into the verification regime, it is assumed that long term monitoring will be used to maintain continuity of knowledge. The requirements for long term storage monitoring include unattended operation for extended periods of time, minimal intrusiveness on the host nation's safety and security activities, data collection incorporating data authentication, and monitoring redundancy to allow resolution of anomalies and to continue coverage in the event of equipment failures. Additional requirements include effective data review and analysis processes, operation during storage facility loading, procedure for removal of inventory items for safety-related surveillance, and low cost, reliable equipment. A monitoring system might include both continuous monitoring of storagecontainers and continuous area monitoring. These would be complemented with periodic on-site inspections. A fissile material storage facility is not a static operation. The initial studies have shown there are a number of valid reasons why a host nation may need them to remove material from the storage facility. A practical monitoring system must be able to accommodate necessary material movements

  7. Sequential Probability Ratio Test for Long-Term Radiation Monitoring

    International Nuclear Information System (INIS)

    Pacific Northwest National Laboratory is currently developing a prototype instrumented container system for the detection of illicit nuclear and radiological materials in maritime scenarios. Data collection during this long-term monitoring of radiation sensor signals will be inherently sequential in that wireless data transmission will occur at set intervals. Among the possible decision-making algorithms for sequentially-acquired radiation sensor data is the Sequential Probability Ratio Test (SPRT). The suitability of the SPRT for this long-term monitoring application is discussed, and the decision-making performance of the SPRT is compared to that of the commonly used single-interval test (SIT). The analysis spans a wide range of signal and background count rates so that results are applicable to sensors of all sizes operating in different ambient conditions, and a spectrum of alarm thresholds. It is demonstrated that for these simulated long-term monitoring scenarios, decisions to issue an alarm when the measured count rate equals the threshold count rate, are made 3-5 times faster using the SPRT than with the SIT. The ability of the SPRT to provide an ''all-clear'' indication when the measured count rate is consistent with the expected background count rate is contrasted to the inconclusive results of the SIT test under the same conditions. The need for SPRT truncation strategies for measured count rate regions where the SPRT decision times become excessive is discussed. Finally, it is shown that the truncated SPRT provides a greater probability of detection than the SIT in a case of ''early termination'' of both tests, a situation likely to occur in long-term monitoring applications

  8. Long-term stability of polymeric integrated optical components

    Science.gov (United States)

    Kwong, Wing-Ying

    2006-02-01

    Traditionally, glass has been a suitable waveguide material and passive integrated optical circuits in glass substrates are widely used as passive components. Long-term tests of optical glass flats with a high level of internal stress revealed gradual systematic-change with time to produce inconsistent results. Since long-term stability has been the primary concern for users of specific applications, investigations of instabilities in various optical materials have been carried out via measurements and tests. From the development of the integrated optical systems' point-of-view, polymers are promising candidates that possess excellent compatibility with all other materials and their associated processes. Polymeric materials offer large refractive-index contrasts, high performance, environmental stability, simple low-cost fabrication and may be processed by unconventional forming techniques. Polymer technologies can be designed to form stress-free films, so that stress-induced losses can be eliminated. Optical polymers may also be tailored to meet specific requirements for optical waveguide devices and can be highly transparent in such a way that they are not a limiting factor in components' lifetime. In this paper, tests results and characteristics of polymeric materials shall be reviewed; different types of polymer are detail-studied and a brief analysis shall be presented. Examples of passive polymeric integrated optical components are single-mode splitters, couplers, polarizers, routers, gratings, bend waveguides, power dividers, wavelength filters and wavelength multiplexers/de-multiplexers, which may find applications in the optical communication and the telecommunication industries.

  9. Long term performance of radon mitigation systems

    International Nuclear Information System (INIS)

    Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985--1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes

  10. A long-term programme for IAEA

    International Nuclear Information System (INIS)

    At its fifth regular session in 1961, the IAEA General Conference adopted a resolution calling for the preparation of a long-term programme for the Agency's activities. The programme, which was prepared after extensive consultations with experts from many Member States and is intended to serve as a guide in planning and carrying out the Agency's work from 1965, has been presented to the seventh session of the General Conference by the Board of Governors and the Director General. It envisages that the Agency's main role during the next few years will be, on the one hand, to assist in preparing Member States for the introduction of atomic energy in its various peaceful uses, especially in the production of power, and, on the other, to stimulate and co-ordinate scientific and technological development with a view to making the advantages of peaceful atomic applications available to the maximum number of countries in the shortest possible time

  11. Estimating long-term health effects

    International Nuclear Information System (INIS)

    The long-term health effects from iodine 131 and cesium 137 as a result of the accident at Chernobyl Nuclear Power Plant in the USSR are discussed. Computer-generated radiation exposure distributions to the population in Europe have resulted in the following estimates: 2000-40,000 thyroid tumor cases from iodine 131 inhalation of which a few percent might be fatal; 10,000-250,000 potential thyroid tumor cases from iodine 131 absorbed via the grass-cow-milk route in the absence of actions by the public health authorities to block this exposure route; 3500-70,000 cancer cases from whole-body doses of cesium 137 (external and internal), of which approximately half might be fatal. Although there are uncertainties in these estimates they serve to indicate the magnitude of the problem

  12. Long-term variations of solar activity

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using the Lomb-Scargle periodogram we analyzed two sunspot series: the one over the past 11000 years at the 10-year interval based upon the survey data of 14C concentration in tree-rings, reconstructed by Solanki et al.; and the sunspot number over the past 7000 years, derived from geomagnetic variations by Usoskin et al. We found the periods and quasi-periods in solar activity, such as about 225, 352, 441, 522 and 561 a, and near 1000 and 2000 a. An approach of wavelet transform was applied to check the two sunspot time series, with emphasis on investigating time-varying characteristics in the long-term fluctuations of solar activity. The results show that the lengths and amplitudes of the periods have changed with time, and large variations have taken place during some periods.

  13. Long-Term Stability of Horseshoe Orbits

    CERN Document Server

    Ćuk, Matija; Holman, Matthew J

    2012-01-01

    Unlike Trojans, horseshoe coorbitals are not generally considered to be long-term stable (Dermott and Murray, 1981; Murray and Dermott, 1999). As the lifetime of Earth's and Venus's horseshoe coorbitals is expected to be about a Gyr, we investigated the possible contribution of late-escaping inner planet coorbitals to the lunar Late Heavy Bombardment. Contrary to analytical estimates, we do not find many horseshoe objects escaping after first 100 Myr. In order to understand this behaviour, we ran a second set of simulations featuring idealized planets on circular orbits with a range of masses. We find that horseshoe coorbitals are generally long lived (and potentially stable) for systems with primary-to-secondary mass ratios larger than about 1200. This is consistent with results of Laughlin and Chambers (2002) for equal-mass pairs or coorbital planets and the instability of Jupiter's horseshoe companions (Stacey and Connors, 2008). Horseshoe orbits at smaller mass ratios are unstable because they must approa...

  14. Long-term reductions in tinnitus severity

    Directory of Open Access Journals (Sweden)

    Folmer Robert L

    2002-09-01

    Full Text Available Abstract Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to their initial appointment at the Oregon Health & Science University Tinnitus Clinic. All patients were then evaluated and treated within a comprehensive tinnitus management program. Follow-up questionnaires were mailed to the same 300 patients 6 to 36 months after their initial tinnitus clinic appointment. Results One hundred ninety patients (133 males, 57 females; mean age 57 years returned follow-up questionnaires 6 to 36 months (mean = 22 months after their initial tinnitus clinic appointment. This group of patients exhibited significant long-term reductions in self-rated tinnitus loudness, Tinnitus Severity Index scores, tinnitus-related anxiety and prevalence of current depression. Patients who improved their sleep patterns or Beck Depression Inventory scores exhibited greater reductions of tinnitus severity scores than patients who continued to experience insomnia and depression at follow-up. Conclusions Individualized tinnitus management programs that were designed for each patient contributed to overall reductions in tinnitus severity exhibited on follow-up questionnaires. Identification and treatment of patients experiencing anxiety, insomnia or depression are vital components of an effective tinnitus management program. Utilization of acoustic therapy also contributed to improvements exhibited by these patients.

  15. Long term radiological impact of thorium extraction

    International Nuclear Information System (INIS)

    Thorium extraction produces a certain amount of radioactive wastes. Potential long term radiological impact of these residues has been calculated using the recent ICRP-68 ingestion dose factors in connection with the computing code DECAY, developed at Orsay and described in this work. This code solves the well known Bateman's equations which govern the time dependence of a set of coupled radioactive nuclei. Monazites will be very likely the minerals to be exploited first, in case of an extensive use of thorium as nuclear fuel. Because monazites contain uranium as well, mining residues will contain not only the descendants of 232Th and a certain proportion of non-extracted thorium (taken here to be 5%), but also this uranium, if left in the wastes for economical reasons. If no uranium would be present at all in the mineral, the potential radiotoxicity would strongly decrease in approximately 60 years, at the pace of the 5.8 years period of 228Ra, which becomes the longest-lived radionuclide of the 4n radioactive family in the residues. Moreover, there is no risk due to radon exhalation, because of the very short period of 220Rn. These significant differences between uranium and thorium mining have to be considered in view of some estimated long term real radiological impacts due to uranium residues, which could reach a value of the order of 1 mSv/year, the dose limit recommended for the public by the recent ICRP-60. (authors). 15 refs., 4 figs., 3 tabs., 43 appendices

  16. Long-term Agroecosystem Research in the Northern Great Plains.

    Science.gov (United States)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

    2015-12-01

    The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

  17. Long-term assessment of residential radon-mitigation systems

    International Nuclear Information System (INIS)

    In New York State a survey in 1982-83 discovered fourteen houses with moderately high natural radon levels, and in early 1984 low-cost radon mitigation systems were installed in these houses. The radon reduction techniques included sealing cracks, sealing and sub-slab depressurization, isolating and venting unpaved crawl-spaces, and installing heat-recovery ventilators. These mitigation systems represent some of the earliest systems installed in the United States using low-cost common residential construction materials and methods. In this report, the authors discuss how they returned to these installations, inspected the longevity of the various components of the systems and assessed their long-term effectiveness

  18. Innovative use of tele-ICU in long-term acute care hospitals.

    Science.gov (United States)

    Mullen-Fortino, Margaret; Sites, Frank D; Soisson, Michael; Galen, Julie

    2012-01-01

    Tele-intensive care units (ICUs) typically provide remote monitoring for ICUs of acute care, short-stay hospitals. As part of a joint venture project to establish a long-term acute level of care, Good Shepherd Penn Partners became the first facility to use tele-ICU technology in a nontraditional setting. Long-term acute care hospitals care for patients with complex medical problems. We describe describes the benefits and challenges of integrating a tele-ICU program into a long-term acute care setting and the impact this model of care has on patient care outcomes. PMID:22828067

  19. Long-term potentiation and long-term depression: a clinical perspective

    Directory of Open Access Journals (Sweden)

    Timothy V.P. Bliss

    2011-01-01

    Full Text Available Long-term potentiation and long-term depression are enduring changes in synaptic strength, induced by specific patterns of synaptic activity, that have received much attention as cellular models of information storage in the central nervous system. Work in a number of brain regions, from the spinal cord to the cerebral cortex, and in many animal species, ranging from invertebrates to humans, has demonstrated a reliable capacity for chemical synapses to undergo lasting changes in efficacy in response to a variety of induction protocols. In addition to their physiological relevance, long-term potentiation and depression may have important clinical applications. A growing insight into the molecular mechanisms underlying these processes, and technological advances in non-invasive manipulation of brain activity, now puts us at the threshold of harnessing long-term potentiation and depression and other forms of synaptic, cellular and circuit plasticity to manipulate synaptic strength in the human nervous system. Drugs may be used to erase or treat pathological synaptic states and non-invasive stimulation devices may be used to artificially induce synaptic plasticity to ameliorate conditions arising from disrupted synaptic drive. These approaches hold promise for the treatment of a variety of neurological conditions, including neuropathic pain, epilepsy, depression, amblyopia, tinnitus and stroke.

  20. Long-term surveillance plan for the Mexican Hat Disposal Site, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    This plan describes the long-term surveillance activities for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Mexican Hat, Utah. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This long-term surveillance plan (LTSP) was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive material (RRM). This LTSP (based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program), documents the land ownership interests and details how the long-term care of the disposal site will be accomplished

  1. Long-term surveillance plan for the Mexican Hat Disposal Site, Mexican Hat, Utah

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    This plan describes the long-term surveillance activities for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Mexican Hat, Utah. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This long-term surveillance plan (LTSP) was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive material (RRM). This LTSP (based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program), documents the land ownership interests and details how the long-term care of the disposal site will be accomplished.

  2. Experimental Simulation of Long Term Weathering in Alkaline Bauxite Residue Tailings

    Directory of Open Access Journals (Sweden)

    Talitha C. Santini

    2015-07-01

    Full Text Available Bauxite residue is an alkaline, saline tailings material generated as a byproduct of the Bayer process used for alumina refining. Developing effective plans for the long term management of potential environmental impacts associated with storage of these tailings is dependent on understanding how the chemical and mineralogical properties of the tailings will change during weathering and transformation into a soil-like material. Hydrothermal treatment of bauxite residue was used to compress geological weathering timescales and examine potential mineral transformations during weathering. Gibbsite was rapidly converted to boehmite; this transformation was examined with in situ synchrotron XRD. Goethite, hematite, and calcite all precipitated over longer weathering timeframes, while tricalcium aluminate dissolved. pH, total alkalinity, and salinity (electrical conductivity all decreased during weathering despite these experiments being performed under “closed” conditions (i.e., no leaching. This indicates the potential for auto-attenuation of the high alkalinity and salinity that presents challenges for long term environmental management, and suggests that management requirements will decrease during weathering as a result of these mineral transformations.

  3. Super long-term creep tests of advanced HP and IP rotor steels

    Energy Technology Data Exchange (ETDEWEB)

    Tchizhik, A.A. [The Polzunov Central Boiler and Turbine Institute, Department the Fatigue Life of Materials for Power Plans Equipment, St. Petersburg (Russian Federation)

    1998-12-31

    A creep model has been developed for predicting the long-term creep behavior, in excess of 200,000 h for advanced materials.The new creep theory is based on a continuum microdamage model and is used to calculate the fields of stress and strain and wedge and cavities damage in critical components of steam and gas turbines. The application of this new model increases the reliability and service life of modern turbines. The accuracy of the model to predict long - term creep behavior, creep ductility was verified using the data bank of super long-term creep tests of advanced materials. (orig.) 12 refs.

  4. ASME Material Challenges for Advanced Reactor Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Ali Siahpush

    2013-07-01

    This study presents the material Challenges associated with Advanced Reactor Concept (ARC) such as the Advanced High Temperature Reactor (AHTR). ACR are the next generation concepts focusing on power production and providing thermal energy for industrial applications. The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The heat exchanger required for AHTR is subjected to a unique set of conditions that bring with them several design challenges not encountered in standard heat exchangers. The corrosive molten salts, especially at higher temperatures, require materials throughout the system to avoid corrosion, and adverse high-temperature effects such as creep. Given the very high steam generator pressure of the supercritical steam cycle, it is anticipated that water tube and molten salt shell steam generators heat exchanger will be used. In this paper, the ASME Section III and the American Society of Mechanical Engineers (ASME) Section VIII requirements (acceptance criteria) are discussed. Also, the ASME material acceptance criteria (ASME Section II, Part D) for high temperature environment are presented. Finally, lack of ASME acceptance criteria for thermal design and analysis are discussed.

  5. Structural materials challenges for advanced reactor systems

    Science.gov (United States)

    Yvon, P.; Carré, F.

    2009-03-01

    Key technologies for advanced nuclear systems encompass high temperature structural materials, fast neutron resistant core materials, and specific reactor and power conversion technologies (intermediate heat exchanger, turbo-machinery, high temperature electrolytic or thermo-chemical water splitting processes, etc.). The main requirements for the materials to be used in these reactor systems are dimensional stability under irradiation, whether under stress (irradiation creep or relaxation) or without stress (swelling, growth), an acceptable evolution under ageing of the mechanical properties (tensile strength, ductility, creep resistance, fracture toughness, resilience) and a good behavior in corrosive environments (reactor coolant or process fluid). Other criteria for the materials are their cost to fabricate and to assemble, and their composition could be optimized in order for instance to present low-activation (or rapid desactivation) features which facilitate maintenance and disposal. These requirements have to be met under normal operating conditions, as well as in incidental and accidental conditions. These challenging requirements imply that in most cases, the use of conventional nuclear materials is excluded, even after optimization and a new range of materials has to be developed and qualified for nuclear use. This paper gives a brief overview of various materials that are essential to establish advanced systems feasibility and performance for in pile and out of pile applications, such as ferritic/martensitic steels (9-12% Cr), nickel based alloys (Haynes 230, Inconel 617, etc.), oxide dispersion strengthened ferritic/martensitic steels, and ceramics (SiC, TiC, etc.). This article gives also an insight into the various natures of R&D needed on advanced materials, including fundamental research to investigate basic physical and chemical phenomena occurring in normal and accidental operating conditions, lab-scale tests to characterize candidate materials

  6. Electronic records long term authenticity and integrity demonstration

    Directory of Open Access Journals (Sweden)

    Jerman Blažič, Aljoša

    2011-01-01

    Full Text Available Long term preservation of electronic data requires introduction of specific technology solutions and organizational measures in order to provide stable environment for electronic record preservation. System solutions must support basic principles of electronic preservation: accessibility of data, usability or reproduction of data in usable form and integrity/authenticity provision including time existence for preserved content.Due to their nature, electronic data may become subjects of manipulation without recursive traceability of content alteration. In order to preserve usability of preserved data, electronic preservation system must provide appropriate measures for demonstrating unalterability of data for the entire preservation period. In this paper technology approach for demonstrating integrity and authenticity of archived data on long term basis is presented. Presented technological concept deals with any type of documentation or archiving material and provides creation of additional security assertions or evidence records that are needed to demonstrate the authenticity and integrity of the material anytime during the archival period. The evidence record syntax (ERS, which has been standardized by international organization body for internet standards (IETF, presents universal technique of security assertions generation and their maintenance for integrity preservation based on document hashing, hash treeing and integration of (qualified time stamps of trusted third parties. Using re-timestamping methods created security assertions may endure their validity for longest periods of time until retention periods of archived data expires. In the paper complementary organizational rules for technology solutions are presented as well, providing an all around overview of long term preservation of data in authentic, reliable and secure manner.

  7. Long-term behaviour of solid oxide fuel cell interconnect materials in contact with Ni-mesh during exposure in simulated anode gas at 700 and 800 °C

    Science.gov (United States)

    Garcia-Fresnillo, L.; Shemet, V.; Chyrkin, A.; de Haart, L. G. J.; Quadakkers, W. J.

    2014-12-01

    In the present study the long-term behaviour of two ferritic steels, Crofer 22 APU and Crofer 22H, in contact with a Ni-mesh during exposure in simulated anode gas, Ar-4%H2-2%H2O, at 700 and 800 °C for exposure times up to 3000 h was investigated. Ni diffusion from the Ni-mesh into the steel resulted in the formation of an austenitic zone whereas diffusion of iron and chromium from the steel into the Ni-mesh resulted in the formation of chromia base oxides in the Ni-mesh. Depending on the chemical composition of the steel, the temperature and the exposure time, interdiffusion processes between ferritic steel and Ni-mesh also resulted in σ-phase formation at the austenite-ferrite interface and in Laves-phase dissolution in the austenitic zone. The extent and morphology of the σ-phase formation are discussed on the basis of thermodynamic considerations, including reaction paths in the ternary alloy system Fe-Ni-Cr.

  8. Predictive calculations to assess the long-term effect of cementitious materials on the pH and solubility of uranium(VI) in a shallow land disposal environment

    International Nuclear Information System (INIS)

    One proposed method of low-level radioactive waste (LLW) disposal is to mix the radioactive waste streams with cement, place the mixture in steel barrels, and dispose of the barrels in near-surface unsaturated sediments. Cement or concrete is frequently used in burial grounds, because cement porewaters are buffered at high pH values and lanthanides and actinides; are very insoluble in highly alkaline environments. Therefore, leaching of these contaminants from the combined cement/low-level radioactive waste streams will at least initially be retarded. The calculations performed in this study demonstrate that the pH of cement porewaters will be maintained at a value greater than 10 for 10,000 years under Hanford specific hydrogeochemical conditions. Ten thousand years is the period generally studied in longterm performance assessments per regulatory guidance. The concentrations of dissolved hexavalent uranium [U(VI)], the valence form of dissolved U usually present in oxidizing surface and groundwaters, are also constrained by the high pH and predicted solution compositions over the 10,000-year period, which is favorable from a long-term performance perspective

  9. Robotics for Long-Term Monitoring

    International Nuclear Information System (INIS)

    While long-term monitoring and stewardship means many things to many people, DOE has defined it as The physical controls, institutions, information, and other mechanisms needed to ensure protection of people and the environment at sites where DOE has completed or plans to complete cleanup (e.g., landfill closures, remedial actions, and facility stabilization). Across the United States, there are thousands of contaminated sites with multiple contaminants released from multiple sources where contaminants have transported and commingled. The U.S. government and U.S. industry are responsible for most of the contamination and are landowners of many of these contaminated properties. These sites must be surveyed periodically for various criteria including structural deterioration, water intrusion, integrity of storage containers, atmospheric conditions, and hazardous substance release. The surveys, however, are intrusive, time-consuming, and expensive and expose survey personnel to radioactive contamination. In long-term monitoring, there's a need for an automated system that will gather and report data from sensors without costly human labor. In most cases, a SCADA (Supervisory Control and Data Acquisition) unit is used to collect and report data from a remote location. A SCADA unit consists of an embedded computer with data acquisition capabilities. The unit can be configured with various sensors placed in different areas of the site to be monitored. A system of this type is static, i.e., the sensors, once placed, cannot be moved to other locations within the site. For those applications where the number of sampling locations would require too many sensors, or where exact location of future problems is unknown, a mobile sensing platform is an ideal solution. In many facilities that undergo regular inspections, the number of video cameras and air monitors required to eliminate the need for human inspections is very large and far too costly. HCET's remote harsh

  10. What long-term road transport future? Trends and policy options.

    OpenAIRE

    Proost, Stef; Van Dender, Kurt

    2011-01-01

    This article examines long-term trends and broad policy options and challenges related to the road transport sector and its congestion and environmental impacts. A brief review of long-term projections of demand for road transport suggests that problems related to road network congestion and greenhouse gas (GHG) emissions are likely to become more pressing in the future than they are now. Next we review, from a macroscopic perspective, three policy measures aimed at addressing these problems:...

  11. Geriatric pain competencies and knowledge assessment for nurses in long term care settings

    OpenAIRE

    Swafford, Kristen L.; Miller, Lois L.; Herr, Keela; Forcucci, Chris; Kelly, Anne Marie L.; Bakerjian, Debra

    2014-01-01

    Pain in older adults is a prevalent problem that affects quality of life and challenges nurses, particularly those caring for older adults living in long term care settings. Despite the national priority of pain management, insufficient knowledge of nurses about geriatric pain is a documented barrier to effective geriatric pain management in all long term care settings. To address this knowledge gap, a website (GeriatricPain.org) was developed by the National Geriatric Pain Collaborative with...

  12. Deep uncertainty in long-term hurricane risk: scenario generation and implications for future climate experiments

    OpenAIRE

    Ranger, Nicola; Niehörster, Falk

    2011-01-01

    Current projections of long-term trends in Atlantic hurricane activity due to climate change are deeply uncertain, both in magnitude and sign. This creates challenges for adaptation planning in exposed coastal communities. We present a framework to support the interpretation of current long-term tropical cyclone projections, which accommodates the nature of the uncertainty and aims to facilitate robust decision making using the information that is available today. The framework is populate...

