WorldWideScience

Sample records for long-term stabilization designs

  1. Methodologies for evaluating long-term stabilization designs of uranium mill tailings impoundments

    International Nuclear Information System (INIS)

    Nelson, J.D.; Abt, S.R.; Volpe, R.L.; Van Zye, D.; Hinkle, N.E.; Staub, W.P.

    1986-06-01

    Uranium mill tailings impoundments require long-term (200 to 1000 years) stabilization. This report reviews currently available methodologies for evaluating factors that can have a significant influence on tailings stabilization and develops methodologies in technical areas where none presently exist. Mill operators can use these methodologies to assist with (1) the selection of sites for mill tailings impoundments, (2) the design of stable impoundments, and (3) the development of reclamation plans for existing impoundments. These methodologies would also be useful for regulatory agency evaluations of proposals in permit or license applications. Methodologies were reviewed or developed in the following technical areas: (1) prediction of the Probable Maximum Precipitation (PMP) and an accompanying Probable Maximum Flood (PMF); (2) prediction of the stability of local and regional fluvial systems; (3) design of impoundment surfaces resistant to gully erosion; (4) evaluation of the potential for surface sheet erosion; (5) design of riprap for protecting embankments from channel flood flow and overland flow; (6) selection of riprap with appropriate durability for its intended use; and (7) evaluation of oversizing required for marginal quality riprap

  2. 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.

  3. Long-Term Stability Evaluation and Pillar Design Criterion for Room-and-Pillar Mines

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2017-10-01

    Full Text Available The collapse of abandoned room-and-pillar mines is often violent and unpredictable. Safety concerns often resulted in mine closures with no post-mining stability evaluations. As a result, large amounts of land resources over room-and-pillar mines are wasted. This paper attempts to establish an understanding of the long-term stability issues of goafs (abandoned mines. Considering progressive pillar failures and the effect of single pillar failure on surrounding pillars, this paper proposes a pillar peeling model to evaluate the long-term stability of coal mines and the associated criteria for evaluating the long-term stability of room-and-pillar mines. The validity of the peeling model was verified by numerical simulation, and field data from 500 pillar cases from China, South Africa, and India. It is found that the damage level of pillar peeling is affected by the peel angle and pillar height and is controlled by the pillar width–height ratio.

  4. Design surface covers: an approach to long-term waste site stabilization

    International Nuclear Information System (INIS)

    Beedlow, P.A.; Cadwell, L.L.; McShane, M.C.

    1983-02-01

    The wide range of existing environmental conditions, potential contaminants and available cover materials at waste disposal sites necessitates site-specific designing of surface covers for effective long-term erosion resistance. This paper presents a systematic approach to designing surface covers for hazardous waste repositories that can be tailored to conditions at any site. The approach consists of three phases: (1) an assessment, during which the degree of required surface protection (erosion potential) is determined; (2) a preliminary design that integrates surface cover design with the need to minimize transport of contaminants; and (3) a final design, where the cost and effectiveness of the surface cover are determined. 1 figure

  5. 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...

  6. Long-term stability of sodium caseinate-stabilized nanoemulsions.

    Science.gov (United States)

    Yerramilli, Manispuritha; Ghosh, Supratim

    2017-01-01

    Oil-in-water (5 wt%) nanoemulsions were prepared with different concentration (2.5-10 wt%) of sodium caseinate as a sole emulsifier and their long-term storage stability was investigated for 6 months. Previous studies associated with sodium caseinate looked only into nanoemulsion formation; hence the challenges with long-term stability were not addressed. All nanoemulsions displayed an average droplet size sodium caseinate-stabilized nanoemulsions.

  7. Modeling flood events for long-term stability

    International Nuclear Information System (INIS)

    Schruben, T.; Portillo, R.

    1985-01-01

    The primary objective for the disposal of uranium mill tailings in the Uranium Mill Tailings Remedial Action (UMTRA) Project is isolation and stabilization to prevent their misuse by man and dispersal by natural forces such as wind, rain, and flood waters (40 CFR-192). Stabilization of sites that are located in or near flood plains presents unique problems in design for long-term performance. This paper discusses the process involved with the selection and hydrologic modeling of the design flood event; and hydraulic modeling with geomorphic considerations of the design flood event. The Gunnison, Colorado, and Riverton, Wyoming, sites will be used as examples in describing the process

  8. Long-term stability of salivary cortisol

    DEFF Research Database (Denmark)

    Garde, A H; Hansen, Åse Marie

    2005-01-01

    either stored in small vials or spiked to polyester Salivette tampons before analysis for cortisol using Spectria RIA kits. The effects of storage were evaluated by a linear regression model (mixed procedure) on a logarithmic scale. No effects on cortisol concentrations were found after storage of saliva......The measurement of salivary cortisol provides a simple, non-invasive, and stress-free measure frequently used in studies of the hypothalamic-pituitary-adrenal axis activity. In research projects, samples are often required to be stored for longer periods of time either because of the protocol...... of the project or because of lack of funding for analysis. The aim of the present study was to explore the effects of long-term storage of samples on the amounts of measurable cortisol. Ten pools of saliva were collected on polyester Salivette tampons from five subjects. After centrifugation the samples were...

  9. Long term physical and chemical stability of polyelectrolyte multilayer membranes

    NARCIS (Netherlands)

    de Grooth, Joris; Haakmeester, Brian; Wever, Carlos; Potreck, Jens; de Vos, Wiebe Matthijs; Nijmeijer, Dorothea C.

    2015-01-01

    This work presents a detailed investigation into the long term stability of polyelectrolyte multilayer (PEM) modified membranes, a key factor for the application of these membranes in water purification processes. Although PEM modified membranes have been frequently investigated, their long term

  10. Long-term stabilization of uranium mill tailings

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1984-01-01

    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 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 (1) rock cover, (2) soil and revegetation, or (3) 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%. For these steeper slopes, the use of rock talus or riprap will be necessary to maximize the probability of long-term stability. The use of vegetation to control erosion on the flatter portions of the site may be practicable in regions of the USA with sufficient rainfall and suitable soil types, but revegetation practices must be carefully evaluated to ensure that long-term

  11. Long-term plutonium storage: Design concepts

    International Nuclear Information System (INIS)

    Wilkey, D.D.; Wood, W.T.; Guenther, C.D.

    1994-01-01

    An important part of the Department of Energy (DOE) Weapons Complex Reconfiguration (WCR) Program is the development of facilities for long-term storage of plutonium. The WCR design goals are to provide storage for metals, oxides, pits, and fuel-grade plutonium, including material being held as part of the Strategic Reserve and excess material. Major activities associated with plutonium storage are sorting the plutonium inventory, material handling and storage support, shipping and receiving, and surveillance of material in storage for both safety evaluations and safeguards and security. A variety of methods for plutonium storage have been used, both within the DOE weapons complex and by external organizations. This paper discusses the advantages and disadvantages of proposed storage concepts based upon functional criteria. The concepts discussed include floor wells, vertical and horizontal sleeves, warehouse storage on vertical racks, and modular storage units. Issues/factors considered in determining a preferred design include operational efficiency, maintenance and repair, environmental impact, radiation and criticality safety, safeguards and security, heat removal, waste minimization, international inspection requirements, and construction and operational costs

  12. Long-term stability scintillation tiles for LHCb detector

    International Nuclear Information System (INIS)

    Grinyov, B.V.; Khlapova, N.P.; Senchyshyn, V.G.; Lebedev, V.N.; Adadurov, A.F.; Melnychuk, S.V.

    2004-01-01

    Accelerated thermal aging tests of materials - UPS-923A, UPS-96G, UPS-96GM and their analogues, SCSN-81 (Kuraray) and BC-408 (Bicron) - were made. A forecast of tile lifetime was made for normal conditions of usage (20% reduction of light output and 50% reduction of the bulk attenuation length (BAL) and technical attenuation length (TAL). Scintillator UPS-96GM has the most long-term stability of parameters--more than 11 yr. BC-408 samples have the minimum lifetime ∼7 yr. The long-term stability, calculated by light yield reduction, of UPS-96G, UPS-923A and SCSN-81 is 10, 9 and 8 yr, respectively

  13. Long-term stability scintillation tiles for LHCb detector

    CERN Document Server

    Grinyov, B V; Khlapova, N P; Lebedev, V N; Melnychuk, S V; Senchyshyn, V G

    2004-01-01

    Accelerated thermal aging tests of materials-UPS-923A, UPS-96G, UPS-96GM and their analogues, SCSN-81 (Kuraray) and BC-408 (Bicron)- were made. A forecast of tile lifetime was made for normal conditions of usage (20% reduction of light output and 50% reduction of the bulk attenuation length (BAL) and technical attenuation length (TAL). Scintillator UPS-96GM has the most long-term stability of parameters- more than 11 yr. BC-408 samples have the minimum lifetime ~7 yr. The long-term stability, calculated by light yield reduction, of UPS-96G, UPS-923A and SCSN-81 is 10, 9 and 8 yr, respectively.

  14. [Stabilization and long-term effect of chromium contaminated soil].

    Science.gov (United States)

    Wang, Jing; Luo, Qi-Shi; Zhang, Chang-Bo; Tan, Liang; Li, Xu

    2013-10-01

    Short-term (3 d and 28 d) and long-term (1 a) stabilization effects of Cr contaminated soil were investigated through nature curing, using four amendments including ferrous sulfide, ferrous sulfate, zero-valent iron and sodium dithionite. The results indicated that ferrous sulfide and zero-valent iron were not helpful for the stabilization of Cr(VI) when directly used because of their poor solubility and immobility. Ferrous sulfate could effectively and rapidly decrease total leaching Cr and Cr(VI) content. The stabilization effect was further promoted by the generation of iron hydroxides after long-term curing. Sodium dithionite also had positive effect on soil stabilization. Appropriate addition ratio of the two chemicals could help maintain the soil pH in range of 6-8.

  15. Long-term stabilization of uranium mill tailings

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1983-01-01

    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%

  16. Ceramics in engines - Long term stability of transformation toughened zirconia

    International Nuclear Information System (INIS)

    Marmach, M.; Swain, M.V.

    1985-01-01

    The long term thermal stability of two types of magnesia partially stabilized zirconia at temperatures below 1000 0 C has been determined. The effect on mechanical properties and phase stability of isothermal heating at 800 0 C and 900 0 C for up to 2000 hours, and with thermal cycling for a similar period between R.T. and 800 0 C in air, was measured. it was found that peak-aged (MS) type Mg-PSZ was much more stable than the thermal shock resistant (TS) type in both tests and showed minimal degradation

  17. Advanced nonlinear theory: Long-term stability at the SSC

    International Nuclear Information System (INIS)

    Heifets, S.

    1987-01-01

    This paper discussed the long-term stability of the particle beams in the Superconducting Super Collider. In particular the dynamics of a single particle beam is considered in depth. The topics of this paper include: the Hamiltonian of this particle approach, perturbation theory, canonical transformations, interaction of the resonances, structure of the phase space, synchro-Betatron oscillations, modulation diffusion and noise-resonance interaction. 36 refs

  18. The design of measuring tubes and their influence on long term stability of EMF in filling machines; Einfluss der Messrohrkonstruktion auf die Langzeitstabilitaet von Abfuell-MID

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, B. [Krohne Messtechnik Gmbh und Co KG, Duisburg (Germany); Hofmann, F.

    2008-07-01

    Electro Magnetic Flow Meters (EMF) have been used for many decades measuring the volumetric flow rate of electric conductive liquids. Changes of the inner diameter because of temperature influences are creating measuring errors. In particular applications, where a high accuracy and repeatability is needed, this can cause trouble. This effect can be recognized after a long use of these meters and the corresponding cleaning procedures with liquid or steam, which is typical for the food and beverage industry. This effect is of a huge importance on electro magnetic flow meters, which are used on rotating filling machines for filling PET (plastic) bottles. Meters with ceramic tubes had a better long term stability than the ones with PFA liner. (orig.)

  19. Long-term stability of orbits in storage rings

    International Nuclear Information System (INIS)

    Warnock, R.L.; Ruth, R.D.

    1990-06-01

    We describe a numerical method to establish long-term bounds on nonlinear Hamiltonian motion. By bounding the change in a nearly constant action variable, uniformly in initial condition, one can predict stability for N turns by tracking many orbits for a member of turns of N 0 much less than N. In a first application to a model sextupole lattice in a region of strong nonlinearity, we predict stability of betatron motion in two degrees of freedom for 10 8 turns. 5 refs., 3 figs

  20. Long term stability of nanowire nanoelectronics in physiological environments.

    Science.gov (United States)

    Zhou, Wei; Dai, Xiaochuan; Fu, Tian-Ming; Xie, Chong; Liu, Jia; Lieber, Charles M

    2014-03-12

    Nanowire nanoelectronic devices have been exploited as highly sensitive subcellular resolution detectors for recording extracellular and intracellular signals from cells, as well as from natural and engineered/cyborg tissues, and in this capacity open many opportunities for fundamental biological research and biomedical applications. Here we demonstrate the capability to take full advantage of the attractive capabilities of nanowire nanoelectronic devices for long term physiological studies by passivating the nanowire elements with ultrathin metal oxide shells. Studies of Si and Si/aluminum oxide (Al2O3) core/shell nanowires in physiological solutions at 37 °C demonstrate long-term stability extending for at least 100 days in samples coated with 10 nm thick Al2O3 shells. In addition, investigations of nanowires configured as field-effect transistors (FETs) demonstrate that the Si/Al2O3 core/shell nanowire FETs exhibit good device performance for at least 4 months in physiological model solutions at 37 °C. The generality of this approach was also tested with in studies of Ge/Si and InAs nanowires, where Ge/Si/Al2O3 and InAs/Al2O3 core/shell materials exhibited stability for at least 100 days in physiological model solutions at 37 °C. In addition, investigations of hafnium oxide-Al2O3 nanolaminated shells indicate the potential to extend nanowire stability well beyond 1 year time scale in vivo. These studies demonstrate that straightforward core/shell nanowire nanoelectronic devices can exhibit the long term stability needed for a range of chronic in vivo studies in animals as well as powerful biomedical implants that could improve monitoring and treatment of disease.

  1. Long-term stability of surfactant-free gold nanostars

    Science.gov (United States)

    Vega, Marienette Morales; Bonifacio, Alois; Lughi, Vanni; Marsi, Stefano; Carrato, Sergio; Sergo, Valter

    2014-11-01

    This work investigates the long-term stability of suspensions of surfactant-free gold nanostars with mean diameter of 78 ± 13 nm (measured from tip to tip across the nanostar).We monitored the optical and morphological properties of the nanostars over the course of several days after synthesis by observing the changes in the UV-visible absorption spectra and mean radius of curvature of the nanostar tips. An aging process can be observed, evident in the blunting of the nanostar tips, leading to a blue shift in the absorption maximum. Stability is greatly improved by depositing on the nanostars a monolayer of mercaptopropionic acid (MPA), possibly because of the formation of the gold-sulfur (Au-S) bond that limits the mobility of the Au atoms. Capping the nanostars with MPA is an easy additional step for extending the stability of the nanostars in suspension without significantly affecting the original plasmonic resonance band.

  2. 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...... 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...

  3. Long-term stabilization considerations for decommissioned and reclaimed uranium sites

    International Nuclear Information System (INIS)

    Abt, S.R.; Nelson, J.D.; Johnson, T.L.

    1988-01-01

    The long-term stabilization of decommissioned uranium mill sites and of reclaimed uranium mill tailings sites encompass a broad spectrum of design capabilities. This paper presents a few of the quantitative methodologies recently developed or refined to evaluate physical factors (i.e. precipitation, fluvial geomorphology, stable slope, slope stabilization with riprap and riprap selection) that influence long-term stabilization of uranium mill and mill tailings sites. It is acknowledged that the degree of refinement of these methodologies are in their infancy and that extensive research and development are warranted to increase the level of assurance. However, these methodologies provide an initial guideline for evaluating long-term stabilization that has not been previously existed. The purpose of this paper is to present a review of currently available state-of-the-art engineering techniques and methodologies for the evaluation of reclamation plans designed to provide long-term stability against potential failure modes. In some cases, evaluative techniques have been developed for long-term stabilization where methodologies have not previously existed. Each methodology to be presented represents a starting point upon which additional research and/or development may be warranted

  4. Long-Term Stability of Oxide Nanowire Sensors via Heavily Doped Oxide Contact.

    Science.gov (United States)

    Zeng, Hao; Takahashi, Tsunaki; Kanai, Masaki; Zhang, Guozhu; He, Yong; Nagashima, Kazuki; Yanagida, Takeshi

    2017-12-22

    Long-term stability of a chemical sensor is an essential quality for long-term collection of data related to exhaled breath, environmental air, and other sources in the Internet of things (IoT) era. Although an oxide nanowire sensor has shown great potential as a chemical sensor, the long-term stability of sensitivity has not been realized yet due to electrical degradation under harsh sensing conditions. Here, we report a rational concept to accomplish long-term electrical stability of metal oxide nanowire sensors via introduction of a heavily doped metal oxide contact layer. Antimony-doped SnO 2 (ATO) contacts on SnO 2 nanowires show much more stable and lower electrical contact resistance than conventional Ti contacts for high temperature (200 °C) conditions, which are required to operate chemical sensors. The stable and low contact resistance of ATO was confirmed for at least 1960 h under 200 °C in open air. This heavily doped oxide contact enables us to realize the long-term stability of SnO 2 nanowire sensors while maintaining the sensitivity for both NO 2 gas and light (photo) detections. The applicability of our method is confirmed for sensors on a flexible polyethylene naphthalate (PEN) substrate. Since the proposed fundamental concept can be applied to various oxide nanostructures, it will give a foundation for designing long-term stable oxide nanomaterial-based IoT sensors.

  5. 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.

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

    International Nuclear Information System (INIS)

    Vernaz, E.; Loida, A.; Malow, G.; Marples, J.A.C.; Matzke, H.J.

    1990-01-01

    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

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

    International Nuclear Information System (INIS)

    Laine, H.; Karttunen, P.

    2010-07-01

    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 SiO 2 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

  8. Summary for working group B on long-term stability

    International Nuclear Information System (INIS)

    Peggs, S.G.

    1992-01-01

    A total of 36 workshop participants attended at least one session of the Long-Term Stability working group. We avoided turning these sessions into a specialized seminar series by meeting in two subgroups, loosely labeled Analysis and Diffusion ampersand Tracking, so that working discussions among a reasonably small number of people were possible. Nonetheless, no attempt is made to categorize the 13 group B papers according to original subgroup. A similar workshop, the Workshop on Accelerator Orbit and Particle Tracking Problems, was held almost exactly 10 years ago at Brookhaven. It is interesting to see how many of the participants in the photograph of that workshop appear again in the photograph at the front of these proceedings. Fortunately, it is not correct to infer that little progress has been made in the last decade, nor that the average age of the participants has increased significantly. Rather, the recent photograph has many more, younger, faces than its predecessor. This attests to the ongoing interest and vigorous activity in an area of central importance to accelerator physics

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

    International Nuclear Information System (INIS)

    Takaji, Kazuhiko; Sugino, Hiroyuki; Okutsu, Kazuo; Miura, Kazuhiko; Tabei, Kazuto; Noda, Masaru; Takahashi, Shinichi; Sugie, Shigehiko

    1999-11-01

    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)

  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. Preliminary long-term stability criteria for compressed air energy storage caverns in salt domes

    Energy Technology Data Exchange (ETDEWEB)

    Thoms, R.L.; Martinez, J.D.

    1978-08-01

    Air storage caverns, which are an essential and integral component of a CAES plant, should be designed and operated so as to perform satisfactorily over the intended life of the overall facility. It follows that the long-term ''stability'' of air storage caverns must be considered as a primary concern in projecting the satisfactory operation of CAES facilities. As used in the report, ''stability'' of a storage cavern implies the extent to which an acceptable amount of cavern storage volume can be utilized with routine maintenance for a specified time interval, e.g., 35 years. In this context, cavern stability is relative to both planned utilization and time interval of operation. The objective of the study was to review the existing literature and consult knowledgeable workers in the storage industry, and then report state-of-the-art findings relative to long-term stability of compressed air energy storage caverns in salt domes. Further, preliminary cavern stability criteria were to be presented in a form consistent with the amount of information available on cavern performance in salt domes. Another objective of the study was to outline a methodology for determining the long-term stability of site-specific CAES cavern systems in salt domes.

  12. Designing indicators of long-term energy supply security

    International Nuclear Information System (INIS)

    Jansen, J.C.; Van Arkel, W.G.; Boots, M.G.

    2004-01-01

    To our knowledge, so far amazingly little research work has been undertaken to construct meaningful indicators of long-run energy supply security for a particular nation or region. Currently, in addressing energy supply security, policy makers tend to emphasise short-term supply disruptions. In contrast, this pre-study accords with the broader Sustainability Outlook in considering the long-term perspective. This report starts with taking stock, in a concise way, of the official EU energy outlook and issues related to the opportunities to administer changes in the energy mix at the level of major energy use categories. Then a brief survey of relevant literature is made on long-term strategies to ensure survival of systems - be it biological, social, etc. - in an environment largely characterised by high uncertainty and a lot of unchartered territory. We found the work of Andrew Stirling very inspiring in this context. Based on his work and considering the limitations of the present research activity, we retained the Shannon index as the best 'simple' indicator of diversity. In the core of the report, the Shannon index is elaborated into four indicators of long-term energy supply security. Stepwise, additional aspects of long-term energy supply security are introduced. These aspects are: Diversification of energy sources in energy supply; Diversification of imports with respect to imported energy sources; Long-term political stability in regions of origin; The resource base in regions of origin, including the home region/country itself. After small adjustments to allow for data availability, these indicators were applied to the reference year 2030 of four long-term scenarios with data of base year 1995 and projections for underlying variables provided by the Netherlands Environmental Assessment Agency (MNP). Preliminary interpretation of the results suggests the usefulness of the indicators presented in this report. A second activity undertaken in this report was

  13. Long-term stability of diurnal salivary cortisol and alpha-amylase secretion patterns.

    Science.gov (United States)

    Skoluda, Nadine; La Marca, Roberto; Gollwitzer, Mario; Müller, Andreas; Limm, Heribert; Marten-Mittag, Birgitt; Gündel, Harald; Angerer, Peter; Nater, Urs M

    2017-06-01

    This study aimed to investigate long-term stability and variability of diurnal cortisol and alpha-amylase patterns. Diurnal cortisol and alpha-amylase secretion patterns were assessed on a single workday with three waves of measurement across a total time period of 24months in 189 participants. Separate hierarchical linear models were analyzed, with and without a number of potential predictor variables (age, BMI, smoking, chronic stress, stress reactivity). While low long-term stability was found in diurnal cortisol, the stability of diurnal alpha-amylase was moderate across the time period of 24months. Several predictor variables had a positive impact on diurnal cortisol and alpha-amylase secretion patterns averaged across waves. Our findings underpin the notion that long-term stability is not necessarily warranted in longitudinal studies. It is important to choose an appropriate study design when attempting to disentangle clinically and biologically relevant changes from naturally occurring variations in diurnal cortisol and alpha-amylase. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Field evaluation of two shallow land burial trench cap designs for long-term stabilization and closure of waste repositories at Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Nyhan, J.; Drennon, B.; Hakonson, T.

    1989-02-01

    The results from several field experiments on methods to control soil erosion, biointrusion, and water infiltration were used to design and test a burial site cover which improves the ability of the disposal site to isolate the wastes. The performance of the improved cover design in managing water and biota at the disposal site was compared with a more conventional design widely used in the industry. The conventional trench cover design consists of 15 cm of sandy loam topsoil over 75 cm of sandy silt backfill, whereas the improved trench cover design consists of 75 cm of topsoil over a minimum of 25 cm of gravel and 90 cm of river cobble. Each plot was lined with an impermeable liner to allow for mass balance calculation of water dynamics and contains hydrologic tracer ions (iodide and bromide) to demonstrate movement of water through the various zones of the trench cap. Cesium was emplaced beneath the trench cap to indicate root penetration through the trench cap, observed by sampling plant samples collected on the plots and assaying them for cesium. The field data are summarized and discussed in terms of its usefulness for waste management decisions. 67 refs., 44 figs., 4 tabs

  15. Study of the effect of aggressive media on the long-term stability of reinforced plates

    International Nuclear Information System (INIS)

    Zelentsov, D.G.; Pochtman, Yu.M.

    1995-01-01

    Many important load-bearing structural elements that operate in agressive media are subjected to simultaneous mechanical and chemical attack. The current status of the problem of designing such members is adequately reflected. It follows from that only a few studies have been devoted to the long-term stability of reinforced plates in aggressive media, and most of them were based on structurally orthotropic theory. Such an approach makes it impossible to construct an adequate model of the deformation process. In particular, it precludes allowance for the effect of the discreteness of the reinforcement on plate stability and determination of changes in the character of deformation of the plate during service

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

    International Nuclear Information System (INIS)

    Engkvist, I.; Albinsson, Y.; Johansson Engkvist, W.

    1996-06-01

    The concrete construction in the Swedish repository for long-lived low and intermediate level waste will give a stable chemical near field environment for 10 5 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

  17. 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....

  18. Long term optical stability of fluorescent solar concentrator plates

    NARCIS (Netherlands)

    Slooff, L.H.; Bakker, N.J.; Sommeling, P.M.; Büchtemann, A.; Wedel, A.; Sark, W.G.J.H.M. van

    2014-01-01

    Fluorescent solar concentrators offer an alternative approach for low-cost photovoltaic energy conversion. For successful application, not only the power conversion efficiency and cost are important, but also lifetime or stability of the devices. As today’s concentrator is made of polymer sheets

  19. Long-term optical stability of fluorescent solar concentrator plates

    NARCIS (Netherlands)

    Slooff, Lenneke H.; Bakker, Nicolaas J.; Sommeling, Paul M.; Büchtemann, Andreas; Wedel, Armin; Van Sark, Wilfried G J H M

    2014-01-01

    Fluorescent solar concentrators offer an alternative approach for low-cost photovoltaic energy conversion. For successful application, not only the power conversion efficiency and cost are important, but also lifetime or stability of the devices. As today's concentrator is made of polymer sheets

  20. Design of microdevices for long-term live cell imaging

    International Nuclear Information System (INIS)

    Chen, Huaying; Nordon, Robert E; Rosengarten, Gary; Li, Musen

    2012-01-01

    Advances in fluorescent live cell imaging provide high-content information that relates a cell's life events to its ancestors. An important requirement to track clonal growth and development is the retention of motile cells derived from an ancestor within the same microscopic field of view for days to weeks, while recording fluorescence images and controlling the mechanical and biochemical microenvironments that regulate cell growth and differentiation. The aim of this study was to design a microwell device for long-term, time-lapse imaging of motile cells with the specific requirements of (a) inoculating devices with an average of one cell per well and (b) retaining progeny of cells within a single microscopic field of view for extended growth periods. A two-layer PDMS microwell culture device consisting of a parallel-plate flow cell bonded on top of a microwell array was developed for cell capture and clonal culture. Cell deposition statistics were related to microwell geometry (plate separation and well depth) and the Reynolds number. Computational fluid dynamics was used to simulate flow in the microdevices as well as cell–fluid interactions. Analysis of the forces acting upon a cell was used to predict cell docking zones, which were confirmed by experimental observations. Cell–fluid dynamic interactions are important considerations for design of microdevices for long-term, live cell imaging. The analysis of force and torque balance provides a reasonable approximation for cell displacement forces. It is computationally less intensive compared to simulation of cell trajectories, and can be applied to a wide range of microdevice geometries to predict the cell docking behavior. (paper)

  1. Performances and long-term stability of the LHAASO-KM2A prototype array

    International Nuclear Information System (INIS)

    Liu Jia; Sheng XiangDong; He Huihai; Zhao Jing; Chang Jinfan; Gu Minhao; Hou Chao; Lu Hongkui

    2014-01-01

    A prototype array for the LHAASO-KM2A, which consists of 42 detector units and fully overlaps the ARGO-YBJ experiment, was set up at the Yangbajing cosmic ray observatory and has been in stable operation since October 2010. The resulting performances of the KM2A electromagnetic particle detector prototypes fully meet the design requirements. Through hybrid observation of cosmic ray showers with the ARGO-YBJ experiment, the performances and long-term stability of the prototype array are tested and the results are consistent with expectation. The cosmic ray moon shadow observed by the prototype array is also presented. (authors)

  2. Long-term memory stabilized by noise-induced rehearsal.

    Science.gov (United States)

    Wei, Yi; Koulakov, Alexei A

    2014-11-19

    Cortical networks can maintain memories for decades despite the short lifetime of synaptic strengths. Can a neural network store long-lasting memories in unstable synapses? Here, we study the effects of ongoing spike-timing-dependent plasticity (STDP) on the stability of memory patterns stored in synapses of an attractor neural network. We show that certain classes of STDP rules can stabilize all stored memory patterns despite a short lifetime of synapses. In our model, unstructured neural noise, after passing through the recurrent network connections, carries the imprint of all memory patterns in temporal correlations. STDP, combined with these correlations, leads to reinforcement of all stored patterns, even those that are never explicitly visited. Our findings may provide the functional reason for irregular spiking displayed by cortical neurons and justify models of system memory consolidation. Therefore, we propose that irregular neural activity is the feature that helps cortical networks maintain stable connections. Copyright © 2014 the authors 0270-6474/14/3415804-12$15.00/0.

  3. Long-term prospects for oil market stability

    Energy Technology Data Exchange (ETDEWEB)

    Subroto, Dr [OPEC, Vienna (AT)

    1989-10-01

    OPEC recognize that energy consumption has its social costs and benefits, and that some energy sources impose fewer costs on society. We must consider the environmental implications of oil extraction. Our policies today should enable future generations to secure their energy needs, and OPEC is well-positioned to supply them. An inward-looking OPEC, distracted by internal wranglings and inconsistencies, cannot expect to be a stabilizing force in the oil markets. We have sought, therefore, to put our own house in order. Aside from the debate on depletion policy, a major strain on OPEC stability is the growing tendency towards regionalization in the world oil market. And the absence of universally acceptable quota allocation criteria means that OPEC may have to live with instability for some time to come, but this will be manageable in the short run. In the medium term, however, the call on OPEC oil in the 1990s is predicted to rise to a level commensurate with the sustainable capacities of member states. Producers and consumers have a common interest and should share a similar perspective on the inter-dependence between energy, the environment and economic development. (author).

  4. Russian national time scale long-term stability

    Science.gov (United States)

    Alshina, A. P.; Gaigerov, B. A.; Koshelyaevsky, N. B.; Pushkin, S. B.

    1994-05-01

    The Institute of Metrology for Time and Space NPO 'VNIIFTRI' generates the National Time Scale (NTS) of Russia -- one of the most stable time scales in the world. Its striking feature is that it is based on a free ensemble of H-masers only. During last two years the estimations of NTS longterm stability based only on H-maser intercomparison data gives a flicker floor of about (2 to 3) x 10(exp -15) for averaging times from 1 day to 1 month. Perhaps the most significant feature for a time laboratory is an extremely low possible frequency drift -- it is too difficult to estimate it reliably. The other estimations, free from possible inside the ensemble correlation phenomena, are available based on the time comparison of NTS relative to the stable enough time scale of outer laboratories. The data on NTS comparison relative to the time scale of secondary time and frequency standards at Golitzino and Irkutsk in Russia and relative to NIST, PTB and USNO using GLONASS and GPS time transfer links gives stability estimations which are close to that based on H-maser intercomparisons.

  5. Design tradeoffs in long-term research for stream salamanders

    Science.gov (United States)

    Brand, Adrianne B,; Grant, Evan H. Campbell

    2017-01-01

    Long-term research programs can benefit from early and periodic evaluation of their ability to meet stated objectives. In particular, consideration of the spatial allocation of effort is key. We sampled 4 species of stream salamanders intensively for 2 years (2010–2011) in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA to evaluate alternative distributions of sampling locations within stream networks, and then evaluated via simulation the ability of multiple survey designs to detect declines in occupancy and to estimate dynamic parameters (colonization, extinction) over 5 years for 2 species. We expected that fine-scale microhabitat variables (e.g., cobble, detritus) would be the strongest determinants of occupancy for each of the 4 species; however, we found greater support for all species for models including variables describing position within the stream network, stream size, or stream microhabitat. A monitoring design focused on headwater sections had greater power to detect changes in occupancy and the dynamic parameters in each of 3 scenarios for the dusky salamander (Desmognathus fuscus) and red salamander (Pseudotriton ruber). Results for transect length were more variable, but across all species and scenarios, 25-m transects are most suitable as a balance between maximizing detection probability and describing colonization and extinction. These results inform sampling design and provide a general framework for setting appropriate goals, effort, and duration in the initial planning stages of research programs on stream salamanders in the eastern United States.

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

    International Nuclear Information System (INIS)

    Matthern, G.E.; Nickelson, D.F.

    1997-01-01

    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

  7. Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies.

    Science.gov (United States)

    da Rocha-Filho, Pedro Alves; Maruno, Mônica; Ferrari, Márcio; Topan, José Fernando

    2016-06-09

    The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w) was combined with liquid vaseline (25.0% w/w) employing a natural self-emulsifying base (SEB) derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

  8. The design of long term care insurance contracts.

    Science.gov (United States)

    Cremer, Helmuth; Lozachmeur, Jean-Marie; Pestieau, Pierre

    2016-12-01

    This paper studies the design of long term care (LTC) insurance contracts in the presence of ex post moral hazard. While this problem bears some similarity with the study of health insurance (Blomqvist, 1997) the significance of informal LTC affects the problem in several crucial ways. It introduces the potential crowding out of informal care by market care financed through insurance coverage. Furthermore, the information structure becomes more intricate. Informal care is not publicly observable and, unlike the insurer, caregivers know the true needs of their relatives. We determine the optimal second-best contract and show that the optimal reimbursement rate can be written as an A-B-C expression à la Diamond (1998). These terms respectively reflect the efficiency loss as measured by the inverse of the demand elasticity, the distribution of needs and the preferences for risk sharing. Interestingly, informal care directly affects only the first term. More precisely the first term decreases with the presence and significance of informal care. Roughly speaking this means that an efficient LTC insurance contract should offer lower (marginal) reimbursement rates than its counterpart in a health insurance context. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Barnes, F.J.; Rodgers, J.C.; Trujillo, G.

    1986-01-01

    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

  10. Guidance for disposal of uranium-mill tailings: long-term stabilization of earthen cover materials

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1983-06-01

    The primary hazard associated with uranium-mill tailings is exposure to a radioactive gas, 222 Rn, 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, depends on long-term protection of these cover materials. 230 Th, which decays to 222 Rn, has a half-life of about 80,000 years. The three major options available for stabilization of uranium-mill tailings are (1) rock cover, (2) soil and revegetation, or (3) 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 0 . For these steeper slopes, riprap will be necessary to maximize the probability of long-term stability. The use of vegetation to control erosion on the flatter portions of the site may be practicable in regions with sufficient rainfall and suitable soil types, but revegetation practices must be carefully evaluated

  11. A novel high pressure, high temperature vessel used to conduct long-term stability measurements of silicon MEMS pressure transducers

    Science.gov (United States)

    Wisniewiski, David

    2014-03-01

    The need to quantify and to improve long-term stability of pressure transducers is a persistent requirement from the aerospace sector. Specifically, the incorporation of real-time pressure monitoring in aircraft landing gear, as exemplified in Tire Pressure Monitoring Systems (TPMS), has placed greater demand on the pressure transducer for improved performance and increased reliability which is manifested in low lifecycle cost and minimal maintenance downtime through fuel savings and increased life of the tire. Piezoresistive (PR) silicon MEMS pressure transducers are the primary choice as a transduction method for this measurement owing to their ability to be designed for the harsh environment seen in aircraft landing gear. However, these pressure transducers are only as valuable as the long-term stability they possess to ensure reliable, real-time monitoring over tens of years. The "heart" of the pressure transducer is the silicon MEMS element, and it is at this basic level where the long-term stability is established and needs to be quantified. A novel High Pressure, High Temperature (HPHT) vessel has been designed and constructed to facilitate this critical measurement of the silicon MEMS element directly through a process of mechanically "floating" the silicon MEMS element while being subjected to the extreme environments of pressure and temperature, simultaneously. Furthermore, the HPHT vessel is scalable to permit up to fifty specimens to be tested at one time to provide a statistically significant data population on which to draw reasonable conclusions on long-term stability. With the knowledge gained on the silicon MEMS element, higher level assembly to the pressure transducer envelope package can also be quantified as to the build-effects contribution to long-term stability in the same HPHT vessel due to its accommodating size. Accordingly, a HPHT vessel offering multiple levels of configurability and robustness in data measurement is presented, along

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

    International Nuclear Information System (INIS)

    Tcholakova, S.; Denkov, N.; Ivanov, I.; Marinov, R.

    2004-01-01

    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)

  13. Long-term stability of oxidative stress biomarkers in human serum.

    NARCIS (Netherlands)

    Jansen, Eugène H J M; Beekhof, Piet K; Viezeliene, Dale; Muzakova, Vladimira; Skalicky, Jiri

    2017-01-01

    The storage time and storage temperature might affect stability of oxidative stress biomarkers, therefore, they have to be analyzed after long-term storage of serum samples. The stability of three biomarkers reflecting oxidative stress: reactive oxygen metabolites (ROM) for hydroperoxides, total

  14. Evaluation of the Long-Term Stability and Temperature Coefficient of Dew-Point Hygrometers

    Science.gov (United States)

    Benyon, R.; Vicente, T.; Hernández, P.; De Rivas, L.; Conde, F.

    2012-09-01

    The continuous quest for improved specifications of optical dew-point hygrometers has raised customer expectations on the performance of these devices. In the absence of a long calibration history, users with a limited prior experience in the measurement of humidity, place reliance on manufacturer specifications to estimate long-term stability. While this might be reasonable in the case of measurement of electrical quantities, in humidity it can lead to optimistic estimations of uncertainty. This article reports a study of the long-term stability of some hygrometers and the analysis of their performance as monitored through regular calibration. The results of the investigations provide some typical, realistic uncertainties associated with the long-term stability of instruments used in calibration and testing laboratories. Together, these uncertainties can help in establishing initial contributions in uncertainty budgets, as well as in setting the minimum calibration requirements, based on the evaluation of dominant influence quantities.

  15. LONG TERM STABILITY STUDY AT FNAL AND SLAC USING BINP DEVELOPED HYDROSTATIC LEVEL SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Seryi, Andrei

    2003-05-28

    Long term ground stability is essential for achieving the performance goals of the Next Linear Collider. To characterize ground motion on relevant time scales, measurements have been performed at three geologically different locations using a hydrostatic level system developed specifically for these studies. Comparative results from the different sites are presented in this paper.

  16. Limitations and possibilities of green synthesis and long-term stability of colloidal Ag nanoparticles

    Science.gov (United States)

    Velgosová, Oksana; Mražíková, Anna

    2017-12-01

    In this paper the influence of algae life cycle and the solutions pH on the green synthesis of colloidal Ag nanoparticles (AgNPs) as well as effect of different storage conditions on AgNPs long-term stability was investigated. Silver nanoparticles were biologically synthesized using extracts of Parachlorella kessleri algae cultivated 1, 2, 3 and 4 weeks. The formation of AgNPs was monitored using a UV-vis spectrophotometer and verified by TEM observation. The results confirmed formation of polyhedron and/or near polyhedron AgNPs, ranging between 5 and 60 nm in diameter. The age of algae influenced the synthesis rate and an amount of AgNPs in solution. The best results were obtained using tree weeks old algae. UV-vis analysis and TEM observation also revealed that the size and the stability of AgNPs depend on the pH of solution. AgNPs formed in solutions of higher pH (8 and 10) are polyhedron, fine, with narrow size interval and stabile. Nanoparticles formed in solutions of low pH (2, 4 and 6) started to lose their stability on 10th day of experiment, and the particle size interval was wide. The long-term stability of AgNPs can be influenced by light and temperature conditions. The most significant stability loss was observed at day light and room temperature (21°C). After 200-days significant amount of agglomerated particles settled on the bottom of the Erlenmeyer flask. AgNPs stored at dark and room temperature showed better long-term stability, weak particles agglomeration was observed. AgNPs stored at dark and at temperature 5°C showed the best long-term stability. Such AgNPs remained spherical, fine (5-20 nm), with narrow size interval and stable (no agglomeration) even after more than six months.

  17. Endogenous, reactive and neurotic depression -- diagnostic stability and long-term outcome

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel

    2004-01-01

    with a diagnosis of endogenous, reactive or neurotic depression according to ICD-8 were identified in a nationwide register of admissions to psychiatric wards. Patients were followed up to 1999 and the long-term diagnostic stability, the risk of relapse leading to readmission and the risk of suicide was analysed...... with reactive depression had less risk of relapse. No differences were found in the risk of completed suicide between the three groups of patients during long-term follow-up. CONCLUSIONS: The study does not provide evidence for re-establishing prior diagnostic systems of depressive disorders based......BACKGROUND: No larger long-term study has been conducted of outcomes of patients diagnosed with endogenous, reactive or neurotic depression and using survival methods in the analyses. SAMPLING AND METHODS: All patients who had had their first-ever discharge in the period from 1970 to 1994...

  18. 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

  19. Long term stability analysis of cast iron shaft linings after Coal Mine closure and flooding

    International Nuclear Information System (INIS)

    Hadj-Hassen, F.; Bienvenu, Y.; Noirel, J.F.; Metz, M.

    2005-01-01

    This paper presents the results of a study conducted to analyse the long term stability of the cast iron shaft lining after coal mine closure and flooding. The attention is mainly focused on the behaviour during the critical phase of flooding as well as the phase corresponding to the disappearance of the water pressure and the stabilization of the environment. This pluri-disciplinary study was conducted by a team combining specialists in rock mechanics who identified the main risks and the conditions of stability of the lining and specialists in metallurgy who studied the composition of the cast iron and its corrosion behaviour after exposure to mine water. (authors)

  20. Long term stability analysis of cast iron shaft linings after Coal Mine closure and flooding

    Energy Technology Data Exchange (ETDEWEB)

    Hadj-Hassen, F. [Ecole des Mines de Paris - CGES, 77 - Fontainebleau (France); Bienvenu, Y. [Ecole des Mines de Paris, CM, 91 - Evry (France); Noirel, J.F. [Charbonnages de France, DTN, 57 - Freyming Merlebach (France); Metz, M. [charbonnages de France, ESA, 57 - Freyming Merlebach (France)

    2005-07-01

    This paper presents the results of a study conducted to analyse the long term stability of the cast iron shaft lining after coal mine closure and flooding. The attention is mainly focused on the behaviour during the critical phase of flooding as well as the phase corresponding to the disappearance of the water pressure and the stabilization of the environment. This pluri-disciplinary study was conducted by a team combining specialists in rock mechanics who identified the main risks and the conditions of stability of the lining and specialists in metallurgy who studied the composition of the cast iron and its corrosion behaviour after exposure to mine water. (authors)

  1. Development of Technique for Testing the Long-Term Stability of Silicon Microstrip Detectors

    International Nuclear Information System (INIS)

    Kosinov, A.V.; Maslov, N.I.; Naumov, S.V.; Ovchinnik, V.D.; Starodubtsev, A.F.; Vasiliev, G.P.; Yalovenko, V.I.; Bosisio, L.

    2006-01-01

    An automatic multi-channel set-up prototype for simultaneous testing of the Long-Term Stability (LTS) of more than ten detectors is described. The Inner Tracking System of the ALICE experiment will include about two thousand Double-sided Microstrip Detectors (DSMD). Efficient automatic measurement techniques are crucial for the LTS test, because the corresponding test procedure should be performed on each detector and requires long time, at least two days. By using special adapters for supporting and connecting the bare DSMDs, failing detectors can be screened out before module assembly, thus minimizing the cost. Automated probe stations developed for a special purpose or for microelectronics industry are used for measuring physical static DSMD characteristics and check good-to-bad elements ratio for DSMD. However, automated (or semi-automatic)test benches for studying LTS or testing DSMD long-term stability before developing a detecting module are absent

  2. On the long-term stability of calibration standards in different matrices

    International Nuclear Information System (INIS)

    Kandić, A.; Vukanac, I.; Djurašević, M.; Novković, D.; Šešlak, B.; Milošević, Z.

    2012-01-01

    In order to assure Quality Control in accordance with ISO/IEC 17025, it was important, from metrological point of view, to examine the long-term stability of calibration standards previously prepared. Comprehensive reconsideration on efficiency curves with respect to the ageing of calibration standards is presented in this paper. The calibration standards were re-used after a period of 5 years and analysis of the results showed discrepancies in efficiency values. - Highlights: ► Long-term stability of calibration standards (ISO 17025 Quality Control) was analyzed. ► Calibration standards covered the wide range of densities and chemical composition. ► Mineralized grass, powdered milk, surface soil and sand were used as standard matrices. ► Calibration standards were re-evaluated after 5 years. ► Results showed discrepancies of efficiency values.

  3. Long-term stability and properties of zirconia ceramics for heavy duty diesel engine components

    Science.gov (United States)

    Larsen, D. C.; Adams, J. W.

    1985-01-01

    Physical, mechanical, and thermal properties of commercially available transformation-toughened zirconia are measured. Behavior is related to the material microstructure and phase assemblage. The stability of the materials is assessed after long-term exposure appropriate for diesel engine application. Properties measured included flexure strength, elastic modulus, fracture toughness, creep, thermal shock, thermal expansion, internal friction, and thermal diffusivity. Stability is assessed by measuring the residual property after 1000 hr/1000C static exposure. Additionally static fatigue and thermal fatigue testing is performed. Both yttria-stabilized and magnesia-stabilized materials are compared and contrasted. The major limitations of these materials are short term loss of properties with increasing temperature as the metastable tetragonal phase becomes more stable. Fine grain yttria-stabilized material (TZP) is higher strength and has a more stable microstructure with respect to overaging phenomena. The long-term limitation of Y-TZP is excessive creep deformation. Magnesia-stabilized PSZ has relatively poor stability at elevated temperature. Overaging, decomposition, and/or destabilization effects are observed. The major limitation of Mg-PSZ is controlling unwanted phase changes at elevated temperature.

  4. Long-term stability of the Clear-PEM detector modules

    International Nuclear Information System (INIS)

    Amaral, Pedro; Bruyndonckx, Peter; Carrico, Bruno; Ferreira, Miguel; Luyten, Joan; Moura, Rui; Ortigao, Catarina; Rodrigues, Pedro; Silva, Jose C. da; Trindade, Andreia; Varela, Joao

    2007-01-01

    Experimental evaluation of the imaging system Clear-PEM for positron emission mammography, under development within the framework of the crystal clear collaboration at CERN, is presented in terms of its long-term stability. The detector modules and experimental setup are described. Time evolution results of signal yield, energy resolution, depth-of-interaction and inter-channel crosstalk for a reference detector module are reported

  5. On the long-term stability of calibration standards in different matrices.

    Science.gov (United States)

    Kandić, A; Vukanac, I; Djurašević, M; Novković, D; Šešlak, B; Milošević, Z

    2012-09-01

    In order to assure Quality Control in accordance with ISO/IEC 17025, it was important, from metrological point of view, to examine the long-term stability of calibration standards previously prepared. Comprehensive reconsideration on efficiency curves with respect to the ageing of calibration standards is presented in this paper. The calibration standards were re-used after a period of 5 years and analysis of the results showed discrepancies in efficiency values. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. A study about the long-term stability of sedimentary rock

    International Nuclear Information System (INIS)

    Yoshino, Naoto; Miyanomae, Shun-ichi; Inoue, Hiroyuki; Nashimoto, Yutaka

    2005-02-01

    In this paper, following two issues were examined and estimated, (1) the influence of near field condition factor to the dynamical behavior of sedimentary soft rock, (2) the long term estimation of the dynamical behavior considering the condition of Horonobe area. As the study about the influence of near field condition factor to the dynamical behavior of sedimentary soft rock, the thermal factor was focused on and the laboratory tests using test pieces which were sampled in Horonobe area were carried out under the water temperature were 20 degrees and 80 degrees. As a result, the time dependence parameter in variable-compliance-type constitutive-equation could be obtained. And comparison between creep property under 20 degrees and 80 degrees was conducted. In addition, the general properties of sedimentary soft rock under several conditions were identified by the survey of the literature. And the way how to confirm the dynamical properties of sedimentary soft rock with in-situ test were presented. For the study on the short-term and long-term stability of rock surrounding buffer materials, numerical simulations were carried out assuming several conditions. The direction of disposal tunnels and the ratio of rock strength by initial stress were estimated to be the main factor affecting the short-term stability of rock. Time dependency of rock and the stiffness of buffer material were estimated to be the main factor affecting the long-term stability of rock. (author)

  7. Advanced design cultures long-term perspective and continuous innovation

    CERN Document Server

    2015-01-01

    This book describes new thinking and practice in Advanced Design (ADD) – design that is not merely highly developed but anticipates the future by envisioning novel products and processes. The focus is especially on the front end of innovation and the search for solutions in complex pioneering processes using design-related tools and practices. The book opens by describing these tools, the approaches that characterize ADD, and its historical dimension. Specific fields in which ADD has flourished are then examined, exploring the dynamics between research and design. The coverage ranges from transportation, lighting, and electrical appliances through to business networks, technology parks, and the development of ground-breaking materials. AdvanceDesign is the name of the research group at the Politecnico di Milano (Italy’s largest technical university) of which the authors are members. It was chosen to reflect both the “advanced”, tangible dimension of design in terms of modern product development, mater...

  8. Decomposition of heterogeneous organic matterand its long-term stabilization in soils

    Science.gov (United States)

    Sierra, Carlos A.; Harmon, Mark E.; Perakis, Steven S.

    2011-01-01

    Soil organic matter is a complex mixture of material with heterogeneous biological, physical, and chemical properties. Decomposition models represent this heterogeneity either as a set of discrete pools with different residence times or as a continuum of qualities. It is unclear though, whether these two different approaches yield comparable predictions of organic matter dynamics. Here, we compare predictions from these two different approaches and propose an intermediate approach to study organic matter decomposition based on concepts from continuous models implemented numerically. We found that the disagreement between discrete and continuous approaches can be considerable depending on the degree of nonlinearity of the model and simulation time. The two approaches can diverge substantially for predicting long-term processes in soils. Based on our alternative approach, which is a modification of the continuous quality theory, we explored the temporal patterns that emerge by treating substrate heterogeneity explicitly. The analysis suggests that the pattern of carbon mineralization over time is highly dependent on the degree and form of nonlinearity in the model, mostly expressed as differences in microbial growth and efficiency for different substrates. Moreover, short-term stabilization and destabilization mechanisms operating simultaneously result in long-term accumulation of carbon characterized by low decomposition rates, independent of the characteristics of the incoming litter. We show that representation of heterogeneity in the decomposition process can lead to substantial improvements in our understanding of carbon mineralization and its long-term stability in soils.

  9. Optimization of scintillator loading with the tellurium-130 isotope for long-term stability

    Science.gov (United States)

    Duhamel, Lauren; Song, Xiaoya; Goutnik, Michael; Kaptanoglu, Tanner; Klein, Joshua; SNO+ Collaboration

    2017-09-01

    Tellurium-130 was selected as the isotope for the SNO + neutrinoless double beta decay search, as 130Te decays to 130Xe via double beta decay. Linear alkyl benzene(LAB) is the liquid scintillator for the SNO + experiment. To load tellurium into scintillator, it is combined with 1,2-butanediol to form an organometallic complex, commonly called tellurium butanediol (TeBD). This study focuses on maximizing the percentage of tellurium loaded into scintillator and evaluates the complex's long-term stability. Studies on the effect of nucleation due to imperfections in the detector's surface and external particulates were employed by filtration and induced nucleation. The impact of water on the stability of TeBD complex was evaluated by liquid-nitrogen sparging, variability in pH and induced humidity. Alternative loading methods were evaluated, including the addition of stability-inducing organic compounds. Samples of tellurium-loaded scintillator were synthesized, treated, and consistently monitored in a controlled environment. It was found that the hydronium ions cause precipitation in the loaded scintillator, demonstrating that water has a detrimental effect on long-term stability. Optimization of loaded scintillator stability can contribute to the SNO + double beta decay search.

  10. Investigation of the long term stability and corrosion resistance of engineering barriers

    International Nuclear Information System (INIS)

    Aoyama, Eri; Tachikawa, Hirokazu; Shimizu, Akihiko

    2005-03-01

    The Japan Nuclear Cycle Development Institute submitted 'Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan' to the Japanese government. This report contains investigations of the long term behavior of alteration of bentonite, and of the corrosion life time of overpack on the basis of experimental data and past research, assuming the ranging geological environment of Japan. However some subjects, such as the behavior of the bentonite and overpack under high pH conditions and the behavior of the engineering barrier with change of near-field environmental condition with time for promoting reliability have still been left. To take into account these conditions, expert committees composed of clay science and metal corrosion science experts were established in the Nuclear Safety Research Association and past research outcomes and the theory of safety assessment were investigated from the view points of long term stability and corrosion resistance of engineering barrier. (author)

  11. Investigation and technical reviews of the long term stability and corrosion resistance of engineering barriers

    International Nuclear Information System (INIS)

    Tachikawa, Hirokazu

    2004-03-01

    The Japan Nuclear Fuel Cycle Development Institute submitted 'Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan' to the Japanese government. This report contains investigations of the long term behavior of alteration of bentonite, and of the corrosion life time of overpack on the basis of experimental data and past research, assuming the ranging geological environment of Japan. However some subjects, such as the behavior of the bentonite and overpack under high pH conditions and the behavior of the engineering barrier with change of near-field environmental condition with time for promoting reliability have still been left. To take into account these conditions, expert committees composed of clay science and metal corrosion science experts were established in the Nuclear Safety Research Association and past research outcomes and the theory of safety assessment were investigated and technically reviewed from the view points of long term stability and corrosion resistance of engineering buffer materials. (author)

  12. Study plan for research on long-term stability of geological environments in FY2009

    International Nuclear Information System (INIS)

    Yasue, Ken-ichi; Hanamuro, Takahiro; Kokubu, Yoko; Ishimaru, Tsuneari; Umeda, Koji

    2009-09-01

    The Japanese islands lie in a region of the Circum-Pacific orogenic belt characterized by active tectonics such as volcanism and earthquakes. The concept of geological disposal of HLW in Japan is based on a multi-barrier system which consists of the engineered barrier in the stable geological environments and the natural barrier. The natural phenomena which potentially affect the geological environments in tectonically active Japan are volcanism, faulting, uplift, denudation, climatic change, and sea-level change. Investigation technologies to evaluate their long-term stability of the geological environments have been developed. In fiscal year 2009, we continue researches to develop technologies for detecting latent geotectonic events in preliminary investigation. With regard to modelling technology, we plan to develop prediction models for evaluating the changes of geological environment (e.g., thermal, hydraulic, mechanical, and geochemical conditions) for long term. In addition to these, the development of dating techniques prerequisite for these studies is also carried out. (author)

  13. Designing remote monitoring systems for long term maintenance and reliability

    International Nuclear Information System (INIS)

    Davis, G.E.; Johnson, G.L.; Schrader, F.D.; Stone, M.A.; Wilson, E.F.

