WorldWideScience

Sample records for cathode long-term stability

  1. A carbon nanotube field emission cathode with high current density and long-term stability

    Energy Technology Data Exchange (ETDEWEB)

    Calderon-Colon, Xiomara; Zhou, Otto [Curriculum in Applied Science and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Geng Huaizhi; Gao Bo [Xintek, Incorporated, 7020 Kit Creek Road, Research Triangle Park, NC (United States); An Lei; Cao Guohua [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2009-08-12

    Carbon nanotube (CNT) field emitters are now being evaluated for a wide range of vacuum electronic applications. However, problems including short lifetime at high current density, instability under high voltage, poor emission uniformity, and pixel-to-pixel inconsistency are still major obstacles for device applications. We developed an electrophoretic process to fabricate composite CNT films with controlled nanotube orientation and surface density, and enhanced adhesion. The cathodes have significantly enhanced macroscopic field emission current density and long-term stability under high operating voltages. The application of this CNT electron source for high-resolution x-ray imaging is demonstrated.

  2. OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Hector Colonmer; Prabhu Ganesan; Nalini Subramanian; Dr. Bala Haran; Dr. Ralph E. White; Dr. Branko N. Popov

    2002-09-01

    This project focused on addressing the two main problems associated with state of art Molten Carbonate Fuel Cells, namely loss of cathode active material and stainless steel current collector deterioration due to corrosion. We followed a dual approach where in the first case we developed novel materials to replace the cathode and current collector currently used in molten carbonate fuel cells. In the second case we improved the performance of conventional cathode and current collectors through surface modification. States of art NiO cathode in MCFC undergo dissolution in the cathode melt thereby limiting the lifetime of the cell. To prevent this we deposited cobalt using an electroless deposition process. We also coated perovskite (La{sub 0.8}Sr{sub 0.2}CoO{sub 3}) in NiO thorough a sol-gel process. The electrochemical oxidation behavior of Co and perovskites coated electrodes is similar to that of the bare NiO cathode. Co and perovskite coatings on the surface decrease the dissolution of Ni into the melt and thereby stabilize the cathode. Both, cobalt and provskites coated nickel oxide, show a higher polarization compared to that of nickel oxide, which could be due to the reduced surface area. Cobalt substituted lithium nickel oxide (LiNi{sub 0.8}Co{sub 0.2}O{sub 2}) and lithium cobalt oxide were also studied. LiNi{sub x}Co{sub 1-x}O{sub 2} was synthesized by solid-state reaction procedure using lithium nitrate, nickel hydroxide and cobalt oxalate precursor. LiNi{sub x}Co{sub 1-x}O{sub 2} showed smaller dissolution of nickel than state of art nickel oxide cathode. The performance was comparable to that of nickel oxide. The corrosion of the current collector in the cathode side was also studied. The corrosion characteristics of both SS304 and SS304 coated with Co-Ni alloy were studied. This study confirms that surface modification of SS304 leads to the formation of complex scales with better barrier properties and better electronic conductivity at 650 C. A three

  3. 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.

  4. Construction of a cathode using amorphous FePO4 nanoparticles for a high-power/energy-density lithium-ion battery with long-term stability

    Science.gov (United States)

    Zhang, Tongbao; Cheng, Xin-Bing; Zhang, Qiang; Lu, Yangcheng; Luo, Guangsheng

    2016-08-01

    Using amorphous FePO4 (a-FePO4) nanoparticles with a high purity, a narrow size distribution and good dispersion, we successfully developed a new strategy to generate a uniformly dispersed a-FePO4-CNT nano-composite using the interface interaction between surface-modified a-FePO4 and CNT dispersion under mild sonication. The uniformly dispersed a-FePO4-CNT nano-composite exhibited the best performance and long-term stability as a cathode material in a lithium-ion battery compared to previously reported results. The developed nano-composite could deliver a theoretical specific capacity at 0.1 C, 162 mAh g-1 at 1 C and 117 mAh g-1 at 5 C. No capacity fading was observed at 1 C after 500 cycles, and nearly 90% of the initial discharge capacity could be retained at 5 C after 2000 cycles. This study confirms the validity of the proposed strategy to construct a cathode structure, and also describes the potential of a-FePO4 for building high-power energy-storage and conversion systems.

  5. 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…

  6. 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

  7. 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....

  8. 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...

  9. Long-term stability test of a triple GEM detector

    CERN Document Server

    Adak, R P; Das, S; Ghosal, D; Ghosh, S K; Mondal, A; Nag, D; Nayak, T K; Patra, R N; Prasad, S K; Raha, S; Sahu, P K; Sahu, S; Swain, S

    2016-01-01

    The main aim of the study is to perform the long-term stability test of gain of the single mask triple GEM detector. A simple method is used for this long- term stability test using a radioactive X-ray source with high activity. The test is continued till accumulation of charge per unit area > 12.0 mC/mm2. The details of the chamber fabrication, the test set-up, the method of measurement and the test results are presented in this paper.

  10. A Long-term Mechanism Needed to Safeguard Financial Stability

    Institute of Scientific and Technical Information of China (English)

    何德旭

    2007-01-01

    In the post-WTO era, China has encountered new difficulties in maintaining financial stability. Quick fix and emergency measures can no longer be relied on in the long run, and therefore, a long-term mechanism of financial stability must be put in place. This article recommends that China should focus on furthering financial reform, accelerating financial innovation and improving the legal system to promote a strong and competitive finance industry that is less vulnerable to financial hazards.

  11. Long-term laser frequency stabilization using fiber interferometers

    CERN Document Server

    Kong, Jia; Jimenez-Martinez, Ricardo; Mitchell, Morgan W

    2014-01-01

    We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer. When used to stabilize a distributed feedback laser at 795 nm, the frequency Allan deviation at 1000 s drops from 5.6*10^{-8} to 6.9*10^{-10}. The performance equals that of an offset lock employing a second laser and an atomic reference.

  12. Long-term stability of TES satellite radiance measurements

    OpenAIRE

    T. C. Connor; M. W. Shephard; V. H. Payne; K. E. Cady-Pereira; Kulawik, S. S.; Luo, M.; G. Osterman; M. Lampel

    2011-01-01

    The utilization of Tropospheric Emission Spectrometer (TES) Level 2 (L2) retrieval products for the purpose of assessing long term changes in atmospheric trace gas composition requires knowledge of the overall radiometric stability of the Level 1B (L1B) radiances. The purpose of this study is to evaluate the stability of the radiometric calibration of the TES instrument by analyzing the difference between measured and calculated brightness temperatures in selected window regions of the spectr...

  13. Long-term stability of TES satellite radiance measurements

    OpenAIRE

    T. C. Connor; M. W. Shephard; V. H. Payne; K. E. Cady-Pereira; Kulawik, S. S.; Luo, M.; G. Osterman; M. Lampel

    2011-01-01

    The utilization of Tropospheric Emission Spectrometer (TES) Level 2 (L2) retrieval products for the purpose of assessing long term changes in atmospheric trace gas composition requires knowledge of the overall radiometric stability of the Level 1B (L1B) radiances. The purpose of this study is to evaluate the stability of the radiometric calibration of the TES instrument by analyzing the difference between measured and calculated brightness temperatures in selected window reg...

  14. Examining the Long-Term Stability of Overgeneral Autobiographical Memory

    OpenAIRE

    Sumner, Jennifer A.; Mineka, Susan; Zinbarg, Richard E; Craske, Michelle G.; Vrshek-Schallhorn, Suzanne; Epstein, Alyssa

    2013-01-01

    Overgeneral autobiographical memory (OGM) is a proposed trait-marker for vulnerability to depression, but relatively little work has examined its long-term stability. This study investigated the stability of OGM over several years in 271 late adolescents and young adults participating in a larger longitudinal study of risk for emotional disorders. The Autobiographical Memory Test (AMT) was administered twice, with test-retest intervals ranging from approximately 3 to 6 years. There was eviden...

  15. Long-term laser frequency stabilization using fiber interferometers.

    Science.gov (United States)

    Kong, Jia; Lucivero, Vito Giovanni; Jiménez-Martínez, Ricardo; Mitchell, Morgan W

    2015-07-01

    We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer to stabilize the frequency reference. When used to stabilize a distributed feedback laser at 795 nm, the frequency Allan deviation at 1000 s drops from 5.6 × 10(-8) to 6.9 × 10(-10). The performance equals that of an offset lock employing a second, atom-stabilized laser in the temperature control. PMID:26233353

  16. Long-term laser frequency stabilization using fiber interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Jia, E-mail: jia.kong@icfo.es [ICFO – Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); Quantum Institute for Light and Atoms, Department of Physics, State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Lucivero, Vito Giovanni; Jiménez-Martínez, Ricardo [ICFO – Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); Mitchell, Morgan W. [ICFO – Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); ICREA – Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona (Spain)

    2015-07-15

    We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer to stabilize the frequency reference. When used to stabilize a distributed feedback laser at 795 nm, the frequency Allan deviation at 1000 s drops from 5.6 × 10{sup −8} to 6.9 × 10{sup −10}. The performance equals that of an offset lock employing a second, atom-stabilized laser in the temperature control.

  17. Long-term laser frequency stabilization using fiber interferometers

    Science.gov (United States)

    Kong, Jia; Lucivero, Vito Giovanni; Jiménez-Martínez, Ricardo; Mitchell, Morgan W.

    2015-07-01

    We report long-term laser frequency stabilization using only the target laser and a pair of 5 m fiber interferometers, one as a frequency reference and the second as a sensitive thermometer to stabilize the frequency reference. When used to stabilize a distributed feedback laser at 795 nm, the frequency Allan deviation at 1000 s drops from 5.6 × 10-8 to 6.9 × 10-10. The performance equals that of an offset lock employing a second, atom-stabilized laser in the temperature control.

  18. Long-term performance of activated carbon air cathodes with different diffusion layer porosities in microbial fuel cells

    KAUST Repository

    Zhang, Fang

    2011-08-01

    Activated carbon (AC) air-cathodes are inexpensive and useful alternatives to Pt-catalyzed electrodes in microbial fuel cells (MFCs), but information is needed on their long-term stability for oxygen reduction. AC cathodes were constructed with diffusion layers (DLs) with two different porosities (30% and 70%) to evaluate the effects of increased oxygen transfer on power. The 70% DL cathode initially produced a maximum power density of 1214±123mW/m 2 (cathode projected surface area; 35±4W/m 3 based on liquid volume), but it decreased by 40% after 1 year to 734±18mW/m 2. The 30% DL cathode initially produced less power than the 70% DL cathode, but it only decreased by 22% after 1 year (from 1014±2mW/m 2 to 789±68mW/m 2). Electrochemical tests were used to examine the reasons for the degraded performance. Diffusion resistance in the cathode was found to be the primary component of the internal resistance, and it increased over time. Replacing the cathode after 1 year completely restored the original power densities. These results suggest that the degradation in cathode performance was due to clogging of the AC micropores. These findings show that AC is a cost-effective material for oxygen reduction that can still produce ~750mW/m 2 after 1 year. © 2011 Elsevier B.V.

  19. 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.

  20. Long-term stability of high-level waste forms

    International Nuclear Information System (INIS)

    The long-term stability of HLW forms is reviewed with regard to temperature, irradiation and aqueous corrosion in a geological environment. The paper focuses on borosilicate glasses, but the radiation stability results are compared with some HLW ceramics. Thermal stability: most nuclear waste glass compositions have been adjusted to ensure a low final crystallized fraction. The crystallization of highly active Pamela glass samples was similar to that of nonradioactive glass. Radiation stability: No adverse effect of irradiation damage was found in glasses doped with short-lived actinides: volume changes were small, no significant change in the leach rate was observed, and the fracture toughness increased. For most ceramics investigated, volume changes of up to 9%, amorphization and higher leach rates were observed as a consequence of high α decay doses. For the KAB 78 ceramic, however, none of these effects were detected since the matrix was not subject to α recoil damage. Chemical stability: It has been demonstrated that alteration by water depends largely on the repository conditions. Most clay act as silica sinks, and increase the glass corrosion rate. It is possible, however, to specify realistic temperature, pressure and environmental conditions to ensure glass integrity for more than 10 000 years

  1. Examining the long-term stability of overgeneral autobiographical memory.

    Science.gov (United States)

    Sumner, Jennifer A; Mineka, Susan; Zinbarg, Richard E; Craske, Michelle G; Vrshek-Schallhorn, Suzanne; Epstein, Alyssa

    2014-01-01

    Overgeneral autobiographical memory (OGM) is a proposed trait-marker for vulnerability to depression, but relatively little work has examined its long-term stability. This study investigated the stability of OGM over several years in 271 late adolescents and young adults participating in a larger longitudinal study of risk for emotional disorders. The Autobiographical Memory Test (AMT) was administered twice, with test-retest intervals ranging from approximately 3 to 6 years. There was evidence of significant but modest stability in OGM over several years. Specifically, Spearman rank correlations (ρs) between the proportions of specific and categoric memories generated on the two AMTs were .31 and .32, respectively. We did not find evidence that the stability of OGM was moderated by the length of the test-retest interval. Furthermore, the stability coefficients for OGM for individuals with and without a lifetime history of major depressive disorder (MDD) were relatively similar in magnitude and not significantly different from one another (ρs=.34 and .42 for the proportions of specific and categoric memories for those with a history of MDD; ρs=.31 for both the proportions of specific and categoric memories for those without a history of MDD). Implications for the conceptualisation of OGM are discussed. PMID:23439226

  2. Long-Term Stability of the NIST Conical Reference Transducer.

    Science.gov (United States)

    Fick, Steven E; Proctor, Thomas M

    2011-01-01

    The National Institute of Standards and Technology (NIST) Conical Reference Transducer (CRT) is designed for purposes requiring frequency response characteristics much more uniform than those attainable with ultrasonic transducers conventionally used for acoustic emission (AE) nondestructive testing. The high performance of the CRT results from the use of design elements radically different from those of conventional transducers. The CRT was offered for sale for 15 years (1985 to 2000). Each CRT was furnished with data which expressed, as a function of frequency, the transducer sensitivity in volts per micrometer of normal displacement on the test block. Of the 22 transducers constructed, eight were reserved for long term research and were stored undisturbed in a laboratory with well controlled temperature and humidity. In 2009, the sensitivities of these eight units were redetermined. The 2009 data have been compared with data from similar tests conducted in 1985. The results of this comparison verify the claim "Results of tests of the long term stability of CRT characteristics indicate that, if proper care is taken, tens of years of service can reasonably be expected." made in the CRT specifications document furnished to prospective customers. PMID:26989602

  3. 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

  4. 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...

  5. Effects of cathode electrolyte interfacial (CEI) layer on long term cycling of all-solid-state thin-film batteries

    Science.gov (United States)

    Wang, Ziying; Lee, Jungwoo Z.; Xin, Huolin L.; Han, Lili; Grillon, Nathanael; Guy-Bouyssou, Delphine; Bouyssou, Emilien; Proust, Marina; Meng, Ying Shirley

    2016-08-01

    All-solid-state lithium-ion batteries have the potential to not only push the current limits of energy density by utilizing Li metal, but also improve safety by avoiding flammable organic electrolyte. However, understanding the role of solid electrolyte - electrode interfaces will be critical to improve performance. In this study, we conducted long term cycling on commercially available lithium cobalt oxide (LCO)/lithium phosphorus oxynitride (LiPON)/lithium (Li) cells at elevated temperature to investigate the interfacial phenomena that lead to capacity decay. STEM-EELS analysis of samples revealed a previously unreported disordered layer between the LCO cathode and LiPON electrolyte. This electrochemically inactive layer grew in thickness leading to loss of capacity and increase of interfacial resistance when cycled at 80 °C. The stabilization of this layer through interfacial engineering is crucial to improve the long term performance of thin-film batteries especially under thermal stress.

  6. 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%

  7. 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

  8. Evaluation of long-term mechanical stability of near field

    International Nuclear Information System (INIS)

    In the near field, as tunnels and pits are excavated, a redistribution of stresses in the surrounding rock will occur. For a long period of time after the emplacement of waste packages various events will take place, such as the swelling of the buffer, sinking of the overpack under its own weight, deformation arising from expansion of overpack corrosion products and the creep deformation of the rock mass. The evaluation of what effects these changes in the stress-state will have on the buffer and rock mass is a major issue from the viewpoint of safety assessment. Therefore, rock creep analysis, overpack corrosion expansion analysis and overpack sinking analysis have been made in order to examine the long-term mechanical stability of the near field and the interaction of various events that may affect the stability of the near field over a long period of time. As the results, rock creep behavior, the variations of the stress-state and the range of the influence zone differ from the rock strength, strength of buffer in the tunnel and side pressure coefficient etc. about the hard rock system and soft rock system established as basic cases. And the magnitude of the stress variations for buffer by the overpack sinking and rock creep deformation is negligible compared with it by the overpack corrosion expansion. Furthermore, though very limited zone of buffer around the overpack is close to the critical state by the overpack corrosion expansion, the engineered barrier system attains a comparatively stable state for a long period of time. (author)

  9. Long-term stability of TES satellite radiance measurements

    Directory of Open Access Journals (Sweden)

    T. C. Connor

    2011-03-01

    Full Text Available The utilization of Tropospheric Emission Spectrometer (TES Level 2 (L2 retrieval products for the purpose of assessing long term changes in atmospheric trace gas composition requires knowledge of the overall radiometric stability of the Level 1B (L1B radiances. The purpose of this study is to evaluate the stability of the radiometric calibration of the TES instrument by analyzing the difference between measured and calculated brightness temperatures in selected window regions of the spectrum. The Global Modeling and Assimilation Office (GMAO profiles for temperature and water vapor and the Real-Time Global Sea Surface Temperature (RTGSST are used as input to the Optimal Spectral Sampling (OSS radiative transfer model to calculate the simulated spectra. The TES reference measurements selected cover a 4-year period of time from mid 2005 through mid 2009 with the selection criteria being; observation latitudes greater than −30° and less than 30°, over ocean, Global Survey mode (nadir view and retrieved cloud optical depth of less than 0.01. The TES cloud optical depth retrievals are used only for screening purposes and no effects of clouds on the radiances are included in the forward model. This initial screening results in over 55 000 potential reference spectra spanning the four year period. Presented is a trend analysis of the time series of the residuals (observation minus calculations in the TES 2B1, 1B2, 2A1, and 1A1 bands which demonstrates that the trend in the residuals is not significantly different from zero over the 4-year period. This is one method used to demonstrate that the relative radiometric calibration is stable over time, which is very important for any longer term analysis of TES retrieved products (L2 particularly well-mixed species such as carbon dioxide and methane.

  10. Long-term stability of TES satellite radiance measurements

    Directory of Open Access Journals (Sweden)

    T. C. Connor

    2011-07-01

    Full Text Available The utilization of Tropospheric Emission Spectrometer (TES Level 2 (L2 retrieval products for the purpose of assessing long term changes in atmospheric trace gas composition requires knowledge of the overall radiometric stability of the Level 1B (L1B radiances. The purpose of this study is to evaluate the stability of the radiometric calibration of the TES instrument by analyzing the difference between measured and calculated brightness temperatures in selected window regions of the spectrum. The Global Modeling and Assimilation Office (GMAO profiles for temperature and water vapor and the Real-Time Global Sea Surface Temperature (RTGSST are used as input to the Optimal Spectral Sampling (OSS radiative transfer model to calculate the simulated spectra. The TES reference measurements selected cover a 4-year period of time from mid 2005 through mid 2009 with the selection criteria being; observation latitudes greater than −30° and less than 30°, over ocean, Global Survey mode (nadir view and retrieved cloud optical depth of less than or equal to 0.01. The TES cloud optical depth retrievals are used only for screening purposes and no effects of clouds on the radiances are included in the forward model. This initial screening results in over 55 000 potential reference spectra spanning the four year period. Presented is a trend analysis of the time series of the residuals (observation minus calculations in the TES 2B1, 1B2, 2A1, and 1A1 bands, with the standard deviation of the residuals being approximately equal to 0.6 K for bands 2B1, 1B2, 2A1, and 0.9 K for band 1A1. The analysis demonstrates that the trend in the residuals is not significantly different from zero over the 4-year period. This is one method used to demonstrate that the relative radiometric calibration is stable over time, which is very important for any longer term analysis of TES retrieved products (L2, particularly well-mixed species such as carbon dioxide and methane.

  11. Influence of (La,Sr)MnO3+δ cathode composition on cathode/electrolyte interfacial structure during long-term operation of solid oxide fuel cells

    Science.gov (United States)

    Matsui, Toshiaki; Mikami, Yuichi; Muroyama, Hiroki; Eguchi, Koichi

    2013-11-01

    Time-dependent events during operation of SOFCs, i.e., performance enhancement and/or deterioration, can be readily observed for the cell composed of strontium-doped lanthanum manganite (LSM) cathode and yttria-stabilized zirconia (YSZ) electrolyte, concomitant with the change in interfacial structure of LSM/YSZ. The influence of LSM composition on the electrochemical properties and microstructure of LSM/YSZ interface during prolonged operation was investigated. Four different LSM cathodes were used and the change in microstructure, especially TPB-length, was evaluated quantitatively by a focused ion beam-scanning electron microscope (FIB-SEM). For LSM cathodes with A-site deficient compositions, the change in TPB-length had a minor contribution to the performance enhancement after 20 h of galvanostatic operation. On the other hand, for 100 h duration an increase in cathode overpotential was confirmed, accompanied with the formation of thin layer of LSM over YSZ electrolyte. A series of phenomena were triggered by the change in oxygen nonstoichiometry of LSM under polarized states. The mechanism for microstructural change was proposed and the long-term stability of LSM/YSZ interface was discussed.

  12. Long-term Stability of 9- to 12 % Cr Steels

    DEFF Research Database (Denmark)

    Hald, John

    2004-01-01

    In the recent 25 years creep rupture strength of 9- to 12 %Cr steels for steam pipes and turbines has been doubled by development of new alloys. This development has formed a basis for improved efficiency of fossil fired steam power plants by introduction of advanced steam temperatures and...... pressures. Newly developed steam pipe steels are based on modifications of well-established steels like the X 20CrMoV12 1. Balanced addition of V, Nb and N to a 9Cr 1 Mo steel led to the Modified 9 Cr steel P 91. Addition of 1% W to a 9Cr 1 MoVNbN base composition led to steel E 911 and partial replacement...... of Mo with 1.8 % W combined with a slight amount of Boron led to steel P 92. The creep rupture strength of these new alloys are now secured with long-term tests up to 100,000 hours, which demonstrate improvements of 50% (P 91), 75 % (E 911) and 100 % (P 92) in strength compared to X 20CrMoV12 1....

  13. The long-term stability of cement - Leaching tests

    International Nuclear Information System (INIS)

    The concrete construction in the Swedish repository for long-lived low and intermediate level waste will give a stable chemical near field environment for 105 years. The pH is expected to exceed 12 for the life time for most of the radionuclides in the repository in both saline and non-saline groundwaters. This is shown by static leaching experiments performed in saline and non-saline granitic groundwater conditions. Five gram portions of crushed ordinary Portland cement paste were equilibrated with 20 ml of synthetic saline or non-saline groundwater in a nitrogen atmosphere. Each week 12 ml (60%) of the water was replaced. The withdrawn water was used for chemical analyses and the results were used to monitor the degradation of the cement paste. After eighty weeks, some samples were analysed for mineral composition and compared with the original unleached paste. The results indicated no secondary ettringite or calcite formation. The results also supported the conclusion that the salinity of the contacting water is of minor importance for the long-term performance of the cement paste. 18 refs, 32 figs

  14. The long-term stability of natural bitumen

    International Nuclear Information System (INIS)

    Natural bitumen can be an aid in the assessment of the long-term behaviour of technical bitumen. Natural occurrences of bitumen usually have the drawback that the original material before alteration or degration began is not known. The present work applies an alternative approach: on the basis of the geology and stratigraphy at a site where bitumen samples have been taken, the existence of a gradient in the parameters of subaerial and microbial degradation processes may be assumed. Therefore relative variation in properties, composition and structure (bitumen content, volative fraction, elemental composition, chromatographic fractions, saturated hydrocarbons, trace metals, humic substances) at different locations within the deposit have been analysed. The bitumen impregnates a bed of porous Jurassic limestone which crops out at the surface and dips under sediments of various permeability. The quality of the bitumen is in compliance with standards for soft technical bitumen, although it can be characterized as highly biodegraded. It has probably not been affected to any marked degree by degradation since the Quarternary or possibly even late Tertiary, however, as observable variations in composition and properties are only minor and seem to exhibit no clear relation to the present geological setting. Only near the present outcrop do there seem to be signs of increased oxidation. Direct exposure to the weather at the surface leads to destruction of the bitumen within a very thin surface layer. Traces of humic substances probably originating from the decomposition of bitumen were found. The rate of bitumen degradation at outcrops seems to coincide with the rate of weathering and erosion of the host rock. It can be concluded from the results that the time scales necessary to achieve significant alteration of bitumen under the given conditions far exceed the time scales dictated by the half-lives of radionuclides in low- and medium-level radioactive waste

  15. 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.

  16. Long-Term Stability of Radio Sources in VLBI Analysis

    Science.gov (United States)

    Engelhardt, Gerald; Thorandt, Volkmar

    2010-01-01

    Positional stability of radio sources is an important requirement for modeling of only one source position for the complete length of VLBI data of presently more than 20 years. The stability of radio sources can be verified by analyzing time series of radio source coordinates. One approach is a statistical test for normal distribution of residuals to the weighted mean for each radio source component of the time series. Systematic phenomena in the time series can thus be detected. Nevertheless, an inspection of rate estimation and weighted root-mean-square (WRMS) variations about the mean is also necessary. On the basis of the time series computed by the BKG group in the frame of the ICRF2 working group, 226 stable radio sources with an axis stability of 10 as could be identified. They include 100 ICRF2 axes-defining sources which are determined independently of the method applied in the ICRF2 working group. 29 stable radio sources with a source structure index of less than 3.0 can also be used to increase the number of 295 ICRF2 defining sources.

  17. Long-term stability of Cu surface nanotips

    Science.gov (United States)

    Jansson, V.; Baibuz, E.; Djurabekova, F.

    2016-07-01

    Sharp nanoscale tips on the metal surfaces of electrodes enhance locally applied electric fields. Strongly enhanced electric fields trigger electron field emission and atom evaporation from the apexes of nanotips. Together, these processes may explain electric discharges in the form of small local arcs observed near metal surfaces in the presence of electric fields, even in ultra-high vacuum conditions. In the present work, we investigate the stability of nanoscale tips by means of computer simulations of surface diffusion processes on copper, the main material used in high-voltage electronics. We study the stability and lifetime of thin copper (Cu) surface nanotips at different temperatures in terms of diffusion processes. For this purpose we have developed a surface kinetic Monte Carlo (KMC) model where the jump processes are described by tabulated precalculated energy barriers. We show that tall surface features with high aspect ratios can be fairly stable at room temperature. However, the stability was found to depend strongly on the temperature: 13 nm nanotips with the major axes in the crystallographic directions were found to flatten down to half of the original height in less than 100 ns at temperatures close to the melting point, whereas no significant change in the height of these nanotips was observed after 10 {{μ }}{{s}} at room temperature. Moreover, the nanotips built up along the crystallographic directions were found to be significantly more stable than those oriented in the or crystallographic directions. The proposed KMC model has been found to be well-suited for simulating atomic surface processes and was validated against molecular dynamics simulation results via the comparison of the flattening times obtained by both methods. We also note that the KMC simulations were two orders of magnitude computationally faster than the corresponding molecular dynamics calculations.

  18. Long-term Stability of Planets in the Centauri System

    Science.gov (United States)

    Quarles, B.; Lissauer, Jack J.

    2016-05-01

    We evaluate the extent of the regions within the α Centauri AB star system where small planets are able to orbit for billion-year timescales, and we calculate the positions on the sky plane where planets on stable orbits about either stellar component may appear. We confirm the qualitative results of Wiegert and Holman (AJ 113, 1445, 1997) regarding the approximate size of the regions of stable orbits, which are larger for retrograde orbits relative to the binary than for prograde orbits. Additionally, we find that mean motion resonances with the binary orbit leave an imprint on the limits of orbital stability, and the effects of the Lidov-Kozai mechanism are also readily apparent.

  19. Long-term cathode performance and the microbial communities that develop in microbial fuel cells fed different fermentation endproducts

    KAUST Repository

    Kiely, Patrick D.

    2011-01-01

    To better understand how cathode performance and substrates affected communities that evolved in these reactors over long periods of time, microbial fuel cells were operated for more than 1year with individual endproducts of lignocellulose fermentation (acetic acid, formic acid, lactic acid, succinic acid, or ethanol). Large variations in reactor performance were primarily due to the specific substrates, with power densities ranging from 835±21 to 62±1mW/m3. Cathodes performance degraded over time, as shown by an increase in power of up to 26% when the cathode biofilm was removed, and 118% using new cathodes. Communities that developed on the anodes included exoelectrogenic families, such as Rhodobacteraceae, Geobacteraceae, and Peptococcaceae, with the Deltaproteobacteria dominating most reactors. Pelobacter propionicus was the predominant member in reactors fed acetic acid, and it was abundant in several other MFCs. These results provide valuable insights into the effects of long-term MFC operation on reactor performance. © 2010 Elsevier Ltd.

  20. Observation of the long term stability of water stations in the Pierre Auger surface detector

    Energy Technology Data Exchange (ETDEWEB)

    Allekotte, I.; Arisaka, K.; Barnhill, D.; Bertou, Xavier; Bonifazi, C.; Healy, M.D.; Lee, J.; Medina, C.; Ohnuki, T.; Tripathi, A.

    2005-07-01

    The results of a study examining the long-term behavior of Pierre Auger surface detectors is presented. The station properties, such as water quality, liner reflectivity and the water level must be continuously monitored. Such monitoring provides information on the long-term stability of the detectors, which have been designed to operate for twenty years. Using pulse height and shapes of cosmic ray muons, water quality changes are monitored and a technique developed to identify and monitor long-term trends in the array.

  1. Long-term stability of maxillary anterior alignment in non-extraction cases

    OpenAIRE

    Luiz Filiphe Gonçalves Canuto; Marcos Roberto de Freitas; Karina Maria Salvatore de Freitas; Rodrigo Hermont Cançado; Leniana Santos Neves

    2013-01-01

    OBJECTIVE: The purpose of this retrospective study was to evaluate long-term stability of maxillary incisors alignment in cases submitted to non-extraction orthodontic treatment. METHODS: The sample comprised 23 patients (13 female; 10 male) at a mean initial age of 13.36 years (SD = 1.81 years), treated with fixed appliances. Dental cast measurements were obtained at three different time points (T1 - pretreatment, T2 - posttreatment and T3 - long-term posttreatment). Variables assessed in ma...

  2. Evaluation of short-term and long-term stability of emulsions by centrifugation and NMR

    International Nuclear Information System (INIS)

    The effect of storage time on the coalescence stability and drop size distribution of egg yolk and whey protein concentrate stabilized emulsions is studied. The emulsion stability is evaluated by centrifugation, whereas the drop size distribution is measured by means of NMR and optical microscopy. The experimental results show that there is no general relation between the emulsion stability and the changes in the mean drop diameter upon shelf-storage of protein emulsions. On the other hand, it is shown that the higher short-term stability, measured by centrifugation immediately after emulsion preparation, corresponds to higher long-term stability (after their self-storage up to 60 days) for emulsions stabilized by the same type of emulsifier. In this way, we are able to obtain information for the long-term stability of emulsions in a relatively short period of time.(authors)

  3. LONG-TERM STABILITY OF FOOD PATTERNS IDENTIFIED BY USE OF FACTOR ANALYSIS AMONG SWEDISH WOMEN

    Science.gov (United States)

    Limited data exist on the reproducibility of food patterns measured using factor analysis, as well as the stability of patterns over time. Our primary objective was to explore the long-term stability of food patterns derived using confirmatory factor analysis among 33,840 women participating in the...

  4. Analysis of long-term performance and microbial community structure in bio-cathode microbial desalination cells.

    Science.gov (United States)

    Zhang, Huichao; Wen, Qinxue; An, Zhongyi; Chen, Zhiqiang; Nan, Jun

    2016-03-01

    A microbial desalination cell (MDC) could desalinate salt water without energy consumption and simultaneously generate bioenergy. Compared with an abiotic cathode MDC, an aerobic bio-cathode MDC is more sustainable and is less expensive to operate. In this study, the long-term operation (5500 h) performance of a bio-cathode MDC was investigated in which the power density, Coulombic efficiency, and salt removal rate were decreased by 71, 44, and 27 %, respectively. The primary reason for the system performance decrease was biofouling on the membranes, which increased internal resistance and reduced the ionic transfer and energy conversion efficiency. Changing membranes was an effective method to recover the MDC performance. The microbial community diversity in the MDC anode was low compared with that of the reported microbial fuel cell (MFC), while the abundance of Proteobacteria was 30 % higher. The content of Planctomycetes in the cathode biofilm sample was much higher than that in biofouling on the cation exchange membrane (CEM), indicating that Planctomycetes were relevant to cathode oxygen reduction. PMID:26596826

  5. Long-Term Performance of Chemically and Physically Modified Activated Carbons in Air Cathodes of Microbial Fuel Cells

    KAUST Repository

    Zhang, Xiaoyuan

    2014-07-31

    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Activated carbon (AC) is a low-cost and effective catalyst for oxygen reduction in air cathodes of microbial fuel cells (MFCs), but its performance must be maintained over time. AC was modified by three methods: 1)pyrolysis with iron ethylenediaminetetraacetic acid (AC-Fe), 2)heat treatment (AC-heat), and 3)mixing with carbon black (AC-CB). The maximum power densities after one month with these AC cathodes were 35% higher with AC-Fe (1410±50mW m-2) and AC-heat (1400±20mW m-2), and 16% higher with AC-CB (1210±30mW m-2) than for plain AC (1040±20mW m-2), versus 1270±50mW m-2 for a Pt control. After 16months, the Pt cathodes produced only 250±10mW m-2. However, the AC-heat and AC-CB cathodes still produced 960-970mW m-2, whereas plain AC produced 860±60mW m-2. The performance of the AC cathodes was restored to >85% of the initial maximum power densities by cleaning with a weak acid solution. Based on cost considerations among the AC materials, AC-CB appears to be the best choice for long-term performance.

  6. Decomposition analysis of CO2 emission in long-term climate stabilization scenarios

    International Nuclear Information System (INIS)

    To achieve the stabilization of greenhouse gas (GHG) concentrations in the atmosphere, the international community will need to intensify its long-term efforts. Many EU countries have released national long-term scenarios toward 2050, and their ambitious targets for CO2 emission reduction are aiming at a decrease of more than 50% of today's emission. In April 2004, Japan began a research project on its long-term climate policy. This paper discusses the long-term scenarios in other countries and the medium-term scenarios in Japan to support the development of a Japan's long-term climate stabilization scenario. In this study, CO2 emission is decomposed with an extended Kaya identity (indexes: CO2 capture and storage, carbon intensity, energy efficiency, energy intensity, economic activity) and a Reduction Balance Table is developed. In order to achieve the ambitious target of a 60-80% reduction, the pace of aggregated energy intensity improvement and carbon intensity decrease must be 2-3 times greater than the previous 40-year historical change, and the change rates need to be maintained for 50 years

  7. Long-Term Stability of an Area-Reversible Atom-Interferometer Sagnac Gyroscope

    Science.gov (United States)

    Durfee, D. S.; Shaham, Y. K.; Kasevich, M. A.

    2006-12-01

    We report the first demonstration of a matter-wave interference gyroscope that meets both the short-term noise and long-term stability requirements for high accuracy navigation. This performance level resulted from implementation of a novel technique to precisely reverse the input axis of the gyroscope.

  8. Long-Term Stability by Lipid Coating Monodisperse Microbubbles Formed by a Flow-Focusing Device

    OpenAIRE

    Talu, Esra; Lozano, Monica M.; Powell, Robert L.; Dayton, Paul A.; Longo, Marjorie L.

    2006-01-01

    In this letter, the long-term stabilization of monodisperse microbubbles produced by flow focusing is demonstrated using lipid encapsulation. Fluorescence microscopy, high-speed camera imaging, and particle size analysis were used to investigate the roles of lipid phase behavior, dissolution, Ostwald ripening, and coalescence in the stability of microbubbles formed by flow focusing. It was found that these behaviors were controlled through compositional changes with respect to lipid, emulsifi...

  9. Long-term orbital stability of exosolar planetary systems with highly eccentric orbits

    CERN Document Server

    Antoniadou, Kyriaki I

    2016-01-01

    Nowadays, many extrasolar planetary systems possessing at least one planet on a highly eccentric orbit have been discovered. In this work, we study the possible long-term stability of such systems. We consider the general three body problem as our model. Highly eccentric orbits are out of the Hill stability regions. However, mean motion resonances can provide phase protection and orbits with long-term stability exist. We construct maps of dynamical stability based on the computation of chaotic indicators and we figure out regions in phase space, where the long-term stability is guaranteed. We focus on regions where at least one planet is highly eccentric and attempt to associate them with the existence of stable periodic orbits. The values of the orbital elements, which are derived from observational data, are often given with very large deviations. Generally, phase space regions of high eccentricities are narrow and thus, our dynamical analysis may restrict considerably the valid domain of the system's locat...

  10. Improvement of the long term stability in the high temperature solid oxide fuel cell using functional layers

    Energy Technology Data Exchange (ETDEWEB)

    Brueckner, B.; Guenther, C.; Ruckdaeschel, R. [Siemens AG, Erlangen (Germany)] [and others

    1996-12-31

    In the planar Siemens design of the solid oxide fuel cell a metallic interconnector is used to seperate the ceramic single cells. A disadvantage of the metallic bipolar plate which consists of a chromium alloy is the formation of high volatile Cr-oxides and hydroxides at the surface at the cathode side. The reaction products evaporate and are reduced at the cathode/electrolyte interface to form new crystalline phases. This process gives rise to long term cell degradation. Protective coatings might be successful in preventing the chromium oxide evaporation. The required properties of the protective layers are (I) high electrical conductivity, (II) similar coefficients of thermal expansion to the bipolar plate (III), chemical compatibility to the bipolar plate and cathode material, (IV) a low diffusion coefficient of Cr and (V) chemical stability up to 1223K under oxygen atmosphere. Furthermore, during operation at 1223K an electrical contact between the metallic plate and the electrodes has to be maintained. This problem could be solved using ceramic layer between the metallic plate and the single cells.

  11. Feed-back from long - term experience with offshore cathodic protection

    Energy Technology Data Exchange (ETDEWEB)

    Brazy, Jean-Louis; Tobiassen, Per [Total S.A., EP Technology Division, CSTJF, Avenue Larribeau, 64000 Pau (France); Roche, Marcel [Total S.A., EP Technology Division, Tour Michelet, 92069 Paris - La Defense (France)

    2004-07-01

    The experience of the Total Group has been compiled in matters of Cathodic Protection (CP) of offshore structures in order to draw conclusions from the cumulated field experience obtained for 40 years in various geographical areas (e.g. North Sea and Gulf of Guinea). More especially, results of monitoring have been used to evaluate the performance in the achieved potentials measured with in-situ reference electrodes together with anode current outputs measured from 'monitored galvanic anodes'. Some 'monitored cathodes' have also been installed giving interesting results on the evolution with time of cathodic current density consumed by steel in seawater. After some initial difficulties due to not adapted designs or low-quality galvanic anodes, CP has been achieved in very good conditions, preventing corrosion and fatigue corrosion failures. Protective potentials have been ensured with much lower current densities than values taken in calculations. It has been demonstrated that anodes have to be sized in such a way that initial output is high enough to ensure a rapid polarization. Current outputs necessary to maintain protection are then much lower, including in geographical areas where protective current density is considered as high. Consequently, residual lifetime of anodes systems is generally much higher than initially foreseen, which often allows interesting prolongation of the platform life when needed. In a few cases, it has been possible to evaluate very precisely any trace of corrosion on the structure and consumption rate and pattern of galvanic anodes when platforms have been removed after their use. The case of the Frcy platform, dismantled after 8 years of operation in the Norwegian sector of North Sea is exposed. It has been possible to check that consumption of anodes has been maximum at the locations foreseen by the modeling. (authors)

  12. Long-term stability investigation of o/w cosmetic creams stabilized by mixed emulsifier

    Directory of Open Access Journals (Sweden)

    Đekić Ljiljana M.

    2012-01-01

    Full Text Available Polyglyceryl-3 Methylglucose Distearate (PMD, TEGO® Care 450, Evonik, Germanyis natural (vegetable, non-ionic, PEG-free emulsifier, suitable for the formulation of oil-in-water (o/w cosmetic creams and lotions. The oil phase components can be selected from mineral oils, vegetable oils and synthetic esters, which enable different variety of application profile of these emulsions. It is possible to prepare stable emulsions using low-level concentration of the PMD (2-3% if lotions contain 10-25%, and creams 20-40 % of oil phase. PMD forms liquid crystal structure in the presence of stearic acid, glyceryl stearate, fatty alcohols, or their combinations. The o/w type creams, stabilized by these mixed emulsifiers are complex, multiphase systems. The aim of this work was to formulate, prepare and investigate long-term stability of the o/w creams stabilized by mixed emulsifier polyglyceryl-3 methylglucose distearate/glyceryl stearate/stearyl alcohol, depending on concentration levels of PMD (2% or 3% and oil:water phase ratio (20:80 and 30:70. The samples were prepared using hot/hot procedure. Organoleptic inspection, centrifugation test, rheological measurements, electric conductivity and pH value measurements were performed 72 h, 1, 3, 12 and 30 months after preparation. The prepared samples were apparently white and homogenous creams. The consistency and homogeneity were preserved after centrifugation of the creams after 72 h, 1, 3, 12 and 30 months storage, and no phase separation could be detected. The pH values obtained are suitable for skin application. Conductivity values (25.2-63.7 μS cm1, 72 h after preparation were attributed to the multiple phase o/w emulsions with high percentages of fixed water. Results of the rheological measurements have shown that the investigated creams exhibited non-Newtonian thyxotropic behavior. The concentration of emulsifier PMD and oil phase content had an influence on the rheological parameters of investigated

  13. Long-term stability performance testing of amorphous silicon modules under natural sunlight

    International Nuclear Information System (INIS)

    A major task of the PV Module Testing and Performance Group at SERI is to develop and coordinate the implementation of standard test procedures and instrumentation for monitoring and analyzing PV submodules and modules for determining the outdoor performance, stability, reliability, and energy output of thin-film PV devices. Through outdoor testing, researchers can identify performance issues that will require further laboratory investigation in support of flat-plate, thin-film collector research and development. To accomplish this, the SERI outdoor PV test facility was established in 1982 in Golden, Colorado. The group has designed testing systems and analysis procedures for numerous thin-film modules and submodules, and has tested them both indoors (under simulator) and outdoors. Long-term outdoor stability tests have been conducted specifically on amorphous silicon thin-film submodules and modules. Cooperative test programs have been established with private US amorphous silicon PV module manufacturers and SERI amorphous silicon subcontractors for short- and long-term outdoor stability and performance testing of submodules, prototype modules, and commercially available modules at SERI's outdoor test facility. Selected test results based on long-term stability performance testing over the past two years are presented

  14. Long-Term Stability of an Area-Reversible Atom-Interferometer Sagnac Gyroscope

    CERN Document Server

    Durfee, D S; Shaham, Y K

    2005-01-01

    We report on a study of the long-term stability and absolute accuracy of an atom interferometer gyroscope. This study included the implementation of an electro-optical technique to reverse the vector area of the interferometer for reduced systematics and a careful study of systematic phase shifts. Our data strongly suggests that drifts less than 96 $\\mu$deg/hr are possible after empirically removing shifts due to measured changes in temperature, laser intensity, and several other experimental parameters.

  15. Long-term stability of maxillary anterior alignment in non-extraction cases

    Directory of Open Access Journals (Sweden)

    Luiz Filiphe Gonçalves Canuto

    2013-06-01

    Full Text Available OBJECTIVE: The purpose of this retrospective study was to evaluate long-term stability of maxillary incisors alignment in cases submitted to non-extraction orthodontic treatment. METHODS: The sample comprised 23 patients (13 female; 10 male at a mean initial age of 13.36 years (SD = 1.81 years, treated with fixed appliances. Dental cast measurements were obtained at three different time points (T1 - pretreatment, T2 - posttreatment and T3 - long-term posttreatment. Variables assessed in maxillary arch were Little Irregularity Index, intercanine, interpremolar and intermolar widths, arch length and perimeter. The statistical analysis was performed by one-way ANOVA and Tukey tests when necessary. Pearson' correlation coefficients were used to investigate possible associations between the evaluated variables. RESULTS: There was no significant change in most arch dimension measurements during and after treatment, however, during the long-term posttreatment period, it was observed a significant maxillary incisors crowding relapse. CONCLUSION: The maxillary incisors irregularity increased significantly (1.52 mm during long-term posttreatment. None of the studied clinical factors demonstrated to be predictive of the maxillary crowding relapse.

  16. Long term stability and dynamical environment of the PSR 1257+12 planetary system

    CERN Document Server

    Gozdziewski, K; Wolszczan, A; Gozdziewski, Krzysztof; Konacki, Maciej; Wolszczan, Alex

    2003-01-01

    We study the long-term dynamics of the PSR 1257+12 planetary system. Using the recently determined accurate initial condition by Konacki & Wolszczan (2003) who derived the orbital inclinations and the absolute masses of the planets, we investigate the system stability by long-term, 1Gyr direct integrations. No secular changes of the semi-major axes, eccentricities and inclinations appear during such an interval. This stable behavior is confirmed with the fast indicator MEGNO. Another feature confirming the long term stability is a negligible exchange of the Angular Momentum Deficit between the innermost planet A and the pair of the outer planets B and C. An important factor for maintaining the stability is also the presence of the secular apsidal resonance (SAR) between the planets B and C with the center of libration about 180deg. We perform a preliminary study of the short-term dynamics of massless particles in the system. It uncovers a relatively extended stable zone between the planets A and B. Beyond...

  17. Standard practice for digital detector array performance evaluation and long-term stability

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice describes the evaluation of DDA systems for industrial radiology. It is intended to ensure that the evaluation of image quality, as far as this is influenced by the DDA system, meets the needs of users, and their customers, and enables process control and long term stability of the DDA system. 1.2 This practice specifies the fundamental parameters of Digital Detector Array (DDA) systems to be measured to determine baseline performance, and to track the long term stability of the DDA system. 1.3 The DDA system performance tests specified in this practice shall be completed upon acceptance of the system from the manufacturer and at intervals specified in this practice to monitor long term stability of the system. The intent of these tests is to monitor the system performance for degradation and to identify when an action needs to be taken when the system degrades by a certain level. 1.4 The use of the gages provided in this standard is mandatory for each test. In the event these tests or ga...

  18. Long-term change and stability in the California Current System: lessons from CalCOFI and other long-term data sets

    Science.gov (United States)

    Rebstock, Ginger A.

    2003-08-01

    The California Current System (CCS) is a highly variable system, both spatially and temporally, that is strongly affected by low-frequency climatic fluctuations. This paper reviews evidence for long-term (decadal-scale) change in the physics and biology of the CCS over the last 50-100 years, as well as evidence for stability in planktonic community structure and long-term persistence of populations. Increases in water temperature, thermocline depth and stratification in the CCS have been accompanied by changes in populations of kelp, diatoms, foraminifera, radiolarians, intertidal invertebrates, zooplankton, fish and seabirds. However, there is also evidence for stability in assemblages of larval fish, calanoid copepods and radiolarians. Statistical averaging (the portfolio effect) may explain some aspects of stability in assemblages. Advection of planktonic populations may account for rapid recovery of biomass and dominance structure following perturbations such as strong El Niño events. Planktonic populations in the CCS may be adapted to large-scale biotic and abiotic variability, through a combination of advection of populations and life history traits. Several lessons may be learned from the California Cooperative Oceanic Fisheries Investigations and other long-term data sets: (1) long time series are needed to understand the dynamics of the ecosystem; (2) life histories are important determinants of species responses to environmental forcing, even in the plankton; and (3) the CCS is simultaneously variable and stable, and these properties are not necessarily in conflict.

  19. Long-term stability analysis of the left bank abutment slope at Jinping I hydropower station

    Institute of Scientific and Technical Information of China (English)

    Long Zhang; Qiang Yang; Yaoru Liu

    2016-01-01

    The time-dependent behavior of the left bank abutment slope at Jinping I hydropower station has a major influence on the normal operation and long-term safety of the hydropower station. To solve this problem, a geomechanical model containing various faults and weak structural planes is established, and numerical simulation is conducted under normal water load condition using FLAC3D, incorporating creep model proposed based on thermodynamics with internal state variables theory. The creep deformations of the left bank abutment slope are obtained, and the changes of principal stresses and deformations of the dam body are analyzed. The long-term stability of the left bank abutment slope is evaluated ac-cording to the integral curves of energy dissipation rate in domain and its derivative with respect to time, and the non-equilibrium evolution rules and the characteristic time can also be determined using these curves. Numerical results show that the left bank abutment slope tends to be stable in a global sense, and the stress concentration is released. It is also indicated that more attention should be paid to some weak regions within the slope in the long-term deformation process.