  13. How Have Long-Term Survivors Coped with Living with HIV?

    OpenAIRE

    Slomka, Jacquelyn; Lim, Jung-won; Gripshover, Barbara; Daly, Barbara

    2012-01-01

    With advances in HIV treatment, more individuals have grown older with the disease. Little is known about factors that have helped these survivors manage everyday life with HIV. In this exploratory, qualitative study, we asked, What has helped survivors cope with challenges of living long-term with HIV? Participants were recruited from a convenience sample of persons living with HIV (PLWH) who obtained treatment at a specialty HIV clinic; 16 long-term survivors of HIV were interviewed. Mean a...

  14. Comparison of long-term care in an acute care institution and in a long-term care institution

    OpenAIRE

    Friedman, R; Kalant, N.

    1998-01-01

    BACKGROUND: Acute care hospitals in Quebec are required to reserve 10% of their beds for patients receiving long-term care while awaiting transfer to a long-term care facility. It is widely believed that this is inefficient because it is more costly to provide long-term care in an acute care hospital than in one dedicated to long-term care. The purpose of this study was to compare the quality and cost of long-term care in an acute care hospital and in a long-term care facility. METHODS: A con...

  15. Elevated rheumatoid factor and long term risk of rheumatoid arthritis

    DEFF Research Database (Denmark)

    Nielsen, Sune F; Bojesen, Stig E; Schnohr, Peter;

    2012-01-01

    To test whether elevated concentration of rheumatoid factor is associated with long term development of rheumatoid arthritis.......To test whether elevated concentration of rheumatoid factor is associated with long term development of rheumatoid arthritis....

  16. Material challenge for flexible organic devices

    Directory of Open Access Journals (Sweden)

    Jay Lewis

    2006-04-01

    Full Text Available Outside of the active device layers, there are a variety of requisite functional layers in flexible organic electronic devices. Whether the application is in displays, lighting, integrated circuits, or photovoltaics, there are materials challenges in implementing flexible and/or organic devices into practical applications. We highlight two topics that are common to most flexible electronic technologies. First, we describe the difficulty in developing suitable permeation barriers on polymer substrates, the approaches being taken to solve this problem, and their current status. Second, we highlight the limited mechanical ruggedness of brittle inorganic films and present approaches for improving overall device flexibility.

  17. DIFFERENTIAL DIAGNOSIS OF LONG TERM TONGUE ULCERS

    Directory of Open Access Journals (Sweden)

    Hegde Nidarsh D.

    2012-08-01

    Full Text Available Oral ulcers is a very common disorder of the oral mucosa. Patients with signs or symptoms of oral ulcers are sometimes referred to gastroenterology clinics, however, in most instances the ulcers does not reflect gastrointestinal disease, some with a chronic non- healing ulcer are advised biopsy. Indeed, a spectrum of disorders can give rise to oral mucosal ulcers ranging from minor local trauma to significant local disease such as malignancy or systemic illness. Lesions of the tongue have a broad differential diagnosis ranging from benign idiopathic processes to infections, cancers, and infiltrative disorders. This article will focus on common ulcerative disorders of the tongue in aspects of their clinical features and differential diagnosis, two case reports with the diagnosis and conservative management for long-term chronic ulcers. The two cases which are reported in this article had a differential diagnosis of Squamous cell carcinoma of the tongue. The clinical picture was craterlike lesion, having a velvety-red base and a rolled, indurated border and most important painless in both cases. Removal of the irritant which was the tooth, rehabilitation of the oral mucosa by lubrication with Cocus Nucifera resulted in the healing of the ulcers. Functional components of Cocus Nucifera are Squaline, tocopherol, phytosterols and other sterols which are all plant steroids.

  18. Long-term corrosion testing pan.

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Frederick Douglas; Brown, Neil R. (Los Alamos National Laboratory, Los Alamos, NM)

    2008-08-01

    This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing needs. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to meet all future testing needs, given that all testing is consolidated to a single location. This report is a revision to SAND2007-7027 to address DOE comments and add a series of tests to address NWTRB recommendations.

  19. Long-term corrosion testing plan.

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Frederick Douglas; Brown, Neil R. (Los Alamos National Laboratory, Los Alamos, NM)

    2009-02-01

    This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing program. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to accommodate all future testing, given that all testing is consolidated to a single location. This report is a revision to SAND2008-4922 to address DOE comments.

  20. Long-term corrosion testing plan

    International Nuclear Information System (INIS)

    This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing program. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to accommodate all future testing, given that all testing is consolidated to a single location. This report is a revision to SAND2008-4922 to address DOE comments.

  1. Long-term corrosion testing pan

    International Nuclear Information System (INIS)

    This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing needs. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to meet all future testing needs, given that all testing is consolidated to a single location. This report is a revision to SAND2007-7027 to address DOE comments and add a series of tests to address NWTRB recommendations

  2. Long term results of mandibular distraction

    Directory of Open Access Journals (Sweden)

    Batra Puneet

    2006-03-01

    Full Text Available Mandibular distraction osteogenesis has become a popular surgical modality due to its many advantages over conventional orthognathic surgical procedures. However, in spite of the technique having been used for over 15 years, no concrete long term results are available regarding the stability of results. We discuss the various studies which have reported either in favour or against the stablility of results after distraction. We report a series of 6 cases (3 unilateral and 3 bilateral distraction where distraction was carried out before puberty and followed them up to seven years after removal of distractors. This case series shows that results achieved by distraction osteogenesis are unstable or best unpredictable with respect to producing a permanent size increase in the mandible. The role of the distraction osteogenesis in overcoming the pterygomassetric sling is questionable. We suggest a multicenter study with adequate patient numbers treated with a similar protocol and documented after growth cessation to have meaningful conclusions on the debate of distraction osteogenesis versus orthognathic surgery.

  3. CERN Services for Long Term Data Preservation

    CERN Document Server

    Shiers, Jamie; Blomer, Jakob; Ganis, Gerardo; Dallmeier-Tiessen, Sunje; Simko, Tibor; Cancio Melia, German; CERN. Geneva. IT Department

    2016-01-01

    In this paper we describe the services that are offered by CERN for Long Term preservation of High Energy Physics (HEP) data, with the Large Hadron Collider (LHC) as a key use case. Data preservation is a strategic goal for European High Energy Physics (HEP), as well as for the HEP community worldwide and we position our work in this global content. Specifically, we target the preservation of the scientific data, together with the software, documentation and computing environment needed to process, (re-)analyse or otherwise (re-)use the data. The target data volumes range from hundreds of petabytes (PB – 10^15 bytes) to hundreds of exabytes (EB – 10^18 bytes) for a target duration of several decades. The Use Cases driving data preservation are presented together with metrics that allow us to measure how close we are to meeting our goals, including the possibility for formal certification for at least part of this work. Almost all of the services that we describe are fully generic – the exception being A...

  4. Long term prediction of flood occurrence

    Science.gov (United States)

    Aguilar, Cristina; Montanari, Alberto; José Polo, María

    2016-05-01

    How long a river remembers its past is still an open question. Perturbations occurring in large catchments may impact the flow regime for several weeks and months, therefore providing a physical explanation for the occasional tendency of floods to occur in clusters. The research question explored in this paper may be stated as follows: can higher than usual river discharges in the low flow season be associated to a higher probability of floods in the subsequent high flow season? The physical explanation for such association may be related to the presence of higher soil moisture storage at the beginning of the high flow season, which may induce lower infiltration rates and therefore higher river runoff. Another possible explanation is persistence of climate, due to presence of long-term properties in atmospheric circulation. We focus on the Po River at Pontelagoscuro, whose catchment area amounts to 71 000 km2. We look at the stochastic connection between average river flows in the pre-flood season and the peak flows in the flood season by using a bivariate probability distribution. We found that the shape of the flood frequency distribution is significantly impacted by the river flow regime in the low flow season. The proposed technique, which can be classified as a data assimilation approach, may allow one to reduce the uncertainty associated to the estimation of the flood probability.

  5. Long term results of Wilms' tumor

    International Nuclear Information System (INIS)

    Sixteen long term survivors of Wilms' tumor which were experienced in our deprtment were analyzed. No patients showed abnormalities in non-specific cell mediated immunity, endocrine function, secondary sexual development or renal function. In patients who were followed more than 10 years after surgery, the function of the remaining kidney, as determined by DMSA uptake, was well developed. In 15 patients who were treated by radiotherapy, changes in the spinal bodies were seen in all 15, scoliosis (average 9 deg) in 14 and hypoplasia in the iliac bone on the irradiated side in 12. In 14 patients who were examined by CT scan, atrophies of the erector spinae and illopsoas muscles on the irradiated side were seen in all cases. A significant correlation between the severity of the atrophic erector spinae muscle and the degree of scoliosis was obtained. Sixty nine patients with Wilms' tumor who survived more than ten years after surgery were found in the files of 13 institutions in our conutry. Our of them, 25 (36%) developed late disturbances and many of them were due to irradiation therapy. (author)

  6. Long term prospects for world gas trade

    International Nuclear Information System (INIS)

    Results are presented from a world gas trade model used to forecast long term gas markets. Assumptions that went into the model are described, including the extent of current proven gas reserves, production ratios, total energy and gas demand, gas supply cost curves for each producing country, available gas liquefaction and transportation facilities, and liquefied natural gas (LNG) shipping costs. The results indicate that even with generally very low supply costs for most gas producing basins, gas trade will continue to be restricted by the relatively high cost of transportation, whether by pipeline or tanker. As a consequence, future gas trade will tend to be regionally oriented. United States gas imports will come mostly from Canada, Venezuela, and Mexico; Western Europe will largely be supplied by the Soviet Union and Africa, and Japan's requirements will generally be met by Pacific Rim producers. Although the Middle East has vast quantities of gas reserves, its export growth will continue to be hampered by its remote location from major markets. 16 figs

  7. Allogeneic radiation chimeras: long-term studies

    International Nuclear Information System (INIS)

    Lethally irradiated mice protected with allogeneic fetal liver cells or with syngeneic or allogeneic marrow and spleen cells treated with antisera to mouse immunoglobulins or to the T cell-associated 0 antigen and their controls were observed for up to 750 days. The best survival rates were found in the large groups given syngeneic marrow and spleen or allogeneic fetal liver cells (70-85 percent 700-day survival); in contrast, 43 percent of the group injected with allogeneic cells treated with anti-0 serum and 19 percent of those given antimmunoglobulin-treated cells were alive 700 days postradiation. Pulmonary infection was the most frequent cause of death of long-term survivors in all groups. Tumor incidence was increased in recipients of allogeneic cells (13 percent versus 4 percent among syngeneic chimeras), but the renal pathology seen in these groups was no greater than that noted in the syngeneic controls. Beginning 600 days after irradiation, mice from experimental and control groups were killed and their spleens were cultured with thymus-dependent antigens and the mitogens concanavalin Λ and lipopolysaccharide, Escherichia coli. The most frequent finding in all groups was mild to moderate impairment of T cell-dependent responses. (U.S.)

  8. Effective long term operation for Dukovany NPP

    International Nuclear Information System (INIS)

    Dukovany NPP now started third decade of service that is also its last decade of design life time. It is clear that the NPP has all considerations for service past the design life time called Long Term Operation (LTO). This LTO has two main aspects, technical and economical, that influence each other. From technical view the age of NPP systems, structures and components (SSCs) affects negatively the ability to perform necessary design changes in a good quality and also the long lived SSC reliability. These possible impacts have also their safety aspects and to obtain regulatory body agreement with LTO of NPP it is necessary to show that these impacts are acceptable. It means to show that all applied design changes are done in agreement with NPP design bases (DB) and all ageing impacts on SSCs functions important for safety are properly managed. From economical view that is significant for NPP owner it is necessary to demonstrate a required profitability of investment for effective LTO. These are reasons why Dukovany NPP performs three following projects: - Safety design bases collation and reconstitution, - Enhancement of plant life management program (New program preparation), - Technical-economical (TE) study of NPP LTO. All of these projects are managed by Nuclear Research Institute Rez plc (NRI) and performed in close cooperation with NPP staff and different co-operaters. This presentation will be concentrated to the last named project.

  9. Downlink Scheduling in Long Term Evolution

    Directory of Open Access Journals (Sweden)

    Anwar Hossain

    2015-06-01

    Full Text Available This is an investigated research article on resource block scheduling of Long Term Evolution (LTE. LTE is one of the evolutions of the Universal Mobile Telecommunication System (UMTS. It provides internet access to mobile users through smart phone, laptop and other android devices. LTE offers a high speed data and multimedia services. It supports data rates up to 100 Mbps in the downlink and 50 Mbps in the uplink transmission. Our research investigation was aim to the downlink scheduling. We have considered The Best CQI scheduling algorithm and the Round Robin scheduling algorithm. The implementation, analysis and comparison of these scheduling algorithms have been performed through MATLAB simulator. We have analyzed the impact of the scheduling schemes on the throughput and the fairness of both scheduling schemes. Here we have proposed a new scheduling algorithm that achieves a compromise between the throughput and the fairness. Orthogonal Frequency Division Multiplexing (OFDM has been adopted as the downlink transmission scheme. We have considered the impact of the channel delay on the throughput. In addition, MIMO transceiver systems have been implemented to increase the throughput

  10. The long term macroeconomic role for energy

    International Nuclear Information System (INIS)

    Arguments about the role of energy in economic systems are incomplete without analysis of the effects of changes in the price of energy. It may be true (because energy can substitute for so many other things) that we can continue to increase energy output per capita as long as we are prepared to increase energy consumption per unit of output, but if the price of energy is higher than consumers are prepared to pay the process will come to a stop. It follows that the output at any point in time is the result of an equilibrium between a great many factors in the economy one of which is the price of energy. The question that I now pose is whether the price of energy is an especially important factor. The subject is analyzed under the headings: the economics of energy price; a first attempt to model long-term effects; what is a price hike; modelling energy price hikes; implications and lessons for nuclear energy; the present reality. (author)

  11. Structural Materials: New Challenges, Manufacturing and Performance

    International Nuclear Information System (INIS)

    Important criteria of innovative fast reactors and advanced fuel cycle initiatives are improved efficiency, economic competitiveness and reduction of waste. To reach these goals and keep high safety standards, at least at the level of currently operating nuclear reactors, key issues are the availability of suitable structural materials and their performance assessment. The authors, on the basis of the wealth of experience gained in the European Union, India and Japan, aim to define the challenges and current status of material development and set the agenda for R and D in the coming years and decades. It is hoped that the joint perspective would enable realizing the expected criteria of sustainability envisaged through sodium cooled fast reactors and closed fuel cycles. (author)

  12. Microscopic study of rock for estimating long-term behavior

    International Nuclear Information System (INIS)

    Micro-structure of rock and rock mass plays an essential role for their long-term behavior of more than ten thousand years. For elucidating long-term characteristics of granite we here present the followings: 1) a series of stress relaxation tests using granite and a polycrystalline rock with quartz and feldspar, 2) molecular dynamics (MD) calculation of rock-forming minerals of granite for determining their material properties, and 3) elasto-visco-plastic homogenization analysis (HA), which treats the micro-inhomogeneous characteristics of granite and the rock structure. Creep and relaxation are typical time dependent phenomena, and we performed a series of laboratory relaxation tests under microscope observation. We used granite and pegmatite. The specimens were kept in water. The aim of the experiment is to observe the sequential propagation of micro-cracks and its affect to the macroscopic response of the rock material under relaxation state. The MD is a computational physics and chemistry method. We applied it to calculate material properties of rock-forming minerals of granite, that is, quartz, feldspar and mica. Since the minerals and their interfaces are of very small scale, it is considerably difficult to determine the material properties by some experiments, especially for mica. The MD method is effective for this problem, if the interatomic potentials are correctly determined. As mentioned above, granite is a typical polycrystalline material with several kinds of rock-forming minerals. For analyzing such a micro-inhomogeneous material behavior, we developed a new elasto-visco-plastic HA scheme. Note that the HA is a mathematical method developed for analyzing mechanics of composite materials with periodic micro-structures. We checked its validity by applying it for a deep underground opening problem. (author)

  13. Optimization approach for water resources long term planning and management

    Science.gov (United States)

    Haguma, D.; Leconte, R.; Krau, S.; Côté, P.

    2012-04-01

    Integration of short-term operation and long-term planning is one of the challenges of development and management of water resources systems. This research is interested in an optimization algorithm consisting of a short-term time step dynamic programming (DP) formulation, coupled with a long-term time step expectation of the future benefit function of flows scenarios. The method takes into account the short-term variability or seasonality of the flow regime as well as long-term uncertainty of flows, which is actuated by either climate change or global climate variability associated with phases of oceanic and atmospheric phenomena. The DP is used to determine an optimum operating policy of flows scenarios for the short-term time step. The use of flows scenarios in optimization problem represents the stochastic aspect of flows, and transition between scenarios is done at long-term time step. This method could be used for water resources planning in the context of future hydrologic regime uncertainties or to evaluate climate change impacts on existing water resources systems. The algorithm was tested for optimum hydropower production of Manicouagan water resources system, Québec, Canada, with two hydropower plants with reservoir and three run-of-river plants, for a period of 90 years, from 2010 to 2099. Future climate weekly time step operating policy was produced with two time steps: annual time step for management of water resources in non-stational climate and a weekly time step for flow seasonality. Annual flows have been used to compute transition probabilities between flow scenarios. Results show that there will be an increase of hydropower production in the future climate thanks to the increase of seasonal and annual flows. However, climate change will reduce the efficiency of the existing hydropower system, with more unproductive spills. The algorithm permitted to evaluate the impact of climate change on water resources without taking any assumptions other

  14. Multiobjective long-term planning of biopharmaceutical manufacturing facilities.

    Science.gov (United States)

    Lakhdar, K; Savery, J; Papageorgiou, L G; Farid, S S

    2007-01-01

    Biopharmaceutical companies with large portfolios of clinical and commercial products typically need to allocate production across several multiproduct facilities, including third party contract manufacturers. This poses several capacity planning challenges which are further complicated by the need to satisfy different stakeholders often with conflicting objectives. This work addresses the question of how a biopharmaceutical manufacturer can make better long-term capacity planning decisions given multiple strategic criteria such as cost, risk, customer service level, and capacity utilization targets. A long-term planning model that allows for multiple facilities and accounts for multiple objectives via goal programming is developed. An industrial case study based on a large scale biopharmaceutical manufacturer is used to illustrate the functionality of the model. A single objective model is used to identify how best to use existing capacity so as to maximize profits for different demand scenarios. Mitigating risk due to unforeseen circumstances by including a dual facility constraint is shown to be a reasonable strategy at base case demand levels but unacceptable if demands are 150% higher than expected. The capacity analysis identifies where existing capacity fails to meet demands given the constraints. A multiobjective model is used to demonstrate how key performance measures change given different decision making policies where different weights are assigned to cost, customer service level, and utilization targets. The analysis demonstrates that a high profit can still be achieved while meeting key targets more closely. The sensitivity of the optimal solution to different limits on the targets is illustrated. PMID:17924645

  15. Long term data preservation for CDF at INFN-CNAF

    International Nuclear Information System (INIS)

    Long-term preservation of experimental data (intended as both raw and derived formats) is one of the emerging requirements coming from scientific collaborations. Within the High Energy Physics community the Data Preservation in High Energy Physics (DPHEP) group coordinates this effort. CNAF is not only one of the Tier-1s for the LHC experiments, it is also a computing center providing computing and storage resources to many other HEP and non-HEP scientific collaborations, including the CDF experiment. After the end of data taking in 2011, CDF is now facing the challenge to both preserve the large amount of data produced during several years of data taking and to retain the ability to access and reuse it in the future. CNAF is heavily involved in the CDF Data Preservation activities, in collaboration with the Fermilab National Laboratory (FNAL) computing sector. At the moment about 4 PB of data (raw data and analysis-level ntuples) are starting to be copied from FNAL to the CNAF tape library and the framework to subsequently access the data is being set up. In parallel to the data access system, a data analysis framework is being developed which allows to run the complete CDF analysis chain in the long term future, from raw data reprocessing to analysis-level ntuple production. In this contribution we illustrate the technical solutions we put in place to address the issues encountered as we proceeded in this activity.

  16. Long term operation of nuclear power plants - economic challenges

    International Nuclear Information System (INIS)

    The lifetime extension of nuclear power plants is an open issue in a lot of countries. At the international scale, the costs of upgrading the plant equipment were assessed in 2012 to be between 500 and 1000 dollars per kWe. The post-Fukushima measures taken for increasing the safety standard of the plant reach around 15% of the bill. In almost all countries the lifetime extension strategy appears to be economical if the extension time is for 10 years at least. For France the lifetime extension strategy is also economical: a recent report of the 'French Court of Auditors' concludes that the complete cost of nuclear energy in 2013 is 59.8 euros/MWh and is estimated to reach 62 euros/MWh in the case of a lifetime extension to 50 years of operation which is still very competitive. Another advantage of the life extension strategy is to allow a smoothing of the investment needs and of the industrial loads: the replacement of reactors would take place on a broader period. (A.C.)

  17. Failing the challenge: Diabetes apps & long-term daily adoption

    OpenAIRE

    Katz, Dmitri; Dalton, Nick; Price, Blaine

    2015-01-01

    Diabetes spending is responsible for more than 10% of worldwide health costs. Mobile health has emerged as a strategy for supporting healthier lifestyles and relieving over-burdened medical systems. In 2013 only 1.2% of diabetics with a smartphone were estimated to be using a diabetes app. We looked at the real-world behavior of people with diabetes who had used these apps, in order to learn more about the effects of these products in their lives. Participants were interviewed about their vie...