    2001-01-01

    Full text: As part of the effort to modernize safeguards equipment, the IAEA is continuing to acquire and install equipment for upgrading obsolete surveillance systems with digital technology; and providing remote-monitoring capabilities where and when economically justified. Remote monitoring is expected to reduce inspection effort, particularly at storage facilities and reactor sites. Remote monitoring technology will not only involve surveillance, but will also include seals, sensors, and other unattended measurement equipment. LLNL's experience with the Argus Security System offers lessons for the design, deployment, and maintenance of remote monitoring systems. Argus is an integrated security system for protection of high-consequence U.S. Government assets, including nuclear materials. Argus provides secure transmission of sensor data, administrative data, and video information to support intrusion detection and access control functions. LLNL developed and deployed the Argus system on its own site in 1988. Since that time LLNL has installed, maintained, and upgraded Argus systems at several Department of Energy and Department of Defense sites in the US as well as at the original LLNL site. Argus has provided high levels of reliability and integrity, as well as reducing overall lifecycle cost through incremental improvements to hardware and software. This philosophy permits expansion of functional capability, hardware upgrade and software upgrade without system outages and with minimum outage of local functions. This presentation will describe Argus design strategies and lessons learned from the Argus program as they apply to the design, development, and maintenance of a remote monitoring network. Hardware failures, software failures, and communication outages are expected and must be addressed by astute selection of system architecture. A combination of redundancy, diversity, and effective functional allocation between field and system level components should

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

    Directory of Open Access Journals (Sweden)

    Long Zhang

    2016-06-01

    Full Text Available 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 according 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.

  15. Robotic Observatory System Design-Specification Considerations for Achieving Long-Term Sustainable Precision Performance

    Science.gov (United States)

    Wray, J. D.

    2003-05-01

    The robotic observatory telescope must point precisely on the target object, and then track autonomously to a fraction of the FWHM of the system PSF for durations of ten to twenty minutes or more. It must retain this precision while continuing to function at rates approaching thousands of observations per night for all its years of useful life. These stringent requirements raise new challenges unique to robotic telescope systems design. Critical design considerations are driven by the applicability of the above requirements to all systems of the robotic observatory, including telescope and instrument systems, telescope-dome enclosure systems, combined electrical and electronics systems, environmental (e.g. seeing) control systems and integrated computer control software systems. Traditional telescope design considerations include the effects of differential thermal strain, elastic flexure, plastic flexure and slack or backlash with respect to focal stability, optical alignment and angular pointing and tracking precision. Robotic observatory design must holistically encapsulate these traditional considerations within the overall objective of maximized long-term sustainable precision performance. This overall objective is accomplished through combining appropriate mechanical and dynamical system characteristics with a full-time real-time telescope mount model feedback computer control system. Important design considerations include: identifying and reducing quasi-zero-backlash; increasing size to increase precision; directly encoding axis shaft rotation; pointing and tracking operation via real-time feedback between precision mount model and axis mounted encoders; use of monolithic construction whenever appropriate for sustainable mechanical integrity; accelerating dome motion to eliminate repetitive shock; ducting internal telescope air to outside dome; and the principal design criteria: maximizing elastic repeatability while minimizing slack, plastic deformation

  16. The nekhoroshev theorem and long-term stabilities in the solar system

    Directory of Open Access Journals (Sweden)

    Guzzo M.

    2015-01-01

    Full Text Available The Nekhoroshev theorem has been often indicated in the last decades as the reference theorem for explaining the dynamics of several systems which are stable in the long-term. The Solar System dynamics provides a wide range of possible and useful applications. In fact, despite the complicated models which are used to numerically integrate realistic Solar System dynamics as accurately as possible, when the integrated solutions are chaotic the reliability of the numerical integrations is limited, and a theoretical long-term stability analysis is required. After the first formulation of Nekhoroshev’s theorem in 1977, many theoretical improvements have been achieved. On the one hand, alternative proofs of the theorem itself led to consistent improvements of the stability estimates; on the other hand, the extensions which were necessary to apply the theorem to the systems of interest for Solar System Dynamics, in particular concerning the removal of degeneracies and the implementation of computer assisted proofs, have been developed. In this review paper we discuss some of the motivations and the results which have made Nekhoroshev’s theorem a reference stability result for many applications in the Solar System dynamics.

  17. Long Term Evaluation of Yield Stability Trend for Cereal Crops in Iran

    Directory of Open Access Journals (Sweden)

    mehdi nassiri mahalati

    2016-05-01

    Full Text Available During the last few decades cereals yield have increased drastically at the national level however, information about yield stability and its resistance to annual environmental variability are scare. In this study long term stability of grin yield of wheat, barley, rice, corn and overall cereals in Iran were evaluated during a 40-year period (1971-2011. Stability analysis was conducted using two different methods. In the first method the residuals of regression between crop yield and time (years were calculated as stability index. For this different segmented regression models including linear, bi-linear and tri-linear were fitted to yield trend data and the best model for each crop was selected based on statistical measures. Absolute residuals (the difference between actual and predicted yields for each year as well as relative residuals (absolute residuals as percent of predicted yield were estimated. In the second method yield stability was estimated from the slope of the regression line between average annual yield of all cereals (environmental index and the yield of each crop in the same year. Results indicted that in wheat and barley absolute and relative residuals were increased during the study period leading to reduction of stability despite considerable yield increment. However, for rice and corn residuals followed a decreasing trend and therefore yield stability of these crops was increased during the last 40 years. The same result was obtained with the environmental index but in this method reduction of yield stability in barley was lower than wheat. Based on the results, yield and yield stability of cereals crops in Iran increased during the last 40 years. However, the percentage increase in stability is lower than that of yield. Application of nitrogen fertilizers was led to reduction in stability. Yield stability of wheat, barley, rice, corn and overall cereals was improved with increasing their cultivated area.

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

    International Nuclear Information System (INIS)

    Arthur, Randy; Apted, Mick; Stenhouse, Mike

    2005-03-01

    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

  19. [Study on mechanism of SOM stabilization of paddy soils under long-term fertilizations].

    Science.gov (United States)

    Luo, Lu; Zhou, Ping; Tong, Cheng-Li; Shi, Hui; Wu, Jin-Shui; Huang, Tie-Ping

    2013-02-01

    Fourier transform infrared spectroscopy (FTIR) was applied to study the structure of soil organic matter (SOM) of paddy soils under long-term different fertilization treatments. The aim was to clarify the different distribution of SOM between different fertilization methods and between topsoil and subsoil, and to explore the stability mechanism of SOM under different fertilization treatments. The results showed that the content of topsoil organic carbon (SOC) was the highest under organic-inorganic fertilizations, with the increment of SOC by 18.5%, 12.9% and 18.4% under high organic manure (HOM), low organic manure (LOM) and straw returning (STW) respectively compared with no fertilization treatment (CK). The long-term fertilizations also changed the chemical structure of SOM. As compared with CK, different fertilization treatments increased the functional group absorbing intensity of chemical resistance compounds (aliphatic, aromaticity), carbohydrate and organo-silicon compounds, which was the most distinctive under treatments of HOM, LOM and STW. For example, the absorbing intensity of alkyl was 0.30, 0.25 and 0.29 under HOM, LOM and STW, respectively. These values were increased by 87% , 56% and 81% as compared with that under CK treatment. The functional group absorbing intensity of SOM in the topsoil was stronger than that in the subsoil, with the most distinctive difference under HOM, LOM and STW treatments. The present research indicated that the enhanced chemical resistance of functional group of SOM may contribute to the high contents of SOC in the paddy soils under long-term organic-inorganic fertilizations, which also suggested a chemical stabilization mechanism of SOM in the paddy soils.

  20. Interplay between black carbon and minerals contributes to long term carbon stabilization and mineral transformation

    Science.gov (United States)

    Liang, B.; Weng, Y. T.; Wang, C. C.; Chiang, C. C.; Liu, C. C.; Lehmann, J.

    2017-12-01

    Black carbon receives increasing global wide research attention due to its role in carbon sequestration, soil fertility enhancement and remediation application. Generally considered chemically stable in bulk, the reactive surface of BC can interplays with minerals and form strong chemical bondage, which renders physical protection of BC and contributes to its long term stabilization. Using historical BC-rich Amazonian Dark Earth (ADE), we probe the in-situ organo-mineral association and transformation of BC and minerals over a millennium scale using various synchrotron-based spectroscopic (XANES, FTIR) and microscopic (TXM) methods. Higher content of SRO minerals was found in BC-rich ADE compare to adjacent tropical soils. The iron signature found in BC-rich ADE was mainly ferrihydrite/lepidocrocite, a more reactive form of Fe compared to goethite, which was dominant in adjacent soil. Abundant nano minerals particles were observed in-situ associated with BC surface, in clusters and layers. The organo-mineral interaction lowers BC bioavailability and enhances its long-term stabilization in environment, while at the same time, transforms associated minerals into more reactive forms under rapid redox/weathering environment. The results suggest that mineral physical protection for BC sequestration may be more important than previous understanding. The scale up application of BC/biochar into agricultural systems and natural environments have long lasting impact on the in-situ transformation of associated minerals.

  1. Long-term performance of aged waste forms treated by stabilization/solidification.

    Science.gov (United States)

    Antemir, Aurora; Hills, Colin D; Carey, Paula J; Gardner, Kevin H; Bates, Edward R; Crumbie, Alison K

    2010-09-15

    Current regulatory testing of stabilized/solidified (S/S) soils is based on short-term performance tests and is insufficient to determine their long-term stability or expected service life. In view of this, and the significant lack of data on long-term field performance in the literature, S/S material has been extracted from full-scale remedial operations and examined using a variety of analytical techniques to evaluate field performance. The results, including those from X-ray analytical techniques, optical and electron microscopy and leaching tests are presented and discussed. The microstructure of retrieved samples was found to be analogous to other cement-based materials, but varied according to the soil type, the contaminants present, the treatment applied and the field exposure conditions. Summary of the key microstructural features in the USA and UK is presented in this work. The work has shown that during 16 years of service the S/S wastes investigated performed satisfactorily. Copyright 2010 Elsevier B.V. All rights reserved.

  2. Long-term performance of aged waste forms treated by stabilization/solidification

    International Nuclear Information System (INIS)

    Antemir, Aurora; Hills, Colin D.; Carey, Paula J.; Gardner, Kevin H.; Bates, Edward R.; Crumbie, Alison K.

    2010-01-01

    Current regulatory testing of stabilized/solidified (S/S) soils is based on short-term performance tests and is insufficient to determine their long-term stability or expected service life. In view of this, and the significant lack of data on long-term field performance in the literature, S/S material has been extracted from full-scale remedial operations and examined using a variety of analytical techniques to evaluate field performance. The results, including those from X-ray analytical techniques, optical and electron microscopy and leaching tests are presented and discussed. The microstructure of retrieved samples was found to be analogous to other cement-based materials, but varied according to the soil type, the contaminants present, the treatment applied and the field exposure conditions. Summary of the key microstructural features in the USA and UK is presented in this work. The work has shown that during 16 years of service the S/S wastes investigated performed satisfactorily.

  3. The long-term hydrological effect of forest stands on the stability of slopes

    Science.gov (United States)

    Bogaard, T. A.; Meng, W.; van Beek, L. P. H.

    2012-04-01

    Forest is widely known to improve slope stability as a result of mechanical and hydrological effects. While the mechanics underlying the stabilizing process of root reinforcement are well understood and quantified, the influence of forest on the occurrence of critical hydrological conditions in terms of suction or pore pressure remains uncertain. Due to seasonal and inter-annual fluctuations, the stabilizing influence of evaporation and transpiration is difficult to isolate from the overall noise of the hydrological signal. More long-term effects of forest stands on soil development are highly variable and thus difficult to observe and quantify. Often these effects are ambivalent, having potentially a stabilizing or destabilizing influence on a slope under particular conditions (e.g., more structured soils leading to both rapid infiltration and drainage). Consequently, it can be postulated that forests will hydrologically influence the magnitude-frequency distribution of landsliding, not only at the stand level but also on a regional scale through the groundwater system. The overall aim of this research is to understand and quantify the stabilizing hydrological effect of forests on potentially unstable slopes. To this end, we focus on the changes in the magnitude-frequency distribution of landsliding that arise as a result of variations in evapotranspiration losses over the life cycle of stands. Temporal variations in evapotranspiration comprise first of all the interception that can account for an important amount of evaporation from a forest, and that changes with seasonal and annual variations in the interception capacity of the canopy and forest floor. Transpiration also represents an important loss that varies over the various growth stages of a forest stand. Based on a literature review of water consumption by tree species and water balance studies of forested catchments we defined the potential transpiration for different growth stages. This information we

  4. Public long-term care insurance for the elderly in Korea: design, characteristics, and tasks.

    Science.gov (United States)

    Seok, Jae Eun

    2010-03-01

    This paper examines the design and issues of the long-term care scheme in Korea: coverage, eligibility, benefit types, financing, delivery system, and role sharing of state, family, and market in long-term care. It also aims to examine the radical change and impacts on service financing, provision, and governance from the introduction of the long-term care insurance for the elderly in Korea. The first noteworthy change is that the long-term care service has transformed from the very selective service applicable only to low-income groups to a universal service for all income groups. The second notable change is that the service provision method has been changed from the provision by nonprofit organizations entrusted by the state under a monopolistic commission arrangement in the past to a new open-service provision arrangement in which free competition among service providers in service market and consumers' choice will be emphasized.

  5. Long-term microwaving of denture base materials: effects on dimensional, color and translucency stability

    Directory of Open Access Journals (Sweden)

    Nick POLYCHRONAKIS

    2018-06-01

    Full Text Available Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Material and Methods Thirty two specimens (32 mm x 10 mm x 2.5 mm from polyamide (Valplast and PMMA (Vertex Rapid Simplified denture base materials were made. Eight specimens from each material were immersed in distilled water (control and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE* and translucency parameter (TP were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%. Results Data analysis showed significant changes in length at baseline with an increasing number of cycles (p0.05. TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001. Conclusions The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.

  6. THE IMPACT OF THE FOREIGN CAPITAL BANKS ON ENSURING FINANCIAL STABILITY ON LONG TERM

    Directory of Open Access Journals (Sweden)

    Isac\tBORS

    2015-06-01

    Full Text Available The present study is focusing on analysing the role played by the foreign banks within the national and international banking system as well the impact the foreign banks have on the autochthon banking system, on the financial activity, on the real economy and on the financial stability on long terms. The research conducted highlights the fact that along the positive impact on the banking system and on the economy of the host country, generated by their quality as vectors of mobilizing and directioning the international financial flows towards the host country, there can also be considered a negative impact. The study shows that the impact of the negative effects, that have as main cause the reversibility of the international financial flows, depends, on a great extent, on the specific conditions of the host country, on the characteristics of the foreign banks, but mostly, by the share held by the foreign countries within the framework of the host banking system. Starting from the role played by the capitalization of the banking system to ensure financial stability, the research made on Romania’s case shows both, the positive effects generated by the presence of the foreign banks and also, their vulnerability in front of this excessive dependence on the foreign capital induced by this presence. The solution to reduce this dependence can only come from the autochthon capital direction whose mobilization may countervail the gap made by the foreign banks and, by surceasing the process of financial disintermediation, to ensure the maintenance of the financial stability on long term.

  7. Film Grain-Size Related Long-Term Stability of Inverted Perovskite Solar Cells.

    Science.gov (United States)

    Chiang, Chien-Hung; Wu, Chun-Guey

    2016-09-22

    The power conversion efficiency (PCE) of the perovskite solar cell is high enough to be commercially viable. The next important issue is the stability of the device. This article discusses the effect of the perovskite grain-size on the long-term stability of inverted perovskite solar cells. Perovskite films composed of various sizes of grains were prepared by controlling the solvent annealing time. The grain-size related stability of the inverted cells was investigated both in ambient atmosphere at relative humidity of approximately 30-40 % and in a nitrogen filled glove box (H 2 Operovskite film having the grain size larger than 1 μm (D-10) decreases less than 10 % with storage in a glove box and less than 15 % when it was stored under an ambient atmosphere for 30 days. However, the cell using the perovskite film composed of small (∼100 nm) perovskite grains (D-0) exhibits complete loss of PCE after storage under the ambient atmosphere for only 15 days and a PCE loss of up to 70 % with storage in the glove box for 30 days. These results suggest that, even under H 2 O-free conditions, the chemical- and thermal-induced production of pin holes at the grain boundaries of the perovskite film could be the reason for long-term instability of inverted perovskite solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Characterization of long-term dose stability of N-isopropylacrylamide polymer gel dosimetry

    International Nuclear Information System (INIS)

    Chang, Y.J.; Central Taiwan University of Science and Technology, Taichung City, Taiwan, ROC; Chen, C.H.; Hsieh, B.T.

    2014-01-01

    In this study, the detailed characteristics, including spatial uniformity, dose distributions, inter-batch variability, reproducibility, and long-term temporal stability, of N-isopropylacrylamide (NIPAM) polymer gel dosimeter were investigated. A commercial 10x fast optical computed tomography scanner (OCTOPUS TM -10×, MGS Research, Inc., Madison, CT, USA) was used to measure NIPAM polymer gel dosimeter. A cylindrical NIPAM gel phantom that measured 10 cm × 10 cm was irradiated via a single-field treatment plan with a field size of 4 cm × 4 cm. The maximum standard deviation of spatial uniformity for NIPAM gel was less than 0.29 %. The average standard deviation among the three batches of gel dosimeters was less than 1 %. The gamma pass rate could reach as high as 96.76 % when a 3 % dose difference and a 3 mm dose-to-agreement criteria were used. The long-term measurement of irradiated NIPAM gel dosimeter indicated that the dose maps attained a gradually stable value 15 h post-irradiation and remained stable until 72 h post-irradiation. The gamma pass rate could achieve a maximum value between 24 and 72 h post-irradiation. The edge enhancement effect that occurred around the irradiated region was observed 72 h post-irradiation. Thus, the results from this study suggest that NIPAM gel dosimeter should be measured approximately 24 h post-irradiation to reduce the occurrence of the edge enhancement effect. (author)

  9. Conceptual designs for a long term 238PuO2 storage vessel

    International Nuclear Information System (INIS)

    Kwon, D.M.; Replogle, W.C.

    1996-08-01

    This is a report on conceptual designs for a long term, 250 years, storage container for plutonium oxide ([sup 238]PuO[sub 2]). These conceptual designs are based on the use of a quartz filter to release the helium generated during the plutonium decay. In this report a review of filter material selection, design concepts, thermal modeling, and filter performance are discussed

  10. The National Long Term Care Demonstration: operational issues encountered in developing the research design.

    Science.gov (United States)

    Carcagno, G J; Kemper, P

    1983-01-01

    This paper describes the design of the National Long Term Care Demonstration and its evaluation and discusses a number of operational issues encountered in the design process: simultaneous design of research and operations, identification of the target population, randomization, collection of comparable data, development of an assessment instrument, potential changes in existing programs, and termination planning.

  11. Using DCM pitch modulation and feedback to improve long term X-ray beam stability

    International Nuclear Information System (INIS)

    Bloomer, C; Dent, A; Diaz-Moreno, S; Dolbnya, I; Pedersen, U; Rehm, G; Tang, C; Thomas, C

    2013-01-01

    In this paper we demonstrate significant improvements to the stability of the monochromatic X-ray beam intensity on several beamlines at Diamond, using a modulation of the pitch axis of the DCM with a piezoelectric actuator. The modulation is detected on an intensity diagnostic (e.g. an ion chamber) using a software lock-in technique. The detected amplitude and phase are used in a feedback to keep the DCM at the peak of the rocking curve, or any arbitrary position 'off-peak' which might be desired to detune the DCM and reject unwanted harmonics. A major advantage of this software based system is the great flexibility offered, using standard, readily available instrumentation. Measurements of the short and long-term performance of the feedback on several beamlines are presented, and the limitations of such a feedback are discussed.

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

    International Nuclear Information System (INIS)

    Umeda, Koji; Nohara, Tsuyoshi; Fujiwara, Osamu; Asamori, Koichi; Kinoshita, Hirohisa; Nakatuka, Noboru

    2004-09-01

    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.)

  13. Analysis to long-term stability of solar cables; Untersuchungen zur Langzeitstabilitaet von Solarleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Funtan, P.

    2005-07-01

    For the moment it is not possible to say anything about the long-term stability of solar cables. Own experiences shows, that the rubber solar cable H07 RN-F (of one manufacturer) is not qualified for installations, longer than 10 years. The outer isolation of the cable first shows embrittlements and later deep cracks. Microscopically analysis confirms this. Measurements of temperature in typical installation areas of solar cables also shows, that the influence of temperature, regarding aging plays not the most important role, when the cable is installed in a sun protected position. Up to now the reason of the cable destruction is not definitely clarified. Chemically analysis of a damaged and an intact part of the cable, which was installed inside of a module junction box (reduced humility), shows no differences in the chemical consistence. It seems, that it is a combinated effect of temperature and humidity. Further analysis will be performed. (orig.)

  14. Evaluation of long-term stability of low thermal expansion coefficient materials using gauge block interferometers

    Science.gov (United States)

    Hirai, Akiko; Bitou, Youichi; Oike, Yoshiyuki

    2018-06-01

    The long-term stability of NEXCERA™ ceramics having a low coefficient of thermal expansion was evaluated over a period of eight years. Several gauge blocks of differing lengths were prepared, using two types of NEXCERA. Each gauge block was kept wrung to a platen and its absolute length was periodically measured by gauge block interferometer during the eight years. Relative uncertainties of measurement of changes in gauge block length were estimated as 4.1  ×  10‑8 and 2.9  ×  10‑8 for 200 mm and 800 mm gauge blocks, respectively. The experimental results show the trend of expansion and a relative change of less than 0.1  ×  10‑6/year for every gauge block.

  15. Long-term monitoring of stream bank stability under different vegetation cover

    Science.gov (United States)

    Krzeminska, Dominika; Skaalsveen, Kamilla; Kerkhof, Tjibbe

    2017-04-01

    Vegetated buffer zones are common environmental measures in many countries, including Norway. The presence of riparian vegetation on stream banks not only provides ecological benefits but also influence bank slope stability, through several complex interactions between riparian vegetation and hydro - mechanical processes. The hydrological processes associated with slope stability are complex and yet difficult to quantify, especially because their transient effects (e.g. changes throughout the vegetation life cycle). Additionally, there is very limited amount of field scale research focusing on investigation of coupled hydrological and mechanical influence of vegetation on stream bank behavior, accounting for both seasonal time scale and different vegetation type, and none dedicated to marine clay soils (typically soil for Norway). In order to fill this gap we established continues, long term hydrogeological monitoring o selected cross - section within stream bank, covered with different types of vegetation, typical for Norwegian agriculture areas (grass, shrubs, and trees). The monitoring involves methods such as spatial and temporal monitoring of soil moisture conditions, ground water level and fluctuation of water level in the stream. Herein we will present first 10 months of monitoring data: observed hydrological trends and differences between three cross - sections. Moreover, we will present first modelling exercises that aims to estimate stream banks stability with accounting on presence of different vegetation types using BSTEM and HYDRUS models. With this presentation, we would like to stimulate the discussion and get feedback that could help us to improve both, our experimental set up and analysis approach.

  16. Long Term Behaviour of 14C and Stability Assessments of Graphite Under Repository Conditions

    International Nuclear Information System (INIS)

    Jones, Abbie N.; McDermott, Lorraine; Worth, Robert; Hagos, Bereket; Black, Greg; Marsden, Barry J

    2016-01-01

    The key objectives of the University of Manchester’s nuclear graphite research within the CRP are to provide analysis on the long term behaviour and stability assessments of irradiated graphite waste. The research will concentrate on isotopic 14 C mobility under repository environments. This also requires an understanding the long-term behaviour of the final waste form under repository conditions. Procedures to evaluate the long term leaching properties of radionuclides from irradiated graphite waste has been developed by combining ANSI 16.1 (USA) and NEN 7345 (Netherlands) standardised diffusion leaching techniques. The ANSI 16.1 standard has been followed to acquire the leachates and to determine the leach rate and diffusion coefficient. The NEN 7345 standard technique has been used to determine the diffusion mechanism of radionuclides. The investigation employs simulated Drigg groundwater as a leachant using semi-dynamic technique for the production of leachate specimens. Analysis of 3 H and 14 C activity release from Magnox graphite was measured using liquid scintillating counting. Preliminary results show that there is an initial high release of activity and decreases when the leaching period increases. This may be due to the depletion of contaminants that were initially bound by the internal pore networks and the free surface. During the leaching test approximately 275.33 ± 18.20 Bq of 3 H and 106.26 ± 7.01 Bq of 14 C was released into the leachant within 91 days. The work reported herein contributed several key findings to the international work on graphite leaching to offer guidance leading toward obtaining leaching data in the future: (a) the effective diffusion coefficient for 14 C from graphite waste has been determined. The diffusion process for 14 C has two stages resulting two different values of diffusion coefficient, i.e., for the fast and slow components; (b) the controlling leaching mechanism for 3 H radionuclide from graphite is shown to be

  17. A study to assess the long-term stability of the ionization chamber reference system in the LNMRI

    Science.gov (United States)

    Trindade Filho, O. L.; Conceição, D. A.; da Silva, C. J.; Delgado, J. U.; de Oliveira, A. E.; Iwahara, A.; Tauhata, L.

    2018-03-01

    Ionization chambers are used as secondary standard in order to maintain the calibration factors of radionuclides in the activity measurements in metrology laboratories. Used as radionuclide calibrator in nuclear medicine clinics to control dose in patients, its long-term performance is not evaluated systematically. A methodology for long-term evaluation for its stability is monitored and checked. Historical data produced monthly of 2012 until 2017, by an ionization chamber, electrometer and 226Ra, were analyzed via control chart, aiming to follow the long-term performance. Monitoring systematic errors were consistent within the limits of control, demonstrating the quality of measurements in compliance with ISO17025.

  18. A study to assess the long-term stability of the ionization chamber reference system in the LNMRI

    Energy Technology Data Exchange (ETDEWEB)

    Filho, Octavio L.T.; Conceição, Dayana A. da; Silva, Carlos J. da; Delgado, José U.; Oliveira, Antônio E. de; Iwahara, Akira; Tauhata, Luiz, E-mail: octavio@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Ionization chambers are used as secondary standard in order to maintain the calibration factors of radionuclides in the activity measurements in metrology laboratories. Used as radionuclide calibrator in nuclear medicine clinics to control dose in patients, its long-term performance is not evaluated systematically. A methodology for long-term evaluation for its stability is monitored and checked. Historical data were analyzed via control chart, produced between 2012-2017 by an ionization chamber, electrometer and {sup 226}Ra, aiming to follow the long-term performance. The results for monitoring systematic errors were consistent within the limits of control, demonstrating the quality of measurements in compliance with ISO17025. (author)

  19. Study on long-term stability of geochemical environments at deep underground

    International Nuclear Information System (INIS)

    Mizuno, Takashi; Iwatsuki, Teruki

    2005-01-01

    Observation and fluid inclusion analysis of fracture filling calcites in granite at the Tono area were conducted to assess long-term stability of geochemical environment at deep underground. The result of observation using SEM and luminoscope shows that precipitation processes of calcite can be divided into four phases (1 to 4) based on their occurrence. (1) Phase 1: indistinct morphology and includes the wall rock fragments. (2) Phase 2: rhombohedral and hexagonal form. (3) Phase 3: elongate rhombohedral form, growth over the layer of phase 2 calcite. (4) Phase 4: small rhombohedral form crystals growth from surface of phase 3 calcite. On Phase 1 calcite, it seems to be hydrothermal origin related to fracture activation. Previous study shows the correlation between the salinity of fluid from which calcite precipitated and morphology of calcite. According to previous studies, the groundwater from which phase 3 calcite precipitated would be the highest salinity such as seawater. Phase 2 and 4 calcite may be precipitated from groundwater with low salinity. On the other hand, fluid inclusions were recognized in phase 2 and 3 calcite. All inclusions indicated mono-phase (liquid phase). These suggest that phase 2 and 3 calcites were precipitated in low-temperature condition. Result of salinity analysis indicates that two groundwaters having different chemical properties had existed during phase 2 and 3 calcite precipitation. Based on these results, geochemical environment had changed by input of high salinity groundwater during Phase 2 and 3 calcite precipitation. It is required to identify the origin of each groundwater in consideration of historical geology for further understanding of long-term hydrochemical condition. (author)

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

    International Nuclear Information System (INIS)

    Orlhac, X.

    2000-01-01

    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 4 , CeCO 2 , ZnCr 2 O 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 2 SiO 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)

  1. Nuclear energy - Standard method for testing the long-term alpha irradiation stability of matrices for solidification of high-level radioactive waste. 2. ed.

    International Nuclear Information System (INIS)

    2004-01-01

    This International Standard specifies a method designed to check the long-term stability of a solid to alpha disintegration by detection of all modifications in the properties of an irradiated sample. The material favoured hitherto is a borosilicate glass, but possible alternatives include: ceramics or glass-ceramics, and other glass compositions

  2. A Cohort Study on Long-Term Adverse Effects of Parental Drinking: Background and Study Design

    Directory of Open Access Journals (Sweden)

    Ingunn Olea Lund

    2015-01-01

    Full Text Available Although many studies have addressed adverse outcomes in children of parents with alcohol abuse/dependence, less is known about the possible long-term effects of more normative patterns of parental alcohol consumption, including drinking at lower risk levels and heavy episodic or binge drinking. The extent of harm from parental drinking may therefore be underestimated. With this research proposal, we describe a project that aims to assess possible long-term adverse effects of parental drinking by combining survey and nationwide registry data. Advantages of a longitudinal general population cohort design include that it allows for detailed information on parental drinking through survey data and identification of possible negative long-term health and social outcomes from exposure to parental drinking 1–19 years after exposure through continuously updated nationwide registers. The rich information available from combining survey and registry data allows us to take into account important confounders, mediators, and moderators.

  3. 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.

  4. Long-term skeletal stability after maxillary advancement with distraction osteogenesis in nongrowing patients.

    Science.gov (United States)

    Kanno, Takahiro; Mitsugi, Masaharu; Hosoe, Michi; Sukegawa, Shintaro; Yamauchi, Kensuke; Furuki, Yoshihiko

    2008-09-01

    We assessed the long-term skeletal stability of the repositioned maxilla, midface in patients who underwent maxillary advancement using distraction osteogenesis (DO). The study included 19 nongrowing patients with maxillary hypoplasia with a Class III relationship, a normally developed mandible, and follow-up after DO exceeding 2 years. Eleven men and 8 women participated, with a mean age at treatment of 20.7 years (range 15.4-33.4 years). Twelve patients had midfacial hypoplasia associated with a cleft lip and palate (CLP), and 7 patients had developed noncleft-related hypoplasia. The surgical treatment included our modified Le Fort I osteotomy in combination with intraoral (5 cases) or extraoral (14 cases) distraction devices. Distraction was started after a latency period of 5 to 7 days and continued until the proper convexity was obtained. After active distraction, a 3- to 4-week period of retention was allowed, followed by rigid internal fixation (IF) with or without distractor removal. Lateral cephalometric films before midfacial distraction (T0), after IF with or without distractor removal (T1), 6 months after T1 (T2), and 2 or more years (mean 2.8 years) after T1 (T3) were analyzed. The maxillary A-point in the Frankfort horizontal reference plane was used to assess the skeletal changes in the maxillary position (x, y) at each time point (T1-T3). In addition, we analyzed the differences in the devices and techniques. Midfacial DO was successful in all cases, resulting in a mean change obtained at point A of 10.3 mm (8.4 mm horizontally, 4.7 mm inferiorly). Point A underwent a moderate amount of skeletal relapse at T2 [0.4 mm (5%) horizontally and 0.6 mm (13%) superiorly], with a mean of 8% (0.6 mm) horizontally and 19% (1.0 mm) superiorly over the mean 2.8-year (2.0-4.8 years) follow-up. After long-term follow-up, the maxillary advancement with DO was stable in both CLP and non-CLP patients with maxillary hypoplasia. In addition, our original technique

  5. 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)

  6. Development and Implementation of a Design Metric for Systems Containing Long-Term Fluid Loops

    Science.gov (United States)

    Steele, John W.

    2016-01-01

    John Steele, a chemist and technical fellow from United Technologies Corporation, provided a water quality module to assist engineers and scientists with a metric tool to evaluate risks associated with the design of space systems with fluid loops. This design metric is a methodical, quantitative, lessons-learned based means to evaluate the robustness of a long-term fluid loop system design. The tool was developed by a cross-section of engineering disciplines who had decades of experience and problem resolution.

  7. Design Principles and Concepts for Enhancing Long-Term Cap Performance and Confidence

    International Nuclear Information System (INIS)

    Steven J. Piet; Robert P. Breckenridge; Gregory J. White; Jacob J. Jacobson; Hilary I. Inyang

    2005-01-01

    The siting of new landfills is becoming increasing difficult as the public and stakeholders want more confidence of performance for longer times and landfill owners want to store more waste in the least area while knowing and limiting their long-term liabilities. These changes motivate re-examination of long-term performance mechanisms and their implications for cap and barrier designs. Accordingly, in this paper we first consider design principles from the standpoint of long-term performance and management, including the ability to monitor and repair barriers. We then consider some design concepts that may implement these principles, especially evapo-transpiration (ET) caps. We suggest five design principles based on experience in the cap and barrier field as well as other engineering disciplines. These principles are as follows: (1) Establish a clear and defendable design basis. (2) Design for ease of monitoring and repair. (3) Analyze the barrier as a dynamic system, not static. (4) Work with nature, not against. (5) Recognize that increased complexity can reduce, not enhance, net performance. ET caps are an excellent embodiment of these design principles. We apply the design principles to ET caps, as well as variants such as erosion armor, capillary breaks, bio-intrusion layers, and low permeability material layers

  8. 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.

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

    International Nuclear Information System (INIS)

    Zhang Lei; Jahng, Deokjin

    2012-01-01

    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 CH 4 /g VS added ) 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.

  10. Long-term patient outcomes after surgical stabilization of rib fractures.

    Science.gov (United States)

    Majercik, Sarah; Cannon, Quinn; Granger, Steven R; VanBoerum, Don H; White, Thomas W

    2014-07-01

    Rib fractures are common, and can be disabling. Recently, there has been increased interest in surgical stabilization of rib fractures (SSRF). It is difficult to define long-term benefits of the procedure. This is a descriptive study of patient outcomes after SSRF. SSRF patients between April 2010 and August 2012 at a Level I trauma center were identified. Data were collected from the medical records. A telephone survey asking about pain, satisfaction, and employment was administered to patients after hospital discharge. One hundred-one patients met inclusion criteria. Fifty (50%) patients completed the survey. Indications for SSRF included flail chest, displaced fractures, pain, and inability to wean from mechanical ventilation. Pain was gone at 5.4 ± 1.1 weeks post discharge. Satisfaction with SSRF on a scale of 1 to 10 was 9.2 ± .2. Ninety percent of employed patients returned to the same work at 8.5 ± 1.2 weeks. SSRF patients are satisfied and are able to return to normal activity with few limitations. A prospective study using modern rib fixation technology is needed to further define benefits. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Microstructure Stability of Inconel 740H Alloy After Long Term Exposure at 750℃

    Directory of Open Access Journals (Sweden)

    DANG Ying-ying

    2016-09-01

    Full Text Available Unstressed exposure tests of Inconel 740H alloy tube were carried out at 750℃ for 500-3000h. The microstructure evolution and microhardness were studied by means of thermodynamic simulation, OM, FEG-SEM and microhardness testing. The results show that the tube is qualified if both chemical composition and tensile properties of the as-received alloy meet the corresponding requirements of ASME. After long term exposure, the main precipitates are γ' and M23C6, and no η and σ phase. With the prolonging of exposure time, the coarsening of γ' becomes faster and the law of relationship between the radius of γ' and time accords with LSW Ostwald ripening law; meanwhile, the change in size of M23C6 is not so obvious. During the whole process, microhardness increases firstly and then decreases, but the fluctuation is slight. The changes of microstructure and hardness indicate that, after long time exposure, the domestic Inconel 740H has good stability and can be used for further carrying out the investigation on the mechanical property of creep-rupture.

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

    International Nuclear Information System (INIS)

    Fischer, W.

    1995-12-01

    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.)

  13. Hydrothermal behaviors and long-term stability of bentonitic buffer material

    International Nuclear Information System (INIS)

    Lee, Jae Owan; Cho, Won Jin

    2007-01-01

    In hydrothermal reaction tests, smectite-to-illite conversion was identified using a domestic bentonite which is favorably considered as a buffer material, and its dependency on various hydrothermal conditions was investigated. The analysis results of the XRD and Si concentration indicated that the smectite-to- illite conversion was a major process of bentonite alteration under the hydrothermal conditions. The temperature, potassium concentration in solution, and pH were observed to significantly affect the smectite-to illite conversion. A model of conversion reaction rate was suggested evaluate the long-term stability of smectite composing a major constituent of bentonitic buffer. It was expected from the evaluation results that the smectite would keep its integrity for very long disposal time under a normal condition, while as it might be converted to illite by 50 percent after over 5 x 10 4 year of disposal time under a conservative condition and consequently lose its swelling capacity as a buffer material of a repository

  14. Long-term stability of the Wechsler Intelligence Scale for Children--Fourth Edition.

    Science.gov (United States)

    Watkins, Marley W; Smith, Lourdes G

    2013-06-01

    Long-term stability of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV; Wechsler, 2003) was investigated with a sample of 344 students from 2 school districts twice evaluated for special education eligibility at an average interval of 2.84 years. Test-retest reliability coefficients for the Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI), Processing Speed Index (PSI), and the Full Scale IQ (FSIQ) were .72, .76, .66, .65, and .82, respectively. As predicted, the test-retest reliability coefficients for the subtests (Mdn = .56) were generally lower than the index scores (Mdn = .69) and the FSIQ (.82). On average, subtest scores did not differ by more than 1 point, and index scores did not differ by more than 2 points across the test-retest interval. However, 25% of the students earned FSIQ scores that differed by 10 or more points, and 29%, 39%, 37%, and 44% of the students earned VCI, PRI, WMI, and PSI scores, respectively, that varied by 10 or more points. Given this variability, it cannot be assumed that WISC-IV scores will be consistent across long test-retest intervals for individual students. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  15. Long-term stability of influenza vaccine in a dissolving microneedle patch.

    Science.gov (United States)

    Mistilis, Matthew J; Joyce, Jessica C; Esser, E Stein; Skountzou, Ioanna; Compans, Richard W; Bommarius, Andreas S; Prausnitz, Mark R

    2017-04-01

    This study tested the hypothesis that optimized microneedle patch formulations can stabilize trivalent subunit influenza vaccine during long-term storage outside the cold chain and when exposed to potential stresses found during manufacturing and storage. Formulations containing combinations of trehalose/sucrose, sucrose/arginine, and arginine/heptagluconate were successful at retaining most or all vaccine activity during storage at 25 °C for up to 24 months as determined by ELISA assay. The best formulation of microneedle patches contained arginine/heptagluconate, which showed no significant loss of vaccine activity during the study. To validate these in vitro findings, mice were immunized using trivalent influenza vaccine stored in microneedle patches for more than 1 year at 25 °C, which elicited antibody titers greater than or equal to fresh liquid vaccine delivered by intradermal injection, indicating the retention of immunogenicity during storage. Finally, influenza vaccine in microneedle patches lost no significant activity during exposure to 60 °C for 4 months, multiple freeze-thaw cycles, or electron beam irradiation. We conclude that optimally formulated microneedle patches can retain influenza vaccine activity during extended storage outside the cold chain and during other environmental stresses, which suggests the possibility of microneedle patch storage on pharmacy shelves without refrigeration.

  16. Long-term thermal stability of Equal Channel Angular Pressed 2024 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Güher, E-mail: guherkotan@gmail.com [Middle East Technical University, Metallurgical and Materials Engineering Department, 06800 Ankara (Turkey); Mersin University, Metallurgical and Materials Engineering Department, 33343 Yenisehir, Mersin (Turkey); Kalay, Y. Eren; Gür, C. Hakan [Middle East Technical University, Metallurgical and Materials Engineering Department, 06800 Ankara (Turkey)

    2016-11-20

    The strength of bulk metallic materials can be improved by creating ultra-fine grained structure via severe plastic deformation (SPD). However, the thermal stability of severely deformed materials has been a major issue that restricts their practical use within the industry. Although there are studies on the thermal stability of SPD metals, the long-term annealing response of particularly complex alloys, such as the age hardenable ones, remains undetermined. In the present study, annealing behavior of the single-pass Equal Channel Angular Pressed age hardenable 2024 Al alloy was investigated in the 0.38–0.52 homologous temperature range for up to 1000 h. Microstructures and the corresponding mechanical properties of the samples were determined by transmission electron microscopy, electron back-scatter diffraction analyses, and micro-hardness measurements. After long annealing durations at 80 °C and 120 °C, a secondary hardening was observed whereas a fast softening occurred at 200 °C. At 150 °C, however, a softening followed by a slight secondary hardening was also detected. The increased coarsening rate of S precipitates accompanied with dislocation annihilation was found to be the major cause of the hardness loss. Furthermore, dislocation-rich structure and Mg clusters remaining from the S precipitate dissolution eased the nucleation of Ω precipitates which are responsible for the secondary hardening. It was concluded that below 120 °C the single pass ECAPed Al 2024 components preserve their improved hardness for a prolonged period of time.

  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. 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)

    Kuramoto, Ken-ichi; Banba, Tsunetaka; Mitamura, Hisayoshi; Sakai, Etsuro; Uno, Masayoshi; Kinoshita, H.; Yamanaka, Shinsuke

    1999-01-01

    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 K IC 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.)

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

    International Nuclear Information System (INIS)

    Novotny, J.; Bhatnagar, J. P.; Xu, Y.; Huq, M. S.

    2014-01-01

    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

  20. 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

  1. Research plan on geosphere stability for long-term isolation of radioactive waste. Scientific programme for fiscal years 2011

    International Nuclear Information System (INIS)

    Yasue, Ken-ichi; Asamori, Koichi; Kusano, Tomohiro; Saito-Kokubu, Yoko; Tanikawa, Shin-ichi; Niwa, Masakazu; Hanamuro, Takahiro; Yamasaki, Seiko; Yamada, Kunimi; Ishimaru, Tsuneari; Umeda, Koji

    2011-07-01

    The concept of geological disposal of HLW in Japan is based on a multi-barrier system which combines a stable geological environment with a robust barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is a plan of research and development (R and D) on geosphere stability for long-term isolation of HLW in JAEA, in fiscal year 2011. The objectives and contents in fiscal year 2011 are described in detail based on the outline of 5 years plan (fiscal years 2010-2014). In addition, the planed framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. (author)

  2. Research plan on geosphere stability for long-term isolation of radioactive waste. Scientific programme for fiscal years 2012

    International Nuclear Information System (INIS)

    Asamori, Koichi; Niwa, Masakazu; Hanamuro, Takahiro; Yamada, Kunimi; Kusano, Tomohiro; Makuuchi, Ayumu; Takatori, Ryoichi; Saito-Kokubu, Yoko; Ishimaru, Tsuneari; Umeda, Koji

    2012-07-01

    The concept of geological disposal of HLW in Japan is based on a multi-barrier system which combines a stable geological environment with a robust barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is a plan of research and development (R and D) on geosphere stability for long-term isolation of HLW in JAEA, in fiscal year 2012. The objectives and contents in fiscal year 2012 are described in detail based on the outline of 5 years plan (fiscal years 2010-2014). In addition, the planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. (author)

  3. Research plan on geosphere stability for long-term isolation of radioactive waste. Scientific programme for fiscal years 2010

    International Nuclear Information System (INIS)

    Yasue, Ken-ichi; Asamori, Koichi; Yamada, Kunimi; Saito-Kokubu, Yoko; Yamasaki, Seiko; Kurosawa, Hideki; Tanikawa, Shin-ichi; Negi, Tateyuki; Kusano, Tomohiro; Hanamuro, Takahiro; Ishimaru, Tsuneari; Umeda, Koji

    2010-09-01

    The concept of geological disposal of HLW in Japan is based on a multibarrier system which combines a stable geological environment with an engineered barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is a plan of research and development (R and D) for geosphere stability for long-term isolation of HLW in JAEA, in fiscal year 2010. The objectives and contents in fiscal year 2010 are described in detail based on the outline of 5 years plan (fiscal years 2010-2014). In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. (author)

  4. Assessment of long-term gas sampling design at two commercial manure-belt layer barns.

    Science.gov (United States)

    Chai, Li-Long; Ni, Ji-Qin; Chen, Yan; Diehl, Claude A; Heber, Albert J; Lim, Teng T

    2010-06-01

    Understanding temporal and spatial variations of aerial pollutant concentrations is important for designing air quality monitoring systems. In long-term and continuous air quality monitoring in large livestock and poultry barns, these systems usually use location-shared analyzers and sensors and can only sample air at limited number of locations. To assess the validity of the gas sampling design at a commercial layer farm, a new methodology was developed to map pollutant gas concentrations using portable sensors under steady-state or quasi-steady-state barn conditions. Three assessment tests were conducted from December 2008 to February 2009 in two manure-belt layer barns. Each barn was 140.2 m long and 19.5 m wide and had 250,000 birds. Each test included four measurements of ammonia and carbon dioxide concentrations at 20 locations that covered all operating fans, including six of the fans used in the long-term sampling that represented three zones along the lengths of the barns, to generate data for complete-barn monitoring. To simulate the long-term monitoring, gas concentrations from the six long-term sampling locations were extracted from the 20 assessment locations. Statistical analyses were performed to test the variances (F-test) and sample means (t test) between the 6- and 20-sample data. The study clearly demonstrated ammonia and carbon dioxide concentration gradients that were characterized by increasing concentrations from the west to east ends of the barns following the under-cage manure-belt travel direction. Mean concentrations increased from 7.1 to 47.7 parts per million (ppm) for ammonia and from 2303 to 3454 ppm for carbon dioxide from the west to east of the barns. Variations of mean gas concentrations were much less apparent between the south and north sides of the barns, because they were 21.2 and 20.9 ppm for ammonia and 2979 and 2951 ppm for carbon dioxide, respectively. The null hypotheses that the variances and means between the 6- and 20

  5. Long-term stability of a one-dimensional current-driven double layer

    International Nuclear Information System (INIS)

    Hori, N.; Yamamoto, T.

    1988-01-01

    Long-term (>an electron transit time over the system) stability of a one-dimensional current-driven double layer is studied by numerical experiments using particles. In these experiments, the potential difference across the system is self-consistently determined by the space charge distributions inside the system. Each boundary of the system supplies a nondrifting half-Maxwellian plasma. The current density is increased by increasing the number density of the source plasma at the injection (right) boundary. A double layer can be developed by injection of a sufficiently high current density. For a fixed level of current injection, plasmas carrying no current with various densities (n/sup ts/ 0 ) are loaded on the left side of the system. Whether or not the generated double layer can maintain its potential drop for a long period depends on the density (n/sup ts/ 0 ) relative to the initial density (n/sup */ 0 ) near the injection boundary: (1) the double layer is found to grow when n/sup ts/ 0 = n/sup */ 0 ; (2) the steady double layer is seen for a long period when n/sup ts/ 0 approx. >n/sup */ 0 ; (3) the double layer is found to decay when n/sup ts/ 0 is even higher than n/sup */ 0 . A new concept of the current polarizability P/sub c/ = J/n/sup number/ is introduced for understanding these results, where J is the current density flowing through the double layer and n/sup number/ is the plasma density at the injection front, i.e., the low-potential edge of the double layer

  6. 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.

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

    International Nuclear Information System (INIS)

    Apted, Mick; Arthur, Randy; Savage, Dave

    2005-09-01

    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

  8. Complex containment design for long-term encapsulation of radioactive waste

    International Nuclear Information System (INIS)

    Sungaila, M.A.; San, E.K.W.; Palmeter, T.

    2011-01-01

    The Port Granby Project is part of the larger Port Hope Area Initiative (PHAI), a community-based program for the development and implementation of a safe, local, long-term management solution for historic low-level radioactive waste in the Municipalities of Port Hope and Clarington. The Port Granby Project includes the construction of a long-term low-level radioactive waste management facility, the transfer of the contaminated material to the new facility from existing storage, construction and operation of a new waste water treatment facility, and monitoring and maintenance of the facility for a period of several hundred years. A key component of the new long-term facility is a highly-engineered containment mound incorporating a composite base liner, a leachate collection system, and a multi-layer final cover system. Issues of interest include the details of the design, the evolution of the design, as well as the field quality assurance measures that will be specified to ensure that the design is correctly implemented. (author)

  9. The driving forces of stability. Exploring the nature of long-term bureaucracy-interest group interactions

    NARCIS (Netherlands)

    Braun, C.H.J.M.

    2013-01-01

    This article explores the nature of long-term interactions between bureaucrats and interest groups by examining two behavioral logics associated with stability in public policy making. In addition to the implicit short-term strategic choices that usually feature in resource-exchange explanations of

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

    KAUST Repository

    Ataherian, Fatemeh; Wu, Nae-Lih

    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

  11. 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.

  12. Identifying Personal Goals of Patients With Long Term Condition: A Service Design Thinking Approach.

    Science.gov (United States)

    Lee, Eunji; Gammon, Deede

    2017-01-01

    Care for patients with long term conditions is often characterized as fragmented and ineffective, and fails to engage the resources of patients and their families in the care process. Information and communication technology can potentially help bridge the gap between patients' lives and resources and services provided by professionals. However, there is little attention on how to identify and incorporate the patients' individual needs, values, preferences and care goals into the digitally driven care settings. We conducted a case study with healthcare professionals and patients participated applying a service design thinking approach. The participants could elaborate some personal goals of patients with long term condition which can potentially be incorporated in digitally driven care plans using examples from their own experiences.

  13. Influence of the design temperature on long-term safety of a salt dome repository

    International Nuclear Information System (INIS)

    Buhmann, D.; Brenner, J.; Storck, R.

    1993-03-01

    All studies made so far within the framwork of the mixed concept system analysis proceeded from a design temperature of the mine structure of 200 C. The concept based on a design temperature of 150 C was aimed at studying whether it made sense to maintain lower temperatures, if necessary. Deterministic and probabilistic calculations were made in order to determine the influence of the lower design temperature on long-term safety. The calculations were based on concept A of Joint Borehole and Gallery Storage. Assuming reference values of the input parameters, the deterministic calculations do not produce any radionuclide release from the mine structure. If, however, one assumes a lower rate for rock convergence, radionuclides are released at maximum dose rates of about 3.10 -5 Sv/a. Even a larger volume of limited brine inclusions may lead to radionuclide releases, in that case with dose commitments of the order of magnitude of 1.10 -5 Sv/a. The probabilistic calculations show that a design temperature of 150 C for long-term safety is less favourable than a higher design temperature. The share of simulations in the probabilistic calculations with a radionuclide release, and the expected value of dose commitment, are almost double as high as in the concept based on 200 C design temperature. Thus a higher design temperature is preferable with regard to the long-term safety of a salt repository. The most important parameters concerning dose commitment are the volume of limited brine inclusions, the convergence rate, and the permeability of barriers and backfilling rock. (orig./HP) [de

  14. The stability of the international oil trade network from short-term and long-term perspectives

    Science.gov (United States)

    Sun, Qingru; Gao, Xiangyun; Zhong, Weiqiong; Liu, Nairong

    2017-09-01

    To examine the stability of the international oil trade network and explore the influence of countries and trade relationships on the trade stability, we construct weighted and unweighted international oil trade networks based on complex network theory using oil trading data between countries from 1996 to 2014. We analyze the stability of international oil trade network (IOTN) from short-term and long-term aspects. From the short-term perspective, we find that the trade volumes play an important role on the stability. Moreover, the weighted IOTN is stable; however, the unweighted networks can better reflect the actual evolution of IOTN. From the long-term perspective, we identify trade relationships that are maintained during the whole sample period to reveal the situation of the whole international oil trade. We provide a way to quantitatively measure the stability of complex network from short-term and long-term perspectives, which can be applied to measure and analyze trade stability of other goods or services.

  15. Stability of selected serum hormones and lipids after long-term storage in the Janus Serum Bank.

    Science.gov (United States)

    Gislefoss, Randi E; Grimsrud, Tom K; Mørkrid, Lars

    2015-04-01

    The potential value of a biobank depends on the quality of the samples, i.e. how well they reflect the biological or biochemical state of the donors at the time of sampling. Documentation of sample quality has become a particularly important issue for researchers and users of biobank studies. The aim of this study was to investigate the long-term stability of selected components: cholesterol, high density cholesterol (HDLC), low density cholesterol (LDLC), apolipoprotein A1 (apo-A1), apolipoprotein B (apo B), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH) and free thyroxin (FT4). Samples, stored at -25°C, from 520 men aged 40-49 years at blood sampling distributed in equally sized groups (n=130) according to length of storage, 0, 4, 17 and 29 years, respectively, were used in a cross sectional design. The freshly collected serum samples were used as a reference group to calculate storage related changes. The differences between fresh samples and samples stored for 29 years were substantial for apo-A1 (+12%), apo-B (+22.3%), HDLC (-69.2%), LDLC (+31.3%), and PRL (-33.5%), while total cholesterol, FSH, LH, TSH and FT4 did not show any significant difference. The study showed large differences in serum level of the selected components. The lipids and apolipoproteins were all changed except for total cholesterol. Most hormones investigated (FSH, LH, TSH and FT4) proved to be stable after 29 years of storage while PRL showed sign of degradation. The observed differences are probably due to long-term storage effects and/or external factors (i.e. diet and smoking). Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  16. Micro-ring structures stabilize microdroplets to enable long term spheroid culture in 384 hanging drop array plates.

    Science.gov (United States)

    Hsiao, Amy Y; Tung, Yi-Chung; Kuo, Chuan-Hsien; Mosadegh, Bobak; Bedenis, Rachel; Pienta, Kenneth J; Takayama, Shuichi

    2012-04-01

    Using stereolithography, 20 different structural variations comprised of millimeter diameter holes surrounded by trenches, plateaus, or micro-ring structures were prepared and tested for their ability to stably hold arrays of microliter sized droplets within the structures over an extended period of time. The micro-ring structures were the most effective in stabilizing droplets against mechanical and chemical perturbations. After confirming the importance of micro-ring structures using rapid prototyping, we developed an injection molding tool for mass production of polystyrene 3D cell culture plates with an array of 384 such micro-ring surrounded through-hole structures. These newly designed and injection molded polystyrene 384 hanging drop array plates with micro-rings were stable and robust against mechanical perturbations as well as surface fouling-facilitated droplet spreading making them capable of long term cell spheroid culture of up to 22 days within the droplet array. This is a significant improvement over previously reported 384 hanging drop array plates which are susceptible to small mechanical shocks and could not reliably maintain hanging drops for longer than a few days. With enhanced droplet stability, the hanging drop array plates with micro-ring structures provide better platforms and open up new opportunities for high-throughput preparation of microscale 3D cell constructs for drug screening and cell analysis.

  17. Evidence for the long-term stability of uranium mill tailings: survivability of ancient man-made earthern structures

    International Nuclear Information System (INIS)

    Lindsey, C.G.; Mishima, J.

    1982-09-01

    Pacific Northwest Laboratory (PNL), as part of a study for the Nuclear Regulatory Commission (NRC), is investigating long-term stabilization techniques for uranium mill tailings piles. Part of this invetigation involves the design of a rock armoring blanket to mitigate wind and water erosion of the underlying soil cover, which, in turn, prevents exposure of the tailings to the environment. However, the need for the armoring blanket, as well as this blanket's effectiveness, depends on the stability of the underlying soil cap (radon suppression cover) and on the tailings themselves. Compelling evidence in archaeological records suggests that large man-made earthen structures can remain sound and intact for time periods comparable to those required for the tailings piles. In this paper we present archaeological evidence of the existence and survivability of man-made earthen and rock structures through specific examples of such structures around the world. We also review factors contributing to the survival or destruction of these structures. Archaeological evidence suggests that whereas natural erosional forces have affected these structures, man's activities (e.g., agriculture, looting) have been the most damaging. The influence of climate, building materials, and construction techniques on survivability is addressed in this paper

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

    DEFF Research Database (Denmark)

    Hauch, Anne; Brodersen, Karen; Karas, Filip

    2014-01-01

    of 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...