  20. Long-Term Stability of Residual Stress Improvement by Water Jet Peening Considering Working Processes.

    Science.gov (United States)

    Hashimoto, Tadafumi; Osawa, Yusuke; Itoh, Shinsuke; Mochizuki, Masahito; Nishimoto, Kazutoshi

    2013-06-01

    To prevent primary water stress corrosion cracking (PWSCC), water jet peening (WJP) has been used on the welds of Ni-based alloys in pressurized water reactors (PWRs). Before WJP, the welds are machined and buffed in order to conduct a penetrant test (PT) to verify the weld qualities to access, and microstructure evolution takes place in the target area due to the severe plastic deformation. The compressive residual stresses induced by WJP might be unstable under elevated temperatures because of the high dislocation density in the compressive stress layer. Therefore, the stability of the compressive residual stresses caused by WJP was investigated during long-term operation by considering the microstructure evolution due to the working processes. The following conclusions were made: The compressive residual stresses were slightly relaxed in the surface layers of the thermally aged specimens. There were no differences in the magnitude of the relaxation based on temperature or time. The compressive residual stresses induced by WJP were confirmed to remain stable under elevated temperatures. The stress relaxation at the surface followed the Johnson-Mehl equation, which states that stress relaxation can occur due to the recovery of severe plastic strain, since the estimated activation energy agrees very well with the self-diffusion energy for Ni. By utilizing the additivity rule, it was indicated that stress relaxation due to recovery is completed during the startup process. It was proposed that the long-term stability of WJP under elevated temperatures must be assessed based on compressive stresses with respect to the yield stress. Thermal elastic-plastic creep analysis was performed to predict the effect of creep strain. After 100 yr of simulated continuous operation at 80% capacity, there was little change in the WJP compressive stresses under an actual operating temperature of 623 K. Therefore, the long-term stability of WJP during actual operation was

  1. Gas Generation Rates as an Indicator for the Long Term Stability of Radioactive Waste Products

    International Nuclear Information System (INIS)

    Pursuant to the 'Act on the Peaceful Utilization of Atomic Energy and the Protection against its Hazards' (Atomic Energy Act) the Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz, BfS) is legally responsible for the construction and operation of federal facilities for the disposal of radioactive waste. Within the scope of this responsibility, particular due to par. 74(1) Ordinance on Radiation Protection, BfS defines all safety-related requirements on waste packages envisaged for disposal, establishes guidelines for the conditioning of radioactive waste and approves the fulfillment of the waste acceptance requirements within the radioactive waste quality control system. BfS also provides criteria to enable the assessment of methods for the treatment and packaging of radioactive waste to produce waste packages suitable for disposal according to par. 74(2) Ordinance on Radiation Protection. Due to the present non-availability of a repository in Germany, quality control measures for all types of radioactive waste products are carried out prior to interim storage with respect to the future disposal. As a result BfS approves the demonstrated properties of the radioactive waste packages and confirms the fulfillment of the respective requirements. After several years of storage the properties of waste packages might have changed. By proving, that such changes have no significant impact on the quality of the waste product, the effort of requalification could be minimized. Therefore, data on the long-term behavior of radioactive waste products need to be acquired and indicators to prove the long-term stability have to be quantified. Preferably, such indicators can be determined easily with non-destructive methods, even for legacy waste packages. A promising parameter is the gas generation rate. The relationship between gas generation rate and long term stability is presented as first result of an ongoing study on behalf of BfS. Permissible gas

  2. Annual report for research on long-term stability of geological environments in FY2008

    International Nuclear Information System (INIS)

    The Japanese islands are located in the Circum-Pacific Mobile Belt. As a result, Japan has a high frequency of earthquakes and eruptions. The concept of geological disposal of HLW in Japan is based on a multi-barrier system which combines stable geological environments with an engineered barrier system. Therefore, special consideration is given to the long-term stability of the geological environments, taking into account volcanism, faulting, uplift, denudation, climatic change and sea-level change in Japan. Development of investigation technologies for geotectonic events has been carried out to evaluate the long-term stability of the geological environments in Japan. In fiscal year 2008, we carried out the following researches, to investigate existence of the phenomena that have influences on the geological disposal system, and to develop the investigation techniques to reconstruct the history of these phenomena. For studies on faulting and seismic activity, we developed investigation techniques for evolutional history and activity of fault, and carried out case studies for development of effective assessment model in the fault zones. For volcanological and geothermal studies, we provided an integrated approach for detecting crustal magma and/or geothermal fluid in deep underground using geophysical and geochemical data. For studies on uplift/denudation and climatic/sea-level change, we arranged investigation techniques for reconstruction of paleo-topography and paleo-climate, and to establish a simulation model for landform development. For the general evaluation study on the long-term stability of the geological environments, we developed simulation techniques for groundwater flow related by crustal movement. (author)

  3. Long Term Stability Evaluation of Prostacyclin Released from Biomedical Device Through Turbiscan Lab Expert

    Science.gov (United States)

    Celia, Christian; Locatelli, Marcello; Cilurzo, Felisa; Cosco, Donato; Gentile, Emanuela; Scalise, Daniela; Carafa, Maria; Ventura, Cinzia Anna; Fleury, Mathias; Tisserand, Christelle; Barbacane, Renato C.; Fresta, Massimo; Marzio, Luisa Di; Paolino, Donatella

    2015-01-01

    Therapeutic guidelines indicate prostacyclin as the first line of treatment in inflammation and vascular diseases. Prostacyclins prevent formation of the platelet plug involved in primary hemostasis by inhibiting platelet activation and, combined with thromboxane, are effective vasodilators in vascular damage. Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease II guidelines indicates prostacyclins; in particular, Iloprost, as the first therapeutic option for treating peripheral arterial disease. However, therapeutic efficacy of Iloprost has witnessed several drawbacks that have occurred in patients receiving repeated weekly administration of the drug by intravenous infusions. Adverse reactions arose under perfusion with Iloprost for 6 h and patient compliance was drastically decreased. Biomedical devices could provide a suitable alternative to overcome these drawbacks. In particular, elastomeric pumps, filled with Iloprost isotonic solution, could slowly release the drug, thus decreasing its side effects, representing a valid alternative to hospitalization of patients affected by peripheral arterial disease. However, the home therapy treatment of patients requires long-term stability of Iloprost in solution-loaded elastomeric pumps. The aim of this work was to investigate the long-term stability of Iloprost isotonic solution in biomedical devices using Turbiscan technology. Turbiscan Lab Expert (L’Union, France) predicts the long-term stability of suspensions, emulsions and colloidal formulations by measuring backscattering and transmission of particulates dispersed in solution. The formulations were evaluated by measuring the variation of physical-chemical properties of colloids and suspensions as a function of backscattering and transmission modifications. In addition, the release profile of Iloprost isotonic solution from the biomedical device was evaluated. PMID:25381994

  4. Identification of long-term containment/stabilization technology performance issues

    International Nuclear Information System (INIS)

    U.S. Department of Energy (DOE) faces a somewhat unique challenge when addressing in situ remedial alternatives that leave long-lived radionuclides and hazardous contaminants onsite. These contaminants will remain a potential hazard for thousands of years. However, the risks, costs, and uncertainties associated with removal and offsite disposal are leading many sites to select in situ disposal alternatives. Improvements in containment, stabilization, and monitoring technologies will enhance the viability of such alternatives for implementation. DOE's Office of Science and Technology sponsored a two day workshop designed to investigate issues associated with the long-term in situ stabilization and containment of buried, long-lived hazardous and radioactive contaminants. The workshop facilitated communication among end users representing most sites within the DOE, regulators, and technologists to define long-term performance issues for in situ stabilization and containment alternatives. Participants were divided into groups to identify issues and a strategy to address priority issues. This paper presents the results of the working groups and summarizes the conclusions. A common issue identified by the work groups is communication. Effective communication between technologists, risk assessors, end users, regulators, and other stakeholders would contribute greatly to resolution of both technical and programmatic issues

  5. Long-term manure amendment increases organic C storage and stabilization in Loess soil

    Science.gov (United States)

    Liang, B.; Zhao, W.; Yang, X.; Zhou, J.

    2011-12-01

    Soil is the largest terrestrial pool for organic carbon in the biosphere. Therefore, sequestration of C in soils is often seen as a 'win-win' proposition. The long-term combined application of manure with chemical fertilizers had increased the accumulation of organic carbon in soil (SOC); and the results from the application of chemical fertilizers on the stock of SOC in soil were inconsistent. Furthermore, less studies have been conducted to evaluate the effect of different fertilization, especially the application of N fertilizer, on the stabilization of SOC in the different fertilized soils. In this study, we hypothesized that the long-term different fertilization not only affect organic C storage, but also its stabilization in soil. Therefore, we conducted an incubation experiment with the soils from a long-term fertilization trials. Soil samples were collected from the three fertilized plots, ((1) no fertilizer, NF soil, (2) inorganic NPK fertilizers, NPK soil; and (3) Manure + NPK fertilizers, MNPK soil) of a long-term fertilization experiment initiated in 1990 in Shaanxi, China. The soils were incubated at 28o C for 30 days with the different treatments, i.e., (1) control with no addition (CK), (2) added 200 mg N kg-1 soil (+ NH4-N), (3) added 1000 mg C kg-1 soil (+ glucose), and (4) added 200 mg N kg-1 soil + 1000 mg C kg-1 soil (+glucose + NH4-N). The evolved CO2 was determined by titration of the excess NaOH with 0.1 M HCl. Decomposition of SOC in the different soils was evaluate with the accumulation of released CO2-C based on dry soil (in mg C kg-1 soil), and the decomposition rate of SOC during the incubation (in % of total organic C in soil). Long-term different fertilization treatments (NPK, and MNPK soil) significantly increased the organic C storage in 0-100 cm soil profile. SOC storage in MNPK soil (83.0 t ha-1) was significantly higher than NPK soil (80.8 t ha-1), and both were significantly higher than the no fertilizer soil. The decomposition

  6. Comment on the Long-Term Chemical and Mineralogical Stability of the Buffer

    International Nuclear Information System (INIS)

    This report examines concepts and data that SKB may use to assess the long-term chemical and mineralogical evolution of bentonite barriers in a KBS-3 repository for spent nuclear fuel. Three interrelated topics are considered: mineral chemistry of the smectite clays; thermodynamic stability of the smectite clays; and bentonite-water interactions during the early thermal period of repository evolution. Smectites are complex solid solutions having variable compositions resulting from ionic substitutions on exchange, octahedral and tetrahedral sites in the crystalline lattice. Although little is known about the mechanisms and rates of reactions involving the latter two sites, abundant observational evidence from natural systems suggests that such reactions could occur to an appreciable extent in the buffer over the million year time frame being considered for an intact canister. We are not aware of any efforts in SKB's current modeling strategy to account for such reactions, and therefore question whether the strategy is appropriate for modeling the long-term chemical evolution of the buffer and associated potential effects on the desirable physical and rheological properties of this barrier material. The variable chemistry of smectites affects their thermodynamic stability. Models of smectite-water equilibria use either a fixed stoichiometric composition to approximate representative smectite varieties, or account for compositional variations using solid solution models and ideal mixing relations among thermodynamic components. In either case the thermodynamic properties of a specific smectite composition or of individual solid-solution components must usually be estimated. Recent reports suggest that SKB will not account explicitly for the thermodynamic properties of smectite in its models of bentonite-water interactions. Rather, the models will assume that this clay mineral has a fixed, though unspecified, composition representing an ion-exchanger phase. This phase

  7. Chitosan-Based Conventional and Pickering Emulsions with Long-Term Stability.

    Science.gov (United States)

    Wang, Xiao-Yan; Heuzey, Marie-Claude

    2016-02-01

    Chitosan-based conventional and Pickering oil-in-water (O/W) emulsions with very fine droplet size (volume average diameter, dv, as low as 1.7 μm) and long-term stability (up to 5 months) were ultrasonically generated at different pH values without the addition of any surfactant or cross-linking agent. The ultrasonication treatment was found to break and disperse chitosan agglomerates effectively (particularly at pH ≥ 4.5) and also reduce the chitosan molecular weight, benefiting its emulsification properties. The emulsion stability and emulsion type could be controlled by chitosan solution pH. Increasing pH from 3.5 to 5.5 led to the formation of conventional emulsions with decreasing droplet size (dv from 14 to 2.1 μm) and increasing emulsion stability (from a few days to 2 months). These results can be explained by the increase of dynamic interfacial pressure, which results from the conformation transition of chitosan molecules from an extended state to a more flexible structure as pH increases. At pH = 6.5 (the acid dissociation constant (pKa) of chitosan), the chitosan molecules self-assembled into well-dispersed nanoparticles (dv = 82.1 nm) with the assistance of ultrasonication, which resulted in a Pickering emulsion with the smallest droplet size (dv = 1.7 μm) and highest long-term stability (up to 5 months) because of the presence of chitosan solid nanoparticles at the oil/water interface. The key originality of this study is the elucidation of the role of pH in the formation of conventional and Pickering chitosan-based O/W emulsions with the assistance of ultrasonication. Our results suggest that chitosan possesses great potential to be used as an effective pH-controlled emulsifier and stabilizer without the need of other additives. PMID:26743171

  8. Reflective point-diffraction microscopic interferometer with long-term stability (Invited Paper)

    Institute of Scientific and Technical Information of China (English)

    Rongli Guo; Baoli Yao; Peng Gao; Junwei Min; Juanjuan Zheng; Tong Ye

    2011-01-01

    An on-axis phase-shifting reflective point-diffraction microscopic interferometer for quantitative phase microscopy based on Michelson architecture is proposed.A cube beamsplitter splits the object wave spectrum into two copies within two arms.Reference wave is rebuilt in one arm by low-pass filtering on the object wave frequency spectrum with a pinhole-mask mirror,and interferes with the object wave from the other arm.Polarization phase-shifting is performed and phase imaging on microscale specimens is implemented.The experimental results demonstrate that the proposed scheme has the advantage of long-term stability due to its quasi common-path geometry with full use of laser energv.%An on-axis phase-shifting reflective point-diffraction microscopic interferometer for quantitative phase microscopy based on Michelson architecture is proposed. A cube beamsplitter splits the object wave spectrum into two copies within two arms. Reference wave is rebuilt in one arm by low-pass filtering on the object wave frequency spectrum with a pinhole-mask mirror, and interferes with the object wave from the other arm. Polarization phase-shifting is performed and phase imaging on microscale specimens is implemented. The experimental results demonstrate that the proposed scheme has the advantage of long-term stability due to its quasi common-path geometry with full use of laser energy.

  9. Long-term stability and temperature variability of Iris AO segmented MEMS deformable mirrors

    CERN Document Server

    Helmbrecht, M A; Kempf, C J; Marchis, F

    2016-01-01

    Long-term stability of deformable mirrors (DM) is a critical performance requirement for instruments requiring open-loop corrections. The effects of temperature changes in the DM performance are equally critical for such instruments. This paper investigates the long-term stability of three different Iris AO PTT111 DMs that were calibrated at different times ranging from 13 months to nearly 29 months prior to subsequent testing. Performance testing showed that only a small increase in positioning errors occurred from the initial calibration date to the test dates. The increases in errors ranged from as little as 1.38 nm rms after 18 months to 5.68 nm rms after 29 months. The paper also studies the effects of small temperature changes, up to 6.2{\\deg}C around room temperature. For three different arrays, the errors ranged from 0.62-1.42 nm rms/{\\deg}C. Removing the effects of packaging shows that errors are $\\le$0.50 nm rms/{\\deg}C. Finally, measured data showed that individual segments deformed $\\le$0.11 nm rm...

  10. Annual report for research on long-term stability of geological environments in FY2006

    International Nuclear Information System (INIS)

    The Japanese islands are located in the tectonically active Circum-Pacific Mobile Belt. As a result, Japan has a high frequency of earthquakes and eruptions. The concept of geological disposal of HLW in Japan is based on a multi-barrier system which combines a stable geological environments with an engineered barrier system. Therefore, special consideration is given to the long-term stability of the geological environments, taking into account volcanism, faulting, uplift, denudation, climatic change and sea-level change in Japan. Development of investigation/evaluation technologies for geotectonic events has been carried out to evaluate the long-term stability of the geological environments in Japan. In fiscal year 2006, we carried out the following researches, to confirm existence of the phenomena that have influences on geological disposal system (e.g., active faulting, volcanism), and to develop the investigation techniques to reconstruct the history of these phenomena. For studies of active faulting and seismic activity, we reviewed the existing techniques to research past activities and distribution of active faults (migration, extension, development process of a deformation zone). For volcanological and geothermal studies, we extracted a technique for detecting crustal magma and/or geothermal fluid in deep underground using geophysical and geochemical data, and models assessing the likelihood of future volcanism and its influence on geological environments. For studies of uplift/denudation and climatic/sea-level change, we constructed conceptual models such as landform development model. (author)

  11. The long-term stability of reconstituted exametazime: a clinical and laboratory evaluation

    International Nuclear Information System (INIS)

    99Tcm-exametazime has become recognized as an effective agent for in vitro leucocyte labelling. However, the material is relatively expensive and exhibits instability, being recommended for use within 30 min. Following subdivision and low-temperature storage of unlabelled exametazime we have evaluated long-term stability in a clinical setting and provided some laboratory support for the observations. Vials of exametazime were reconstituted with sodium chloride injection BP and subdivided into three aliquots prior to storage at -66oC. At intervals up to 27 days they were used for routine leucocyte labelling with percentage labelling efficiency being recorded. Additional aliquots were tested for lipophilic primary complex and radiochemical impurities using thin layer chromatography over a similar period. Results on 92 patients gave a mean leucocyte labelling efficiency of 37% (range 10-78%). Chromatography supported the patient data. The percentage of primary exametazime remaining after 24 days' storage (55%) compared favourably with that in a freshly prepared aliquot, subdispensed but not stored (66%). Subdivision and refrigerated storage of unlabelled exametazime at -66oC appears to preserve its radiolabelling capacity and the ability of the 99Tcm-exametazime to label leucocytes. This combination of long-term stability and improved cost-effectiveness may promote more widespread utilization of this pharmaceutical in clinical nuclear medicine. (author)

  12. Long-term stability of conservative orthodontic treatment in a patient with temporomandibular joint disorder.

    Science.gov (United States)

    Mitsui, Silvia Naomi; Yasue, Akihiro; Kuroda, Shingo; Tanaka, Eiji

    2016-01-01

    This article reports the orthodontic treatment of a 20-year-old patient with dental crowding and temporomandibular joint disorders (TMDs). The patient presented moderate anterior crowding with a Class I molar relationship and masticatory disturbance in the mandibular position induced by previous splint therapy. Orthodontic treatment with multi-bracket appliance was initiated to correct the anterior crowding in both dental arches, after the extraction of first premolars and third molars, and also to maintain the splint-induced position of the condyles. After 26 months of treatment, an acceptable occlusion was achieved without any TMD symptoms. After 18-month retention, flattening on the right condyle was observed, possibly as an adaptative remodeling. After 16-year retention period, the occlusion was maintained without recurrence of any TMD symptoms, indicating a long-term stability of occlusion and temporomandibular joint (TMJ) components. Our results suggest the possibility of compromised treatment in patients with TMD to achieve a long-term stability in occlusion and TMJ function. PMID:27556023

  13. Optimization of Long-Term Stability of Magnetic Fluids from Magnetite and Synthetic Polyelectrolytes

    Science.gov (United States)

    Mendenhall; Geng; Hwang

    1996-12-25

    Nanometer-sized suspensions of magnetite (Fe3O4) stabilized with polymeric surfactants, principally poly(methacrylic acid) (PMAA), were prepared by precipitation or sonication and studied by a variety of techniques. The long-term stability of the ferrofluids made with PMAA was optimal at pH 7 (close to the measured isoelectric point of the magnetite, 5.9) and improved at all pH values with increasing surfactant concentration. With extended times of sonication the molecular weight and polydispersity of the PMAA decreased, although magnetite in the ferrofluid was not oxidized (X-ray). Particle diameters of 9-38 nm were measured by saturation magnetization, electron microscopy, and dynamic light scattering. Centrifugation at 8,000 rpm removed the magnetite from the suspensions together with roughly one molecule of PMAA for each magnetite particle in the fluid, with the average number increasing with higher concentrations and average molecular weights of the polymer. PMID:8978555

  14. Improvement in medium-long term frequency stability of integrating sphere cold atom clock

    CERN Document Server

    Liu, Peng; Wan, Jinyin; Wang, Xiumei; Wang, Yaning; Xiao, Ling; Cheng, Huadong; Liu, Liang

    2016-01-01

    The medium-long term frequency stability of the integrating sphere cold atom clock was improved.During the clock operation, Rb atoms were cooled and manipulated using cooling light diffusely reflected by the inner surface of a microwave cavity in the clock. This light heated the cavity and caused a frequency drift from the resonant frequency of the cavity. Power fluctuations of the cooling light led to atomic density variations in the cavity's central area, which increased the clock frequency instability through a cavity pulling effect. We overcame these limitations with appropriate solutions. A frequency stability of 3.5E-15 was achieved when the integrating time ? increased to 2E4 s.

  15. Role of water balance in the long-term stability of hazardous waste site cover treatments

    International Nuclear Information System (INIS)

    After the 30-year post-closure maintenance period at hazardous waste landfills, long-term stability must be assured without continued intervention. Understanding water balance in the established vegetative cover system is central to predicting such stability. A Los Alamos National Laboratory research project has established a series of experimental cover treatment plots on a closed waste disposal site which will permit the determination of the effects of such critical parameters as soil cover design, leaf area index, and rooting characteristics on water balance under varied conditions. Data from these experiments are being analyzed by water balance modeling and other means. The results show consistent differences in soil moisture storage between soil profiles and between vegetation cover treatments

  16. Investigations of the long-term stability of a GEM-TPC

    Energy Technology Data Exchange (ETDEWEB)

    Fedorchuk, Oleksiy [DESY, Hamburg (Germany); Collaboration: LCTPC-Deutschland-Collaboration

    2015-07-01

    For the International Large Detector (ILD) at the planned International Linear Collider (ILC), a Time Projection Chamber (TPC) is foreseen as the main tracking detector. The gas amplification will be done by Micro Pattern Gaseous Detectors (MPGD). One option is to use Gas Electron Multipliers (GEM). While the applicability of GEMs for the gas amplification in a TPC readout has been shown, the focus of the current research is to improve the stability and reliability of the readout modules. This is a crucial requirement for the operation in the final ILD TPC. This presentation shows results from precise discharge current measurements and parallel optical investigations. Ways to improve the long-term stability of the amplification system have been studied.

  17. Performance and Long Term Stability of Mesoporous Silica Membranes for Desalination

    Directory of Open Access Journals (Sweden)

    João C. Diniz da Costa

    2013-07-01

    Full Text Available This work shows the preparation of silica membranes by a two-step sol-gel method using tetraethyl orthosilicate in ethanolic solution by employing nitric acid and ammonia as co-catalysts. The sols prepared in pH 6 resulted in the lowest concentration of silanol (Si–OH species to improve hydrostability and the optimized conditions for film coating. The membrane was tested to desalinate 0.3–15 wt % synthetic sodium chloride (NaCl solutions at a feed temperature of 22 °C followed by long term membrane performance of up to 250 h in 3.5 wt % NaCl solution. Results show that the water flux (and salt rejection decrease with increasing salt concentration delivering an average value of 9.5 kg m–2 h–1 (99.6% and 1.55 kg m–2 h–1 (89.2% from the 0.3 and 15 wt % saline feed solutions, respectively. Furthermore, the permeate salt concentration was measured to be less than 600 ppm for testing conditions up to 5 wt % saline feed solutions, achieving below the recommended standard for potable water. Long term stability shows that the membrane performance in water flux was stable for up to 150 h, and slightly reduced from thereon, possibly due to the blockage of large hydrated ions in the micropore constrictions of the silica matrix. However, the integrity of the silica matrix was not affected by the long term testing as excellent salt rejection of >99% was maintained for over 250 h.

  18. Fast symplectic mapping and long-term stability near broad resonances

    International Nuclear Information System (INIS)

    Fast symplectic mapping, based on a canonical generator of the full-turn map in polar coordinates (I, Φ), is a powerful tool to study long-term stability in large hadron storage rings. Accurate maps for realistic lattices can be constructed in a few hours on a workstation computer, and can be iterated to follow orbits for 107 turns in less than 4 hours. Orbits of the map can also be used in a non-perturbative construction of quasi-invariant actions. By bounding the small changes in quasi-invariants along many short orbits, one can derive conservative estimates of survival time for long orbits, for any initial condition in a region of phase space. A first quasi-invariant vector, J, arises from a canonical transformation (1, Φ) → (J, Ψ), based on interpolation of invariant tori surrounding the origin. The variation of J is relatively large near a broad resonance. In such a region a second canonical transformation, associated with pendulum-like motion in appropriate variables, is required to produce a good quasi-invariant. This quasi-invariant is used to set a long-term bound on motion near a broad, large-amplitude resonance in a realistic model of the Large Hadron Collider (LHC). Interesting general properties of the pseudo-pendulum motion are studied

  19. Preparation of information bases on long-term stability of geological environment

    International Nuclear Information System (INIS)

    From a point of clear grasp of change of thermal and dynamic properties of rock, and flow and geochemical characteristics of groundwater, the special phenomena in Japan such as upheaval, submergence, erosion, igneous activity, seismicity and fault and change of climate and seawater were investigated. Some figures and databases are prepared by collecting information and knowledge related. They contained seven databases: active faults map of Japan, structural map of sea region in Japan and its environs, quaternary volcanoes in Japan, well temperature database, spring geochemistry database, marine terrace in Japan and distribution of landslide configuration, and four figures: geothermal gradient, marine terrace, distribution of upheaval velocity and distribution of erosion velocity in Japan. These databases and figures are explained. The characteristics of diastrophism and igneous activity in Japan are discussed from the viewpoint of long-term stability of geological environment. (S.Y.)

  20. The Performance and Long Term Stability of the D0 Run II Forward Muon Scintillation Counters

    Energy Technology Data Exchange (ETDEWEB)

    Bezzubov, V. [Serpukhov, IHEP; Denisov, D. [Fermilab; Evdokimov, V. [Serpukhov, IHEP; Lipaev, V. [Serpukhov, IHEP; Shchukin, A. [Serpukhov, IHEP; Vasilyev, I. [Serpukhov, IHEP

    2014-07-21

    The performance of the D0 experiment forward muon scintillation counters system during Run II of the Tevatron from 2001 to 2011 is described. The system consists of 4214 scintillation counters in six layers. The long term stability of the counters amplitude response determined using LED calibration system and muons produced in proton-antiproton collisions is presented. The average signal amplitude for counters of all layers has gradually decreased over ten years by 11%. The reference timing, determined using LED calibration, was stable within 0.26 ns. Average value of muon timing peak position was used for periodic D0 clock signal adjustments to compensate seasonal drift caused by temperature variations. Counters occupancy for different triggers in physics data collection runs and for minimum bias triggers are presented. The single muon yields versus time and the luminosity dependence of yields were stable for the forward muon system within 1% over 10 years.

  1. Analysis and research of long-term stability about the gob site in Northern Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-pei; PENG Hui

    2011-01-01

    Based on the analysis of the basic characteristics for the gob site in Northern Shaanxi Province and the room and pillar mining way about coal mine, the variety rule of the coal beds below the site was studied by the using of FEM during the process of coal mining. The statuses of the stresses and strains and the varieties of the plastic area were simulated in the whole rock and coal pillars. The characters of stresses and deformation of the gob area of the coalmine were analyzed and evaluated after the site built in weathering. Moreover, the long-term stability of the gob area was predicted. As a result, the deformation of the gob area under the site is not been finished, and there is the danger that the gob site will collapsing as a whole; therefore,relative measures must be taken.

  2. Long Term Stability of the LHC Superconducting Cryodipoles after Outdoor Storage

    CERN Document Server

    Seyvet, F; Bertarelli, A; Denis, O; El-Kallassi, P; Fernández-Cano, E D; Fessia, P; Ilie, S D; Jeanneret, J B; Letant, D; Poncet, A; Pugnat, P; Savary, F; Sgobba, Stefano; Siemko, A; Todesco, E; Tommasini, D; Veness, R; Vullierme, B; Wildner, E

    2006-01-01

    The main superconducting dipoles for the LHC are being stored outdoors for periods from a few weeks to several years after conditioning with dry nitrogen gas. Such a storage before installation in the 27 km circumference tunnel may affect not only the mechanical and cryogenic functionality of the cryodipoles but also their quench and field performance. A dedicated task force was established to study all aspects of long term behaviour of the stored cryodipoles, with particular emphasis on electrical and vacuum integrity, quench training behaviour, magnetic field quality, performance of the thermal insulation, mechanical stability of magnet shape and of the interface between cold mass and cryostat, degradation ofmaterials and welds. In particular, one specifically selected cryodipole stored outdoors for more than one year, was retested at cold. In addition, various tests have been carried out on the cryodipole assembly and on the most critical subcomponents to study aspects such as the hygrothermal behaviour of...

  3. Long-term functional stability of sacrospinous ligament-fixation repair of pelvic organ prolapse.

    Science.gov (United States)

    Souviat, C; Bricou, A; Porcher, R; Demaria, F; Fritel, X; Benifla, J-L; Pigné, A

    2012-11-01

    The objective of this study was to evaluate the variation over 5 years of functional discomfort associated with pelvic organ prolapse (POP) repaired by sacrospinous ligament fixation (SLF). A total of 178 women who had undergone SLF from 1992 to 2001. In 2002 and 2008, patients were sent a questionnaire including the pelvic floor distress inventory (PFDI-20); 79 responded and comparison of those data served to evaluate subjective signs at 5 years. This population was divided into two groups: ≤60 and >60 years old, and their 2002-2008 differences were compared. The outcomes were satisfaction, functional results and sexuality. Mean follow-up was 115 (72-173) months. Our results showed the long-term stability of SLF functional outcomes for women >60 years. However, for those≤60 years, functional outcomes and satisfaction had declined at 5 years. PMID:23075356

  4. Long Term Stability Testing Results for Savannah River Site Organic and Aqueous Waste streams

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) has tasked MSE Technology Applications, Inc. (MSE) with evaluating the long-term stability of various commercially available sorbent materials to solidify two organic surrogate waste streams (both volatile and nonvolatile), a volatile organic waste stream with a residual aqueous phase, an aqueous waste stream, and an aqueous waste stream with a residual organic phase. The Savannah River Site (SRS) legacy plutonium/uranium extraction (PUREX) process waste and the F-Canyon PUREX waste constituted the volatile organic wastes and various oils constituted the nonvolatile organic waste stream. The aqueous waste streams included a rainwater waste stream and an aqueous organic waste stream. MSE also evaluated the PUREX waste stream with a residual aqueous component with and without aqueous-type sorbent materials. Based on testing performed at MSE, the rainwater waste stream was successfully solidified by SRS personnel using two different sorbents. Several small oil wastes were also successfully solidified by SRS personnel using granular clay sorbents based on information provided by MSE from the oils waste stream testing and 75,706 Liters (L) [20,000 gallons (gal)] of the F-Canyon PUREX waste was solidified at Waste Consolidation Specialists (WCS). Solidification of the various surrogate waste streams listed above was performed from 2004 to 2006 at the MSE testing and evaluation facility located at the Mike Mansfield Advanced Technology Center in Butte, Montana. This paper summarizes the comparison of the initial liquid release testing (LRT) values with LRT results obtained over three years later in an attempt to understand the long-term stability characteristics of the solidified waste streams. The paper also includes solidification results for B-25 box samples generated late in 2005. (authors)

  5. Thermal stability of the French nuclear waste glass - long term behavior modeling

    International Nuclear Information System (INIS)

    The thermal stability of the French nuclear waste glass was investigated experimentally and by modeling to predict its long-term evolution at low temperature. The crystallization mechanisms were analyzed by studying devitrification in the supercooled liquid. Three main crystalline phases were characterized (CaMoO4, CeCO2, ZnCr2O4). Their crystallisation was TO 4.24 wt%, due to the low concentration of the constituent elements. The nucleation and growth curves showed that platinoid elements catalysed nucleation but did not affect growth, which was governed by volume diffusion. The criteria of classic nucleation theory were applied to determine the thermodynamic and diffusional activation energies. Viscosity measurements illustrate the analogy between the activation energy of viscous flow and diffusion, indicating control of crystallization by viscous flow phenomena. The combined action of nucleation and growth was assessed by TTT plots, revealing a crystallization equilibrium line that enables the crystallized fractions to be predicted over the long term. The authors show that hetero-genetics catalyze the transformation without modifying the maximum crystallized fraction. A kinetic model was developed to describe devitrification in the glass based on the nucleation and growth curves alone. The authors show that the low-temperature growth exhibits scale behavior (between time and temperature) similar to thermo-rheological simplicity. The analogy between the resulting activation energy and that of the viscosity was used to model growth on the basis of viscosity. After validation with a simplified (BaO2SiO2) glass, the model was applied to the containment glass. The result indicated that the glass remained completely vitreous after a cooling scenario with the one measured at the glass core. Under isothermal conditions, several million years would be required to reach the maximum theoretical crystallization fraction. (author)

  6. Long-Term Stability of a Cellulose-Based Glucose Oxidase Membrane

    Directory of Open Access Journals (Sweden)

    Soichi Yabuki

    2014-01-01

    Full Text Available A cellulose-based glucose oxidase membrane was prepared on a glassy carbon (GC electrode. The current response of the electrode to glucose was measured by applying a potential of 1.0 V vs. Ag/AgCl on the base GC and was proportional to the concentration of glucose up to 1 mM. The long-term stability of the electrode was examined by measuring the daily glucose response. Over four months, the response magnitude was maintained and then gradually decreased. After 11 months, though the response magnitude decreased to 50% of the initial value, the linear response range did not change. Therefore, the electrode could be used as a glucose biosensor even after 11 months of use. The entrapment of the enzyme in the cellulose matrix promoted the stability of the enzyme, as revealed by data on the enzyme activity after the enzyme electrode was immersed in urea. Therefore, the cellulose matrix may be used to improve the performance of biosensors, bioreactors and bio-fuel cells.

  7. Long-Term Stability of WC-C Peritectic Fixed Point

    Science.gov (United States)

    Khlevnoy, B. B.; Grigoryeva, I. A.

    2015-03-01

    The tungsten carbide-carbon peritectic (WC-C) melting transition is an attractive high-temperature fixed point with a temperature of . Earlier investigations showed high repeatability, small melting range, low sensitivity to impurities, and robustness of WC-C that makes it a prospective candidate for the highest fixed point of the temperature scale. This paper presents further study of the fixed point, namely the investigation of the long-term stability of the WC-C melting temperature. For this purpose, a new WC-C cell of the blackbody type was built using tungsten powder of 99.999 % purity. The stability of the cell was investigated during the cell aging for 50 h at the cell working temperature that tooks 140 melting/freezing cycles. The method of investigation was based on the comparison of the WC-C tested cell with a reference Re-C fixed-point cell that reduces an influence of the probable instability of a radiation thermometer. It was shown that after the aging period, the deviation of the WC-C cell melting temperature was with an uncertainty of.

  8. Thermal stability of the French nuclear waste glass - long term behavior modeling; Etude de la stabilite thermique du verre nucleaire. Modelisation de son evolution a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Orlhac, X

    2000-07-01

    The thermal stability of the French nuclear waste glass was investigated experimentally and by modeling to predict its long-term evolution at low temperature. The crystallization mechanisms were analyzed by studying devitrification in the supercooled liquid. Three main crystalline phases were characterized (CaMoO{sub 4}, CeCO{sub 2}, ZnCr{sub 2}O{sub 4}). Their crystallisation was TO 4.24 wt%, due to the low concentration of the constituent elements. The nucleation and growth curves showed that platinoid elements catalysed nucleation but did not affect growth, which was governed by volume diffusion. The criteria of classic nucleation theory were applied to determine the thermodynamic and diffusional activation energies. Viscosity measurements illustrate the analogy between the activation energy of viscous flow and diffusion, indicating control of crystallization by viscous flow phenomena. The combined action of nucleation and growth was assessed by TTT plots, revealing a crystallization equilibrium line that enables the crystallized fractions to be predicted over the long term. The authors show that hetero-genetics catalyze the transformation without modifying the maximum crystallized fraction. A kinetic model was developed to describe devitrification in the glass based on the nucleation and growth curves alone. The authors show that the low-temperature growth exhibits scale behavior (between time and temperature) similar to thermo-rheological simplicity. The analogy between the resulting activation energy and that of the viscosity was used to model growth on the basis of viscosity. After validation with a simplified (BaO{sub 2}SiO{sub 2}) glass, the model was applied to the containment glass. The result indicated that the glass remained completely vitreous after a cooling scenario with the one measured at the glass core. Under isothermal conditions, several million years would be required to reach the maximum theoretical crystallization fraction. (author)

  9. Dynamics of polymerization in polyacrylamide gel (PAG) dosimeters: (I) ageing and long-term stability

    International Nuclear Information System (INIS)

    Few quantitative data are available on the kinetics of polymerization reactions in polymer gel (PAG) dosimeters and their long-term stability. Post-irradiation polymerization reactions have been found to continue for several weeks, posing questions regarding dosimeter stability and its achievement. In this paper we report an investigation of polymerization kinetics in PAG dosimeters and the effect of diffusing oxygen into the dosimeter, post-irradiation, as a potential method of inhibiting further polymerization and stabilizing the dose distribution. Results show continuous post-irradiation changes in transverse relaxation rate R2 with time over the five week study period and that a steady-state may not be reached for a period of months. An assessment is made of the appropriate time to image the dosimeter which shows that after three to four days the polymerization change is slow compared with imaging time. The implications of the time delay between irradiation and imaging are discussed in terms of the resultant sensitivity of the dosimeter and accuracy of the dose measured. In pairs of dosimeters, one sealed the other open to air, oxygen diffusing into the dosimeter arrests polymerization. However, the diffusion rate is too slow to make this method practicable. The slow diffusion means that while in regions near the air/gel interface polymerization is quickly arrested, in deeper regions it may continue for many hours, causing artefacts in the dose distribution. In the companion paper to this from a collaborating team, a study focusing on modelling oxygen diffusion in dosimeter gel will be presented. (author)

  10. Amorphous iron–chromium oxide nanoparticles with long-term stability

    Energy Technology Data Exchange (ETDEWEB)

    Iacob, Mihail [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania); Institute of Chemistry of ASM, Academiei str. 3, Chisinau 2028, Republic of Moldova (Moldova, Republic of); Cazacu, Maria, E-mail: mcazacu@icmpp.ro [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania); Turta, Constantin [Institute of Chemistry of ASM, Academiei str. 3, Chisinau 2028, Republic of Moldova (Moldova, Republic of); Doroftei, Florica [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania); Botko, Martin; Čižmár, Erik; Zeleňáková, Adriana; Feher, Alexander [Institute of Physics, Faculty of Science, P.J. Šafárik University, Park Angelinum 9, SK-04154 Košice (Slovakia)

    2015-05-15

    Highlights: • Fe–Cr oxide nanoparticles with pre-established metals ratio were obtained. • The amorphous state and its long-term stability were highlighted by X-ray diffraction. • The average diameter of dried nanoparticles was 3.5 nm, as was estimated by TEM, AFM. • In hexane dispersion, nanoparticles with diameter in the range 2.33–4.85 nm were found. • Superparamagnetic state of NPs co-exists with diamagnetism of the organic layer. - Abstract: Iron–chromium nanoparticles (NPs) were obtained through the thermal decomposition of μ{sub 3}-oxo heterotrinuclear (FeCr{sub 2}O) acetate in the presence of sunflower oil and dodecylamine (DA) as surfactants. The average diameter of the NPs was 3.5 nm, as estimated on the basis of transmission electron microscopy and atomic force microscopy images. Both techniques revealed the formation of roughly approximated spheres with some irregularities and agglomerations in larger spherical assemblies of 50–100 nm. In hexane, NPs with diameters in the 2.33–4.85 nm range are individually dispersed, as emphasized by dynamic light scattering measurements. The amorphous nature of the product was emphasized by X-ray powder diffraction. The study of the magnetic properties shows the presence of superparamagnetic state of iron–chromium oxide NPs and the diamagnetic contribution from DA layer forming a shell of NPs.

  11. Biogas production from mono-digestion of maize silage-long-term process stability and requirements.

    Science.gov (United States)

    Lebuhn, M; Liu, F; Heuwinkel, H; Gronauer, A

    2008-01-01

    Biogas production from mono-digestion of maize silage was studied for more than one year in six continuously stirred, daily fed 36 L fermenters. Chemical and microbiological parameters were analysed concomitantly. The reactors acidified already after 8 months of operation at a low organic loading rate (OLR) of 2 g VS*(L*d)(-1). The TVA/TAC ratio was the most reliable parameter to indicate early process instabilities leading to acidification. A TVA/TAC threshold of 0.5 should not be exceeded. After acidification and recovery of the fermenters, propionic acid was no reliable parameter anymore to indicate process failure, since values far below the threshold of 1 g*L(-1) were obtained although the process had collapsed.The acidified reactors recovered better, showed greatly improved stability and allowed a higher OLR when a trace element (TE) cocktail was supplemented. Hydrolysis was obviously not process-limiting, results indicated that methanogens were affected. The most limiting element in long-term mono-digestion of maize silage turned out to be cobalt, but data obtained suggest that molybdenum and selenium should also be provided. TE supplementation should be designed specifically in order to meet the actual needs. TE availability for the biocenosis appears to be a key issue in biogas production, not only in mono-but also in co-digestion processes. PMID:19001720

  12. DORIS-based point mascons for the long term stability of precise orbit solutions

    Science.gov (United States)

    Cerri, L.; Lemoine, J. M.; Mercier, F.; Zelensky, N. P.; Lemoine, F. G.

    2013-08-01

    In recent years non-tidal Time Varying Gravity (TVG) has emerged as the most important contributor in the error budget of Precision Orbit Determination (POD) solutions for altimeter satellites' orbits. The Gravity Recovery And Climate Experiment (GRACE) mission has provided POD analysts with static and time-varying gravity models that are very accurate over the 2002-2012 time interval, but whose linear rates cannot be safely extrapolated before and after the GRACE lifespan. One such model based on a combination of data from GRACE and Lageos from 2002-2010, is used in the dynamic POD solutions developed for the Geophysical Data Records (GDRs) of the Jason series of altimeter missions and the equivalent products from lower altitude missions such as Envisat, Cryosat-2, and HY-2A. In order to accommodate long-term time-variable gravity variations not included in the background geopotential model, we assess the feasibility of using DORIS data to observe local mass variations using point mascons. In particular, we show that the point-mascon approach can stabilize the geographically correlated orbit errors which are of fundamental interest for the analysis of regional Mean Sea Level trends based on altimeter data, and can therefore provide an interim solution in the event of GRACE data loss. The time series of point-mass solutions for Greenland and Antarctica show good agreement with independent series derived from GRACE data, indicating a mass loss at rate of 210 Gt/year and 110 Gt/year respectively.

  13. An experimental study on the long-term stability of particle motion in hadron storage rings

    International Nuclear Information System (INIS)

    Nonlinear magnetic fields in conjunction with tune modulation may lead to chaotic particle motion and thereby limit the dynamic aperture in hadron storage rings. This is on particular interest for high energy storage rings with superconducting magnets at injection energy where magnetic field errors and the beam size have their maximum values. At the CERN SPS a dynamic aperture experiment was performed with the aim of finding the relevant effects for the stability of single particle motion in hadron storage rings. Experimental results are compared to long-term particle tracking to test to which extent computer programs can predict the dynamic aperture under well known conditions. In addition, detailed investigations of the loss mechanisms were pursued to improve the phenomenological understanding of the intricate details of particle motion in phase space. In a complementary experiment at the HERA proton ring at injection energy the dynamic aperture was measured under normal operating conditions. The computer simulations for these measurements included a very detailed model of the nonlinear fields which were measured for each individual magnet. Simulation results for the LHC are shown that estimate the effect of tune ripple of different strength on the dynamic aperture for different sets of random nonlinear field errors. (orig.)

  14. Long-term anaerobic digestion of food waste stabilized by trace elements

    International Nuclear Information System (INIS)

    Highlights: ► Korean food waste was found to contain low level of trace elements. ► Stable anaerobic digestion of food waste was achieved by adding trace elements. ► Iron played an important role in anaerobic digestion of food waste. ► Cobalt addition further enhanced the process performance in the presence of iron. - Abstract: The purpose of this study was to examine if long-term anaerobic digestion of food waste in a semi-continuous single-stage reactor could be stabilized by supplementing trace elements. Contrary to the failure of anaerobic digestion of food waste alone, stable anaerobic digestion of food waste was achieved for 368 days by supplementing trace elements. Under the conditions of OLR (organic loading rates) of 2.19–6.64 g VS (volatile solid)/L day and 20–30 days of HRT (hydraulic retention time), a high methane yield (352–450 mL CH4/g VSadded) was obtained, and no significant accumulation of volatile fatty acids was observed. The subsequent investigation on effects of individual trace elements (Co, Fe, Mo and Ni) showed that iron was essential for maintaining stable methane production. These results proved that the food waste used in this study was deficient in trace elements.

  15. Amorphous iron–chromium oxide nanoparticles with long-term stability

    International Nuclear Information System (INIS)

    Highlights: • Fe–Cr oxide nanoparticles with pre-established metals ratio were obtained. • The amorphous state and its long-term stability were highlighted by X-ray diffraction. • The average diameter of dried nanoparticles was 3.5 nm, as was estimated by TEM, AFM. • In hexane dispersion, nanoparticles with diameter in the range 2.33–4.85 nm were found. • Superparamagnetic state of NPs co-exists with diamagnetism of the organic layer. - Abstract: Iron–chromium nanoparticles (NPs) were obtained through the thermal decomposition of μ3-oxo heterotrinuclear (FeCr2O) acetate in the presence of sunflower oil and dodecylamine (DA) as surfactants. The average diameter of the NPs was 3.5 nm, as estimated on the basis of transmission electron microscopy and atomic force microscopy images. Both techniques revealed the formation of roughly approximated spheres with some irregularities and agglomerations in larger spherical assemblies of 50–100 nm. In hexane, NPs with diameters in the 2.33–4.85 nm range are individually dispersed, as emphasized by dynamic light scattering measurements. The amorphous nature of the product was emphasized by X-ray powder diffraction. The study of the magnetic properties shows the presence of superparamagnetic state of iron–chromium oxide NPs and the diamagnetic contribution from DA layer forming a shell of NPs

  16. 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.)

  17. Stabilization of soil hydraulic properties under a long term no-till system

    Directory of Open Access Journals (Sweden)

    Luis Alberto Lozano

    2014-08-01

    Full Text Available The area under the no-tillage system (NT has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy loam from the Argentinean Pampas region under long-term NT treatments in order to determine if stabilization of soil physical properties is reached apart from a specific time in the crop sequence. In addition, we compared two procedures for evaluating water-conducting macroporosities, and evaluated the efficiency of the pedotransfer function ROSETTA in estimating the parameters of the van Genuchten-Mualem (VGM model in these soils. Soil pore configuration and hydraulic properties were not stable and changed according to the crop sequence and the last crop grown in both sites. For both sites, saturated hydraulic conductivity, K0, water-conducting macroporosity, εma, and flow-weighted mean pore radius, R0ma, increased from the 1st to the 2nd year of the crop sequence, and this was attributed to the creation of water-conducting macropores by the maize roots. The VGM model adequately described the water retention curve (WRC for these soils, but not the hydraulic conductivity (K vs tension (h curve. The ROSETTA function failed in the estimation of these parameters. In summary, mean values of K0 ranged from 0.74 to 3.88 cm h-1. In studies on NT effects on soil physical properties, the crop effect must be considered.

  18. ORTHODONTIC RETENTION. Studies of retention capacity, cost-effectiveness and long-term stability.

    Science.gov (United States)

    Tynelius, Gudrun Edman

    2014-01-01

    Retention strategies, cost-effectiveness and long-term stability of treatment outcome are essential aspects of orthodontic treatment planning. The overall aim of this thesis was to compare and evaluate three different retention strategies, with special reference to short- and long-term clinical stability and cost-effectiveness. The approach was evidence-based, hence randomized controlled methodology was used in order to generate high levels of evidence. This thesis is based on four studies: Papers I and II are based on randomized controlled trials, evaluating the stability of treatment outcome after one and two years of retention, using three different retention strategies: a maxillary vacuum-formed retainer combined with a mandibular canine-to-canine retainer; a maxillary vacuum-formed retainer combined with stripping of the mandibular anterior teeth and a prefabricated positioner. Paper III presents a cost-minimization analysis of two years of retention treatment. Paper IV is based on a randomized controlled trial documenting the results five years post-retention. The following conclusions were drawn: Papers I and II. From a clinical perspective, asssessment after one year of retention disclosed that the three retention methods were successful in retaining the orthodontic treatment results. After two years of retention, all three retention methods were equally effective in controlling relapse at a clinically acceptable level. Most of the relapse occurred during the first year of retention; only minor or negligible changes were found during the second year. The subjects were grouped according to the level of compliance (excellent or good). After two years of retention there was a negative correlation between growth in body height and relapse of mandibular LII in the group of subjects with excellent compliance. The group with good compliance showed a positive correlation (Paper II, Figure 3). After two years of retention, growth in body height, initial crowding and

  19. Long term stability in hadron colliders in presence of synchrotron oscillations and tune ripple

    CERN Document Server

    Scandale, Walter

    1998-01-01

    The problem of long-term losses in hadron colliders such as the Large Hadron Collider (LHC) is considered. A previous formula that provides the reduction of dynamic aperture with the number of turns is generalized to include also the relevant cases of off-momentum and tune ripple. The dynamic aperture turns out to shrink with a power of the inverse logarithm of the number of turns. Long-term tracking data of the LHC are analysed in this framework. The formula proves to hold in all cases, and the possibility of using its extrapolation to predict long-term losses are explored.

  20. Long-term stability of the Leksell Gamma Knife® Perfexion™ patient positioning system (PPS)

    International Nuclear Information System (INIS)

    Purpose: To assess the long-term mechanical stability and accuracy of the patient positioning system (PPS) of the Leksell Gamma Knife® Perfexion™ (LGK PFX). Methods: The mechanical stability of the PPS of the LGK PFX was evaluated using measurements obtained between September 2007 and June 2011. Three methods were employed to measure the deviation of the coincidence of the radiological focus point (RFP) and the PPS calibration center point (CCP). In the first method, the onsite diode test tool with single diode detector was used together with the 4 mm collimator on a daily basis. In the second method, a service diode test tool with three diode detectors was used biannually at the time of the routine preventive maintenance. The test performed with the service diode test tool measured the deviations for all three collimators 4, 8, and 16 mm and also for three different positions of the PPS. The third method employed the conventional film pin-prick method. This test was performed annually for the 4 mm collimator at the time of the routine annual QA. To estimate the effect of the patient weight on the performance of the PPS, the focus precision tests were also conducted with varying weights on the PPS using a set of lead bricks. Results: The average deviations measured from the 641 daily focus precision tests were 0.1 ± 0.1, 0.0 ± 0.0, and 0.0 ± 0.0 mm, respectively, for the 4 mm collimator in the X (left/right of the patient), Y (anterior/posterior of the patient), and Z (superior/inferior of the patient) directions. The average of the total radial deviations as measured during ten semiannual measurements with the service diode test tool were 0.070 ± 0.029, 0.060 ± 0.022, and 0.103 ± 0.028 mm, respectively for the central, long, and short diodes for the 4 mm collimator. Similarly, the average total radial deviations measured during the semiannual measurements for the 4, 8, and 16 mm collimators and using the central diode were 0.070 ± 0.029, 0.097 ± 0

  1. Engineered Barrier System - Long-term Stability of Buffer and Backfill. Synthesis and extended abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Apted, Mick; Arthur, Randy [Monitor Scientific LLC, Denver, CO (United States); Savage, Dave [Quintessa Ltd., Nottingham (GB)] (eds.)

    2005-09-15

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for an encapsulation plant and a deep repository for the geological disposal of spent nuclear fuel. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS) of the repository. This workshop concerns the longterm stability of the buffer and the backfill. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS and the performance confirmation for the EBS. The goal of this work is to achieve a comprehensive overview of all aspects of SKB's EBS work prior to the handling of forthcoming license applications. The reports from the EBS workshops will be used as one important basis in future review work. The workshops involve the gathering of a sufficient number of independent experts in different subjects of relevance to the particular aspect of EBS. A workshop starts with presentations and discussions among these experts. Following this, SKB presents recent results and responds to questions as part of an informal hearing. Finally, the independent experts and the SKI staff examine the SKB responses from different viewpoints. This report aims to summarise the issues discussed at the buffer and backfill workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of the discussions and individual statements made by workshop participants should be regarded as opinions rather than proven facts. This reports includes apart from the workshop synthesis, questions to SKB identified prior or during the workshop, and extended abstracts for introductory presentations.