  18. Demonstrating the Safety of Long-Term Dry Storage - 13468

    International Nuclear Information System (INIS)

    Commercial nuclear plants in the United States were originally designed with the expectation that used nuclear fuel would be moved directly from the reactor pools and transported off site for either reprocessing or direct geologic disposal. However, Federal programs intended to meet this expectation were never able to develop the capability to remove used fuel from reactor sites - and these programs remain stalled to this day. Therefore, in the 1980's, with reactor pools reaching capacity limits, industry began developing dry cask storage technology to provide for additional on-site storage. Use of this technology has expanded significantly since then, and has today become a standard part of plant operations at most US nuclear sites. As this expansion was underway, Federal programs remained stalled, and it became evident that dry cask systems would be in use longer than originally envisioned. In response to this challenge, a strong technical basis supporting the long term dry storage safety has been developed. However, this is not a static situation. The technical basis must be able to address future challenges. Industry is responding to one such challenge - the increasing prevalence of high burnup (HBU) used fuel and the need to provide long term storage assurance for these fuels equivalent to that which has existed for lower burnup fuels over the past 25 years. This response includes a confirmatory demonstration program designed to address the aging characteristics of HBU fuel and set a precedent for a learning approach to aging management that will have broad applicability across the used fuel storage landscape. (authors)

  19. 2003 Long-Term Surveillance and Maintenance Program Report

    International Nuclear Information System (INIS)

    Radioactive waste was created by the Federal Government and private industry at locations around the country in support of national defense, research, and civilian power-generation programs. If not controlled, much of this legacy waste would remain hazardous to human health and the environment indefinitely. Current technology does not allow us to render this waste harmless, so the available methods to control risk rely on consolidation, isolation, and long-term management of the waste. The U.S. Department of Energy (DOE) has an obligation to safely control the radioactive waste and to inform and train future generations to maintain and, perhaps, improve established protections. DOE is custodian for much of the radioactive and other hazardous waste under control of the Federal Government. DOE established the Formerly Utilized Sites Remedial Action Program (FUSRAP) in 1974 and the Defense Decontamination and Decommissioning (D&D) Program and the Surplus Facilities Management Program in the 1980s. Congress passed the Uranium Mill Tailings Radiation Control Act (UMTRCA) in 1978. These federal programs and legislation were established to identify, remediate, and manage legacy waste. Remedial action is considered complete at a radioactive waste site when the identified hazardous material is isolated and the selected remedial action remedy is in place and functioning. Radioactive or other hazardous materials remain in place as part of the remedy at many DOE sites. Long-term management of radioactive waste sites incorporates a set of actions necessary to maintain protection of human health and the environment. These actions include maintaining physical impoundment structures in good repair to ensure that they perform as designed, preventing exposure to the wastes by maintaining access restrictions and warnings, and recording site conditions and activities for future custodians. Any actions, therefore, that will prevent exposure to the radioactive waste now or in the future

  20. 2003 Long-Term Surveillance and Maintenance Program Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-07-01

    Radioactive waste was created by the Federal Government and private industry at locations around the country in support of national defense, research, and civilian power-generation programs. If not controlled, much of this legacy waste would remain hazardous to human health and the environment indefinitely. Current technology does not allow us to render this waste harmless, so the available methods to control risk rely on consolidation, isolation, and long-term management of the waste. The U.S. Department of Energy (DOE) has an obligation to safely control the radioactive waste and to inform and train future generations to maintain and, perhaps, improve established protections. DOE is custodian for much of the radioactive and other hazardous waste under control of the Federal Government. DOE established the Formerly Utilized Sites Remedial Action Program (FUSRAP) in 1974 and the Defense Decontamination and Decommissioning (D&D) Program and the Surplus Facilities Management Program in the 1980s. Congress passed the Uranium Mill Tailings Radiation Control Act (UMTRCA) in 1978. These federal programs and legislation were established to identify, remediate, and manage legacy waste. Remedial action is considered complete at a radioactive waste site when the identified hazardous material is isolated and the selected remedial action remedy is in place and functioning. Radioactive or other hazardous materials remain in place as part of the remedy at many DOE sites. Long-term management of radioactive waste sites incorporates a set of actions necessary to maintain protection of human health and the environment. These actions include maintaining physical impoundment structures in good repair to ensure that they perform as designed, preventing exposure to the wastes by maintaining access restrictions and warnings, and recording site conditions and activities for future custodians. Any actions, therefore, that will prevent exposure to the radioactive waste now or in the future

  1. Scientific Understanding from Long Term Observations: Insights from the Long Term Ecological Research (LTER) Program

    Science.gov (United States)

    Gosz, J.

    2001-12-01

    The network dedicated to Long Term Ecological Research (LTER) in the United States has grown to 24 sites since it was formed in 1980. Long-term research and monitoring are performed on parameters thatare basic to all ecosystems and are required to understand patterns, processes, and relationship to change. Collectively, the sites in the LTER Network provide opportunities to contrast marine, coastal, and continental regions, the full range of climatic gradients existing in North America, and aquatic and terrestrial habitats in a range of ecosystem types. The combination of common core areas and long-term research and monitoring in many habitats have allowed unprecedented abilities to understand and compare complex temporal and spatial dynamics associated with issues like climate change, effects of pollution, biodiversity and landuse. For example, McMurdo Dry Valley in the Antarctic has demonstrated an increase in glacier mass since 1993 which coincides with a period of cooler than normal summers and more than average snowfall. In contrast, the Bonanza Creek and Toolik Lake sites in Alaska have recorded a warming period unprecedented in the past 200 years. Nitrogen deposition effects have been identified through long-term watershed studies on biogeochemical cycles, especially at Coweeta Hydrological Lab, Harvard Forest, and the Hubbard Brook Experimental Forest. In aquatic systems, such as the Northern Temperate Lakes site, long-term data revealed time lags in effects of invaders and disturbance on lake communities. Biological recovery from an effect such as lake acidification was shown to lag behind chemical recovery. The long-term changes documented over 2 decades have been instrumental in influencing management practices in many of the LTER areas. In Puerto Rico, the Luquillo LTER demonstrated that dams obstruct migrations of fish and freshwater shrimp and water abstraction at low flows can completely obliterate downstream migration of juveniles and damage

  2. High-level Waste Long-term management technology development

    International Nuclear Information System (INIS)

    The purpose of this project is to develop a long-term management system(A-KRS) which deals with spent fuels from domestic nuclear power stations, HLW from advanced fuel cycle and other wastes that are not admitted to LILW disposal site. Also, this project demonstrate the feasibility and reliability of the key technologies applied in the A-KRS by evaluating them under in-situ condition such as underground research laboratory and provide important information to establish the safety assessment and long-term management plan. To develop the technologies for the high level radioactive wastes disposal, demonstrate their reliability under in-situ condition and establish safety assessment of disposal system, The major objects of this project are the following: Ο An advanced disposal system including waste containers for HLW from advanced fuel cycle and pyroprocess has been developed. Ο Quantitative assessment tools for long-term safety and performance assessment of a radwaste disposal system has been developed. Ο Hydrological and geochemical investigation and interpretation methods has been developed to evaluate deep geological environments. Ο The THMC characteristics of the engineered barrier system and near-field has been evaluated by in-situ experiments. Ο The migration and retardation of radionuclides and colloid materials in a deep geological environment has been investigated. The results from this project will provide important information to show HLW disposal plan safe and reliable. The knowledge from this project can also contribute to environmental conservation by applying them to the field of oil and gas industries to store their wastes safe

  3. Selection and challenges for LFR reactor materials

    International Nuclear Information System (INIS)

    Nuclear energy using Fast GenIV reactors can fulfil future demands concerning CO2 free, base load capability and sustainability. One of the most promising coolants especially due to its high thermal inertia is liquid lead (Pb). Since several years researches all over the world investigate this coolant and its impact on the reactor design and by that on the materials to be selected. The LEADER project, a follow up of ELSY, aims to design a prototypical demonstrator ALFRED and to continue with several design related aspects of the ELFR reactor. For a demonstrator the criteria of material selection are somewhat different to a commercial type like the ELFR. Material selection for ELFR of course considers all the aspects relevant for ALFRED plus the targeted burn up and the expected total dpa related damage especially of the fuel pins. In the past compatibility of structural material (steels like 316L, T91 and 15-15Ti (1.4970)) that can be employed for Pb cooled fast nuclear reactors were investigated in several EU projects like EUROTRANS and worldwide. Solubility of steel alloying elements like Ni, Fe, Cr is the driving force for the reduced corrosion resistance in contact with Pb. In-situ oxidation is the acknowledged measure to protect steels in Pb up to certain temperatures that are material dependent. Based on experiments and the derived temperature limits the average core outlet temperatures of ALFRED and the ELFR are set to 480 C. The most challenging conditions with respect to temperature are at the fuel assembly and the heat exchangers. For both, thin stable oxide scales with negligible reduction in heat transfer are the requested protection method. This presentation will give an overview on the selected materials for ALFRED and ELFR considering, beside pure compatibility, the influence of mechanical interaction like creep and fretting. (orig.)

  4. HLW Long-term Management Technology Development

    International Nuclear Information System (INIS)

    Permanent disposal of spent nuclear fuels from the power generation is considered to be the unique method for the conservation of human being and nature in the present and future. In spite of spent nuclear fuels produced from power generation, based on the recent trends on the gap between supply and demand of energy, the advance on energy price and reduction of carbon dioxide, nuclear energy is expected to play a role continuously in Korea. It means that a new concept of nuclear fuel cycle is needed to solve problems on spent nuclear fuels. The concept of the advanced nuclear fuel cycle including PYRO processing and SFR was presented at the 255th meeting of the Atomic Energy Commission. According to the concept of the advanced nuclear fuel cycle, actinides and long-term fissile nuclides may go out of existence in SFR. And then it is possible to dispose of short term decay wastes without a great risk bearing. Many efforts had been made to develop the KRS for the direct disposal of spent nuclear fuels in the representative geology of Korea. But in the case of the adoption of Advanced nuclear fuel cycle, the disposal of PYRO wastes should be considered. For this, we carried out the Safety Analysis on HLW Disposal Project with 5 sub-projects such as Development of HLW Disposal System, Radwaste Disposal Safety Analysis, Feasibility study on the deep repository condition, A study on the Nuclide Migration and Retardation Using Natural Barrier, and In-situ Study on the Performance of Engineered Barriers

  5. Perinatal respiratory infections and long term consequences

    Directory of Open Access Journals (Sweden)

    Luciana Indinnimeo

    2015-10-01

    Full Text Available Respiratory syncytial virus (RSV is the most important pathogen in the etiology of respiratory infections in early life. 50% of children are affected by RSV within the first year of age, and almost all children become infected within two years. Numerous retrospective and prospective studies linking RSV and chronic respiratory morbidity show that RSV bronchiolitis in infancy is followed by recurrent wheezing after the acute episod. According to some authors a greater risk of wheezing in children with a history of RSV bronchiolitis would be limited to childhood, while according to others this risk would be extended into adolescence and adulthood. To explain the relationship between RSV infection and the development of bronchial asthma or the clinical pathogenetic patterns related to a state of bronchial hyperreactivity, it has been suggested that RSV may cause alterations in the response of the immune system (immunogenic hypothesis, activating directly mast cells and basophils and changing the pattern of differentiation of immune cells present in the bronchial tree as receptors and inflammatory cytokines. It was also suggested that RSV infection can cause bronchial hyperreactivity altering nervous airway modulation, acting on nerve fibers present in the airways (neurogenic hypothesis.The benefits of passive immunoprophylaxis with palivizumab, which seems to represent an effective approach in reducing the sequelae of RSV infection in the short- and long-term period, strengthen the implementation of prevention programs with this drug, as recommended by the national guidelines of the Italian Society of Neonatology. Proceedings of the 11th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy · October 26th-31st, 2015 · From the womb to the adultGuest Editors: Vassilios Fanos (Cagliari, Italy, Michele Mussap (Genoa, Italy, Antonio Del Vecchio (Bari, Italy, Bo Sun (Shanghai, China, Dorret I. Boomsma (Amsterdam, the

  6. Structural materials: New challenges, manufacturing and performance

    International Nuclear Information System (INIS)

    Full texct: This paper reviews international perspectives on materials, manufacturing and performance on structural materials for fast reactors. It is recognized that fast reactors with closed fuel cycle shall play an eminent and major role to realize energy sustainability. Large scale exploitation of fast reactors shall require meeting of sustainability requirements such as economic competitiveness, safe and optimized waste management, increased proliferation resistance, improved use of uranium and thorium and enhanced efficiency. The designers of these reactors along with material specialists have a key role in meeting the above mentioned criteria of sustainability. The paper shall describe features of advanced sodium cooled fast reactors and the resulting requirements on the performance of the structural materials. The choice of the fuel governs the cladding material for these reactors. Considering the choice as oxide, carbide, metallic with or without minor actinides; cladding materials are chosen based on performance modeling, available experience and expertise. Improved varieties of 316 austenitic stainless steels and oxide dispersion ferritice-martensitic steels emerge as front runners to meet the requirements. The developments in Ti modified 316 austenitic stainless steels give enough confidence to take these fuels to burn-up of 120,000 MWd/t. It is inferred that the target burn-up of 250,000 MWd/t would only be achieved with oxide dispersion strengthened iron- chromium base steels. Research and development of modified austenitic stainless steels and ODS alloys in Japan, Europe and India would be described in the paper. For achieving high burn-up of 250,000 MWd/t, ferritic-martensitic steel has emerged as the choice for the wrapper material. The current status of development and the challenges shall be described in the paper. In particular, the European contribution to this paper addresses the development and performance assessment of the preferred

  7. Approaching the concept of self-managing illness in long term illness. A review of literature.

    Directory of Open Access Journals (Sweden)

    Stavrou V

    2014-04-01

    Full Text Available Abstract: The management of long term illness is globally challenging and the common concerns are mainly found in developed, developing and transitory countries as the increase in the ageing of the population deteriorates the problems. For patients who are suffering from long term illnesses, there is an interest for programs of self managing the disease, which highlight the core essence of educating patients on managing the disease. Purpose: The purpose of the current study is to a present the basic definitions of self managing the disease, b identify the current situation and c discuss and support nursing staff in educating the patient on self managing the illness. Materials- Methods: A review of relevant articles was conducted on the electronic database Medline/ Pubmed as well as through Scholar Google search engine and a secondary search on the references found on the articles. This occurred irrespective of the publication time.Conclusions The role of the nurse as a member of the interdisciplinary group is important because it helps the patient to develop skills of self care. Complete programs of self-managing the illness with the participation of the nurses in the planning, application and evaluation of the results, will contribute significantly to the patient, notwithstanding the professional benefit for the nurses.

  8. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the U.S. Department of Energy`s (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials.

  9. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the US Department of Energy`s (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials.

  10. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the U.S. Department of Energy's (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials

  11. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the US Department of Energy's (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials

  12. Long-term preservation of analysis software environment

    International Nuclear Information System (INIS)

    Long-term preservation of scientific data represents a challenge to experiments, especially regarding the analysis software. Preserving data is not enough; the full software and hardware environment is needed. Virtual machines (VMs) make it possible to preserve hardware “in software”. A complete infrastructure package has been developed for easy deployment and management of VMs, based on CERN virtual machine (CernVM). Further, a HTTP-based file system, CernVM file system (CVMFS), is used for the distribution of the software. It is possible to process data with any given software version, and a matching, regenerated VM version. A point-and-click web user interface is being developed for setting up the complete processing chain, including VM and software versions, number and type of processing nodes, and the particular type of analysis and data. This paradigm also allows for distributed cloud-computing on private and public clouds, for both legacy and contemporary experiments.

  13. Long term stability of cannabis resin and cannabis extracts

    DEFF Research Database (Denmark)

    Lindholst, Christian

    2010-01-01

      The aim of the present study was to investigate the stability of cannabinoids in cannabis resin slabs and cannabis extracts upon long-term storage. The levels of tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and cannabigerol (CBG) on both neutral and acidic form were measured at...... room temperature, 4 °C and - 20 °C for up to 4 years. Acidic THC degrades exponentially via decarboxylation with concentration halve-lives of approximately 330 and 462 days in daylight and darkness, respectively. The degradation of neutral THC seems to occur somewhat slower. When cannabinoids were...... stored in extracted form at room temperature the degradation rate of acidic THC increased significantly relative to resin material with concentration halve-lives of 35 and 91 days in daylight and darkness, respectively. Once cannabis material is extracted into organic solvents, care should be taken to...

  14. Who owns the long term? Perspectives from global business leaders.

    Science.gov (United States)

    Lévy, Maurice; Eskew, Mike; Bernotat, Wulf H; Barner, Marianne

    2007-01-01

    Day-to-day management is challenging enough for CEOs. How do they manage for the long term as well? We posed that question to four top executives of global companies. According to Maurice Levy, chairman and CEO of Publicis Groupe, building the future is really about building the present and keeping close to the front line--those who deal with your customers and markets. He also attributes his company's success in large part to knowing when to take action: In a market where clients' needs steer your long-term future, timing is everything. UPS Chairman and CEO Mike Eskew emphasizes staying true to your vision and values over the long run, despite meeting obstacles along the way. It took more than 20 years, and many lessons learned, to produce consistent profits in what is today the company's fastest-growing and most profitable business: international small packages. Wulf H. Bernotat, CEO of E.ON, examines the challenges facing business leaders and politicians as they try to balance energy needs against potential environmental damage. He calls for educating people about consumption and waste, and he maintains that a diverse and reliable mix of energy sources is the only way to ensure a secure supply while protecting our environment. Finally, Marianne Barner, the director of corporate communications and ombudsman for children's issues at IKEA, discusses how the company is taking steps to improve the environment and be otherwise socially responsible. For example, it's partnering with NGOs to address child labor issues and, on its own, is working to help mitigate climate change. IKEA's goals include using renewable sources for 100% of its energy needs and cutting its overall energy consumption by 25%. PMID:17642126

  15. Long term use of thalidomide: Safe and effective

    Directory of Open Access Journals (Sweden)

    Sharma A

    2007-01-01

    Full Text Available Purpose : To assess the efficacy and safety of high dose thalidomide therapy for longer duration of time in relapsed or refractory Multiple Myeloma (MM patients. Materials and Methods : Twelve relapsed/refractory MM patients (7 Males, 5 Females, who received thalidomide for more than 2 years were selected from the Out Patient Department of Institute Rotary Cancer Hospital (IRCH, AIIMS, India. Patients received thalidomide beginning at a dose of 200 mg/day with fortnightly increment to a maximum dose of 800 mg/day. Patients were assessed for response on the basis of M proteins (MP, bone marrow biopsy with touch preparation and skeletal X-rays. Results : Nine patients tolerated a maximum dose of 800 mg/day whereas three patients were given 600 mg/day. All patients showed ≥ 25-50% decline in serum /urine M proteins. Complete response/ near complete response was seen in 50%, partial response in 17% and minimal response (SD in 34% patients. Median duration of thalidomide therapy was 47 months (range 29-60 months. Currently 11 patients are alive. Toxicity : Varying degree of constipation and sedation were seen universally. One patient had DVT, which responded to anti-coagulant therapy. Other toxic effects included infections, skin reactions. There was no toxic death. Conclusion : long-term use of thalidomide is safe, effective and feasible. We feel that this is one of few reports describing safety and efficacy of long-term thalidomide in relapsed and refractory MM.

  16. Long-term global nuclear energy and fuel cycle strategies

    International Nuclear Information System (INIS)

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E3 (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E3 model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E3 model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues

  17. Life assessment of gas turbine blades after long term service

    Energy Technology Data Exchange (ETDEWEB)

    Auerkari, Pertti; Salonen, Jorma [VTT, Espoo (Finland); Maekinen, Sari [Helsingin Energia, Helsinki (Finland); Karvonen, Ikka; Tanttari, Heikki [Lappeenrannan Laempoevoima, Lappeenranta (Finland); Kangas, Pekka [Neste Oil, Kilpilahti (Finland); Scholz, Alfred [Technische Univ. Darmstadt (Germany); Vacchieri, Erica [Ansaldo Richerche, Genoa (Italy)

    2010-07-01

    Turbine blade samples from three land based gas turbines have been subjected to systematic condition and life assessment after long term service (88000 - 109000 equivalent operating hours, eoh), when approaching the nominal or suggested life limits. The blades represent different machine types, materials and design generations, and uncooled blading outside the hottest front end of the turbine, i.e. blades with relatively large size and considerable expected life. For a reasonable assessment, a range of damage mechanisms need to be addressed and evaluated for the impact in the residual life. The results suggested significant additional safe life for all three blade sets. In some cases this could warrant yet another life cycle comparable to that of new blades, even after approaching the nominal end of life in terms of recommended equivalent operating hours. This is thought to be partly because of base load combined cycle operation and natural gas fuel, or modest operational loading if the design also accounted for more intensive cycling operation and more corrosive oil firing. In any case, long term life extension is only appropriate if not intervened by events of overloading, overheating or other sudden events such as foreign object damage (FOD), and if supported by the regular inspection and maintenance program to control in-service damage. Condition based assessment therefore remains an important part of the blade life management after the decision of accepted life extension. (orig.)

  18. Long-term global nuclear energy and fuel cycle strategies

    Energy Technology Data Exchange (ETDEWEB)

    Krakowski, R.A. [Los Alamos National Lab., NM (United States). Technology and Safety Assessment Div.

    1997-09-24

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E{sup 3} (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E{sup 3} model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E{sup 3} model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues.

  19. Health Practice in Long-Term Survivors of Hodgkin's Lymphoma

    International Nuclear Information System (INIS)

    Purpose: To compare the health practice of Hodgkin's lymphoma (HL) survivors and their siblings, and to assess the impact of socioeconomic status and disease history on health practice of HL survivors. Methods and Materials: We conducted a questionnaire study on long-term HL survivors and their siblings on health care utilization, health habits, and screening behavior. Results: A total of 511 HL survivors (response rate of 50%, including survivors lost to contact) and 224 siblings (response rate, 58%) participated. Median time from HL diagnosis was 15 years. Significantly more survivors than siblings had a physical examination in the past year (63% vs. 49%, p = 0.0001). Male survivors were significantly more likely than siblings to perform monthly self-testicular examinations (19% vs. 9%, p = 0.02). Among survivors, higher household income (p = 0.01) independently predicted for having had a physical examination in the past year. Lower educational level (p = 0.0004) and history of relapsed HL (p = 0.03) were independent predictors for smoking, moderate/heavy alcohol use, and/or physical inactivity. Conclusions: Compared with siblings, long-term HL survivors have a higher level of health care utilization and better screening practice. Survivors from lower socioeconomic background had lower adherence to routine health care and greater report of unhealthy habits. Survivors with history of relapsed HL were also more likely to engage in unhealthy habits

  20. Model for low temperature oxidation during long term interim storage

    International Nuclear Information System (INIS)

    For high-level nuclear waste containers in long-term interim storage, dry oxidation will be the first and the main degradation mode during about one century. The metal lost by dry oxidation over such a long period must be evaluated with a good reliability. To achieve this goal, modelling of the oxide scale growth is necessary and this is the aim of the dry oxidation studies performed in the frame of the COCON program. An advanced model based on the description of elementary mechanisms involved in scale growth at low temperatures, like partial interfacial control of the oxidation kinetics and/or grain boundary diffusion, is developed in order to increase the reliability of the long term extrapolations deduced from basic models developed from short time experiments. Since only few experimental data on dry oxidation are available in the temperature range of interest, experiments have also been performed to evaluate the relevant input parameters for models like grain size of oxide scale, considering iron as simplified material. (authors)

  1. The transport of radioactive materials - Future challenges

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) Regulations for the Safe Transport of Radioactive Materials, TS-R-1, set the standards for the packages used in the transport of radioactive materials under both normal and accident conditions. Transport organisations are also required to implement Radiation Protection Programmes to control radiation dose exposure to both workers and the public. The industry has now operated under this regulatory regime safely and efficiently for nearly 50 years. It is vital that this record be maintained in the future when the demands on the transport industry are increasing. Nuclear power is being called upon more and more to satisfy the world's growing need for sustainable, clean and affordable electricity and there will be a corresponding demand for nuclear fuel cycle services. There will also be a growing need for other radioactive materials, notably large sources such as Cobalt 60 sources for a range of important medical and industrial uses, as well as radio-pharmaceuticals. A reliable transport infrastructure is essential to support all these industry sectors and the challenge will be to ensure that this can be maintained safely and securely in a changing world where public and political concerns are increasing. This paper will discuss the main issues which need to be addressed. The demand for uranium has led to increased exploration and the development of mines in new locations far removed from the demand centres. This inevitably leads to more transport, sometimes from areas potentially lacking in transport infrastructure, service providers, and experience. The demand for sources for medical applications will also increase, particularly from the rapidly developing regions and this will also involve new transport routes and increased traffic. This raises a variety of issues concerning the ability of the transport infrastructure to meet the future challenge, particularly in an environment where there already exists reluctance on

  2. Effect of strengthening rate on durability and long-term plasticity of semifinished metal products

    International Nuclear Information System (INIS)

    A connection between the changes of long-term properties of a metal of different melting and intermediate products of one and the same material with the features of their real tension diagram, is ascertained on the base of plastic instability model. The value of deviation by the level of long-term strength and plasiticity is characterized by a simple parameter-strengthening rate, which is determined by the Ludwick strengthening equation coefficients

  3. Safety Aspects of Long Term Spent Fuel Dry Storage

    International Nuclear Information System (INIS)

    As a consequence of the lack of a final repository for spent nuclear fuel (SF) and high level waste (HLW), long term interim storage of SF and HLW will be necessary. As with the storage of all radioactive materials, the long term storage of SF and HLW must conform to safety requirements. Safety aspects such as safe enclosure of radioactive materials, safe removal of decay heat, sub-criticality and avoidance of unnecessary radiation exposure must be achieved throughout the complete storage period. The implementation of these safety requirements can be achieved by dry storage of SF and HLW in casks as well as in other systems such as dry vault storage systems or spent fuel pools, where the latter is neither a dry nor a passive system. After the events of Fukushima, the advantages of passively and inherently safe dry storage systems have become more obvious. In Germany, dry storage of SF in casks fulfils both transport and storage requirements. Mostly, storage facilities are designed as concrete buildings above the ground; one storage facility has also been built as a rock tunnel. In all these facilities the safe enclosure of radioactive materials in dry storage casks is achieved by a double-lid sealing system with surveillance of the sealing system. The safe removal of decay heat is ensured by the design of the storage containers and the storage facility, which also secures to reduce the radiation exposure to acceptable levels. TUV and BAM, who work as independent experts for the competent authorities, inform about spent fuel management and issues concerning dry storage of spent nuclear fuel, based on their long experience in these fields. All relevant safety issues such as safe enclosure, shielding, removal of decay heat and sub-criticality are checked and validated with state-of-the-art methods and computer codes before the license approval. In our presentation we discuss which of these aspects need to be examined closer for a long term interim storage. It is shown

  4. A Long-Term View on Perovskite Optoelectronics.

    Science.gov (United States)

    Docampo, Pablo; Bein, Thomas

    2016-02-16

    Recently, metal halide perovskite materials have become an exciting topic of research for scientists of a wide variety of backgrounds. Perovskites have found application in many fields, starting from photovoltaics and now also making an impact in light-emitting applications. This new class of materials has proven so interesting since it can be easily solution processed while exhibiting materials properties approaching the best inorganic optoelectronic materials such as GaAs and Si. In photovoltaics, in only 3 years, efficiencies have rapidly increased from an initial value of 3.8% to over 20% in recent reports for the commonly employed methylammonium lead iodide (MAPI) perovskite. The first light emitting diodes and light-emitting electrochemical cells have been developed already exhibiting internal quantum efficiencies exceeding 15% for the former and tunable light emission spectra. Despite their processing advantages, perovskite optoelectronic materials suffer from several drawbacks that need to be overcome before the technology becomes industrially relevant and hence achieve long-term application. Chief among these are the sensitivity of the structure toward moisture and crystal phase transitions in the device operation regime, unreliable device performance dictated by the operation history of the device, that is, hysteresis, the inherent toxicity of the structure, and the high cost of the employed charge selective contacts. In this Account, we highlight recent advances toward the long-term viability of perovskite photovoltaics. We identify material decomposition routes and suggest strategies to prevent damage to the structure. In particular, we focus on the effect of moisture upon the structure and stabilization of the material to avoid phase transitions in the solar cell operating range. Furthermore, we show strategies to achieve low-cost chemistries for the development of hole transporters for perovskite solar cells, necessary to be able to compete with other

  5. Cuts Threaten Long-Term Vision

    Science.gov (United States)

    Etherington, Stuart

    2010-01-01

    All corners of the media are scrutinising David Cameron's "Big Society", from every conceivable angle. While the concept has caught the public's imagination, the greater challenge of fleshing out what the Big Society will actually offer and require of communities is unfinished business. The National Council for Voluntary Organisations (NCVO)…

  6. Incestuous Abuse: Its Long-Term Effects.

    Science.gov (United States)

    Russell, Diana E. H.

