WorldWideScience

Sample records for released large amounts

  1. Environmental contamination due to release of a large amount of tritium

    International Nuclear Information System (INIS)

    Kawai, Hiroshi

    1988-01-01

    Tritium release incidents have occurred many times in the Savannah Rever Plant in the U.S. A tritium release incident also took place in the Lawrence Livermore Laboratory. The present article outlines the reports by the plant and laboratory on these incidents and makes some comments on environmental contamination that may results from release of a large amount of tritium from nuclear fusion facilities. Tritium is normally released in the form of a combination of chemical compounds such as HT, DT and T 2 and oxides such as HTO, DTO and T 2 O. The percentage of the oxides is given in the reports by the plant. Oxides, which can be absorbed through the skin, are considered to be nearly a thousand times more toxic than the other type of tritium compounds. The HT type compounds (HT, DT and T 2 ) can be oxidized by microorganisms in soil into oxides (HTO, DTO and T 2 O) and therefore, great care should also given to this type of compounds. After each accidental tritium release, the health physics group of the plant collected various environmental samples, including ground surface water, milk, leaves of plants, soil and human urine, in leeward areas. Results on the contamination of surface water, fish and underground water are outlined and discussed. (Nogami, K.)

  2. Proposal of the concept of selection of accidents that release large amounts of radioactive substances in the high temperature engineering test reactor

    International Nuclear Information System (INIS)

    Ono, Masato; Honda, Yuki; Takada, Shoji; Sawa, Kazuhiro

    2015-01-01

    In Position, construction and equipment of testing and research reactor to be subjected to the use standards for rules Article 53 (prevention of expansion of the accident to release a large amount of radioactive material) generation the frequency is a lower accident than design basis accident, when what is likely to release a large amount of radioactive material or radiation from the facility has occurred, and take the necessary measures in order to prevent the spread of the accident. There is provided a lower accident than frequency design basis accidents, for those that may release a large amount of radioactive material or radiation. (author)

  3. Study on large release frequency of nuclear power plants

    International Nuclear Information System (INIS)

    Chen Yan; Song Wei; Li Chaojun; Fu Zhiwei; Wang Zhe; Zuo Jiaxu; Tong Jiejuan

    2014-01-01

    There are several definitions of large release frequency of nuclear power plant. This paper reviews the meanings of large release and requirement of large release frequency provided by IAEA, NRC and WENRA, analyses the relationship between the meanings of large release, compares the calculations of several large release frequencies, It is different frequency that the definition of LRF is not same. Last we discuss the difference between large release frequency and large early release frequency and explore the suitable definitions of LRF for nuclear power plants in China. (authors)

  4. Possible chaoticity for the time series of the amount of nuclear information released by the newsmedia

    International Nuclear Information System (INIS)

    Ohnishi, T.

    1995-01-01

    The amount of information concerning nuclear problems was time analysed which has been released by three types of the newsmedia in Japan, the press, television and magazines during the past 20 years. The time series of the logarithmic value of the amount released by some of the newsmedia was found to be possibly chaotic, or at least to be non-stochastic. Such a characteristic of time series can be interpreted as a result of the exertion of a certain sort of selection process in the interior of the newsmedia in deciding an event as news to be released. (author)

  5. Another way of managing large amounts of data

    CERN Multimedia

    2009-01-01

    Jeff Hammerbacher is Vice President of Products and Chief Scientist at Cloudera, a US software company that provides solutions for managing and analysing very large data sets. His invited talk on 21 August was a good opportunity to exchange views with the CERN experts who face similar problems. Although still relatively young, Jeff has considerable experience in developing tools for storing and processing large amounts of data. Before Cloudera Jeff conceived, built and led the Data team at Facebook. He has also worked as a quantitative analyst on Wall Street. Jeff holds a Bachelor’s Degree in mathematics from Harvard University. At CERN, handling large amounts of data is the job of the Grid; Hadoop, the software Cloudera is developing, is intended for the same scope but has different technical features and implementations. "The Grid software products are designed for many organisations to collaborate on large-scale data analysis across many data centres. In contrast, Had...

  6. Nuclear refugees after large radioactive releases

    International Nuclear Information System (INIS)

    Pascucci-Cahen, Ludivine; Groell, Jérôme

    2016-01-01

    However improbable, large radioactive releases from a nuclear power plant would entail major consequences for the surrounding population. In Fukushima, 80,000 people had to evacuate the most contaminated areas around the NPP for a prolonged period of time. These people have been called “nuclear refugees”. The paper first argues that the number of nuclear refugees is a better measure of the severity of radiological consequences than the number of fatalities, although the latter is widely used to assess other catastrophic events such as earthquakes or tsunami. It is a valuable partial indicator in the context of comprehensive studies of overall consequences. Section 2 makes a clear distinction between long-term relocation and emergency evacuation and proposes a method to estimate the number of refugees. Section 3 examines the distribution of nuclear refugees with respect to weather and release site. The distribution is asymmetric and fat-tailed: unfavorable weather can lead to the contamination of large areas of land; large cities have in turn a higher probability of being contaminated. - Highlights: • Number of refugees is a good indicator of the severity of radiological consequences. • It is a better measure of the long-term consequences than the number of fatalities. • A representative meteorological sample should be sufficiently large. • The number of refugees highly depends on the release site in a country like France.

  7. Influence of ultrasonic energy on dispersion of aggregates and released amounts of organic matter and polyvalent cations

    Science.gov (United States)

    Kaiser, M.; Kleber, M.; Berhe, A. A.

    2010-12-01

    Aggregates play important roles in soil carbon storage and stabilization. Identification of scale-dependent mechanisms of soil aggregate formation and stability is necessary to predict and eventually manage the flow of carbon through terrestrial ecosystems. Application of ultrasonic energy is a common tool to disperse soil aggregates. In this study, we used ultra sonic energy (100 to 2000 J cm-3) to determine the amount of polyvalent cations and organic matter involved in aggregation processes in three arable and three forest soils that varied in soil mineral composition. To determine the amount of organic matter and cations released after application of different amount of ultrasonic energy, we removed the coarse fraction (>250 µm). The remaining residue (solid residue freeze dried before we analyzed the amounts of water-extracted organic carbon (OC), Fe, Al, Ca, Mn, and Mg in the filtrates. The extracted OM and solid residues were further characterized by Fourier Transformed Infra Red spectroscopy and Scanning Electron Microscopy. Our results show a linear increase in amount of dissolved OC with increasing amounts of ultra sonic energy up to 1500 J cm-3 indicating maximum dispersion of soil aggregates at this energy level independent from soil type or land use. In contrast to Mn, and Mg, the amounts of dissolved Ca, Fe, and Al increase with increasing ultra sonic energy up to 1500 J cm-3. At 1500 J cm-3, the absolute amounts of OC, Ca, Fe, and Al released were specific for each soil type, likely indicating differences in type of OM-mineral interactions involved in micro-scaled aggregation processes. The amounts of dissolved Fe, and Al released after an application of 1500 J cm-3 are not related to oxalate- and dithionite- extractable, or total Al content indicating less disintegration of pedogenic oxides or clay minerals due to high levels of ultrasonic energy.

  8. Calculations in support of a potential definition of large release

    International Nuclear Information System (INIS)

    Hanson, A.L.; Davis, R.E.; Mubayi, V.

    1994-05-01

    The Nuclear Regulatory Commission has stated a hierarchy of safety goals with the qualitative safety goals as Level I of the hierarchy, backed up by the quantitative health objectives as Level II and the large release guideline as Level III. The large release guideline has been stated in qualitative terms as a magnitude of release of the core inventory whose frequency should not exceed 10 -6 per reactor year. However, the Commission did not provide a quantitative specification of a large release. This report describes various specifications of a large release and focuses, in particular, on an examination of releases which have a potential to lead to one prompt fatality in the mean. The basic information required to set up the calculations was derived from the simplified source terms which were obtained from approximations of the NUREG-1150 source terms. Since the calculation of consequences is affected by a large number of assumptions, a generic site with a (conservatively determined) population density and meteorology was specified. At this site, various emergency responses (including no response) were assumed based on information derived from earlier studies. For each of the emergency response assumptions, a set of calculations were performed with the simplified source terms; these included adjustments to the source terms, such as the timing of the release, the core inventory, and the release fractions of different radionuclides, to arrive at a result of one mean prompt fatality in each case. Each of the source terms, so defined, has the potential to be a candidate for a large release. The calculations show that there are many possible candidate source terms for a large release depending on the characteristics which are felt to be important

  9. Evaluation of release amount of radioactivity from Chernobyl accident and of resulting radiological consequence in China

    International Nuclear Information System (INIS)

    Zhang Yongxing

    1987-01-01

    Three kinds of methods are used to evaluate the release amount from Chernoby1 RBMK-1000 reactor accident, i.e. (1) estimation by comparison with Windscale accident; (2) estimation in terms of the stock in the core; and (3) estimation according to the available monitoring data form adjacent countries such as Poland and Finland. The results obtained are as follows: the release of I-131 was 0.1-1.5 EBq, which is approximately 4-50% of the stock in the core; the release amount of Ru-103 was comparable to that of Cs-137, both approximately 5-10% of that of I-131; the volatile nuclides such as Mo-99, Ru-103, Te-132, Cs-137 etc., were in the order of 0.4 EBq; involatile nuclides were 0.2 EBq; noble gases and other fission products 10 EBq; and the total amount released was about 20 EBq, which taken together 8% of the stock in the core. The radioactive cloud cluster passed through over the area of China in the beginning of May. It was estimated that the total amount of I-131 in air over China area was about 1.6 PB q , Cs-137 about 0.3 PB q , Ru-103 about 0.2 PB q ; the total fallout in the area of China was about 3 PB q for I-131, about 0.1 PB q for Cs-137, about 0.3 PB q for Ru-103. The resulting effective dose equavalent commitment to critical group individual was about 60 μSv, collective effective dose equavalent commitment received by the population of China was about 1 x 10 4 man.Sv

  10. A simple biosynthetic pathway for large product generation from small substrate amounts

    Science.gov (United States)

    Djordjevic, Marko; Djordjevic, Magdalena

    2012-10-01

    A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways.

  11. A simple biosynthetic pathway for large product generation from small substrate amounts

    Energy Technology Data Exchange (ETDEWEB)

    Djordjevic, Marko [Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade (Serbia); Djordjevic, Magdalena [Institute of Physics Belgrade, University of Belgrade (Serbia)

    2012-10-01

    A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways. (paper)

  12. A simple biosynthetic pathway for large product generation from small substrate amounts

    International Nuclear Information System (INIS)

    Djordjevic, Marko; Djordjevic, Magdalena

    2012-01-01

    A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways. (paper)

  13. Effect of increased exposure times on amount of residual monomer released from single-step self-etch adhesives.

    Science.gov (United States)

    Altunsoy, Mustafa; Botsali, Murat Selim; Tosun, Gonca; Yasar, Ahmet

    2015-10-16

    The aim of this study was to evaluate the effect of increased exposure times on the amount of residual Bis-GMA, TEGDMA, HEMA and UDMA released from single-step self-etch adhesive systems. Two adhesive systems were used. The adhesives were applied to bovine dentin surface according to the manufacturer's instructions and were polymerized using an LED curing unit for 10, 20 and 40 seconds (n = 5). After polymerization, the specimens were stored in 75% ethanol-water solution (6 mL). Residual monomers (Bis-GMA, TEGDMA, UDMA and HEMA) that were eluted from the adhesives (after 10 minutes, 1 hour, 1 day, 7 days and 30 days) were analyzed by high-performance liquid chromatography (HPLC). The data were analyzed using 1-way analysis of variance and Tukey HSD tests. Among the time periods, the highest amount of released residual monomers from adhesives was observed in the 10th minute. There were statistically significant differences regarding released Bis-GMA, UDMA, HEMA and TEGDMA between the adhesive systems (p<0.05). There were no significant differences among the 10, 20 and 40 second polymerization times according to their effect on residual monomer release from adhesives (p>0.05). Increasing the polymerization time did not have an effect on residual monomer release from single-step self-etch adhesives.

  14. Large scientific releases

    International Nuclear Information System (INIS)

    Pongratz, M.B.

    1981-01-01

    The motivation for active experiments in space is considered, taking into account the use of active techniques to obtain a better understanding of the natural space environment, the utilization of the advantages of space as a laboratory to study fundamental plasma physics, and the employment of active techniques to determine the magnitude, degree, and consequences of artificial modification of the space environment. It is pointed out that mass-injection experiments in space plasmas began about twenty years ago with the Project Firefly releases. Attention is given to mass-release techniques and diagnostics, operational aspects of mass release active experiments, the active observation of mass release experiments, active perturbation mass release experiments, simulating an artificial modification of the space environment, and active experiments to study fundamental plasma physics

  15. Comparison of the Amount of Fluoride Release from Nanofilled Resin Modified Glass Ionomer Conventional and Resin Modified Glass Ionomer Cements

    Directory of Open Access Journals (Sweden)

    Sumitha Upadhyay

    2013-01-01

    Full Text Available Objective: To investigate and compare the amount of fluoride release of conventional, resin modified and nanofilled resin modified glass ionomer cements.Materials and Methods: Tablets of glass-ionomer cements were immersed in deionized water and incubated at 37◦C. After 1, 2, 7, 15 and 30 days, fluoride ion was measured under normal atmospheric conditions by fluoride ion selective electrode. Buffer (TISAB II was used to decomplex the fluoride ion and to provide a constant background ionic strength and to maintain the pH of water between 5.0 and 5.5 as the fluoride electrode is sensitive to changes in pH. Statistical evaluation was carried out by one way ANOVA (Analysis of Variance using SPSS 11.0. The significance level was set at p< 0.05.Results: The release of fluoride was highest on day 1 and there was a sudden fall on day 2 in all three groups. Initially fluoride release from conven-tional glass-ionomer cement was highest compared to the other two glass-ionomer cements, but the amount drastically reduced over the period. Although the amount of fluoride release was less than both the resin modified and nanofilled resin modified glass-ionomer cement, the release was sustained consistently for 30 daysConclusion: The cumulative fluoride release of nanofilled resin modified glass ionomer cement was very less compared to the conventional and resin modified glass ionomer cements and Nanofilled resin modified glass ionomer cement released less but steady fluoride as compared to other resin modified glass ionomer cements.

  16. Risk of a large amount of high-radioactive contaminated water leaking into the reactor building basement of Fukushima Daiichi nuclear power station

    International Nuclear Information System (INIS)

    Ebisawa, Toru; Sawai, Masako

    2013-01-01

    In November 2012 about one and half year after the accident at units 1, 2 and 3 of Fukushima Daiichi nuclear power station, some 405 m 3 /day cooling water was being injected into the melt damaged core and leaked as highly-radioactive contaminated water from damaged lower part of containment into the basement of turbine hall. To treat a large amount of contaminated water in the basement, waste processing plant to remove cesium was installed in June 2011 with desalination plant, which produced clean water for circulating coolant system of damaged nuclear fuel while the rest went to storage. Radioactivity of contaminated water in the basement accumulated at initial almost 80 days of the accident was evaluated about 20% for Cs-137 of core inventory of units 1, 2 and 3 and 2.3% for Sr-90 of core inventory of units 2 and 3. Sr-90 from unit 1 was not released into the basement and almost remained at suppression chamber. By November 2012, Cs-137 released into the basement was evaluated to total about 40% of core inventory and stored contaminated water amounted to about 360 kilotons, while Cs-137 released into the atmosphere was estimated about 3.6% of core inventory with its one third contributed for land contamination. Sr-90 released into the basement was estimated as 6.3% or 4.4% of core inventory based on Sr-90 measured activity of treated water in December or September 2011 with stored contaminated water of 300 kilotons. Cs-137 and Sr-90 contaminated water kept continuously releasing into the basement as long as melt damaged core existed and cooling water washed out Cs-137 and Sr-90 attached on containment walls. Safe store of released radioactivity was highly important and acquired important data was recommended to publish for check and review. (T. Tanaka)

  17. Environmental Release Prevention and Control Plan

    International Nuclear Information System (INIS)

    Mamatey, A.; Arnett, M.

    1997-01-01

    During the history of SRS, continual improvements in facilities, process, and operations, and changes in the site''s mission have reduced the amount of radioactive liquid releases. In the early years of SRS (1958 to 1965), the amount of tritium discharged to the Savannah River averaged approximately 61,000 curies a year. During the mid-1980''s (1983 to 1988), liquid releases of tritium averaged 27,000 curies a year. By 1996, liquid releases of tritium are projected to be just 3000 curies for the year. This large projected decrease is the result of the planned shut-down of all reactors and the anticipated significant decline in the amount of tritium migrating from the site seepage basins and the Solid Waste Disposal Facility

  18. Transport of large particles released in a nuclear accident

    International Nuclear Information System (INIS)

    Poellaenen, R.; Toivonen, H.; Lahtinen, J.; Ilander, T.

    1995-10-01

    Highly radioactive particulate material may be released in a nuclear accident or sometimes during normal operation of a nuclear power plant. However, consequence analyses related to radioactive releases are often performed neglecting the particle nature of the release. The properties of the particles have an important role in the radiological hazard. A particle deposited on the skin may cause a large and highly non-uniform skin beta dose. Skin dose limits may be exceeded although the overall activity concentration in air is below the level of countermeasures. For sheltering purposes it is crucial to find out the transport range, i.e. the travel distance of the particles. A method for estimating the transport range of large particles (aerodynamic diameter d a > 20 μm) in simplified meteorological conditions is presented. A user-friendly computer code, known as TROP, is developed for fast range calculations in a nuclear emergency. (orig.) (23 refs., 13 figs.)

  19. Transport of large particles released in a nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Poellaenen, R; Toivonen, H; Lahtinen, J; Ilander, T

    1995-10-01

    Highly radioactive particulate material may be released in a nuclear accident or sometimes during normal operation of a nuclear power plant. However, consequence analyses related to radioactive releases are often performed neglecting the particle nature of the release. The properties of the particles have an important role in the radiological hazard. A particle deposited on the skin may cause a large and highly non-uniform skin beta dose. Skin dose limits may be exceeded although the overall activity concentration in air is below the level of countermeasures. For sheltering purposes it is crucial to find out the transport range, i.e. the travel distance of the particles. A method for estimating the transport range of large particles (aerodynamic diameter d{sub a} > 20 {mu}m) in simplified meteorological conditions is presented. A user-friendly computer code, known as TROP, is developed for fast range calculations in a nuclear emergency. (orig.) (23 refs., 13 figs.).

  20. Big Jump of Record Warm Global Mean Surface Temperature in 2014-2016 Related to Unusually Large Oceanic Heat Releases

    Science.gov (United States)

    Yin, Jianjun; Overpeck, Jonathan; Peyser, Cheryl; Stouffer, Ronald

    2018-01-01

    A 0.24°C jump of record warm global mean surface temperature (GMST) over the past three consecutive record-breaking years (2014-2016) was highly unusual and largely a consequence of an El Niño that released unusually large amounts of ocean heat from the subsurface layer of the northwestern tropical Pacific. This heat had built up since the 1990s mainly due to greenhouse-gas (GHG) forcing and possible remote oceanic effects. Model simulations and projections suggest that the fundamental cause, and robust predictor of large record-breaking events of GMST in the 21st century, is GHG forcing rather than internal climate variability alone. Such events will increase in frequency, magnitude, and duration, as well as impact, in the future unless GHG forcing is reduced.

  1. Release measurement of great amount of waste. Conveyor belt versus wire mesh pallet systems

    Energy Technology Data Exchange (ETDEWEB)

    Sokcic-Kostic, Marina; Schultheis, Roland; Langer, Felix [NUKEM Technologies Engineering Services GmbH, Alzenau (Germany)

    2014-08-15

    Great amount of waste has to be measured for release during the decommissioning and rebuilding of nuclear facilities and installation. Since the enclosed storage or decontamination is very expensive it is advisable for economic reasons to separate contaminated material. The necessary measurement is however a time and cost intensive work which has carefully provided. There are two general methods to perform this task: one is a continuously running system on the basis of a conveyor belt system. The other approach is a discontinuously running system using wire mesh pallets. With the knowledge from existing installations this article will discuss the pro's and contra's and show the limits of the systems.

  2. A simple assessment scheme for severe accident consequences using release parameters

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Kampanart, E-mail: kampanarts@tint.or.th [Thailand Institute of Nuclear Technology, 16 Vibhavadi-Rangsit Rd., Latyao, Chatuchak, 10900 (Thailand); Okamoto, Koji [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8654 (Japan)

    2016-08-15

    Highlights: • Nuclear accident consequence index can assess overall consequences of an accident. • Correlations between the index and release parameters are developed. • Relation between the index and release amount follows power function. • The exponent of the power function is the key to the relation. - Abstract: Nuclear accident consequence index (NACI) which can assess the overall consequences of a severe accident on people and the environment is developed based on findings from previous studies. It consists of three indices: radiation effect index, relocation index and decontamination index. Though the NACI can cover large range of consequences, its assessment requires extensive resources. The authors then attempt to simplify the assessment, by investigating the relations between the release parameters and the NACI, in order to use the release parameters for severe accident consequence assessment instead of the NACI. NACI and its components increase significantly when the release amount is increased, while the influences of the release period and the release starting time on the NACI are nearly negligible. Relations between the release amount and the NACI and its components follow simple power functions (y = ax{sup b}). The exponent of the power functions seems to be the key to the relations. The exponent of the relation between the release amount and the NACI was around 0.8–1.0 when the release amount is smaller than 100 TBq, and it increased to around 1.3–1.4 when the release amount is equal to or larger than 100 TBq.

  3. Heat release rate from the combustion of uranium

    International Nuclear Information System (INIS)

    Solbrig, C.W.

    1995-01-01

    Fuel treatment is planned at the Argonne National Laboratory on EBR-II spent fuel. The electrochemical treatment process is carried out in a cell with an argon atmosphere to prevent any reaction. The amount of fuel processed at any time is limited by the amount of energy which could be released by metal combustion if air is inadvertently allowed into the cell since the heat release would increase the cell pressure. The cell pressure is required to be below atmospheric even if combustion occurs to ensure no cell gas/aerosol is released to the environment. Metal fires can release large amounts of heat. In certain configurations such as fine particulate, metal can be pyrophoric at room temperature. When the metal is a nuclear fuel, it is important to be able to predict the reaction/heat release rate if the metal is inadvertently exposed to air. A realistic combustion model is needed to predict heat release rates for the many different flow and transport configurations which exist in the various fuel processing steps. A model for the combustion of uranium is developed here which compares satisfactorily to experimental data

  4. The evaluation of failure stress and released amount of fission product gas of power ramped rod by fuel behaviour analysis code 'FEMAXI-III'

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki; Fujita, Misao

    1984-01-01

    Pellet-Cladding Interaction(PCI) related in-pile failure of Zircaloy sheathed fuel rod is in general considered to be caused by combination of pellet-cladding mechanical interaction(PCMI) with fuel-cladding chemical interaction(FCCI). An understanding of a basic mechanism of PCI-related fuel failure is therefore necessary to get actual cladding hoop stress from mechanical interaction and released amounts of fission product(FP) gas of aggressive environmental agency from chemical interaction. This paper describes results of code analysis performed on fuel failure to cladding hoop stress and amounts of FP gas released under the condition associated with power ramping. Data from Halden(HBWR) and from Studsvik(R2) are used for code analysis. The fuel behaviour analysis code ''FEMAXI-III'' is used as an analytical tool. The followings are revealed from the study: (1) PCI-related fuel failure is dependent upon cladding hoop stress and released amounts of FP gas at power ramping. (2) Preliminary calculated threshold values of hoop stress and of released amounts of FP gas to PCI failure are respectively 330MPa, 10% under the Halden condition, 190MPa, 5% under the Inter ramp(BWR) condition, and 270MPa, 14% under the Over ramp(PWR) condition. The values of hoop stress calculated are almost in the similar range of those obtained from ex-reactor PCI simulated tests searched from references published. (3) The FEMAXI-III code verification is made in mechanical manner by using in-pile deformation data(diametral strain) obtained from power ramping test undertaken by JAERI. While, the code verification is made in thermal manner by using punctured FP gas data obtained from post irradiation examination performed on non-defected power ramped fuel rods. The calculations are resulted in good agreements to both, mechanical and thermal experimental data suggesting the validity of the code evaluation. (J.P.N.)

  5. Postulated weather modification effects of large energy releases

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

    1977-02-01

    Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific.

  6. Postulated weather modification effects of large energy releases

    International Nuclear Information System (INIS)

    Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

    1977-02-01

    Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific

  7. Method for optical 15N analysis of small amounts of nitrogen gas released from an automatic nitrogen analyzer

    International Nuclear Information System (INIS)

    Arima, Yasuhiro

    1981-01-01

    A method of optical 15 N analysis is proposed for application to small amounts of nitrogen gas released from an automatic nitrogen analyzer (model ANA-1300, Carlo Erba, Milano) subjected to certain set modifications. The ANA-1300 was combined with a vacuum line attached by a molecular sieve 13X column. The nitrogen gas released from the ANA-1300 was introduced with a carrier gas of helium into the molecular sieve column which was pre-evacuated at 10 -4 Torr and cooled with outer liquid nitrogen. After removal of the helium by evacuation, the nitrogen gas fixed on the molecular sieve was released by warming the column, and then, it was sealed into pre-evacuated pyrex glass tubes at 4.5 - 5.0 Torr. In the preparation of discharge tubes, contamination of unlabelled nitrogen occurred from the carrier gas of standard grade helium, and the relative lowering of the 15 N value by it was estimated to be less than 1% when over 700 μg nitrogen was charged on the ANA-1300; when 200 μg nitrogen was charged, it was about 3.5%. However, the effect of the contamination could be corrected for by knowing the amount of contaminant nitrogen. In the analysis of plant materials by the proposed method, the coefficient of variation was less than 2%, and no significant difference was observed between results given by the present method and by the ordinary method in which samples were directly pyrolyzed in the discharge tubes by the Dumas method. The present method revealed about 1.5 μg of cross-contaminated nitrogen and was applicable to more than 200 μg of sample nitrogen. (author)

  8. Radionuclide Release after LBLOCA with Loss of Class IV Power Accident in CANDU-6 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hoon [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    A large break in a pipe train of a primary heat transport system discharges coolant, which has high energy and large mass, into the containment building. Reactor shutdown and emergency core cooling water will limit the fuel cladding failure, but cannot prevent it entirely. The containment building is the last barrier of radionuclide release to the environment. Containment isolation and pressure suppression by dousing and local air cooler reduce the amount of radionuclide release to the environment. The objective of containment behavior analysis for large break loss of coolant with loss of class IV power accident is to assess the amount of radionuclide release to the ambient atmosphere. Radionuclide release rates in this event, with all safety system available, that is, the containment building is intact, as well as with containment system impairment, are analyzed with GOTHIC and SMART code

  9. Large Eddy Simulation study of the development of finite-channel lock-release currents at high Grashof numbers

    Science.gov (United States)

    Ooi, Seng-Keat

    2005-11-01

    Lock-exchange gravity current flows produced by the instantaneous release of a heavy fluid are investigated using 3-D well resolved Large Eddy Simulation simulations at Grashof numbers up to 8*10^9. It is found the 3-D simulations correctly predict a constant front velocity over the initial slumping phase and a front speed decrease proportional to t-1/3 (the time t is measured from the release) over the inviscid phase, in agreement with theory. The evolution of the current in the simulations is found to be similar to that observed experimentally by Hacker et al. (1996). The effect of the dynamic LES model on the solutions is discussed. The energy budget of the current is discussed and the contribution of the turbulent dissipation to the total dissipation is analyzed. The limitations of less expensive 2D simulations are discussed; in particular their failure to correctly predict the spatio-temporal distributions of the bed shear stresses which is important in determining the amount of sediment the gravity current can entrain in the case in advances of a loose bed.

  10. Fission gas release during post irradiation annealing of large grain size fuels from Hinkley point B

    International Nuclear Information System (INIS)

    Killeen, J.C.

    1997-01-01

    A series of post-irradiation anneals has been carried out on fuel taken from an experimental stringer from Hinkley Point B AGR. The stringer was part of an experimental programme in the reactor to study the effect of large grain size fuel. Three differing fuel types were present in separate pins in the stringer. One variant of large grain size fuel had been prepared by using an MgO dopant during fuel manufactured, a second by high temperature sintering of standard fuel and the third was a reference, 12μm grain size fuel. Both large grain size variants had similar grain sizes around 35μm. The present experiments took fuel samples from highly rated pins from the stringer with local burn-up in excess of 25GWd/tU and annealed these to temperature of up to 1535 deg. C under reducing conditions to allow a comparison of fission gas behaviour at high release levels. The results demonstrate the beneficial effect of large grain size on release rate of 85 Kr following interlinkage. At low temperatures and release rates there was no difference between the fuel types, but at temperatures in excess of 1400 deg. C the release rate was found to be inversely dependent on the fuel grain size. The experiments showed some differences between the doped and undoped large grains size fuel in that the former became interlinked at a lower temperature, releasing fission gas at an increased rate at this temperature. At higher temperatures the grain size effect was dominant. The temperature dependence for fission gas release was determined over a narrow range of temperature and found to be similar for all three types and for both pre-interlinkage and post-interlinkage releases, the difference between the release rates is then seen to be controlled by grain size. (author). 4 refs, 7 figs, 3 tabs

  11. Fission gas release during post irradiation annealing of large grain size fuels from Hinkley point B

    Energy Technology Data Exchange (ETDEWEB)

    Killeen, J C [Nuclear Electric plc, Barnwood (United Kingdom)

    1997-08-01

    A series of post-irradiation anneals has been carried out on fuel taken from an experimental stringer from Hinkley Point B AGR. The stringer was part of an experimental programme in the reactor to study the effect of large grain size fuel. Three differing fuel types were present in separate pins in the stringer. One variant of large grain size fuel had been prepared by using an MgO dopant during fuel manufactured, a second by high temperature sintering of standard fuel and the third was a reference, 12{mu}m grain size fuel. Both large grain size variants had similar grain sizes around 35{mu}m. The present experiments took fuel samples from highly rated pins from the stringer with local burn-up in excess of 25GWd/tU and annealed these to temperature of up to 1535 deg. C under reducing conditions to allow a comparison of fission gas behaviour at high release levels. The results demonstrate the beneficial effect of large grain size on release rate of {sup 85}Kr following interlinkage. At low temperatures and release rates there was no difference between the fuel types, but at temperatures in excess of 1400 deg. C the release rate was found to be inversely dependent on the fuel grain size. The experiments showed some differences between the doped and undoped large grains size fuel in that the former became interlinked at a lower temperature, releasing fission gas at an increased rate at this temperature. At higher temperatures the grain size effect was dominant. The temperature dependence for fission gas release was determined over a narrow range of temperature and found to be similar for all three types and for both pre-interlinkage and post-interlinkage releases, the difference between the release rates is then seen to be controlled by grain size. (author). 4 refs, 7 figs, 3 tabs.

  12. Differential antibiotic-induced endotoxin release in severe melioidosis

    NARCIS (Netherlands)

    Simpson, A. J.; Opal, S. M.; Angus, B. J.; Prins, J. M.; Palardy, J. E.; Parejo, N. A.; Chaowagul, W.; White, N. J.

    2000-01-01

    Severe melioidosis is a life-threatening, systemic bacterial infection caused by Burkholderia pseudomallei. A prospective, randomized treatment trial was conducted in northeast Thailand to compare ceftazidime (a penicillin-binding protein [PBP]-3-specific agent that causes release of large amounts

  13. The regulation of radioactive effluent release in France (mainly from large nuclear installations)

    International Nuclear Information System (INIS)

    Hebert, Jean.

    1978-01-01

    In parallel with the licensing system for construction and operation of classified or so-called large nuclear installations (INB) there are in France regulations for the release of radioactive effuents from such installations. The regulations applicable to installations other than INBs are not specifically of a nuclear nature, while those covering INBs, which are analysed in this study, in particular, cover effluent release in liquid or gaseous form. The licensing and control procedures for such release are analysed in detail. (NEA) [fr

  14. The Dynamics of Pheromone Gland Synthesis and Release: a Paradigm Shift for Understanding Sex Pheromone Quantity in Female Moths.

    Science.gov (United States)

    Foster, Stephen P; Anderson, Karin G; Casas, Jérôme

    2018-05-10

    Moths are exemplars of chemical communication, especially with regard to specificity and the minute amounts they use. Yet, little is known about how females manage synthesis and storage of pheromone to maintain release rates attractive to conspecific males and why such small amounts are used. We developed, for the first time, a quantitative model, based on an extensive empirical data set, describing the dynamical relationship among synthesis, storage (titer) and release of pheromone over time in a moth (Heliothis virescens). The model is compartmental, with one major state variable (titer), one time-varying (synthesis), and two constant (catabolism and release) rates. The model was a good fit, suggesting it accounted for the major processes. Overall, we found the relatively small amounts of pheromone stored and released were largely a function of high catabolism rather than a low rate of synthesis. A paradigm shift may be necessary to understand the low amounts released by female moths, away from the small quantities synthesized to the (relatively) large amounts catabolized. Future research on pheromone quantity should focus on structural and physicochemical processes that limit storage and release rate quantities. To our knowledge, this is the first time that pheromone gland function has been modeled for any animal.

  15. Health impacts of large releases of radionuclides. Proceedings

    International Nuclear Information System (INIS)

    Lake, J.V.; Bock, G.R.; Cardew, Gail

    1997-01-01

    There have been various large-scale releases of radionuclides into the environment in the 20th century. Some of these have been accidental and some deliberate. In order to minimize the risk to human health of such releases, it is important that we understand how these substances are transported throughout the terrestrial and aquatic environments and the ways in which they can ultimately affect human health. This book contains contributions from the world's leading radioecologists and health scientists who discuss the progress in understanding these transport processes and exposure pathways of radionuclides to humans; the problems and latest techniques of quantitating retrospectively the actual doses received by individuals; the time course of effects of exposure in relation to structure and function at the cellular tissue, organ and whole organism level; the genetic effects, and effects on reproductive health, in populations and individuals, including fetal effects in pregnant women and inherited genetic effects; and scientific approaches to evaluate the important problem of the mental health consequences of perceived risk of radiation damage to health. (author)

  16. Detection of tiny amounts of fissile materials in large-sized containers with radioactive waste

    Science.gov (United States)

    Batyaev, V. F.; Skliarov, S. V.

    2018-01-01

    The paper is devoted to non-destructive control of tiny amounts of fissile materials in large-sized containers filled with radioactive waste (RAW). The aim of this work is to model an active neutron interrogation facility for detection of fissile ma-terials inside NZK type containers with RAW and determine the minimal detectable mass of U-235 as a function of various param-eters: matrix type, nonuniformity of container filling, neutron gen-erator parameters (flux, pulse frequency, pulse duration), meas-urement time. As a result the dependence of minimal detectable mass on fissile materials location inside container is shown. Nonu-niformity of the thermal neutron flux inside a container is the main reason of the space-heterogeneity of minimal detectable mass in-side a large-sized container. Our experiments with tiny amounts of uranium-235 (<1 g) confirm the detection of fissile materials in NZK containers by using active neutron interrogation technique.

  17. Detection of tiny amounts of fissile materials in large-sized containers with radioactive waste

    Directory of Open Access Journals (Sweden)

    Batyaev V.F.

    2018-01-01

    Full Text Available The paper is devoted to non-destructive control of tiny amounts of fissile materials in large-sized containers filled with radioactive waste (RAW. The aim of this work is to model an active neutron interrogation facility for detection of fissile ma-terials inside NZK type containers with RAW and determine the minimal detectable mass of U-235 as a function of various param-eters: matrix type, nonuniformity of container filling, neutron gen-erator parameters (flux, pulse frequency, pulse duration, meas-urement time. As a result the dependence of minimal detectable mass on fissile materials location inside container is shown. Nonu-niformity of the thermal neutron flux inside a container is the main reason of the space-heterogeneity of minimal detectable mass in-side a large-sized container. Our experiments with tiny amounts of uranium-235 (<1 g confirm the detection of fissile materials in NZK containers by using active neutron interrogation technique.

  18. Large amounts of antiproton production by heavy ion collision

    International Nuclear Information System (INIS)

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    To produce large amounts of antiprotons, on the order of several grams/year, use of machines to produce nuclear collisions are studied. These can be of either proton-proton, proton-nucleus and nucleus-nucleus in nature. To achieve high luminosity colliding beams, on the order of 10 41 m/cm 2 , a self-colliding machine is required, rather than a conventional circular colliding type. The self-colliding machine can produce additional antiprotons through successive collisions of secondary particles, such as spectator nucleons. A key problem is how to collect the produced antiprotons without capture by beam nuclei in the collision zone. Production costs for anti-matter are projected for various energy source options and technology levels. Dedicated facilities using heavy ion collisions could produce antiproton at substantially less than 1 million $/milligram. With co-production of other valuable products, e.g., nuclear fuel for power reactors, antiproton costs could be reduced to even lower values

  19. Large amounts of antiproton production by heavy ion collision

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    To produce large amounts of antiprotons, on the order of several grams/year, use of machines to produce nuclear collisions are studied. These can be of either proton-proton, proton-nucleus and nucleus-nucleus in nature. To achieve high luminosity colliding beams, on the order of 10/sup 41/ m/cm/sup 2/, a self-colliding machine is required, rather than a conventional circular colliding type. The self-colliding machine can produce additional antiprotons through successive collisions of secondary particles, such as spectator nucleons. A key problem is how to collect the produced antiprotons without capture by beam nuclei in the collision zone. Production costs for anti-matter are projected for various energy source options and technology levels. Dedicated facilities using heavy ion collisions could produce antiproton at substantially less than 1 million $/milligram. With co-production of other valuable products, e.g., nuclear fuel for power reactors, antiproton costs could be reduced to even lower values.

  20. Simplified approach for estimating large early release frequency

    International Nuclear Information System (INIS)

    Pratt, W.T.; Mubayi, V.; Nourbakhsh, H.; Brown, T.; Gregory, J.

    1998-04-01

    The US Nuclear Regulatory Commission (NRC) Policy Statement related to Probabilistic Risk Analysis (PRA) encourages greater use of PRA techniques to improve safety decision-making and enhance regulatory efficiency. One activity in response to this policy statement is the use of PRA in support of decisions related to modifying a plant's current licensing basis (CLB). Risk metrics such as core damage frequency (CDF) and Large Early Release Frequency (LERF) are recommended for use in making risk-informed regulatory decisions and also for establishing acceptance guidelines. This paper describes a simplified approach for estimating LERF, and changes in LERF resulting from changes to a plant's CLB

  1. Discovering Related Clinical Concepts Using Large Amounts of Clinical Notes.

    Science.gov (United States)

    Ganesan, Kavita; Lloyd, Shane; Sarkar, Vikren

    2016-01-01

    The ability to find highly related clinical concepts is essential for many applications such as for hypothesis generation, query expansion for medical literature search, search results filtering, ICD-10 code filtering and many other applications. While manually constructed medical terminologies such as SNOMED CT can surface certain related concepts, these terminologies are inadequate as they depend on expertise of several subject matter experts making the terminology curation process open to geographic and language bias. In addition, these terminologies also provide no quantifiable evidence on how related the concepts are. In this work, we explore an unsupervised graphical approach to mine related concepts by leveraging the volume within large amounts of clinical notes. Our evaluation shows that we are able to use a data driven approach to discovering highly related concepts for various search terms including medications, symptoms and diseases.

  2. Discovering Related Clinical Concepts Using Large Amounts of Clinical Notes

    Directory of Open Access Journals (Sweden)

    Kavita Ganesan

    2016-01-01

    Full Text Available The ability to find highly related clinical concepts is essential for many applications such as for hypothesis generation, query expansion for medical literature search, search results filtering, ICD-10 code filtering and many other applications. While manually constructed medical terminologies such as SNOMED CT can surface certain related concepts, these terminologies are inadequate as they depend on expertise of several subject matter experts making the terminology curation process open to geographic and language bias. In addition, these terminologies also provide no quantifiable evidence on how related the concepts are. In this work, we explore an unsupervised graphical approach to mine related concepts by leveraging the volume within large amounts of clinical notes. Our evaluation shows that we are able to use a data driven approach to discovering highly related concepts for various search terms including medications, symptoms and diseases.

  3. Integration of large amounts of wind power. Markets for trading imbalances

    Energy Technology Data Exchange (ETDEWEB)

    Neimane, Viktoria; Axelsson, Urban [Vattenfall Research and Development AB, Stockholm (Sweden); Gustafsson, Johan; Gustafsson, Kristian [Vattenfall Nordic Generation Management, Stockholm (Sweden); Murray, Robin [Vattenfall Vindkraft AB, Stockholm (Sweden)

    2008-07-01

    The well-known concerns about wind power are related to its intermittent nature and difficulty to make exact forecasts. The expected increase in balancing and reserve requirements due to wind power has been investigated in several studies. This paper takes the next step in studying integration of large amounts of wind power in Sweden. Several wind power producers' and corresponding balance providers' perspective is taken and their imbalance costs modeled. Larger producers having wind power spread over larger geographical areas will have lower relative costs than producers having their units concentrated within limited geographical area. Possibilities of the wind power producers to reduce the imbalance costs by acting on after sales market are exposed and compared. (orig.)

  4. Estimation of large early release frequency for Advanced Heavy Water Reactor

    International Nuclear Information System (INIS)

    Santhosh, T.V.; Thangamani, I.; Shrivastava, A.; Vinod, Gopika; Verma, Vishnu; Vijayan, P.K.

    2015-01-01

    Level 2 probabilistic safety assessment (PSA) examines severe accidents through a combination of probabilistic and deterministic approaches, in order to determine the release of radionuclides from containment, including the physical processes that are involved in the loss of structural integrity of the reactor core. The probabilistic part focuses on the reliability evaluation of containment systems and the deterministic part focuses on the analysis of the physical processes of an accident (timing and magnitude of radioactivity release), and the response of the containment. The important tasks involved are: (i) grouping and categorization of accident sequences into plant damage states (PDSs) (ii) development of a containment event trees (CETs) (iii) development of CET top event definitions and quantification of failure probabilities, and (iv) assigning the release categories and estimation of large early release frequency (LERF). LERF is defined as the frequency of those accidents leading to rapid, unmitigated release of airborne fission products from the containment to the environment occurring before the effective implementation of offsite emergency response and protective actions such that there is the potential for early health effects. Such accidents generally include unscrubbed releases associated with early containment failure shortly after vessel breach, containment bypass events, and loss of containment isolation. Preliminary assessment of LERF, based on release categorization from qualitative expert judgement, has been carried out and the estimated LERF is found to be 1e-13/yr. The dominant contributors are: (a) LB LOCA with the failure of prompt shutdown coupled with containment isolation failure, (b) containment bypass event from main steam line break outside containment coupled with failure of main steam isolation valves, and (c) LB LOCA with complete failure of emergency core cooling system (ECCS) and loss of moderator cooling

  5. Alternative containers for low-level wastes containing large amounts of tritium

    International Nuclear Information System (INIS)

    Gause, E.P.; Lee, B.S.; MacKenzie, D.R.; Wiswall, R. Jr.

    1984-11-01

    High-activity tritiated waste generated in the United States is mainly composed of tritium gas and tritium-contaminated organic solvents sorbed onto Speedi-Dri which are packaged in small glass bulbs. Low-activity waste consists of solidified and adsorbed liquids. In this report, current packages for high-activity gaseous and low-activity adsorbed liquid wastes are emphasized with regard to containment potential. Containers for low-level radioactive waste containing large amounts of tritium need to be developed. An integrity may be threatened by: physical degradation due to soil corrosion, gas pressure build-up (due to radiolysis and/or biodegradation), rapid permeation of tritium through the container, and corrosion from container contents. Literature available on these points is summarized in this report. 136 references, 20 figures, 40 tables

  6. Sample preparation method for ICP-MS measurement of 99Tc in a large amount of environmental samples

    International Nuclear Information System (INIS)

    Kondo, M.; Seki, R.

    2002-01-01

    Sample preparation for measurement of 99 Tc in a large amount of soil and water samples by ICP-MS has been developed using 95m Tc as a yield tracer. This method is based on the conventional method for a small amount of soil samples using incineration, acid digestion, extraction chromatography (TEVA resin) and ICP-MS measurement. Preliminary concentration of Tc has been introduced by co-precipitation with ferric oxide. The matrix materials in a large amount of samples were more sufficiently removed with keeping the high recovery of Tc than previous method. The recovery of Tc was 70-80% for 100 g soil samples and 60-70% for 500 g of soil and 500 L of water samples. The detection limit of this method was evaluated as 0.054 mBq/kg in 500 g soil and 0.032 μBq/L in 500 L water. The determined value of 99 Tc in the IAEA-375 (soil sample collected near the Chernobyl Nuclear Reactor) was 0.25 ± 0.02 Bq/kg. (author)

  7. Analytics to Better Interpret and Use Large Amounts of Heterogeneous Data

    Science.gov (United States)

    Mathews, T. J.; Baskin, W. E.; Rinsland, P. L.

    2014-12-01

    Data scientists at NASA's Atmospheric Science Data Center (ASDC) are seasoned software application developers who have worked with the creation, archival, and distribution of large datasets (multiple terabytes and larger). In order for ASDC data scientists to effectively implement the most efficient processes for cataloging and organizing data access applications, they must be intimately familiar with data contained in the datasets with which they are working. Key technologies that are critical components to the background of ASDC data scientists include: large RBMSs (relational database management systems) and NoSQL databases; web services; service-oriented architectures; structured and unstructured data access; as well as processing algorithms. However, as prices of data storage and processing decrease, sources of data increase, and technologies advance - granting more people to access to data at real or near-real time - data scientists are being pressured to accelerate their ability to identify and analyze vast amounts of data. With existing tools this is becoming exceedingly more challenging to accomplish. For example, NASA Earth Science Data and Information System (ESDIS) alone grew from having just over 4PBs of data in 2009 to nearly 6PBs of data in 2011. This amount then increased to roughly10PBs of data in 2013. With data from at least ten new missions to be added to the ESDIS holdings by 2017, the current volume will continue to grow exponentially and drive the need to be able to analyze more data even faster. Though there are many highly efficient, off-the-shelf analytics tools available, these tools mainly cater towards business data, which is predominantly unstructured. Inadvertently, there are very few known analytics tools that interface well to archived Earth science data, which is predominantly heterogeneous and structured. This presentation will identify use cases for data analytics from an Earth science perspective in order to begin to identify

  8. All polymer chip for amperometric studies of transmitter release from large groups of neuronal cells

    DEFF Research Database (Denmark)

    Larsen, Simon T.; Taboryski, Rafael

    2012-01-01

    We present an all polymer electrochemical chip for simple detection of transmitter release from large groups of cultured PC 12 cells. Conductive polymer PEDOT:tosylate microelectrodes were used together with constant potential amperometry to obtain easy-to-analyze oxidation signals from potassium......-induced release of transmitter molecules. The nature of the resulting current peaks is discussed, and the time for restoring transmitter reservoirs is studied. The relationship between released transmitters and potassium concentration was found to fit to a sigmoidal dose–response curve. Finally, we demonstrate...