  2. Fundamental study on long-term stability of rock from the macroscopic point of view

    International Nuclear Information System (INIS)

    In 1994, this project was started, a pneumatic creep testing machine was modified. Inada granite was purchased, and the preliminary tests such as P-wave velocity measurement and Schmidt hammer testing were carried out. In 1995, a specimen of Tage tuff under water-saturated condition had been loaded in uniaxial condition in the pneumatic creep testing machine. The uniaxial compression and tension tests, and the short-term creep test of Inada granite were also carried out in the servo-controlled testing machines to obtain the complete stress-strain curves. In 1996, creep, compression and tension tests were carried out. Though creep stress of Tage tuff was set at as low as 30% of the uniaxial compressive strength, creep strain was continuously increasing after elapsed time exceeded 2 years. Creep tests of sandstone and Inada granite were also carried out. Uniaxial compression, uniaxial tension tests of sandstone were carried out in servo-controlled testing machines to obtain the complete stress-strain curves. Also, indirect tension test was carried out to compare with the results obtained in uniaxial condition. Two types of pressure maintenance equipment were developed and examined. The hydraulic type equipment modified for long-term creep testing to ensure durability and stability was, found to be precise and reliable. The pneumatic type equipment newly developed was comparatively less precise and reliable. A constitutive equation of variable compliance type was discussed based on the experimental results. Several ways how to obtain a set of four constants required to solve the equation were described. The constant strain-rate test, comparing with creep, constant stress-rate and relaxation tests, is recommended to be most appropriate for obtaining constants readily and easily. Based on seven Japanese rocks, the effects of confining pressure and moisture content on the value of each constant were discussed. (J.P.N.)

  3. Engineered Barrier System - Long-term Stability of Buffer and Backfill. Synthesis and extended abstracts

    International Nuclear Information System (INIS)

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for an encapsulation plant and a deep repository for the geological disposal of spent nuclear fuel. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS) of the repository. This workshop concerns the longterm stability of the buffer and the backfill. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS and the performance confirmation for the EBS. The goal of this work is to achieve a comprehensive overview of all aspects of SKB's EBS work prior to the handling of forthcoming license applications. The reports from the EBS workshops will be used as one important basis in future review work. The workshops involve the gathering of a sufficient number of independent experts in different subjects of relevance to the particular aspect of EBS. A workshop starts with presentations and discussions among these experts. Following this, SKB presents recent results and responds to questions as part of an informal hearing. Finally, the independent experts and the SKI staff examine the SKB responses from different viewpoints. This report aims to summarise the issues discussed at the buffer and backfill workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of the discussions and individual statements made by workshop participants should be regarded as opinions rather than proven facts. This reports includes apart from the workshop synthesis, questions to SKB identified prior or during the workshop, and extended abstracts for introductory presentations

  4. HST/WFC3: new capabilities, improved IR detector calibrations, and long-term performance stability

    Science.gov (United States)

    MacKenty, John W.; Baggett, Sylvia M.; Brammer, Gabriel; Hilbert, Bryan; Long, Knox S.; McCullough, Peter; Riess, Adam G.

    2014-08-01

    the causes of its temporal and spatial variation has led to the appreciation of the impact of He I 1.083 micron emission from the earth's atmosphere. This adds a significant and variable background to the two filters and two grisms which include this spectral feature when the HST spacecraft is outside of the earth's shadow. After nearly five years in orbit, long term trending of the scientific and engineering behavior of WFC3 demonstrates excellent stability other than the expected decline in CCD charge transfer efficiency. Addition of post-flash signal to images is shown to markedly improve the transfer efficiency for low level signals. Combined with a pixel based correction algorithm developed at STScl, CCD performance is stabilized at levels only slightly degraded from its initial values.

  5. Dipeptide synthesis in near-anhydrous organic media: Long-term stability and reusability of immobilized Alcalase

    NARCIS (Netherlands)

    Vossenberg, P.; Beeftink, H.H.; Nuijens, T.; Quaedflieg, P.J.L.M.; Cohen Stuart, M.A.; Tramper, J.

    2013-01-01

    The long-term stability and re-use of Alcalase covalently immobilized onto macroporous acrylic beads (Cov) in tetrahydrofuran (THF) were investigated. Cov can be used to synthesize dipeptides under near-anhydrous conditions in THF. Cov was incubated with and without molecular sieves (beads or powder

  6. Double quantization of the regressor space for long-term time series prediction: method and proof of stability.

    Science.gov (United States)

    Simon, Geoffroy; Lendasse, Amaury; Cottrell, Marie; Fort, Jean-Claude; Verleysen, Michel

    2004-01-01

    The Kohonen self-organization map is usually considered as a classification or clustering tool, with only a few applications in time series prediction. In this paper, a particular time series forecasting method based on Kohonen maps is described. This method has been specifically designed for the prediction of long-term trends. The proof of the stability of the method for long-term forecasting is given, as well as illustrations of the utilization of the method both in the scalar and vectorial cases. PMID:15555859

  7. Sulfur Poisoning of Ni/stabilized-zirconia Anodes – Effect on Long-Term Durability

    DEFF Research Database (Denmark)

    Hauch, Anne; Hagen, Anke; Hjelm, Johan;

    2013-01-01

    Sulfur impurities in carbon containing fuels for solid oxide fuel cells (SOFC), e.g. natural gas and biogas, can lead to significant losses in performance due to the sulfur sensitivity of Ni/YSZ SOFC anodes. Full cells having Ni/YSZ and Ni/ScYSZ anodes have been characterized during long-term gal...... focus on the long-term effect over a few hundred of hours. This work describes and correlates the observed evolution of anode performance, over hundreds of hours, with sulfur poisoning with the different operating conditions....

  8. Mainstream partial nitritation and anammox: long-term process stability and effluent quality at low temperatures.

    Science.gov (United States)

    Laureni, Michele; Falås, Per; Robin, Orlane; Wick, Arne; Weissbrodt, David G; Nielsen, Jeppe Lund; Ternes, Thomas A; Morgenroth, Eberhard; Joss, Adriano

    2016-09-15

    The implementation of autotrophic anaerobic ammonium oxidation processes for the removal of nitrogen from municipal wastewater (known as "mainstream anammox") bears the potential to bring wastewater treatment plants close to energy autarky. The aim of the present work was to assess the long-term stability of partial nitritation/anammox (PN/A) processes operating at low temperatures and their reliability in meeting nitrogen concentrations in the range of typical discharge limits below 2  [Formula: see text] and 10 mgNtot·L(-1). Two main 12-L sequencing batch reactors were operated in parallel for PN/A on aerobically pre-treated municipal wastewater (21 ± 5 [Formula: see text] and residual 69 ± 19 mgCODtot·L(-1)) for more than one year, including over 5 months at 15 °C. The two systems consisted of a moving bed biofilm reactor (MBBR) and a hybrid MBBR (H-MBBR) with flocculent biomass. Operation at limiting oxygen concentrations (0.15-0.18 [Formula: see text] ) allowed stable suppression of the activity of nitrite-oxidizing bacteria at 15 °C with a production of nitrate over ammonium consumed as low as 16% in the MBBR. Promising nitrogen removal rates of 20-40 mgN·L(-1)·d(-1) were maintained at hydraulic retention times of 14 h. Stable ammonium and total nitrogen removal efficiencies over 90% and 70% respectively were achieved. Both reactors reached average concentrations of total nitrogen below 10 mgN·L(-1) in their effluents, even down to 6 mgN·L(-1) for the MBBR, with an ammonium concentration of 2 mgN·L(-1) (set as operational threshold to stop aeration). Furthermore, the two PN/A systems performed almost identically with respect to the biological removal of organic micropollutants and, importantly, to a similar extent as conventional treatments. A sudden temperature drop to 11 °C resulted in significant suppression of anammox activity, although this was rapidly recovered after the temperature was increased back to 15 °C. Analyses of 16S

  9. Ni/YSZ microstructure optimization for long-term stability of solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Hauch, Anne; Brodersen, Karen; Karas, Filip; Chen, Ming

    keeping the Ni particles in their required positions in the porous Ni/YSZ cermet close to the electrolyte. In this work we report cell tests and microstructures from reference and long-term tested SOEC with varied initial Ni/YSZ ratio with the aim of investigating the effect of changed Ni/YSZ ratio on...

  10. The characteristics of soft rocks and their effect on the long term stability of abandoned room and pillar lignite mines

    International Nuclear Information System (INIS)

    It is well known that some caving, collapses and subsidence take place from time to time in the areas where abandoned room and pillar type mines exist. The authors have been involved with the stability of abandoned mines beneath urbanized residential areas in Tokai region and there is a great concern about the stability of these abandoned mines during large earthquakes as well as in long term. The 2003 Miyagi Hokubu earthquake caused great damage to abandoned mines and resulted in many collapses. The authors present the experimental results on the characteristics of soft rocks from abandoned lignite mines in Tokai Region as well as the results of some analyses of their effects on the long-term stability of abandoned lignite mines. (authors)

  11. Failed stabilization for long-term potentiation in the auditory cortex of FMR1 knockout mice.

    Directory of Open Access Journals (Sweden)

    Sungchil Yang

    Full Text Available Fragile X syndrome is a developmental disorder that affects sensory systems. A null mutation of the Fragile X Mental Retardation protein 1 (Fmr1 gene in mice has varied effects on developmental plasticity in different sensory systems, including normal barrel cortical plasticity, altered ocular dominance plasticity and grossly impaired auditory frequency map plasticity. The mutation also has different effects on long-term synaptic plasticity in somatosensory and visual cortical neurons, providing insights on how it may differentially affect the sensory systems. Here we present evidence that long-term potentiation (LTP is impaired in the developing auditory cortex of the Fmr1 knockout (KO mice. This impairment of synaptic plasticity is consistent with impaired frequency map plasticity in the Fmr1 KO mouse. Together, these results suggest a potential role of LTP in sensory map plasticity during early sensory development.

  12. The long-term stability of new hippocampal place fields requires new protein synthesis

    OpenAIRE

    Agnihotri, Naveen T.; Hawkins, Robert D.; Kandel, Eric R.; Kentros, Clifford

    2004-01-01

    The hippocampus is critical for formation of spatial memories. Hippocampal pyramidal neurons in freely behaving animals exhibit spatially selective firing patterns, which taken together form an internal representation of the environment. This representation is thought to contribute to the hippocampal spatial memory system. Behavioral long-term memories differ from short-term memories in requiring the synthesis of new proteins. Does the development of the internal hippocampal representation al...

  13. Passivation of gas microstrip detectors and stability of long-term operation

    International Nuclear Information System (INIS)

    We have studied the long-term operation of gas microstrip detectors which have been passivated with a layer of nickel oxide. We have used as the active gas CF4/isobutane (80 : 20) and three different types of substrates: Tedlar, glass and Upilex. In all three cases we found that the detectors are stable after passivation and can operate for a month without changes in gain at rates of MHz. The total accumulated charge was approximately 100 mC. ((orig.))

  14. Long-term assessment of best cathode position to maximise microbial fuel cell performance in horizontal subsurface flow constructed wetlands.

    Science.gov (United States)

    Corbella, Clara; Garfí, Marianna; Puigagut, Jaume

    2016-09-01

    The cathode of microbial fuel cells (MFCs) implemented in constructed wetlands (CWs) is generally set in close contact with water surface to provide a rich oxygen environment. However, water level variations caused by plants evapotranspiration in CWs might decrease MFC performance by limiting oxygen transfer to the cathode. Main objective of this work was to quantify the effect of water level variation on MFC performance implemented in HSSF CW. For the purpose of this work two MFCs were implemented within a HSSF CW pilot plant fed with primary treated domestic wastewater. Cell voltage (Ecell) and the relative distance between the cathode and the water level were recorded for one year. Results showed that Ecell was greatly influenced by the relative distance between the cathode and the water level, giving an optimal cathode position of about 1 to 2cm above water level. Both water level variation and Ecell were daily and seasonal dependent, showing a pronounced day/night variation during warm periods and showing almost no daily variation during cold periods. Energy production under pronounced daily water level variation was 40% lower (80±56mWh/m(2)·day) than under low water level variation (131±61mWh/m(2)·day). Main conclusion of the present work is that of the performance of MFC implemented in HSSF CW is highly dependent on plants evapotranspiration. Therefore, MFC that are to be implemented in CWs shall be designed to be able to cope with pronounced water level variations. PMID:27151501

  15. Investigation and technical reviews on the long term stability of buffer. Document prepared by other institute, based on the contract

    International Nuclear Information System (INIS)

    The main objectives of future research and development of geological disposal are to confirm that previous investigation and assessment method which have been arranged for generic geological environment will apply to real geological disposal environment, and the margin of system performance, which was assessed under simple and conservative viewpoint in the past, with assessment and recognition long term behavior of realistic system. Under present condition, we organized clay science specialist committee in Nuclear Safety Research Association and considered following themes comprehensively. To confirm the assessment methods for log term stability of the buffer in H12: Project to establish the scientific and technical basis for HLW disposal in Japan' and in other performance assessment reports, and to pick up subjects from them. Review on the research for long term stability assessment in Japan Nuclear Cycle Development Institute and in other researchers. This report is summarized the result of investigation. (author)

  16. Long Term Thermal Stability In Air Of Ionic Liquid Based Alternative Heat Transfer Fluids For Clean Energy Production

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the effect of long-term aging on the thermal stability and chemical structure of seven different ILs so as to explore their suitability for use as a heat transfer fluid. This was accomplished by heating the ILs for 15 weeks at 200 °C in an oxidizing environment and performing subsequent analyses on the aged chemicals

  17. Long-term stability of surgical-orthodontic correction of class III malocclusions with long-face syndrome

    OpenAIRE

    Gallego-Romero, David; Llamas-Carrera, José M.; Torres-Lagares, Daniel; Paredes, Vanessa; Espinar, Eduardo; Guevara, Eduardo; Gutiérrez-Pérez, José L.

    2011-01-01

    Objectives: In the first place, to evaluate skeletal changes of the maxilla and mandible induced by surgical-orthodontic correction of malocclusions class III with long-face syndrome and secondly, to analyze the stability of these skeletal changes in the long term (more than 6 years). Design of Study: A retrospective, unicentric and longitudinal study of 19 patients who had undergone surgical and orthodontic therapy for class III skeletal malocclusion with long-face syndrome was undertaken. A...

  18. Aligned Single-Crystalline Perovskite Microwire Arrays for High-Performance Flexible Image Sensors with Long-Term Stability.

    Science.gov (United States)

    Deng, Wei; Zhang, Xiujuan; Huang, Liming; Xu, Xiuzhen; Wang, Liang; Wang, Jincheng; Shang, Qixun; Lee, Shuit-Tong; Jie, Jiansheng

    2016-03-16

    A simple, low-cost blade-coating method is developed for the large-area fabrication of single-crystalline aligned CH3NH3PbI3 microwire (MW) arrays. The solution-coating method is applicable to flexible substrates, enabling the fabrication of MW-array-based photodetectors with excellent long-term stability, flexibility, and bending durability. Integrated devices from such photodetectors demonstrate high performance for high-resolution, flexible image sensors. PMID:26780594

  19. Clinical characteristics and long-term response to mood stabilizers in patients with bipolar disorder and different age at onset

    OpenAIRE

    Dell’Osso, Bernardo; Buoli, Massimiliano; Riundi, Riccardo; D’Urso, Nazario; Pozzoli, Sara; Bassetti, Roberta; Mundo, Emanuela; Altamura, A Carlo

    2009-01-01

    Introduction Bipolar disorder (BD) is a prevalent, comorbid, and impairing condition. Potential predictors of response to pharmacological treatment are object of continuous investigation in patients with BD. The present naturalistic study was aimed to assess clinical features and long-term response to mood stabilizers in a sample of bipolar subjects with different ages at onset. Methods The study sample included 108 euthymic patients, diagnosed as affected by BD, either type I or II, accordin...

  20. Evaluation of X-Inactivation Status and Cytogenetic Stability of Human Dermal Fibroblasts after Long-Term Culture

    OpenAIRE

    Zhi-Gang Xue; Zhan-Ping Shi; Juan Dong; Ting-Ting Liao; Yan-Peng Wang; Xue-Ping Sun; Zheng-Jie Yan; Xiao-Qiao Qian; Yu-Gui Cui; Juan Chen; Jia-Yin Liu; Guoping Fan

    2010-01-01

    Human primary fibroblasts are a popular type of somatic cells for the production of induced pluripotent stem (iPS) cells. Here we characterized biological properties of primary fibroblasts in terms of cell-growth rate, cytogenetic stability, and the number of inactive X chromosomes during long-term passaging. We produced eight lines of female human dermal fibroblasts (HDFs) and found normal karyotype and expected pattern of X chromosome inactivation (XCI) at low passages (Passage P1-5). Howev...

  1. BIOGEOCHEMICAL CYCLING AND ENVIRONMENTAL STABILITY OF PLUTONIUM RELEVANT TO LONG-TERM STEWARDSHIP OF DOE SITES

    Energy Technology Data Exchange (ETDEWEB)

    Francis, A.J.; Gillow, J.B.; Dodge, C.J.

    2006-06-01

    Pu is generally considered to be relatively immobile in the terrestrial environment, with the exception of transport via airborne and erosion mechanisms. More recently the transport of colloidal forms of Pu is being studied as a mobilization pathway from subsurface contaminated soils and sediments. The overall objective of this research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for retardation of Pu transport.

  2. BIOGEOCHEMICAL CYCLING AND ENVIRONMENTAL STABILITY OF PLUTONIUM RELEVANT TO LONG-TERM STEWARDSHIP OF DOE SITES.

    Energy Technology Data Exchange (ETDEWEB)

    FRANCIS, A.J.; GILLOW, J.P.; DODGE, C.J.

    2006-11-16

    Pu is generally considered to be relatively immobile in the terrestrial environment, with the exception of transport via airborne and erosion mechanisms. More recently the transport of colloidal forms of Pu is being studied as a mobilization pathway from subsurface contaminated soils and sediments. The overall objective of this research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for retardation of Pu transport.

  3. Long-Term Evolution of Email Networks: Statistical Regularities, Predictability and Stability of Social Behaviors.

    Science.gov (United States)

    Godoy-Lorite, Antonia; Guimerà, Roger; Sales-Pardo, Marta

    2016-01-01

    In social networks, individuals constantly drop ties and replace them by new ones in a highly unpredictable fashion. This highly dynamical nature of social ties has important implications for processes such as the spread of information or of epidemics. Several studies have demonstrated the influence of a number of factors on the intricate microscopic process of tie replacement, but the macroscopic long-term effects of such changes remain largely unexplored. Here we investigate whether, despite the inherent randomness at the microscopic level, there are macroscopic statistical regularities in the long-term evolution of social networks. In particular, we analyze the email network of a large organization with over 1,000 individuals throughout four consecutive years. We find that, although the evolution of individual ties is highly unpredictable, the macro-evolution of social communication networks follows well-defined statistical patterns, characterized by exponentially decaying log-variations of the weight of social ties and of individuals' social strength. At the same time, we find that individuals have social signatures and communication strategies that are remarkably stable over the scale of several years. PMID:26735853

  4. Macroregulation in all-around recovery:Maintain stability and orient to long-term priorities

    Institute of Scientific and Technical Information of China (English)

    陈东琪

    2009-01-01

    Since last October, loose monetary and credit policies and the stimulus package have produced desired results. The economy has entered into a "V-shaped" recovery in the second quarter of this year after hitting the bottom in the first quarter, with various economic indicators rising fast, rescue missions completed and short-term objectives basically met. In this context, the next step of macro-regulation should focus on long-term objectives, speed up institutional innovation and restructuring, control the intensity, pattern and pace of short-term policy loosening and prevent inflation and wild swings in the economy so as to achieve a new round of sustained and rapid economic growth.

  5. Annual report in the fiscal year 2002. Long-term stability of geological environment

    International Nuclear Information System (INIS)

    The report consists of eight chapters; introduction, summary of investigation, study of upheaval and encroach, change of season and sea standard, volcanic activity, earthquake and fault, long-range estimation of geological environment and a plan for the future. Two technologies of a long-term estimation and investigation of change of underground are studied. On the first technology, estimation model of change of three dimensional topographies (large area) and volcanic activity and analytical method of position of hypocenter fault and activity were developed. On the latter one, estimation model of change of three dimensional topographies (small area), estimation method of displacement of coast line, precise restoration technology for Quaternary igneous activity, exploration technique of hypocenter fault and magma reservoir in the deep underground and evaluation technology of change of ground water caused fault activity were developed. An analytical tool of diastrophism considered gliding fault is going to finish. (S.Y.)

  6. Transient calnexin interaction confers long-term stability on folded K+ channel protein in the ER.

    Science.gov (United States)

    Khanna, Rajesh; Lee, Eun Jeon; Papazian, Diane M

    2004-06-15

    We recently showed that an unglycosylated form of the Shaker potassium channel protein is retained in the endoplasmic reticulum (ER) and degraded by proteasomes in mammalian cells despite apparently normal folding and assembly. These results suggest that channel proteins with a native structure can be substrates for ER-associated degradation. We have now tested this hypothesis using the wild-type Shaker protein. Wild-type Shaker is degraded by cytoplasmic proteasomes when it is trapped in the ER and prevented from interacting with calnexin. Neither condition alone is sufficient to destabilize the protein. Proteasomal degradation of the wild-type protein is abolished when ER mannosidase I trimming of the core glycan is inhibited. Our results indicate that transient interaction with calnexin provides long-term protection from ER-associated degradation. PMID:15161937

  7. Fiscal report on long-term stability of geological environment The 2003 fiscal year

    International Nuclear Information System (INIS)

    Tono Geoscience Center reported research process and results on upheaval, erosion, clime and sea level change, volcanic activity, active fault, seismicity, long-term estimation of geological environment, and underground structure in land. The upheaval and erosion velocity data were collected and change of topography during 120.000 years was simulated. The resistivity structure in deep ground was estimated by measurement of geomagnetism and earth current by the magneto telluric (MT) method. Database of the well temperature and the spring geochemistry is prepared. The hypocentral region of Tottori earthquake (in 2000) was agreed with distribution of monogenetic volcano group in Yokota. Diastrophism analysis program was developed. Accurately controlled routinely operated signal system (ACROSS) has been developed and measured seismic phase. (S.Y.)

  8. The stability of vacuum phototriodes to varying light pulse loads and long term changes in response.

    CERN Document Server

    Hobson, Peter

    2012-01-01

    Mesh anode Vacuum Phototriodes (VPTs) are radiation resistant, single gain-stage photomultipliers which are designed to operate in a strong quasi-axial magnetic field. These VPTs are used in the endcap electromagnetic calorimeter of the CMS experiment at the CERN LHC to detect scintillation light from lead tungstate crystals. Short term dynamic response changes occur because of pulse rate variations during normal LHC operation cycles. Over the longer term the effect of increasing integrated charge taken from the photocathode causes an overall degradation of response. We have investigated these effects over time periods exceeding two years of simulated operation and discuss the implications for the long term performance of the VPTs in CMS.

  9. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    Energy Technology Data Exchange (ETDEWEB)

    Honeyman, Bruce D.; Francis, A.J.; Gillow, Jeffrey B.; Dodge, Cleveland J.; Santschi, Peter H.; Chin-Chang Hung; Diaz, Angelique; Tinnacher, Ruth; Roberts, Kimberly; Schwehr, Kathy

    2006-04-05

    The overall objective of this research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation and immobilization) is the role of microorganisms. The hypothesis underlying this work is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  10. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Arokiasamy J.; Santschi, Peter H.; Honeyman, Bruce D.

    2005-06-01

    The overall objective of this proposed research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation to immobilization) is the role of microorganisms. The hypothesis underlying this proposal is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases, and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  11. Annual report of research project on long-term stability of geological environment in the 2003 fiscal year

    International Nuclear Information System (INIS)

    The report consists of introduction, abstract of results until the 2002 fiscal year, abstract of research plan and research plan in the 2003 fiscal year. It is important to develop the following technologies for increasing reliance on predicting and estimating long-term stability of geological environment; to estimate the change of stratum and topography depends on diastrophism, erosion and sea level change, to grasp the origins of abnormal temperature in the non-volcanic zone, to estimate future volcanic activity around monogenic volcano, extraction of hypocentral fault in underground and evaluation of effects of these natural phenomena on the geological environment. The research plan in this fiscal year includes six themes on study of upheaval and erosion, climate and sea level change, volcanic activity, long-term prospect of geological environment and underground. Each theme is described by object and the working plans. (S.Y.)

  12. The stability of hydrogen evolution activity and corrosion behavior of NiCu coatings with long-term electrolysis in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Solmaz, Ramazan; Doener, Ali; Kardas, Guelfeza [Cukurova University, Science and Letters Faculty, Chemistry Department, 01330, Balcali, Adana (Turkey)

    2009-03-15

    In this study, NiCu composite coating was electrochemically deposited on a copper electrode (Cu/NiCu) and tested for hydrogen evolution reaction (HER) in 1 M KOH solution for long-term electrolysis with the help of cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. The bulk and surface composition of the coating was determined using atomic absorption spectroscopy (AAS) and energy dispersive X-ray (EDX) analysis. The surface morphology was investigated by scanning electron microscopy (SEM). The effect of electrolysis on the corrosion behavior of the Cu/NiCu electrode was also reported. It was found that the NiCu coating had a compact and porous structure with good time stability. The HER activity of the coating was stable over 120 h electrolysis and the HER mechanism was not modified during the operation. The corrosion tests showed that the corrosion resistance of the Cu/NiCu electrode changed when a cathodic current was applied to the electrolysis system. (author)

  13. The Dynamical State and Long-term Stability of HIP 102589

    Science.gov (United States)

    Xia, Fang; Fu, Yanning

    2015-11-01

    The dynamical state (component masses and kinematic parameters) of the triple star HIP 102589 is redetermined by fitting the simple double two-body model and the accurate three-body model, respectively, to observational data including those accumulated since the last orbit determination in 1992. Though the precision-weighted sum of squared residuals calculated from our results with both models are significantly smaller than the previous ones, only the result with the three-body model is statistically acceptable according to the goodness-of-fit test. The forward and backward long-term dynamical evolutions are numerically explored on the timescale of an estimated age of the components. It is found that the three-body system remains integrated and its hierarchical configuration keeps unchanged since the formation of the components, despite the fact that the instantaneous double two-body orbits vary significantly. This implies that the triple star may not be formed by a three-body encounter. Also, the possibility that the most massive component is itself a tightly bounded binary is discussed based on the redetermined mass and a stellar empirical mass-luminosity relation.

  14. 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

  15. FACT - Long-term stability and observations during strong Moon light

    CERN Document Server

    Knoetig, M L; Bretz, T; Buß, J; Dorner, D; Einecke, S; Eisenacher, D; Hildebrand, D; Krähenbühl, T; Lustermann, W; Mannheim, K; Meier, K; Neise, D; Overkemping, A -K; Paravac, A; Pauss, F; Rhode, W; Ribordy, M; Steinbring, T; Temme, F; Thaele, J; Vogler, P; Walter, R; Weitzel, Q; Zänglein, M

    2013-01-01

    The First G-APD Cherenkov Telescope (FACT) is the first Cherenkov telescope equipped with a camera made of silicon photon detectors (G-APD aka. SiPM). Since October 2011, it is regularly taking data on the Canary Island of La Palma. G-APDs are ideal detectors for Cherenkov telescopes as they are robust and stable. Furthermore, the insensitivity of G-APDs towards strong ambient light allows to conduct observations during bright Moon and twilight. This gain in observation time is essential for the long-term monitoring of bright TeV blazars. During the commissioning phase, hundreds of hours of data (including data from the the Crab Nebula) were taken in order to understand the performance and sensitivity of the instrument. The data cover a wide range of observation conditions including different weather conditions, different zenith angles and different light conditions (ranging from dark night to direct full Moon). We use a new parmetrisation of the Moon light background to enhance our scheduling and to monitor ...

  16. Reprogramming suppresses premature senescence phenotypes of Werner syndrome cells and maintains chromosomal stability over long-term culture.

    Directory of Open Access Journals (Sweden)

    Akira Shimamoto

    Full Text Available Werner syndrome (WS is a premature aging disorder characterized by chromosomal instability and cancer predisposition. Mutations in WRN are responsible for the disease and cause telomere dysfunction, resulting in accelerated aging. Recent studies have revealed that cells from WS patients can be successfully reprogrammed into induced pluripotent stem cells (iPSCs. In the present study, we describe the effects of long-term culture on WS iPSCs, which acquired and maintained infinite proliferative potential for self-renewal over 2 years. After long-term cultures, WS iPSCs exhibited stable undifferentiated states and differentiation capacity, and premature upregulation of senescence-associated genes in WS cells was completely suppressed in WS iPSCs despite WRN deficiency. WS iPSCs also showed recapitulation of the phenotypes during differentiation. Furthermore, karyotype analysis indicated that WS iPSCs were stable, and half of the descendant clones had chromosomal profiles that were similar to those of parental cells. These unexpected properties might be achieved by induced expression of endogenous telomerase gene during reprogramming, which trigger telomerase reactivation leading to suppression of both replicative senescence and telomere dysfunction in WS cells. These findings demonstrated that reprogramming suppressed premature senescence phenotypes in WS cells and WS iPSCs could lead to chromosomal stability over the long term. WS iPSCs will provide opportunities to identify affected lineages in WS and to develop a new strategy for the treatment of WS.

  17. Preparation of 125I-labeled human growth hormone of high quality binding properties endowed with long-term stability

    International Nuclear Information System (INIS)

    125I-labeled human growth hormone (125I-labeled.hGH) was prepared by using two variants of the chloramine T labelling procedure and purified by polyacrylamide gel electrophoresis (PAGE) of the reaction mixture. Variant A produced a tracer with high specific activity (100 +/- 10 microCi/microgram), high maximal binding capacity to antibodies (93%) and long-term stability (at least 150 days at -20/degree/C). No diiodinated tyrosil residues could be detected in this tracer. Variant B was devised to obtain higher yields of labeled hormone. The electrophoresis of the iodination mixture revealed two radioactive components with Rm values of 0.49 and 0.55 which result from the iodination of hGH variants preexisting in the starting material. Both tracers had similar specific activities (70 +/- 10 microCi/microgram), high maximal binding capacity to antibodies or receptors (80-100%, after 80 days of their obtention) and high stability (at least 100 days at -20/degree/C). It is concluded that the iododerivatives of hGH obtained by either method are adequate to perform radioimmunoassay and receptor studies and have long-term stability

  18. Long-term manure amendments reduced soil aggregate stability via redistribution of the glomalin-related soil protein in macroaggregates

    Science.gov (United States)

    Xie, Hongtu; Li, Jianwei; Zhang, Bin; Wang, Lianfeng; Wang, Jingkuan; He, Hongbo; Zhang, Xudong

    2015-10-01

    Glomalin-related soil protein (GRSP) contributes to the formation and maintenance of soil aggregates, it is however remains unclear whether long-term intensive manure amendments alter soil aggregates stability and whether GRSP regulates these changes. Based on a three-decade long fertilization experiment in northeast China, this study examined the impact of long-term manure input on soil organic carbon (SOC), total and easily extractable GRSP (GRSPt and GRSPe) and their respective allocations in four soil aggregates (>2000 μm 2000-250 μm 250-53 μm and <53 μm). The treatments include no fertilization (CK), low and high manure amendment (M1, M2), chemical nitrogen, phosphorus and potassium fertilizers (NPK), and combined manure and chemical fertilizers (NPKM1, NPKM2). Though SOC, GRSPe and GRSPt in soil and SOC in each aggregate generally increased with increasing manure input, GRSPt and GRSPe in each aggregate showed varying changes with manure input. Both GRSP in macroaggregates (2000-250 μm) were significantly higher under low manure input, a pattern consistent with changes in soil aggregate stability. Constituting 38~49% of soil mass, macroaggregates likely contributed to the nonlinear changes of aggregate stability under manure amendments. The regulatory process of GRSP allocations in soil aggregates has important implications for manure management under intensive agriculture.

  19. Cement Waste Matrix Evaluation and Modelling of the Long Term Stability of Cementitious Waste Matrices

    International Nuclear Information System (INIS)

    Cement based materials are often used as a solidification matrix for wet radioactive waste from nuclear power plants such as ion exchange resins, sludge and evaporator concentrates. The mechanical and chemical properties of the cement-waste matrix are affected by the type and the concentration of the waste. For this reason the recipe used in the solidification process has to be carefully adjusted to respond to the variations of the waste. At the Ringhals Nuclear Power Plant (RNPP) an evaporator was to be taken into operation during the mid 2005. As a result of this process an evaporator concentrate containing boric acid was expected. The aims of the present study were to develop a recipe for the solidification of artificial evaporator concentrates, (AEC), containing H3BO3 and measure the compressive strength of the waste/cement matrix over a period of 4 years. The confirmation of the previously reported retarding properties of H3BO3 and the studies of AEC without H3BO3 were also included as a part of this work. Finally, thermodynamic calculations were used as a tool in order to predict the evolution of the mineralogy and integrity for the different cement-waste specimens over very long periods of time, i.e. up to about 100 000 years. The most important finding was that when an optimized waste/cement matrix recipe was used the compressive strength increased during the entire 4 year period and no signs of degradation were noticed. It was also found that the long-term performance of the waste matrices is to a large extent site-specific. In general, the composition of the infiltrating water is more influential than the waste matrices, both on the degradation of the waste matrices itself as well as on the engineered barriers. (author)

  20. The Critical Choice of PEDOT: PSS Additives for Long Term Stability of Roll‐to‐Roll Processed OPVs

    DEFF Research Database (Denmark)

    Roth, Bérenger; Benatto, Gisele Alves dos Reis; Corazza, Michael;

    2015-01-01

    The impact of additives mixed with poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) on the stability of organic photovoltaic modules is investigated for fully ambient roll-to-roll (R2R) processed indium tin oxide free modules. Four different PEDOT:PSS inks from two different...... on organic photovoltaic stability (ISOS). For the harsh indoor test (ISOS-L-3) only a slight difference in stability is observed between the different modules. During both ISOS-L-3 and ISOS-D-3 one new failure mode is observed as a result of tiny air inclusions in the barrier foil and a R2R method...... is identified. The data are extended in an ongoing experiment where DMSO is used as additive for long-term outdoor testing in a solar park....

  1. Long term stability of magnetorheological fluids using high viscosity linear polysiloxane carrier fluids

    Science.gov (United States)

    Xie, Lei; Choi, Young-Tai; Liao, Chang-Rong; Wereley, Norman M.

    2016-07-01

    Stability of magnetorheological fluids (MRFs) or suspensions has been a key issue in the development of various practical applications. In our prior work, it was experimentally confirmed that a high viscosity linear polysiloxane carrier fluid based MRF (hereinafter HVLP MRF) with 26% particle volume fraction (hereinafter 26 vol%) showed high sedimentation stability for 96 days because HVLP carrier fluids have remarkable shear thinning behavior, that is, very high viscosity at low shear rate but low viscosity at high shear rate. In addition, the effects of HVLP carrier fluid viscosity and carbonyl iron (CI) particle concentration on suspension stability were investigated with the objective of synthesizing highly stable HVLP MRFs for practical applications. The HVLP MRFs were synthesized by suspending nominally 32 vol% of CI particles in carrier fluids with different viscosities (i.e., 140, 440, and 800 Pa s). To illustrate the effect of particle concentration on suspension stability, because it is well known that suspension stability increases as particle concentration increases, two low concentrations, 5 and 10 vol%, and two high concentrations, 20 and 32 vol%, were prepared to demonstrate MRFs with relatively severe sedimentation, and stable suspensions, respectively. A vertical axis inductance monitoring system was employed to evaluate the suspension stability of the HVLP MRFs for 365 days by scanning the inductance of the MRF samples in a vertical fluid column, and logging this data with respect to height and time. In addition, the suspension stability of a commercially available MRF (i.e., Lord MRF-132DG) was also measured and compared with similar measurements for HVLP MRFs.

  2. Stability of Caribbean coral communities quantified by long-term monitoring and autoregression models.

    Science.gov (United States)

    Gross, Kevin; Edmunds, Peter J

    2015-07-01

    Tropical coral reefs exemplify ecosystems imperiled by environmental change. Anticipating the future of reef ecosystems requires understanding how scleractinian corals respond to the multiple environmental disturbances that threaten their survival. We analyzed the stability of coral reefs at three habitats at different depths along the south shore of St. John, U.S. Virgin Islands, using multivariate autoregression (MAR) models and two decades of monitoring data. We quantified several measures of ecosystem stability, including the magnitude of typical stochastic fluctuations, the rate of recovery following disturbance, and the sensitivity of coral cover to hurricanes and elevated sea temperature. Our results show that, even within a -4 km shore, coral communities in different habitats display different stability properties, and that the stability of each habitat corresponds with the habitat's known synecology. Two Orbicella-dominated habitats are less prone to annual stochastic fluctuations than coral communities in shallower water, but they recover slowly from disturbance, and one habitat has suffered recent losses in scleractinian cover that will not be quickly reversed. In contrast, a shallower, low-coral-cover habitat is subject to greater stochastic fluctuations, but rebounds more quickly from disturbance and is more robust to hurricanes and seawater warming. In some sense, the shallower community is more stable, although the stability arguably arises from having little coral cover left. Our results sharpen understanding of recent changes in coral communities at these habitats, provide a more detailed understanding of how these habitats may change in future environments, and illustrate how MAR models can be used to assess stability of communities founded upon long-lived species. PMID:26378304

  3. Accuracy and stability of positioning in radiosurgery: long-term results of the Gamma Knife system.

    Science.gov (United States)

    Heck, Bernhard; Jess-Hempen, Anja; Kreiner, Hans Jürg; Schöpgens, Hans; Mack, Andreas

    2007-04-01

    The primary aim of this investigation was to determine the long term overall accuracy of an irradiation position of Gamma Knife systems. The mechanical accuracy of the system as well as the overall accuracy of an irradiation position was examined by irradiating radiosensitive films. To measure the mechanical accuracy, the GafChromic film was fixed by a special tool at the unit center point (UCP). For overall accuracy the film was mounted inside a phantom at a target position given by a two-dimensional cross. Its position was determined by CT or MRI scans, a treatment was planned to hit this target by use of the standard planning software and the radiation was finally delivered. This procedure is named "system test" according to DIN 6875-1 and is equivalent to a treatment simulation. The used GafChromic films were evaluated by high resolution densitometric measurements. The Munich Gamma Knife UCP coincided within x; y; z: -0.014 +/- 0.09 mm; 0.013 +/- 0.09 mm; -0.002 +/- 0.06 mm (mean +/- SD) to the center of dose distribution. There was no trend in the measured data observed over more than ten years. All measured data were within a sphere of 0.2 mm radius. When basing the target definition in the system test on MRI scans, we obtained an overall accuracy of an irradiation position in the x direction of 0.21 +/- 0.32 mm and in the y direction 0.15 +/- 0.26 mm (mean +/- SD). When a CT-based target definition was used, we measured distances in x direction 0.06 +/- 0.09 mm and in y direction 0.04 +/- 0.09 mm (mean +/- SD), respectively. These results were compared with those obtained with a Gamma Knife equipped with an automatic positioning system (APS) by use of a different phantom. This phantom was found to be slightly less accurate due to its mechanical construction and the soft fixation into the frame. The phantom related position deviation was found to be about +/- 0.2 mm, and therefore the measured accuracy of the APS Gamma Knife was evidently less precise by

  4. Long-Term Morphological and Microarchitectural Stability of Tissue-Engineered, Patient-Specific Auricles In Vivo.

    Science.gov (United States)

    Cohen, Benjamin Peter; Hooper, Rachel C; Puetzer, Jennifer L; Nordberg, Rachel; Asanbe, Ope; Hernandez, Karina A; Spector, Jason A; Bonassar, Lawrence J

    2016-03-01

    Current techniques for autologous auricular reconstruction produce substandard ear morphologies with high levels of donor-site morbidity, whereas alloplastic implants demonstrate poor biocompatibility. Tissue engineering, in combination with noninvasive digital photogrammetry and computer-assisted design/computer-aided manufacturing technology, offers an alternative method of auricular reconstruction. Using this method, patient-specific ears composed of collagen scaffolds and auricular chondrocytes have generated auricular cartilage with great fidelity following 3 months of subcutaneous implantation, however, this short time frame may not portend long-term tissue stability. We hypothesized that constructs developed using this technique would undergo continued auricular cartilage maturation without degradation during long-term (6 month) implantation. Full-sized, juvenile human ear constructs were injection molded from high-density collagen hydrogels encapsulating juvenile bovine auricular chondrocytes and implanted subcutaneously on the backs of nude rats for 6 months. Upon explantation, constructs retained overall patient morphology and displayed no evidence of tissue necrosis. Limited contraction occurred in vivo, however, no significant change in size was observed beyond 1 month. Constructs at 6 months showed distinct auricular cartilage microstructure, featuring a self-assembled perichondrial layer, a proteoglycan-rich bulk, and rounded cellular lacunae. Verhoeff's staining also revealed a developing elastin network comparable to native tissue. Biochemical measurements for DNA, glycosaminoglycan, and hydroxyproline content and mechanical properties of aggregate modulus and hydraulic permeability showed engineered tissue to be similar to native cartilage at 6 months. Patient-specific auricular constructs demonstrated long-term stability and increased cartilage tissue development during extended implantation, and offer a potential tissue-engineered solution for

  5. Clinical characteristics and long-term response to mood stabilizers in patients with bipolar disorder and different age at onset

    Directory of Open Access Journals (Sweden)

    Bernardo Dell’Osso

    2009-07-01

    Full Text Available Bernardo Dell’Osso1, Massimiliano Buoli1, Riccardo Riundi2, Nazario D’Urso1, Sara Pozzoli1, Roberta Bassetti2, Emanuela Mundo1,  A Carlo Altamura11Department of Psychiatry, University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milano, Italy; 2Department of Clinical Sciences, Luigi Sacco, Milano, ItalyIntroduction: Bipolar disorder (BD is a prevalent, comorbid, and impairing condition. Potential predictors of response to pharmacological treatment are object of continuous investigation in patients with BD. The present naturalistic study was aimed to assess clinical features and longterm response to mood stabilizers in a sample of bipolar subjects with different ages at onset. Methods: The study sample included 108 euthymic patients, diagnosed as affected by BD, either type I or II, according to the DSM-IV-TR, who were started on mood stabilizer treatment. Patients were followed-up for 24 months and the occurrence of any mood episode collected. At the end of the follow-up, patients were divided in three subgroups according to the age at onset (early-onset ≤30 years, middle-onset >30–≤45 years, and late-onset >45 years, respectively and the long-term response to mood stabilizers was compared between them along with other clinical features.Results: The three subgroups showed significant differences in terms of clinical and demographic features and, with respect to long-term response to mood stabilizers, the early-onset subgroup showed a better outcome in terms of reduction of major depressive episodes during the 24-month follow-up compared to the other subgroups (one way ANOVA, F = 3.57, p = 0.032. Conclusions: Even though further controlled studies are needed to clarify the relationship between age at onset and outcome in BD, the present follow-up study suggests clinical peculiarities and different patterns of response to mood stabilizers across distinct subgroups of patients with BD and

  6. Long-Term Stability of Core Language Skill in Children with Contrasting Language Skills

    Science.gov (United States)

    Bornstein, Marc H.; Hahn, Chun-Shin; Putnick, Diane L.

    2016-01-01

    This 4-wave longitudinal study evaluated stability of core language skill in 421 European American and African American children, half of whom were identified as low (n = 201) and half of whom were average-to-high (n = 220) in later language skill. Structural equation modeling supported loadings of multivariate age-appropriate multisource measures…

  7. Effects of short- and long-term thermal exposures on the stability of a Ni-Co-Cr-Si alloy

    International Nuclear Information System (INIS)

    Long-term thermal stability is often needed for high temperature alloys used in a variety of industrial applications for extended operating lifetimes. In this paper, the effects of thermal exposures or aging on the mechanical properties and microstructure of a Ni-Co-Cr-Si alloy (HAYNES (registered) HR-160 (registered) alloy) were studied. It includes both short- and long-term elevated temperature exposures ranging from 649 oC to 1093 oC (1200-2000 F) for duration of 6 min (0.1 h) to 6 years (50,000 h). The residual room temperature (RT) tensile and Charpy-V impact toughness properties were evaluated and correlated to microstructural changes as well as to fracture surfaces of the tensile tested samples. It was found that the RT ductility and impact toughness of the HR-160 alloy decreased continuously with time. A significant percentage of reduction in the ductility occurred in the initial 1000 h of exposure and the subsequent exposure led only to a minimal loss of ductility and impact toughness values. The concomitant microstructural changes were studied using optical metallography, SEM/EDS and X-ray diffraction of extracted residues. The results presented in this paper demonstrated that the HR-160 alloy exhibits good thermal stability characterized by >16% RT elongation after 50,000 h exposures at 649 oC, 760 oC, and 871 oC.

  8. Accuracy and stability of positioning in radiosurgery: Long term results of the Gamma Knife system

    International Nuclear Information System (INIS)

    The primary aim of this investigation was to determine the long term overall accuracy of an irradiation position of Gamma Knife systems. The mechanical accuracy of the system as well as the overall accuracy of an irradiation position was examined by irradiating radiosensitive films. To measure the mechanical accuracy, the GafChromic registered film was fixed by a special tool at the unit center point (UCP). For overall accuracy the film was mounted inside a phantom at a target position given by a two-dimensional cross. Its position was determined by CT or MRI scans, a treatment was planned to hit this target by use of the standard planning software and the radiation was finally delivered. This procedure is named ''system test'' according to DIN 6875-1 and is equivalent to a treatment simulation. The used GafChromic registered films were evaluated by high resolution densitometric measurements. The Munich Gamma Knife UCP coincided within x;y;z: -0.014±0.09 mm; 0.013±0.09 mm; -0.002±0.06 mm (mean±SD) to the center of dose distribution. There was no trend in the measured data observed over more than ten years. All measured data were within a sphere of 0.2 mm radius. When basing the target definition in the system test on MRI scans, we obtained an overall accuracy of an irradiation position in the x direction of 0.21±0.32 mm and in the y direction 0.15±0.26 mm (mean±SD). When a CT-based target definition was used, we measured distances in x direction 0.06±0.09 mm and in y direction 0.04±0.09 mm (mean±SD), respectively. These results were compared with those obtained with a Gamma Knife equipped with an automatic positioning system (APS) by use of a different phantom. This phantom was found to be slightly less accurate due to its mechanical construction and the soft fixation into the frame. The phantom related position deviation was found to be about ±0.2 mm, and therefore the measured accuracy of the APS Gamma Knife was evidently less precise by additional ±0

  9. Long-term stability of core language skill in children with contrasting language skills.

    Science.gov (United States)

    Bornstein, Marc H; Hahn, Chun-Shin; Putnick, Diane L

    2016-05-01

    This 4-wave longitudinal study evaluated stability of core language skill in 421 European American and African American children, half of whom were identified as low (n = 201) and half of whom were average-to-high (n = 220) in later language skill. Structural equation modeling supported loadings of multivariate age-appropriate multisource measures of child language on single latent variables of core language skill at 15 and 25 months and 5 and 11 years. Significant stability coefficients were obtained between language latent variables for children of low and average-to-high language skill, even accounting for child positive social interaction and nonverbal intelligence, maternal education and language, and family home environment. Prospects for children with different language skills and intervention implications are discussed. (PsycINFO Database Record PMID:26998572

  10. Kinetic concept of monitoring the long-term stability of a deep repository for radioactive waste

    International Nuclear Information System (INIS)

    This paper extends the recent works of the authors who now apply a rock fracture model based on kinetic theory to the monitoring of stability of radioactive waste repositories constructed in geological formations. The kinetic approach to the failure process was first formulated by Zhurkov (1957) for polymers and later expanded to cover rocks by Regel et al. , Petrov and others. A similar approach has been successfully applied in the field of solid state physics by Mikhailov, and Anikolenko and Mikhailov. 12 refs

  11. Long-term stability of global erosion rates and weathering during late-Cenozoic cooling

    OpenAIRE

    J. Willenbring; Friedhelm von Blanckenburg

    2010-01-01

    Over geologic timescales,CO2 is emitted from the Earth’s interior and is removed from the atmosphere by silicate rock weathering and organic carbon burial. This balance is thought to have stabilized greenhouse conditions within a range that ensured habitable conditions1. Changes in this balance have been attributed to changes in topographic relief, where varying rates of continental rock weathering and erosion1,2 are superimposed on fluctuations in organic carbon burial3. Geological strata pr...

  12. The Effects of Student Loans on Long-Term Household Financial Stability

    OpenAIRE

    Gicheva, Dora; Thompson, Jeffrey

    2014-01-01

    By examining how student borrowers fare financially after graduation, we attempt to further the existing knowledge of the costs associated with education debt and the manageability of the typical debt burden. We compare the financial stability of individuals who have borrowed for education to similar individuals who have not. We show that, keeping education constant, more student debt is associated with higher probability of being credit constrained and greater likelihood of declaring bankrup...

  13. Long term stability of paraoxonase-1 and high-density lipoprotein in human serum

    Directory of Open Access Journals (Sweden)

    Beekhof Piet K

    2012-05-01

    Full Text Available Abstract Background Paraoxonase-1 (PON1 is an enzyme with numerous functions and receives an increasing interest in clinical and epidemiological studies. Sometimes samples are stored for longer periods at a certain temperature. Therefore the stability of PON1 activity must be checked and retained upon storage for longer periods. Results In this study the stability of PON1 activity has been tested in human serum samples during storage up to 12 months at 3 commonly used temperatures, -20°C, -70°C and −196°C. It was found that the stability of the PON1 activity is constant during 12 months of storage at −70°C and −196°C. Storage at −20°C resulted in a small but statistically significant decrease after 6 months to about 94% of its original value. Nonetheless, the rank order between the samples at T = 0 and 12 months remained the same. The same temperature dependence was found for the associated high-density lipoprotein. Conclusions It can be concluded that −70°C is the right temperature for storage to maintain the PON1 activity for at least one year. Storage at a lower temperature in liquid nitrogen (−196°C is not necessary.