    Despite the growing recognition of the prevalence of incest which is challenging traditional views about the family as a safe haven for children, there is a serious paucity of scientific research on incest in South Africa in the new field of family violence. Almost a century after Sigmund Freud dismissed most women's reports of incest…

  7. R&D of MCFC matrix for long term operation

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Takashi; Fujita, Yoji; Urushibata, Hiroaki; Sasaki, Akira [Mitsubishi Electric Corp., Hyogo (Japan)

    1996-12-31

    Long term operation is an essential subject in the commercialization of the Molten Carbonate Fuel Cell (MCFC). Material stability is important for the development of the MCFC. particularly for long term operation. In this paper, the specification and the stabilization of MCFC matrix arc investigated, with the aim of producing 40000 hours of operation. It is common knowledge that matrix thickness has a large influence on shorting time, as shorting is caused by the dissolution of the nickel oxide cathodes. Therefore, the optimum thickness of a matrix designed for 40000 hours operation without the nickel shorting was sought. The influences of different electrolytes and matrix specifications on the shorting time were measured with accelerated cell tests. The internal resistance of the matrix was also estimated. Gamma( {gamma} )-lithium aluminate (LiAlO{sub 2}) powder with a sub-micron particle diameter is commonly used for a raw material of matrix to retain molten carbonate electrolytes. This is because most researchers found that {gamma}-LiA1O{sub 2} was the most stable material in the MCFC environment among the three allotropic forms alpha ( {alpha} ), beta ( {beta} ), and {gamma}. However. two problems with the stability of {gamma} -LiAlO{sub 2} are being vigorously discussed. especially in Japan: particle growth causes decreasing electrolyte retention, and the transformation of {gamma} to {alpha}. This transformation contradicts the accepted opinion that {gamma} is the most stable form. In this paper, the particle growth and the phase transformation of LiAlO{sub 2} are examined with post-test analyses. The influence of matrix degradation on cell performance is also considered.

  8. Long-term Ozone monitoring from space

    Science.gov (United States)

    Ahmad, S.; Johnson, J.; Serafino, G.; McPeters, R.

    Ultraviolet Spectrometer (SBUV), are archived at the Goddard DAAC and are freely available to the public. Standard products from TOMS include daily global total ozone and effective UV reflectivity of the earth-atmosphere system. Data products from future upper atmospheric research missions, e.g., the Ozone Monitoring Instrument (OMI), the Microwave Limb Sounder (MLS), and the High Resolution Dynamics Limb Sounder (HIRDLS) aboard Aura, will also be archived at the Goddard DAAC. For ozone trend analysis, a long-term data set consisting of over twenty years of ozone measurements from space and some value added research products have been produced by the NASA Goddard Space Flight Center scientists (Atmospheric Chemistry and Dynamics Branch/ Code 916) and are made available to the research community (http://code916.gsfc.nasa.gov). Examples of some of these research products are:1) daily erythermal UV exposure -estimates of harmful UV-B radiation at the surface, 2) an index to track the global transport of ash and sulfur dioxide resulting from volcanic eruptions, 3) another index to track smoke emanating from large fires and dust plumes originating from desert regions, 4) aerosol optical depth, 5) tropospheric ozone obtained from cloud-slicing techniques, and 6) a merged total ozone data product consisting of monthly mean ozone merged from six satellite instruments. The Upper Atmospheric Data Support Team has been providing science and data support to assist users in accessing and using the upper atmospheric data products. A number of tools for data access, subsetting, reprojection and mapping of orbital (Level-2) products, visualization of global gridded (Level-3) products, and data analysis have been developed at the Goddard DAAC and are freely available to the data user (http://daac.gsfc.nasa.gov) This presentation will provide highlights of the standard and value-added ozone and ancillary products, and the data services provided by the DAAC Upper Atmosphere Data Support Team.

  9. Long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia): survey methods, data management, and long-term population trends

    Science.gov (United States)

    Ojanen, Sami P; Nieminen, Marko; Meyke, Evgeniy; Pöyry, Juha; Hanski, Ilkka

    2013-01-01

    Long-term observational studies conducted at large (regional) spatial scales contribute to better understanding of landscape effects on population and evolutionary dynamics, including the conditions that affect long-term viability of species, but large-scale studies are expensive and logistically challenging to keep running for a long time. Here, we describe the long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia) that has been conducted since 1991 in a large network of 4000 habitat patches (dry meadows) within a study area of 50 by 70 km in the Åland Islands in Finland. We explain how the landscape structure has been described, including definition, delimitation, and mapping of the habitat patches; methods of field survey, including the logistics, cost, and reliability of the survey; and data management using the EarthCape biodiversity platform. We describe the long-term metapopulation dynamics of the Glanville fritillary based on the survey. There has been no long-term change in the overall size of the metapopulation, but the level of spatial synchrony and hence the amplitude of fluctuations in year-to-year metapopulation dynamics have increased over the years, possibly due to increasing frequency of exceptional weather conditions. We discuss the added value of large-scale and long-term population studies, but also emphasize the need to integrate more targeted experimental studies in the context of long-term observational studies. For instance, in the case of the Glanville fritillary project, the long-term study has produced an opportunity to sample individuals for experiments from local populations with a known demographic history. These studies have demonstrated striking differences in dispersal rate and other life-history traits of individuals from newly established local populations (the offspring of colonizers) versus individuals from old, established local populations. The long-term observational study has stimulated the

  10. Methadone Maintenance and Long-Term Lactation

    OpenAIRE

    Jansson, Lauren M.; Choo, Robin; VELEZ, MARTHA L.; Lowe, Ross; Huestis, Marilyn A.

    2008-01-01

    Breastfeeding among methadone-maintained women is frequently challenged because of unclear guidelines regarding this practice. Previous research has confirmed that concentrations of methadone in breastmilk in the neonatal period are low. Currently unknown are the concentrations of methadone in breastmilk among women who breastfeed for longer periods of time. The purpose of this research is to examine concentrations of methadone in the plasma and breastmilk of women who breastfeed their infant...

  11. Long-term behavior of domestic waste slags

    International Nuclear Information System (INIS)

    Vitrification is one of the envisaged solutions to face French legal requirements related to the solidification/stabilisation of some wastes. It results in glassy or crystallized aluminosilicate and calcium-rich materials which trap heavy metals notably contained by the ashes of purification residues from incineration smokes of domestic wastes. This research thesis addresses the study of the long term behaviour of such materials in order to check that toxic compounds they contain will not be released in the environment so that these materials can become common and even valorised. Four vitrified products have been studied. It appeared that their alteration mechanisms in aqueous phase are close to that of already known natural and artificial silicate materials. Alteration rates depend on material composition and structure on the one hand, and on solution temperature, pH, composition and renewal rate on the other hand. The influence of surrounding materials is also taken into account within the frame of a scenario of use in road construction. Modelling studies are also performed and it appears that the containment of toxic elements contained in vitrified products obtained from domestic waste is sustainable

  12. Interim storage is not long-term disposal

    International Nuclear Information System (INIS)

    Starting in June 30, 1994 South Carolina enforced an embargo on regular shipments of low-level radioactive waste to the Barnwell repository. The failure of 31 states and their respective compacts to provide access to a long-term disposal facility as stipulated by the low-level radioactive Waste Policy Act of 1980 promotes waste disposal gridlock and anticipates another waste disposal crisis. This article discusses the problem using the following topics: Appalachian Compact Users of Radioactive Isotopes (ACURI) Association's interest; the problem of denial of access to Barnwell; pro and contra interim storage; vital services and benefits at risk; issues at the ACURI meeting; nobel Prize winners use radioactive materials; if perception is reality, politics is prevalent

  13. Model for low temperature oxidation during long term interim storage

    International Nuclear Information System (INIS)

    Low-alloyed steels or carbon steels are considered as candidate materials for the fabrication of some nuclear waste package containers for long term interim storage. The containers are required to remain retrievable for centuries. One factor limiting their performance on this time scale is corrosion. The estimation of the metal thickness lost by dry oxidation over such long periods requires the construction of reliable models from short-time experimental data. In a first step, models based on simplified oxidation theories have been derived from experimental data on iron and a low-alloy steel oxidation. Their extrapolation to long oxidation periods confirms that the expected damage due to dry oxidation could be small. In order to improve the reliability of these predictions advanced models taking into account the elementary processes involved in the whole oxidation mechanism, are under development. (authors)

  14. Long term cooling analysis after Fukushima Daiichi accident

    International Nuclear Information System (INIS)

    The objective of this study is to analyze of the long term cooling after Fukushima Daiichi accident by RELAP5mode3.3 code and to check the validity of the cooling method. In order to simulate the cooling conditions in Fukushima plants after accident, the model is nodalized on the assumption of the existence of steam/liquid leak position from RPV/PCV and the variety of debris distribution in RPV/PCV. As a result, we estimated the debris distribution in RPV by referring plant parameter such as reactor pressure and temperature. In addition, we performed the analysis of the loss of injection water accident for the current cooling system installed in Fukushima Daiichi cite after the earthquake. In this case, we develop simplified nodalization of RPV to analyze temperature behavior of reactor structural materials by using the radiation heat transfer model. (author)

  15. Long-term outcome of abusive head trauma.

    Science.gov (United States)

    Chevignard, Mathilde P; Lind, Katia

    2014-12-01

    Abusive head trauma is a severe inflicted traumatic brain injury, occurring under the age of 2 years, defined by an acute brain injury (mostly subdural or subarachnoidal haemorrhage), where no history or no compatible history with the clinical presentation is given. The mortality rate is estimated at 20-25% and outcome is extremely poor. High rates of impairments are reported in a number of domains, such as delayed psychomotor development; motor deficits (spastic hemiplegia or quadriplegia in 15-64%); epilepsy, often intractable (11-32%); microcephaly with corticosubcortical atrophy (61-100%); visual impairment (18-48%); language disorders (37-64%), and cognitive, behavioral and sleep disorders, including intellectual deficits, agitation, aggression, tantrums, attention deficits, memory, inhibition or initiation deficits (23-59%). Those combined deficits have obvious consequences on academic achievement, with high rates of special education in the long term. Factors associated with worse outcome include demographic factors (lower parental socioeconomic status), initial severe presentation (e.g., presence of a coma, seizures, extent of retinal hemorrhages, presence of an associated cranial fracture, extent of brain lesions, cerebral oedema and atrophy). Given the high risk of severe outcome, long-term comprehensive follow-up should be systematically performed to monitor development, detect any problem and implement timely adequate rehabilitation interventions, special education and/or support when necessary. Interventions should focus on children as well as families, providing help in dealing with the child's impairment and support with psychosocial issues. Unfortunately, follow-up of children with abusive head trauma has repeatedly been reported to be challenging, with very high attrition rates. PMID:25501726

  16. Long-term Surveillance Plan for the Falls City Disposal Site, Falls City, Texas. Revision 1

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Falls City disposal site, Falls City, Texas, describes the surveillance activities for the disposal site. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  17. Long-term surveillance plan for the Collins Ranch Disposal Site, Lakeview, Oregon. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    This long-term surveillance plan (LTSP) for the Lakeview, Oregon, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Lakeview (Collins Ranch) disposal cell, which will be referred to as the Collins Ranch disposal cell throughout this document. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States or an Indian tribe, and details how the long-term care of the disposal site will be carried out. It is based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a).

  18. Long-term surveillance plan for the Collins Ranch disposal site, Lakeview, Oregon

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Collins Ranch disposal site, Lakeview, Oregon, describes the surveillance activities for the disposal cell. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  19. Long-term surveillance plan for the Collins Ranch Disposal Site, Lakeview, Oregon

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Lakeview, Oregon, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Lakeview (Collins Ranch) disposal cell, which will be referred to as the Collins Ranch disposal cell throughout this document. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States or an Indian tribe, and details how the long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  20. Long-term surveillance plan for the Green River, Utah disposal site. Revision 1

    International Nuclear Information System (INIS)

    The long-term surveillance plan (LTSP) for the Green River, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Green River disposal cell. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials (RRM). This LTSP documents whether the land and interests are owned by the United States or an Indian tribe and details how the long-term care of the disposal site will be carried out. The Green River, Utah, LTSP is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  1. Long-term surveillance plan for the Falls City Disposal Site, Falls City, Texas

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Falls City disposal site, Falls City, Texas, describes the surveillance activities for the disposal site. DOE will carry out these activities to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  2. Long-term Surveillance Plan for the Falls City Disposal Site, Falls City, Texas. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Falls City disposal site, Falls City, Texas, describes the surveillance activities for the disposal site. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a).

  3. Long-term surveillance plan for the Falls City Disposal Site, Falls City, Texas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Falls City disposal site, Falls City, Texas, describes the surveillance activities for the disposal site. DOE will carry out these activities to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a).

  4. Long-term surveillance plan for the Collins Ranch disposal site, Lakeview, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Collins Ranch disposal site, Lakeview, Oregon, describes the surveillance activities for the disposal cell. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a).

  5. Long-term surveillance plan for the Green River, Utah, disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The long-term surveillance plan (LTSP) for the Green River, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Green River disposal cell. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials (RRM). This LTSP documents whether the land and interests are owned by the United States or an Indian tribe and details how the long-term care of the disposal site will be carried out. The Green River, Utah, LTSP is based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a).

  6. Long-term surveillance plan for the Shiprock Disposal site, Shiprock, New Mexico

    International Nuclear Information System (INIS)

    The long-term surveillance plan (LTSP) for the Shiprock, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Shiprock disposal cell. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials (RRM). This LTSP documents the land ownership interests and details how the long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  7. A cost of long-term memory in Drosophila

    OpenAIRE

    Mery, Frederic; Kawecki, Tadeusz J

    2005-01-01

    Two distinct forms of consolidated associative memory are known in Drosophila: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of anesthesia-resistant memory had no detectable effect on desiccation resistance. This finding may hel...

  8. Long-Term Unemployment in the Varieties of Capitalism

    OpenAIRE

    Alberto Chilosi

    2014-01-01

    This paper considers how the different varieties of capitalism affect the rate of long-term unemployment. The liberal market variety, where employment protection is the lowest, presents lower rates of long-term unemployment than the continental European, or the Mediterranean varieties. In the latter both employment protection and long-term unemployment are the highest and labour market participation the lowest. But the social-democratic Scandinavian variety gets the best of both worlds: low r...

  9. Long-term care financing through Federal tax incentives

    OpenAIRE

    Donald W. Moran; Weingart, Janet M.

    1988-01-01

    Congress and the Administration are currently exploring various methods of promoting access to long-term care. In this article, an inventory of recent legislative proposals for using the Federal tax code to expand access to long-term care services is provided. Proposals are arrayed along a functional typology that includes tax mechanisms to encourage accumulation of funds, promote purchase of long-term care insurance, or induce the diversion of funds accumulated for another purpose (such as i...

  10. Long-Term Inflation Outcomes after Hyperinflation: Theory and Evidence

    OpenAIRE

    Federico Guerrero

    2006-01-01

    This paper does two things. First, it shows both anecdotal and cross-country evidence that indicates that countries that have experienced hyperinflation display significantly lower long-term rates of inflation than countries that lack the same experience. Secondly, it presents a model to rationalize the main empirical finding. There is more than one mechanism through which the long-term effects of hyperinflation may have an impact on long-term inflation outcomes. The suggested explanation thi...

  11. Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men

    International Nuclear Information System (INIS)

    First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could

  12. Collaborative Establishment of a Long-Term Archive for Stewardship of Interdisciplinary Scientific Data

    Science.gov (United States)

    Downs, R. R.; Chen, R. S.; Cartolano, R. T.; Bose, R.

    2008-12-01

    Much of the scientific data that are being collected today cannot be recreated if they are not properly preserved and documented. Establishment of reliable long-term digital archives is essential to preserving these data and associated documentation beyond the working lifetimes of current scientists. Numerous challenges, both technical and institutional, need to be addressed before these data or their documentation become lost or inaccessible. Direct collaboration between university research libraries and active scientific data centers is one approach to addressing these challenges. We report here on the collaboration between the Columbia Libraries / Information Services and the Center for International Earth Science Information Network (CIESIN) to establish an interdisciplinary long-term archive for data from the NASA Socioeconomic Data and Applications Center (SEDAC). The SEDAC long-term archive serves as a trustworthy digital repository to support preparation, submission, appraisal, ingest, discovery, integration, and interoperability of scientific data that are expected to be of long-term interest to both natural and social scientists. Significant progress has been made in establishing the necessary policies and procedures, implementing needed standards and technologies, and assessing strengths and possible weaknesses in the long-term sustainability of the archive. Benefits have included sharing approaches and best practices for information technology solutions and scientific data stewardship. A key issue is the expected future integration of this specialized archive into the long-term digital repository currently being developed by the University. Planned activities include testing the migration of selected data from the SEDAC long-term archive to the forthcoming Libraries repository and the development of interfaces between the digital object management systems being implemented by SEDAC and the Libraries, which are both based on the Flexible Extensible

  13. Long-term mechanical properties of rubber

    OpenAIRE

    Bin Kamaruddin, Shamsul

    2013-01-01

    Natural rubber has a good potential to be used as a material for the development of wave energy converters (WECs). Generally, rubber has the ability to withstand very large strains without permanent deformation or fracture and is not much affected by exposure to water. This makes it ideal for applications related to wave energy converter (WECs). However, there is a need to predict the efficiency of performance over the full lifetime of such an application given that WECs will represent large,...

  14. The long-term future for civilian nuclear power generation in France: The case for breeder reactors. Breeder reactors: The physical and physical chemistry parameters, associate material thermodynamics and mechanical engineering: Novelties and issues

    International Nuclear Information System (INIS)

    The author gives a summary overview of the knowledge base acquired since the first breeder reactors became operational in the fifties. Neutron transport theory, thermal phenomena, reactor core cooling, various coolants used and envisioned for this function, fuel fabrication from separated materials, main equipment (pumps, valves, heat exchanges...) have now attained maturity, sufficient to implement sodium cooling circuits. However, the use of metallic sodium still raises certain severe questions in terms of safe handling and security considerations. The structural components, both inside the reactor core and outside (i.e. heat exchangers) are undergoing in-depth research so as to last longer. The fuel cycle, notably the re-fabrication of fuel elements and fertile elements, the case of transuranic elements, etc., call for studies into radiation induced phenomena, chemistry separation, separate or otherwise treatments for materials that have different radioactive, physical, thermodynamical, chemical and biological properties. The concerns that surround the definitive disposal of certain radioactive wastes could be qualitatively improved with respect to the pressurized water reactors (PWRs) in service today. Lastly, the author notes that breeder reactors eliminate the need for an isotope separation facility, and this constitutes a significant contribution to contain nuclear proliferation. France was in the forefront of nuclear breeder power generation science, technological research and also in the knowledge base related to breeder reactors. It is in the country's interest to pursue these efforts. (author)

  15. Microscopic study of rock for estimating long-term behavior

    International Nuclear Information System (INIS)

    One must consider micro-structures of rock and rock mass in order to predict the long-term behavior for more than ten thousand years. First we observe the micro-crack distribution of granite which is commonly distributed in Japan, and is widely used for several structures. The creep under constant load and the relaxation under constant displacement are typical time dependent phenomena, and we performed a series of relaxation tests under microscope observation in laboratory. The specimen that is preserved in water is granite as mentioned above. The aim of this experiment is to observe the sequential propagation of micro-cracks and its affect to the macroscopic response of the rock material under relaxation state. Next, a viscoelastic homogenization method is applied for analyzing the behavior of granite that is composed of several kinds of minerals (i.e., a polycrystalline material). The homogenization method developed for analyzing mechanics of composite materials is a mathematical theory that can describe the macroscopic behavior accounting for the microscopic characteristics with periodic microstructures. In this study, it is applied to a polycrystalline rock which involves a few minerals and micro-cracks. Furthermore, it is required to apply the homogenization analysis for rock materials which show a nonlinear time dependent behavior, so we develop a new elasto-visco-plastic homogenization theory, and its validity is checked for some ground structures made by clay. (author)

  16. Coated conductors for power applications: materials challenges

    International Nuclear Information System (INIS)

    This manuscript reports on the recent progress and the remaining materials challenges in the development of coated conductors (CCs) for power applications and magnets, with a particular emphasis on the different initiatives being active at present in Europe. We first summarize the scientific and technological scope where CCs have been raised as a complex technology product and then we show that there exists still much room for performance improvement. The objectives and CC architectures being explored in the scope of the European project EUROTAPES are widely described and their potential in generating novel breakthroughs emphasized. The overall goal of this project is to create synergy among academic and industrial partners to go well beyond the state of the art in several scientific issues related to CCs’ enhanced performances and to develop nanoengineered CCs with reduced costs, using high throughput manufacturing processes which incorporate quality control tools and so lead to higher yields. Three general application targets are considered which will require different conductor architectures and performances and so the strategy is to combine vacuum and chemical solution deposition approaches to achieve the targeted goals. A few examples of such approaches are described related to defining new conductor architectures and shapes, as well as vortex pinning enhancement through novel paths towards nanostructure generation. Particular emphasis is made on solution chemistry approaches. We also describe the efforts being made in transforming the CCs into assembled conductors and cables which achieve appealing mechanical and electromagnetic performances for power systems. Finally, we briefly mention some outstanding superconducting power application projects being active at present, in Europe and worldwide, to exemplify the strong advances in reaching the demands to integrate them in a new electrical engineering paradigm. (paper)

  17. Coated conductors for power applications: materials challenges

    Science.gov (United States)

    Obradors, Xavier; Puig, Teresa

    2014-04-01

    This manuscript reports on the recent progress and the remaining materials challenges in the development of coated conductors (CCs) for power applications and magnets, with a particular emphasis on the different initiatives being active at present in Europe. We first summarize the scientific and technological scope where CCs have been raised as a complex technology product and then we show that there exists still much room for performance improvement. The objectives and CC architectures being explored in the scope of the European project EUROTAPES are widely described and their potential in generating novel breakthroughs emphasized. The overall goal of this project is to create synergy among academic and industrial partners to go well beyond the state of the art in several scientific issues related to CCs’ enhanced performances and to develop nanoengineered CCs with reduced costs, using high throughput manufacturing processes which incorporate quality control tools and so lead to higher yields. Three general application targets are considered which will require different conductor architectures and performances and so the strategy is to combine vacuum and chemical solution deposition approaches to achieve the targeted goals. A few examples of such approaches are described related to defining new conductor architectures and shapes, as well as vortex pinning enhancement through novel paths towards nanostructure generation. Particular emphasis is made on solution chemistry approaches. We also describe the efforts being made in transforming the CCs into assembled conductors and cables which achieve appealing mechanical and electromagnetic performances for power systems. Finally, we briefly mention some outstanding superconducting power application projects being active at present, in Europe and worldwide, to exemplify the strong advances in reaching the demands to integrate them in a new electrical engineering paradigm.