  19. The Association between Physical Activity During the Day and Long-Term Memory Stability.

    Science.gov (United States)

    Pontifex, Matthew B; Gwizdala, Kathryn L; Parks, Andrew C; Pfeiffer, Karin A; Fenn, Kimberly M

    2016-12-02

    Despite positive associations between chronic physical activity and memory; we have little understanding of how best to incorporate physical activity during the day to facilitate the consolidation of information into memory, nor even how time spent physically active during the day relates to memory processes. The purpose of this investigation was to examine the relation between physical activity during the day and long-term memory. Ninety-two young adults learned a list of paired-associate items and were tested on the items after a 12-hour interval during which heart rate was recorded continuously. Although the percentage of time spent active during the day was unrelated to memory, two critical physical activity periods were identified as relating to the maintenance of long-term memory. Engaging in physical activity during the period 1 to 2-hours following the encoding of information was observed to be detrimental to the maintenance of information in long-term memory. In contrast, physical activity during the period 1-hour prior to memory retrieval was associated with superior memory performance, likely due to enhanced retrieval processing. These findings provide initial evidence to suggest that long-term memory may be enhanced by more carefully attending to the relative timing of physical activity incorporated during the day.

  20. Stability of rapid maxillary expansion and facemask therapy: a long-term controlled study.

    Science.gov (United States)

    Masucci, Caterina; Franchi, Lorenzo; Defraia, Efisio; Mucedero, Manuela; Cozza, Paola; Baccetti, Tiziano

    2011-10-01

    The aim of this prospective controlled study was to evaluate the long-term effects of rapid maxillary expansion and facemask therapy in Class III subjects. Twenty-two subjects (9 boys, 13 girls; mean age, 9.2 years ± 1.6) with Class III disharmony were treated consecutively with rapid maxillary expansion and facemask therapy followed by fixed appliances. The patients were reevaluated at the end of the 2-phase treatment (mean age, 14.5 years ± 1.9) and then recalled about 8.5 years after the end of rapid maxillary expansion and facemask treatment (mean age, 18.7 years ± 2.1). Two groups of controls with untreated Class III malocclusion were used for statistical comparisons of the short-term and long-term intervals. Statistical comparisons were performed with the Mann-Whitney U test. In the long term, no significant differences in maxillary changes were recorded, whereas the treatment group showed significantly smaller increases in mandibular protrusion. The sagittal maxillomandibular skeletal variables maintained significant improvements in the treatment group vs the control groups. In the long term, rapid maxillary expansion and facemask therapy led to successful outcomes in about 73% of the Class III patients. Favorable skeletal changes were mainly due to significant improvements in the sagittal position of the mandible. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  1. Research on geosphere stability for long-term isolation of radioactive waste. Scientific programme for fiscal years 2015-2021

    International Nuclear Information System (INIS)

    Umeda, Koji; Yasue, Ken-ichi; Saito-Kokubu, Yoko; Niwa, Masakazu; Asamori, Koichi; Fujita, Natsuko; Shimizu, Mayuko; Shimada, Akiomi; Matsubara, Akihiro; Tamura, Hajimu; Yokoyama, Tatsunori; Watanabe, Takahiro; Tokuyasu, Kayoko; Hama, Yuki

    2015-08-01

    The study on long-term geological stability has three objectives, namely, (1) development of technologies for determining the past and present conditions of the geological environment, (2) development of technologies for long-term prediction and evaluation of impacts and (3) development of dating techniques using advanced equipment on isotope geology and geochronology, in order to make contribution to site investigation and safety assessment for the geological disposal of high-level radioactive waste (HLW). This report is to outline 7 years plan (fiscal years 2015-2021) of research and development (R and D) for geosphere stability for long-term isolation of the HLW in Japan Atomic Energy Agency. Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. The objectives, outline, contents and schedule during the next 7 years are described in detail. In addition, the plan framework is structured into the following categories: (1) Development and Systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. (author)

  2. Training of Ability for Engineering Design through Long Term Internship Program

    Science.gov (United States)

    Konishi, Masami; Gofuku, Akio; Tomita, Eiji

    The education program for engineering design capabilities through long term internship of Okayama University had started in 2006. The program supported by the MEXT is aimed to educate students in the Graduate School of Natural Science and Technology of Okayama University. The internship satellite laboratory of the University is settled in the near place of collaborative companies in which students are engaged with the project themes extracted from problems in the factory of collaborative companies. Through the program, promotion of abilities for setup and solving a problem considering cost and due date together with performance of the solution. Students are also expected to gain knowledge on patent and ethics required for skillful engineers.

  3. 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...... to 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.......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...

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

    International Nuclear Information System (INIS)

    Salomon, M.; Armitage, J.; Chapman, G.; Dixit, M.; Dubeau, J.; Faszer, W.; Hamel, L.A.; Oakham, G.

    1994-01-01

    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 CF 4 /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.))

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

    OpenAIRE

    Zhang, Long; Yang, Qiang; Liu, Yaoru

    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 defo...

  6. Prediction of long term stability for geological disposal of radioactive waste

    International Nuclear Information System (INIS)

    Sasaki, Takeshi; Morikawa, Seiji; Koide, Hitoshi; Kono, Itoshi

    1998-01-01

    On geological disposal of radioactive wastes, study on prediction of diastrophism has been paid many attentions, and then long term future prediction ranging from some thousands to some tends thousands years may be necessary for some target nuclides. As there are various methods in the future prediction, it is essential to use a computational dynamic procedure to conduct a quantitative prediction. However, it causes an obstacle to advancement of the prediction method that informations on deep underground have a lot of uncertain elements because of their few and indirect data. In this paper, a long term prediction procedure of diastrophism relating to geological disposal of radioactive wastes with low level but isolation terms required to some thousands years was investigated and each one example was shown on flow of the investigation and its modeling method by using the finite element method. It seems to be a key to upgrade accuracy of future diastrophism prediction how an earth fault can be analyzed. And, as the diastrophism is a long term and complex phenomenon and its prediction has many uncertain elements, it is important to judge comprehensively results of its numerical analysis geologically and on rock engineering. (G.K.)

  7. 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)

    Takasu, Aki

    2003-03-01

    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)

  8. Long-term Stabilization of Disturbed Slopes Resulting from Construction Operations

    Science.gov (United States)

    2018-01-01

    Highway construction disturbs soil, which must be stabilized to prevent migration of soil particles into water bodies. Stabilization is enforced by law, regulation, and a permit system. Stabilization is most efficiently attained by reestablishment of...

  9. 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.

  10. 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)

    Winters, M.; Merry-Libby, P.; Hinchman, R.

    1985-01-01

    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

  11. 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.

  12. Design and long-term monitoring of DSC/CIGS tandem solar module

    International Nuclear Information System (INIS)

    Vildanova, M F; Nikolskaia, A B; Kozlov, S S; Shevaleevskiy, O I

    2015-01-01

    This paper describes the design and development of tandem dye-sensitized/Cu(In, Ga)Se (DSC/CIGS) PV modules. The tandem PV module comprised of the top DSC module and a bottom commercial 0,8 m 2 CIGS module. The top DSC module was made of 10 DSC mini-modules with the field size of 20 × 20 cm 2 each. Tandem DSC/CIGS PV modules were used for providing the long-term monitoring of energy yield and electrical parameters in comparison with standalone CIGS modules under outdoor conditions. The outdoor test facility, containing solar modules of both types and a measurement unit, was located on the roof of the Institute of Biochemical Physics in Moscow. The data obtained during monitoring within the 2014 year period has shown the advantages of the designed tandem DSC/CIGS PV-modules over the conventional CIGS modules, especially for cloudy weather and low-intensity irradiation conditions. (paper)

  13. Research on geosphere stability for long-term isolation of radioactive waste. Scientific programme for fiscal years 2010-2014

    International Nuclear Information System (INIS)

    Umeda, Koji; Ishimaru, Tsuneari; Yasue, Ken-ichi; Asamori, Koichi; Yamada, Kunimi; Saito-Kokubu, Yoko; Hanamuro, Takahiro; Tanikawa, Shin-ichi; Kusano, Tomohiro

    2010-09-01

    The concept of geological disposal of HLW in Japan is based on a multibarrier system which combines a stable geological environment with an engineered barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is to outline 5 years plan (fiscal years 2010-2014) of research and development (R and D) for geosphere stability for long-term isolation of the high-level radioactive waste in JAEA. Background of this research are clarified with the necessity and the significance, and the past progresses in this report. The objectives, outline, contents and schedule during the next 5 years are described in detail. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. (author)

  14. Long-term Dose Stability of OnabotulinumtoxinA Injection for Adductor Spasmodic Dysphonia: A 19-Year Single Institution Experience

    Directory of Open Access Journals (Sweden)

    Paul Paddle

    2017-11-01

    Full Text Available ObjectivesAdductor spasmodic dysphonia (AdSD is a focal dystonia predominantly involving the laryngeal adductor muscles. AdSD is reported to be a largely non-progressive neurological disorder, though fluctuations in symptom severity do occur. Repeated laryngeal onabotulinumtoxinA (BTX-A injections are the primary management for AdSD. A number of studies have demonstrated long-term dose stability as evidence of this long-term disease stability.MethodsA retrospective review was performed on all patients undergoing BTX-A injections for AdSD from April 1994 to September 2013 by a single laryngologist at a tertiary referral laryngology center. Patient demographics, injection doses, use of diazepam and/or lidocaine, and self-reported vocal function were recorded. Multiple linear regression analyses were performed.Results83 patients underwent a total of 1,168 injections over 19 years. The mean starting dose was 2.35 MU (0.79 SD. The mean long-term dose was 2.36 MU (0.79 SD. After adjusting for confounders, the change in the relative dose of BTX-A, with every year elapsed since initial dose was 0.13% (95% confidence interval −0.31 to 0.57%, p = 0.568.ConclusionBTX-A dose is stable over time in our large cohort of patients treated with bilateral thyroarytenoid injections for AdSD.

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

    Science.gov (United States)

    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, 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 3 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 different ages at onset. PMID:19649214

  16. On the Properties and Long-Term Stability of Infiltrated Lanthanum Cobalt Nickelates (LCN) in Solid Oxide Fuel Cell Cathodes

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Zielke, Philipp; Veltzé, Sune

    2017-01-01

    Infiltration as a fabrication method for solid oxide fuel cells (SOFC) electrodes is offering significant improvements in cell performance at reduced materials and fabrication costs, especially when combined with co-sintering. However, important questions regarding the long-term performance...... and microstructural stability remain unanswered. Here, we present the results of a three-year project, where large footprint anode-supported SOFCs with a co-sintered cathode backbone and infiltrated La0.95Co0.4Ni0.6O3 (LCN) cathodes were developed and thoroughly characterized. The initial long-term performance...... in the electrode properties using SEM, BET area, and in-plane conductivity measurements. Finally, the mechanical properties of co-sintered cathode backbone cells were determined in four-point bending tests carried out both at room temperature and at 800°C in air. Based on these results, degradation mechanisms were...

  17. Research plan on geosphere stability for long-term isolation of radioactive waste. Scientific programme for fiscal year 2016

    International Nuclear Information System (INIS)

    Ishimaru, Tsuneari; Yasue, Kenichi; Kokubu, Yoko; Niwa, Masakazu; Asamori, Koichi; Watanabe, Takahiro; Yokoyama, Tatsunori; Fujita, Natsuko; Shimizu, Mayuko; Hama, Yuki

    2016-08-01

    This report is a plan of research and development (R and D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency, in fiscal year 2016. The objectives and contents in fiscal year 2016 are described in detail based on the outline of 7 years plan (fiscal years 2015-2021). Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. (author)

  18. Optimization strategies for cask design and container loading in long term spent fuel storage

    International Nuclear Information System (INIS)

    2006-12-01

    As delays are incurred in implementing reprocessing and in planning for geologic repositories, storage of increasing quantities of spent fuel for extended durations is becoming a growing reality. Accordingly, effective management of spent fuel continues to be a priority topic. In response, the IAEA has organized a series of meetings to identify cask loading optimisation issues in preparation for a technical publication on Optimization Strategies for Cask/Container Loading in Long Term Spent Fuel Storage. This publication outlines the optimisation process for cask design, licensing and utilization, describing three principal groups of optimization activities in terms of relevant technical considerations such as criticality, shielding, structural design, operations, maintenance and retrievability. The optimization process for cask design, licensing, and utilization is outlined. The general objectives for the design of storage casks, including storage casks that are intended to be transportable, are summarized. The nature of optimization within the design process is described. The typical regulatory and licensing process is outlined, focusing on the roles of safety regulations, the regulator, and the designer/applicant in the optimization process. Based on the foregoing, a description of the three principal groups of optimization activities is provided. The subsequent chapters of this document then describe the specific optimization activities within these three activity groups, in each of the several design disciplines

  19. Long-term stability of contour augmentation in the esthetic zone

    DEFF Research Database (Denmark)

    Jensen, Simon S; Bosshardt, Dieter D; Gruber, Reinhard

    2014-01-01

    , recent data from cone beam computed tomography studies have shown the augmented volume to be stable long-term. However, no human histologic data are available to document the tissue reactions to this bone augmentation procedure. METHODS: Over an 8-year period, 12 biopsies were harvested 14 to 80 months......BACKGROUND: Contour augmentation around early-placed implants (Type 2 placement) using autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) and a collagen barrier membrane has been documented to predictably provide esthetically satisfactory clinical outcomes. In addition...... after implant placement with simultaneous contour augmentation in 10 patients. The biopsies were subjected to histologic and histomorphometric analysis. RESULTS: The biopsies consisted of 32.0% ± 9.6% DBBM particles and 40.6% ± 14.6% mature bone. 70.3% ± 14.5% of the DBBM particle surfaces were covered...

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

    Energy Technology Data Exchange (ETDEWEB)

    Honeyman, Bruce D.

    2006-06-01

    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.

  1. 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.

  2. LONG-TERM CALIBRATION STABILITY OF A RADIO ASTRONOMICAL PHASED ARRAY FEED

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, Michael; Jeffs, Brian D.; Warnick, Karl F. [Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602 (United States)

    2013-01-01

    There are many challenges associated with the implementation of a phased array feed for radio astronomy applications. Among these is the need to have an adequate set of calibration measurements so that reliable beamformers can be computed. Changes in the operating environment and temporal gain drift in the electronics contribute to calibration drift, which affects the beamformer performance. We will show that calibration measurements are relatively stable over a 5 day period and may remain so for up to 70 days or longer. We have incorporated the use of a calibration update system that has the potential to refresh a set of old calibrators, specifically correcting for electronic gain drift. However, the long-term variations that are present with fresh, current calibrators are greater than the degradation due to using an old calibration set, suggesting that, at this time, there is not a need for sophisticated calibration update systems or algorithms.

  3. Geochemical constraints on sustainable development: Can an advanced global economy achieve long-term stability?

    Science.gov (United States)

    Pickard, William F.

    2008-04-01

    The eighty-one stable chemical elements are examined individually with respect to (i) recent annual demand and (ii) worst case long-term availability in a distant future in which they must be extracted from the background sources of air, seawater, and ordinary rock. It is shown that, if a conventional use scenario is envisioned, the supplies of ruthenium, rhodium, palladium, tellurium, rhenium, osmium, iridium, platinum, gold, and especially phosphorus will be questionable while the supplies of copper, zinc, molybdenum, silver, cadmium, tin, antimony, tungsten, mercury, lead, and bismuth will be inadequate. It is therefore concluded that, in the long run, only the promotion of massive recycling and substitution technologies will suffice to maintain the global industrial society now developing.

  4. Design and fabrication of a unique electromechanical machine for long-term fatigue testing

    International Nuclear Information System (INIS)

    Boling, K.W.

    1984-12-01

    An electromechanical machine has been designed and fabricated for performing long-term fatigue tests under conditions that simulate those in modern plants. The machine is now commercially available. Its advantages over current electrohydraulic machines are lower initial cost, minimum maintenance requirements, and greater reliability especially when performing long tests. The machine operates in closed-loop fashion by utilizing continuous feedback signals from the specimen extensometer or load cell, it is programmable for testing in strain or load control. The maximum ram rate is 0.056 mm/s (0.134 in./min), maximum ram travel is 102 mm (4 in.) and load capacity is +-44 (+-10 kips). Induction heating controls speciment temperatures to 1000 0 C

  5. Numerical analysis for long-term stability of disposal facility considering thermal and hydraulic effect. Uncoupled analysis for long-term deformation of rock and buffer material and for transport of heat and water

    International Nuclear Information System (INIS)

    Sawada, Masataka; Okada, Tetsumi; Hasegawa, Takuma

    2004-01-01

    For the early realization of HLW geological repository and for its rational and economical design and safety assessment, it is important to evaluate the stability of repository facilities in deep underground, where high temperature, earth pressure and underground water flow affect the stability. This report discusses the numerical approaches that are useful for attaining these objectives. One of the efficient approaches is to develop models capable of simulating coupled thermo-hydro-mechanical (T-H-M) processes. Several T-H-M coupled simulation codes have been proposed and the international cooperative research project DECOVALEX has been held from 1991 in order to develop and validate the T-H-M coupled simulations. But mechanical models adopted in these simulation codes are too simple to be applied to the evaluation of long-term interaction of materials that show nonlinear mechanical behavior (especially in the case that surrounding rock is soft sedimentary rock). Before simulating the long-term and coupled phenomena, uncoupled simulations for four phenomena (creep behavior of surrounding rock mass, consolidation and deformation behavior of buffer material, transport of water, and transport of heat) are conducted using various parameters and boundary condition sets. From the results of those simulations, following conclusions are obtained: (1) swelling property of buffer material is important to evaluate mechanical behavior of barrier materials, (2) hydraulic properties of natural barrier can be more important than that of buffer material because suction effect of buffer material is so strong that transport of water in the buffer material is fast, (3) change of thermal properties and filling of gaps caused by water saturation of buffer material have a strong effect on the temperature field. On the next stage, we will develop a T-H-M coupled simulation code to evaluate the mechanical interaction between barrier materials based on the above study. (author)

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

    International Nuclear Information System (INIS)

    Ruizhi Chen; Kakkuri, J.

    1994-01-01

    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.)

  7. Enabling Product Design Reuse by Long-term Preservation of Engineering Knowledge

    Directory of Open Access Journals (Sweden)

    Jörg Brunsmann

    2009-12-01

    Full Text Available In the highly competitive engineering industry, product innovations are created with the help of a product lifecycle management (PLM tool chain. In order to support fast-paced product development, a major company goal is the reuse of product designs and product descriptions. Due to the product’s complexity, the design of a product not only consists of geometry data but also of valuable engineering knowledge that is created during the various PLM phases. The need to preserve such intellectual capital leads engineering companies to introduce knowledge management and archiving their machine-readable formal representation. However, archived knowledge is in danger of becoming unusable since it is very likely that knowledge semantics and knowledge representation will evolve over long time periods, for example during the 50 operational years of some products. Knowledge evolution and knowledge representation technology changes are crucial issues since a reuse of the archived product information can only be ensured if its rationale and additional knowledge are interpretable with future software and technologies. Therefore, in order to reuse design data fully, knowledge about the design must also be migrated to be interoperable with future design systems and knowledge representation methods. This paper identifies problems, issues, requirements, challenges and solutions that arise while tackling the long-term preservation of engineering knowledge.

  8. Aggregate Stability of Tropical Soils Under Long-Term Eucalyptus Cultivation

    Science.gov (United States)

    Eucalyptus cultivation has increased in all Brazilian regions. Despite the large amount of cultivated area, little is known about how this kind of management system affects soil properties, mainly the aggregate stability. Aggregate stability analyses have proved to be a sensitive tool to measure soi...

  9. Long-term Stability of Urinary Biomarkers of Acute Kidney Injury in Children.

    Science.gov (United States)

    Schuh, Meredith P; Nehus, Edward; Ma, Qing; Haffner, Christopher; Bennett, Michael; Krawczeski, Catherine D; Devarajan, Prasad

    2016-01-01

    Recent meta-analyses support the utility of urinary biomarkers for the diagnosis and prognosis of acute kidney injury. It is critical to establish optimal sample handling conditions for short-term processing and long-term urinary storage prior to widespread clinical deployment and meaningful use in prospective clinical trials. Prospective study. 80 children (median age, 1.1 [IQR, 0.5-4.2] years) undergoing cardiac surgery with cardiopulmonary bypass at our center. 50% of patients had acute kidney injury (defined as ≥50% increase in serum creatinine from baseline). We tested the effect on biomarker concentrations of short-term urine storage in ambient, refrigerator, and freezer conditions. We also tested the effects of multiple freeze-thaw cycles, as well as prolonged storage for 5 years. Urine concentrations of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule 1 (KIM-1), and interleukin 18 (IL-18). All biomarkers were measured using commercially available kits. All 3 biomarkers were stable in urine stored at 4°C for 24 hours, but showed significant degradation (5.6%-10.1% from baseline) when stored at 25°C. All 3 biomarkers showed only a small although significant decrease in concentration (0.77%-2.9% from baseline) after 3 freeze-thaw cycles. Similarly, all 3 biomarkers displayed only a small but significant decrease in concentration (0.84%-3.2%) after storage for 5 years. Only the 3 most widely studied biomarkers were tested. Protease inhibitors were not evaluated. Short-term storage of urine samples for measurement of NGAL, KIM-1, and IL-18 may be performed at 4°C for up to 24 hours, but not at room temperature. These urinary biomarkers are stable at -80°C for up to 5 years of storage. Our results are reassuring for the deployment of these assays as biomarkers in clinical practice, as well as in prospective clinical studies requiring long-term urine storage. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier

  10. Cytoskeletal stability and metabolic alterations in primary human macrophages in long-term microgravity.

    Directory of Open Access Journals (Sweden)

    Svantje Tauber

    Full Text Available The immune system is one of the most affected systems of the human body during space flight. The cells of the immune system are exceptionally sensitive to microgravity. Thus, serious concerns arise, whether space flight associated weakening of the immune system ultimately precludes the expansion of human presence beyond the Earth's orbit. For human space flight, it is an urgent need to understand the cellular and molecular mechanisms by which altered gravity influences and changes the functions of immune cells. The CELLBOX-PRIME (= CellBox-Primary Human Macrophages in Microgravity Environment experiment investigated for the first time microgravity-associated long-term alterations in primary human macrophages, one of the most important effector cells of the immune system. The experiment was conducted in the U.S. National Laboratory on board of the International Space Station ISS using the NanoRacks laboratory and Biorack type I standard CELLBOX EUE type IV containers. Upload and download were performed with the SpaceX CRS-3 and the Dragon spaceship on April 18th, 2014 / May 18th, 2014. Surprisingly, primary human macrophages exhibited neither quantitative nor structural changes of the actin and vimentin cytoskeleton after 11 days in microgravity when compared to 1g controls. Neither CD18 or CD14 surface expression were altered in microgravity, however ICAM-1 expression was reduced. The analysis of 74 metabolites in the cell culture supernatant by GC-TOF-MS, revealed eight metabolites with significantly different quantities when compared to 1g controls. In particular, the significant increase of free fucose in the cell culture supernatant was associated with a significant decrease of cell surface-bound fucose. The reduced ICAM-1 expression and the loss of cell surface-bound fucose may contribute to functional impairments, e.g. the activation of T cells, migration and activation of the innate immune response. We assume that the surprisingly small

  11. Long-term stability of intracortical recordings using perforated and arrayed Parylene sheath electrodes

    Science.gov (United States)

    Hara, Seth A.; Kim, Brian J.; Kuo, Jonathan T. W.; Lee, Curtis D.; Meng, Ellis; Pikov, Victor

    2016-12-01

    . This study provided support for the importance of creating a supportive biological environment around the probes to promote the long-term electrophysiological performance of flexible probes in the cerebral cortex. In particular, we demonstrated beneficial effects of the Matrigel coating and the long-term expression of Caveolin-1. Furthermore, we provided support to an idea of using an artificial acellular tissue compartment as a way to counteract the walling-off effect of the astrocytic scar formation around the probes as a means of establishing a more intimate and stable neural interface.

  12. 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.

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

    Science.gov (United States)

    Shimamoto, Akira; Kagawa, Harunobu; Zensho, Kazumasa; Sera, Yukihiro; Kazuki, Yasuhiro; Osaki, Mitsuhiko; Oshimura, Mitsuo; Ishigaki, Yasuhito; Hamasaki, Kanya; Kodama, Yoshiaki; Yuasa, Shinsuke; Fukuda, Keiichi; Hirashima, Kyotaro; Seimiya, Hiroyuki; Koyama, Hirofumi; Shimizu, Takahiko; Takemoto, Minoru; Yokote, Koutaro; Goto, Makoto; Tahara, Hidetoshi

    2014-01-01

    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.

  14. Long-term stability of the near-field about high-level radioactive waste repository in thermo-hydro-mechanical coupling action condition

    International Nuclear Information System (INIS)

    Liu Yuemiao; Wang Ju; Ke Dan; Cai Meifeng

    2008-01-01

    It is a long-term process for the high-level radioactive waste repository, from opening, construction to end of its service. The long-term stability of the near-field is the key issue for the design of HLW repository because the opening and heat generated from the HLW. Through a nationwide investigation, Beishan area, a Gobi desert in Gansu province, is considered as a suitable candidate and GMZ bentonite deposit which located in Xinghe County, Inner Mongolia has been proposed for the supplier of buffer/backfill material for HLW geological repository in China. According to the R and D guide of high-level radioactive waste disposal in China, the 3D model of HLW repository with high-level radioactive waste, canister and buffer/backfill material is established using FLAC3D. To take into account in situ stress, geothermal gradient, groundwater, thermal relief of HLW and swelling pressure of buffer/backfill material, the evolution of temperature, stress and displacement of HLW repository under thermo-mechanical coupling, hydro-mechanical coupling and thermo-hydro-mechanical coupling conditions was analyzed respectively. The long-term stability of HLW repository in Beishan area was studied. (authors)

  15. 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.

  16. A kinase-dependent feedforward loop affects CREBB stability and long term memory formation.

    Science.gov (United States)

    Lee, Pei-Tseng; Lin, Guang; Lin, Wen-Wen; Diao, Fengqiu; White, Benjamin H; Bellen, Hugo J

    2018-02-23

    In Drosophila , long-term memory (LTM) requires the cAMP-dependent transcription factor CREBB, expressed in the mushroom bodies (MB) and phosphorylated by PKA. To identify other kinases required for memory formation, we integrated Trojan exons encoding T2A-GAL4 into genes encoding putative kinases and selected for genes expressed in MB. These lines were screened for learning/memory deficits using UAS-RNAi knockdown based on an olfactory aversive conditioning assay. We identified a novel, conserved kinase, Meng-Po ( MP , CG11221 , SBK1 in human), the loss of which severely affects 3 hr memory and 24 hr LTM, but not learning. Remarkably, memory is lost upon removal of the MP protein in adult MB but restored upon its reintroduction. Overexpression of MP in MB significantly increases LTM in wild-type flies showing that MP is a limiting factor for LTM. We show that PKA phosphorylates MP and that both proteins synergize in a feedforward loop to control CREBB levels and LTM. key words: Drosophila, Mushroom bodies, SBK1, deGradFP, T2A-GAL4, MiMIC.

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

    International Nuclear Information System (INIS)

    Peterson, S.R.; Erikson, R.L.; Gee, G.W.

    1982-11-01

    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

  18. Long term carrier envelope phase stabilization of a grating based high power femtosecond laser using the direct locking method

    International Nuclear Information System (INIS)

    Lee, Jae Hwan; Lee, Youg Soo; Park, Juyun; Nam, Chang Hee; Yu, Tae Jun

    2008-01-01

    The carrier envelope phase (CEP)stabilization of femtosecond laser pulses has been intensively investigated for ultrafast science as well as for frequency metrology. In the case of few cycle pulses stabilization and control of the CEP is an important issue, since the electric field profile changes with CEP variation. We have developed the direct locking method to stabilize the CEP for the investigation of attosecond physics. The direct locking method uses the beating signal itself, measured using an f to 2f interferometer, as an error signal to a feedback loop. The direct locking method quenches the beating signal so that the CEP variation between successive pulses become zero and every pulses from the oscillator ts identical. Due to the direct use of the beating signal, the signal processing is simple and complex equipment, used in the case of the phase locked loop (PLL)method operating in the frequency domain, are not required. For long term stability, we have proposed and implemented a double feedback technique, and achieved CEP stabilization of the oscillator for 24 hours, as shown in Fig. 1. This long term CEP stabilization was achieved without realignment of any optical components. The CEP stabilization for a whole day is a clear demonstration of the robustness of the direct locking method. The amplification of CEP stabilized laser pulses induces additional CEP variation. Even though the CEP of an oscillator is stabilized, the CEP drift is generated again during amplification due to external perturbations, such as pumping power fluctuation and beam pointing fluctuation. To measure the CEP drift of the amplified pulses, a spectral interferometer (SI)was employed. The CEP drift obtained from SI was used as the error signal of another feedback loop installed in the amplifier chain. To compensate for the large CEP drift induced during amplification, the grating separation of the pulse compressor was adjusted. Figure 2 shows the result of CEP stabilization of

  19. One-step transversal palatal distraction and maxillary repositioning: technical considerations, advantages, and long-term stability.

    Science.gov (United States)

    Cortese, Antonio; Savastano, Mauro; Savastano, Germano; Claudio, Pier Paolo

    2011-09-01

    Transversal maxillary hypoplasia in adolescence is a frequently seen pathology, which can be treated with a combination of surgery and orthodontic treatment to widen the maxilla in skeletally matured patients.We evaluated the advantages of a new surgical technique: Le Fort I distraction osteogenesis using a bone-borne device. Because relapse is one of the main problems in surgical maxillary expansion, long-term stability of this new technique was evaluated. Data from 4 adult patients with maxillary restriction, class III malocclusion, or maxillary malposition were collected preoperatively, 4 months after distraction, and 5 years after distraction. Measurements were recorded on dental models to detect palatal expansion at dental level; cephalograms by lateral and posteroanterior plane were analyzed to detect maxillary movements. Maxillary measurements were substantially stable 5 years after distractions. Only minor dental movements occurred at the dental analysis after 5 years related to a lack of orthodontic contention without any compromise of the dental result (no crossbite relapse and class I stability). Le Fort I with down-fracture for expansion and repositioning by bone-borne distractor device can [corrected] be used to simultaneously widen, advance, and vertically reposition the maxilla without causing healing problems, particularly using a rigid distraction device. Long-term stability can be achieved; however, further studies with a larger number of patients will be necessary for better evaluation.

  20. Microstructure, surface characterization and long-term stability of new quaternary Ti-Zr-Ta-Ag alloy for implant use.

    Science.gov (United States)

    Vasilescu, C; Osiceanu, P; Moreno, J M Calderon; Drob, S I; Preda, S; Popa, M; Dan, I; Marcu, M; Prodana, M; Popovici, I A; Ionita, D; Vasilescu, E

    2017-02-01

    The novel Ti-20Zr-5Ta-2Ag alloy was characterised concerning its microstructure, morphology, mechanical properties, its passive film composition and thickness, its long-term electrochemical stability, corrosion resistance, ion release rate in Ringer solution of acid, neutral and alkaline pH values and antibacterial activity. The new alloy has a crystalline α microstructure (by XRD). Long-term XPS and SEM analyses show the thickening of the passive film and the deposition of hydroxyapatite in neutral and alkaline Ringer solution. The values of the electrochemical parameters confirm the over time stability of the new alloy passive film. All corrosion parameters have very favourable values in time which attest a high resistance to corrosion. Impedance spectra evinced a bi-layered passive film formed by the barrier, insulating layer and the porous layer. The monitoring of the open circuit potentials indicated the stability of the protective layers and their thickening in time. The new alloy releases (by ICP-MS measurements) very low quantities of Ti, Zr, Ag ions and no Ta ions. The new alloy exhibits a low antibacterial activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. 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

    2015-01-01

    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 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. PMID:26423355

  2. Long-Term Stability of Spaceflight Food for Multi-Year Exploration Missions

    Science.gov (United States)

    Douglas, G. L.; Barr, Y. R.

    2018-02-01

    Stability of macro- and micro-nutrients and undesirable changes to texture and taste will be evaluated in food samples returned from the Deep Space Gateway after 1, 3, and 5 years of storage in the deep space radiation environment.

  3. Long-term stability of an adult Class III open-bite malocclusion treated with multiloop edgewise archwire

    Directory of Open Access Journals (Sweden)

    Chien-Chun Kuo

    2009-09-01

    Full Text Available This case report describes the treatment of a 17-year-old girl with an anterior open- bite and Class III malocclusion, who had a history of thumb-sucking habit in childhood. The multiloop edgewise archwire technique was used on the mandibular arch to facilitate uprighting of the mandibular posterior teeth, change the cant of occlusal plane, close the anterior open-bite, and correct the Class III malocclusion. At the end of treatment, Class I occlusion and correction of the anterior open-bite had been achieved. An examination 8 years 8 months after treatment revealed long-term stability of the treatment results.

  4. Design and development of microbioreactors for long-term cell culture in controlled oxygen microenvironments.

    Science.gov (United States)

    Abaci, Hasan E; Devendra, Raghavendra; Smith, Quinton; Gerecht, Sharon; Drazer, German

    2012-02-01

    The ability to control the oxygen level to which cells are exposed in tissue culture experiments is crucial for many applications. Here, we design, develop and test a microbioreactor (MBR) for long-term cell culture studies with the capability to accurately control and continuously monitor the dissolved oxygen (DO) level in the cell microenvironment. In addition, the DO level can be controlled independently from other cues, such as the viscous shear-stress acting on the cells. We first analyze the transport of oxygen in the proposed device and determine the materials and dimensions that are compatible with uniform oxygen tension and low shear-stress at the cell level. The device is also designed to culture a statistically significant number of cells. We use fully transparent materials and the overall design of the device is compatible with live-cell imaging. The proposed system includes real-time read-out of actual DO levels, is simple to fabricate at low cost, and can be easily expanded to control the concentration of other microenvironmental solutes. We performed control experiments in the absence of cells to demonstrate that the MBR can be used to accurately modulate DO levels ranging from atmospheric level to 1%, both under no flow and perfusion conditions. We also demonstrate cancer cell attachment and viability within the MBR. The proposed MBR offers the unprecedented capability to perform on-line measurement and analysis of DO levels in the microenvironment of adherent cultures and to correlate them with various cellular responses.

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

    International Nuclear Information System (INIS)

    Okubo, Seisuke

    2004-02-01

    In the fiscal year of 1994 when this project was started, a pneumatic creep testing machine was modified. At the end of the fiscal year of 1994, Inada granite was purchased, and the preliminary tests such as P-wave velocity measurement and Schmidt hammer testing were carried out. Through the fiscal year of 1995, a specimen of Tage tuff under water-saturated condition had been loaded in uniaxial condition in the pneumatic creep testing machine. In the fiscal year of 1995, 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. A hydraulic creep testing machine which was planned to use in the next year was modified for long-term creep testing. Finally, a constitutive equation of variable compliance type was examined based on the experimental results. In the fiscal year of 1996, creep, compression and tension tests were carried out. Two types of pressure maintenance equipment (hydraulic and pneumatic types) were developed and examined. In the fiscal year of 1997, creep, compression and tension tests etc. were again carried out on the basis of the results heretofore. The experimental results of long-term creep testing of Tage tuff, middle-term creep testing of Inada granite were described. In both creep tests, samples were submerged in water. In the fiscal year of 1998, creep testing of Tage tuff was conducted. Results of relatively short-term (middle-term) creep conducted on a servo-controlled testing machine were also described. Sample rock was Sirahama sandstone that showed a considerably large creep strain in low stress level such as 17% of the uniaxial compression strength. Results of triaxial compression test and uniaxial tension test including unloading-reloading tests were described. In the fiscal years of 1999-2002, creep testing of Tage tuff was continuously conducted. A multi-cylinder hydraulic creep testing machine

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

    International Nuclear Information System (INIS)

    Martensson, P.; Cronstrand, P.

    2013-01-01

    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 H 3 BO 3 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 H 3 BO 3 and the studies of AEC without H 3 BO 3 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)

  7. Design and implementation of an interactive website to support long-term maintenance of weight loss.

    Science.gov (United States)

    Stevens, Victor J; Funk, Kristine L; Brantley, Phillip J; Erlinger, Thomas P; Myers, Valerie H; Champagne, Catherine M; Bauck, Alan; Samuel-Hodge, Carmen D; Hollis, Jack F

    2008-01-25

    For most individuals, long-term maintenance of weight loss requires long-term, supportive intervention. Internet-based weight loss maintenance programs offer considerable potential for meeting this need. Careful design processes are required to maximize adherence and minimize attrition. This paper describes the development, implementation and use of a Web-based intervention program designed to help those who have recently lost weight sustain their weight loss over 1 year. The weight loss maintenance website was developed over a 1-year period by an interdisciplinary team of public health researchers, behavior change intervention experts, applications developers, and interface designers. Key interactive features of the final site include social support, self-monitoring, written guidelines for diet and physical activity, links to appropriate websites, supportive tools for behavior change, check-in accountability, tailored reinforcement messages, and problem solving and relapse prevention training. The weight loss maintenance program included a reminder system (automated email and telephone messages) that prompted participants to return to the website if they missed their check-in date. If there was no log-in response to the email and telephone automated prompts, a staff member called the participant. We tracked the proportion of participants with at least one log-in per month, and analyzed log-ins as a result of automated prompts. The mean age of the 348 participants enrolled in an ongoing randomized trial and assigned to use the website was 56 years; 63% were female, and 38% were African American. While weight loss data will not be available until mid-2008, website use remained high during the first year with over 80% of the participants still using the website during month 12. During the first 52 weeks, participants averaged 35 weeks with at least one log-in. Email and telephone prompts appear to be very effective at helping participants sustain ongoing website use

  8. Microcrack growing and long-term mechanical stability in a HLW deep-borehole repository in granite

    International Nuclear Information System (INIS)

    Biurrun, E.; Hahne, K.

    1989-01-01

    The long-term host rock integrity assessment of a deep borehole emplacement for HLW in granite has been addressed with a detailed new constitutive model considering temperature and pressure effects on microscale phenomena (as microcracking) under repository conditions. The results of these finite element calculations have been compared with results obtained using conventional, state-of-the-art constitutive modelling. While the results of conventional modelling did suggest the existence of an important safety margin before failure, the improved calculations with the new model predict a thin but very long region of degradated host rock along the waste canister column. The results obtained up to now may well be considered as safety relevant, because they suggest that the actual long-term granite strength lies well below the conventionally determined failure limits, thus challenging the barrier properties of this host rock if the actual strength is not properly considered in the repository design

  9. Extrapolated long-term stability of titanium dioxide nanoparticles and multi-walled carbon nanotubes in artificial freshwater

    Energy Technology Data Exchange (ETDEWEB)

    Brunelli, Andrea; Zabeo, Alex; Semenzin, Elena; Hristozov, Danail; Marcomini, Antonio, E-mail: marcom@unive.it [University Ca’ Foscari of Venice, Department of Environmental Sciences, Informatics and Statistics (Italy)

    2016-05-15

    Long-term stability of two engineered nanomaterials (ENMs), i.e., the inorganic n-TiO{sub 2} and the organic Multi-Walled Carbon Nanotubes (MWCNTs), dispersed in artificial freshwater (5–100 mg l{sup −1}), was investigated from short-term settling velocity, particle size distribution, and surface charge. Hydrodynamic diameter and ζ-pot, calculated by means of dynamic and electrophoretic light scattering, respectively, qualitatively indicated a general ENMs dispersion instability over 1 h time. Sedimentation results, obtained by centrifugal separation analysis using the LUMiSizer over approx. 30 min analysis time, allowed to estimate the quantitative long-term (over 30 days) stability of ENMs. Settling data fitted satisfactorily with a first-order kinetic equation (R{sup 2} in the range of 0.918–0.989). The settling rate constant k values extrapolated at gravity spanned one order of magnitude, i.e., from 7.21 × 10{sup −5} to 4.12 × 10{sup −4} s{sup −1}, and with the increasing of initial ENMs concentration. Sedimentation velocities were in good agreement with short- to long-term literature data (7.8 × 10{sup −2}–1.7 × 10{sup −}1 m day{sup −1} vs. 5 × 10{sup −4}–3 × 10{sup −1} m day{sup −1} for n-TiO{sub 2} and 5.9 × 10{sup −2}–3.4 × 10{sup −1} m day{sup −1} vs. 2 × 10{sup −1}–1.2 m day{sup −1} for MWCNTs). n-TiO{sub 2} showed a higher long-term stability with respect to MWCNTs (average: 1 × 10{sup −1} ± 3.4 × 10{sup −2} m day{sup −1} instead of 1.7 × 10{sup −1} ± 1.1 × 10{sup −1} m day{sup −1}, respectively).

  10. Epicardial clip occlusion of the left atrial appendage during cardiac surgery provides optimal surgical results and long-term stability.

    Science.gov (United States)

    Kurfirst, Vojtech; Mokrácek, Aleš; Canádyová, Júlia; Frána, Radim; Zeman, Petr

    2017-07-01

    Occlusion of the left atrial appendage (LAA) has become an integral and important part of the surgical treatment of atrial fibrillation. Different methods of surgical occlusion of the LAA have been associated with varying levels of short- and long-term success for closure. The purpose of this study was to evaluate long-term results of epicardial placement and endocardial occlusion in patients undergoing cardiac operative procedures. A total of 101 patients (average age 65.7 years) undergoing cardiac operative procedures with the epicardial AtriClip Exclusion System of the LAA were enrolled in the study. The AtriClip was placed via a sternotomy or a thoracotomy or from a thoracoscopic approach. Postoperative variables, such as thromboembolic events, clip stability and endocardial leakage around the device, were examined by transoesophageal echocardiography (TEE) and/or computed tomography. Perioperative clip implantation was achieved in 98% of patients. TEE and/or computed tomography conducted during the follow-up period, comprising 1873 patient-months with a mean duration of 18 ± 11 months, revealed no clip migration, no leakage around the device and no clot formation near the remnant cul-de-sac. During the follow-up period, 4 of the cardiac patients experienced transitory ischaemic attacks, whereas no patient experienced a cerebrovascular attack. The Epicardial AtriClip Exclusion System of the LAA appears to be a feasable and safe operative method with a high success rate. Long-term follow-up confirmed clip stability, complete occlussion of the LAA and absence of any atrial fibrilation-related thromboembolic events. These results need to be confirmed by a larger, multicentre study. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  11. Combined Statistical Analyses for Long-Term Stability Data with Multiple Storage Conditions : A Simulation Study

    NARCIS (Netherlands)

    Almalik, Osama; Nijhuis, Michiel B.; van den Heuvel, Edwin R.

    2014-01-01

    Shelf-life estimation usually requires that at least three registration batches are tested for stability at multiple storage conditions. The shelf-life estimates are often obtained by linear regression analysis per storage condition, an approach implicitly suggested by ICH guideline Q1E. A linear

  12. Long-term stability in the Big Five personality traits in adulthood.

    Science.gov (United States)

    Rantanen, Johanna; Metsäpelto, Riitta-Leena; Feldt, Taru; Pulkkinen, Lea; Kokko, Katja

    2007-12-01

    This study investigated the stability of the Big Five personality traits in adulthood from age 33 to 42. Participants (89 men, 103 women) were drawn from the ongoing Jyväskylä Longitudinal Study of Personality and Social Development. The results showed that the mean-level of Neuroticism decreased whereas the mean-level of Extraversion, Openness to Experience, Agreeableness, and Conscientiousness increased from age 33 to 42. The Structural Equation Modeling analyses revealed both gender differences and similarities in the rank-order stability of the Big Five: Neuroticism and Extraversion were more stable in men than in women, whereas Openness to Experience, Agreeableness, and Conscientiousness were as stable in men as in women. Stability coefficients for the Big Five personality traits across 9 years were moderate to high, ranging from 0.73 to 0.97 in men and from 0.65 to 0.95 in women. The highest gender-equal stability was found for Openness to Experience and the lowest for Conscientiousness.

  13. Long-term stability of glucose: glycolysis inhibitor vs. gel barrier tubes.

    Science.gov (United States)

    Winter, Theresa; Hannemann, Anke; Suchsland, Juliane; Nauck, Matthias; Petersmann, Astrid

    2018-03-12

    Measuring the glucose concentration in whole blood samples is critical due to unsatisfactory glycolysis inhibition. Previous studies showed that Terumo tubes were superior, but they were taken off the European market in 2016 and alternatives were required. This initiated the present evaluation of glucose stability in five available tube types. Venous blood samples were collected from 61 healthy volunteers to test tubes supplied by Terumo (two sets), Greiner FC-Mix, BD FX-Mixture and BD serum. After sampling, the contents were thoroughly mixed and centrifuged within an hour. The glucose concentrations were determined and the samples resuspended except for BD serum tubes (gel barrier). The first 30 samples were stored at room temperature and the remaining 31 at 4°C. After 24, 48, 72 and 96 h, all tubes were (re)centrifuged, and glucose concentration measurements were repeated. Changes in glucose concentrations over time differed significantly between the investigated tube types and to a certain extent between the two storing conditions. Glycolysis was most evident in the BD FX-mixture tubes. Good glucose stability was observed in samples retrieved form BD serum and Greiner tubes. The stability in both Terumo tubes was comparable to that in other studies. Although Greiner and both Terumo tubes are supposed to contain the same glycolysis inhibitor, glucose stability differed between these tubes. We showed that Greiner is an acceptable alternative to Terumo and that glucose in serum that was rapidly separated from corpuscles by a gel barrier is stable for an extended time.

  14. SU-F-P-11: Long Term Dosimetric Stability of 6 TomoTherapy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Smilowitz, J; Dunkerley, D; Geurts, M; Hill, P; Yadav, P [University of Wisconsin, Madison, WI (United States)

    2016-06-15

    Purpose: The dosimetric stability of six TomoTherapy units was analyzed to investigate changes in performance over time and with system upgrades. Methods: Energy and output were tracked using monitor chamber signal, onboard MVCT detector signal and external ion chamber measurements. The systems (and monitoring periods) include 3 Hi-Art (67, 61 and 65 mos.), 2 HDA (29 and 25 mos.) and one research unit (7 mo.). Dose Control Stability system (DCS) was installed on 4 systems. Output stability is reported as deviation from reference monitor chamber signal for all systems, and from an external chamber for 4 systems. Energy stability was monitored using the relative (center versus off-axis) MVCT detector signal and/or the ratio of chamber measurements at 2 depths. The results from the clinical systems were used to benchmark the stability of the research unit, which has the same linear accelerator but runs at a higher dose rate. Results: The output based on monitor chamber data of all six systems is very stable. Non- DCS had a standard deviation of 1.7% and 1.8%. As expected, DCS systems had improved standard deviation: 0.003–0.05%. The energy was also very stable for all units. The standard deviation in exit detector flatness was 0.02–0.3%. Ion chamber output and 20/10 cm ratios supported these results. The stability for the research system, as monitored with a variety of metrics, is on par with the existing systems. Conclusion: The output and energy of six TomoTherapy units over a total of almost 10 years is quite stable. For each system, the results are consistent between the different measurement tools and techniques, proving not only the dosimetric stability, but that these quality parameters can be confirmed with various metrics. A research unit operating at a higher dose rate performed as well as the clinical treatment units. University of Wisconsin and Accuray Inc. (vendor of TomoTherapy systems) have a research agreement which supplies funds for research to

  15. Design of the Long-term Waste Management Facility for Historic LLRW Port Hope Project - 13322

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Don; Barton, David [Conestoga-Rovers and Associates, 651 Colby Drive, Waterloo, Ontario N2V 1C2 (Canada); Case, Glenn [Atomic Energy of Canada Limited, 115 Toronto Road, Port Hope, Ontario L1A 3S4 (Canada)

    2013-07-01

    The Municipality of Port Hope is located on the northern shores of Lake Ontario approximately 100 km east of Toronto, Ontario, Canada. Starting in the 1930's, radium and later uranium processing by Eldorado Gold Mines Limited (subsequently Eldorado Nuclear Limited) (Eldorado) at their refinery in Port Hope resulted in the generation of process residues and wastes that were disposed of indiscriminately throughout the Municipality until about the mid-1950's. These process residues contained radium (Ra- 226), uranium, arsenic and other contaminants. Between 1944 and 1988, Eldorado was a Federal Crown Corporation, and as such, the Canadian Federal Government has assumed responsibility for the clean-up and long-term management of the historic waste produced by Eldorado during this period. The Port Hope Project involves the construction and development of a new long-term waste management facility (LTWMF), and the remediation and transfer of the historic wastes located within the Municipality of Port Hope to the new LTWMF. The new LTWMF will consist of an engineered above-ground containment mound designed to contain and isolate the wastes from the surrounding environment for the next several hundred years. The design of the engineered containment mound consists of a primary and secondary composite base liner system and composite final cover system, made up of both natural materials (e.g., compacted clay, granular materials) and synthetic materials (e.g., geo-synthetic clay liner, geo-membrane, geo-textiles). The engineered containment mound will cover an area of approximately 13 hectares and will contain the estimated 1.2 million cubic metres of waste that will be generated from the remedial activities within Port Hope. The LTWMF will also include infrastructure and support facilities such as access roads, administrative offices, laboratory, equipment and personnel decontamination facilities, waste water treatment plant and other ancillary facilities

  16. Design of the Long-term Waste Management Facility for Historic LLRW Port Hope Project - 13322

    International Nuclear Information System (INIS)

    Campbell, Don; Barton, David; Case, Glenn

    2013-01-01

    The Municipality of Port Hope is located on the northern shores of Lake Ontario approximately 100 km east of Toronto, Ontario, Canada. Starting in the 1930's, radium and later uranium processing by Eldorado Gold Mines Limited (subsequently Eldorado Nuclear Limited) (Eldorado) at their refinery in Port Hope resulted in the generation of process residues and wastes that were disposed of indiscriminately throughout the Municipality until about the mid-1950's. These process residues contained radium (Ra- 226), uranium, arsenic and other contaminants. Between 1944 and 1988, Eldorado was a Federal Crown Corporation, and as such, the Canadian Federal Government has assumed responsibility for the clean-up and long-term management of the historic waste produced by Eldorado during this period. The Port Hope Project involves the construction and development of a new long-term waste management facility (LTWMF), and the remediation and transfer of the historic wastes located within the Municipality of Port Hope to the new LTWMF. The new LTWMF will consist of an engineered above-ground containment mound designed to contain and isolate the wastes from the surrounding environment for the next several hundred years. The design of the engineered containment mound consists of a primary and secondary composite base liner system and composite final cover system, made up of both natural materials (e.g., compacted clay, granular materials) and synthetic materials (e.g., geo-synthetic clay liner, geo-membrane, geo-textiles). The engineered containment mound will cover an area of approximately 13 hectares and will contain the estimated 1.2 million cubic metres of waste that will be generated from the remedial activities within Port Hope. The LTWMF will also include infrastructure and support facilities such as access roads, administrative offices, laboratory, equipment and personnel decontamination facilities, waste water treatment plant and other ancillary facilities. Preliminary

  17. Simulating future uncertainty to guide the selection of survey designs for long-term monitoring

    Science.gov (United States)

    Garman, Steven L.; Schweiger, E. William; Manier, Daniel J.; Gitzen, Robert A.; Millspaugh, Joshua J.; Cooper, Andrew B.; Licht, Daniel S.

    2012-01-01

    A goal of environmental monitoring is to provide sound information on the status and trends of natural resources (Messer et al. 1991, Theobald et al. 2007, Fancy et al. 2009). When monitoring observations are acquired by measuring a subset of the population of interest, probability sampling as part of a well-constructed survey design provides the most reliable and legally defensible approach to achieve this goal (Cochran 1977, Olsen et al. 1999, Schreuder et al. 2004; see Chapters 2, 5, 6, 7). Previous works have described the fundamentals of sample surveys (e.g. Hansen et al. 1953, Kish 1965). Interest in survey designs and monitoring over the past 15 years has led to extensive evaluations and new developments of sample selection methods (Stevens and Olsen 2004), of strategies for allocating sample units in space and time (Urquhart et al. 1993, Overton and Stehman 1996, Urquhart and Kincaid 1999), and of estimation (Lesser and Overton 1994, Overton and Stehman 1995) and variance properties (Larsen et al. 1995, Stevens and Olsen 2003) of survey designs. Carefully planned, “scientific” (Chapter 5) survey designs have become a standard in contemporary monitoring of natural resources. Based on our experience with the long-term monitoring program of the US National Park Service (NPS; Fancy et al. 2009; Chapters 16, 22), operational survey designs tend to be selected using the following procedures. For a monitoring indicator (i.e. variable or response), a minimum detectable trend requirement is specified, based on the minimum level of change that would result in meaningful change (e.g. degradation). A probability of detecting this trend (statistical power) and an acceptable level of uncertainty (Type I error; see Chapter 2) within a specified time frame (e.g. 10 years) are specified to ensure timely detection. Explicit statements of the minimum detectable trend, the time frame for detecting the minimum trend, power, and acceptable probability of Type I error (

  18. Long-Term Stability of Pre-Orthodontic Orthognathic Bimaxillary Surgery Using Intraoral Vertical Ramus Osteotomy Versus Conventional Surgery.

    Science.gov (United States)

    Jeong, Jeong-Hwa; Choi, Sung-Hwan; Kim, Kee-Deog; Hwang, Chung-Ju; Lee, Sang-Hwy; Yu, Hyung-Seog

    2018-02-20

    The aim of the present study was to compare the long-term stability of bimaxillary surgery using an intraoral vertical ramus osteotomy (IVRO) with and without presurgical orthodontic treatment. The present retrospective study included 31 consecutive patients with skeletal Class III malocclusions who had undergone bimaxillary surgery (Le Fort I osteotomy and bilateral IVRO). Patients were divided into 2 groups based on treatment type: pre-orthodontic orthognathic surgery (POGS; n = 17) and conventional surgery with presurgical orthodontic treatment (CS; n = 14). Lateral cephalograms were obtained before surgery, 1 day after surgery, 1 month after surgery, 1 year after surgery, and 2 years after surgery to evaluate skeletal and soft tissue changes between the 2 groups. Data were analyzed using χ 2 tests, Mann-Whitney U tests, repeated-measures analyses of variance, and independent t tests. There was no significant difference in skeletal or soft tissue measurements-with the exception of the angle between the sella-and-nasion plane and the occlusal plane (SN-OP; P surgery. These findings suggest that POGS and CS have similar long-term stability in patients with skeletal Class III malocclusion. Copyright © 2018. Published by Elsevier Inc.

  19. Long-term urine biobanking: storage stability of clinical chemical parameters under moderate freezing conditions without use of preservatives.