  9. Improved recovery of trace amounts of gold (III), palladium (II) and platinum (IV) from large amounts of associated base metals using anion-exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, I. [Lab. of Chemistry, Tokyo Women' s Medical Univ. (Japan); Takeda, Y.; Ishida, K. [Lab. of Chemistry, Nippon Medical School, Kawasaki-shi, Kanagawa-ken (Japan)

    2000-02-01

    The adsorption and desorption behaviors of gold (III), palladium (II) and platinum (IV) were surveyed in column chromatographic systems consisting of one of the conventional anion-exchange resins of large ion-exchange capacity and dilute thiourea solutions. The noble metals were strongly adsorbed on the anion-exchange resins from dilute hydrochloric acid, while most base metals did not show any marked adsorbability. These facts made it possible to separate the noble metals from a large quantity of base metals such as Ag (I), Al (III), Co (II), Cu (II), Fe (III), Mn (II), Ni (II), Pb (II), and Zn (II). Although it used to be very difficult to desorb the noble metals from the resins used, the difficulty was easily overcome by use of dilute thiourea solutions as an eluant. In the present study, as little as 1.00 {mu}g of the respective noble metals was quantitatively separated and recovered from as much as ca. 10 mg of a number of metals on a small column by elution with a small amount of dilute thiourea solution. The present systems should be applicable to the separation, concentration and recovery of traces of the noble metals from a number of base metals coexisting in a more extended range of amounts and ratios. (orig.)

  10. Imbalance costs in the Swedish system with large amounts of wind power

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Fredrik; Neimane, Viktoria [Vattenfall Research and Development AB, Stockholm (Sweden)

    2009-07-01

    The well-known concerns about wind power are related to its intermittent nature and difficulty to make exact forecasts. The expected increase in balancing and reserve requirements due to wind power has been investigated in several studies. This paper takes the next step in studying integration of large amounts of wind power in Sweden. Several wind power producers' and corresponding balance providers' perspective is taken and their imbalance costs modeled. Larger producers having wind power spread over larger geographical areas will have lower relative costs than producers having their units concentrated within limited geographical area. Possibilities of the wind power producers to reduce the imbalance costs by acting on after sales market are exposed and compared. (orig.)

  11. Knowledge discovery: Extracting usable information from large amounts of data

    International Nuclear Information System (INIS)

    Whiteson, R.

    1998-01-01

    The threat of nuclear weapons proliferation is a problem of world wide concern. Safeguards are the key to nuclear nonproliferation and data is the key to safeguards. The safeguards community has access to a huge and steadily growing volume of data. The advantages of this data rich environment are obvious, there is a great deal of information which can be utilized. The challenge is to effectively apply proven and developing technologies to find and extract usable information from that data. That information must then be assessed and evaluated to produce the knowledge needed for crucial decision making. Efficient and effective analysis of safeguards data will depend on utilizing technologies to interpret the large, heterogeneous data sets that are available from diverse sources. With an order-of-magnitude increase in the amount of data from a wide variety of technical, textual, and historical sources there is a vital need to apply advanced computer technologies to support all-source analysis. There are techniques of data warehousing, data mining, and data analysis that can provide analysts with tools that will expedite their extracting useable information from the huge amounts of data to which they have access. Computerized tools can aid analysts by integrating heterogeneous data, evaluating diverse data streams, automating retrieval of database information, prioritizing inputs, reconciling conflicting data, doing preliminary interpretations, discovering patterns or trends in data, and automating some of the simpler prescreening tasks that are time consuming and tedious. Thus knowledge discovery technologies can provide a foundation of support for the analyst. Rather than spending time sifting through often irrelevant information, analysts could use their specialized skills in a focused, productive fashion. This would allow them to make their analytical judgments with more confidence and spend more of their time doing what they do best

  12. Large methane releases lead to strong aerosol forcing and reduced cloudiness

    Directory of Open Access Journals (Sweden)

    T. Kurtén

    2011-07-01

    Full Text Available The release of vast quantities of methane into the atmosphere as a result of clathrate destabilization is a potential mechanism for rapid amplification of global warming. Previous studies have calculated the enhanced warming based mainly on the radiative effect of the methane itself, with smaller contributions from the associated carbon dioxide or ozone increases. Here, we study the effect of strongly elevated methane (CH4 levels on oxidant and aerosol particle concentrations using a combination of chemistry-transport and general circulation models. A 10-fold increase in methane concentrations is predicted to significantly decrease hydroxyl radical (OH concentrations, while moderately increasing ozone (O3. These changes lead to a 70 % increase in the atmospheric lifetime of methane, and an 18 % decrease in global mean cloud droplet number concentrations (CDNC. The CDNC change causes a radiative forcing that is comparable in magnitude to the longwave radiative forcing ("enhanced greenhouse effect" of the added methane. Together, the indirect CH4-O3 and CH4-OH-aerosol forcings could more than double the warming effect of large methane increases. Our findings may help explain the anomalously large temperature changes associated with historic methane releases.

  13. Decontamination for free release

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, K A; Elder, G R [Bradtec Ltd., Bristol (United Kingdom)

    1997-02-01

    Many countries are seeking to treat radioactive waste in ways which meet the local regulatory requirements, but yet are cost effective when all contributing factors are assessed. In some countries there are increasing amounts of waste, arising from nuclear plant decommissioning, which are categorized as low level waste: however with suitable treatment a large part of such wastes might become beyond regulatory control and be able to be released as non-radioactive. The benefits and disadvantages of additional treatment before disposal need to be considered. Several processes falling within the overall description of decontamination for free release have been developed and applied, and these are outlined. In one instance the process seeks to take advantage of techniques and equipment used for decontaminating water reactor circuits intermittently through reactor life. (author). 9 refs, 1 fig., 3 tabs.

  14. Fission product release from nuclear fuel II. Validation of ASTEC/ELSA on analytical and large scale experiments

    International Nuclear Information System (INIS)

    Brillant, G.; Marchetto, C.; Plumecocq, W.

    2013-01-01

    Highlights: • A wide range of experiments is presented for the ASTEC/ELSA code validation. • Analytical tests such as AECL, ORNL and VERCORS are considered. • A large-scale experiment, PHEBUS FPT1, is considered. • The good agreement with measurements shows the efficiency of the ASTEC modelling. • Improvements concern the FP release modelling from MOX and high burn-up UO 2 fuels. - Abstract: This article is the second of two articles dedicated to the mechanisms of fission product release from a degraded core. The models of fission product release from nuclear fuel in the ASTEC code have been described in detail in the first part of this work (Brillant et al., this issue). In this contribution, the validation of ELSA, the module of ASTEC that deals with fission product and structural material release from a degraded core, is presented. A large range of experimental tests, with various temperature and conditions for the fuel surrounding atmosphere (oxidising and reducing), is thus simulated with the ASTEC code. The validation database includes several analytical experiments with both bare fuel (e.g. MCE1 experiments) and cladded fuel (e.g. HCE3, VERCORS). Furthermore, the PHEBUS large-scale experiments are used for the validation of ASTEC. The rather satisfactory comparison between ELSA calculations and experimental measurements demonstrates the efficiency of the analytical models to describe fission product release in severe accident conditions

  15. Measuring method for amount of fissionable gas in spent fuel pellet

    International Nuclear Information System (INIS)

    Kashibe, Shinji.

    1992-01-01

    The method of the present invention separately measures the amount of both of a fission product (FP) gas accumulated in bubbles at the crystal grain boundary of spent fuel pellets and an FP gas accumulated in the crystal grains. That is, in a radial position of the spent fuel pellet, a microfine region is mechanically destroyed. The amount of the FP gas released by the destruction from the crystal grains is measured by using a mass analyzer. Then, when the destroyed pieces formed by the destruction are recovered and dissolved, FP gas accumulated in the crystal grains of the pellet is released. The amount released is measured by the mass analyzer. With such procedures, the amount of FP gas accumulated in the bubbles at the crystal grain boundary and in the crystal grains at the radial position of the spent fuel pellet can be measured discriminately. Accordingly, the integrity of the fuel pellet can be recognized appropriately. (I.S.)

  16. Determination of accident related release data

    International Nuclear Information System (INIS)

    Koch, W.; Nolte, O.; Lange, F.; Martens, R.

    2004-01-01

    For accident safety analyses, for the assessment of potential radiological consequences, for the review of current requirements of the Transport Regulations and for their possible further development as well as for the demonstration that radioactive materials such as LDM candidate material fulfil the regulatory requirements reliable release data following mechanical impact are required. This is definitely one of the demanding issues in the field of transport safety of radioactive materials. In this context special attention has to be paid to radioactive wastes immobilised in brittle materials, e.g. cement/concrete, glass, ceramics or other brittle materials such as fresh and spent fuel. In this presentation we report on a long-term experimental program aiming at improving the general physical understanding of the release process as well as the quantity and the quality of release data. By combining laboratory experiments using small scale test specimens with a few key scaling experiments with large scale test objects significant progress was achieved to meet this objective. The laboratory equipment enables the in-situ determination of the amount and aerodynamic size distribution of the airborne particles generated upon impact of the test specimen on a hard target. Impact energies cover the range experienced in transport accidents including aircraft accidents. The well defined experimental boundary conditions and the good reproducibility of the experimental procedure allowed for systematic studies to exactly measure the amount and aerodynamic size distribution of the airborne release and to quantify its dependence on relevant parameters such as energy input, material properties, and specimen geometry. The experimental program was performed within the scope of various national and international (e.g. EU-funded) projects. The small scale experiments with brittle materials revealed a pronounced universality of the airborne release in view of the material properties and

  17. Fission product release from high gap-inventory LWR fuel under LOCA conditions

    International Nuclear Information System (INIS)

    Lorenz, R.A.; Collins, J.L.; Osborne, M.F.; Malinauskas, A.P.

    1980-01-01

    Fission product release tests were performed with light water reactor (LWR) fuel rod segments containing large amounts of cesium and iodine in the pellet-to-cladding gap space in order to check the validity of the previously published Source Term Model for this type of fuel. The model describes the release of fission product cesium and iodine from LWR fuel rods for controlled loss-of-coolant accident (LOCA) transients in the temperature range 500 to 1200 0 C. The basis for the model was test data obtained with simulated fuel rods and commercial fuel irradiated to high burnup but containing relatively small amounts of cesium and iodine in the pellet-to-cladding gap space

  18. Tritium release experiments with CATS and numerical simulation

    International Nuclear Information System (INIS)

    Munakata, Kenzo; Wajima, Takaaki; Hara, Keisuke; Wada, Kohei; Takeishi, Toshiharu; Shinozaki, Yohei; Mochizuki, Kazuhiro; Katekari, Kenichi; Kobayashi, Kazuhiro; Iwai, Yasunori; Hayashi, Takumi; Yamanishi, Toshihiko

    2010-01-01

    In D-T fusion power plants, large amounts of tritium would be handled. Tritium is the radioisotope of protium, and is easily taken into the human body, and thus the behavior of tritium accidentally released in fusion power plants should be studied for the safety design and radioprotection of workers. Therefore, it is necessary to investigate the behavior of tritium released into large rooms with objectives, since complex flow fields should exist in such rooms and they could influence the ventilation of the air containing released tritium. Thus, tritium release experiments were conducted using Caisson Assembly for Tritium Safety Study (CATS) in TPL/JAEA. Some data were taken for tritium behavior in the ventilated area and response of tritium monitors. In the experiments, approximately 17 GBq of tritium was released into Caisson with the total volume of 12 m 3 , and the room was ventilated at the rate of 12 m 3 /h after release of tritium. It was found that placement of an objective in the vessel substantially affects decontamination efficiency. With regard to an experimental result, numerical calculation was performed and the experimental result and the result of numerical calculation were compared, which indicates that experimental results are qualitatively reproduced by numerical calculation. However, further R and D needs to be carried out for quantitative reproduction of the experimental results.

  19. Tritium release experiments with CATS and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Munakata, Kenzo, E-mail: kenzo@gipc.akita-u.ac.jp [Faculty of Engineering and Resource Sciences, Akita University, Tegata-gakuen-cho 1-1, Akita 010-8502 (Japan); Wajima, Takaaki; Hara, Keisuke; Wada, Kohei [Faculty of Engineering and Resource Sciences, Akita University, Tegata-gakuen-cho 1-1, Akita 010-8502 (Japan); Takeishi, Toshiharu; Shinozaki, Yohei; Mochizuki, Kazuhiro; Katekari, Kenichi [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581 (Japan); Kobayashi, Kazuhiro; Iwai, Yasunori; Hayashi, Takumi; Yamanishi, Toshihiko [Tritium Technology Group, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

    2010-12-15

    In D-T fusion power plants, large amounts of tritium would be handled. Tritium is the radioisotope of protium, and is easily taken into the human body, and thus the behavior of tritium accidentally released in fusion power plants should be studied for the safety design and radioprotection of workers. Therefore, it is necessary to investigate the behavior of tritium released into large rooms with objectives, since complex flow fields should exist in such rooms and they could influence the ventilation of the air containing released tritium. Thus, tritium release experiments were conducted using Caisson Assembly for Tritium Safety Study (CATS) in TPL/JAEA. Some data were taken for tritium behavior in the ventilated area and response of tritium monitors. In the experiments, approximately 17 GBq of tritium was released into Caisson with the total volume of 12 m{sup 3}, and the room was ventilated at the rate of 12 m{sup 3}/h after release of tritium. It was found that placement of an objective in the vessel substantially affects decontamination efficiency. With regard to an experimental result, numerical calculation was performed and the experimental result and the result of numerical calculation were compared, which indicates that experimental results are qualitatively reproduced by numerical calculation. However, further R and D needs to be carried out for quantitative reproduction of the experimental results.

  20. Observations of the release of non-methane hydrocarbons from fractured shale.

    Science.gov (United States)

    Sommariva, Roberto; Blake, Robert S; Cuss, Robert J; Cordell, Rebecca L; Harrington, Jon F; White, Iain R; Monks, Paul S

    2014-01-01

    The organic content of shale has become of commercial interest as a source of hydrocarbons, owing to the development of hydraulic fracturing ("fracking"). While the main focus is on the extraction of methane, shale also contains significant amounts of non-methane hydrocarbons (NMHCs). We describe the first real-time observations of the release of NMHCs from a fractured shale. Samples from the Bowland-Hodder formation (England) were analyzed under different conditions using mass spectrometry, with the objective of understanding the dynamic process of gas release upon fracturing of the shale. A wide range of NMHCs (alkanes, cycloalkanes, aromatics, and bicyclic hydrocarbons) are released at parts per million or parts per billion level with temperature- and humidity-dependent release rates, which can be rationalized in terms of the physicochemical characteristics of different hydrocarbon classes. Our results indicate that higher energy inputs (i.e., temperatures) significantly increase the amount of NMHCs released from shale, while humidity tends to suppress it; additionally, a large fraction of the gas is released within the first hour after the shale has been fractured. These findings suggest that other hydrocarbons of commercial interest may be extracted from shale and open the possibility to optimize the "fracking" process, improving gas yields and reducing environmental impacts.

  1. A Case of Special Complication following a Large Amount of Polyacrylamide Hydrogel Injected into the Epicranial Aponeurosis: Leukocytopenia

    Directory of Open Access Journals (Sweden)

    Li Rong

    2015-01-01

    Full Text Available Polyacrylamide hydrogel (PAAG has been used as an injectable filler for soft tissue augmentation of different body parts, such as the face, breasts, and penis. However, this is the first report of leukocytopenia after injection of a large amount of PAAG in the epicranial aponeurosis. After receiving PAAG injection for craniofacial contouring, the female patient described herein experienced recurrent swelling, temporal pain (particularly with changes in ambient temperature and facial expression, and ultimately leukocytopenia due to widespread migration of the injected PAAG. We removed most of the PAAG from the affected tissues and the leukocytopenia disappeared 1 year after the operation. Based on this case, we hypothesize that injection of a large amount of PAAG into tissues that have ample blood supply, such as the epicranial aponeurosis, may induce leukocytopenia.

  2. Assessing and Projecting Greenhouse Gas Release due to Abrupt Permafrost Degradation

    Science.gov (United States)

    Saito, K.; Ohno, H.; Yokohata, T.; Iwahana, G.; Machiya, H.

    2017-12-01

    Permafrost is a large reservoir of frozen soil organic carbon (SOC; about half of all the terrestrial storage). Therefore, its degradation (i.e., thawing) under global warming may lead to a substantial amount of additional greenhouse gas (GHG) release. However, understanding of the processes, geographical distribution of such hazards, and implementation of the relevant processes in the advanced climate models are insufficient yet so that variations in permafrost remains one of the large source of uncertainty in climatic and biogeochemical assessment and projections. Thermokarst, induced by melting of ground ice in ice-rich permafrost, leads to dynamic surface subsidence up to 60 m, which further affects local and regional societies and eco-systems in the Arctic. It can also accelerate a large-scale warming process through a positive feedback between released GHGs (especially methane), atmospheric warming and permafrost degradation. This three-year research project (2-1605, Environment Research and Technology Development Fund of the Ministry of the Environment, Japan) aims to assess and project the impacts of GHG release through dynamic permafrost degradation through in-situ and remote (e.g., satellite and airborn) observations, lab analysis of sampled ice and soil cores, and numerical modeling, by demonstrating the vulnerability distribution and relative impacts between large-scale degradation and such dynamic degradation. Our preliminary laboratory analysis of ice and soil cores sampled in 2016 at the Alaskan and Siberian sites largely underlain by ice-rich permafrost, shows that, although gas volumes trapped in unit mass are more or less homogenous among sites both for ice and soil cores, large variations are found in the methane concentration in the trapped gases, ranging from a few ppm (similar to that of the atmosphere) to hundreds of thousands ppm We will also present our numerical approach to evaluate relative impacts of GHGs released through dynamic

  3. The variation of health effects based on the scenarios considering release parameters and meteorological data

    International Nuclear Information System (INIS)

    Jeong, Jong Tae; Ha, Jae Joo

    2000-01-01

    The variation of health effects resulting from the severe accidents of the YGN 3 and 4 nuclear power plants was examined based on scenarios considering the release parameters and meteorological data. The release parameters and meteorological data considered in making basic scenarios are release height, heat content, release time, warning time, wind speed, rainfall rate, and atmospheric stability class. The seasonal scenarios were also made in order to estimate the seasonal variation of health effects by considering seasonal characteristics of Korea. According to the results, there are large differences in consequence analysis from scenario to although an equal amount of radioactive materials is released to the atmosphere. Also, there are large differences in health effects from season to season due to distinct seasonal characteristics of Korea. Therefore, it is necessary to consider seasonal characteristics in developing optimum emergency response strategies

  4. Analysis of hydrogen sulfide releases in heavy water production facilities

    International Nuclear Information System (INIS)

    Croitoru, Cornelia; Dumitrescu, Maria; Preda, Irina; Lazar, Roxana

    1996-01-01

    Safety analyses conducted at ICIS concern primarily the heavy water production installations. The quantitative risk assessment needs the frequency calculation of accident sequences and consequences. In heavy water plants which obtain primary isotopic concentration of water by H 2 O - H 2 S exchange, large amounts of hydrogen sulfide which is a toxic, inflammable and explosive gas, are circulated. The first stage in calculating the consequences consists in potential analysis of H 2 S release. This work presents a study of this types of releases for pilot installations of the heavy water production at ICIS (Plant 'G' at Rm. Valcea). The installations which contain and maneuver large quantities of H 2 S and the mathematical models for different types of releases are presented. The accidents analyzed are: catastrophic column, container, spy-hole failures or gas-duct rupture and wall cracks in the installation. The main results are given as tables while the time variations of the flow rate and quantities of H 2 O released by stack disposal are plotted

  5. 131I release from a HTGR during the LOFC accident

    International Nuclear Information System (INIS)

    Foley, J.E.

    1975-03-01

    The time-dependent release of 131 I from both the core and the containment building of a high temperature gas-cooled (HTGR) reactor during the loss of forced coolant (LOFC) accident is studied. A simplified core release model is combined with a containment building release model so that the total amount of the isotope released to the environment can be calculated. The time-dependent release of 131 I from the core during the LOFC accident is primarily a function of the time-dependent core temperatures and the failed fuel release constants. The most important factor in calculating the amount of the isotope released to the environment is the total amount released into the containment building. (U.S.)

  6. Determination of small amounts of nitric acid in the presence of large amounts of uranium (VI) and extraction of nitric acid into TBP solutions highly loaded with uranyl nitrate

    International Nuclear Information System (INIS)

    Kolarik, Z.; Schuler, R.

    1982-10-01

    A new method for the determination of small amounts of nitric acid in the presence of large amounts of uranium(VI) was elaborated. The method is based on the precipitation of uranium(VI) as iodate and subsequent alkalimetric titration of the acid in the supernatant. The extraction of nitric acid and uranium(VI) with 30% TBP in dodecane was studied at high loading of the organic phase with uranyl nitrate and at 25, 40 and 60 0 C. The results are compared with available published data on the extraction of nitric acid under similar conditions. (orig.) [de

  7. Operational experience in mitigating flammable gas releases from Hanford Site Tank 241-SY-101

    International Nuclear Information System (INIS)

    Lentsch, J.W.; Babad, H.; Kirch, N.W.

    1995-01-01

    Flammable gases consisting of hydrogen, nitrous oxide, ammonia, and methane are periodically released from Hanford Site waste tank 241-SY-101 at concentrations above the flammable limit. A large mixer pump installed in the tank in 1993 has effectively mitigated this problem by continuously releasing small amounts of the flammable gases at the rate they are generated. Tank 241-SY-101 is also equipped with multiple high-sensitivity gas monitoring systems and level detection systems to measure the quantity of gas that is retained in and released from the waste

  8. Orthodontic forces released by low-friction versus conventional systems during alignment of apically or buccally malposed teeth.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Camporesi, Matteo; Defraia, Efisio

    2011-02-01

    The aim of the present study was to analyse the forces released by passive stainless steel self-ligating brackets (SLBs) and by a non-conventional elastomeric ligature-bracket system on conventional brackets ([slide ligatures on conventional brackets (SLCB)]) when compared with conventional elastomeric ligatures on conventional brackets (CLCB) during the alignment of apically or buccally malposed teeth in the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the three different bracket-ligature systems with 0.012-inch super-elastic (SE) nickel-titanium (NiTi) wires in the presence of different amounts of apical or buccal canine misalignment of the canine (ranging from 1.5 to 6 mm). The forces released by each wire/bracket/ligature combination with the three different amounts of apical or buccal canine misalignment were tested 20 times. Comparisons between the different types of wire/bracket/ligature systems were carried out by means of analysis of variance on ranks with Dunnett's post hoc test (P < 0.05). No difference in the amount of force released in presence of a misalignment of 1.5 mm was recorded among the three systems. At 3 mm of apical misalignment a significantly greater amount of orthodontic force was released by SLB or SLCB when compared with CLCB, while no significant differences were found among the three systems at 3 mm of buccal canine displacement. When correction of a large amount of misalignment (6 mm) was attempted, a noticeable amount of force for alignment was still generated by the passive SLB and SLCB systems while no force was released in presence of CLCB.

  9. Impacts of large amounts of wind power on design and operation of power systems, results of IEA collaboration

    DEFF Research Database (Denmark)

    Holttinen, Hannele; Meibom, Peter; Orths, Antje

    2011-01-01

    There are dozens of studies made and ongoing related to wind integration. However, the results are not easy to compare. IEA WIND R&D Task 25 on Design and Operation of Power Systems with Large Amounts of Wind Power collects and shares information on wind generation impacts on power systems......, with analyses and guidelines on methodologies. In the state-of-the-art report (October, 2007), and the final report of the 3 years period (July, 2009) the most relevant wind power grid integration studies have been analysed especially regarding methodologies and input data. Several issues that impact...... on the amount of wind power that can be integrated have been identified. Large balancing areas and aggregation benefits of wide areas help in reducing the variability and forecast errors of wind power as well as help in pooling more cost effective balancing resources. System operation and functioning...

  10. A large amount synthesis of nanopowder using modulated induction thermal plasmas synchronized with intermittent feeding of raw materials

    International Nuclear Information System (INIS)

    Tanaka, Y; Tsuke, T; Guo, W; Uesugi, Y; Ishijima, T; Watanabe, S; Nakamura, K

    2012-01-01

    A large amount synthesis method for titanium dioxide (TiO 2 ) nanopowder is proposed by direct evaporation of titanium powders using Ar-O 2 pulse-modulated induction thermal plasma (PMITP). To realize a large amount synthesis of nanopowder, the PMITP method was combined with the intermittent and heavy load feeding of raw material powder, as well as the quenching gas injection. The intermittent powder feeding was synchronized with the modulation of the coil current sustaining the PMITP for complete evaporation of the injected powder. Synthesized particles by the developed method were analyzed by FE-SEM and XRD. Results indicated that the synthesized particles by the 20-kW PMITP with a heavy loading rate of 12.3 g min −1 had a similar particle size distribution with the mean diameter about 40 nm to those with light loading of 4.2 g min −1 .

  11. Highly Sensitive GMO Detection Using Real-Time PCR with a Large Amount of DNA Template: Single-Laboratory Validation.

    Science.gov (United States)

    Mano, Junichi; Hatano, Shuko; Nagatomi, Yasuaki; Futo, Satoshi; Takabatake, Reona; Kitta, Kazumi

    2018-03-01

    Current genetically modified organism (GMO) detection methods allow for sensitive detection. However, a further increase in sensitivity will enable more efficient testing for large grain samples and reliable testing for processed foods. In this study, we investigated real-time PCR-based GMO detection methods using a large amount of DNA template. We selected target sequences that are commonly introduced into many kinds of GM crops, i.e., 35S promoter and nopaline synthase (NOS) terminator. This makes the newly developed method applicable to a wide range of GMOs, including some unauthorized ones. The estimated LOD of the new method was 0.005% of GM maize events; to the best of our knowledge, this method is the most sensitive among the GM maize detection methods for which the LOD was evaluated in terms of GMO content. A 10-fold increase in the DNA amount as compared with the amount used under common testing conditions gave an approximately 10-fold reduction in the LOD without PCR inhibition. Our method is applicable to various analytical samples, including processed foods. The use of other primers and fluorescence probes would permit highly sensitive detection of various recombinant DNA sequences besides the 35S promoter and NOS terminator.

  12. Biological soil crusts emit large amounts of NO and HONO affecting the nitrogen cycle in drylands

    Science.gov (United States)

    Tamm, Alexandra; Wu, Dianming; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J.; Su, Hang; Pöschl, Ulrich; Weber, Bettina

    2016-04-01

    Dryland systems currently cover ˜40% of the world's land surface and are still expanding as a consequence of human impact and global change. In contrast to that, information on their role in global biochemical processes is limited, probably induced by the presumption that their sparse vegetation cover plays a negligible role in global balances. However, spaces between the sparse shrubs are not bare, but soils are mostly covered by biological soil crusts (biocrusts). These biocrust communities belong to the oldest life forms, resulting from an assembly between soil particles and cyanobacteria, lichens, bryophytes, and algae plus heterotrophic organisms in varying proportions. Depending on the dominating organism group, cyanobacteria-, lichen-, and bryophyte-dominated biocrusts are distinguished. Besides their ability to restrict soil erosion they fix atmospheric carbon and nitrogen, and by doing this they serve as a nutrient source in strongly depleted dryland ecosystems. In this study we show that a fraction of the nitrogen fixed by biocrusts is metabolized and subsequently returned to the atmosphere in the form of nitric oxide (NO) and nitrous acid (HONO). These gases affect the radical formation and oxidizing capacity within the troposphere, thus being of particular interest to atmospheric chemistry. Laboratory measurements using dynamic chamber systems showed that dark cyanobacteria-dominated crusts emitted the largest amounts of NO and HONO, being ˜20 times higher than trace gas fluxes of nearby bare soil. We showed that these nitrogen emissions have a biogenic origin, as emissions of formerly strongly emitting samples almost completely ceased after sterilization. By combining laboratory, field, and satellite measurement data we made a best estimate of global annual emissions amounting to ˜1.1 Tg of NO-N and ˜0.6 Tg of HONO-N from biocrusts. This sum of 1.7 Tg of reactive nitrogen emissions equals ˜20% of the soil release under natural vegetation according

  13. Crustacean zooplankton release copious amounts of dissolved organic matter as taurine in the ocean.

    Science.gov (United States)

    Clifford, Elisabeth L; Hansell, Dennis A; Varela, Marta M; Nieto-Cid, Mar; Herndl, Gerhard J; Sintes, Eva

    2017-11-01

    Taurine (Tau), an amino acid-like compound, is present in almost all marine metazoans including crustacean zooplankton. It plays an important physiological role in these organisms and is released into the ambient water throughout their life cycle. However, limited information is available on the release rates by marine organisms, the concentrations and turnover of Tau in the ocean. We determined dissolved free Tau concentrations throughout the water column and its release by abundant crustacean mesozooplankton at two open ocean sites (Gulf of Alaska and North Atlantic). At both locations, the concentrations of dissolved free Tau were in the low nM range (up to 15.7 nM) in epipelagic waters, declining sharply in the mesopelagic to about 0.2 nM and remaining fairly stable throughout the bathypelagic waters. Pacific amphipod-copepod assemblages exhibited lower dissolved free Tau release rates per unit biomass (0.8 ± 0.4 μmol g -1 C-biomass h -1 ) than Atlantic copepods (ranging between 1.3 ± 0.4 μmol g -1 C-biomass h -1 and 9.5 ± 2.1 μmol g -1 C-biomass h -1 ), in agreement with the well-documented inverse relationship between biomass-normalized excretion rates and body size. Our results indicate that crustacean zooplankton might contribute significantly to the dissolved organic matter flux in marine ecosystems via dissolved free Tau release. Based on the release rates and assuming steady state dissolved free Tau concentrations, turnover times of dissolved free Tau range from 0.05 d to 2.3 d in the upper water column and are therefore similar to those of dissolved free amino acids. This rapid turnover indicates that dissolved free Tau is efficiently consumed in oceanic waters, most likely by heterotrophic bacteria.

  14. Metal release from coffee machines and electric kettles.

    Science.gov (United States)

    Müller, Frederic D; Hackethal, Christin; Schmidt, Roman; Kappenstein, Oliver; Pfaff, Karla; Luch, Andreas

    2015-01-01

    The release of elemental ions from 8 coffee machines and 11 electric kettles into food simulants was investigated. Three different types of coffee machines were tested: portafilter espresso machines, pod machines and capsule machines. All machines were tested subsequently on 3 days before and on 3 days after decalcification. Decalcification of the machines was performed with agents according to procedures as specified in the respective manufacturer's manuals. The electric kettles showed only a low release of the elements analysed. For the coffee machines decreasing concentrations of elements were found from the first to the last sample taken in the course of 1 day. Metal release on consecutive days showed a decreasing trend as well. After decalcification a large increase in the amounts of elements released was encountered. In addition, the different machine types investigated clearly differed in their extent of element release. By far the highest leaching, both quantitatively and qualitatively, was found for the portafilter machines. With these products releases of Pb, Ni, Mn, Cr and Zn were in the range and beyond the release limits as proposed by the Council of Europe. Therefore, a careful rinsing routine, especially after decalcification, is recommended for these machines. The comparably lower extent of release of one particular portafilter machine demonstrates that metal release at levels above the threshold that triggers health concerns are technically avoidable.

  15. Very large amounts of radiation are needed to change cancer frequency

    International Nuclear Information System (INIS)

    Brooks, A.; Couch, L.

    2006-01-01

    Full text: A marked radio-phobia or excessive fear of radiation exposure is shared by the general public. A major factor in this fear is that the perception that each and every radiation-induced ionization increases the risk for cancer, thus even the smallest radiation exposure needs to be avoided. It is important to realize that this is not the case. It requires very large amounts of radiation delivered to large populations to produce an increase in cancer frequency. This has been demonstrated in many in experimental systems, animal studies and in human populations. If either the population size or the dose is reduced it is not possible to detect an increase in cancer frequency. This paper deals with real radiation-induced increases in cancer frequency that are statistically significant, rather than in extrapolated or calculated small increases in radiation-induced risks using linear models. Further, it demonstrates that there are barriers below which increases in cancer cannot be detected. Finally, the manuscript helps explain that there are transitions in the mechanisms of biological action as a function of radiation dose with very different mechanisms being triggered at high and at low doses. These transitions suggest the need for paradigm shifts. Concepts such as hit theory, independence in individual cellular responses and single mutations being responsible for cancer need to be re-evaluated. New paradigms such as b ystander effects , showing that the size of the responding target is much larger than the hit target, adaptive response demonstrating that cell/cell communication modifies individual cellular responses and genomic instability that is not dependent on radiation induced mutations in individual cells

  16. Transient Stability Assessment of Power System with Large Amount of Wind Power Penetration

    DEFF Research Database (Denmark)

    Liu, Leo; Chen, Zhe; Bak, Claus Leth

    2012-01-01

    Recently, the security and stability of power system with large amount of wind power are the concerned issues, especially the transient stability. In Denmark, the onshore and offshore wind farms are connected to distribution system and transmission system respectively. The control and protection...... methodologies of onshore and offshore wind farms definitely affect the transient stability of power system. In this paper, the onshore and offshore wind farms are modeled in detail in order to assess the transient stability of western Danish power system. Further, the computation of critical clearing time (CCT...... plants, load consumption level and high voltage direct current (HVDC) transmission links are taken into account. The results presented in this paper are able to provide an early awareness of power system security condition of the western Danish power system....

  17. Preparation of microspheres for slow release drug by radiation-induced suspension polymerization and their properties

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Asano, Masaharu; Kaetsu, Isao

    1982-01-01

    The polymer microspheres containing drugs as drug delivery system were made by means of suspension-polymerization by radiation at low temperature by using glass-forming monomers which have stable supercooling properties and large polymerizability at low temperature. The particle distribution depended on the kind of monomer. It was found that the entrapping yield of drug in polymer microspheres increased with increasing viscosity of monomer and that the maximum value on the particle size distribution curve was also shifted to large particle diameter side. In the case of trimethylolpropane trimethacrylate monomer (43 cps), TMPT, the entrapping yield of drug reached 74% and the maximum value in particle size distribution curve appeared in the neighborhood of 105 to 210 mu m ranges. On the other hand, those values in neopentyl glycol dimethacrylate monomer (4 cps) were 12% in former and 44 -- 105 mu m in the latter. The release phenomenon of drugs from polymer microspheres was investigated. for example, the cumulative amount of mitomycin C (water soluble drug) released from TMPT polymer microsphere was about 90% after 30-day dissolution, while in the case of water-insoluble drug such as testosterone the amount of release was about 49% after 40-day dissolution. In all cases, the release rate is constant during the experimental period. Therefore, it was concluded that the release of drugs from polymer microspheres obtained in this study is possible over the long periods. (author)

  18. Release of Streptomyces albus propagules from contaminated surfaces

    International Nuclear Information System (INIS)

    Gorny, R.L.; Mainelis, Gediminas; Grinshpun, Sergey A.; Willeke, Klaus; Dutkiewicz, Jacek; Reponen, Tiina

    2003-01-01

    The release of Streptomyces albus propagules from contaminated agar an ceiling tile surfaces was studied under controlled environmental condition in a newly developed aerosolization chamber. The experiments revealed tha both spores and cell fragments can be simultaneously released from the colonized surface by relatively gentle air currents of 0.3 m s -1 . A 100x increase of the air velocity can result in a 50-fold increase in the number of released propagules. The aerosolization rate depends strongly on the typ and roughness of the contaminated surface. Up to 90% of available actinomycete propagules can become airborne during the first 10 min of th release process. Application of vibration to the surface did not reveal an influence on the aerosolization process of S. albus propagules under th tested conditions. This study has shown that propagules in the fine particle size range can be released in large amounts from contaminated surfaces Measurement of the number of S. albus fragments in the vicinity of contaminated area, as an alternative to conventional air or surface sampling appears to be a promising approach for quantitative exposure assessment

  19. Formation and release of cellulolytic enzymes during growth of Trichoderma reesei on cellobiose and glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Vaheri, M.P.; Vaheri, M.E.O.; Kaupinen, V.S.

    1979-01-01

    Production and release of cellulolytic enzymes by T. reesei QM 9414 were studied under induced and non-induced conditions and glycerol, respectively, as the only C source. There was a base level of cell debris-bound hydrolytic activity against filter paper and p-nitrophenyl glycoside even in T. reesei grown non-induced on glycerol. T. reesei grown on cellobiose was induced to produce large amounts of extracellular filter paper- and CMC-hydrolyzing enzymes, which were actively released even in the early stages of cultivation. Beta-Glucosidase was mainly detected in the cell debris and was not released unless the cells were autolyzing.

  20. Future trends in the assessment of hazards from fission product releases

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, J. R.

    1983-11-15

    In comparing and selecting sites for reactors from the point of view of safety, one considers the remote possibility of an accidental release of moderately large amounts of fission products and its effects in relation to the present and future distribution of population in the neighbourhood. At present, until experience is gained of the reliability and safety of reactors, there is a tendency to site them remotely from centres of industry and population, although for economic reasons there will be a need to site large power reactors more closely to such centres in the future. With, among other objectives, the aim of adopting, in the proper course or time, less restrictive siting criteria, improvements are continually made in the intrinsic safety of reactor system and more sophisticated forms of reactor containment are devised, in order to reduce the possibility and scale of any fission product release. Changes and improvements in reactor systems could affect the nature and proportion of an accidental release of fission products if this should occur in the future. It is appropriate to consider what such a release and its radiobiological effects might be.

  1. Degassing, gas retention and release in Fe(0) permeable reactive barriers.

    Science.gov (United States)

    Ruhl, Aki S; Jekel, Martin

    2014-04-01

    Corrosion of Fe(0) has been successfully utilized for the reductive treatment of multiple contaminants. Under anaerobic conditions, concurrent corrosion leads to the generation of hydrogen and its liberation as a gas. Gas bubbles are mobile or trapped within the irregular pore structure leading to a reduction of the water filled pore volume and thus decreased residence time and permeability (gas clogging). With regard to the contaminant transport to the reactive site, the estimation of surface properties of the reactive material indicated that individual gas bubbles only occupied minor contact areas of the reactive surface. Quantification of gas entrapment by both gravimetrical and tracer investigations revealed that development of preferential flow paths was not significant. A novel continuous gravimetrical method was implemented to record variations in gas entrapment and gas bubble releases from the reactive filling. Variation of grain size fractions revealed that the pore geometry had a significant impact on gas release. Large pores led to the release of comparably large gas amounts while smaller volumes were released from finer pores with a higher frequency. Relevant processes are explained with a simplified pictorial sequence that incorporates relevant mechanisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Approach and issues toward development of risk-based release standards for radioactive scrap metal recycle and reuse

    International Nuclear Information System (INIS)

    Chen, S.Y.; Nieves, L.A.; Nabelssi, B.K.; LePoire, D.J.

    1994-01-01

    The decontamination and decommissioning of nuclear facilities is expected to generate large amounts of slightly radioactive scrap metal (RSM). It is likely that some of these materials will be suitable for recycling and reuse. The amount of scrap steel from DOE facilities, for instance, is estimated to be more than one million tons (Hertzler 1993). However, under current practice and without the establishment of acceptable recycling standards, the RSM would be disposed of primarily as radioactive low-level waste (LLW). In the United States, no specific standards have been developed for the unrestricted release of bulk contaminated materials. Although standards for unrestricted release of radioactive surface contamination (NRC 1974) have existed for about 20 years, the release of materials is not commonly practiced because of the lack of risk-based justifications. Recent guidance from international bodies (IAEA 1988) has established a basis for deriving risk-based release limits for radioactive materials. It is important, therefore, to evaluate the feasibility of recycling and associated issues necessary for the establishment of risk-based release limits for the radioactive metals

  3. The estimation of early health effects for different combinations of release parameters and meteorological data

    International Nuclear Information System (INIS)

    Jeong, Jong Tae; Jung, Won Dea

    2001-01-01

    Variations in the number of early health effects resulting from the severe accidents of the YGN 3 and 4 nuclear power plants were examined for different combinations of release parameters and meteorological data. The release parameters and meteorological data were selected in combination to define a limited number of basic spectra characterized by release height, heat content, release time, warning time, wind speed, rainfall rate, and atmospheric stability class. Variant seasonal spectra were also defined in order to estimate the potential significance of seasonal variations as a factor determining the incidence or number of early health effects. The results show that there are large differences in consequences from spectrum to spectrum, although an equal amount and mix of radioactive material is released to the atmosphere in each case. Also, there are large differences in the estimated number of health effects from season to season due to distinct seasonal variations in meteorological combinations in Korea. Therefore, it is necessary to consider seasonal characteristics in developing optimum emergency response strategies

  4. Towards a Spiderman suit: large invisible cables and self-cleaning releasable superadhesive materials

    International Nuclear Information System (INIS)

    Pugno, Nicola M

    2007-01-01

    Spiders can produce cobwebs with high strength to density ratio and surprisingly display self-cleaning, strong and releasable adhesion (like geckos). Nanointerlocking, capillary and van der Waals forces, all potential adhesive mechanisms, are thus discussed, demonstrating the key role played by hierarchy in the design of superhydrophobic, i.e. self-cleaning (dry or wet and enhanced by activating Fakir drops as in lotus leaves) and superadhesive materials. The reversibility of the strong attachment is quantified thanks to an improved nonlinear peeling model including friction, for which the solution in closed form is provided. Thus, mimicking nature, thanks to carbon-nanotube-based technology, we suggest the feasibility of large invisible cables, as well as of self-cleaning, superadhesive and releasable hierarchical smart materials. We found that a man can theoretically be supported by a transparent cable with cross-section of 1 cm 2 and feasibly, with spider material gloves and boots, could remain attached even to a ceiling: a preliminary step towards a Spiderman suit

  5. Towards a Spiderman suit: large invisible cables and self-cleaning releasable superadhesive materials

    Science.gov (United States)

    Pugno, Nicola M.

    2007-10-01

    Spiders can produce cobwebs with high strength to density ratio and surprisingly display self-cleaning, strong and releasable adhesion (like geckos). Nanointerlocking, capillary and van der Waals forces, all potential adhesive mechanisms, are thus discussed, demonstrating the key role played by hierarchy in the design of superhydrophobic, i.e. self-cleaning (dry or wet and enhanced by activating Fakir drops as in lotus leaves) and superadhesive materials. The reversibility of the strong attachment is quantified thanks to an improved nonlinear peeling model including friction, for which the solution in closed form is provided. Thus, mimicking nature, thanks to carbon-nanotube-based technology, we suggest the feasibility of large invisible cables, as well as of self-cleaning, superadhesive and releasable hierarchical smart materials. We found that a man can theoretically be supported by a transparent cable with cross-section of 1 cm2 and feasibly, with spider material gloves and boots, could remain attached even to a ceiling: a preliminary step towards a Spiderman suit.

  6. Towards a Spiderman suit: large invisible cables and self-cleaning releasable superadhesive materials

    Energy Technology Data Exchange (ETDEWEB)

    Pugno, Nicola M [Department of Structural Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy)

    2007-10-03

    Spiders can produce cobwebs with high strength to density ratio and surprisingly display self-cleaning, strong and releasable adhesion (like geckos). Nanointerlocking, capillary and van der Waals forces, all potential adhesive mechanisms, are thus discussed, demonstrating the key role played by hierarchy in the design of superhydrophobic, i.e. self-cleaning (dry or wet and enhanced by activating Fakir drops as in lotus leaves) and superadhesive materials. The reversibility of the strong attachment is quantified thanks to an improved nonlinear peeling model including friction, for which the solution in closed form is provided. Thus, mimicking nature, thanks to carbon-nanotube-based technology, we suggest the feasibility of large invisible cables, as well as of self-cleaning, superadhesive and releasable hierarchical smart materials. We found that a man can theoretically be supported by a transparent cable with cross-section of 1 cm{sup 2} and feasibly, with spider material gloves and boots, could remain attached even to a ceiling: a preliminary step towards a Spiderman suit.

  7. The Application Law of Large Numbers That Predicts The Amount of Actual Loss in Insurance of Life

    Science.gov (United States)

    Tinungki, Georgina Maria

    2018-03-01

    The law of large numbers is a statistical concept that calculates the average number of events or risks in a sample or population to predict something. The larger the population is calculated, the more accurate predictions. In the field of insurance, the Law of Large Numbers is used to predict the risk of loss or claims of some participants so that the premium can be calculated appropriately. For example there is an average that of every 100 insurance participants, there is one participant who filed an accident claim, then the premium of 100 participants should be able to provide Sum Assured to at least 1 accident claim. The larger the insurance participant is calculated, the more precise the prediction of the calendar and the calculation of the premium. Life insurance, as a tool for risk spread, can only work if a life insurance company is able to bear the same risk in large numbers. Here apply what is called the law of large number. The law of large numbers states that if the amount of exposure to losses increases, then the predicted loss will be closer to the actual loss. The use of the law of large numbers allows the number of losses to be predicted better.

  8. Metal release from simulated fixed orthodontic appliances.

    Science.gov (United States)

    Hwang, C J; Shin, J S; Cha, J Y

    2001-10-01

    Most orthodontic appliances and archwires are stainless steel or nickel-titanium (NiTi) alloys that can release metal ions, with saliva as the medium. To measure metal released from the fixed orthodontic appliances currently in use, we fabricated simulated fixed orthodontic appliances that corresponded to half of the maxillary arch and soaked them in 50 mL of artificial saliva (pH 6.75 +/- 0.15, 37 degrees C) for 3 months. We used brackets, tubes, and bands made by Tomy (Tokyo, Japan). Four groups were established according to the appliance manufacturer and the type of metal in the .016 x .022-in archwires. Groups A and B were stainless steel archwires from Ormco (Glendora, Calif) and Dentaurum (Ispringen, Germany), respectively, and groups C and D were both NiTi archwires with Ormco's copper NiTi and Tomy's Bioforce sentalloy, respectively. Stainless steel archwires were heat treated in an electric furnace at 500 degrees C for 1 minute and quenched in water. We measured the amount of metal released from each group by immersion time. Our conclusions were as follows: (1) there was no increase in the amount of chromium released after 4 weeks in group A, 2 weeks in group B, 3 weeks in group C, and 8 weeks in group D; (2) there was no increase in the amount of nickel released after 2 weeks in group A, 3 days in group B, 7 days in group C, and 3 weeks in group D; and (3) there was no increase in the amount of iron released after 2 weeks in group A, 3 days in group B, and 1 day in groups C and D. In our 3-month-long investigation, we saw a decrease in metal released as immersion time increased.