  14. Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal years 2010

    International Nuclear Information System (INIS)

    This annual report documents the progress of R and D in the first fiscal year during the JAEA 2nd Midterm Plan (FY 2010 - 2014) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planed framework is structured into the following categories: 1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, 2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and 3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this paper, the current status of R and D activities with previous scientific and technological progress is summarized. (author)

  15. Long-term microstructural stability of oxide-dispersion strengthened Eurofer steel annealed at 800 °C

    International Nuclear Information System (INIS)

    Oxide-dispersion strengthened ferritic martensitic steels such as ODS-Eurofer grade are good candidates for structural applications in future fusion power reactors. Long-term annealing treatments in vacuum were carried out in cold-rolled samples (80% reduction in thickness) from 1 h up to 4320 h (6 months) at 800 °C, i.e. the maximum temperature in the ferritic phase field, to follow its softening behavior. The microstructural stability of this steel was mapped using several characterization techniques including scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction, Vickers microhardness testing, X-ray diffraction texture measurements, low-temperature electrical resistivity, and magnetic coercive field measurements. ODS-Eurofer steel displays good microstructural stability. Discontinuous recrystallization occurs at the early stages of annealing resulting in a low volume fraction of recrystallized grains. Extended recovery is the predominant softening mechanism at this temperature for longer times

  16. Long-term microstructural stability of oxide-dispersion strengthened Eurofer steel annealed at 800 °C

    Energy Technology Data Exchange (ETDEWEB)

    Zilnyk, K.D. [Escola de Engenharia de Lorena – USP, 12600-970 Lorena, SP (Brazil); Sandim, H.R.Z., E-mail: hsandim@demar.eel.usp.br [Escola de Engenharia de Lorena – USP, 12600-970 Lorena, SP (Brazil); Bolmaro, R.E. [Instituto de Física Rosario, CONICET-UNR, 2000 Rosario (Argentina); Lindau, R.; Möslang, A. [Karlsruher Institut für Technologie, KIT, IAM-AWP, D-72061 Karlsruhe (Germany); Kostka, A.; Raabe, D. [Max-Planck Institut für Eisenforschung, MPI-E, D-40237 Düsseldorf (Germany)

    2014-05-01

    Oxide-dispersion strengthened ferritic martensitic steels such as ODS-Eurofer grade are good candidates for structural applications in future fusion power reactors. Long-term annealing treatments in vacuum were carried out in cold-rolled samples (80% reduction in thickness) from 1 h up to 4320 h (6 months) at 800 °C, i.e. the maximum temperature in the ferritic phase field, to follow its softening behavior. The microstructural stability of this steel was mapped using several characterization techniques including scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction, Vickers microhardness testing, X-ray diffraction texture measurements, low-temperature electrical resistivity, and magnetic coercive field measurements. ODS-Eurofer steel displays good microstructural stability. Discontinuous recrystallization occurs at the early stages of annealing resulting in a low volume fraction of recrystallized grains. Extended recovery is the predominant softening mechanism at this temperature for longer times.

  17. Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal years 2012

    International Nuclear Information System (INIS)

    This annual report documents the progress of R and D in the 3rd fiscal year during the JAEA 2nd Midterm Plan (FY 2010 - 2014) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: 1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, 2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and 3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this report, the current status of R and D activities with previous scientific and technological progress is summarized. (author)

  18. Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal years 2011

    International Nuclear Information System (INIS)

    This annual report documents the progress of R and D in the 2nd fiscal year during the JAEA 2nd Midterm Plan (FY 2010 - 2014) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: 1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, 2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and 3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this paper, the current status of R and D activities with previous scientific and technological progress is summarized. (author)

  19. Cesium Enhances Long-Term Stability of Lead Bromide Perovskite-Based Solar Cells

    OpenAIRE

    Kulbak, Michael; Gupta, Satyajit; Kedem, Nir; Levine, Igal; Bendikov, Tatyana; Hodes, Gary; Cahen, David

    2015-01-01

    Direct comparison between perovskite-structured hybrid organic-inorganic - methyl ammonium lead bromide (MAPbBr3) and all-inorganic cesium lead bromide (CsPbBr3), allows identifying possible fundamental differences in their structural, thermal and electronic characteristics. Both materials possess a similar direct optical band-gap, but CsPbBr3 demonstrates a higher thermal stability than MAPbBr3. In order to compare device properties we fabricated solar cells, with similarly synthesized MAPbB...

  20. Long-term stability of phase-separated Half-Heusler compounds

    OpenAIRE

    Krez, Julia; Balke, Benjamin; Felser, Claudia; Hermes, Wilfried; Schwind, Markus

    2015-01-01

    Half-Heusler (HH) compounds have shown high Figure of merits up to 1.5. The key to these high thermoelectric efficiencies is an intrinsic phase separation, which occurs in multicomponent Half-Heusler compounds and leads to an significantly reduction of the thermal conductivity. For commercial applications, compatible n- and p-type materials are essential and their thermal stability under operating conditions, e.g. for an automotive up to 873 K, needs to be guaranteed. For the first time, the ...

  1. Industrial concentrates of dermal hesperidin smartCrystals®--production, characterization & long-term stability.

    Science.gov (United States)

    Romero, Gregori B; Chen, Run; Keck, Cornelia M; Müller, Rainer H

    2015-03-30

    Industrial concentrates of hesperidin nanocrystals (5.0% nominal concentration) were produced applying the smartCrystal(®) combination technology of wet bead milling and subsequent high pressure homogenization. Stabilization was performed by Kolliphor(®) P 188, preservation by Euxyl PE 9010 and glycerol. Physical and chemical stability were monitored over 1.5 years of storage at 4-6 °C. The size of the bulk population stayed unchanged with about 250 nm (photon correlation spectroscopy). Absence of crystal growth by Ostwald ripening and absence of agglomerates were shown by laser diffraction (LD) and light microscopy. The LD diameter 90% was still 0.7 μm after 1.5 years. Despite the large surface of the nanosuspension in contact with the water phase, the chemical content proved also stable, only a reduction by 0.15% from 5.70% to 5.55% content was observed. The nanocrystals kept their crystalline state unchanged as shown by X-ray diffraction. The saturation solubility of the nanosuspension was more than triple compared to the raw drug powder in water. The data show the availability of a stable hesperidin concentrate as intermediate for industry to produce dermal formulations. PMID:25448556

  2. Long-term stability of sensitivity to intracortical microstimulation of somatosensory cortex

    Science.gov (United States)

    Callier, Thierri; Schluter, Erik W.; Tabot, Gregg A.; Miller, Lee E.; Tenore, Francesco V.; Bensmaia, Sliman J.

    2015-10-01

    Objective. The dexterous manipulation of objects depends heavily on somatosensory signals from the limb. The development of anthropomorphic robotic arms and of algorithms to decode intended movements from neuronal signals has stimulated the need to restore somatosensation for use in upper-limb neuroprostheses. Without touch and proprioception, patients have difficulty controlling prosthetic limbs to a level that justifies the required invasive surgery. Intracortical microstimulation (ICMS) through chronically implanted electrode arrays has the potential to provide rich and intuitive sensory feedback. This approach to sensory restoration requires, however, that the evoked sensations remain stable over time. Approach. To investigate the stability of ICMS-evoked sensations, we measured the ability of non-human primates to detect ICMS over experimental sessions that spanned years. Main results. We found that the performance of the animals remained highly stable over time, even when they were tested with electrodes that had experienced extensive stimulation. Significance. Given the stability of the sensations that it evokes, ICMS may thus be a viable approach for sensory restoration.

  3. Differences in long-term memory stability and AmCREB level between forward and backward conditioned honeybees (Apis mellifera

    Directory of Open Access Journals (Sweden)

    Johannes eFelsenberg

    2015-04-01

    Full Text Available In classical conditioning a predictive relationship between a neutral stimulus (conditioned stimulus; CS and a meaningful stimulus (unconditioned stimulus; US is learned when the CS precedes the US. In backward conditioning the sequence of the stimuli is reversed. In this situation animals might learn that the CS signals the end or the absence of the US. In honeybees 30 min and 24 h following backward conditioning a memory for the excitatory and inhibitory properties of the CS could be retrieved, but it remains unclear whether a late long-term memory is formed that can be retrieved 72 h following backward conditioning. Here we examine this question by studying late long-term memory formation in forward and backward conditioning of the proboscis extension response (PER. We report a difference in the stability of memory formed upon forward and backward conditioning with the same number of conditioning trials. We demonstrate a transcription-dependent memory 72 h after forward conditioning but do not observe a 72 h memory after backward conditioning. Moreover we find that protein degradation is differentially involved in memory formation following these two conditioning protocols. We report differences in the level of a transcription factor, the cAMP response element binding protein (CREB known to induce transcription underlying long-term memory formation, following forward and backward conditioning. Our results suggest that these alterations in CREB levels might be regulated by the proteasome. We propose that the differences observed are due to the sequence of stimulus presentation between forward and backward conditioning and not to differences in the strength of the association of both stimuli.

  4. Study on long-term stability of geological environment. A planning report in fiscal year of 2001

    International Nuclear Information System (INIS)

    According to the long-term program on nuclear energy in Japan and the report on division of nuclear energy of the Committee on Search of Natural Energy, the Japan Nuclear Cycle Development Institute (JNC) is required for secure promotion on R and Ds forward scientific research on deep underground upgrading of reliability on geological disposal technology based on secure accumulation of actually tested data and upgrading of model, and upgrading on safety evaluation', for its future R and D on geological disposal technology. Therefore, JNC intends to carry out the titled study in addition to plans of the Underground Research Laboratory, for scientific study on deep underground, in its middle and long-term business program. In the 'study on long-term stability of geological environment', some surveys and studies on natural phenomena capable of assuming feasibilities affected to the geological disposal system such as earthquakes/dislocations, volcanic actions, swells/erosions, climate/seawater level change, and so on, and for elucidation on their efforts on geological environments such as groundwater flow, regularity and scale of change, and so on, have been progressed. On the other hand, to upgrade technical reliability on the geological disposal, it is important to understand effect of crust changes on the geological environment and also to accumulate scientific knowledges on plate motions and forming mechanism on active faults capable of considering their causes. And, on the (frontier study on land region underground structure, behaviors of rock boards at deep underground is focused to intend to elucidate mechanism on earthquake formation and active faults generation. Here was summarized a performing program on these surveys and studies in fiscal year of 2002, at the Tono Geoscience Center of JNC. (G.K.)

  5. A long term stability of compressive residual stress in dissimilar welds by shot peening

    International Nuclear Information System (INIS)

    Stress improvement processes are countermeasures against stress corrosion cracking in nuclear power plant components. It is necessary to confirm whether the compressive residual stress exerted by stress improvement processes can be sustained under operation environment. In order to evaluate the stability of the compressive residual stress in operating conditions, the welded specimen after shot peening received 0.07% cyclic strain of 200 times at 593 K and a thermal aging treatment for 1.66 Ms at 673 K. Also, received thermal cycles at 593 K in 10 times repeatedly. As the result, it was confirmed that compressive residual stress by shot peening was sustained on the surface of the dissimilar welds of austenite stainless steel (SUS316L) and nickel base alloy (NCF600 and alloy182) under operating conditions. (author)

  6. Mathematical model of thermal shields for long-term stability optical resonators

    CERN Document Server

    Sanjuan, Josep; Braxmaier, Claus

    2015-01-01

    Modern experiments aiming at tests of fundamental physics, like measuring gravitational waves or testing Lorentz Invariance with unprecedented accuracy, require thermal environments that are highly stable over long times. To achieve such a stability, the experiment including typically an optical resonator is nested in a thermal enclosure, which passively attenuates external temperature fluctuations to acceptable levels. These thermal shields are usually designed using tedious numerical simulations or with simple analytical models. In this paper, we propose an accurate analytical method to estimate the performance of passive thermal shields in the frequency domain, which allows for fast evaluation and optimization. The model analysis has also unveil interesting properties of the shields, such as dips in the transfer function for some frequencies under certain combinations of materials and geometries. We validate the results by comparing them to numerical simulations performed with commercial software based on ...

  7. Long-Term Stability of Planets in the $\\alpha$ Centauri System

    CERN Document Server

    Quarles, Billy

    2016-01-01

    We evaluate the extent of the regions within the $\\alpha$ Centauri AB star system where small planets are able to orbit for billion-year timescales, and we calculate the positions on the sky plane where planets on stable orbits about either stellar component may appear. We confirm the qualitative results of Wiegert and Holman (AJ 113, 1445, 1997) regarding the approximate size of the regions of stable orbits, which are larger for retrograde orbits relative to the binary than for prograde orbits. Additionally, we find that mean motion resonances with the binary orbit leave an imprint on the limits of orbital stability, and the effects of the Lidov-Kozai mechanism are also readily apparent.

  8. Investigation of long term reactive stability of ceria for use in solar thermochemical cycles

    International Nuclear Information System (INIS)

    The use of an intermediate reactive material composed of cerium (IV) oxide (ceria) is explored for solar fuel production through a CO2-splitting thermochemical redox cycle. To this end, powder and porous ceria samples are tested with TGA (thermogravimetric analysis) to ascertain their maximum fuel production potential from the CeO2 → CeO2−δ cycle. A maximum value of the non-stoichiometric reduction factor δ of ceria powder was 0.0383 at 1450 °C. The reactive stability of a synthesized porous ceria sample is then observed with carbon dioxide splitting at 1100 °C and thermal reduction at 1450 °C. Approximately 86.4% of initial fuel production is retained after 2000 cycles, and the mean value of δ is found to be 0.0197. SEM (scanning electron microscopy) imaging suggests that the porous ceria structure is retained over 2000 cycles despite apparent loss of some surface area. EDS (energy dispersive x-ray spectroscopy) line scans show that oxidation of porous ceria becomes increasingly homogenous throughout the bulk material over an increasing number of cycles. Significant retention of reactivity and porous structure demonstrates the potential of porous ceria for use in a commercial thermochemical reactor. - Highlights: • Ceria is explored for solar fuel production through a CO2-splitting redox cycle. • Stability of porous ceria is observed with carbon dioxide splitting at 1100 °C. • Greater than 86% of initial fuel production is retained after 2000 cycles. • SEM imaging reveals that the porous structure is retained over 2000 cycles. • Findings reveal that ceria structures are compatible with actual implementation

  9. Long term thermomechanical stability of a spent fuel final repository located in granite at large depth

    International Nuclear Information System (INIS)

    The research program at INR Pitesti includes among other issues, the item of final disposal of the spent fuel from Cernavoda NPP. The heat release by the spent fuel and high radioactive waste leads to an increase of the temperature around each canister and in the granite rock. A series of processes such as canister's corrosion are dependent on the temperature. On the other hand, the temperature distribution inside the repository affects the stress and deformation state in different zones of the repository and implicitly its stability. The present work reports the results of a 3-D thermomechanical analysis carried out by means of ANSYS code for the final disposal of CANDU spent fuel from the Cernavoda NPP. The repository proposed consists in 72 parallel tunnels drilled in the granite rock at a 500 m depth. The spent fuel canisters are placed in parallel wells located at a 6 m distance from tunnel axis. The 3-D distribution of the temperature increase inside the repository after placing the fuel containers and tunnel closing are presented. The peak temperatures reached at the container's center and on its surface amount about 134 deg. C and 116 deg. C, respectively. These temperature values were reached at 25 years after containers' disposal inside the repository. Also, the stress distribution directly after excavation and after 25 years from containers' disposal was evaluated. The highest values of the axial stress were obtained in the canister's vicinity and at the tunnel ends. To evaluate the rock stability directly after excavation and at 25 years after containers' disposal the Hoek and Brown braking criterion was used

  10. A study on the long-term stability of the geological environments in and around the Horonobe area. Consideration of site specific features in assessing of the long-term stability of the geological environments

    International Nuclear Information System (INIS)

    This article provides the preliminary results of literature and field survey in terms of the long-term stability in and around the Horonobe area. The Horonobe area is situated in the Tenpoku Basin, and is dominated by the Neogene to Quaternary sedimentary sequences. Based on the time-stratigraphy and sedimentary analysis, depositional area has migrated from east to west in the basin. The distribution of hypocenters for micro-earthquake, geologic structures, and the Quaternary sediments indicate that present-day activity has been localized with the western part of the Horonobe area. In addition, the seismic reflection profiles of the Horonobe area show the growth structures of the fold-and-thrust belt of central Hokkaido suggesting that the ongoing-tectonics (neotectonics) in the study area has been begun in three to two million years ago. The Horonobe area has widespread distribution of the marine terrace deposits, which are correlated to the marine oxygen isotope stages (MIS) 9 through 5c. The elevation of these marine-terrace surfaces on axial part is higher than that of on limb in the Sarobetsu Anticline at the western part of the Horonobe area. The former shoreline of MIS 1 proceeded ca. 14 km away from that of MIS 7 although there is no great difference in global-scale sea-level in each stage. The active folds are distributed in area to be changed into land in MIS 1. In order to assess the long-term stability of geological environments in the test-field Horonobe area it is important to consider the faulting and folding effects to the uplifting, subsidence, migration of former shoreline and so on. (author)

  11. Long term adjustment of canopy root depth and strength: Implications catchment hydrology and slope stability

    Science.gov (United States)

    Hales, T. C.; Taehee, H.; Band, L.; Vose, J.

    2007-12-01

    The species composition of southern Appalachian forests is changing rapidly due to fire suppression, residential expansion and introduced parasites, such as the woody adelgid. Changes in the distribution and age of tree and understory species cause changes in rooting characteristics and therefore the stability of slopes. Roots increase soil cohesive strength and fail in tension during debris flows. The amount of root reinforcement to the soil mass is dependent on the number, size and tensile strength of the roots. We have characterized how changes in the composition of southern Appalachian forests, particularly the expansion of Rhododenron maximum due to fire suppression, may affect the potential for slope failure. We measured the vertical distribution and tensile strength of roots for fifteen individual trees and two mixed species locations in the Coweeta Hydrological Laboratory, North Carolina. The individual pits were chosen to capture variations in species (10 species total), topographic position (nose, side slope, hollow), and age (a range of DBH between 5 cm and 60 cm). Root tensile strengths from different hardwood species were very similar, while rhododendron, a woody shrub, has considerably weaker roots. Roots are concentrated close to the soil surface (at least 70% of biomass occurs within 50 cm of the surface) and variations in this pattern occur primarily as a function of age. R. maximum roots are shallower and weaker than tree roots, which when coupled with low transpiration rates, lowers the total cohesive strength and makes them susceptible to high pore pressure events. We have investigated the potential for mapping R. maximum based on the ratio of near-infrared to red within leaf-off color infrared images. When we combine the remotely-sensed distribution of R. maximum with the root cohesion data from individual pits, we can produce a realistic spatial distribution of root cohesion for southern Appalachian forests. The spatial distribution of root

  12. Long-term stability of underground operated CZT detectors based on the analysis of intrinsic 113Cd β--decay

    Science.gov (United States)

    Ebert, J.; Gößling, C.; Gehre, D.; Hagner, C.; Heidrich, N.; Klingenberg, R.; Kröninger, K.; Nitsch, C.; Oldorf, C.; Quante, T.; Rajek, S.; Rebber, H.; Rohatsch, K.; Tebrügge, J.; Temminghoff, R.; Theinert, R.; Timm, J.; Wonsak, B.; Zatschler, S.; Zuber, K.

    2016-06-01

    The COBRA collaboration operates a demonstrator setup at the underground facility Laboratori Nazionali del Gran Sasso (LNGS, located in Italy) to prove the technological capabilities of this concept for the search for neutrinoless double beta-decay. The setup consists of 64 (1×1×1) cm3 Cadmium-Zinc-Telluride (CZT) detectors in Coplanar-Grid (CPG) configuration. One purpose of this demonstrator is to test if reliable long-term operation of CZT-CPG detectors in such a setup is possible. The demonstrator has been operated under ultra low-background conditions for more than three years and collected data corresponding to a total exposure of 218 kg days. The presented study focuses on the long-term stability of CZT detectors by analyzing the intrinsic, fourfold forbidden non-unique 113Cd single beta-decay. It can be shown that CZT detectors can be operated stably for long periods of time and that the 113Cd single beta-decay can be used as an internal monitor of the detector performance during the runtime of the experiment.

  13. Long-Term Stability of Underground Operated CZT Detectors Based on the Analysis of Intrinsic $^{113}$Cd \\beta$^{-}$-Decay

    CERN Document Server

    Ebert, J; Gehre, D; Hagner, C; Heidrich, N; Klingenberg, R; Kroeninger, K; Nitsch, C; Oldorf, C; Quante, T; Rajek, S; Rebber, H; Rohatsch, K; Tebruegge, J; Temminghoff, R; Theinert, R; Timm, J; Wonsak, B; Zatschler, S; Zuber, K

    2015-01-01

    The COBRA collaboration operates a demonstrator setup at the underground facility LNGS (Laboratori Nazionali del Gran Sasso, located in Italy) to prove the technological capabilities of this concept for the search for neutrinoless double beta-decay. The setup consists of 64 $(1\\times\\!1\\times\\!1)$ cm$^{3}$ CZT detectors in CPG configuration. One purpose of this demonstrator is to test if reliable long-term operation of CZT-CPG detectors in such a setup is possible. The demonstrator has been operated under ultra low-background conditions since more than three years and collected data corresponding to an exposure of 218 kg$\\cdot$days. The presented study focuses on the long-term stability of CZT detectors by analyzing the intrinsic, fourfold forbidden non-unique $^{113}$Cd single beta-decay. It can be shown that CZT detectors can be operated stably for long periods of time and that the $^{113}$Cd single beta-decay can be used as an internal monitor of the detector performance during the runtime of the experimen...

  14. Long-Term Stability of Planets in the Alpha Centauri System

    Science.gov (United States)

    Lissauer, Jack; Quarles, Billy

    2015-01-01

    The alpha Centauri system is billions of years old, so planets are only expected to be found in regions where their orbits are long-lived. We evaluate the extent of the regions within the alpha Centauri AB star system where small planets are able to orbit for billion-year timescales, and we map the positions in the sky plane where planets on stable orbits about either stellar component may appear. We confirm the qualitative results of Wiegert & Holman (Astron. J. 113, 1445, 1997) regarding the approximate size of the regions of stable orbits of a single planet, which are larger for retrograde orbits relative to the binary than for pro-grade orbits. Additionally, we find that mean motion resonances with the binary orbit leave an imprint on the limits of orbital stability, and the effects of the Lidov-Kozai mechanism are also readily apparent. Overall, orbits of a single planet in the habitable zones near the plane of the binary are stable, whereas high-inclination orbits are short-lived. However, even well within regions where single planets are stable, multiple planet systems must be significantly more widely-spaced than they need to be around an isolated star in order to be long-lived.

  15. Feasibility study and technical proposal for long-term observations of bedrock stability with gps

    International Nuclear Information System (INIS)

    In order to study the regional crustal deformation pattern in the territory of Finland, the Finnish Geodetic Institute is establishing the Finnish Permanent GPS Network, which is part of the Fennoscandian Permanent GPS Network. The Finnish GPS Network consists of a 12 stations located in different geological structures. The operation procedure of the network is described in the report. Feasibility study for monitoring the bedrock stability at local scale was performed. The study was carried out on the basis of an experiment on a baseline of 1041 metres. Twelve artificial movements ranging from 1 mm to 22 mm were generated with a precision-manufactured screw drive (with an accuracy of better than +-0.05 mm). The artificial movements were then detected with the GPS measurements. A preliminary analysis of the GPS data shows that the maximum difference between the GPS detected movements and the artificial movements is 0.9 mm with a standard deviation of +-0.46 mm. The observation time for reaching such accuracy is about 55 minutes. Three GPS networks were preliminarily designed for the radioactive waste disposal investigation sites of Olkiluoto, Kivetty and Romuvaara. Detailed research plan for achieving the best possible result from GPS measurements was proposed. (58 refs., 25 figs., 1 tab.)

  16. An analysis of the long-term stability of the particle dynamics in hadron storage rings

    International Nuclear Information System (INIS)

    This thesis extends the stability analysis of the particle motion in a storage ring and estimates the diffusion rates well inside the dynamic aperture. The calculation of the drift and diffusion coefficients focuses on an application to the proton storage ring in HERA, where the proton beam lifetime drops considerably after the proton and electron beams are brought to collision. The analysis shows that the combined effect of slow and fast modulation frequencies leads to an increased emittance growth in the storage ring. HERA the slow frequency components are caused by ground motion in the HERA tunnel and the fast frequency components by ripples in the power supplies. The thesis provides upper limits for the modultion depths of a fast tune modulation which result in tolerable growth rates for the proton emittance. The analytically calculated drift coefficients agree numerical simulations for the particle dynamics. A comparison of the calculated drift coefficients with those measured in the HERA proton storage ring shows that the analyzed mechanism can lead to growth rates of the same order of magnitude as the ones measured during the luminosity operation in the HERA storage ring. Analytical estimates for the proton growth rates predict a high sensitivity to the particle diffusion on the frequency components of the fast fast tune modulation. This prediction was confirmed by a subsequent modulation experiment in the proton storage ring of HERA, where an external tune modulation with fast frequency components led to a drastic increase in the growth rates

  17. The dynamical structure of the MEO region: long-term stability, chaos, and transport

    Science.gov (United States)

    Daquin, Jérôme; Rosengren, Aaron J.; Alessi, Elisa Maria; Deleflie, Florent; Valsecchi, Giovanni B.; Rossi, Alessandro

    2016-04-01

    It has long been suspected that the Global Navigation Satellite Systems exist in a background of complex resonances and chaotic motion; yet, the precise dynamical character of these phenomena remains elusive. Recent studies have shown that the occurrence and nature of the resonances driving these dynamics depend chiefly on the frequencies of nodal and apsidal precession and the rate of regression of the Moon's nodes. Woven throughout the inclination and eccentricity phase space is an exceedingly complicated web-like structure of lunisolar secular resonances, which become particularly dense near the inclinations of the navigation satellite orbits. A clear picture of the physical significance of these resonances is of considerable practical interest for the design of disposal strategies for the four constellations. Here we present analytical and semi-analytical models that accurately reflect the true nature of the resonant interactions, and trace the topological organization of the manifolds on which the chaotic motions take place. We present an atlas of FLI stability maps, showing the extent of the chaotic regions of the phase space, computed through a hierarchy of more realistic, and more complicated, models, and compare the chaotic zones in these charts with the analytical estimation of the width of the chaotic layers from the heuristic Chirikov resonance-overlap criterion. As the semi-major axis of the satellite is receding, we observe a transition from stable Nekhoroshev-like structures at three Earth radii, where regular orbits dominate, to a Chirikov regime where resonances overlap at five Earth radii. From a numerical estimation of the Lyapunov times, we find that many of the inclined, nearly circular orbits of the navigation satellites are strongly chaotic and that their dynamics are unpredictable on decadal timescales.

  18. Long-term stability of global erosion rates and weathering during late-Cenozoic cooling.

    Science.gov (United States)

    Willenbring, Jane K; von Blanckenburg, Friedhelm

    2010-05-13

    Over geologic timescales, CO(2) is emitted from the Earth's interior and is removed from the atmosphere by silicate rock weathering and organic carbon burial. This balance is thought to have stabilized greenhouse conditions within a range that ensured habitable conditions. Changes in this balance have been attributed to changes in topographic relief, where varying rates of continental rock weathering and erosion are superimposed on fluctuations in organic carbon burial. Geological strata provide an indirect yet imperfectly preserved record of this change through changing rates of sedimentation. Widespread observations of a recent (0-5-Myr) fourfold increase in global sedimentation rates require a global mechanism to explain them. Accelerated uplift and global cooling have been given as possible causes, but because of the links between rates of erosion and the correlated rate of weathering, an increase in the drawdown of CO(2) that is predicted to follow may be the cause of global climate change instead. However, globally, rates of uplift cannot increase everywhere in the way that apparent sedimentation rates do. Moreover, proxy records of past atmospheric CO(2) provide no evidence for this large reduction in recent CO(2) concentrations. Here we question whether this increase in global weathering and erosion actually occurred and whether the apparent increase in the sedimentation rate is due to observational biases in the sedimentary record. As evidence, we recast the ocean dissolved (10)Be/(9)Be isotope system as a weathering proxy spanning the past approximately 12 Myr (ref. 14). This proxy indicates stable weathering fluxes during the late-Cenozoic era. The sum of these observations shows neither clear evidence for increased erosion nor clear evidence for a pulse in weathered material to the ocean. We conclude that processes different from an increase in denudation caused Cenozoic global cooling, and that global cooling had no profound effect on spatially and

  19. Influence of Previous Crop on Durum Wheat Yield and Yield Stability in a Long-term Experiment

    Directory of Open Access Journals (Sweden)

    Anna Maria Stellacci

    2011-02-01

    Full Text Available Long-term experiments are leading indicators of sustainability and serve as an early warning system to detect problems that may compromise future productivity. So the stability of yield is an important parameter to be considered when judging the value of a cropping system relative to others. In a long-term rotation experiment set up in 1972 the influence of different crop sequences on the yields and on yield stability of durum wheat (Triticum durum Desf. was studied. The complete field experiment is a split-split plot in a randomized complete block design with two replications; the whole experiment considers three crop sequences: 1 three-year crop rotation: sugar-beet, wheat + catch crop, wheat; 2 one-year crop rotation: wheat + catch crop; 3 wheat continuous crop; the split treatments are two different crop residue managements; the split-split plot treatments are 18 different fertilization formulas. Each phase of every crop rotation occurred every year. In this paper only one crop residue management and only one fertilization treatment have been analized. Wheat crops in different rotations are coded as follows: F1: wheat after sugar-beet in three-year crop rotation; F2: wheat after wheat in three-year crop rotation; Fc+i: wheat in wheat + catch crop rotation; Fc: continuous wheat. The following two variables were analysed: grain yield and hectolitre weight. Repeated measures analyses of variance and stability analyses have been perfomed for the two variables. The stability analysis was conducted using: three variance methods, namely the coefficient of variability of Francis and Kannenberg, the ecovalence index of Wricke and the stability variance index of Shukla; the regression method of Eberhart and Russell; a method, proposed by Piepho, that computes the probability of one system outperforming another system. It has turned out that each of the stability methods used has enriched of information the simple variance analysis. The Piepho

  20. An experimental set-up to measure the long-term stability of large-mirror supports

    CERN Document Server

    D'Ambrosio, C; Wertelaers, Piet; Wertelaers, Piet

    2000-01-01

    20-2000 Precision of the Cherenkov ring pattern recognition and reconstruction relies, apart from other factors, on highly precise and stable positioning of the spherical mirrors, which focus the Cherenkov light cones produced by the particle to form ring-images on the focal plane. Prototypes of adjustable mirror mountings that hold the mirrors on the support structure have to be tested for their long-term angular stability, in order to ensure that the mirrors will not change their precisely adjusted positions inside the detector vessel. A method, together with a set-up, for such a measurement is presented. As an example, measurement results from a mirror support prototype developed for the RICH2 detector in LHCb are described and discussed.

  1. Long-Term Charge/Discharge Cycling Stability of MnO2 Aqueous Supercapacitor under Positive Polarization

    KAUST Repository

    Ataherian, Fatemeh

    2011-01-01

    The long-term charge/discharge cycling stability of MnO 2 electrode under positive polarization in aqueous KCl electrolyte has been studied over different potential windows spanning from the open circuit potential to varied higher-end potential limited by O 2 evolution. Cycling up to 1.2 V (vs Ag/AgCl (aq)) causes partial (35) capacitance fading to a plateau value within the initial cycles, accompanied by morphological reconstruction, reduction of surface Mn ions and oxygen evolution. The surface Mn-ion reduction has been attributed to a two-step oxidation-reduction mechanism involving OH oxidation in electrolyte, based on electrochemical analysis. When cycling potential extends to 1.4 V, extensive oxygen evolution takes place. The combination of surface passivation of current collector and extensive gas bubbling, which deteriorates electrical contact among the constituent particles within the electrode, results in further monotonic capacitance reduction. © 2011 The Electrochemical Society.

  2. Wheat Grain Yield and Yield Stability in a Long-Term Fertilization Experiment on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    HAO Ming-De; FAN Jun; WANG Quan-Jiu; DANG Ting-Hui; GUO Sheng-Li; WANG Ji-Jun

    2007-01-01

    To provide a scientific basis for sustainable land management,a 20-year fertility experiment Was conducted in Changwu County,Shaanxi Province,China to investigate the effects of long-term application of chemical fertilizers on wheat grain yield and yield stability on the Loess Plateau using regression and stability analysis.The experiment consisted of 17fertilizer treatments.containing the combinations of different N and P levels,with three replications arranged in a randomized complete block design.Nitrogen fertilizer was applied as urea,and P was applied as calcium superphosphate.Fertilizer rates had a large effect on the response of wheat yield to fertilization.Phosphorus,combined with N,increased yield significantly(P≤0.01).In the unfertilized control and the N or P sole application treatments,wheat yield had a declining trend although it was not statistically significant.Stability analysis combined with the trend analysis indicated that integrated use of fertilizer N and P was better than their sole application in increasing and sustaining the productivity of rainfed winter wheat.

  3. Long term stability of yttria-stabilized zirconia waste forms. Stability for secular change of partitioned TRU waste composition by disintegration

    International Nuclear Information System (INIS)

    In this study, the stability of YSZ waste forms for secular change of partitioned TRU waste composition by disintegration, one of important terms in long-term stability, is the special concern. Designed amount of waste and YSZ powder were mixed and sintered. These TRU waste forms were submitted to tests of phase stability, chemical durability, mechanical property and compactness. The results were compared with those of another YSZ waste forms, non-radioactive Ce and/or Nd doped YSZ samples, and glass and Synroc waste forms. Experimental results show following: (1) Phase stability of (Np+Am)-, (Np+U)-, and (Np+U+Bi)-doped YSZ waste forms could be maintained of that of the initial Np+Am-doped YSZ waste form permanently even when the composition of partitioned TRU waste were changed by disintegration. (2) Secular change also accelerated volume increase of YSZ waste forms as well as alpha-decay damage. (3) Hv, E and KIC of (Np+U)- and (Np+U+Bi)-doped YSZ waste forms were independent of the secular change of the partitioned TRU waste composition by disintegration. (4) Mechanical properties of YSZ waste forms were more than those of a glass and Synroc waste forms. (5) Compactness of YSZ waste forms was good as waste forms for the partitioned TRU wastes. (J.P.N.)

  4. Carbazole dye with phosphonic acid anchoring groups for long-term heat stability of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    In dye-sensitized solar cells (DSSCs), the binding strength between the dye and TiO2 surface may affect the heat stability of the DSSCs. Carboxylic acids have generally been used as the anchoring groups for the adsorption of dyes on TiO2 surfaces. However, a phosphonic acid anchor is expected to effect more stable bonding to a TiO2 surface because of its tridentate binding capability. In this study, we developed a new carbazole dye that employed a phosphonic acid anchor, MK-94. We studied the effect of the dye anchoring group on the heat stability of DSSCs by comparing MK-94, MK-2 (a carbazole dye with a carboxylic acid anchoring group), and Z-907 (a well-known, robust Ru complex dye with a carboxylic acid anchoring group). In the initial performance assessment, the DSSC with MK-94 exhibited a lower short circuit current (jsc) but a higher open circuit voltage (ΔVoc) than MK-2. With respect to heat stability, decreases in jsc and ΔVoc were suppressed with MK-94, and the drop of the power conversion efficiency (PCE) was kept within 6% after 504 h of heating. In addition, MK-94 demonstrated the longest electron lifetime and largest charge transfer resistance than the other dyes during the stability test. In contrast, the PCE decreased 27% from the initial value in the DSSC with MK-2. Thus, the phosphonic acid anchor was effective in extending the long-term heat stability of the DSSCs

  5. Growth kinetics and long-term stability of CdS nanoparticles in aqueous solution under ambient conditions

    International Nuclear Information System (INIS)

    The ubiquity of naturally occurring nanoparticles in the aquatic environment is now widely accepted, but a better understanding of the conditions that promote their formation and persistence is needed. Using cadmium sulfide (CdS) as a model metal sulfide species, thiolate-capped CdS nanoparticles were prepared in the laboratory to evaluate how aquatic conditions influence metal sulfide nanoparticle growth and stability. This work examines CdS nanoparticle growth directly in aqueous solution at room temperature by utilizing the size-dependent spectroscopic properties of semiconductors detectable by UV/vis. CdS nanoparticle growth was governed by oriented attachment, a non-classical mechanism of crystallization in which small precursor nanoparticles coalesce to form larger nanoparticle products. Nanoparticle growth was slowed with increasing capping agent and decreasing ionic strength. In addition to examining the short-term (hours) growth of the nanoparticles, a long-term study was conducted in which cysteine-capped CdS nanoparticles were monitored over 3 weeks in solutions of various ionic strengths. The long-term study revealed an apparent shift from small nanoparticles to nanoparticles twice their original size, suggesting nanoparticle growth may continue through oriented attachment over longer time scales. High-ionic strength solutions resulted in salt-induced aggregation and eventual settling of nanoparticles within days, whereas low-ionic strength solutions were stable against settling over the course of the experiment. Sulfide recovery from cysteine-capped CdS nanoparticles as acid volatile sulfide was nearly quantitative after 2 weeks in fully oxygenated water, demonstrating significantly slowed oxidation of sulfide when complexed to Cd(II) within CdS nanoparticles. The nanoparticles were also shown to be resistant to oxidation by Fe(III) (hydr)oxide. This study illustrates that aggregation, rather than chemical oxidation, is likely more important to the

  6. Impact of long-term storage at ambient temperatures on the total quality and stability of high-pressure processed tomato juice

    OpenAIRE

    Jayathunge, K. G. L. R.; Grant, Irene R.; Linton, Mark; Patterson, Margaret F.; Koidis, Anastasios

    2015-01-01

    High-pressure processing (HPP) can produce tomato juice of high quality and safety with a short shelf life under refrigeration temperatures. Long-term higher temperature storage studies are rare and temperature tolerant products are challenging to develop. The effect of high-pressure processing (HPP) on the total quality (colour, microbial counts, phytochemical levels, antioxidant and enzymatic activities) and stability (retention over time) of tomato juice during long-term storage was invest...

  7. Predictors of long-term stability of maxillary dental arch dimensions in patients treated with a transpalatal arch followed by fixed appliances

    OpenAIRE

    Raucci, Gaetana; Elyasi, Maryam; Pachêco-Pereira, Camila; Grassia, Vincenzo; d’Apuzzo, Fabrizia; Flores-Mir, Carlos; Perillo, Letizia

    2015-01-01

    Background The aim of this retrospective study was to identify which dental and/or cephalometric variables were predictors of long-term maxillary dental arch stability in patients treated with a transpalatal arch (TPA) during the mixed dentition phase followed by full fixed appliances in the permanent dentition. Methods Thirty-six patients, treated with TPA followed up by full fixed appliances, were divided into stable and relapse groups based on the long-term presence or not of relapse. Inte...

  8. Long-term effective population sizes, temporal stability of genetic composition and potential for local adaptation in anadromous brown trout ( Salmo trutta ) populations

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Ruzzante, D.E.; Eg Nielsen, Einar;

    2002-01-01

    We examined the long-term temporal (1910s to 1990s) genetic variation at eight microsatellite DNA loci in brown trout (Salmo trutta L) collected from five anadromous populations in Denmark to assess the long-term stability of genetic composition and to estimate effective population sizes (N...... populations, and the documented recent declines of many other anadromous brown trout populations may affect the persistence of local adaptation....

  9. Key factors influencing the stability of silane solution during long-term surface treatment on carbon steel

    International Nuclear Information System (INIS)

    Highlights: •The corrosion-resistance time of silane films decreases with increasing cycle numbers. •The morphology of silane films prepared from aged solution is inhomogeneous. •Introduction of contamination ions is one reason for the poor property of aged solution. •Consumption of silane is the other reason for the poor property of aged solution. •Fe3+ accumulated is the key factor influencing the property of silane solution. -- Abstract: The mixtures of bis-[trimethoxysilylpropyl]amine and vinyltriacetoxysilane were used for surface treatment of carbon steel, aiming to investigate the factors influencing the stability of silane solution during long-term experiment from two aspects. One is the concentrations of contamination ions, and the other is mass of silane consumed per cycle which is calculated according to concentration of Si measured by silicon molybdenum blue photometry. The results indicate that the accumulation of contamination ions, especially Fe3+, is the main factor leading to the condensation between the Si–OH groups in silane solution, which is responsible for the downward stability of silane solution

  10. Long Term Stability Of Farmer Type Ionization Chamber Calibration Coefficient belonging To Local Radiotherapy Centres In Malaysia

    International Nuclear Information System (INIS)

    The accuracy of the ionization chambers calibration coefficient is one of the factors that would contribute to efficient radiotherapy treatment. The IAEA therefore has recommended that an ionization chamber be calibrated every year, with a condition that the deviations between the previous and new calibration coefficients ND,w should not differ by ±1.5 %. It has been identified that Farmer type ionization chambers is the most popular ionization chamber among the radiotherapy centres in Malaysia. For this reason, the purpose of this work is to evaluate the calibration coefficients long term stability of the Farmer type ionization chambers. A total of 33 Farmer type ionization chambers were studied and the mean μ of the ND,w deviation together with its standard error SE were calculated. This μ ±SE will be used to measure stability of ND,w. Our results showed that most chambers have μ ±SE lies within the ±1.5 %. It is thus concluded that most of the Farmer type ionization chamber were stable in their ND,w and safe to be used for radiotherapy treatment. (author)

  11. Monitoring of malolactic fermentation in wine using an electrochemical bienzymatic biosensor for L-lactate with long term stability.

    Science.gov (United States)

    Giménez-Gómez, Pablo; Gutiérrez-Capitán, Manuel; Capdevila, Fina; Puig-Pujol, Anna; Fernández-Sánchez, César; Jiménez-Jorquera, Cecilia

    2016-01-28

    L-lactic acid is monitored during malolactic fermentation process of wine and its evolution is strongly related with the quality of the final product. The analysis of L-lactic acid is carried out off-line in a laboratory. Therefore, there is a clear demand for analytical tools that enabled real-time monitoring of this process in field and biosensors have positioned as a feasible alternative in this regard. The development of an amperometric biosensor for L-lactate determination showing long-term stability is reported in this work. The biosensor architecture includes a thin-film gold electrochemical transducer selectively modified with an enzymatic membrane, based on a three-dimensional matrix of polypyrrole (PPy) entrapping lactate oxidase (LOX) and horseradish peroxidase (HRP) enzymes. The experimental conditions of the biosensor fabrication regarding the pyrrole polymerization and the enzymes entrapment are optimized. The biosensor response to L-lactate is linear in a concentration range of 1 × 10(-6)-1 × 10(-4) M, with a detection limit of 5.2 × 10(-7) M and a sensitivity of - (13500 ± 600) μA M(-1) cm(-2). The biosensor shows an excellent working stability, retaining more than 90% of its original sensitivity after 40 days. This is the determining factor that allowed for the application of this biosensor to monitor the malolactic fermentation of three red wines, showing a good agreement with the standard colorimetric method. PMID:26755146

  12. Effect of soil erosion on the long-term stability of FUSRAP near-surface waste-burial sites

    International Nuclear Information System (INIS)

    Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m3) of low-activity radioactive wastes (primarily contaminated soil and building materials) requiring subsequent disposal. It is likely that near-surface burial will be seriously considered as an option for disposal of these materials. A number of factors - including soil erosion - could adversely affect the long-term stability of a near-surface waste-burial site. The majority of FUSRAP sites are located in the humid eastern United States, where the principal cause of erosion is the action of water. This report examines the effect of soil erosion by water on burial-site stability based on analysis of four hypothetical near-surface burial sites. The Universal Soil Loss Equation was employed to estimate average annual soil loss from burial sites and the 1000-year effects of soil loss on the soil barrier (burial trench cap) placed over low-activity wastes. Results suggest that the land use of the burial site and the slope gradient of the burial trench cap significantly affect the rate of soil erosion. The development of measures limiting the potential land use of a burial site (e.g., mixing large rocks into the burial trench cap) may be required to preserve the integrity of a burial trench for long periods of time

  13. Long-term stability of decontamination effect in recreational areas near the town Novozybkov, Bryansk Region, Russia

    International Nuclear Information System (INIS)

    In 1995 and 1997, experimental decontamination campaigns were carried out in two recreational areas, Novie Bobovichi and Guta-Muravinka, near the town of Novozybkov, Bryansk Region, Russia. These areas were strongly affected by the Chernobyl fallout in 1986. In order to examine the long-term stability of the clean-up procedures, a programme has been carried out to continuously monitor the radiological situation in and around the decontaminated areas. This follow-up program consists of regular (1-3 times per year) measurements of absorbed gamma-dose rate in air (DR) at reference indoor and outdoor locations, repeated DR measurements on a grid, and gamma-spectrometric analysis of soil and other environmental samples. Very similar dynamics of the Chernobyl-related DR, mostly attributed to radiocaesium decay, were found in all the locations. For the period under study (September 1995-May 2003), the half-lives (years) for the reduction in radiocaesium-dependent DR contribution due to contaminant migration (in the following termed 'DRM half-lives') were, respectively, 52 ± 26, 57 ± 23, 43 ± 21, 46 ± 15, and 80 ± 56 for the following locations: untreated outdoors, treated outdoors, untreated indoors, treated indoors, and undisturbed forest-grassland plots outside the recreational areas. These relatively high values of the current DRM half-lives correspond very well with the results of soil core analyses, which showed no time-dependent changes in the mean mass depths of the 137Cs distribution, neither at treated nor at undisturbed plots. The following signs of natural restoration of the disturbed forest-meadow ecosystems have been observed at treated areas: formation of a new litter layer, development of grassy spots, mushroom growths and new generations of pines and birches. The levels of the 137Cs content in grass and mushrooms from treated plots were one or two orders of magnitude lower, than those registered in the samples from untreated areas. The follow-up study

  14. Long term stability studies of the Harshaw Tld 6600 system used for personal dosimetry monitoring in Ghana

    International Nuclear Information System (INIS)

    A dosimetry system made up of the Harshaw TLD 6600 has been used in the monitoring of occupationally exposed workers and for research purposes in Ghana since 1998. Continuous use, calibration and maintenance have been done periodically on the equipment at the Personal Monitoring Service (PMS) laboratory since its installation at the PMS laboratory of the Radiation Protection Institute in Ghana. The Daily Electronics Quality Control (DEQC) test carried out to ensure that the Harshaw 6600 TLD Reader was in good working condition prior to the reading of TLD cards. The present work was done to assess the long term stability of the system with respect to the DEQC parameter in order to ensure quality control and accurate measurements for personal dosimetry in Ghana. The parameters under investigation included the high voltage, temperature, reference light, plus and minus 15 volts, ground, digital to analog conversion and the photomultiplier tube noise. WINREMS software is incorporated into a computer to monitor these parameters in order to verify whether they conform to performance standards. The annual mean reference light values in nano coulomb for chip (ii) were 471.0±49.5, 77.0±109.2, 18.5±7.9, 31.0±81.1 and 18.7±3.2; for chip (iii) were 475.1±45.7, 102.4±132.8, 74.3±107.4, 83.7±125.3 and 8.6±3.1 respectively. These values are outside the reference ranges indicating instability for the period of five (5) years (2008 to 2012). Measurement of exposed TLDs to known doses at the SSDL confirmed the PMT gain stability of system. The instability in the reference light readings was due to ageing and yellowing of the optical portion of the reference light. The high voltage and the reference light were unstable. The temperature, plus and minus 15 volts, ground and digital to analog conversion and PMT noise were all stable. The study indicates the PMS therefore provides a reliable and accurate dosimetry in the long term. (au)

  15. Feasibility study and technical proposal for the use of microseismic methods in the long-term observation of bedrock stability

    International Nuclear Information System (INIS)

    Recent geodetic and seismological studies have paid attention to the slow deformation occurring in the Fennoscandian Shield. On the basis of these studies, together with in-situ stress measurements, the idea has been put forth that horizontal movement can be even greater than vertical movement. Local seismotectonics has importance in relation to the predictions of the long-term stability of the bedrock at the final disposal site. Potential direct and - what in Finland is more likely - indirect effects on the vault are due to local earthquakes of creep. The direct effects on the repository include rock vibration and displacement on an increasing fault. The indirect effects are changes in the surrounding structure, in the stress field, in the groundwater table, pressure, flux and chemistry. The block movements are controlled mainly by the network of fracture zones. The report deals with the possibilities to monitor by seismic methods slow movements occurring in the bedrock at the local level. The report includes descriptions of instrumentation for recording microearthquakes, the seismic network and an interpretation of the observations. The potential sites for disposal (Kuhmo, Aeaenekoski, Eurajoki) are compared in relation to seismic monitoring. Also the experiences of other investigations and a proposal for microearthquake investigations as well as of prospective developments within monitoring are presented. (28 refs., 17 figs.)

  16. A survey of short-term and long-term stability of tube parameters in a mammography unit

    Directory of Open Access Journals (Sweden)

    Praskalo Jovica Ž.

    2014-01-01

    Full Text Available In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012. The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems. [Projekat Ministarstva nauke Republike Srbije, br. 171007

  17. The long term stabilization of uranium mill tailings. Final report of a co-ordinated research project 2000-2004

    International Nuclear Information System (INIS)

    Mining and milling of uranium ores has been undertaken in many places around the world, resulting in large volumes of mining/milling residues with low activity concentrations of long lived nuclides that often have been disposed of in a haphazard fashion. This report summarizes the current state of the art of uranium mill tailings disposal and the results from an IAEA Coordinated Research Project (CRP) on technologies and strategies for their long term stabilization. The aim of the CRP was to develop conceptual and technical solutions that render tailings more inert over prolonged time spans, that render impounded materials and engineered structures stable over prolonged time spans, that minimize the need for active maintenance, and that are technically and economically feasible. The emphasis was on solutions that can be applied retrospectively, i.e. in a restoration/remediation context. It was recognized, however, that these objectives cannot be met by engineering design only, but must also involve appropriate management and planning procedures. Present day practices and new approaches of Brazil, Canada, China, Czech Republic, France, Germany, Kazakhstan, the Republic of Korea, Poland, the Russian Federation, Ukraine and the United States are discussed and indexed individually

  18. Field Supervisory Test of DREB-Transgenic Populus: Salt Tolerance, Long-Term Gene Stability and Horizontal Gene Transfer

    Directory of Open Access Journals (Sweden)

    Nan Lu

    2014-05-01

    Full Text Available Improving saline resistance may be useful for reducing environmental susceptibility and improving yields in poplar plantations. However, the instability of genetically engineered traits and gene transfer reduce their usefulness and commercial value. To investigate whether the foreign gene is still present in the genome of receptor plants after seven years (i.e., long-term foreign gene stability and gene transfer, we randomly analyzed ten field-grown transgenic hybrid Populus ((Populus tomentosa × Populus bolleana × P. tomentosa carrying the DREB1 gene from Atriplex hortensis. The results of PCR and tissue culture experiments showed that AhDREB1 was present in the transgenic trees and was still expressed. However, the transcriptional expression level had decreased compared with that four years earlier. The PCR results also indicated no foreign gene in the genomic DNA of microorganisms in the soil near the transgenic poplars, indicating that no significant gene transfer had occurred from the transgenic poplars to the microorganisms at seven years after planting.