    Science.gov (United States)

    Remer, Thomas; Montenegro-Bethancourt, Gabriela; Shi, Lijie

    2014-12-01

    To examine the long-term stability and validity of analyte concentrations of 21 clinical biochemistry parameters in 24-h urine samples stored for 12 or 15 yr at -22°C and preservative free. Healthy children's 24-h urine samples in which the respective analytes had been measured shortly after sample collection (baseline) were reanalyzed. Second measurement was performed after 12 yr (organic acids) and 15 yr (creatinine, urea, osmolality, iodine, nitrogen, anions, cations, acid-base parameters) with the same analytical methodology. Paired comparisons and correlations between the baseline and repeated measurements were done. Recovery rates were calculated. More than half of the analytes (creatinine, urea, iodine, nitrogen, sodium, potassium, magnesium, calcium, ammonium, bicarbonate, citric & uric acid) showed measurement values after >10 yr of storage not significantly different from baseline. 15 of the 21 parameters were highly correlated (r=0.99) between baseline and second measurement. Poorest correlation was r=0.77 for oxalate. Recovery ranged from 73% (oxalate) to 105% (phosphate). Our results suggest high long-term stability and measurement validity for numerous clinical chemistry parameters stored at -22°C without addition of any urine preservative. Prospective storage of urine aliquots at -22°C for periods even exceeding 10 yr, appears to be an acceptable and valid tool in epidemiological settings for later quantification of several urine analytes. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  20. Long-Term Stability Testing Results Using Surrogates And Sorbents For Savannah River Site Organic And Aqueous Wastestreams - 10016

    International Nuclear Information System (INIS)

    Burns, H.

    2009-01-01

    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 wastestreams (both volatile and nonvolatile), a volatile organic surrogate with a residual aqueous phase, an aqueous surrogate, and an aqueous surrogate with a residual organic phase. The Savannah River Site (SRS) Legacy and F-Canyon plutonium/uranium extraction (PUREX) process waste surrogates constituted the volatile organic surrogates, and various oils constituted the nonvolatile organic surrogates. The aqueous surrogates included a rainwater surrogate and an aqueous organic surrogate. MSE also evaluated the PUREX surrogate with a residual aqueous component with and without aqueous type sorbent materials. Solidification of the various surrogate wastestreams listed above was performed from 2004 to 2006 at the MSE Test Facility located in Butte, Montana. This paper summarizes the comparison of the initial liquid release test (LRT) values with LRT results obtained during subsequent sampling events in an attempt to understand and define the long-term stability characteristics for the solidified wastestreams.

  1. Stabilization of Neem Oil Biodiesel with Corn Silk Extract during Long-term Storage.

    Science.gov (United States)

    Ali, Rehab Farouk M; El-Anany, Ayman M

    2017-02-01

    The current study aimed to evaluate the antioxidant efficiency of different extracts of corn silk. In addition, the impact of corn silk extract on oxidative stability of neem biodiesel during storage was studied. The highest phenolics, DPPH radical scavenging and reducing power activities were recorded for methanol-water extract. The longest oxidation stability (10 h) was observed for biodiesel samples blended with 1000 ppm of corn silk extract (CSE). At the end of storage period the induction time of biodiesel samples mixed with 1000 ppm of CSE or butylated hydroxytoluene (BHT) were about 6.72 and 5.63 times as high as in biodiesel samples without antioxidants. Biodiesel samples blended with 1000 ppm of CSE had the lowest acidity at the end of storage period. Peroxide value of biodiesel samples containing 1000 ppm of CSE was about 4.28 times as low as in control sample without antioxidants.

  2. Thermal and long-term freezing stability of ivermectin residues in sheep milk

    NARCIS (Netherlands)

    Cerkvenik, V.; Doganoc, D.Z.; Skubic, V.; Beek, W.M.J.; Keukens, H.J.

    2001-01-01

    The stability of ivermectin residues in sheep milk under conditions of pasteurization (74 °C, 40 s), high pasteurization (80 °C, 1 min), and boiling (100 °C, 10 s) based on residue content (at a level of concentration of about 2 ?g/kg and 30 ?g/kg of H2B1a) and sort of ingestion (in vitro, in vivo)

  3. Long-Term Stability of NIST Chip-Scale Atomic Clock Physics Packages

    Science.gov (United States)

    2007-01-01

    vacuum packaging), as has been demonstrated by Lutwak et al. [3]. Nevertheless, we tried to investigate the causes for the frequency shifts of...stability,” Optics Express, 13, 1249-1253. [3] R. Lutwak , J. Deng, W. Riley, M. Varghese, J. Leblanc, G. Tepolt, M. Mescher, D. K. Serkland, K. M. Geib...the 1st Annual Multiconference on Electronics and Photonics, 7-11 November 2006, Guanajuato, Mexico, in press. [6] R. Lutwak , P. Vlitas, M

  4. 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.

  5. Predictors of long term opioid withdrawal outcome after short-term stabilization with buprenorphine.

    Science.gov (United States)

    Saleh, M I

    2014-01-01

    We aim to examine predictors of opiate abstinence status 3 months after the end of buprenorphine/naloxone treatment for opioid-dependent participants. Participants (n= 516, age > 15 years) received buprenorphine/ naloxone treatment for 4 weeks and then randomly assigned to undergo dose tapering over either 7 days or 28 days. Bivariate analysis was performed to identify possible predictors of successful opiate abstinence outome (p-value opioid and drug urine tests result at the end taper; employment status, family problems, and alcohol use domains of addiction severity index (ASI) score; and clinical opiate withdrawal scale (COWS) at the end of stabilization. Final predictor list identified by logistic regression include: ASI score for family and alcohol problems, COWS at the end of stabilization and opiate urine test at the end of taper. Participants presenting with a negative urine test for opiate, more severe alcohol, more severe family problems, or more symptoms of opiate withdrawal at the end of stabilization were more likely to have a successful opiate abstinence.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fedorchuk, Oleksiy [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: LCTPC-Deutschland-Collaboration

    2016-07-01

    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 high voltage stability and reliability of the readout modules. This is a crucial requirement for the operation in the final ILD TPC. The main focus of the research presented in this talk is on studies of the discharge stability and operational features of large area 22 x 18 cm{sup 2} GEM foils. We present systematic studies of the stability of GEM foils under different operation conditions. These studies include measurements and calculations of the dynamic behavior of charges in the GEM foils after a trip. The results will be used to develop methods to avoid destructive discharges in the final readout module.

  7. Photo-induced electrochemical anodization of p-type silicon: achievement and demonstration of long term surface stability

    International Nuclear Information System (INIS)

    Dhanekar, Saakshi; Islam, S S; Harsh

    2012-01-01

    Surface stability is achieved and demonstrated by porous silicon (PS) fabricated using a wavelength-dependent photo-electrochemical (PEC) anodization technique. During anodization, the photon flux for all wavelengths was kept constant while only the effect of light wavelength on the surface morphology of PS was investigated. PS optical sensors were realized, characterized and tested using a photoluminescence (PL) quenching technique. An aliphatic chain of alcohols (methanol to n-octanol) was detected in the range of 10–200 ppm. Long term surface stability was observed from samples prepared under red (750–620 nm) and green illumination (570–495 nm), where the PL quenching cycles evoke the possibility of using PS for stable sensor device applications. This study provides a route for preparing highly sensitive organic vapour sensors with a precise selection of the fabrication parameters and demonstrating their prolonged performance. (paper)

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

    International Nuclear Information System (INIS)

    Yasue, Ken-ichi; Asamori, Koichi; Niwa, Masakazu; Hanamuro, Takahiro; Saito-Kokubu, Yoko; Sueoka, Shigeru; Makuuchi, Ayumu; Ikuta, Masafumi; Matsubara, Akihiro; Tamura, Hajimu; Kobori, Kazuo; Ishimaru, Tsuneari; Umeda, Koji

    2014-03-01

    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)

  9. Short and long-term genome stability analysis of prokaryotic genomes.

    Science.gov (United States)

    Brilli, Matteo; Liò, Pietro; Lacroix, Vincent; Sagot, Marie-France

    2013-05-08

    Gene organization dynamics is actively studied because it provides useful evolutionary information, makes functional annotation easier and often enables to characterize pathogens. There is therefore a strong interest in understanding the variability of this trait and the possible correlations with life-style. Two kinds of events affect genome organization: on one hand translocations and recombinations change the relative position of genes shared by two genomes (i.e. the backbone gene order); on the other, insertions and deletions leave the backbone gene order unchanged but they alter the gene neighborhoods by breaking the syntenic regions. A complete picture about genome organization evolution therefore requires to account for both kinds of events. We developed an approach where we model chromosomes as graphs on which we compute different stability estimators; we consider genome rearrangements as well as the effect of gene insertions and deletions. In a first part of the paper, we fit a measure of backbone gene order conservation (hereinafter called backbone stability) against phylogenetic distance for over 3000 genome comparisons, improving existing models for the divergence in time of backbone stability. Intra- and inter-specific comparisons were treated separately to focus on different time-scales. The use of multiple genomes of a same species allowed to identify genomes with diverging gene order with respect to their conspecific. The inter-species analysis indicates that pathogens are more often unstable with respect to non-pathogens. In a second part of the text, we show that in pathogens, gene content dynamics (insertions and deletions) have a much more dramatic effect on genome organization stability than backbone rearrangements. In this work, we studied genome organization divergence taking into account the contribution of both genome order rearrangements and genome content dynamics. By studying species with multiple sequenced genomes available, we were

  10. Long-term colloidal stability of 10 carbon nanotube types in the absence/presence of humic acid and calcium

    International Nuclear Information System (INIS)

    Schwyzer, Irène; Kaegi, Ralf; Sigg, Laura; Smajda, Rita; Magrez, Arnaud; Nowack, Bernd

    2012-01-01

    The colloidal stabilities of ten carbon nanotubes (CNTs) having varying physico-chemical properties were compared in long-term experiments. The presence of Suwannee River Humic Acid (SRHA) increased the fraction of CNTs in the supernatants (4–88% for the various CNT types) after addition in pre-dispersed form and 20 days of shaking and 5 days of settling. These suspensions were monomodal, containing individually suspended CNTs with highly negative surface charges. Calcium (2 mM) removed most of the CNT types from the supernatant, due to CNT-agglomerate formation initiated by reduction in surface charge. The amount of SRHA adsorbed to the different CNT types did not correlate (r 2 < 0.1) with the percentage of CNTs remaining in suspension. Multiple linear regression analysis revealed that the oxygen content and the diameter of the CNTs significantly influenced the percentage of stabilized CNTs, resulting in an increased fraction of functionalized and large-diameter CNTs that remained in suspension. Highlights: ► Ten different CNT types with varying physico-chemical properties were used. ► The presence of SRHA increased the fraction of CNTs in the supernatants for all CNT-types. ► The O-content and diameter of the CNTs influenced the percentage of CNTs stabilized. ► Functionalization and large diameter made CNTs resistant against Ca flocculation. - The long-term colloidal stability of 10 different CNT types in the presence of humic acid was dependent on oxygen content and diameter of the CNTs.

  11. Negative feedback mechanism for the long-term stabilization of earth's surface temperature

    International Nuclear Information System (INIS)

    Walker, J.C.G.; Hays, P.B.; Kasting, J.F.

    1981-01-01

    We suggest that the partial pressure of carbon dioxide in the atmosphere is buffered, over geological time scales, by a negative feedback mechanism in which the rate of weathering of silicate minerals (followed by deposition of carbonate minerals) depends on surface temperature, and surface temperature, in turn, depends on carbon dioxide partial pressure through the green effect. Although the quantitative details of this mechanism are speculative, it appears able partially to stabilize earth's surface temperature against the steady increase of solar luminosity believed to have occured since the origin of the solar system

  12. Tai Chi for treating knee osteoarthritis: Designing a long-term follow up randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Rones Ramel

    2008-07-01

    Full Text Available Abstract Background Knee Osteoarthritis (KOA is a major cause of pain and functional impairment among elders. Currently, there are neither feasible preventive intervention strategies nor effective medical remedies for the management of KOA. Tai Chi, an ancient Chinese mind-body exercise that is reported to enhance muscle function, balance and flexibility, and to reduce pain, depression and anxiety, may safely and effectively be used to treat KOA. However, current evidence is inconclusive. Our study examines the effects of a 12-week Tai Chi program compared with an attention control (wellness education and stretching on pain, functional capacity, psychosocial variables, joint proprioception and health status in elderly people with KOA. The study will be completed by July 2009. Methods/Design Forty eligible patients, age > 55 yr, BMI ≤ 40 kg/m2 with tibiofemoral osteoarthritis (American College of Rheumatology criteria are identified and randomly allocated to either Tai Chi (10 modified forms from classical Yang style Tai Chi or attention control (wellness education and stretching. The 60-minute intervention sessions take place twice weekly for 12 weeks. The study is conducted at an urban tertiary medical center in Boston, Massachusetts. The primary outcome measure is the Western Ontario and McMaster Universities (WOMAC pain subscale at 12 weeks. Secondary outcomes include weekly WOMAC pain, function and stiffness scores, patient and physician global assessments, lower-extremity function, knee proprioception, depression, self-efficacy, social support, health-related quality of life, adherence and occurrence of adverse events after 12, 24 and 48 weeks. Discussion In this article, we present the challenges of designing a randomized controlled trial with long-term follow up. The challenges encountered in this design are: strategies for recruitment, avoidance of selection bias, the actual practice of Tai Chi, and the maximization of adherence

  13. Urease immobilized polymer hydrogel: Long-term stability and enhancement of enzymatic activity.

    Science.gov (United States)

    Kutcherlapati, S N Raju; Yeole, Niranjan; Jana, Tushar

    2016-02-01

    A method has been developed in which an enzyme namely urease was immobilized inside hydrogel matrix to study the stability and enzymatic activity in room temperature (∼27-30°C). This urease coupled hydrogel (UCG) was obtained by amine-acid coupling reaction and this procedure is such that it ensured the wider opening of mobile flap of enzyme active site. A systematic comparison of urea-urease assay and the detailed kinetic data clearly revealed that the urease shows activity for more than a month when stored at ∼27-30°C in case of UCG whereas it becomes inactive in case of free urease (enzyme in buffer solution). The aqueous microenvironment inside the hydrogel, unusual morphological features and thermal behaviour were believed to be the reasons for unexpected behaviour. UCG displayed enzyme activity at basic pH and up to 60°C. UCG showed significant enhancement in activity against thermal degradation compared to free urease. In summary, this method is a suitable process to stabilize the biomacromolecules in standard room temperature for many practical uses. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. 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.

  15. Differential algebras with remainder and rigorous proofs of long-term stability

    International Nuclear Information System (INIS)

    Berz, Martin

    1997-01-01

    It is shown how in addition to determining Taylor maps of general optical systems, it is possible to obtain rigorous interval bounds for the remainder term of the n-th order Taylor expansion. To this end, the three elementary operations of addition, multiplication, and differentiation in the Differential Algebraic approach are augmented by suitable interval operations in such a way that a remainder bound of the sum, product, and derivative is obtained from the Taylor polynomial and remainder bound of the operands. The method can be used to obtain bounds for the accuracy with which a Taylor map represents the true map of the particle optical system. In a more general sense, it is also useful for a variety of other numerical problems, including rigorous global optimization of highly complex functions. Combined with methods to obtain pseudo-invariants of repetitive motion and extensions of the Lyapunov- and Nekhoroshev stability theory, the latter can be used to guarantee stability for storage rings and other weakly nonlinear systems

  16. Stability enhancement of an atomic force microscope for long-term force measurement including cantilever modification for whole cell deformation

    Science.gov (United States)

    Weafer, P. P.; McGarry, J. P.; van Es, M. H.; Kilpatrick, J. I.; Ronan, W.; Nolan, D. R.; Jarvis, S. P.

    2012-09-01

    Atomic force microscopy (AFM) is widely used in the study of both morphology and mechanical properties of living cells under physiologically relevant conditions. However, quantitative experiments on timescales of minutes to hours are generally limited by thermal drift in the instrument, particularly in the vertical (z) direction. In addition, we demonstrate the necessity to remove all air-liquid interfaces within the system for measurements in liquid environments, which may otherwise result in perturbations in the measured deflection. These effects severely limit the use of AFM as a practical tool for the study of long-term cell behavior, where precise knowledge of the tip-sample distance is a crucial requirement. Here we present a readily implementable, cost effective method of minimizing z-drift and liquid instabilities by utilizing active temperature control combined with a customized fluid cell system. Long-term whole cell mechanical measurements were performed using this stabilized AFM by attaching a large sphere to a cantilever in order to approximate a parallel plate system. An extensive examination of the effects of sphere attachment on AFM data is presented. Profiling of cantilever bending during substrate indentation revealed that the optical lever assumption of free ended cantilevering is inappropriate when sphere constraining occurs, which applies an additional torque to the cantilevers "free" end. Here we present the steps required to accurately determine force-indentation measurements for such a scenario. Combining these readily implementable modifications, we demonstrate the ability to investigate long-term whole cell mechanics by performing strain controlled cyclic deformation of single osteoblasts.

  17. Stability and buffering capacity of the geosphere for long-term isolation of radioactive waste

    International Nuclear Information System (INIS)

    2004-01-01

    Most experts worldwide agree that radioactive waste disposal in engineered facilities, or repositories, located in appropriate formations deep underground, provide a suitable waste management option for protecting humans and the environment now and. in the future. An NEA workshop was organised on 9-11 December 2003 in Braunschweig, Germany, devoted specifically to argillaceous settings for deep geological repositories. The workshop brought together scientists from academic institutions, engineers from various research institutions or companies, consultants, regulatory authorities and national waste management organisations to establish the scientific basis for stability and buffering capacity of deep geological waste management systems. The present report synthesizes the main outcomes of that workshop and presents a compilation of the related abstracts. (author)

  18. The long-term behavior of stabilized coal ash in the sea

    International Nuclear Information System (INIS)

    van der Sloot, H.A.; Hockley, D.; Woodhead, P.M.J.; Roethel, F.J.

    1991-01-01

    Over an eight year period blocks of stabilized coal fly-ash and FGD scrubber sludge were placed in the Atlantic Ocean where they served as substrate for an artificial fishing reef. Structural testing has shown that these blocks have maintained their physical integrity over this extended time period. The concentrations of Ca, As, Sb and Mo have declined. The concentrations of Mg, Na, Br and CO 3 have increased. The influx of mass entering the block exceeds the leaching of inorganic constituents and results in the deposition of material in the pore spaces. This pore-blocking affects the diffusion of ions from the block and could potentially result in the cessation of contaminant release to the water column

  19. The state of external equilibrium in Croatia and its long term stability

    Directory of Open Access Journals (Sweden)

    Dražen Derado

    2002-01-01

    Full Text Available From the outset of transition Croatia faces a serious problem of external imbalance as a consequence of unfinished structural and institutional reforms. The external balance crisis can be seen through raising international trade deficit and structural characteristics of trade flows. To these unfavorable characteristics belong export reorientation from developed to less developed countries, increasing number of industries in which Croatia has position of net-importer and export structure in which dominate low-value-added products. Increasing trade deficit in 2001 and 2002 followed by further growth in external indebtedness cause increasing burden of debt service and limit the possibilities for economic growth. Taking all this as well as real limits in further external imbalance growth into consideration it can be said that Croatia realizes high level of external disequilibrium. In contrast, advanced transition countries achieve fairly good and stabile external positions thanks to successful economic restructuring and strong export growth.

  20. 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

  1. Long-Term Stability of Tramadol and Ketamine Solutions for Patient-Controlled Analgesia Delivery.

    Science.gov (United States)

    Gu, Junfeng; Qin, Wengang; Chen, Fuchao; Xia, Zhongyuan

    2015-08-26

    Subanesthetic doses of ketamine as an adjuvant to tramadol in patient-controlled analgesia (PCA) for postoperative pain have been shown to improve the quality of analgesia. However, there are no such commercially available drug mixtures, and the stability of the combination has rarely been assessed. Admixtures were assessed for periods of up to 14 days at 4°C and 25°C. Three different mixtures of tramadol and ketamine (tramadol 5.0 mg/mL + ketamine 0.5 mg/mL, tramadol 5.0 mg/mL + ketamine 1.0 mg/mL, and tramadol 5.0 mg/mL + ketamine 2.0 mg/mL) were prepared in polyolefin bags by combining these 2 drugs with 0.9% sodium chloride (normal saline [NS]). The chemical stability of the admixtures was evaluated by a validated high-performance liquid chromatography (HPLC) method and by measurement of pH values. Solution appearance and color were assessed by observing the samples against black and white backgrounds. Solutions were considered stable if they maintained 90% of the initial concentration of each drug. The percentages of initial concentration of tramadol and ketamine in the various solutions remained above 98% when stored at 4°C or 25°C over the testing period. No changes in color or turbidity were observed in any of the prepared solutions. Throughout this period, pH values remained stable. The results indicate that the drug mixtures of tramadol with ketamine in NS for PCA delivery systems were stable for 14 days when stored in polyolefin bags at 4°C or 25°C.

  2. Stability analysis of roadway embankments supported by stone columns with the presence of water table under short-term and long-term conditions

    Directory of Open Access Journals (Sweden)

    Kadhim Shaymaa Tareq

    2018-01-01

    Full Text Available Use of stone column technique to improve soft foundation soils under roadway embankments has proven to increase the bearing capacity and reduce the potential settlement. The potential contribution of stone columns to the stability of roadway embankments against general (i.e. deep-seated failure needs to be thoroughly investigated. Therefore, a two-dimensional finite difference model implemented by FLAC/SLOPE 7.0 software, was employed in this study to assess the stability of a roadway embankment fill built on a soft soil deposit improved by stone column technique. The stability factor of safety was obtained numerically under both short-term and long-term conditions with the presence of water table. Two methods were adopted to convert the three-dimensional model into plane strain condition: column wall and equivalent improved ground methods. The effect of various parameters was studied to evaluate their influence on the factor of safety against embankment instability. For instance, the column diameter, columns’ spacing, soft soil properties for short-term and long-term conditions, and the height and friction angle of the embankment fill. The results of this study are developed in several design charts.

  3. Using the fluorescence red edge effect to assess the long-term stability of lyophilized protein formulations.

    Science.gov (United States)

    Qian, Ken K; Grobelny, Pawel J; Tyagi, Madhusudan; Cicerone, Marcus T

    2015-04-06

    Nanosecond relaxation processes in sugar matrices are causally linked through diffusional processes to protein stability in lyophilized formulations. Long-term protein degradation rates track mean-squared displacement (⟨u(2)⟩) of hydrogen atoms in sugar glasses, a parameter describing dynamics on a time scale of picoseconds to nanoseconds. However, measurements of ⟨u(2)⟩ are usually performed by neutron scattering, which is not conducive to rapid formulation screening in early development. Here, we present a benchtop technique to derive a ⟨u(2)⟩ surrogate based on the fluorescence red edge effect. Glycerol, lyophilized trehalose, and lyophilized sucrose were used as model systems. Samples containing 10(-6) mole fraction of rhodamine 6G, a fluorophore, were excited at either 532 nm (main peak) or 566 nm (red edge), and the ⟨u(2)⟩ surrogate was determined based the corresponding Stokes shifts. Results showed reasonable agreement between ⟨u(2)⟩ from neutron scattering and the surrogate from fluorescence, although deviations were observed at very low temperatures. We discuss the sources of the deviations and suggest technique improvements to ameliorate these. We expect that this method will be a valuable tool to evaluate lyophilized sugar matrices with respect to their ability to protect proteins from diffusion-limited degradation processes during long-term storage. Additionally, the method may have broader applications in amorphous pharmaceutical solids.

  4. Examination of the long-term stability of radiation survey meters and electronic pocket dosemeters

    International Nuclear Information System (INIS)

    Chida, K.; Nishimura, Y.; Sato, Y.; Endo, A.; Sakamoto, M.; Hoshi, C.; Zuguchi, M.

    2008-01-01

    To describe the stability of radiation survey meters (RSMs) and electronic pocket dosemeters (EPDs), we examined 28 EPDs and 24 RSMs: 12 used NaI(Tl) scintillation RSMs and 12 used Geiger-Muller (GM) RSMs. We used simple methods for the relative calibration of the 24 RSMs and 28 EPDs. The RSM and EPD measurements were compared with a calibrated RSM and EPD (reference: traceable from the national standard of exposure) using a homemade measurement device to maintain the reproducibility of the measurements with reference radiation sources (i.e. 137 Cs, 90 Sr and 67 Ga). The response of RSMs and EPDs, especially after prolonged use, should be checked periodically. In particular, GMRSMs that have been in use for many years have very low sensitivity and poor reproducibility. Our simple method for the relative calibration of RSMs and EPDs was shown to be effective for quality assurance purposes in checking RSMs and EPDs. We recommend regular checks and calibration for sustained performance of RSMs and EPDs. (authors)

  5. Long term OSLD reader stability in the ACDS level one audit

    International Nuclear Information System (INIS)

    Alves, Andrew D.C.; Lye, Jessica; Kenny, John; Dunn, Leon; Lehmann, Joerg; Cole, Andrew; Williams, Ivan; Kron, Tomas; Butler, Duncan; Johnston, Peter

    2015-01-01

    The Australian Clinical Dosimetry Service (ACDS) has demonstrated the capacity to perform a basic dosimetry audit on all radiotherapy clinics across Australia. During the ACDS’s three and a half year trial the majority of the audits were performed using optically stimulated luminescence dosimeters (OSLD) mailed to facilities for exposure to a reference dose, and then returned to the ACDS for analysis. This technical note investigates the stability of the readout process under the large workload of the national dosimetry audit. The OSLD readout uncertainty contributes to the uncertainty of several terms of the dose calculation equation and is a major source of uncertainty in the audit. The standard deviation of four OSLD readouts was initially established at 0.6 %. Measurements over 13 audit batches—each batch containing 200−400 OSLDs—showed variability (0.5−0.9 %) in the readout standard deviation. These shifts have not yet necessitated a change to the audit scoring levels. However, a standard deviation in OSLD readouts greater than 0.9 % will change the audit scoring levels. We identified mechanical wear on the OSLD readout adapter as a cause of variability in readout uncertainty, however, we cannot rule out other causes. Additionally we observed large fluctuations in the distribution of element correction factors (ECF) for OSLD batches. We conclude that the variability in the width of the ECF distribution from one batch to another is not caused by variability in readout uncertainty, but rather by variations in the OSLD stock.

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

    International Nuclear Information System (INIS)

    Bruening, O.S.

    1994-05-01

    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

  7. Occlusal stabilization splint for patients with temporomandibular disorders: Meta-analysis of short and long term effects.

    Directory of Open Access Journals (Sweden)

    Jovana Kuzmanovic Pficer

    Full Text Available Psychological discomfort, physical disability and functional limitations of the orofacial system have a major impact on everyday life of patients with temporomandibular disorders (TMDs. In this study we sought to determine short and long term effects of stabilization splint (SS in treatment of TMDs, and to identify factors influencing its efficacy.MEDLINE, Web of Science and EMBASE were searched for randomized controlled trials (RCTs comparing SS to: non-occluding splint, occlusal oral appliances, physiotherapy, behavioral therapy, counseling and no treatment. Random effects method was used to summarize outcomes. The effect estimates were expressed as odds ratio (OR or standardized mean difference (SMD with 95% confidence interval. Subgroup analyses were carried out according to the use of Research Diagnostic Criteria (RDC/TMD and TMDs origin. Strength of evidence was assessed by GRADE. Meta-regression was applied.Thirty three eligible RCTs were included in meta-analysis. In short term, SS presented positive overall effect on pain reduction (OR 2.08; p = 0.01 and pain intensity (SMD -0.33; p = 0.02. Subgroup analyses confirmed SS effect in studies used RDC/TMD and revealed its effect in patients with TMDs of muscular origin. Important decrease of muscle tenderness (OR 1.97; p = 0.03 and improvement of mouth opening (SMD -0.30; p = 0.04 were found. SS in comparison to oral appliances showed no difference (OR 0.74; p = 0.24. Meta-regression identified continuous use of SS during the day as a factor influencing efficacy (p = 0.01. Long term results showed no difference in observed outcomes between groups. Low quality of evidence was found for primary outcomes.SS presented short term benefit for patients with TMDs. In long term follow up, the effect is equalized with other therapeutic modalities. Further studies based on appropriate use of standardized criteria for patient recruitment and outcomes under assessment are needed to better define SS

  8. The design, fabrication, and testing of WETF high-quality, long-term-storage, secondary containment vessels

    International Nuclear Information System (INIS)

    Fisher, Kane J.

    2000-01-01

    Los Alamos National Laboratory's Weapons Engineering Tritium Facility (WETF) requires secondary containment vessels to store primary tritium containment vessels. The primary containment vessel provides the first boundary for tritium containment. The primary containment vessel is stored within a secondary containment vessel that provides the secondary boundary for tritium containment. WETF requires high-quality, long-term-storage, secondary tritium containment vessels that fit within a Mound-designed calorimeter. In order to qualify the WETF high-quality, long-term-storage, secondary containment vessels for use at WETF, steps have been taken to ensure the appropriate design, adequate testing, quality in fabrication, and acceptable documentation

  9. 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.

  10. Short-term influences and long-term fundamentals: stabilizing and destabilizing effects in the energy industries

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Silvan [Royal Inst. of International Affairs, London (United Kingdom)

    1992-10-01

    The ideology of the market economy has become dominant in all walks of economic life and the energy industries are no exception. In the oil business, the stabilizing structures of the international majors and of long-term prices have been replaced by industrial fragmentation and market price mechanisms. Monopolies in other energy industries are being progressively dismantled. This live experiment is being conducted on an industry which historically has suffered from feast and famine economics and has tried to protect itself through various forms of cartelization. The short-term effects of this open market have so far tended to improve flexibility and consumer choice. The price instability has proved manageable. The danger is that cash flow compression will reduced investments in the future and an ability to make very long lead time shifts in the energy mix. For this some government intervention in markets is necessary. (author).

  11. Platinum monolayer electrocatalysts for oxygen reduction: effect of substrates, and long-term stability

    Directory of Open Access Journals (Sweden)

    J. ZHANG

    2005-03-01

    Full Text Available We describe a novel concept for a Ptmonolayer electrocatalyst and present the results of our electrochemical, X-ray absorption spectroscopy, and scanning tunneling microscopy studies. The electrocatalysts were prepared by a new method for depositing Pt monolayers involving the galvanic displacement by Pt of an underpotentially deposited Cu monolayer on substrates of Au (111, Ir(111, Pd(111, Rh(111 and Ru(0001 single crylstals, and Pd nanoparticles. The kinetics of O2 reduction showed significant enhancement with Pt monolayers on Pd(111 and Pd nanoparticle surfaces in comparisonwith the reaction on Pt(111 and Pt nanoparticles, respectively. This increase in catalytic activity is attributed partly to the decreased formation of PtOH, as shown by in situ X-ray absorption spectroscopy. The results illustrate that placing a Pt monolayer on a suitable substrate of metal nanoparticles is an attractive way of designing better O2 reduction electrocatalysts with very low Pt contents.

  12. Parenteral emulsions stabilized with a mixture of phospholipids and PEG-660-12-hydroxy-stearate: evaluation of accelerated and long-term stability.

    Science.gov (United States)

    Jumaa, Muhannad; Müller, Bernd W

    2002-09-01

    Different emulsion formulations were prepared using phospholipids (Lipoid S57) and PEG-660-12-hydroxy-stearate (Solutol HS15) as single emulsifiers or in mixtures. The accelerated stability after autoclaving, freezing and centrifugation was investigated. The long-term stability was also studied at different temperatures (4, 20, and 37 degrees C) for 8 months. Emulsion stabilized with phospholipids displayed a stable behavior after the autoclaving and centrifugation, but it broke down after the freezing process. In mixture with Solutol HS15, however, the emulsion showed appropriate shelf stability at different temperatures for 8 months. A change in the particle size of the emulsion prepared only with Solutol HS15 was observed after centrifugation (slight) and after autoclaving (marked). In contrast to phospholipid emulsion, this emulsion (with only Solutol HS15) was less prone to breaking down after the freezing, as no complete phase separation was observed. The results obtained using an emulsifier mixture revealed that a combination of an anionic surfactant (phospholipids) and non-ionic surfactant (PEG-660-12-hydroxy-stearate) improves the emulsion's stability, compared to the emulsion's stability prepared using only a single emulsifier. However, no direct correlation could be found between the accelerated and the long-term stability data.

  13. Environmental factors affecting long-term stabilization of radon suppression covers for uranium mill tailings

    International Nuclear Information System (INIS)

    Young, J.K.; Long, L.W.; Reis, J.W.

    1982-04-01

    Pacific Northwest Laboratory is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon suppression cover applied to uranium mill tailings. To help determine design stresses for the tailings piles, environmental parameters are characterized for the five active uranium-producing regions on a site-specific basis. Only conventional uranium mills that are currently operating or that are scheduled to open in the mid 1980s are considered. Available data indicate that flooding has the most potential for disrupting a tailings pile. The arid regions of the Wyoming Basins and the Colorado Plateau are subject to brief storms of high intensity. The Texas Gulf Coast has the highest potential for extreme precipitation from hurricane-related storms. Wind data indicate average wind speeds from 3 to 6 m/sec for the sites, but extremes of 40 m/sec can be expected. Tornado risks range from low to moderate. The Colorado Plateau has the highest seismic potential, with maximum acceleration caused by earthquakes ranging from 0.2 to 0.4 g. Any direct effect from volcanic eruption is negligible, as all mills are located 90 km or more from an igneous or hydrothermal system

  14. 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)

    Aswath, P.B.

    1994-01-01

    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 α 2 +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 α 2 phase reduces the resistance of the microstructure to fatigue crack growth at room temperature

  15. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Danielsen, Hilmar K. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Mechanical Engineering; Hald, John [DONG Energy A/S (Denmark); Vattenfall (Denmark)

    2010-07-01

    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 high-temperature 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. However 9%Cr steels do not seem to be affected by the Z-phase. Careful control of the Z-phase precipitation process has led to the design of experimental 12%Cr martensitic steels strengthened by fine Z-phase nitrides based on Nb or Ta. 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.)

  17. Design and validation of a clinical-scale bioreactor for long-term isolated lung culture.

    Science.gov (United States)

    Charest, Jonathan M; Okamoto, Tatsuya; Kitano, Kentaro; Yasuda, Atsushi; Gilpin, Sarah E; Mathisen, Douglas J; Ott, Harald C

    2015-06-01

    The primary treatment for end-stage lung disease is lung transplantation. However, donor organ shortage remains a major barrier for many patients. In recent years, techniques for maintaining lungs ex vivo for evaluation and short-term (advance to more complex interventions for lung repair and regeneration, the need for a long-term organ culture system becomes apparent. Herein we describe a novel clinical scale bioreactor capable of maintaining functional porcine and human lungs for at least 72 h in isolated lung culture (ILC). The fully automated, computer controlled, sterile, closed circuit system enables physiologic pulsatile perfusion and negative pressure ventilation, while gas exchange function, and metabolism can be evaluated. Creation of this stable, biomimetic long-term culture environment will enable advanced interventions in both donor lungs and engineered grafts of human scale. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The effects of maxillary protraction and its long-term stability--a clinical trial in Chinese adolescents.

    Science.gov (United States)

    Chen, LinLing; Chen, RongJing; Yang, YiMing; Ji, GuoPing; Shen, Gang

    2012-02-01

    The purpose of this study was to evaluate the effect of reverse pull headgear (RPHG) in the treatment of Class III malocclusions in the late mixed and early permanent dentition and its long-term stability at the time when facial growth was close to completion. The treatment group comprised 22 subjects (12 males and 10 females, mean age: 11.38 ± 0.69 years). The control group included 17 subjects (7 males and 10 females, mean age: 11.54 ± 1.07 years). The mean RPHG treatment time was 1.5 ± 0.95 years and the observation time for the control group was 1.75 ± 0.83 years. For each subject, lateral cephalograms were obtained before (T1) and after (T2) treatment or observation. These cephalograms were traced and analyzed and the differences between T1 and T2 values were examined with paired t-tests. Of the 22 treated cases, 10 patients were followed up until at the mean age of 16.18 years (T3). Since there was no relapse in anterior crossbite, the long-term effects of RPHG were evaluated by measuring the maxillary and mandibular skeletal changes. The follow-up patients were divided into two groups based on the change in ANB: a stable group (decrease in ANB 2 degrees). The skeletal effects of RPHG in treating Class III anomalies just before or at the beginning of the pubertal growth spurt include protraction of the maxilla and dentition and inhibition of forward growth of the mandible. With regard to the long-term change, a slight alteration in the position of the maxilla and in the position and growth direction of the mandible resulted in a slight decrease in ANB in the stable group. The slight retrusion in the maxilla, combined with the significant protrusion in the mandible and the more horizontal mandibular growth direction, resulted in a decrease in ANB in the unstable group. This indicated that the maxilla remained relatively stable and that the unstable factor was continuing mandibular growth during the pubertal and post-pubertal period. For patients with an

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

    International Nuclear Information System (INIS)

    Mullaugh, Katherine M.; Luther, George W.

    2011-01-01

    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

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

    International Nuclear Information System (INIS)

    Mukhtar, A.M.; Samat, S.B.; Mohd Taufik Dolah

    2014-01-01

    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 N D,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 N D,w deviation together with its standard error SE were calculated. This μ ±SE will be used to measure stability of N D,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 N D,w and safe to be used for radiotherapy treatment. (author)

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

    International Nuclear Information System (INIS)

    Xian, Xiaochao; Chen, Minglu; Li, Lixin; Lin, Zhen; Xiang, Jun; Zhao, Shuo

    2013-01-01

    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. •Fe 3+ 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 Fe 3+ , 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

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

    International Nuclear Information System (INIS)

    Knight, M.J.

    1983-04-01

    Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m 3 ) 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

  3. Stability of Folate and Vitamin B 12 in Human Serum after Long-Term Storage: A Follow-Up after 13 Years

    NARCIS (Netherlands)

    Jansen, Eugène H. J. M.; Beekhof, Piet K.; Centre for Health Protection, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, Netherlands; Centre for Health Protection, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, Netherlands

    2018-01-01

    In epidemiological and nutrition research, it is very important to evaluate the stability of biomarkers as function of both storage time and temperature. In this study, the stability of folate and vitamin B 12 in human serum samples has been tested after long-term

  4. Long-Term Stability of Scores on the Wechsler Intelligence Scale for Children-Fourth Edition in Children with Learning Disabilities

    Science.gov (United States)

    Lander, Jenny

    2010-01-01

    The present investigation explored the stability of scores on the Wechsler Intelligence Scale for Children-IV (WISC-IV) over approximately a three-year period. Previous research has suggested that some children with Learning Disabilities (LD) do not demonstrate long-term stability of intelligence. Legally, school districts are no longer required…

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

    International Nuclear Information System (INIS)

    Ramzaev, V.; Andersson, K.G.; Barkovsky, A.; Fogh, C.L.; Mishine, A.; Roed, J.

    2006-01-01

    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 137 Cs 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 137 Cs 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

  6. OECD MCCI project long-term 2-D molten core concrete interaction test design report, Rev. 0. September 30, 2002

    International Nuclear Information System (INIS)

    Farmer, M.T.; Kilsdonk, D.J.; Lomperski, S.; Aeschliman, R.W.; Basu, S.

    2011-01-01

    The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following two technical objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of the first program objective, the Small-Scale Water Ingression and Crust Strength (SSWICS) test series has been initiated to provide fundamental information on the ability of water to ingress into cracks and fissures that form in the debris during quench, thereby augmenting the otherwise conduction-limited heat transfer process. A test plan for Melt Eruption Separate Effects Tests (MESET) has also been developed to provide information on the extent of crust growth and melt eruptions as a function of gas sparging rate under well-controlled experiment conditions. In terms of the second program objective, the project Management Board (MB) has approved startup activities required to carry out

  7. Long-term stability study of Prussian blue - a quality assessment of water content and thallium binding.

    Science.gov (United States)

    Mohammad, Adil; Faustino, Patrick J; Khan, Mansoor A; Yang, Yongsheng

    2014-12-30

    The purpose of this study is to assess the long-term stability of Prussian blue (PB) drug product (DP) and active pharmaceutical ingredient (API) under laboratory storage conditions by monitoring the loss in water content and the corresponding change of the in vitro thallium binding capacity that represents product performance. The bound water content and the in vitro thallium binding capacity of PB DPs and APIs were measured in 2003 and 2013, respectively. Water content, a critical quality attribute that directly correlates to the thallium (Tl) binding capacity was measured by thermal gravimetric analysis (TGA). The thallium binding study was conducted by testing PB in buffered solutions over the human gastrointestinal pH range with thallium concentrations ranging from 600 to 1,500 ppm. Samples were incubated at physiological temperature of 37°C in a shaking water bath to mimic gastric flux and intestinal transport. The binding equilibrium was reached at 24h. Following incubation, each sample was filtered and the free thallium was analyzed using a validated inductively coupled plasma spectroscopic method (ICP). The Langmuir isotherm was plotted to calculate maximum binding capacity (MBC). Compared with 2003, the water content of DP-1 decreased by about 14.1% (from 15.6 to 13.4 mol), and the MBC of DP-1 decreased by about 12.5% (from 714 to 625 mg/g) at pH 7.5. When low concentration of thallium (600 ppm) was used at pH 7.5, the Tl binding remained comparable for both API-1 (286 vs 276 mg/g) and DP-1 (286 vs 268 mg/g). Similarly, the Tl binding remained unchanged for both API-1 (237 vs 255 mg/g) and DP-1 (234 vs 236 mg/g) at pH 5.0. However, at pH 1.0 the binding was reduced 32.3% and 25.9% for API-1 and DP-1, respectively. Since the majority of binding takes place in the upper GI tract where pH around 5 can be expected, and therefore, the Tl binding capacity of PB should be comparable for new and aged samples. The findings that Tl binding changes with the water

  8. Long-term stability study of Prussian blue-A quality assessment of water content and cyanide release.

    Science.gov (United States)

    Mohammad, A; Yang, Y; Khan, M A; Faustino, P J

    2015-02-01

    Prussian blue, ferric hexacyanoferrate is approved for (oral) treatment of internal contamination with radioisotopes of cesium or thallium. Cyanide makes up 35-40% of Prussian blue's molecular composition; thus, cyanide may be released during transit through the digestive tract under physiological pH conditions. The purpose of this study is to assess the long-term stability of Prussian blue drug products and active pharmaceutical ingredients and its impact on cyanide release. The study involves the determination and comparison of the loss in water content and cyanide released from Prussian blue under pH conditions that bracket human physiological exposure. Test samples of active pharmaceutical ingredient and drug product were stored for 10 years at ambient temperatures that mimic warehouse storage conditions. Water loss from Prussian blue was measured using thermogravimetric analysis. An in vitro physiological pH model that brackets gastric exposure and gastrointestinal transit was utilized for cyanide release. Prussian blue was incubated in situ at pH: 1.0, 5.0, and 7.0 @ 37°C for 1-24 h. Cyanide was measured using a validated colorimetric method by UV-Vis spectroscopy. Although the water content (quality attribute) of Prussian blue active pharmaceutical ingredient and drug product decreased by about 10.5% and 13.8%, respectively, since 2003, the cyanide release remained comparable. At pH of 7.0 for 24 h cyanide released from active pharmaceutical ingredient-1 was 21.33 ± 1.76 μg/g in 2004, and 28.45 ± 3.15 μg/g in 2013; cyanide released from drug product-1 was 21.89 ± 0.56 μg/g in 2004, and 27.31 ± 5.78 μg/g in 2013. At gastric pH of 1.0 and upper gastrointestinal pH of 5.0, the data for active pharmaceutical ingredients and drug products were also comparable in 2013. The cyanide release is still pH-dependent and follows the same trend as observed in 2003 with minimum release at pH of 5.0 and maximal release at pH of 1.0. In summary, this is the long-term

  9. 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.

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

    International Nuclear Information System (INIS)

    Saari, J.

    1995-04-01

    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.)

  11. 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

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

    Directory of Open Access Journals (Sweden)

    Zhi-Gang Xue

    2010-01-01

    Full Text Available 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. However, four out of the eight HDF lines at high passage numbers (≥P10 exhibited duplicated hallmarks of inactive X chromosome including two punctuate signals of histone H3 lysine 27 trimethylation (H3K27me3 and X inactive-specific transcript (XIST RNA signals in approximately 8.5–18.5% of the cells. Our data suggest that the copy number of inactive X chromosomes in a subset of female HDF is increased by a two-fold. Consistently, DNA fluorescent in situ hybridization (FISH identified 3-4 copies of X chromosomes in one nucleus in this subset of cells with two inactive Xs. We conclude that female HDF cultures exhibit a higher risk of genetic anomalies such as carrying an increased number of X chromosomes including both active and inactive X chromosomes at a high passage (≥P10.

  13. 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.

  14. Enhancement of electron emission and long-term stability of tip-type carbon nanotube field emitters via lithium coating

    International Nuclear Information System (INIS)

    Kim, Jong-Pil; Chang, Han-Beet; Kim, Bu-Jong; Park, Jin-Seok

    2013-01-01

    Carbon nanotubes (CNTs) were deposited on conical tip-type substrates via electrophoresis and coated with lithium (Li) thin films with diverse thicknesses via electroplating. For the as-deposited (i.e., without Li coating) CNT, the turn-on (or triggering) electric field was 0.92 V/μm, and the emission current, which was generated at an applied field of 1.2 V/μm was 56 μA. In the case of the 4.7 nm-thick Li-coated CNT, the turn-on field decreased to 0.65 V/μm and the emission current at the same applied field increased more than ten times to 618 μA. The analysis based on the Kelvin probe measurement and Fowler–Nordheim theory indicated that the coating of Li caused a loss in the structural-aspect-ratio of the CNTs and it reduced their effective work functions from 5.36 eV to 4.90 eV, which led to a great improvement of their electron emission characteristics. The results obtained in this study also showed that the long-term emission stability could be enhanced by the coating of thin Li films on CNTs. - Highlights: ► CNTs are deposited via electrophoretic deposition (EPD). ► Thin films of Li are coated on CNTs via electroplating, without plasma damage. ► Li coating enhanced field emission properties and emission stability of CNTs. ► The effective work functions and field enhancement factors of CNTs are evaluated

  15. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Integrated community profiling indicates long-term temporal stability of the predominant faecal microbiota in captive cheetahs.

    Directory of Open Access Journals (Sweden)

    Anne A M J Becker

    Full Text Available Understanding the symbiotic relationship between gut microbes and their animal host requires characterization of the core microbiota across populations and in time. Especially in captive populations of endangered wildlife species such as the cheetah (Acinonyx jubatus, this knowledge is a key element to enhance feeding strategies and reduce gastrointestinal disorders. In order to investigate the temporal stability of the intestinal microbiota in cheetahs under human care, we conducted a longitudinal study over a 3-year period with bimonthly faecal sampling of 5 cheetahs housed in two European zoos. For this purpose, an integrated 16S rRNA DGGE-clone library approach was used in combination with a series of real-time PCR assays. Our findings disclosed a stable faecal microbiota, beyond intestinal community variations that were detected between zoo sample sets or between animals. The core of this microbiota was dominated by members of Clostridium clusters I, XI and XIVa, with mean concentrations ranging from 7.5-9.2 log10 CFU/g faeces and with significant positive correlations between these clusters (P<0.05, and by Lactobacillaceae. Moving window analysis of DGGE profiles revealed 23.3-25.6% change between consecutive samples for four of the cheetahs. The fifth animal in the study suffered from intermediate episodes of vomiting and diarrhea during the monitoring period and exhibited remarkably more change (39.4%. This observation may reflect the temporary impact of perturbations such as the animal's compromised health, antibiotic administration or a combination thereof, which temporarily altered the relative proportions of Clostridium clusters I and XIVa. In conclusion, this first long-term monitoring study of the faecal microbiota in feline strict carnivores not only reveals a remarkable compositional stability of this ecosystem, but also shows a qualitative and quantitative similarity in a defined set of faecal bacterial lineages across the five

  17. Integrated Community Profiling Indicates Long-Term Temporal Stability of the Predominant Faecal Microbiota in Captive Cheetahs

    Science.gov (United States)

    Becker, Anne A. M. J.; Janssens, Geert P. J.; Snauwaert, Cindy; Hesta, Myriam; Huys, Geert

    2015-01-01

    Understanding the symbiotic relationship between gut microbes and their animal host requires characterization of the core microbiota across populations and in time. Especially in captive populations of endangered wildlife species such as the cheetah (Acinonyx jubatus), this knowledge is a key element to enhance feeding strategies and reduce gastrointestinal disorders. In order to investigate the temporal stability of the intestinal microbiota in cheetahs under human care, we conducted a longitudinal study over a 3-year period with bimonthly faecal sampling of 5 cheetahs housed in two European zoos. For this purpose, an integrated 16S rRNA DGGE-clone library approach was used in combination with a series of real-time PCR assays. Our findings disclosed a stable faecal microbiota, beyond intestinal community variations that were detected between zoo sample sets or between animals. The core of this microbiota was dominated by members of Clostridium clusters I, XI and XIVa, with mean concentrations ranging from 7.5-9.2 log10 CFU/g faeces and with significant positive correlations between these clusters (Pcheetahs. The fifth animal in the study suffered from intermediate episodes of vomiting and diarrhea during the monitoring period and exhibited remarkably more change (39.4%). This observation may reflect the temporary impact of perturbations such as the animal’s compromised health, antibiotic administration or a combination thereof, which temporarily altered the relative proportions of Clostridium clusters I and XIVa. In conclusion, this first long-term monitoring study of the faecal microbiota in feline strict carnivores not only reveals a remarkable compositional stability of this ecosystem, but also shows a qualitative and quantitative similarity in a defined set of faecal bacterial lineages across the five animals under study that may typify the core phylogenetic microbiome of cheetahs. PMID:25905625

  18. Designing Program Roadmaps to Catalyze Community Formation: A Case Study of the Long-Term Stewardship Science and Technology Roadmapword

    International Nuclear Information System (INIS)

    Dixon, Brent; Hanson, Duane; Matthern, Gretchen

    2003-01-01

    A number of broad perspective technology roadmaps have been developed in the last few years as tools for coordinating nation-wide research in targeted areas. These roadmaps share a common characteristic of coalescing the associated stakeholder groups into a special-interest community that is willing to work cooperatively in achieving the roadmap goals. These communities are key to roadmap implementation as they provide the collaborative energy necessary to obtain the political support and funding required for identified science and technology development efforts. This paper discusses the relationship between roadmaps and special-interest communities, using the recently drafted Department of Energy's Long-Term Stewardship Science and Technology Roadmap as a case study. Specific aspects this roadmap's design facilitated the development of a long-term stewardship community while specific realities during roadmap development impacted the realization of the design

  19. 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...... for the main strengthening precipitate, Laves phase. The alloy was proven to have good microstructural stability without observable coarsening of strengthening precipitates during long-term creep up to around 37,667 h. It was also verified that the growth kinetics of Laves phase can be well described...

  20. Characterizing Long-Term Groundwater Conditions and Lithology for the Design of Large-Scale Borehole Heat Exchangers

    Science.gov (United States)

    Smith, David Charles

    Construction of large scale ground coupled heat pump (GCHP) systems that operate with hundreds or even thousands of boreholes for the borehole heat exchangers (BHE) has increased in recent years with many coming on line in the past 10 years. Many large institutions are constructing these systems because of their ability to store energy in the subsurface for indoor cooling during the warm summer months and extract that energy for heating during the cool winter months. Despite the increase in GCHP system systems constructed, there have been few long term studies on how these large systems interact with the subsurface. The thermal response test (TRT) is the industry standard for determining the thermal properties of the rock and soil. The TRT is limited in that it can only be used to determine the effective thermal conductivity over the whole length of a single borehole at the time that it is administered. The TRT cannot account for long-term changes in the aquifer saturation, changes in groundwater flow, or characterize different rock and soil units by effectiveness for heat storage. This study established new methods and also the need for the characterization of the subsurface for the purpose of design and long-term monitoring for GCHP systems. These new methods show that characterizing the long-term changes in aquifer saturation and groundwater flow, and characterizing different rock and soil units are an important part of the design and planning process of these systems. A greater understanding of how large-scale GCHP systems interact with the subsurface will result in designs that perform more efficiently over a longer period of time and expensive modifications due to unforeseen changes in system performance will be reduced.

  1. Freeze drying optimization of polymeric nanoparticles for ocular flurbiprofen delivery: effect of protectant agents and critical process parameters on long-term stability.

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; Calpena Campmany, Ana Cristina; Egea Gras, María Antonia; Espina García, Marta; García López, María Luisa

    2017-04-01

    The stabilization of flurbiprofen loaded poly-ɛ-caprolactone nanoparticles (FB-PɛCL-NPs) for ocular delivery under accurate freeze-drying (FD) process provides the basis for a large-scale production and its commercial development. Optimization of the FD to improve long-term stability of ocular administration's FB-PɛCL-NPs. FB-PɛCL-NPs were prepared by solvent displacement method with poloxamer 188 (P188) as stabilizer. Freezing and primary drying (PD) were studied and optimized through freeze-thawing test and FD microscopy. Design of experiments was used to accurate secondary drying (SD) conditions and components concentration. Formulations were selected according to desired physicochemical properties. Furthermore, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to study interactions components. Optimized FB-PɛCL-NPs, stabilized with 3.5% (w/w) P188 and protected with 8% (w/w) poly(ethylene glycol), was submitted to precooling at +10 °C for 1 h, freezing at -50 °C for 4 h, PD at +5 °C and 0.140 mbar for 24 h and a SD at +45 °C during 10 h. These conditions showed 188.4 ± 1.3 nm, 0.087 ± 0.014, 85.5 ± 1.4%, 0.61 ± 0.12%, -16.4 ± 0.1 mV and 325 ± 7 mOsm/kg of average size, polydispersity index, entrapment efficiency, residual moisture, surface charge and osmolality, respectively. It performed a long-term stability >12 months. DSC and XRD spectra confirmed adequate chemical interaction between formulation components and showed a semi-crystalline state after FD. An optimal freeze dried ocular formulation was achieved. Evidently, the successful design of this promising colloidal system resulted from rational cooperation between a good formulation and the right conditions in the FD process.

  2. 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.

  3. Long term stability of learning outcomes in undergraduates after an open-inquiry instruction on thermal science

    Science.gov (United States)

    Persano Adorno, Dominique; Pizzolato, Nicola; Fazio, Claudio

    2018-02-01

    This paper investigates the efficacy of an open-inquiry approach to achieve a long term stability of physics instruction. This study represents the natural continuation of a research project started four years ago when a sample of thirty engineering undergraduates, having already attended traditional university physics instruction, were involved in a six-week long learning experience of open-inquiry research activities within the highly motivating context of developing a thermodynamically efficient space base on Mars. Four years later, we explore the effectiveness of that learning experience by analyzing the outcomes that the students achieved by answering again the same questionnaire that was administered them both prior to and immediately after those activities. As we did in the first work, students' answers were classified within three epistemological profiles. Now, a comparison among students' outcomes during the three phases, namely, preinstruction, postinstruction, and after four years has been carried out. Immediately after the open-inquiry experience, the students obtained significant benefits in terms of the strengthening of their practical and reasoning abilities, by proficiently applying the learned concepts to face and solve real-world problem situations. In this study, the students' answers do not highlight any significant regress towards their preinstruction profiles. The global robustness of the teaching strategy adopted four years ago is confirmed by a statistically significant comparison with a control group of students who experienced the same curricular instruction except for the open inquiry-based workshop. Nevertheless, some changes have been observed and discussed in the light of the answers the students provided to a short interview regarding their studying or working experiences across the four-year temporal window.

  4. 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

    2016-03-05

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. New simulation tools for long-term hydraulic design for a geological repository

    International Nuclear Information System (INIS)

    Richard, S.; Chaudon, L.