  9. Cetirizine release from cyclodextrin formulated compressed chewing gum

    DEFF Research Database (Denmark)

    Stojanov, Mladen; Larsen, Kim Lambertsen

    2012-01-01

    release patterns, but with variations in the total amount released. Chewing gum formulated with cetirizine alone, demonstrated a release of 75% after 8 min of chewing. The presence of CDs resulted in increased cetirizine release. The analysis of variance (ANOVA) demonstrated that parameters with the most...... the statistical analysis (ANOVA) demonstrated significance in the release (P

  10. Preliminary analysis of public dose from CFETR gaseous tritium release

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Baojie [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei, Anhui 230027 (China); Ni, Muyi, E-mail: muyi.ni@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Lian, Chao; Jiang, Jieqiong [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2015-02-15

    Highlights: • Present the amounts and limit dose of tritium release to the environment for CFETR. • Perform a preliminary simulation of radiation dose for gaseous tritium release. • Key parameters about soil types, wind speed, stability class, effective release height and age were sensitivity analyzed. • Tritium release amount is recalculated consistently with dose limit in Chinese regulation for CFETR. - Abstract: To demonstrate tritium self-sufficiency and other engineering issues, the scientific conception of Chinese Fusion Engineering Test Reactor (CFETR) has been proposed in China parallel with ITER and before DEMO reactor. Tritium environmental safety for CFETR is an important issue and must be evaluated because of the huge amounts of tritium cycling in reactor. In this work, different tritium release scenarios of CFETR and dose limit regulations in China are introduced. And the public dose is preliminarily analyzed under normal and accidental events. Furthermore, after finishing the sensitivity analysis of key input parameters, the public dose is reevaluated based on extreme parameters. Finally, tritium release amount is recalculated consistently with the dose limit in Chinese regulation for CFETR, which would provide a reference for tritium system design of CFETR.

  11. Evaluating Potential for Large Releases from CO2 Storage Reservoirs: Analogs, Scenarios, and Modeling Needs

    International Nuclear Information System (INIS)

    Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Tsang, Chin-Fu; Karimjee, Anhar

    2005-01-01

    While the purpose of geologic storage of CO 2 in deep saline formations is to trap greenhouse gases underground, the potential exists for CO 2 to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. Such discharge is not necessarily a serious concern, as CO 2 is a naturally abundant and relatively benign gas in low concentrations. However, there is a potential risk to health, safety and environment (HSE) in the event that large localized fluxes of CO 2 were to occur at the land surface, especially where CO 2 could accumulate. In this paper, we develop possible scenarios for large CO 2 fluxes based on the analysis of natural analogues, where large releases of gas have been observed. We are particularly interested in scenarios which could generate sudden, possibly self-enhancing, or even eruptive release events. The probability for such events may be low, but the circumstances under which they might occur and potential consequences need to be evaluated in order to design appropriate site selection and risk management strategies. Numerical modeling of hypothetical test cases is needed to determine critical conditions for such events, to evaluate whether such conditions may be possible at designated storage sites, and, if applicable, to evaluate the potential HSE impacts of such events and design appropriate mitigation strategies

  12. Modeling of methane bubbles released from large sea-floor area: Condition required for methane emission to the atmosphere

    OpenAIRE

    Yamamoto, A.; Yamanaka, Y.; Tajika, E.

    2009-01-01

    Massive methane release from sea-floor sediments due to decomposition of methane hydrate, and thermal decomposition of organic matter by volcanic outgassing, is a potential contributor to global warming. However, the degree of global warming has not been estimated due to uncertainty over the proportion of methane flux from the sea-floor to reach the atmosphere. Massive methane release from a large sea-floor area would result in methane-saturated seawater, thus some methane would reach the atm...

  13. Atmospheric releases from severe nuclear accidents: Environmental transport and pathways to man: Modelling of radiation doses to man from Chernobyl releases

    International Nuclear Information System (INIS)

    Anspaugh, L.R.; Goldman, M.; Catlin, R.J.

    1987-01-01

    The Chernobyl accident released a large amount of highly fractionated radioactive debris, including approximately 89 PBq of 137 Cs. We calculated the resulting collective dose commitment to the Northern Hemisphere via the pathways of external exposure and ingestion of radionuclides withd food. We developed a rural/urban model of external dose and we used the PATHWAY model for ingestion. The results are a collective dose commitment of 630,000 person-Gy over the first year and 1,200,000 person-Gy over 50 years. 13 refs., 1 tab

  14. Fluoride and sodium trimetaphosphate (TMP release from fluoride varnishes supplemented with TMP

    Directory of Open Access Journals (Sweden)

    Michele Mauricio MANARELLI

    2016-01-01

    Full Text Available Abstract This study assessed fluoride (F and sodium trimetaphosphate (TMP release into artificial saliva from varnishes containing 0%, 2.5%, and 5% NaF, supplemented or not with 5% TMP. The varnishes were applied on polyester sheets (n = 8/group, and F and TMP released into artificial saliva were measured for up to 24 hours. The amount of F and TMP released were directly related to NaF and TMP concentrations in the varnishes. The highest F release was seen for 5% NaF and 5% NaF + 5% TMP, whereas 5% TMP released the highest amount of TMP. However, the simultaneous addition of NaF and TMP to varnishes significantly reduced the amount of F and TMP released from the products.

  15. Equilibrium and kinetic models for colloid release under transient solution chemistry conditions.

    Science.gov (United States)

    Bradford, Scott A; Torkzaban, Saeed; Leij, Feike; Simunek, Jiri

    2015-10-01

    We present continuum models to describe colloid release in the subsurface during transient physicochemical conditions. Our modeling approach relates the amount of colloid release to changes in the fraction of the solid surface area that contributes to retention. Equilibrium, kinetic, equilibrium and kinetic, and two-site kinetic models were developed to describe various rates of colloid release. These models were subsequently applied to experimental colloid release datasets to investigate the influence of variations in ionic strength (IS), pH, cation exchange, colloid size, and water velocity on release. Various combinations of equilibrium and/or kinetic release models were needed to describe the experimental data depending on the transient conditions and colloid type. Release of Escherichia coli D21g was promoted by a decrease in solution IS and an increase in pH, similar to expected trends for a reduction in the secondary minimum and nanoscale chemical heterogeneity. The retention and release of 20nm carboxyl modified latex nanoparticles (NPs) were demonstrated to be more sensitive to the presence of Ca(2+) than D21g. Specifically, retention of NPs was greater than D21g in the presence of 2mM CaCl2 solution, and release of NPs only occurred after exchange of Ca(2+) by Na(+) and then a reduction in the solution IS. These findings highlight the limitations of conventional interaction energy calculations to describe colloid retention and release, and point to the need to consider other interactions (e.g., Born, steric, and/or hydration forces) and/or nanoscale heterogeneity. Temporal changes in the water velocity did not have a large influence on the release of D21g for the examined conditions. This insensitivity was likely due to factors that reduce the applied hydrodynamic torque and/or increase the resisting adhesive torque; e.g., macroscopic roughness and grain-grain contacts. Our analysis and models improve our understanding and ability to describe the amounts

  16. Influence of environmental factors on mercury release in hydroelectric reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, K.; Therien, N.

    1991-04-01

    Due to increased mercury concentrations in fish in hydro-electric reservoirs after flooding, a study was carried out to evaluate the release and transformation of mercury due to vegetation and soil flooded as a result of reservoir creation. Samples of vegetation and soils were immersed in water and concentrations of total mercury, methylmercury and nutrients were followed. The effects of anoxia, pH and temperature on release and transformation were examined. An existing dynamic model of decomposition of flooded materials in reservoirs was modified to include mercury release and transformation, and was calibrated to the experimental data. Amounts of mercury released by the different substrates was of the same order of magnitude. Tree species contributed to the greatest amounts of methylmercury per unit biomass, but the biomass used for these was twigs and foliage. Soil released significant amounts of mercury, but methylation was very low. The model was able to fit well for all substrates except lichen. The model can be adapted to proposed reservoirs to predict nutrient and mecury release and transformation. 175 refs., 38 figs., 38 tabs.

  17. Analysis of drug effects on neurotransmitter release

    International Nuclear Information System (INIS)

    Rowell, P.; Garner, A.

    1986-01-01

    The release of neurotransmitter is routinely studied in a superfusion system in which serial samples are collected and the effects of drugs or other treatments on the amount of material in the superfusate is determined. With frequent sampling interval, this procedure provides a mechanism for dynamically characterizing the release process itself. Using automated data collection in conjunction with polyexponential computer analysis, the equation which describes the release process in each experiment is determined. Analysis of the data during the nontreated phase of the experiment allows an internal control to be used for accurately assessing any changes in neurotransmitter release which may occur during a subsequent treatment phase. The use of internal controls greatly improves the signal to noise ratio and allows determinations of very low concentrations of drugs on small amounts of tissue to be made. In this presentation, the effects of 10 μM nicotine on 3 H-dopamine release in rat nucleus accumbens is described. The time course, potency and efficacy of the drug treatment is characterized using this system. Determinations of the exponential order of the release as well as the rate constants allow one to study the mechanism of the release process. A description of 3 H-dopamine release in normal as well as Ca ++ -free medium is presented

  18. Profile of Fluoride Release from a Nanohybrid Composite Resin

    Directory of Open Access Journals (Sweden)

    Raquel Assed Bezerra Silva

    2015-02-01

    Full Text Available The aim of this study was to evaluate in vitro the amount and profile of fluoride release from a fluoride-containing nanohybrid composite resin (Tetric® N-Ceram by direct potentiometry. Thirty specimens (5 mm diameter x 3 mm high; n=10/material were made of Tetric® N-Ceram, Vitremer® resin-modified glass ionomer cement (RMGIC (positive control or Filtek® Z350 nanofill composite resin (negative control. The specimens were stored individually in plastic tubes containing 1 mL of artificial saliva at 37°C, which was daily renewed during 15 days. At each renewal of saliva, the amount of fluoride ions released in the solution was measured using a fluoride ion-selective electrode with ion analyzer, and the values obtained in mV were converted to ppm (µg/mL. Data were analyzed statistically by ANOVA and Tukey’s post-hoc test at a significance level of 5%. The results showed that the resins Tetric® N-Ceram and Filtek® Z350 did not release significant amounts of fluoride during the whole period of evaluation (p>0.05. Only Vitremer® released significant amounts of fluoride ions during the 15 days of the experiment, with greater release in first 2 days (p0.05. In conclusion, the nanohybrid composite resin Tetric® N-Ceram did not present in vitro fluoride-releasing capacity throughout the 15 days of study.

  19. Consistency check of iron and sodium cross sections with integral benchmark experiments using a large amount of experimental information

    International Nuclear Information System (INIS)

    Baechle, R.-D.; Hehn, G.; Pfister, G.; Perlini, G.; Matthes, W.

    1984-01-01

    Single material benchmark experiments are designed to check neutron and gamma cross-sections of importance for deep penetration problems. At various penetration depths a large number of activation detectors and spectrometers are placed to measure the radiation field as completely as possible. The large amount of measured data in benchmark experiments can be evaluated best by the global detector concept applied to nuclear data adjustment. A new iteration procedure is presented for adjustment of a large number of multigroup cross sections, which has been implemented now in the modular adjustment code ADJUST-EUR. A theoretical test problem has been deviced to check the total program system with high precision. The method and code are going to be applied for validating the new European Data Files (JEF and EFF) in progress. (Auth.)

  20. Site Release Report for C-Well Pipeline, UE-25 Large Rocks Test Site, and 29 GSF Test Pits

    International Nuclear Information System (INIS)

    K.E. Rasmuson

    2002-01-01

    The U.S. Department of Energy has implemented a program to reclaim lands disturbed by site characterization at Yucca Mountain. Long term goals of the program are to re-establish processes on disturbed sites that will lead to self-sustaining plant communities. The Biological Opinion for Yucca Mountain Site Characterization Studies required that the U.S. Department of Energy develop a Reclamation Standards and Monitoring Plan to evaluate the success of reclamation efforts. According to the Reclamation Standards and Monitoring Plan, reclaimed sites will be monitored periodically, remediated if necessary, and eventually compared to an appropriate reference area to determine whether reclamation goals have been achieved and the site can be released from further monitoring. Plant cover, density, and species richness (success parameters) on reclaimed sites are compared to 60 percent of the values (success criteria) for the same parameters on the reference area. Small sites (less than 0.1 ha) are evaluated for release using qualitative methods while large sites (greater than 0.1 ha) are evaluated using quantitative methods. In the summer of 2000, 31 small sites reclaimed in 1993 and 1994 were evaluated for reclamation success and potential release from further monitoring. Plant density, cover, and species richness were estimated on the C-Well Pipeline, UE-25 Large Rocks test site, and 29 ground surface facility test pits. Evidence of erosion, reproduction and natural recruitment, exotic species abundance, and animal use (key attributes) also were recorded for each site and used in success evaluations. The C-Well Pipeline and ground surface facility test pits were located in a ''Larrea tridentata - Ephedra nevadensis'' vegetation association while the UE-25 Large Rocks test site was located in an area dominated by ''Coleogyne ramosissima and Ephedra nevadensis''. Reference areas in the same vegetation associations with similar slope and aspect were chosen for comparison to

  1. Site Release Reports for C-Well Pipeline, UE-25 Large Rocks Test Site, and 29 GSF Test Pits

    Energy Technology Data Exchange (ETDEWEB)

    K.E. Rasmuson

    2002-04-02

    The U.S. Department of Energy has implemented a program to reclaim lands disturbed by site characterization at Yucca Mountain. Long term goals of the program are to re-establish processes on disturbed sites that will lead to self-sustaining plant communities. The Biological Opinion for Yucca Mountain Site Characterization Studies required that the U.S. Department of Energy develop a Reclamation Standards and Monitoring Plan to evaluate the success of reclamation efforts. According to the Reclamation Standards and Monitoring Plan, reclaimed sites will be monitored periodically, remediated if necessary, and eventually compared to an appropriate reference area to determine whether reclamation goals have been achieved and the site can be released from further monitoring. Plant cover, density, and species richness (success parameters) on reclaimed sites are compared to 60 percent of the values (success criteria) for the same parameters on the reference area. Small sites (less than 0.1 ha) are evaluated for release using qualitative methods while large sites (greater than 0.1 ha) are evaluated using quantitative methods. In the summer of 2000, 31 small sites reclaimed in 1993 and 1994 were evaluated for reclamation success and potential release from further monitoring. Plant density, cover, and species richness were estimated on the C-Well Pipeline, UE-25 Large Rocks test site, and 29 ground surface facility test pits. Evidence of erosion, reproduction and natural recruitment, exotic species abundance, and animal use (key attributes) also were recorded for each site and used in success evaluations. The C-Well Pipeline and ground surface facility test pits were located in a ''Larrea tridentata - Ephedra nevadensis'' vegetation association while the UE-25 Large Rocks test site was located in an area dominated by ''Coleogyne ramosissima and Ephedra nevadensis''. Reference areas in the same vegetation associations with similar slope

  2. Effects of Large-Scale Releases on the Genetic Structure of Red Sea Bream (Pagrus major, Temminck et Schlegel) Populations in Japan.

    Science.gov (United States)

    Blanco Gonzalez, Enrique; Aritaki, Masato; Knutsen, Halvor; Taniguchi, Nobuhiko

    2015-01-01

    Large-scale hatchery releases are carried out for many marine fish species worldwide; nevertheless, the long-term effects of this practice on the genetic structure of natural populations remains unclear. The lack of knowledge is especially evident when independent stock enhancement programs are conducted simultaneously on the same species at different geographical locations, as occurs with red sea bream (Pagrus major, Temminck et Schlegel) in Japan. In this study, we examined the putative effects of intensive offspring releases on the genetic structure of red sea bream populations along the Japanese archipelago by genotyping 848 fish at fifteen microsatellite loci. Our results suggests weak but consistent patterns of genetic divergence (F(ST) = 0.002, p Red sea bream in Japan appeared spatially structured with several patches of distinct allelic composition, which corresponded to areas receiving an important influx of fish of hatchery origin, either released intentionally or from unintentional escapees from aquaculture operations. In addition to impacts upon local populations inhabiting semi-enclosed embayments, large-scale releases (either intentionally or from unintentional escapes) appeared also to have perturbed genetic structure in open areas. Hence, results of the present study suggest that independent large-scale marine stock enhancement programs conducted simultaneously on one species at different geographical locations may compromise native genetic structure and lead to patchy patterns in population genetic structure.

  3. Drug release kinetic analysis and prediction of release data via polymer molecular weight in sustained release diltiazem matrices.

    Science.gov (United States)

    Adibkia, K; Ghanbarzadeh, S; Mohammadi, G; Khiavi, H Z; Sabzevari, A; Barzegar-Jalali, M

    2014-03-01

    This study was conducted to investigate the effects of HPMC (K4M and K100M) as well as tragacanth on the drug release rate of diltiazem (DLTZ) from matrix tablets prepared by direct compression method.Mechanism of drug transport through the matrices was studied by fitting the release data to the 10 kinetic models. 3 model independent parameters; i. e., mean dissolution time (MDT), mean release rate (MRR) and release rate efficacy (RE) as well as 5 time point approaches were established to compare the dissolution profiles. To find correlation between fraction of drug released and polymer's molecular weight, dissolution data were fitted into two proposed equations.All polymers could sustain drug release up to 10 h. The release data were fitted best to Peppas and Higuchi square root kinetic models considering squared correlation coefficient and mean percent error (MPE). RE and MRR were decreased when polymer to drug ratio was increased. Conversely, t60% was increased with raising polymer /drug ratio. The fractions of drug released from the formulations prepared with tragacanth were more than those formulated using the same amount of HPMC K4M and HPMC K100M.Preparation of DLTZ matrices applying HPMCK4M, HPMC K100M and tragacanth could effectively extend the drug release. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Atmospheric effects of heat release at large power plants

    International Nuclear Information System (INIS)

    Kikuchi, Yukio

    1979-01-01

    In power plants, the thermal efficiency of generating electricity is generally 1/3, the rest 2/3 being carried away by cooling water. To release the heat, there are three alternative methods; i.e. cooling water released into sea, cooling water released into a cooling pond, and cooling of such water with a cooling tower. In the third method, cooling towers are stacks of 10m -- 80m bore, and warm cooling water flowing on the side wall is cooled with atmospheric air. The resultant heated air is discharged as plume from their top. Upon condensation, it becomes visible and then leads to the formation of clouds. In this manner, the weather around the sites of power plants is affected, such as reduction of insolation reaching ground and increase in precipitation. The following matters are described: cooling towers; phenomena and prediction methods of visible plume, cloud formation, increase of precipitation and deposition of drifting waterdrops; and effects of the group of power plants. (J.P.N.)

  5. Generation Expansion Planning With Large Amounts of Wind Power via Decision-Dependent Stochastic Programming

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Yiduo; Zheng, Qipeng P.; Wang, Jianhui; Pinson, Pierre

    2017-07-01

    Power generation expansion planning needs to deal with future uncertainties carefully, given that the invested generation assets will be in operation for a long time. Many stochastic programming models have been proposed to tackle this challenge. However, most previous works assume predetermined future uncertainties (i.e., fixed random outcomes with given probabilities). In several recent studies of generation assets' planning (e.g., thermal versus renewable), new findings show that the investment decisions could affect the future uncertainties as well. To this end, this paper proposes a multistage decision-dependent stochastic optimization model for long-term large-scale generation expansion planning, where large amounts of wind power are involved. In the decision-dependent model, the future uncertainties are not only affecting but also affected by the current decisions. In particular, the probability distribution function is determined by not only input parameters but also decision variables. To deal with the nonlinear constraints in our model, a quasi-exact solution approach is then introduced to reformulate the multistage stochastic investment model to a mixed-integer linear programming model. The wind penetration, investment decisions, and the optimality of the decision-dependent model are evaluated in a series of multistage case studies. The results show that the proposed decision-dependent model provides effective optimization solutions for long-term generation expansion planning.

  6. Large methane releases lead to strong aerosol forcing and reduced cloudiness

    DEFF Research Database (Denmark)

    Kurten, T.; Zhou, L.; Makkonen, R.

    2011-01-01

    forcing that is comparable in magnitude to the long-wave radiative forcing ("enhanced greenhouse effect") of the added methane. Together, the indirect CH4-O-3 and CH4-OHaerosol forcings could more than double the warming effect of large methane increases. Our findings may help explain the anomalously......The release of vast quantities of methane into the atmosphere as a result of clathrate destabilization is a potential mechanism for rapid amplification of global warming. Previous studies have calculated the enhanced warming based mainly on the radiative effect of the methane itself, with smaller...... contributions from the associated carbon dioxide or ozone increases. Here, we study the effect of strongly elevated methane (CH4) levels on oxidant and aerosol particle concentrations using a combination of chemistry-transport and general circulation models. A 10-fold increase in methane concentrations...

  7. Large methane releases lead to strong aerosol forcing and reduced cloudiness

    DEFF Research Database (Denmark)

    Kurten, T.; Zhou, L.; Makkonen, R.

    2011-01-01

    The release of vast quantities of methane into the atmosphere as a result of clathrate destabilization is a potential mechanism for rapid amplification of global warming. Previous studies have calculated the enhanced warming based mainly on the radiative effect of the methane itself, with smaller...... is predicted to significantly decrease hydroxyl radical (OH) concentrations, while moderately increasing ozone (O-3). These changes lead to a 70% increase in the atmospheric lifetime of methane, and an 18% decrease in global mean cloud droplet number concentrations (CDNC). The CDNC change causes a radiative...... forcing that is comparable in magnitude to the long-wave radiative forcing ("enhanced greenhouse effect") of the added methane. Together, the indirect CH4-O-3 and CH4-OHaerosol forcings could more than double the warming effect of large methane increases. Our findings may help explain the anomalously...

  8. Two Mechanisms for Methane Release at the Paleocene/Eocene Boundary

    Science.gov (United States)

    Katz, M. E.; Cramer, B. S.; Mountain, G. S.; Mountain, G. S.; Katz, S.; Miller, K. G.; Miller, K. G.

    2001-12-01

    The rapid global warming of the Paleocene/Eocene thermal maximum (PETM) has been attributed to a massive methane release from marine gas hydrate reservoirs. Two mechanisms have been proposed for this methane release. The first relies on a deepwater circulation change and water temperature increase that was sufficiently large and rapid to trigger massive thermal dissociation of gas hydrate frozen beneath the seafloor (Dickens et al., 1995). The second relies on slope failure (via erosion or seismic activity) of the oversteepened continental margins of the western North Atlantic to allow methane to escape from gas reservoirs trapped between the hydrate-bearing sediments and the underlying reef front (Katz et al., in press). We evaluate thermal dissociation by modeling heat flow through the sediments to show the effect of the temperature change on the gas hydrate stability zone through time. We use Paleocene bottom water temperatures (constrained by isotope records) and assume an instantaneous water temperature increase (i.e., no time allotted for ocean circulation change and water mass mixing). This yields an end-member minimum estimate of >2350 years necessary to melt all gas hydrate at locations shallower than 1570m; gas hydrates at greater depths remain frozen. We also use this model to predict the amount of C12-enriched methane that could have contributed to the carbon isotope excursion (CIE). Using reasonable methane distributions within sediments, we conclude that thermal dissociation alone cannot account for the full magnitude of the CIE. We propose that thermal dissociation did not initiate the CIE; rather, a different mechanism injected a large amount of carbon into the atmosphere, causing global greenhouse warming that could have led to subsequent thermal dissociation. Methane remains a plausible source for this initial carbon injection; however, initial release would have resulted from mechanical disruption of sediments rather than thermal dissociation

  9. Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.

    Science.gov (United States)

    Barclay, C J

    2012-12-01

    The aims of this study were to quantify the Ca(2+) release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca(2+) release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca(2+) release was quantified from the amount of ATP used to remove Ca(2+) from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca(2+) pump ATP turnover. At 20°C, Ca(2+) release in response to a single stimulus was 34 and 84 μmol (kg muscle)(-1) for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg(-1); EDL, 168 μmol kg(-1)). Delivery of another stimulus within 100 ms of the first produced a smaller Ca(2+) release. The maximum magnitude of the decrease in Ca(2+) release was greater in EDL than soleus. Ca(2+) release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca(2+) released and crossbridge cycles performed are consistent with a scheme in which Ca(2+) binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles.

  10. Bioactive Glass Nanoparticles as a New Delivery System for Sustained 5-Fluorouracil Release: Characterization and Evaluation of Drug Release Mechanism

    Directory of Open Access Journals (Sweden)

    Abeer M. El-Kady

    2015-01-01

    Full Text Available Bioactive glass nanoparticles were synthesized and tested for the first time as a new delivery system for sustained 5-fluorouracil (5-FU release. They were characterized by TEM, DTA, TGA, and FT-IR. The porosity % and specific surface area of glass nanoparticles were 85.59% and 378.36 m2/g, respectively. The in vitro bioactivity evaluation confirmed that bioactive glass disks prepared from these nanoparticles could induce hydroxyapatite layer over their surfaces in simulated body fluid. The in vitro drug release experiment indicated that glass nanoparticles could serve as long-term local delivery vehicles for sustained 5-FU release. The release profile of 5-FU showed an initial fast release stage followed by a second stage of slower release. The initial burst release of 5-FU in the first day was about 23% (28.92 mg·L−1 of the total amount of loaded 5-FU, while the final cumulative percentage of the 5-FU released after 32 days was about 45.6% (57.31 mg·L−1 of the total amount of loaded 5-FU. The application of different mathematical models indicated that 5-FU was released by diffusion controlled mechanism and suggested that its release rate was dependent on glass particles dissolution, changes of surface area as well as diameter of glass particles, and concentration of loaded drug.

  11. The synthesis and application involving regulation of the insoluble drug release from mesoporous silica nanotubes

    International Nuclear Information System (INIS)

    Li, Jia; Wang, Yan; Zheng, Xin; Zhang, Ying; Sun, Changshan; Gao, Yikun; Jiang, Tongying; Wang, Siling

    2015-01-01

    Highlights: • Mesoporous silica nanotubes (SNT) were synthesized by using CNT as hard template, and the formation of the SNT shows that CTAB played a significant effect on the coating process. • The tube mesoporous silica materials which were seldom reported were applied in the drug delivery system to improve the loading amount and the drug dissolution. • The release rate could be controlled by the gelatin layer on the silica surface and the mechanism was illustrated. - Abstract: Mesoporous silica nanotubes (SNT) were synthesized using hard template carbon nanotubes (CNT) with the aid of cetyltrimethyl ammonium bromide (CTAB) in a method, which was simple and inexpensive. Scanning electron microscopy, transmission electron microscopy and specific surface area analysis were employed to characterize the morphology and structure of SNT, and the formation mechanism of SNT was also examined by Fourier transform infrared spectroscopy. There are few published reports of the mesoporous SNT with large specific surface area applied in the drug delivery systems to improve the amount of drug loading. In addition, the structure of SNT allows investigators to control the drug particle size in the pore channels and significantly increase the drug dissolution rate. The insoluble drug, cilostazol, was chosen as a model drug to be loaded into SNT and we developed a simple and efficient method for regulating the drug release by using a gelatin coating with different thicknesses around the SNT. The release rate was adjusted by the amount of gelatin surrounding the SNT, with an increased barrier leading to a reduction in the release rate. A model developed on the basis of the Weibull modulus was established to fit the release results

  12. Mercury release from fly ashes and hydrated fly ash cement pastes

    Science.gov (United States)

    Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

    2018-04-01

    The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

  13. Carbon nanotube release from polymers into a food simulant

    International Nuclear Information System (INIS)

    Xia, Yining; Uysal Unalan, Ilke; Rubino, Maria; Auras, Rafael

    2017-01-01

    The release assessment of multi-walled carbon nanotubes (CNTs) was performed on two types of polymer-CNT nanocomposites: polypropylene (PP) and polyamide 6 (PA6) containing 3 wt% CNT. Nanocomposite films were prepared and then exposed to ethanol as a fatty-food simulant at 40 °C, and the amount of CNT release into ethanol was determined by ultraviolet-visible spectroscopy (UV-Vis) and graphite furnace atomic absorption spectrometry (GFAAS). The CNTs released into ethanol were visualized by transmission electron microscopy (TEM) and verified by Raman spectroscopy. UV-Vis analysis showed a very small amount of CNT release from the nanocomposite films into ethanol over 60 d: maximum CNT concentrations in ethanol were 1.3 mg/L for the PP-CNT film and 1.2 mg/L for the PA6-CNT film. GFAAS results indicated that the amount of CNTs released into ethanol after 12 d was over 20-fold higher than the results obtained by UV-Vis. Overestimation of CNT release by GFAAS suggested aggregation and poor dispersion of CNTs in the solvent. This assumption was verified by TEM images exhibiting the embedded CNTs in the polymer flakes, which could be poorly dispersed in the solvent. In general, CNT release from the nanocomposite films was considered a surface phenomenon, as indicated by detachment of CNT-containing polymer flakes from the film surface. - Highlights: • Release of CNT from polypropylene and polyamide nanocomposites were quantified and validated with TEM and Raman. • Spectroscopy and silane-labeled CNT were used for tracking the release of CNT. • The release behavior of CNT from nanocomposites was mostly generated from the polymer surfaces.

  14. Hindered disulfide bonds to regulate release rate of model drug from mesoporous silica.

    Science.gov (United States)

    Nadrah, Peter; Maver, Uroš; Jemec, Anita; Tišler, Tatjana; Bele, Marjan; Dražić, Goran; Benčina, Mojca; Pintar, Albin; Planinšek, Odon; Gaberšček, Miran

    2013-05-01

    With the advancement of drug delivery systems based on mesoporous silica nanoparticles (MSNs), a simple and efficient method regulating the drug release kinetics is needed. We developed redox-responsive release systems with three levels of hindrance around the disulfide bond. A model drug (rhodamine B dye) was loaded into MSNs' mesoporous voids. The pore opening was capped with β-cyclodextrin in order to prevent leakage of drug. Indeed, in absence of a reducing agent the systems exhibited little leakage, while the addition of dithiothreitol cleaved the disulfide bonds and enabled the release of cargo. The release rate and the amount of released dye were tuned by the level of hindrance around disulfide bonds, with the increased hindrance causing a decrease in the release rate as well as in the amount of released drug. Thus, we demonstrated the ability of the present mesoporous systems to intrinsically control the release rate and the amount of the released cargo by only minor structural variations. Furthermore, an in vivo experiment on zebrafish confirmed that the present model delivery system is nonteratogenic.

  15. Under-expanded jets and dispersion in supercritical CO_2 releases from a large-scale pipeline

    International Nuclear Information System (INIS)

    Guo, Xiaolu; Yan, Xingqing; Yu, Jianliang; Zhang, Yongchun; Chen, Shaoyun; Mahgerefteh, Haroun; Martynov, Sergey; Collard, Alexander; Proust, Christophe

    2016-01-01

    Highlights: • A large-scale full instrumented CO_2 test pipeline (258 m long, 233 mm id) has been developed. • The dynamic pressure evolutions near the orifice were recorded with differential pressure transducers. • The highly under-expanded jet flow structure in the near-field was studied in supercritical leakage. • The formation of the visible cloud, the distributions of temperature and concentration in the far-field were analysed. - Abstract: Long-distance CO_2 pipelines will be widely applied to transport captured CO_2 from fossil fuel fired power plants for subsequent sequestration. In the event of pipeline failure a large mass of the inventory may be discharged within a short time, this represents a significant hazard if leaks continue undetected. An important result of the risk assessment for a CO_2 pipeline is the safety distance. At present the lack of knowledge concerning near-field source terms and the far-field dispersion behavior of CO_2 leaking from pipelines can make the calculation of safety distances imprecise. Study of near-field source terms and dispersion behavior is therefore necessary and of paramount importance for assessing safety distances and the impact of CO_2 pipeline releases on the surrounding environment. In order to study CO_2 pipeline leakage, a large-scale pipeline set-up with a total length of 258 m and an internal diameter of 233 mm was constructed to study the near-field characteristics and dispersion behavior of supercritical CO_2 during sudden releases. The dynamic pressure near the orifice and CO_2 concentrations and temperatures within the downstream dispersion region were measured together with the pressures inside the pipeline. The under-expanded jet flow structure and phase transitions in the near-field were studied for supercritical CO_2 released though different orifice diameters (15 mm, 50 mm and Full Bore Rupture). The formation of the visible cloud, the distribution of cloud temperatures and CO_2

  16. Quantitative analysis of large amounts of journalistic texts using topic modelling

    NARCIS (Netherlands)

    Jacobi, C.; van Atteveldt, W.H.; Welbers, K.

    2016-01-01

    The huge collections of news content which have become available through digital technologies both enable and warrant scientific inquiry, challenging journalism scholars to analyse unprecedented amounts of texts. We propose Latent Dirichlet Allocation (LDA) topic modelling as a tool to face this

  17. Consequences of severe radioactive releases to Nordic Marine environment

    DEFF Research Database (Denmark)

    Iosjpe, M.; Isaksson, M.; Joensen, H.P.

    - or minor – radioactive releases to Nordic marine environment. As a reference, the release amounts from a 3000 MWth reactor size were used. Based on source term analyses, the chosen release fractions in the study were: iodine 20% (of the total core inventory), caesium 10%, tellurium 10%, strontium 0...

  18. Carbon nanotube release from polymers into a food simulant.

    Science.gov (United States)

    Xia, Yining; Uysal Unalan, Ilke; Rubino, Maria; Auras, Rafael

    2017-10-01

    The release assessment of multi-walled carbon nanotubes (CNTs) was performed on two types of polymer-CNT nanocomposites: polypropylene (PP) and polyamide 6 (PA6) containing 3 wt% CNT. Nanocomposite films were prepared and then exposed to ethanol as a fatty-food simulant at 40 °C, and the amount of CNT release into ethanol was determined by ultraviolet-visible spectroscopy (UV-Vis) and graphite furnace atomic absorption spectrometry (GFAAS). The CNTs released into ethanol were visualized by transmission electron microscopy (TEM) and verified by Raman spectroscopy. UV-Vis analysis showed a very small amount of CNT release from the nanocomposite films into ethanol over 60 d: maximum CNT concentrations in ethanol were 1.3 mg/L for the PP-CNT film and 1.2 mg/L for the PA6-CNT film. GFAAS results indicated that the amount of CNTs released into ethanol after 12 d was over 20-fold higher than the results obtained by UV-Vis. Overestimation of CNT release by GFAAS suggested aggregation and poor dispersion of CNTs in the solvent. This assumption was verified by TEM images exhibiting the embedded CNTs in the polymer flakes, which could be poorly dispersed in the solvent. In general, CNT release from the nanocomposite films was considered a surface phenomenon, as indicated by detachment of CNT-containing polymer flakes from the film surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Expert system shell to reason on large amounts of data

    Science.gov (United States)

    Giuffrida, Gionanni

    1994-01-01

    The current data base management systems (DBMS's) do not provide a sophisticated environment to develop rule based expert systems applications. Some of the new DBMS's come with some sort of rule mechanism; these are active and deductive database systems. However, both of these are not featured enough to support full implementation based on rules. On the other hand, current expert system shells do not provide any link with external databases. That is, all the data are kept in the system working memory. Such working memory is maintained in main memory. For some applications the reduced size of the available working memory could represent a constraint for the development. Typically these are applications which require reasoning on huge amounts of data. All these data do not fit into the computer main memory. Moreover, in some cases these data can be already available in some database systems and continuously updated while the expert system is running. This paper proposes an architecture which employs knowledge discovering techniques to reduce the amount of data to be stored in the main memory; in this architecture a standard DBMS is coupled with a rule-based language. The data are stored into the DBMS. An interface between the two systems is responsible for inducing knowledge from the set of relations. Such induced knowledge is then transferred to the rule-based language working memory.

  20. Activated-Lignite-Based Super Large Granular Slow-Release Fertilizers Improve Apple Tree Growth: Synthesis, Characterizations, and Laboratory and Field Evaluations.

    Science.gov (United States)

    Tang, Yafu; Wang, Xinying; Yang, Yuechao; Gao, Bin; Wan, Yongshan; Li, Yuncong C; Cheng, Dongdong

    2017-07-26

    In this work, lignite, a low-grade coal, was modified using the solid-phase activation method with the aid of a Pd/CeO 2 nanoparticle catalyst to improve its pore structure and nutrient absorption. Results indicate that the adsorption ability of the activated lignite to NO 3 - , NH 4 + , H 2 PO 4 - , and K + was significantly higher than that of raw lignite. The activated lignite was successfully combined with the polymeric slow-release fertilizer, which exhibits typical slow-release behavior, to prepare the super large granular activated lignite slow-release fertilizer (SAF). In addition to the slow-release ability, the SAF showed excellent water-retention capabilities. Soil column leaching experiments further confirmed the slow-release characteristics of the SAF with fertilizer nutrient loss greatly reduced in comparison to traditional and slow-release fertilizers. Furthermore, field tests of the SAF in an orchard showed that the novel SAF was better than other tested fertilizers in improve the growth of young apple trees. Findings from this study suggest that the newly developed SAF has great potential to be used in apple cultivation and production systems in the future.

  1. Hydrophobic polymers modification of mesoporous silica with large pore size for drug release

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Shenmin, E-mail: smzhu@sjtu.edu.c [Shanghai Jiao Tong University, State Key Lab of Metal Matrix Composites (China); Zhang Di; Yang Na [Fudan University, Ministry of Education, Key Lab of Molecular Engineering of Polymers (China)

    2009-04-15

    Mesostructure cellular foam (MCF) materials were modified with hydrophobic polyisoprene (PI) through free radical polymerization in the pores network, and the resulting materials (MCF-PI) were investigated as matrices for drug storage. The successful synthesis of PI inside MCF was characterized by Fourier transform infrared (FT-IR), hydrogen nuclear magnetic resonance ({sup 1}H NMR), X-ray diffraction patterns (XRD) and nitrogen adsorption/desorption measurements. It was interesting to find the resultant system held a relatively large pore size (19.5 nm) and pore volume (1.02 cm{sup 3} g{sup -1}), which would benefit for drug storage. Ibuprofen (IBU) and vancomycin were selected as model drugs and loaded onto unmodified MCF and modified MCF (MCF-PI). The adsorption capacities of these model drugs on MCF-PI were observed increase as compared to that of on pure MCF, due to the trap effects induced by polyisoprene chains inside the pores. The delivery system of MCF-PI was found to be more favorable for the adsorption of IBU (31 wt%, IBU/silica), possibly attributing to the hydrophobic interaction between IBU and PI formed on the internal surface of MCF matrix. The release of drug through the porous network was investigated by measuring uptake and release of IBU.

  2. Effect of the foodchain in radioactivities released from thermal power plants

    International Nuclear Information System (INIS)

    Okamoto, K.

    1980-01-01

    Among many radionuclides released when burning fossil fuel 210 Pb and 210 Po are especially important, because they are very volatile, are released at higher rates than others, and are concentrated very strongly in marine organisms. This is particularly important in Japan, because most power plants in Japan are built near the seacoast and seawater contamination is likely. 210 Pb and 210 Po could also contaminate leafy vegetables by fallout. Since Japanese consume large amounts of seafoods and vegetables, this foodchain is important. The dose due to this foodchain is estimated. Although uncertainties are large and a definite conclusion cannot be drawn, the dose is one to three orders of magnitude higher when considering this foodchain than when not considering it. The average individual dose of Japanese due to this foodchain is of the order of several mrem/y. Although much smaller than the natural background, it is comparable to the dose of the total fuel cycle of full scale nuclear electricity generation, and so its social implication cannot be overlooked. (H.K.)

  3. Biodegradable Magnetic Silica@Iron Oxide Nanovectors with Ultra-Large Mesopores for High Protein Loading, Magnetothermal Release, and Delivery

    KAUST Repository

    Omar, Haneen

    2016-11-29

    The delivery of large cargos of diameter above 15 nm for biomedical applications has proved challenging since it requires biocompatible, stably-loaded, and biodegradable nanomaterials. In this study, we describe the design of biodegradable silica-iron oxide hybrid nanovectors with large mesopores for large protein delivery in cancer cells. The mesopores of the nanomaterials spanned from 20 to 60 nm in diameter and post-functionalization allowed the electrostatic immobilization of large proteins (e.g. mTFP-Ferritin, ~ 534 kDa). Half of the content of the nanovectors was based with iron oxide nanophases which allowed the rapid biodegradation of the carrier in fetal bovine serum and a magnetic responsiveness. The nanovectors released large protein cargos in aqueous solution under acidic pH or magnetic stimuli. The delivery of large proteins was then autonomously achieved in cancer cells via the silica-iron oxide nanovectors, which is thus a promising for biomedical applications.

  4. ABOVEGROUND BIOMASS DISTRIBUTION OF US EASTERN HARDWOOD FORESTS AND THE USE OF LARGE TREES AS AN INDICATOR OF FOREST DEVELOPMENT

    Science.gov (United States)

    Past clearing and harvesting of the deciduous hardwood forests of eastern USA released large amount of carbon dioxide into the atmosphere, but through recovery and regrowth these forests are now accumulating atmospheric carbon (C). This study examined quantities and distribution ...

  5. Phagocytosis-induced 51Cr release from activated macrophages and blood mononuclears. Effect of colchicine and antioxidants

    International Nuclear Information System (INIS)

    McGee, M.P.; Hale, A.H.

    1981-01-01

    The chromium-release test was adapted to the measurement of the cellular injury induced when activated macrophages phagocytose particulates. Macrophages obtained from rabbit lungs undergoing BCG-induced chronic inflammation released more chromium when incubated in the presence of phagocytosable particles than when incubated under resting conditions. Blood mononuclear cells, 40-60% monocytes, procured from the same BCG-injected animals, were less susceptible to phagocytosis-induced injury than the macrophages obtained from the lungs. The amount of chromium released by the activated macrophages was proportional to the number of particles present during incubation. In the presence of catalase, the amounts of chromium released by phagocytosing and resting macrophages were similar; in the presence of superoxide dismutase and cytochrome c, the amount of chromium released by phagocytosing macrophages was 13-35% less than the amount of chromium released by macrophages incubated without the antioxidants. In addition, colchicine, an inhibitor of degranulation also exerted partial inhibition of the chromium release. These results suggest that oxygen radicals and lysosomal contents contribute to the cellular injury that results from phagocytosis

  6. Chlorine release from biomass. Part 6; Kloravgaang fraan biobraenslen. Del 6

    Energy Technology Data Exchange (ETDEWEB)

    Zintl, Frank; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    Chlorine release from model compounds and different biomass fuels has been studied during thermal treatment in an electric oven in inert atmosphere (N{sub 2}) and with addition of 10% O{sub 2}. The amount of chlorine in all investigated materials has been kept to 2% with addition of KCl solution in methanol. The amount of chlorine was analysed before and after treatment in the decided atmosphere and to the temperature chosen. The influence from different functional groups on the chlorine release at low temperatures has been studied in pyrolysis experiments of simple model compounds with different structures. A good correlation between the chlorine release and the functional groups in the model substances was achieved. Results from the experiments shows that the early chlorine release, is most likely to occur in all biofuels, since all biomass fuels contains biological material with significant amounts of functional groups which can interact with fuel chlorine ( inorganic chlorine)

  7. Release of metal ions from round and rectangular NiTi wires

    Directory of Open Access Journals (Sweden)

    Arash Azizi

    2016-04-01

    Full Text Available Abstract Background The aim of this study was to evaluate the amount of nickel and titanium ions released from two wires with different shapes and a similar surface area. Methods Forty round nickel-titanium (NiTi arch wires with the diameter of 0.020 in. and 40 rectangular NiTi arch wires with the diameter of 0.016 × 0.016 in. were immersed in artificial saliva during a 21-day period. The surface area of both wires was 0.44 in.2. Wires were separately dipped into polypropylene tubes containing 50 ml of buffer solution and were incubated and maintained at 37 °C. Inductively coupled plasma atomic emission spectrometry (ICP-AES was used to measure the amount of ions released after exposure lengths of 1 h, 24 h, 1 week, and 3 weeks. Repeated measures ANOVA and Tukey tests were used to evaluate the data. Results The results indicated that the amount of nickel and titanium concentrations was significantly higher in the rectangular wire group. The most significant release of all metals was measured after the first hour of immersion. In the rectangular wire group, 243 ± 4.2 ng/ml of nickel was released after 1 h, while 221.4 ± 1.7 ng/ml of nickel was released in the round wire group. Similarly, 243.3 ± 2.8 ng/ml of titanium was released in the rectangular wire group and a significantly lower amount of 211.9 ± 2.3 ng/ml of titanium was released in the round wire group. Conclusions Release of metal ions was influenced by the shape of the wire and increase of time.

  8. Tritium behavior intentionally released in the room

    International Nuclear Information System (INIS)

    Kobayashi, K.; Hayashi, T.; Iwai, Y.; Yamanishi, T.; Willms, R. S.; Carlson, R. V.

    2008-01-01

    To construct a fusion reactor with high safety and acceptability, it is necessary to establish and to ensure tritium safe handling technology. Tritium should be well-controlled not to be released to the environment excessively and to prevent workers from excess exposure. It is especially important to grasp tritium behavior in the final confinement area, such as the room and/or building. In order to obtain data for actual tritium behavior in a room and/or building, a series of intentional Tritium Release Experiments (TREs) were planned and carried out within a radiologically controlled area (main cell) at Tritium System Test Assembly (TSTA) in Los Alamos National Laboratory (LANL) under US-JAPAN collaboration program. These experiments were carried out three times. In these experiments, influence of a difference in the tritium release point and the amount of hydrogen isotope for the initial tritium behavior in the room were suggested. Tritium was released into the main cell at TSTA/LANL. The released tritium reached a uniform concentration about 30 - 40 minutes in all the experiments. The influence of the release point and the amount of hydrogen isotope were not found to be important in these experiments. The experimental results for the initial tritium behavior in the room were also simulated well by the modified three-dimensional eddy flow analysis code FLOW-3D. (authors)

  9. Inhibition of insulin release by cyproheptadine: Effects on 3',5'-cyclic-AMP-content and /sup 45/Ca-accumulation of incubated mouse islets

    Energy Technology Data Exchange (ETDEWEB)

    Joost, H G; Beckmann, J; Lenzen, S; Hasselblatt, A [Goettingen Univ. (F.R. Germany)

    1976-01-01

    Cyproheptadine (1, 10 and 100 ..mu..m) significantly reduced insulin release from isolated mouse islets in response to glucose. In contrast, 1 mM cyproheptadine induced a large release of insulin into the incubation medium probably due to islet cell damage, since the islets had lost a considerable amount of their protein content. 3',5'-cyclic-AMP-levels of the islets were not significantly affected by 10 ..mu..M cyproheptadine in the presence as well as in the absence of theophylline (10 mM). As the inhibitory effect of cyproheptadine on insulin release was correlated with reduced accumulation of calcium-45, the agent may inhibit insulin release by interfering with the calcium handling of the ..beta..-cell.