  19. Long-term stability of organic carbon-stimulated chromatereduction in contaminated soils, and its relation to manganese redoxstatus

    Energy Technology Data Exchange (ETDEWEB)

    Tokunaga, Tetsu K.; Wan, Jiamin; Lanzirotti, Antonio; Sutton,Steve R.; Newville, Matthew; Rao, William

    2007-03-13

    In-situ reduction of toxic Cr(V1) to less hazardous Cr(II1)is becoming a popular strategy for remediating contaminated soils.However, the long term stability of reduced Cr remains to be understood,especially given the common presence of MnfIIIJV) oxides that reoxidizeCr(II1). This 4.6 year laboratory study tracked Cr and Mn redoxtransformations in soils contaminated with Cr(V1) which were then treatedwith different amounts of organic carbon (OC). Changes in Cr and Mnoxidation states within soils were directly and nondestructively measuredusing micro X-ray absorption near edge structure spectroscopy. Chromatereduction was roughly lst-order, and the extent of reduction was enhancedwith higher OC additions. However, significant Cr(||1) reoxidationoccurred in soils exposed to the highest Cr(V1) concentrations (2,560 mgkg"'). Transient Cr(II1) reoxidation up to 420 mg kg1 was measured at 1.1years after OC treatment, followed by further reduction. Chromateconcentrations increased by 220 mg kgm1a t the end of the study (4.6years) in one soil. The causal role that Mn oxidation state had inreoxidizing Cr was supported by trends in Mn K-edge energies. Theseresults provide strong evidence for longterm dependence of soil Croxidation states on balances between OC availability and Mn redoxstatus.

  20. KURD-ARAB TENSIONS ALONG THE GREEN LINE: IRAQ’S ROADBLOCK TO LONG-TERM STABILITY

    Directory of Open Access Journals (Sweden)

    Eugene J. Palka

    2011-08-01

    Full Text Available For nearly two millennia, the Kurds have inhabited a mountainous region known as Kurdistan, a territory including parts of Iraq, Syria, Turkey and Iran. Within Iraq, Kurds are the second largest ethnic group, comprising 15–20% of the population and constituting the majority of citizens in the provinces of Dohuk, Irbil and Sulaymaniyah. Historic rivalries between Iraqi Kurds and Arabs contribute to current social and political unrest, and pose an even greater challenge to long-term stability in the country. One of the most volatile issues fuelling Kurd-Arab tensions concerns the „Green Line‟, which on various maps separates Iraq‟s Kurdish and Arab populations. Initially established by Saddam Hussein in 1991, the ambiguous boundary has shifted north during Arabisation schemes and south as a result of Kurdish settlement and encroachment. More recently, on 19 March 2003, the Green Line was defined as the area controlled by the Kurdish Regional Government (KRG and recognised by the Iraqi Transitional Government when it passed the Transitional Administrative Law (TAL in 2004. Although the Iraqi Constitution recognises Kurdistan as a federal region, the precise boundary remains contentious. At stake are the historical ties to the territory along the Green Line, the associated oil reserves, and the status of the symbolic city of Kirkuk. Resolution of the disputed territories along the Green Line, the associated revenue sharing of the oil wealth, and the fate of Kirkuk, constitute a single, complex, multifaceted issue that will have a decisive impact on the future stability, if not integrity, of Iraq.

  1. Aspartame-stabilized gold-silver bimetallic biocompatible nanostructures with plasmonic photothermal properties, antibacterial activity, and long-term stability.

    Science.gov (United States)

    Fasciani, Chiara; Silvero, M Jazmin; Anghel, Maria Alexandra; Argüello, Gerardo A; Becerra, Maria Cecilia; Scaiano, Juan C

    2014-12-17

    Gold-silver core-shell nanoparticles stabilized with a common sweetener, aspartame (AuNP@Ag@Asm), combine the antimicrobial properties of silver with the photoinduced plasmon-mediated photothermal effects of gold. The particles were tested with several bacterial strains, while biocompatibility was verified with human dermal fibroblasts. PMID:25487127

  2. Long-term stability of the Leksell Gamma Knife{sup ®} Perfexion™ patient positioning system (PPS)

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, J., E-mail: josef.novotnyml@homolka.cz [Department of Radiation Oncology, Medical Physics Division, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213 (United States); Department of Medical Physics, Na Homolce Hospital, Prague 150 30 (Czech Republic); Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University in Prague, Prague 120 00 (Czech Republic); Department of Dosimetry and Application of Ionizing Radiation, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague 115 19 (Czech Republic); Department of Radiation Oncology, University Hospital Motol, Prague 150 06 (Czech Republic); Bhatnagar, J. P.; Xu, Y.; Huq, M. S. [Department of Radiation Oncology, Medical Physics Division, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213 (United States)

    2014-03-15

    Purpose: To assess the long-term mechanical stability and accuracy of the patient positioning system (PPS) of the Leksell Gamma Knife{sup ®} Perfexion™ (LGK PFX). Methods: The mechanical stability of the PPS of the LGK PFX was evaluated using measurements obtained between September 2007 and June 2011. Three methods were employed to measure the deviation of the coincidence of the radiological focus point (RFP) and the PPS calibration center point (CCP). In the first method, the onsite diode test tool with single diode detector was used together with the 4 mm collimator on a daily basis. In the second method, a service diode test tool with three diode detectors was used biannually at the time of the routine preventive maintenance. The test performed with the service diode test tool measured the deviations for all three collimators 4, 8, and 16 mm and also for three different positions of the PPS. The third method employed the conventional film pin-prick method. This test was performed annually for the 4 mm collimator at the time of the routine annual QA. To estimate the effect of the patient weight on the performance of the PPS, the focus precision tests were also conducted with varying weights on the PPS using a set of lead bricks. Results: The average deviations measured from the 641 daily focus precision tests were 0.1 ± 0.1, 0.0 ± 0.0, and 0.0 ± 0.0 mm, respectively, for the 4 mm collimator in the X (left/right of the patient), Y (anterior/posterior of the patient), and Z (superior/inferior of the patient) directions. The average of the total radial deviations as measured during ten semiannual measurements with the service diode test tool were 0.070 ± 0.029, 0.060 ± 0.022, and 0.103 ± 0.028 mm, respectively for the central, long, and short diodes for the 4 mm collimator. Similarly, the average total radial deviations measured during the semiannual measurements for the 4, 8, and 16 mm collimators and using the central diode were 0.070 ± 0.029, 0.097 ± 0

  3. Enhanced stability of multilayer graphene-supported catalysts for polymer electrolyte membrane fuel cell cathodes

    Science.gov (United States)

    Marinkas, A.; Hempelmann, R.; Heinzel, A.; Peinecke, V.; Radev, I.; Natter, H.

    2015-11-01

    One of the biggest challenges in the field of polymer electrolyte membrane fuel cells (PEMFC) is to enhance the lifetime and the long-term stability of PEMFC electrodes, especially of cathodes, furthermore, to reduce their platinum loading, which could lead to a cost reduction for efficient PEMFCs. These demands could be achieved with a new catalyst support architecture consisting of a composite of carbon structures with significant different morphologies. A highly porous cathode catalyst support layer is prepared by addition of various carbon types (carbon black particles, multi-walled carbon nanotubes (MWCNT)) to multilayer graphene (MLG). The reported optimized cathodes shows extremely high durability and similar performance to commercial standard cathodes but with 89% lower Pt loading. The accelerated aging protocol (AAP) on the membrane electrode assemblies (MEA) shows that the presence of MLG increases drastically the durability and the Pt-extended electrochemical surface area (ECSA). In fact, after the AAP slightly enhanced performance can be observed for the MLG-containing cathodes instead of a performance loss, which is typical for the commercial carbon-based cathodes. Furthermore, the presence of MLG drastically decreases the ECSA loss rate. The MLG-containing cathodes show up to 6.8 times higher mass-normalized Pt-extended ECSA compared to the commercial standard systems.

  4. Long-term stability of RNA in post-mortem bovine skeletal muscle, liver and subcutaneous adipose tissues

    Directory of Open Access Journals (Sweden)

    Schmidt Olaf

    2007-11-01

    Full Text Available Abstract Background Recovering high quality intact RNA from post-mortem tissue is of major concern for gene expression studies in animals and humans. Since the availability of post-mortem tissue is often associated with substantial delay, it is important that we understand the temporal variation in the stability of total RNA and of individual gene transcripts so as to be able to appropriately interpret the data generated from such studies. Hence, the objective of this experiment was to qualitatively and quantitatively assess the integrity of total and messenger RNA extracted from bovine skeletal muscle, subcutaneous adipose tissue and liver stored at 4°C at a range of time points up to 22 days post-mortem. These conditions were designed to mimic the environment prevailing during the transport of beef from the abattoir to retail outlets. Results The 28S and 18S rRNA molecules of total RNA were intact for up to 24 h post-mortem in liver and adipose tissues and up to 8 days post-mortem in skeletal muscle. The mRNA of housekeeping genes (GAPDH and ACTB and two diet-related genes (RBP5 and SCD were detectable up to 22 days post-mortem in skeletal muscle. While the mRNA stability of the two housekeeping genes was different in skeletal muscle and liver, they were similar to each other in adipose tissue. After 22 days post-mortem, the relative abundance of RBP5 gene was increased in skeletal muscle and in adipose tissue and decreased in liver. During this period, the relative abundance of SCD gene also increased in skeletal muscle whereas it decreased in both adipose tissue and liver. Conclusion Stability of RNA in three tissues (skeletal muscle, subcutaneous adipose tissue and liver subjected to long-term post-mortem storage at refrigeration temperature indicated that skeletal muscle can be a suitable tissue for recovering biologically useful RNA for gene expression studies even if the tissue is subjected to post-mortem storage for weeks, whereas

  5. [Implantable cardioverter/defibrillator: long-term stability of the defibrillation threshold with a unipolar electrode configuration (active-can")].

    Science.gov (United States)

    Knuefermann, P; Wolpert, C; Spehl, S; Korte, T; Manz, M; Lüderitz, B; Jung, W

    2000-09-01

    .291). Although there was an initial decrease in the DFT at seven to ten days, the long-term stability of the DFT up to one year remained stable in the devices with the "active-can" lead system. PMID:11077687

  6. The influence of biochar type on long-term stabilization for Cd and Cu in contaminated paddy soils.

    Science.gov (United States)

    Li, Hongying; Ye, Xinxin; Geng, Zhigang; Zhou, Hongjian; Guo, Xisheng; Zhang, Yunxia; Zhao, Huijun; Wang, Guozhong

    2016-03-01

    Long-term effect of biochar on PTEs (potential toxic elements) immobilization depends upon biochar own property and its aging process in soil. To understand the role of biachar type on PTEs stabilization, two types of biochar, corn-straw-derived biochar (CB) and hardwood-derived biochar (HB), were compared for their efficacy in achieving a stable decrease in the bio-availability of Cd and Cu in soils. The 3-year pot-culture experiment showed that HB reduced the concentration of CaCl2-extractable Cd and Cu by 57.9 and 63.8% in soil, and Cd and Cu uptake by 63.6 and 56.3% in rice tissue respectively, in the first year, whereas these values increased in the next two years. On the other hand, CB decreased these values steadily year by year. At the end of the 3 years, CB at 5% level had lowered the levels of CaCl2-extractable Cd and Cu by 53.6 and 66.8%, respectively. These variations between CB and HB were due to the differences in the way the two types of biochar age in the soil. The aging process was simulated in the laboratory, and the XPS results showed that the oxidization of the biochars introduced more oxygen-containing groups (especially carboxyl) on the surface of CB than HB, leading to a correspondingly greater number of oxygenated binding sites for Cd and Cu in the case of CB. The content of lignin was the major factor resulting in the variation of oxidation degree in two biochars. These results suggest that it is important to select the right kind of biochar to stably decrease the bio-availability of potential toxic elements (Cd and Cu) in contaminated soils. PMID:26546702

  7. Long-term stability of neural prosthetic control signals from silicon cortical arrays in rhesus macaque motor cortex

    Science.gov (United States)

    Chestek, Cynthia A.; Gilja, Vikash; Nuyujukian, Paul; Foster, Justin D.; Fan, Joline M.; Kaufman, Matthew T.; Churchland, Mark M.; Rivera-Alvidrez, Zuley; Cunningham, John P.; Ryu, Stephen I.; Shenoy, Krishna V.

    2011-08-01

    Cortically-controlled prosthetic systems aim to help disabled patients by translating neural signals from the brain into control signals for guiding prosthetic devices. Recent reports have demonstrated reasonably high levels of performance and control of computer cursors and prosthetic limbs, but to achieve true clinical viability, the long-term operation of these systems must be better understood. In particular, the quality and stability of the electrically-recorded neural signals require further characterization. Here, we quantify action potential changes and offline neural decoder performance over 382 days of recording from four intracortical arrays in three animals. Action potential amplitude decreased by 2.4% per month on average over the course of 9.4, 10.4, and 31.7 months in three animals. During most time periods, decoder performance was not well correlated with action potential amplitude (p > 0.05 for three of four arrays). In two arrays from one animal, action potential amplitude declined by an average of 37% over the first 2 months after implant. However, when using simple threshold-crossing events rather than well-isolated action potentials, no corresponding performance loss was observed during this time using an offline decoder. One of these arrays was effectively used for online prosthetic experiments over the following year. Substantial short-term variations in waveforms were quantified using a wireless system for contiguous recording in one animal, and compared within and between days for all three animals. Overall, this study suggests that action potential amplitude declines more slowly than previously supposed, and performance can be maintained over the course of multiple years when decoding from threshold-crossing events rather than isolated action potentials. This suggests that neural prosthetic systems may provide high performance over multiple years in human clinical trials.

  8. Estimation of absorbed dose in clinical radiotherapy linear accelerator beams: effect of ion chamber calibration and long-term stability

    International Nuclear Information System (INIS)

    The measured dose in water at reference point in phantom is a primary parameter for planning the treatment monitor units (MU); both in conventional and intensity modulated/image guided treatments. Traceability of dose accuracy therefore still depends mainly on the calibration factor of the ion chamber/dosimeter provided by the accredited Secondary Standard Dosimetry Laboratories (SSDLs), under International Atomic Energy Agency (IAEA) network of laboratories. The data related to Nd,water calibrations, thermoluminescent dosimetry (TLD) postal dose validation, inter-comparison of different dosimeter/electrometers, and validity of Nd,water calibrations obtained from different calibration laboratories were analyzed to find out the extent of accuracy achievable. Nd,w factors in Gray/Coulomb calibrated at IBA, GmBH, Germany showed a mean variation of about 0.2% increase per year in three Farmer chambers, in three subsequent calibrations. Another ion chamber calibrated in different accredited laboratory (PTW, Germany) showed consistent Nd,w for 9 years period. The Strontium-90 beta check source response indicated long-term stability of the ion chambers within 1% for three chambers. Results of IAEA postal TL 'dose intercomparison' for three photon beams, 6 MV (two) and 15 MV (one), agreed well within our reported doses, with mean deviation of 0.03% (SD 0.87%) (n = 9). All the chamber/electrometer calibrated by a single SSDL realized absorbed doses in water within 0.13% standard deviations. However, about 1-2% differences in absorbed dose estimates observed when dosimeters calibrated from different calibration laboratories are compared in solid phantoms. Our data therefore imply that the dosimetry level maintained for clinical use of linear accelerator photon beams are within recommended levels of accuracy and uncertainities are within reported values. (author)

  9. An investigation on the chemical stability and a novel strategy for long-term stabilization of diphenylalanine nanostructures in aqueous solution

    Directory of Open Access Journals (Sweden)

    H. Nezammahalleh

    2015-01-01

    Full Text Available The stability of diphenylalanine (FF microwires and microtubes in phosphate buffer solution was investigated and a novel strategy was developed for their chemical stabilization. This stability investigation was carried out by optical microscopy and by high performance liquid chromatography (HPLC. These microstructures dissolve in the solution depending upon their degree of FF saturation. The dissolution mechanisms of the structures in kinetically limited processes were found by accurately fitting the experimental dissolution data to a theoretical kinetic equation. The dissolution data were well fitted to the particular Avrami-Erofe’ev kinetic expression (R2 > 0.98. These findings suggest that the structures can be stabilized by a decrease in the hydration of the constituent molecules thorough a chemical conformational induced transition upon heat treatment. The stable microtubes were fabricated in a novel three step procedure consisting of the reduction of silver ions in unstable FF microtubes by a citrate reductant, the stabilization by chemical conformational induced transition upon heat treatment, and the consequent oxidation of the reduced silver by a persulfate oxidant. These materials were characterized by electron microscopy and powder X-ray diffraction techniques. The long-term stability of both structures was also confirmed by optical microscopy and HPLC.

  10. An investigation on the chemical stability and a novel strategy for long-term stabilization of diphenylalanine nanostructures in aqueous solution

    Science.gov (United States)

    Nezammahalleh, H.; Amoabediny, G.; Kashanian, F.; Foroughi Moghaddam, M. H.

    The stability of diphenylalanine (FF) microwires and microtubes in phosphate buffer solution was investigated and a novel strategy was developed for their chemical stabilization. This stability investigation was carried out by optical microscopy and by high performance liquid chromatography (HPLC). These microstructures dissolve in the solution depending upon their degree of FF saturation. The dissolution mechanisms of the structures in kinetically limited processes were found by accurately fitting the experimental dissolution data to a theoretical kinetic equation. The dissolution data were well fitted to the particular Avrami-Erofe'ev kinetic expression (R2 > 0.98). These findings suggest that the structures can be stabilized by a decrease in the hydration of the constituent molecules thorough a chemical conformational induced transition upon heat treatment. The stable microtubes were fabricated in a novel three step procedure consisting of the reduction of silver ions in unstable FF microtubes by a citrate reductant, the stabilization by chemical conformational induced transition upon heat treatment, and the consequent oxidation of the reduced silver by a persulfate oxidant. These materials were characterized by electron microscopy and powder X-ray diffraction techniques. The long-term stability of both structures was also confirmed by optical microscopy and HPLC.

  11. Several Days of CPEB-Dependent Local Protein Synthesis Are Required to Stabilize Synaptic Growth for Persistence of Long-Term Facilitation in Aplysia

    OpenAIRE

    Miniaci, Maria Concetta; Kim, Joung-Hun; Puthenveettil, Sathyanarayanan; Si, Kausik; Zhu, Huixiang; Kandel, Eric R.; Bailey, Craig H.

    2008-01-01

    The time course of the requirement for local protein synthesis in the stabilization of learning-related synaptic growth and the persistence of long-term memory was examined using Aplysia bifurcated sensory neuron-motor neuron cultures. We find that following repeated pulses of serotonin (5-HT) the local perfusion of emetine, an inhibitor of protein synthesis, or a TAT-AS oligonucleotide directed against ApCPEB blocks long-term facilitation (LTF) at either 24 hr or 48 hr and leads to a selecti...

  12. Stability of treatment with self-ligating brackets and conventional brackets in adolescents: a long-term follow-up retrospective study

    OpenAIRE

    Yu, Zhou; Jiaqiang, Lin; Weiting, Chen; Wang, Yi; Zhen, MinLing; Ni, Zhenyu

    2014-01-01

    Objectives The aim of this study was to assess the long-term stability of treatment with self-ligating brackets compared with conventional brackets. Materials and methods The long-term follow-up retrospective study sample consisted of two groups of patients: group SL (including passive and interactive self ligating braces) comprised 30 subjects treated with self-ligating brackets at a mean pretreatment (T0) age of 13.56 years, with a mean follow up period for 7.24 years; group CL comprised 30...

  13. LONG-TERM STABILITY OF THE LOCAL GROUND CONTROL NETWORK AT THE CO-LOCATION SITE OF MEDICINA

    Science.gov (United States)

    Abbondanza, C.; Sarti, P.; Legrand, J.

    2009-12-01

    ITRF combinations rely on the availability of accurate tie vectors linking reference points of space geodetic techniques. Co-located instruments are assumed to move consistently and no local relative motion is taken into account. Instabilities may degrade the quality of the co-location itself and perturb the result of ITRF combinations. This work aims to determine the stability of the local ground control network at Medicina (Italy) with independent surveying methods. The observatory hosts a co-location between a VLBI telescope and two GPS antennas, MEDI and MSEL. It is located in the Po Plain where thick layers of clays are the prevalent soil characteristics. Hence, provision of long term stability of geodetic monuments is a challenge and monitoring their stability is an issue. MEDI and the VLBI station regularly contribute to the determination of ITRF, while MSEL is part of the EUREF network. A set of five tie vectors observations linking the VLBI and MEDI reference points was acquired between 2001 and 2007. It is our main tool for performing local deformation analysis. Additionally, the GPS time series of MEDI and MSEL were used to cross check and confirm the local instability detected by terrestrial methods. To achieve a rigorous and reliable investigation of the local stability, multi-epoch terrestrial observations were homogeneously processed according to common parameterizations in a consistent reference frame. Similarly, continuous GPS observations from MEDI and MSEL were analysed according to the new EPN reprocessing strategy in order to monitor the short baseline between MEDI and MSEL; to spotlight any change in its length. Both approaches confirm differential motions at the site which can be related to monument instabilities originated by the particularly unfavourable local geological setting and the inapt design of the monuments foundation. The monuments move non homogeneously at rates reaching up to 1.6 mm/year, this value being comparable to intra

  14. Long-term evolution of techno-social networks: Statistical regularities, predictability and stability of social behaviors

    CERN Document Server

    Godoy-Lorite, Antonia; Sales-Pardo, Marta

    2016-01-01

    In social networks, individuals constantly drop ties and replace them by new ones in a highly unpredictable fashion. This highly dynamical nature of social ties has important implications for processes such as the spread of information or of epidemics. Several studies have demonstrated the influence of a number of factors on the intricate microscopic process of tie replacement, but the macroscopic long-term effects of such changes remain largely unexplored. Here we investigate whether, despite the inherent randomness at the microscopic level, there are macroscopic statistical regularities in the long-term evolution of social networks. In particular, we analyze the email network of a large organization with over 1,000 individuals throughout four consecutive years. We find that, although the evolution of individual ties is highly unpredictable, the macro-evolution of social communication networks follows well-defined statistical laws, characterized by exponentially decaying log-variations of the weight of socia...

  15. Characterization of long-term stability of PDMS-based chemo-optical transducer driving distributed fiber optic sensor of ammonia gas

    Science.gov (United States)

    Aubrecht, Jan; Kalvoda, Ladislav; Fojtikova, Jaroslava

    2016-05-01

    Long-term chemical stability of organometallic reagents incorporated into polydimethylsiloxane matrix of polymer-clad optical fibres by soaking method is investigated by means of VIS/NIR absorption spectroscopy, proton-induced X-ray emission and electron paramagnetic resonance spectroscopy. Based on the obtained experimental results, a modified procedure of sensing coatings preparation is proposed leading to significantly reduced decay of optical properties with time and allowing thus fabrication of practically applicable long sensing fibres.

  16. Treatment outcome and long-term stability of skeletal changes following maxillary distraction in adult subjects of cleft lip and palate

    OpenAIRE

    Satinder Pal Singh; Ashok Kumar Jena; Vidya Rattan; Ashok Kumar Utreja

    2012-01-01

    Aim : To evaluate the treatment outcome and long-term stability of skeletal changes following maxillary advancement with distraction osteogenesis in adult subjects of cleft lip and palate. Materials and Methods: Total 12 North Indian adult patients in the age range of 17-34 years with cleft lip and palate underwent advancement of maxilla by distraction osteogenesis. Lateral cephalograms recorded prior to distraction, at the end of distraction, 6 months after distraction, and at least 24 month...

  17. 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)

  18. Long-Term Stability and Safety of Transgenic Cultured Epidermal Stem Cells in Gene Therapy of Junctional Epidermolysis Bullosa

    Directory of Open Access Journals (Sweden)

    Laura De Rosa

    2014-01-01

    Full Text Available We report a long-term follow-up (6.5 years of a phase I/II clinical trial envisaging the use of autologous genetically modified cultured epidermal stem cells for gene therapy of junctional epidermolysis bullosa, a devastating genetic skin disease. The critical goals of the trial were to evaluate the safety and long-term persistence of genetically modified epidermis. A normal epidermal-dermal junction was restored and the regenerated transgenic epidermis was found to be fully functional and virtually indistinguishable from a normal control. The epidermis was sustained by a discrete number of long-lasting, self-renewing transgenic epidermal stem cells that maintained the memory of the donor site, whereas the vast majority of transduced transit-amplifying progenitors were lost within the first few months after grafting. These data pave the way for the safe use of epidermal stem cells in combined cell and gene therapy for genetic skin diseases.

  19. Influence of Z-phase on long-term creep stability of martensitic 9-12%Cr steels

    Energy Technology Data Exchange (ETDEWEB)

    Hald, J. [DONG Energy (Denmark)]|[Vattenfall Europe AG, Berlin (Germany)]|[DTU Mechanical Engineering (Denmark); Danielsen, H.K. [DTU Mechanical Engineering (Denmark)

    2008-07-01

    The long-term creep strength of the new generation of martensitic creep resistant 9- 12% Cr steels since the well-known steel Grade 91 relies strongly on particle strengthening by fine MN nitrides based on V and Nb. During long-term hightemperature exposures the MN nitrides may be replaced by the thermodynamically more stable Z-phases (Cr(V,Nb)N) causing a breakdown in creep strength. Cr contents above 10.5% strongly accelerate Z-phase precipitation, which explains the lack of success for all attempts to develop martensitic creep resistant steels with high Cr content for oxidation protection. The Z-phase nucleation process by Cr-diffusion into pre-existing MN nitrides is rate controlling for the Z-phase transformation. More work is needed before effects of chemical composition on the nucleation process can be reliably modeled. Careful control of the Z-phase precipitation process has led to the design of experimental 12%Cr martensitic steels strengthened by Z-phase. Such steels may again enable the combination of high strength and oxidation resistance in the same alloy. This opens a new pathway for further alloy development of the heat resistant martensitic steels. (orig.)

  20. Comparison of long-term stability of containment systems for residues and wastes contaminated with naturally occurring radionuclides at an arid site and two humid sites

    International Nuclear Information System (INIS)

    The long-term stability of near-surface containment systems designed for the management of radioactive wastes and residues contaminated with naturally occurring radionuclides are compared at the three different sites. The containment designs are: (1) a diked 8.9-m high mound, including a 3.2-m layered cap at a site (humid) near Lewiston, New York, (2) a 6.8-m-high mound, including a similar 3.2-m cap at a site (humid) near Oak Ridge, Tennessee, and (3) 4.8-m deep trenches with 3.0-m backfilled caps at a site (arid) near Hanford, Washington. Geological, hydrological, and biological factors affecting the long-term (1000-year) integrity of the containment systems at each site are examined, including: erosion, flooding, drought, wildfire, slope and cover failure, plant root penetration, burrowing animals, other soil-forming processes, and land-use changes. For the containment designs evaluated, releases of radon-222 at the arid site are predicted to be several orders of magnitude higher than at the two humid sites-upon initial burial and at 1000 years (after severe erosion). Transfer of wastes containing naturally occurring radionuclides from a humid to an arid environment offers little or no advantage relative to long-term stability of the containment system and has a definite disadvantage in terms of gaseous radioactive releases. 26 references, 2 figures, 4 tables

  1. Comparison of long-term stability of containment systems for residues and wastes contaminated with naturally occurring radionuclides at an arid site and two humid sites

    International Nuclear Information System (INIS)

    The long-term stability of near-surface containment systems designed for the management of radioactive wastes and residues contaminated with naturally occurring radionuclides are compared at the three different sites. The containment designs are: (1) a diked 8.9-m high mound, including a 3.2-m layered cap at a site (humid) near Lewiston, New York, (2) a 6.8-m-high mound, including a similar 3.2-m cap at a site (humid) near Oak Ridge, Tennessee, and (3) 4.8-m deep trenches with 3.0-m backfilled caps at a site (arid) near Hanford, Washington. Geological, hydrological, and biological factors affecting the long-term (1000-year) integrity of the containment systems at each site are examined, including: erosion, flooding, drought, wildfire, slope and cover failure, plant root penetration, burrowing animals, other soil-forming processes, and land-use changes. For the containment designs evaluated, releases of radon-222 at the arid site are predicted to be several orders of magnitude higher than at the two humid sites - upon initial burial and at 1000 years (after severe erosion). Transfer of wastes containing naturally occurring radionuclides from a humid to an arid environment offers little or no advantage relative to long-term stability of the containment system and has a definite disadvantage in terms of gaseous radioactive releases. 26 references, 3 figures, 4 tables

  2. Long-term effective population sizes, temporal stability of genetic composition and potential for local adaptation in anadromous brown trout ( Salmo trutta ) populations

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Ruzzante, D.E.; Eg Nielsen, Einar; Bekkevold, Dorte; Mensberg, Karen-Lise Dons

    2002-01-01

    We examined the long-term temporal (1910s to 1990s) genetic variation at eight microsatellite DNA loci in brown trout (Salmo trutta L) collected from five anadromous populations in Denmark to assess the long-term stability of genetic composition and to estimate effective population sizes (N...... (3 km) river showed Ne greater than or equal to 300. Assuming a stepping-stone model of gene flow we considered the relative roles of gene flow, random genetic drift and selection to assess the possibilities for local adaptation. The requirements for local adaptation were fulfilled, but only...... adaptations resulting from strong selection were expected to occur at the level of individual populations. Adaptations resulting from weak selection were more likely to occur on a regional basis, i.e. encompassing several populations. N-e appears to have declined recently in at least one of the studied...

  3. Frequency stabilization of a 399-nm laser by modulation transfer spectroscopy in an ytterbium hollow cathode lamp

    International Nuclear Information System (INIS)

    The modulation transfer spectroscopy in an ytterbium hollow cathode lamp at 399 nm is measured. The error signal for frequency locking is optimized by measuring the dependences of its slope, linewidth and magnitude on various parameters. Under the optimum condition, the laser frequency at 399 nm can be stabilized. The long-term stability of laser frequency is measured by monitoring the fluorescence signal of the ytterbium atomic beam induced by the locked laser. The laser frequency is shown to be tightly locked, and the stabilized laser is successfully applied to the cooling of ytterbium atoms. (atomic and molecular physics)

  4. Characterization of a clock based on coherent population trapping in a thermal cesium vapor. Main effects that may affect its mid- and long-term frequency stability

    International Nuclear Information System (INIS)

    This thesis describes a Cs - buffer gas vapor cell atomic clock based on coherent population trapping (CPT), and the main frequency shifts affecting its mid- and long-term stability. The developed atomic clock based on CPT uses two original techniques: a so-called double-Λ scheme for the CPT-resonance excitation and a temporal Ramsey interrogation technique, which produce a high contrast and narrow resonances with reduced light shift dependence. Generally, the mid and long term stability of the vapor cell atomic clock is limited by the collisional shift induced by alkali-buffer gas collisions and the light shift (or the effects depending on the laser intensity). We report on the study of the collisional shift of Cs clock frequency in the presence of Ne, N2 or Ar buffer gas, and its temperature dependence. The coefficient values of this dependence for these three buffer gases were revealed (some of them for the first time), allowing us to realise a cell with optimal combination of buffer gases to cancel the temperature dependence around the working temperature. Following the study of the signal amplitude and the coherence relaxation rate the optimal values for such parameters as interrogation cycle, magnetic field, cell temperature, pressure of the buffer gas mixture, etc. were found for the chosen cell. The investigation on the light shift and the effects depending on the laser intensity allowed us to determine the most sensitive parameters (laser intensity ratio, temperature) and to implement the required stabilizations in order to better control them. Finally, the mid- and long-term clock frequency stability was improved by a factor 40, reaching 2.5 10-14 at 1 hour. (author)

  5. Long-term stability of grazing lawns in a small protected area, the Mountain Zebra National Park

    Directory of Open Access Journals (Sweden)

    Peter Novellie

    2013-02-01

    Full Text Available We examined a heavily grazed plant community dominated by creeping grass species with the aim of, (1 determining its response to the exclusion of grazing and (2 its long-term persistence. This plant community was particularly favoured by wild ungulate species that prefer short grasses – blesbok (Damaliscus dorcas phillipsi, springbok (Antidorcas marsupialis and black wildebeest (Connochaetes gnou. Exclusion of grazing by large herbivores by means of fencing resulted in the virtual disappearance of the creeping grasses and their replacement by tall tufted species. On plots that remained unfenced, the plant species composition was found to be little changed after an interval of more than 20 years. The number large stock unit equivalents (LSU per ha carried by the plant community was used as a proxy for grazing intensity. Monitored for approximately 2 years at the start of the study, LSU per ha was found to greatly exceed levels recommended for commercial livestock production. This plant community conforms to a recently published definition of a grazing lawn, in that intense grazing promotes palatable, grazing-tolerant grass species.Conservation implications: The positive association between grazers and grazing-tolerant grass species evidently persisted for more than 20 years and there was no evidence of an increase in abundance of unpalatable plant species. Despite the small size of the park, which limited the extent of large herbivore movements, localised heavy grazing did not lead to range degradation.

  6. Long-term performance of structures comprising nuclear power plants PART 1: Deterioration assessment of nuclear power station buildings PART 2: Long-term stability and the leak-tightness of reactor containments

    International Nuclear Information System (INIS)

    The objective of this research was to study the long-term performance of structures comprising nuclear power plants. The time period of interest for this study is 140 years (this figure is based on maximum periods of 40 years for operation and 100 years of storage). It was divided in two parts: - the first based on four UK nuclear power plants examine the principle deterioration mechanism of reinforced structure which is chloride ingress and carbonation penetration - the second based on 2 German nuclear power plants examine the long term behaviour of reinforced and prestressed concrete and also the corrosion of steel containments with particular reference on plastic seals and potential risk areas

  7. Two-Stage System Based on a Software-Defined Radio for Stabilizing of Optical Frequency Combs in Long-Term Experiments

    Czech Academy of Sciences Publication Activity Database

    Čížek, Martin; Hucl, Václav; Hrabina, Jan; Šmíd, Radek; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    2014-01-01

    Roč. 14, č. 1 (2014), s. 1757-1770. ISSN 1424-8220 R&D Projects: GA ČR GPP102/11/P819; GA ČR GAP102/10/1813; GA MŠk ED0017/01/01; GA MŠk EE2.4.31.0016 Institutional support: RVO:68081731 Keywords : optical frequency combs * digital signal processing * software-defined radio * beat note * stabilization * long-term operation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.245, year: 2014

  8. Investigation on Long-term Creep Rupture Properties and Microstructure Stability of Fe-Ni based Alloy Ni-23Cr-7W at 700°C

    DEFF Research Database (Denmark)

    Tokairin, Tsuyoshi; Dahl, Kristian Vinter; Danielsen, Hilmar Kjartansson;

    2013-01-01

    Long-term creep rupture properties and microstructural stability of Fe–Ni based alloy Ni–23Cr–7W (HR6W, ASME Code Case 2684) were experimentally investigated. Crept specimens at 700 °C for durations up to 37,667 h were chosen, the microstructure evolution during creep was characterized. Besides the...... MC and M23C6 carbides found in the as-received sample, the formation of α-W phase, α-Cr phase and Laves phase in crept samples were confirmed with scanning/transmission electron microscopes. Statistical quantitative image analysis was used to evaluate the precipitation behavior and growth kinetics...

  9. Stability of Uncemented Cups - Long-Term Effect of Screws, Pegs and HA Coating: A 14-Year RSA Follow-Up of Total Hip Arthroplasty.

    Science.gov (United States)

    Otten, Volker T C; Crnalic, Sead; Röhrl, Stephan M; Nivbrant, Bo; Nilsson, Kjell G

    2016-01-01

    Screws, pegs and hydroxyapatite-coating are used to enhance the primary stability of uncemented cups. We present a 14-year follow-up of 48 hips randomized to four groups: press-fit only, press-fit plus screws, press-fit plus pegs and hydroxyapatite-coated cups. Radiostereometric migration measurements showed equally good stability regardless cup augmentation. The mean wear rate was high, 0.21 mm/year, with no differences between the groups. Seven hips had radiographical osteolysis but only in hips with augmented cups. Cups without screw-holes compared with cups with screw-holes resulted in better clinical outcome at the 14-year follow-up. Thus, augmentation of uncemented cups with screws, pegs, or hydroxyapatite did not appear to improve the long-term stability compared with press-fit only. PMID:26260783

  10. Dynamic Relationship Between Biologically Active Soil Organic Carbon and Aggregate Stability in Long-Term Organically Fertilized Soils

    Institute of Scientific and Technical Information of China (English)

    LI Cheng-Liang; XU Jiang-Bing; HE Yuan-Qiu; LIU Yan-Li; FAN Jian-Bo

    2012-01-01

    Biologically active soil organic carbon (BASOC) is an important fraction of soil organic carbon (SOC),but our understanding of the correlation between BASOC and soil aggregate stability is limited.At an ecological experimental station (28° 04′-28° 37′ N,116°41′-117° 09′ E) in Yujiang County,Jiangxi Province,China,we analyzed the dynamic relationship between soil aggregate stability and BASOC content over time in the red soil (Udic Ferrosols) fertilized with a nitrogen-phosphorus-potassium chemical fertilizer (NPK)without manure or with NPK plus livestock manure or green manure.The dynamics of BASOC was evaluated using CO2 efflux,and soil aggregates were separated according to size using a wet-sieving technique.The soils fertilized with NPK plus livestock manure had a significantly higher content of BASOC and an improved aggregate stability compared to the soils fertilized with NPK plus green manure or NPK alone The BASOC contents in all fertilized soils decreased over time The contents of large aggregates (800-2000μm) dramatically decreased over the first 7 d of incubation,but the contents of small aggregates (< 800.μm) either remained the same or increased,depending on the incubation time and specific aggregate sizes.The aggregate stability did not differ significantly at the beginning and end of incubation,but the lowest stability inall fertilized soils occurred in the middle of the incubation,which implied that the soils had a strong resilience for aggregate stability.The change in BASOC content was only correlated with aggregate stability during the first 27 d of incubation.

  11. PCR-DGGE-Based Study of Fecal Microbial Stability during the Long-Term Chitosan Supplementation of Humans

    Czech Academy of Sciences Publication Activity Database

    Mrázek, Jakub; Koppová, Ingrid; Kopečný, Jan; Šimůnek, Jiří; Fliegerová, Kateřina

    2010-01-01

    Roč. 55, č. 4 (2010), s. 352-358. ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA525/08/0803 Institutional research plan: CEZ:AV0Z50450515 Keywords : Chitosan * Microbial stability * Microflora Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 0.977, year: 2010

  12. Glow Curve Analysis of Long-term Stability of LiF:Mg,Cu,P as Compared to LiF:Mg,Ti

    International Nuclear Information System (INIS)

    Over a six month period, the long-term stability of LiF:Mg,Cu,P (GR-200A, Beijing China) was compared with LiF:Mg,Ti (GR-100, Beijing China). This is of particular interest in applications where there can be considerable variations in the time intervals between TLD preparation, irradiation and readout, such as environmental, accident personal and mailed dosimetry. For each TLD material, slow and fast cool-down anneals, characteristic of those used in the above-mentioned applications, were employed to study the effect of annealing procedure on long term stability. An analytical approximation based on the Randal-Wilkins model employing first order kinetics was used to fit individual peaks. Glow curve features unique for each TLD material and annealing condition were quantified and compared. From computerised glow curve analysis, annealing at 220 deg. C, instead of the pre-set temperature of 240 deg. C, caused an increase in the contribution from peak 3 in LiF:Mg,Cu,P, causing the material to be more susceptible to fading and peak area interchanges. (author)

  13. Long term stability and mechanical properties of Al2O3-NiAl composites reinforced with partially fragmented long fibers

    International Nuclear Information System (INIS)

    Highlights: → The long term thermal stability of Al2O3-NiAl composite was investigated for in-service requirements. → For the first time a method to predict the strength of this composite is proposed. → The theoretical predictions show good agreement with experimental results. - Abstract: Long fiber reinforced NiAl composites, fabricated by high temperature processing, are designed for long term thermal exposure during service. This treatment causes partial fragmentation of the long fibers, which degrades the mechanical performance of the composite. We investigated the mechanical properties of Al2O3-NiAl long fiber composites, fabricated by hot pressing and exposed to 2000 h annealing at 700 deg. C and 1100 deg. C. The composites showed basically good thermal stability during annealing except for grain coarsening of NiAl. Owing to fiber fragmentation during cooling after composite fabrication, the mechanical performance of the composites is determined by the load partitioning in a mixture of long and broken fibers. We propose a method to calculate the strength of such composites, based on microstructural information and composite fracture mechanisms. The theoretical predictions show good agreement with experimental results.

  14. Decision method for the investment in shunt capacitors based on a long-term voltage stability analysis

    OpenAIRE

    Cazaux, Vincent

    2012-01-01

    As the electric consumption increases and the constraints multiply, the grid becomes weaker and may not be able to face critical voltage stability problems. Indeed, in the past decades some blackouts occurred in Europe and America, due to voltage instabilities. At a 5-year horizon, new lines or new power plants cannot be built in time, it is therefore necessary to invest in capacitors to prevent voltage collapses. The core of this project is the best localization of these investments, to make...

  15. Leptin contributes to long-term stabilization of HIF-1α in cancer cells subjected to oxygen limiting conditions.

    Science.gov (United States)

    Calgani, Alessia; Delle Monache, Simona; Cesare, Patrizia; Vicentini, Carlo; Bologna, Mauro; Angelucci, Adriano

    2016-06-28

    Leptin, a cytokine produced by the adipose tissue in response to food intake, is a key player in the regulation of energy balance and body weight control. Physiological action of leptin in modulating the metabolic adaptation of different peripheral tissues supports the hypothesis that it could also exert a direct effect on cancer cells. In vitro, treatment with leptin up-regulated HIF-1α and stimulated adhesion and invasion of prostate cancer cells cultured in hypoxia. Leptin action was effective in both low and high glycolytic cancer cell lines, and determined the up-regulation of lactate exporter MCT4 and its associated protein CD147. HIF-1α stabilization was oligomycin-independent and was associated with an important modulation of mitochondrial homeostasis. In fact, leptin treatment produced mitochondrial biogenesis, stabilization of mitochondrial membrane potential and increased uncoupled respiration through the up-regulation of UCP2. Furthermore, leptin counteracted the downmodulation of SIRT1 induced by hypoxia, and persistent high levels of SIRT1 were directly involved in HIF-1α stabilization. Leptin can sustain cancer progression in hypoxic environment and when mitochondrial respiration is impaired. Leptin signaling axis, including the new proposed intermediate SIRT1, could represent a new diagnostic and therapeutic target in prostate cancer. PMID:26996298

  16. Chest wall stabilization and reconstruction: short and long-term results 5 years after the introduction of a new titanium plates system

    Science.gov (United States)

    Sollitto, Francesco; Loizzi, Domenico; Di Gennaro, Francesco; Scarascia, Daniele; Carlucci, Annalisa; Giudice, Giuseppe; Armenio, Andrea; Ludovico, Rossana; Loizzi, Michele

    2016-01-01

    Background We report short and long-term results with the dedicated Synthes® titanium plates system, introduced 5 years ago, for chest wall stabilization and reconstruction. Methods We retrospectively analyzed (January 2010 to December 2014) 27 consecutive patients (22 males, 5 females; range 16–83 years, median age 60 years), treated with this system: primary [3] and secondary [8] chest wall tumor; flail chest [5]; multiple ribs fractures [5]; sternal dehiscence-diastasis [3]; sternal fracture [1]; sternoclavicular joint dislocation [1]; Poland syndrome [1]. Short-term results were evaluated as: operating time, post-operative morbidity, mortality, hospital stay; long-term results as: survival, plates-related morbidity, spirometric values, chest pain [measured with Verbal Rating Scale (VRS) and SF12 standard V1 questionnaire]. Results Each patient received from 1 to 10 (median 2) titanium plates/splints; median operating time was 150 min (range: 115–430 min). Post-operative course: 15 patients (55.6%) uneventful, 10 (37%) minor complications, 2 (7.4%) major complications; no post-operative mortality. Median post-operative hospital stay was 13 days (range: 5–129 days). At a median follow-up of 20 months (range: 1–59 months), 21 patients (78%) were alive, 6 (22%) died. Three patients presented long-term plates-related morbidity: plates rupture [2], pin plate dislodgment [1]; two required a second surgical look. One-year from surgery median spirometric values were: FVC 3.31 L (90%), FEV1 2.46 L (78%), DLCO 20.9 mL/mmHg/min (76%). On 21 alive patients, 7 (33.3%) reported no pain (VRS score 0), 10 (47.6%) mild (score 2), 4 (19.1%) moderate (score 4), no-one severe (score >4); 15 (71.5%) reported none or mild, 6 (28.5%) moderate pain influencing quality of life. Conclusions An optimal chest wall stabilization and reconstruction was achieved with the Synthes® titanium plates system, with minimal morbidity, no post-operative mortality, acceptable operating time

  17. Effect of long term exposure at elevated temperature on the microstructural stability and micromechanics of fatigue crack growth of Ti-24Al-11Nb

    International Nuclear Information System (INIS)

    Titanium intermetallics are being developed for long term applications at elevated temperatures. Typical approaches include the design of appropriate microstructure for room and elevated temperature fatigue resistance. However, a little explored area is the stability of these microstructures at elevated temperature and its effect on fatigue crack growth. A coarse two phase α2+β Widmanstaetten microstructure was studied. Microstructural stability and elemental segregation were studied as a function of exposure time for up to 500 hours at 800 C using transmission electron microscopy. Results indicate that the Widmanstaetten microstructure is metastable and the β phase breaks up into particles. The absence of a continuous β phase surrounding the α2 phase reduces the resistance of the microstructure to fatigue crack growth at room temperature

  18. 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

  19. Viscoelastic gels of guar and xanthan gum mixtures provide long-term stabilization of iron micro- and nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Xue Dingqi [Politecnico di Torino, Dipartimento Scienza Applicata e Tecnologia-DISAT and Dipartimento di Ingegneria dell' Ambiente, del Territorio e delle Infrastrutture-DIATI (Italy); Sethi, Rajandrea, E-mail: rajandrea.sethi@polito.it [Politecnico di Torino, Dipartimento di Ingegneria dell' Ambiente, del Territorio e delle Infrastrutture-DIATI (Italy)

    2012-11-15

    Iron micro- and nanoparticles used for groundwater remediation and medical applications are prone to fast aggregation and sedimentation. Diluted single biopolymer water solutions of guar gum (GG) or xanthan gum (XG) can stabilize these particles for few hours providing steric repulsion and by increasing the viscosity of the suspension. The goal of the study is to demonstrate that amending GG solutions with small amounts of XG (XG/GG weight ratio 1:19; 3 g/L of total biopolymer concentration) can significantly improve the capability of the biopolymer to stabilize highly concentrated iron micro- and nanoparticle suspensions. The synergistic effect between GG and XG generates a viscoelastic gel that can maintain 20 g/L iron particles suspended for over 24 h. This is attributed to (i) an increase in the static viscosity, (ii) a combined polymer structure the yield stress of which contrasts the downward stress exerted by the iron particles, and (iii) the adsorption of the polymers to the iron surface having an anchoring effect on the particles. The XG/GG viscoelastic gel is characterized by a marked shear thinning behavior. This property, coupled with the low biopolymer concentration, determines small viscosity values at high shear rates, facilitating the injection in porous media. Furthermore, the thermosensitivity of the soft elastic polymeric network promotes higher stability and longer storage times at low temperatures and rapid decrease of viscosity at higher temperatures. This feature can be exploited in order to improve the flowability and the delivery of the suspensions to the target as well as to effectively tune and control the release of the iron particles.

  20. Viscoelastic gels of guar and xanthan gum mixtures provide long-term stabilization of iron micro- and nanoparticles

    International Nuclear Information System (INIS)

    Iron micro- and nanoparticles used for groundwater remediation and medical applications are prone to fast aggregation and sedimentation. Diluted single biopolymer water solutions of guar gum (GG) or xanthan gum (XG) can stabilize these particles for few hours providing steric repulsion and by increasing the viscosity of the suspension. The goal of the study is to demonstrate that amending GG solutions with small amounts of XG (XG/GG weight ratio 1:19; 3 g/L of total biopolymer concentration) can significantly improve the capability of the biopolymer to stabilize highly concentrated iron micro- and nanoparticle suspensions. The synergistic effect between GG and XG generates a viscoelastic gel that can maintain 20 g/L iron particles suspended for over 24 h. This is attributed to (i) an increase in the static viscosity, (ii) a combined polymer structure the yield stress of which contrasts the downward stress exerted by the iron particles, and (iii) the adsorption of the polymers to the iron surface having an anchoring effect on the particles. The XG/GG viscoelastic gel is characterized by a marked shear thinning behavior. This property, coupled with the low biopolymer concentration, determines small viscosity values at high shear rates, facilitating the injection in porous media. Furthermore, the thermosensitivity of the soft elastic polymeric network promotes higher stability and longer storage times at low temperatures and rapid decrease of viscosity at higher temperatures. This feature can be exploited in order to improve the flowability and the delivery of the suspensions to the target as well as to effectively tune and control the release of the iron particles.

  1. Synthesis of hierarchical porous honeycomb carbon for lithium-sulfur battery cathode with high rate capability and long cycling stability

    International Nuclear Information System (INIS)

    Highlights: • A novel HPHC was prepared by a simple template process. • The HPHC as matrix to load sulfur for Lithium-Sulfur battery cathodes. • S-HPHC cathode shows high rate capability and long cycling stability. • The sulfur-HPHC composite presents electrochemical stability up to 300 cycles at 1.5 C. - Abstract: Sulfur has a high specific capacity of 1675 mAh g−1 as lithium battery cathode, but its rapid capacity fading due to polysulfides dissolution presents a significant challenge for practical applications. Here we report a novel hierarchical porous honeycomb carbon (HPHC) for lithium-sulfur battery cathode with effective trapping of polysulfides. The HPHC was prepared by a simple template process, and a sulfur-carbon composite based on HPHC was synthesized for lithium-sulfur batteries by a melt-diffusion method. It is found that the elemental sulfur was dispersed inside the three-dimensionally hierarchical pores of HPHC based on the analyses. Electrochemical tests reveal that the sulfur-HPHC composite shows high rate capability and long cycling stability as cathode materials. The sulfur-HPHC composite with sulfur content of 66.3 wt% displays an initial discharge capacity of 923 mAh g−1 and a reversible discharge capacity of 564 mAh g−1 after 100 cycles at 2 C charge-discharge rate. In particular, the sulfur-HPHC composite presents a long term cycling stability up to 300 cycles at 1.5 C. The results illustrate that the electrochemical reaction constrained inside the interconnected macro/meso/micropores of HPHC would be the dominant factor for the excellent high rate capability and long cycling stability of the sulfur cathode, and the three-dimensionally honeycomb carbon network would be a promising carbon matrix structure for lithium-sulfur battery cathode

  2. Long-term stabilization of deep soil carbon by fire and burial during early Holocene climate change

    Science.gov (United States)

    Marin-Spiotta, Erika; Chaopricha, Nina T.; Plante, Alain F.; Diefendorf, Aaron F.; Mueller, Carsten W.; Grandy, A. Stuart; Mason, Joseph A.