    1995-01-01

    Hydraulic concepts for a geological repository were investigated. Numerical simulations were adapted for this purpose and an experimental rheoelectric method based on an analogy between hydraulic flows and electric currents was developed. The results are discussed in this paper. A simplified representation of the host rock was adopted to account for the geometric details of the concept; this rock was described by a homogeneous porous medium associated with two major discontinuities. Steady-state hydraulic conditions were considered, and heating by the waste packages was assumed to be negligible (these conditions correspond to the long-term repository setting). The hydraulic structures obtained by the two methods are comparable, but significant differences were observed in the drained water distribution in the excavations; these discrepancies highlight the importance of the calculation mesh dimensions. Drainage barriers (drainage drifts and boreholes) surrounding the disposal boreholes may reduce water circulation in the disposal areas to their initial levels by constituting a partial hydraulic Faraday cage. This could be achieved with a reasonable number of boreholes if necessary

  6. Long-term impact of reduced tillage and residue management on soil carbon stabilization: Implications for conservation agriculture on contrasting soil

    NARCIS (Netherlands)

    Chivenge, P.P.; Murwira, H.K.; Giller, K.E.; Mapfumo, P.; Six, J.

    2007-01-01

    Residue retention and reduced tillage are both conservation agricultural management options that may enhance soil organic carbon (SOC) stabilization in tropical soils. Therefore, we evaluated the effects of long-term tillage and residue management on SOC dynamics in a Chromic Luvisol (red clay soil)

  7. A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect

    Directory of Open Access Journals (Sweden)

    Lennart Visser

    2017-11-01

    Full Text Available This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students (N = 54. The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23, the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks, the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.

  8. A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect.

    Science.gov (United States)

    Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A J

    2017-01-01

    This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students ( N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.

  9. Use of Long-Term Lysimeter Data in Support of Shallow Land Waste Disposal Cover Design

    International Nuclear Information System (INIS)

    Desotell, L.T.; Hudson, D.B.; Yucel, V.; Carilli, J.T.

    2006-01-01

    Water balance studies using two precision weighing lysimeters have been conducted at the Nevada Test Site in support of low-level radioactive waste disposal since 1994. The lysimeters are located in northern Frenchman Flat approximately 400 meters (m) from the southwest corner of the Area 5 Radioactive Waste Management Site. Frenchman Flat is in the northern Mojave Desert and has an average annual precipitation of 125 millimeters (mm). Each lysimeter consists of a 2 m by 4 m by 2 m deep steel tank filled with native alluvium, supported on a sensitive scale. The scale is instrumented with an electronic load-cell and data-logger for continuous measurement of total soil water storage with a precision of approximately ±800 grams or ±0.1 mm of soil water storage. Data-loggers are linked to cell phone modems for remote data acquisition. One lysimeter is vegetated with native creosote bush, four wing salt bush, and annual grass at the approximate density of the surrounding landscape while the other is maintained as bare soil. Since no drainage has been observed from the bottom of the lysimeters and run-on/run-off is precluded, the change in soil-water storage is equal to precipitation minus evaporation/evapotranspiration. After equilibration, the bare lysimeter contains approximately 20.2 centimeters (cm) of water (10.1 % volumetric water content) and the vegetated lysimeter contains approximately 11.6 cm of water (5.8 % volumetric water content). The finite difference code UNSAT-H was used to simulate the continuous water balance of the lysimeters. Calibrated one-dimensional model simulations were generally in agreement with field data. 30-year model simulations were conducted to evaluate long-term potential transport of radionuclides via the soil water migration pathway. A 30-year climate record was generated by repeating the existing data record. Simulations indicate a 2 m thick closure cover, in conjunction with native vegetation, will essentially eliminate drainage

  10. An optical model for implementing Parrondo’s game and designing stochastic game with long-term memory

    International Nuclear Information System (INIS)

    Si Tieyan

    2012-01-01

    Highlights: ► Using a photon propagating through a designed array of beam splitters to simulate Parrondo’s game paradox. ► Design the optical flowchart for implementing Parrondo history-dependent game paradox. ► Design new game with long-term memory on a designed tree lattice and loop lattice. - Abstract: An optical model for a photon propagating through a designed array of beam splitters is developed to give a physical implementation of Parrondo’s game and Parrondo’s history-dependent game. The winner in this optical model is a photon passed the beam splitter. The loser is a photon being reflected by the beam splitter. The optical beam splitter is the coin-tosser. We designed new games with long-term memory by using this optical diagram method. The optical output of the combined game of two losing games could be a win, or a loss, or an oscillation between win and loss. The modern technology to implement this optical model is well developed. A circularly polarized photon is a possible candidate for this physical implementation in laboratory.

  11. Assessment of chemical and biochemical stabilization of organic C in soils from the long-term experiments at Rothamsted (UK).

    Science.gov (United States)

    De Nobili, M; Contin, M; Mahieu, N; Randall, E W; Brookes, P C

    2008-01-01

    Biological and chemical stabilization of organic C was assessed in soils sampled from the long-term experiments at Rothamsted (UK), representing a wide range of carbon inputs and managements by extracting labile, non-humified organic matter (NH) and humic substances (HS). Four sequentially extracted humic substances fractions of soil organic matter (SOM) were extracted and characterized before and after a 215-day laboratory incubation at 25 degrees C from two arable soils, a woodland soil and an occasionally stubbed soil. The fractions corresponded to biochemically stabilised SOM extracted in 0.5M NaOH (free fulvic acids (FA) and humic acids (HA)) and chemically plus biochemically stabilised SOM extracted from the residue with 0.1M Na4P2O7 plus 0.1M NaOH (bound FA and HA). Our aim was to investigate the effects of chemical and biochemical stabilization on carbon sequestration. The non-humic to humic (NH/H) C ratio separated the soils into two distinct groups: arable soils (unless fertilised with farmyard manure) had an NH/H C ratio between 1.05 and 0.71, about twice that of the other soils (0.51-0.26). During incubation a slow, but detectable, decrease in the NH/H C ratio occurred in soils of C input equivalent or lower to 4Mgha(-1)y(-1), whereas the ratio remained practically constant in the other soils. Before incubation the free to bound humic C ratio increased linearly (R2=0.91) with C inputs in the soils from the Broadbalk experiment and decreased during incubation, showing that biochemical stabilization is less effective than chemical stabilization in preserving humic C. Changes in delta13C and delta15N after incubation were confined to the free FA fractions. The delta13C of free FA increased by 1.48 and 0.80 per thousand, respectively, in the stubbed and woodland soils, indicating a progressive biological transformation. On the contrary, a decrease was observed for the bound FA of both soils. Concomitantly, a Deltadelta15N of up to +3.52 per thousand was

  12. INAA applied to halogen (Br and I) stability in long-term storage of lyophilized biological materials

    International Nuclear Information System (INIS)

    Zaichick, V.; Zaichick, S.

    2000-01-01

    Instrumental neutron activation analysis (INAA) was used to determine the Br and I concentration in the same ten lyophilized and homogenized human thyroid samples prior and after a 20-year storage at room temperature. It was found that long-term storage had no effect on the iodine content. At the same time, the bromine content was about 2-fold lower (p<0.01). It was assumed that possible losses of other halogens can occur under long-term storage of lyophilized biological materials at room temperature. (author)

  13. Engineering solutions to the long-term stabilization and isolation of uranium mill tailings in the United States

    International Nuclear Information System (INIS)

    Sanders, D.R.; Lommler, J.C.

    1995-01-01

    Engineering solutions to the safe and environmentally protective disposal and isolation of uranium mill tailings in the US include many factors. Cover design, materials selection, civil engineering, erosive forces, and cost effectiveness are only a few of those factors described in this paper. The systems approach to the engineering solutions employed in the US is described, with emphasis on the standards prescribed for the Uranium Mill Tailings Remedial Action Project. Stabilization and isolation of the tailings from humans and the environment are the primary goals of the US uranium mill tailings control standards. The performance of cover designs with respect to water infiltration, radon exhalation, geotechnical stability, erosion protection, human and animal intrusion prevention, and longevity are addressed. The need for and frequency of surveillance efforts to ensure continued disposal system performance are also assessed

  14. Stability and development of psychotic symptoms and the use of antipsychotic medication - long-term follow-up

    DEFF Research Database (Denmark)

    Gotfredsen, D R; Wils, R S; Hjorthøj, C

    2017-01-01

    BACKGROUND: Few studies have evaluated the development in the use of antipsychotic medication and psychotic symptoms in patients with first-episode psychosis on a long-term basis. Our objective was to investigate how psychotic symptoms and the use of antipsychotic medication changed over a 10-yea...

  15. Accelerated long-term assessment of thermal and chemical stability of bio-based phase change materials

    Science.gov (United States)

    Thermal energy storage (TES) systems incorporated with phase change materials (PCMs) have potential applications to control energy use by building envelopes. However, it is essential to evaluate long term performance of the PCMs and cost effectiveness prior to full scale implementation. For this rea...

  16. Driving forces shaping advanced reactor designs: Near-term and long-term prospects

    International Nuclear Information System (INIS)

    Sholly, S.C.

    1990-01-01

    This paper explores the forces which have driven and which in the opinion of the author should be driving advanced reactor development programs. Four general driving forces are identified: cost, safety, environmental concerns, and non-proliferation concerns. It is suggested that the primary driving forces should be cost and safety concerns. It is suggested that advanced reactors need to demonstrate the following characteristics: (a) A design which explicitly accounts for severe accidents, including severe external events (not necessarily limited to contemporary design basis events) and which results in a frequency of severe core damage substantially lower than in current plants. The goal for the frequency of severe core damage should reflect a reasonable assurance that a severe core damage accident will not occur during the operating lifetime of a fleet' of such plants. (b) A design which explicitly accounts for severe accidents in terms of accident mitigation, resulting in a very low conditional likelihood of a substantial fission product release given a severe accident. (c) A design which utilizes near-passive and passive concepts (whose safety and reliability are demonstrable by experiment and/or full-scale test) for both accident prevention and accident mitigation to the maximum extent feasible. (d) A design which allows f a suitably long time between refueling outages, with a balance struck between refueling outage duration and refueling outage frequency so as to maximize availability and capacity factor. (e) A design which emphasizes modular construction and exceptional quality control. (f) A design which de emphasizes the importance of maintenance and human reliability more generally to assure that safety functions are performed with acceptable reliability, and to assure that passive safety characteristics are not compromised by design, manufacturing, or installation defects. It is further suggested that key factors in gaining public acceptance are the early

  17. Driving forces shaping advanced reactor designs: Near-term and long-term prospects

    Energy Technology Data Exchange (ETDEWEB)

    Sholly, S C [MHB Technical Associates, San Jose, CA (United States)

    1990-07-01

    This paper explores the forces which have driven and which in the opinion of the author should be driving advanced reactor development programs. Four general driving forces are identified: cost, safety, environmental concerns, and non-proliferation concerns. It is suggested that the primary driving forces should be cost and safety concerns. It is suggested that advanced reactors need to demonstrate the following characteristics: (a) A design which explicitly accounts for severe accidents, including severe external events (not necessarily limited to contemporary design basis events) and which results in a frequency of severe core damage substantially lower than in current plants. The goal for the frequency of severe core damage should reflect a reasonable assurance that a severe core damage accident will not occur during the operating lifetime of a fleet' of such plants. (b) A design which explicitly accounts for severe accidents in terms of accident mitigation, resulting in a very low conditional likelihood of a substantial fission product release given a severe accident. (c) A design which utilizes near-passive and passive concepts (whose safety and reliability are demonstrable by experiment and/or full-scale test) for both accident prevention and accident mitigation to the maximum extent feasible. (d) A design which allows f a suitably long time between refueling outages, with a balance struck between refueling outage duration and refueling outage frequency so as to maximize availability and capacity factor. (e) A design which emphasizes modular construction and exceptional quality control. (f) A design which de emphasizes the importance of maintenance and human reliability more generally to assure that safety functions are performed with acceptable reliability, and to assure that passive safety characteristics are not compromised by design, manufacturing, or installation defects. It is further suggested that key factors in gaining public acceptance are the early

  18. Visualization of regulations to support design and quality control--a long-term study.

    Science.gov (United States)

    Blomé, Mikael

    2012-01-01

    The aim of the study was to visualize design regulations of furniture by means of interactive technology based on earlier studies and practical examples. The usage of the visualized regulations was evaluated on two occasions: at the start when the first set of regulations was presented, and after six years of usage of all regulations. The visualized regulations were the result of a design process involving experts and potential users in collaboration with IKEA of Sweden AB. The evaluations by the different users showed a very positive response to using visualized regulations. The participative approach, combining expertise in specific regulations with visualization of guidelines, resulted in clear presentations of important regulations, and great attitudes among the users. These kinds of visualizations have proved to be applicable in a variety of product areas at IKEA, with a potential for further dissemination. It is likely that the approaches to design and visualized regulations in this case study could function in other branches.

  19. Long-term strategies for flood risk management: scenario definition and strategic alternative design

    NARCIS (Netherlands)

    Bruijn, de K.; Klijn, F.; McGahey, C.; Mens, M.; Wolfert, H.P.

    2008-01-01

    This report reviews some mainstream existing methods of scenario development and use, as well as experiences with the design and assessment of strategic alternatives for flood risk management. Next, a procedure and methods are proposed and discussed. Thirdly, the procedure and methods are tried on

  20. Design challenges for long-term interaction with a robot in a science classroom

    NARCIS (Netherlands)

    Davison, Daniel Patrick; Charisi, Vasiliki; Wijnen, Frances Martine; Papenmeier, Andrea; van der Meij, Jan; Reidsma, Dennis; Evers, Vanessa

    This paper aims to present the main challenges that emerged during the process of the research design of a longitudinal study on child-robot interaction for science education and to discuss relevant suggestions in the context. The theoretical rationale is based on aspects of the theory of social

  1. Geosphere Stability for long-term isolation of radioactive waste. Case study for hydrological change with earthquakes and faulting

    International Nuclear Information System (INIS)

    Niwa, Masakazu

    2016-01-01

    Appropriate estimation and safety assessment for long-term changes in geological environment are essential to an improvement of reliability for geological disposal. Specifically, study on faults is important for understanding regional groundwater flow as well as an assessment as a trigger of future earthquakes. Here, possibility of changes in permeability of faulted materials induced by earthquakes was examined based on monitoring data of groundwater pressure before and after the 2011 off the Pacific coast of Tohoku Earthquake. (author)

  2. Design prediction for long term stress rupture service of composite pressure vessels

    Science.gov (United States)

    Robinson, Ernest Y.

    1992-01-01

    Extensive stress rupture studies on glass composites and Kevlar composites were conducted by the Lawrence Radiation Laboratory beginning in the late 1960's and extending to about 8 years in some cases. Some of the data from these studies published over the years were incomplete or were tainted by spurious failures, such as grip slippage. Updated data sets were defined for both fiberglass and Kevlar composite stand test specimens. These updated data are analyzed in this report by a convenient form of the bivariate Weibull distribution, to establish a consistent set of design prediction charts that may be used as a conservative basis for predicting the stress rupture life of composite pressure vessels. The updated glass composite data exhibit an invariant Weibull modulus with lifetime. The data are analyzed in terms of homologous service load (referenced to the observed median strength). The equations relating life, homologous load, and probability are given, and corresponding design prediction charts are presented. A similar approach is taken for Kevlar composites, where the updated stand data do show a turndown tendency at long life accompanied by a corresponding change (increase) of the Weibull modulus. The turndown characteristic is not present in stress rupture test data of Kevlar pressure vessels. A modification of the stress rupture equations is presented to incorporate a latent, but limited, strength drop, and design prediction charts are presented that incorporate such behavior. The methods presented utilize Cartesian plots of the probability distributions (which are a more natural display for the design engineer), based on median normalized data that are independent of statistical parameters and are readily defined for any set of test data.

  3. Long-term stability of intra-oral maxillary distraction in unilateral cleft lip and palate: a case report.

    Science.gov (United States)

    Nevzatoğlu, Sirin; Küçükkeleş, Nazan; Güzel, Zeki

    2013-11-01

    This case report presents short and long-term treatment results of a unilateral cleft lip and palate patient treated with a modified intra-oral tooth-bone borne distraction appliance. The chief complaints of a 16 year-old, unilateral cleft lip and palate patient were poor facial aesthetics, crowding and a fistula. Severe maxillary retrognathism was treated via distraction osteogenesis of the maxilla and performed using an intra-oral tooth-bone borne appliance. Treatment continued to completion with a multibracket system. At an eight-year review following the distraction procedure, the short and long-term results were determined cephalometrically. Following the distraction, A-point advanced 7 mm, 2 mm of which relapsed during fixed appliance treatment. At the end of the active treatment, the patient's skeletal and dental Class III relationship improved to Class I, which was preserved at the long-term review. The profile was markedly improved by the distraction osteogenesis. In cases of severe maxillary retrognathism as a result of a cleft lip and palate, maxillary distraction osteogenesis provides a viable alternative to orthognathic surgery.

  4. Sampling design for long-term regional trends in marine rocky intertidal communities

    Science.gov (United States)

    Irvine, Gail V.; Shelley, Alice

    2013-01-01

    Probability-based designs reduce bias and allow inference of results to the pool of sites from which they were chosen. We developed and tested probability-based designs for monitoring marine rocky intertidal assemblages at Glacier Bay National Park and Preserve (GLBA), Alaska. A multilevel design was used that varied in scale and inference. The levels included aerial surveys, extensive sampling of 25 sites, and more intensive sampling of 6 sites. Aerial surveys of a subset of intertidal habitat indicated that the original target habitat of bedrock-dominated sites with slope ≤30° was rare. This unexpected finding illustrated one value of probability-based surveys and led to a shift in the target habitat type to include steeper, more mixed rocky habitat. Subsequently, we evaluated the statistical power of different sampling methods and sampling strategies to detect changes in the abundances of the predominant sessile intertidal taxa: barnacles Balanomorpha, the mussel Mytilus trossulus, and the rockweed Fucus distichus subsp. evanescens. There was greatest power to detect trends in Mytilus and lesser power for barnacles and Fucus. Because of its greater power, the extensive, coarse-grained sampling scheme was adopted in subsequent years over the intensive, fine-grained scheme. The sampling attributes that had the largest effects on power included sampling of “vertical” line transects (vs. horizontal line transects or quadrats) and increasing the number of sites. We also evaluated the power of several management-set parameters. Given equal sampling effort, sampling more sites fewer times had greater power. The information gained through intertidal monitoring is likely to be useful in assessing changes due to climate, including ocean acidification; invasive species; trampling effects; and oil spills.

  5. Influence of the dynamic Stark effect on long-term frequency stability of a self-oscillating magnetometer with laser-pumped alkali atoms

    Science.gov (United States)

    Baranov, A. A.; Ermak, S. V.; Kulachenkov, N. K.; Petrenko, M. V.; Sagitov, E. A.; Semenov, V. V.

    2017-11-01

    This paper presents the results of investigation Stark shift effect influence on the long-term stability of a dual scheme of quantum magnetometers. Such scheme allows suppressing Stark shift components when a certain pumping light polarization is applied. As a result, long-term stability of a quantum sensor increases. However, when low-frequency (LF) and microwave fields are attached to a single vapor cell a coherence circulation in hyperfine structure of alkali atoms takes place. Physical origin of this effect is associated with the so called “dressed” atom theory, when atom is “dressed” by LF field. It yields in multiphoton absorption and resonance frequency shift. First estimates for this shift based on density matrix evolution formalism are provided in the paper.

  6. Status of Siemens steam generator design and measures to assure continuous long-term reliable operation

    International Nuclear Information System (INIS)

    Hoch, G.

    1999-01-01

    Operating pressurized water reactors with U-tube steam generators have encountered difficulties with either one or a combination of inadequate material selection, poor design or manufacturing and an insufficient water chemistry control which resulted in excessive tube degradation. In contrast to the above mentioned problems, steam generators from Siemens/KWU are proving by operating experience that all measures undertaken at the design stage as well as during the operating and maintenance phase were effective enough to counteract any tube corrosion phenomena or other steam generator related problem. An Integrated Service Concept has been developed, applied and wherever necessary improved in order to ensure reliable steam generator operation. The performance of the steam generators is updated continuously, evaluated and implemented in lifetime databases. The main indicator for steam generator integrity are the results of the eddy current testing of the steam generator tubes. Tubes with indications are rated with lifetime threshold values and if necessary plugged, based on individual assessment criteria.(author)

  7. Long-term follow-up for keystone design perforator island flap for closure of myelomeningocele.

    Science.gov (United States)

    Donaldson, Christopher; Murday, Hamsaveni K M; Gutman, Matthew J; Maher, Rory; Goldschlager, Tony; Xenos, Chris; Danks, R Andrew

    2018-04-01

    We have previously reported a small series on the closure of large myelomeningocele (MMC) defects with a keystone design perforator island flap (KDPIF) in a paediatric neurosurgical centre in Australia. We are now presenting an updated longer term follow-up of an expanded series demonstrating longer term durability of this vascularized flap for large myelomeningocele defects. The prospective data from the Monash Neurosurgical Database were used to select all cases of MMC between December 2008 and September 2016. Retrospective analysis of the neurosurgical database revealed an additional three patients who underwent KDPIF closure at the Monash Medical Centre for MMC repair at birth. Wound healing was satisfactory in all six cases. With delayed follow-up, there was no associated skin flap separation, skin flap dehiscence, skin flap necrosis, cerebro-spinal fluid leak, however two infections were encountered, both resolved with conservative management including antibiotics and simple washout. In this expanded case series with increased longevity of follow-up, the keystone design perforator island flap remains a robust alternative for closure of large myelomeningocele defects.

  8. Long-term performance of different aluminum alloy designs as sacrificial anodes for rebars

    Directory of Open Access Journals (Sweden)

    de Rincón, O.

    2003-12-01

    Full Text Available This paper presents the performance of various cathodic-protection designs using Aluminum alloys to protect prestressed piles. The results obtained with different system designs (bracelete type-Al/Zn/In alloy, thermosprayed aluminum (3-year evaluation and conventional Al/Zn/In anocies in an epoxy-painted steel bracelet (12-year evaluation, indicated that all of these systems may be used as sacrificial anodes for pile protection. However, the thermosprayed aluminum type can not be used in prestressed concrete piles because the very negative potentials ( < -1100 mV vs. Cu/CuSO4 they supply to the reinforcement could lead to hydrogen embrittlement.

    Este trabajo presenta la realización de varios diseños de protección catódica utilizando aleaciones de aluminio para la protección de pilotes pretensados. Los resultados obtenidos con diferentes diseños (aleación de Al/Zn/In, tipo brazalete y aluminio termorociado (3 años de evaluación y ánodos convencionales de Al/Zn/In colocados en un brazalete de acero pintado con epoxy (12 años de evaluación, indicaron que todos estos sistemas pueden ser utilizados como ánodos de sacrificio para la protección de los pilotes. Sin embargo, el sistema con aluminio termorociado no puede ser utilizado en pilotes de acero pretensado debido al potencial muy negativo alcanzado por la armadura (<-1100 mV vs Cu/CuSO4, lo cual podría inducir a daños por hidrógeno.

  9. 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...

  10. Long-term impact of reduced tillage and residue management on soil carbon stabilization: Implications for conservation agriculture on contrasting soils

    OpenAIRE

    Chivenge, P.P.; Murwira, H.K.; Giller, K.E.; Mapfumo, P.; Six, J.

    2007-01-01

    Metadata only record The long-term effects of tillage system and residue management on soil organic carbon stabilization are studied in two tropical soils in Zimbabwe, a red clay and a sandy soil. The four tillage systems evaluated were conventional tillage (CT), mulch ripping (MR), clean ripping (CR) and tied ridging (TR). Soil organic carbon (SOC) content was measured for each size fraction as well as total SOC. Based on the findings, the authors conclude that residue management - mainta...

  11. Issues at stake when considering long term storage of HLW. A comprehensive approach to designing the facility

    International Nuclear Information System (INIS)

    Marvy, A.; Ochem, D.

    2002-01-01

    CEA has been conducting a comprehensive R and D program to identify and study key HLW storage design criteria to possibly meet the lifetime goal of a century and beyond. A novel approach is being used since such installations must be understood as a global system comprised of various materials and hardware components, canisters, concrete and steel structures and specific procedures covering engineering steps from construction to operation including monitoring, care and maintenance as well as licensing. The challenge set by such a lifetime design goal made the R and D people focus on issues at stake and relevant to long term HLW storage in particular heat management, the effect of time on materials and the sustainability of care and maintenance. This opened up the R and D field from fundamental research areas to more conventional and technical aspects. Two major guiding principles have been devised as key design goals for the storage concepts under consideration. One is the paramount function of retrievability, which must allow the safe retrieval of any HLW package from the facility at any given time. Next is the passive containment philosophy requiring that a two-barrier system be considered. In the case of spent fuel, CEA's early assessment of the long-term behaviour of cladding shows that it cannot qualify as a reliable barrier over a long period of time. Therefore, the overriding strategy of preventing corrosion and material degradation to achieve canister protection, and therefore containment of radioactive material throughout the time of period envisaged, is at the heart of the R and D program and several design alternatives are being studied to meet that objective. For instance available thermal power from SF is used to establish dry corrosion conditions within the storage facility. The paper reviews all of these different R and D and engineering aspects. (author)

  12. System design description PFP thermal stabilization

    International Nuclear Information System (INIS)

    RISENMAY, H.R.

    1998-01-01

    The purpose of this document is to provide a system design description and design basis for the Plutonium Finishing P1ant (PFP) Thermal Stabilization project. The sources of material for this project are residues scraped from glovebox floors and materials already stored in vault storage that need further stabilizing to meet the 3013 storage requirements. Stabilizing this material will promote long term storage and reduced worker exposure. This document addresses: function design, equipment, and safety requirements for thermal stabilization of plutonium residues and oxides

  13. Beyond "Home-Like" Design: Visitor Responses to an Immersive Creative Space in a Canadian Long-Term Care Facility.

    Science.gov (United States)

    Graham, Megan E; Fabricius, Andréa

    2017-11-01

    This study examined the benefits of expanding upon the "home-like" design by introducing an immersive creative space for residents, staff, and visitors to explore in a long-term care facility in Eastern Ontario, Canada. Data were collected through guestbook comments ( N = 93) and coded for themes according to guidelines for thematic analysis. Selected themes included visitors' enjoyment of the winter aesthetic, expressions of gratitude to the artists, time spent socializing with family and visitors in a creative milieu, and the experience of remembering in an evocative space. The results indicate that residents and visitors benefited from the experience of a creative space that was neither institutional, nor "home-like." Implications for future research are discussed.

  14. Developing a long-term local society design methodology towards a low-carbon economy: An application to Shiga Prefecture in Japan

    International Nuclear Information System (INIS)

    Shimada, Koji; Tanaka, Yoshitaka; Gomi, Kei; Matsuoka, Yuzuru

    2007-01-01

    To tackle global climate stabilization concretely, we have developed a method formulating long-term scenarios towards a low-carbon economy at local level. As a result of the pioneering application of this method to Shiga Prefecture, we have found the following: (i) it is possible to design scenarios for moving towards a low-carbon economy in which CO 2 emission is lowered by 30-50% from the 1990 level by 2030, while the prefecture's gross production continues to grow by 1.6% annually; (ii) in order to halve the emission by 2030, socio-economic structural changes as well as technological measures are essential; and (iii) innovative measures at the prefectural level, such as land planning, renewable energy promotion and lifestyle change, play an increasingly important role as the target reduction rate gets higher

  15. Long term evaluation and identification of the proper testing program for ASTM Class C fly ash stabilized soils : technical summary.

    Science.gov (United States)

    1993-07-01

    The objectives of this research were to further evaluate the characteristics of locally produced fly ash and to develop test procedures which would expedite the evaluation of fly ash stabilized soils. Because cement and lime stabilization techniques ...

  16. Long-term consequences of an intensive care unit stay in older critically ill patients: design of a longitudinal study

    Directory of Open Access Journals (Sweden)

    Hantikainen Virpi

    2011-09-01

    Full Text Available Abstract Background Modern methods in intensive care medicine often enable the survival of older critically ill patients. The short-term outcomes for patients treated in intensive care units (ICUs, such as survival to hospital discharge, are well documented. However, relatively little is known about subsequent long-term outcomes. Pain, anxiety and agitation are important stress factors for many critically ill patients. There are very few studies concerned with pain, anxiety and agitation and the consequences in older critically ill patients. The overall aim of this study is to identify how an ICU stay influences an older person's experiences later in life. More specific, this study has the following objectives: (1 to explore the relationship between pain, anxiety and agitation during ICU stays and experiences of the same symptoms in later life; and (2 to explore the associations between pain, anxiety and agitation experienced during ICU stays and their effect on subsequent health-related quality of life, use of the health care system (readmissions, doctor visits, rehabilitation, medication use, living situation, and survival after discharge and at 6 and 12 months of follow-up. Methods/Design A prospective, longitudinal study will be used for this study. A total of 150 older critically ill patients in the ICU will participate (ICU group. Pain, anxiety, agitation, morbidity, mortality, use of the health care system, and health-related quality of life will be measured at 3 intervals after a baseline assessment. Baseline measurements will be taken 48 hours after ICU admission and one week thereafter. Follow-up measurements will take place 6 months and 12 months after discharge from the ICU. To be able to interpret trends in scores on outcome variables in the ICU group, a comparison group of 150 participants, matched by age and gender, recruited from the Swiss population, will be interviewed at the same intervals as the ICU group. Discussion Little

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

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ralph E. White; Dr. Branko N. Popov

    2001-10-01

    The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Lithium Cobalt oxide was coated on Ni cathode by a sol-gel coating. The morphology and the LiCoO{sub 2} formation of LiCoO{sub 2} coated NiO was studied using scanning electron microscopy and X-Ray diffraction studies respectively. The electrochemical performance lithium cobalt oxide coated NiO cathodes were investigated with open circuit potential measurement and current-potential polarization studies. These results were compared to that of bare NiO. Dissolution of nickel into the molten carbonate melt was less in case of lithium cobalt oxide coated nickel cathodes. LiCoO{sub 2} coated on the surface prevents the dissolution of Ni in the melt and thereby stabilizes the cathode. Finally, lithium cobalt oxide coated nickel shows similar polarization characteristics as nickel oxide. Conventional theoretical models for the molten carbonate fuel cell cathode are based on the thin film agglomerate model. The principal deficiency of the agglomerate model, apart from the simplified pore structure assumed, is the lack of measured values for film thickness and agglomerate radius. Both these parameters cannot be estimated appropriately. Attempts to estimate the thickness of the film vary by two orders of magnitude. To avoid these problems a new three phase homogeneous model has been developed using the volume averaging technique. The model considers the potential and current variation in both liquid and solid phases. Using this approach, volume averaged

  18. [Stabilizing the social and health status of drug dependent patients with methadone. Long-term maintainance therapy--Vienna results].

    Science.gov (United States)

    Loimer, N; Werner, E; Hollerer, E; Pfersmann, V; Schmid-Siegel, B; Presslich, O

    1991-01-01

    On September 25th, 1987 methadone was legalized in Austria for therapeutic use in drug addiction treatment in case of: 1. Long-term drug addiction with intravenous application of the drug, and several unsuccessful withdrawal therapies and/or 2. opiate addiction through intravenous application of the drug along with an existing HIV-1 infection. Since than, 291 patients were treated with methadone at the drug-dependency outpatient clinic of the Psychiatric Clinic of the University of Vienna. In 1990, 96 patients treated for more than one year were investigated using a standardized questionnaire. The image in which crime, prostitution, poverty, ill health all merge was broken by this decriminalization. Methadone treatment offers a first step toward social rehabilitation for drug addicts who have been living as criminals on the fringe of society.

  19. A strategy for evaluating the long-term stability of hole-plugging materials in their geological environments

    International Nuclear Information System (INIS)

    Lambert, S.J.

    1980-01-01

    Material used to plug boreholes will not in general be in chemical equilibrium with its host rock. Adverse long-term performance of a plug can involve changes in phase assemblage in the plug/rock system which are difficult to observe at low temperatures in real time. The thermodynamics of multiphase equilibria provides a technique of predicting what phase changes might occur. The thermodynamic treatment of plug/rock systems utilizes (1) a formulation of possible chemical reactions among phases in the system and (2) determinations of changes in values of Gibbs' free energies for the hypothetical reactions, to identify the theoretically-permitted reactions which could degrade plug performance. Time-dependent prediction of phase changes requires a knowledge of rate laws and constants for specific reactions whose mechanisms are well known

  20. Strategy for evaluating the long-term stability of hole-plugging materials in their geological environments

    International Nuclear Information System (INIS)

    Lambert, S.J.

    1980-01-01

    Material used to plug boreholes will not in general be in chemical equilibrium with its host rock. Adverse long-term performance of a plug can involve changes in phase assemblage in the plug/rock system which are difficult to observe at low temperatures in real time. The thermodynamics of multiphase equilibria provides a technique of predicting what phase changes might occur. The thermodynamic treatment of plug/rock systems utilizes (1) a formulation of possible chemical reactions among phases in the system and (2) determinations of changes in values of Gibbs' free energies for the hypothetical reactions, to identify the theoretically-permitted reactions which could degrade plug performance. Time-dependent prediction of phase changes requires a knowledge of rate laws and constants for specific reactions whose mechanisms are well known

  1. Engineering report (conceptual design) PFP solution stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Witt, J.B.

    1997-07-17

    This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.

  2. Engineering report (conceptual design) PFP solution stabilization

    International Nuclear Information System (INIS)

    Witt, J.B.

    1997-01-01

    This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage

  3. Stability issues of high-energy resolution diode type CdTe nuclear radiation detectors in a long-term operation

    CERN Document Server

    Niraula, M; Aoki, T; Tomita, Y; Hatanaka, Y

    2002-01-01

    High-energy resolution diode type CdTe detectors were fabricated by growing an n-type epitaxial layer on high resistivity p-like crystal wafers, and their stability issues during a long-term operation were studied. Room temperature stability of the detectors was not good at low operating biases of around 200 V. However, it could be improved significantly by operating them at higher biases under full depletion conditions. On the other hand, detectors exhibited excellent stability by cooling them slightly below room temperature down to 0 deg. C. The effect of this low level of cooling on detector stability was found to be more significant than that of applying high biases at room temperature. By using the detector type presented here, stable operation could be obtained at moderate operating voltages of around 400 V and with a modest degree of cooling.

  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)

    Kozlova, Olga

    2013-01-01

    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, N 2 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 tidal and diel-related patterns in mangrove creek fish assemblages in North Brazil

    Science.gov (United States)

    Castellanos-Galindo, G. A.; Krumme, U.

    2014-08-01

    Intertidal fish assemblages are thought to respond to tidal and diel rhythms although the assumption that these patterns are stable over long time scales (>1 year) is largely untested. Testing the validity of this assumption is necessary to assess whether short-term temporal patterns, once established, can be extrapolated over time and give a better understanding of the temporal dynamics of fish assemblages in coastal habitats. Here, we compare the fish assemblage structure from two intertidal mangrove creeks in North Brazil (Bragança Peninsula, Caeté estuary) sampled with the same sampling methodology (block nets), effort (two lunar cycles) and design (accounting for the combination of tidal and diel cycle) in the rainy seasons of 1999 and 2012 to evaluate the persistence, stability and recurrence of short-term patterns in the fish community organization. The interaction of tidal and diel cycles (inundations at spring tide-night, spring tide-day, neap tide-night, neap tide-day), found to be stable after 13 years, resulted in recurrent and stable intertidal mangrove fish assemblage compositions. The intertidal mangrove creek fish assemblage consisted of a persistent number of dominant species (seven). However, there were notable changes in fish catch mass, abundance and species dominance between 1999 and 2012. The most severe drought in North Brazil in 30 years, linked to lower precipitation and river runoff in the rainy season of 2012, may have resulted in (1) lower abundance of small juveniles of several dominant species in this assemblage (especially Ariidae - Cathorops agassizii and Sciades herzbergii) and (2) increased dominance of large-sized specimens of the tetraodontid Colomesus psittacus. Our findings highlight: (1) the overriding importance and stability of the interactive pulse of the tidal and diel cycles in determining short-term temporal patterns in intertidal mangrove fish assemblages in neotropical macrotidal estuaries despite the occurrence of

  6. Processing, microstructure, leaching, and long-term stability studies related to titanate high-level waste forms

    International Nuclear Information System (INIS)

    Dosch, R.G.; Headley, T.J.; Northrup, C.J.; Hlava, P.F.

    1983-05-01

    A process leading to titanate-based waste forms for commercial high-level nuclear waste is described. Radionuclides are fixed on hydrous calcium titanate by ion exchange/sorption reactions and the material is converted to a dense, ceramic form by hot pressing. Transmission electron microscopy-electron microprobe characterization was done to determine the effects of compositional changes and process variations on microstructure. Leaching studies in the range of 22 to 150 0 C and pH 2 to 12 were done to assess the effects of the same variables on leaching behavior. Samples of a reference borosilicate glass waste form were leached under the same conditions to provide a direct comparison between the two waste forms. Lead-ion implantation was used to simulate long-term α-recoil damage in the crystalline titanate phases. Comparison of α-recoil damage in natural minerals with damage induced in synthesized samples of the same mineral suggest that Pb-ion implantation is a valid technique for simulating α-recoil effects. All the titanate phases sustained significant lattice damage at equivalent α-doses of 1 x 10 19 /cm 3 ; however, Rutherford backscattering and transmission electron microscopy studies showed that the damage did not result in significant matrix dissolution in these leaching tests

  7. LONG-TERM X-RAY STABILITY AND ULTRAVIOLET VARIABILITY OF THE IONIZED ABSORPTION IN NGC 3783

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A. E.; Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Behar, E.; Kaspi, S. [Department of Physics, Technion, Haifa 32000 (Israel); Crenshaw, D. M. [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Suite 605, Atlanta, GA 30303 (United States); Gabel, J. R. [Physics Department, Creighton University, Omaha, NE 68178 (United States); Gibson, R. R. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Kraemer, S. B. [Institute for Astrophysics and Computational Sciences, Department of Physics, The Catholic University of America, Washington, DC 20064 (United States); Turner, T. J., E-mail: amyscott@psu.edu [Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2014-12-20

    We present the results of recent Chandra High-Energy Transmission Grating Spectrometer and Hubble Space Telescope Cosmic Origins Spectrograph observations of the nearby Seyfert 1 galaxy NGC 3783, which show a strong, nonvarying X-ray warm absorber and physically related and kinematically varying UV absorption. We compare our new observations to high-resolution, high signal-to-noise archival data from 2001, allowing a unique investigation into the long-term variations of the absorption over a 12 yr period. We find no statistically significant changes in the physical properties of the X-ray absorber, but there is a significant drop of ∼40% in the UV and X-ray flux and a significant flattening of the underlying X-ray power-law slope. Large kinematic changes are seen in the UV absorbers, possibly due to radial deceleration of the material. Similar behavior is not observed in the X-ray data, likely due to its lower-velocity resolution, which shows an outflow velocity of v {sub out} ∼ –655 km s{sup –1} in both epochs. The narrow iron Kα emission line at 6.4 keV shows no variation between epochs, and its measured width places the material producing the line at a radial distance of ∼0.03 pc from the central black hole.

  8. Effect of long-term aging on microstructural stabilization and mechanical properties of 20Cr32Ni1Nb steel

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xiaofeng; Jia, Xiankai [School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816 (China); Gong, Jianming, E-mail: gongjm@njtech.edu.cn [School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816 (China); Key Lab of Design and Manufacture of Extreme Pressure Equipment, Jiangsu Province (China); Geng, Luyang; Tang, Jianqun; Jiang, Yong [School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816 (China); Key Lab of Design and Manufacture of Extreme Pressure Equipment, Jiangsu Province (China); Ni, Yingying; Yang, Xinyu [School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816 (China)

    2017-04-06

    The centrifugally cast 20Cr32Ni1Nb stainless steel aged at 950 ℃ from 200 h up to 5000 h was investigated on the mechanical properties and microstructural evolution using post-aged tensile tests, post-aged Charpy impact tests, Optical microscopy (OM) observations, and field emission-scanning electron microscopy (FE-SEM) examinations. Experimental results indicate that the as-cast microstructure of the steel typically consists of a supersaturated solid solution of austenite matrix with a network of interdendritic primary carbides (NbC and M{sub 23}C{sub 6}). During aging process, the growth and coarsening of NbC carbides and M{sub 23}C{sub 6} carbides as well as the transformation of NbC carbide into G phase take place. Meanwhile, the transformation of NbC into G phase releases C into the matrix during aging exposure. This released C tends to combine with Cr, and forms M{sub 23}C{sub 6} at the dendrite boundaries. Compared with a continuous reduction of the elongation in the whole aging period, the strength parameters (σ{sub ult} and σ{sub ys}) exhibit an initial increase followed by a continuous decrease with the aging time prolonged from 1000 h to 5000 h. Additionally, the variation of Charpy impact absorbed energy is relatively complex during aging process. The microstructural evolution during long-term aging process is consistent with the variation of mechanical properties.

  9. Dual-Function Au@Y2O3:Eu3+ Smart Film for Enhanced Power Conversion Efficiency and Long-Term Stability of Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Chang Woo; Eom, Tae Young; Yang, In Seok; Kim, Byung Su; Lee, Wan In; Kang, Yong Soo; Kang, Young Soo

    2017-07-28

    In the present study, a dual-functional smart film combining the effects of wavelength conversion and amplification of the converted wave by the localized surface plasmon resonance has been investigated for a perovskite solar cell. This dual-functional film, composed of Au nanoparticles coated on the surface of Y 2 O 3 :Eu 3+ phosphor (Au@Y 2 O 3 :Eu 3+ ) nanoparticle monolayer, enhances the solar energy conversion efficiency to electrical energy and long-term stability of photovoltaic cells. Coupling between the Y 2 O 3 :Eu 3+ phosphor monolayer and ultraviolet solar light induces the latter to be converted into visible light with a quantum yield above 80%. Concurrently, the Au nanoparticle monolayer on the phosphor nanoparticle monolayer amplifies the converted visible light by up to 170%. This synergy leads to an increased solar light energy conversion efficiency of perovskite solar cells. Simultaneously, the dual-function film suppresses the photodegradation of perovskite by UV light, resulting in long-term stability. Introducing the hybrid smart Au@Y 2 O 3 :Eu 3+ film in perovskite solar cells increases their overall solar-to-electrical energy conversion efficiency to 16.1% and enhances long-term stability, as compared to the value of 15.2% for standard perovskite solar cells. The synergism between the wavelength conversion effect of the phosphor nanoparticle monolayer and the wave amplification by the localized surface plasmon resonance of the Au nanoparticle monolayer in a perovskite solar cell is comparatively investigated, providing a viable strategy of broadening the solar spectrum utilization.

  10. 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...

  11. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. 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

  13. The long-term stability of self-esteem: its time-dependent decay and nonzero asymptote.

    Science.gov (United States)

    Kuster, Farah; Orth, Ulrich

    2013-05-01

    How stable are individual differences in self-esteem? We examined the time-dependent decay of rank-order stability of self-esteem and tested whether stability asymptotically approaches zero or a nonzero value across long test-retest intervals. Analyses were based on 6 assessments across a 29-year period of a sample of 3,180 individuals aged 14 to 102 years. The results indicated that, as test-retest intervals increased, stability exponentially decayed and asymptotically approached a nonzero value (estimated as .43). The exponential decay function explained a large proportion of variance in observed stability coefficients, provided a better fit than alternative functions, and held across gender and for all age groups from adolescence to old age. Moreover, structural equation modeling of the individual-level data suggested that a perfectly stable trait component underlies stability of self-esteem. The findings suggest that the stability of self-esteem is relatively large, even across very long periods, and that self-esteem is a trait-like characteristic.

  14. Comparison of short-term and long-term performances for polymer-stabilized sand and clay

    Directory of Open Access Journals (Sweden)

    Sepehr Rezaeimalek

    2017-04-01

    Full Text Available A series of tests were carried out on sulfate rich, high-plasticity clay and poorly-graded natural sand to study the effectiveness of a methylene diphenyl diisocyanate based liquid polymer soil stabilizer in improving the unconfined compressive strength (UCS of freshly stabilized soils and aged sand specimens. The aged specimens were prepared by exposing the specimens to ultraviolet radiation, freeze-thaw, and wet-dry weathering. The polymer soil stabilizer also mitigated the swelling of the expansive clay. For clay, the observations indicated that the sequence of adding water and liquid polymer had great influence on the gained UCS of stabilized specimens. However, this was shown to be of little importance for sand. Furthermore, sand samples showed incremental gains in UCS when they were submerged in water. This increase was significant for up to 4 days of soaking in water after 4 days of ambient air curing. Conversely, the clay samples lost a large fraction of their UCS when soaked in water; however, their remaining strength was still considerable. The stabilized specimens showed acceptable endurance under weathering action, although sample yellowing due to ultraviolet radiation was evident on the surface of the specimens. Except for moisture susceptibility of the clay specimens, the results of this study suggested the liquid stabilizer could be successfully utilized to provide acceptable strength, durability and mitigated swelling.

  15. Genetic stability of foot-and-mouth disease virus during long-term infections in natural hosts.

    Science.gov (United States)

    Ramirez-Carvajal, Lisbeth; Pauszek, Steven J; Ahmed, Zaheer; Farooq, Umer; Naeem, Khalid; Shabman, Reed S; Stockwell, Timothy B; Rodriguez, Luis L

    2018-01-01

    Foot-and-mouth disease (FMD) is a severe infection caused by a picornavirus that affects livestock and wildlife. Persistence in ruminants is a well-documented feature of Foot-and-mouth disease virus (FMDV) pathogenesis and a major concern for disease control. Persistently infected animals harbor virus for extended periods, providing a unique opportunity to study within-host virus evolution. This study investigated the genetic dynamics of FMDV during persistent infections of naturally infected Asian buffalo. Using next-generation sequencing (NGS) we obtained 21 near complete FMDV genome sequences from 12 sub-clinically infected buffalo over a period of one year. Four animals yielded only one virus isolate and one yielded two isolates of different serotype suggesting a serial infection. Seven persistently infected animals yielded more than one virus of the same serotype showing a long-term intra-host viral genetic divergence at the consensus level of less than 2.5%. Quasi-species analysis showed few nucleotide variants and non-synonymous substitutions of progeny virus despite intra-host persistence of up to 152 days. Phylogenetic analyses of serotype Asia-1 VP1 sequences clustered all viruses from persistent animals with Group VII viruses circulating in Pakistan in 2011, but distinct from those circulating on 2008-2009. Furthermore, signature amino acid (aa) substitutions were found in the antigenically relevant VP1 of persistent viruses compared with viruses from 2008-2009. Intra-host purifying selective pressure was observed, with few codons in structural proteins undergoing positive selection. However, FMD persistent viruses did not show a clear pattern of antigenic selection. Our findings provide insight into the evolutionary dynamics of FMDV populations within naturally occurring subclinical and persistent infections that may have implications to vaccination strategies in the region.

  16. Genetic stability of foot-and-mouth disease virus during long-term infections in natural hosts.

    Directory of Open Access Journals (Sweden)

    Lisbeth Ramirez-Carvajal

    Full Text Available Foot-and-mouth disease (FMD is a severe infection caused by a picornavirus that affects livestock and wildlife. Persistence in ruminants is a well-documented feature of Foot-and-mouth disease virus (FMDV pathogenesis and a major concern for disease control. Persistently infected animals harbor virus for extended periods, providing a unique opportunity to study within-host virus evolution. This study investigated the genetic dynamics of FMDV during persistent infections of naturally infected Asian buffalo. Using next-generation sequencing (NGS we obtained 21 near complete FMDV genome sequences from 12 sub-clinically infected buffalo over a period of one year. Four animals yielded only one virus isolate and one yielded two isolates of different serotype suggesting a serial infection. Seven persistently infected animals yielded more than one virus of the same serotype showing a long-term intra-host viral genetic divergence at the consensus level of less than 2.5%. Quasi-species analysis showed few nucleotide variants and non-synonymous substitutions of progeny virus despite intra-host persistence of up to 152 days. Phylogenetic analyses of serotype Asia-1 VP1 sequences clustered all viruses from persistent animals with Group VII viruses circulating in Pakistan in 2011, but distinct from those circulating on 2008-2009. Furthermore, signature amino acid (aa substitutions were found in the antigenically relevant VP1 of persistent viruses compared with viruses from 2008-2009. Intra-host purifying selective pressure was observed, with few codons in structural proteins undergoing positive selection. However, FMD persistent viruses did not show a clear pattern of antigenic selection. Our findings provide insight into the evolutionary dynamics of FMDV populations within naturally occurring subclinical and persistent infections that may have implications to vaccination strategies in the region.

  17. 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)

    Pocock, D.C.; Worthington, J.C.; Oberpichler, R.; Van Exel, H.; Beukelmann, D.; Huth, R.; Rose, B.

    1990-01-01

    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

  18. Long-term stability of the BDNPF/BDNPA nitroplaticizer system: an MMR analysis. Progress report, October--December 1975

    International Nuclear Information System (INIS)

    Clink, G.L.

    1976-01-01

    NMR analysis of the BDNPF/BDNPA eutectic system reaffirms the molecular integrity of the constituents, the stability of their molar ratios, and the effective retardant effect of the phenyl-beta-napthylamine antioxidant. Additional work on the analysis of the PBX 9501 system is underway at the present time

  19. 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

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

    Directory of Open Access Journals (Sweden)

    Satinder Pal Singh

    2012-01-01

    Full Text Available 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 months (mean 25.5 ± 1.94 months after distraction osteogenesis were used for the evaluation of treatment outcome and long-term stability of the skeletal changes. Descriptive analysis, ANOVA, and post-hoc test were used, and P-value 0.05 was considered as a statistically significant level. Results: Maxillary distraction resulted in significant advancement of maxilla (P<0.001. Counterclockwise rotation of the palatal plane took place after maxillary distraction. The position of the mandible and facial heights were stable during distraction. During the first 6 months of the post-distraction period, the maxilla showed relapse of approximately 30%. However, after 6 months post distraction, the relapse was very negligible. Conclusions: Successful advancement of maxilla was achieved by distraction osteogenesis in adult subjects with cleft lip and palate. Most of the relapse occurred during the first 6 months of post-distraction period, and after that the outcomes were stable.

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

    Science.gov (United States)

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

    2012-04-01

    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. 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 months (mean 25.5 ± 1.94 months) after distraction osteogenesis were used for the evaluation of treatment outcome and long-term stability of the skeletal changes. Descriptive analysis, ANOVA, and post-hoc test were used, and P-value 0.05 was considered as a statistically significant level. Maxillary distraction resulted in significant advancement of maxilla (Pmaxillary distraction. The position of the mandible and facial heights were stable during distraction. During the first 6 months of the post-distraction period, the maxilla showed relapse of approximately 30%. However, after 6 months post distraction, the relapse was very negligible. Successful advancement of maxilla was achieved by distraction osteogenesis in adult subjects with cleft lip and palate. Most of the relapse occurred during the first 6 months of post-distraction period, and after that the outcomes were stable.

  2. Substantial improvements of long-term stability in encapsulation-free WS2 using highly interacting graphene substrate

    Science.gov (United States)

    Kim, Se-Yang; Kwak, Jinsung; Kim, Jung Hwa; Lee, Jae-Ung; Jo, Yongsu; Youb Kim, Sung; Cheong, Hyeonsik; Lee, Zonghoon; Kwon, Soon-Yong

    2017-03-01

    We report the novel role of graphene substrates in obstructing the aging propagation in both the basal planes and edges of two-dimensitional sheets of transition metal dichalcogenides (TMDs). Even after 300 d in ambient air conditions, the epitaxially grown WS2/graphene samples have a clean, uniform surface without any encapsulation. We show that high crystallinity is an effective factor that determines the excellent air stability of WS2/graphene, and we present impressive experimental evidence of the relation between defects and the aging phenomena. Moreover, we reveal the strong interlayer charge interaction as an additional factor for the enhanced air stability as a result of charge transfer-induced doping. This work not only proposes a simple method to create highly stable TMDs by the selection of a suitable substrate but also paves the way for the realization of practical TMDs-based applications.

  3. Interfacial, mechanical properties of Al{sub 2}O{sub 3}-NiAl composites respective to long term thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jia; Hu, Weiping; Gottstein, Guenter [RWTH Aachen Univ. (Germany). Inst. of Physical Metallurgy and Metal Physics

    2010-07-01

    The long term thermal stability of NiAl-Al{sub 2}O{sub 3} composites was investigated. During annealing of the composites at 973 K and 1373 K for 2000 hours, the NiAl-Al{sub 2}O{sub 3} system showed excellent chemical stability. However, grain growth and embrittlement progressed in the polycrystalline NiAl matrix. The interfacial shear strength decreased from 222{+-}50 MPa for the as-fabricated sample to 197{+-}48 MPa and 150{+-}38 MPa for the samples annealed at 973 K and 1373 K, respectively. The microstructure change during annealing at 973K and 1373 K affected the tensile strength differently. The potential causes of microstructure and interface structure change and their impact on mechanical properties are discussed. (orig.)

  4. 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)

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

    2016-03-01

    We report short and long-term results with the dedicated Synthes(®) titanium plates system, introduced 5 years ago, for chest wall stabilization and reconstruction. 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]. 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. 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 and post-operative hospital stay. Long-term

  5. 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.

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

    International Nuclear Information System (INIS)

    Xue Dingqi; Sethi, Rajandrea

    2012-01-01

    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.

  7. Long-term thermal stability of nanoclusters in ODS-Eurofer steel: An atom probe tomography study

    Science.gov (United States)

    Zilnyk, K. D.; Pradeep, K. G.; Choi, P.; Sandim, H. R. Z.; Raabe, D.

    2017-08-01

    Oxide-dispersion strengthened materials are important candidates for several high-temperature structural applications in advanced nuclear power plants. Most of the desirable mechanical properties presented by these materials are due to the dispersion of stable nanoparticles in the matrix. Samples of ODS-Eurofer steel were annealed for 4320 h (6 months) at 800 °C. The material was characterized using atom probe tomography in both conditions (prior and after heat treatment). The particles number density, size distribution, and chemical compositions were determined. No significant changes were observed between the two conditions indicating a high thermal stability of the Y-rich nanoparticles at 800 °C.

  8. Comparing the short and long term stability of biodegradable, ceramic and cation exchange membranes in microbial fuel cells.

    Science.gov (United States)

    Winfield, Jonathan; Chambers, Lily D; Rossiter, Jonathan; Ieropoulos, Ioannis

    2013-11-01

    The long and short-term stability of two porous dependent ion exchange materials; starch-based compostable bags (BioBag) and ceramic, were compared to commercially available cation exchange membrane (CEM) in microbial fuel cells. Using bi-directional polarisation methods, CEM exhibited power overshoot during the forward sweep followed by significant power decline over the reverse sweep (38%). The porous membranes displayed no power overshoot with comparably smaller drops in power during the reverse sweep (ceramic 8%, BioBag 5.5%). The total internal resistance at maximum power increased by 64% for CEM compared to 4% (ceramic) and 6% (BioBag). Under fixed external resistive loads, CEM exhibited steeper pH reductions than the porous membranes. Despite its limited lifetime, the BioBag proved an efficient material for a stable microbial environment until failing after 8 months, due to natural degradation. These findings highlight porous separators as ideal candidates for advancing MFC technology in terms of cost and operation stability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Long-Term Stability of Anode-Supported Solid Oxide Fuel Cells with a Co-Sintered Cathode Backbone and Infiltrated La0.95Co0.4Ni0.6O3 (LCN) Electro-Catalyst

    DEFF Research Database (Denmark)

    Küngas, Rainer; Veltzé, Sune; Ovtar, Simona

    2016-01-01

    Infiltration is a fabrication method that is offering potentially significant improvements in cell performance at reduced materials and fabrication costs, especially when combined with co-sintering. However, important questions regarding the long-term performance and microstructural stability of ...