  10. Stimuli responsive nanomaterials for controlled release applications

    KAUST Repository

    Li, Song

    2012-01-01

    The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. Coupled with excellent biocompatibility profiles, various nanomaterials have showed great promise for biomedical applications. Stimuli-responsive nanomaterials guarantee the controlled release of cargo to a given location, at a specific time, and with an accurate amount. In this review, we have combined the major stimuli that are currently used to achieve the ultimate goal of controlled and targeted release by "smart" nanomaterials. The most heavily explored strategies include (1) pH, (2) enzymes, (3) redox, (4) magnetic, and (5) light-triggered release.

  11. Dexamethasone-induced haptoglobin release by calf liver parenchymal cells.

    Science.gov (United States)

    Higuchi, H; Katoh, N; Miyamoto, T; Uchida, E; Yuasa, A; Takahashi, K

    1994-08-01

    Parenchymal cells were isolated from the liver of male calves, and monolayer cultures formed were treated with glucocorticoids to examine whether haptoglobin, appearance of which is associated with hepatic lipidosis (fatty liver) in cattle, is induced by steroid hormones. Without addition of dexamethasone, only trace amounts of haptoglobin were detected in culture medium. With addition of dexamethasone (10(-12) to 10(-4) M), considerable amounts of haptoglobin were released into the medium. Maximal release was observed at concentrations of 10(-8) to 10(-6) M dexamethasone. Haptoglobin release was similarly induced by cortisol, although the effect was less potent than that of dexamethasone. Actinomycin D (a known protein synthesis inhibitor) dose-dependently reduced amounts of haptoglobin released in response to 10(-8) M dexamethasone. Dexamethasone also induced annexin I, which is known to be synthesized in response to glucocorticoids. Dexamethasone treatment resulted in reduced protein kinase C activity in the cell cytosol, which has been shown to be an early event in dexamethasone-treated cells. Other than glucocorticoids, estradiol induced haptoglobin release, whereas progesterone was less effective. The association of haptoglobin with hepatic lipidosis can be reasonably explained by the fact that haptoglobin production by the liver is induced by glucocorticoids and estradiol, and these steroid hormones are triggers for development of hepatic lipidosis in cattle.

  12. Effectiveness of cleanup criteria relative to an accidental nuclear release

    International Nuclear Information System (INIS)

    Chen, S.Y.; Yuan, Y.C.

    1988-01-01

    In the event of an accidental nuclear release, the associated long-term radiological risks would result primarily from ground contamination pathways. Cleanup of the contaminated ground surfaces is a necessary step toward reducing the radiological risk to the general population. Ideally, the radiological risk decreases as the level of cleanup effort increases; however, as the cleanup criterion (i.e., the required contaminant concentration after cleanup) becomes more stringent, the cleanup effort may become prohibitively costly. This study examines several factors that are important in determining the effectiveness of the cleanup criteria for selected radionuclides: (a) annual individual dose commitment (mrem/yr), (b) total population environmental dose commitment (person-rem), and (c) total area (km 2 ) requiring cleanup following an accident. To effectively protect the general population, the benefits of cleanup should be weighed against the potentially large increase in cleanup area (and the associated costs) as the cleanup criterion becomes more stringent. The effectiveness of cleanup will vary, depending largely on site-specific parameters such as population density and agricultural productivity as well as on the amount and type of radionuclide released. Determination of an optimum cleanup criterion should account for all factors, including a comprehensive cost/benefit analysis

  13. ATP Release Channels

    Directory of Open Access Journals (Sweden)

    Akiyuki Taruno

    2018-03-01

    Full Text Available Adenosine triphosphate (ATP has been well established as an important extracellular ligand of autocrine signaling, intercellular communication, and neurotransmission with numerous physiological and pathophysiological roles. In addition to the classical exocytosis, non-vesicular mechanisms of cellular ATP release have been demonstrated in many cell types. Although large and negatively charged ATP molecules cannot diffuse across the lipid bilayer of the plasma membrane, conductive ATP release from the cytosol into the extracellular space is possible through ATP-permeable channels. Such channels must possess two minimum qualifications for ATP permeation: anion permeability and a large ion-conducting pore. Currently, five groups of channels are acknowledged as ATP-release channels: connexin hemichannels, pannexin 1, calcium homeostasis modulator 1 (CALHM1, volume-regulated anion channels (VRACs, also known as volume-sensitive outwardly rectifying (VSOR anion channels, and maxi-anion channels (MACs. Recently, major breakthroughs have been made in the field by molecular identification of CALHM1 as the action potential-dependent ATP-release channel in taste bud cells, LRRC8s as components of VRACs, and SLCO2A1 as a core subunit of MACs. Here, the function and physiological roles of these five groups of ATP-release channels are summarized, along with a discussion on the future implications of understanding these channels.

  14. Large-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.; Kurath, Dean E.; Adkins, Harold E.; Billing, Justin M.; Burns, Carolyn A.; Davis, James M.; Enderlin, Carl W.; Fischer, Christopher M.; Jenks, Jeromy WJ; Lukins, Craig D.; MacFarlan, Paul J.; Shutthanandan, Janani I.; Smith, Dennese M.

    2012-12-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  15. Environmental risks due to radionuclide releases Environmental Risks Due To Radionuclide Releases From The Oil And Gas Industry

    International Nuclear Information System (INIS)

    Steinhausler, F.

    2005-01-01

    Full text : Exploration and transport in the oil- and gas industry result in the release of elevated levels of natural radioactivity into the environment. This has the following impact: Due to the large volumes of water needed during the extraction of gas and oil the resulting waste water can contain increased concentration of natural radionuclides, such as radium (Ra 226) and its decay products; At the oil/water interface waste water and sludge precipitate and form scalings, containing elevated levels of radium (Ra 226); At oil- and gas extraction sites tanks and equipment can be coated with long-lived radon (Rn 222) decay products; Along oil- and gas pipelines (e.g., at compressor stations) radon (Rn 222) decay products can be deposited internally on metal surfaces, such as valves. Typical U 238-series concentration values in production water range from 8 to 42 kBq/ m3, respectively in scale from 1 to 1 000 kBq/kg. In addition, oil- and gas extraction results in significant releases of natural radionuclides to the atmosphere (Rn 222) and to the water (Th 228, Ra 226, Rn 222, Pb 210, Po 210); for example, about 0.15 GBq/a of Rn 222 are released to the atmosphere per 106 m3 of oil extracted. The disposal of large amounts of contaminated wastes (scales, sludges) represents an environmental problem for the scrap metal industry (recycling of steel pipes containing scales) and the housing industry (use of sludge for landfill below a residential area). Using data from the oil- and gas industry in Latin America, Europe and the Asia-Pacific region, the various exposure pathways are reviewed. Furthermore, the current efforts in defining a suitable regulatory framework are discussed

  16. The 2017 Release Cloudy

    Science.gov (United States)

    Ferland, G. J.; Chatzikos, M.; Guzmán, F.; Lykins, M. L.; van Hoof, P. A. M.; Williams, R. J. R.; Abel, N. P.; Badnell, N. R.; Keenan, F. P.; Porter, R. L.; Stancil, P. C.

    2017-10-01

    We describe the 2017 release of the spectral synthesis code Cloudy, summarizing the many improvements to the scope and accuracy of the physics which have been made since the previous release. Exporting the atomic data into external data files has enabled many new large datasets to be incorporated into the code. The use of the complete datasets is not realistic for most calculations, so we describe the limited subset of data used by default, which predicts significantly more lines than the previous release of Cloudy. This version is nevertheless faster than the previous release, as a result of code optimizations. We give examples of the accuracy limits using small models, and the performance requirements of large complete models. We summarize several advances in the H- and He-like iso-electronic sequences and use our complete collisional-radiative models to establish the densities where the coronal and local thermodynamic equilibrium approximations work.

  17. Protecting privacy in data release

    CERN Document Server

    Livraga, Giovanni

    2015-01-01

    This book presents a comprehensive approach to protecting sensitive information when large data collections are released by their owners. It addresses three key requirements of data privacy: the protection of data explicitly released, the protection of information not explicitly released but potentially vulnerable due to a release of other data, and the enforcement of owner-defined access restrictions to the released data. It is also the first book with a complete examination of how to enforce dynamic read and write access authorizations on released data, applicable to the emerging data outsou

  18. Large indoor cage study of the suppression of stable Aedes aegypti populations by the release of thiotepa-sterilised males

    Directory of Open Access Journals (Sweden)

    René Gato

    2014-06-01

    Full Text Available The sterile insect technique (SIT is a promising pest control method in terms of efficacy and environmental compatibility. In this study, we determined the efficacy of thiotepa-sterilised males in reducing the target Aedes aegypti populations. Treated male pupae were released weekly into large laboratory cages at a constant ratio of either 5:1 or 2:1 sterile-to-fertile males. A two-to-one release ratio reduced the hatch rate of eggs laid in the cage by approximately a third and reduced the adult catch rate by approximately a quarter, but a 5:1 release drove the population to elimination after 15 weeks of release. These results indicate that thiotepa exposure is an effective means of sterilising Ae. aegypti and males thus treated are able to reduce the reproductive capacity of a stable population under laboratory conditions. Further testing of the method in semi-field enclosures is required to evaluate the mating competitiveness of sterile males when exposed to natural environmental conditions. If proven effective, SIT using thiotepa-sterilised males may be incorporated into an integrated programme of vector control to combat dengue in Cuba.

  19. Ensuring Adequate Health and Safety Information for Decision Makers during Large-Scale Chemical Releases

    Science.gov (United States)

    Petropoulos, Z.; Clavin, C.; Zuckerman, B.

    2015-12-01

    The 2014 4-Methylcyclohexanemethanol (MCHM) spill in the Elk River of West Virginia highlighted existing gaps in emergency planning for, and response to, large-scale chemical releases in the United States. The Emergency Planning and Community Right-to-Know Act requires that facilities with hazardous substances provide Material Safety Data Sheets (MSDSs), which contain health and safety information on the hazardous substances. The MSDS produced by Eastman Chemical Company, the manufacturer of MCHM, listed "no data available" for various human toxicity subcategories, such as reproductive toxicity and carcinogenicity. As a result of incomplete toxicity data, the public and media received conflicting messages on the safety of the contaminated water from government officials, industry, and the public health community. Two days after the governor lifted the ban on water use, the health department partially retracted the ban by warning pregnant women to continue avoiding the contaminated water, which the Centers for Disease Control and Prevention deemed safe three weeks later. The response in West Virginia represents a failure in risk communication and calls to question if government officials have sufficient information to support evidence-based decisions during future incidents. Research capabilities, like the National Science Foundation RAPID funding, can provide a solution to some of the data gaps, such as information on environmental fate in the case of the MCHM spill. In order to inform policy discussions on this issue, a methodology for assessing the outcomes of RAPID and similar National Institutes of Health grants in the context of emergency response is employed to examine the efficacy of research-based capabilities in enhancing public health decision making capacity. The results of this assessment highlight potential roles rapid scientific research can fill in ensuring adequate health and safety data is readily available for decision makers during large

  20. Modeling the release, spreading, and burning of LNG, LPG, and gasoline on water

    International Nuclear Information System (INIS)

    Johnson, David W.; Cornwell, John B.

    2007-01-01

    Current interest in the shipment of liquefied natural gas (LNG) has renewed the debate about the safety of shipping large volumes of flammable fuels. The size of a spreading pool following a release of LNG from an LNG tank ship has been the subject of numerous papers and studies dating back to the mid-1970s. Several papers have presented idealized views of how the LNG would be released and spread across a quiescent water surface. There is a considerable amount of publicly available material describing these idealized releases, but little discussion of how other flammable fuels would behave if released from similar sized ships. The purpose of this paper is to determine whether the models currently available from the United States Federal Energy Regulatory Commission (FERC) can be used to simulate the release, spreading, vaporization, and pool fire impacts for materials other than LNG, and if so, identify which material-specific parameters are required. The review of the basic equations and principles in FERC's LNG release, spreading, and burning models did not reveal a critical fault that would prevent their use in evaluating the consequences of other flammable fluid releases. With the correct physical data, the models can be used with the same level of confidence for materials such as LPG and gasoline as they are for LNG

  1. Modulation of drug release kinetics of shellac-based matrix tablets by in-situ polymerization through annealing process.

    Science.gov (United States)

    Limmatvapirat, Sontaya; Limmatvapirat, Chutima; Puttipipatkhachorn, Satit; Nunthanid, Jurairat; Luangtana-anan, Manee; Sriamornsak, Pornsak

    2008-08-01

    A new oral-controlled release matrix tablet based on shellac polymer was designed and developed, using metronidazole (MZ) as a model drug. The shellac-based matrix tablets were prepared by wet granulation using different amounts of shellac and lactose. The effect of annealing temperature and pH of medium on drug release from matrix tablets was investigated. The increased amount of shellac and increased annealing temperature significantly affected the physical properties (i.e., tablet hardness and tablet disintegration) and MZ release from the matrix tablets. The in-situ polymerization played a major role on the changes in shellac properties during annealing process. Though the shellac did not dissolve in acid medium, the MZ release in 0.1N HCl was faster than in pH 7.3 buffer, resulting from a higher solubility of MZ in acid medium. The modulation of MZ release kinetics from shellac-based matrix tablets could be accomplished by varying the amount of shellac or annealing temperature. The release kinetics was shifted from relaxation-controlled release to diffusion-controlled release when the amount of shellac or the annealing temperature was increased.

  2. Observation of electrostatically released DNA from gold electrodes with controlled threshold voltages.

    Science.gov (United States)

    Takeishi, Shunsaku; Rant, Ulrich; Fujiwara, Tsuyoshi; Buchholz, Karin; Usuki, Tatsuya; Arinaga, Kenji; Takemoto, Kazuya; Yamaguchi, Yoshitaka; Tornow, Marc; Fujita, Shozo; Abstreiter, Gerhard; Yokoyama, Naoki

    2004-03-22

    DNA oligo-nucleotides, localized at Au metal electrodes in aqueous solution, are found to be released when applying a negative bias voltage to the electrode. The release was confirmed by monitoring the intensity of the fluorescence of cyanine dyes (Cy3) linked to the 5' end of the DNA. The threshold voltage of the release changes depending on the kind of linker added to the DNA 3'-terminal. The amount of released DNA depends on the duration of the voltage pulse. Using this technique, we can retain DNA at Au electrodes or Au needles, and release the desired amount of DNA at a precise location in a target. The results suggest that DNA injection into living cells is possible with this method. (c) 2004 American Institute of Physics

  3. [Preparation of hydrophilic matrix sustained release tablets of total lactones from Andrographis paniculata and study on its in vitro release mechanism].

    Science.gov (United States)

    Xu, Fang-Fang; Shi, Wei; Zhang, Hui; Guo, Qing-Ming; Wang Zhen-Zhong; Bi, Yu-An; Wang, Zhi-Min; Xiao, Wei

    2015-01-01

    In this study, hydrophilic matrix sustained release tablets of total lactones from Andrographis paniculata were prepared and the in vitro release behavior were also evaluated. The optimal prescription was achieved by studying the main factor of the type and amount of hydroxypropyl methylcellulose (HPMC) using single factor test and evaluating through cumulative release of three lactones. No burst drug release from the obtained matrix tablets was observed. Drug release sustained to 14 h. The release mechanism of three lactones from A. paniculata was accessed by zero-order, first-order, Higuchi and Peppas equation. The release behavior of total lactones from A. paniculata was better agreed with Higuchi model and the drug release from the tablets was controlled by degradation of the matrix. The preparation of hydrophilic matrix sustained release tablets of total lactones from A. paniculata with good performance of drug release was simple.

  4. Airborne engineered nanomaterials in the workplace—a review of release and worker exposure during nanomaterial production and handling processes

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yaobo [Institute for Work and Health (IST), Universities of Lausanne and Geneva, Route de la Corniche 2, 1066, Epalinges (Switzerland); Kuhlbusch, Thomas A.J. [Institute of Energy and Environmental Technology (IUTA), Air Quality & Sustainable Nanotechnology Unit, Bliersheimer Straße 58-60, 47229 Duisburg (Germany); Centre for Nanointegration (CENIDE), University Duisburg-Essen, Duisburg (Germany); Van Tongeren, Martie; Jiménez, Araceli Sánchez [Centre for Human Exposure Science, Institute of Occupational Medicine (IOM), Research Avenue North, Edinburgh EH14 4AP (United Kingdom); Tuinman, Ilse [TNO, Lange Kleiweg 137, Rijswijk (Netherlands); Chen, Rui [CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing 100190 (China); Alvarez, Iñigo Larraza [ACCIONA Infrastructure, Materials Area, Innovation Division, C/Valportillo II 8, 28108, Alcobendas (Spain); Mikolajczyk, Urszula [Nofer Institute of Occupational Medicine, Lodz (Poland); Nickel, Carmen; Meyer, Jessica; Kaminski, Heinz [Institute of Energy and Environmental Technology (IUTA), Air Quality & Sustainable Nanotechnology Unit, Bliersheimer Straße 58-60, 47229 Duisburg (Germany); Wohlleben, Wendel [Dept. Material Physics, BASF SE, Advanced Materials Research, Ludwigshafen (Germany); Stahlmecke, Burkhard [Institute of Energy and Environmental Technology (IUTA), Air Quality & Sustainable Nanotechnology Unit, Bliersheimer Straße 58-60, 47229 Duisburg (Germany); Clavaguera, Simon [NanoSafety Platform, Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Univ. Grenoble Alpes, Grenoble, 38054 (France); and others

    2017-01-15

    Highlights: • Release characteristics can be grouped by the type of occupational activities. • Release levels may be linked to process energy. • A better data reporting practice will facilitate exposure assessment. • The results help prioritize industrial processes for human risk assessment. - Abstract: For exposure and risk assessment in occupational settings involving engineered nanomaterials (ENMs), it is important to understand the mechanisms of release and how they are influenced by the ENM, the matrix material, and process characteristics. This review summarizes studies providing ENM release information in occupational settings, during different industrial activities and using various nanomaterials. It also assesses the contextual information — such as the amounts of materials handled, protective measures, and measurement strategies — to understand which release scenarios can result in exposure. High-energy processes such as synthesis, spraying, and machining were associated with the release of large numbers of predominantly small-sized particles. Low-energy processes, including laboratory handling, cleaning, and industrial bagging activities, usually resulted in slight or moderate releases of relatively large agglomerates. The present analysis suggests that process-based release potential can be ranked, thus helping to prioritize release assessments, which is useful for tiered exposure assessment approaches and for guiding the implementation of workplace safety strategies. The contextual information provided in the literature was often insufficient to directly link release to exposure. The studies that did allow an analysis suggested that significant worker exposure might mainly occur when engineering safeguards and personal protection strategies were not carried out as recommended.

  5. Airborne engineered nanomaterials in the workplace—a review of release and worker exposure during nanomaterial production and handling processes

    International Nuclear Information System (INIS)

    Ding, Yaobo; Kuhlbusch, Thomas A.J.; Van Tongeren, Martie; Jiménez, Araceli Sánchez; Tuinman, Ilse; Chen, Rui; Alvarez, Iñigo Larraza; Mikolajczyk, Urszula; Nickel, Carmen; Meyer, Jessica; Kaminski, Heinz; Wohlleben, Wendel; Stahlmecke, Burkhard; Clavaguera, Simon

    2017-01-01

    Highlights: • Release characteristics can be grouped by the type of occupational activities. • Release levels may be linked to process energy. • A better data reporting practice will facilitate exposure assessment. • The results help prioritize industrial processes for human risk assessment. - Abstract: For exposure and risk assessment in occupational settings involving engineered nanomaterials (ENMs), it is important to understand the mechanisms of release and how they are influenced by the ENM, the matrix material, and process characteristics. This review summarizes studies providing ENM release information in occupational settings, during different industrial activities and using various nanomaterials. It also assesses the contextual information — such as the amounts of materials handled, protective measures, and measurement strategies — to understand which release scenarios can result in exposure. High-energy processes such as synthesis, spraying, and machining were associated with the release of large numbers of predominantly small-sized particles. Low-energy processes, including laboratory handling, cleaning, and industrial bagging activities, usually resulted in slight or moderate releases of relatively large agglomerates. The present analysis suggests that process-based release potential can be ranked, thus helping to prioritize release assessments, which is useful for tiered exposure assessment approaches and for guiding the implementation of workplace safety strategies. The contextual information provided in the literature was often insufficient to directly link release to exposure. The studies that did allow an analysis suggested that significant worker exposure might mainly occur when engineering safeguards and personal protection strategies were not carried out as recommended.

  6. Release to the environment and diffusion of radioiodine in the environment, 1

    International Nuclear Information System (INIS)

    Murata, Toshifumi

    1979-01-01

    1. Radioactivity of iodine nuclides accumulated in nuclear facilities. Radioactive iodine nuclides which are produced in nuclear plants consist mainly of short lived 131 I- 135 I, while 129 I with long half life is being produced in a small amount. The radioactivity of iodine in a power reactor of 1,000 MWe which burns uranium fuel amounts to about 6 x 10 8 C sub(i). In the case of fuel which is handled in a reprocessing plant of spent fuel, almost all radioactive iodine remaining in the fuel is 129 I (half life: 1.7 x 10 7 years) because of cooling period of more than 6 months which is imposed by the plant. 2. Release of radioactive iodine during normal operating conditions. In an event of fuel failure in light water cooled reactors, a part of radioactive iodine is dissolved in water and very small amount is released as gaseous iodine to the environment through the ventillation system. The actual amount of radioactive iodine which was released from various types of nuclear reactors in the world between 1970 to 1974 is recorded as much lower than to the presently regulated value in all cases. 3. Behavior of radioactive iodine during postulated accident. The amount of radioactive iodine which will be released from reactor core to the containment vessel varies with conditions to be assumed. In the event of a severe accidental condition such as fuel melt down or oxidation, 25% of radioactive iodine in the fuel are assumed to be released. The iodine released to the containment vessel is mostly removed by planting out to the wall of the containment or washed out by core spray, while the remaining part in air is to be removed by a filter unit which is installed in the emergency gas treatment system. (author)

  7. A summary of the assessment of fuel behaviour, fission product release and pressure tube integrity following a postulated large loss-of-coolant accident

    International Nuclear Information System (INIS)

    Langman, V.J.; Weaver, K.R.

    1984-05-01

    The Ontario Hydro analyses of fuel and pressure tube temperatures, fuel behaviour, fission product release and pressure tube integrity for large break loss-of-coolant accidents in Bruce A or Pickering A have been critically reviewed. The determinations of maximum fuel temperatures and fission product release are very uncertain, and pressure tube integrity cannot be assured where low steam flows are predicted to persist for times on the order of minutes

  8. Realistic methods for calculating the releases and consequences of a large LOCA

    International Nuclear Information System (INIS)

    Stephenson, W.; Dutton, L.M.C.; Handy, B.J.; Smedley, C.

    1992-01-01

    This report describes a calculational route to predict realistic radiological consequences for a successfully terminated large-loss-of-coolant accident (LOCA) at a pressurized-water reactor (PWR). All steps in the calculational route are considered. For each one, a brief comment is made on the significant differences between the methods of calculation that were identified in the benchmark studies and recommendations are made for the methods and data for carrying out realistic calculations. These are based on the best supportable methods and data and the technical basis for each recommendation is given. Where the lack of well-validated methods or data means that the most realistic method that can be justified is considered to be very conservative, the need for further research is identified. The behaviour of inorganic iodine and the removal of aerosols from the atmosphere of the reactor building are identified as areas of particular importance. Where the retention of radioactivity is sensitive to design features, these are identified and, for the most importance features, the impact of different designs on the release of activity is indicated. The predictions of the proposed model are calculated for each stage and compared with the releases of activity predicted by the licensing methods that were used in the earlier benchmark studies. The conservative nature of the latter is confirmed. Methods and data are also presented for calculating the resulting doses to members of the public of the National Radiological Protection Boards as a result of work carried out by several national bodies in the UK. Other, equally acceptable, models are used in other countries of the Community and some examples are given

  9. Nitrate capture and slow release in biochar amended compost and soil.

    Directory of Open Access Journals (Sweden)

    Nikolas Hagemann

    Full Text Available Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h extractions ("slow release". In this study, we quantified nitrate and ammonium release by biochar-amended soil and compost during up to 167 h of repeated extractions in up to six consecutive steps to determine the effect of biochar on the overall mineral nitrogen retention. We used composts produced from mixed manures amended with three contrasting biochars prior to aerobic composting and a loamy soil that was amended with biochar three years prior to analysis and compared both to non-biochar amended controls. Composts were extracted with 2 M KCl at 22°C and 65°C, after sterilization, after treatment with H2O2, after removing biochar particles or without any modification. Soils were extracted with 2 M KCl at 22°C. Ammonium was continuously released during the extractions, independent of biochar amendment and is probably the result of abiotic ammonification. For the pure compost, nitrate extraction was complete after 1 h, while from biochar-amended composts, up to 30% of total nitrate extracted was only released during subsequent extraction steps. The loamy soil released 70% of its total nitrate amount in subsequent extractions, the biochar-amended soil 58%. However, biochar amendment doubled the amount of total extractable nitrate. Thus, biochar nitrate capture can be a relevant contribution to the overall nitrate retention in agroecosystems. Our results also indicate that the total nitrate amount in biochar amended soils and composts may frequently be underestimated. Furthermore, biochars could prevent nitrate loss from agroecosystems and may be developed into slow-release fertilizers to

  10. Tritium breeding and release-rate kinetics from neutron-irradiated lithium oxide

    International Nuclear Information System (INIS)

    Quanci, J.F.

    1989-01-01

    The research encompasses the measurement of the tritium breeding and release-rate kinetics from lithium oxide, a ceramic tritium-breeding material. A thermal extraction apparatus which allows the accurate measurement of the total tritium inventory and release rate from lithium oxide samples under different temperatures, pressures and carrier-gas compositions with an uncertainty not exceeding 3% was developed. The goal of the Lithium Blanket Module program was to determine if advanced computer codes could accurately predict the tritium production in the lithium oxide blanket of a fusion power plant. A fusion blanket module prototype, was built and irradiated with a deuterium-tritium fusion-neutron source. The tritium production throughout the module was modeled with the MCNP three dimensional Monte Carlo code and was compared to the assay of the tritium bred in the module. The MCNP code accurately predicted tritium-breeding trends but underestimated the overall tritium breeding by 30%. The release rate of tritium from small grain polycrystalline sintered lithium oxide with a helium carrier gas from 300 to 450 C was found to be controlled by the first order surface desorption of mono-tritiated water. When small amounts of hydrogen were added to the helium carrier gas, the first order rate constant increased from the isotopic exchange of hydrogen for tritium at the lithium oxide surface occurring in parallel with the first order desorption process. The isotopic-exchange first order rate constant temperature dependence and hydrogen partial pressure dependence were evaluated. Large single crystals of lithium oxide were fabricated by the vacuum fusion technique. The release rate of tritium from the large single crystals was found to be controlled by diffusion, and the mixed diffusion-desorption controlled release regime

  11. PIXE investigation of in-vitro release of chloramphenicol across polyvinyl alcohol/ acrylamide hydrogel

    International Nuclear Information System (INIS)

    Rihawi, M.; Al-Zeer, A.; Allaf, A.

    2012-01-01

    Hydrogels based on polyvinyl alcohol (PVA) and different amounts of acrylamide monomer (AAm) were prepared by thermal crosslinking process in solid state. The PVA/AAm hydrogels were investigated for drug delivery system applications. Chloramphenicol was adopted as a model drug to study its release behaviour across the prepared hydrogels. Particle induced X-ray emission (PIXE) analytical technique was utilized to study the drug release behaviour across the hydrogels. A comparison study between PIXE and UV measurements was performed. FTIR measurements were carried out to perform the molecular characterization. The releasing behaviour of the drug across the hydrogels demonstrates a decrease and a subsequent increase in the drug release rate, as the AAm amount increases. The FTIR characterization of the prepared hydrogels has shown a competitive behaviour between the crosslinking of PVA with AAm monomer or oligomerized AAm, depending on the amount of AAm added to prepare the PVA/AAm hydrogels. (author)

  12. A method for prevention of radioactive material release

    International Nuclear Information System (INIS)

    Uchida, Shunsuke; Sato, Chikara; Kitamura, Masao.

    1975-01-01

    Object: To provide a method for preventing an underwater radioactive material from being released in a simple and highly reliable manner, which can decrease an amount of radioactive materials discharged into open air from reactor water containing a large amount of radioactive materials such as a reactor core pool. Structure: Pure warm water higher in temperature than that of reactor water is poured from the top of a water surface of a water tank which stores reactor water containing radioactive materials such as radioactive iodine, and water is drawn through an outlet located downwardly of the pure warm water inlet to form a layer of pure warm water at the upper part of the water tank while preventing diffusion of the reactor water into the pure warm water by the difference in density between the reactor water and the pure warm water and downward movement of the pure warm water, thereby preventing contact of the reactor water with the atmosphere and diffusion of the radioactive material into the atmosphere. (Kamimura, M.)

  13. Determination of metal ions released by stainless steel arch bar into bio-fluids

    Directory of Open Access Journals (Sweden)

    Lori A. Joseph

    2009-04-01

    Full Text Available The amounts of cobalt, iron, manganese, nickel and chromium ions released from new and reused stainless steel arch bar used for maxillomandibular fixation was determined in Hank’s solutions of different hydrogen and chloride ions concentrations, whole blood serum and phosphate buffered saline (PBS in vitro, over a six-week immersion time at 37 oC, by atomic absorption spectrophotometry. The corrosion levels of the wires due to effects of media and incubation times in the bio-fluids were compared by Duncan’s two-way ANOVA (P less than 0.05. Pearson’s correlation was used in establishing relationship in the amounts of metal ions released by new and reused arch bars. The study indicated that the reused wires released more ions than new ones at all time points. The variation of pH and chloride ions of the bio-fluids had a significant effect on the amount of Ni, Mn and Cr ions released. Ageing prior use of arch bars significantly increased Ni ions released into the bio-fluids.

  14. Slow-release fertilizer

    Science.gov (United States)

    Ming, Douglas W.; Golden, D. C.

    1992-10-01

    A synthetic apatite containing agronutrients and a method for making the apatite are disclosed. The apatite comprises crystalline calcium phosphate having agronutrients dispersed in the crystalline structure. The agronutrients can comprise potassium, magnesium, sulfur, iron, manganese, molybdenum, chlorine, boron, copper and zinc in amounts suited for plant growth. The apatite can optionally comprise a carbonate and/or silicon solubility control agent. The agronutrients are released slowly as the apatite dissolves.

  15. Slow-release fertilizer

    Science.gov (United States)

    Ming, Douglas W. (Inventor); Golden, Dadigamuwage C. (Inventor)

    1995-01-01

    A synthetic apatite containing agronutrients and a method for making the apatite are disclosed. The apatite comprises crystalline calcium phosphate having agronutrients dispersed in the crystalline structure. The agronutrients can comprise potassium, magnesium, sulfur, iron, manganese, molybdenum, chlorine, boron, copper and zinc in amounts suited for plant growth. The apatite can optionally comprise a carbonate and/or silicon solubility control agent. The agronutrients are released slowly as the apatite dissolves.

  16. Simulated food effects on drug release from ethylcellulose: PVA-PEG graft copolymer-coated pellets.

    Science.gov (United States)

    Muschert, Susanne; Siepmann, Florence; Leclercq, Bruno; Carlin, Brian; Siepmann, Juergen

    2010-02-01

    Food effects might substantially alter drug release from oral controlled release dosage forms in vivo. The robustness of a novel type of controlled release film coating was investigated using various types of release media and two types of release apparatii. Importantly, none of the investigated conditions had a noteworthy impact on the release of freely water-soluble diltiazem HCl or slightly water-soluble theophylline from pellets coated with ethylcellulose containing small amounts of PVA-PEG graft copolymer. In particular, the presence of significant amounts of fats, carbohydrates, surfactants, bile salts, and calcium ions in the release medium did not alter drug release. Furthermore, changes in the pH and differences in the mechanical stress the dosage forms were exposed to did not affect drug release from the pellets. The investigated film coatings allowing for oral controlled drug delivery are highly robust in vitro and likely to be poorly sensitive to classical food effects in vivo.

  17. Release of Liposomal Contents by Cell-Secreted Matrix Metalloproteinase-9

    Science.gov (United States)

    Banerjee, Jayati; Hanson, Andrea J.; Gadam, Bhushan; Elegbede, Adekunle I.; Tobwala, Shakila; Ganguly, Bratati; Wagh, Anil; Muhonen, Wallace W.; Law, Benedict; Shabb, John B.; Srivastava, D. K.; Mallik, Sanku

    2011-01-01

    Liposomes have been widely used as a drug delivery vehicle and currently, more than 10 liposomal formulations are approved by the Food and Drug Administration for clinical use. However, upon targeting, the release of the liposome-encapsulated contents is usually slow. We have recently demonstrated that contents from appropriately-formulated liposomes can be rapidly released by the cancer-associated enzyme matrix metalloproteinase-9 (MMP-9). Herein, we report our detailed studies to optimize the liposomal formulations. By properly selecting the lipopeptide, the major lipid component and their relative amounts, we demonstrate that the contents are rapidly released in the presence of cancer-associated levels of recombinant human MMP-9. We observed that the degree of lipid mismatch between the lipopepides and the major lipid component profoundly affects the release profiles from the liposomes. By utilizing the optimized liposomal formulations, we also demonstrate that cancer cells (HT-29) which secrete low levels of MMP-9 failed to release significant amount of the liposomal contents. Metastatic cancer cells (MCF7) secreting high levels of the enzyme rapidly release the encapsulated contents from the liposomes. PMID:19601658

  18. Study on mitigation of in-vessel release of fission products in severe accidents of PWR

    International Nuclear Information System (INIS)

    Huang, G.F.; Tong, L.L.; Li, J.X.; Cao, X.W.

    2010-01-01

    Research highlights: → In-vessel release of fission products in severe accidents for 600 MW PWR is analyzed. → Mitigation effect of primary feed-and-bleed on in-vessel release is investigated. → Mitigation effect of secondary feed-and-bleed on in-vessel release is studied. → Mitigation effect of ex-vessel cooling on in-vessel release is evaluated. - Abstract: During the severe accidents in a nuclear power plant, large amounts of fission products release with accident progression, including in-vessel and ex-vessel release. Mitigation of fission products release is demanded for alleviating radiological consequence in severe accidents. Mitigation countermeasures to in-vessel release are studied for Chinese 600 MW pressurized water reactor (PWR), including feed-and-bleed in primary circuit, feed-and-bleed in secondary circuit and ex-vessel cooling. SBO, LOFW, SBLOCA and LBLOCA are selected as typical severe accident sequences. Based on the evaluation of in-vessel release with different startup time of countermeasure, and the coupling relationship between thermohydraulics and in-vessel release of fission products, some results are achieved. Feed-and-bleed in primary circuit is an effective countermeasure to mitigate in-vessel release of fission products, and earlier startup time of countermeasure is more feasible. Feed-and-bleed in secondary circuit is also an effective countermeasure to mitigate in-vessel release for most severe accident sequences that can cease core melt progression, e.g. SBO, LOFW and SBLOCA. Ex-vessel cooling has no mitigation effect on in-vessel release owing to inevitable core melt and relocation.

  19. Cell-swelling-induced taurine release from isolated perfused rat liver

    NARCIS (Netherlands)

    Brand, H. S.; Meijer, A. J.; Gustafson, L. A.; Jörning, G. G.; Leegwater, A. C.; Maas, M. A.; Chamuleau, R. A.

    1994-01-01

    Astrocytes and lymphocytes are able to release significant amounts of taurine during periods of hypotonicity to reduce the increase in cell volume. To investigate this mechanism in the liver, we studied the release of free amino acids from isolated perfused rat liver during hypotonicity. The

  20. Sustained release of radioprotective agents

    International Nuclear Information System (INIS)

    Shani, J.

    1980-11-01

    New pharmaceutical formulations for the sustained release into the G.I. tract of radioprotective agents have been developed by the authors. The experimental method initially consisted in the production of methylcellulose microcapsules. This method failed apparently because of the premature ''explosion'' of the microcapsules and the consequent premature release of massive amounts of the drug. A new method has been developed which consists in drying and pulverising cysteamine and cysteine preparations, mixing them in various proportions with stearic acid and ethylcellulose as carriers. The mixture is then compressed into cylindrical tablets at several pressure values and the leaching rate of the radioprotective agents is then measured by spectrophotometry. The relation between the concentration of the active drug and its rate of release, and the effect on the release rate of the pressure applied to the tablet during its formation were also investigated. Results indicating that the release rate was linearly related to the square root of ''t'' seem to be in agreement with what is predictable, according to Higuchi's equation, save for the very initial and terminal phases. A clear correlation was also established between the stearic acid/ethylcellulose ratios and the release of 20% cysteine, namely a marked decrease in the rate of cysteine release was observed with increasing concentrations of stearic acid. Finally, it was observed that a higher formation pressure results in quicker release of the drug

  1. Effect of cutter type on sediment pollutants release in channel dredging

    Science.gov (United States)

    Yu, Y. R.; Chen, Y.; Dong, M. M.; Yang, B. L.

    2016-08-01

    Dredging activities are often used to maintain existing navigation channels. However’ traditional dredging equipment inevitably leads to sediment resuspension and nutrient loading in water. In this work’ the existing cutter used for dredging was transformed environmentally to reduce the release amount of sediment pollutants’ and to avoid the formation of secondary pollution to water bodies. Simulated tests with a general cutter’ a spiral cutter’ along with a general and spiral cutter equipped with the anti-diffusion device were conducted respectively in this study. The change of pollutants concentration in overlying water was examined. The environmental performance of each different structure cutter was comparatively analysed as well. The result revealed that in channel dredging with a spiral cutter’ the release amount of sediment pollutants was less than with a general cutter’ and that a general/spiral cutter equipped with the anti-diffusion device could effectively reduce the release amount of sediment contaminants’ particularly the release of the nitrogen nutrient during the 1h after the dredging treatment. The best transformation scheme for a cutter suction dredger (CSD) in its environmental-protection function may be: a spiral cutter equipped with the anti-diffusion device.

  2. Impacts of Large Amounts of Wind Power on Design and Operation of Power Systems; Results of IEA Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ela, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Holttinen, H. [VTT (Finland); Meibom, P. [DTU Riso (Denmark); Orths, A. [Energinet.dk (Denmark); O' Malley, M. [Univ. College Dubline (Ireland); Ummels, B. C. [Delft Univ. of Technology (Netherlands); Tande, J. [SINTEF (Norway); Estanqueiro, A. [INETI (Portugal); Gomez, E. [Univ. Castilla la Mancha (Spain); Smith, J. C. [Utility Wind Integration Group (UWIG), Reston, VA (United States)

    2008-06-01

    There are a multitude of studies completed and ongoing related to the cost of wind integration. However, the results are not easy to compare. An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. IEA WIND R&D Task 25 on “Design and Operation of Power Systems with Large Amounts of Wind Power” produced a state-of-the-art report in October 2007, where the most relevant wind-power grid integration studies were analyzed, especially regarding methodologies and input data. This paper summarizes the results from 18 case studies, with discussion on differences in methodology as well as issues that have been identified to impact the cost of wind integration.

  3. Empirical relationships between tree fall and landscape-level amounts of logging and fire.

    Science.gov (United States)

    Lindenmayer, David B; Blanchard, Wade; Blair, David; McBurney, Lachlan; Stein, John; Banks, Sam C

    2018-01-01

    Large old trees are critically important keystone structures in forest ecosystems globally. Populations of these trees are also in rapid decline in many forest ecosystems, making it important to quantify the factors that influence their dynamics at different spatial scales. Large old trees often occur in forest landscapes also subject to fire and logging. However, the effects on the risk of collapse of large old trees of the amount of logging and fire in the surrounding landscape are not well understood. Using an 18-year study in the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, we quantify relationships between the probability of collapse of large old hollow-bearing trees at a site and the amount of logging and the amount of fire in the surrounding landscape. We found the probability of collapse increased with an increasing amount of logged forest in the surrounding landscape. It also increased with a greater amount of burned area in the surrounding landscape, particularly for trees in highly advanced stages of decay. The most likely explanation for elevated tree fall with an increasing amount of logged or burned areas in the surrounding landscape is change in wind movement patterns associated with cutblocks or burned areas. Previous studies show that large old hollow-bearing trees are already at high risk of collapse in our study area. New analyses presented here indicate that additional logging operations in the surrounding landscape will further elevate that risk. Current logging prescriptions require the protection of large old hollow-bearing trees on cutblocks. We suggest that efforts to reduce the probability of collapse of large old hollow-bearing trees on unlogged sites will demand careful landscape planning to limit the amount of timber harvesting in the surrounding landscape.

  4. Drug Release Studies from Caesalpinia pulcherrima Seed Polysaccharide.

    Science.gov (United States)

    Jeevanandham, Somasundaram; Dhachinamoorthi, Duraiswamy; Bannoth Chandra Sekhar, Kothapalli

    2011-01-01

    This study examines the controlled release behavior of both water-soluble (acetaminophen, caffeine, theophylline and salicylic acid) and water insoluble (indomethacin) drugs derived from Caesalpinia pulcherrima seed Gum isolated from Caesalpinia pulcherrima kernel powder. It further investigates the effect of incorporating diluents such as microcrystalline cellulose and lactose on caffeine release. In addition the effect the gum's (polysaccharide) partial cross-linking had on release of acetaminophen was examined. Applying the exponential equation, the soluble drugs mechanism of release was found to be anomalous. The insoluble drugs showed a near case II or zero order release mechanism. The rate of release in descending order was caffeine, acetaminophen, theophylline, salicylic acid and indomethacin. An increase in the release kinetics of the drug was observed on blending with diluents. However, the rate of release varied with the type and amount of blend within the matrix. The mechanism of release due to effect of diluents was found to be anomalous. The rate of drug release decreased upon partial cross-linking and the mechanism of release was found to be of super case II.

  5. Effect of a new drug releasing system on microencapsulated islet transplantation

    Science.gov (United States)

    Lu, Binjie; Gao, Qingkun; Liu, Rui; Ren, Ming; Wu, Yan; Jiang, Zaixing; Zhou, Yi

    2015-01-01

    Objective: This study aimed to develop a novel release system for grafted islets. Materials and methods: A graphene oxide-FTY720 release system was constructed to test the drug loading and releasing capacity. The recipient rats were divided into four groups as following: Experiment group A (EG A) and B (EG B); Control group A (CG A) and B (CG B). In each group, (2000±100) IEQ microencapsulated islets were implanted into the abdominal cavity of the recipients with oral FTY720, local graphene oxide-FTY720 injection, without immunosuppressants, and with graphene oxide-saturated solution respectively. We detected the immunological data, the blood glucose level, and pericapsular overgrowth to show the transplantation effect. Results: 31% of adsorptive FTY720 was released within 6 h, and 82% of FTY720 was released within 48 h. From day 5 to 8, the amount of PBL in EG B was significantly less than those in EG A (PGraphene oxide-FTY720 complex showed a drug releasing effect. Local application of graphene-FTY720 releasing system could decrease the amount of peripheral blood lymphocytes (PBL) and the percentage of CD3 and CD8 T lymphocytes in blood for longer time than oral drug application. This releasing system could achieve a better blood glucose control. PMID:26722425

  6. Subtype-specific suppression of Shiga toxin 2 released from Escherichia coli upon exposure to protein synthesis inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Malene Gantzhorn; Hansen, Claus; Riise, Erik

    2008-01-01

    Shiga toxins (Stx) are important virulence factors in the pathogenesis of severe disease including hemolytic-uremic syndrome, caused by Stx-producing Escherichia coli (STEC). STEC strains increase the release of Stx in vitro following the addition of fluoroquinolones, whereas protein synthesis...... inhibitors previously have been reported to suppress the release of Stx. The amount of Stx released from wild-type STEC strains incubated with protein synthesis inhibitors was examined by a Vero cell cytotoxicity assay. The amounts released were compared to the Stx type (Stx1 or Stx2) and additionally...... to the individual subtypes and toxin variants of Stx2. In general, Stx2 release was suppressed significantly upon exposure to protein synthesis inhibitors at MICs, which was not observed in the case of Stx1. Also, the average amount of different Stx2 toxin variants released was suppressed to various levels ranging...

  7. Comparative evaluation of metal ions release from titanium and Ti-6Al-7Nb into bio-fluids

    Directory of Open Access Journals (Sweden)

    Lori A Joseph

    2009-01-01

    Full Text Available Background: The study was designed to investigate the effects of pH, chloride ions and nature of some bio-fluids on the amount of metal ions released from titanium and TiAl 6 Nb 7 plates following incubation in actual and simulated bio-fluids over time. Methods: The amounts of released metal ions from commercially pure titanium (CpTi and TiAl 6 Nb 7 of surgical grade on immersion in 20 mL Hank′s solution of pH 4.0 or 7.0, Hank′s solution of high chloride ions concentration, Whole Blood Serum (WBS and Phosphate Buffered Saline (PBS at 37° C were determined over an incubation time of 20 weeks using atomic absorption spectrophotometry. The levels of released metal ions were compared by two-way ANOVA and Duncan′s post-hoc tests. The amounts of titanium ions released by the samples were analyzed by Pearson′s correlation. Results: TiAl 6 Nb 7 plate showed no release of Ti ions into the test solutions until after 12 weeks of incubation, while Ti ions were released from the CpTi plate from the 1 day immersion time. The re-lease of measurable amount of Al ions from TiAl 6 Nb 7 was after 12 weeks of incubation. The rate of release of Ti and Al ions from the samples increased initially with incubation time and then stabilized due to adsorption-desorption equilibrium. Conclusion: The results showed that variations in pH and chloride ions of the test media has a sig-nificant effect on the amounts of Ti ions released, while increase in chloride ions concentration sig-nificantly elevates the release of Al ions into the bio-fluids.

  8. Effect of food simulating liquids on release of monomers from two dental resin composites

    Directory of Open Access Journals (Sweden)

    Ghavam M

    2010-06-01

    Full Text Available "nBackground and Aims: The elution of residual monomers from cured dental composites to oral cavity has a harmful effect on human health and can affect their clinical durability. The purpose of this study was to evaluate the amount of eluted monomers (Bis-GMA, TEGDMA, UDMA from two types of composites (Gradia and P60 after exposure to food simulating liquids such as ethanol (25, 50, 75 % and heptane 50 % for 24 hours and 7 days. "nMaterials and Methods: Forty specimens of each composite were prepared. Equal numbers of each composite were immersed in tubes containing 2cc volumes of 25, 50, 75 % ethanole and 50 % heptane. The amount of eluted monomers in standard condition such as Bis-GMA, TEGDMA and UDMA was measured by GC/MS (Gas Chromatography/Mass Spectroscopy and results were statistically analysed by three way and one way ANOVA. P<0.05 was considered as the level of significancy. "nResults: The results showed that Gradia released more TEGDMA than P60. In assessing the effect of environment, the result showed that ethanol caused releasing monomers more than heptane and the concentration rate of 75 % ethanole resulted in most releasing of monomers. In assessing the effect of time, the observation showed that more monomers were released 7 days compared to 24 hours. Bis-GMA and UDMA were not detected in any solutions in these conditions. "nConclusion: Ethanole caused more release of monomers than heptane and 75 % ethanole released the most amount of monomers. Gradia released more amount of TEGDMA than P60.