    2014-06-01

    Buried soils contain large reservoirs of organic carbon at depths that are not typically included in regional and global soil carbon inventories. One such palaeosol, the Brady soil of southwestern Nebraska, USA, is buried under six metres of loess. The Brady soil developed at the land surface on the late-Pleistocene-aged Peoria Loess in a period of warmth and wetness during which dunefields and dust sources across the region were stabilized. Abrupt climate change in the early Holocene led to increased loess deposition that buried the soil. Here, we used spectroscopic and isotopic analyses to determine the composition and stability of organic carbon in the Brady soil. We identify high levels of black carbon, indicating extensive biomass burning. In addition, we found intact vascular plant lipids in soil organic matter with radiocarbon ages ranging from 10,500 to 12,400 cal yr BP, indicating decomposition was slowed by rapid burial at the start of the Holocene. We conclude that landscape disturbance caused by abrupt climate change, fire and the loss of vegetative cover contributed to deep carbon sequestration as the soil was quickly buried under accumulating loess. We suggest that terrestrial soil carbon storage in arid and semi-arid environments could undergo landscape-scale shifts in response to rising temperatures, increased fire activity or drought.

  3. Long-term physicochemical and immunological stability of a liquid formulated intact ovine immunoglobulin-based antivenom.

    Science.gov (United States)

    Al-Abdulla, Ibrahim; Casewell, Nicholas R; Landon, John

    2013-03-15

    An antivenom should be stable under the conditions that it will be both transferred and stored. Thus instability may lead to a loss of efficacy and an increased incidence and severity of adverse effects. Stability is a particular problem in countries where the temperatures and humidity are high. Here we investigate the stability of a liquid-formulated, intact ovine immunoglobulin-based antivenom, EchiTAbG™, which is used extensively in Nigeria to treat envenoming by the West African saw-scaled viper, Echis ocellatus. Ampoules of antivenom were assessed as to their specific antibody content by small scale affinity chromatography and their purity by size exclusion gel filtration and turbidity. Three different batches of the antivenom revealed no significant changes, using these assessment techniques, during 42 months storage at 4 °C or at ambient temperature, followed by one month at 37 °C. These real-time studies indicate that the antivenom remains stable for a minimum of 3.5 years and that it can be exposed to tropical temperatures without any loss in immunoglobulin binding activity. This further highlights the clinical utility of liquid formulated ovine IgG antivenoms by demonstrating their retention of potency in the event of a short term failing in the cold chain. PMID:23319075

  4. Origin of Long-Term Storage Stability and Nitric Oxide Release Behavior of CarboSil Polymer Doped with S-Nitroso-N-acetyl-D-penicillamine.

    Science.gov (United States)

    Wo, Yaqi; Li, Zi; Brisbois, Elizabeth J; Colletta, Alessandro; Wu, Jianfeng; Major, Terry C; Xi, Chuanwu; Bartlett, Robert H; Matzger, Adam J; Meyerhoff, Mark E

    2015-10-14

    The prolonged and localized delivery of nitric oxide (NO), a potent antithrombotic and antimicrobial agent, has many potential biomedical applications. In this work, the origin of the long-term storage stability and sustained NO release mechanism of S-nitroso-N-acetyl-D-penicillamine (SNAP)-doped CarboSil 20 80A polymer, a biomedical thermoplastic silicone-polycarbonate-urethane, is explored. Long-term (22 days) localized NO release is achieved by utilizing a cross-linked silicone rubber as topcoats, which can greatly reduce the amount of SNAP, NAP, and NAP disulfide leaching from the SNAP-doped CarboSil films, as measured by LC-MS. Raman spectroscopy and powder X-ray diffraction characterization of SNAP-doped CarboSil films demonstrate that a polymer-crystal composite is formed during the solvent evaporation process when SNAP exceeds its solubility in CarboSil (ca. 3.4-4.0 wt %). Further, when exceeding this solubility threshold, SNAP exists in an orthorhombic crystal form within the bulk of the polymer. The proposed mechanism of sustained NO release in SNAP-doped CarboSil is that the solubilized SNAP in the polymer matrix decomposes and releases NO, primarily in the water-rich regions near the polymer/solution interface, and the dissolved SNAP in the bulk polymeric phase becomes unsaturated, resulting in the dissolution of crystalline SNAP within the bulk of the polymer. This is a very slow process that ultimately leads to NO release at the physiological flux levels for >3 weeks. The increased stability of SNAP within CarboSil is attributed to the intermolecular hydrogen bonds between the SNAP molecules that crystallize. This crystallization also plays a key role in maintaining RSNO stability within the CarboSil polymer for >8 months at 37 °C (88.5% remains). Further, intravascular catheters fabricated with this new material are demonstrated to significantly decrease the formation of Staphylococcus aureus biofilm (a leading cause of nosocomial bloodstream

  5. Long-term stability and effective population size in North Sea and Baltic Sea cod ( Gadus morhua )

    DEFF Research Database (Denmark)

    Poulsen, Nina Aagaard; Eg Nielsen, Einar; Schierup, M.H.; Loeschcke, V.; Grønkjær, P.

    2006-01-01

    DNA from archived otoliths was used to explore the temporal stability of the genetic composition of two cod populations, the Moray Firth (North Sea) sampled in 1965 and 2002, and the Bornholm Basin (Baltic Sea) sampled in 1928 and 1997. We found no significant changes in the allele frequencies for...... the Moray Firth population, while subtle but significant genetic changes over time were detected for the Bornholm Basin population. Estimates of the effective population size (N-e) generally exceeded 500 for both populations when employing a number of varieties of the temporal genetic method. However...... the number of alleles commonly reported at microsatellite loci in Atlantic cod is best explained by N-e's exceeding thousand. Recent fishery-induced bottlenecks can, however, not be ruled out as an explanation for the apparent discrepancy between high levels of variability and recently reported...

  6. Investigation on the long-term stability of IRMM-1027 series of Large-Sized Dried (LSD) spikes

    International Nuclear Information System (INIS)

    The IRMM-1027 is a certified reference material for nuclear material control and accountancy. Each individual spike contains about 50 mg uranium (m(235U)/m(U) ∼ 20%) and about 1.8 mg plutonium (m(239Pu)/m(Pu) ∼ 98%) in dried form. They are used for the determination of U and Pu content of spent fuel solutions with isotope dilution mass spectrometry (IDMS) by plant operators and safeguards authorities. The dried uranyl and plutonium nitrates are embedded in an organic substance, which provides a stable layer at the bottom of the vial and preserves the integrity of the spike during storage and transport. Cellulose acetate butyrate (CAB) with 19 wt% butyryl content has been applied on the IRMM-1027 spikes for the last decade. However, the cellulose matrix containing the spike material tends to flake off after about two years. In order to prolong the shelf life of the spikes, JRC-IRMM has been investigating CABs with higher butyryl contents – 35 wt% and 52 wt% –, to optimize the chemical stability and to achieve a longer lasting layer. Empirical tests have shown that the higher the butyryl content, chemically the more stable and the more resistant the CAB is. Accordingly, future series of LSD spikes will be prepared with CAB containing 35 wt% butyryl, which should remain intact for at least 4 years. Furthermore, JRC-IRMM together with CPMT is investigating the chemical and mechanical properties of the three different CABs to further improve understanding on their stability and durability.

  7. Simulation of long-term debris flow sediment transport based on a slope stability and a debris flow routing model

    Science.gov (United States)

    Müller, T.; Hoffmann, T.

    2012-04-01

    Debris flows play a crucial role in the coupling of hillslope-sediment sources and channels in mountain environments. In most landscape evolution models (LEMs), the sediment transport by debris flows is (if at all) often represented by simple empirical rules. This generally results from the mismatch of the coarse resolution of the LEMs and the small scale impacts of debris flow processes. To extend the accuracy and predictive power of LEMs, either a higher resolution of LEMs in combination with process-based debris flow models or a better parametrisation of subpixel scale debris flow processes is necessary. Furthermore, the simulation of sediment transport by debris flows is complicated by their episodic nature and unknown factors controlling the frequency and magnitude of events. Here, we present first results using a slope stability model (SINMAP) and an event-based debris flow routing model (SCIDDICA-S4c) to simulate the effects of debris flows in LEMs. The model was implemented in the XULU modelling platform developed by the Department of Computer Science at the University of Bonn. The combination of the slope stability model and the event-based routing and mass balance model enables us to simulate the triggering and routing of debris flow material through the iteration of single events over several thousand years. Although a detailed calibration and validation remains to be done, the resulting debris flow-affected areas in a test elevation model correspond well with data gained from a geomorphological mapping of the corresponding area, justifying our approach. The increased computation speed allows to run high resolution LEM in convenient short time at relatively low cost. This should encourage the development of more detailed LEMs, in which process-based models should be incorporated.

  8. 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.

  9. Study of the long-term stability of peaks 4 and 5 in TLD-100: correlation with isothermal decay measurements at elevated temperatures

    International Nuclear Information System (INIS)

    The long-term fading of peak 5 has been studied using four different annealing regimes in order to isolate the behaviour of peak 5 free from interference effects of peaks 2, 3, and 4. Peak 4 grows over the first nine months of storage and only then begins to decay; peak 5, on the other hand, decays rapidly in the first six months and then stabilizes or even begins to grow. Peaks (4+5) together, however, fade monotonically by approximately 8% per annum. Using thermal cleaning procedures to isolate the behaviour of peak 5, we have determined that its mean lifetime at 200C is 5.8 ± 1.2 years (1 sd). This mean lifetime is orders of magnitude smaller than predicted by the exponential extrapolation of the mean lifetimes measured at higher temperatures or via peak shape techniques. The discrepancy suggests that the long-term decay of peak 5 is strongly influenced by other forms of decay not associated with charge carrier detrapping. The short-term fading behaviour of peak 5 alone, on the other hand, does appear to be 'well behaved', at a rate of 3.4 ± 0.8% (1 sd) per month (for the first month) irrespective of annealing routine, or the presence of peaks 2 and 3. This suggests the possibility of universal short-term fading corrections in environmental and personnel dosimetry if only peak 5 is used in dosimetric measurements. (author)

  10. Lower cytotoxicity, high stability, and long-term antibacterial activity of a poly(methacrylic acid)/isoniazid/rifampin nanogel against multidrug-resistant intestinal Mycobacterium tuberculosis.

    Science.gov (United States)

    Chen, Tao; Li, Qiang; Guo, Lina; Yu, Li; Li, Zhenyan; Guo, Huixin; Li, Haicheng; Zhao, Meigui; Chen, Liang; Chen, Xunxun; Zhong, Qiu; Zhou, Lin; Wu, Ting

    2016-01-01

    To overcome the undesirable side effects and reduce the cytotoxicity of isoniazid (INH) and rifampin (RMP) in the digestive tract, a poly(methacrylic acid) (PMAA) nanogel was developed as a carrier of INH and RMP. This PMAA/INH/RMP nanogel was prepared as a treatment for intestinal tuberculosis caused by multidrug-resistant Mycobacterium tuberculosis (MTB). The morphology, size, and in vitro release properties were evaluated in a simulated gastrointestinal medium, and long-term antibacterial performance, cytotoxicity, stability, and activity of this novel PMAA/INH/RMP nanogel against multidrug-resistant MTB in the intestine were investigated. Our results indicate that the PMAA/INH/RMP nanogel exhibited extended antibacterial activity by virtue of its long-term release of INH and RMP in the simulated gastrointestinal medium. Further, this PMAA/INH/RMP nanogel exhibited lower cytotoxicity than did INH or RMP alone, suggesting that this PMAA/INH/RMP nanogel could be a more useful dosage form than separate doses of INH and RMP for intestinal MTB. The novel aspects of this study include the cytotoxicity study and the three-phase release profile study, which might be useful for other researchers in this field. PMID:26478357

  11. Long-term reactive transport modelling of stabilized/solidified waste: from dynamic leaching tests to disposal scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Windt, Laurent de [Ecole des Mines de Paris, CG-Hydrodynamics and Reaction Group, 35 R. St-Honore, 77300 Fontainebleau (France)]. E-mail: laurent.dewindt@ensmp.fr; Badreddine, Rabia [INERIS, Direction des Risques Chroniques, Unite Dechets et Sites Pollues, Parc Technologique Alata BP 2, 60550 Verneuil-en-Halatte (France); Lagneau, Vincent [Ecole des Mines de Paris, CG-Hydrodynamics and Reaction Group, 35 R. St-Honore, 77300 Fontainebleau (France)

    2007-01-31

    Environmental impact assessment of hazardous waste disposal relies, among others, on standardized leaching tests characterized by a strong coupling between diffusion and chemical processes. In that respect, this study shows that reactive transport modelling is a useful tool to extrapolate laboratory results to site conditions characterized by lower solution/solid (L/S) ratios, site specific geometry, infiltration, etc. A cement solidified/stabilized (S/S) waste containing lead is investigated as a typical example. The reactive transport model developed in a previous study to simulate the initial state of the waste as well as laboratory batch and dynamic tests is first summarized. Using the same numerical code (HYTEC), this model is then integrated to a simplified waste disposal scenario assuming a defective cover and rain water infiltration. The coupled evolution of the S/S waste chemistry and the pollutant plume migration are modelled assessing the importance of the cracking state of the monolithic waste. The studied configurations correspond to an undamaged and fully sealed system, a few main fractures between undamaged monoliths and, finally, a dense crack-network in the monoliths. The model considers the potential effects of cracking, first the increase of rain water and carbon dioxide infiltration and, secondly, the increase of L/S ratio and reactive surfaces, using either explicit fracture representation or dual porosity approaches.

  12. High Performance and Long-Term Stability in Ambiently Fabricated Segmented Solid-State Polymer Electrochromic Displays.

    Science.gov (United States)

    Remmele, Julian; Shen, D Eric; Mustonen, Tero; Fruehauf, Norbert

    2015-06-10

    This work reports on the performance of a segmented polymer electrochromic display that was fabricated with solution-based processes in ambient atmosphere. An encapsulation process and the combination of structured wells for the polymer electrochrome and electrolyte layers as well as the use of a preoxidized counter polymer yields high contrasts and fast switching speeds. Asymmetric driving-with respect to time-of the display is investigated for the first time and the degradation effects in the electrochrome layer are analyzed and addressed to yield a stable device exceeding 100,000 switching cycles. A printed circuit board was integrated with the display, allowing the device to be run as a clock, where the segments only required short pulses to switch without the need for a constant current to maintain its state. Such an application pairs well with the advantages of electrochromic polymers, drawing on its high contrast, stability, and ability to maintain its colored or colorless state without the need for a constant power supply, to demonstrate the promise as well as the challenges of developing more sophisticated electrochromic devices. PMID:25978306

  13. Studies of water-in-oil emulsions : long-term stability, oil properties, and emulsions formed at sea

    International Nuclear Information System (INIS)

    The stability of water-in-oil emulsions of more than 100 oils, including a sample from the ERIKA spill, were determined. An emulsion must be characterized as stable, meso-stable or unstable before its unique properties can be characterized. The samples from this study were analysed after one year of storage to study the change in properties over time. The samples were made in a rotary agitator and then their rheometric, viscosity and water content characteristics were studied. Observations were made on the appearance of the emulsions and were used to classify them. A summary of the property changes for the different types of emulsions over three time periods was tabulated. It was confirmed that water can occur in oil as entrained water where large droplets are suspended temporarily by viscous forces. Results also showed that the viscosity of a stable emulsion at a shear rate of one reciprocal second is about three times greater than that of the starting oil, and is highly elastic. An unstable emulsion generally has a viscosity of up to 20 time greater than that of the starting oil and is not elastic. A meso-stable emulsion has properties between stable and unstable and breaks down within a few days. It was concluded that asphaltene and resin content plus the viscosity of the starting oil are the most important property factors in determining what type of water-in-oil state is produced. 4 refs., 6 tabs

  14. Engineered In-Situ Precipitation of Technetium and Uranium in Groundwater at the Savannah River Site: Treatment Targeting Long-Term Stability (Invited)

    Science.gov (United States)

    Gillow, J. B.; Lutes, C. C.; Frizzell, A.; Clark, B.; Horst, J.

    2009-12-01

    The U.S. Department of Energy (DOE) Savannah River Site (SRS) is a former nuclear weapons facility that is undergoing clean-up of groundwater and soil contamination. Alternatives to conventional pump-and-treat are being evaluated through DOE’s Advanced Remediation Technologies (ART) program as part of the EM-22 Groundwater and Soil Remediation program. A pilot project is underway to evaluate an emerging approach to remediation through the in-situ precipitation of insoluble forms of technetium and uranium. The demonstration involves the injection of organic carbon into the aquifer to stimulate biogeochemical processes leading to the transformation of soluble radionuclides to insoluble forms. However, once carbon addition is ceased and geochemical conditions return to oxidizing, the insoluble radionuclides may re-dissolve. The pilot project will target long term stability by enhancing the creation of reduced mineral forms in and around the precipitated radionuclides to act as both a redox buffer for oxidizing groundwater and as a sorptive medium for any dissolved uranium and technetium. Successful treatment with respect to in situ radionuclide precipitation extends beyond numeric cleanup goals and invokes a standard of care that considers not only short-term solubility achieved during active remediation, but the range of factors that might erode/compromise the stability of the precipitated solids over the long-term. Long-term stability may be achieved by incorporating the targeted radionuclide in a matrix of other precipitates formed through the treatment process. In the short term, this can include the precipitates of other more abundant metals (e.g., iron) that can preferentially scavenge oxygen. Longer term, this is expected to transition to passivation within a matrix of more stable mineral phases, such that rates of rebound dissolution are sufficiently suppressed to maintain dissolved concentrations below remedial targets. The in situ reactive zone (IRZ

  15. Long-term stability of an subsurface ocean in Ganymede and its effect to tidal response, toward future altimetry measurement

    Science.gov (United States)

    Kimura, J.; Kamata, S.; Vance, S.; Hussmann, H.

    2015-12-01

    The outer solar system provides potential habitats for extra-terrestrial life. Previous spacecraft's and telescopic observations support that the Jovian icy moons may harbor water oceans beneath the icy crusts. However evidence for oceans is not definitive and awaits confirmation measurements. Also their depth and composition remain unclear, as do their stability and variability with time. Here we focus on Ganymede, the primary target of the Jupiter Icy Moons Explorer (JUICE). To investigate the lifetime of an ocean (thickness change through time), we perform numerical simulations for the internal thermal evolution using a one-dimensional spherically symmetric model for the convective and conductive heat transfer, with radial dependences of viscosity, heat source distribution, and other material properties. We assume an initially entirely liquid H2O layer which is an end-member case, and take into account the energy production due to decay of long-lived radioactive elements and also evaluate the effect of tidal heating. To see the temporal change of the boundary position between solid ice layers including ice shell and high-pressure ice mantle, we also evaluate the energy balance at the phase boundaries between the solid and liquid H2O layer, and the movements of the positions of these boundaries are calculated by evaluating the heat balance between incoming and outgoing flux at the boundaries considering with latent heat (classically known as a Stefan problem). In addition, the existence of a subsurface ocean and internal rheological structure (essentially based on thermal structure) would determine Ganymede's tidal response. JUICE mission,measurements of tidal deformation of Ganymede using laser altimetry will provide key information about its interior. We investigate the parameter dependence (e.g., elastic/rheological properties of ice and depth/thickness of the ocean, etc.) of Ganymede's tidal response, adopting a depth-dependent viscosity prole assuming a

  16. 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.

  17. Thermal stability and long term hydrogen/deuterium release from soft to hard amorphous carbon layers analyzed using in-situ Raman spectroscopy. Comparison with Tore Supra deposits

    CERN Document Server

    Pardanaud, C; Giacometti, G; Mellet, N; Pégourié, B; Roubin, P

    2015-01-01

    The thermal stability of 200 nm thick plasma enhanced chemical vapor deposited a-C:H and a-C:D layers ranging from soft to hard layers has been studied and compared to that of deposits collected on the Tore Supra tokamak plasma facing components by means of in-situ Raman spectroscopy. Linear ramp heating and long term isotherms (from several minutes to 21 days) have been performed and correlations between spectrometric parameters have been found. The information obtained on the sp 2 clustering has been investigated by comparing the G band shift and the 514 nm photon absorption evolution due to the thermal treatment of the layer. The effects of isotopic substitution have also been investigated.

  18. Long-term stability of demethylation after transient exposure to 5-aza-2'-deoxycytidine correlates with sustained RNA polymerase II occupancy.

    Science.gov (United States)

    Kagey, Jacob D; Kapoor-Vazirani, Priya; McCabe, Michael T; Powell, Doris R; Vertino, Paula M

    2010-07-01

    DNA methyltransferase inhibitors are currently the standard of care for myelodysplastic syndrome and are in clinical trials for leukemias and solid tumors. However, the molecular basis underlying their activity remains poorly understood. Here, we studied the induction and long-term stability of gene reactivation at three methylated tumor suppressor loci in response to the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-azaCdR) in human breast cancer cells. At the TMS1/ASC locus, treatment with 5-azaCdR resulted in partial DNA demethylation, the reengagement of RNA polymerase II (Pol II), and a shift from a repressive chromatin profile marked with H3K9me2 and H4K20me3 to an active profile enriched in H3ac and H3K4me2. Using a single-molecule approach coupling chromatin immunoprecipitation with bisulfite sequencing, we show that H3ac, H3K4me2, and Pol II selectively associated with the demethylated alleles, whereas H3K9me2 preferentially marked alleles resistant to demethylation. H4K20me3 was unaffected by DNA demethylation and associated with both unmethylated and methylated alleles. After drug removal, TMS1 underwent partial remethylation, yet a subset of alleles remained stably demethylated for over 3 months. These alleles remained selectively associated with H3K4me2, H3ac, and Pol II and correlated with a sustained low level of gene expression. TMS1 alleles reacquired H3K9me2 over time, and those alleles that became remethylated retained H3ac. In contrast, CDH1 and ESR1 were remethylated and completely silenced within approximately 1 week of drug removal, and failed to maintain stably unmethylated alleles. Our data suggest that the ability to maintain Pol II occupancy is a critical factor in the long-term stability of drug-induced CpG island demethylation. PMID:20587535

  19. Long-term stability of demethylation after transient exposure to 5-aza-2′-deoxycytidine correlates with sustained RNA polymerase II occupancy*

    Science.gov (United States)

    Kagey, Jacob D.; Kapoor-Vazirani, Priya; McCabe, Michael T.; Powell, Doris R.; Vertino, Paula M.

    2010-01-01

    DNA methyltransferase (DNMT) inhibitors are currently the standard of care for myelodysplastic syndrome and are in clinical trials for leukemias and solid tumors. However, the molecular basis underlying their activity remains poorly understood. Here we studied the induction and long-term stability of gene reactivation at three methylated tumor suppressor loci in response to the DNMT inhibitor 5-aza-2′-deoxycytidine (5-azaCdR)in human breast cancer cells. At the TMS/ASC locus, treatment with 5-azaCdR resulted in partial DNA demethylation, the re-engagement of RNA polymerase II (Pol II), and a shift from a repressive chromatin profile marked with H3K9me2 and H4K20me3 to an active profile enriched in H3ac and H3K4me2. Using a single molecule approach coupling chromatin immunoprecipitation with bisulfite sequencing, we show that H3ac, H3K4me2, and Pol II selectively associated with the demethylated alleles, whereas H3K9me2 preferentially marked alleles resistant to demethylation. H4K20me3 was unaffected by DNA demethylation and associated with unmethylated and methylated alleles. After drug removal, TMS1 underwent partial remethylation yet a subset of alleles remained stably demethylated for over three months. These alleles remained selectively associated with H3K4me2, H3ac, and Pol II and correlated with a sustained low level of gene expression. TMS1 alleles reacquire H3K9me2over time and those alleles that became remethylated retained H3ac. In contrast, CDH1and ESR1 were remethylated and completely silenced within ~1 week of drug removal, and failed to maintain stably unmethylated alleles. Our data suggest that the ability to maintain Pol II occupancy is a critical factor in the long-term stability of drug-induced CpG island demethylation. PMID:20587535

  20. Long-term efficiency and stability of wetlands for treating wastewater of a lead/zinc mine and the concurrent ecosystem development

    International Nuclear Information System (INIS)

    A constructed wetland system in Guangdong Province, South of China has been used for treating Pb/Zn mine discharge since 1985. The performance in the purification of the mine discharge and the concurrent ecosystem development within the system during the period of 1985-2000 has been studied. The untreated wastewater contained rather high concentrations of cadmium (Cd) (0.05 mg L-1), lead (Pb) (11.5 mg L-1), and zinc (Zn) (14.5 mg L-1), which greatly exceed the upper limits for industrial wastewater discharge in China. The constructed wetland system effectively removed Cd by 94.00%, Pb by 99.04%, Zn by 97.30%, and total suspended solids (TSS) by 98.95% from the mine discharge over a long period (over 16 years) leading to significant improvement in water quality; it was also found that there were no significantly annual or monthly variations in pH values, As, Cd, Hg, Pb, and Zn concentrations in water collected from the outlet of the wetland. Moreover, diversity and abundance of living organisms, including protozoan, higher plants, terrestrial animals, and birds, increased gradually. The 16-year monitoring results showed a reciprocal relationship, at a certain extent, between restoration of the wetland ecosystem, in other words, the maturity of the wetland, and the long-term efficiency and stability on purifying heavy metal-contaminated wastewater. - Relationship between the maturity of a constructed wetland and the long-term efficiency and stability of purifying heavy metal-contaminated wastewater

  1. Ground-based assessment of the bias and long-term stability of 14 limb and occultation ozone profile data records

    Science.gov (United States)

    Hubert, Daan; Lambert, Jean-Christopher; Verhoelst, Tijl; Granville, José; Keppens, Arno; Baray, Jean-Luc; Bourassa, Adam E.; Cortesi, Ugo; Degenstein, Doug A.; Froidevaux, Lucien; Godin-Beekmann, Sophie; Hoppel, Karl W.; Johnson, Bryan J.; Kyrölä, Erkki; Leblanc, Thierry; Lichtenberg, Günter; Marchand, Marion; McElroy, C. Thomas; Murtagh, Donal; Nakane, Hideaki; Portafaix, Thierry; Querel, Richard; Russell, James M., III; Salvador, Jacobo; Smit, Herman G. J.; Stebel, Kerstin; Steinbrecht, Wolfgang; Strawbridge, Kevin B.; Stübi, René; Swart, Daan P. J.; Taha, Ghassan; Tarasick, David W.; Thompson, Anne M.; Urban, Joachim; van Gijsel, Joanna A. E.; Van Malderen, Roeland; von der Gathen, Peter; Walker, Kaley A.; Wolfram, Elian; Zawodny, Joseph M.

    2016-06-01

    profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of 14 limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20 and 40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5-12 % and the drifts are at most ±5 % decade-1 (or even ±3 % decade-1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10 % and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY) and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions

  2. Theory, Investigation and Stability of Cathode Electrocatalytic Activity

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Dong; Liu, Mingfei; Lai, Samson; Blinn, Kevin; Liu, Meilin

    2012-09-30

    The main objective of this project is to systematically characterize the surface composition, morphology, and electro-catalytic properties of catalysts coated on LSCF, aiming to establish the scientific basis for rational design of high-performance cathodes by combining a porous backbone (such as LSCF) with a thin catalyst coating. The understanding gained will help us to optimize the composition and morphology of the catalyst layer and microstructure of the LSCF backbone for better performance. More specifically, the technical objectives include: (1) to characterize the surface composition, morphology, and electro-catalytic properties of catalysts coated on LSCF; (2) to characterize the microscopic details and stability of the LSCF-catalyst (e.g., LSM) interfaces; (3) to establish the scientific basis for rational design of high-performance cathodes by combining a porous backbone (such as LSCF) with a thin catalyst coating; and (4) to demonstrate that the performance and stability of porous LSCF cathodes can be enhanced by the application of a thin-film coating of LSM through a solution infiltration process in small homemade button cells and in commercially available cells of larger dimension. We have successfully developed dense, conformal LSM films with desired structure, composition, morphology, and thickness on the LSCF surfaces by two different infiltration processes: a non-aqueous and a water-based sol-gel process. It is demonstrated that the activity and stability of LSCF cathodes can be improved by the introduction of a thin-film LSM coating through an infiltration process. Surface and interface of the LSM-coated LSCF cathode were systematically characterized using advanced microscopy and spectroscopy techniques. TEM observation suggests that a layer of La and Sr oxide was formed on LSCF surfaces after annealing. With LSM infiltration, in contrast, we no longer observe such La/Sr oxide layer on the LSM-coated LSCF samples after annealing under similar

  3. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

    Science.gov (United States)

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-10-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

  4. The long-term effect of hydrogen on the UO2 spent fuel stability under anoxic conditions: Findings from the Cigar Lake Natural Analogue study

    International Nuclear Information System (INIS)

    Highlights: • We have reviewed current information on the effect of hydrogen in UO2 spent fuel. • We explored the radiolytic models generated in the Cigar Lake project. • The Cigar Lake data supports that H2 reduces alpha radiolysis oxidants. • The results indicate the hydrogen effect is present after 100.000 years deposition. - Abstract: The present paradigm on UO2 spent fuel stability under anoxic conditions assumes that the potential oxidative alteration of the matrix is suppressed in the presence of the hydrogen generated by the anoxic corrosion of iron by water. The observations from the Cigar Lake Natural Analogue project indicated the long-term stability of the uraninite ore under anoxic conditions and with substantial hydrogen generation. The radiolytic models developed in the analogue project have been used to test some of the hypothesis concerning the activation of hydrogen on the uranium(IV) oxide surface. Suggestions to pathways of radiolytic oxidant consumption by other processes than uranium dioxide or sulphide oxidation are presented. The stability of the ore body for billions of year indicates the presence of processes which neutralise radiolytic oxidants and one major factor may be the presence of dissolved hydrogen in the groundwaters contacting the ore body. The results from this test would indicate that hydrogen is activated on the surface of the Cigar Lake uraninites by alpha radiation consuming the generated radiolytic oxidants

  5. Long-term stability of liquid ionization chambers with regard to their qualification as local reference dosimeters for low dose-rate absorbed dose measurements in water

    International Nuclear Information System (INIS)

    The long-term sensitivity and calibration stability of liquid ionization chambers (LICs) has been studied at a local and a secondary standards dosimetry laboratory over a period of 3 years. The chambers were transported several times by mail between the two laboratories for measurements. The LICs used in this work are designed for absorbed dose measurements in the dose rate region of 0.1-100 mGy min-1 and have a liquid layer thickness of 1 mm and a sensitive volume of 16.2 mm3. The liquids used as sensitive media in the chambers are mixtures of isooctane (C8H18) and tetramethylsilane (Si(CH3)4) in different proportions (about 2 to 1). Operating at a polarizing voltage of 300 V the leakage current of the chambers was stable and never exceeded 3% of the observable current at a dose rate of about 1 mGy min-1. The volume sensitivity of the chambers was measured to be of the order of 10-9 C Gy-1 mm-3. No systematic changes in the absorbed dose to water calibration was observed for any of the chambers during the test period (σ<0.2%). Variations in chamber dose response with small changes in the polarizing voltage as well as sensitivity changes with accumulated absorbed dose were also investigated. Measurements showed that the LIC response varies by 0.15% per 1% change in applied voltage around 300 V. No significant change could be observed in the LIC sensitivity after a single absorbed dose of 15 kGy. The results indicate that the LIC can be made to serve as a calibration transfer instrument and a reference detector for absorbed dose to water determinations providing good precision and long-term reproducibility. (author)

  6. 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.

  7. 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...

  8. A long-term frequency-stabilized erbium-fiber-laser-based optical frequency comb with an intra-cavity electro-optic modulator

    CERN Document Server

    Zhang, Y; Zhao, W; Meng, S; Fan, S; Zhang, L; Guo, G; Zhang, S; Jiang, H

    2014-01-01

    We demonstrate a home-made optical frequency comb based on an erbium-doped-fiber femtosecond laser with a ring cavity. The repetition rate of the laser is about 209 MHz determined by optical length of the laser cavity. By controlling an intra-cavity electro-optic modulator and a Piezo-transducer, the repetition rate can be stabilized with megahertz bandwidth in a range of 3 kilohertz, enabling long-term repetition rate phase-locking. The in-loop frequency instability of the repetition rate, limited by measurement system, is 1.3E-13 at 1 second integration time and inversely proportional to integration time for short terms. Using a common path f-2f interferometer, the carrier envelope offset (CEO) frequency of the frequency comb is obtained with a signal-to-noise ratio of 40 dB for 3 megahertz resolution spectrum. Stabilized CEO frequency exhibits a deviation of 0.6 milihertz at 1 second integration time.

  9. Two-Stage System Based on a Software-Defined Radio for Stabilizing of Optical Frequency Combs in Long-Term Experiments

    Directory of Open Access Journals (Sweden)

    Martin Čížek

    2014-01-01

    Full Text Available A passive optical resonator is a special sensor used for measurement of lengths on the nanometer and sub-nanometer scale. A stabilized optical frequency comb can provide an ultimate reference for measuring the wavelength of a tunable laser locked to the optical resonator. If we lock the repetition and offset frequencies of the comb to a high-grade radiofrequency (RF oscillator its relative frequency stability is transferred from the RF to the optical frequency domain. Experiments in the field of precise length metrology of low-expansion materials are usually of long-term nature so it is required that the optical frequency comb stay in operation for an extended period of time. The optoelectronic closed-loop systems used for stabilization of combs are usually based on traditional analog electronic circuits processing signals from photodetectors. From an experimental point of view, these setups are very complicated and sensitive to ambient conditions, especially in the optical part, therefore maintaining long-time operation is not easy. The research presented in this paper deals with a novel approach based on digital signal processing and a software-defined radio. We describe digital signal processing algorithms intended for keeping the femtosecond optical comb in a long-time stable operation. This need arose during specialized experiments involving measurements of optical frequencies of tunable continuous-wave lasers. The resulting system is capable of keeping the comb in lock for an extensive period of time (8 days or more with the relative stability better than 1.6 × 10−11.

  10. Long-term cycle stability at a high current for nanocrystalline LiFePO4 coated with a conductive polymer

    International Nuclear Information System (INIS)

    Highly uniform hierarchical-microstructured LiFePO4 particles with dumbbell- and donut-shape and individual LiFePO4 nanocrystals were prepared by a hydrothermal method utilizing citric acid or a triblock copolymer (Pluronic P123) as a surfactant. The cathode composed of the individual nanocrystalline LiFePO4 particles exhibited higher specific capacity than the cathodes composed of the hierarchically assembled microparticles. Coating a conductive polymer, poly-3,4-ethylenedioxythiophene (PEDOT), on the surface of LiFePO4 particles improved the battery performances such as large specific capacities, high rate capability and an improved cycle stability. The nanocrystalline LiFePO4 particles coated with PEDOT (20 wt%) exhibited the highest discharge capacities of 175 and 136 mAh g−1 for the first battery cycle and 163 and 128 mAh g−1 after 500 battery cycles, with a degradation rate of 6–7%, at the rates of 1 and 10 C, respectively. (paper)

  11. An investigation on the chemical stability and a novel strategy for long-term stabilization of diphenylalanine nanostructures in aqueous solution

    OpenAIRE

    H. Nezammahalleh; Amoabediny, G.; F. Kashanian; M.H. Foroughi Moghaddam

    2015-01-01

    The stability of diphenylalanine (FF) microwires and microtubes in phosphate buffer solution was investigated and a novel strategy was developed for their chemical stabilization. This stability investigation was carried out by optical microscopy and by high performance liquid chromatography (HPLC). These microstructures dissolve in the solution depending upon their degree of FF saturation. The dissolution mechanisms of the structures in kinetically limited processes were found by accurately f...

  12. ATLAS monitored drift tube long-term stability and aging study performed for the first time with the gas-recirculation system planned for LHC

    CERN Document Server

    Zimmermann, S

    2004-01-01

    The monitored drift tubes (MDTs) of the ATLAS muon spectrometer have to sustain count rates up to 1500 Hz/cm and must be able to survive an accumulated charge of up to 0.6 C/cm during 10 years of operation. This paper presents results of aging studies carried out at the CERN Gamma Irradiation Facility GIF for the first time with a final ATLAS muon chamber and a prototype of the gas recirculation system planned at LHC. A loss in pulse height was observed for MDTs under gas recirculation after an accumulated charge equivalent to only 1 year of LHC operation; the effect was traced to a silicone contamination from bad components in the gas recirculation system. Tubes operated with the classical one-pass, flushing mode did not show any evidence of aging, thus (re)validating the materials and components used in the MDT construction. Questions of long-term stability when recycling the major part of the operating gas could also be addressed by the measurements performed; results on this will also be discussed. (6 ref...

  13. Improving the Long-Term Stability of Atmospheric Surface Deformation Predictions by Mitigating the Effects of Orography Updates in Operational Weather Forecast Models

    Science.gov (United States)

    Dill, Robert; Bergmann-Wolf, Inga; Thomas, Maik; Dobslaw, Henryk

    2016-04-01

    The global numerical weather prediction model routinely operated at the European Centre for Medium-Range Weather Forecasts (ECMWF) is typically updated about two times a year to incorporate the most recent improvements in the numerical scheme, the physical model or the data assimilation procedures into the system for steadily improving daily weather forecasting quality. Even though such changes frequently affect the long-term stability of meteorological quantities, data from the ECMWF deterministic model is often preferred over alternatively available atmospheric re-analyses due to both the availability of the data in near real-time and the substantially higher spatial resolution. However, global surface pressure time-series, which are crucial for the interpretation of geodetic observables, such as Earth rotation, surface deformation, and the Earth's gravity field, are in particular affected by changes in the surface orography of the model associated with every major change in horizontal resolution happened, e.g., in February 2006, January 2010, and May 2015 in case of the ECMWF operational model. In this contribution, we present an algorithm to harmonize surface pressure time-series from the operational ECMWF model by projecting them onto a time-invariant reference topography under consideration of the time-variable atmospheric density structure. The effectiveness of the method will be assessed globally in terms of pressure anomalies. In addition, we will discuss the impact of the method on predictions of crustal deformations based on ECMWF input, which have been recently made available by GFZ Potsdam.

  14. Long-Term Field Study of Microbial Community and Dechlorinating Activity Following Carboxymethyl Cellulose-Stabilized Nanoscale Zero-Valent Iron Injection.

    Science.gov (United States)

    Kocur, Chris M D; Lomheim, Line; Molenda, Olivia; Weber, Kela P; Austrins, Leanne M; Sleep, Brent E; Boparai, Hardiljeet K; Edwards, Elizabeth A; O'Carroll, Denis M

    2016-07-19

    Nanoscale zerovalent iron (nZVI) is an emerging technology for the remediation of contaminated sites. However, there are concerns related to the impact of nZVI on in situ microbial communities. In this study, the microbial community composition at a contaminated site was monitored over two years following the injection of nZVI stabilized with carboxymethyl cellulose (nZVI-CMC). Enhanced dechlorination of chlorinated ethenes to nontoxic ethene was observed long after the expected nZVI oxidation. The abundance of Dehalococcoides (Dhc) and vinyl chloride reductase (vcrA) genes, monitored using qPCR, increased by over an order of magnitude in nZVI-CMC-impacted wells. The entire microbial community was tracked using 16S rRNA gene amplicon pyrosequencing. Following nZVI-CMC injection, a clear shift in microbial community was observed, with most notable increases in the dechlorinating genera Dehalococcoides and Dehalogenimonas. This study suggests that coupled abiotic degradation (i.e., from reaction with nZVI) and biotic degradation fueled by CMC led to the long-term degradation of chlorinated ethenes at this field site. Furthermore, nZVI-CMC addition stimulated dehalogenator growth (e.g., Dehalococcoides) and biotic degradation of chlorinated ethenes. PMID:27305345

  15. Improving the long-term stability of Ti6Al4V abutment screw by coating micro/nano-crystalline diamond films.

    Science.gov (United States)

    Xie, Youneng; Zhou, Jing; Wei, Qiuping; Yu, Z M; Luo, Hao; Zhou, Bo; Tang, Z G

    2016-10-01

    Abutment screw loosening is the most common complication of implanting teeth. Aimed at improving the long-term stability of them, well-adherent and homogeneous micro-crystalline diamond (MCD) and nano-crystalline diamond (NCD) were deposited on DIO(®) (Dong Seo, Korea) abutment screws using a hot filament chemical vapor deposition (HFCVD) system. Compared with bare DIO(®) screws, diamond coated ones showed higher post reverse toque values than the bare ones (pcoated disks showed lower friction coefficients of 0.15 and 0.18 in artificial saliva when countered with ZrO2 than that of bare Ti6Al4V disks of 0.40. Though higher cell apoptosis rate was observed on film coated disks, but no significant difference between MCD group and NCD group. And the cytotoxicity of diamond films was acceptable for the fact that the cell viability of them was still higher than 70% after cultured for 72h. It can be inferred that coating diamond films might be a promising modification method for Ti6Al4V abutment screws. PMID:27393893

  16. Preferential flow paths in paraglacial catchments: first order controls on the long-term stability of 'biodiversity hotspots' in a changing climate

    Science.gov (United States)

    Grocott, Michael; Kettridge, Nick; Bradley, Chris; Milner, Alexander

    2016-04-01

    PFPs are a fundamental first order control upon the occurrence of 'biodiversity hotspots' within paraglacial floodplains, and highlights their role as an important conduit for hillslope-floodplain connectivity. Given the expected changes in the hydrological dynamics of paraglacial catchments this research raises questions about the long-term stability of GW-fed streams, and whether the increasing relative importance of groundwater sources (e.g. from colluvium) can sustain flow of GW-fed streams. In addition glacial retreat and associated long-term declines in sediment yields could have negative implications for the development and renewal of PFPs across paraglacial floodplains, which would be detrimental to the persistence of 'biodiversity hotspots'.

  17. Research on geosphere stability for long-term isolation of radioactive waste. Progress report for fiscal years 2005-2009: H22 report

    International Nuclear Information System (INIS)

    This progress report (H22 Report) documents progress made during JAEA 1st Midterm Plan (FY 2005 - 2009) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. For the current 5-year R and D programme, three major goals have been defined as follows: 1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, 2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and 3) development of new dating techniques for providing information about geologic history and the timing of geologic events. For investigation techniques, an extracting technique of active faults with weak surface expressions by LiDAR, an integrated approach combining geophysical and geochemical methods for detecting crustal magma storage and an estimating method for uplift rates in an inland area using relative heights of fluvial terraces have been made. A numerical simulation code for predicting landform evolution in the next 100,000 years, and incorporating models of geophysical processes directly into probabilistic assessments for renewed volcanism using Bayesian inference (multiple inference model) have been prepared for prediction models. Improvement of AMS system for 14C dating was conducted in order to precisely determine isotopic compositions. (U-Th)/He and K-Ar dating systems were also installed at Tono Geoscience Center (TGC) for determining the production age of fault gouge and precipitated within open fractures. In this paper, the current status of R and D activities with previous scientific and technological progress is summarized. (author)

  18. Amorphous Co(OH)2 nanosheet electrocatalyst and the physical mechanism for its high activity and long-term cycle stability

    Science.gov (United States)

    Gao, Y. Q.; Li, H. B.; Yang, G. W.

    2016-01-01

    Good conductivity is conventionally considered as a typical reference standard in terms of selecting water electrolysis catalysts. Cobalt hydroxide (Co(OH)2) has received extensive attention for its exceptional properties as a promising electrocatalysis catalyst. However, research on Co(OH)2 so far prefers to its crystal phase instead of amorphous phase because the former generally exhibits better conductivity. Here, we have demonstrated that the amorphous Co(OH)2 electrocatalyst synthesized via a simple, facile, green, and low-cost electrochemistry technique possesses high activity and long-term cycle stability in the oxygen evolution reaction (OER). The as-synthesized Co(OH)2 electrode was found to be a promising electrocatalyst for mediating OER in alkaline media, as evidenced by the overpotential of 0.38 V at a current density of 10 mA cm-2 and a Tafel slope of 68 mV dec-1. The amorphous Co(OH)2 also presented outstanding durability and its stability was just as well as that of crystalline Co(OH)2. Generally, the integrated electrochemical performances of the amorphous Co(OH)2 in the OER process were much superior to that of the crystalline Co(OH)2 materials. We also established that the short-range order, i.e., nanophase, of amorphous Co(OH)2 creates a lot of active sites for OER which can greatly promote the electrocatalysis performance of amorphous catalysts. These findings showed that the conventional understanding of selecting electrocatalysts with conductivity as a typical reference standard seems out of date for developing new catalysts at the nanometer, which actually open a door to applications of amorphous nanomaterials as an advanced electrocatalyst in the field of water oxidation.

  19. 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...

  20. Stability, Survival, and Tolerability of an Auditory Osseointegrated Implant for Bone Conduction Hearing: Long-Term Follow-Up of a Randomized Controlled Trial

    Science.gov (United States)

    den Besten, Christine A.; Stalfors, Joacim; Wigren, Stina; Blechert, Johan Ivarsson; Flynn, Mark; Eeg-Olofsson, Måns; Aggarwal, Rohini; Green, Kevin; Nelissen, Rik C.; Mylanus, Emmanuel A. M.; Hol, Myrthe K. S.

    2016-01-01

    Objective: To compare implant stability, survival, and soft tissue reactions for a novel (test) and previous generation (control) percutaneous auditory osseointegrated implant for bone conduction hearing at long-term follow-up of 5 years. Study Design: Single follow-up visit of a previously completed multicenter, randomized, controlled trial. Patients: Fifty-seven of the 77 participants of a completed randomized controlled trial on a new auditory osseointegrated implant underwent a single follow-up visit 5 years after implantation, which comprised implant stability measurements and collection of Holgers scores. Additionally, implant survival was recorded for all 77 patients from the original trial. Results: The test implant showed significantly higher implant stability quotient (ISQ) values compared with the control implant throughout the 5-year follow-up. Mean area under the curve of ISQ high from baseline to 5 years was 71.6 (standard deviation [SD] ±2.0) and 66.7 (SD ±3.4) for the test and control implant, respectively (p < 0.0001). For both implants, the mean ISQ value recorded at 5 years was higher compared with implantation (test group +2.03 [SD ±2.55, within group p < 0.0001] and control group +2.25 [SD ±4.95, within group p = 0.12]). No difference was noticed in increase from baseline between groups (p = 0.64). Furthermore, evaluation of soft tissue reactions continued to show superiority of the test implant. At the 5-year follow-up visit, one patient (2.5%) presented with a Holgers grade 2 in the test group, compared with four patients (23.5%) in the control group (p = 0.048); no patient presented with more severe soft tissue reactions. Excluding explantations, the survival rate was 95.8% for the test group and 95.0% for the control group. The corresponding rates including explantations were 93.9 and 90.0%. Conclusion: The test implant showed superiority in terms of higher mean ISQ values and less adverse soft tissue reactions, both

  1. Thermal stability of waste glasses, nucleation and crystallization, and long term behaviour at low temperature (below TG); Stabilite thermique du materiau verre rappel des theories de la nucleation et de la devitrification comportement a long terme sous TG

    Energy Technology Data Exchange (ETDEWEB)

    Olhac, X.; Fillet, C. [CEA Valrho, Dir. de l' Energie Nucleaire, DEN, 30 - Marcoule (France); Phalippou, J. [Montpellier-2 Univ., Lab. des Verres, 34 (France)

    1997-07-01

    Since the quality of the glass will be affected by its thermal history, an assessment of thermal stability of waste glasses is necessary. A brief review of the classical nucleation theory in glass forming systems is presented. Particular emphasis is given to the driving force and the kinetic barrier which control the beginning of nucleation. The general theory of phase transformation kinetics derived by Kolmogorov-Johnson-Mehl-Avrami is also exposed, including an application of this model to follow the overall crystallization. Special attention is given to devitrification at low temperature. The long time storage of waste glasses at low temperature (below Tg) is next studied with regard to crystallization. Some provisional studies of devitrification rates at low temperature are introduced, based on extrapolation of high temperature measures. Furthermore, in order to understand the mechanisms occurring in the low temperature range, others experiments in concern with specific properties (viscosity, diffusion) are presented. They demonstrate that the occurrence of nucleation and crystal growth at low temperature indicates a decoupling between the kinetic coefficient for transport at the crystal/glass interface and the bulk viscosity. (authors)

  2. Geologic processes in the RWMC area, Idaho National Engineering Laboratory: Implications for long term stability and soil erosion at the radioactive waste management complex

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, W.R.; Tullis, J.A.; Smith, R.P. [and others

    1995-09-01

    The Radioactive Waste Management Complex (RWMC) is the disposal and storage facility for low-level radioactive waste at the Idaho National Engineering Laboratory (INEL). Transuranic waste and mixed wastes were also disposed at the RWMC until 1970. It is located in the southwestern part of the INEL about 80 km west of Idaho Falls, Idaho. The INEL occupies a portion of the Eastern Snake River Plain (ESRP), a low-relief, basalt, and sediment-floored basin within the northern Rocky Mountains and northeastern Basin and Range Province. It is a cool and semiarid, sagebrush steppe desert characterized by irregular, rolling terrain. The RWMC began disposal of INEL-generated wastes in 1952, and since 1954, wastes have been accepted from other Federal facilities. Much of the waste is buried in shallow trenches, pits, and soil vaults. Until about 1970, trenches and pits were excavated to the basalt surface, leaving no sediments between the waste and the top of the basalt. Since 1970, a layer of sediment (about 1 m) has been left between the waste and the basalt. The United States Department of Energy (DOE) has developed regulations specific to radioactive-waste disposal, including environmental standards and performance objectives. The regulation applicable to all DOE facilities is DOE Order 5820.2A (Radioactive Waste Management). An important consideration for the performance assessment of the RWMC is the long-term geomorphic stability of the site. Several investigators have identified geologic processes and events that could disrupt a radioactive waste disposal facility. Examples of these {open_quotes}geomorphic hazards{close_quotes} include changes in stream discharge, sediment load, and base level, which may result from climate change, tectonic processes, or magmatic processes. In the performance assessment, these hazards are incorporated into scenarios that may affect the future performance of the RWMC.

  3. Geologic processes in the RWMC area, Idaho National Engineering Laboratory: Implications for long term stability and soil erosion at the radioactive waste management complex

    International Nuclear Information System (INIS)

    The Radioactive Waste Management Complex (RWMC) is the disposal and storage facility for low-level radioactive waste at the Idaho National Engineering Laboratory (INEL). Transuranic waste and mixed wastes were also disposed at the RWMC until 1970. It is located in the southwestern part of the INEL about 80 km west of Idaho Falls, Idaho. The INEL occupies a portion of the Eastern Snake River Plain (ESRP), a low-relief, basalt, and sediment-floored basin within the northern Rocky Mountains and northeastern Basin and Range Province. It is a cool and semiarid, sagebrush steppe desert characterized by irregular, rolling terrain. The RWMC began disposal of INEL-generated wastes in 1952, and since 1954, wastes have been accepted from other Federal facilities. Much of the waste is buried in shallow trenches, pits, and soil vaults. Until about 1970, trenches and pits were excavated to the basalt surface, leaving no sediments between the waste and the top of the basalt. Since 1970, a layer of sediment (about 1 m) has been left between the waste and the basalt. The United States Department of Energy (DOE) has developed regulations specific to radioactive-waste disposal, including environmental standards and performance objectives. The regulation applicable to all DOE facilities is DOE Order 5820.2A (Radioactive Waste Management). An important consideration for the performance assessment of the RWMC is the long-term geomorphic stability of the site. Several investigators have identified geologic processes and events that could disrupt a radioactive waste disposal facility. Examples of these open-quotes geomorphic hazardsclose quotes include changes in stream discharge, sediment load, and base level, which may result from climate change, tectonic processes, or magmatic processes. In the performance assessment, these hazards are incorporated into scenarios that may affect the future performance of the RWMC

  4. 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...