  18. Barrier and long term creep properties of polymer nanocomposites

    Science.gov (United States)

    Ranade, Ajit

    The barrier properties and long term strength retention of polymers are of significant importance in a number of applications. Enhanced lifetime food packaging, substrates for OLED based flexible displays and long duration scientific balloons are among them. Higher material requirements in these applications drive the need for an accurate measurement system. Therefore, a new system was engineered with enhanced sensitivity and accuracy. Permeability of polymers is affected by permeant solubility and diffusion. One effort to decrease diffusion rates is via increasing the transport path length. We explore this through dispersion of layered silicates into polymers. Layered silicates with effective aspect ratio of 1000:1 have shown promise in improving the barrier and mechanical properties of polymers. The surface of these inorganic silicates was modified with surfactants to improve the interaction with organic polymers. The micro and nanoscale dispersion of the layered silicates was probed using optical and transmission microscopy as well as x-ray diffraction. Thermal transitions were analyzed using differential scanning calorimetry. Mechanical and permeability measurements were correlated to the dispersion and increased density. The essential structure-property relationships were established by comparing semicrystalline and amorphous polymers. Semicrystalline polymers selected were nylon-6 and polyethylene terephthalate. The amorphous polymer was polyethylene terphthalate-glycol. Densification due to the layered silicate in both semicrystalline and amorphous polymers was associated with significant impact on barrier and long term creep behavior. The inferences were confirmed by investigating a semi-crystalline polymer---polyethylene---above and below the glass transition. The results show that the layered silicate influences the amorphous segments in polymers and barrier properties are affected by synergistic influences of densification and uniform dispersion of the

  19. Long-term outcomes for adult craniopharyngioma following radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Masson-Cote, Laurence; Masucci, Giuseppina Laura; Millar, Barbara-Ann; Laperriere, Normand J. [Dept. of Radiation Oncology, Princess Margaret Hospital, Univ. of Toronto, Toronto (Canada); Atenafu, Eshetu G. [Dept. of Biostatistics, Princess Margaret Hospital, Univ. of Toronto, Toronto (Canada); Cusimano, Michael [Dept. of Surgery, Div. of Neurosurgery, St. Michaels Hospital, Toronto (Canada); Croul, Sidney [Dept. of Pathology, Univ. of Toronto, Toronto (Canada); Mason, Warren [Dept. of Medicine, Princess Margaret Hospital, Univ. of Toronto, Toronto (Canada); Sahgal, Arjun [Dept. of Radiation Oncology, Princess Margaret Hospital, Univ. of Toronto, Toronto (Canada), E-mail: Arjun.sahgal@rmp.uhn.on.ca; Dept. of Radiation Oncology, Sunnybrook Health Sciences Center, Univ. of Toronto, Toronto (Canada)

    2013-01-15

    Background. We report long-term outcomes in adult patients with craniopharyngioma following surgery and radiation therapy (RT). Material and methods. Fifty-three patients treated with RT (median, 50 Gy in 25 fractions) between 1980 and 2009 with pathologically confirmed craniopharyngioma were reviewed (53% solid and 47% cystic/solid). The median age was 53 years (range, 22-76), 53% were female, 83% were sub-totally resected, 6% were gross totally resected and 11% had a biopsy and/or cyst aspiration alone. RT was delivered adjuvantly in 53% of patients as opposed to salvage intent upon progression. Results. Median follow-up was seven years (86 months, range, 8-259). The 5- and 10-year progression-free survival (PFS) rates were 85% and 69%, overall survival (OS) rates were 76% and 70%, and cause-specific survival (CSS) rates were both 88%, respectively. Both univariable and multivariable analysis identified age (<53 or {>=}53) as a prognostic factor for OS (p =0.0003) and CSS (p =0.05). PFS was observed to be worse in patients with >2 surgeries prior to RT (p =0.01). Neither the intent of radiation or tumor type (cystic vs. solid/cystic) were prognostic or predictive. New endocrinopathies and visual dysfunction were observed in 53% and 17% of patients post-surgery, and in 11% and 6% post-RT, respectively. Conclusion. We report long-term favorable PFS, CSS and OS for craniopharyngioma post-RT. We observe age as a significant prognostic factor, however, timing of radiation was not.

  20. Enhanced Polyhydroxybutyrate Production for Long-Term Spaceflight Applications

    Science.gov (United States)

    Putman, Ryan J.; Rahman, Asif; Miller, Charles D.; Hadi, Masood Z.

    2015-01-01

    Synthetic biology holds the promise of advancing long term space fight by the production of medicine, food, materials, and energy. One such application of synthetic biology is the production of biomaterials, specifically polyhydroxyalkanoates (PHAs), using purposed organisms such as Escherichia coli. PHAs are a group of biodegradable bioplastics that are produced by a wide variety of naturally occurring microorganisms, mainly as an energy storage intermediate. PHAs have similar melting point to polypropylene and a Youngs modulus close to polystyrene. Due to limited resources and cost of transportation, large-scale extraction of biologically produced products in situ is extremely cumbersome during space flight. To that end, we are developing a secretion systems for exporting PHA from the cell in order to reduce unit operations. PHAs granules deposited inside bacteria are typically associated with proteins bound to the granule surface. Phasin, a granule bound protein, was targeted for type I secretion by fusion with HlyA signal peptide for indirect secretion of PHAs. In order to validate our secretion strategy, a green fluorescent protein (GFP) was tagged to the PHA polymerase enzyme (phaC), this three part gene cassette consists of phaA and phaB and are required for PHA production. Producing PHAs in situ during space flight or planet colonization will enable mission success by providing a valuable source of biomaterials that can have many potential applications thereby reducing resupply requirements. Biologically produced PHAs can be used in additive manufacturing such as three dimensional (3D) printing to create products that can be made on demand during space flight. After exceeding their lifetime, the PHAs could be melted and recycled back to 3D print other products. We will discuss some of our long term goals of this approach.

  1. Long-Term MRI Findings in Operated Rotator Cuff Tear

    International Nuclear Information System (INIS)

    Purpose: To describe magnetic resonance imaging (MRI) findings at long-term follow-up after rotator cuff (RC) tear using standard MRI sequences without fat saturation. Material and Methods: Twenty-eight patients aged 55.8±7.6 underwent MRI examination 4.6±2.1 years after surgery for RC tear. Standard sequences in oblique coronal, oblique sagittal, and axial planes were obtained. The RC, including re-tears and tendon degeneration, was independently evaluated by two observers. Thickness of the supraspinatus tendon and narrowing of the subacromial space were measured. The clinical outcome was evaluated with the Constant score and compared with the MRI findings. Results: The RC tear was traumatic in 18 (64%) patients and degenerative in 10 (36%). At follow-up, 11 (39%) had normal RC tendons with good clinical outcome. Four (14%) patients had painful tendinosis without RC tear. A full-thickness RC tear was found in 7 (25%) patients and a partial tear in 6 (21%). In one patient with a full-thickness tear, and in two with partial tear, tendinosis was found in another of the RC tendons. The subacromial space was narrowed in 13 (46%) of the patients. A narrowing of the subacromial space correlated with re-tear (P<0.05). Conclusions: The RC may be evaluated with standard MRI sequences without fat saturation at long-term follow-up. A normal appearance of the RC is correlated with good clinical outcome, while re-tear and tendinosis are associated with pain

  2. Combined management of retroperitoneal sarcoma with dose intensification radiotherapy and resection: Long-term results of a prospective trial.

    LENUS (Irish Health Repository)

    Smith, Myles J F

    2014-01-07

    Late failure is a challenging problem following resection of retroperitoneal sarcoma (RPS). We investigated the effects of preoperative XRT plus dose escalation with early postoperative brachytherapy (BT) on long-term survival and recurrence in RPS.

  3. Standards for Psychological Services in Long-Term Care Facilities.

    Science.gov (United States)

    Morrow-Howell, Nancy; Lichtenberg, Peter A.; Smith, Michael; Frazer, Deborah; Molinari, Victor; Rosowsky, Erlene; Crose, Royda; Stillwell, Nick; Kramer, Nanette; Hartman-Stein, Paula; Qualls, Sara; Salamon, Michael; Duffy, Michael; Parr, Joyce; Gallagher-Thompson, Dolores

    1998-01-01

    Describes the development of standards for psychological practice in long-term care facilities. The standards, which were developed by Psychologists in Long-Term Care, address provider characteristics, methods of referral, assessment practices, treatment, and ethical issues. Offers suggestions for use of the standards. (MKA)

  4. Factors associated with long-term mortality in acute pancreatitis

    DEFF Research Database (Denmark)

    Nøjgaard, Camilla; Matzen, Peter; Bendtsen, Flemming;

    2011-01-01

    Knowledge of the long-term prognosis of acute pancreatitis (AP) is limited. The aims were to investigate: (1) prognostic factors associated with long-term mortality in patients with AP; (2) whether or not the level of serum (S-)amylase at admission had an impact on the prognosis; (3) causes of...

  5. How Does Long-Term Finance Affect Economic Volatility?

    OpenAIRE

    Demirguc-Kunt, Asli; BÁLINT L. HORVÁTH; Huizinga, Harry

    2016-01-01

    This paper examines how the ability to access long-term debt affects firm-level growth volatility. The analysis finds that firms in industries with stronger preference to use long-term finance relative to short-term finance experience lower growth volatility in countries with better-developed financial systems, as these firms may benefit from reduced refinancing risk. Institutions that fac...

  6. [Developing the core competencies of long-term care professionals].

    Science.gov (United States)

    Chen, Huey-Tzy; Lee, Kuang-Ting

    2012-12-01

    Longer average life expectancies and an ageing society have made long-term care an urgent and important issue in Taiwan. Although the implementation of Long-Term Care Ten-year Project four years ago has begun showing success in terms of assessing Taiwan's needs in terms of long-term care services and resources, there has been little forward progress in terms of training, recruiting and maintaining more competent professionals in the long-term care sector. This paper explores the current state of long-term care competency in Taiwan and educational strategies in place to improve the competency of long-term care professionals. Results indicate that the term geriatric competency embraces sub-competencies in direct care, communication, assessment, teamwork, cultural sensitivities and career care competencies. The term long-term care competency embraces the sub-competencies of supervision, management, information technology, resource management, and organizational skill. As a main contributor to effective long-term care, the nursing profession must employ effective strategies to develop competency-based education. Also, the profession must have an adequate supply of competent manpower to effectively respond to Taiwan's aging society. PMID:23212250

  7. Long-term hearing preservation in vestibular schwannoma

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Thomsen, Jens; Tos, Mirko;

    2010-01-01

    The aim of the present study was to evaluate the long-term hearing during "wait and scan" management of vestibular schwannomas.......The aim of the present study was to evaluate the long-term hearing during "wait and scan" management of vestibular schwannomas....

  8. Helping People Make Better Long-Term-Care Decisions

    Science.gov (United States)

    Kane, Robert L.; Boston, Krista; Chilvers, Mary

    2007-01-01

    Purpose: The purpose of this article is to describe an innovative online system to support long-term-care decision making. Design and Methods: The Long-Term Care Choices tool is a web-based system that uses expert opinion and structures decision making. Results: The system has been well accepted, and most users find it easy to use. Implications:…

  9. Determinants of long-term renal allograft outcome

    NARCIS (Netherlands)

    Leeuwen-Artz, M.A.

    2005-01-01

    Long-term renal allograft survival is markedly affected by premature death with a functioning graft, chronic allograft nephropathy, and recurrence of the original kidney disease. To improve long-term graft survival, focus is shifting from the prevention of acute rejections to the recognition and tre

  10. 24 CFR 971.5 - Long-term viability.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Long-term viability. 971.5 Section... ASSESSMENT OF THE REASONABLE REVITALIZATION POTENTIAL OF CERTAIN PUBLIC HOUSING REQUIRED BY LAW § 971.5 Long-term viability. (a) Reasonable investment. (1) Proposed revitalization costs for viability must...

  11. Interim analysis in long-term clinical trials

    NARCIS (Netherlands)

    G.A. van Es (Gerrit Anne)

    1990-01-01

    textabstractThe purpose of this dissertation is to evaluate the usefulness of both stopping rules and estimation methods in long-term clinical trials with interim analyses. The ASPECT trial, a long-term clinical trial to assess the effect of anticoagulant therapy on mortality in patients after myoca

  12. The long-term future for civilian nuclear power generation in France: The case for breeder reactors. Breeder reactors: The physical and physical chemistry parameters, associate material thermodynamics and mechanical engineering: Novelties and issues

    Science.gov (United States)

    Dautray, Robert

    2011-06-01

    The author firstly gives a summary overview of the knowledge base acquired since the first breeder reactors became operational in the 1950s. "Neutronics", thermal phenomena, reactor core cooling, various coolants used and envisioned for this function, fuel fabrication from separated materials, main equipment (pumps, valves, taps, waste cock, safety circuits, heat exchange units, etc.) have now attained maturity, sufficient to implement sodium cooling circuits. Notwithstanding, the use of metallic sodium still raises certain severe questions in terms of safe handling (i.e. inflammability) and other important security considerations. The structural components, both inside the reactor core and outside (i.e. heat exchange devices) are undergoing in-depth research so as to last longer. The fuel cycle, notably the refabrication of fuel elements and fertile elements, the case of transuranic elements, etc., call for studies into radiation induced phenomena, chemistry separation, separate or otherwise treatments for materials that have different radioactive, physical, thermodynamical, chemical and biological properties. The concerns that surround the definitive disposal of certain radioactive wastes could be qualitatively improved with respect to the pressurized water reactors (PWRs) in service today. Lastly, the author notes that breeder reactors eliminate the need for an isotope separation facility, and this constitutes a significant contribution to contain nuclear proliferation. Among the priorities for a fully operational system (power station - the fuel cycle - operation-maintenance - the spent fuel pool and its cooling system-emergency cooling system-emergency electric power-transportation movements-equipment handling - final disposal of radioactive matter, independent safety barriers), the author includes materials (fabrication of targets, an irradiation and inspection instrument), the chemistry of all sorting processes, equipment "refabrication" or rehabilitation

  13. Collaboration in long-term stewardship at DOE Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Moren, R. J.; Zeisloft, J. H.; Feist, E. T.; Brown, D.; Grindstaff, K. D.

    2013-01-10

    The U.S. Department of Energy's (DOE) Hanford Site comprises approximately 1,517 km{sup 2} (586 mi{sup 2}) of land in southeastern Washington. The site was established in 1943 as part of the Manhattan Project to produce plutonium for the nation's nuclear weapons program. As the Cold War era came to an end, the mission of the site transitioned from weapons production to environmental cleanup. As the River Corridor area of the site cleanup is completed, the mission for that portion of the site will transition from active cleanup to continued protection of environment through the Long-Term Stewardship (LTS) Program. The key to successful transition from cleanup to LTS is the unique collaboration among three (3) different DOE Programs and three (3) different prime contractors with each contractor having different contracts. The LTS Program at the site is a successful model of collaboration resulting in efficient resolution of issues and accelerated progress that supports DOE's Richland Office 2015 Vision for the Hanford Site. The 2015 Vision for the Hanford Site involves shrinking the active cleanup footprint of the surface area of the site to approximately 20 mi{sup 2} on the Central Plateau. Hanford's LTS Program is defined in DOE's planning document, Hanford Long-Term Stewardship Program Plan, DOE/RL-2010-35 Rev 1. The Plan defines the relationship and respective responsibilities between the federal cleanup projects and the LTS Program along with their respective contractors. The LTS Program involves these different parties (cleanup program and contractors) who must work together to achieve the objective for transition of land parcels. Through the collaborative efforts with the prime contractors on site over the past two years, 253.8 km{sup 2} (98 mi{sup 2}) of property has been successfully transitioned from the cleanup program to the LTS Program upon completion of active surface cleanup. Upcoming efforts in the near term will include transitioning another large

  14. Long-Term Dynamics of Autonomous Fractional Differential Equations

    Science.gov (United States)

    Liu, Tao; Xu, Wei; Xu, Yong; Han, Qun

    This paper aims to investigate long-term dynamic behaviors of autonomous fractional differential equations with effective numerical method. The long-term dynamic behaviors predict where systems are heading after long-term evolution. We make some modification and transplant cell mapping methods to autonomous fractional differential equations. The mapping time duration of cell mapping is enlarged to deal with the long memory effect. Three illustrative examples, i.e. fractional Lotka-Volterra equation, fractional van der Pol oscillator and fractional Duffing equation, are studied with our revised generalized cell mapping method. We obtain long-term dynamics, such as attractors, basins of attraction, and saddles. Compared with some existing stability and numerical results, the validity of our method is verified. Furthermore, we find that the fractional order has its effect on the long-term dynamics of autonomous fractional differential equations.

  15. India’s long-term growth potential and the implications for Australia

    OpenAIRE

    Ben Ralston; Wilson Au-Yeung; Bill Brummitt

    2011-01-01

    After 20 years of economic reform this article discusses India’s long-term growth potential and canvasses some of the challenges that Indian policy makers will need to overcome to realise this potential. Some of the consequences of India’s growth for Australia are also explored.

  16. Measuring Worker Turnover in Long-Term Care: Lessons from the Better Jobs Better Care Demonstration

    Science.gov (United States)

    Piercy, Kathleen Walsh, Ed.; Barry, Theresa; Kemper, Peter; Brannon, S. Diane

    2008-01-01

    Purpose: Turnover among direct-care workers (DCWs) continues to be a challenge in long-term care. Both policy makers and provider organizations recognize this issue as a major concern and are designing efforts to reduce turnover among these workers. However, there is currently no standardized method of measuring turnover to define the scope of the…

  17. Reintegration Services for Long-Term Dangerous Offenders: A Case Study and Discussion

    Science.gov (United States)

    Day, Andrew; Ward, Tony; Shirley, Lyn

    2011-01-01

    Successfully reintegrating long-term prisoners back into the community often presents significant challenges for service providers. Ex-prisoners typically experience high levels of social stigma; present with multiple needs; and can struggle to find meaningful employment, stable accommodation, and to maintain supportive relationships. There have,…

  18. A novel method for long-term monitoring of intracranial pressure in rats

    DEFF Research Database (Denmark)

    Uldall, Maria; Juhler, Marianne; Skjolding, Anders Daehli;

    2014-01-01

    BACKGROUND: In preclinical neurological studies, monitoring intracranial pressure (ICP) in animal models especially in rodents is challenging. Further, the lack of methods for long-term ICP monitoring has limited the possibilities to conduct prolonged studies on ICP fluctuations in parallel...

  19. Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Rodney C.

    2003-09-14

    The successful disposal of spent nuclear fuel (SNF) is one of the most serious challenges to the successful completion of the nuclear fuel cycle and the future of nuclear power generation. In the United States, 21 percent of the electricity is generated by 107 commercial nuclear power plants (NPP), each of which generates 20 metric tons of spent nuclear fuel annually. In 1996, the total accumulation of spent nuclear fuel was 33,700 metric tons of heavy metal (MTHM) stored at 70 sites around the country. The end-of-life projection for current nuclear power plants (NPP) is approximately 86,000 MTHM. In the proposed nuclear waste repository at Yucca Mountain over 95% of the radioactivity originates from spent nuclear fuel. World-wide in 1998, approximately 130,000 MTHM of SNF have accumulated, most of it located at 236 NPP in 36 countries. Annual production of SNF is approximately 10,000 MTHM, containing about 100 tons of ''reactor grade'' plutonium. Any reasonable increase in the proportion of energy production by NPP, i.e., as a substitute for hydrocarbon-based sources of energy, will significantly increase spent nuclear fuel production. Spent nuclear fuel is essentially UO{sub 2} with approximately 4-5 atomic percent actinides and fission product elements. A number of these elements have long half-lives hence, the long-term behavior of the UO{sub 2} is an essential concern in the evaluation of the safety and risk of a repository for spent nuclear fuel. One of the unique and scientifically most difficult aspects of the successful disposal of spent nuclear fuel is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3} to 10{sup 5} years) as required by the performance objectives set in regulations, i.e. 10 CFR 60. The direct verification of these extrapolations or interpolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the

  20. Long-term stabilization of uranium mill tailings

    International Nuclear Information System (INIS)

    The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%

  1. Long term thermal aging of cast duplex stainless steels

    International Nuclear Information System (INIS)

    Cast duplex stainless steels of CF8M and CF8 are used in major components because of their superior characteristics, such as corrosion resistance, weldability and so on. But, these stainless steels are known to have tendency of thermal aging embrittlement after long term service. Therefore, mechanical properties and metallurgical structure were investigated using materials aged at 290--400 C up to 30,000 hours. As the results show, effects of thermal aging on mechanical properties and metallurgical behavior were identified. In addition, prediction method for Charpy absorbed energy and fracture toughness was established. The following results have been obtained: (1) it was recognized that Charpy absorbed energy and fracture toughness tend to decrease and the tensile strength tend to increase with the increasing aging time; (2) it was confirmed that thermal aging embrittlement was caused by the phase separation in ferrite from the test results of APFIM; (3) in the degradation prediction model development the prediction model was applied to the material test data, including materials aged for 30,000 hours. As the results, the degradation prediction formulas for CVRT, CVHT, JIC and J6 were obtained. The toughness of cast duplex stainless steels during service could be estimated from chemical composition using this method

  2. Long term thermal aging of cast duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Isao; Koyama, Masakuni [Japan Power Engineering and Inspection Corp., Tokyo (Japan); Kawaguchi, Seiichi [Mitsubishi Heavy Industries, Ltd., Takasago (Japan); Mimaki, Hidehito [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Akiyama, Mamoru; Mishima, Yoshitsugu [Univ. of Tokyo (Japan); Okubo, Tadatsune [Sophia Univ., Tokyo (Japan); Mager, T.R.