  9. Disposition of actinides released from high-level waste glass

    International Nuclear Information System (INIS)

    Ebert, W.L.; Bates, J.K.; Buck, E.C.; Gong, M.; Wolf, S.F.

    1994-01-01

    The disposition of actinide elements released from high-level waste glasses into a tuff groundwater in laboratory tests at 90 degrees C at various glass surface area/leachant volume ratios (S/V) between dissolved, suspended, and sorbed fractions has been measured. While the maximum release of actinides is controlled by the corrosion rate of the glass matrix, their solubility and sorption behavior affects the amounts present in potentially mobile phases. Actinide solubilities are affected by the solution pH and the presence of complexants released from the glass, such as sulfate, phosphate, and chloride, radiolytic products, such as nitrate and nitrite, and carbonate. Sorption onto inorganic colloids formed during lass corrosion may increase the amounts of actinides in solution, although subsequent sedimentation of these colloids under static conditions leads to a significant reduction in the amount of actinides in solution. The solution chemistry and observed actinide behavior depend on the S/V of the test. Tests at high S/V lead to higher pH values, greater complexant concentrations, and generate colloids more quickly than tests at low S/V. The S/V also affects the rate of glass corrosion

  10. Observations on the release of air from the rear end of ventilated cavities

    International Nuclear Information System (INIS)

    Verron, J.; Michel, J.M.

    1976-01-01

    In ventilated cavity flows, produced by air injection at the base of bi or tri-dimensional foils, the relation between the air flow rate and the relative cavity underpressure depends particularly on the way in which the air is released from the rear end of the cavity. The experiments show flow configurations of various kinds, revealing the influence of many parameters which interact to determine the closure region of the cavity. Examples are given in the cases of pulsating and non-pulsating cavities. The hydrodynamical tunnel is also briefly described with emphasis on the special units which allow to inject a large amount of air into the water and to produce large cavities without modifying the other characteristics: velocity, ambient pressure and air content in water [fr

  11. Radionuclides release possibility analysis of MSR at various accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choong Wie; Kim, Hee Reyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    There are some accidents which go beyond our expectation such as Fukushima Daiichi nuclear disaster and amounts of radionuclides release to environment, so more effort and research are conducted to prevent it. MSR (Molten Salt Reactor) is one of GEN-IV reactor types, and its coolant and fuel are mixtures of molten salt. MSR has a schematic like figure 1 and it has different features with the solid fuel reactor, but most important and interesting feature of MSR is its many safety systems. For example, MSR has a large negative void coefficient. Even though power increases, the reactor slows down soon. Radionuclides release possibility of MSR was analyzed at various accident conditions including Chernobyl and Fukushima ones. The MSR was understood to prevent the severe accident by the negative reactivity coefficient and the absence of explosive material such as water at the Chernobyl disaster condition. It was expected to contain fuel salts in the reactor building and not to release radionuclides into environment even if the primary system could be ruptured or broken and fuel salts would be leaked at the Fukushima Daiichi nuclear disaster condition of earthquake and tsunami. The MSR, which would not lead to the severe accident and therefore prevents the fuel release to the environment at many expected scenarios, was thought to have priority in the aspect of accidents. A quantitative analysis and a further research are needed to evaluate the possibility of radionuclide release to the environment at the various accident conditions based on the simple comparison of the safety feature between MSR and solid fuel reactor.

  12. PIXE investigation of in vitro release of chloramphenicol across polyvinyl alcohol/acrylamide hydrogel

    International Nuclear Information System (INIS)

    Rihawy, M.S.; Alzier, A.; Allaf, A.W.

    2011-01-01

    Hydrogels based on polyvinyl alcohol and different amounts of acrylamide monomer were prepared by thermal cross-linking in the solid state. The hydrogels were investigated for drug delivery system applications. Chloramphenicol was adopted as a model drug to study its release behavior. Particle induced X-ray emission was utilized to study the drug release behavior across the hydrogels and a comparison study with ultraviolet measurements was performed. Fourier Transform Infrared measurements were carried out for molecular characterization. The releasing behavior of the drug exhibits a decrease and a subsequent increase in the release rate, as the acrylamide monomer increases. Characterization of the hydrogels has shown a competitive behavior between crosslinking with AAm acrylamide monomer or oligomerized version, depending on the amount added to prepare the hydrogels.

  13. Sterile insect supply, emergence, and release

    International Nuclear Information System (INIS)

    Dowell, R.V.; Worley, J.; Gomes, P.J.

    2005-01-01

    Insect mass-rearing for a sterile insect technique (SIT) programme is designed to move beyond the large-scale rearing of insects in a laboratory to the industrial production of consistently high-quality insects for sterilization and release. Each facility reflects the unique biology of the insect reared within it, but there are some generalities for all rearing facilities. Rearing insects in self-contained modules offers flexibility, and increased safety from catastrophic occurrences, compared with using a single building which houses all facets of the rearing process. Although mechanizing certain aspects of the rearing steps helps provide a consistently high-quality insect, successful mass-rearing and delivery depends largely upon the human component. Besides production in centralized facilities, insects can be produced from purchased eggs, or nowadays, adult insects are often obtained from specialized satellite emergence/collection facilities. Interest in commercializing insect production and release is increasing. Shipping sterile insects, sometimes over long distances, is now common practice. Procedures for handling and chilling adult insects, and providing food and water prior to release, are continually being improved. Sterile insects are released via static-release receptacles, ground-release systems, or most commonly from the air. The aerial release of chilled sterile insects is the most efficient method of release, especially when aircraft flight paths are guided by a Global Positioning System (GPS) linked to a computer-controlled release mechanism. (author)

  14. A CASE STUDY OF CHLORINE TRANSPORT AND FATE FOLLOWING A LARGE ACCIDENTAL RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R.; Hunter, C.; Werth, D.; Whiteside, M.; Chen, K.; Mazzola, C.

    2012-08-01

    A train derailment that occurred in Graniteville, South Carolina during the early morning hours of 06 January, 2005 resulted in the prompt release of approximately 60 tons of chlorine to the environment. Comprehensive modeling of the transport and fate of this release was performed including the characterization of the initial three-phased chlorine release, a detailed determination of the local atmospheric conditions acting to generate, disperse, and deplete the chlorine vapor cloud, the establishment of physical exchange mechanisms between the airborne vapor and local surface waters, and local aquatic dilution and mixing.

  15. Studies on renin release in vitro

    DEFF Research Database (Denmark)

    Skøtt, O

    1989-01-01

    1) Measurements of renin secretion from single arterioles at time intervals down to 20 seconds showed that the renin secretion is episodic, the amount of renin released during each episode corresponding to the estimated content of one secretory granule. 2) A decrease in osmolality elicits episodi...

  16. Unraveling the complexities of the velocity dependency of E. coli retention and release parameters in saturated porous media.

    Science.gov (United States)

    Sasidharan, Salini; Bradford, Scott A; Torkzaban, Saeed; Ye, Xueyan; Vanderzalm, Joanne; Du, Xinqiang; Page, Declan

    2017-12-15

    Escherichia coli transport and release experiments were conducted to investigate the pore-water velocity (v) dependency of the sticking efficiency (α), the fraction of the solid surface area that contributed to retention (S f ), the percentage of injected cells that were irreversibly retained (M irr ), and cell release under different (10-300mM) ionic strength (IS) conditions. Values of α, S f , and M irr increased with increasing IS and decreasing v, but the dependency on v was greatest at intermediate IS (30 and 50mM). Following the retention phase, successive increases in v up to 100 or 150mday -1 and flow interruption of 24h produced negligible amounts of cell release. However, excavation of the sand from the columns in excess electrolyte solution resulted in the release of >80% of the retained bacteria. These observations were explained by: (i) extended interaction energy calculations on a heterogeneous sand collector; (ii) an increase in adhesive strength with the residence time; and (iii) torque balance consideration on rough surfaces. In particular, α, S f , and M irr increased with IS due to lower energy barriers and stronger primary minima. The values of α, S f , and M irr also increased with decreasing v because the adhesive strength increased with the residence time (e.g., an increased probability to diffuse over the energy barrier) and lower hydrodynamic forces diminished cell removal. The controlling influence of lever arms at microscopic roughness locations and grain-grain contacts were used to explain negligible cell removal with large increases in v and large amounts of cell recovery following sand excavation. Results reveal the underlying causes (interaction energy, torque balance, and residence time) of the velocity dependency of E. coli retention and release parameters (k sw , α, and S f ) that are not accounted for in colloid filtration theory. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Consumption of energy and release of entropy into the biosphere

    International Nuclear Information System (INIS)

    Deutscher, G.

    2014-01-01

    The short-term threat on humanity is not the shortage of energy but rather the contamination of the environment. The concept of entropy is useful to assess the impact of humane activities on the environment. During most of earth history the increase of entropy was more than compensated by the energy brought by the sun. Today the intensive use of fossil fuels has reversed the trend: the biosphere entropy increases as CO 2 piles up in the atmosphere. The release of entropy is linked to the amount of energy we consume and to the efficiency of the process we use to produce it. Nuclear power plants release entropy as low-temperature heat but this amount of entropy is far less than the entropy released by fossil-fuel power plants under the form of CO 2 . (A.C.)

  18. Results of Large-Scale Testing on Effects of Anti-Foam Agent on Gas Retention and Release

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Charles W.; Guzman-Leong, Consuelo E.; Arm, Stuart T.; Butcher, Mark G.; Golovich, Elizabeth C.; Jagoda, Lynette K.; Park, Walter R.; Slaugh, Ryan W.; Su, Yin-Fong; Wend, Christopher F.; Mahoney, Lenna A.; Alzheimer, James M.; Bailey, Jeffrey A.; Cooley, Scott K.; Hurley, David E.; Johnson, Christian D.; Reid, Larry D.; Smith, Harry D.; Wells, Beric E.; Yokuda, Satoru T.

    2008-01-03

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) will process and treat radioactive waste that is stored in tanks at the Hanford Site. The waste treatment process in the pretreatment facility will mix both Newtonian and non-Newtonian slurries in large process tanks. Process vessels mixing non-Newtonian slurries will use pulse jet mixers (PJMs), air sparging, and recirculation pumps. An anti-foam agent (AFA) will be added to the process streams to prevent surface foaming, but may also increase gas holdup and retention within the slurry. The work described in this report addresses gas retention and release in simulants with AFA through testing and analytical studies. Gas holdup and release tests were conducted in a 1/4-scale replica of the lag storage vessel operated in the Pacific Northwest National Laboratory (PNNL) Applied Process Engineering Laboratory using a kaolin/bentonite clay and AZ-101 HLW chemical simulant with non-Newtonian rheological properties representative of actual waste slurries. Additional tests were performed in a small-scale mixing vessel in the PNNL Physical Sciences Building using liquids and slurries representing major components of typical WTP waste streams. Analytical studies were directed at discovering how the effect of AFA might depend on gas composition and predicting the effect of AFA on gas retention and release in the full-scale plant, including the effects of mass transfer to the sparge air. The work at PNNL was part of a larger program that included tests conducted at Savannah River National Laboratory (SRNL) that is being reported separately. SRNL conducted gas holdup tests in a small-scale mixing vessel using the AZ-101 high-level waste (HLW) chemical simulant to investigate the effects of different AFAs, their components, and of adding noble metals. Full-scale, single-sparger mass transfer tests were also conducted at SRNL in water and AZ-101 HLW simulant to provide data for PNNL

  19. Stimuli responsive nanomaterials for controlled release applications

    KAUST Repository

    Li, Song; Li, Wengang; Khashab, Niveen M.

    2012-01-01

    applications. Stimuli-responsive nanomaterials guarantee the controlled release of cargo to a given location, at a specific time, and with an accurate amount. In this review, we have combined the major stimuli that are currently used to achieve the ultimate

  20. IL-10 release by bovine epithelial cells cultured with Trichomonas vaginalis and Tritrichomonas foetus

    Directory of Open Access Journals (Sweden)

    Ricardo Chaves Vilela

    2013-02-01

    Full Text Available Trichomonas vaginalis and Tritrichomonas foetus are parasitic protists of the human and bovine urogenital tracts, respectively. Several studies have described the cytotoxic effects of trichomonads on urogenital tract epithelial cells. However, little is known about the host cell response against trichomonads. The aim of this study was to determine whether T. foetus and T. vaginalis stimulated the release of the cytokine interleukin (IL-10 from cultured bovine epithelial cells. To characterise the inflammatory response induced by these parasites, primary cultures of bovine oviduct epithelial cells were exposed to either T. vaginalis or T. foetus. Within 12 h after parasite challenge, supernatants were collected and cytokine production was analysed. Large amounts of IL-10 were detected in the supernatants of cultures that had been stimulated with T. foetus. Interestingly, T. vaginalis induced only a small increase in the release of IL-10 upon exposure to the same bovine cells. Thus, the inflammatory response of the host cell is species-specific. Only T. foetus and not T. vaginalis induced the release of IL-10 by bovine oviduct epithelial cells.

  1. Controlled drug release on amine functionalized spherical MCM-41

    International Nuclear Information System (INIS)

    Szegedi, Agnes; Popova, Margarita; Goshev, Ivan; Klébert, Szilvia; Mihály, Judit

    2012-01-01

    MCM-41 silica with spherical morphology and small particle sizes (100 nm) was synthesized and modified by post-synthesis method with different amounts of 3-aminopropyltriethoxysilane (APTES). A comparative study of the adsorption and release of a model drug, ibuprofen, was carried out. The modified and drug loaded mesoporous materials were characterized by XRD, TEM, N 2 physisorption, elemental analysis, thermal analysis and FT-IR spectroscopy. A new method was developed for the quantitative determination of amino groups in surface modified mesoporous materials by the ninhydrin reaction. Good correlation was found between the amino content of the MCM-41 materials determined by the ninhydrin method and their ibuprofen adsorption capacity. Amino modification resulted in high degree of ibuprofen loading and slow release rate in comparison to the parent non-modified MCM-41. - Graphical abstract: Determination of surface amino groups by ninhidrin method. Highlights: ► Spherical MCM-41 modified by different amounts of APTES was studied. ► Ibuprofen (IBU) adsorption and release characteristics was tested. ► The ninhydrin reaction was used for the quantitative determination of amino groups. ► Stoichiometric amount of APTES is enough for totally covering the surface with amino groups. ► Good correlation was found between the amino content and IBU adsorption capacity.

  2. Experiments to Measure Hydrogen Release from Graphite Walls During Disruptions in DIII-D

    International Nuclear Information System (INIS)

    Hollmann, E.M.; Pablant, N.A.; Rudakov, D.L.; Boedo, J.A.; Brooks, N.H.; Jernigan, Thomas C.; Pigarov, A.Y.

    2009-01-01

    Spectroscopy and wall the bake-out measurements are performed in the DIII-D tokamak to estimate the amount of hydrogen stored in and released from the walls during disruptions. Both naturally occurring disruptions and disruptions induced by massive gas injection (MGI) are investigated. The measurements indicate that both types of disruptions cause a net release of order 10(21) hydrogen (or deuterium) atoms from the graphite walls. This is comparable to the pre-disruptions plasma particle inventory, so the released hydrogen is important for accurate modeling of disruptions. However, the amount of hydrogen released is small compared to the total saturated wall inventory of order 10(22)-10(23), So it appears that many disruptions are necessary to provide full pump-out of the vessel walls. (C) 2009 Published by Elsevier B.V.

  3. PWR-GALE, Radioactive Gaseous Release and Liquid Release from PWR

    International Nuclear Information System (INIS)

    Chandrasekaran, T.; Lee, J.Y.; Willis, C.A.

    1988-01-01

    1 - Description of program or function: The PWR-GALE (Boiling Water Reactor Gaseous and Liquid Effluents) Code is a computerized mathematical model for calculating the release of radioactive material in gaseous and liquid effluents from pressurized water reactors (PWRs). The calculations are based on data generated from operating reactors, field tests, laboratory tests, and plant-specific design considerations incorporated to reduce the quantity of radioactive materials that may be released to the environment. 2 - Method of solution: GALE calculates expected releases based on 1) standardized coolant activities derived from ANS Standards 18.1 Working Group recommendations, 2) release and transport mechanisms that result in the appearance of radioactive material in liquid and gaseous waste streams, 3) plant-specific design features used to reduce the quantities of radioactive materials ultimately released to the environs, and 4) information received on the operation of nuclear power plants. 3 - Restrictions on the complexity of the problem: The liquid release portion of GALE uses subroutines taken from the ORIGEN (CCC-217) to calculate radionuclide buildup and decay during collection, processing, and storage of liquid radwaste. Memory requirements for this part of the program are determined by the large nuclear data base accessed by these subroutines

  4. Formulation And Evaluation Of Bilayer Tablet for Bimodal Release of Venlafaxine Hydrochloride

    Directory of Open Access Journals (Sweden)

    Munira eMomin

    2015-07-01

    Full Text Available The aim of the present research was to develop a bilayer tablet of venlafexine hydrochloride for bimodal drug release. In the present investigation authors have tried to explore Fenugreek Mucilage (FNM for bioadhesive sustained release layer. The attempt has been made to combine FNM with well studied bioahesive polymers like Hydroxy Propyl Methyl Cellulose, Carbopol and Xanthan Gum. The formulations were evaluated for swelling Index, ex-vivo bioadhesion, water uptake studies, in-vitro drug release and dissolution kinetics was studied. Substantial bioadhesion force (2.4±0.023 gms and tablet adhesion retention time (24±2 hrs was observed with FNM and HPMC combination at 80:20 ratio. The dissolution kinetics followed the Higuchi model (R2 =0.9913 via a non-Fickian diffusion controlled release mechanism after the initial burst. The 32 full factorial design was employed in the present study. The type of polymers used in combination with FNM (X1 and percent polymer replaced with FNM (X2 were taken as independent formulations variables. The selected responses, bioadhesion force (0.11-0.25±0.023gm, amount of drug released in 10 h, Y10 (78.20–95.78±1.24 % and bioadhesive strength, (19-24±2hrs presented good correlation with the selected independent variables. Statistical analysis (ANOVA of the optimized bilayer formulations showed no significant difference in the cumulative amount of drug release after 15 min, but significant difference (p < 0.05 in the amount of drug released after 1 hr till 12 h from optimized formulations was observed. The natural mucilage like FNM could be successfully incorporated into tablet with only 20% replacement with HPMC and it showed good bioadhesiveness and sustained drug release.

  5. Preparation and controlled release of mesoporous MCM-41/propranolol hydrochloride composite drug.

    Science.gov (United States)

    Zhai, Qing-Zhou

    2013-01-01

    This article used MCM-41 as a carrier for the assembly of propranolol hydrochloride by the impregnation method. By means of chemical analysis, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy and low-temperature N(2) adsorption-desorption at 77 K, the characterization was made for the prepared materials. The propranolol hydrochloride guest assembly capacity was 316.20 ± 0.31 mg/g (drug/MCM-41). Powder XRD test results indicated that during the process of incorporation, the frameworks of the MCM-41 were not destroyed and the crystalline degrees of the host-guest nanocomposite materials prepared still remained highly ordered. Characterization by SEM and TEM showed that the composite material presented spherical particle and the average particle size of composite material was 186 nm. FT-IR spectra showed that the MCM-41 framework existed well in the (MCM-41)-propranolol hydrochloride composite. Low-temperature nitrogen adsorption-desorption results at 77 K showed that the guest partially occupied the channels of the molecular sieves. Results of the release of the prepared composite drug in simulated body fluid indicated that the drug can release up to 32 h and its maximum released amount was 99.20 ± 0.11%. In the simulated gastric juice release pattern of drug, the maximum time for the drug release was discovered to be 6 h and the maximum cumulative released amount of propranolol hydrochloride was 45.13 ± 0.23%. The drug sustained-release time was 10 h in simulated intestinal fluid and the maximum cumulative released amount was 62.05 ± 0.13%. The prepared MCM-41 is a well-controlled drug delivery carrier.

  6. Effect of non-cross-linked calcium on characteristics, swelling behaviour, drug release and mucoadhesiveness of calcium alginate beads.

    Science.gov (United States)

    Dalaty, Adnan Al; Karam, Ayman; Najlah, Mohammad; Alany, Raid G; Khoder, Mouhamad

    2016-04-20

    In this study, ibuprofen-loaded calcium alginate beads (CABs) with varying amounts of non-cross-linked calcium (NCL-Ca) were prepared using different washing methods. The influence of NCL-Ca on beads properties was investigated. Increasing the number or duration of washes led to significant decreases in the amount of NCL-Ca whereas the impact of the volume of washes was not significant. Approximately 70% of the initial amount of Ca(2+) was NCL-Ca which was removable by washing while only 30% was cross-linked (CL-Ca). Ca(2+) release from the CABs was bimodal; NCL-Ca was burst-released followed by a slower release of CL-Ca. Washing methods and the amount of NCL-Ca had significant influences on the encapsulation efficiency, beads weight, beads swelling, drug release profile and the mucoadhesiveness of CABs. This study highlighted the importance of washing methods and the amount of NCL-Ca to establish CABs properties and understand their behaviour in the simulated intestinal fluids (SIFs). Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Automated analysis for large amount gaseous fission product gamma-scanning spectra from nuclear power plant and its data mining

    International Nuclear Information System (INIS)

    Weihua Zhang; Kurt Ungar; Ian Hoffman; Ryan Lawrie; Jarmo Ala-Heikkila

    2010-01-01

    Based on the Linssi database and UniSampo/Shaman software, an automated analysis platform has been setup for the analysis of large amounts of gamma-spectra from the primary coolant monitoring systems of a CANDU reactor. Thus, a database inventory of gaseous and volatile fission products in the primary coolant of a CANDU reactor has been established. This database is comprised of 15,000 spectra of radioisotope analysis records. Records from the database inventory were retrieved by a specifically designed data-mining module and subjected to further analysis. Results from the analysis were subsequently used to identify the reactor coolant half-life of 135 Xe and 133 Xe, as well as the correlations of 135 Xe and 88 Kr activities. (author)

  8. Equilibrium and kinetic models for colloid release under transient solution chemistry conditions

    Science.gov (United States)

    We present continuum models to describe colloid release in the subsurface during transient physicochemical conditions. Our modeling approach relates the amount of colloid release to changes in the fraction of the solid surface area that contributes to retention. Equilibrium, kinetic, equilibrium and...

  9. Effect of Food Emulsifiers on Aroma Release

    Directory of Open Access Journals (Sweden)

    Jia-Jia Li

    2016-04-01

    Full Text Available This study aimed to determine the influence of different emulsifiers or xanthan-emulsifier systems on the release of aroma compounds. Solid-phase microextraction (SPME and GC-MS were used to study the effects of varying concentrations of xanthan gum, sucrose fatty acid ester, Tween 80 and soybean lecithin on the release of seven aroma compounds. The effects of the emulsifier systems supplemented with xanthan gum on aroma release were also studied in the same way. The results showed varying degrees of influence of sucrose fatty acid ester, soybean lecithin, Tween 80 and xanthan gum on the release of aroma compounds. Compared with other aroma compounds, ethyl acetate was more likely to be conserved in the solution system, while the amount of limonene released was the highest among these seven aroma compounds. In conclusion, different emulsifiers and complexes showed different surface properties that tend to interact with different aroma molecules. The present studies showed that the composition and structure of emulsifiers and specific interactions between emulsifiers and aroma molecules have significant effects on aroma release.

  10. The virion RNA species of the Kirsten murine sarcoma-leukemia virus complex released from a clonally related series of mouse cells

    International Nuclear Information System (INIS)

    Clewley, J.P.; Avery, R.J.

    1982-01-01

    We have characterized the virion RNA species of Kirsten sarcoma (KiSV) and Kirsten leukemia (KiLV) viruses released from a clonally related series of mouse cells (14). We have identified the KiLV and KiSV genome RNAs. In addition to the viral RNA species we find large amounts of a virus-like RNA (VL30 RNA), which is heterogeneous and shows variability in its expression. The amount of VL30 RNA in virions does not correlate with the state of transformation of the cells releasing the virus or the ability of the virus to transform other cells. Characterization of RNA rescued from non-producer cells has revealed a sarcoma virus (KiSVsub(SB3) with an oligonucleotide fingerprint different from that of a standard KiSV RNA, suggesting that it has lost some viral sequences. The oligonucleotide fingerprints of KiLV and VL30 RNAs are distinct from each other and from those reported for other murine leukemia virus RNAs. (Author)

  11. Influence of Bifidobacterium bifidum on release of minerals from bread with differing bran content.

    Science.gov (United States)

    Nalepa, Beata; Siemianowska, Ewa; Skibniewska, Krystyna Anna

    2012-01-01

    Bread is considered an important source of minerals; however, the presence of fiber and phytic acid reduces bioavailability of minerals from cereal products. It is well established that activity of microorganisms in human gut increases the amount of nutrients released during digestion. The aim of this study was to determine the influence of Bifidobacterium bifidum on release of some minerals from bread using an in vitro process of enzymatic digestion. White bread and with addition of 15, 30, or 45% of bran was baked in a bakery by traditional methods, with addition of yeasts and rye leaven, from flour made of wheat, Tonacja variety. Concentrations of calcium, magnesium, manganese, zinc, copper, and iron were determined by atomic absorption spectrometry. Bread was enzymatically digested in vitro without and with the addition of Bifidobacterium bifidum KD6 (inoculum 10(6) CFU/cm(3)) and percentages of minerals released were determined. The concentration of minerals released during enzymatic digestion varied depending upon the element, quantity of bran, and presence of bacteria. Increase in bran content decreased release of elements. Bifidobacterium bifidum KD6 enhanced amounts of magnesium and zinc released from all types of bread, while manganese and copper rose only from white bread with 15% bran addition. Bacteria decreased amounts of calcium and iron released from bread. Data indicate that diets rich in beneficial bacteria (probiotics) but not balanced with minerals might increase mineral deficiency.

  12. Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

    Directory of Open Access Journals (Sweden)

    César A. Estévez

    2014-12-01

    Full Text Available All mammals lose their ability to produce lactase (β-galactosidase, the enzyme that cleaves lactose into galactose and glucose, after weaning. The prevalence of lactase deficiency (LD spans from 2 to 15% among northern Europeans, to nearly 100% among Asians. Following lactose consumption, people with LD often experience gastrointestinal symptoms such as abdominal pain, bowel distension, cramps and flatulence, or even systemic problems such as headache, loss of concentration and muscle pain. These symptoms vary depending on the amount of lactose ingested, type of food and degree of intolerance. Although those affected can avoid the uptake of dairy products, in doing so, they lose a readily available source of calcium and protein. In this work, gels obtained by complexation of Tetronic 90R4 with α-cyclodextrin loaded with β-galactosidase are proposed as a way to administer the enzyme immediately before or with the lactose-containing meal. Both molecules are biocompatible, can form gels in situ, and show sustained erosion kinetics in aqueous media. The complex was characterized by FTIR that evidenced an inclusion complex between the polyethylene oxide block and α-cyclodextrin. The release profiles of β-galactosidase from two different matrices (gels and tablets of the in situ hydrogels have been obtained. The influence of the percentage of Tetronic in media of different pH was evaluated. No differences were observed regarding the release rate from the gel matrices at pH 6 (t50 = 105 min. However, in the case of the tablets, the kinetics were faster and they released a greater amount of 90R4 (25%, t50 = 40–50 min. Also, the amount of enzyme released was higher for mixtures with 25% Tetronic. Using suitable mathematical models, the corresponding kinetic parameters have been calculated. In all cases, the release data fit quite well to the Peppas–Sahlin model equation, indicating that the release of β-galactosidase is governed by a

  13. Assessment of the Potential Release of Radioactivity from Installations at AERE, Harwell. Implications for Emergency Planning

    Energy Technology Data Exchange (ETDEWEB)

    Flew, Elizabeth M.; Lister, B. A.J. [Atomic Energy Research Establishment, Harwell, Didcot, Berks. (United Kingdom)

    1969-10-15

    As part of a review of the site emergency organization at AERE, a realistic reappraisal has been made of the potential hazard to the establishment and district of all the buildings containing significant amounts of radioactive materials. To assess the amount of radioactive material which might be released under specified accident conditions, four factors have been applied to the total building stock: (a) the fraction of the stock involved, (b) the percentage conversion to an aerosol form, (c) release from primary containment and (d) release from the building. These potential release figures have been compared with ''site hazardous release'' figures for relevant radionuclides i.e., amounts which could give rise to exposure above defined reference levels. Those buildings with more than one tenth of the potential for causing; a site or district hazard have been designated ''risk buildings''. Such a quantitative assessment, although necessarily very approximate, has been of considerable value in determining the type and complexity of the central emergency organization required and in producing the right emphasis on exercises, training, liaison with outside bodies, etc. (author)

  14. Influence of Citric Acid on the Metal Release of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Mazinanian, N.; Wallinder, I. Odnevall; Hedberg, Y. S. [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Stockholm (Sweden)

    2015-08-15

    Knowledge of how metal releases from the stainless steels used in food processing applications and cooking utensils is essential within the framework of human health risk assessment. A new European standard test protocol for testing metal release in food contact materials made from metals and alloys has recently been published by the Council of Europe. The major difference from earlier test protocols is the use of citric acid as the worst-case food simulant. The objectives of this study were to assess the effect of citric acid at acidic, neutral, and alkaline solution pH on the extent of metal release for stainless steel grades AISI 304 and 316, commonly used as food contact materials. Both grades released lower amounts of metals than the specific release limits when they were tested according to test guidelines. The released amounts of metals were assessed by means of graphite furnace atomic absorption spectroscopy, and changes in the outermost surface composition were determined using X-ray photoelectron spectroscopy. The results demonstrate that both the pH and the complexation capacity of the solutions affected the extent of metal release from stainless steel and are discussed from a mechanistic perspective. The outermost surface oxide was significantly enriched in chromium upon exposure to citric acid, indicating rapid passivation by the acid. This study elucidates the effect of several possible mechanisms, including complex ion- and ligand-induced metal release, that govern the process of metal release from stainless steel under passive conditions in solutions that contain citric acid.

  15. Rhizosphere Environment and Labile Phosphorus Release from Organic Waste-Amended Soils.

    Science.gov (United States)

    Dao, Thanh H.

    2015-04-01

    Crop residues and biofertilizers are primary sources of nutrients for organic crop production. However, soils treated with large amounts of nutrient-enriched manure have elevated phosphorus (P) levels in regions of intensive animal agriculture. Surpluses occurred in these amended soils, resulting in large pools of exchangeable inorganic P (Pi) and enzyme-labile organic P (Po) that averaging 30.9 and 68.2 mg kg-1, respectively. Organic acids produced during crop residue decomposition can promote the complexation of counter-ions and decouple and release unbound Pi from metal and alkali metal phosphates. Animal manure and cover crop residues also contain large amounts of soluble organic matter, and likely generate similar ligands. However, a high degree of heterogeneity in P spatial distribution in such amended fields, arising from variances in substrate physical forms ranging from slurries to dried solids, composition, and diverse application methods and equipment. Distinct clusters of Pi and Po were observed, where accumulation of the latter forms was associated with high soil microbial biomass C and reduced phosphomonoesterases' activity. Accurate estimates of plant requirements and lability of soil P pools, and real-time plant and soil P sensing systems are critical considerations to optimally manage manure-derived nutrients in crop production systems. An in situ X-ray fluorescence-based approach to sensing canopy and soil XRFS-P was developed to improve the yield-soil P relationship for optimal nutrient recommendations in addition to allowing in-the-field verification of foliar P status.

  16. Amount and timing of permafrost carbon release in response to climate warming

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Kevin; Zhang, Tingjun; Barrett, Andrew P. (National Snow and Ice Data Center, Cooperative Inst. for Research in Environmental Sciences, Univ. of Colorado at Boulder, Boulder (United States)), e-mail: kevin.schaefer@nsidc.org; Bruhwiler, Lori (National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Boulder (United States))

    2011-04-15

    The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO{sub 2} concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate.We use surface weather from three global climate models based on the moderate warming, A1B Intergovernmental Panel on Climate Change emissions scenario and the SiBCASA land surface model to estimate the strength and timing of the PCF and associated uncertainty. By 2200, we predict a 29-59% decrease in permafrost area and a 53-97 cm increase in active layer thickness. By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 +- 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO{sub 2} concentration

  17. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  18. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    International Nuclear Information System (INIS)

    S.O. Bader

    1999-01-01

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  19. How restrained eaters perceive the amount they eat.

    Science.gov (United States)

    Jansen, A

    1996-09-01

    The cognitive model of binge eating states that it is the awareness of a broken diet that disinhibits the restrained eater. It is, according to that model, the perception of having overeaten that triggers disinhibited eating. However, although the perception of the amount eaten plays a central role in cognitive restraint theory, it has never directly been tested how restrained subjects perceive the amount of food they eat. In the present studies, participants were given ad libitum access to large amounts of palatable food and both their perception of the amount eaten and their estimated caloric intake were compared with the amount they actually ate. The restrained participants in these studies ate more than the unrestrained participants. In the first and second studies, the restrained participants consumed 571 and 372 'forbidden' calories respectively, without having the feeling that they had eaten very much, let alone too much. Moreover in both studies, the restrained eaters underestimated their caloric intake, whereas unrestrained eaters estimated their caloric intake quite well. The potential implications of the present findings for the cognitive restraint model are discussed.

  20. Antimony leaching release from brake pads: Effect of pH, temperature and organic acids.

    Science.gov (United States)

    Hu, Xingyun; He, Mengchang; Li, Sisi

    2015-03-01

    Metals from automotive brake pads pollute water, soils and the ambient air. The environmental effect on water of antimony (Sb) contained in brake pads has been largely untested. The content of Sb in one abandoned brake pad reached up to 1.62×10(4) mg/kg. Effects of initial pH, temperature and four organic acids (acetic acid, oxalic acid, citric acid and humic acid) on Sb release from brake pads were studied using batch reactors. Approximately 30% (97 mg/L) of the total Sb contained in the brake pads was released in alkaline aqueous solution and at higher temperature after 30 days of leaching. The organic acids tested restrained Sb release, especially acetic acid and oxalic acid. The pH-dependent concentration change of Sb in aqueous solution was best fitted by a logarithmic function. In addition, Sb contained in topsoil from land where brake pads were discarded (average 9×10(3) mg/kg) was 3000 times that in uncontaminated soils (2.7±1 mg/kg) in the same areas. Because potentially high amounts of Sb may be released from brake pads, it is important that producers and environmental authorities take precautions. Copyright © 2015. Published by Elsevier B.V.

  1. Large-scale deposition of weathered oil in the Gulf of Mexico following a deep-water oil spill.

    Science.gov (United States)

    Romero, Isabel C; Toro-Farmer, Gerardo; Diercks, Arne-R; Schwing, Patrick; Muller-Karger, Frank; Murawski, Steven; Hollander, David J

    2017-09-01

    The blowout of the Deepwater Horizon (DWH) drilling rig in 2010 released an unprecedented amount of oil at depth (1,500 m) into the Gulf of Mexico (GoM). Sedimentary geochemical data from an extensive area (∼194,000 km 2 ) was used to characterize the amount, chemical signature, distribution, and extent of the DWH oil deposited on the seafloor in 2010-2011 from coastal to deep-sea areas in the GoM. The analysis of numerous hydrocarbon compounds (N = 158) and sediment cores (N = 2,613) suggests that, 1.9 ± 0.9 × 10 4 metric tons of hydrocarbons (>C9 saturated and aromatic fractions) were deposited in 56% of the studied area, containing 21± 10% (up to 47%) of the total amount of oil discharged and not recovered from the DWH spill. Examination of the spatial trends and chemical diagnostic ratios indicate large deposition of weathered DWH oil in coastal and deep-sea areas and negligible deposition on the continental shelf (behaving as a transition zone in the northern GoM). The large-scale analysis of deposited hydrocarbons following the DWH spill helps understanding the possible long-term fate of the released oil in 2010, including sedimentary transformation processes, redistribution of deposited hydrocarbons, and persistence in the environment as recycled petrocarbon. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Do the monomers release from the composite resins after artificial aging?

    Science.gov (United States)

    Tokay, Ugur; Koyuturk, Alp Erdin; Aksoy, Abdurrahman; Ozmen, Bilal

    2015-04-01

    The aim of this study is to measure the effect of thermal cycling on the amount of monomer released from three different composite materials by HPLC analysis method. Three different composite materials, inlay composite, posterior composite and micro-hybrid composite were used. Sixty cylinder specimens each with a dimension of approximately 1 cm width and 3 mm depth, were prepared before experiments were carried out. Inlay composite material was polymerized according to manufacturers' instructions. Thermal cycling device was used to simulate thermal differences which occur in the mouth media. Monomers were analyzed using HPLC technic after thermal cycling process. The amount of ethoxylated Bis-GMA and urethane dimethacrylate (UDMA) in inlay composite material, the amount of ethoxylated Bis-GMA in posterior composite material, the amount of ethoxylated Bis-GMA and triethyleneglycol dimethacrylate (TEGDMA) in micro-hybrid composite material were investigated. Monomer release of thermal cycles levels showed a linear increase in UDMA and TEGDMA (P < 0.05). In terms of thermal cycles levels, Bis-EMA released from posterior composite showed a cubic change (P < 0.001). It was observed that use of additional polymerization processes might have positive effect on the decrease of residual monomer. In the light of the results, we suggest that indirect composite resins have more outstanding features than direct composite resins in terms of biocompatibility. © 2015 Wiley Periodicals, Inc.

  3. An in vitro comparison of nickel and chromium release from brackets

    Directory of Open Access Journals (Sweden)

    Ana Cristina Soares Santos Haddad

    2009-12-01

    Full Text Available This study aimed at comparing amounts of nickel (Ni and chromium (Cr released from brackets from different manufacturers in simulated oral environments. 280 brackets were equally divided into 7 groups according to manufacturer. 6 groups of brackets were stainless steel, and 1 group of brackets was made of a cobalt-chromium alloy with low Ni content (0.5%. International standard ISO 10271/2001 was applied to provide test methods. Each bracket was immersed in 0.5 ml of synthetic saliva (SS or artificial plaque fluid (PF over a period of 28 days at 37ºC. Solutions were replaced every 7 days, and were analyzed by spectrometry. The Kruskal-Wallis test was applied. Amounts of Ni release in SS (µg L-1 per week varied between groups from "bellow detection limits" to 694, and from 49 to 5,948.5 in PF. The group of brackets made of cobalt-chromium alloy, with the least nickel content, did not release the least amounts of Ni. Amounts of Cr detected in SS and in PF (µg L-1 per week were from 1 to 10.4 and from 50.5 to 8,225, respectively. It was therefore concluded that brackets from different manufacturers present different corrosion behavior. Further studies are necessary to determine clinical implications of the findings.

  4. Radioisotopic composition of yellowcake: an estimation of stack release rates

    International Nuclear Information System (INIS)

    Momeni, M.H.; Kisieleski, W.E.; Rayno, D.R.; Sabau, C.S.

    1979-12-01

    Uranium concentrate (yellowcake) composites from four mills (Anaconda, Kerr-McGee, Highland, and Uravan) were analyzed for U-238, U-235, U-234, Th-230, Ra-226, and Pb-210. The ratio of specific activities of U-238 to U-234 in the composites suggested that secular radioactive equilibrium exists in the ore. The average activity ratios in the yellowcake were determined to be 2.7 x 10 -3 (Th-230/U-238), 5 x 10 -4 (Ra-226/U-238) and 2 x 10 -4 (Pb-210/U-238). Based on earlier EPA measurements of the release rates from the stacks, the amount of yellowcake released was determined to be 0.1% of the amount processed

  5. Synthesis of biodiesel from waste vegetable oil with large amounts of free fatty acids using a carbon-based solid acid catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Qing; Gao, Jixian; Nawaz, Zeeshan; Liao, Yuhui; Wang, Dezheng; Wang, Jinfu [Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

    2010-08-15

    A carbon-based solid acid catalyst was prepared by the sulfonation of carbonized vegetable oil asphalt. This catalyst was employed to simultaneously catalyze esterification and transesterification to synthesis biodiesel when a waste vegetable oil with large amounts of free fatty acids (FFAs) was used as feedstock. The physical and chemical properties of this catalyst were characterized by a variety of techniques. The maximum conversion of triglyceride and FFA reached 80.5 wt.% and 94.8 wt.% after 4.5 h at 220 C, when using a 16.8 M ratio of methanol to oil and 0.2 wt.% of catalyst to oil. The high catalytic activity and stability of this catalyst was related to its high acid site density (-OH, Broensted acid sites), hydrophobicity that prevented the hydration of -OH species, hydrophilic functional groups (-SO{sub 3}H) that gave improved accessibility of methanol to the triglyceride and FFAs, and large pores that provided more acid sites for the reactants. (author)

  6. Controlled drug release on amine functionalized spherical MCM-41

    Energy Technology Data Exchange (ETDEWEB)

    Szegedi, Agnes, E-mail: szegedi@chemres.hu [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67 (Hungary); Popova, Margarita; Goshev, Ivan [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Klebert, Szilvia [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67 (Hungary); Mihaly, Judit [Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67 (Hungary)

    2012-10-15

    MCM-41 silica with spherical morphology and small particle sizes (100 nm) was synthesized and modified by post-synthesis method with different amounts of 3-aminopropyltriethoxysilane (APTES). A comparative study of the adsorption and release of a model drug, ibuprofen, was carried out. The modified and drug loaded mesoporous materials were characterized by XRD, TEM, N{sub 2} physisorption, elemental analysis, thermal analysis and FT-IR spectroscopy. A new method was developed for the quantitative determination of amino groups in surface modified mesoporous materials by the ninhydrin reaction. Good correlation was found between the amino content of the MCM-41 materials determined by the ninhydrin method and their ibuprofen adsorption capacity. Amino modification resulted in high degree of ibuprofen loading and slow release rate in comparison to the parent non-modified MCM-41. - Graphical abstract: Determination of surface amino groups by ninhidrin method. Highlights: Black-Right-Pointing-Pointer Spherical MCM-41 modified by different amounts of APTES was studied. Black-Right-Pointing-Pointer Ibuprofen (IBU) adsorption and release characteristics was tested. Black-Right-Pointing-Pointer The ninhydrin reaction was used for the quantitative determination of amino groups. Black-Right-Pointing-Pointer Stoichiometric amount of APTES is enough for totally covering the surface with amino groups. Black-Right-Pointing-Pointer Good correlation was found between the amino content and IBU adsorption capacity.

  7. Comparison Analysis among Large Amount of SNS Sites

    Science.gov (United States)

    Toriumi, Fujio; Yamamoto, Hitoshi; Suwa, Hirohiko; Okada, Isamu; Izumi, Kiyoshi; Hashimoto, Yasuhiro

    In recent years, application of Social Networking Services (SNS) and Blogs are growing as new communication tools on the Internet. Several large-scale SNS sites are prospering; meanwhile, many sites with relatively small scale are offering services. Such small-scale SNSs realize small-group isolated type of communication while neither mixi nor MySpace can do that. However, the studies on SNS are almost about particular large-scale SNSs and cannot analyze whether their results apply for general features or for special characteristics on the SNSs. From the point of view of comparison analysis on SNS, comparison with just several types of those cannot reach a statistically significant level. We analyze many SNS sites with the aim of classifying them by using some approaches. Our paper classifies 50,000 sites for small-scale SNSs and gives their features from the points of network structure, patterns of communication, and growth rate of SNS. The result of analysis for network structure shows that many SNS sites have small-world attribute with short path lengths and high coefficients of their cluster. Distribution of degrees of the SNS sites is close to power law. This result indicates the small-scale SNS sites raise the percentage of users with many friends than mixi. According to the analysis of their coefficients of assortativity, those SNS sites have negative values of assortativity, and that means users with high degree tend to connect users with small degree. Next, we analyze the patterns of user communication. A friend network of SNS is explicit while users' communication behaviors are defined as an implicit network. What kind of relationships do these networks have? To address this question, we obtain some characteristics of users' communication structure and activation patterns of users on the SNS sites. By using new indexes, friend aggregation rate and friend coverage rate, we show that SNS sites with high value of friend coverage rate activate diary postings

  8. Employment of the porous particles for preparation of the capsules containing aspirin and drug release property

    International Nuclear Information System (INIS)

    Hosoi, Fumio; Makuuchi, Keizo; Saito, Kenji; Koishi, Masumi.

    1985-01-01

    Polymer-coated porous particles containing aspirin as a drug were prepared and the rate of release of aspirin was studied. The impregnation of aspirin was carried out by post-graft polymerization, where methyl methacrylate or methacrylic acid was treated with porous particles, pre-irradiated with γ-ray from 60 Co, in the presence of aspirin. Release of aspirin from modified particles was tested with 50 % methanol solution and/or pH 5.2 buffer solution of acetic acid. The amount of aspirin released from capsules increased with time and reached a constant values after 140 h. The amount of aspirin absorbed in porous particles was increased with graft polymerization. In addition, absorption of aspirin in porous particles was significantly enhanced by treating the particle surface with TiO 2 before irradiation. The amount of aspirin released was linearly to the square root of time. It was concluded that the diffusion of aspirin through the polymer matrix was the rate limiting step. (author)

  9. Ultrasound stimulated release of gallic acid from chitin hydrogel matrix

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huixin; Kobayashi, Takaomi, E-mail: takaomi@nagaokaut.ac.jp

    2017-06-01

    Ultrasound (US) stimulated drug release was examined in this study using a chitin hydrogel matrix loaded with gallic acid (GA), a drug used for wound healing and anticancer. Using phase inversion, GA-chitin hydrogels were prepared from chitin-dimethylacetamide (DMAc)/lithium chloride (LiCl) solution in the presence of GA, with 24 h exposure of the solution to water vapor. The GA release from the GA-chitin hydrogel was examined under different US powers of 0–30 W at 43 kHz. The effects of GA loading amounts in the hydrogels (0.54, 0.43, and 0.25 mg/cm{sup 3}) and chitin concentrations (0.1, 0.5, and 1 wt%) on the release behaviors were recorded under 43 kHz US exposure at 30 W. Results show that US accelerated the release efficiencies for all samples. Furthermore, the release efficiency increased concomitantly with increasing US power, GA loading amount, and decrease of the chitin concentration. The highest release rate of 0.74 μg/mL·min was obtained from 0.54 mg/cm{sup 3} of GA-loaded hydrogel fabricated from a 0.1 wt% chitin mixture solution under 43 kHz US exposure at 30 W: nine times higher than that of the sample without US exposure. The hydrogel viscoelasticity demonstrated that the US irradiation rigidified the material. FT-IR showed that US can break the hydrogen bonds in the GA-chitin hydrogels. - Highlights: • Ultrasound (US) stimulated Gallic acid (GA) release from chitin hydrogel was studied. • The release efficiency of GA from chitin hydrogel increased nine times when irradiated by 43 kHz US compared with the sample without US. • Generalized 2D correlation and deconvolution study of FT-IR showed that US could promote the GA release by breaking hydrogen bonds.