  10. An analogue of long-term stability of flow-path structure in crystalline rocks distributed in the orogenic belt, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, H. [Nagoya University, University Museum Material Research Section, 464-8601, Chikusa, Nagoya, 464-8601 (Japan)]. E-mail: dora@num.nagoya-u.ac.jp; Takeuchi, M. E-mail: takeuchi@eps.nagoya-u.ac.jp

    2004-07-01

    In the orogenic belt, in the Japanese islands, crystalline rocks from the youngest to older ages and of different orders have been identified which have formed massive areas. The fracture system observed within these rock masses implies that the groundwater and solute can be conducted through the fracture's network. It is expected that the nuclides can be retarded due to chemical sorption and/or physical retardation by the fracture fillings and fracture open pore geometry. Most of the evaluation framework of the nuclides retardation process in the geological disposal of high level radioactive waste (HLW) is, however, basically taken into account in the present geological state, without changes of structural and mineralogical features, and in its influence on the groundwater flow system over a long period of time. This paper seeks analogous evidence that can provide the confidence of such evaluation methodology and its long-term applicability. Here, we describe the fracture system developed in the crystalline rock with the different ages intruded in the orogenic belt in order to build the long-term fracturing and its 'stability' model. In particular, comparisons with the rock of 1.9-0.8 Ma Takidani Granodiorite (the youngest pluton in the world), ca. 67 Ma of Toki Granite and ca. 117 Ma Kurihashi Granodiorite located in central to northwest Japan suggest a unique characteristic of the fracture forming process and their relatively stable geometrical changing. This analogue enables us to provide a model to build the confidence of a safety context applicable for the geological setting under the orogenic field with a long-term scale. The model may also be useful for other stable tectonic settings as well as for a site characterisation methodology of crystalline rock for HLW geological disposal. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ralph E. White; Dr. Branko N. Popov

    2002-04-01

    The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Two approaches have been adopted to get a stable cathode material. First approach is the use of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}, a commercially available lithium battery cathode material and the second is the use of tape cast electrodes prepared from cobalt coated nickel powders. The morphology and the structure of LiNi{sub 0.8}Co{sub 0.2}O{sub 2} and tape cast Co coated nickel powder electrodes were studied using scanning electron microscopy and X-Ray diffraction studies respectively. The electrochemical performance of the two materials was investigated by electrochemical impedance spectroscopy and polarization studies. A three phase homogeneous model was developed to simulate the performance of the molten carbonate fuel cell cathode. The homogeneous model is based on volume averaging of different variables in the three phases over a small volume element. The model gives a good fit to the experimental data. The model has been used to analyze MCFC cathode performance under a wide range of operating conditions.

  12. Construction of the Courant-Snyder invariants for the non-linear equations of motion and criterion for the long-term stability of the beam in a storage ring

    International Nuclear Information System (INIS)

    Garczynski, V.

    1993-01-01

    The Courant-Snyder invariants become Lyapunov functions when the β-functions admit non-zero lower, and finite upper bounds. The long-term stability of motion then follows. This alternative criterion for the long-term stability of motion can be generalized to the nonlinear case. A single particle subjected to an arbitrary static magnetic field is considered in some detail, as an example

  13. Effect of freeze-thawing on the long-term stability of calcium levofolinate in 5% dextrose stored on polyolefin infusion bags.

    Science.gov (United States)

    Lebitasy, M; Hecq, J-D; Athanassopoulos, A; Vanbeckbergen, D; Jamart, J; Galanti, L

    2009-08-01

    Calcium levofolinate infusions could be prepared in advance by a centralized intravenous additive service (CIVAS) to improve safety and time management. To investigate the effect of freezing, microwave thawing and long-term storage at 5 +/- 3 degrees C on the stability of calcium levofolinate in 5% dextrose solution. Solutions of 250 mL of 5% dextrose in polyolefin bags (n = 5) containing approximately 400 mg of calcium levofolinate were prepared under aseptic conditions and frozen for 95 days at -20 degrees C. The solutions were then thawed using microwaves and stored at 5 +/- 3 degrees C for 1 month. The calcium levofolinate concentrations were measured by high performance liquid chromatography (HPLC). Visual inspection was performed and pH was measured periodically during the storage at 5 +/- 3 degrees C. Stability of the solution was defined as a concentration remaining superior to 90% of the initial concentration by regression analysis as recommended by the Food and Drug Administration (FDA). No colour change or precipitation in the solutions was observed. Calcium levofolinate infusions were stable when stored at 5 +/- 3 degrees C during 1 month after freeze-thaw treatment. Throughout this period, the lower confidence limit of the estimated regression line of concentration-time profile remained above 90% of the initial concentration. Slight change in pH values from 6.52 +/- 0.01 to 6.50 +/- 0.01 during storage time did not affect retention time on HPLC and has no clinical consequence, the solutions remaining in the acceptable range for perfusion (4 long-term stability and releases pharmacist's time for major activities such as checking medication order errors.

  14. Long-term Stability of Soft Tissue Esthetic Outcomes Following Conventional Single Implant Treatment in the Anterior Maxilla: 10-12 Year Results.

    Science.gov (United States)

    Rokn, A; Bassir, S H; Rasouli Ghahroudi, A A; Kharazifard, M J; Manesheof, R

    2016-01-01

    The present study aimed to evaluate the long-term stability of esthetic outcomes of soft tissue around maxillary anterior single-tooth implants after 10-to-12 years of loading. Patients who had been treated for single-tooth implants in the anterior maxilla between February 2000 and July 2002 were invited to participate in the study. All implants had been placed according to delayed implant placement and conventional loading protocols without any connective tissue graft or papilla preservation flaps. Pink Esthetic Score (PES) was rated using standardized clinical photographs to assess the esthetic outcomes of the implant treatment at the time of crown placement and at time of follow-up examination which was at least 10 years after the crown placement. A total of 19 patients were included. The mean score of PES was 11.63 (SD 1.61; range 7-14) at baseline. After 10-to-12 years of function, a mean PES score of 11.05 (SD 2.09; range 6-14) was recorded. No significant differences were found in the esthetic outcomes, categorized based on clinically relevant levels, between the baseline and follow-up session (p>0.05). Within limitation of the present study, it can be concluded that the esthetic outcomes of soft tissue around the maxillary anterior single-tooth implants placed using conventional implant placement technique remained stable in the long-term.

  15. Long-term stability of contour augmentation in the esthetic zone: histologic and histomorphometric evaluation of 12 human biopsies 14 to 80 months after augmentation.

    Science.gov (United States)

    Jensen, Simon S; Bosshardt, Dieter D; Gruber, Reinhard; Buser, Daniel

    2014-11-01

    Contour augmentation around early-placed implants (Type 2 placement) using autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) and a collagen barrier membrane has been documented to predictably provide esthetically satisfactory clinical outcomes. In addition, recent data from cone beam computed tomography studies have shown the augmented volume to be stable long-term. However, no human histologic data are available to document the tissue reactions to this bone augmentation procedure. Over an 8-year period, 12 biopsies were harvested 14 to 80 months after implant placement with simultaneous contour augmentation in 10 patients. The biopsies were subjected to histologic and histomorphometric analysis. The biopsies consisted of 32.0% ± 9.6% DBBM particles and 40.6% ± 14.6% mature bone. 70.3% ± 14.5% of the DBBM particle surfaces were covered with bone. On the remaining surface, multinucleated giant cells with varying intensity of tartrate-resistant acid phosphatase staining were regularly present. No signs of inflammation were visible, and no tendency toward a decreasing volume fraction of DBBM over time was observed. The present study confirms previous findings that osseointegrated DBBM particles do not tend to undergo substitution over time. This low substitution rate may be the reason behind the clinically and radiographically documented long-term stability of contour augmentation using a combination of autogenous bone chips, DBBM particles, and a collagen membrane.

  16. Long-term stability in biomass and production of terpene indole alkaloids by hairy root culture of Rauvolfia serpentina and cost approximation to endorse commercial realism.

    Science.gov (United States)

    Pandey, Pallavi; Kaur, Ranjeet; Singh, Sailendra; Chattopadhyay, Sunil Kumar; Srivastava, Santosh Kumar; Banerjee, Suchitra

    2014-07-01

    The effect of 6 years of cultivation and use of table-sugar (TS) on the biomass/terpene alkaloid productivities and rol gene expression were studied in a hairy root (HR) clone of Rauvolfia serpentina. The media cost could be reduced >94 % by replacing sucrose (SUC) with TS—an unexplored avenue for HR cultivation. The overall productivities increased over long-term cultivation with sugar proving superior to SUC for biomass (24.4 ± 2.11 g/l DW after 40 days to 17.31 % higher) and reserpine (0.094 ± 0.008 % DW after 60 days to 193.8 % more) production. The latter however revealed comparatively better yields concerning ajmaline (0.507 ± 0.048 % DW after 60 days to 61.98 % higher) and yohimbine (0.628 ± 0.062 % DW after 60 days to 38.32 % higher), respectively. PCR amplification of rol genes confirmed long-term expression stability.

  17. 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

    2012-02-01

    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. African American youths (M age, pretest = 17.7 years) were assigned randomly to the AIM (n = 174) or control (n = 173) group. Past 3-month alcohol use, past 6-month substance use problems, risk taking, and susceptibility cognitions were assessed at pretest and at 6.4, 16.6, and 27.5 months after pretest. Pretest assessments of parent-child conflict, affiliations with substance-using companions, and perceived racial discrimination were used to construct a contextual risk factor index. A protective stabilizing hypothesis was supported; the long-term efficacy of AIM in preventing escalation of alcohol use and substance use problems was greater for youths with higher pretest contextual risk scores. Consistent with a mediation-moderation hypothesis, AIM-induced reductions over time in risk taking and susceptibility cognitions were responsible for the AIM × contextual risk prevention effects on alcohol use and substance use problems. Training in developmentally appropriate protective parenting processes and self-regulatory skills during the transition from adolescence to emerging adulthood for rural African Americans may contribute to a self-sustaining decreased interest in alcohol use and a lower likelihood of developing substance use problems. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  18. Long-Term Stability of Polymer-Coated Surface Transverse Wave Sensors for the Detection of Organic Solvent Vapors.

    Science.gov (United States)

    Stahl, Ullrich; Voigt, Achim; Dirschka, Marian; Barié, Nicole; Richter, Christiane; Waldbaur, Ansgar; Gruhl, Friederike J; Rapp, Bastian E; Rapp, Michael; Länge, Kerstin

    2017-11-03

    Arrays with polymer-coated acoustic sensors, such as surface acoustic wave (SAW) and surface transverse wave (STW) sensors, have successfully been applied for a variety of gas sensing applications. However, the stability of the sensors' polymer coatings over a longer period of use has hardly been investigated. We used an array of eight STW resonator sensors coated with different polymers. This sensor array was used at semi-annual intervals for a three-year period to detect organic solvent vapors of three different chemical classes: a halogenated hydrocarbon (chloroform), an aliphatic hydrocarbon (octane), and an aromatic hydrocarbon (xylene). The sensor signals were evaluated with regard to absolute signal shifts and normalized signal shifts leading to signal patterns characteristic of the respective solvent vapors. No significant time-related changes of sensor signals or signal patterns were observed, i.e., the polymer coatings kept their performance during the course of the study. Therefore, the polymer-coated STW sensors proved to be robust devices which can be used for detecting organic solvent vapors both qualitatively and quantitatively for several years.

  19. 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.

  20. Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of bank voles (Myodes glareolus) in NE Poland.

    Science.gov (United States)

    Grzybek, Maciej; Bajer, Anna; Bednarska, Małgorzata; Al-Sarraf, Mohammed; Behnke-Borowczyk, Jolanta; Harris, Philip D; Price, Stephen J; Brown, Gabrielle S; Osborne, Sarah-Jane; Siński, Edward; Behnke, Jerzy M

    2015-12-01

    Parasites are considered to be an important selective force in host evolution but ecological studies of host-parasite systems are usually short-term providing only snap-shots of what may be dynamic systems. We have conducted four surveys of helminths of bank voles at three ecologically similar woodland sites in NE Poland, spaced over a period of 11 years, to assess the relative importance of temporal and spatial effects on helminth infracommunities. Some measures of infracommunity structure maintained relative stability: the rank order of prevalence and abundance of Heligmosomum mixtum, Heligmosomoides glareoli and Mastophorus muris changed little between the four surveys. Other measures changed markedly: dynamic changes were evident in Syphacia petrusewiczi which declined to local extinction, while the capillariid Aonchotheca annulosa first appeared in 2002 and then increased in prevalence and abundance over the remaining three surveys. Some species are therefore dynamic and both introductions and extinctions can be expected in ecological time. At higher taxonomic levels and for derived measures, year and host-age effects and their interactions with site are important. Our surveys emphasize that the site of capture is the major determinant of the species contributing to helminth community structure, providing some predictability in these systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Anand Durairajan; Bala Haran; Branko N. Popov; Ralph E. White

    2000-05-01

    stability of the cathode at high temperatures. Deposition of refractory metals (Mo, W, Li{sub 2}NiCrO{sub 4}) will impart stability to the cathode at high temperatures. Further it will also increase the electrocatalytic activity and corrosion resistance of the cathode. Doping with Co will decrease the alloy dissolution and increase the cycle life of the cathode. In the reporting period the oxidation behavior of Ni and Co in Li + Na carbonate eutectic was investigated under oxidizing environment using cyclic voltammetry, electrochemical impedance spectroscopy and potentiodynamic technique. The open circuit potential was monitored as a function of time in order to evaluate the material's reactivity in the melt.

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

    KAUST Repository

    Mateker, William R.; Douglas, Jessica D.; Cabanetos, Clement; Sachs-Quintana, I. T.; Bartelt, Jonathan A.; Hoke, Eric T.; El Labban, Abdulrahman; Beaujuge, Pierre; Frechet, Jean; McGehee, Michael D.

    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.

  3. [Stability of long-term professional objectives of young physicians during postgraduate training. Results of a multicenter cohort study].

    Science.gov (United States)

    Birck, S; Gedrose, B; Robra, B-P; Schmidt, A; Schultz, J-H; Stosch, C; Wagner, R; Janßen, N; Scherer, M; van den Bussche, H

    2014-10-01

    We investigated persistences and changes of career preferences of medical residents in Germany after two years of postgraduate training with regard to future working place and position. The results are compared with those forwarded at graduation from medical school in a gender comparative perspective. The study is based on a standardized postal survey among the participants in the "KarMed" study, originally based on 1012 graduates of the medical faculties of Erlangen, Giessen, Hamburg, Heidelberg, Cologne, Leipzig and Magdeburg in 2009. 2107 persons were contacted. The return rate at baseline was 48 %, and the two surveys after the baseline reached return rates of 87 % and 89 % respectively. In all samples 2/3 were women as in actual medical undergraduate education. Descriptive statistics and regression analysis were performed. After 2 years of residency, residents after 2 years of postgraduate training still preferred the hospital over private practice as their final workplace after postgraduate training. The attractiveness of leading positions in the hospital declined among men, whereas it was already low for women at graduation. A large proportion of those physicians preferring the ambulatory sector, especially women, wishes to work as employee instead of private practice. At the personal level, almost 60 % forwarded the same preferences as those at graduation. Gender, parenthood and region of study (East vs. West Germany) did not influence stability or change of preferences. The results demonstrate the persistence of professional preferences regarding future sector and position of medical work during postgraduate training. These preferences do neither match with principles of gender equality nor with future workforce needs (e. g. in primary care). © Georg Thieme Verlag KG Stuttgart · New York.

  4. Long-term Measurement of Sediment Resuspension and Gas Hydrate Stability at a Gulf of Mexico Seep Site

    Science.gov (United States)

    Vardaro, M. F.; Bender, L. C.; MacDonald, I. R.

    2003-12-01

    To study the temporal topographic and hydrologic changes in Gulf of Mexico cold seeps, we deployed a deep-sea time-lapse camera, several temperature probes and an ADCP mooring at the continental shelf seep community surrounding a gas hydrate outcropping. The digital camera recorded one still image every six hours for three months in 2001, every two hours for the month of June 2002 and every six hours for the month of July 2002. A pair of 300 kHz Workhorse acoustic Doppler current profilers (ADCPs) attached to a 540 meter-long mooring were anchored approximately 2 km from the site in 2002. Temperature probes were deployed at the site over the entire experimental period. The data recovered provide a comprehensive record of gas hydrate mound processes. We calculated biological activity by identifying fauna observed in the time-lapse record and recording the number of individuals and species seen in each image. 1,381 individual organisms representing over 20 species were observed. An average of 4.6 (+/-3.0) organisms were seen in each frame during the three-month deployment, while 3.6 (+/-4.2) were seen per frame in the one-month deployment. An extensive amount of sediment suspension and redistribution occurred during the deployment period. By digitally analyzing the luminosity of the water column above the mound and plotting the results over time the turbidity at the site could be quantified. A 24.1-hour diurnal pattern can be seen in the record, indicating a possible tidal or inertial component to deep-sea currents in this area. Contrary to expectations, there was no major change in shape or size of the gas hydrate outcrop being studied. This indicates a higher degree of stability than laboratory studies or prior in situ observations have shown. The stable topography of the gas hydrate mound combines with high organic output and sediment turnover to serve as a focus of benthic predatory activity. The frequency and recurrence of sediment resuspension indicate that

  5. Cross calibration of the Siemens mMR: easily acquired accurate PET phantom measurements, long term stability and reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Sune H [Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Jakoby, Bjorn [University of Surrey, Guildford (United Kingdom); Hansen, Adam Espe; Svalling, Susanne; Klausen, Thomas L [Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

    2015-05-18

    We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens mMR PET/MR scanner. We perform regular cross calibrations (Xcals) of our PET scanners, including the Siemens mMR PET/MR, with a Siemens mCT water phantom. We evaluate the mMR cross calibration stability over a 3-year period. Recently, the mMR software (VB20P) offered the option of using predefined μ-maps. We evaluated this option by using either the predefined μ-map of the long mMR water phantom or a system-integrated user defined CT-based μ-map of the mCT water phantom used for Xcal. On 54 cross calibrations that were acquired over 3 years, the mMR on average underestimated the concentration by 16% due to the use of MR-based μ-maps. The mMR produced the narrowest range and lowest standard deviation of the Xcal ratios, implying it and is the most stable of the 6 scanners included in this study over a 3 year period. With correctly segmented μ-maps, the mMR produced Xcal ratios of 1.00-1.02, well within the acceptance range [0.95-1.05]. Measuring the concentration in a centrally placed cylindrical VOI allows for some robustness against misregistration of the μ-maps but it should be no more than a few millimeters in the x-y plane, while the tolerance is larger on the z-axis (when, as always with PET, keeping clear of the axial edges of the FOV). The mMR is the most stable scanner in this study and the mean underestimation is no longer an issue with the easily accessible μ-map, which in all 7 tests resulted in correct Xcal ratios. We will share the user defined μ-map of the mCT phantom and the protocol with interested mMR users.

  6. Cross calibration of the Siemens mMR: easily acquired accurate PET phantom measurements, long term stability and reproducibility

    International Nuclear Information System (INIS)

    Keller, Sune H; Jakoby, Bjorn; Hansen, Adam Espe; Svalling, Susanne; Klausen, Thomas L

    2015-01-01

    We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens mMR PET/MR scanner. We perform regular cross calibrations (Xcals) of our PET scanners, including the Siemens mMR PET/MR, with a Siemens mCT water phantom. We evaluate the mMR cross calibration stability over a 3-year period. Recently, the mMR software (VB20P) offered the option of using predefined μ-maps. We evaluated this option by using either the predefined μ-map of the long mMR water phantom or a system-integrated user defined CT-based μ-map of the mCT water phantom used for Xcal. On 54 cross calibrations that were acquired over 3 years, the mMR on average underestimated the concentration by 16% due to the use of MR-based μ-maps. The mMR produced the narrowest range and lowest standard deviation of the Xcal ratios, implying it and is the most stable of the 6 scanners included in this study over a 3 year period. With correctly segmented μ-maps, the mMR produced Xcal ratios of 1.00-1.02, well within the acceptance range [0.95-1.05]. Measuring the concentration in a centrally placed cylindrical VOI allows for some robustness against misregistration of the μ-maps but it should be no more than a few millimeters in the x-y plane, while the tolerance is larger on the z-axis (when, as always with PET, keeping clear of the axial edges of the FOV). The mMR is the most stable scanner in this study and the mean underestimation is no longer an issue with the easily accessible μ-map, which in all 7 tests resulted in correct Xcal ratios. We will share the user defined μ-map of the mCT phantom and the protocol with interested mMR users.

  7. The photoelectrocatalytic activity, long term stability and corrosion performance of NiMo deposited titanium oxide nano-tubes for hydrogen production in alkaline medium

    Science.gov (United States)

    Mert, Mehmet Erman; Mert, Başak Doğru; Kardaş, Gülfeza; Yazıcı, Birgül

    2017-11-01

    In this study, titanium oxide nano-tubes are doped with Ni and Mo particles with various chemical compositions, in order to put forth the efficiency of single and binary coatings on hydrogen evolution reaction (HER) in 1 M KOH. The characterization was achieved by cyclic voltammetry, scanning electron microscopy and energy dispersive X-ray analysis. The water wettability characteristics of electrode surfaces were investigated using contact angle. The long-term catalyst stability and corrosion performance were determined by current-potential curves and electrochemical impedance spectroscopy. Furthermore, photoelectrochemical behavior was determined via linear sweep voltammetry. Results showed that, nano-structured Ni and Mo deposited titanium oxide nano-tubes decrease the hydrogen over potential and increase HER efficiency, it is stable over 168 h electrolysis and it exhibits higher corrosion performance.

  8. Long-term stability assessment of AlGaN/GaN field effect transistors modified with peptides: Device characteristics vs. surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Rohrbaugh, Nathaniel; Bryan, Isaac; Bryan, Zachary; Collazo, Ramon; Ivanisevic, Albena, E-mail: ivanisevic@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

    2015-09-15

    AlGaN/GaN Field Effect Transistors (FETs) are promising biosensing devices. Functionalization of these devices is explored in this study using an in situ approach with phosphoric acid etchant and a phosphonic acid derivative. Devices are terminated on peptides and soaked in water for up to 168 hrs to examine FETs for both device responses and surface chemistry changes. Measurements demonstrated threshold voltage shifting after the functionalization and soaking processes, but demonstrated stable FET behavior throughout. X-ray photoelectron spectroscopy and atomic force microscopy confirmed peptides attachment to device surfaces before and after water soaking. Results of this work point to the stability of peptide coated functionalized AlGaN/GaN devices in solution and support further research of these devices as disposable, long term, in situ biosensors.

  9. Long-term stability of soft tissue changes in anterior open bite adults treated with zygomatic miniplate-anchored maxillary posterior intrusion.

    Science.gov (United States)

    Marzouk, Eiman S; Kassem, Hassan E

    2018-03-01

    To evaluate soft tissue changes and their long-term stability in skeletal anterior open bite adults treated by maxillary posterior teeth intrusion using zygomatic miniplates and premolar extractions. Lateral cephalograms of 26 patients were taken at pretreatment (T1), posttreatment (T2), 1 year posttreatment (T3), and 4 years posttreatment (T4). At the end of treatment, the soft tissue facial height and profile convexity were reduced. The lips increased in length and thickness, with backward movement of the upper lip and forward movement of the lower lip. The total relapse rate ranged from 20.2% to 31.1%. At 4 years posttreatment, 68.9% to 79.8% of the soft tissue treatment effects were stable. The changes in the first year posttreatment accounted for approximately 70% of the total relapse. Soft tissue changes following maxillary posterior teeth intrusion with zygomatic miniplates and premolar extractions appear to be stable 4 years after treatment.

  10. Improvement in switching characteristics and long-term stability of Zn-O-N thin-film transistors by silicon doping

    Directory of Open Access Journals (Sweden)

    Hiroshi Tsuji

    2017-06-01

    Full Text Available The effects of silicon doping on the properties of Zn-O-N (ZnON films and on the device characteristics of ZnON thin-film transistors (TFTs were investigated by co-sputtering silicon and zinc targets. Silicon doping was effective at decreasing the carrier concentration in ZnON films; therefore, the conductivity of the films can be controlled by the addition of a small amount of silicon. Doped silicon atoms also form bonds with nitrogen atoms, which suppresses nitrogen desorption from the films. Furthermore, Si-doped ZnON-TFTs are demonstrated to exhibit less negative threshold voltages, smaller subthreshold swings, and better long-term stability than non-doped ZnON-TFTs.

  11. Improved Long-Term Stability of Transparent Conducting Electrodes Based on Double-Laminated Electrosprayed Antimony Tin Oxides and Ag Nanowires

    Directory of Open Access Journals (Sweden)

    Koo B.-R.

    2017-06-01

    Full Text Available We fabricated double-laminated antimony tin oxide/Ag nanowire electrodes by spin-coating and electrospraying. Compared to pure Ag nanowire electrodes and single-laminated antimony tin oxide/Ag nanowire electrodes, the double-laminated antimony tin oxide/Ag nanowire electrodes had superior transparent conducting electrode performances with sheet resistance ~19.8 Ω/□ and optical transmittance ~81.9%; this was due to uniform distribution of the connected Ag nanowires because of double lamination of the metallic Ag nanowires without Ag aggregation despite subsequent microwave heating at 250°C. They also exhibited excellent and superior long-term chemical and thermal stabilities and adhesion to substrate because double-laminated antimony tin oxide thin films act as the protective layers between Ag nanowires, blocking Ag atoms penetration.

  12. Design and Formative Evaluation of the Policy Liaison Initiative: A Long-Term Knowledge Translation Strategy to Encourage and Support the Use of Cochrane Systematic Reviews for Informing

    Science.gov (United States)

    Brennan, Sue E.; Cumpston, Miranda; Misso, Marie L.; McDonald, Steve; Murphy, Matthew J.; Green, Sally E.

    2016-01-01

    The Policy Liaison Initiative (PLI) is a long-term knowledge translation initiative designed to support the use of Cochrane systematic reviews in health policy. A joint initiative between the Australasian Cochrane Centre and Australian Government Department of Health and Ageing, the PLI includes: 1) a community of practice for evidence-informed…

  13. Work package 1B.2 under the European Commission: Integrated wind turbine design (UPWIND): Specification of long-term load measurement technique

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt Paulsen, U.; Cutululis, N.; Soerensen, Poul

    2007-02-15

    The present report is the 12 month intermediate report of the UPWIND WP1B2 transmission and conversion. It describes the developed measurement technique for long-term load measurement technique, presents the hardware details, type of sensors and location, data storage and data analysis technique to verify design load assumptions. (au)

  14. 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

  15. Long-term stability of return to work after a workplace-oriented intervention for patients on sick leave for burnout.

    Science.gov (United States)

    Karlson, Björn; Jönsson, Peter; Österberg, Kai

    2014-08-09

    The period from the mid-1990s to the mid-2000s saw a rapid increase in long-term sick leave in Sweden, primarily due to mental illness and often related to job burnout. This led to an urge for effective treatment programs that could prevent the often long sick leaves. In 2010 we presented a newly developed work-place intervention method, showing that 89% of the intervention group had returned to work at a 1.5 year follow-up, compared to 73% of the control group. The main aim of this study was to assess the long-term stability of these promising results. Sick leave registry data from the Regional Social Insurance Office were analyzed for an additional year (50 weeks) beyond the original 1.5 year period (80 weeks). Data from 68 matched pairs of intervention participants (IP) and controls were available. The proportions of participants being on full-time sick leave versus having returned to work to any extent were computed for every 10th week. Generalized estimating equations were used with GROUP (IP versus controls) as between-subjects factor, WEEKS and AGE as covariates, and return-to-work (RTW) as dependent variable. Significant differences (Wald χ2 with α ≤ .05) was followed up with polynomial contrasts. Individual relapses to higher degrees of sick leave (e.g. from 50% to 100%) and whether partial RTW led to later full-time RTW, were also analyzed. The omnibus test over all 130 weeks showed a GROUP*WEEKS interaction effect (p = .02), indicating differential group developments in RTW, though similarly high at week 130 in both groups with 82.4% of the IP and 77.9% of the controls having RTW (p = .22; χ2-test). A significant interaction with age led to separate analyses of the younger and older subgroups, indicating a stable pattern of superior RTW only among younger IP (week 130: 88.6% vs. 69.7%, p = .054; χ2-test). There was no group difference in relapses into increased degree of sick leave. Part-time sick leave did not predict a later

  16. Introduction: Long term prediction

    International Nuclear Information System (INIS)

    Beranger, G.

    2003-01-01

    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

  17. 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)

    Bruno, Jordi; Spahiu, Kastriot

    2014-01-01

    Highlights: • We have reviewed current information on the effect of hydrogen in UO 2 spent fuel. • We explored the radiolytic models generated in the Cigar Lake project. • The Cigar Lake data supports that H 2 reduces alpha radiolysis oxidants. • The results indicate the hydrogen effect is present after 100.000 years deposition. - Abstract: The present paradigm on UO 2 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

  18. 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

    2015-01-01

    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. PMID:26503629

  19. Long-term efficiency of soil stabilization with apatite and Slovakite: the impact of two earthworm species (Lumbricus terrestris and Dendrobaena veneta) on lead bioaccessibility and soil functioning.

    Science.gov (United States)

    Tica, D; Udovic, M; Lestan, D

    2013-03-01

    Remediation soil is exposed to various environmental factors over time that can affect the final success of the operation. In the present study, we assessed Pb bioaccessibility and microbial activity in industrially polluted soil (Arnoldstein, Austria) stabilized with 5% (w/w) of Slovakite and 5% (w/w) of apatite soil after exposure to two earthworm species, Lumbricus terrestris and Dendrobaena veneta, used as model environmental biotic soil factors. Stabilization resulted in reduced Pb bioaccessibility, as assessed with one-step extraction tests and six-step sequential extraction, and improved soil functioning, mirrored in reduced β-glucosidase activity in soil. Both earthworm species increased Pb bioaccessibility, thus decreasing the initial stabilization efficacy and indicating the importance of considering the long-term fate of remediated soil. The earthworm species had different effects on soil enzyme activity, which can be attributed to species-specific microbial populations in earthworm gut acting on the ingested soil. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. 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.

  1. Outcome quality and long-term (≥15 years) stability after Class II:2 Herbst-multibracket appliance treatment in comparison to untreated Class I controls.

    Science.gov (United States)

    Bock, Niko C; Saffar, Mitra; Hudel, Helge; Evälahti, Marjut; Heikinheimo, Kaisa; Rice, David P; Ruf, Sabine

    2017-12-09

    To investigate the outcome quality and the long-term (≥15 years) post-treatment (Tx) changes after Class II:2 Herbst-multibracket appliance (MBA) Tx. In this longitudinal observational study, a recall of Class II:2 patients who had been treated by a Herbst-MBA during adolescence was conducted. Study models from before and after active Tx, after retention and after recall were assessed using standard occlusal variables and the peer assessment rating index (PAR). These data were compared to historical untreated Class I controls. Twenty out of 33 patients (61%) could be located and participated at age 33.9 ± 2.7 years. When comparing their data to the 13 patients who did not participate, the pre- and post-Tx occlusal findings did not differ systematically; however, the PAR scores of the non-participants were by 3.3-8.2 points higher at all times and the non-participants were 2.1-2.5 years older. Pre-Tx at age 14.4 ± 2.7 years, the participants showed the following mean values: PAR = 15.0 ± 7.0, Class II molar relationship (MR) = 0.8 ± 0.3 cusp widths (cw), overbite = 5.3 ± 1.3 mm. After Tx, a PAR score of 2.9 ± 1.3 and a super Class I MR (-0.1 ± 0.1 cw) with normal overbite (1.2 ± 0.8 mm) existed. At recall, a PAR score increase to 5.9 ± 3.6 points had occurred, mainly caused by an increase of overbite to 2.5 ± 1.5 mm. The average MR remained Class I (0.0 ± 0.2 cw). For all variables, the untreated controls exhibited similar findings. The occlusal outcome of Class II:2 Herbst-MBA Tx exhibited very good long-term stability. While mild post-Tx changes occurred, the long-term findings are similar to untreated Class I controls. © The Author(s) 2017. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com

  2. Marital stability, satisfaction and well-being in old age: variability and continuity in long-term continuously married older persons.

    Science.gov (United States)

    Margelisch, Katja; Schneewind, Klaus A; Violette, Jeanine; Perrig-Chiello, Pasqualina

    2017-04-01

    Recent research shows that the well-documented positive effects of marital stability on well-being and health outcomes are conditional upon the quality of marriage. To date, few studies have explored the relationship between marital satisfaction, well-being and health among very long-term married individuals. This study aims at identifying groups of long-term married persons with respect to marital satisfaction and comparing them longitudinally concerning their well-being outcomes, marital stressors, personality and socio-demographic variables. Data are derived from a survey (data collection 2012 and 2014) with 374 continuously married individuals at wave 1 (mean age: 74.2 years, length of marriage: 49.2 years) and 252 at wave 2. Cluster analyses were performed comparing the clusters with regard to various well-being outcomes. The predictive power of cluster affiliation and various predictors at wave 1 on well-being outcomes at wave 2 was tested using regression analyses. Two groups were identified, one happily the other unhappily married, with the happily married scoring higher on all well-being and health outcomes. Regression analyses revealed that group affiliation at wave 1 was not any longer predictive of health, emotional loneliness and hopelessness two years later, when taking into account socio-demographic variables, psychological resilience and marital strain, whereas it remained an important predictor of life satisfaction and social loneliness. Marital satisfaction is associated with health and well-being in older couples over time, whereas psychological resilience and marital strain are major predictors explaining the variance of these outcomes.

  3. Long-term stabilization of crop residues and soil organic carbon affected by residue quality and initial soil pH.

    Science.gov (United States)

    Wang, Xiaojuan; Butterly, Clayton R; Baldock, Jeff A; Tang, Caixian

    2017-06-01

    Residues differing in quality and carbon (C) chemistry are presumed to contribute differently to soil pH change and long-term soil organic carbon (SOC) pools. This study examined the liming effect of different crop residues (canola, chickpea and wheat) down the soil profile (0-30cm) in two sandy soils differing in initial pH as well as the long-term stability of SOC at the amended layer (0-10cm) using mid-infrared (MIR) and solid-state 13 C nuclear magnetic resonance (NMR) spectroscopy. A field column experiment was conducted for 48months. Chickpea- and canola-residue amendments increased soil pH at 0-10cm in the Podzol by up to 0.47 and 0.36units, and in the Cambisol by 0.31 and 0.18units, respectively, at 48months when compared with the non-residue-amended control. The decomposition of crop residues was greatly retarded in the Podzol with lower initial soil pH during the first 9months. The MIR-predicted particulate organic C (POC) acted as the major C sink for residue-derived C in the Podzol. In contrast, depletion of POC and recovery of residue C in MIR-predicted humic organic C (HOC) were detected in the Cambisol within 3months. Residue types showed little impact on total SOC and its chemical composition in the Cambisol at 48months, in contrast to the Podzol. The final HOC and resistant organic C (ROC) pools in the Podzol amended with canola and chickpea residues were about 25% lower than the control. This apparent priming effect might be related to the greater liming effect of these two residues in the Podzol. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Investigation of a methanol reformer concept considering the particular impact of dynamics and long-term stability for use in a fuel-cell-powered passenger car

    Science.gov (United States)

    Peters, R.; Düsterwald, H. G.; Höhlein, B.

    A methanol reformer concept including a reformer, a catalytic burner, a gas cleaning unit, a PEMFC and an electric motor for use in fuel-cell-powered passenger cars was investigated. Special emphasis was placed on the dynamics and the long-term stability of the reformer. Experiments on a laboratory scale were performed in a methanol steam reformer consisting of four different reactor tubes, which were separately balanced. Due to the endothermy of the steam reforming reaction of methanol, a sharp drop in the reaction temperature of about 50 K occurs at the beginning of the catalyst bed. This agrees well with the high catalytic activity at the entrance of the catalyst bed. Forty-five percent of the methanol was converted within the first 10 cm of the catalyst bed where 12.6 g of the CuO/ZnO catalyst was located. Furthermore, CO formation during methanol steam reforming strongly depends on methanol conversion. Long-term measurements for more than 700 h show that the active reaction zone moved through the catalyst bed. Calculations, on the basis of these experiments, revealed that 63 g of reforming catalyst was necessary for mobile PEMFC applications, in this case for 400 W el at a system efficiency of 42% and a theoretical specific hydrogen production of 5.2 m 3n/(h kg Cat). This amount of catalyst was assumed to maintain a hydrogen production of at least 80% of the original amount over an operating range of 3864 h. Cycled start-up and shut-down processes of the methanol steam reformer under nitrogen and hydrogen atmospheres did not harm the catalytic activity. The simulation of the breakdown of the heating system, in which a liquid water/methanol mixture was in close contact with the catalyst, did not reveal any deactivation of the catalytic activity.

  5. Minimizing predatory lending: Designing a long-term compensation structure to minimize the actions of opportunistic mortgage brokers

    Directory of Open Access Journals (Sweden)

    Patrick Payne

    2013-07-01

    Full Text Available This paper addresses the inadequacies in the current compensation structure for mortgage brokers, and asserts that the resulting opportunistic behavior by brokers played a major role in the 2008 collapse of the mortgage market. We utilize agency theory as an underpinning to suggest that increased regulation will have only a limited impact on self-serving behavior due to the complex information asymmetries possessed by brokers. We posit that a restructured long-term compensation package would be effective in aligning the interests of borrowers and brokers, ultimately reducing the level of mortgage defaults and foreclosures.

  6. Long-term follow-up of a randomized controlled trial on additional core stability exercises training for improving dynamic sitting balance and trunk control in stroke patients.

    Science.gov (United States)

    Cabanas-Valdés, Rosa; Bagur-Calafat, Caritat; Girabent-Farrés, Montserrat; Caballero-Gómez, Fernanda Mª; du Port de Pontcharra-Serra, Helena; German-Romero, Ana; Urrútia, Gerard

    2017-11-01

    Analyse the effect of core stability exercises in addition to conventional physiotherapy training three months after the intervention ended. A randomized controlled trial. Outpatient services. Seventy-nine stroke survivors. In the intervention period, both groups underwent conventional physiotherapy performed five days/week for five weeks, and in addition the experimental group performed core stability exercises for 15 minutes/day. Afterwards, during a three-month follow-up period, both groups underwent usual care that could eventually include conventional physiotherapy or physical exercise but not in a controlled condition. Primary outcome was trunk control and dynamic sitting balance assessed by the Spanish-Version of Trunk Impairment Scale 2.0 and Function in Sitting Test. Secondary outcomes were standing balance and gait evaluated by the Berg Balance Scale, Tinetti Test, Brunel Balance Assessment, Spanish-Version of Postural Assessment Scale for Stroke and activities of daily living using the Barthel Index. A total of 68 subjects out of 79 completed the three-month follow-up period. The mean difference (SD) between groups was 0.78 (1.51) points ( p = 0.003) for total score on the Spanish-Version of Trunk Impairment Scale 2.0, 2.52 (6.46) points ( p = 0.009) for Function in Sitting Test, dynamic standing balance was 3.30 (9.21) points ( p= 0.009) on the Berg Balance Scale, gait was 0.82 (1.88) points ( p = 0.002) by Brunel Balance Assessment (stepping), and 1.11 (2.94) points ( p = 0.044) by Tinetti Test (gait), all in favour of core stability exercises. Core stability exercises plus conventional physiotherapy have a positive long-term effect on improving dynamic sitting and standing balance and gait in post-stroke patients.

  7. 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.

  8. Performance and Long-Term Stability of Pd/PSS and Pd/Al2O3 Membranes for Hydrogen Separation.

    Science.gov (United States)

    Liguori, Simona; Iulianelli, Adolfo; Dalena, Francesco; Pinacci, Pietro; Drago, Francesca; Broglia, Maria; Huang, Yan; Basile, Angelo

    2014-03-06

    The present work is focused on the investigation of the performance and long-term stability of two composite palladium membranes under different operating conditions. One membrane (Pd/porous stainless steel (PSS)) is characterized by a ~10 µm-thick palladium layer on a porous stainless steel substrate, which is pretreated by means of surface modification and oxidation; the other membrane (Pd/Al2O3) is constituted by a ~7 µm-thick palladium layer on an asymmetric microporous Al2O3 substrate. The operating temperature and pressure ranges, used for studying the performance of these two kinds of membranes, are 350-450 °C and 200-800 kPa, respectively. The H2 permeances and the H2/N2 selectivities of both membranes were investigated and compared with literature data. At 400 °C and 200 kPa as pressure difference, Pd/PSS and Pd/Al2O3 membranes exhibited an H2/N2 ideal selectivity equal to 11700 and 6200, respectively, showing stability for 600 h. Thereafter, H2/N2 selectivity of both membranes progressively decreased and after around 2000 h, dropped dramatically to 55 and 310 for the Pd/PSS and Pd/Al2O3 membranes, respectively. As evidenced by Scanning Electron Microscope (SEM) analyses, the pinholes appear on the whole surface of the Pd/PSS membrane and this is probably due to release of sulphur from the graphite seal rings.

  9. Status of GENIUS-TF-II and TF-III-The long-term stability of naked detectors in liquid nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Klapdor-Kleingrothaus, H.V. [Max-Planck-Institut fuer Kernphysik, P.O. Box 10 39 80, D-69029 Heidelberg (Germany)]. E-mail: H.Klapdor@mpi-hd.mpg.de; Krivosheina, I.V. [Max-Planck-Institut fuer Kernphysik, P.O. Box 10 39 80, D-69029 Heidelberg (Germany)

    2006-10-15

    GENIUS-TF-II is a setup of six naked high purity Ge detectors (15kg) in liquid nitrogen in Gran Sasso. It has been installed in October, 2004-after the first four naked Ge detectors had been installed on May 5, 2003 (GENIUS-TF-I). The GENIUS-Test-Facility (GENIUS-TF) is the first and up to now only setup ever testing the novel technique aiming at extreme background reduction in search for rare decays in particular underground. The goal of GENIUS-TF was to test some key operational parameters of the full GENIUS project proposal in 1997 [H.V. Klapdor-Kleingrothaus, Int. J. Mod. Phys. A 13 (1998) 3953; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, GENIUS-Proposal, 20 November 1997; J. Hellmig and H.V. Klapdor-Kleingrothaus, Z. Phys. A 359 ( 1997) 351 and nucl-ex/9801004; H.V. Klapdor-Kleingrothaus, M. Hirsch, Z. Phys. A 359 (1997) 361; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, J. Phys. G 24 (1998) 483; H.V. Klapdor-Kleingrothaus, CERN Courier, November 1997, pp. 16-18]. Simultaneous physical goal is to search for the annual modulation of the Dark Matter signal [H.V. Klapdor-Kleingrothaus, et al., Nucl. Instr. and Meth. A 481 (2002) 149; C. Tomei, A. Dietz, I. Krivosheina, H.V. Klapdor-Kleingrothaus, Nucl. Instr. and Meth. 508 (2003) 343]. After operation of GENIUS-TF over three years with finally six naked Ge detectors (15kg) in liquid nitrogen in Gran Sasso we realize serious problems for realization of a full-size GENIUS-like experiment: (1) Background from Rn222 diffusing into the setup, on a level far beyond the expectation. (2) Limited long-term stability of naked detectors in liquid nitrogen as result of increasing leakage current. None of the six detectors is running after three years with the nominal leakage current. Three of the six detectors do not work any more at all. The results of our three years of investigation of the long-term stability may cast doubt on the possibility to perform full GENIUS-like projects.

  10. Status of GENIUS-TF-II and TF-III-The long-term stability of naked detectors in liquid nitrogen

    International Nuclear Information System (INIS)

    Klapdor-Kleingrothaus, H.V.; Krivosheina, I.V.

    2006-01-01

    GENIUS-TF-II is a setup of six naked high purity Ge detectors (15kg) in liquid nitrogen in Gran Sasso. It has been installed in October, 2004-after the first four naked Ge detectors had been installed on May 5, 2003 (GENIUS-TF-I). The GENIUS-Test-Facility (GENIUS-TF) is the first and up to now only setup ever testing the novel technique aiming at extreme background reduction in search for rare decays in particular underground. The goal of GENIUS-TF was to test some key operational parameters of the full GENIUS project proposal in 1997 [H.V. Klapdor-Kleingrothaus, Int. J. Mod. Phys. A 13 (1998) 3953; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, GENIUS-Proposal, 20 November 1997; J. Hellmig and H.V. Klapdor-Kleingrothaus, Z. Phys. A 359 ( 1997) 351 and nucl-ex/9801004; H.V. Klapdor-Kleingrothaus, M. Hirsch, Z. Phys. A 359 (1997) 361; H.V. Klapdor-Kleingrothaus, J. Hellmig, M. Hirsch, J. Phys. G 24 (1998) 483; H.V. Klapdor-Kleingrothaus, CERN Courier, November 1997, pp. 16-18]. Simultaneous physical goal is to search for the annual modulation of the Dark Matter signal [H.V. Klapdor-Kleingrothaus, et al., Nucl. Instr. and Meth. A 481 (2002) 149; C. Tomei, A. Dietz, I. Krivosheina, H.V. Klapdor-Kleingrothaus, Nucl. Instr. and Meth. 508 (2003) 343]. After operation of GENIUS-TF over three years with finally six naked Ge detectors (15kg) in liquid nitrogen in Gran Sasso we realize serious problems for realization of a full-size GENIUS-like experiment: (1) Background from Rn222 diffusing into the setup, on a level far beyond the expectation. (2) Limited long-term stability of naked detectors in liquid nitrogen as result of increasing leakage current. None of the six detectors is running after three years with the nominal leakage current. Three of the six detectors do not work any more at all. The results of our three years of investigation of the long-term stability may cast doubt on the possibility to perform full GENIUS-like projects

  11. Multicentric cohort study on the long-term efficacy and safety of electronic cigarettes: study design and methodology.

    Science.gov (United States)

    Manzoli, Lamberto; La Vecchia, Carlo; Flacco, Maria Elena; Capasso, Lorenzo; Simonetti, Valentina; Boccia, Stefania; Di Baldassarre, Angela; Villari, Paolo; Mezzetti, Andrea; Cicolini, Giancarlo

    2013-09-24

    While electronic cigarettes are forbidden in several countries, their sales are exploding in many others. Although e-cigarettes have been proposed as long-term substitutes for traditional smoking or as a tool for smoking cessation, very scarce data are available on their efficacy and safety.We describe the protocol of a 5-year multicentric prospective study aimed to evaluate short- and long-term adherence to e-cigarette smoking and the efficacy of e-cigarettes in reducing and/or quitting traditional cigarette smoking. The study will also compare the health effects of electronic vs traditional vs mixed cigarette smoking. From June to December 2013, we will enroll adult smokers of: (EC) e-cigarettes (self-reported inhaling ≥ 50 puffs per week since ≥ 6 months); (TC) traditional cigarettes (≥ 1 per day since ≥ 6 m); (Mixed) both electronic and traditional cigarettes (≥ 1 per day since ≥ 6 m). Eligible subjects will be requested participation through newspaper advertisements and direct contact at the shops. Each subject will have to compile a structured questionnaire at enrolment and after 6, 12, 24, 36 and 60 months. The level of carbon monoxide in expired after breath will be evaluated in all subjects declaring no traditional cigarette smoking in any follow-up phase, using portable carbon monoxide analyzers. The primary outcomes are traditional smoking cessation rates and number of smoked cigarettes. Secondary outcomes include adherence to e-cigarettes, self-reported adverse events, quality of life, and time to hospital admission for one among cardiovascular diseases, chronic obstructive pulmonary diseases, cancer of the lung, esophagus, larynx, oral cavity, bladder, pancreas, kidney, stomach, cervix, and myeloid leukemia. Admissions will be checked using official discharge data of the Abruzzo Region. A minimum of 500 subjects in each group will be enrolled, for a total of 1500 participants. Cox proportional hazards analysis will be used to calculate

  12. Biofiltration of volatile pollutants: Engineering mechanisms for improved design, long-term operation, prediction, and implementation. 1997 annual progress report

    International Nuclear Information System (INIS)

    Barton, J.W.; Davison, B.H.; Klasson, K.T.

    1997-01-01

    'Biofiltration systems can be used to treat volatile organic compounds (VOCs); however, the systems are poorly understood and are currently operated as black boxes. Common operational problems associated with biofilters include fouling, deactivation, and overgrowth, all of which make biofilters ineffective for continuous, long-term use. The objective of this investigation is to develop generic methods for long-term stable operation, in particular by using selective limitation of supplemental nutrients while maintaining high activity and the ability to regenerate biofilter activity. As part of this effort, the authors will provide a deeper fundamental understanding of the important biological and transport mechanisms in biodestruction of sparingly soluble VOCs and will extend this engineering approach and developed mathematical models to two additional systems of high-priority environmental management (EM) relevance-direct degradation and cometabolic degradation of priority pollutants such as BTEX (benzene, toluene, ethylbenzene, and xylene) and TCE (trichioroethylene), respectively. Preliminary results indicate that the author can control overgrowth of the biofilm while sustaining high degradation rates and develop basic predictive models that elucidate mass transfer and kinetic limitations in this system for alkanes. The alkanes are degraded into CO, and waterwith minimal biomass (due to the methodology proposed). This system will be used to test and model additional supplemental nutrient feeding strategies as well as methods to increase the fundamental driving forces by modification of the system. Models will be extended to non-steady-state, long-term operation. The author will examine the nature of the mixed microbial community in the VOC-degrading biofilm and test for new degradative activities. He will use cosolvents with surfactant properties to enhance hydrocarbon solubility in the biofilm and evaluate their impact on mass transfer and reaction rate in an

  13. Long-Term Stability of New Co-Amorphous Drug Binary Systems: Study of Glass Transitions as a Function of Composition and Shelf Time

    Directory of Open Access Journals (Sweden)

    Luz María Martínez

    2016-12-01

    Full Text Available The amorphous state is of particular interest in the pharmaceutical industry due to the higher solubility that amorphous active pharmaceutical ingredients show compared to their respective crystalline forms. Due to their thermodynamic instability, drugs in the amorphous state tend to recrystallize; in order to avoid crystallization, it has been a common strategy to add a second component to hinder the crystalline state and form a thermally stable co-amorphous system, that is to say, an amorphous binary system which retains its amorphous structure. The second component can be a small molecule excipient (such as a sugar or an aminoacid or a second drug, with the advantage that a second active pharmaceutical ingredient could be used for complementary or combined therapeutic purposes. In most cases, the compositions studied are limited to 1:1, 2:1 and 1:2 molar ratios, leaving a gap of information about phase transitions and stability on the amorphous state in a wider range of compositions. In the present work, a study of novel co–amorphous formulations in which the selection of the active pharmaceutical ingredients was made according to the therapeutic effect is presented. Resistance against crystallization and behavior of glass transition temperature ( T g were studied through calorimetric measurements as a function of composition and shelf time. It was found that binary formulations with T g temperatures higher than those of pure components presented long-term thermal stability. In addition, significant increments of T g values, of as much as 15 ∘ C, were detected as a result of glass relaxation at room temperature during storage time; this behavior of glass transition has not been previously reported for co-amorphous drugs. Based on these results, it can be concluded that monitoring behavior of T g and relaxation processes during the first weeks of storage leads to a more objective evaluation of the thermomechanical stability of an amorphous

  14. Review of the seismic risk in the design of civil engineering of nuclear installations excepted the long term storage of radioactive wastes

    International Nuclear Information System (INIS)

    2006-01-01

    This guide aims to define, for the nuclear installations excepted the long term storage of radioactive wastes, from site data, the design specifications of earthquake resistant civil engineering and the possible methods for: the determination of the seismic response of the buildings, taking into account the interactions with the materials and the evaluation of the associated strains to size the installation; the determination of seismic displacements to be considered to size the materials. (A.L.B.)

  15. [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 fertilizers alone, combined application of organic amendments and NPK fertilizers facilitated the storage of newly sequestered SOC in silt- and clay-sized fractions, which could be more conducive to the stability of SOC. Based on 13C-NMR spectra, both silt and clay fractions were composed of Alkyl-C, O-alkyl-C, Aromatic-C and carbonyl-C. Changes in the relative proportion of different C species were observed between silt and clay fractions: the clay fraction had relatively more Alkyl-C, carbonyl-C and less O-alkyl-C, Aromatic-C than those in the silt fraction. This might be ascribed to the fact that the organic matter complexed with clay was dominated by microbial products, whereas the silt appeared to be rich in aromatic residues derived from plants. The spectra also showed that the relative proportion of different C species was modified by fertilization practices. In comparison with organic amendments alone, the relative proportion of Alkyl-C was decreased by 9.1%-11.9% and 13.7%-19.9% under combined application of organic amendments and chemical fertilizers, for silt and clay, respectively, and that of O-alkyl-C was increased by 2.9%-6.3% and 13.4%-22.1%, respectively. These results indicated that NPKOM and NPKRS treatments reduced the 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

  16. 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)

    Kusano, Tomohiro; Asamori, Koichi; Kurosawa, Hideki; Saito-Kokubu, Yoko; Tanikawa, Shin-ichi; Negi, Tateyuki; Hanamuro, Takahiro; Yasue, Ken-ichi; Yamasaki, Seiko; Yamada, Kunimi; Ishimaru, Tsuneari; Umeda, Koji

    2011-01-01

    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 14 C 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)

  17. Long-term stability of morphine, codeine, and 6-acetylmorphine in real-life whole blood samples, stored at -20°C.

    Science.gov (United States)

    Høiseth, Gudrun; Fjeld, Bente; Burns, Margrete Larsen; Strand, Dag Helge; Vindenes, Vigdis

    2014-06-01

    Stability of drugs during storage is important in forensic toxicology. For the analytes detected after intake of heroin (6-acetylmorphine (6-AM), morphine and codeine), long-time stability in real life whole blood samples are studied in only a small number of cases. Whole blood post mortem (n=37) and whole blood samples from living persons (n=22) containing morphine and codeine as well as 6-AM in blood or urine were selected. All cases represented intake of heroin. All samples contained fluoride and were initially analysed and stored in normal conditions (-20°C) for 4-9 years. All samples were then reanalysed using the same analytical methods and the results were compared. For samples from living persons, the median change in concentration was -3.7% for morphine and -5.3% for codeine. For post mortem samples, the median change in concentration was -12% for morphine and -11% for codeine. Both for samples from living persons and post mortem samples, the decrease in the concentrations from the original analysis to reanalysis were statistically significant for morphine and codeine. Regarding 6-AM, all living samples were negative at reanalysis. For post mortem samples, four cases still tested positive for 6-AM at reanalysis with a median change in the concentrations of -81%. There was no significant change in the morphine to codeine concentration ratios neither for living nor post mortem samples. This study showed that in real life whole blood samples, the concentrations of morphine and codeine are relatively stable during long-term storage at -20°C. 6-AM on the other hand, shows a considerable decrease in concentrations that is important to consider when interpreting results from reanalyses of forensic cases. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Rapid fabrication of superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film with excellent energy-release characteristics and long-term storage stability

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Xiang; Zhou, Xiang, E-mail: zhouxiang@njust.edu.cn; Hao, Gaozi; Xiao, Lei; Liu, Jie; Jiang, Wei, E-mail: superfine_jw@126.com

    2017-06-15

    Highlights: • Superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film is prepared by combining electrophoretic deposition and surface modification technologies. • The deposition system and kinetics of electrophoretic deposition process are investigated to optimize parameters to obtain smooth films. • Energy-release characteristics of superhydrophobic films are significantly improved for both fresh and aged samples. • Superhydrophobic films exhibit excellent long-time storage stability both in natural and accelerated aging test. • A preignition reaction is found to enhance the energy-release characteristics of superhydrophobic nanothermite film. - Abstract: One of the challenges for the application of energetic materials is their energy-retaining capabilities after long-term storage. In this study, we report a facile method to fabricate superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film by combining electrophoretic deposition and surface modification technologies. Different concentrations of dispersion solvents and additives are investigated to optimize the deposition parameters. Meanwhile, the dependence of deposition rates on nanoparticle concentrations is also studied. The surface morphology and chemical composition are characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. A static contact angles as high as 156° shows the superhydrophobicity of the nanothermite film. Natural and accelerated aging tests are performed and the thermal behavior is analyzed. Thermal analysis shows that the surface modification contributes to significantly improved energy-release characteristics for both fresh and aged samples, which is supposed to be attributed to the preignition reaction between Al{sub 2}O{sub 3} shell and FAS-17. Superhydrophobic Al/Fe{sub 2}O{sub 3} nanothermite film exhibits excellent long-time storage stability with 83.4% of energy left in

  19. Effect of freezing, long-term storage and microwave thawing on the stability of a mixture of diclofenac and sodium bicarbonate in glucose 5% polyolefin bags.