    1996-09-01

    Cast duplex stainless steels of CF8M and CF8 are used in major components because of their superior characteristics, such as corrosion resistance, weldability and so on. But, these stainless steels are known to have tendency of thermal aging embrittlement after long term service. Therefore, mechanical properties and metallurgical structure were investigated using materials aged at 290--400 C up to 30,000 hours. As the results show, effects of thermal aging on mechanical properties and metallurgical behavior were identified. In addition, prediction method for Charpy absorbed energy and fracture toughness was established. The following results have been obtained: (1) it was recognized that Charpy absorbed energy and fracture toughness tend to decrease and the tensile strength tend to increase with the increasing aging time; (2) it was confirmed that thermal aging embrittlement was caused by the phase separation in ferrite from the test results of APFIM; (3) in the degradation prediction model development the prediction model was applied to the material test data, including materials aged for 30,000 hours. As the results, the degradation prediction formulas for CVRT, CVHT, J{sub IC} and J{sub 6} were obtained. The toughness of cast duplex stainless steels during service could be estimated from chemical composition using this method.

  3. The Womanly World of Long Term Care: The Plight of the Long Term Care Worker. Gray Paper.

    Science.gov (United States)

    Older Women's League, Washington, DC.

    Long-term care workers (those who are paid to provide custodial care for long-term patients in nursing homes or at home) must care for a growing number of increasingly disabled or dependent persons. They are working for agencies and institutions under growing pressure to increase productivity. They face new training and competency requirements,…

  4. Long-term integrity of copper overpack

    International Nuclear Information System (INIS)

    The results from extended uniaxial and multiaxial creep testing confirm the earlier indications of microstructural changes at relatively low temperatures (150-175 deg C) in Cu-OFP. These changes are probably related to recovery processes directed by the favourable crystallographic orientation on one side the related grain boundary, resulting in characteristically widening grain boundary zones. With further straining, these zones become chains of small grains decorating the original grain boundaries. The observed microstructural changes do not appear to represent particular disadvantages in terms of remaining life. In creep testing with natural weld defects (FSW, inclusion sheet 20% of cross-section), the results show much faster decreasing creep strength in time than what is observed for base material or welds without defects. However, extrapolation to 50 MPa stress level across such a defective region would still suggest a safe life of approximately 26,000 years in spite of much elevated testing temperature (175 deg C) from expected service temperature (below 100 deg C). For predicting mechanical behaviour, a creep model has been developed to include the full creep curves in a simple and robust manner. The model has been adapted to the most recent creep testing results (up to about 48,000 h in uniaxial testing). Applying this model for the extrapolated case of steady loading at 100 deg C / 50 MPa predicts time to 10% strain of about one million years. For comparison on creep ductility, also a testing program on low-phosphorus (OFHC) copper was initiated. The testing program with model vessels was completed after confirming safe short term limit load predictions. This program continues with compact tension specimens to study the potential combined effect of creep and corrosion in simulated groundwater

  5. Deep geological disposal, a long-term option for long-lived waste?

    International Nuclear Information System (INIS)

    Certain types of long-lived waste are radioactive for more than 100,000 years. Finding sustainable solutions for the long-term management of them is thus an immense challenge. Since the first nuclear power plant started in Belgium, SCK-CEN has invested in research into the management of long-lived waste. This research, together with ONDRAF/NIRAS, is focused on deep geological disposal in clay as a possible long-term solution. It is the essential scientific foundation of the Waste Plan, with which ONDRAF/NIRAS will publish its strategy for the management of long-lived waste in 2010.

  6. Long-term outcomes of children after solid organ transplantation

    Directory of Open Access Journals (Sweden)

    Jon Jin Kim

    2014-01-01

    Full Text Available Solid organ transplantation has transformed the lives of many children and adults by providing treatment for patients with organ failure who would have otherwise succumbed to their disease. The first successful transplant in 1954 was a kidney transplant between identical twins, which circumvented the problem of rejection from MHC incompatibility. Further progress in solid organ transplantation was enabled by the discovery of immunosuppressive agents such as corticosteroids and azathioprine in the 1950s and ciclosporin in 1970. Today, solid organ transplantation is a conventional treatment with improved patient and allograft survival rates. However, the challenge that lies ahead is to extend allograft survival time while simultaneously reducing the side effects of immunosuppression. This is particularly important for children who have irreversible organ failure and may require multiple transplants. Pediatric transplant teams also need to improve patient quality of life at a time of physical, emotional and psychosocial development. This review will elaborate on the long-term outcomes of children after kidney, liver, heart, lung and intestinal transplantation. As mortality rates after transplantation have declined, there has emerged an increased focus on reducing longer-term morbidity with improved outcomes in optimizing cardiovascular risk, renal impairment, growth and quality of life. Data were obtained from a review of the literature and particularly from national registries and databases such as the North American Pediatric Renal Trials and Collaborative Studies for the kidney, SPLIT for liver, International Society for Heart and Lung Transplantation and UNOS for intestinal transplantation.

  7. Long-term mortality among adults with asthma

    DEFF Research Database (Denmark)

    Ali, Zarqa; Dirks, Christina Glattre; Ulrik, Charlotte Suppli

    2013-01-01

    from an out-patient clinic in 1974 to 1990, and followed up until the end of 2011. Subjects were classified as having allergic or non-allergic asthma on the basis of detailed history, spirometric tests, tests for IgE-mediated allergy (skin prick tests and RAST), and bronchial challenge tests......ABSTRACT BACKGROUND: Data from long-term follow-up studies of well-characterised patients with asthma are limited. We studied all-cause and cause-specific mortality, and risk factors, in a large cohort of adults with asthma. METHODS: A total of 1.075 adult asthmatics were recruited consecutively...... compared with controls (261 cases vs. 124 controls; relative risk (RR) 2.1, 95% confidence interval (CI) 1.4 to 3.0; p<0.001). The excess mortality was primarily due to death from obstructive lung disease (95 deaths). Subsequent death from asthma was significantly associated with age (p<0.001), level of...

  8. Long-term scenarios for sustainable energy use in Germany

    International Nuclear Information System (INIS)

    The study was able to show, and explain vividly through scenarios describing change processes, that a sustainable use of energy (aimed, among other things, at reducing CO2 emissions by 80% by 2050 compared with 1990 levels) is technically feasible, economically viable, compatible with farther-reaching objectives of energy policy (e.g. supply security), and does not, in spite of the substantial need for change, present the players involved with any insurmountable problems but, rather, constitutes both a challenge and an opportunity. Such a development is possible only if the efforts launched to give momentum to the increased use of renewable energy sources are continued consistently, the impending need for replacement and renewal within the generation system is consistently utilised for increasing efficiency and a reorientation mainly towards combined heat and power production, and energy saving is made a new focal point of energy policy. Furthermore, with regard to long-term infrastructure requirements (decentralisation, new fuels), the necessary decisions must be prepared at an early stage and sufficiently robust lines of development must be identified and followed. (orig.)

  9. Long-term object tracking combined offline with online learning

    Science.gov (United States)

    Hu, Mengjie; Wei, Zhenzhong; Zhang, Guangjun

    2016-04-01

    We propose a simple yet effective method for long-term object tracking. Different from the traditional visual tracking method, which mainly depends on frame-to-frame correspondence, we combine high-level semantic information with low-level correspondences. Our framework is formulated in a confidence selection framework, which allows our system to recover from drift and partly deal with occlusion. To summarize, our algorithm can be roughly decomposed into an initialization stage and a tracking stage. In the initialization stage, an offline detector is trained to get the object appearance information at the category level, which is used for detecting the potential target and initializing the tracking stage. The tracking stage consists of three modules: the online tracking module, detection module, and decision module. A pretrained detector is used for maintaining drift of the online tracker, while the online tracker is used for filtering out false positive detections. A confidence selection mechanism is proposed to optimize the object location based on the online tracker and detection. If the target is lost, the pretrained detector is utilized to reinitialize the whole algorithm when the target is relocated. During experiments, we evaluate our method on several challenging video sequences, and it demonstrates huge improvement compared with detection and online tracking only.

  10. Long-term consequences of adolescent fertility: The Colombian case

    Directory of Open Access Journals (Sweden)

    B. Piedad Urdinola

    2015-06-01

    Full Text Available Background: Estimating the long-term effects of adolescent motherhood is challenging for all developing countries, including Colombia, where this rate has been steadily increasing for 24 years, despite the reduction in the overall fertility rate. We propose a replicable methodology by applying a pseudo panel that evaluates the consequences of adolescent motherhood on outcomes previously neglected in the literature, such as job quality, marriage instability, partner's job class, presence of physical abuse by current partner, and children's health. Objective: To examine how adolescent mothers compare with non-adolescent mothers in outcomes not previously studied, such as job quality, marriage instability, partner's job class, if respondent has been physically abused by current partner, and health outcomes for their children Methods: We built a pseudo panel using four Demographic and Health Surveys (1995-2010 and compared the effects of older adolescent childbearing (ages 18-19 with those of women who postponed motherhood for just a couple of years (ages 20-21, exploiting the natural difference between adolescents and young adults who become mothers. Results: The results revealed younger mothers as well as their partners hold lower-class jobs, suffer higher rates of domestic violence at the hands of their partners, and have a higher share of deceased children. Conclusions: The latter two results lead us to suggest aggressive and comprehensive targeted public policies both for prevention of adolescent motherhood and for following their just-born babies' health.

  11. Long-Term Stewardship Baseline Report and Transition Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Kristofferson, Keith

    2001-11-01

    Long-term stewardship consists of those actions necessary to maintain and demonstrate continued protection of human health and the environment after facility cleanup is complete. As the Department of Energy’s (DOE) lead laboratory for environmental management programs, the Idaho National Engineering and Environmental Laboratory (INEEL) administers DOE’s long-term stewardship science and technology efforts. The INEEL provides DOE with technical, and scientific expertise needed to oversee its long-term environmental management obligations complexwide. Long-term stewardship is administered and overseen by the Environmental Management Office of Science and Technology. The INEEL Long-Term Stewardship Program is currently developing the management structures and plans to complete INEEL-specific, long-term stewardship obligations. This guidance document (1) assists in ensuring that the program leads transition planning for the INEEL with respect to facility and site areas and (2) describes the classes and types of criteria and data required to initiate transition for areas and sites where the facility mission has ended and cleanup is complete. Additionally, this document summarizes current information on INEEL facilities, structures, and release sites likely to enter long-term stewardship at the completion of DOE’s cleanup mission. This document is not intended to function as a discrete checklist or local procedure to determine readiness to transition. It is an overarching document meant as guidance in implementing specific transition procedures. Several documents formed the foundation upon which this guidance was developed. Principal among these documents was the Long-Term Stewardship Draft Technical Baseline; A Report to Congress on Long-Term Stewardship, Volumes I and II; Infrastructure Long-Range Plan; Comprehensive Facility Land Use Plan; INEEL End-State Plan; and INEEL Institutional Plan.

  12. Long-Term Results for Trigeminal Schwannomas Treated With Gamma Knife Surgery

    International Nuclear Information System (INIS)

    Purpose: Surgical resection is considered the desirable curative treatment for trigeminal schwannomas. However, complete resection without any complications remains challenging. During the last several decades, stereotactic radiosurgery (SRS) has emerged as a minimally invasive treatment modality. Information regarding long-term outcomes of SRS for patients harboring trigeminal schwannomas is limited because of the rarity of this tumor. The aim of this study was to evaluate long-term tumor control and functional outcomes in patients harboring trigeminal schwannomas treated with SRS, specifically with gamma knife surgery (GKS). Methods and Materials: Fifty-three patients harboring trigeminal schwannomas treated with GKS were evaluated. Of these, 2 patients (4%) had partial irradiation of the tumor, and 34 patients (64%) underwent GKS as the initial treatment. The median tumor volume was 6.0 cm3. The median maximum and marginal doses were 28 Gy and 14 Gy, respectively. Results: The median follow-up period was 98 months. On the last follow-up image, 7 patients (13%) had tumor enlargement, including the 2 patients who had partial treatment. Excluding the 2 patients who had partial treatment, the actuarial 5- and 10-year progression-free survival (PFS) rates were 90% and 82%, respectively. Patients with tumors compressing the brainstem with deviation of the fourth ventricle had significantly lower PFS rates. If those patients with tumors compressing the brainstem with deviation of the fourth ventricle are excluded, the actuarial 5- and 10-year PFS rates increased to 95% and 90%, respectively. Ten percent of patients had worsened facial numbness or pain in spite of no tumor progression, indicating adverse radiation effect. Conclusions: GKS can be an acceptable alternative to surgical resection in patients with trigeminal schwannomas. However, large tumors that compress the brainstem with deviation of the fourth ventricle should be surgically removed first and then

  13. Long-Term Results for Trigeminal Schwannomas Treated With Gamma Knife Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Toshinori, E-mail: h-toshi@komakihp.gr.jp; Kato, Takenori; Iizuka, Hiroshi; Kida, Yoshihisa

    2013-12-01

    Purpose: Surgical resection is considered the desirable curative treatment for trigeminal schwannomas. However, complete resection without any complications remains challenging. During the last several decades, stereotactic radiosurgery (SRS) has emerged as a minimally invasive treatment modality. Information regarding long-term outcomes of SRS for patients harboring trigeminal schwannomas is limited because of the rarity of this tumor. The aim of this study was to evaluate long-term tumor control and functional outcomes in patients harboring trigeminal schwannomas treated with SRS, specifically with gamma knife surgery (GKS). Methods and Materials: Fifty-three patients harboring trigeminal schwannomas treated with GKS were evaluated. Of these, 2 patients (4%) had partial irradiation of the tumor, and 34 patients (64%) underwent GKS as the initial treatment. The median tumor volume was 6.0 cm{sup 3}. The median maximum and marginal doses were 28 Gy and 14 Gy, respectively. Results: The median follow-up period was 98 months. On the last follow-up image, 7 patients (13%) had tumor enlargement, including the 2 patients who had partial treatment. Excluding the 2 patients who had partial treatment, the actuarial 5- and 10-year progression-free survival (PFS) rates were 90% and 82%, respectively. Patients with tumors compressing the brainstem with deviation of the fourth ventricle had significantly lower PFS rates. If those patients with tumors compressing the brainstem with deviation of the fourth ventricle are excluded, the actuarial 5- and 10-year PFS rates increased to 95% and 90%, respectively. Ten percent of patients had worsened facial numbness or pain in spite of no tumor progression, indicating adverse radiation effect. Conclusions: GKS can be an acceptable alternative to surgical resection in patients with trigeminal schwannomas. However, large tumors that compress the brainstem with deviation of the fourth ventricle should be surgically removed first and then

  14. Long-term behavior of glass-ceramic zirconolite

    International Nuclear Information System (INIS)

    This work is a part of the investigation of new containment matrices considered for specific conditioning of radionuclides after separation. The aim was to demonstrate the long-term aqueous corrosion resistance of the glass-ceramic zirconolite considered for the conditioning of plutonium and the minor actinides. This material is composed of crystals of zirconolite (CaZrTi2O7) dispersed in a residual vitreous phase. It appears that glass-ceramic zirconolite presents a better kinetic behavior than the nuclear glass R 7T7. This is mainly due to a more important rate decrease that occurs more rapidly, that induces a quantity of glass altered at least 10 times as small as for R 7T7 glass. This high slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have demonstrated that the rate decrease was controlled as for the R7T7 glass by the amorphous phase of the alteration film forming a diffusion barrier for reactive species. It seems that the porosity is not the single parameter that explains the protective effect of the gel. The main differences compared with R7T7 glass are that silicon does not control the alteration of the material and that the gel is composed of two distinct phases. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics. (author)

  15. Japan's universal long-term care system reform of 2005: containing costs and realizing a vision.

    Science.gov (United States)

    Tsutsui, Takako; Muramatsu, Naoko

    2007-09-01

    Japan implemented a mandatory social long-term care insurance (LTCI) system in 2000, making long-term care services a universal entitlement for every senior. Although this system has grown rapidly, reflecting its popularity among seniors and their families, it faces several challenges, including skyrocketing costs. This article describes the recent reform initiated by the Japanese government to simultaneously contain costs and realize a long-term vision of creating a community-based, prevention-oriented long-term care system. The reform involves introduction of two major elements: "hotel" and meal charges for nursing home residents and new preventive benefits. They were intended to reduce economic incentives for institutionalization, dampen provider-induced demand, and prevent seniors from being dependent by intervening while their need levels are still low. The ongoing LTCI reform should be critically evaluated against the government's policy intentions as well as its effect on seniors, their families, and society. The story of this reform is instructive for other countries striving to develop coherent, politically acceptable long-term care policies. PMID:17767690

  16. Salvage radical prostatectomy: indications, complications and long-term results

    International Nuclear Information System (INIS)

    Before the PSA era, radiation failures, diagnosed on clinical grounds, were not detected until most tumors were locally advanced. When combined with needle biopsy of the prostate, a rising PSA level allows us to detect radiation failures earlier, when the cancer may still be confined within the prostate or immediate periprostatic tissue and local therapy may effectively eradicate all remaining cancer. Nevertheless, salvage local therapy -- whether with surgery, interstitial irradiation therapy, or cryotherapy -- has been accompanied by substantial complications and the benefits, in terms of long-term cancer control, have not been well documented Candidates for salvage radical prostatectomy should have biopsy-proven local recurrence and should be in excellent health with a life expectancy of > 10 years. The initial tumor, before radiotherapy, should have been organ-confined (T1 or T2) and the PSA level should have normalized ( 10 ng/ml few patients had an undetectable PSA at 5 years. However, clinical local control was excellent and the actuarial cancer-specific survival rate at 8 years was 85%. Salvage radical prostatectomy is a technically challenging procedure and complication rates are higher than after standard radical prostatectomy. The most common complications are rectal injuries, incontinence, bladder neck strictures, and impotence. In the Baylor series, complications were more likely in patients who had prior lymphadenectomy and brachytherapy (31%) compared with those who had external beam therapy alone (9%). Rectal injuries have been reported in 5% to 15% of patients compared with less than 1% in standard radical prostatectomy patients. Incontinence persists in 25% to 60% of patients and 25% of our patients have required an artificial urinary sphincter. The availability of PSA to monitor the results of radiation therapy, combined with the ease of ultrasound-directed needle biopsy of the prostate, now allows the detection of local recurrence earlier than

  17. Long term storage of spent nuclear fuel -- Survey and recommendations. Final report of a co-ordinated research project 1994-1997

    International Nuclear Information System (INIS)

    Two Technical Committee meetings were held at the IAEA in Vienna to share the experiences of Member States with regard to extended of long term storage of spent nuclear fuel. Potential technological, regulatory and societal concerns and impacts associated with storage were discussed. Participants presented papers during these two meetings covering all the relevant issues. Smaller discussion groups were formed which enabled the participants to provide detailed information within the context of four general subjects: 1. Long term behaviour of spent fuel; 2. Long term behaviour of dry storage systems; 3. Wet spent fuel storage facilities; and 4. Regulatory concerns related to long term spent fuel storage. The nuclear industry worldwide has accumulated significant fuel storage operating experience over the past decades. This experience, however, is largely based on safe and effective wet storage and the effect of time on structures and materials during this limited period of time. The new challenges are to extend the life of existing and new wet and dry storage facilities and guarantee their safe performance for much longer periods of time. Participants in each group have therefore reflected on past experience in order to define the issues and questions, which should to be addresses through future research and development. This document summarizes their contributions

  18. Neural correlates of long-term intense romantic love

    OpenAIRE

    Acevedo, Bianca P.; Aron, Arthur; Fisher, Helen E.; Brown, Lucy L.

    2011-01-01

    The present study examined the neural correlates of long-term intense romantic love using functional magnetic resonance imaging (fMRI). Ten women and 7 men married an average of 21.4 years underwent fMRI while viewing facial images of their partner. Control images included a highly familiar acquaintance; a close, long-term friend; and a low-familiar person. Effects specific to the intensely loved, long-term partner were found in: (i) areas of the dopamine-rich reward and basal ganglia system,...

  19. Long-Term Mean Wind Profiles Based on Similarity Theory

    DEFF Research Database (Denmark)

    Kelly, Mark C.; Gryning, Sven-Erik

    2010-01-01

    We provide general forms for long-term mean wind profiles from similarity-based wind profiles, beginning with a probabilistic adaptation of Monin–Obukhov similarity theory. We develop an analytical formulation for the stability distributions prevailing in the atmospheric surface layer, which in...... turn facilitates the derivation of a long-term mean wind profile based on Monin–Obukhov similarity theory. The modelled stability distributions exhibit good agreement with measurements from sites having different local conditions. The long-term wind profile formulation is further extended to include...

  20. Home and Away: Reflections on Long-term Care in the UK and Australia

    OpenAIRE

    Melanie Henwood

    1999-01-01

    The challenges posed by an ageing population are major preoccupations of governments throughout the developed world. There are many dimensions to such challenges, and this paper focuses on issues relating to long-term care in old age. The debate around such matters has been similar in the UK and in Australia. In both countries, a history of incrementalism and poorly presented policy reform has contributed to widespread public mistrust, and a sense of injustice at the extension of means-testin...

  1. Measuring the Impact of Energy Technology Investment on Long-term Sustainability

    OpenAIRE

    Turton, H.

    2005-01-01

    The global energy system currently faces a number of significant challenges which have the potential to undermine long-term sustainable development, including the need to maintain secure access to affordable energy supplies and mitigate climate change. This report explores the role of energy technology investment policies, including R&D and demonstration and deployment (D&D) programs in overcoming these challenges. The analysis considers the mechanisms by which energy technology policy initia...

  2. Long term storage of clonal material of lily (Lilium L.).

    NARCIS (Netherlands)

    Bonnier, F.J.M.