  10. Ultrasound stimulated release of gallic acid from chitin hydrogel matrix

    International Nuclear Information System (INIS)

    Jiang, Huixin; Kobayashi, Takaomi

    2017-01-01

    Ultrasound (US) stimulated drug release was examined in this study using a chitin hydrogel matrix loaded with gallic acid (GA), a drug used for wound healing and anticancer. Using phase inversion, GA-chitin hydrogels were prepared from chitin-dimethylacetamide (DMAc)/lithium chloride (LiCl) solution in the presence of GA, with 24 h exposure of the solution to water vapor. The GA release from the GA-chitin hydrogel was examined under different US powers of 0–30 W at 43 kHz. The effects of GA loading amounts in the hydrogels (0.54, 0.43, and 0.25 mg/cm 3 ) and chitin concentrations (0.1, 0.5, and 1 wt%) on the release behaviors were recorded under 43 kHz US exposure at 30 W. Results show that US accelerated the release efficiencies for all samples. Furthermore, the release efficiency increased concomitantly with increasing US power, GA loading amount, and decrease of the chitin concentration. The highest release rate of 0.74 μg/mL·min was obtained from 0.54 mg/cm 3 of GA-loaded hydrogel fabricated from a 0.1 wt% chitin mixture solution under 43 kHz US exposure at 30 W: nine times higher than that of the sample without US exposure. The hydrogel viscoelasticity demonstrated that the US irradiation rigidified the material. FT-IR showed that US can break the hydrogen bonds in the GA-chitin hydrogels. - Highlights: • Ultrasound (US) stimulated Gallic acid (GA) release from chitin hydrogel was studied. • The release efficiency of GA from chitin hydrogel increased nine times when irradiated by 43 kHz US compared with the sample without US. • Generalized 2D correlation and deconvolution study of FT-IR showed that US could promote the GA release by breaking hydrogen bonds.

  11. STUDIES ON THE PATHOGENESIS OF FEVER. 13. THE EFFECT OF PHAGOCYTOSIS ON THE RELEASE OF ENDOGENOUS PYROGEN BY POLYMORPHONUCLEAR LEUKOCYTES.

    Science.gov (United States)

    BERLIN, R D; WOOD, W B

    1964-05-01

    1. Phagocytosis promotes the release of endogenous pyrogen from polymorphonuclear leucocytes. 2. The release of pyrogen, though initiated by the phagocytic event, is not synchronous with it. 3. The postphagocytic release mechanism is not inhibited by sodium fluoride and, therefore, appears not to require continued production of energy by the cell. 4. The release process, on the other hand, is inhibited by arsenite, suggesting the participation of one or more sulfhydryl-dependent enzymes in the over-all reaction. 5. Particle for particle, the ingestion of heat-killed rough pneumococci causes the release of approximately 100 times as much pyrogen as the ingestion of polystyrene beads of the same size. 6. The pyrogen release mechanism of polymorphonuclear leucocytes separated directly from blood, unlike that of granulocytes in acute inflammatory exudates, is not readily activated by incubation of the cells in K-free saline. Despite this difference, both blood and exudate leucocytes following phagocytosis release large amounts of pyrogen, even in the presence of K(+). The fact that the postphagocytic reaction is uninhibited by the concentrations of K(+) which are present in plasma and extracellular fluids, suggests that this mechanism of pyrogen release may well operate in vivo. 7. As might be expected from the foregoing observations, the intravenous injection of a sufficiently large number of heat-killed pneumococci causes fever in the intact host. Intravenously injected polystyrene beads, on the other hand, are significantly less pyrogenic. Evidence is presented to support the conclusion that the fever in both instances is caused by pyrogen released from the circulating leucocytes which have phagocyted the injected particles. 8. The possible relationships of these findings to the pathogenesis of fevers caused by acute bacterial infections are discussed.

  12. Methane release

    International Nuclear Information System (INIS)

    Seifert, M.

    1999-01-01

    The Swiss Gas Industry has carried out a systematic, technical estimate of methane release from the complete supply chain from production to consumption for the years 1992/1993. The result of this survey provided a conservative value, amounting to 0.9% of the Swiss domestic output. A continuation of the study taking into account new findings with regard to emission factors and the effect of the climate is now available, which provides a value of 0.8% for the target year of 1996. These results show that the renovation of the network has brought about lower losses in the local gas supplies, particularly for the grey cast iron pipelines. (author)

  13. The interrelationships of thyroid and growth hormones: effect of growth hormone releasing hormone in hypo- and hyperthyroid male rats.

    Science.gov (United States)

    Root, A W; Shulman, D; Root, J; Diamond, F

    1986-01-01

    Growth hormone (GH) and the thyroid hormones interact in the hypothalamus, pituitary and peripheral tissues. Thyroid hormone exerts a permissive effect upon the anabolic and metabolic effects of GH, and increases pituitary synthesis of this protein hormone. GH depresses the secretion of thyrotropin and the thyroid hormones and increases the peripheral conversion of thyroxine to triiodothyronine. In the adult male rat experimental hypothyroidism produced by ingestion of propylthiouracil depresses the GH secretory response to GH-releasing hormone in vivo and in vitro, reflecting the lowered pituitary stores of GH in the hypothyroid state. Short term administration of large amounts of thyroxine with induction of the hyperthyroid state does not affect the in vivo GH secretory response to GH-releasing hormone in this animal.

  14. DETERMINATION OF METAL IONS RELEASED BY STAINLESS ...

    African Journals Online (AJOL)

    The amounts of cobalt, iron, manganese, nickel and chromium ions released from new and reused stainless steel arch bar used for maxillomandibular fixation was determined in Hank's solutions of different hydrogen and chloride ions concentrations, whole blood serum and phosphate buffered saline (PBS) in vitro, over a ...

  15. Released air during vapor and air cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Jablonská, Jana, E-mail: jana.jablonska@vsb.cz; Kozubková, Milada, E-mail: milada.kozubkova@vsb.cz [VŠB-Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Hydromechanics and Hydraulic Equipment, 17. listopadu 15, 708 33 Ostrava-Poruba (Czech Republic)

    2016-06-30

    Cavitation today is a very important problem that is solved by means of experimental and mathematical methods. The article deals with the generation of cavitation in convergent divergent nozzle of rectangular cross section. Measurement of pressure, flow rate, temperature, amount of dissolved air in the liquid and visualization of cavitation area using high-speed camera was performed for different flow rates. The measurement results were generalized by dimensionless analysis, which allows easy detection of cavitation in the nozzle. For numerical simulation the multiphase mathematical model of cavitation consisting of water and vapor was created. During verification the disagreement with the measurements for higher flow rates was proved, therefore the model was extended to multiphase mathematical model (water, vapor and air), due to release of dissolved air. For the mathematical modeling the multiphase turbulence RNG k-ε model for low Reynolds number flow with vapor and air cavitation was used. Subsequently the sizes of the cavitation area were verified. In article the inlet pressure and loss coefficient depending on the amount of air added to the mathematical model are evaluated. On the basis of the approach it may be create a methodology to estimate the amount of released air added at the inlet to the modeled area.

  16. Computational modeling and analysis of iron release from macrophages.

    Directory of Open Access Journals (Sweden)

    Alka A Potdar

    2014-07-01

    Full Text Available A major process of iron homeostasis in whole-body iron metabolism is the release of iron from the macrophages of the reticuloendothelial system. Macrophages recognize and phagocytose senescent or damaged erythrocytes. Then, they process the heme iron, which is returned to the circulation for reutilization by red blood cell precursors during erythropoiesis. The amount of iron released, compared to the amount shunted for storage as ferritin, is greater during iron deficiency. A currently accepted model of iron release assumes a passive-gradient with free diffusion of intracellular labile iron (Fe2+ through ferroportin (FPN, the transporter on the plasma membrane. Outside the cell, a multi-copper ferroxidase, ceruloplasmin (Cp, oxidizes ferrous to ferric ion. Apo-transferrin (Tf, the primary carrier of soluble iron in the plasma, binds ferric ion to form mono-ferric and di-ferric transferrin. According to the passive-gradient model, the removal of ferrous ion from the site of release sustains the gradient that maintains the iron release. Subcellular localization of FPN, however, indicates that the role of FPN may be more complex. By experiments and mathematical modeling, we have investigated the detailed mechanism of iron release from macrophages focusing on the roles of the Cp, FPN and apo-Tf. The passive-gradient model is quantitatively analyzed using a mathematical model for the first time. A comparison of experimental data with model simulations shows that the passive-gradient model cannot explain macrophage iron release. However, a facilitated-transport model associated with FPN can explain the iron release mechanism. According to the facilitated-transport model, intracellular FPN carries labile iron to the macrophage membrane. Extracellular Cp accelerates the oxidation of ferrous ion bound to FPN. Apo-Tf in the extracellular environment binds to the oxidized ferrous ion, completing the release process. Facilitated-transport model can

  17. Follow-up Study of ITER Safety Analysis : Large In-vessel First Wall Pipe Break with Wet Confinement Bypass

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Bo; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    Previous researches have been analyzed risk assessments of fusion reactors that are dangerous in the severe accidents where the radioactive material released from confinement building to the environment. To simulate the severe accidents in ITER, a number of thermal hydraulics simulation codes were used. Before construction of the fusion reactor, to obtain ITER license about safety issue, MELCOR is chosen as one of the several codes to be used to perform ITER safety analyses. Qualification of the simulation code is to simulate the cooling system in ITER, the transport of radionuclides during design basis accidents (DBAs) including beyond design basis accidents (BDBAs). MELCOR is fully integrated code that models the accidents in Light Water Reactor (LWR). To analyze the accidents in ITER, MELCOR 1.8.2 version is modified. In the nuclear fusion system, the amount of released radioactive material is criteria for safety permission. Tritium (or tritiated water: HTO) and radioactive dust aerosol are the source of radioactive leakage. In the Generic Site Safety Report (GSSR) for the ITER plant, Table I lists the release guidelines for tritium and activation products for normal operation, incidents and accidents. Several accident analyses have been studied to know how much radioactive material could be released from the severe accidents. In the present work, The MELCOR input deck of large First Wall (FW) coolant leak (pipe break) is used to study and radioactive material leakage thorough bypass accident are studied to follow up the ITER safety analysis. In this research, follow-up study of the in-vessel inboard/inboard-outboard FW pipe break was analyzed to investigate the amount of leakage of radioactive aerosol. All of the accident cases released the lower amount of radioactive aerosol compared to the IAEA guide lines. In addition, the OBB pipe break made lower HTO aerosol leakage because of condensation of HTO and adsorption between coolant and aerosol.

  18. In vitro assay for ACTH-releasing activity using ACTH radioimmunoassay. ACTH releasing activities by various drugs

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, K; Takahara, J; Hosogi, H; Ofuji, N; Yasuhara, T [Okayama Univ. (Japan). School of Medicine

    1976-02-01

    This report deals with an in vitro assay of ACTH releasing activity utilizing pituitary incubation combined with ACTH radioimmunoassay. Half of a rat pituitary was preincubated in 2ml Krebs Ringer bicarbonate buffer containing 0.2% glucose and 0.25% BSA (KRBG-BSA) for 1.5 hr (45 min x 2). The medium was replaced by 1 ml KRBG-BSA and incubated for 30 min. Then the medium was again replaced by 1 ml KRBG-BSA or KRBG-BSA containing test materials and incubated for another 30 min. The amount of ACTH assayed by radioimmunoassay in the 2nd 30 min incubation was compared with that in the 1st 30 min incubation, and the result was expressed as a percentage. In the ACTH radioimmunoassay, anti-ACTH serum was diluted to 1:1,500-3,000. The /sup 125/I-..cap alpha../sup 1 -24/ACTH-antibody system was not affected by lysine-vasopressin (LVP), arginine-vasopressin (AVP), rat's pituitary LH, GH or prolactin. Human /sup 1 -39/ACTH was used as the ACTH standard. The dilution curve of the incubation medium was parallel to the standard curve. Reproducibility of immunoassayable ACTH within-assay was 174 +- 5.0 pg/tube (CV=2.9%). A log dose-relationship was observed between the amounts of stalk median eminence extracts (SME; NIAMDD) added to the incubation medium and its ACTH releasing activities. The sensitivity of this assay method was at least 0.1 SME or 10 mU of LVP and AVP. Using this method, it was found that LVP, AVP, norepinephrine (100 ng/ml--200 ng/ml) and 5-hydroxytryptophane (1 ..mu..g/ml) had ACTH releasing activities, but LH-RH, TRH, glucagon, dopamine, phentolamine, propranolol, haloperidol, prostaglandin E/sub 1/ and indomethacin did not affect the release of ACTH.

  19. Release of nickel and chromium ions from orthodontic wires following the use of teeth whitening mouthwashes

    Directory of Open Access Journals (Sweden)

    AmirHossein Mirhashemi

    2018-02-01

    Full Text Available Abstract Background Corrosion resistance is an important requirement for orthodontic appliances. Nickel and chromium may be released from orthodontic wires and can cause allergic reactions and cytotoxicity when patients use various mouthwashes to whiten their teeth. Our study aimed to assess the release of nickel and chromium ions from nickel titanium (NiTi and stainless steel (SS orthodontic wires following the use of four common mouthwashes available on the market. Methods This in vitro, experimental study was conducted on 120 orthodontic appliances for one maxillary quadrant including five brackets, one band and half of the required length of SS, and NiTi wires. The samples were immersed in Oral B, Oral B 3D White Luxe, Listerine, and Listerine Advance White for 1, 6, 24, and 168 h. The samples immersed in distilled water served as the control group. Atomic absorption spectroscopy served to quantify the amount of released ions. Results Nickel ions were released from both wires at all time-points; the highest amount was in Listerine and the lowest in Oral B mouthwashes. The remaining two solutions were in-between this range. The process of release of chromium from the SS wire was the same as that of nickel. However, the release trend in NiTi wires was not uniform. Conclusions Listerine caused the highest release of ions. Listerine Advance White, Oral B 3D White Luxe, and distilled water were the same in terms of ion release. Oral B showed the lowest amount of ion release.

  20. Controlled release system for ametryn using polymer microspheres: Preparation, characterization and release kinetics in water

    International Nuclear Information System (INIS)

    Grillo, Renato; Pereira, Anderson do Espirito Santo; Ferreira Silva de Melo, Nathalie; Porto, Raquel Martins; Feitosa, Leandro Oliveira; Tonello, Paulo Sergio; Dias Filho, Newton L.; Rosa, Andre Henrique; Lima, Renata; Fraceto, Leonardo Fernandes

    2011-01-01

    The purpose of this work was to develop a modified release system for the herbicide ametryn by encapsulating the active substance in biodegradable polymer microparticles produced using the polymers poly(hydroxybutyrate) (PHB) or poly(hydroxybutyrate-valerate) (PHBV), in order to both improve the herbicidal action and reduce environmental toxicity. PHB or PHBV microparticles containing ametryn were prepared and the efficiencies of herbicide association and loading were evaluated, presenting similar values of approximately 40%. The microparticles were characterized by scanning electron microscopy (SEM), which showed that the average sizes of the PHB and PHBV microparticles were 5.92 ± 0.74 μm and 5.63 ± 0.68 μm, respectively. The ametryn release profile was modified when it was encapsulated in the microparticles, with slower and more sustained release compared to the release profile of pure ametryn. When ametryn was associated with the PHB and PHBV microparticles, the amount of herbicide released in the same period of time was significantly reduced, declining to 75% and 87%, respectively. For both types of microparticle (PHB and PHBV) the release of ametryn was by diffusion processes due to anomalous transport (governed by diffusion and relaxation of the polymer chains), which did not follow Fick's laws of diffusion. The results presented in this paper are promising, in view of the successful encapsulation of ametryn in PHB or PHBV polymer microparticles, and indications that this system may help reduce the impacts caused by the herbicide, making it an environmentally safer alternative.

  1. Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 5. Accidental Releases

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, S

    2007-08-15

    Over the course of fifty-three years, LLNL had six acute releases of tritiated hydrogen gas (HT) and one acute release of tritiated water vapor (HTO) that were too large relative to the annual releases to be included as part of the annual releases from normal operations detailed in Parts 3 and 4 of the Tritium Dose Reconstruction (TDR). Sandia National Laboratories/California (SNL/CA) had one such release of HT and one of HTO. Doses to the maximally exposed individual (MEI) for these accidents have been modeled using an equation derived from the time-dependent tritium model, UFOTRI, and parameter values based on expert judgment. All of these acute releases are described in this report. Doses that could not have been exceeded from the large HT releases of 1965 and 1970 were calculated to be 43 {micro}Sv (4.3 mrem) and 120 {micro}Sv (12 mrem) to an adult, respectively. Two published sets of dose predictions for the accidental HT release in 1970 are compared with the dose predictions of this TDR. The highest predicted dose was for an acute release of HTO in 1954. For this release, the dose that could not have been exceeded was estimated to have been 2 mSv (200 mrem), although, because of the high uncertainty about the predictions, the likely dose may have been as low as 360 {micro}Sv (36 mrem) or less. The estimated maximum exposures from the accidental releases were such that no adverse health effects would be expected. Appendix A lists all accidents and large routine puff releases that have occurred at LLNL and SNL/CA between 1953 and 2005. Appendix B describes the processes unique to tritium that must be modeled after an acute release, some of the time-dependent tritium models being used today, and the results of tests of these models.

  2. Sodium lauryl sulfate impedes drug release from zinc-crosslinked alginate beads: switching from enteric coating release into biphasic profiles.

    Science.gov (United States)

    Taha, Mutasem O; Nasser, Wissam; Ardakani, Adel; Alkhatib, Hatim S

    2008-02-28

    The aim of this research is to investigate the effects of sodium lauryl sulfate (SLS) on ionotropically cross-linked alginate beads. Different levels of SLS were mixed with sodium alginate and chlorpheniramine maleate (as loaded model drug). The resulting viscous solutions were dropped onto aqueous solutions of zinc or calcium ions for ionotropic curing. The generated beads were assessed by their drug releasing profiles, infrared and differential scanning colorimetery (DSC) traits. SLS was found to exert profound concentration-dependent impacts on the characteristics of zinc-crosslinked alginate beads such that moderate modifications in the levels of SLS switched drug release from enteric coating-like behavior to a biphasic release modifiable to sustained-release by the addition of minute amounts of xanthan gum. Calcium cross-linking failed to reproduce the same behavior, probably due to the mainly ionic nature of calcium-carboxylate bonds compared to the coordinate character of their zinc-carboxylate counterparts. Apparently, moderate levels of SLS repel water penetration into the beads, and therefore minimize chlorpheniramine release. However, higher SLS levels seem to discourage polymeric cross-linking and therefore allow biphasic drug release.

  3. Preparation and Optimization of Immediate Release/Sustained Release Bilayered Tablets of Loxoprofen Using Box-Behnken Design.

    Science.gov (United States)

    Tak, Jin Wook; Gupta, Biki; Thapa, Raj Kumar; Woo, Kyu Bong; Kim, Sung Yub; Go, Toe Gyeong; Choi, Yongjoo; Choi, Ju Yeon; Jeong, Jee-Heon; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2017-05-01

    The aim of our current study was to characterize and optimize loxoprofen immediate release (IR)/sustained release (SR) tablet utilizing a three-factor, three-level Box-Behnken design (BBD) combined with a desirability function. The independent factors included ratio of drug in the IR layer to total drug (X 1 ), ratio of HPMC to drug in the SR layer (X 2 ), and ratio of Eudragit RL PO to drug in the SR layer (X 3 ). The dependent variables assessed were % drug released in distilled water at 30 min (Y 1 ), % drug released in pH 1.2 at 2 h (Y 2 ), and % drug released in pH 6.8 at 12 h (Y 3 ). The responses were fitted to suitable models and statistical validation was performed using analysis of variance. In addition, response surface graphs and contour plots were constructed to determine the effects of different factor level combinations on the responses. The optimized loxoprofen IR/SR tablets were successfully prepared with the determined amounts of ingredients that showed close agreement in the predicted and experimental values of tablet characterization and drug dissolution profile. Therefore, BBD can be utilized for successful optimization of loxoprofen IR/SR tablet, which can be regarded as a suitable substitute for the current marketed formulations.

  4. Thermal effects from the release of selenium from a coal combustion during high-temperature processing: a review.

    Science.gov (United States)

    Hu, Jianjun; Sun, Qiang; He, Huan

    2018-04-11

    The release of selenium (Se) during coal combustion can have serious impacts on the ecological environment and human health. Therefore, it is very important to study the factors that concern the release of Se from coal combustion. In this paper, the characteristics of the release of Se from coal combustion, pyrolysis, and gasification of different coal species under different conditions are studied. The results show that the amount of released Se increases at higher combustion temperatures. There are obvious increases in the amount of released Se especially in the temperature range of 300 to 800 °C. In addition, more Se is released from the coal gasification than coal combustion process, but more Se is released from coal combustion than pyrolysis. The type of coal, rate of heating, type of mineral ions, and combustion atmosphere have different effects on the released percentage of Se. Therefore, having a good understanding of the factors that surround the release of Se during coal combustion, and then establishing the combustion conditions can reduce the impacts of this toxic element to humans and the environment.

  5. Release fraction of PWR after severe accidents. Vol. 4

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, M; El-Messeiry, A M [National Center for Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Fission fragments and gases are emitted after accidents as a result of core meltdown and core concrete interactions. These aerosols are transported and fill the reactor containment. With increasing the pressure above pressure design bases, a failure of containment may occur and subsequently these aerosols will release into the external environment leading to a source term of radioactivity that affects the safety of workers and public. The amount of aerosol which escapes to the environment can be described by the release fraction which is defined as the total accumulated aerosol which initially enters the containment. The factors that affect the release fraction is studied, and the aerosol dynamics equation is used to model the release of aerosol to the outside atmosphere. These factors are containment pressure, failure time,break area, the size of aerosol particle. It found that early failure time and higher pressure increase the release fraction, also the release faction is affected by the area and the aerosol particle size. 7 figs., 2 tabs.

  6. Release fraction of PWR after severe accidents. Vol. 4

    International Nuclear Information System (INIS)

    Aziz, M.; El-Messeiry, A.M.

    1996-01-01

    Fission fragments and gases are emitted after accidents as a result of core meltdown and core concrete interactions. These aerosols are transported and fill the reactor containment. With increasing the pressure above pressure design bases, a failure of containment may occur and subsequently these aerosols will release into the external environment leading to a source term of radioactivity that affects the safety of workers and public. The amount of aerosol which escapes to the environment can be described by the release fraction which is defined as the total accumulated aerosol which initially enters the containment. The factors that affect the release fraction is studied, and the aerosol dynamics equation is used to model the release of aerosol to the outside atmosphere. These factors are containment pressure, failure time,break area, the size of aerosol particle. It found that early failure time and higher pressure increase the release fraction, also the release faction is affected by the area and the aerosol particle size. 7 figs., 2 tabs

  7. 2001 Toxic Chemical Release Inventory Emergency Planning and Community Right to Know Act SEC 313

    International Nuclear Information System (INIS)

    ZALOUDEK, D.E.

    2002-01-01

    Pursuant to section 313 of the Emergency Planning and Community Right-To-Know Act of 1986 (EPCRA), and Executive Order 13148, Greening the Government Through Leadership in Environmental Management, the US Department of Energy has prepared and submitted a Toxic Chemical Release Inventory for the Hanford Site covering activities performed during calendar year 2001. EPCRA Section 313 requires facilities that manufacture, process, or otherwise use listed toxic chemicals in quantities exceeding established threshold levels to report total annual releases of those chemicals. During calendar year 2001, Hanford Site activities resulted in one chemical used in amounts exceeding an activity threshold. Accordingly, the Hanford Site 2001 Toxic Chemical Release Inventory, DOE/RL-2002-37, includes total annual amount of lead released to the environment, transferred to offsite locations, and otherwise managed as waste

  8. Investigation of tritium release and retention in lithium aluminate

    International Nuclear Information System (INIS)

    Kopasz, J.P.; Tistchenko, S.; Botter, F.

    1991-01-01

    Tritium release from lithium aluminate, although previously investigated by both in-reactor and ex-reactor experiments, remains poorly understood. Agreement between experiments is lacking, and the mechanisms responsible for tritium release from lithium aluminate are under debate. In an effort to improve our understanding of the mechanisms of tritium release from lithium ceramics, we have investigated tritium release from pure lithium aluminate and lithium aluminate doped with impurities. The results of these experiments on large grain size material indicate that after anneals at low temperature, a large fraction of the tritium present before the anneal remains in the sample. We have modeled this behavior based on first-order release from three types of sites. At the lowest temperature, the release is dominated by one site, while the tritium in the other sites is retained in the solid. Adding magnesium dopant to the ceramic appears to alter the distribution of tritium between the sites. This addition decreases the fraction of tritium released at 777 degree C, while increasing the fractions released at 538 and 950 degree C. 11 refs., 8 figs., 1 tab

  9. Evaluation of the potential for significant ammonia releases from Hanford waste tanks

    International Nuclear Information System (INIS)

    Palmer, B.J.; Anderson, C.M.; Chen, G.; Cuta, J.M.; Ferryman, T.A.; Terrones, G.

    1996-07-01

    Ammonia is ubiquitous as a component of the waste stored in the Hanford Site single-shell tanks (SSTs) and double-shell tanks (DSTs). Because ammonia is both flammable and toxic, concerns have been raised about the amount of ammonia stored in the tanks and the possible mechanisms by which it could be released from the waste into the head space inside the tanks as well as into the surrounding atmosphere. Ammonia is a safety issue for three reasons. As already mentioned, ammonia is a flammable gas and may contribute to a flammability hazard either directly, if it reaches a high enough concentration in the tank head space, or by contributing to the flammability of other flammable gases such as hydrogen (LANL 1994). Ammonia is also toxic and at relatively low concentrations presents a hazard to human health. The level at which ammonia is considered Immediately Dangerous to Life or Health (IDLH) is 300 ppm (WHC 1993, 1995). Ammonia concentrations at or above this level have been measured inside the head space in a number of SSTs. Finally, unlike hydrogen and nitrous oxide, ammonia is highly soluble in aqueous solutions, and large amounts of ammonia can be stored in the waste as dissolved gas. Because of its high solubility, ammonia behaves in a qualitatively different manner from hydrogen or other insoluble gases. A broader range of scenarios must be considered in modeling ammonia storage and release

  10. Polymeric nanoparticles containing diazepam: preparation, optimization, characterization, in-vitro drug release and release kinetic study

    Science.gov (United States)

    Bohrey, Sarvesh; Chourasiya, Vibha; Pandey, Archna

    2016-03-01

    Nanoparticles formulated from biodegradable polymers like poly(lactic-co-glycolic acid) (PLGA) are being extensively investigated as drug delivery systems due to their two important properties such as biocompatibility and controlled drug release characteristics. The aim of this work to formulated diazepam loaded PLGA nanoparticles by using emulsion solvent evaporation technique. Polyvinyl alcohol (PVA) is used as stabilizing agent. Diazepam is a benzodiazepine derivative drug, and widely used as an anticonvulsant in the treatment of various types of epilepsy, insomnia and anxiety. This work investigates the effects of some preparation variables on the size and shape of nanoparticles prepared by emulsion solvent evaporation method. These nanoparticles were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM). Zeta potential study was also performed to understand the surface charge of nanoparticles. The drug release from drug loaded nanoparticles was studied by dialysis bag method and the in vitro drug release data was also studied by various kinetic models. The results show that sonication time, polymer content, surfactant concentration, ratio of organic to aqueous phase volume, and the amount of drug have an important effect on the size of nanoparticles. Hopefully we produced spherical shape Diazepam loaded PLGA nanoparticles with a size range under 250 nm with zeta potential -23.3 mV. The in vitro drug release analysis shows sustained release of drug from nanoparticles and follow Korsmeyer-Peppas model.

  11. Analysis of fission product release from HTGR core during transient temperature excursion

    International Nuclear Information System (INIS)

    Saito, Takao; Yamatoya, Naotoshi; Onuma, Mamoru

    1978-01-01

    The computer program ''FRANC'' was developed to calculate the release activity of fission products from a high-temperature gas cooled reactor (HTGR) core during transient temperature excursions such as a hypothetical loss of forced circulation combined with design basis depressurization. The program utilizes a segmented cylindrical core spatial model with the associated values of the prior fuel irradiation history and temperature conditions. The fission product transport and decay chain behavior is expressed by a set of differential equations. This set of equations describes the entire core inventory of fission products by means of calculated parameters based on the detailed spatial core conditions. The program determines the time-dependent amounts of fission product nuclides escaping from the core into the coolant. Coded in Continuous System Simulation Language (CSSL) with double precision, FRANC showed appropriate results for both short- and long-lived fission product nuclides. The sample calculation conducted by applying the program to a large HTGR indicated that it would take about one hour for noble gases and volatile nuclides to be released to the coolant, and several hours for metalic nuclides. (auth.)

  12. Commercial SNF Accident Release Fractions

    Energy Technology Data Exchange (ETDEWEB)

    J. Schulz

    2004-11-05

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

  13. Commercial SNF Accident Release Fractions

    International Nuclear Information System (INIS)

    Schulz, J.

    2004-01-01

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M andO 1999). In contrast to bare unconfined fuel assemblies, the

  14. Toxic chemical considerations for tank farm releases. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Van Keuren, J.C.

    1995-11-01

    This document provides a method of determining the toxicological consequences of accidental releases from Hanford Tank Farms. A determination was made of the most restrictive toxic chemicals that are expected to be present in the tanks. Concentrations were estimated based on the maximum sample data for each analyte in all the tanks in the composite. Composite evaluated were liquids and solids from single shell tanks, double shell tanks, flammable gas watch list tanks, as well as all solids, all liquids, head space gases, and 241-C-106 solids. A sum of fractions of the health effects was computed for each composite for unit releases based emergency response planning guidelines (ERPGs). Where ERPGs were not available for chemical compounds of interest, surrogate guidelines were established. The calculation method in this report can be applied to actual release scenarios by multiplying the sum of fractions by the release rate for continuous releases, or the release amount for puff releases. Risk guidelines are met if the product is less than for equal to one.

  15. Toxic chemical considerations for tank farm releases. Revision 1

    International Nuclear Information System (INIS)

    Van Keuren, J.C.

    1995-11-01

    This document provides a method of determining the toxicological consequences of accidental releases from Hanford Tank Farms. A determination was made of the most restrictive toxic chemicals that are expected to be present in the tanks. Concentrations were estimated based on the maximum sample data for each analyte in all the tanks in the composite. Composite evaluated were liquids and solids from single shell tanks, double shell tanks, flammable gas watch list tanks, as well as all solids, all liquids, head space gases, and 241-C-106 solids. A sum of fractions of the health effects was computed for each composite for unit releases based emergency response planning guidelines (ERPGs). Where ERPGs were not available for chemical compounds of interest, surrogate guidelines were established. The calculation method in this report can be applied to actual release scenarios by multiplying the sum of fractions by the release rate for continuous releases, or the release amount for puff releases. Risk guidelines are met if the product is less than for equal to one

  16. Application of the HGSYSTEM/UF6 model to simulate atmospheric dispersion of UF6 releases from uranium enrichment plants

    International Nuclear Information System (INIS)

    Goode, W.D. Jr.; Bloom, S.G.; Keith, K.D. Jr.

    1995-01-01

    Uranium hexafluoride is a dense, reactive gas used in Gaseous Diffusion Plants (GDPs) to make uranium enriched in the 235 U isotope. Large quantities of UF 6 exist at the GDPs in the form of in-process gas and as a solid in storage cylinders; smaller amounts exist as hot liquid during transfer operations. If liquid UF 6 is released to the environment, it immediately flashes to a solid and a dense gas that reacts rapidly with water vapor in the air to form solid particles of uranyl fluoride and hydrogen fluoride gas. Preliminary analyses were done on various accidental release scenarios to determine which scenarios must be considered in the safety analyses for the GDPS. These scenarios included gas releases due to failure of process equipment and liquid/gas releases resulting from a breach of transfer piping from a cylinder. A major goal of the calculations was to estimate the response time for mitigating actions in order to limit potential off-site consequences of these postulated releases. The HGSYSTEM/UF 6 code was used to assess the consequences of these release scenarios. Inputs were developed from release calculations which included two-phase, choked flow followed by expansion to atmospheric pressure. Adjustments were made to account for variable release rates and multiple release points. Superpositioning of outputs and adjustments for exposure time were required to evaluate consequences based on health effects due to exposures to uranium and HF at a specific location

  17. [Characteristics of dissolved organic carbon release under inundation from typical grass plants in the water-level fluctuation zone of the Three Gorges Reservoir area].

    Science.gov (United States)

    Tan, Qiu-Xia; Zhu, Boi; Hua, Ke-Ke

    2013-08-01

    The water-level fluctuation zone of the Three Gorges Reservoir (TGR) exposes in spring and summer, then, green plants especially herbaceous plants grow vigorously. In the late of September, water-level fluctuation zone of TGR goes to inundation. Meanwhile, annually accumulated biomass of plant will be submerged for decaying, resulting in organism decomposition and release a large amount of dissolved organic carbon (DOC). This may lead to negative impacts on water environment of TGR. The typical herbaceous plants from water-level fluctuation zone were collected and inundated in the laboratory for dynamic measurements of DOC concentration of overlying water. According to the determination, the DOC release rates and fluxes have been calculated. Results showed that the release process of DOC variation fitted in a parabolic curve. The peak DOC concentrations emerge averagely in the 15th day of inundation, indicating that DOC released quickly with organism decay of herbaceous plant. The release process of DOC could be described by the logarithm equation. There are significant differences between the concentration of DOC (the maximum DOC concentration is 486.88 mg x L(-1) +/- 35.97 mg x L(-1) for Centaurea picris, the minimum is 4.18 mg x L(-1) +/- 1.07 mg x L(-1) for Echinochloacrus galli) and the release amount of DOC (the maximum is 50.54 mg x g(-1) for Centaurea picris, the minimum is 6.51 mg x g(-1) for Polygonum hydropiper) due to different characteristics of plants, especially, the values of C/N of herbaceous plants. The cumulative DOC release quantities during the whole inundation period were significantly correlated with plants' C/N values in linear equations.

  18. Serum release boosts sweetness intensity in gels

    NARCIS (Netherlands)

    Sala, G.; Stieger, M.A.; Velde, van de F.

    2010-01-01

    This paper describes the effect of serum release on sweetness intensity in mixed whey protein isolate/gellan gum gels. The impact of gellan gum and sugar concentration on microstructure, permeability, serum release and large deformation properties of the gels was determined. With increasing gellan

  19. Tailored sequential drug release from bilayered calcium sulfate composites

    International Nuclear Information System (INIS)

    Orellana, Bryan R.; Puleo, David A.

    2014-01-01

    The current standard for treating infected bony defects, such as those caused by periodontal disease, requires multiple time-consuming steps and often multiple procedures to fight the infection and recover lost tissue. Releasing an antibiotic followed by an osteogenic agent from a synthetic bone graft substitute could allow for a streamlined treatment, reducing the need for multiple surgeries and thereby shortening recovery time. Tailorable bilayered calcium sulfate (CS) bone graft substitutes were developed with the ability to sequentially release multiple therapeutic agents. Bilayered composite samples having a shell and core geometry were fabricated with varying amounts (1 or 10 wt.%) of metronidazole-loaded poly(lactic-co-glycolic acid) (PLGA) particles embedded in the shell and simvastatin directly loaded into either the shell, core, or both. Microcomputed tomography showed the overall layered geometry as well as the uniform distribution of PLGA within the shells. Dissolution studies demonstrated that the amount of PLGA particles (i.e., 1 vs. 10 wt.%) had a small but significant effect on the erosion rate (3% vs. 3.4%/d). Mechanical testing determined that introducing a layered geometry had a significant effect on the compressive strength, with an average reduction of 35%, but properties were comparable to those of mandibular trabecular bone. Sustained release of simvastatin directly loaded into CS demonstrated that changing the shell to core volume ratio dictates the duration of drug release from each layer. When loaded together in the shell or in separate layers, sequential release of metronidazole and simvastatin was achieved. By introducing a tunable, layered geometry capable of releasing multiple drugs, CS-based bone graft substitutes could be tailored in order to help streamline the multiple steps needed to regenerate tissue in infected defects. - Highlights: • Bilayered CS composites were fabricated as potential bone graft substitutes. • The shell

  20. Tailored sequential drug release from bilayered calcium sulfate composites

    Energy Technology Data Exchange (ETDEWEB)

    Orellana, Bryan R.; Puleo, David A., E-mail: puleo@uky.edu

    2014-10-01

    The current standard for treating infected bony defects, such as those caused by periodontal disease, requires multiple time-consuming steps and often multiple procedures to fight the infection and recover lost tissue. Releasing an antibiotic followed by an osteogenic agent from a synthetic bone graft substitute could allow for a streamlined treatment, reducing the need for multiple surgeries and thereby shortening recovery time. Tailorable bilayered calcium sulfate (CS) bone graft substitutes were developed with the ability to sequentially release multiple therapeutic agents. Bilayered composite samples having a shell and core geometry were fabricated with varying amounts (1 or 10 wt.%) of metronidazole-loaded poly(lactic-co-glycolic acid) (PLGA) particles embedded in the shell and simvastatin directly loaded into either the shell, core, or both. Microcomputed tomography showed the overall layered geometry as well as the uniform distribution of PLGA within the shells. Dissolution studies demonstrated that the amount of PLGA particles (i.e., 1 vs. 10 wt.%) had a small but significant effect on the erosion rate (3% vs. 3.4%/d). Mechanical testing determined that introducing a layered geometry had a significant effect on the compressive strength, with an average reduction of 35%, but properties were comparable to those of mandibular trabecular bone. Sustained release of simvastatin directly loaded into CS demonstrated that changing the shell to core volume ratio dictates the duration of drug release from each layer. When loaded together in the shell or in separate layers, sequential release of metronidazole and simvastatin was achieved. By introducing a tunable, layered geometry capable of releasing multiple drugs, CS-based bone graft substitutes could be tailored in order to help streamline the multiple steps needed to regenerate tissue in infected defects. - Highlights: • Bilayered CS composites were fabricated as potential bone graft substitutes. • The shell

  1. Release of fission products from irradiated aluminide fuel at high temperature

    International Nuclear Information System (INIS)

    Shibata, Toshikazu; Kanda, Keiji; Mishima, Kaichiro; Tamai, Tadaharu; Hayashi, Masatoshi; Snelgrove, James L.; Stahl, David; Matos, James E.; Travelli, Armando; Case, F. Neil; Posey, John C.

    1983-01-01

    Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel cladding material. The release of fission products from the fuel plate at temperature below 500 deg. C was found negligible. The first rapid release of fission products was observed with the occurrence of blistering at 561±1 deg. C on the plates. The next release at 585. C might be caused by melting of the cladding material of 6061-Al alloy. The last release of fission product gases was occurred at the eutectic temperature of 640 deg. C of U-Al x . The released material was mostly xenon, but small amounts of iodine and cesium were observed. (author)

  2. Release of fission products from irradiated aluminide fuel at high temperature

    International Nuclear Information System (INIS)

    Shibata, T.; Kanda, K.; Mishima, K.

    1982-01-01

    Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel-cladding material. The release of fission products from the fuel plate at temperature below 500 0 C was found negligible. The firist rapid release of fission products was observed with the occurrence of blistering at 561 +- 1 0 C on the plates. The next release at 585 0 C might be caused by melting of the cladding material of 6061-Al alloy. The last release of fission product gases was occurred at the eutectic temperature of 640 0 C of U-Al/sub x/. The released material was mostly xenon, but small amounts of iodine and cesium were observed

  3. Massive radioactive releases have a great impact on the accident costs

    International Nuclear Information System (INIS)

    Pascucci-Cahen, L.; Momal, P.

    2013-01-01

    This article investigates the costs of the consequences of a nuclear accident. The importance of the costs is very dependant on the amount of radioactivity released in the environment during the accident. 2 severe accidents are considered, each accident involves the fusion of the core but the first is characterized by a limited amount of radioactivity released in the atmosphere while the second involves massive radioactive releases. The list of consequences is as comprehensive as possible: site decontamination and dismantlement, land decontamination, sanitary impacts, population displacement, agricultural and economical losses, impact on tourism, impact on the production of electricity...In the first case the total cost reaches 120 billion euros which is still manageable at the scale of a country whereas in the second case the bill reaches 430 billion euros which is unbearable for a country. The very slight probability of such events does not compensate for their catastrophic potentials. (A.C.)

  4. Effect of bioceramic functional groups on drug binding and release kinetics

    Science.gov (United States)

    Trujillo, Christopher

    DI water for 2 days and the concentrations of dissolved silicate and phosphate ions released from the surface of Cris were measured using Inductively Coupled Plasma -- Optical Emission Spectrometry (ICP-OES). The phosphate ions released from the material activated the surface and exposed the silicate functional groups as indicated by the FTIR analysis. Pre-immersed Cris particles and control non-immersed samples (200 mg, n=5 for each sample) of particle size 90-150 mum were immersed in 2 mL of vancomycin (Vanc) solution (8 mg/ml) in PBS on an orbital shaker at 37°C for 24 hours. The amount of drug bound to the material was measured by High Performance Liquid Chromatography (HPLC). Control non-immersed Cris samples P-0 and P-39.1 adsorbed a comparable amount of drug. While there was a statistically significant lower amount of drug adsorbed onto P-78.2 than that adsorbed onto P-39.1 (p P-165.5 > P-331; p HPLC and FTIR analyses showed that ceramics that had higher content of O-Si-O bending (at ~498 cm-1 and ~620 cm-1) bands facilitated Vanc adsorption. On the other hand surfaces with a higher content of nu 4 PO4/O-P-O bending (at ~557 cm-1) and P=O stretching (at ~1343.9 cm-1) bands did not enhance Vanc adsorption. Drug loaded pre-immersed and control non-immersed Cris samples (each 200 mg, n=5 for each sample) were immersed in 2 mL of PBS on an orbital shaker at 37°C, and a 0.5 mL aliquot was removed from the solution and replenished at 1, 3, 6, 8, 24, and 48 hour, and every 48 hour intervals to 22 days thereafter. Drug concentration released from Cris samples after each time point was measured using HPLC. The drug release kinetics demonstrated a statistically significant decrease (p < 0.05) in the cumulative and percent of Vanc released from control non-immersed Cris samples P-0 (1.521 +/- .026 mg; 37.66 +/- .89 %) to P-331 (1.276 +/- .016 mg; 33.46 +/- .77 %) of Vanc, respectively. Additionally, release kinetics also demonstrated statistically significant increase

  5. pH responsive N-succinyl chitosan/Poly (acrylamide-co-acrylic acid hydrogels and in vitro release of 5-fluorouracil.

    Directory of Open Access Journals (Sweden)

    Shahid Bashir

    Full Text Available There has been significant progress in the last few decades in addressing the biomedical applications of polymer hydrogels. Particularly, stimuli responsive hydrogels have been inspected as elegant drug delivery systems capable to deliver at the appropriate site of action within the specific time. The present work describes the synthesis of pH responsive semi-interpenetrating network (semi-IPN hydrogels of N-succinyl-chitosan (NSC via Schiff base mechanism using glutaraldehyde as a crosslinking agent and Poly (acrylamide-co-acrylic acid(Poly (AAm-co-AA was embedded within the N-succinyl chitosan network. The physico-chemical interactions were characterized by Fourier transform infrared (FTIR, X-ray diffraction (XRD, thermogravimetric analysis (TGA, and field emission scanning electron microscope (FESEM. The synthesized hydrogels constitute porous structure. The swelling ability was analyzed in physiological mediums of pH 7.4 and pH 1.2 at 37°C. Swelling properties of formulations with various amounts of NSC/ Poly (AAm-co-AA and crosslinking agent at pH 7.4 and pH 1.2 were investigated. Hydrogels showed higher swelling ratios at pH 7.4 while lower at pH 1.2. Swelling kinetics and diffusion parameters were also determined. Drug loading, encapsulation efficiency, and in vitro release of 5-fluorouracil (5-FU from the synthesized hydrogels were observed. In vitro release profile revealed the significant influence of pH, amount of NSC, Poly (AAm-co-AA, and crosslinking agent on the release of 5-FU. Accordingly, rapid and large release of drug was observed at pH 7.4 than at pH 1.2. The maximum encapsulation efficiency and release of 5-FU from SP2 were found to be 72.45% and 85.99%, respectively. Kinetics of drug release suggested controlled release mechanism of 5-FU is according to trend of non-Fickian. From the above results, it can be concluded that the synthesized hydrogels have capability to adapt their potential exploitation as targeted oral drug

  6. Reductive Alkaline Release of N-Glycans Generates a Variety of Unexpected, Useful Products.

    Science.gov (United States)

    Figl, Rudolf; Altmann, Friedrich

    2018-02-01

    Release of O-glycans by reductive β-elimination has become routine in many glyco-analytical laboratories and concomitant release of N-glycans has repeatedly been observed. Revisiting this somewhat forgotten mode of N-glycan release revealed that all kinds of N-glycans including oligomannosidic and complex-type N-glycans from plants with 3-linked fucose and from mammals with or without 6-linked fucose and with sialic acid could be recovered. However, the mass spectra of the obtained products revealed very surprising facts. Even after 16 h incubation in 1 M sodium borohydride, a large part of the glycans occurred in reducing form. Moreover, about one third emerged in the form of the stable amino-functionalized 1-amino-1-deoxy-glycitol. When avoiding acidic conditions, considerable amounts of glycosylamine were observed. In addition, a compound with a reduced asparagine and de-N-acetylation products, in particular of sialylated glycans, was seen. The relative yields of the products reducing glycosylamine, reducing N-glycan, 1-amino-1-deoxy-glycitol or glycitol could be controlled by the release conditions, foremost by temperature and borohydride concentration. Thus, chemical release of N-glycans constitutes a cost-saving alternative to enzymatic hydrolysis for the preparation of precursors for the production of reference compounds for various formats of N-glycan analysis. Moreover, it allows to obtain a stable amino-functionalized glycan derivative, which can be employed to construct glycan arrays or affinity matrices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Development of a Sustainable Release System for a Ranibizumab Biosimilar Using Poly(lactic-co-glycolic acid) Biodegradable Polymer-Based Microparticles as a Platform.