  5. 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%.

  6. 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 ...

  7. The Adults in the Making Program: Long-Term Protective Stabilizing Effects on Alcohol Use and Substance Use Problems for Rural African American Emerging Adults

    Science.gov (United States)

    Brody, Gene H.; Yu, Tianyi; Chen, Yi-fu; Kogan, Steven M.; Smith, Karen

    2012-01-01

    Objective: This report addresses the long-term efficacy of the Adults in the Making (AIM) prevention program on deterring the escalation of alcohol use and development of substance use problems, particularly among rural African American emerging adults confronting high levels of contextual risk. Method: African American youths (M age, pretest =…

  8. Predictive tools and data needs for long term performance of in-situ stabilization and containment systems: DOE/OST stabilization workshop, June 26-27, Park City, Utah

    International Nuclear Information System (INIS)

    This paper summarizes the discussion within the Predictive Tools and Data Needs for Long Term Performance Assessment Subgroup. This subgroup formed at the DOE Office of Science and Technology workshop to address long-term performance of in situ stabilization and containment systems. The workshop was held in Park City, Utah, 26 and 27 June, 1996. All projects, engineering and environmental, have built-in decision processes that involve varying risk/reward scenarios. Such decision-processes maybe awkward to describe but are utilized every day following approaches that range from intuitive to advanced mathematical and numerical. Examples are the selection of components of home sound system, the members of a sports team, investments in a portfolio, and the members of a committee. Inherent in the decision method are an understanding of the function or process of the system requiring a decision or prediction, an understanding of the criteria on which decisions are made such as cost, performance, durability and verifiability. Finally, this process requires a means to judge or predict how the objects, activities, people and processes being analyzed will perform relative to the operations and functions of the system and relative to the decision criteria posed for the problem. These risk and decision analyses are proactive and iterative throughout the life of a remediation project. Prediction inherent to the analyses are based on intuition, experience, trial and error, and system analysis often using numerical approaches

  9. Long-term stability of dentoalveolar, skeletal, and soft tissue changes after non-extraction treatment with a self-ligating system

    Science.gov (United States)

    Basciftci, Faruk Ayhan; Akin, Mehmet; Bayram, Sinem

    2014-01-01

    Objective To evaluate the long-term effects of self-ligating brackets (SLBs) on transverse dimensions of arches and skeletal and soft tissues and to quantitatively evaluate the treatment outcome after non-extraction treatment with SLBs. Methods The sample consisted of 24 (18 female and six male) subjects, with a mean age of 14.23 ± 2.19 years, who received treatment with the Damon®3 appliances. Complete records including cephalometric radiographs and plaster models were obtained before treatment (T1), immediately after treatment (T2), six months after treatment (T3), and two years (T4) after treatment. Digital study models were generated. Twenty lateral cephalometric, six frontal cephalometric, and eight dental cast measurements were examined. The Peer Assessment Rating index was used to measure the treatment outcome. The Wilcoxon test was applied for statistical analysis of the changes. Results There were significant increases in all transverse dental cast measurements with active treatment. There was some significant relapse in the long term, particularly in maxillary width (p < 0.05). Statistically significant increases were found in nasal (p < 0.001), maxillary base, upper molar, lower intercanine, and antigonial (p < 0.05) widths in T1-T2. Lower incisors were proclined and protruded in T1-T2. Conclusions SLBs correct crowding by mechanisms involving incisor proclination and protrusion and expansion of the dental arches, without induction of clinically significant changes in hard and soft tissues of the face. PMID:24892025

  10. [Effect of Long-term Fertilizer Application on the Stability of Organic Carbon in Particle Size Fractions of a Paddy Soil in Zhejiang Province, China].

    Science.gov (United States)

    Mao, Xia-li; Lu, Kou-ping; Sun, Tao; Zhang, Xiao-kai; He, Li-zhi; Wang, Hai-long

    2015-05-01

    Effects of chemical fertilizers and organic manure on the soil organic carbon (SOC) content in particle size fractions of paddy soil were investigated in a 17-year long-term fertilization field experiment in Zhejiang Province, China. The inherent chemical composition of silt- and clay-associated SOC was evaluated with solid-state 13C-NMR spectroscopy. Compared to CK (no fertilizer treatment), NPKRS (NPK fertilizers plus rice straw) , NPKOM (NPK fertilizers plus organic manure) , NPK (NPK fertilizers) and OM (organic manure alone) treatments significantly (P decomposition rate of SOC. The aromaticity, hydrophobicity and, hence, chemical recalcitrance of silt- and clay-associated SOC in the NPK fertilizer treatments were lower than those of the organically amended plots and unfertilized treatments, indicating decreased recalcitrance of SOC against decomposition. We concluded that long-term application of organic manure combined with chemical fertilizers, either through increased accumulation of both recalcitrant compounds and carbohydrates or reduced decomposition of organic matter, was a sustainable strategy for facilitating carbon accumulation of the paddy soil investigated in this study. PMID:26314136

  11. Effect of a cathode buffer layer on the stability of organic solar cells

    International Nuclear Information System (INIS)

    We present the effect of a cathode buffer layer on the performance and stability of organic photovoltaics (OPVs) based on a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Six kinds of cathode buffer layers, i.e. lithium fluoride, sodium chloride, NaCl/Mg, tris-(8-hydroxy-quinoline) aluminum, bathocuproine and 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene, were inserted between the photoactive layer and an Al cathode, which played a dominant role in the device’s performance. Devices with the cathode buffer layers above exhibited improved performance. The degradation of these devices with encapsulation was further investigated in an inert atmosphere. The results indicated that devices with inorganic cathode buffer layers exhibited better stability than those with organic cathode buffer layers. (paper)

  12. 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.

  13. Effect of long-term aging at 815/sup 0/C on the tensile properties and microstructural stability of four cobalt- and nickel-base superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, J.P.

    1976-08-01

    Two heats of Haynes alloy 25 and one heat each of Haynes alloy 188, Hastelloy N, and Inconel 625 were tensile tested after aging for 11,000 h at 816/sup 0/C. Yield strength, ultimate tensile strength, and elongation were determined 24, 316, 760, and 982/sup 0/C and compared with typical properties for these materials in the solution annealed condition. Toughness values were determined for these materials from their engineering stress-strain curves. The long-term aging treatment degraded ductility and toughness at room temperature but, contrary to behavior expected for overaging, enhanced them over those for the solution annealed condition in tests at 760/sup 0/C. The tensile properties of the aged superalloys were correlated with mode of fracture and the amounts, identity, and morphology of the precipitates. Aging substantially depleted the hardener tungsten from the matrix in the cobalt-base alloys.

  14. Long-term performance and stability of a continuous granular airlift reactor treating a high-strength wastewater containing a mixture of aromatic compounds.

    Science.gov (United States)

    Ramos, Carlos; Suárez-Ojeda, María Eugenia; Carrera, Julián

    2016-02-13

    Continuous feeding operation of an airlift reactor and its inoculation with mature aerobic granules allowed the successful treatment of a mixture of aromatic compounds (p-nitrophenol, o-cresol and phenol). Complete biodegradation of p-nitrophenol, o-cresol, phenol and their metabolic intermediates was achieved at an organic loading rate of 0.61 g COD L(-1)d(-1). Stable granulation was obtained throughout the long-term operation (400 days) achieving an average granule size of 2.0 ± 1 mm and a sludge volumetric index of 26 ± 1 mL g(-1) TSS. The identified genera in the aerobic granular biomass were heterotrophic bacteria able to consume aromatic compounds. Therefore, the continuous feeding regimen and the exposure of aerobic granules to a mixture of aromatic compounds make possible to obtain good granulation and high removal efficiency. PMID:26530892

  15. The study on long-term stability of the geological environment. Plan of the investigation program for the 2004 fiscal year

    International Nuclear Information System (INIS)

    The project consisted of six themes such as research for upheaval and erosion, climate and sea level change, volcanic activity, active fault and earthquake, structure of underground in land, and natural analog. The practical researches contend development and systematization of the estimation and analysis technology of change of geographical features, upheaval and submergence rate, the thermal, hydraulic and water quality model of geothermal activity, long-term estimation model of volcanic activity, abstraction technology of fault as earthquake source, investigation technology of history of fault activity and development of the accurately controlled routinely operated signal system, restoration of climate change in the past, old environment, and volcanic and hydrothermal activity. Summary of researches until 2003 fiscal year, objects of researches are stated. (S.Y.)

  16. Long-Term IQ Stability Using the WISC-IV and WAIS-IV among a Sample of Special Education Students

    Science.gov (United States)

    Spector, Hayley

    2013-01-01

    The present study investigated the stability of scores on the WISC-IV and WAIS-IV over an approximate six-year period. Previous research using older versions of the WISC and WAIS have suggested that these scales demonstrate strong stability of scores. Since research that has compared the stability of scores between the WISC-IV and the WAIS-IV is…

  17. Chemical characteristics and long-term stability of the cement. Deduction from A. Atkinson's articles on 'evolution of pH in a radwaste repository'

    International Nuclear Information System (INIS)

    In the radioactive waste disposal system, cement materials have been used as (1) structural materials in disposal facilities, (2) solidifying materials for enclosing radioactive nuclides, and (3) internal filling mortar for the space between the waste and the concrete. One of the important features of cement materials is its ability to establish a high pH in the water within the repository. A high pH is beneficial because in this condition the solubilities of many radionuclides, especially TRU, in aqueous solution are low. It is necessary to maintain the high degree of sorption of radionuclides based on the high pH for the long term safety of the system. Then the important thing is to gain a reasonable evaluation of the pH within the repository. Atkinson et al. have presented a method of evaluating pH in the leaching groundwater from cement. They predicted the dissolution property of cement based on a simplified model using equilibrium data for the CaO-SiO2-H2O system. In the present report, we explain the Atkinson proposed method of evaluating the pH in the repository. Our studies on solubility of cement hydrate are also discussed. (author)

  18. Decontamination tests in the recreational areas affected by the Chernobyl accident. Efficiency of decontamination and long-term stability of the effects

    International Nuclear Information System (INIS)

    The paper provides a review of the decontamination tests and the follow up monitoring program conducted by the Russian and Danish researchers in two recreational areas in the period 1995-2003. The recreational areas Novie Bobovichi and Muravinka consisted of sets of wooden and brick summer houses in forest-grassland surroundings. The sites are located on the territory of the Bryansk region (Russia) at a distance of about 180 km north-east of the Chernobyl Nuclear Power Plant. Before intervention began, the inventory of 137Cs in soil was determined at a level of 1000 kBq m-2. The collaborative research project showed that use of simple countermeasures involving hand-tools and light machinery could reduce the external dose rate considerably, even though 10 years had passed since fallout of the Chernobyl radiocesium. The long-term monitoring of the recreational areas did not demonstrate significant re-contamination of cleaned ground plots within the time period of 15-17 years after intervention. The technologies and the methods implemented to clean up the recreational areas may be recommended for restoration of some Japanese sites that were strongly contaminated in 2011 as a result of the Fukushima accident. (author)

  19. 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.

  20. Deep crustal faults and the origin and long-term flank stability of Mt. Etna : First results from the CIRCEE cruise (Oct. 2013)

    Science.gov (United States)

    Gutscher, Marc-Andre; Dominguez, Stephane; Mercier de Lepinay, Bernard; Pinheiro, Luis; Babonneau, Nathalie; Cattaneo, Antonio; LeFaou, Yann; Barreca, Giovanni; Micallef, Aaron; Rovere, Marzia

    2014-05-01

    The relation between deep crustal faults and the origin of Mount Etna, the largest and most active volcano in Europe has long been suspected due to its unusual geodynamic location. Results from a new marine geophysical survey offshore Eastern Sicily reveal the detailed geometry (location, length, dip and orientation) of a two-branched 200-km long, lithospheric scale fault system, long sought for as being the cause of Mount Etna. Using high-resolution bathymetry and seismic profiling, we image a 60-km long, previously unidentified, NW trending fault with evidence of recent displacement at the seafloor, offsetting Holocene sediments. This newly identified fault connects NE of Catania, to a known 40-km long, offshore-onshore fault system dissecting the southeastern flank of Mount Etna, generally interpreted as purely gravitational collapse structures. Geological and morphological field studies together with earthquake focal mechanisms indicate active dextral strike-slip motion along the onshore and shallow offshore portion of this 40 + 60 km long segment. The southern 100 km branch of the fault is associated with a sub-vertical lithospheric scale tear fault showing pure down to the East normal faulting and a 500+m thick elongate basin marked by syn-tectonic Plio-quaternary sediment fill. Together they represent two kinematically distinct strands of the long sought "STEP" (Subduction Tear Edge Propagator) fault, whose expression at depth controls the position of Mount Etna. Both 100-km long branches of the fault system are mechanically capable of generating magnitude 7 earthquakes (e.g. - like the 1693 Catania earthquake, the strongest in Italian history, causing 40,000 deaths). We conclude this deep-rooted lithospheric weakness guides gradual down slope creep of Mount Etna and may lead to long-term catastrophic flank collapse with associated tsunami by large-scale mass wasting.

  1. Working Fluid Stability in Large-Scale Organic Rankine Cycle-Units Using Siloxanes—Long-Term Experiences and Fluid Recycling

    Directory of Open Access Journals (Sweden)

    Tobias G. Erhart

    2016-05-01

    Full Text Available The results in this work show the influence of long-term operation on the decomposition of working fluids in eight different organic rankine cycle (ORC power plants (both heat-led and electricity-led in a range of 900 kW el to 2 MW el . All case study plants are using octamethyltrisiloxane (MDM as a working fluid; the facilities are between six to 12 years old. Detailed analyses, including the fluid distribution throughout the cycle, are conducted on one system. All presented fluid samples are analyzed via head space gas chromatography mass spectrometry (HS-GC-MS. Besides the siloxane composition, the influence of contaminants, such as mineral oil-based lubricants (and their components, is examined. In most cases, the original working fluid degrades to fractions of siloxanes with a lower boiling point (low boilers and fractions with a higher boiling point (high boilers. As a consequence of the analyses, a new fluid recycling and management system was designed and tested in one case study plant (Case Study #8. Pre-post comparisons of fluid samples prove the effectiveness of the applied methods. The results show that the recovery of used working fluid offers an alternative to the purchase of fresh fluid, since operating costs can be significantly reduced. For large facilities, the prices for new fluid range from € 15 per liter (in 2006 to € 22 per liter (in 2013, which is a large reinvestment, especially in light of filling volumes of 4000 liters to 7000 liters per unit. Using the aforementioned method, a price of € 8 per liter of recovered MDM can be achieved.

  2. Dosimetric properties and stability of thermoluminescent foils made from LiF:Mg,Cu,P or CaSO4:Dy during long-term use

    International Nuclear Information System (INIS)

    A few dosimetric systems based on thermoluminescence [TL] foils were developed in recent years (Nariyama et al. 2006, Radiat. Prot. Dosim. 120, 213–218; Olko et al. 2006 Radiat. Prot. Dosim. 118, 213–218) (Czopyk et al. 2008, Radiat. Meas., 43, 977–980; Kłosowski et al. 2010, Radiat. Meas., 45, 719–721; Kopeć et al. 2013, Radiat.Meas., 56, 380–383). Major application of these systems is mapping of 2D dose distribution for medical treatment plan verification, similarly to photochromic or radiochromic films. The advantage of TL foils compared to other films is their re-usability. In this work we present dosimetric properties as dose linearity and fadding of the foils made from LiF:Mg,Cu,P or CaSO4:Dy phosphors and high temperature polymers. Both types of the foils have good linearity in the range 1–20 Gy for LiF:Mg,Cu,P and 0.1–2 Gy for CaSO4:Dy. Their long term fading does not exceed 3.7% and 9% respectively. We additionally investigated effects of sensitivity loss and emission spectra for both types of the foils. One shortcoming of TL foils is that every heat process may have negative influence on their properties, causing changes of their sensitivity. Register signal of the foils after 15 readouts may be reduced by 16% of the initial. We consider that the main reason of these changes is oxidation of organic contamination on the surface and degradation of a polymer which is one of the components of the foils. Effect of sensitivity decreasing may be slowed down by proper use and cleaning detectors by solvent. - Highlights: • Dosimetric properties of the detectors foils made from LiF:Mg,Cu,P and CaSO4:Dy are present. • Sensitivity loss of the detectors during usage is observed. • 2D detector foils should be cleaned thorough the solvent to increase its use time

  3. Assessment of the long-term stability of cementitious barriers of radioactive waste repositories by using digital-image-based microstructure generation and reactive transport modelling

    International Nuclear Information System (INIS)

    Cement-based grout plays a significant role in the design and performance of nuclear waste repositories: used correctly, it can enhance their safety. However, the high water-to-binder ratios, which are required to meet the desired workability and injection ability at early age, lead to high porosity that may affect the durability of this material and undermine its long-term geochemical performance. In this paper, a new methodology is presented in order to help the process of mix design which best meets the compromise between these two conflicting requirements. It involves the combined use of the computer programs CEMHYD3D for the generation of digital-image-based microstructures and CrunchFlow, for the reactive transport calculations affecting the materials so simulated. This approach is exemplified with two grout types, namely, the so-called Standard mix 5/5, used in the upper parts of the structure, and the 'low-pH' P308B, to be injected at higher depths. The results of the digital reconstruction of the mineralogical composition of the hardened paste are entirely logical, as the microstructures display high degrees of hydration, large porosities and low or nil contents of aluminium compounds. Diffusion of solutes in the pore solution was considered to be the dominant transport process. A single scenario was studied for both mix designs and their performances were compared. The reactive transport model adequately reproduces the process of decalcification of the C-S-H and the precipitation of calcite, which is corroborated by empirical observations. It was found that the evolution of the deterioration process is sensitive to the chemical composition of groundwater, its effects being more severe when grout is set under continuous exposure to poorly mineralized groundwater. Results obtained appear to indicate that a correct conceptualization of the problem was accomplished and support the assumption that, in absence of more reliable empirical data, it might

  4. Paddy Soil Stability and Mechanical Properties as Affected by Long-Term Application of Chemical Fertilizer and Animal Manure in Subtropical China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Wet stability, penetration resistance (PR), and tensile strength (TS) of paddy soils under a fertilization experiment for 22 years were determined to elucidate the function of soil organic matter in paddy soil stabilization. The treatments included no fertilization (CK), normal chemical fertilization (NPK), double the NPK application rates (2NPK), and NPK mixed with organic manure (NPK+OM). Compared with CK, fertilization increased soil organic carbon (SOC) and soil porosity. The results of soil aggregate fragmentation degree (SAFD) showed that fast wetting by water was the key fragmentation mechanism. Among the treatments, the NPK+OM treatment had the largest size of water-stable aggregates and greatest normal mean weight diameter (NMWD) (P ≤ 0.05), but the lowest PR and TS in both cultivated horizon (Ap) and plow pan. The CK and 2NPK treatments were measured with PR > 2.0 MPa and friability index < 0.20,respectively, in the Ap horizon, suggesting that the soils was mechanically unfavourable to root growth and tillage. In the plow pan, the fertilization treatments had greater TS and PR than in CK. TS and PR of the tested soil aggregates were negatively correlated to SOC content and soil porosity. This study suggested that chemical fertilization could cause deterioration of mechanical properties while application of organic manure could improve soil stability and mechanical properties.

  5. 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.

  6. Using amorphous manganese oxide for remediation of smelter-polluted soils: a pH-dependent long-term stability study

    Science.gov (United States)

    Ettler, Vojtech; Tomasova, Zdenka; Komarek, Michael; Mihaljevic, Martin; Sebek, Ondrej

    2015-04-01

    In soil systems, manganese (Mn) oxides are commonly found to be powerful sorbents of metals and metalloids and are thus potentially useful in soil remediation. A novel amorphous manganese oxide (AMO) and a Pb smelter-polluted agricultural soil amended with the AMO and incubated for 2 and 6 months were subjected to a pH-static leaching procedure (pH = 3 - 8) to verify the chemical stabilization effect on metals and metalloids. The AMO stability in pure water was pH-dependent with the highest Mn release at pH 3 (47% dissolved) and the lowest at pH 8 (0.14% dissolved). Secondary rhodochrosite (MnCO3) was formed at the AMO surfaces at pH > 5. The AMO dissolved significantly less after 6 months of incubation. Sequential extraction analysis indicated that "labile" fraction of As, Pb and Sb in soil significantly decreased after AMO amendment. The pH-static experiments indicated that no effect on leaching was observed for Cd and Zn after AMO treatments, whereas the leaching of As, Cu, Pb and Sb decreased down to 20%, 35%, 7% and 11% of the control, respectively. The remediation efficiency was more pronounced under acidic conditions and the time of incubation generally led to increased retention of the targeted contaminants. The AMO was found to be a promising agent for the chemical stabilization of polluted soils and other in situ applications need to be evaluated. This study was supported by the Czech Science Foundation (GAČR 15-07117S).

  7. Long-term stability of the Hounsfield unit to electron density calibration curve in cone-beam computed tomography images for adaptive radiotherapy treatment planning

    OpenAIRE

    Takemura, Akihiro; Tanabe, Shogo; Tokai, Mei; Ueda, Shinichi; Noto, Kimiya; Isomura, Naoki; Kojima, Hironori

    2015-01-01

    Aim To use cone-beam computed tomography (CBCT) images for treatment planning, the Hounsfield unit (HU)-electron density (ED) calibration table for CBCT should be stable. The purpose of this study was to verify the stability of the HU values for the CBCT system over 1 year and to evaluate the effects of variation in HU-ED calibration curves on dose calculation. Materials and Methods A tissue characterisation phantom was scanned with the field of view (FOV) of size S (FOV-S) and FOV of size M ...

  8. Long-Term Stability of Human Genomic and Human Papillomavirus DNA Stored in BD SurePath and Hologic PreservCyt Liquid-Based Cytology Media

    OpenAIRE

    Agreda, Patricia M.; Beitman, Gerard H.; Gutierrez, Erin C.; Harris, James M.; Koch, Kristopher R.; LaViers, William D.; Leitch, Sharon V.; Maus, Courtney E.; McMillian, Ray A.; Nussbaumer, William A.; Palmer, Marcus L. R.; Porter, Michael J; Richart, Gregory A.; Schwab, Ryan J.; Vaughan, Laurence M.

    2013-01-01

    We evaluated the effect of storage at 2 to 8°C on the stability of human genomic and human papillomavirus (HPV) DNA stored in BD SurePath and Hologic PreservCyt liquid-based cytology media. DNA retained the ability to be extracted and PCR amplified for more than 2.5 years in both medium types. Prior inability to detect DNA in archived specimens may have been due to failure of the extraction method to isolate DNA from fixed cells.

  9. Enhanced photovoltaic performance and long-term stability of dye-sensitized solar cells by incorporating SiO2 nanoparticles in binary ionic liquid electrolytes

    International Nuclear Information System (INIS)

    Hydrophilic SiO2 nanoparticles in a binary ionic liquid (bi-IL) consisting of 1-propyl-3-methylimidazolium iodide (PMII) and 1-ethyl-3-methyl-imidazolium dicyanimide (EMIDCA) facilitated electron transfer and solidified the electrolyte for a dye-sensitized solar cell (DSC). We investigated the dependence of charge transport and photovoltaic performance on the composition of bi-IL electrolytes with varied ratio of SiO2 nanoparticles. The electrochemical impedance spectra revealed a decreased resistance to charge transfer at the Pt counter electrode (Rct1) when SiO2 (up to 2.0 wt.%) was added, improving the photovoltaic parameters. The DSC based on a TiO2 nanocrystalline film (thickness 14.2 μm) with a composite ionic gel electrolyte of EMIDCA/PMII bi-IL (33 vol.% of EMIDCA) incorporating SiO2 (2 wt.%) exhibited a power conversion efficiency of 5.28% under simulated solar illumination (AM 1.5 G, 100 mW cm− 2). The durability of DSC with a SiO2 solidified electrolyte was superior to that of a liquid one, exhibiting good stability at 60 °C in darkness during an accelerated test for 1000 h. - Highlights: ► SiO2 nanoparticles were introduced in a binary ionic liquid electrolyte. ► Effect of various ratios of SiO2 nanoparticles in gel electrolytes was studied. ► Mechanism of charge transfer with addition of SiO2 nanoparticles was discussed. ► An enhanced solar to electric energy conversion efficiency of 5.28% was achieved. ► Thermal stability of a quasi-solid state dye-sensitized solar cell was improved

  10. Enhanced photovoltaic performance and long-term stability of dye-sensitized solar cells by incorporating SiO{sub 2} nanoparticles in binary ionic liquid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hsin-Fang; Wu, Jhih-Lin; Hsu, Po-Ya [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC (China); Tung, Yung-Liang [Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 30013, Taiwan, ROC (China); Ouyang, Fan-Yi [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC (China); Kai, Ji-Jung, E-mail: jjkai@ess.nthu.edu.tw [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC (China)

    2013-02-01

    Hydrophilic SiO{sub 2} nanoparticles in a binary ionic liquid (bi-IL) consisting of 1-propyl-3-methylimidazolium iodide (PMII) and 1-ethyl-3-methyl-imidazolium dicyanimide (EMIDCA) facilitated electron transfer and solidified the electrolyte for a dye-sensitized solar cell (DSC). We investigated the dependence of charge transport and photovoltaic performance on the composition of bi-IL electrolytes with varied ratio of SiO{sub 2} nanoparticles. The electrochemical impedance spectra revealed a decreased resistance to charge transfer at the Pt counter electrode (R{sub ct1}) when SiO{sub 2} (up to 2.0 wt.%) was added, improving the photovoltaic parameters. The DSC based on a TiO{sub 2} nanocrystalline film (thickness 14.2 μm) with a composite ionic gel electrolyte of EMIDCA/PMII bi-IL (33 vol.% of EMIDCA) incorporating SiO{sub 2} (2 wt.%) exhibited a power conversion efficiency of 5.28% under simulated solar illumination (AM 1.5 G, 100 mW cm{sup −} {sup 2}). The durability of DSC with a SiO{sub 2} solidified electrolyte was superior to that of a liquid one, exhibiting good stability at 60 °C in darkness during an accelerated test for 1000 h. - Highlights: ► SiO{sub 2} nanoparticles were introduced in a binary ionic liquid electrolyte. ► Effect of various ratios of SiO{sub 2} nanoparticles in gel electrolytes was studied. ► Mechanism of charge transfer with addition of SiO{sub 2} nanoparticles was discussed. ► An enhanced solar to electric energy conversion efficiency of 5.28% was achieved. ► Thermal stability of a quasi-solid state dye-sensitized solar cell was improved.

  11. 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

  12. Studies on the long-term stabilities of the background of radionuclides in inductively coupled plasma mass spectrometry (ICP-MS). A review of radionuclide determination by ICP-MS

    International Nuclear Information System (INIS)

    The long-term stabilities of the ICP-MS background of nine radionuclides are studied, of which the signals are partially superimposed by polyatomic interferences or affected from carry-over and memory effects. The background generated by the ICP flame, by two pure waters, and by nitric acid (2% v/v) was investigated in detail. A minimum of 50 measurement points was used for each long-term investigation. The detection limits of the radionuclides of the masses 90 amu (90Sr: 30 Bq/mL), 99 amu (99Tc: 4 mBq/mL), 238 amu (238U: 10 nBq/mL), and 244 amu (244Pu: 0.6 μBq/mL) are calculated from the mean standard deviation of the background signals. For all nine radioisotopes, the calculated detection limits are between 0.8 and 6 pg/mL. While the detection limit of the mass 90 amu is blank limited, those of the mass 99 amu and the actinides are totally uneffected by the blank solutions. The detection limits are compared with those given in literature. (orig.). With 3 figs., 3 tabs

  13. 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%.

  14. 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

  15. [{sup 131}I]Iodoazomycin arabinoside for low-dose-rate isotope radiotherapy: radiolabeling, stability, long-term whole-body clearance and radiation dosimetry estimates in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Piyush [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); McQuarrie, Steven A. [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); Zhou, Aihya [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); McEwan, Alexander J.B. [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); Wiebe, Leonard I. [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada) and Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada)]. E-mail: leonard.wiebe@ualberta.ca

    2005-08-01

    Background: The preliminary characterization of [{sup 131}I]iodoazomycin arabinoside ([{sup 131}I]IAZA) as a potential radiotherapeutic radiopharmaceutical is described. Methods: High-specific-activity [{sup 131}I]IAZA was prepared in therapeutic doses (up to 3 GBq per batch) by isotope exchange in pivalic acid melt and was purified on Sep-Pak cartridges. Stability in 15% ethanol in saline at 4 deg C was determined by high-performance liquid chromatography. IAZA cytotoxicity (IC{sub 50}, {approx}0.1 mM) against both murine (EMT-6) and human (143B, 143B-LTK) tumor cells determined by MTT test was in the range previously reported for EMT-6 cells using a clonogenic assay. Tissue radioactivity levels were measured in a murine tumor model for the 24- to 168-h postinjection period. Radiation dose estimates obtained from the tissue activity levels for this period were calculated from pharmacokinetic (WinNonlin) and dosimetry (MIRD and RAdiation Dose Assessment Resource) parameters. Results: The radioiodination efficiency was >90%, but with systematic losses during Sep-Pak purification, the recovered yields of [{sup 131}I]IAZA were {approx}75%. The product (specific activity, 4.6-6.4 GBq/{mu}mol) was stable for at least 2 weeks, with only {approx}6% degradation over this storage period. Extended biodistribution studies in Balb/c mice bearing implanted EMT-6 tumors showed that the highest tumor/blood radioactivity ratio (T/B; 4.8) occurred 24 h after dosing; the T/B ratio was {approx}1.5 at the end of the 7-day study. The 24- to 168-h tissue radioactivity data fit a one-compartment model except for liver data, which best fit a two-compartment model. Dosimetry estimates showed a tumor self-dose of 7.4 mGy/MBq, which is several-fold higher than for the liver or the kidney. Conclusions: [{sup 131}I]IAZA can be efficiently radiolabeled at high specific activity, purified by a simple Sep-Pak technique and stored with little radiolysis or chemical decomposition at these specific

  16. Thermo-Span合金在650℃长期时效稳定性%Long-term thermal stability of Thermo-Span alloy at 650 ℃

    Institute of Scientific and Technical Information of China (English)

    胡轶嵩; 于连旭; 杨连忠; 李晓欣; 王志宏

    2013-01-01

    Microstructure and properties of oxidation resistant low thermal expansion Thermo-Span alloy unexposed and after ageing at 650 ℃ for 1000 h were investigated.The results show that after ageing at 650 ℃ for 1000 h,the blocky and bar-like Laves phase shows no significant difference compared with that of the unexposed alloy,but the grain boundary precipitation is promoted.There are more zones precipitated with lamellar phase within the grains,and the diameter of γ' phase grows from 10 nm to 30 nm in the aged alloy.The room temperature tensile strength of the aged alloy decreases by nearly 8% and the ductility is kept the same.The tensile strength at 650 ℃ decreases by nearly 5% and the ductility is hardly varied.The stress rupture life of smooth bars are shortened by nearly 41% and the rupture ductility is markedly increased,and the aged alloy shows no notch sensitivity.As a conclusion,Thermo-Span alloy shows good thermal stability at 650 ℃.%对标准热处理和650℃长期时效下的低膨胀Thermo-Span合金的组织和性能进行观察和分析,结果表明:650℃时效1000 h后,合金块状和棒状Laves相无明显变化,但晶界析出相数量有所增加;晶内小条块状相聚集析出的区域更多,γ'相由约10 nm长大到约30 nm.合金的室温拉伸强度稍有下降,降幅约为8%,塑性基本不变;650℃拉伸强度降低约5%,塑性变化不大.合金的光滑持久寿命降低约41%,持久塑性明显提高,时效后合金仍无缺口敏感性.Thermo-Span合金在650℃长期时效下具有良好的组织和力学性能的稳定性.

  17. Sustainability of large-scale constructed stormwater treatment areas (STAs) in the Everglades basin: Long-term stability and phosphorus removal performance

    Science.gov (United States)

    Bhomia, R. K.; Reddy, R.

    2012-12-01

    Treatment wetlands are utilized globally to reduce the amount of nutrients discharged into downstream water bodies. Sustainability of these wetlands depend on accumulation of stable (non-reactive) forms of retained nutrients. Storage of such stable pools of nutrients is influenced by a range of environmental factors such as hydrology, temperature, vegetation and nutrient loading. Our focus was to characterize phosphorus (P) retained by treatment wetlands in the Everglades Agricultural Area Basin. Six stormwater treatment areas (STAs) covering approx. 18,000 ha area are currently operational in south Florida. To date STAs have removed over 1,400 mt of P. The importance of wetland vegetation in P removal is well documented, however limited information is available on the role of different vegetation types on stability of accreted P. Based on dominant vegetation species, existing cells of these STAs are designated and maintained as emergent aquatic vegetation (EAV) and submerged aquatic vegetation (SAV) cells. We characterized soil P into reactive and stable pools and compared these pools between SAV and EAV. By using operationally defined P fractionation scheme we determined inorganic, organic and residual P fractions, of which first two fractions constituted reactive forms, while residual P represented stable form. Intact soil cores were collected from 44 sites spanning STA-1W and STA-2. Soil cores were divided into 3 layers- floc, RAS and pre-STA soil. Floc and RAS accumulated after STA became operational, while underlying peat represented pre-STA soils. Across the sites, SAV and EAV cells did not differ significantly in relative proportion of reactive and stable P pools. Reactive P constituted 75% of TP in floc sections of EAV cells and 62% of TP in SAV cells. In RAS, the reactive P was 64% of TP for EAV and 67% of TP for SAV cells. However, floc and RAS sections of EAV cells showed higher organic P fractions (50% and 40% of TP) compared to SAV (23% and 37% of TP

  18. 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...

  19. MIPAS IMK/IAA CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements: accuracy, precision and long-term stability

    Science.gov (United States)

    Eckert, E.; Laeng, A.; Lossow, S.; Kellmann, S.; Stiller, G.; von Clarmann, T.; Glatthor, N.; Höpfner, M.; Kiefer, M.; Oelhaf, H.; Orphal, J.; Funke, B.; Grabowski, U.; Haenel, F.; Linden, A.; Wetzel, G.; Woiwode, W.; Bernath, P. F.; Boone, C.; Dutton, G. S.; Elkins, J. W.; Engel, A.; Gille, J. C.; Kolonjari, F.; Sugita, T.; Toon, G. C.; Walker, K. A.

    2015-07-01

    the FR period. Above approximately 15 km, most comparisons are close to excellent, apart from ILAS-II, which shows large differences above ~ 17 km. Overall, percentage differences are usually smaller for CFC-12 than for CFC-11. For both species - CFC-11 and CFC-12 - we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS Envisat profiles have a maximum in the mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Estimated measurement noise alone can, in most cases, not explain the standard deviation of the differences. This is attributed to error components not considered in the error estimate and also to natural variability which always plays a role when the compared instruments do not measure exactly the same air mass. Investigations concerning the temporal stability show very small negative drifts in MIPAS Envisat CFC-11 measurements. These drifts vary between ~ 1-3 % decade-1. For CFC-12, the drifts are also negative and close to zero up to ~ 30 km. Above that altitude larger drifts of up to ~ 50 % decade-1 appear which are negative up to ~ 35 km and positive, but of a similar magnitude, above.

  20. 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.

  1. A single-mode external cavity diode laser using an intra-cavity atomic Faraday filter with short-term linewidth $<400$ kHz and long-term stability of $<1$ MHz

    CERN Document Server

    Keaveney, James; Adams, Charles S; Hughes, Ifan G

    2016-01-01

    We report on the development of a diode laser system - the `Faraday laser' - using an atomic Faraday filter as the frequency-selective element. In contrast to typical external-cavity diode laser systems which offer tunable output frequency but require additional control systems in order to achieve a stable output frequency, our system only lases at a single frequency, set by the peak transmission frequency of the internal atomic Farady filter. Our system has both short-term and long-term stability of less than 1~MHz, which is less than the natural linewidth of alkali-atomic D-lines, making similar systems suitable for use as a `turn-key' solution for laser cooling experiments.

  2. Analysis of the measurement precision of an amorphous silicon EPID used for MLC leaf position quality control and the long-term calibration stability of an optically controlled MLC

    International Nuclear Information System (INIS)

    Electronic portal imaging devices (EPIDs) have been shown to be suitable for multileaf collimator (MLC) leaf positioning quality control (QC). In our centre, a continuous dataset is available of 2 years of film measurements followed by 3 years of EPID measurements on five MLC-equipped linear accelerators of identical head design. The aim of this work was to analyse this unique dataset in order to determine the relative precision of film and EPID for MLC leaf positioning measurements and to determine the long-term stability of the MLC calibration. The QC dataset was examined and periods without MLC adjustments that contained at least four successive collimator position measurements (a minimum of 6 months) were identified. By calculating the standard deviations (SD) of these results, the reproducibility of the measurements can be determined. Comparison of the film and EPID results enables their relative measurement precision to be assessed; on average film gave an SD of 0.52 mm compared to 0.13 mm for EPIDs. The MLC and conventional collimator results were compared to assess MLC calibration stability; on average, for EPID measurements, the MLC gave an SD of 0.12 mm compared to 0.14 mm for a conventional collimator. The long-term relative individual leaf positions were compared and found to vary between 0.07 and 0.15 mm implying that they are stable over long time periods. These results suggest that the calibration of an optically controlled MLC is inherently very stable between disturbances to the optical system which normally occur on service days. (note)

  3. 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.

  4. Chemical stability of La2O3 in La2O3-Mo cathode materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Chemical stability of La2O3 in carbonized and uncarbonized La2O3-Mo cathodes was studied by in-situ XPS analysis. Experimental results show that chemical stability of La2O3 is not good enough. In vacuum and at high temperature, oxygen can be dissociated from the lattice of La2O3 in the uncarbonized La2O3-Mo cathode. Binding energy shifts of La?3d5/2 and La?3d3/2 core peaks, and obvious decrease of satellite peak intensity in La?3d doublet with increasing temperature show that metallic La appears at carbonized La2O3-Mo cathode surface at high temperature.

  5. Long-term water immersion and freeze-thaw cycles experiment of cement-stabilized macadam bases%水泥稳定碎石基层长期浸水及冻融试验研究

    Institute of Scientific and Technical Information of China (English)

    吴瑞麟; 张良陈; 韩卓; 樊金山

    2011-01-01

    试验研究了水泥稳定碎石试件,在室内静荷载作用下,浸水时间10~360d范围内的抗压强度、间接抗拉强度变化情况.同时,对比了冻融循环(-8~8℃)前后的试件抗压强度.试验数据表明:水泥稳定碎石试件的抗压强度和间接抗拉强度都保持前期较快、后期平缓的增长趋势,3次冻融循环后的抗压强度未出现明显的降低;因此,在长期浸水及冻融循环条件下,水泥稳定碎石基层能保持的良好路用性能.%At present,cement-stabilized macadam is a typical base course material widely used in highway and street engineering in China,whose strength change will directly affect the service life of the road under long-term water immersion and freeze-thaw cycles.The changing compressive strength and tensile strength of the cement-stabilized macadam base samples were tested.Their conditions were as follows: laboratory test static load with immersion time 10~360 d.The comparison between the compressive strength of the samples before and after the freeze-thaw cycles(-8~8℃) were researched and discussed.The result of the experiment shows that the compressive strength and tensile strength both keep up a fast growth trend at earlier stage and stay smooth trend at late stage while the compressive strength does not decrease apparently after three freeze-thaw cycles.Thus,the cement-stabilized macadam base can hold over its performance in the condition of long-term water immersion and freeze-thaw cycles.

  6. Power Conversion Efficiency and Device Stability Improvement of Inverted Perovskite Solar Cells by Using a ZnO:PFN Composite Cathode Buffer Layer.

    Science.gov (United States)

    Jia, Xiaorui; Zhang, Lianping; Luo, Qun; Lu, Hui; Li, Xueyuan; Xie, Zhongzhi; Yang, Yongzhen; Li, Yan-Qing; Liu, Xuguang; Ma, Chang-Qi

    2016-07-20

    We have demonstrated in this article that both power conversion efficiency (PCE) and performance stability of inverted planar heterojunction perovskite solar cells can be improved by using a ZnO:PFN nanocomposite (PFN: poly[(9,9-bis(3'-(N,N-dimethylamion)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl)-fluorene]) as the cathode buffer layer (CBL). This nanocomposite could form a compact and defect-less CBL film on the perovskite/PC61BM surface (PC61BM: phenyl-C61-butyric acid methyl ester). In addition, the high conductivity of the nanocomposite layer makes it works well at a layer thickness of 150 nm. Both advantages of the composite layer are helpful in reducing interface charge recombination and improving device performance. The power conversion efficiency (PCE) of the best ZnO:PFN CBL based device was measured to be 12.76%, which is higher than that of device without CBL (9.00%), or device with ZnO (7.93%) or PFN (11.30%) as the cathode buffer layer. In addition, the long-term stability is improved by using ZnO:PFN composite cathode buffer layer when compare to that of the reference cells. Almost no degradation of open circuit voltage (VOC) and fill factor (FF) was found for the device having ZnO:PFN, suggesting that ZnO:PFN is able to stabilize the interface property and consequently improve the solar cell performance stability. PMID:27349330

  7. Effects of enhancing soil organic carbon sequestration in the topsoil by fertilization on crop productivity and stability: Evidence from long-term experiments with wheat-maize cropping systems in China.

    Science.gov (United States)

    Zhang, Xubo; Sun, Nan; Wu, Lianhai; Xu, Minggang; Bingham, Ian J; Li, Zhongfang

    2016-08-15

    Although organic carbon sequestration in agricultural soils has been recommended as a 'win-win strategy' for mitigating climate change and ensuring food security, great uncertainty still remains in identifying the relationships between soil organic carbon (SOC) sequestration and crop productivity. Using data from 17 long-term experiments in China we determined the effects of fertilization strategies on SOC stocks at 0-20cm depth in the North, North East, North West and South. The impacts of changes in topsoil SOC stocks on the yield and yield stability of winter wheat (Triticum aestivum L.) and maize (Zea mays L.) were determined. Results showed that application of inorganic fertilizers (NPK) plus animal manure over 20-30years significantly increased SOC stocks to 20-cm depth by 32-87% whilst NPK plus wheat/maize straw application increased it by 26-38% compared to controls. The efficiency of SOC sequestration differed between regions with 7.4-13.1% of annual C input into the topsoil being retained as SOC over the study periods. In the northern regions, application of manure had little additional effect on yield compared to NPK over a wide range of topsoil SOC stocks (18->50MgCha(-1)). In the South, average yield from manure applied treatments was 2.5 times greater than that from NPK treatments. Moreover, the yield with NPK plus manure increased until SOC stocks (20-cm depth) increased to ~35MgCha(-1). In the northern regions, yield stability was not increased by application of NPK plus manure compared to NPK, whereas in the South there was a significant improvement. We conclude that manure application and straw incorporation could potentially lead to SOC sequestration in topsoil in China, but beneficial effects of this increase in SOC stocks to 20-cm depth on crop yield and yield stability may only be achieved in the South. PMID:27100005

  8. 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 ...

  9. 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.

  10. 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...

  11. Can Edman degradation be used for quantification? Isotope-dilution liquid chromatography-electrospray ionization tandem mass spectrometry and the long-term stability of 20 phenylthiohydantoin-amino acids.

    Science.gov (United States)

    Satoh, Ryo; Goto, Takaaki; Lee, Seon Hwa; Oe, Tomoyuki

    2013-10-01

    Edman degradation is a well-known method for obtaining amino acid (AA) sequences from a peptide by means of sequential reactions that release the N-terminal AAs from the peptide as a phenylthiohydantoin (PTH) derivative. Because of unexpected loss during the reaction and handling, there are few reports of use of this reaction for quantification. This manuscript describes the development of isotope-dilution liquid chromatography-electrospray ionization tandem mass spectrometry for 20 PTH-AA derivatives, and long-term stability testing of PTH-AAs to ensure quantitative quality in the reaction. The 20 corresponding [(13)C6]-PTH-AAs were prepared by use of a one-pot reaction involving a mixture of [(13)C6]-Edman reagent and 20 AAs. Good linearity was observed for standard curves for the PTH-AAs, using the corresponding [(13)C6]-PTH-AAs as internal standards (1-100 pmol per injection, r(2) = 0.989-1.000). Serum albumin (human), pepsin (porcine stomach mucosa), α-casein (bovine milk), ribonuclease A (bovine), lysozyme (chicken egg white), and insulin (bovine) subjected to Edman degradation were examined as model proteins and peptides for N-terminal AA analysis. The results of the impurity test were satisfactory. Yield from the entire reaction with human serum albumin was estimated to be at least 75%, indicating great potential for absolute quantification of proteins without protein standards. PMID:23545858

  12. Ultrafast characterization of the electron injection from CdSe quantum dots and dye N719 co-sensitizers into TiO2 using sulfide based ionic liquid for enhanced long term stability

    International Nuclear Information System (INIS)

    Combination of inorganic quantum dots (QDs) and organic/metallorganic dyes as supracollectors nanocomposites could have an important role on the development of efficient photovoltaic devices based on the synergistic action of the hybrid-sensitizers. Here we have analyzed the combination of CdSe QDs and polypyridil N719 ruthenium dye. By ultrafast transient grating measurements we show that the cascading structure (type II) of this system takes full advantage to augment electron injection and hole regeneration efficiencies. Co-sensitized TiO2 electrodes lead to an improvement in charge separation, increasing the number of injected electrons from the CdSe QDs to the TiO2 as a consequence of the suppression of back reaction, by fast regeneration of holes by the dye action. The potentiality of this supracollector system has been verified in a complete cell configuration. Sulfide/polysulfide based ionic liquid in which both sensitizers (QD and dye) are stable has been employed as hole conducting media. In spite of the limited efficiencies of the analyzed cells, the higher photocurrents measured for CdSe/N719 co-sensitization compared to the cells sensitized using a single sensitizer constitutes a valid proof of the concept. Impedance spectroscopy unveiled the recombination limitation of the analyzed cells. On the other hand, ionic liquid exhibits an enhanced cell stability maintaining cell efficiency after one week and keeping it at 80% after 21 days. The reported results highlight a huge potential of the synergetic combination of QD and dyes for improving solar cell performance and of novel sulfide/polysulfide ionic liquid-based electrolytes for enhancing long term stability and sustainability of QD sensitizers

  13. Degradation study by 3D reconstruction of a nickel-yttria stabilized zirconia cathode after high temperature steam electrolysis operation

    Science.gov (United States)

    Lay-Grindler, E.; Laurencin, J.; Villanova, J.; Cloetens, P.; Bleuet, P.; Mansuy, A.; Mougin, J.; Delette, G.

    2014-12-01

    Microstructural evolution of a Solid Oxide Electrolyser Cell (SOEC) Ni-YSZ cermet cathode is investigated using three dimensional electrode characterisations. 3D reconstructions are obtained on a reference and two long-term tested cells, which were maintained at -0.5 and -0.8 A cm-2 for 1000 h at 800 °C. During the long term tests, air was fed at the anode and a mixture of 10% H2-90% H2O was fed at the cathode. In this framework, reconstructions have been obtained from synchrotron X-ray nano-tomography technique. Microstructural properties extracted from the 3D reconstructions exhibit an evolution during the tests. Triple Phase Boundary length is decreasing from 10.49 ± 1.18 μm-2 for the reference cell to 6.18 ± 0.6 μm-2 for the long term tested cell at -0.8 A cm-2. Evolutions of morphological parameters were introduced in an in-house multi-scale model to evaluate their impacts on the electrode degradation, and hence, on the global SOEC performance.

  14. Effects of earthworms and plants on the soil structure, the physical stabilization of soil organic matter and the microbial abundance and diversity in soil aggregates in a long term study

    Science.gov (United States)

    Zangerlé, Anne; Hissler, Christophe; Lavelle, Patrick

    2014-05-01

    roots by 2.4% when compared to macrocosms without plants. Additionally, the presence of roots increased the total C and N concentration in earthworm casts, while earthworms increased C storage in microaggregates within root-derived aggregates. Analyses of 13C abundances revealed that OM had been incorporated in earthworm casts from the fifth month of the experiment. Earthworms showed an impact on bacterial abundance of 26.7% of increase in single species macroaggregates and 35.5% in mixt species macroaggregates after the first harvest of corn plants. Trends however changed on the long term since bacterial abundances decreased dramatically (67.1% in single species treatments and 59.3% in mixed species treatments) during the second year and fungal abundances, stable during the first 5 months of the experiment, later increased 80% and 73.2% in earthworm and mixed species macroaggregates. This experiment showed how interactions between plants and earthworms can influence the soil structure and the soil aggregates dynamics by cooperating in macroaggregate formation. Both organisms need to be considered simultaneously for proper management of soils.

  15. 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

  16. 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…

  17. Factors affecting long-term integrity of transmission pipelines; Facteurs affectant l'integrite a long terme des gazoducs

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, N.; Masuda, T.; Oguchi, N. [Tokyo Gas Co., Ltd. (Japan)

    2000-07-01

    For upgrading long-term integrity of transmission pipelines, two types of delayed fracture in regions of mechanical damage in pipelines were investigated. Experimental and numerical studies clarified factors affecting the fatigue behavior of line pipes containing an idealized flaw under fluctuating internal pressure. To investigate fatigue cracking at mechanical damage in pipelines, degradation of fracture toughness and fatigue properties due to plastic pre-strain was also evaluated. A fracture mechanics-based study revealed conditions necessarily for initiation of hydrogen stress cracking (HSC) at a surface defect in line pipes under cathodic protection. (authors)

  18. 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.

  19. 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.

  20. Stabilization of a cold cathode electron beam glow discharge for surface treatment

    International Nuclear Information System (INIS)

    We have demonstrated that the reproducibility of electron beam pulses generated by a high power, cold cathode glow discharge is greatly improved by adding a small continuous keep-alive discharge current. A current of the order of 200 μA was found to limit the shot to shot current variation to within 1.5%. This stabilization in turn reduces by an order of magnitude the fluctuations of the energy density deposited on the target, demonstrating a reliable energy source for surface treatment. copyright 1997 American Institute of Physics

  1. 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

  2. Microstructure and long-term creep properties of 9–12% Cr steels

    DEFF Research Database (Denmark)

    Hald, John

    2008-01-01

    Advanced microstructure characterisation and microstructure modelling has demonstrated that long-term microstructure stability in 9–12% Cr steels under technical loading conditions is equivalent to precipitate stability. Mo and W can have a positive influence on long-term creep strength of 9–12% ...