    1997-01-01

    Germplasm collections are important for crop improvement and research. Lily genotypes must be preserved vegetatively as clones, because the genotypes are unique and heterozygous. Using seeds would affect the unique genetic combinations. Collections of bulb crops are usually maintained by yearly

  3. Global prospects for nuclear power development in the long term

    International Nuclear Information System (INIS)

    supply, in the world and by region. In the long term, up to 2100, the broad range of uncertainties with regard to population, economic growth and technology evolution prevent from any sound forecast in the field of energy and in particular of nuclear power. The scenario presented in the paper has been prepared for the Inter Governmental Panel on Climate Change (IPCC) in order to illustrate the potential role of nuclear power in alleviating greenhouse gas emissions. The global energy demand projections established by IPCC, which serve as a basis for the nuclear power scenario, assume high economic growth, drastic energy efficiency improvement and the implementation of voluntary policies for greenhouse gas reduction. Under these assumptions, it is estimated that the total primary energy consumption in the world will reach some 660 EJ per annum in 2100 as compared to 330 EJ per annum in 1985. Since the world population is expected to more than double during this time frame, it means that the average energy consumption per capita will a sustained deployment of nuclear power worldwide as a means to reduce greenhouse gas emissions from the energy sector. Although this scenario would require strong commitment to the development of nuclear energy, technical and industrial capabilities would enable its implementation. In view of the potential role of nuclear power in sustainable energy supply strategies, there is a need for continued research and development aiming towards the design and implementation of advanced reactors with enhanced safety, technical and economic performance. Natural nuclear fuel resources could support a broad deployment of nuclear energy production as a major part of the mix of options for sustainable supply in the long term. The challenge for the nuclear industry is to restore the confidence in nuclear energy and enhance its social acceptability through the design and implementation of sound technical solutions for nuclear power plants, fuel cycle

  4. Photovoltaic materials: Present efficiencies and future challenges.

    Science.gov (United States)

    Polman, Albert; Knight, Mark; Garnett, Erik C; Ehrler, Bruno; Sinke, Wim C

    2016-04-15

    Recent developments in photovoltaic materials have led to continual improvements in their efficiency. We review the electrical characteristics of 16 widely studied geometries of photovoltaic materials with efficiencies of 10 to 29%. Comparison of these characteristics to the fundamental limits based on the Shockley-Queisser detailed-balance model provides a basis for identifying the key limiting factors, related to efficient light management and charge carrier collection, for these materials. Prospects for practical application and large-area fabrication are discussed for each material. PMID:27081076

  5. Long term radiological impact of a uranium mine restoration

    International Nuclear Information System (INIS)

    During the 1990s, many uranium mines were closed as consequence of low prices of this mineral. It was due to a decrease in the demand for uranium and an increase in the overall supply. The resulting was a further complicated implementation of sites restorations. This report deals with one of the relevant aspects of the radiological protection scope: 'the evaluation of the long term radiological impact in the population due to the uranium mine restoration activities' for the uranium mine sited in Saelices el Chico (Salamanca, Spain). These restoration activities have basically consisted of recovering the original site by filling the old open pits with the material stockpiled in the waste dumps. The main problems associated with this material include radon release and particles emission. The strategy used to solve this problem has been covered these structures with a layer with beds of clay material rock, waste material and a cover tree. The pathways considered for the radiological impact have been: 1) Inhalation; 2) Ingestion of contaminated water, milk, vegetables and meat; 3) External exposure from clouds immersion, grounds concentrations and direct gamma radiation. Three computer codes have been used with the object of evaluating the above-mentioned impact. Two of them are well-known NRC (Nuclear Regulatory Commission) codes: RESRAD 6.30 and MILDOS-AREA. We have also applied DOEFLURA, developed in ENUSA [1, 2, 3]. Four scenarios have been studied: Resident Farmer Scenario, Resident scenario, Livestock pasture scenario and Forest scenario, Estimation of radioactive doses for the member of the public in the different scenarios has been calculated with this programme. A period of 3500 years from now has been studied. (author)

  6. Long-Term Ecological Monitoring Field Sampling Plan for 2007

    Energy Technology Data Exchange (ETDEWEB)

    T. Haney

    2007-07-31

    This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used t determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality.

  7. Long-term Outcomes of Childhood Onset Nephrotic Syndrome

    Science.gov (United States)

    Hjorten, Rebecca; Anwar, Zohra; Reidy, Kimberly Jean

    2016-01-01

    There are limited studies on long-term outcomes of childhood onset nephrotic syndrome (NS). A majority of children with NS have steroid-sensitive nephrotic syndrome (SSNS). Steroid-resistant nephrotic syndrome (SRNS) is associated with a high risk of developing end-stage renal disease. Biomarkers and analysis of genetic mutations may provide new information for prognosis in SRNS. Frequently relapsing and steroid-dependent NS is associated with long-term complications, including dyslipidemia, cataracts, osteoporosis and fractures, obesity, impaired growth, and infertility. Long-term complications of SSNS are likely to be under-recognized. There remain many gaps in our knowledge of long-term outcomes of childhood NS, and further study is indicated. PMID:27252935

  8. Assisted Living Facilities - MO 2010 Long Term Care Facilities (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Long Term Care facilities (nursing homes) in Missouri - Data will not be made available for download via MSDIS. Interested parties should send an email inquiry to...

  9. Salmonella enterica Serovar Typhi Variants in Long-Term Carriers

    OpenAIRE

    Chiou, Chien-Shun; Wei, Hsiao-Lun; Mu, Jung-Jung; Liao, Ying-Shu; Liang, Shiu-Yun; Liao, Chun-Hsing; Tsao, Chi-Sen; Wang, Shu-Chuan

    2013-01-01

    Long-term typhoid carriers can simultaneously excrete Salmonella enterica serovar Typhi variants with considerable genetic differences, a situation that complicates the interpretation of the subtyping data used in outbreak investigations and disease surveillance.

  10. In search of the elusive long-term price

    International Nuclear Information System (INIS)

    The Uranium Institute, WNFM, and past USCEA sessions described and compared existing price reporting systems. The McGraw-Hill conference led to a rather heated discussion as to the propriety of spot prices having the influence they do on amounts paid in long-term contracts. The Ux representative proposed a future's market as a way that producers could hedge against some of the uncertainty of volatile spot market. In discussing the search for the elusive long-term price, there are two interrelated issues. The first is obvious-the search for a starting or initializing price that is representative of recently-signed or pending long-term contracts. The second is less obvious, but perhaps more important-the search for a successful mechanism for determining later delivery values in long-term contracts. This paper addresses the question of pricing mechanisms first

  11. Long-Term Ecological Monitoring Field Sampling Plan for 2007

    International Nuclear Information System (INIS)

    This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used to determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality

  12. Personal Decisionmaking Styles and Long-Term Care Choices

    OpenAIRE

    Maloney, Susan K.; Finn, Jeffrey; Bloom, Diane L.; Andresen, Julie

    1996-01-01

    To learn more about how older people make decisions about long-term care (LTC), in-depth interviews were conducted with 63 elderly individuals and 56 of their relatives to obtain information on the decisionmaking process. This qualitative research showed that LTC decisionmaking does not always follow typical consumer dedisionmaking models, in which a consumer seeks a product or service, selects among the alternatives, and assesses the choice. Further, the interviews yielded four long-term car...

  13. Long-Term Contracts in Major League Baseball

    OpenAIRE

    Hakes, Jahn K.; Chad Turner

    2008-01-01

    Long-term deals are one tool that both players and franchises use to manage risk. That tool has been much discussed and empirically tested with respect to player shirking, and has more briefly, and only theoretically, discussed with respect to reducing variance in future payrolls. Our work looks at how patterns of use of long-term contracts are affected by changes in contracting rules established through collective bargaining and by expected changes in franchise revenue streams. To accomplish...

  14. Long-Term Use of Benzodiazepines: Implications and guidelines

    OpenAIRE

    Potts, Nicholas L.S.; K Ranga R Krishnan

    1992-01-01

    Problems associated with physical dependence and abuse of benzodiazepines by a small percentage of patients have reduced their popularity from the most commonly prescribed psychoactive drug in the 1970s to being prescribed for mainly short periods. Patients who benefit from long-term benzodiazepine use are nearly ignored by the medical community as a whole. This article details what patient population can improve from long-term benzodiazepine therapy, the risks and benefits of treatment, and ...

  15. How Does Long-Term Finance Affect Economic Volatility?

    OpenAIRE

    Demirgüç-Kunt, A.; Horváth, Bálint; Huizinga, Harry

    2016-01-01

    In an approach analogous to Rajan and Zingales (1998), we examine how the ability to access long-term debt affects firm-level growth volatility. We find that firms in industries with stronger preference to use long-term finance relative to short-term finance experience lower growth volatility in countries with better-developed financial systems, as these firms may benefit from reduced refinancing risk. Institutions that facilitate the availability of credit information and contract enforcemen...

  16. Long Term Treatment Concepts and Proactive Therapy for Atopic Eczema

    OpenAIRE

    Wollenberg, Andreas; Ehmann, Laura Maximiliane

    2012-01-01

    Atopic eczema, also known as atopic dermatitis, is a frequent, highly pruritic, chronic skin disease, which is typically running in flares. The traditional treatment mainly consists of the reactive application of topical anti-inflammatory agents such as topical corticosteroids and topical calcineurin inhibitors. The short term benefit of this approach is well known, but long term remission between flares is difficult to achieve. Therefore, innovative long-term treatment strategies targeting f...

  17. Long-term physical ageing in vitreous arsenic selenides

    International Nuclear Information System (INIS)

    Effects of long-term physical aging (approx 20 years) studied in vitreous arsenic selenides using differential scanning calorimetry are compared with conventional short-term physical aging (up to 1 year). It is shown that these effects differ not only by their amplitudes but also by compositional dependences. These results clearly testify in a favour of a sufficient difference in microstructural origin for short- and long-term physical aging in chalcogenide glasses

  18. Long-term Outcomes of Laparoscopic Surgery for Colorectal Cancer

    OpenAIRE

    Lee, Jeong-Eun; Joh, Yong-Geul; Yoo, Sang-hwa; Jeong, Geu-Young; Kim, Sung-Han; Chung, Choon-Sik; Lee, Dong-Gun; Kim, Seon Hahn

    2011-01-01

    Purpose The long-term results of a laparoscopic resection for colorectal cancer have been reported in several studies, but reports on the results of laparoscopic surgery for rectal cancer are limited. We investigated the long-term outcomes, including the five-year overall survival, disease-free survival and recurrence rate, after a laparoscopic resection for colorectal cancer. Methods Using prospectively collected data on 303 patients with colorectal cancer who underwent a laparoscopic resect...

  19. Long-Term Unemployment in the Varieties of Capitalism

    OpenAIRE

    Chilosi, Alberto

    2014-01-01

    Usually, when the attention is focused on the different performances of the labour market, the overall rate of unemployment is at the center stage. But this is misleading: while short term unemployment can be seen as physiological for the the working of the labour market, long-term unemployment is certainly pathological. The paper considers how the different varieties of capitalism affect the rate of long-term unemployment, rather than the aggregate rate. The liberal market variety, where emp...

  20. Long-term Planning by Short-term Prediction

    OpenAIRE

    SHALEV-SHWARTZ, Shai; Ben-Zrihem, Nir; Cohen, Aviad; Shashua, Amnon

    2016-01-01

    We consider planning problems, that often arise in autonomous driving applications, in which an agent should decide on immediate actions so as to optimize a long term objective. For example, when a car tries to merge in a roundabout it should decide on an immediate acceleration/braking command, while the long term effect of the command is the success/failure of the merge. Such problems are characterized by continuous state and action spaces, and by interaction with multiple agents, whose beha...

  1. A perspective on long-term care for the elderly

    OpenAIRE

    Scanlon, William J.

    1988-01-01

    Long-term care represents a significant burden to the approximately 7 million elderly in need, their families, and the Medicaid program. Concerns exist about access, quality, cost, and the distribution of the burden of care. In this article each area is discussed, highlighting the principal issues, identifying the unique aspects that pertain to long-term care, and exploring the implications for research and policy development. Future trends, especially the growth of the elderly population, ar...

  2. Archiving Primary Data: Solutions for Long-Term Studies.

    OpenAIRE

    Mills J.A.; Teplitsky C.; Arroyo B.; Charmantier A.; Becker P.H.; Birkhead T.R.; Bize P.; Blumstein D.T.; Bonenfant C.; Boutin S.; Bushuev A.; Cam E.; Cockburn A.; Côté S.D.; Coulson J.C.

    2015-01-01

    The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, op...

  3. Seamless Long Term Learning in Agile Teams for Sustainable Leadership

    CERN Document Server

    Qureshi, M R J

    2012-01-01

    Seamless and continuous support for long term organizational learning needs is essential for long lasting progress of the organization. Agile process model provides an excellent opportunity to cater that specific problem and also helps in motivation, satisfaction, coordination, presentation and technical skills enhancement of agile teams. This long term learning process makes organization to sustain their current successes and lead both organization and team members to successful and dynamic market leaders.

  4. Insuring Long-Term Care in the United States

    OpenAIRE

    Jeffrey R. Brown; Amy Finkelstein

    2011-01-01

    Long-term care expenditures constitute one of the largest uninsured financial risks facing the elderly in the United States and thus play a central role in determining the retirement security of elderly Americans. In this essay, we begin by providing some background on the nature and extent of long-term care expenditures and insurance against those expenditures, emphasizing in particular the large and variable nature of the expenditures and the extreme paucity of private insurance coverage. W...

  5. Long-Term Neuropsychological Outcome in Preterm Twins

    OpenAIRE

    Giovanni Iannone; Clelia Tripaldi; Antonino Chindemi; Lorenzo Piscitelli; Antonio Mastrorocco; Silvano Palazzo; Luigi Esposito

    2006-01-01

    Few long-term studies have yet described neuropsychological outcome in preterm twins. Our aim was to assess, by long-term evaluation, neuropsychological outcome in preterm twins in order to define a correct follow-up program. Our study was a cohort one, with an index and a comparison group. Neonatal medical records of all preterm newborns admitted to our centre between 1991 and 1997 were reviewed and selected patients were recalled. The sample population included two matched groups of childre...

  6. Coastal Long Term Ecological Research: Introduction to the Special Issue

    OpenAIRE

    Karen McGlathery; Daniel Reed; Meryl Alber

    2013-01-01

    The US National Science Foundation's Long Term Ecological Research (LTER) network was established in 1980 to provide the scientific expertise, research platforms, and long-term data sets necessary to document and analyze environmental change (http://www.lternet.edu). There are currently 25 sites in the US LTER network representing a range of ecosystems, including deserts, prairies, forests, tundra, lakes, urban areas, estuaries, coastal reefs, the pelagic ocean, and production agriculture. Al...

  7. Long- term outcome of paediatric patients with ANCA vasculitis

    OpenAIRE

    Arulkumaran, Nishkantha; Jawad, Susan; Smith, Stuart W.; Harper, Lorraine; Brogan, Paul; Charles D. Pusey; Salama, Alan D

    2011-01-01

    Background Primary systemic vasculitis presenting in childhood is an uncommon but serious condition. As these patients transfer to adult clinics for continuing care, defining long term outcomes with emphasis on disease and treatment- related morbidity and mortality is important. The aim of this study is to describe the long- term clinical course of paediatric patients with ANCA vasculitis. Methods The adult patients in our vasculitis clinics who had presented in childhood, with a follow up ti...

  8. Long- term outcome of paediatric patients with ANCA vasculitis

    OpenAIRE

    Pusey Charles D; Brogan Paul; Harper Lorraine; Smith Stuart W; Jawad Susan; Arulkumaran Nishkantha; Salama Alan D

    2011-01-01

    Abstract Background Primary systemic vasculitis presenting in childhood is an uncommon but serious condition. As these patients transfer to adult clinics for continuing care, defining long term outcomes with emphasis on disease and treatment- related morbidity and mortality is important. The aim of this study is to describe the long- term clinical course of paediatric patients with ANCA vasculitis. Methods The adult patients in our vasculitis clinics who had presented in childhood, with a fol...

  9. Case management for long-term and acute medical care

    OpenAIRE

    Capitman, John A.

    1988-01-01

    Case management has developed as an administrative service for controlling costs and improving the quality of health and social service delivery. Long-term care case management combined with service expansion has been examined in some detail with varied results. Less research has focused on case management for users of high-cost medical care. This overview highlights five programs and patient groups where integrated delivery and/or financing of medical and long-term care services are being de...

  10. Influential Factors in Long-term Product Service System Contracts

    OpenAIRE

    Hosseini Taklimi, Seyed Reza

    2011-01-01

    This dissertation presents different aspects of long-term contract for product service system (PSS); also different issues that companies are dealt for implementation of PSS. The study consists of literature review for understanding factors which can affect long-term PSS contracts. Different generic categories of green business models which are used in PSS contracts have been addressed and in addition, various models of contracts for PSS in industries have been identified too. The important f...

  11. Informed Consent to Research in Long-Term Care Settings

    OpenAIRE

    Lingler, Jennifer Hagerty; Jablonski, Rita A; Bourbonniere, Meg; Kolanowski, Ann

    2009-01-01

    Informed consent to nursing home research is a two-tiered process that begins with obtaining the consent of a long-term care community at the institutional level and progresses to the engagement of individuals in the consent process. Drawing on a review of the literature and the authors’ research experiences and institutional review board service, this paper describes the practical implications of nurse investigators’ obligation to ensure informed consent among participants in long-term care ...

  12. Endoscopic Management of Attic Cholesteatoma: Long-Term Results.

    Science.gov (United States)

    Alicandri-Ciufelli, Matteo; Marchioni, Daniele; Kakehata, Seiji; Presutti, Livio; Villari, Domenico

    2016-10-01

    The main application of endoscopic surgery relies on the middle ear cholesteatoma surgical treatment, although for a definitive validation and acceptance by scientific community, long-term results are needed about recurrent and residual rates of the pathology. The aim of the present paper was to analyze the single institution experience with the long-term results of surgical treatment of attic cholesteatoma. PMID:27565391

  13. Ethical issues in long-term psychiatric management.

    OpenAIRE

    Dickenson, D

    1997-01-01

    Two general ethical problems in psychiatry are thrown into sharp relief by long term care. This article discusses each in turn, in the context of two anonymised case studies from actual clinical practice. First, previous mental health legislation soothed doubts about patients' refusal of consent by incorporating time limits on involuntary treatment. When these are absent, as in the provisions for long term care which have recently come into force, the justification for compulsory treatment an...

  14. Long-term visual changes following pituitary irradiation

    International Nuclear Information System (INIS)

    Purpose: To analyze possible long-term effects of pituitary irradiation on visual fields and acuity. Methods and Materials: Eighty-six patients were treated with radiotherapy for pituitary tumors at the National Cancer Institute between 1980 and 1991. Twenty-one patients had baseline preradiation and long-term follow-up visual fields. Eyes were followed with serial Goldmann or Humphrey visual field testing. Neuroradiologic correlation was made with the available brain scans. There were 12 females and 9 males with an median age of 44. Eighteen patients had hormone-secreting tumors and three had chromophobe adenomas. All but one patient with an inoperable invasive macroadenoma were irradiated after one or more transphenoidal resections or a craniotomy. The indications for radiation in the operable patients were: nine patients, partial tumor resection; nine patients, tumor recurrence; and two patients, persistent hormonal elevation after surgery. The median dose delivered was 50 Gy (45-59.4 Gy). The average field size was 6 x 6 cm (5 x 5 cm to 10 x 12.5 cm). Results: With a median follow-up of 48 months (14-128) after radiotherapy, 1 out of 21 patients has recurred (at 8 months) and all patients are alive. Of the 38 sighted eyes, 27 had normal visual fields before and after radiation, 7 eyes showed improvement, and 4 eyes had a stable defect, mostly in the superior temporal region. There were no cases of radiation-induced visual field or acuity deterioration. Six out of 21 patients (29%) had neurologic symptoms in follow-up, most of which appeared vascular in nature. Four patients complained of atypical migranous-like headaches that first began 1.5-3 years following treatment. One patient complained of recurrent vertical diplopia and one patient had a cerebral vascular accident 7 years following therapy. A dose-related association with these neurovascular symptoms approached statistical significance. Only 1 out of 11 (9%) patients who received doses less than or equal

  15. Long-term safety of geological disposal: practices in Korea

    International Nuclear Information System (INIS)

    Full text of publication follows. The 253. meeting of AEC held on 17 December 2004 issued the 'National Radioactive Waste Management Policy' regarding SF management. It can be summarised that the national policy for spent fuel management will be decided later in consideration of the domestic and international technology development. At this time, spent fuels generated in NPPs have been stored within each plant by expanding the storage capacity. And the national policy for spent fuel management including the construction of the interim storage facility for spent fuel shall be timely decided considering the saturation of spent fuel storage capacity from 2016 through national consensus by public consultation among stakeholders. As a case of the long-lived LILW, long-term radiological safety criteria for long-lived HLW disposal facilities are presented separately for periods of operation and after post-closure. During the operation of radioactive waste disposal facilities, as with other nuclear facilities in operation, the standards for prevention of hazards to the environment as well as dose limits for the general public are to be applied. Technical standard described at MOST Notice define the technical standards for securing long-term safety incurred from disposal. Performance objectives for the post-closure period of geological repository are set up as radiological risks on individuals of critical groups in future. Annual dose due to normal natural phenomena must not exceed 0.1 mSv as the dose limit. In addition, annual risk due to unpredictable phenomena caused by natural or artificial factors must be restricted to 10-6 or less as the risk limit. The evaluation period for post-closure for HLW geological disposal is not decided in national regulation yet but is expected to be at least 10 000 years and longer. However, when the predicted risk does not reach a maximum value within the period above, verification that the leakage of radioactive materials into the

  16. Long term performance of the Waterloo denitrification barrier

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, W.D.; Cherry, J.A. [Univ. of Waterloo, Ontario (Canada)

    1997-12-31

    Beginning in 1991 a series of laboratory tests and small scale field trials were initiated to test the performance of an innovative permeable reactive barrier for treatment of nitrate from septic systems. The barrier promotes denitrification by providing an energy source in the form of solid organic carbon mixed into the porous media material. Advantages of the system for nitrate treatment are that the reaction is passive and in situ and it is possible to incorporate sufficient carbon mass in conveniently sized barriers to potentially provide treatment for long periods (decades) without the necessity for maintenance. However, longevity can only be demonstrated by careful long term monitoring of field installations. This paper documents four years of operating history at three small scale field trials; two where the denitrification barrier is installed as a horizontal layer positioned in the unsaturated zone below conventional septic system infiltration beds and one where the barrier is installed as a vertical wall intercepting a septic system plume at a downgradient location. The barriers have successfully attenuated 50-100% of NO{sup -}{sub 3}-N levels of up to 170 mg/L and treatment has remained consistent over the four year period in each case, thus considerable longevity is indicated. Other field trials have demonstrated this technology to be equally effective in treating nitrogen contamination from other sources such as landfill leachate and farm field runoff.

  17. Long-term deterioration of composite resin and amalgam restorations.

    Science.gov (United States)

    Smales, R J

    1991-01-01

    Previous long-term longitudinal studies of two different methods of placing an auto-cured conventional anterior composite resin, and of a low- and a high-copper amalgam alloy, had shown similar restoration survivals despite the different resin treatment methods used or the types of amalgam alloy placed. Therefore, the aim of the present study was to assess several clinical factors or characteristics of these restorations that were believed to affect the survival of the restorative materials. The 950 composite resin and the 1042 amalgam restorations examined were placed by many operators in numerous patients attending a dental hospital. The composite resin restorations were placed using unetched- and etched-enamel-bonding treatment methods, and the amalgam restorations were polished after insertion. Clinical ratings supplemented by color transparencies were used for the assessment of four factors for the resin, and four factors for the amalgam restoration. Significant deterioration differences were found for several of the clinical factors assessed for both the two different composite resin treatment methods, and for the two different amalgam alloys, which were not directly related to the restoration survivals. PMID:1840079

  18. Evaluating File Formats for Long-term Preservation

    Institute of Scientific and Technical Information of China (English)

    JUDITH ROG; CAROLINE VAN WIJK

    2008-01-01

    National and international publishers have been depositing digital publications at the National Library of the Netherlands(KB)since 2003.Until recently,most of these publications were deposited in the Portable Document Format.New projects,for example the Web archiving project,force the KB to handle more heterogeneous material.Therefore,the KB has developed a quantifiable file format risk assessment method.This method can be used to define digital preservation strategies for specific file formats.The choice for a specific file format at creation time or later in the life cycle of a digital object influences the long-term access to the digital object.The evaluation method contains seven sustainability criteria for file formats that are weighed for importance.There seems to be consensus on the sustainability criteria.However,as the weighing of these criteria is connected to an institution's policy,the KB wonders whether agreement on the relative importance of the criteria can be reached at all.With this paper,the KB hopes to inspire other cultural heritage institutions to define their own quantifiable file format evaluation method.

  19. Accelerated characterization for long-term creep behavior of polymer

    Science.gov (United States)

    Zhao, Rongguo; Chen, Chaozhong; Li, Qifu; Luo, Xiyan

    2008-11-01

    Based on the observation that high stress results in increasing creep rate of polymeric material, which is analogous to the time-temperature equivalence, where high temperature accelerates the process of creep or relaxation of polymer, the time-stress equivalence is investigated. The changes of intrinsic time in polymer induced by temperature and stress are studied using the free volume theory, and a clock model based on the time-temperature and time-stress equivalence is constructed to predict the long-term creep behavior of polymer. Polypropylene is used for this work. The specimens with shape of dumbbell are formed via injection molding. The short-term creep tests under various stress levels are carried out at ambient temperature. The creep strains of specimens are modeled according to the concept of time-stress equivalence, and the corresponding stress shift factors are calculated. A master creep curve is built by the clock model. The result indicates that the time-stress superposition principle provides an accelerated characterization method in the laboratory. Finally, the time-dependent axial elongations at sustained stress levels, whose values are close to the tensile strength of polypropylene, are measured. The three phases of creep, i.e., the transient, steady state and accelerated creep phases, are studied, and the application and limitation of the time-stress superposition principle are discussed.