    Science.gov (United States)

    Tanetsugu, Yusuke; Tagami, Tatsuaki; Terukina, Takayuki; Ogawa, Takaya; Ohta, Masato; Ozeki, Tetsuya

    2017-01-01

    Ranibizumab is a humanized monoclonal antibody fragment against vascular endothelial growth factor (VEGF)-A and is widely used to treat age-related macular degeneration (AMD) caused by angiogenesis. Ranibizumab has a short half-life in the eye due to its low molecular weight and susceptibility to proteolysis. Monthly intravitreal injection of a large amount of ranibizumab formulation is a burden for both patients and medical staff. We therefore sought to develop a sustainable release system for treating the eye with ranibizumab using a drug carrier. A ranibizumab biosimilar (RB) was incorporated into microparticles of poly(lactic-co-glycolic acid) (PLGA) biodegradable polymer. Ranibizumab was sustainably released from PLGA microparticles (80+% after 3 weeks). Assay of tube formation by endothelial cells indicated that RB released from PLGA microparticles inhibited VEGF-induced tube formation and this tendency was confirmed by a cell proliferation assay. These results indicate that RB-loaded PLGA microparticles are useful for sustainable RB release and suggest the utility of intraocular sustainable release systems for delivering RB site-specifically to AMD patients.

  8. Nutrient digestibility of veal calves fed large amounts of different solid feeds during the first 80 days of fattening

    Directory of Open Access Journals (Sweden)

    Marta Brscic

    2014-10-01

    Full Text Available The study aimed at evaluating nutrients apparent digestibility in veal calves fed 3 feeding plans based on milk-replacer plus large amounts of solid feeds differing in their composition during the first 80 days of fattening. Twelve Polish Friesian male calves (70.6±1.9 kg were randomly assigned to one of the following feeding treatments: i milk-replacer plus corn grain (CG; ii milk-replacer plus 80:20 mixture (as fed basis of corn grain and wheat straw (CGS; and iii milk-replacer plus 72:20:8 mixture of corn grain, wheat straw and extruded soybean (CGSES. Calves received the same milk-replacer but the daily amount was restricted (96% for CGSES calves to balance dietary protein. Total dry matter intake from milk-replacer and solid feeds was similar among treatments, but CGSES calves showed better growth performance than CG ones. Calves were introduced into a metabolism stall (1/pen during week 9 of fattening for a 3- day adaptation period and a 4-day digestibility trial. Calves fed CG showed the greatest DM, NFC, and ash digestibility while CGSES calves showed the lowest CP digestibility. Haemoglobin concentrations measured at day 5, 31 and 80 were similar among feeding treatments and significantly decreased over time. In CGSES treatment, the combination of milkreplacer with solid feed closer to a complete diet for ruminants led to better calves’ growth performance. However, the reduced protein digestibility with CGSES indicates that protein quality becomes a key factor when formulating diets for veal calves using alternatives to dairy sources.

  9. Presynaptic M1 muscarinic receptor modulates spontaneous release of acetylcholine from rat basal forearm slices

    International Nuclear Information System (INIS)

    Suzuki, T.; Fujimoto, LK.; Oohata, H.; Kawashima, K.

    1988-01-01

    Spontaneous release of (ACh) from rat basal forebrain slices in the presence of cholinesterase inhibitor was directly determined using a specific radioimmunoassay for ACh. The release was calcium dependent. A consistent amount of ACh release was observed throughout the experiment. Atropine (10- 8 to 10- 5 M) and pirenzepine (10- 7 to 10- 5 M) enhanced spontaneous ACh release. These findings indicate the presence of an M 1 muscarenic autoreceptor that modulates spontaneous release of ACh in the rat forebrain

  10. 2015 TRI National Analysis: Toxics Release Inventory Releases at Various Summary Levels

    Science.gov (United States)

    The TRI National Analysis is EPA's annual interpretation of TRI data at various summary levels. It highlights how toxic chemical wastes were managed, where toxic chemicals were released and how the 2015 TRI data compare to data from previous years. This dataset reports US state, county, large aquatic ecosystem, metro/micropolitan statistical area, and facility level statistics from 2015 TRI releases, including information on: number of 2015 TRI facilities in the geographic area and their releases (total, water, air, land); population information, including populations living within 1 mile of TRI facilities (total, minority, in poverty); and Risk Screening Environmental Indicators (RSEI) model related pounds, toxicity-weighted pounds, and RSEI score. The source of administrative boundary data is the 2013 cartographic boundary shapefiles. Location of facilities is provided by EPA's Facility Registry Service (FRS). Large Aquatic Ecosystems boundaries were dissolved from the hydrologic unit boundaries and codes for the United States, Puerto Rico, and the U.S. Virgin Islands. It was revised for inclusion in the National Atlas of the United States of America (November 2002), and updated to match the streams file created by the USGS National Mapping Division (NMD) for the National Atlas of the United States of America.

  11. Fission product release from core-concrete mixtures

    International Nuclear Information System (INIS)

    Roche, M.F.; Settle, J.; Leibowitz, L.; Johnson, C.E.; Ritzman, R.L.

    1988-01-01

    The objective of this research is to measure the amount of strontium, barium, and lanthanum that is vaporized from core-concrete mixtures. The measurements are being done using a transpiration method. Mixtures of limestone-aggregated concrete, urania doped with a small amount of La, Sr, Ba, and Zr oxides, and stainless steel were vaporized at 2150 K from a zirconia crucible into flowing He-6% H 2 -0.06% H 2 O (a partial molar free energy of oxygen of -420 kJ). The amounts that were vaporized was determined by weight change and by chemical analyses on condensates. The major phases present in the mixture were inferred from electron probe microanalysis (EPM). They were: (1) urania containing calcia and zirconia, (2) calcium zirconate, (3) a calcium magnesium silicate, and (4) magnesia. About 10% of the zirconia crucible was dissolved by the concrete-urania mixture during the experiment, which accounts for the presence of zirconia-containing major phases. To circumvent the problem of zirconia dissolution, we repeated the experiments using mixtures of the limestone-aggregate concrete and the doped urania in molybdenum crucibles. These studies show that thermodynamic calculations of the release of refractory fission products will yield release fractions that are a factor of sixteen too high if the effects of zirconate formation are ignored

  12. Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet.

    Science.gov (United States)

    Bhalekar, M R; Madgulkar, A R; Sheladiya, D D; Kshirsagar, S J; Wable, N D; Desale, S S

    2008-01-01

    The purpose of this research was to prepare a sustained release drug delivery system of venlafaxine hydrochloride by using a wax matrix system. The effects of bees wax and carnauba wax on drug release profile was investigated. A 3(2) full factorial design was applied to systemically optimize the drug release profile. Amounts of carnauba wax (X(1)) and bees wax (X(2)) were selected as independent variables and release after 12 h and time required for 50% (t(50)) drug release were selected as dependent variables. A mathematical model was generated for each response parameter. Both waxes retarded release after 12 h and increases the t(50) but bees wax showed significant influence. The drug release pattern for all the formulation combinations was found to be approaching Peppas kinetic model. Suitable combination of two waxes provided fairly good regulated release profile. The response surfaces and contour plots for each response parameter are presented for further interpretation of the results. The optimum formulations were chosen and their predicted results found to be in close agreement with experimental findings.

  13. UV imaging for in vitro dissolution and release studies: Initial experiences

    DEFF Research Database (Denmark)

    Østergaard, Jesper; Lenke, James; Jensen, Sabrine Smedegaard

    2014-01-01

    UV imaging has recently been introduced as a method in drug dissolution and release testing. Spatially and temporally resolved mapping of drug oncentrations in a 7 × 9 mm imaging area provides new opportunities for visualization and study of drug dissolution and release. This review describes...... in hydrogels with relevance for characterization of parenteral depots. UV imaging may be of particular use when the amounts of material are sparse and detailed insights into dissolution and release processes are required, that is in solid form screening, preformulation, and early drug development....

  14. Large scale disposal of waste sulfur: From sulfide fuels to sulfate sequestration

    International Nuclear Information System (INIS)

    Rappold, T.A.; Lackner, K.S.

    2010-01-01

    Petroleum industries produce more byproduct sulfur than the market can absorb. As a consequence, most sulfur mines around the world have closed down, large stocks of yellow sulfur have piled up near remote operations, and growing amounts of toxic H 2 S are disposed of in the subsurface. Unless sulfur demand drastically increases or thorough disposal practices are developed, byproduct sulfur will persist as a chemical waste problem on the scale of 10 7 tons per year. We review industrial practices, salient sulfur chemistry, and the geochemical cycle to develop sulfur management concepts at the appropriate scale. We contend that the environmentally responsible disposal of sulfur would involve conversion to sulfuric acid followed by chemical neutralization with equivalent amounts of base, which common alkaline rocks can supply cheaply. The resulting sulfate salts are benign and suitable for brine injection underground or release to the ocean, where they would cause minimal disturbance to ecosystems. Sequestration costs can be recouped by taking advantage of the fuel-grade thermal energy released in the process of oxidizing reduced compounds and sequestering the products. Sulfate sequestration can eliminate stockpiles and avert the proliferation of enriched H 2 S stores underground while providing plenty of carbon-free energy to hydrocarbon processing.

  15. The influence of "host release factor" on carbon release by zooxanthellae isolated from fed and starved Aiptasia pallida (Verrill).

    Science.gov (United States)

    Davy, S K; Cook, C B

    2001-06-01

    Symbiotic dinoflagellates (zooxanthellae) typically respond to extracts of host tissue with enhanced release of short-term photosynthetic products. We examined this "host release factor" (HRF) response using freshly isolated zooxanthellae of differing nutritional status. The nutritional status was manipulated by either feeding or starving the sea anemone Aiptasia pallida (Verrill). The release of fixed carbon from isolated zooxanthellae was measured using 14C in 30 min experiments. Zooxanthellae in filtered seawater alone released approximately 5% of photosynthate irrespective of host feeding history. When we used a 10-kDa ultrafiltrate of A. pallida host tissue as a source of HRF, approximately 14% of photosynthate was released to the medium. This increased to over 25% for zooxanthellae from anemones starved for 29 days or more. The cell-specific photosynthetic rate declined with starvation in these filtrate experiments, but the decline was offset by the increased percentage release. Indeed, the total amount of released photosynthate remained unchanged, or even increased, as zooxanthellae became more nutrient deficient. Similar trends were also observed when zooxanthellae from A. pallida were incubated in a 3-kDa ultrafiltrate of the coral Montastraea annularis, suggesting that HRF in the different filtrates operated in a similar manner. Our results support the suggestion that HRF diverts surplus carbon away from storage compounds to translocated compounds such as glycerol.

  16. Evaluation of the release behavior of the dexamethasone embedded in polycarbonate polyurethane membranes: an in vitro study

    International Nuclear Information System (INIS)

    Kim, Dong Hyun; Kang, Sung Gwon; Lee, Chul Gab; Park, Sang Soo; Lee, Don Haeng; Lee, Gyu Baek; Song, Ho Young

    2003-01-01

    To evaluate the release behavior of dexamethasone embedded in a polycarbonate polyurethane membrane. Both water-soluble and water-insoluble dexamethasone were tested, and the release behavior of five water-insoluble dexamethasone films of different thickness (78 to 211 μm) was also evaluated. The amount of dexamethasone used was 10% of the total weight of the polyurethan film mass. Each film was placed in a centrifuge tube containing 25 ml of 0.1-M neutral phosphate buffer, and the tubes were placed in a shaking incubator to quantify the amount of drug released into the buffer, absorption spectroscopy (λ max=242 nm) was employed. In the test involving water-soluble dexamethasone, 60%, of the drug was released during the first two hours of the study. Films containing water-insoluble dexamethasone, on the other hand, released 40%, 60% and 75% of the dexamethasone in one, three and seven days, respectively. Both types of film maintained low-dose drug release for 28 days. When release behavior was compared between water-insoluble films of different thickness, thicker film showed less initial burst and more sustained release. Dexamethasone release behavior varies according to drug solubility and membrane thickness, and may thus be conrolled

  17. Effects of amphiphilic chitosan-g-poly(ε-caprolactone) polymer additives on paclitaxel release from drug eluting implants

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Weibin [Department of General Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092 (China); Gu, Chunhua [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Jiang, Han [Department of General Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092 (China); Zhang, Mengru [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Lang, Meidong, E-mail: mdlang@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2014-12-01

    Bioresorbable polymer stents have been proposed as promising medical implants to avoid long-term safety concerns and other potential issues caused by traditional materials. As an important member, poly(ε-caprolactone) (PCL) was used as the implant matrix with different drug loadings. To better regulate drug release rate, the hydrophilicity of PCL was adjusted by addition of amphiphilic graft copolymers, chitosan-g-poly(ε-caprolactone) (CP). The in vitro release results indicated that the improvement of bulk hydrophilicity could accelerate drug release better than that of surface coating. The optimum additive amount was 25% with CP9. Further study showed that the effect of aspirin molecules displayed no obvious difference to that of CP macromolecules on drug release rate. Moreover, these release profiles were fitted with mathematical models. The similarities were evaluated with similarity factors. Scanning electron microscopy (SEM) images displayed surface/cross-section morphologies of pure PCL and modified implants before and after release. - Highlights: • The improvement of bulk hydrophilicity better accelerated drug release. • The higher weight ratio of CP implants had, the faster the drug released. • The shorter PCL chain in CP graft coploymers, the faster the drug released. • The optimum additive amount was 25% with CP9. • Drug release profile conformed to controllable Fick diffusional release mechanism.

  18. The 2014 water release into the arid Colorado River delta and associated water losses by evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Daesslé, L.W., E-mail: walter@uabc.edu.mx [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, CarreteraTranspeninsular Tijuana-Ensenada No. 3917, Fraccionamiento Playitas, CP 22860 Ensenada, Baja California (Mexico); Friedrich-Alexander University of Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany); Geldern, R. van [Friedrich-Alexander University of Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany); Orozco-Durán, A. [Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, CarreteraTranspeninsular Tijuana-Ensenada No. 3917, Fraccionamiento Playitas, CP 22860 Ensenada, Baja California (Mexico); Barth, J.A.C. [Friedrich-Alexander University of Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany)

    2016-01-15

    For the first time in history, water was intentionally released for environmental purposes into the final, otherwise dry, 160-km stretch of the Colorado River basin, south of the Mexican border. Between March and May 2014 three pulses of water with a total volume of 132 × 10{sup 6} m{sup 3} were released to assess the restoration potential of endemic flora along its course and to reach its estuary. The latter had not received a sustained input of fresh water and nutrients from its main fluvial source for over 50 years because of numerous upstream dam constructions. During this pulse flow large amounts of water were lost and negligible amounts reached the ocean. While some of these water losses can be attributed to plant uptake and infiltration, we were able to quantify evaporation losses between 16.1 to 17.3% of the original water mass % within the first 80 km after the Morels Dam with water stable isotope data. Our results showed no evidence for freshwater reaching the upper Colorado River estuary and it is assumed that the pulse flow had only negligible influences on the coastal ecosystem. Future water releases that aim on ecological restoration need to become more frequent and should have larger volumes if more significant effects are to be established on the area. - Highlights: • Isotope ratios of oxygen and hydrogen quantify water lost through evaporation. • Evaporation losses between 16.1 and 17.3% during the 2014 Colorado River • Larger water volumes are required to influence the estuary ecosystem.

  19. The 2014 water release into the arid Colorado River delta and associated water losses by evaporation

    International Nuclear Information System (INIS)

    Daesslé, L.W.; Geldern, R. van; Orozco-Durán, A.; Barth, J.A.C.

    2016-01-01

    For the first time in history, water was intentionally released for environmental purposes into the final, otherwise dry, 160-km stretch of the Colorado River basin, south of the Mexican border. Between March and May 2014 three pulses of water with a total volume of 132 × 10"6 m"3 were released to assess the restoration potential of endemic flora along its course and to reach its estuary. The latter had not received a sustained input of fresh water and nutrients from its main fluvial source for over 50 years because of numerous upstream dam constructions. During this pulse flow large amounts of water were lost and negligible amounts reached the ocean. While some of these water losses can be attributed to plant uptake and infiltration, we were able to quantify evaporation losses between 16.1 to 17.3% of the original water mass % within the first 80 km after the Morels Dam with water stable isotope data. Our results showed no evidence for freshwater reaching the upper Colorado River estuary and it is assumed that the pulse flow had only negligible influences on the coastal ecosystem. Future water releases that aim on ecological restoration need to become more frequent and should have larger volumes if more significant effects are to be established on the area. - Highlights: • Isotope ratios of oxygen and hydrogen quantify water lost through evaporation. • Evaporation losses between 16.1 and 17.3% during the 2014 Colorado River • Larger water volumes are required to influence the estuary ecosystem.

  20. Caught you: threats to confidentiality due to the public release of large-scale genetic data sets.

    Science.gov (United States)

    Wjst, Matthias

    2010-12-29

    Large-scale genetic data sets are frequently shared with other research groups and even released on the Internet to allow for secondary analysis. Study participants are usually not informed about such data sharing because data sets are assumed to be anonymous after stripping off personal identifiers. The assumption of anonymity of genetic data sets, however, is tenuous because genetic data are intrinsically self-identifying. Two types of re-identification are possible: the "Netflix" type and the "profiling" type. The "Netflix" type needs another small genetic data set, usually with less than 100 SNPs but including a personal identifier. This second data set might originate from another clinical examination, a study of leftover samples or forensic testing. When merged to the primary, unidentified set it will re-identify all samples of that individual. Even with no second data set at hand, a "profiling" strategy can be developed to extract as much information as possible from a sample collection. Starting with the identification of ethnic subgroups along with predictions of body characteristics and diseases, the asthma kids case as a real-life example is used to illustrate that approach. Depending on the degree of supplemental information, there is a good chance that at least a few individuals can be identified from an anonymized data set. Any re-identification, however, may potentially harm study participants because it will release individual genetic disease risks to the public.

  1. Caught you: threats to confidentiality due to the public release of large-scale genetic data sets

    Directory of Open Access Journals (Sweden)

    Wjst Matthias

    2010-12-01

    Full Text Available Abstract Background Large-scale genetic data sets are frequently shared with other research groups and even released on the Internet to allow for secondary analysis. Study participants are usually not informed about such data sharing because data sets are assumed to be anonymous after stripping off personal identifiers. Discussion The assumption of anonymity of genetic data sets, however, is tenuous because genetic data are intrinsically self-identifying. Two types of re-identification are possible: the "Netflix" type and the "profiling" type. The "Netflix" type needs another small genetic data set, usually with less than 100 SNPs but including a personal identifier. This second data set might originate from another clinical examination, a study of leftover samples or forensic testing. When merged to the primary, unidentified set it will re-identify all samples of that individual. Even with no second data set at hand, a "profiling" strategy can be developed to extract as much information as possible from a sample collection. Starting with the identification of ethnic subgroups along with predictions of body characteristics and diseases, the asthma kids case as a real-life example is used to illustrate that approach. Summary Depending on the degree of supplemental information, there is a good chance that at least a few individuals can be identified from an anonymized data set. Any re-identification, however, may potentially harm study participants because it will release individual genetic disease risks to the public.

  2. Alginate-based pellets prepared by extrusion/spheronization: effect of the amount and type of sodium alginate and calcium salts.

    Science.gov (United States)

    Sriamornsak, Pornsak; Nunthanid, Jurairat; Luangtana-anan, Manee; Weerapol, Yossanun; Puttipipatkhachorn, Satit

    2008-05-01

    Pellets containing microcrystalline cellulose (MCC), a model drug (theophylline) and a range of levels of sodium alginate (i.e., 10-50% w/w) were prepared by extrusion/spheronization. Two types of sodium alginate were evaluated with and without the addition of either calcium acetate or calcium carbonate (0, 0.3, 3 and 10% w/w). The effects of amount and type of sodium alginate and calcium salts on pellet properties, e.g., size, shape, morphology and drug release behavior, were investigated. Most pellet formulations resulted in pellets of a sufficient quality with respect to size, size distribution and shape. The results showed that the amounts of sodium alginate and calcium salts influenced the size and shape of the obtained pellets. However, different types of sodium alginate and calcium salt responded to modifications to a different extent. A cavity was observed in the pellet structure, as seen in the scanning electron micrographs, resulting from the forces involved in the spheronization process. Most of pellet formulations released about 75-85% drug within 60 min. Incorporation of calcium salts in the pellet formulations altered the drug release, depending on the solubility of the calcium salts used. The drug release data showed a good fit into both Higuchi and Korsmeyer-Peppas equations.

  3. Multivesicular release underlies short term synaptic potentiation independent of release probability change in the supraoptic nucleus.

    Directory of Open Access Journals (Sweden)

    Michelle E Quinlan

    Full Text Available Magnocellular neurons of the supraoptic nucleus receive glutamatergic excitatory inputs that regulate the firing activity and hormone release from these neurons. A strong, brief activation of these excitatory inputs induces a lingering barrage of tetrodotoxin-resistant miniature EPSCs (mEPSCs that lasts for tens of minutes. This is known to accompany an immediate increase in large amplitude mEPSCs. However, it remains unknown how long this amplitude increase can last and whether it is simply a byproduct of greater release probability. Using in vitro patch clamp recording on acute rat brain slices, we found that a brief, high frequency stimulation (HFS of afferents induced a potentiation of mEPSC amplitude lasting up to 20 min. This amplitude potentiation did not correlate with changes in mEPSC frequency, suggesting that it does not reflect changes in presynaptic release probability. Nonetheless, neither postsynaptic calcium chelator nor the NMDA receptor antagonist blocked the potentiation. Together with the known calcium dependency of HFS-induced potentiation of mEPSCs, our results imply that mEPSC amplitude increase requires presynaptic calcium. Further analysis showed multimodal distribution of mEPSC amplitude, suggesting that large mEPSCs were due to multivesicular glutamate release, even at late post-HFS when the frequency is no longer elevated. In conclusion, high frequency activation of excitatory synapses induces lasting multivesicular release in the SON, which is independent of changes in release probability. This represents a novel form of synaptic plasticity that may contribute to prolonged excitatory tone necessary for generation of burst firing of magnocellular neurons.

  4. TEGDMA and UDMA monomers released from composite dental material polymerized with diode and halogen lamps.

    Science.gov (United States)

    Wacławczyk, Agnieszka; Postek-Stefańska, Lidia; Pietraszewska, Daria; Birkner, Ewa; Zalejska-Fiolka, Jolanta; Wysoczańska-Jankowicz, Iwona

    2018-03-20

    More than 35 substances released from composite fillings have been identified. Among these, basic monomers and the so-called co-monomers are most often reported. The substances released from polymer-based materials demonstrate allergenic, cytotoxic, genotoxic, mutagenic, embryotoxic, teratogenic, and estrogenic properties. The aim of this study was to measure the amounts of triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) monomers released from composite dental fillings to citrate-phosphate buffer with the pH of 4, 6, 8 after 24 h and 6 months from the polymerization. Ten samples for each polymerization method had been made from the composite material (Filtek Supreme XT, 3M ESPE, St. Paul, USA), which underwent polymerization using the following lamps: halogen lamp (Translux CL, Heraeus Kulzer, Hanau, Germany) (sample H) and diode lamp (Elipar Freelight 2, 3M ESPE), with soft start function (group DS) and without that function (group DWS). It has been demonstrated that the type of light-curing units has a significant impact on the amount of TEGDMA and UDMA released. The amount of UDMA and TEGDMA monomers released from composite fillings differed significantly depending on the source of polymerization applied, as well as the pH of the solution and sample storage time. Elution of the monomers from composite material polymerized using halogen lamp was significantly greater as compared to curing with diode lamps.

  5. Investigation of chloride-release of nuclear grade resin in PWR primary system coolant

    International Nuclear Information System (INIS)

    Cao Xiaoning; Li Yunde; Li Jinghong; Lin Fangliang

    1997-01-01

    A new preparation technique is developed for making the low-chloride nuclear-grade resin by commercial resin. The chloride remained in nuclear grade resin may release to PWR primary coolant. The amount of released chloride is depended on the concentration of boron, lithium, other anion impurities, and remained chloride concentration in resin

  6. An advanced model for spreading and evaporation of accidentally released hazardous liquids on land

    NARCIS (Netherlands)

    Trijssenaar-Buhre, I.J.M.; Sterkenburg, R.P.; Wijnant-Timmerman, S.I.

    2009-01-01

    Pool evaporation modelling is an important element in consequence assessment of accidentally released hazardous liquids. The evaporation rate determines the amount of toxic or flammable gas released into the atmosphere and is an important factor for the size of a pool fire. In this paper a

  7. An advanced model for spreading and evaporation of accidentally released hazardous liquids on land

    NARCIS (Netherlands)

    Trijssenaar-Buhre, I.J.M.; Wijnant-Timmerman, S.L.

    2008-01-01

    Pool evaporation modelling is an important element in consequence assessment of accidentally released hazardous liquids. The evaporation rate determines the amount of toxic or flammable gas released into the atmosphere and is an important factor for the size of a pool fire. In this paper a

  8. Controlled Release Formulations of Auxinic Herbicides

    Science.gov (United States)

    Kowalski, Witold J.; Siłowiecki, Andrzej.; Romanowska, Iwona; Glazek, Mariola; Bajor, Justyna; Cieciwa, Katarzyna; Rychter, Piotr

    2013-04-01

    Controlled release formulations are applied extensively for the release of active ingredients such as plant protection agents and fertilizers in response to growing concern for ecological problems associated with increased use of plant protection chemicals required for intensive agricultural practices [1]. We synthesized oligomeric mixtures of (R,S)-3-hydroxy butyric acid chemically bonded with 2,4-D, Dicamba and MCPA herbicides (HBA) respectively, and determined their molecular structure and molecular weight dispersion by the size exclusion chromatography, proton magnetic resonance spectrometry and electro-spray ionization mass spectrometry. Further we carried out bioassays of herbicidal effectiveness of the HBA herbicides vs. series of dicotyledonous weeds and crop injury tests [2, 3, 4]. Field bioassays were accomplished according to the EPPO standards [5]. Groups of representative weeds (the development stages in the BCCH scale: 10 - 30) were selected as targets. Statistical variabilities were assessed by the Fisher LSD test for plants treated with the studied herbicides in form of HBA oligomers, the reference herbicides in form of dimethyl ammonium salts (DMA), and untreated plants. No statistically significant differences in the crop injuries caused by the HBA vs. the DMA reference formulation were observed. The effectiveness of the HBA herbicides was lower through the initial period (ca. 2 weeks) relative to the DMA salts, but a significant increase in the effectiveness of the HBA systems followed during the remaining fraction of each assay. After 6 weeks all observed efficiencies approached 100%. The death of weeds treated with the HBA herbicides was delayed when compared with the DMA reference herbicides. The delayed uptake observed for the HBA oligomers relative to the DMA salts was due to controlled release phenomena. In case of the DMA salts the total amount of active ingredients was available at the target site. By contrast, the amount of an active

  9. Gas release and leachates at bark storage: Laboratory and field studies. Final report

    International Nuclear Information System (INIS)

    Jirjis, Raida; Andersson, Paal; Aronsson, Paer

    2005-01-01

    Large volumes of bark are produced as a by-product from saw mills and pulp and paper industry all year round in Sweden. Most of the bark is used as a biofuel. Due to the uneven demand for the fuel during the year, bark has to be often stored for a few months. Storage normally takes place outdoors in fairly large piles. A number of biological and chemical processes are known to occur during storage. These processes can lead to the emission and leakage of environmentally unaccepted products which can also affect working environment. The aim of this project was to evaluate the outcome of some of these processes and to asses its effect on working environment as well as the surrounding environment. This study investigates the storage of fresh bark from pine and spruce in laboratory scale experiments and a large scale storage trial. Results of the analyses of bark material, before and after storage, and the chemical constituents of the released gases and leached material are presented. Estimation of the total amounts that can be released in gas form or leached out from bark piles during storage, and possible environmental consequences are discussed. Conclusions and some practical suggestion concerning bark storage are given in this report. The laboratory experiment involved storage of fresh bark in a 34 litres cylindrical chamber at room temperature (RT) or heated to an average of 55 deg C. The chambers were designed to provide gas samples during emissions experiment and allow irrigation during leakage experiments. Sampling of the released gases (using Tenax-adsorbent) was performed during two or three weeks of storage for spruce and pine bark respectively. The total volatile organic compounds (VOC) and individual monoterpenes were determined. Changes in the chemical constituents of bark during storage were studied using different extraction methods and measuring instruments including Gas spectroscopy (GC)-flame ionization detector (FID) and GC- mass spectroscopy (MS

  10. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Wanyika, Harrison, E-mail: hwanyika@gmail.com [Jomo Kenyatta University of Agriculture and Technology, Department of Chemistry (Kenya)

    2013-08-15

    The use of nanomaterials for the controlled delivery of pesticides is nascent technology that has the potential to increase the efficiency of food production and decrease pollution. In this work, the prospect of mesoporous silica nanoparticles (MSN) for storage and controlled release of metalaxyl fungicide has been investigated. Mesoporous silica nanospheres with average particle diameters of 162 nm and average pore sizes of 3.2 nm were prepared by a sol-gel process. Metalaxyl molecules were loaded into MSN pores from an aqueous solution by a rotary evaporation method. The loaded amount of metalaxyl as evaluated by thermogravimetric analysis was about 14 wt%. Release of the fungicide entrapped in the MSN matrix revealed sustained release behavior. About 76 % of the free metalaxyl was released in soil within a period of 30 days while only 11.5 and 47 % of the metalaxyl contained in the MSN carrier was released in soil and water, respectively, within the same period. The study showed that MSN can be used to successfully store metalaxyl molecules in its mesoporous framework and significantly delay their release in soil.

  11. Sustained release of fungicide metalaxyl by mesoporous silica nanospheres

    International Nuclear Information System (INIS)

    Wanyika, Harrison

    2013-01-01

    The use of nanomaterials for the controlled delivery of pesticides is nascent technology that has the potential to increase the efficiency of food production and decrease pollution. In this work, the prospect of mesoporous silica nanoparticles (MSN) for storage and controlled release of metalaxyl fungicide has been investigated. Mesoporous silica nanospheres with average particle diameters of 162 nm and average pore sizes of 3.2 nm were prepared by a sol–gel process. Metalaxyl molecules were loaded into MSN pores from an aqueous solution by a rotary evaporation method. The loaded amount of metalaxyl as evaluated by thermogravimetric analysis was about 14 wt%. Release of the fungicide entrapped in the MSN matrix revealed sustained release behavior. About 76 % of the free metalaxyl was released in soil within a period of 30 days while only 11.5 and 47 % of the metalaxyl contained in the MSN carrier was released in soil and water, respectively, within the same period. The study showed that MSN can be used to successfully store metalaxyl molecules in its mesoporous framework and significantly delay their release in soil

  12. Normalization of doxorubicin release from graphene oxide: New approach for optimization of effective parameters on drug loading.

    Science.gov (United States)

    Hashemi, Mohadeseh; Yadegari, Amir; Yazdanpanah, Ghasem; Omidi, Meisam; Jabbehdari, Sayena; Haghiralsadat, Fatemeh; Yazdian, Fatemeh; Tayebi, Lobat

    2017-05-01

    Graphene oxide (GO) has been recently introduced as a suitable anticancer drug carrier, which could be loaded with doxorubicin (DOX) as a general chemotherapy agent. Herein, the attempts were made to optimize the effective parameters on both loading and release of DOX on GO. GO and GO-DOX were characterized using transition electron microscopy , zeta potential, Raman spectroscopy, UV-visible spectroscopy, and Fourier transform infrared spectroscopy. In addition, loading and releasing behaviors of DOX on GO were studied in terms of different temperature and pH values. The primary optimized values of pH and temperature for best-loaded amount of DOX were 8.9 and 309 K, respectively. Moreover, we found that the smallest amount of released DOX, in pH of cancer microenvironment (5.4), occurs when DOX had been previously loaded in pH 7.8 and 310 K. Although the highest amount of loaded DOX was in basic pH, the results of efficient release of DOX from the GO-DOX complex and also cellular toxicity assay revealed that the best pH for loading of DOX on GO was 7.8. Therefore, in addition to optimization of parameters for efficient loading of DOX on GO, this study suggested that normalization of a released drug compared with the amount of a loaded drug could be a new approach for optimization of drug loading on nanocarriers. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  13. Xyce parallel electronic simulator release notes.

    Energy Technology Data Exchange (ETDEWEB)

    Keiter, Eric R; Hoekstra, Robert John; Mei, Ting; Russo, Thomas V.; Schiek, Richard Louis; Thornquist, Heidi K.; Rankin, Eric Lamont; Coffey, Todd S; Pawlowski, Roger P; Santarelli, Keith R.

    2010-05-01

    The Xyce Parallel Electronic Simulator has been written to support, in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. Specific requirements include, among others, the ability to solve extremely large circuit problems by supporting large-scale parallel computing platforms, improved numerical performance and object-oriented code design and implementation. The Xyce release notes describe: Hardware and software requirements New features and enhancements Any defects fixed since the last release Current known defects and defect workarounds For up-to-date information not available at the time these notes were produced, please visit the Xyce web page at http://www.cs.sandia.gov/xyce.

  14. Release isentrope measurements with the LLNL electric gun

    Energy Technology Data Exchange (ETDEWEB)

    Gathers, G.R.; Osher, J.E.; Chau, H.H.; Weingart, R.C.; Lee, C.G.; Diaz, E.

    1987-06-01

    The liquid-vapor coexistence boundary is not well known for most metals because the extreme conditions near the critical point create severe experimental difficulties. The isentropes passing through the liquid-vapor region typically begin from rather large pressures on the Hugoniot. We are attempting to use the high velocities achievable with the Lawrence Livermore National Laboratory (LLNL) electric gun to obtain these extreme states in aluminum and measure the release isentropes by releasing into a series of calibrated standards with known Hugoniots. To achieve large pressure drops needed to explore the liquid-vapor region, we use argon gas for which Hugoniots have been calculated using the ACTEX code, as one of the release materials.

  15. Building Adjustable Pre-storm Reservoir Flood-control Release Rules

    Science.gov (United States)

    Yang, Shun-Nien; Chang, Li-Chiu; Chang, Fi-John; Hsieh, Cheng-Daw

    2017-04-01

    Typhoons hit Taiwan several times every year, which could cause serious flood disasters. Because mountainous terrains and steep landforms can rapidly accelerate the speed of flood flow during typhoon events, rivers cannot be a stable source of water supply. Reservoirs become the most effective floodwater storage facilities for alleviating flood damages in Taiwan. The pre-storm flood-control release can significantly increase reservoir storage capacity available to store floodwaters for reducing downstream flood damage, while the uncertainties of total forecasted rainfalls are very high in different stages of an oncoming typhoon, which may cause the risk of water shortage in the future. This study proposes adjustable pre-storm reservoir flood-control release rules in three designed operating stages with various hydrological conditions in the Feitsui Reservoir, a pivot reservoir for water supply to Taipei metropolitan in Taiwan, not only to reduce the risk of reservoir flood control and downstream flooding but also to consider water supply. The three operating stages before an oncoming typhoon are defined upon the timings when: (1) typhoon news is issued (3-7days before typhoon hit); (2) the sea warning is issued (2-4 days before typhoon hit); and (3) the land warning is issued (1-2 days before typhoon hit). We simulate 95 historical typhoon events with 3000 initial water levels and build some pre-storm flood-control release rules to adjust the amount of pre-release based on the total forecasted rainfalls at different operating stages. A great number of simulations (68.4 millions) are conducted to extract their major consequences and then build the adjustable pre-storm reservoir flood-control release rules. Accordingly, given a total forecasted rainfall and a water level, reservoir decision makers can easily identify the corresponding rule to tell the amount of pre-release in any stage. The results show that the proposed adjustable pre-release rules can effectively

  16. Calcitonin gene-related peptide and somatostatin releases correlated with the area under the lafutidine concentration-time curve in human plasma.

    Science.gov (United States)

    Ikawa, K; Shimatani, T; Azuma, Y; Inoue, M; Morikawa, N

    2006-08-01

    To examine the effects of the histamine H(2)-receptor antagonist, lafutidine, at clinical dosage (10 mg tablet after a standardized meal) on plasma levels of the gastrointestinal peptides, calcitonin gene-related peptide (CGRP), somatostatin and gastrin. Six healthy male volunteers ate a standardized meal, and received either lafutidine orally at a dose of 10 mg or water only (control). Blood samples were taken before and up to 4 h after the drug administration. Plasma lafutidine concentrations were determined by high pressure liquid chromatography. Pharmacokinetic analysis of lafutidine was performed using one-compartmental model. The levels of immunoreactive substances of plasma CGRP, somatostatin and gastrin were measured by enzyme immunoassay, and the amount of peptide release was calculated by the trapezoidal method. Lafutidine significantly increased plasma CGRP levels at 1, 1.5, 2.5 and 4 h and the total amount of CGRP release (192 +/- 14.0 pg.h/mL) compared with the control group (128 +/- 21.5 pg.h/mL). Lafutidine significantly increased the plasma somatostatin levels at 1 and 1.5 h, and the total amount of somatostatin released (107 +/- 18.2 pg.h/mL) compared with the control (78.4 +/- 7.70 pg.h/mL). The area under the drug concentration-time curve (AUC) from 0 to 4 h after administration correlated well with the Delta-CGRP and Delta-somatostatin release but not with total amount of gastrin released. However, plasma gastrin levels were significantly elevated at 1.5 h after drug administration. Lafutidine at clinical dosage increases plasma CGRP and the somatostatin. The amounts released correlated with the AUC of lafutidine in humans. These results suggest that the increased release of CGRP and somatostatin may contribute to its gastroprotective and anti-acid secretory effect.

  17. Drug Release Profile from Calcium-Induced Alginate-Phosphate Composite Gel Beads

    Directory of Open Access Journals (Sweden)

    Yoshifumi Murata

    2009-01-01

    Full Text Available Calcium-induced alginate-phosphate composite gel beads were prepared, and model drug release profiles were investigated in vitro. The formation of calcium phosphate in the alginate gel matrix was observed and did not affect the rheological properties of the hydrogel beads. X-ray diffraction patterns showed that the calcium phosphate does not exist in crystalline form in the matrix. The initial release amount and release rate of a water-soluble drug, diclofenac, from the alginate gel beads could be controlled by modifying the composition of the matrix with calcium phosphate. In contrast, the release profile was not affected by the modification for hydrocortisone, a drug only slightly soluble in water.

  18. Forest amount affects soybean productivity in Brazilian agricultural frontier

    Science.gov (United States)

    Rattis, L.; Brando, P. M.; Marques, E. Q.; Queiroz, N.; Silverio, D. V.; Macedo, M.; Coe, M. T.

    2017-12-01

    Over the past three decades, large tracts of tropical forests have been converted to crop and pasturelands across southern Amazonia, largely to meet the increasing worldwide demand for protein. As the world's population continue to grow and consume more protein per capita, forest conversion to grow more crops could be a potential solution to meet such demand. However, widespread deforestation is expected to negatively affect crop productivity via multiple pathways (e.g., thermal regulation, rainfall, local moisture, pest control, among others). To quantify how deforestation affects crop productivity, we modeled the relationship between forest amount and enhanced vegetation index (EVI—a proxy for crop productivity) during the soybean planting season across southern Amazonia. Our hypothesis that forest amount causes increased crop productivity received strong support. We found that the maximum MODIS-based EVI in soybean fields increased as a function of forest amount across three spatial-scales, 0.5 km, 1 km, 2 km, 5 km, 10 km, 15 km and 20 km. However, the strength of this relationship varied across years and with precipitation, but only at the local scale (e.g., 500 meters and 1 km radius). Our results highlight the importance of considering forests to design sustainable landscapes.

  19. Gas Release as a Deformation Signal

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Radiogenic noble gases are contained in crustal rock at inter and intra granular sites. The gas composition depends on lithology, geologic history, fluid phases, and the aging effect by decay of U, Th, and K. The isotopic signature of noble gases found in rocks is vastly different than that of the atmosphere which is contributed by a variety of sources. When rock is subjected to stress conditions exceeding about half its yield strength, micro-cracks begin to form. As rock deformation progresses a fracture network evolves, releasing trapped noble gases and changing the transport properties to gas migration. Thus, changes in gas emanation and noble gas composition from rocks could be used to infer changes in stress-state and deformation. The purpose of this study has been to evaluate the effect of deformation/strain rate upon noble gas release. Four triaxial experiments were attempted for a strain rate range of %7E10-8 /s (180,000s) to %7E 10-4/s (500s); the three fully successful experiments (at the faster strain rates) imply the following: (1) helium is measurably released for all strain rates during deformation, this release is in amounts 1-2 orders of magnitude greater than that present in the air, and (2) helium gas release increases with decreasing strain rate.

  20. Estimation of cobalt release from feed water heater tubes of BWRs

    International Nuclear Information System (INIS)

    Uchida, S.; Kitamura, M.; Ozawa, Y.

    1983-01-01

    To evaluate the release source of cobalt from heater tubes of the feed water line, release rate measurements were carried out by detecting 60 Co released from irradiated stainless steel in contact with neutral water at an oxygen concentration of 20 ppb. The dependences of cobalt release rate on temperature, flow velocity and exposure time were studied after 670 hours of release experiments, and an empirical equation (which is presented) was obtained in the temperature range from 150 to 240 deg C. A decrease in the cobalt release rate above 250 deg C was considered due to the formation of a protective oxide layer. From these data, the amount of cobalt released from individual feed water heaters was evaluated. It was demonstrated that low cobalt containing stainless steel was economically applied only in the higher temperature region of the heater (20% of the total surface) to reduce cobalt feed rate into the reactor (to approx. 1/2). (author)

  1. Study of steam condensation in SG tubes with large amount of nitrogen to be accumulated

    Energy Technology Data Exchange (ETDEWEB)

    Logvinov, S.A.; Sitnik, Y.K. [EDO Gidropress, Podolsk (Russian Federation)

    1997-12-31

    The effect of nitrogen during SG heat transfer under SBLOCA conditions have been studied. Depressurization of the primary side leads to release of nitrogen dissolved in the hydroaccumulator water. Nitrogen can accumulate in SGs and affect adversely heat transfer under reflux condenser conditions. The main objective of the study has been to show that nitrogen does not prevent heat transfer in SGs of the VVER-640 which is reactor plant of new generation. (orig.).

  2. Study of steam condensation in SG tubes with large amount of nitrogen to be accumulated

    Energy Technology Data Exchange (ETDEWEB)

    Logvinov, S A; Sitnik, Y K [EDO Gidropress, Podolsk (Russian Federation)

    1998-12-31

    The effect of nitrogen during SG heat transfer under SBLOCA conditions have been studied. Depressurization of the primary side leads to release of nitrogen dissolved in the hydroaccumulator water. Nitrogen can accumulate in SGs and affect adversely heat transfer under reflux condenser conditions. The main objective of the study has been to show that nitrogen does not prevent heat transfer in SGs of the VVER-640 which is reactor plant of new generation. (orig.).

  3. Gas retention and release behavior in Hanford single-shell waste tanks

    International Nuclear Information System (INIS)

    Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

    1996-12-01

    This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large (∼100 m 3 ) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given

  4. Stimuli-Responsive Materials for Controlled Release Applications

    KAUST Repository

    Li, Song

    2015-04-01

    The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. To address this outstanding problem, the design and fabrication of stimuli-responsive materials are pursued to guarantee the controlled release of cargo at a specific time and with an accurate amount. Upon applying different stimuli such as light, magnetic field, heat, pH change, enzymes or redox, functional materials change their physicochemical properties through physical transformation or chemical reactions, allowing the release of payload agents on demand. This dissertation studied three stimuli-responsive membrane systems for controlled release from films of macro sizes to microcapsules of nano sizes. The first membrane system is a polymeric composite film which can decrease and sustain diffusion upon light irradiation. The photo-response of membranes is based on the photoreaction of cinnamic derivatives. The second one is composite membrane which can improve diffusion upon heating. The thermo-response of membranes comes from the volume phase transition ability of hydrogels. The third one is microcapsule which can release encapsulated agents upon light irradiation. The photo-response of capsules results from the photoreaction of nitrobenzyl derivatives. The study on these membrane systems reveals that stimuli-responsive release can be achieved by utilizing different functional materials on either macro or micro level. Based on the abundant family of smart materials, designing and fabricating stimuli-responsive systems shall lead to various advanced release processes on demand for biomedical applications.

  5. Plasmonic Titania Photo catalysts Active under UV and Visible-Light Irradiation: Influence of Gold Amount, Size, and Shape

    International Nuclear Information System (INIS)

    Kowalska, E.; Rau, S.; Kowalska, E.; Kowalska, E.; Ohtani, B.

    2012-01-01

    Plasmonic titania photo catalysts were prepared by titania modification with gold by photo deposition. It was found that for smaller amount of deposited gold (≤ 0.1 wt%), anatase presence and large surface area were beneficial for efficient hydrogen evolution during methanol dehydrogenation. After testing twelve amounts of deposited gold on large rutile titania, the existence of three optima for 0.5, 2 and >6 wt% of gold was found during acetic acid degradation. Under visible light irradiation, in the case of small gold NPs deposited on fine anatase titania, the dependence of photo activity on gold amount was parabolic, and large gold amount (2 wt%), observable as an intensively coloured powder, caused photo activity decrease. While for large gold NPs deposited on large rutile titania, the dependence represented cascade increase, due to change of size and shape of deposited gold with its amount increase. It has been thought that spherical/hemispherical shape of gold NPs, in comparison with rod-like ones, is beneficial for higher level of photo activity under visible light irradiation. For all tested systems and regardless of deposited amount of gold, each rutile Au/TiO 2 photo catalyst of large gold and titania NPs exhibited much higher photo activity than anatase Au/TiO 2 of small gold and titania NPs

  6. Release of Phosphorus Forms from Cover Crop Residues in Agroecological No-Till Onion Production

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    Full Text Available ABSTRACT Cover crops grown alone or in association can take up different amounts of phosphorus (P from the soil and accumulate it in different P-forms in plant tissue. Cover crop residues with a higher content of readily decomposed forms may release P more quickly for the next onion crop. The aim of this study was to evaluate the release of P forms from residues of single and mixed cover crops in agroecological no-till onion (Allium cepa L. production. The experiment was conducted in Ituporanga, Santa Catarina (SC, Brazil, in an Inceptisol, with the following treatments: weeds, black oat (Avena sativa L., rye (Secale cereale L., oilseed radish (Raphanus sativus L., oilseed radish + black oat, and oilseed radish + rye. Cover crops were sown in April 2013. In July 2013, plant shoots were cut close to the soil surface and part of the material was placed in litterbags. The bags were placed on the soil surface and residues were collected at 0, 15, and 45 days after deposition (DAD. Residues were dried and ground and P in the plant tissue was determined through chemical fractionation. The release of P contained in the tissue of cover crops depends not only on total P content in the tissue, but also on the accumulation of P forms and the quality of the residue in decomposition. The highest accumulation of P in cover crops occurred in the soluble inorganic P fraction, which is the fraction of fastest release in plants. Black oat had the highest initial release rate of soluble inorganic P, which became equal to the release rate of other cover crop residues at 45 DAD. Weeds released only half the amount of soluble inorganic P in the same period, despite accumulating a considerable amount of P in their biomass. The mixtures of oilseed radish + rye and oilseed radish + black oat showed higher release of P associated with RNA at 45 DAD in comparison to the single treatments.