  3. 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...

  4. 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

  5. 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 ...

  6. 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...

  7. 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....

  8. 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...

  9. Do the long-term unemployed adapt to unemployment?

    Directory of Open Access Journals (Sweden)

    De Witte, Hans

    2010-04-01

    Full Text Available The literature on the psychological consequences of unemployment suggests that an adaptation process takes place among the long-term unemployed. Their psychological well-being decreases strongly at the beginning of unemployment, to stabilize at a lower level after a certain time. This stabilization is due to an adaptation process, in which the unemployed decrease their job search behaviors and lower their employment commitment. In this cross-sectional study from Belgium, 563 short-term and 195 long-term unemployed are compared on psychological well-being, the experience of unemployment, employment commitment and job search behavior. The results are in line with the hypothesis of an adaptation process among the long-term unemployed. The short-term unemployed experienced more psychological distress than the long-term unemployed. The short-term unemployed also showed stronger employment commitment and more often applied for jobs. The results of some retrospective questions, in which the respondents had to compare their actual behaviors and well-being with those in the past, suggest that an adaptation process took place. Some policy recommendations are discussed.

  10. 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 ...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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). ...

  16. A nickel molybdenite cathode for the hydrogen evolution reaction in alkaline media

    Energy Technology Data Exchange (ETDEWEB)

    Albertini, L.B.; Angelo, A.C.D.; Gonzalez, E.R. (Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica)

    1992-09-01

    The characteristics and mechanism of the hydrogen evolution reaction on a nickel sulphide electrode incorporating molybdenite particles are described. At 25[sup o]C the overpotential for the reaction is 300mV lower than that of the mild steel cathodes used in unipolar electrolysers. The material shows good stability under long term operation. (Author).

  17. Benefits from Long-Term Treatment in Irritable Bowel Syndrome

    OpenAIRE

    Stefano Evangelista

    2012-01-01

    It is known that irritable bowel syndrome (IBS) is a chronic disease of cyclic nature characterized by recurrent symptoms. IBS patients should receive, as initial therapeutic approach a short course of treatment which, if effective, has the additional value of confirming the diagnosis. Long-term treatment should be reserved to diagnosed IBS patients with recurrent symptoms. Clinical trials with stabilized therapies and new active treatments showed an improvement of the symptoms over placebo t...

  18. Changes of gamut volume during long-term tests

    OpenAIRE

    Káčerová, Silvia; Veselý, Michal; Dzik, Petr; Štěpánková, Eva

    2013-01-01

    The stability of inkjet prints and photographs is influenced by the factors of the surrounding environment. The most harmful factors of environment are the light and the pollutants like ozone. Durability of inkjet prints is besides the ink composition, affected by the type of receiving layer. In this paper will be discussed the lightfastness of inkjet prints and photographs during the long-term ageing tests. Inkjet prints were prepared using both dye-based and pigment-based inks. The sampl...

  19. Geo scientific basis for making the safety case for a SF/HL W/ILW repository in Opalinus clay in ne Switzerland (project Entsorgungsnachweis) 4: geosphere stability: learning from the past to predict future long-term evolution

    International Nuclear Information System (INIS)

    A number of safety-relevant issues need to be addressed when considering long-term evolution, out of which uplift/erosion, changes in the geochemical and hydrogeological environment are particularly important and are discussed below. Among the strongest arguments in the prediction of future evolution is the extrapolation of events and processes that occurred over a long period of time in the geological past (e.g. 10 Ma) to a shorter period in the future. The future long-term evolution of Opalinus Clay in the investigation area in the Zurcher Weinland (NE Switzerland) is considered over a time period of around 1 Ma. The geological evolution can be predicted plausibly within reasonable limits over such a time period based on a detailed analysis of geological history. Predictions extending beyond this time period are feasible but contain an increasing element of uncertainty. This paper summarises the project-related conclusions, which are presented in greater detail in Nagra (2002a). (author)

  20. 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.

  1. 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)

  2. Strategies to curb structural changes of lithium/transition metal oxide cathode materials & the changes’ effects on thermal & cycling stability

    Science.gov (United States)

    Xiqian, Yu; Enyuan, Hu; Seongmin, Bak; Yong-Ning, Zhou; Xiao-Qing, Yang

    2016-01-01

    Structural transformation behaviors of several typical oxide cathode materials during a heating process are reviewed in detail to provide in-depth understanding of the key factors governing the thermal stability of these materials. We also discuss applying the information about heat induced structural evolution in the study of electrochemically induced structural changes. All these discussions are expected to provide valuable insights for designing oxide cathode materials with significantly improved structural stability for safe, long-life lithium ion batteries, as the safety of lithium-ion batteries is a critical issue; it is widely accepted that the thermal instability of the cathodes is one of the most critical factors in thermal runaway and related safety problems. Project supported by the U.S. Department of Energy, the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies (Grant No. DE-SC0012704).

  3. 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...

  4. 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)...

  5. 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)...

  6. 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)...

  7. Microstructure and long-term creep properties of 9-12% Cr steels

    International Nuclear Information System (INIS)

    Advanced microstructure characterisation and microstructure modelling has demonstrated that long-term microstructure stability in 9-12% Cr steels under technical loading conditions is equivalent to precipitate stability. Mo and W can have a positive influence on long-term creep strength of 9-12% Cr steels by Laves phase precipitation hardening. Unexpected breakdown of long-term creep stability of a number of alloys is caused by precipitation of the complex Z-phase nitride, which may completely dissolve fine V and Nb containing MX nitrides. High Cr contents of 10% and above in the steels accelerate Z-phase precipitation

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Characterization of aluminum nanopowders after long-term storage

    International Nuclear Information System (INIS)

    Highlights: • The aluminum nanopowders produced by electrical explosion of wires after long-term storage (27 and 10 years) under natural conditions are characterized. • The phase composition and thermal stability of aluminum nanopowders after long-term storage are determined. • The surface chemical changes in the aged aluminum nanopowders are examined. • The high reactivity of aluminum nanopowder is due to the presence of the protective oxide–hydroxide layer on the particles surface. - Abstract: The characteristics of aluminum nanopowders obtained by electrical explosion of wires, passivated by air and stored for a long time under natural conditions are analyzed. The aluminum nanopowder produced in hydrogen had been stored for 27 years; the nanopowders produced in argon and nitrogen had been stored for 10 years. The powders were studied using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier transform infrared spectrometry (FTIR). The influence of the obtaining conditions and storage period of nanopowders on their thermal stability under heating in air is shown. The aluminum nanopowders after long-term storage in air under ambient conditions are found to be extremely active

  13. Carbon-free bifunctional cathodes for the use in Lithium - Air Batteries with an aqueous alkaline electrolyte

    OpenAIRE

    Wittmaier, Dennis; Wagner, Norbert; Friedrich, K. Andreas

    2014-01-01

    Carbon materials are widely used in gas diffusion electrodes due to their high electronic conductivity, relatively low costs and catalytic activity towards oxygen reduction reaction (ORR), the cathodic reaction during discharging. During charging a lithium-air battery the cathode is operated in oxygen evolution reaction (OER) mode. Carbon materials corrode in OER mode, this leads to degradation and a power loss of the electrode. To improve long-term stability and reduce side reactions as H2 a...

  14. Electricity generation of microbial fuel cell with waterproof breathable membrane cathode

    Science.gov (United States)

    Xing, Defeng; Tang, Yu; Mei, Xiaoxue; Liu, Bingfeng

    2015-12-01

    Simplification of fabrication and reduction of capital cost are important for scale-up and application of microbial electrochemical systems (MES). A fast and inexpensive method of making cathode was developed via assembling stainless steel mesh (SSM) with waterproof breathable membrane (WBM). Three assemble types of cathodes were fabricated; Pt@SSM/WBM (SSM as cathode skeleton, WBM as diffusion layer, platinum (Pt) catalyst applied on SSM), SSM/Pt@WBM and Pt@WBM. SSM/Pt@WBM cathode showed relatively preferable with long-term stability and favorable power output (24.7 W/m3). Compared to conventional cathode fabrication, air-cathode was made for 0.5 h. The results indicated that the novel fabrication method could remarkably reduce capital cost and simplify fabrication procedures with a comparable power output, making MFC more prospective for future application.

  15. Strategies for Stabilizing Nitrogenous Compounds in ECLSS Wastewater: Top-Down System Design and Unit Operation Selection with Focus on Bio-Regenerative Processes for Short and Long Term Scenarios

    Science.gov (United States)

    Lunn, Griffin M.

    2011-01-01

    Water recycling and eventual nutrient recovery is crucial for surviving in or past low earth orbit. New approaches and syste.m architecture considerations need to be addressed to meet current and future system requirements. This paper proposes a flexible system architecture that breaks down pretreatment , steps into discrete areas where multiple unit operations can be considered. An overview focusing on the urea and ammonia conversion steps allows an analysis on each process's strengths and weaknesses and synergy with upstream and downstream processing. Process technologies to be covered include chemical pretreatment, biological urea hydrolysis, chemical urea hydrolysis, combined nitrification-denitrification, nitrate nitrification, anammox denitrification, and regenerative ammonia absorption through struvite formation. Biological processes are considered mainly for their ability to both maximize water recovery and to produce nutrients for future plant systems. Unit operations can be considered for traditional equivalent system mass requirements in the near term or what they can provide downstream in the form of usable chemicals or nutrients for the long term closed-loop ecological control and life support system. Optimally this would allow a system to meet the former but to support the latter without major modification.

  16. Thermophilic two-phase anaerobic digestion of source-sorted organic fraction of municipal solid waste for bio-hythane production: effect of recirculation sludge on process stability and microbiology over a long-term pilot-scale experience.

    Science.gov (United States)

    Giuliano, A; Zanetti, L; Micolucci, F; Cavinato, C

    2014-01-01

    A two-stage thermophilic anaerobic digestion process for the concurrent production of hydrogen and methane through the treatment of the source-sorted organic fraction of municipal solid waste was carried out over a long-term pilot scale experience. Two continuously stirred tank reactors were operated for about 1 year. The results showed that stable production of bio-hythane without inoculum treatment could be obtained. The pH of the dark fermentation reactor was maintained in the optimal range for hydrogen-producing bacteria activity through sludge recirculation from a methanogenic reactor. An average specific bio-hythane production of 0.65 m(3) per kg of volatile solids fed was achieved when the recirculation flow was controlled through an evaporation unit in order to avoid inhibition problems for both microbial communities. Microbial analysis indicated that dominant bacterial species in the dark fermentation reactor are related to the Lactobacillus family, while the population of the methanogenic reactor was mainly composed of Defluviitoga tunisiensis. The archaeal community of the methanogenic reactor shifted, moving from Methanothermobacter-like to Methanobacteriales and Methanosarcinales, the latter found also in the dark fermentation reactor when a considerable methane production was detected. PMID:24901613

  17. Mesoporous LiFeBO3/C hollow spheres for improved stability lithium-ion battery cathodes

    Science.gov (United States)

    Chen, Zhongxue; Cao, Liufei; Chen, Liang; Zhou, Haihui; Zheng, Chunman; Xie, Kai; Kuang, Yafei

    2015-12-01

    Polyanionic compounds are regarded as one of the most promising cathode materials for the next generation lithium-ion batteries due to their abundant resource and thermal stability. LiFeBO3 has a relatively higher capacity than olivine LiFePO4, however, moisture sensitivity and low conductivity hinder its further development. Here, we design and synthesize mesoporous LiFeBO3/C (LFB/C) hollow spheres to enhance its structural stability and electric conductivity, two LiFeBO3/C electrodes with different carbon content are prepared and tested. The experimental results show that mesoporous LiFeBO3/C hollow spheres with higher carbon content exhibit superior lithium storage capacity, cycling stability and rate capability. Particularly, the LFB/C electrode with higher carbon content demonstrates good structural stability, which can maintain its original crystal structure and Li storage properties even after three months of air exposure at room temperature. The exceptional structural stability and electrochemical performance may justify their potential use as high-performance cathode materials for advanced lithium-ion batteries. In addition, the synthesis strategy demonstrated herein is simple and versatile for the fabrication of other polyanionic cathode materials with mesoporous hollow spherical structure.

  18. 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.

  19. [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

  20. 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...

  1. 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...

  2. 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.

  3. 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 ...

  4. 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

  5. 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...

  6. 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.

  7. 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

  8. 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

  9. 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.)

  10. 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...

  11. 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....

  12. 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...

  13. 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...

  14. 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 ...

  15. 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.

  16. 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.

  17. [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

  18. The coevolution of long-term pair bonds and cooperation.

    Science.gov (United States)

    Song, Z; Feldman, M W

    2013-05-01

    The evolution of social traits may not only depend on but also change the social structure of the population. In particular, the evolution of pairwise cooperation, such as biparental care, depends on the pair-matching distribution of the population, and the latter often emerges as a collective outcome of individual pair-bonding traits, which are also under selection. Here, we develop an analytical model and individual-based simulations to study the coevolution of long-term pair bonds and cooperation in parental care, where partners play a Snowdrift game in each breeding season. We illustrate that long-term pair bonds may coevolve with cooperation when bonding cost is below a threshold. As long-term pair bonds lead to assortative interactions through pair-matching dynamics, they may promote the prevalence of cooperation. In addition to the pay-off matrix of a single game, the evolutionarily stable equilibrium also depends on bonding cost and accidental divorce rate, and it is determined by a form of balancing selection because the benefit from pair-bond maintenance diminishes as the frequency of cooperators increases. Our findings highlight the importance of ecological factors affecting social bonding cost and stability in understanding the coevolution of social behaviour and social structures, which may lead to the diversity of biological social systems. PMID:23496797

  19. Cathodic micro-arc electrodeposition of yttrium stabilized zirconia (YSZ) coatings on FeCrAl alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The formation of ceramic coatings on metal substrate by cathodic electrolytic deposition (CELD) has received more attention in recent years. But only thin films can be prepared via CELD. Yttrium stabilized zirconia (YSZ) ceramic coatings were deposited on FeCrAl alloy by a novel technique--cathodic micro-arc electrodeposition (CMED). The result shows that, when a high pulse electric field is applied to the cathode which was pre-deposited with a thin YSZ film, dielectric breakdown occurs and micro-arc discharges appear. Coatings with reasonably thickness of ~300μm and crystalline structure can be deposited on the cathode by utilizing the energy of the micro-arc. The thickness of the as-deposited coating is dominated by the voltage and the frequency. Y2O3 is co-deposited with ZrO2 when Y(NO3)3 was added to the electrolyte, which stabilize t-phase, t′- phase and c-phase of ZrO2 at room temperature. The amount of the m-ZrO2 in the coating is diminished by increasing the concentration of Y(NO3)3 in the electrolyte. This report describes the processing of CMED and studies the microstructure of the deposited YSZ coatings.

  20. 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.

  1. 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)

  2. 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)

  3. Long-Term Monitoring of Anomalous X-ray Pulsars

    CERN Document Server

    Gavriil, F P; Chakraborty, D; Gavriil, Fotis P.; Kaspi, Victoria M.; Chakrabarty, Deepto

    2001-01-01

    We report on long-term monitoring of anomalous X-ray pulsars (AXPs) using the Rossi X-ray Timing Explorer. Using phase-coherent timing, we find a wide variety of behaviors among the sources, ranging from high stability (in 1E 2259.1+586 and 4U 0142+61), to instabilities so severe that phase-coherent timing is not possible (in 1E 1048.1-5937). We note a correlation in which timing stability in AXPs decreases with increasing spin-down rate. The timing stability of soft gamma repeaters in quiescence is consistent with this trend, which is similar to one seen in radio pulsars. We consider high signal-to-noise ratio average pulse profiles as a function of energy for each AXP, and find a variety of behaviors. We find no large variability in pulse morphology nor in pulsed flux as a function of time.

  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. 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.

  11. 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...

  12. 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...

  13. 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.

  14. 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

  15. 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.)

  16. 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

  17. 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

  18. 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.)

  19. 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.

  20. Modeling of Automatic Generation Control for Power System Transient, Medium-Term and Long-Term Stabilities Simulations%电力系统全过程动态仿真中的自动发电控制模型

    Institute of Scientific and Technical Information of China (English)

    宋新立; 王成山; 仲悟之; 汤涌; 卓峻峰; 旸吴国; 苏志达

    2013-01-01

    针对大规模电力系统二次调频控制的动态仿真问题,采用混杂系统的建模方法,提出一种适于机电暂态及中长期动态全过程仿真的自动发电控制模型。模型主要由属于连续动态系统的区域控制偏差计算、属于离散动态系统的控制策略和机组调节指令计算3个模块组成。通过与电力系统全过程动态仿真程序中已有模型的接口,该模型可以模拟大规模电网中基于A标准和CPS控制性能评价标准的控制策略,以及定频率控制、定交换功率控制和联络线功率频率偏差控制等多种方式。与我国特高压交流联络线相关的2个算例仿真表明,该模型可为大规模电网联络线功率波动限制、多区域AGC控制策略的协调配合和二次调频的优化控制等实际电网问题提供有效的仿真手段。%In order to dynamically simulate secondary power frequency control in large power systems, a new automatic generation control (AGC) model, which can be applied for power system electro-mechanical transient, medium-term and long-term dynamics simulation, is proposed based on the modeling method of hybrid system. It mainly consists of three parts:calculation of area control error (ACE), simulation of control strategy, and calculation of generating power regulation. The first module is modeled by the method of continuous dynamic systems, and the last two modules are modeled by the method of discrete event dynamic systems. By interfacing to the existing models in the power system unified dynamic simulation program, it is capable of simulating not only the three main control modes of AGC for large power systems, i.e., flat frequency control (FFC), constant net interchange control (CIC), and tie line bias frequency control (TBC), but also the widely-used control strategies based on CPS and A standard. Two simulation cases, which are related to the active power control for the tie-line in China UHVAC interconnected

  1. Long-term experimental testing of a-silicon modules

    International Nuclear Information System (INIS)

    Long-term stability of photovoltaic module electrical performance is critically important to the economic viability of PV in large-scale energy-generation applications. Equally important is having the means to conclusively demonstrate long life to potential users; this requires proven test methods that accurately predict field performance trends. To assess the long-term stability of a-Si modules and the usefulness of existing crystalline-Si test methods a number of first generation a-Si photovoltaic modules have been acquired from leading manufacturers and subjected to a variety of accelerated and real-time outdoor aging tests. Data to date indicate that the degradation of a-Si modules involves complex dependencies that negate some of the key test correlations previously established for crystalline-Si modules. Key research priorities are highlighted including light induced effects, cell corrosion leading to increased series resistance, glass breaking strength for large modules, and the development of protective encapsulants that meet the outdoor weathering and voltage isolation required for long module life

  2. Enhanced Oxygen and Hydroxide Transport in a Cathode Interface by Efficient Antibacterial Property of a Silver Nanoparticle-Modified, Activated Carbon Cathode in Microbial Fuel Cells.

    Science.gov (United States)

    Li, Da; Qu, Youpeng; Liu, Jia; Liu, Guohong; Zhang, Jie; Feng, Yujie

    2016-08-17

    A biofilm growing on an air cathode is responsible for the decreased performance of microbial fuel cells (MFCs). For the undesired biofilm to be minimized, silver nanoparticles were synthesized on activated carbon as the cathodic catalyst (Ag/AC) in MFCs. Ag/AC enhanced maximum power density by 14.6% compared to that of a bare activated carbon cathode (AC) due to the additional silver catalysis. After operating MFCs over five months, protein content on the Ag/AC cathode was only 38.3% of that on the AC cathode, which resulted in a higher oxygen concentration diffusing through the Ag/AC cathode. In addition, a lower pH increment (0.2 units) was obtained near the Ag/AC catalyst surface after biofouling compared to 0.8 units of the AC cathode, indicating that less biofilm on the Ag/AC cathode had a minor resistance on hydroxide transported from the catalyst layer interfaces to the bulk solution. Therefore, less decrements of the Ag/AC activity and MFC performance were obtained. This result indicated that accelerated transport of oxygen and hydroxide, benefitting from the antibacterial property of the cathode, could efficiently maintain higher cathode stability during long-term operation. PMID:27441786

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Radionuclide Incorporation and Long Term Performance of Apatite Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianwei [Louisiana State Univ., Baton Rouge, LA (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-01-04

    This project aims to combines state-of-the-art experimental and characterization techniques with atomistic simulations based on density functional theory (DFT) and molecular dynamics (MD) simulations. With an initial focus on long-lived I-129 and other radionuclides such as Cs, Sr in apatite structure, specific research objectives include the atomic scale understanding of: (1) incorporation behavior of the radionuclides and their effects on the crystal chemistry and phase stability; (2) stability and microstructure evolution of designed waste forms under coupled temperature and radiation environments; (3) incorporation and migration energetics of radionuclides and release behaviors as probed by DFT and molecular dynamics (MD) simulations; and (4) chemical durability as measured in dissolution experiments for long term performance evaluation and model validation.

  11. Apinhamento ântero-superior: revisão e análise crítica da literatura Maxillary crowding and long-term stability: a review of literature

    Directory of Open Access Journals (Sweden)

    Patrícia Paschoal Martins

    2007-04-01

    Full Text Available INTRODUÇÃO: o tratamento do apinhamento dentário da região anterior superior e inferior é comumente acometido pela recidiva, entretanto a maior parte dos estudos aborda apenas a estabilidade do tratamento do arco dentário inferior. OBJETIVO: este artigo propõe uma revisão e análise crítica da literatura, enfatizando os fatores etiológicos do apinhamento dentário, as diversas formas de tratamento e a recidiva no arco superior, considerando o plano de tratamento, os fatores periodontais e a expansão rápida da maxila. CONCLUSÕES: a severidade inicial da má oclusão, as alterações dimensionais dos arcos dentários e as alterações na fisiologia do ligamento periodontal são os principais fatores etiológicos de recidiva. O estudo da etiologia da recidiva permite ao ortodontista o correto planejamento dos casos clínicos e a previsibilidade da estabilidade pós-contenção.INTRODUCTION: The treatment of crowding of maxillary and mandibular anterior teeth commonly suffers relapse. Therefore, major studies focus only on stability of mandibular anterior segment. OBJECTIVE: This article propose a review and critical analysis of the literature, emphasizing the etiologic factors of incisors crowding, the various treatment plans and the relapse of the maxillary anterior segment, considering the treatment protocols, the periodontal factors and the rapid maxillary expansion. CONCLUSIONS: The main factors influencing the relapse are the severity of the initial malocclusion, the changes in arch dimensions and the changes in physiology of periodontal tissue. The study of the causes of relapse is important to help in achieving a correct treatment planning and to predict the postretention stability.

  12. Electrochemical performance and thermal stability of LiCoO{sub 2} cathodes surface-modified with a sputtered thin film of lithium phosphorus oxynitride

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kwan-Ho; Jeon, Jun-Hong; Lee, Sung-Man [Department of Advanced Materials Science and Engineering, Kangwon National University, Chunchon, Kangwon-Do 200-701 (Korea); Park, Hong-Kyu [Battery Research Institute, LG Chemical Limited, Taejon 305-380 (Korea)

    2010-12-15

    A lithium phosphorus oxynitride (LiPON) glass-electrolyte thin film is coated on a lithium cobalt oxide (LiCoO{sub 2}) composite cathode by means of a radio frequency (RF) magnetron sputtering method. The effect of the LiPON coating layer on the electrochemical performance and thermal stability of the LiCoO{sub 2} cathode is investigated. The thermal stability of the delithiated LiCoO{sub 2} cathode in the presence of liquid electrolyte is examined by differential scanning calorimetry (DSC). It is found that the LiPON coating, improves the rate capability and the thermal stability of the charged LiCoO{sub 2} cathode. The LiPON film appears to suppress impedance growth during cycling and inhibits side-reactions between delithiated LiCoO{sub 2} and the electrolyte. (author)

  13. 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.

  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. Synthesis on the spent fuel long term evolution

    International Nuclear Information System (INIS)

    The French research on spent fuel long term evolution has been performed by CEA (Commissariat a l'Energie Atomique) since 1999 in the PRECCI project with the support of EDF (Electricite de France). These studies focused on the spent fuel behaviour under various conditions encountered in dry storage or in deep geological disposal. Three main types of conditions were discerned: - The evolution in a closed system which corresponds to the normal scenario in storage and to the first confinement phase in disposal; - The evolution in air which corresponds to an incidental loss of confinement during storage or to a rupture of the canister before the site re-saturation in geological disposal; - The evolution in water which corresponds to the normal scenario after the breaching of the canister in repository conditions. This document produced in the frame of the PRECCI project is an overview of the state of knowledge in 2004 concerning the long-term behavior of spent fuel under these various conditions. The state of the art was derived from the results obtained under the PRECCI project as well as from a review of the literature and of data acquired under the European project on Spent Fuel Stability under Repository Conditions. The main results issued from the French research are underlined. (authors)

  17. Synthesis on the spent fuel long term evolution

    Energy Technology Data Exchange (ETDEWEB)

    Ferry, C.; Poinssot, Ch.; Lovera, P.; Poulesquen, A. [CEA Saclay, Dept. de Physico-Chimie (DEN/DPC), 91 - Gif sur Yvette (France); Broudic, V. [CEA Cadarache, Direction des Reacteurs Nucleaires (DRN), 13 - Saint Paul lez Durance (France); Cappelaere, Ch. [CEA Saclay, Dept. des Materiaux pour le Nucleaire(DMN), 91 - Gif-sur-Yvette (France); Desgranges, L. [CEA Cadarache, Direction des Reacteurs Nucleaires (DRN), 13 - Saint-Paul-lez-Durance (France); Garcia, Ph. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC), 13 - Saint Paul lez Durance (France); Jegou, Ch.; Roudil, D. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN), 30 - Marcoule (France); Lovera, P.; Poulesquen, A. [CEA Saclay, Dept. de Physico-Chimie (DPC), 91 - Gif sur Yvette (France); Marimbeau, P. [CEA Cadarache, Dir. de l' Energie Nucleaire (DEN), 13 - Saint-Paul-lez-Durance (France); Gras, J.M.; Bouffioux, P. [Electricite de France (EDF), 75 - Paris (France)

    2005-07-01

    The French research on spent fuel long term evolution has been performed by CEA (Commissariat a l'Energie Atomique) since 1999 in the PRECCI project with the support of EDF (Electricite de France). These studies focused on the spent fuel behaviour under various conditions encountered in dry storage or in deep geological disposal. Three main types of conditions were discerned: - The evolution in a closed system which corresponds to the normal scenario in storage and to the first confinement phase in disposal; - The evolution in air which corresponds to an incidental loss of confinement during storage or to a rupture of the canister before the site re-saturation in geological disposal; - The evolution in water which corresponds to the normal scenario after the breaching of the canister in repository conditions. This document produced in the frame of the PRECCI project is an overview of the state of knowledge in 2004 concerning the long-term behavior of spent fuel under these various conditions. The state of the art was derived from the results obtained under the PRECCI project as well as from a review of the literature and of data acquired under the European project on Spent Fuel Stability under Repository Conditions. The main results issued from the French research are underlined. (authors)

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  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. 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. 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.)

  9. 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.

  10. 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

  11. 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)

  12. Charge storage: stability measures in implantable electrodes.

    Science.gov (United States)

    Peixoto, Nathalia; Jackson, Kassandra; Samiyi, Raamin; Minnikanti, Saugandhika

    2009-01-01

    Here we report on long-term (300 to 600 hours) stability measures for implantable stimulating electrodes. We have considered several measures of stability as they refer to reliability of charge carrying capacity in implantable electrodes. We have designed and manufactured coatings for large area (1 to 2mm(2)) stainless steel substrates. Materials tested were electrodeposited iridium oxide films, multi-walled carbon nanotube mesh, and PEDOT:PSS. Traditional characterization techniques such as cyclic voltammetry and electrochemical impedance spectroscopy cover a small fraction of the characterization framework needed for ensuring the safety and performance of electrodes designed for long-term implants. The stability measures suggested here rely on continuous low frequency cycling and evaluation of cathodic charge storage capacity during cycling. We experimentally show, in this paper, that the stability may be measured and is relevant for long-term applications of such coatings. PMID:19963977

  13. Preparation, characterization and application of alkaline leached CuNiZn ternary coatings for long-term electrolysis in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Solmaz, Ramazan [Bingoel University, Science and Letters Faculty, Chemistry Department, 12000 Bingoel (Turkey); Doener, Ali; Kardas, Guelfeza [Cukurova University, Science and Letters Faculty, Chemistry Department, 01330 Balcali Adana (Turkey)

    2010-10-15

    The NiCuZn ternary coating was electrochemically deposited on a copper electrode. Then, it was etched in a concentrated alkaline solution (30% NaOH) to produce a porous and electrocatalytic surface suitable for use in the hydrogen evolution reaction (HER). The surface composition of coating before and after alkaline leaching was determined by energy dispersive X-ray (EDX) analysis. The surface morphologies were investigated by scanning electron microscopy (SEM). The long-term stability of electrode prepared for alkaline water electrolysis was investigated in 1 M KOH solution with the help of cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that, the NiCuZn coating has a compact and porous structure with good physical stability. Alkaline leaching process further improved the activity of NiCuZn coating in comparison with binary NiCu deposit for the HER. The long-term operation at -100 mA cm{sup -2} showed good electrochemical stability over 120 h. (author)

  14. 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

  15. La2NiO4+δ Infiltration of Plasma-Sprayed LSCF Coating for Cathode Performance Improvement

    Science.gov (United States)

    Li, Ying; Zhang, Shan-Lin; Li, Cheng-Xin; Wei, Tao; Yang, Guan-Jun; Li, Chang-Jiu; Liu, Meilin

    2016-01-01

    Perovskite-structured (La0.6Sr0.4Co0.2Fe0.8O3) LSCF has been widely studied as a cathode material for intermediate-temperature solid oxide fuel cells. However, the application of LSCF cathode is likely to be limited by its sluggish surface catalytic properties and long-term stability issues. Oxygen hyper-stoichiometric La2NiO4+δ with K2NiF4 structure exhibits higher catalytic properties, ionic conductivity, and stability in comparison with LSCF cathode. Due to the good chemical compatibility of these two cathode materials, it is possible to prepare a composite cathode by the infiltration of La2NiO4+δ in the porous LSCF. This composite structure fully utilizes the advantages of the two cathodes and enhances the LSCF cathode performance. In this study, the LSCF cathode was deposited by using an atmospheric plasma spray technique, and the porous LSCF cathode was then infiltrated by La2NiO4+δ. The atmospheric plasma spray technique was used to reduce the SOFC manufacturing cost. The microstructure of coatings was characterized by SEM and EDS. The cathode polarization resistance was found to decrease by ~40% after the La2NiO4+δ infiltration. Also, the activation energy decreased from 1.53 to 1.40 eV.

  16. 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

  17. 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

  18. Vertebral sarcoidosis: long-term follow-up with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, M. [University Hospitals Gasthuisberg, Department of Radiology, Leuven (Belgium); Larbi, A.; Malghem, J.; Vande Berg, B.; Dallaudiere, B. [University Hospitals St Luc, Department of Radiology, Brussels (Belgium)

    2014-08-15

    Vertebral involvement in sarcoidosis is rare and its clinical and imaging features are non-specific. Indeed, because the lesions are hard to differentiate from metastatic disease based on imaging alone, a histological confirmation is advised. Fatty replacement is a well-known finding indicating stabilization and healing in both benign and malignant conditions. It can be used as an indicator of a favorable disease course and response to treatment. We report the case of a 43-year-old woman with multifocal vertebral sarcoidosis lesions and long-term follow-up showing progressive and gradual fatty involution on magnetic resonance imaging (MRI) during 4 years of steroid treatment with a final favorable outcome. (orig.)

  19. Study on long-term behavior of weak rock

    International Nuclear Information System (INIS)

    Using the boring core obtained in the Horonobe region, the beta in triaxial compression stress state was acquired, and the examination was carried out on the effect of the confirming pressure on long-term deformation or stability of the sample rock. At first, triaxial compression tests were carried out. In the test, loading rate (strain rate) was changed several times to obtain viscoelastic properties of the sample rock. Multi-stage creep tests were also performed in triaxial compression stress. The parameter set of a constitutive equation of variable compliance type was obtained based on the testing results. In this study, a transparent triaxial cell recently developed by this author was used. The external cylinder of this vessel was made of the transparent acrylic resin. Therefore, gradual deformation of the sample under testing was easily and clearly observed. (author)

  20. Long-term operation of manure-microbial fuel cell.

    Science.gov (United States)

    Zhang, Guodong; Zhao, Qingliang; Jiao, Yan; Lee, Duu-Jong

    2015-03-01

    Microbial fuel cell (MFC) is applied to produce electricity using dairy manure as a fuel. Since the way MFC utilizes manure as a fuel and the long-term operation stability of manure-MFC remains unclear, this study examined the evolution of dissolved organic matter (DOM) in anodic chamber and power generation by MFC in a 171days test. The tested MFC can produce electricity over the entire testing period by single feed of manure, with stable power output and total chemical oxygen demand (TCOD) removal rate in the period of day 30-140. The hydrophobic acid (HPO-A) and hydrophilic (HPI) fractions of manure were the principal components of anolyte DOM, with the concentrations of both being reduced over MFC operation. The degradable organic matters were converted to compounds with high aromaticity. PMID:25603729

  1. 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).

  2. Influence of operating current on the stability of deuterium arcs and hydrogen hollow cathode lamps used as background correctors in atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    The instability of deuterium arcs and hydrogen hollow cathode lamps influences significantly the reproducibility of atomic absorption measurements. The effect of current flowing through the lamp was studied as a factor influencing the stability of deuterium arcs and hydrogen lamps. Using longer integration times, it is possible to average the instability to some degree when working in the double beam mode. Considerable wavelength dependence of precision was found for both the deuterium arcs and the hydrogen hollow cathode lamps. (author)

  3. Long-Term Stability of Personality: Implications for Behavior

    OpenAIRE

    Nave, Christopher Scott

    2011-01-01

    After vigorous debate regarding the validity of personality traits, a growing body of research demonstrates that personality a) is quite stable across the lifespan and that b) personality matters because it predicts important outcomes of interest. One important, yet understudied area of research involves how personality traits manifest in a wide variety of behaviors both across contexts and over time. Understanding the relationship between personality and behavior yields a deeper understandin...

  4. Long-term magnetic field stability of Vega

    CERN Document Server

    Alina, D; Lignières, F; Wade, G A; Fares, R; Aurière, M; Böhm, T; Carfantan, H

    2011-01-01

    We present new spectropolarimetric observations of the normal A-type star Vega, obtained during the summer of 2010 with NARVAL at T\\'elescope Bernard Lyot (Pic du Midi Observatory). This new time-series is constituted of 615 spectra collected over 6 different nights. We use the Least-Square-Deconvolution technique to compute, from each spectrum, a mean line profile with a signal-to-noise ratio close to 20,000. After averaging all 615 polarized observations, we detect a circularly polarized Zeeman signature consistent in shape and amplitude with the signatures previously reported from our observations of 2008 and 2009. The surface magnetic geometry of the star, reconstructed using the technique of Zeeman-Doppler Imaging, agrees with the maps obtained in 2008 and 2009, showing that most recognizable features of the photospheric field of Vega are only weakly distorted by large-scale surface flows (differential rotation or meridional circulation).

  5. Long-term magnetic field stability of Vega

    OpenAIRE

    Alina, D.; Petit, P.; Lignières, F.; Wade, G. A.; Fares, R.; Aurière, M.; Böhm, T.; Carfantan, H.

    2011-01-01

    We present new spectropolarimetric observations of the normal A-type star Vega, obtained during the summer of 2010 with NARVAL at T\\'elescope Bernard Lyot (Pic du Midi Observatory). This new time-series is constituted of 615 spectra collected over 6 different nights. We use the Least-Square-Deconvolution technique to compute, from each spectrum, a mean line profile with a signal-to-noise ratio close to 20,000. After averaging all 615 polarized observations, we detect a circularly polarized Ze...

  6. Long-term stability of evaporite minerals: geochronological evidence

    International Nuclear Information System (INIS)

    Our recommended Rb-Sr isochron date for potash-ore formation, and the minimum date of sedimentation for the Salado and Castile Formations of southeastern New Mexico is 214 +- 15 MYBP (millions of years before the present). This data indicates that these evaporite rocks have remained closed systems since pre-200 MYBP. Our recommended date for major polyhalite formation is 208 +- 10 MYBP. This date includes a polyhalite inclusion from a rubble chimney and from highly distorted beds near the chimney from the Mississippi Chemical Corporation Mine which in turn indicate a lack of large amounts of water accompanying the formation of the rubble chimney. Polyhalite-sylvite (+- halite) mixtures yield post-200 MYBP dates due to loss of 40Ar; this is consistent with the work of many other investigators. Polyhalite from the contact zone of a 32 +- 1MYBP amprophyre dike intrusive into the evaporites approximately 70 kilometers southeast of the WIPP site yields a K-Ar date of 21.4 +- 0.8 MYBP; this confirms the application of K-Ar dating of polyhalites to trace post-formational events in the evaporative sequence. The forty one data with very low (i.e. less than 0.1) 87Rb/86Sr ratios yield initial (87Sr/86SR)0 = 0.7086 +- 0.0014. This value is within the limits of that for Permian sea water. Rb-Sr dating of detrital clay minerals indicate an apparent age of 390 +- 77 MYBP which is interpreted to indicate incomplete clay mineral-brine interaction during sedimentation and diagenesis. Earlier suggestions for more-or-less continuous and significant alkali-alkaline earth migration post-200 MYBP is refuted by our work. Instead we propose that the evaporites have remained closed to Rb and Sr snce pre-200 MYBP as indicated by the Rb-Sr work and supported by the K-Ar polyhalite dates. This in turn is favorably interpreted as to the suitability of the WIPP site evaporites for retention of radioactive wastes

  7. Long-Term Stability of the NIST Conical Reference Transducer

    OpenAIRE

    Fick, Steven E.; Proctor, Thomas M.

    2011-01-01

    The National Institute of Standards and Technology (NIST) Conical Reference Transducer (CRT) is designed for purposes requiring frequency response characteristics much more uniform than those attainable with ultrasonic transducers conventionally used for acoustic emission (AE) nondestructive testing. The high performance of the CRT results from the use of design elements radically different from those of conventional transducers. The CRT was offered for sale for 15 years (1985 to 2000). Each ...

  8. Long-term stability of amorphous-silicon modules

    Science.gov (United States)

    Ross, R. G., Jr.

    1986-01-01

    The Jet Propulsion Laboratory (JPL) program of developing qualification tests necessary for amorphous silicon modules, including appropriate accelerated environmental tests reveal degradation due to illumination. Data were given which showed the results of temperature-controlled field tests and accelerated tests in an environmental chamber.

  9. Long term stability of immiscible ferrofluid/water interfaces

    Science.gov (United States)

    Malouin, Bernard; Posada, David; Hirsa, Amir

    2010-11-01

    Recently we have demonstrated pinned-contact, coupled droplet pairs of aqueous ferrofluids in air that can form electromagnetically-activated capillary switches and oscillators. The great variety of available ferrofluids, however, enables the use of immiscible oil-based ferrofluid droplets in a water environment to obtain the same behavior. Such immersed ferrofluid oscillators exhibit natural frequencies (for 5 mm devices) of about 10 Hz. Here we report on the observation of a gradual increase in the resonant frequency of the system in time. Experimental observations suggest that the drift in the natural frequency is a consequence of changes occurring at the ferrofluid/water interface. The interfacial structure of such a complex system (water, oil, surfactant, iron particles) is examined along with its evolution in time, using various microscopy techniques.

  10. Long-term stability of compozite zeolite MFI membranes

    Czech Academy of Sciences Publication Activity Database

    Hrabánek, Pavel; Zikánová, Arlette; Bernauer, B.; Fíla, V.; Brabec, Libor; Kočiřík, Milan

    Oxford: Elsevier B.V./Ltd, 2008 - (Gédéon, A.; Massiani, P.; Babonneau, F.), s. 673-676. (Studies in surface science and catalysis. Vol. 174). ISBN 978-0-444-53297-8. [International FEZA Conference /4./. Paris (FR), 01.09.2008-04.09.2008] R&D Projects: GA ČR GA203/07/1443 Institutional research plan: CEZ:AV0Z40400503 Keywords : MFI zeolite * membrane * synthesis * separation Subject RIV: CF - Physical ; Theoretical Chemistry

  11. Mechanistic Enhancement of SOFC Cathode Durability

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-01

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

  12. 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

  13. 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

  14. 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

  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. 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

  17. A long-term degradation study of power generation characteristics of anode-supported solid oxide fuel cells using LaNi(Fe)O{sub 3} electrode

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Takeshi; Watanabe, Kimitaka; Arakawa, Masayasu; Arai, Hajime [NTT Corporation, NTT Energy and Environment Systems Laboratories, Morinosato-Wakamiya 3-1, Atsugi-shi, Kanagawa 243-0198 (Japan)

    2009-09-05

    The long-term operation of an anode-supported solid oxide fuel cell was examined to study the degradation factor. The cell was constructed using LaNi{sub 0.6}Fe{sub 0.4}O{sub 3} (LNF), alumina-doped scandia stabilized zirconia (SASZ), and NiO-SASZ as the cathode, electrolyte, and anode respectively. The cell had Pt current collectors and was operated for 6500 h. The test was carried out at 1073 K with a constant load of 0.4 A cm{sup -2} and included thermal cycling. The cell voltage degradation rate was below 0.86%/1000 h when the cell was operated for up to 5200 h. Changes in the resistance of the cells during the experiments were analyzed by impedance spectroscopy. The cathode polarization resistance and ohmic resistance increased with time. The elements (Si and B) contained in the water condensed from the cathode exhaust gas were identified using inductively coupled plasma (ICP). (author)

  18. 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.

  19. Fundamental Investigations and Rational Design of Durable High-Performance SOFC Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu [Georgia Inst. of Technology, Atlanta, GA (United States); Ding, Dong [Georgia Inst. of Technology, Atlanta, GA (United States); Wei, Tao [Georgia Inst. of Technology, Atlanta, GA (United States); Liu, Meilin [Georgia Inst. of Technology, Atlanta, GA (United States)

    2016-03-31

    The main objective of this project is to unravel the degradation mechanism of LSCF cathodes under realistic operating conditions with different types of contaminants, aiming towards the rational design of cathodes with high-performance and enhanced durability by combining a porous backbone (such as LSCF) with a thin catalyst coating. The mechanistic understanding will help us to optimize the composition and morphology of the catalyst layer and microstructure of the LSCF backbone for better performance and durability. More specifically, the technical objectives include: (1) to unravel the degradation mechanism of LSCF cathodes under realistic operating conditions with different types of contaminants using in situ and ex situ measurements performed on specially-designed cathodes; (2) to examine the microstructural and compositional evolution of LSCF cathodes as well as the cathode/electrolyte interfaces under realistic operating conditions; (3) to correlate the fuel cell performance instability and degradation with the microstructural and morphological evolution and surface chemistry change of the cathode under realistic operating conditions; (4) to explore new catalyst materials and electrode structures to enhance the stability of the LSCF cathode under realistic operating conditions; and (5) to validate the long term stability of the modified LSCF cathode in commercially available cells under realistic operating conditions. We have systematically evaluated LSCF cathodes in symmetrical cells and anode supported cells under realistic conditions with different types of contaminants such as humidity, CO2, and Cr. Electrochemical models for the design of test cells and understanding of mechanisms have been developed for the exploration of fundamental properties of electrode materials. It is demonstrated that the activity and stability of LSCF cathodes can be degraded by the introduction of contaminants. The microstructural and compositional evolution of LSCF

  20. Long-term supersensitive magnetic observation at Eilat test site

    International Nuclear Information System (INIS)

    Complete text of publication follows. Three highly sensitive potassium total field sensors (GSMP-20S3, GEM systems) with intrinsic noise of 0.05 pT/Hz-1/2 constitute a horizontal gradiometer. The magnetic gradiometer was installed in a horizontal 170-m man-made in-rock tunnel used during a long time as a geophysical observatory. The distance between sensors was varied in the range 3-50 m to test the system operation in real field conditions. Continuous magnetic component measurements are implemented with the help of DIDD vector magnetometer. Our results show that gradiometer time series contain external field variations, which are essentially homogenous in distances of the tunnel. That gradiometer variations could be explain by inhomogeneous magnetic field results from surrounding rocks leading to slight non-parallelism of magnetic field vector at the places where the sensors were located. High correlation between gradiometer and outer field variations provide to be an effective method of correcting gradiometer data. 'Cleaning' procedure based on mutual regression analysis of gradiometer and vector magnetometer time series. Long term regression coefficients changes may tell about the sensors stability and/or about local magnetic field changes. Regression analysis of gradiometer and vector magnetometer time series over the period 2002-2007 shows the absence from a long-term trend in the regression coefficients, whereas availability of yearly variations is evident. Conceivable reasons for yearly variations of regression coefficients will be discussed. Investigations are implemented within the framework of a joint Canada-Israel scientific project sponsored by CIIRDF.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. Electrodeposited synthesis of self-supported Ni-P cathode for efficient electrocatalytic hydrogen generation

    Directory of Open Access Journals (Sweden)

    Ruixian Wu

    2016-06-01

    Full Text Available One of the key challenges for electrochemical water splitting is the development of low-cost and efficient hydrogen evolution cathode. In this work, a self-supported Ni-P cathode was synthesized by a facile electrodeposition method. The composition and morphology were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The Ni-P cathode performed low onset over-potential, good catalytic activity and long-term stability under neutral and alkaline conditions. The mechanism of Ni-P electrode for hydrogen production was discussed by electrochemical impedance spectroscopy. The excellent performance of Ni-P cathode was mainly attributed to the synergistic effect of phosphate anions and the self-supported feature.

  7. Fluid and kinetic stability of virtual cathodes for the periodically oscillating plasma sphere

    International Nuclear Information System (INIS)

    Recent theoretical work [R. A. Nebel and D. C. Barnes, Fusion Technol. 38, 28 (1998); D. C. Barnes and R. A. Nebel, Phys. Plasmas 5, 2498 (1998)] has suggested that a tiny oscillating ion cloud (referred to as the periodically oscillating plasma sphere or POPS) may undergo a self-similar collapse that can result in the periodic and simultaneous attainment of ultrahigh densities and temperatures. However, a major uncertainty in this plasma system is the behavior of the electron cloud that forms a virtual cathode. Here it is demonstrated that the required electron cloud (which forms a harmonic oscillator potential) is susceptible to an instability related to buoyancy-driven modes present in compressible fluids. Although it is demonstrated that no absolutely stable profiles with uniform electron density exist, stable profiles that are close to the required harmonic oscillator potential are found. A simple two-stream analysis indicates that kinetic effects lead to a critical limit in λD/a above which the virtual cathodes are stable. This result is consistent with previous experimental observations

  8. Low-voltage pulse exciting electron emission from ferroelectric copolymer film cathode: Role of film thickness and emission stability

    International Nuclear Information System (INIS)

    Ferroelectric copolymer thin films P(VDF-TrFE) are used as a ferroelectric cathode for investigation of their electron emission properties. This ferroelectric copolymer films with different thicknesses are deposited by spin-coating method, and then the annealing process is carried out to improve the crystallinities of as-deposited copolymer films. The measurement results of ferroelectric electron emission showed that the copolymer P(VDF-TrFE) films had a desired ferroelectric electron emission ability excited at low-voltage pulse, and its peak emission current can reach to be ∼1.3 μA when the pulse voltage is 280 V. In addition, the effect of film thickness on electron emission property and emission stability of copolymer thin film P(VDF-TrFE) are discussed.

  9. Li-ion capacitors with carbon cathode and hard carbon/stabilized lithium metal powder anode electrodes

    Science.gov (United States)

    Cao, W. J.; Zheng, J. P.

    2012-09-01

    A lithium-ion capacitor was developed using a mixture of stabilized lithium metal powder and hard carbon as the anode electrode, while activated carbon was used as the cathode. A specific energy of approximately 82 Wh kg-1 was obtained based on the weight of electrode materials; however, when the electrolyte, separator, and current collectors were included, the specific energy of an assembled Li-ion capacitor was about 25 Wh kg-1. The capacitor was able to deliver over 60% of the maximum energy at a discharge C-rate of 44C. Through continuous galvanostatic charge/discharge cycling, the capacitance of the Li-ion capacitor degraded less than 3% over 600 cycles.

  10. 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)

  11. 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...

  12. 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...

  13. [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

  14. 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....

  15. 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:…

  16. 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

  17. 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...

  18. 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

  19. Electrocatalytic Activity and Stability of M-Fe Catalysts Synthesized by Polymer Complex Method for PEFC Cathode

    KAUST Repository

    Ou, Yiwei

    2011-11-01

    The polymerized complex (PC) method was used to synthesize highly dispersed iron-based catalysts for the oxygen reduction reaction (ORR). The catalysts were prepared with an addition of 1,10-phenanthroline (Phen) and transition metals (M), such as Ta, Ti, and W, in an attempt to enhance the ORR activity and durability of the catalysts. The composition and properties of the catalysts were characterized by thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. The catalyst components, after extensive dissolution in a strong acid solution, were characterized by inductively coupled plasma mass spectroscopy and ultraviolet-visible spectroscopy. It was found that the Ti-Fe catalyst showed improved ORR performance, and the Ta-Fe catalyst showed enhanced stability towards ORR in acidic solution. The catalytic activity and stability for ORR was observed by adding Ti or Ta into the catalyst formulation, suggesting that the interaction between added hetero-ions (Ti and Ta) and ionic Fe active sites was beneficial for the ORR. A single-cell test with the synthesized catalyst in the cathode initially generated a high power density, but the low stability remains an issue to be solved.

  20. Silver nanowires as catalytic cathodes for stabilizing lithium-oxygen batteries

    Science.gov (United States)

    Kwak, Won-Jin; Jung, Hun-Gi; Lee, Seon-Hwa; Park, Jin-Bum; Aurbach, Doron; Sun, Yang-Kook

    2016-04-01

    Silver nanowires have been investigated as a catalytic cathode material for lithium-oxygen batteries. Their high aspect ratio contributes to the formation of a corn-shaped layer structure of the poorly crystalline lithium peroxide (Li2O2) nanoparticles produced by oxygen reduction in poly-ether based electrolyte solutions. The nanowire morphology seems to provide the necessary large contact area and facile electron supply for a very effective oxygen reduction reaction. The unique morphology and structure of the Li2O2 deposits and the catalytic nature of the silver nano-wires promote decomposition of Li2O2 at low potentials (below 3.4 V) upon the oxygen evolution. This situation avoids decomposition of the solution species and oxidation of the electrodes during the anodic (charge) reactions, leading to high electrical efficiently of lithium-oxygen batteries.