  20. Long term waste management: Historical considerations and societal risks

    International Nuclear Information System (INIS)

    In the past decade, the concept of deep geological disposal of radioactive waste has been revised. The following paper presents the state of discussion on radioactive waste disposal strategies in the deep geological formations and at surface facilities. It considers ethical, social and technical criteria, and shows the advantages and weaknesses of the different concepts. Based on a discussion of methodology, the predictability of models - and, therefore, of waste disposal or storage strategies - is discussed, for natural as well as for social systems and for different periods of prediction. Historical considerations about the resistance and durability of materials or structures as well as about the breakdown of structures by natural or social events shows that the safety of human-made structures is less influenced by natural catastrophes than by social effects. Finally, the paper discusses the concept of monitored long term geological disposal (the EKRA concept) developed by a commission of the Swiss Federal Department of Environment, Transport, Energy and Communication in order to assess the advantages of a deep underground repository and monitoring of the repository site. The combination of definitive disposal and deep underground monitored waste disposal sites should ensure a safety optimum of the disposal facility and provide better acceptance of disposal projects. (author)

  1. Lyophilization as a method for pathogens long term preservation

    Directory of Open Access Journals (Sweden)

    Milošević Mirjana B.

    2007-01-01

    Full Text Available Lyophilization (freeze-drying is one of the most suitable methods used for a long term preservation of pathogens. The aim of this paper was the application of lyophilization for storage of three significant plant pathogens: Fusarium graminearum, Helminthosporium gramineum, and Pseudomonas syringae pv. gylicinea, respectively. The plant material was collected continuously (during a four year period 2002-2006, depending on a plant development stage, from different localities in Vojvodina. Pathogens were isolated from diseased parts with characteristic symptoms, and placed on nutritive media specific for a certain pathogen, using standard phytopathological methods. Lyophilization was carried out in marked and coded ampoules by freezing and drying of pathogen suspension and nutritive medium. Revitalization of lyophilized isolates was done after four days. High percentage of revitalization was characteristic for all studied isolates, and it ranged from 85-92%, confirming that lyophilized pathogens would be capable of keeping viability for a long time in the collection. Besides above mentioned pathogens, there were 200 isolates in the collection, originating mostly from field and vegetable crops. Each isolate that was put into the Collection, was followed by all the necessary data such as: name of the pathogen, number of isolates, locality, host plant year of isolation, name of the researcher and other relevant data.

  2. Long-term proliferation and safeguards issues in future technologies

    Energy Technology Data Exchange (ETDEWEB)

    Keisch, B.; Auerbach, C.; Fainberg, A.; Fiarman, S.; Fishbone, L.G.; Higinbotham, W.A.; Lemley, J.R.; O' Brien, J.

    1986-02-01

    The purpose of the task was to assess the effect of potential new technologies, nuclear and non-nuclear, on safeguards needs and non-proliferation policies, and to explore possible solutions to some of the problems envisaged. Eight subdivisions were considered: New Enrichment Technologies; Non-Aqueous Reprocessing Technologies; Fusion; Accelerator-Driven Reactor Systems; New Reactor Types; Heavy Water and Deuterium; Long-Term Storage of Spent Fuel; and Other Future Technologies (Non-Nuclear). For each of these subdivisions, a careful review of the current world-wide effort in the field provided a means of subjectively estimating the viability and qualitative probability of fruition of promising technologies. Technologies for which safeguards and non-proliferation requirements have been thoroughly considered by others were not restudied here (e.g., the Fast Breeder Reactor). The time scale considered was 5 to 40 years for possible initial demonstration although, in some cases, a somewhat optimistic viewpoint was embraced. Conventional nuclear-material safeguards are only part of the overall non-proliferation regime. Other aspects are international agreements, export controls on sensitive technologies, classification of information, intelligence gathering, and diplomatic initiatives. The focus here is on safeguards, export controls, and classification.

  3. Stereotactic Radiosurgery for Acoustic Neuromas: What Happens Long Term?

    Energy Technology Data Exchange (ETDEWEB)

    Roos, Daniel E., E-mail: daniel.roos@health.sa.gov.au [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); University of Adelaide School of Medicine, Adelaide, South Australia (Australia); Potter, Andrew E. [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); Brophy, Brian P. [Department of Neurosurgery, Royal Adelaide Hospital, Adelaide, South Australia (Australia); University of Adelaide School of Medicine, Adelaide, South Australia (Australia)

    2012-03-15

    Purpose: To determine the clinical outcomes for acoustic neuroma treated with low-dose linear accelerator stereotactic radiosurgery (SRS) >10 years earlier at the Royal Adelaide Hospital using data collected prospectively at a dedicated SRS clinic. Methods and Materials: Between November 1993 and December 2000, 51 patients underwent SRS for acoustic neuroma. For the 44 patients with primary SRS for sporadic (unilateral) lesions, the median age was 63 years, the median of the maximal tumor diameter was 21 mm (range, 11-34), and the marginal dose was 14 Gy for the first 4 patients and 12 Gy for the other 40. Results: The crude tumor control rate was 97.7% (1 patient required salvage surgery for progression at 9.75 years). Only 8 (29%) of 28 patients ultimately retained useful hearing (interaural pure tone average {<=}50 dB). Also, although the Kaplan-Meier estimated rate of hearing preservation at 5 years was 57% (95% confidence interval, 38-74%), this decreased to 24% (95% confidence interval, 11-44%) at 10 years. New or worsened V and VII cranial neuropathy occurred in 11% and 2% of patients, respectively; all cases were transient. No case of radiation oncogenesis developed. Conclusions: The long-term follow-up data of low-dose (12-14 Gy) linear accelerator SRS for acoustic neuroma have confirmed excellent tumor control and acceptable cranial neuropathy rates but a continual decrease in hearing preservation out to {>=}10 years.

  4. Long term performance of the Waterloo denitrification barrier

    International Nuclear Information System (INIS)

    Beginning in 1991 a series of laboratory tests and small scale field trials were initiated to test the performance of an innovative permeable reactive barrier for treatment of nitrate from septic systems. The barrier promotes denitrification by providing an energy source in the form of solid organic carbon mixed into the porous media material. Advantages of the system for nitrate treatment are that the reaction is passive and in situ and it is possible to incorporate sufficient carbon mass in conveniently sized barriers to potentially provide treatment for long periods (decades) without the necessity for maintenance. However, longevity can only be demonstrated by careful long term monitoring of field installations. This paper documents four years of operating history at three small scale field trials; two where the denitrification barrier is installed as a horizontal layer positioned in the unsaturated zone below conventional septic system infiltration beds and one where the barrier is installed as a vertical wall intercepting a septic system plume at a downgradient location. The barriers have successfully attenuated 50-100% of NO-3-N levels of up to 170 mg/L and treatment has remained consistent over the four year period in each case, thus considerable longevity is indicated. Other field trials have demonstrated this technology to be equally effective in treating nitrogen contamination from other sources such as landfill leachate and farm field runoff

  5. Long-term proliferation and safeguards issues in future technologies

    International Nuclear Information System (INIS)

    The purpose of the task was to assess the effect of potential new technologies, nuclear and non-nuclear, on safeguards needs and non-proliferation policies, and to explore possible solutions to some of the problems envisaged. Eight subdivisions were considered: New Enrichment Technologies; Non-Aqueous Reprocessing Technologies; Fusion; Accelerator-Driven Reactor Systems; New Reactor Types; Heavy Water and Deuterium; Long-Term Storage of Spent Fuel; and Other Future Technologies (Non-Nuclear). For each of these subdivisions, a careful review of the current world-wide effort in the field provided a means of subjectively estimating the viability and qualitative probability of fruition of promising technologies. Technologies for which safeguards and non-proliferation requirements have been thoroughly considered by others were not restudied here (e.g., the Fast Breeder Reactor). The time scale considered was 5 to 40 years for possible initial demonstration although, in some cases, a somewhat optimistic viewpoint was embraced. Conventional nuclear-material safeguards are only part of the overall non-proliferation regime. Other aspects are international agreements, export controls on sensitive technologies, classification of information, intelligence gathering, and diplomatic initiatives. The focus here is on safeguards, export controls, and classification

  6. Probabilistic simulation of long term behavior in polymer matrix composites

    Science.gov (United States)

    Shah, A. R.; Singhal, S. N.; Murthy, P. L. N.; Chamis, C. C.

    1995-01-01

    A methodology to compute cumulative probability distribution functions (CDF) of fatigue life for different ratios, r of applied stress to the laminate strength based on first ply failure criteria has been developed and demonstrated. Degradation effects due to long term environmental exposure and mechanical cyclic loads are considered in the simulation process. A unified time-stress dependent multi-factor interaction equation model developed at NASA Lewis Research Center has been used to account for the degradation/aging of material properties due to cyclic loads. Fast probability integration method is used to perform probabilistic simulation of uncertainties. Sensitivity of fatigue life reliability to uncertainties in the primitive random variables are computed and their significance in the reliability based design for maximum life is discussed. The results show that the graphite/epoxy (0/+45/90) deg laminate with ply thickness 0.125 in. has 500,000 cycles life for applied stress to laminate strength ratio of 0.6 and a reliability of 0.999. Also, the fatigue life reliability has been found to be most sensitive to the ply thickness and matrix tensile strength. Tighter quality controls must therefore be enforced on ply thickness and matrix strength in order to achieve high reliability of the structure.

  7. Long term Integrity of PWR Spent Fuel in Dry Storage

    International Nuclear Information System (INIS)

    The newly established organization KRMC (Korea radioactive waste management corporation) which is responsible for all kinds of radioactive waste generated in the Republic of Korea launched the PWR spent fuel dry storage research project in June 2009. This project has objectives to develop a storage system and evaluate the integrity of PWR fuel in dry storage. The project consists of three steps. At first step, it would develop own degradation models by referring to pre-exist good models and develop the hot test scenarios. Second step, test facilities would be constructed and used for testing the degradation behaviour in each mechanisms and in total. As a final step, total evaluation code would be developed by integrating each degradation model produced in the first step and the test data produced in the second step. All the activities would be summarized into a report and applied to licensing work. The Republic of Korea PWR spent fuels have unique characteristics of various fuel types (array type, clad material) and high capacity factor (maximum usage of fuel which is bad for integrity). These facts could impact on the research ranges of experimental data needed for degradation evaluation. In this research, spent fuel performance data concerning long term dry storage will be analysed and the major degradation mechanisms like creep and hydride behaviour will be studied and proposed for Korean PWR spent fuels

  8. Long-term stability of the APS storage ring

    International Nuclear Information System (INIS)

    The Advanced Photon Source (APS), a third-generation synchrotrons light source, was commissioned in 1995 at Argonne ''National Laboratory and has been fully-operational for beamline users since 1997. The APS storage ring can accommodate up to 68 user beamlines; about 70% of the available beamlines are currently in use by various collaborative access teams (CATS). The 7-GeV synchrotrons light source produces light in the soft to hard x-ray range that is used for research in such areas as x-ray instrumentation; material, chemical and atomic sciences; biology; and geo/soil/ environmental sciences. For the successful operation of an x-ray light source such as the Advanced Photon Source, the long-term stability of the concrete floor supporting the beam components and user beamlines is crucial. Settlements impact the orbit and location of the x-ray source points as well as the position of the x-ray beamlines. This paper compares the results of two successive resurveys of the APS accelerator components performed in 1995 and 1998

  9. Long-term Corrosion of Copper Container in Bentonite Buffer

    International Nuclear Information System (INIS)

    The experimental method for the evaluation of copper corrosion was discussed in this report. Especially, the corrosion behavior of a copper container in a compacted bentonite environment was reviewed in detail. Several previous studies on the copper corrosion in a bentonite environment were summarized and the applied methods were illustrated firstly. On the basis of the review, it is discussed how to execute long-term copper corrosion test as regarding korean disposal environment. The selection of bentonite medium and the composition of a medium such as bentonite-sand mixture or bentonite-sand double layer was mentioned in this report. The need for protection layer on copper surface was also discussed for reducing initial copper corrosion rate. As key aspects on the corrosion test, a measuring of corrosion rate, an observation of surface morphology, an analysis of corrosion product, and a measuring of corrosion potential were pointed out. For the purpose of a experimental consistency, the necessity of standard composition for a bentonite and a underground water might be confirmed before the test. Consequently, three experimental designs were derived for the corrosion test such as a corrosion testing design at creep condition, a simple corrosion design for the evaluation for other candidate materials, and lastly, a corrosion testing design in compacted bentonite. Through this survey and discussion for a copper corrosion in bentonite environment it would be very helpful for a high level radioactive waste disposal plan in the future

  10. Materials Challenges for Advanced Combustion and Gasification Fossil Energy Systems

    Science.gov (United States)

    Sridhar, S.; Rozzelle, P.; Morreale, B.; Alman, D.

    2011-04-01

    This special section of Metallurgical and Materials Transactions is devoted to materials challenges associated with coal based energy conversion systems. The purpose of this introductory article is to provide a brief outline to the challenges associated with advanced combustion and advanced gasification, which has the potential of providing clean, affordable electricity by improving process efficiency and implementing carbon capture and sequestration. Affordable materials that can meet the demanding performance requirements will be a key enabling technology for these systems.

  11. Long Term Degradation of Resin for High Temperature Composites

    Science.gov (United States)

    Patekar, Kaustubh A.

    2000-01-01

    The durability of polymer matrix composites exposed to harsh environments is a major concern. Surface degradation and damage are observed in polyimide composites used in air at 125 to 300 C. It is believed that diffusion of oxygen into the material and oxidative chemical reactions in the matrix are responsible. Previous work has characterized and modeled diffusion behavior, and thermogravimetric analyses (TGAs) have been carried out in nitrogen, air, and oxygen to provide quantitative information on thermal and oxidative reactions. However, the model developed using these data was not able to capture behavior seen in isothermal tests, especially those of long duration. A test program that focuses on lower temperatures and makes use of isothermal tests was undertaken to achieve a better understanding of the degradation reactions under use conditions. A new low-cost technique was developed to collect chemical degradation data for isothermal tests lasting over 200 hr in the temperature range 125 to 300 C. Results indicate complex behavior not captured by the previous TGA tests, including the presence of weight-adding reactions. Weight gain reactions dominated in the 125 to 225 C temperature range, while weight loss reactions dominated beyond 225 C. The data obtained from isothermal tests was used to develop a new model of the material behavior. This model was able to fully capture the behavior seen in the tests up to 275 C. Correlation of the current model with both isothermal data at 300 C and high rate TGA test data is mediocre. At 300 C and above, the reaction mechanisms appear to change. Attempts (which failed) to measure non-oxidative degradation indicate that oxidative reactions dominate the degradation at low temperatures. Based on this work, long term isothermal testing in an oxidative atmosphere is recommended for studying the degradation behavior of this class of materials.

  12. Challenges in structural materials for thermal reactors

    International Nuclear Information System (INIS)

    The safe, reliable and economic operation of nuclear power plants is critically dependent on good performance of materials. Material selection is one of the most important steps in the design of the engineering components. Functional requirements and operating conditions such as stress, temperature and environment dictate the choice of materials and their properties. Criteria for selection of materials for non-nuclear components include mechanical properties (strength-ductility-toughness), corrosion properties (resistance to uniform and localized corrosion), fabricability (forming-welding-heat treatment) and cost. Additional considerations for nuclear components include neutron absorption, induced radioactivity and resistance to radiation damage. Nuclear core components are continuously subjected to bombardment by fast neutrons. Important effects of fast neutron irradiation on properties of materials are : (i) change in mechanical properties by irradiation hardening and irradiation embrittlement (ii) dimensional changes by irradiation growth, irradiation creep and void swelling and (iii) change in corrosion properties like increase in corrosion rate and introduction of new corrosion mode. There are 2 types of thermal power reactors viz., Pressure Vessel Type (BWRs and PWRs) and Pressure Tube Type (PHWRs). A very wide range of materials are used for nuclear reactor components. These include carbon and low alloy steels, stainless steels (austenitic, martensitic, precipitation hardenable), nickel-base alloys (inconels, incoloys), zirconium base alloys, etc. Three most important classes of materials are : (1) Low alloy steels for Reactor Pressure Vessel : the main concerns are increase in Ductile-Brittle transition temperature (DBTT) and decrease in toughness due to neutron irradiation. (2) Zirconium Alloys for Reactor Core Components : main concerns are Delayed Hydride cracking (DHC) and change in dimensions due to Irradiation Creep and Growth. (3) Stainless Steels

  13. The uranium industry: long-term planning for short-term competition

    International Nuclear Information System (INIS)

    Long term planning for short term competition Today, uranium producers face new challenges in terms of both production (new regulatory, environmental and social constraints) and market conditions (new sources of uranium supply, very low prices and tough competition). In such a context, long-term planning is not just a prerequisite to survive in the nuclear fuel cycle industry. In fact, it also contributes to sustaining nuclear electricity generation facing fierce competition from other energy sources in increasingly deregulated markets. Firstly, the risk of investing in new mining projects in western countries is growing because, on the one hand, of very erratic market conditions and, on the other hand, of increasingly lengthy, complex and unpredictable regulatory conditions. Secondly, the supply of other sources of uranium (uranium derived from nuclear weapons, uranium produced in CIS countries, ...) involve other risks, mainly related to politics and commercial restrictions. Consequently, competitive uranium supply requires not only technical competence but also financial strength and good marketing capabilities in order to anticipate long-term market trends, in terms of both demand and supply. It also requires taking into account new parameters such as politics, environment, regulations, etc. Today, a supplier dedicated to the sustainable production of nuclear electricity must manage a broad range of long-term risks inherent to the procurement of uranium. Taking into account all these parameters in a context of short-term, fast-changing market is a great challenge for the future generation. World Uranium Civilian Supply and Demand. (authors)

  14. Long-term degradation (or improvement?) of cementitious grout/concrete for waste disposal at Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Piepho, M.G. [Daniel B. Stephens & Associates, Inc., Richland, WA (United States)

    1997-12-31

    If grout and/or concrete barriers and containments are considered for long-term (500 yrs to 100,000 ) waste disposal, then long-term degradation of grout/cement materials (and others) need to be studied. Long-term degradations of a cementitious grout monolith (15.4mW x 10.4mH x 37.6mL) and its containment concrete shell and asphalt shell (each 1-m thick) were analyzed. The main degradation process of the concrete shell was believed to be fractures due to construction joints, shrinkage, thermal stress, settlement, and seismic events. A scenario with fractures was modeled (flow and transport model) for long-term risk performance (out to a million yrs). Even though the concrete/grout is expected to fracture, the concrete/grout chemistry, which has high Ph value, is very beneficial in causing calcite deposits from calcium in the water precipitating in the fractures. These calcite deposits will tend to plug the fracture and keep water from entering. The effectiveness of such plugging needs to be studied more. It`s possible that the plugged fractures are more impermeable than the original concrete/grout. The long-term performance of concrete/grout barriers will be determined by its chemistry, not its mechanical properties.

  15. Modulation of working memory updating: Does long-term memory lexical association matter?

    Science.gov (United States)

    Artuso, Caterina; Palladino, Paola

    2016-02-01

    The aim of the present study was to investigate how working memory updating for verbal material is modulated by enduring properties of long-term memory. Two coexisting perspectives that account for the relation between long-term representation and short-term performance were addressed. First, evidence suggests that performance is more closely linked to lexical properties, that is, co-occurrences within the language. Conversely, other evidence suggests that performance is linked more to long-term representations which do not entail lexical/linguistic representations. Our aim was to investigate how these two kinds of long-term memory associations (i.e., lexical or nonlexical) modulate ongoing working memory activity. Therefore, we manipulated (between participants) the strength of the association in letters based on either frequency of co-occurrences (lexical) or contiguity along the sequence of the alphabet (nonlexical). Results showed a cost in working memory updating for strongly lexically associated stimuli only. Our findings advance knowledge of how lexical long-term memory associations between consonants affect working memory updating and, in turn, contribute to the study of factors which impact the updating process across memory systems. PMID:26323831

  16. Methods for estimation of long-term non-carbonate neutralisation of acid rock drainage.

    Science.gov (United States)

    Miller, Stuart D; Stewart, Warwick S; Rusdinar, Yuni; Schumann, Russell E; Ciccarelli, Joseph M; Li, Jun; Smart, Roger St C

    2010-04-01

    In the long-term phase of an acid rock drainage (ARD) evolution profile, after any short-term neutralisation capacity provided by carbonate minerals is exhausted, the net acid release is a product of a declining acid generation rate (AGR) and a slower, long-term acid neutralisation rate mainly provided by gangue silicate minerals. At some point, the AGR and the non-carbonate acid neutralisation rate (ANRnc) will be similar. Matching of the AGR and ANRnc near 10mg H(2)SO(4)/kg/week is demonstrated in data from 10-year columns. This long-term neutralisation is not measured at present in any accepted assessment tests. Methods to estimate ANRnc, based on silicate mineralogy and solution assays from long-term column leach tests, are compared. Good agreement is demonstrated between rates measured from the solution assay data and those calculated from mineralogy using kinetic databases. More rigorous analysis of the leachate chemistry of selected long-term leach tests also suggests possible cover design criteria based on the maximum AGR that will maintain a pH>4 in leachate from ARD materials. The data show a distinct break at an AGR of 3mg H(2)SO(4)/kg/week, below which no leachate pH is less than 4. The results indicate that an AGR of 10t H(2)SO(4)/ha/year is conservative and a suitable cover design target for ARD control that would be matched by ANRnc. PMID:20097405

  17. What Does it Take to Develop a Long-term Pleasure Reading Habit?

    OpenAIRE

    Cho, Kyung-Sook; Krashen, Stephen

    2015-01-01

    Six case histories of second language acquirers were examined to attempt to determine what factors play a role in developing a long-term pleasure reading habit in a second language (English). The cases provided support for several hypotheses: Long-term readers are first stimulated to read through a pleasant reading experience, they have access to books and time and a place (or places) to read, they select their own reading material, feel free to stay with certain authors and genres if they wa...

  18. Long-term surveillance plan for the Tuba City, Arizona disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Tuba City, Arizona, describes the site surveillance activities. The U.S. Department of Energy (DOE) will carry out these activities to ensure the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials (RRM) (10 CFR {section}40.27).

  19. High Temperature Steam Electrolysis: Demonstration of Improved Long-Term Performance

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-01

    Long-term performance is an ongoing issue for hydrogen production based on high-temperature steam electrolysis (HTSE). For commercial deployment, solid-oxide electrolysis stacks must achieve high performance with long-term degradation rates of {approx}0.5%/1000 hours or lower. Significant progress has been achieved toward this goal over the past few years. This paper will provide details of progress achieved under the Idaho National Laboratory high temperature electrolysis research program. Recent long-term stack tests have achieved high initial performance with degradation rates less than 5%/khr. These tests utilize internally manifolded stacks with electrode-supported cells. The cell material sets are optimized for the electrolysis mode of operation. Details of the cells and stacks will be provided along with details of the test apparatus, procedures, and results.

  20. Long-term surveillance plan for the Bodo Canyon Disposal Site, Durango, Colorado

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Durango, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Durango (Bodo Canyon) disposal site, which will be referred to as the disposal site throughout this document. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials (RRM). RRMs include tailings and other uranium ore processing wastes still at the site, which the DOE determines to be radioactive. This LTSP is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992)