    Science.gov (United States)

    François, J-H; Hecq, J-D; Vanbeckbergen, D; Jamart, J; Galanti, L

    2009-11-01

    Preparation in advance of intravenous solution could be efficient to improve quality assurance, security, time management and cost saving of drug delivery. The aim of this study was to investigate the stability of a mixture of diclofenac 75 mg/100 ml and sodium bicarbonate 42 mg/100 ml in 5% glucose polyolefin bags after freezing, long-term storage, and microwave thawing. The stability of five polyolefin bags containing approximately 75 mg/100ml of diclofenac and 42 mg/100ml of sodium bicarbonate in 5% glucose prepared under aseptic conditions was studied after freezing for 2 months at -20 degrees C, thawing in a microwave oven with a validated cycle, and stored at 5 + or - 3 degrees C. Diclofenac concentrations were measured by high-pressure liquid chromatography using a reversed-phase column, a mobile phase consisting of 40% of acetonitrile (v/v) in KH(2)PO(4) buffer 0.02 M, pH 8.40 + or - 0.05, and UV detection at 276.0 nm. Visual inspection, microscope observation, spectrophotometric measurements and pH measurement were also performed. No colour change or precipitation occurred in the preparations. No microaggregate was observed with optical microscopy or revealed by a change of absorbance. Based on a shelf-life of 90% residual potency, diclofenac was stable for at least 30 days after freezing and microwave thawing, period where 95% lower confidence limit of the concentration-time profile remained superior to 90% of the initial concentration. During this period, the pH values of drug solutions have not been altered. Within these limits, diclofenac in 5% glucose infusion may be prepared and frozen in advance by a centralized intravenous admixture service, then thawed before use in clinical units.

  20. A new long-term care facilities model in nova scotia, Canada: protocol for a mixed methods study of care by design.

    Science.gov (United States)

    Marshall, Emily Gard; Boudreau, Michelle Anne; Jensen, Jan L; Edgecombe, Nancy; Clarke, Barry; Burge, Frederick; Archibald, Greg; Taylor, Anthony; Andrew, Melissa K

    2013-11-29

    Prior to the implementation of a new model of care in long-term care facilities in the Capital District Health Authority, Halifax, Nova Scotia, residents entering long-term care were responsible for finding their own family physician. As a result, care was provided by many family physicians responsible for a few residents leading to care coordination and continuity challenges. In 2009, Capital District Health Authority (CDHA) implemented a new model of long-term care called "Care by Design" which includes: a dedicated family physician per floor, 24/7 on-call physician coverage, implementation of a standardized geriatric assessment tool, and an interdisciplinary team approach to care. In addition, a new Emergency Health Services program was implemented shortly after, in which specially trained paramedics dedicated to long-term care responses are able to address urgent care needs. These changes were implemented to improve primary and emergency care for vulnerable residents. Here we describe a comprehensive mixed methods research study designed to assess the impact of these programs on care delivery and resident outcomes. The results of this research will be important to guide primary care policy for long-term care. We aim to evaluate the impact of introducing a new model of a dedicated primary care physician and team approach to long-term care facilities in the CDHA using a mixed methods approach. As a mixed methods study, the quantitative and qualitative data findings will inform each other. Quantitatively we will measure a number of indicators of care in CDHA long-term care facilities pre and post-implementation of the new model. In the qualitative phase of the study we will explore the experience under the new model from the perspectives of stakeholders including family doctors, nurses, administration and staff as well as residents and family members. The proposed mixed method study seeks to evaluate and make policy recommendations related to primary care in long-term

  1. 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.

  2. Design and Delivery of Professional Development Through Partnerships: Long-Term, Short-Term, and Everything In-Between

    Science.gov (United States)

    Urquhart, M. L.; Curry, B.; Hairston, M. R.

    2009-12-01

    Professional development for teachers can take a variety of forms, each with unique challenges and needs. At the University of Texas at Dallas (UTD), we have leveraged partnerships between multiple groups including the Masters of Arts in Teaching program in Science Education, the joint US Air Force/NASA CINDI mission, an ionospheric explorer built at UTD, and the UTD Regional Collaborative for Excellence in Science Teaching. Each effort models, and in the case of the later two has created, inquiry-based lessons around Earth-systems science. A space science mission, currently in low Earth orbit aboard the Air Force satellite C/NOFS, provides real world connections to classroom science, scientific data and visualizations, and funding to support delivery of professional development in short courses and workshops at teacher conferences. Workshops and short course in turn often serve to recruit teachers into our longer-term programs. Long-term professional development programs such as the Collaborative provide opportunities to test curriculum and teacher learning, an interface to high-quality sustained efforts within talented communities of teachers, and much more. From the birth of our CINDI Educational Outreach program to the Collaborative project that produced geoscience kit-based modules and associated professional development adopted throughout the state of Texas, we will share highlights of our major professional development initiatives and how our partnerships have enabled us to better serve the needs of K-12 teachers expected to deliver geoscience and space science content in their classrooms.

  3. Study Design to Test the Hypothesis That Long-Term Space Travel Harms the Human and Animal Immune Systems

    Science.gov (United States)

    Shearer, William T.; Lugg, Desmond J.; Ochs, H. D.; Pierson, Duane L.; Reuben, James M.; Rosenblatt, Howard M.; Sams, Clarence; Smith, C. Wayne; Smith, E. Obrian; Smolen, James E.

    1999-01-01

    The potential threat of immunosuppression and abnormal inflammatory responses in long-term space travel, leading to unusual predilection for opportunistic infections, malignancy, and death, is of ma or concern to the National Aeronautics and Space Administration (NASA) Program. This application has been devised to seek answers to questions of altered immunity in space travel raised by previous investigations spanning 30-plus years. We propose to do this with the help of knowledge gained by the discovery of the molecular basis of many primary and secondary immunodeficiency diseases and by application of molecular and genetic technology not previously available. Two areas of immunity that previously received little attention in space travel research will be emphasized: specific antibody responses and non-specific inflammation and adhesion. Both of these areas of research will not only add to the growing body of information on the potential effects of space travel on the immune system, but be able to delineate any functional alterations in systems important for antigen presentation, specific immune memory, and cell:cell and cell:endothelium interactions. By more precisely defining molecular dysfunction of components of the immune system, it is hoped that targeted methods of prevention of immune damage in space could be devised.

  4. The pH-dependent long-term stability of an amorphous manganese oxide in smelter-polluted soils: implication for chemical stabilization of metals and metalloids.

    Science.gov (United States)

    Ettler, Vojtěch; Tomášová, Zdeňka; Komárek, Michael; Mihaljevič, Martin; Šebek, Ondřej; Michálková, Zuzana

    2015-04-09

    An 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Monitoring the long term stability of the IRS-P6 AWiFS sensor using the Sonoran and RVPN sites

    Science.gov (United States)

    Chander, Gyanesh; Sampath, Aparajithan; Angal, Amit; Choi, Taeyoung; Xiong, Xiaoxiong

    2010-10-01

    This paper focuses on radiometric and geometric assessment of the Indian Remote Sensing (IRS-P6) Advanced Wide Field Sensor (AWiFS) sensor using the Sonoran desert and Railroad Valley Playa, Nevada (RVPN) ground sites. Imageto- Image (I2I) accuracy and relative band-to-band (B2B) accuracy were measured. I2I accuracy of the AWiFS imagery was assessed by measuring the imagery against Landsat Global Land Survey (GLS) 2000. The AWiFS images were typically registered to within one pixel to the GLS 2000 mosaic images. The B2B process used the same concepts as the I2I, except instead of a reference image and a search image; the individual bands of a multispectral image are tested against each other. The B2B results showed that all the AWiFS multispectral bands are registered to sub-pixel accuracy. Using the limited amount of scenes available over these ground sites, the reflective bands of AWiFS sensor indicate a long-term drift in the top-of-atmosphere (TOA) reflectance. Because of the limited availability of AWiFS scenes over these ground sites, a comprehensive evaluation of the radiometric stability using these sites is not possible. In order to overcome this limitation, a cross-comparison between AWiFS and Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) was performed using image statistics based on large common areas observed by the sensors within 30 minutes. Regression curves and coefficients of determination for the TOA trends from these sensors were generated to quantify the uncertainty in these relationships and to provide an assessment of the calibration differences between these sensors.

  6. 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)

    Hackett, W.R.; Tullis, J.A.; Smith, R.P.

    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 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

  7. Rock riprap design methods and their applicability to long-term protection of uranium mill tailings impoundments

    International Nuclear Information System (INIS)

    Walters, W.H.

    1982-08-01

    This report reviews the more accepted or recommended riprap design methods currently used to design rock riprap protection against soil erosion by flowing water. The basic theories used to develop the various methods are presented. The Riprap Design with Safety Factors Method is identified as the logical choice for uranium mill tailings impoundments. This method is compared to the other methods and its applicability to the protection requirements of tailings impoundments is discussed. Other design problems are identified and investigative studies recommended

  8. Changes in carbon stability and microbial activity in size fractions of micro-aggregates in a rice soil chronosequence under long term rice cultivation

    Science.gov (United States)

    Pan, Genxing; Liu, Yalong; Wang, Ping; Li, Lianqinfg; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Bian, Rongjun; Ding, Yuanjun; Ma, Chong

    2016-04-01

    of archaeal followed a similar trend to that of bacterial but showing an increasing trend with prolonged rice cultivation in both sand and clay fractions. Change in community diversity with sizes of aggregate fractions was found of fungi and weakly of bacterial but not of archaeal. Soil respiration ratio (Respired CO2-C to SOC) was highest in silt fraction, followed by the fine sand fraction but lowest in sand and clay fractions in the rice soils cultivated over 100 years. Again, scaled by total gen concentration, respiration was higher in silt fraction than in other fractions for these rice soils. For the size fractions other than clay fraction, soil gene concentration, Archaeal gen abundance, normalized enzyme activity and carbon sequestration was seen increased but SOC- and gene- scaled soil respiration decreased, more or less with prolonged rice cultivation. As shown with regression analysis, SOC content was positively linearly correlated to recalcitrant carbon proportion but negatively linearly correlated to labile carbon, in both sand and clay fractions. However, soil respiration was found positively logarithmically correlated to total DNA contents and bacterial gen abundance in both sand and clay fractions. Total DNA content was found positively correlated to SOC and labile carbon content, recalcitrant carbon proportion and normalized enzyme activity but negatively to soil respiration, in sand fraction only. Our findings suggested that carbon accumulation and stabilization was prevalent in both sand and clay fraction, only the coarse sand fraction was found responsible for bioactivity dynamics in the rice soils. Thus, soil carbon sequestration was primarily by formation of the macro-aggregates, which again mediated carbon stability and bioactivity in the rice soils under long term rice cultivation.

  9. Long-term stability of Sm2Co17-type magnets for control rod drive mechanism (CRDM) in a nuclear reactor

    International Nuclear Information System (INIS)

    Iida, H.; Imayoshi, S.; Morimoto, K.; Watanabe, M.; Komada, N.; Takeshita, T.

    1995-01-01

    Control rod drive mechanism (CRDM) is an apparatus that regulates vertical position of control rods in a nuclear reactor by using a driving motor of synchronous type. While CRDM is usually placed outside the reactor vessel to escape from the severe environment inside the vessel, built-in type CRDM, which is now being developed for advanced marine reactors, is placed inside the vessel for making the reactor compact. The driving motor must stand in high-temperature (573--603 K) and high-pressure (approximately 120 atm) water which contains a trace amount of hydrogen. Although the magnet rotor is sealed by corrosion-resistant alloy, the magnets still need to have excellent thermal and chemical stabilities in order to ensure the reliability of the system. For an application of Sm 2 Co 17 -type magnets for a driving motor of control rod drive mechanism (CRDM) placed inside a nuclear reactor vessel, long-term stabilities of Sm(Co 0.61 Fe 0.28 Cu 0.08 Ni 0.01 Zr 0.02 ) 7.3 magnets were evaluated under the severe conditions. Initial magnetic properties of the specimens at room temperature were: B r = 1.03 T, H cJ = 1,400 kA/m and (BH) max = 207 kJ/m 3 . Irreversible losses of open-circuit remanent flux of the specimens exposed for 19,000 hours in 1 atm Ar atmosphere were 5--10% at the temperature (573--603 K) and the operating point (permeance coefficient of 1.7--2.4) of the actual driving motor application. Large fraction of the irreversible loss is attributed to permanent flux loss due to oxidation of the specimen. Losses due to thermal fluctuation aftereffect of these specimens are estimated to be less than 5%. Multilayer coating of Ni, Cu, Ni and Au was found to be effective to protect the magnets from the oxidation. The coated specimens exhibited a small permanent loss value of 0.5% after the exposure to 120 atm water for 2,000 hours at 613 K

  10. Long-term Stability of Esomeprazole in 5% Dextrose Infusion Polyolefin Bags at 5 degrees C +/- 3 degrees C after Microwave Freeze-thaw Treatment.

    Science.gov (United States)

    Hecq, Jean-daniel; Rolin, Catherine; Godet, Marie; Gillet, Patricia; Jamart, Jacques; Galanti, Laurence M

    2015-01-01

    To improve quality assurance, security, time management, and cost saving of drug delivery, preparation in advance of intravenous solutions has been developed for several infusion solutions. The objective of this study was to investigate the stability of esomeprazole 0.4 mg/mL and 0.8 mg/mL in 5% dextrose polyolefin bags after freezing, long-term storage, and microwave thawing. The stability of five polyolefin bags containing approximately 0.4 mg/mL of esomeprazole and five other bags containing approximately 0.8 mg/mL in 5% dextrose prepared under aseptic conditions was studied after freezing for 1 month at -20 degrees C, thawing in a microwave oven with a validated cycle, and stored at 5 degrees C +/- 3 degrees C. Esomeprazole concentration was measured by high-pressure liquid chromatography using a reversed-phase column C8, a mobile phase consisting of 35% of acetonitrile and 65% of Na2HPO4 buffer at pH 7.59 with HPO4 (2 M) and NaOH (0.5 M), and detection with a diode array detector at 280 nm. Visual, microscopic, and spectrophotometric observation and pH measurements were also performed. No precipitation occurred in the preparations but little change of color was observed. No microaggregate was observed with optical microscopy or revealed by a change of absorbance at 350, 410, and 550 nm. Based on a shelf life of 90% residual potency, esomeprazole solutions (0.4 and 0.8 mg/mL) were stable for at least 20 or 29 days, respectively, after a freezing and microwave thawing period, where 95% one-side lower confidence limit of the concentration-time profile remained superior to 90% of the initial concentration. During this period, the pH values of drug solutions have been observed to decrease without affecting chromatographic parameters. Within these limits, esomeprazole (0.4 and 0.8 mg/mL) in 5% dextrose infusions may be prepared and frozen in advance by a centralized intravenous admixture service, thawed, and stored at least 20 days at 5 degrees C +/- 3 degrees C

  11. Hybrid Electricity Markets with Long-Term Risk-Sharing Arrangements: Adapting Market Design to Security of Supply and decarbonization Objectives

    International Nuclear Information System (INIS)

    ROQUES, Fabien; FINON, Dominique

    2017-01-01

    The re-emergence of policy interventionism in electricity markets raises questions as to how market design can best be adapted to meeting the investment challenge associated with security of supply (SoS) and decarbonization objectives. This paper takes an institutionalist approach in terms of modularity of the market design, and reviews the standard historical approach towards competitive markets, in order to analyse the roles and interactions of the initial and additional market 'modules'. We argue that a number of additional modules is required to achieve long-term policy objectives, such as decarbonization and security of supply (SoS). But, in turn, they destabilise the initial modules of the market design, in particular by the entries of renewables. We review the international experience with hybrid market design and draw a number of policy recommendations at to best practices, as well as suggesting ways in which the initial market modules can be improved to prevent inconsistencies with the new modules. The move towards a hybrid market regime, which relies on a combination of planning, long-term risk sharing arrangements and improved markets entrenched in a function of short-term coordination, appears to be unavoidable where decarbonization policies are adopted. (authors)

  12. GMDPtoolbox: A Matlab library for designing spatial management policies. Application to the long-term collective management of an airborne disease.

    Science.gov (United States)

    Cros, Marie-Josée; Aubertot, Jean-Noël; Peyrard, Nathalie; Sabbadin, Régis

    2017-01-01

    Designing management policies in ecology and agroecology is complex. Several components must be managed together while they strongly interact spatially. Decision choices must be made under uncertainty on the results of the actions and on the system dynamics. Furthermore, the objectives pursued when managing ecological systems or agroecosystems are usually long term objectives, such as biodiversity conservation or sustainable crop production. The framework of Graph-Based Markov Decision Processes (GMDP) is well adapted to the qualitative modeling of such problems of sequential decision under uncertainty. Spatial interactions are easily modeled and integrated control policies (combining several action levers) can be designed through optimization. The provided policies are adaptive, meaning that management actions are decided at each time step (for instance yearly) and the chosen actions depend on the current system state. This framework has already been successfully applied to forest management and invasive species management. However, up to now, no "easy-to-use" implementation of this framework was available. We present GMDPtoolbox, a Matlab toolbox which can be used both for the design of new management policies and for comparing policies by simulation. We provide an illustration of the use of the toolbox on a realistic crop disease management problem: the design of long term management policy of blackleg of canola using an optimal combination of three possible cultural levers. This example shows how GMDPtoolbox can be used as a tool to support expert thinking.

  13. Preliminary Field Tests and Long-Term Monitoring as a Method of Design Risk Mitigation: A Case Study of Gdańsk Deepwater Container Terminal

    Directory of Open Access Journals (Sweden)

    Miśkiewicz Mikołaj

    2017-09-01

    Full Text Available Appropriate risk assessment plays a fundamental role in the design. . The authors propose a possible method of design risk mitigation, which follows recommendations included in Eurocode 7. The so-called “Observational Method” (OM can produce savings in costs and programmes on engineering projects without compromising safety. The case study presented is a complex design solution that deals with the heavy foundations of a gantry crane beam as one of the elements of a Deepwater Container Terminal extension. The paper presents a detailed process of the design of the rear crane beam being a part of the brand new berth, together with its static analysis, as well as the long-term results of observations, which have revealed the real performance of the marine structure. The case presented is based on excessive preliminary field tests and technical monitoring of the structure, and is an example of a successful OM implementation and design risk mitigation.

  14. 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.

  15. Long-Term Collections

    CERN Multimedia

    Staff Association

    2016-01-01

    45 years helping in developing countries! CERN personnel have been helping the least fortunate people on the planet since 1971. How? With the Long-Term Collections! Dear Colleagues, The Staff Association’s Long-Term Collections (LTC) Committee is delighted to share this important milestone in the life of our Laboratory with you. Indeed, whilst the name of CERN is known worldwide for scientific discoveries, it also shines in the many humanitarian projects which have been supported by the LTC since 1971. Several schools and clinics, far and wide, carry its logo... Over the past 45 years, 74 projects have been supported (9 of which are still ongoing). This all came from a group of colleagues who wanted to share a little of what life offered them here at CERN, in this haven of mutual understanding, peace and security, with those who were less fortunate elsewhere. Thus, the LTC were born... Since then, we have worked as a team to maintain the dream of these visionaries, with the help of regular donat...

  16. Long-Term Collection

    CERN Multimedia

    Staff Association

    2016-01-01

    Dear Colleagues, As previously announced in Echo (No. 254), your delegates took action to draw attention to the projects of the Long-Term Collections (LTC), the humanitarian body of the CERN Staff Association. On Tuesday, 11 October, at noon, small Z-Cards were widely distributed at the entrances of CERN restaurants and we thank you all for your interest. We hope to have achieved an important part of our goal, which was to inform you, convince you and find new supporters among you. We will find out in the next few days! An exhibition of the LTC was also set up in the Main Building for the entire week. The Staff Association wants to celebrate the occasion of the Long-Term Collection’s 45th anniversary at CERN because, ever since 1971, CERN personnel have showed great support in helping the least fortunate people on the planet in a variety of ways according to their needs. On a regular basis, joint fundraising appeals are made with the Directorate to help the victims of natural disasters around th...

  17. Collectes à long terme

    CERN Multimedia

    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...

  18. Influence of long-term land use (arable and forest) and soil mineralogy on organic carbon stocks as well as composition and stability of soil organic matter

    Science.gov (United States)

    Kaiser, M.; Ellerbrock, R. H.; Wulf, M.; Dultz, S.; Hierath, C.; Sommer, M.

    2009-04-01

    The function of soils to sequester organic carbon (OC) and their related potential to mitigate the greenhouse effect is strongly affected by land use and soil mineralogy. This study is aimed to clarify long-term impacts of arable and forest land use as well as soil mineralogy on topsoil soil organic carbon (SOC) stocks as well as soil organic matter (SOM) composition and stability. Topsoil samples were taken from deciduous forest and adjacent arable sites (within Germany) that are continuously used for more than 100 years. The soils are different in genesis (Albic and Haplic Luvisol (AL, HL), Colluvic and Haplic Regosol (CR, HR), Haplic and Vertic Cambisol (HC, VC), Haplic Stagnosol (HSt)). First, particulate and water soluble organic matter were separated from the topsoil samples (Ap and Ah horizons). From the remaining solid extraction residues the Na-pyrophosphate soluble organic matter fractions (OM(PY)) were extracted, analysed for its OC content (OC(PY)) and characterized by FTIR spectroscopy and 14C analyses. The SOC stocks calculated for 0-40 cm depth are in general larger for the forest as compared to the adjacent arable soils (except VC). The largest difference between forest and arable topsoils was detected for the HR site (5.9 kg m-2) and seemed to be caused by a two times larger stock of exchangeable Ca of the forest topsoil. For the arable topsoils multiple regression analyses indicate a strong influence of clay, oxalate soluble Al and pyrophosphate soluble Mg on the content of OC(PY) weighted with its C=O content. Such relation is not found for the forest topsoils. Further, a positive relation between Δ14C values of OM(PY) and the following independent variables: (i) specific mineral surface area, (ii) relative C=O group content in OM(PY) and (iii) soil pH is found for the arable topsoils (pH 6.7 - 7.5) suggesting an increase in OM(PY) stability with increasing interactions between OM(PY) and soil mineral surfaces via cation bridging. A similar

  19. Long term radioactive waste management

    International Nuclear Information System (INIS)

    Lavie, J.M.

    1984-01-01

    In France, waste management, a sensitive issue in term of public opinion, is developing quickly, and due to twenty years of experience, is now reaching maturity. With the launching of the French nuclear programme, the use of radioactive sources in radiotherapy and industry, waste management has become an industrial activity. Waste management is an integrated system dealing with the wastes from their production to the long term disposal, including their identification, sortage, treatment, packaging, collection and transport. This system aims at guaranteing the protection of present and future populations with an available technology. In regard to their long term management, and the design of disposals, radioactive wastes are divided in three categories. This classification takes into account the different radioisotopes contained, their half life and their total activity. Presently short-lived wastes are stored in the shallowland disposal of the ''Centre de la Manche''. Set up within the French Atomic Energy Commission (CEA), the National Agency for waste management (ANDRA) is responsible within the framework of legislative and regulatory provisions for long term waste management in France [fr

  20. Condensation of long-term wave climates for the fatigue design of hydrodynamically sensitive offshore wind turbine support structures

    DEFF Research Database (Denmark)

    Passon, Patrik; Branner, Kim

    2016-01-01

    important for hydrodynamically sensitive structures since the applied met-ocean parameters have a non-linear influence on calculated fatigue design loads. The present article introduces a new wave lumping method for condensation of the wave climate. The novelty is predominantly based on refined equivalence......Cost-efficient and reliable fatigue designs of offshore wind turbine support structures require an adequate representation of the site-specific wind–wave joint distribution. Establishment of this wind–wave joint distribution for design load calculation purposes requires typically a correlation...... of the marginal wind and wave distribution. This is achieved by condensation of the site-specific wave climate in terms of wave period or wave height lumping, subsequently used as input for a correlation with the corresponding wind climate. The quality of this resulting wind–wave correlation is especially...

  1. Human-centered approaches in geovisualization design: investigating multiple methods through a long-term case study.

    Science.gov (United States)

    Lloyd, David; Dykes, Jason

    2011-12-01

    Working with three domain specialists we investigate human-centered approaches to geovisualization following an ISO13407 taxonomy covering context of use, requirements and early stages of design. Our case study, undertaken over three years, draws attention to repeating trends: that generic approaches fail to elicit adequate requirements for geovis application design; that the use of real data is key to understanding needs and possibilities; that trust and knowledge must be built and developed with collaborators. These processes take time but modified human-centred approaches can be effective. A scenario developed through contextual inquiry but supplemented with domain data and graphics is useful to geovis designers. Wireframe, paper and digital prototypes enable successful communication between specialist and geovis domains when incorporating real and interesting data, prompting exploratory behaviour and eliciting previously unconsidered requirements. Paper prototypes are particularly successful at eliciting suggestions, especially for novel visualization. Enabling specialists to explore their data freely with a digital prototype is as effective as using a structured task protocol and is easier to administer. Autoethnography has potential for framing the design process. We conclude that a common understanding of context of use, domain data and visualization possibilities are essential to successful geovis design and develop as this progresses. HC approaches can make a significant contribution here. However, modified approaches, applied with flexibility, are most promising. We advise early, collaborative engagement with data – through simple, transient visual artefacts supported by data sketches and existing designs – before moving to successively more sophisticated data wireframes and data prototypes. © 2011 IEEE

  2. 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)

    Galindez, Juan Manuel; Molinero, Jorge

    2010-01-01

    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

  3. Use of inexpensive vegetable oils to ensure the long-term stability of sweet sorghum syrups for the manufacture of bioproducts

    Science.gov (United States)

    Fundamental processing needs identified by industry for the large-scale manufacture of biofuels and bioproducts from sweet sorghum (Sorghum bicolor L. Moench), include the long-term storage of 65 Brix syrups for year-round supply, efficient transport, and acceptable end-product yields. Sweet sorghu...

  4. Experimentation of a LiBr–H2O absorption process for long-term solar thermal storage: Prototype design and first results

    International Nuclear Information System (INIS)

    N'Tsoukpoe, K.E.; Le Pierrès, N.; Luo, L.

    2013-01-01

    The long-term thermal storage by absorption process studied in this paper is devoted to building heating. A demonstrative prototype that can store 8 kWh of heat and produce a heating power of 1 kW has been designed and built. It has been tested in static and dynamic operating conditions, which are compatible with domestic solar thermal and heating plants. The process operating principle, the prototype design and first experimental results are presented and discussed in this contribution. The charging process has been proved successful. The observed power during the charging phases is satisfactory, according to the process design for a real plant (2–5 kW). Absorption during discharging phase is also verified. Discharging tests show that absorption operates in conditions that could allow house heating as the absorber outlet solution temperature can reach 40 °C. However, some problems related to the absorber design have not allowed observing the heat recovery by the heat transfer fluid as expected. Some avenues are explored prior to a new and more appropriate design and eventually a new operating mode. Various aspects such as the use of a heat and mass transfer enhancement additive and stratification in the solution storage tank have also been addressed. - Highlights: ► A long-term thermal storage prototype is tested under practical conditions. ► For the prototype design, a separate reactor is used with integrated components. ► The observed powers during the charging phases are satisfactory (2–5 kW). ► Following crystallisation phases, discharging tests enabled the crystal dissolution. ► Absorber temperature that could allow house heating (up to 40°C) has been observed

  5. Long-term stability of FeSO{sub 4} and H{sub 2}SO{sub 4} treated chromite ore processing residue (COPR): Importance of H{sup +} and SO{sub 4}{sup 2−}

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Jingdong [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Linling, E-mail: wanglinling@mail.hust.edu.cn [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen, Jing, E-mail: chenjing@mail.hust.edu.cn [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Hou, Huijie; Yang, Jiakuan [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Xiaohua [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2017-01-05

    Highlights: • The long-term stability of the FeSO{sub 4}-H{sub 2}SO{sub 4} treated COPR was evaluated. • Reliable long-term stability for samples curing 400 days was achieved. • H{sub 2}SO{sub 4} significantly enhanced the stabilization efficiency of COPR using FeSO{sub 4}. • H{sup +} and SO{sub 4}{sup 2−} both reinforced Cr(VI) release from COPR core to react with Fe(II). - Abstract: In this study, the long-term stability of Cr(VI) in the FeSO{sub 4} and H{sub 2}SO{sub 4} (FeSO{sub 4}-H{sub 2}SO{sub 4}) treated chromite ore processing residue (COPR) after 400 curing days and the stabilization mechanisms were investigated. FeSO{sub 4}-H{sub 2}SO{sub 4} treatment significantly reduced toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) Cr(VI) concentrations to lower than the regulatory limit of 1.5 mg L{sup −1} (HJ/T 301-2007, China EPA) even for the samples curing 400 days, achieving an outstanding long-term stability. Our independent leaching tests revealed that H{sup +} and SO{sub 4}{sup 2−} have synergistic effect on promoting the release of Cr(VI), which would make Cr(VI) easier accessed by Fe(II) during stabilization. The contributions of H{sup +} and SO{sub 4}{sup 2−} to Cr(VI) release ratio were 25%–44% and 19%–38%, respectively, as 5 mol H{sub 2}SO{sub 4} per kg COPR was used. X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and alkaline digestion analyses were also employed to interpret the possible stabilization mechanism. Cr(VI) released from COPR solid was reduced to Cr(III) by Fe(II), and then formed stable Fe{sub x}Cr{sub (1−x)}(OH){sub 3} precipitate. This study provides a facile and reliable scheme for COPR stabilization, and verifies the excellent long-term stability of the FeSO{sub 4}-H{sub 2}SO{sub 4} treated COPR.

  6. Dry Storage at long term of nuclear fuels: Influence of the fuel design and commercial irradiation conditions

    International Nuclear Information System (INIS)

    Marino, Armando C

    2009-01-01

    The BaCo code was applied to simulate the behaviour for a PHWR fuel under storage conditions showing a strong dependence on the original design of the fuel and the irradiation history. In particular, the results of the statistical analysis of BaCo indicate that the integrity of the fuel is influenced by the manufacture tolerances and the solicitations during the NPP irradiation. The main conclusion of the present study is that the fuel temperature of the device should be carefully controlled in order to ensure safe storage conditions. [es

  7. Design, construction, commissioning and long term operational experience with the D0 Uranium/Liquid Argon calorimeter

    OpenAIRE

    Schamberger, Dean

    2014-01-01

    The D0 experiment was designed in the mid 1980s and ran at the Fermilab pp collider from 1992 through 2011. I describe the uranium-liquid argon calorimeter and its readout electronic which was upgraded in the late 1990s to handle the higher luminosity of the upgraded Tevatron during its second running period from 2001-2011. I summarize maintaining the calorimeter for 20 years of data taking. I further describe a few issues that arose during that time, including different types of noise and th...

  8. Stability in designer gravity

    International Nuclear Information System (INIS)

    Hertog, Thomas; Hollands, Stefan

    2005-01-01

    We study the stability of designer gravity theories, in which one considers gravity coupled to a tachyonic scalar with anti-de Sitter (AdS) boundary conditions defined by a smooth function W. We construct Hamiltonian generators of the asymptotic symmetries using the covariant phase space method of Wald et al and find that they differ from the spinor charges except when W = 0. The positivity of the spinor charge is used to establish a lower bound on the conserved energy of any solution that satisfies boundary conditions for which W has a global minimum. A large class of designer gravity theories therefore have a stable ground state, which the AdS/CFT correspondence indicates should be the lowest energy soliton. We make progress towards proving this by showing that minimum energy solutions are static. The generalization of our results to designer gravity theories in higher dimensions involving several tachyonic scalars is discussed

  9. Profiling Patients’ Healthcare Needs to Support Integrated, Person-Centered Models for Long-Term Disease Management (Profile: Research Design

    Directory of Open Access Journals (Sweden)

    Arianne MJ Elissen

    2016-04-01

    Full Text Available Background: This article presents the design of PROFILe, a study investigating which (biomedical and non-(biomedical patient characteristics should guide more tailored chronic care. Based on this insight, the project aims to develop and validate ‘patient profiles’ that can be used in practice to determine optimal treatment strategies for subgroups of chronically ill with similar healthcare needs and preferences. Methods/Design: PROFILe is a practice-based research comprising four phases. The project focuses on patients with type 2 diabetes. During the first study phase, patient profiles are drafted based on a systematic literature research, latent class growth modeling, and expert collaboration. In phase 2, the profiles are validated from a clinical, patient-related and statistical perspective. Phase 3 involves a discrete choice experiment to gain insight into the patient preferences that exist per profile. In phase 4, the results from all analyses are integrated and recommendations formulated on which patient characteristics should guide tailored chronic care. Discussion: PROFILe is an innovative study which uses a uniquely holistic approach to assess the healthcare needs and preferences of chronically ill. The patient profiles resulting from this project must be tested in practice to investigate the effects of tailored management on patient experience, population health and costs.

  10. 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)

    Borns, D.J.

    1997-01-01

    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

  11. Ontology Design Patterns: Bridging the Gap Between Local Semantic Use Cases and Large-Scale, Long-Term Data Integration

    Science.gov (United States)

    Shepherd, Adam; Arko, Robert; Krisnadhi, Adila; Hitzler, Pascal; Janowicz, Krzysztof; Chandler, Cyndy; Narock, Tom; Cheatham, Michelle; Schildhauer, Mark; Jones, Matt; Raymond, Lisa; Mickle, Audrey; Finin, Tim; Fils, Doug; Carbotte, Suzanne; Lehnert, Kerstin

    2015-04-01

    Integrating datasets for new use cases is one of the common drivers for adopting semantic web technologies. Even though linked data principles enables this type of activity over time, the task of reconciling new ontological commitments for newer use cases can be daunting. This situation was faced by the Biological and Chemical Oceanography Data Management Office (BCO-DMO) as it sought to integrate its existing linked data with other data repositories to address newer scientific use cases as a partner in the GeoLink Project. To achieve a successful integration with other GeoLink partners, BCO-DMO's metadata would need to be described using the new ontologies developed by the GeoLink partners - a situation that could impact semantic inferencing, pre-existing software and external users of BCO-DMO's linked data. This presentation describes the process of how GeoLink is bridging the gap between local, pre-existing ontologies to achieve scientific metadata integration for all its partners through the use of ontology design patterns. GeoLink, an NSF EarthCube Building Block, brings together experts from the geosciences, computer science, and library science in an effort to improve discovery and reuse of data and knowledge. Its participating repositories include content from field expeditions, laboratory analyses, journal publications, conference presentations, theses/reports, and funding awards that span scientific studies from marine geology to marine ecology and biogeochemistry to paleoclimatology. GeoLink's outcomes include a set of reusable ontology design patterns (ODPs) that describe core geoscience concepts, a network of Linked Data published by participating repositories using those ODPs, and tools to facilitate discovery of related content in multiple repositories.

  12. Radio-tracking manatees from land and space: tag design, implementation, and lessons learned from long-term study

    Science.gov (United States)

    Deutsch, C.J.; Bonde, R.K.; Reid, J.P.

    1998-01-01

    West Indian manatees (Trichechus manatus) were tracked along the Atlantic coast of Florida and Georgia (N = 83 manatees, n = 439 tag deployments, 1986-1996) and in eastern Puerto Rico (N = 8, n = 43, 1992-1996) using conventional and satellite-based radio-telemetry systems. A floating radio-tag, attached by a flexible tether to a padded belt around the base of the tail, enabled us to track manatees in saltwater environments. The tag incorporated VHF (very high frequency) and ultrasonic transmitters for field tracking and tag recovery, and an Argos satellite-monitored transmitter for remote tracking. We located each animal in the field about twice per week, received more than 60 000 good-quality Argos locations, and recovered tags in over 90% of deployments. The tag was designed to detach from the belt when entangled to prevent injury or drowning, and this often led to premature termination of tracking bouts. We had considerable success, however, in retagging belted manatees without recapture (97% of 392 retagging events). Most individuals were radio-tagged more than once (median = 3.0, maximum = 43) for a median total duration of 7.5 months (maximum = 6.8 yr). Data obtained through Argos have been valuable in addressing questions relating to long-distance movements, site fidelity, and identification of high-use areas. Fine-scale analyses of manatee habitat use and movements may require restricting the data set to the highest location quality or developing new analytical techniques to incorporate locational error. Field tracking provided useful ancillary data on life-history parameters, but sample sizes were small and survival estimates imprecise. Modification of the existing tag design to include Global Positioning System (GPS) functionality, with its finer spatial and temporal resolution, will offer new opportunities to address critical research and management problems facing this endangered species.

  13. The long-term effect of minimalist shoes on running performance and injury: design of a randomised controlled trial

    Science.gov (United States)

    Fuller, Joel T; Thewlis, Dominic; Tsiros, Margarita D; Brown, Nicholas A T; Buckley, Jonathan D

    2015-01-01

    Introduction The outcome of the effects of transitioning to minimalist running shoes is a topic of interest for runners and scientists. However, few studies have investigated the longer term effects of running in minimalist shoes. The purpose of this randomised controlled trial (RCT) is to investigate the effects of a 26 week transition to minimalist shoes on running performance and injury risk in trained runners unaccustomed to minimalist footwear. Methods and analysis A randomised parallel intervention design will be used. Seventy-six trained male runners will be recruited. To be eligible, runners must be aged 18–40 years, run with a habitual rearfoot footfall pattern, train with conventional shoes and have no prior experience with minimalist shoes. Runners will complete a standardised transition to either minimalist or control shoes and undergo assessments at baseline, 6 and 26 weeks. 5 km time-trial performance (5TT), running economy, running biomechanics, triceps surae muscle strength and lower limb bone mineral density will be assessed at each time point. Pain and injury will be recorded weekly. Training will be standardised during the first 6 weeks. Primary statistical analysis will compare 5TT between shoe groups at the 6-week time point and injury incidence across the entire 26-week study period. Ethics and dissemination This RCT has been approved by the Human Research Ethics Committee of the University of South Australia. Participants will be required to provide their written informed consent prior to participation in the study. Study findings will be disseminated in the form of journal publications and conference presentations after completion of planned data analysis. Trial registration number This RCT has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613000642785). PMID:26297368

  14. Design of governmental policies for oil production rates and oil income spending. A long-term perspective. [Norway

    Energy Technology Data Exchange (ETDEWEB)

    Moxnes, E

    1982-09-01

    In 1980, oil production in Norway amounted to 1 million barrels per day. Taxes and royalties to the government from this production provides 9 per cent of the GNP. With current estimates of recoverable reserves, the 1980 production rate would last for 100 years. Decisions about oil production rates and oil income spending have tremendous impact on society. Attemps to design an appropriate oil policy are complicated by uncertainty about total reserves, future oil prices and complex economic responses to production and income. This report provides and integrating framework to aid government officials in their evaluation of policy options. A system dynamics model of the Norwegian national economy is developed for the analysis. The model determines endogenously the spending of oil income, GNP, consumption and investments, imports and exports, unemployment and labor migration from exporting industries to service industries; all variables result from exogenous decisions about oil production. Though the model is based on behavioral theory of economic decision making at the microeconomic level, it reproduces well major behavior modes of macroeconomic indicators from the 1970s. The most attractive oil policy has been found to be a dynamic and firm ceiling on spending. Dynamic means that growth in spending should be limited, spending should not increase unless the economy is appropriately buffered against oil price drops by foreign savings and spending should never exceed a maximum ceiling set to ensure a desirabel distribution of benefits and problems over time. Firm means that the ceiling cannot be changed by Parliament within an election period. If a firm ceiling on spending is politically infeasible, oil production should be kept lower than otherwise.

  15. Long-Term Symbolic Learning

    National Research Council Canada - National Science Library

    Kennedy, William G; Trafton, J. G

    2007-01-01

    What are the characteristics of long-term learning? We investigated the characteristics of long-term, symbolic learning using the Soar and ACT-R cognitive architectures running cognitive models of two simple tasks...

  16. 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 ...

  17. A National Long-term Outcomes Evaluation of U.S. Premedical Postbaccalaureate Programs Designed to Promote Health care Access and Workforce Diversity.

    Science.gov (United States)

    McDougle, Leon; Way, David P; Lee, Winona K; Morfin, Jose A; Mavis, Brian E; Matthews, De'Andrea; Latham-Sadler, Brenda A; Clinchot, Daniel M

    2015-08-01

    The National Postbaccalaureate Collaborative (NPBC) is a partnership of Postbaccalaureate Programs (PBPs) dedicated to helping promising college graduates from disadvantaged and underrepresented backgrounds get into and succeed in medical school. This study aims to determine long-term program outcomes by looking at PBP graduates, who are now practicing physicians, in terms of health care service to the poor and underserved and contribution to health care workforce diversity. We surveyed the PBP graduates and a randomly drawn sample of non-PBP graduates from the affiliated 10 medical schools stratified by the year of medical school graduation (1996-2002). The PBP graduates were more likely to be providing care in federally designated underserved areas and practicing in institutional settings that enable access to care for vulnerable populations. The NPBC graduates serve a critical role in providing access to care for underserved populations and serve as a source for health care workforce diversity.

  18. The PANGAEA study design - a prospective, multicenter, non-interventional, long-term study on fingolimod for the treatment of multiple sclerosis in daily practice.

    Science.gov (United States)

    Ziemssen, Tjalf; Kern, Raimar; Cornelissen, Christian

    2015-06-18

    Fingolimod (Gilenya) is an oral medication for patients with highly active relapsing-remitting Multiple Sclerosis (RRMS). Clinical trials and post-marketing experience on more than 114,000 patients have established a detailed safety profile. Total patient exposure now exceeds 195,000 patient-years as stated in the last financial report (Dec 2014) of the Novartis Pharma AG, Basel, Switzerland. However, less is known about the safety of long-term fingolimod use in daily practice. Here, we describe the study design of PANGAEA (Post-Authorization Non-interventional German sAfety of GilEnyA in RRMS patients), a prospective, multicenter, non-interventional, long-term study to collect safety, efficacy, and pharmacoeconomic data on RRMS patients treated with fingolimod (0.5 mg/daily) under real-world conditions in Germany. PANGAEA is striving to assess a real-world safety and efficacy profile of fingolimod, based on data from 4,000 RRMS patients, obtained during a 60-month observational phase. A pharmacoeconomic sub-study of 800 RRMS patients further collects patient-reported outcome measures of disability, quality of life, compliance, treatment satisfaction, and usage of resources during a 24-month observational phase. Descriptive statistical analyses of the safety set as well as of stratified subgroups such as patients with concomitant diabetes mellitus and pretreated patients (e.g., natalizumab) will be conducted. PANGAEA seeks to confirm the current safety profile of fingolimod obtained in phase I-III clinical trials. The study design presented here will additionally provide guidance on the therapeutic use of fingolimod in clinical practice and possibly assists physicians in making evidence-based decisions.

  19. Evaluating long term forecasts

    Energy Technology Data Exchange (ETDEWEB)

    Lady, George M. [Department of Economics, College of Liberal Arts, Temple University, Philadelphia, PA 19122 (United States)

    2010-03-15

    The U.S. Department of Energy's Energy Information Administration (EIA), and its predecessor organizations, has published projections of U.S. energy production, consumption, distribution and prices annually for over 30 years. A natural issue to raise in evaluating the projections is an assessment of their accuracy compared to eventual outcomes. A related issue is the determination of the sources of 'error' in the projections that are due to differences between the actual versus realized values of the associated assumptions. One way to do this would be to run the computer-based model from which the projections are derived at the time the projected values are realized, using actual rather than assumed values for model assumptions; and, compare these results to the original projections. For long term forecasts, this approach would require that the model's software and hardware configuration be archived and available for many years, possibly decades, into the future. Such archival creates many practical problems; and, in general, it is not being done. This paper reports on an alternative approach for evaluating the projections. In the alternative approach, the model is run many times for cases in which important assumptions are changed individually and in combinations. A database is assembled from the solutions and a regression analysis is conducted for each important projected variable with the associated assumptions chosen as exogenous variables. When actual data are eventually available, the regression results are then used to estimate the sources of the differences in the projections of the endogenous variables compared to their eventual outcomes. The results presented here are for residential and commercial sector natural gas and electricity consumption. (author)

  20. Decontamination tests in the recreational areas affected by the Chernobyl accident: efficiency of decontamination and long-term stability of the effects

    DEFF Research Database (Denmark)

    Ramzaev, V.; Barkovsky, A.; Mishine, A.

    2013-01-01

    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...

  1. Long-term process of reforming the economy of Republic of Serbia in order to achieve macroeconomic stabilization: From transient changes to the activist approach

    Directory of Open Access Journals (Sweden)

    Gavrilović Milica

    2015-01-01

    Full Text Available In today's economy, which is burdened by problems such as non-productive economy, high unemployment rates, constant inflationary pressures, great attention is paid to the interaction of monetary and fiscal policies in order to achieve macroeconomic stability. There is no universal model of economic policy even in countries around the world, nor in the Serbian economy, and policy makers are looking for the optimal design of monetary and fiscal strategies and their synchronization with other non-negligible specific economic policy objectives (in terms of balance of payments, objectives related to foreign currency course, the distribution of income, implemented stage of market reforms of the nineties, and then phase of reforms in the first decade of the 21st century. How good coordination of monetary and fiscal measures can be no qualitative basis, or as it is not possible to reconstruct and degrade previous economic structure, and that there is no definition of the new strategy, and continued the process of reforming and in the period from the time of deepening global financial crisis in 2008 . The Republic of Serbia, a country whose economy in the long process of reforming, seeks better use of comparative advantages, encouraging production and employment, adequate planning and allocation of available resources of its own and charge, absorption of new technologies, intensifying exports, encouraging investment, and with a constant potential danger which increase the vulnerability of small economies. The solid foundations of macroeconomic stability and discipline must be in production, proper allocation of resources, which will run the economy, and then increase the employment rate, and therefore national income. of crucial importance of good projections of macroeconomic aggregates, because of them depend on public revenue and public expenditure.

  2. Effect of long-term aging at 8150C on the tensile properties and microstructural stability of four cobalt- and nickel-base superalloys

    International Nuclear Information System (INIS)

    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 0 C. Yield strength, ultimate tensile strength, and elongation were determined 24, 316, 760, and 982 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 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

  3. Long Term Financing of Infrastructure

    OpenAIRE

    Sinha, Sidharth

    2014-01-01

    Infrastructure projects, given their long life, require long term financing. The main sources of long term financings are insurance and pension funds who seek long term investments with low credit risk. However, in India household financial savings are mainly invested in bank deposits. Insurance and pension funds account for only a small percentage of household financial savings. In addition most infrastructure projects do not qualify for investment by insurance and pension funds because of t...

  4. Secondary health conditions in persons with a spinal cord injury for at least 10 years : design of a comprehensive long-term cross-sectional study

    NARCIS (Netherlands)

    Adriaansen, Jacinthe J. E.; van Asbeck, Floris W. A.; Lindeman, Eline; van der Woude, Lucas H. V.; de Groot, Sonja; Post, Marcel W. M.

    2013-01-01

    Purpose: To describe the prevalence of secondary health conditions (SHCs) (urinary tract and bowel problems, pressure ulcers, spasticity, musculoskeletal and neuropathic pain, sexual dysfunction, respiratory and cardiovascular disorders) in persons with long-term spinal cord injury (SCI), and to

  5. Referral from primary care to a physical activity programme: establishing long-term adherence? A randomized controlled trial. Rationale and study design

    Directory of Open Access Journals (Sweden)

    Puig-Ribera Anna

    2009-01-01

    . Discussion The pilot study showed the effectiveness of an enhanced low-cost, evidence-based intervention in increased physical activity and improved social support. If successful in demonstrating long-term improvements, this randomised controlled trial will be the first sustainable physical activity intervention based in primary care in our country to demonstrate long-term adherence to physical activity. Trial Registration A service of the U.S. National Institutes of Health. Developed by the National Library of Medicine. ClinicalTrials.gov ID: NCT00714831.

  6. Informing the Design of "Lifestyle Monitoring" Technology for the Detection of Health Deterioration in Long-Term Conditions: A Qualitative Study of People Living With Heart Failure.

    Science.gov (United States)

    Hargreaves, Sarah; Hawley, Mark S; Haywood, Annette; Enderby, Pamela M

    2017-06-28

    Health technologies are being developed to help people living at home manage long-term conditions. One such technology is "lifestyle monitoring" (LM), a telecare technology based on the idea that home activities may be monitored unobtrusively via sensors to give an indication of changes in health-state. However, questions remain about LM technology: how home activities change when participants experience differing health-states; and how sensors might capture clinically important changes to inform timely interventions. The objective of this paper was to report the findings of a study aimed at identifying changes in activity indicative of important changes in health in people with long-term conditions, particularly changes indicative of exacerbation, by exploring the relationship between home activities and health among people with heart failure (HF). We aimed to add to the knowledge base informing the development of home monitoring technologies designed to detect health deterioration in order to facilitate early intervention and avoid hospital admissions. This qualitative study utilized semistructured interviews to explore everyday activities undertaken during the three health-states of HF: normal days, bad days, and exacerbations. Potential recruits were identified by specialist nurses and attendees at an HF support group. The sample was purposively selected to include a range of experience of living with HF. The sample comprised a total of 20 people with HF aged 50 years and above, and 11 spouses or partners of the individuals with HF. All resided in Northern England. Participant accounts revealed that home activities are in part shaped by the degree of intrusion from HF symptoms. During an exacerbation, participants undertook activities specifically to ease symptoms, and detailed activity changes were identified. Everyday activity was also influenced by a range of factors other than health. The study highlights the importance of careful development of LM

  7. New design of logistics for export of ethanol: a long-term vision; Novo desenho logistico para exportacao de etanol: uma visao de longo prazo

    Energy Technology Data Exchange (ETDEWEB)

    Scandiffio, Mirna Ivonne Gaya [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico], e-mail: mirna@fem.unicamp.br; Leal, Manoel Regis Lima Verde [Centro de Energias Alternativas e Meio Ambiente - CENEA, Fortaleza, CE (Brazil)], e-mail: regislv@energiabr.org.br

    2008-07-01

    Production of ethanol from sugarcane, in Brazil, has presented continued expansion. Estimates of harvest from season 2007-2008 show a production of near 27 million m3 of ethanol, 20% over the previous season. Internal market responded, in 2005, for close to eighty five percent of national supply and the remaining 3.5 million m3 were sent abroad. A prospective study from NIPE-UNICAMP projects an increase in exports to reach 105 million m3 by 2025. All that projected growth, whether for internal consumption or exports, is not reflected in the very small amounts of investment in infrastructure in the last decades, pointing out the fragility and distortion of the transportation matrix of the country. Above sixty percent of national cargo is made by roads. Transportation of ethanol using pipelines represented, in the Eighties, close to 13% and hydro ways were responsible for 22% of its flow. Nowadays, ethanol dedicated pipelines respond only for 2%. Ethanol transportation by pipes seems to be the more competitive way of transporting when considering cost, time and delivery credibility, plus its positive environmental impact due to the substitution of diesel use. The experience of 30 years, since the launch of the National Program of Alcohol PROALCOOL, gives the country a solid knowledge, not only regarding the agricultural area and ethanol production, but also in logistics transporting by pipelines. The objective of this article is to analyze a new logistic design for transporting ethanol supported by a long term view, up to 2025. (author)

  8. Work Package 1B.2 under the European Commission, Integrated Wind Turbine Design (UPWIND): Verification of long-term load measurement technique

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt Paulsen, U.

    2011-02-15

    The present report is the final effort of tasks carried out under UPWIND WP1B2 transmission and conversion, which describes: 1) results and recommendations developed in the course of developing the long-term load measurement technique. 2) the hardware details, type of sensors and location, data storage and. 3) data analysis technique to verify design load assumptions. The work is carried out under Contract no 019945 (SES6) 'UPWIND' within the European Commission The interaction between the mechanical and electrical generator subsystems is described rudimentarily, based primarily on HAWC2 simulations below stall of the mechanical system with simple generator and gearbox systems. The electrical system simulations were not carried out as intended in DOW[2], but indications of the conditions for establishing the interaction have been described by measurements and by argument, that this might have an effect as indicated. The hypothesis stating, that the power signal can be utilized as a basic signal for extended analysis of mechanical as well as electrical power signal with static and dynamic features, has been demonstrated on performance and dynamic bandwidth capability. It is however from present analysis obvious that improved signal conditions could be achieved with other mechanical joint solutions than with the present torque signal as measured with the cardan joint. For the reasons mentioned, the comparison with a signal showing the mechanical properties could be improved, with a likely gain on the accuracy as a result. (Author)

  9. Long-term urethral catheterisation.

    Science.gov (United States)

    Turner, Bruce; Dickens, Nicola

    This article discusses long-term urethral catheterisation, focusing on the relevant anatomy and physiology, indications for the procedure, catheter selection and catheter care. It is important that nurses have a good working knowledge of long-term catheterisation as the need for this intervention will increase with the rise in chronic health conditions and the ageing population.

  10. Review of the seismic risk in the design of civil engineering of nuclear installations excepted the long term storage of radioactive wastes; Prise en compte du risque sismique a la conception des ouvrages de genie civil d'installations nucleaires de base a l'exception des stockages a long terme des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This guide aims to define, for the nuclear installations excepted the long term storage of radioactive wastes, from site data, the design specifications of earthquake resistant civil engineering and the possible methods for: the determination of the seismic response of the buildings, taking into account the interactions with the materials and the evaluation of the associated strains to size the installation; the determination of seismic displacements to be considered to size the materials. (A.L.B.)

  11. Analysis of Al2O3—parylene C bilayer coatings and impact of microelectrode topography on long term stability of implantable neural arrays

    Science.gov (United States)

    Caldwell, Ryan; Mandal, Himadri; Sharma, Rohit; Solzbacher, Florian; Tathireddy, Prashant; Rieth, Loren

    2017-08-01

    Objective. Performance of many dielectric coatings for neural electrodes degrades over time, contributing to loss of neural signals and evoked percepts. Studies using planar test substrates have found that a novel bilayer coating of atomic-layer deposited (ALD) Al2O3 and parylene C is a promising candidate for neural electrode applications, exhibiting superior stability to parylene C alone. However, initial results from bilayer encapsulation testing on non-planar devices have been less positive. Our aim was to evaluate ALD Al2O3-parylene C coatings using novel test paradigms, to rigorously evaluate dielectric coatings for neural electrode applications by incorporating neural electrode topography into test structure design. Approach. Five test devices incorporated three distinct topographical features common to neural electrodes, derived from the utah electrode array (UEA). Devices with bilayer (52 nm Al2O3  +  6 µm parylene C) were evaluated against parylene C controls (N  ⩾  6 per device type). Devices were aged in phosphate buffered saline at 67 °C for up to 311 d, and monitored through: (1) leakage current to evaluate encapsulation lifetimes (>1 nA during 5VDC bias indicated failure), and (2) wideband (1-105 Hz) impedance. Main results. Mean-times-to-failure (MTTFs) ranged from 12 to 506 d for bilayer-coated devices, versus 10 to  >2310 d for controls. Statistical testing (log-rank test, α  =  0.05) of failure rates gave mixed results but favored the control condition. After failure, impedance loss for bilayer devices continued for months and manifested across the entire spectrum, whereas the effect was self-limiting after several days, and restricted to frequencies  physiological fluids may improve performance. Testing frameworks which take neural electrode complexities into account will be well suited to reliably evaluate such encapsulation schemes.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Highlights: • Aerobic biodegradation of a mixture of aromatics is feasible in a granular reactor. • Applied organic loading rate is a key parameter for an optimal reactor performance. • Stable mature aerobic granules were maintained 400 days in a continuous reactor. • Sphingobium, Cytophaga and Comamonas were the main genera in the aerobic granules. - Abstract: 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Carlos; Suárez-Ojeda, María Eugenia; Carrera, Julián, E-mail: julian.carrera@uab.cat

    2016-02-13

    Highlights: • Aerobic biodegradation of a mixture of aromatics is feasible in a granular reactor. • Applied organic loading rate is a key parameter for an optimal reactor performance. • Stable mature aerobic granules were maintained 400 days in a continuous reactor. • Sphingobium, Cytophaga and Comamonas were the main genera in the aerobic granules. - Abstract: 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{sup −1} d{sup −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{sup −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.

  14. Minimal doses of a sequence-optimized transgene mediate high-level and long-term EPO expression in vivo: challenging CpG-free gene design.

    Science.gov (United States)

    Kosovac, D; Wild, J; Ludwig, C; Meissner, S; Bauer, A P; Wagner, R

    2011-02-01

    Advanced gene delivery techniques can be combined with rational gene design to further improve the efficiency of plasmid DNA (pDNA)-mediated transgene expression in vivo. Herein, we analyzed the influence of intragenic sequence modifications on transgene expression in vitro and in vivo using murine erythropoietin (mEPO) as a transgene model. A single electro-gene transfer of an RNA- and codon-optimized mEPOopt gene into skeletal muscle resulted in a 3- to 4-fold increase of mEPO production sustained for >1 year and triggered a significant increase in hematocrit and hemoglobin without causing adverse effects. mEPO expression and hematologic levels were significantly lower when using comparable amounts of the wild type (mEPOwt) gene and only marginal effects were induced by mEPOΔCpG lacking intragenic CpG dinucleotides, even at high pDNA amounts. Corresponding with these observations, in vitro analysis of transfected cells revealed a 2- to 3-fold increased (mEPOopt) and 50% decreased (mEPOΔCpG) erythropoietin expression compared with mEPOwt, respectively. RNA analyses demonstrated that the specific design of the transgene sequence influenced expression levels by modulating transcriptional activity and nuclear plus cytoplasmic RNA amounts rather than translation. In sum, whereas CpG depletion negatively interferes with efficient expression in postmitotic tissues, mEPOopt doses <0.5 μg were sufficient to trigger optimal long-term hematologic effects encouraging the use of sequence-optimized transgenes to further reduce effective pDNA amounts.

  15. Glycemic Stability Through Islet-After-Kidney Transplantation Using an Alemtuzumab-Based Induction Regimen and Long-Term Triple-Maintenance Immunosuppression.

    Science.gov (United States)

    Nijhoff, M F; Engelse, M A; Dubbeld, J; Braat, A E; Ringers, J; Roelen, D L; van Erkel, A R; Spijker, H S; Bouwsma, H; van der Boog, P J M; de Fijter, J W; Rabelink, T J; de Koning, E J P

    2016-01-01

    Pancreatic islet transplantation is performed in a select group of patients with type 1 diabetes mellitus. Immunosuppressive regimens play an important role in long-term islet function. We aimed to investigate the efficacy of islet transplantation in patients with type 1 diabetes and a previous kidney transplantation using an alemtuzumab-based induction regimen and triple maintenance immunosuppression. Patients with type 1 diabetes, who had received a kidney transplant previously, were treated with alemtuzumab as induction therapy for their first islet transplantation and basiliximab induction therapy for subsequent islet transplantations. Maintenance immunosuppression consisted of triple immunosuppression (tacrolimus, mycophenolate mofetil, and prednisolone). Thirteen patients (age 50.9 ± 9.2 years, duration of diabetes 35 ± 9 years) received a total of 22 islet transplantations. One- and 2-year insulin independence was 62% and 42%, respectively; graft function was 100% and 92%, respectively. HbA1c dropped from 57.2 ± 13.1 (7.4 ± 1.2%) to 44.5 ± 11.8 mmol/molHb (6.2 ± 0.9%) (p = 0.003) after 2 years. Six of 13 patients suffered from severe hypoglycemia before islet transplantation. After transplantation, severe hypoglycemia was restricted to the only patient who lost graft function. Creatinine clearance was unchanged. Islet-after-kidney transplantation in patients with type 1 diabetes using an alemtuzumab-based induction regimen leads to considerable islet allograft function and improvement in glycemic control. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  16. Long-term usability

    International Nuclear Information System (INIS)

    Holmgren, M.

    1998-01-01

    Longitudinal studies of the usability of a computer based system for process control has been performed. The whole life-cycle of one system has been of interest, as the problems are varying over time. Repeated measurements of the operators' experiences of this system have been made during 15 years. Of main interest have been the advantages/ disadvantages of computer based system for process control compared with conventional instrumentation. The results showed among other things that (1) computer based systems made it easier to control the process and increased security (2) age differences could be explained by other factors (3 ) expectations before the installation may influence the attitudes and use of equipment for quite some time In some questions the attitudes changed over time while in others they were quite stable, for example, in questions concerning preference for type of equipment. What do operators appreciate in a computer based system for process control? About 300 operators were asked about that. The main factor seems to include a reliable system with valid information that functions during disturbances. Hopefully new systems are designed with that in mind. (author)

  17. Design analysis of various transportation package options for BN-350 SNF in terms of nuclear radiation safety in planning for long-terms dry storage

    International Nuclear Information System (INIS)

    Aisabekov, A.Z.; Mukenova, S.A.; Tur, E.S.; Tsyngaev, V.M.

    2004-01-01

    Full text: This effort is performed under the BN-350 reactor facility decommissioning project. One of the project tasks - spent nuclear fuel handling - includes the following: fuel packaging into sealed canisters, transportation of the canisters in multi-seat metallo-concrete containers and placement of the containers for a long-term dry storage. The goal of this effort is to computationally validate nuclear and radiation safety of the SNF containers placed for storage both under normal storage conditions and probable accident situations. The basic unit structure and design configurations are presented: assemblies, canisters, transportation containers. The major factors influencing nuclear and radiation safety are presented: fuel burn-up, enrichment, fabrication tolerance, types of fuel assemblies, configuration of assemblies in the canister and canisters in the container, background of assemblies placed in the reactor and cooling pool. Conditions under which the SNF containers will be stored are described and probable accident situations are listed. Proceeding from the conservatism principle, selection of the assemblies posing the greatest nuclear hazard is validated. A neutron effective multiplication factor is calculated for the SNF containers under the normal storage conditions and for the case of emergency. The effective multiplication factor is shown to be within a standard value of 0.95 in any situation. Based on the experimental data on assembly and canister dose rates, canisters posing the highest radiation threat are selected. Activities of sources and gamma-radiation spectral composition are calculated. Distribution of the dose rate outside the containers both under the normal storage conditions and accident situations are calculated. The results obtained are analyzed

  18. The Future Through the Past: The Use of Analog Sites for Design Criteria and Long Term Performance Assessment of Evapotranspiration Landfill Covers

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, D. S.; Miller, J. J.; Young, M. H.; Edwards, S. C.; Rawlinson, S. E.

    2002-02-26

    There is growing support for using evapotranspiration (ET) covers for closure of low-level waste (LLW) and other types of waste disposal sites, particularly in the lower latitude arid regions of the western United States. At the Nevada Test Site (NTS), monolayer ET covers are the baseline technology for closure of LLW and mixed LLW cells. To better predict the long-term performance of monolayer ET covers, as well as to identify design criteria that will potentially improve their performance, the properties of, and processes occurring on, analog sites for ET covers on the NTS are being studied. The project is funded through the Subsurface Contaminants Focus Area of the U.S. Department of Energy. Four analog sites on the NTS have been selected to predict performance of ET covers over a 1,000-year compliance period. Two sites are relatively recently disturbed (within the last 50 years) and have been selected to evaluate processes and changes on ET covers for the early period after active cover maintenance is discontinued. Two other sites, late to mid-Holocene in age, are intended as analogs for the end of the compliance period (1,000 years or more); both surfaces are abandoned alluvial/colluvial deposits. The history of the early post-institutional control analog sites are being evaluated by an archaeologist to help determine when the sites were last disturbed or modified, and the mode of disturbance to help set baseline conditions. Similar to other ''landforms,'' ET covers will evolve over time because of pedogenic, biotic, and climatic processes. Properties of analog sites that could affect ET water balance performance will be evaluated to help understand ET cover performance over time.

  19. Long term complications of diabetes

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000327.htm Long-term complications of diabetes To use the sharing features on this page, ... other tests. All these may help you keep complications of diabetes away. You will need to check your blood ...

  20. Few-layer antimonene decorated microfiber: ultra-short pulse generation and all-optical thresholding with enhanced long term stability

    Science.gov (United States)

    Song, Yufeng; Liang, Zhiming; Jiang, Xiantao; Chen, Yunxiang; Li, Zhongjun; Lu, Lu; Ge, Yanqi; Wang, Ke; Zheng, Jilin; Lu, Shunbin; Ji, Jianhua; Zhang, Han

    2017-12-01

    Antimonene, a new type of mono/few-layer two-dimensional (2D) mono-elemental material purely consisting of antimony similar as graphene and phosphorene, has been theoretically predicted with excellent optical response and enhanced stability. Herein, we experimentally investigated the broadband nonlinear optical response of highly stable few-layer antimonene (FLA) by performing an open-aperture Z-scan laser measurement. Thanks to the direct bandgap and resonant absorption at the telecommunication band, we demonstrated the feasibility of FLA-decorated microfiber not only as an optical saturable absorber for ultrafast photonics operation, but also as a stable all-optical pulse thresholder that can effectively suppress the transmission noise, boost the signal-to-noise ratio (SNR), and reshape the deteriorated input signal. Our findings, as the first prototypic device of absorption of antimonene, might facilitate the development of antimonene-based optical communication technologies towards high stability and practical applications in the future.

  1. Dynamic posterior stabilization for degenerative lumbar spine disease: a large consecutive case series with long-term follow-up by additional postal survey.

    Science.gov (United States)

    Greiner-Perth, R; Sellhast, N; Perler, G; Dietrich, D; Staub, L P; Röder, C

    2016-08-01

    Dynamic stabilization of the degenerated spine was invented to overcome the negative side effects of fusion surgery like adjacent segment degeneration. Amongst various different implants DSS(®) is a pedicle-based dynamic device for stabilizing the spine and preserving motion. Nearly no clinical data of the implant have been reported so far. The current analysis presents results from a single spine surgeon who has been using DSS(®) for the past 5 years and recorded all treatment and outcome data in the international Spine Tango registry. From the prospectively documented overall patient pool 436 cases treated with DSS(®) could be identified. The analysis was enhanced with a mailing of COMI patient questionnaires for generating longer-term follow-ups up to 4 years. 387 patients (189 male, 198 female; mean age 67.3 years) with degenerative lumbar spinal disease including degenerative spondylolisthesis (6.1 %) could be evaluated. The type of degeneration was mainly spinal stenosis (89.9 %). After a mean follow-up of 1.94 years, the COMI score and NRS back and leg pain improved significantly and to a clinically relevant extent. The postoperative trend analysis could not determine a relevant deterioration of these outcomes until 4 years postoperative. 10 patients were revised (2.6 %) and the implant was removed; in most cases, a fusion was performed. Another 5 cases (1.3 %) had an extension of the dynamic stabilization system to the adjacent level. 84.2 % of patients rated that the surgery had helped a lot or had helped. The results of this large consecutive series with a follow-up up to 4 years could demonstrate a good and stable clinical outcome after posterior dynamic stabilization with DSS(®). For degenerative diseases of the lumbar spine, this treatment seems to be a valid alternative to fusion surgery.

  2. THE GREEN RENOVATION AND EXPANSION OF THE AIKEN CENTER: A SUSTAINABLE GREEN BUILDING DESIGN, COLLABORATIVE PLANNING PROCESS AND LONG-TERM DEMONSTRATION AND RESEARCH PROJECT

    Science.gov (United States)

    One important outcome of this project will be the development of a long-term demonstration program that will provide teaching and research tools for many decades. In addition, we will develop models that will be available for others to use, present our findings to others, and ...

  3. The effects of hybrid cycle training in inactive people with long-term spinal cord injury : design of a multicenter randomized controlled trial

    NARCIS (Netherlands)

    Bakkum, Arjan J. T.; de Groot, Sonja; van der Woude, Lucas H. V.; Janssen, Thomas W. J.

    2013-01-01

    Purpose: Physical activity in people with long-term spinal cord injury (SCI) is important to stay fit and healthy. The purpose of this study is to evaluate the effects of hybrid cycle training (hand cycling in combination with functional electrical stimulation-induced leg cycling) on fitness,

  4. Compensating for non-response in a study estimating the incidence of mental disorders in long-term sickness absence by a two-phased design

    DEFF Research Database (Denmark)

    Søgaard, Hans Jørgen; Bech, Per

    2010-01-01

    AIMS: The study compensates for the non-response that was observed in a previous study that estimated the frequencies of mental disorders in long-term sickness absence (LSA) (more than eight weeks of continuous sickness absence). In this study, the frequency of any mental disorder was estimated a...

  5. Non-Contact Sensor for Long-Term Continuous Vital Signs Monitoring: A Review on Intelligent Phased-Array Doppler Sensor Design.

    Science.gov (United States)

    Hall, Travis; Lie, Donald Y C; Nguyen, Tam Q; Mayeda, Jill C; Lie, Paul E; Lopez, Jerry; Banister, Ron E

    2017-11-15

    It has been the dream of many scientists and engineers to realize a non-contact remote sensing system that can perform continuous, accurate and long-term monitoring of human vital signs as we have seen in many Sci-Fi movies. Having an intelligible sensor system that can measure and record key vital signs (such as heart rates and respiration rates) remotely and continuously without touching the patients, for example, can be an invaluable tool for physicians who need to make rapid life-and-death decisions. Such a sensor system can also effectively help physicians and patients making better informed decisions when patients' long-term vital signs data is available. Therefore, there has been a lot of research activities on developing a non-contact sensor system that can monitor a patient's vital signs and quickly transmit the information to healthcare professionals. Doppler-based radio-frequency (RF) non-contact vital signs (NCVS) monitoring system are particularly attractive for long term vital signs monitoring because there are no wires, electrodes, wearable devices, nor any contact-based sensors involved so the subjects may not be even aware of the ubiquitous monitoring. In this paper, we will provide a brief review on some latest development on NCVS sensors and compare them against a few novel and intelligent phased-array Doppler-based RF NCVS biosensors we have built in our labs. Some of our NCVS sensor tests were performed within a clutter-free anechoic chamber to mitigate the environmental clutters, while most tests were conducted within the typical Herman-Miller type office cubicle setting to mimic a more practical monitoring environment. Additionally, we will show the measurement data to demonstrate the feasibility of long-term NCVS monitoring. The measured data strongly suggests that our latest phased array NCVS system should be able to perform long-term vital signs monitoring intelligently and robustly, especially for situations where the subject is sleeping

  6. Long-term corrosion studies

    International Nuclear Information System (INIS)

    Gdowski, G.

    1998-01-01

    The scope of this activity is to assess the long-term corrosion properties of metallic materials under consideration for fabricating waste package containers. Three classes of metals are to be assessed: corrosion resistant, intermediate corrosion resistant, and corrosion allowance. Corrosion properties to be evaluated are general, pitting and crevice corrosion, stress-corrosion cracking, and galvanic corrosion. The performance of these materials will be investigated under conditions that are considered relevant to the potential emplacement site. Testing in four aqueous solutions, and vapor phases above them, and at two temperatures are planned for this activity. (The environmental conditions, test metals, and matrix are described in detail in Section 3.0.) The purpose and objective of this activity is to obtain the kinetic and mechanistic information on degradation of metallic alloys currently being considered for waste package containers. This information will be used to provide assistance to (1) waste package design (metal barrier selection) (E-20-90 to E-20-92), (2) waste package performance assessment activities (SIP-PA-2), (3) model development (E-20-75 to E-20-89). and (4) repository license application

  7. Surface Detail Reproduction and Effect of Disinfectant and Long-Term Storage on the Dimensional Stability of a Novel Vinyl Polyether Silicone Impression Material.

    Science.gov (United States)

    Nassar, Usama; Chow, Ava K

    2015-08-01

    This study investigated the surface detail reproduction and dimensional stability of a vinyl polyether silicone (VPES) in comparison to a vinylpolysiloxane (VPS) material as a function of prolonged storage for up to 2 weeks. Heavy-body VPES (EXA'lence(TM) Fast Set) and VPS (Imprint(TM) 3 Quick Step) were compared. Forty impression ingots of each material were made using a stainless steel die as described by ANSI/ADA specification No. 19. Twenty impressions of each material were disinfected by immersion in a 2.5% buffered glutaraldehyde solution. Surface quality was assessed and scored immediately after making the ingots. Dimensional stability measurements were made immediately and repeated on the same ingots after 7 and 14 days storage in ambient laboratory conditions. Data were analyzed using the D'Agostino and Pearson omnibus normality test followed by two-way repeated measures ANOVA with post hoc Bonferroni tests. Values of p < 0.01 were deemed to be significant. Disinfected VPES and VPS specimens had significantly reduced dimensional changes at 7 and 14 days when compared with the nondisinfected ones (p < 0.0001). The dimensional stability of both materials was within ANSI/ADA specification No. 19's acceptable limit throughout the 2-week test period, regardless of whether they were disinfected. Out of the initial 80 ingots, 8 VPES and 1 VPS ingot scored a 2 on the surface detail test, while the remaining 71 ingots scored 1. Heavy-body fast-set VPES experienced minimal contraction in vitro after prolonged storage, though surface detail scores were not as consistent as those of the VPS tested. The least contraction occurred when the material was examined immediately after ingot production. © 2014 by the American College of Prosthodontists.

  8. Long-term stability of superhydrophilic oxygen plasma-modified single-walled carbon nanotube network surfaces and the influence on ammonia gas detection

    Energy Technology Data Exchange (ETDEWEB)

    Min, Sungjoon [Department of Biomicrosystem Technology, Korea University, Seoul 136-713 (Korea, Republic of); Kim, Joonhyub [Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-ro, Sejong City 339-770 (Korea, Republic of); Park, Chanwon [Department of Electrical and Electronic Engineering, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Jin, Joon-Hyung, E-mail: jj1023@chol.com [Department of Chemical Engineering, Kyonggi University, 154-42 Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227 (Korea, Republic of); Min, Nam Ki, E-mail: nkmin@korea.ac.kr [Department of Biomicrosystem Technology, Korea University, Seoul 136-713 (Korea, Republic of)

    2017-07-15

    Graphical abstract: Superhydrophilic single-walled carbon nanotube obtained by O{sub 2} plasma treatment voluntarily and non-reversibly reverts to a metastable state. This aerobic aging is an essential process to develop a stable carbon nanotube-based sensor. - Highlights: • Superhydrophilic single-walled carbon nanotube network can be obtained by O{sub 2} plasma-based surface modification. • The modified carbon nanotube surface invariably reverts to a metastable state in a non-reversible manner. • Aerobic aging is essential to stabilize the modified carbon nanotube and the carbon nanotube-based sensing device due to minimized sensor-to-sensor variation. - Abstract: Single-walled carbon nanotube (SWCNT) networks are subjected to a low-powered oxygen plasma for the surface modification. Changes in the surface chemical composition and the stability of the plasma-treated SWCNT (p-SWCNT) with aging in air for up to five weeks are studied using X-ray photoelectron spectroscopy (XPS) and contact angle analysis. The contact angle decreases from 120° of the untreated hydrophobic SWCNT to 0° for the superhydrophilic p-SWCNT. Similarly, the ratio of oxygen to carbon (O:C) based on the XPS spectra increases from 0.25 to 1.19, indicating an increase in surface energy of the p-SWCNT. The enhanced surface energy is gradually dissipated and the p-SWCNT network loses the superhydrophilic surface property. However, it never revert to the original hydrophobic surface state but to a metastable hydrophilic state. The aging effect on sensitivity of the p-SWCNT network-based ammonia sensor is investigated to show the importance of the aging process for the stabilization of the p-SWCNT. The best sensitivity for monitoring NH{sub 3} gas is observed with the as-prepared p-SWCNT, and the sensitivity decreases as similar as the p-SWCNT loses its hydrophilicity with time goes by. After a large performance degradation during the aging time for about two weeks, the response

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

    Science.gov (United States)

    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.

    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. PMID:23678069

  10. [Long-term psychiatric hospitalizations].

    Science.gov (United States)

    Plancke, L; Amariei, A

    2017-02-01

    Long-term hospitalizations in psychiatry raise the question of desocialisation of the patients and the inherent costs. Individual indicators were extracted from a medical administrative database containing full-time psychiatric hospitalizations for the period 2011-2013 of people over 16 years old living in the French region of Nord-Pas-de-Calais. We calculated the proportion of people who had experienced a hospitalization with a duration of 292 days or more during the study period. A bivariate analysis was conducted, then ecological data (level of health-care offer, the deprivation index and the size of the municipalities of residence) were included into a multilevel regression model in order to identify the factors significantly related to variability of long-term hospitalization rates. Among hospitalized individuals in psychiatry, 2.6% had had at least one hospitalization of 292 days or more during the observation period; the number of days in long-term hospitalization represented 22.5% of the total of days of full-time hospitalization in psychiatry. The bivariate analysis revealed that seniority in the psychiatric system was strongly correlated with long hospitalization rates. In the multivariate analysis, the individual indicators the most related to an increased risk of long-term hospitalization were: total lack of autonomy (OR=9.0; 95% CI: 6.7-12.2; P<001); diagnoses of psychological development disorders (OR=9.7; CI95%: 4.5-20.6; P<.001); mental retardation (OR=4.5; CI95%: 2.5-8.2; P<.001): schizophrenia (OR=3.0; CI95%: 1.7-5.2; P<.001); compulsory hospitalization (OR=1.7; CI95%: 1.4-2.1; P<.001); having experienced therapeutic isolation (OR=1.8; CI95%: 1.5-2.1; P<.001). Variations of long-term hospitalization rates depending on the type of establishment were very high, but the density of hospital beds or intensity of ambulatory activity services were not significantly linked to long-term hospitalization. The inhabitants of small urban units had

  11. Long term storage techniques for 85Kr

    International Nuclear Information System (INIS)

    Foster, B.A.; Pence, D.T.; Staples, B.A.

    1975-01-01

    As new nuclear fuel reprocessing plants go on stream, the collection of fission product 85 Kr will be required to avoid potential local release problems and long-term atmospheric buildup. Storage of the collected 85 Kr for a period of at least 100 years will be necessary to allow approximately 99.9 percent decay before it is released. A program designed to develop and evaluate proposed methods for long-term storage of 85 Kr is discussed, and the results of a preliminary evaluation of three methods, high pressure steel cylinders, zeolite encapsulation, and clathrate inclusion are presented. (U.S.)

  12. A comparative study of ancient sedimentary DNA, pollen and macrofossils from permafrost sediments of northern Siberia reveals long-term vegetational stability

    DEFF Research Database (Denmark)

    Jørgensen, Tina; Haile, James Seymour; Möller, Per

    2012-01-01

    and the determination of indicator species to describe environmental changes. Combining data from all three proxies reveals an area continually dominated by a mosaic vegetation of tundra-steppe, pioneer and wet-indicator plants. Such vegetational stability is unexpected, given the severe climate changes taking place...... in the Northern Hemisphere during this time, with changes in average annual temperatures of >22 °C. This may explain the abundance of ice-age mammals such as horse and bison in Taymyr Peninsula during the Pleistocene and why it acted as a refugium for the last mainland woolly mammoth. Our finding reveals...... the benefits of combining sedaDNA, pollen and macrofossil for palaeovegetational reconstruction and adds to the increasing evidence suggesting large areas of the Northern Hemisphere remained ecologically stable during the Late Pleistocene....

  13. 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.

  14. A randomized controlled trial of tai chi for long-term low back pain (TAI CHI: Study rationale, design, and methods

    Directory of Open Access Journals (Sweden)

    Hall Amanda M

    2009-05-01

    Full Text Available Abstract Background Low back pain persisting for longer than 3 months is a common and costly condition for which many current treatments have low-moderate success rates at best. Exercise is among the more successful treatments for this condition, however, the type and dosage of exercise that elicits the best results is not clearly defined. Tai chi is a gentle form of low intensity exercise that uses controlled movements in combination with relaxation techniques and is currently used as a safe form of exercise for people suffering from other chronic pain conditions such as arthritis. To date, there has been no scientific evaluation of tai chi as an intervention for people with back pain. Thus the aim of this study will be to examine the effects of a tai chi exercise program on pain and disability in people with long-term low back pain. Methods and design The study will recruit 160 healthy individuals from the community setting to be randomised to either a tai chi intervention group or a wait-list control group. Individuals in the tai chi group will attend 2 tai chi sessions (40 minutes/week for 8 weeks followed by 1 tai chi session/week for 2 weeks. The wait-list control will continue their usual health care practices and have the opportunity to participate in the tai chi program once they have completed the follow-up assessments. The primary outcome will be bothersomeness of back symptoms measured with a 0–10 numerical rating scale. Secondary outcomes include, self-reports of pain-related disability, health-related quality of life and global perceived effect of treatment. Statistical analysis of primary and secondary outcomes will be based on the intention to treat principle. Linear mixed models will be used to test for the effect of treatment on outcome at 10 weeks follow up. This trial has received ethics approval from The University of Sydney Human Research Ethics Committee. HREC Approval No.10452 Discussion This study will be the first

  15. Designing and evaluating an electronic patient falls reporting system: perspectives for the implementation of health information technology in long-term residential care facilities.

    Science.gov (United States)

    Mei, Yi You; Marquard, Jenna; Jacelon, Cynthia; DeFeo, Audrey L

    2013-11-01

    Patient falls are the leading cause of unintentional injury and death among older adults. In 2000, falls resulted in over 10,300 elderly deaths, costing the United States approximately $179 million in incidence and medical costs. Furthermore, non-fatal injuries caused by falls cost the United States $19 billion annually. Health information technology (IT) applications, specifically electronic falls reporting systems, can aid quality improvement efforts to prevent patient falls. Yet, long-term residential care facilities (LTRCFs) often do not have the financial resources to implement health IT, and workers in these settings are often not ready to adopt such systems. Additionally, most health IT evaluations are conducted in large acute-care settings, so LTRCF administrators currently lack evidence to support the value of health IT. In this paper, we detail the development of a novel, easy-to-use system to facilitate electronic patient falls reporting within a LTRCF using off-the-shelf technology that can be inexpensively implemented in a wide variety of settings. We report the results of four complimentary system evaluation measures that take into consideration varied organizational stakeholders' perspectives: (1) System-level benefits and costs, (2) system usability, via scenario-based use cases, (3) a holistic assessment of users' physical, cognitive, and marcoergonomic (work system) challenges in using the system, and (4) user technology acceptance. We report the viability of collecting and analyzing data specific to each evaluation measure and detail the relative merits of each measure in judging whether the system is acceptable to each stakeholder. The electronic falls reporting system was successfully implemented, with 100% reporting at 3-months post-implementation. The system-level benefits and costs approach showed that the electronic system required no initial investment costs aside from personnel costs and significant benefits accrued from user time savings

  16. Study design: two long-term observational studies of the biosimilar filgrastim Nivestim™ (Hospira filgrastim) in the treatment and prevention of chemotherapy-induced neutropenia

    International Nuclear Information System (INIS)

    Kamioner, Didier; Fruehauf, Stefan; Maloisel, Fréderic; Cals, Laurent; Lepretre, Stéphane; Berthou, Christian

    2013-01-01

    407 patients, and NEXT in September 2013 with 2123 patients. Last patient, last visit for each study will be December 2013 and March 2014 respectively. The NEXT and VENICE studies will provide long-term safety, efficacy and practice pattern data in patients receiving Nivestim™ to support myelosuppressive chemotherapy in real world clinical practice. These data will improve our understanding of the performance of Nivestim™ in patients encountered in the general patient population. NEXT http://www.clinicaltrials.gov/ct2/show/NCT01574235?term, VENICE http://www.clinicaltrials.gov/ct2/show/NCT01627990?term

  17. The long-term effects on aggregate stability (AS) from a forest fire of varying intensity in a Mediterranean environment (1994-2012).

    Science.gov (United States)

    Velasco, Antonio; Alcañiz, Meritxell; Úbeda, Xavier; Pereira, Paulo; Mataix-Solera, Jorge

    2013-04-01

    Forest fires can affect many soil properties and this fact is deeply connected with fire severity, intensity, soil type and many others factors. Aggregate stability (AS) indicates the soil structure resilience in response to external mechanical forces. AS is one of the factors that strongly affect on soil erodibility and infiltration. This property can be used as an indicator of the state of the soil structure and physical stability. The aim of this study is to analyze the soil AS of a determined area that suffered a wildfire in 1994 and compare them with a control area with the same characteristics. The study area is located in the Cadiretes Massif, in the northernmost zone of the Catalan Coastal Ranges, northeast Spain, at an altitude of around 190 - 250 m.a.m.s.l. The Cadiretes Massif is predominantly granite, although soils developed over Paleozoic metamorphic rocks such as schist and slates can also be found. In some areas metamorphic features underlie this relief. The massif is covered by dense Mediterranean vegetation, e.g. Quercus suber, Arbutus unedo, Erica arborea, and in some places Pinus pinaster plantations are found. This area receives about 700 - 800 mm of annual rainfall, with a fairly marked seasonal variability. The maximum is registered in autumn. Summer temperatures often surpass 25°C, while in winter temperatures are generally mild. The predominant soil type in Cadiretes is classified as a Lithic Xerept, with a 15 cm deep sandy-loam A horizon. In the control forest area, this horizon is protected by a 3 cm deep O horizon of moder humus. Three areas with different burnt intensity were identified in 1994 and they are the same plots that were chosen to sample in 2012. The 4 plots (Low intensity, Medium Intensity, High Intensity and Control) had the same orientation (S) and slope (5%). The TDI (Ten Drop Impact) test, that simulates rainfall impact on aggregates, was used to measure AS in the laboratory. Twenty samples were collected per plot. Ten

  18. Evaluation of long-term antinociceptive properties of stabilized hyaluronic acid preparation (NASHA) in an animal model of repetitive joint pain

    Science.gov (United States)

    2011-01-01

    Introduction Clinical trials provided controversial results on whether the injection of hyaluronan preparations into osteoarthritic joints reduces pain. Problems of clinical studies may be the substantial placebo effects of intra-articular injections, different severity and rate of progression of the disease and others. We hypothesize that the use of preclinical pain models may help to clarify whether a certain hyaluronan exerts antinociceptive effects upon intra-articular injection. In the present study we tested in the bradykinin/prostaglandin E2 (PGE2) model primarily the putative antinociceptive effect of stabilized hyaluronic acid from a non animal source (NASHA), a stabilized hyaluronic acid based gel for intra-articular treatment of OA. We established a dose-response relationship for NASHA and we compared NASHA to other hyaluronans with different formulations that are in clinical use. Methods To induce transient joint pain episodes bradykinin and PGE2 were repetitively administered intra-articularly and unilaterally into rat knee joints during short anaesthesia. After establishment of the predrug nociceptive responses, a single intra-articular injection of saline or NASHA at different concentrations was administered and pain responses to further bradykinin/PGE2 injections were monitored up to 56 days after NASHA. Furthermore, the obtained effective dose was compared to clinically defined concentrations of Hylan GF20 and sodium hyaluronate. The primary outcome measures were primary mechanical hyperalgesia at the knee joint and pain-induced weight bearing. Results On day 1 after injection, all tested hyaluronan preparations showed an antinociceptive effect >50% compared to saline. Single injections of higher doses of NASHA (50, 75 and 100 μl) were antinociceptive up to 56 days. When injection volumes in rat knee joints were adapted to clinical injection volumes in humans, the antinociceptive effects of the cross-linked NASHA and Hylan GF20 had a longer

  19. Long-term stability of thermophilic co-digestion submerged anaerobic membrane reactor encountering high organic loading rate, persistent propionate and detectable hydrogen in biogas.

    Science.gov (United States)

    Qiao, Wei; Takayanagi, Kazuyuki; Niu, Qigui; Shofie, Mohammad; Li, Yu You

    2013-12-01

    The performance of thermophilic anaerobic co-digestion of coffee grounds and sludge using membrane reactor was investigated for 148 days, out of a total research duration of 263 days. The OLR was increased from 2.2 to 33.7 kg-COD/m(3)d and HRT was shortened from 70 to 7 days. A significant irreversible drop in pH confirmed the overload of reactor. Under a moderately high OLR of 23.6 kg-COD/m(3)d, and with HRT and influent total solids of 10 days and 150 g/L, respectively, the COD removal efficiency was 44.5%. Hydrogen in biogas was around 100-200 ppm, which resulted in the persistent propionate of 1.0-3.2g/L. The VFA consumed approximately 60% of the total alkalinity. NH4HCO3 was supplemented to maintain alkalinity. The stability of system relied on pH management under steady state. The 16SrDNA results showed that hydrogen-utilizing methanogens dominates the archaeal community. The propionate-oxidizing bacteria in bacterial community was insufficient. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Long-term temporal stability of the National Institute of Standards and Technology spectral irradiance scale determined with absolute filter radiometers

    International Nuclear Information System (INIS)

    Yoon, Howard W.; Gibson, Charles E.

    2002-01-01

    The temporal stability of the National Institute of Standards and Technology (NIST) spectral irradiance scale as measured with broadband filter radiometers calibrated for absolute spectral irradiance responsivity is described. The working standard free-electron laser (FEL) lamps and the check standard FEL lamps have been monitored with radiometers in the ultraviolet and the visible wavelength regions. The measurements made with these two radiometers reveal that the NIST spectral irradiance scale as compared with an absolute thermodynamic scale has not changed by more than 1.5% in the visible from 1993 to 1999. Similar measurements in the ultraviolet reveal that the corresponding change is less than 1.5% from 1995 to 1999. Furthermore, a check of the spectral irradiance scale by six different filter radiometers calibrated for absolute spectral irradiance responsivity based on the high-accuracy cryogenic radiometer shows that the agreement between the present scale and the detector-based scale is better than 1.3% throughout the visible to the near-infrared wavelength region. These results validate the assigned spectral irradiance of the widely disseminated NIST or NIST-traceable standard sources

  1. Process stability and the recovery control associated with inhibition factors in a UASB-anammox reactor with a long-term operation.

    Science.gov (United States)

    Niu, Qigui; He, Shilong; Zhang, Yanlong; Ma, Haiyuan; Liu, Yuan; Li, Yu-You

    2016-03-01

    A UASB-anammox reactor was operated for 900 days to study its process stability. The negative effects of free ammonia (FA) and free nitrous acid (FNA) were investigated over three separate inhibitions and recoveries. The IC10, IC50 and IC90 (inhibitory concentration/a 10%, 50% and 90% activity loss) of FNA and FA responding to the NH4(+)-N, NO2(-)-N and TN removal efficiency were evaluated. In the 1st inhibition, the average FNA-IC10 observed was 0.67 μg L(-1) and the FA-IC10 for TN removal was 4.85 mg L(-1). In the 2nd inhibition, an FNA-IC10 of 0.44μ g L(-1) and an FA-IC10 of 3.56 were found. In the 3rd inhibition, however, both the FNA-IC10 and FA-IC10 were found to have increased, with values of 0.50 μg L(-1) and 4.42 mg L(-1), respectively. A clear control region was established for multiple inhibitions and the recoveries, which followed (pH 7.5-8.5, FA below 10mg/100mg NH4(+)-N and an FNA below 0.005 mg/100 mg NO2(-)-N) for the purpose of optimizing the operation conditions of the UASB-anammox reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Influence of bone morphogenetic protein-2 on the extracellular matrix, material properties, and gene expression of long-term articular chondrocyte cultures: loss of chondrocyte stability.

    Science.gov (United States)

    Krawczak, David A; Westendorf, Jennifer J; Carlson, Cathy S; Lewis, Jack L

    2009-06-01

    The aim of this study was to determine the effects of bone morphogenetic protein-2 (BMP-2) on articular chondrocyte tissues grown as monolayers in vitro for up to 8 weeks. Articular chondrocytes were isolated from New Zealand White rabbits and plated in monolayer cultures. The cultures were supplemented with 100 ng/mL of BMP-2 for up to 8 weeks and the extracellular matrix (ECM) composition, material properties, and messenger RNA (mRNA) expression were analyzed. mRNA expression of cartilage-specific genes, type II collagen, and aggrecan showed that BMP-2 enhanced chondrocyte stability for up to 3 weeks. After 3 weeks in culture, there was substantially more type I collagen expression and more osteopontin and runt-related transcription factor 2 expression in 5- and 8-week cultures treated with BMP-2 than in controls. Additionally, matrix metalloproteinase-13 and ADAMTS-5 (A disintegrin-like and metalloproteinase with thrombospondin 5) were upregulated in 5- and 8-week cultures treated with BMP-2, coinciding with a loss of ECM density, collagen, and proteoglycan. Eight-week tissue stimulated with BMP-2 was more fragile and tore more easily when removed from the culture dish as compared to controls, suggesting temporal limitations to the effectiveness of BMP-2 in monolayer systems and perhaps other models to enhance the generation of a cartilage-like tissue for tissue engineering purposes.

  3. Effects of MgO on short and long term stabilities in water of R7T7 and M7 nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Advocat, T; Vernaz, E; Dussossoy, J [CEA Centre d` Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. des Procedes de Retraitement; Crovisier, J L [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France)

    1993-12-31

    Magnesium oxide was added to the standard R7T7 and M7 glass compositions developed for containment of fission product solutions. M7 differs from the R7T7 reference glass mainly by a larger proportion of network modifier elements and a correspondingly lower proportion of glass network forming elements. The percentage of fission products, simulated in this study by inactive elements, was the same in both cases. Increasing the MgO content of the glass compositions by 2 to 5 wt% resulted in significant variations in the aqueous leaching resistance at 90 and 100 deg C. Experimental findings demonstrated that the initial dissolution rate measured at 100 deg C in a Soxhlet apparatus was proportional to the MgO content and inversely proportional to the network former content (mainly SiO2). This was confirmed by a glass hydration model based on the thermodynamic stability of the glass matrix components. Aqueous corrosion tests were also conducted at 90 deg C under static conditions at various SA/V ratios to simulate the progress of the reaction. Under these conditions, the glass dissolution rate diminished more slowly in time when the initial magnesium content was high and the network former content was low. This may be due primarily to a variation in the glass silica solubility limit related to the glass composition; it may also be related to the formation of secondary silica and magnesia alteration products controlling the glass dissolution reaction affinity.

  4. Non-Contact Sensor for Long-Term Continuous Vital Signs Monitoring: A Review on Intelligent Phased-Array Doppler Sensor Design

    Science.gov (United States)

    Hall, Travis; Nguyen, Tam Q.; Mayeda, Jill C.; Lie, Paul E.; Lopez, Jerry; Banister, Ron E.

    2017-01-01

    It has been the dream of many scientists and engineers to realize a non-contact remote sensing system that can perform continuous, accurate and long-term monitoring of human vital signs as we have seen in many Sci-Fi movies. Having an intelligible sensor system that can measure and record key vital signs (such as heart rates and respiration rates) remotely and continuously without touching the patients, for example, can be an invaluable tool for physicians who need to make rapid life-and-death decisions. Such a sensor system can also effectively help physicians and patients making better informed decisions when patients’ long-term vital signs data is available. Therefore, there has been a lot of research activities on developing a non-contact sensor system that can monitor a patient’s vital signs and quickly transmit the information to healthcare professionals. Doppler-based radio-frequency (RF) non-contact vital signs (NCVS) monitoring system are particularly attractive for long term vital signs monitoring because there are no wires, electrodes, wearable devices, nor any contact-based sensors involved so the subjects may not be even aware of the ubiquitous monitoring. In this paper, we will provide a brief review on some latest development on NCVS sensors and compare them against a few novel and intelligent phased-array Doppler-based RF NCVS biosensors we have built in our labs. Some of our NCVS sensor tests were performed within a clutter-free anechoic chamber to mitigate the environmental clutters, while most tests were conducted within the typical Herman-Miller type office cubicle setting to mimic a more practical monitoring environment. Additionally, we will show the measurement data to demonstrate the feasibility of long-term NCVS monitoring. The measured data strongly suggests that our latest phased array NCVS system should be able to perform long-term vital signs monitoring intelligently and robustly, especially for situations where the subject is

  5. Non-Contact Sensor for Long-Term Continuous Vital Signs Monitoring: A Review on Intelligent Phased-Array Doppler Sensor Design

    Directory of Open Access Journals (Sweden)

    Travis Hall

    2017-11-01

    Full Text Available It has been the dream of many scientists and engineers to realize a non-contact remote sensing system that can perform continuous, accurate and long-term monitoring of human vital signs as we have seen in many Sci-Fi movies. Having an intelligible sensor system that can measure and record key vital signs (such as heart rates and respiration rates remotely and continuously without touching the patients, for example, can be an invaluable tool for physicians who need to make rapid life-and-death decisions. Such a sensor system can also effectively help physicians and patients making better informed decisions when patients’ long-term vital signs data is available. Therefore, there has been a lot of research activities on developing a non-contact sensor system that can monitor a patient’s vital signs and quickly transmit the information to healthcare professionals. Doppler-based radio-frequency (RF non-contact vital signs (NCVS monitoring system are particularly attractive for long term vital signs monitoring because there are no wires, electrodes, wearable devices, nor any contact-based sensors involved so the subjects may not be even aware of the ubiquitous monitoring. In this paper, we will provide a brief review on some latest development on NCVS sensors and compare them against a few novel and intelligent phased-array Doppler-based RF NCVS biosensors we have built in our labs. Some of our NCVS sensor tests were performed within a clutter-free anechoic chamber to mitigate the environmental clutters, while most tests were conducted within the typical Herman-Miller type office cubicle setting to mimic a more practical monitoring environment. Additionally, we will show the measurement data to demonstrate the feasibility of long-term NCVS monitoring. The measured data strongly suggests that our latest phased array NCVS system should be able to perform long-term vital signs monitoring intelligently and robustly, especially for situations where the

  6. Phase behavior of fluorocarbon and hydrocarbon double-chain hydroxylated and galactosylated amphiphiles and bolaamphiphiles. Long-term shelf-stability of their liposomes.

    Science.gov (United States)

    Clary, L; Gadras, C; Greiner, J; Rolland, J P; Santaella, C; Vierling, P; Gulik, A

    1999-06-01

    This paper describes the morphological characterization, by freeze-fracture electron microscopy, and the thermotropic phase behavior, by differential scanning calorimetry and/or X-ray scattering, of aqueous dispersions of various hydroxylated and galactosylated double-chain amphiphiles and bolaamphiphiles, several of them containing one or two hydrophobic fluorocarbon chains. Colloidal systems are observed in water with the hydroxylated hydrocarbon or fluorocarbon bolaamphiphiles only when they are dispersed with a co-amphiphile such as rac-1,2-dimyristoylphosphatidylcholine (DMPC) or rac-1,2-distearoylphosphatidylcholine (DSPC). Liposomes are formed providing the relative content of bolaamphiphiles does not exceed 20% mol. Most of these liposomes can be thermally sterilized and stored at room temperature for several months without any significant modification of their size and size distribution. The hydrocarbon galactosylated bolaamphiphile HO[C24][C12]Gal forms in water a lamellar phase (the gel to liquid-crystal phase transition is complete at 45 degrees C) and a Im3m cubic phase above 47 degrees C. The fluorocarbon HO[C24][F6C5]Gal analog displays a more complex and metastable phase behavior. The fluorinated non-bolaform galactosylated [F8C7][C16]AEGal and SerGal amphiphiles form lamellar phases in water. Low amounts (10% molar ratio) of the HO[C24][F6C5]Gal or HO[C24][C12]Gal bolaamphiphiles or of the single-headed [F8C7][C16]AEGal improve substantially the shelf-stability of reference phospholipon/cholesterol 2/1 liposomes. These liposomes when co-formulated with a single-headed amphiphile from the SerGal series are by far less stable.

  7. Stability of Zircon and Its Isotopic Ratios in High-Temperature Fluids: Long-Term (4 months Isotope Exchange Experiment at 850°C and 50 MPa

    Directory of Open Access Journals (Sweden)

    Ilya N. Bindeman

    2018-05-01

    Full Text Available Stability of zircon in hydrothermal fluids and vanishingly slow rates of diffusion identify zircon as a reliable recorder of its formation conditions in recent and ancient rocks. Debate, however, persists on how rapidly oxygen and key trace elements (e.g., Li, B, Pb diffuse when zircon is exposed to silicate melt or hot aqueous fluids. Here, we report results of a nano- to micrometer-scale investigation of isotopic exchange using natural zircon from Mesa Falls Tuff (Yellowstone treated with quartz-saturated, isotopically (18O, D, 7Li, and 11B labeled water with a nominal δ18O value of +450%0 over 4 months at 850°C and 50 MPa. Frontside (crystal rim inwards δ18O depth profiling of zircon by magnetic sector SIMS shows initially high but decreasing 18O/16O over a ~130 nm non-Fickian profile, with a decay length comparable to the signal from surficial Au coating deposited onto zircon. In contrast, backside (crystal interior outwards depth profiling on a 2-3 μm thick wafer cut and thinned from treated zircon by focused ion beam (FIB milling lacks any significant increase in 18O/16O during penetration of the original surface layer. Near-surface time-of-flight (TOF-SIMS frontside profiles of uncoated zircon from 4-month and 1-day-long experiments as well as untreated zircons display similar enrichments of 18O over a distance of ~20 nm. All frontside 18O profiles are here interpreted as transient surface signals from nm-thick surface enrichment or contamination unrelated to diffusion. Likewise, frontside depth profiling of H, Li, and B isotopes are similar for long- and short-duration experiments. Additionally, surface U-Pb dating of zircon from the 4-month experiment returned U-Pb ages by depth profiling with ~1 μm penetration that were identical to untreated samples. Frontside and backside depth-profiling thus demonstrate that diffusive 18O enrichment in the presence of H2O is much slower than predicted from experiments in Watson and Cherniak

  8. 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.

    2016-07-01

    the comparison of HATS and MIPAS measurements taken at 3 km below the tropopause mainly stay within 10-50 pptv (corresponding to ˜ 2-10 % for CFC-12) for the RR and the FR period. Between ˜ 15 and 30 km, most comparisons agree within 10-20 pptv (10-20 %), apart from ILAS-II, which shows large differences above ˜ 17 km. Overall, relative 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 profiles have a maximum in their mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Comparisons of the standard deviation in a quiescent atmosphere (polar summer) show that only the CFC-12 FR error budget can fully explain the observed variability, while for the other products (CFC-11 FR and RR and CFC-12 RR) only two-thirds to three-quarters can be explained. Investigations regarding the temporal stability show very small negative drifts in MIPAS CFC-11 measurements. These instrument drifts vary between ˜ 1 and 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.

  9. Long-term selenium status in humans

    International Nuclear Information System (INIS)

    Baskett, C.K.; Spate, V.L.; Mason, M.M.; Nichols, T.A.; Williams, A.; Dubman, I.M.; Gudino, A.; Denison, J.; Morris, J.S.

    2001-01-01

    The association of sub-optimal selenium status with increased risk factors for some cancers has been reported in two recent epidemiological studies. In both studies the same threshold in selenium status was observed, below which, cancer incidence increased. To assess the use of nails as a biologic monitor to measure the long-term selenium status, an eight-year longitudinal study was undertaken with a group of 11 adult subjects, 5 women and 6 men. Selenium has been measured by instrumental neutron activation analysis. Differences between fingernails and toenails with be discussed. In addition, the results will be discussed in the context of the long-term stability of the nail monitor to measure selenium status during those periods when selenium determinants are static; and the changes that occur as a result of selenium supplementation. (author)

  10. Ancient DNA Investigation of a Medieval German Cemetery Confirms Long-Term Stability of CCR5-Δ32 Allele Frequencies in Central Europe.

    Science.gov (United States)

    Bouwman, Abigail; Shved, Natallia; Akgül, Gülfirde; Rühli, Frank; Warinner, Christina

    2017-04-01

    The CCR5-Δ32 mutation present in European populations is among the most prominently debated cases of recent positive selection in humans. This allele, a 32-bp deletion that renders the T-cell CCR5 receptor nonfunctional, has important epidemiological and public health significance, as homozygous carriers are resistant to several HIV strains. However, although the function of this allele in preventing HIV infection is now well described, its human evolutionary origin is poorly understood. Initial attempts to determine the emergence of the CCR5-Δ32 allele pointed to selection during the 14th-century Black Death pandemic; however, subsequent analyses suggest that the allele rose in frequency more than 5,000 years ago, possibly through drift. Recently, three studies have identified populations predating the 14th century CE that are positive for the CCR5-Δ32 allele, supporting the claim for a more ancient origin. However, these studies also suggest poorly understood regional differences in the recent evolutionary history of the CCR5-Δ32 allele. Here a new hydrolysis-probe-based real-time PCR assay was designed to ascertain CCR5 allele frequency in 53 individuals from a 10th- to 12th-century CE church and convent complex in central Germany that predates outbreaks of the Black Death pandemic. High-confidence genotypes were obtained for 32 individuals, and results show that CCR5-Δ32 allele frequency has remained unchanged in this region of Central Europe over the last millennium, suggesting that there has been no strong positive selective pressure over this time period and confirming a more ancient origin for the allele.

  11. Nuclear Energy, Long Term Requirements

    International Nuclear Information System (INIS)

    Knapp, V.

    2006-01-01

    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. French Approach for Long Term Storage Safety

    International Nuclear Information System (INIS)

    Marciano, Jacob; Carreton, Jean-Pierre; Lizot, Marie Therese; Lhomme, Veronique

    2014-01-01

    IRSN presents its statement regarding long-term storage facilities; in France, the regulatory documents do not define the long term duration. The storage facility lifetime can only be appreciated according to the needs and materials stored therein. However, the magnitude of the long-term can be estimated at a few hundred years compared to a few decades for current storage. Usually, in France, construction of storage facilities is driven from the necessity various necessities, linked to the management of radioactive material (eg spent fuel) and to the management of radioactive waste. Because of the variety of 'stored materials and objects' (fission product solutions, plutonium oxide powders, activated solids, drums containing technological waste, spent fuel...), a great number of storage facility design solutions have been developed (surface, subsurface areas, dry or wet conditions...) in the World. After describing the main functions of a storage facility, IRSN displays the safety principles and the associated design principles. The specific design principles applied to particular storage (dry or wet spent fuel storage, depleted uranium or reprocessed uranium storage, plutonium storage, waste containing tritium storage, HLW and ILLW storage...) are also presented. Finally, the concerns due to the long-term duration storage and related safety assessment are developed. After discussing these issues, IRSN displays its statement. The authorization procedures governing the facility lifetime are similar to those of any basic nuclear installation, the continuation of the facility operation remaining subject to periodic safety reviews (in France, every 10 years). The applicant safety cases have to show, that the safety requirements are always met; this requires, at minimum, to take into account at the design stage, comfortable design margins. (author)

  13. Analysing long term discursive processes

    DEFF Research Database (Denmark)

    Horsbøl, Anders

    which extend beyond the single interaction, for instance negotiations or planning processes, seems to have played a less important role, with studies such as Iedema 2001 and Wodak 2000 as exceptions. These long term processes, however, are central to the constitution and workings of organizations......What do timescales - the notion that processes take place or can be viewed within a shorter or longer temporal range (Lemke 2005) - mean for the analysis of discourse? What are the methodological consequences of analyzing discourse at different timescales? It may be argued that discourse analysis...... in general has favored either the analysis of short term processes such as interviews, discussions, and lessons, or the analysis of non-processual entities such as (multimodal) texts, arguments, discursive repertoires, and discourses (in a Foucaultian sense). In contrast, analysis of long term processes...

  14. Comparing long term energy scenarios

    International Nuclear Information System (INIS)

    Cumo, M.; Simbolotti, G.

    2001-01-01

    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 [it

  15. 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....

  16. High somatic distress with high long-term stability in selected patients with chronic depression: a 3-year follow-up of ratings with Karolinska Scales of Personality (KSP).

    Science.gov (United States)

    Gardner, Ann; Hällström, Tore

    2004-01-01

    The main aim of the present study was to investigate mean levels and long-term stability of three scales from the Karolinska Scales of Personality (KSP), assessing somatic components of anxiety proneness in selected patients with chronic depressive symptoms. The KSP was filled in by 84 patients (26 men and 58 women) with a history of or ongoing major depression and audiological, or other comorbid somatic, symptoms. Mean scores for the Somatic Anxiety, Muscular Tension and Psychasthenia scales were above two standard deviations compared to a normative group sampled from the population. The KSP was filled in at follow-up by 65 patients. The mean interval between the ratings was 3.5 years. Comparisons between the ratings of the three scales revealed no significant mean score differences, and quite high individual stability. The mean scores were significantly increased in comparisons with depressed patients in primary care suggesting that these patients with chronic depression may comprise a depressive sub-type characterized by high "somatic distress". A putative origin for the high and stable scores in the presented sub-group of depressed patients, and the concept of "personality trait" in use even for pronounced symptoms, are discussed.

  17. A simple technique to strengthen the initial and mid-term to long-term stability of the cup during total hip arthroplasty in developmental dysplasia of the hip.

    Science.gov (United States)

    Guan, Mingqiang; Zhou, Guanming; Li, Xue

    2018-04-01

    To assess the effects of a technique of cup blocking screws combined with impaction bone grafting during total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH). From August 2011 to July 2015, 53 patients (59 hips) with DDH in our hospital were treated with THA using the technique of cup blocking screws combined with impaction particulate bone grafting. These patients were prospectively followed, and the clinical and imaging results were collected. Harris hip score (HHS) was raised from 41.24 before surgery to 91.49 at the latest follow-up (p less than 0.001). Length discrepancy (LLD) was reduced from 28.97 mm before surgery to 6.08 mm after surgery (p less than 0.001). No loosening of the cup was detected at the last follow-up. The differences were insignificant in cup inclination and rate of cup coverage among the 3 groups of Crowe type II, type III, and type IV DDH (p greater than 0.05). The technique of cup blocking screws combined with impaction particulate bone grafting is simple and reliable, and it not only simplifies the attainment of initial stability, but also strengthens the mid-term to long-term stability during THA in DDH.

  18. 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.

  19. Experimental Researches on Long-Term Strength of Granite Gneiss

    Directory of Open Access Journals (Sweden)

    Lin Liu

    2015-01-01

    Full Text Available It is important to confirm the long-term strength of rock materials for the purpose of evaluating the long-term stability of rock engineering. In this study, a series of triaxial creep tests were conducted on granite gneiss under different pore pressures. Based on the test data, we proposed two new quantitative methods, tangent method and intersection method, to confirm the long-term strength of rock. Meanwhile, the isochronous stress-strain curve method was adopted to make sure of the accuracy and operability of the two new methods. It is concluded that the new methods are suitable for the study of the long-term strength of rock. The effect of pore pressure on the long-term strength of rock in triaxial creep tests is also discussed.

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