  7. Hypsometric amplification and routing moderation of Greenland ice sheet meltwater release

    Science.gov (United States)

    van As, Dirk; Mikkelsen, Andreas Bech; Holtegaard Nielsen, Morten; Box, Jason E.; Claesson Liljedahl, Lillemor; Lindbäck, Katrin; Pitcher, Lincoln; Hasholt, Bent

    2017-06-01

    Concurrent ice sheet surface runoff and proglacial discharge monitoring are essential for understanding Greenland ice sheet meltwater release. We use an updated, well-constrained river discharge time series from the Watson River in southwest Greenland, with an accurate, observation-based ice sheet surface mass balance model of the ˜ 12 000 km2 ice sheet area feeding the river. For the 2006-2015 decade, we find a large range of a factor of 3 in interannual variability in discharge. The amount of discharge is amplified ˜ 56 % by the ice sheet's hypsometry, i.e., area increase with elevation. A good match between river discharge and ice sheet surface meltwater production is found after introducing elevation-dependent transit delays that moderate diurnal variability in meltwater release by a factor of 10-20. The routing lag time increases with ice sheet elevation and attains values in excess of 1 week for the upper reaches of the runoff area at ˜ 1800 m above sea level. These multi-day routing delays ensure that the highest proglacial discharge levels and thus overbank flooding events are more likely to occur after multi-day melt episodes. Finally, for the Watson River ice sheet catchment, we find no evidence of meltwater storage in or release from the en- and subglacial environments in quantities exceeding our methodological uncertainty, based on the good match between ice sheet runoff and proglacial discharge.

  8. Metallic fission product releases from HTR-spherical fuel elements

    International Nuclear Information System (INIS)

    Helmbold, M.; Amian, W.; Stoever, D.; Hecker, R.

    1978-01-01

    Fission product releases from fuel determines to a large extent the feasibility of a special reactor concept. Basic data describing the diffusion behaviour from coated particle fuel are presented concerning isotopes Cs 137 , Sr 90 and Agsup(110m). Taking into account these data for typical 3000MWth plants release calculations are performed. Sensitive release parameters could be defined and the results show low release figures for all the considered reactor concepts. (author)

  9. Thermoresponsive latexes for fragrance encapsulation and release.

    Science.gov (United States)

    Popadyuk, N; Popadyuk, A; Kohut, A; Voronov, A

    2016-04-01

    To synthesize cross-linked latex particles protecting the encapsulated fragrance at ambient temperatures and facilitating the release of cargo at the temperature of the surface of the skin that varies in different regions of the body between 33.5 and 36.9°C. Poly(stearyl acrylate) (PSA), a polymer with long crystallizable alkyl side chains (undergoes order-disorder transitions at 45°C), was chosen as the main component of the polymer particles. As a result, new thermoresponsive polymer particles for fragrance encapsulation were synthesized and characterized, including assessing the performance of particles in triggered release by elevated temperature. To obtain network domains of various crystallinity, stearyl acrylate was copolymerized with dipropylene glycol acrylate caprylate (DGAC) (comonomer) in the presence of a dipropylene glycol diacrylate sebacate (cross-linker) using the miniemulsion process. Comonomers and a cross-linker were mixed directly in a fragrance during polymerization. Fragrance release was evaluated at 25, 31, 35 and 39°C to demonstrate a new material potential in personal/health care skin-related applications. Particles protect the fragrance from evaporation at 25°C. The fragrance release rate gradually increases at 31, 35 and 39°C. Two slopes were found on release plots. The first slope corresponds to a rapid fragrance release. The second slope indicates a subsequent reduction in the release rate. Crystalline-to-amorphous transition of PSA triggers the release of fragrances from cross-linked latex particles at elevated temperatures. The presence of the encapsulated fragrance, as well as the inclusion of amorphous fragments in the polymer network, reduces the particle crystallinity and enhances the release. Release profiles can be tuned by temperature and controlled by the amount of loaded fragrance and the ratio of comonomers in the feed mixture. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  10. Ultra trace analysis of PAHs by designing simple injection of large amounts of analytes through the sample reconcentration on SPME fiber after magnetic solid phase extraction.

    Science.gov (United States)

    Khodaee, Nader; Mehdinia, Ali; Esfandiarnejad, Reyhaneh; Jabbari, Ali

    2016-01-15

    A simple solventless injection method was introduced based on the using of a solid-phase microextraction (SPME) fiber for injection of large amounts of the analytes extracted by the magnetic solid phase extraction (MSPE) procedure. The resulted extract from MSPE procedure was loaded on a G-coated SPME fiber, and then the fiber was injected into the gas chromatography (GC) injection port. This method combines the advantages of exhaustive extraction property of MSPE and the solvent-less injection of SPME to improve the sensitivity of the analysis. In addition, the analytes were re-concentrated prior to inject into the gas chromatography (GC) inlet because of the organic solvent removing from the remaining extract of MSPE technique. Injection of the large amounts of analytes was made possible by using the introduced procedure. Fourteen polycyclic aromatic hydrocarbons (PAHs) with different volatility were used as model compounds to investigate the method performance for volatile and semi-volatile compounds. The introduced method resulted in the higher enhancement factors (5097-59376), lower detection limits (0.29-3.3pgmL(-1)), and higher sensitivity for the semi-volatile compounds compared with the conventional direct injection method. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. 21 CFR 101.12 - Reference amounts customarily consumed per eating occasion.

    Science.gov (United States)

    2010-04-01

    ...,3,4 Product category Reference amount Label statement 5 Cereals, dry instant 15 g _ cup (_ g...) (_ g); _ piece(s) (_ g) for large pieces (e.g., large shells or lasagna noodles) or 2 oz (56 g/visual... chow mein noodles 25 g _ cup(s) (_ g) Starches, e.g., cornstarch, potato starch, tapioca, etc. 10 g...

  12. A controlled release of ibuprofen by systematically tailoring the morphology of mesoporous silica materials

    International Nuclear Information System (INIS)

    Qu Fengyu; Zhu Guangshan; Lin Huiming; Zhang Weiwei; Sun Jinyu; Li Shougui; Qiu Shilun

    2006-01-01

    A series of mesoporous silica materials with similar pore sizes, different morphologies and variable pore geometries were prepared systematically. In order to control drug release, ibuprofen was employed as a model drug and the influence of morphology and pore geometry of mesoporous silica on drug release profiles was extensively studied. The mesoporous silica and drug-loaded samples were characterized by X-ray diffraction, Fourier transform IR spectroscopy, N 2 adsorption and desorption, scanning electron microscopy, and transmission electron microscopy. It was found that the drug-loading amount was directly correlated to the Brunauer-Emmett-Teller surface area, pore geometry, and pore volume; while the drug release profiles could be controlled by tailoring the morphologies of mesoporous silica carriers. - Graphical abstract: The release of ibuprofen is controlled by tailoring the morphologies of mesoporous silica. The mesoporous silica and drug-loaded samples are characterized by powder X-ray diffraction, Fourier transform IR spectroscopy, N 2 adsorption and desorption, scanning electron microscopy, and transmission electron microscopy. The drug-loading amount is directly correlated to the Brunauer-Emmett-Teller surface area, pore geometry, and pore volume; while the drug release profiles can be controlled by tailoring the morphologies of mesoporous silica carriers

  13. Assessment of released organics from leaf biomass on air quality in the state of California

    International Nuclear Information System (INIS)

    Badgett-West, C.R.; Cort, R.P.

    1991-01-01

    Air quality scientists today are concerned that significant amounts of volatile organic compounds (VOCs), specifically isoprenes and monoterpenes, are released by vegetative matter during biological processes. These emissions have not been previously accounted for and therefore the magnitude of their contribution to ozone concentrations has not been determined. A study of the emissions in the State of California was performed using 1987 as a base year. Data were collected on the acerages of natural and agricultural vegetation for each county in the state. Vegetation acreages were divided by season for direct input into air quality models. Generally, an inventory of the agricultural lands was more complicated than accounting for natural vegetation acreages. This was due to a large extent to crop rotation and production of more than one crop on the same land within the same calendar year. The amount of leaf biomass per acre was very difficult to define. Very little research has been completed in this area. In addition, several variables influence the amount of leaf biomass per acre. These include moisture, temperature, type of soil, insect/animal consumption, and agricultural practices

  14. Shock compression and quasielastic release in tantalum

    International Nuclear Information System (INIS)

    Johnson, J.N.; Hixson, R.S.; Tonks, D.L.; Gray, G.T. III

    1994-01-01

    Previous studies of quasielastic release in shock-loaded FCC metals have shown a strong influence of the defect state on the leading edge, or first observable arrival, of the release wave. This is due to the large density of pinned dislocation segments behind the shock front, their relatively large pinning separation, and a very short response time as determined by the drag coefficient in the shock-compressed state. This effect is entirely equivalent to problems associated with elastic moduli determination using ultrasonic methods. This is particularly true for FCC metals, which have an especially low Peierls stress, or inherent lattice resistance, that has little influence in pinning dislocation segments and inhibiting anelastic deformation. BCC metals, on the other hand, have a large Peierls stress that essentially holds dislocation segments in place at low net applied shear stresses and thus allows fully elastic deformation to occur in the complete absence of anelastic behavior. Shock-compression and release experiments have been performed on tantalum (BCC), with the observation that the leading release disturbance is indeed elastic. This conclusion is established by examination of experimental VISAR records taken at the tantalum/sapphire (window) interface in a symmetric-impact experiment which subjects the sample to a peak longitudinal stress of approximately 7.3 GPa, in comparison with characteristic code calculations. copyright 1994 American Institute of Physics

  15. The release of silver nanoparticles from commercial toothbrushes

    Energy Technology Data Exchange (ETDEWEB)

    Mackevica, Aiga, E-mail: aima@env.dtu.dk; Olsson, Mikael Emil; Hansen, Steffen Foss

    2017-01-15

    Highlights: • Ag and Ag nanoparticle release was measured from two types of toothbrushes. • Maximum release for entire intended product use period was 10 ng Ag per toothbrush. • Released Ag nanoparticles had median sizes from 42 to 47 nm. • Up to 2.8% of total Ag released was detected in nanoparticulate form. - Abstract: The use of silver nanoparticles (NPs) in commercial products has become increasingly common in the past decade, mostly due to their antimicrobial properties. Using Ag NP-containing articles may lead to particle release, which raises concern of human and environmental safety. The published literature addressing particle release is scarce, especially when it comes to quantifying exposure to NPs specifically. In this study, we have experimentally investigated the release of total Ag and Ag NP from commercially available toothbrushes i.e. biodegradable toothbrushes for adults and toothbrushes for children. Toothbrushes were immersed and abraded in tap water for 24 h corresponding to more than the whole intended usage time of a toothbrush. The total amount of released Ag was quantified by inductively coupled plasma—mass spectrometry (ICP-MS) analysis, and the Ag NPs were characterized by single particle ICP-MS and transmission electron microscopy (TEM). The median size of the released Ag NPs ranged from 42 to 47 nm, and the maximum total Ag release was 10.2 ng per toothbrush. The adult toothbrushes were generally releasing more total Ag and NPs than children toothbrushes. In conclusion, our results indicate that the use of Ag NP-impregnated toothbrushes can cause consumer as well as environmental exposure to Ag NPs.

  16. The release of silver nanoparticles from commercial toothbrushes

    International Nuclear Information System (INIS)

    Mackevica, Aiga; Olsson, Mikael Emil; Hansen, Steffen Foss

    2017-01-01

    Highlights: • Ag and Ag nanoparticle release was measured from two types of toothbrushes. • Maximum release for entire intended product use period was 10 ng Ag per toothbrush. • Released Ag nanoparticles had median sizes from 42 to 47 nm. • Up to 2.8% of total Ag released was detected in nanoparticulate form. - Abstract: The use of silver nanoparticles (NPs) in commercial products has become increasingly common in the past decade, mostly due to their antimicrobial properties. Using Ag NP-containing articles may lead to particle release, which raises concern of human and environmental safety. The published literature addressing particle release is scarce, especially when it comes to quantifying exposure to NPs specifically. In this study, we have experimentally investigated the release of total Ag and Ag NP from commercially available toothbrushes i.e. biodegradable toothbrushes for adults and toothbrushes for children. Toothbrushes were immersed and abraded in tap water for 24 h corresponding to more than the whole intended usage time of a toothbrush. The total amount of released Ag was quantified by inductively coupled plasma—mass spectrometry (ICP-MS) analysis, and the Ag NPs were characterized by single particle ICP-MS and transmission electron microscopy (TEM). The median size of the released Ag NPs ranged from 42 to 47 nm, and the maximum total Ag release was 10.2 ng per toothbrush. The adult toothbrushes were generally releasing more total Ag and NPs than children toothbrushes. In conclusion, our results indicate that the use of Ag NP-impregnated toothbrushes can cause consumer as well as environmental exposure to Ag NPs.

  17. Determinants of carbon release from the active layer and permafrost deposits on the Tibetan Plateau

    Science.gov (United States)

    Chen, Leiyi; Liang, Junyi; Qin, Shuqi; Liu, Li; Fang, Kai; Xu, Yunping; Ding, Jinzhi; Li, Fei; Luo, Yiqi; Yang, Yuanhe

    2016-01-01

    The sign and magnitude of permafrost carbon (C)-climate feedback are highly uncertain due to the limited understanding of the decomposability of thawing permafrost and relevant mechanistic controls over C release. Here, by combining aerobic incubation with biomarker analysis and a three-pool model, we reveal that C quality (represented by a higher amount of fast cycling C but a lower amount of recalcitrant C compounds) and normalized CO2–C release in permafrost deposits were similar or even higher than those in the active layer, demonstrating a high vulnerability of C in Tibetan upland permafrost. We also illustrate that C quality exerts the most control over CO2–C release from the active layer, whereas soil microbial abundance is more directly associated with CO2–C release after permafrost thaw. Taken together, our findings highlight the importance of incorporating microbial properties into Earth System Models when predicting permafrost C dynamics under a changing environment. PMID:27703168

  18. Effects of exogenous salinity (NaCl) gradient on Cd release in acidified contaminated brown soil

    Science.gov (United States)

    Zhang, Lina; Rong, Yong; Mao, Li; Gao, Zhiyuan; Liu, Xiaoyu; Dong, Zhicheng

    2018-02-01

    Taking acidified Cd contaminated brown soil in Yantai as the research object, based on different exogenous salinity (NaCl) gradient (0%, 0.3%, 0.6%, 0.9%, 1.5%, 2% and 5%), indoor simulation experiments of Cd release were carried out after field investigation. Results showed that there was a significantly positive relation (r>0.90) between Cd release concentration/amount/ratio and exogenous salt (NaCl). Besides, the more exogenous salt (NaCl) was added; maximum release concentration/amount of Cd appeared the earlier. It was found that exogenous salt (NaCl) addition could obviously promote Cd release from acidified Cd contaminated brown soil. It was believed that this could be mainly due to the cation exchange between Cd2+ and Na+, together with the dissociation and/or complexation between Cl- and Cd2+. In addition, available adsorption sites reduction by exchange base in soil causing Cd changed from solid state to soil solution was also a probable reason.

  19. Assessment of Ions released from Three Types of Orthodontic Brackets immersed in Different Mouthwashes: An in vitro Study.

    Science.gov (United States)

    Nahidh, Mohammed; Garma, Noor Mh; Jasim, Esraa S

    2018-01-01

    Herbs are used widely in medicine. The purpose of the present study was to assess the ion release from gold-plated orthodontic bracket compared with other stainless steel brackets, and based on the findings of the study, the orthodontists can choose the most biocompatible brackets and mouthwashes useful in the clinical practice. A total of 150 orthodontic brackets from Orthotechnology™ Company, USA (50 stainless steel one-piece brackets, 50 stainless steel two-piece brackets, and 50 gold brackets) were immersed in four mouthwashes in addition to distilled water. Ten of each type of brackets in every media were immersed under 37°C for 45 days. Ions released in these mouthwashes were measured, and comparisons among different bracket types and among various mouthwashes were done by one-way analysis of variance (ANOVA) and then with Games-Howell tests. Increased amounts of ions released in herbal mouth-washes were recorded in gold and two-piece brackets in comparison with one-piece stainless steel brackets. Herbal mouthwashes must be used with caution as they showed an increased amount of ions released in comparison with chlorhexidine. One-piece stainless steel bracket system is the most compatible bracket type, as they released the least amount of ions. One-piece stainless steel brackets are better than two-piece brackets in terms of ions released.

  20. Querying Large Biological Network Datasets

    Science.gov (United States)

    Gulsoy, Gunhan

    2013-01-01

    New experimental methods has resulted in increasing amount of genetic interaction data to be generated every day. Biological networks are used to store genetic interaction data gathered. Increasing amount of data available requires fast large scale analysis methods. Therefore, we address the problem of querying large biological network datasets.…

  1. The total release of xenon-133 from the Fukushima Dai-ichi nuclear power plant accident

    International Nuclear Information System (INIS)

    Stohl, Andreas; Seibert, Petra; Wotawa, Gerhard

    2012-01-01

    The accident at the Fukushima Dai-ichi nuclear power plant (FD-NPP) on 11 March 2011 released large amounts of radioactivity into the atmosphere. We determine the total emission of the noble gas xenon-133 ( 133 Xe) using global atmospheric concentration measurements. For estimating the emissions, we used three different methods: (i) using a purely observation-based multi-box model, (ii) comparisons of dispersion model results driven with GFS meteorological data with the observation data, and (iii) such comparisons with the dispersion model driven by ECMWF data. From these three methods, we have obtained total 133 Xe releases from FD-NPP of (i) 16.7 ± 1.9 EBq, (ii) 14.2 ± 0.8 EBq, and (iii) 19.0 ± 3.4 EBq, respectively. These values are substantially larger than the entire 133 Xe inventory of FD-NPP of about 12.2 EBq derived from calculations of nuclear fuel burn-up. Complete release of the entire 133 Xe inventory of FD-NPP and additional release of 133 Xe due to the decay of iodine-133 ( 133 I), which can add another 2 EBq to the 133 Xe FD-NPP inventory, is required to explain the atmospheric observations. Two of our three methods indicate even higher emissions, but this may not be a robust finding given the differences between our estimates. - Highlights: ► We determine the total release of xenon-133 from the Fukushima nuclear accident. ► We used global measurements and a box model, as well as dispersion model estimates. ► Total 133 Xe release is about 14.2-19 EBq, more than Fukushima 133 Xe inventory. ► Additional release of iodine-133 and decay into 133 Xe needed to explain results.

  2. The effect of platform switching on the levels of metal ion release from different implant–abutment couples

    Science.gov (United States)

    Alrabeah, Ghada O; Knowles, Jonathan C; Petridis, Haralampos

    2016-01-01

    The improved peri-implant bone response demonstrated by platform switching may be the result of reduced amounts of metal ions released to the surrounding tissues. The aim of this study was to compare the levels of metal ions released from platform-matched and platform-switched implant–abutment couples as a result of accelerated corrosion. Thirty-six titanium alloy (Ti-6Al-4V) and cobalt–chrome alloy abutments were coupled with titanium cylinders forming either platform-switched or platform-matched groups (n=6). In addition, 18 unconnected samples served as controls. The specimens were subjected to accelerated corrosion by static immersion in 1% lactic acid for 1 week. The amount of metal ions ion of each test tube was measured using inductively coupled plasma mass spectrometry. Scanning electron microscope (SEM) images and energy dispersive spectroscopy X-ray analyses were performed pre- and post-immersion to assess corrosion at the interface. The platform-matched groups demonstrated higher ion release for vanadium, aluminium, cobalt, chrome, and molybdenum compared with the platform-switched groups (Pabutment size or connection (Pabutment platform surfaces. In conclusion, implant–abutment couples underwent an active corrosion process resulting in metal ions release into the surrounding environment. The highest amount of metal ions released was recorded for the platform-matched groups, suggesting that platform-switching concept has a positive effect in reducing the levels of metal ion release from the implant–abutment couples. PMID:27357323

  3. Optimization of sustained release aceclofenac microspheres using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, Rameshwar K.; Naik, Jitendra B., E-mail: jitunaik@gmail.com

    2015-03-01

    Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14 ± 0.015% to 85.34 ± 0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12 h. The optimized microspheres formulation showed E.E. of 84.87 ± 0.005 with small error value (1.39). The low magnitudes of error and the significant value of R{sup 2} in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects. - Highlights: • Aceclofenac microspheres

  4. Effects of compost age on the release of nutrients

    Directory of Open Access Journals (Sweden)

    Bilal B. Al-Bataina

    2016-09-01

    Full Text Available Composted organic materials are applied to help restore disturbed soils, speed revegetation, and control erosion; these changes are generally beneficial for stormwater quality. Ensuring that nutrient release from compost is adequate for plant needs without degrading stormwater quality is important since composts release nitrogen at variable rates (1–3% of total N/yr and the leaching process can extend for many years. The aim of this work was to understand the effect of compost age on the extent and rates of nitrogen release by conducting detailed rainfall simulation studies of one compost type at three different ages. Models describing temporal changes in nitrogen release to runoff during a single storm and across multiple storms were developed and applied to the runoff data. Nitrogen content (% and bulk density of compost increased with the increase in compost age and total nitrogen release decreased with increasing compost age. The three rain simulations (storms performed on each of the three compost ages show that nitrogen release declined each day of the repeated daily storms. A first-order kinetic model was used to estimate the amount of nitrogen remaining on compost after several storms.

  5. Application of isotope tracer technique on the study of the filling and release behavior of carbon nanotubes

    International Nuclear Information System (INIS)

    Wu Shengwei; Guo Jinxue; Li Yan; Li Yulan; Li Wenxin; Liu Shiyuan

    2004-01-01

    The behaviors of washing and release of 110 Ag m -AgNO 3 from carbon nanotubes (CNTs), following soak of opened CNTs in 110 Ag m -AgNO 3 solutions are investigated with the isotope tracer technique. The filled CNTs samples are characterized by HREM, SEM, XRD and EDS. The amount of filled materials is also estimated by the isotope tracer technique. It shows that there are silver materials filled in the CNTs and would not release from the cavities. The results indicate that radioactive tracer is an effective and powerful technique to be applied into study of filling and release behaviors of CNTs as well as estimating the amount of filled materials. (authors)

  6. Savannah River Site radioiodine atmospheric releases and offsite maximum doses

    International Nuclear Information System (INIS)

    Marter, W.L.

    1990-01-01

    Radioisotopes of iodine have been released to the atmosphere from the Savannah River Site since 1955. The releases, mostly from the 200-F and 200-H Chemical Separations areas, consist of the isotopes, I-129 and 1-131. Small amounts of 1-131 and 1-133 have also been released from reactor facilities and the Savannah River Laboratory. This reference memorandum was issued to summarize our current knowledge of releases of radioiodines and resultant maximum offsite doses. This memorandum supplements the reference memorandum by providing more detailed supporting technical information. Doses reported in this memorandum from consumption of the milk containing the highest I-131 concentration following the 1961 1-131 release incident are about 1% higher than reported in the reference memorandum. This is the result of using unrounded 1-131 concentrations of I-131 in milk in this memo. It is emphasized here that this technical report does not constitute a dose reconstruction in the same sense as the dose reconstruction effort currently underway at Hanford. This report uses existing published data for radioiodine releases and existing transport and dosimetry models

  7. Carbon-14 releases from an unsaturated repository: A senseless but expensive dilemma

    International Nuclear Information System (INIS)

    Pflum, C.G.

    1993-01-01

    The purpose of the US Environmental Protection Agency (EPA) Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR Part 191 or standards) is to protect public health and safety. The 1985 rule was developed on the basis of the assumption that the repository would be located in a geologic formation that lies below the water table. It is appropriate to examine gaseous releases and transport of pollutants in order to determine site adequacy. When the provisions of the 1985 standard are applied to Yucca Mountain, specifically the limits for carbon-14, we can release in 10,000 years no more than 7,000 curies of carbon-14 in the form of carbon dioxide. Meanwhile, the US Department of Energy (DOE) and others indicate that the repository may release about 8,000 curies of carbon-14 dioxide, an amount that exceeds the standard by 10 to 20 percent. The original basis of the 1985 standards was that, in a site below the water table, the limit for carbon-14 was technically achievable. It was not a standard based on a release level that would prevent a danger to public health. If we examine the danger to public health of the release of 8,000 curies of carbon-14 dioxide during and 8,000-year period, this release would not a pose a significant threat to the average individual. Industry and natural sources release many times this amount of carbon-14 dioxide each year. The question therefore becomes: is it appropriate to spend an additional $3.2 billion on waste packages when the expenditure does not measurably improve the public health?

  8. Gas retention and release behavior in Hanford single-shell waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

    1996-12-01

    This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large ({approximately}100 m{sup 3}) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given.

  9. Fluoride release and recharge behavior of a nano-filled resin-modified glass ionomer compared with that of other fluoride releasing materials.

    Science.gov (United States)

    Mitra, Sumita B; Oxman, Joe D; Falsafi, Afshin; Ton, Tiffany T

    2011-12-01

    To compare the long-term fluoride release kinetics of a novel nano-filled two-paste resin-modified glass-ionomer (RMGI), Ketac Nano (KN) with that of two powder-liquid resin-modified glass-ionomers, Fuji II LC (FLC) and Vitremer (VT) and one conventional glass-ionomer, Fuji IX (FIX). Fluoride release was measured in vitro using ion-selective electrodes. Kinetic analysis was done using regression analysis and compared with existing models for GIs and compomers. In a separate experiment the samples of KN and two conventional glass-ionomers, FIX and Ketac Molar (KM) were subjected to a treatment with external fluoride source (Oral-B Neutra-Foam) after 3 months of fluoride release and the recharge behavior studied for an additional 7-day period. The cumulative amount of fluoride released from KN, VT and FLC and the release profiles were statistically similar but greater than that for FIX at P coating of KN with its primer and of DY with its adhesive did not significantly alter the fluoride release behavior of the respective materials. The overall rate for KN was significantly higher than for the compomer DY. DY showed a linear rate of release vs. t and no burst effect as expected for compomers. The nanoionomer KN showed fluoride recharge behavior similar to the conventional glass ionomers FIX and KM. Thus, it was concluded that the new RMGI KN exhibits fluoride ion release behavior similar to typical conventional and RMGIs and that the primer does not impede the release of fluoride.

  10. Modulation of precipitation by conditional symmetric instability release

    Science.gov (United States)

    Glinton, Michael R.; Gray, Suzanne L.; Chagnon, Jeffrey M.; Morcrette, Cyril J.

    2017-03-01

    Although many theoretical and observational studies have investigated the mechanism of conditional symmetric instability (CSI) release and associated it with mesoscale atmospheric phenomena such as frontal precipitation bands, cloud heads in rapidly developing extratropical cyclones and sting jets, its climatology and contribution to precipitation have not been extensively documented. The aim of this paper is to quantify the contribution of CSI release, yielding slantwise convection, to climatological precipitation accumulations for the North Atlantic and western Europe. Case studies reveal that CSI release could be common along cold fronts of mature extratropical cyclones and the North Atlantic storm track is found to be a region with large CSI according to two independent CSI metrics. Correlations of CSI with accumulated precipitation are also large in this region and CSI release is inferred to be occurring about 20% of the total time over depths of over 1 km. We conclude that the inability of current global weather forecast and climate prediction models to represent CSI release (due to insufficient resolution yet lack of subgrid parametrization schemes) may lead to errors in precipitation distributions, particularly in the region of the North Atlantic storm track.

  11. Radionuclide releases to the Columbia River from Hanford Operations, 1944--1971

    International Nuclear Information System (INIS)

    Heeb, C.M.; Bates, D.J.

    1994-05-01

    The purpose of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. One source of radionuclide releases to the Columbia River was from production reactor operations. This report provides a quantitative estimate of the amount of radioactivity released each month (1944--1971) to the Columbia River from eleven radionuclides as well as from gross beta activity

  12. New approaches to deriving limits of the release of radioactive material into the environment

    International Nuclear Information System (INIS)

    Lindell, B.

    1977-01-01

    During the last few years, new principles have been developed for the limitation of the release of radioactive material into the environment. It is no longer considered appropriate to base the limitation on limits for the concentrations of the various radionuclides in air and water effluents. Such limits would not prevent large amounts of radioactive material from reaching the environment should effluent rates be high. A common practice has been to identify critical radionuclides and critical pathways and to base the limitation on authorized dose limits for local ''critical groups''. If this were the only limitation, however, larger releases could be permitted after installing either higher stacks or equipment to retain the more short-lived radionuclides for decay before release. Continued release at such limits would then lead to considerably higher exposure at a distance than if no such installation had been made. Accordingly there would be no immediate control of overlapping exposures from several sources, nor would the system guarantee control of the future situation. The new principles described in this paper take the future into account by limiting the annual dose commitments rather than the annual doses. They also offer means of controlling the global situation by limiting not only doses in critical groups but also global collective doses. Their objective is not only to ensure that individual dose limits will always be respected but also to meet the requirement that ''all doses be kept as low as reasonably achievable''. The new approach is based on the most recent recommendations by the ICRP and has been described in a report by an IAEA panel (Procedures for establishing limits for the release of radioactive material into the environment). It has been applied in the development of new Swedish release regulations, which illustrate some of the problems which arise in the practical application

  13. New approaches to deriving limits of the release of radioactive material into the environment

    International Nuclear Information System (INIS)

    Lindell, B.

    1977-01-01

    During the last few years, new principles have been developed for the limitation of the release of radioactive material into the environment. It is no longer considered appropriate to base the limitation on limits for the concentrations of the various radionuclides in air and water effluents. Such limits would not prevent large amounts of radioactive material from reaching the environment should effluent rates be high. A common practice has been to identify critical radionuclides and critical pathways and to base the limitation on authorized dose limits for local ''critical groups''. If this were the only limitation, however, larger releases could be permitted after installing either higher stacks or equipment to retain the more shortlived radionuclides for decay before release. Continued release at such limits would then lead to considerably higher exposure at a distance than if no such installation had been made. Accordingly there would be no immediate control of overlapping exposures from several sources, nor would the system guarantee control of the future situation. The new principles described in this paper take the future into account by limiting the annual dose commitments rather than the annual doses. They also offer means of controlling the global situation by limiting not only doses in critical groups but also global collective doses. Their objective is not only to ensure that individual dose limits will always be respected but also to meet the requirement that ''all doses be kept as low as reasonably achievable''. The new approach is based on the most recent recommendations by the ICRP and has been described in a report by an IAEA panel (Procedures for Establishing Limits for the Release of Radioactive Material into the Environment). It has been applied in the development of new Swedish release regulations, which illustrate some of the problems which arise in the practical application. (author)

  14. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 4: Hatteras abyssal red clay

    International Nuclear Information System (INIS)

    Schmidt, R.L.

    1982-07-01

    A study in which neutron-activated 347 stainless steel was exposed to surficial sediment from a site in the Hatteras Abyssal Plain of the Northwest Atlantic Ocean is described. This sediment consists of approx. 20% CaCO 3 , which could lead to the formation of calcareous scale on the metal surface and reduce the corrosion rate. The distribution of indigenous metals among different chemical fractions shows that extractable Cr, Mn, Fe, Co, and Zn were associated with amorphous Mn and Fe oxides. Most of the remaining extractable Cr, and about a third of the extractable Cu appear to have been weakly complexed. Major fractions (25 to 36%) of extractable Mn, Co and Ni were present as adsorbed cations. Organic complexation appears to account for a large amount of extractable Fe, Ni, Cu and Zn. Neutron-activated 347 stainless steel specimens were exposed to sediment slurry under aerobic and non-oxygenated conditions for a period of 94 days. The redox potential measurements for air-sparged and N 2 , CO 2 -sparged sediment slurries were +410 and +60 mv, respectively. The presence of 0 2 produced increased amounts of corrosion products. Chemical extraction showed that relatively labile substances constituted about 84% of the 60 Co activity released in aerated sediment. Relatively labile substances constitute about 82% of the total 60 Co activity released under non-oxygenated conditions. A large fraction of 60 Co which was in the soluble or easily dissolved forms under non-oxygenated conditions appears to have been more strongly adsorbed to the sediment under aerated conditions

  15. Stretch-induced Ca2+ independent ATP release in hippocampal astrocytes.

    Science.gov (United States)

    Xiong, Yingfei; Teng, Sasa; Zheng, Lianghong; Sun, Suhua; Li, Jie; Guo, Ning; Li, Mingli; Wang, Li; Zhu, Feipeng; Wang, Changhe; Rao, Zhiren; Zhou, Zhuan

    2018-02-28

    Similar to neurons, astrocytes actively participate in synaptic transmission via releasing gliotransmitters. The Ca 2+ -dependent release of gliotransmitters includes glutamate and ATP. Following an 'on-cell-like' mechanical stimulus to a single astrocyte, Ca 2+ independent single, large, non-quantal, ATP release occurs. Astrocytic ATP release is inhibited by either selective antagonist treatment or genetic knockdown of P2X7 receptor channels. Our work suggests that ATP can be released from astrocytes via two independent pathways in hippocampal astrocytes; in addition to the known Ca 2+ -dependent vesicular release, larger non-quantal ATP release depends on P2X7 channels following mechanical stretch. Astrocytic ATP release is essential for brain functions such as synaptic long-term potentiation for learning and memory. However, whether and how ATP is released via exocytosis remains hotly debated. All previous studies of non-vesicular ATP release have used indirect assays. By contrast, two recent studies report vesicular ATP release using more direct assays. In the present study, using patch clamped 'ATP-sniffer cells', we re-investigated astrocytic ATP release at single-vesicle resolution in hippocampal astrocytes. Following an 'on-cell-like' mechanical stimulus of a single astrocyte, a Ca 2+ independent single large non-quantal ATP release occurred, in contrast to the Ca 2+ -dependent multiple small quantal ATP release in a chromaffin cell. The mechanical stimulation-induced ATP release from an astrocyte was inhibited by either exposure to a selective antagonist or genetic knockdown of P2X7 receptor channels. Functional P2X7 channels were expressed in astrocytes in hippocampal brain slices. Thus, in addition to small quantal ATP release, larger non-quantal ATP release depends on P2X7 channels in astrocytes. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

  16. Upper-bound fission product release assessment for large break LOCA in CANFLEX bundle reactor core

    International Nuclear Information System (INIS)

    Oh, Duk Ju; Lee, Kang Moon

    1996-07-01

    Quarter-core gap inventory assessment for CANDU-6 reactor core loaded with CANFLEX fuel bundles has been performed as one of the licensing safety analyses required for 24 natural uranium CANFLEX bundle irradiation in CANDU-6 reactor. The quarter-core gap inventory for the CANFLEX bundle core is 5 - 10 times lower than that for the standard bundle core, depending on the half-life of the isotope. The lower gap inventory of the CANFLEX bundle core is attributed to the lower linear power of the CANFLEX bundle compared with the standard bundle. However, the whole core total inventories for both the CANFLEX and standard bundle cores are nearly the same. The 6 - 8 times lower upper-bound fission product releases of the CANFLEX bundle core for large break LOCA than those of the standard bundle core imply that the loading of 24 natural uranium CANFLEX bundles would improve the predicted consequences of the postulated accident described in the Wolsung 2 safety report. 2 tabs., 6 figs., 3 refs. (Author)

  17. The market for equity release products: Lessons from the ...

    African Journals Online (AJOL)

    Home Equity Release Products (ERPs) are innovative fi nancial instruments that enable elderly, retired people to use their unencumbered houses as a source of income/funding while they continue to reside in them, thereby seeking to address the constraints of the life cycle hypothesis. The loan and outstanding amounts ...

  18. Effects on LOCA mass and energy release of the SIT Fluidic device for SKN 3 and 4

    International Nuclear Information System (INIS)

    Song, Jeung Hyo; Kim, Tae Yoon; Choi, Han Rim; Choi, Chul Jin; Seo, Jong Tae

    2003-01-01

    A fluidic device is employed for the control of safety injection tank flow during a large break loss of coolant accident in Shin Kori Nuclear power plant Unit 3 and 4. It is installed in the safety injection tank and provides two stages of safety injection tank flow injection, initially high flow injection and then low flow injection after the reactor vessel downcomer annulus full. This allows a more effective use of safety injection tank water inventory during a loss of coolant accident. However, the fluidic device may have an adverse impact on the mass and energy release during the accident. That is, the steam mass and energy release will be increased by a considerable amount because the safety injection tank low flow injection via fluidic device is not credited to condense the steam flows through intact cold legs. The increased mass and energy releases have an impact on the peak pressure and temperature of the containment. This effect of the fluidic device is analyzed on the mass and energy release and the peak pressure and temperature of the containment. The calculation has been done using the CEFLASH-4A, the FLOOD3 with some modifications for the fluidic device and the CONTEMPT-LT code. The results show that the mass and energy release and the peak pressure and temperature were considerably increased when compared with the case without the fluidic device. However, the results satisfy the required design margin

  19. Effects on LOCA mass and energy release of the SIT Fluidic device for SKN 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jeung Hyo; Kim, Tae Yoon; Choi, Han Rim; Choi, Chul Jin; Seo, Jong Tae [Korea Power Engineering Company, Daejon (Korea, Republic of)

    2003-07-01

    A fluidic device is employed for the control of safety injection tank flow during a large break loss of coolant accident in Shin Kori Nuclear power plant Unit 3 and 4. It is installed in the safety injection tank and provides two stages of safety injection tank flow injection, initially high flow injection and then low flow injection after the reactor vessel downcomer annulus full. This allows a more effective use of safety injection tank water inventory during a loss of coolant accident. However, the fluidic device may have an adverse impact on the mass and energy release during the accident. That is, the steam mass and energy release will be increased by a considerable amount because the safety injection tank low flow injection via fluidic device is not credited to condense the steam flows through intact cold legs. The increased mass and energy releases have an impact on the peak pressure and temperature of the containment. This effect of the fluidic device is analyzed on the mass and energy release and the peak pressure and temperature of the containment. The calculation has been done using the CEFLASH-4A, the FLOOD3 with some modifications for the fluidic device and the CONTEMPT-LT code. The results show that the mass and energy release and the peak pressure and temperature were considerably increased when compared with the case without the fluidic device. However, the results satisfy the required design margin.

  20. NIR responsive liposomal system for rapid release of drugs in cancer therapy

    Directory of Open Access Journals (Sweden)

    Chen MM

    2017-06-01

    Full Text Available Ming-Mao Chen,1 Yuan-Yuan Liu,1 Guang-Hao Su,2 Fei-Fei Song,1 Yan Liu,3 Qi-Qing Zhang1,4 1Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou, 2Institute of Pediatric Research, Children’s Hospital of Soochow University, Suzhou, 3State Key Lab of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 4Key Laboratory of Biomedical Material of Tianjin, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, People’s Republic of China Abstract: To design a rapid release liposomal system for cancer therapy, a NIR responsive bubble-generating thermosensitive liposome (BTSL system combined with photothermal agent (Cypate, doxorubicin (DOX, and NH4HCO3 was developed. Cypate/DOX-BTSL exhibited a good aqueous stability, photostability, and photothermal effect. In vitro release suggested that the amounts of DOX released from BTSL were obviously higher than that of (NH42SO4 liposomes at 42°C. After NIR irradiation, the hyperthermic temperature induced by Cypate led to the decomposition of NH4HCO3 and the generation of a large number of CO2 bubbles, triggering a rapid release of drugs. Confocal laser scanning microscope and acridine orange staining indicated that Cypate/DOX-BTSL upon irradiation could facilitate to disrupt the lysosomal membranes and realize endolysosomal escape into cytosol, improving the intracellular uptake of DOX clearly. MTT and trypan blue staining implied that the cell damage of Cypate/DOX-BTSL with NIR irradiation was more severe than that in the groups without irradiation. In vivo results indicated that Cypate/DOX-BTSL with irradiation could dramatically increase the accumulation of DOX in tumor, inhibit tumor growth, and reduce systemic side effects of DOX. These data demonstrated that Cypate/DOX-BTSL has the potential to be used as a NIR responsive liposomal system for a rapid

  1. Aqueous studies of hydrogen sulfide releases from a heavy water extraction facility

    International Nuclear Information System (INIS)

    Kiser, D.L.

    1979-03-01

    Upsets in the operation of the wastewater strippers in the 400 Area of the Savannah River Plant have released hydrogen sulfide in quantities as large as 1800 kg to the effluent stream. Fish kills in the swamp area of Beaver Dam Creek have occurred following the large releases. A literature survey revealed volatilization and oxidation as the major loss mechanisms of H 2 S. Laboratory investigations supported the literature survey. The computer code for pollutant transport in a stream, LODIPS, has an option to account for sink-source effects in a stream. Volatilization and oxidation rate constants were developed for the sink option from two H 2 S releases (18 kg and 118 kg) and results were predicted with LODIPS. Based on the predicted concentration-time profiles for various hypothetical cases, releases as small as 568 kg if discharged over a 30-minute period or releases as large as 1818 kg if discharged over a 360-minute period or less are lethal to swamp fish

  2. 29 CFR 4219.14 - Amount of liability for 20-year-limitation amounts.

    Science.gov (United States)

    2010-07-01

    ... amount equal to the present value of all initial withdrawal liability payments for which the employer was not liable pursuant to section 4219(c)(1)(B) of ERISA. The present value of such payments shall be... 29 Labor 9 2010-07-01 2010-07-01 false Amount of liability for 20-year-limitation amounts. 4219.14...

  3. Dynamic Model for the Stocks and Release Flows of Engineered Nanomaterials.

    Science.gov (United States)

    Song, Runsheng; Qin, Yuwei; Suh, Sangwon; Keller, Arturo A

    2017-11-07

    Most existing life-cycle release models for engineered nanomaterials (ENM) are static, ignoring the dynamics of stock and flows of ENMs. Our model, nanoRelease, estimates the annual releases of ENMs from manufacturing, use, and disposal of a product explicitly taking stock and flow dynamics into account. Given the variabilities in key parameters (e.g., service life of products and annual release rate during use) nanoRelease is designed as a stochastic model. We apply nanoRelease to three ENMs (TiO 2 , SiO 2 and FeO x ) used in paints and coatings through seven product applications, including construction and building, household and furniture, and automotive for the period from 2000 to 2020 using production volume and market projection information. We also consider model uncertainties using Monte Carlo simulation. Compared with 2016, the total annual releases of ENMs in 2020 will increase by 34-40%, and the stock will increase by 28-34%. The fraction of the end-of-life release among total release flows will increase from 11% in 2002 to 43% in 2020. As compared to static models, our dynamic model predicts about an order of magnitude lower values for the amount of ENM released from this sector in the near-term while stock continues to build up in the system.

  4. Large CO2 and CH4 release from a flooded formerly drained fen

    Science.gov (United States)

    Sachs, T.; Franz, D.; Koebsch, F.; Larmanou, E.; Augustin, J.

    2016-12-01

    Drained peatlands are usually strong carbon dioxide (CO2) sources. In Germany, up to 4.5 % of the national CO2 emissions are estimated to be released from agriculturally used peatlands and for some peatland-rich northern states, such as Mecklenburg-Western Pomerania, this share increases to about 20%. Reducing this CO2 source and restoring the peatlands' natural carbon sink is one objective of large-scale nature protection and restoration measures, in which 37.000 ha of drained and degraded peatlands in Mecklenburg-Western Pomerania are slated for rewetting. It is well known, however, that in the initial phase of rewetting, a reduction of the CO2 source strength is usually accompanied by an increase in CH4 emissions. Thus, whether and when the intended effects of rewetting with regard to greenhouse gases are achieved, depends on the balance of CO2 and CH4 fluxes and on the duration of the initial CH4 emission phase. In 2013, a new Fluxnet site went online at a flooded formerly drained river valley fen site near Zarnekow, NE Germany (DE-Zrk), to investigate the combined CO2 and CH4 dynamics at such a heavily degraded and rewetted peatland. The site is dominated by open water with submerged and floating vegetation and surrounding Typha latifolia.Nine year after rewetting, we found large CH4 emissions of 53 g CH4 m-2 a-1 from the open water area, which are 4-fold higher than from the surrounding vegetation zone (13 g CH4 m-2 a-1). Surprisingly, both the open water and the vegetated area were net CO2 sources of 158 and 750 g CO2 m-2 a-1, respectively. Unusual meteorological conditions with a warm and dry summer and a mild winter might have facilitated high respiration rates, particularly from temporally non-inundated organic mud in the vegetation zone.

  5. Chemical evolution. XXI - The amino acids released on hydrolysis of HCN oligomers

    Science.gov (United States)

    Ferris, J. P.; Wos, J. D.; Nooner, D. W.; Oro, J.

    1974-01-01

    Major amino acids released by hydrolysis of acidic and basic HCN oligomers are identified by chromatography as Gly, Asp, and diaminosuccinic acid. Smaller amounts of Ala, Ile and alpha-aminoisobutyric acid are also detected. The amino acids released did not change appreciably when the hydrolysis medium was changed from neutral to acidic or basic. The presence of both meso and d, l-diaminosuccinic acids was established by paper chromatography and on an amino acid analyzer.

  6. Controlled release of phenytoin for epilepsy treatment from titania and silica based materials

    International Nuclear Information System (INIS)

    Lopez, Tessy; Ortiz, Emma; Meza, Doraliz; Basaldella, Elena; Bokhimi, Xim; Magana, Carlos; Sepulveda, Antonio; Rodriguez, Francisco; Ruiz, Javier

    2011-01-01

    Research highlights: → Template technique was used to obtain well ordered nanostructured materials: SBA-15 and titania tubes. → Phenytoin (PH), a drug used in epilepsy treatment, was loaded in these materials to used como PH release. → Loaded PH showed a good stability inside the used materials as observed by spectroscopy analysis. → The load-release PH are faster in nanostructured TiO2 tubes than in mesoporous silica matrix. → There is an inverse effect of the surface area of the structured materials on the amount of released PH. - Abstract: Template technique was used to obtain well ordered nanostructured materials: mesoporous silica and nanostructured titania tubes. This technique permits the synthesis of solids with controlled mesoporosity, where a large variety of molecules that have therapeutic activity can be hosted and further released to specific sites. In this work phenytoin (PH), a drug used in epilepsy treatment, was loaded in ordered mesoporous silica (SBA 15) and nanostructured titania tubes (TiO 2 ). The pure materials and those containing PH were characterized by X-ray diffraction, FTIR spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and N 2 adsorption-desorption at 77 K. In order to determine the loading capacity of the antiepileptic drug on these silica- and titania-based materials, the loading and release of PH was investigated using UV-vis spectroscopy. Tubular structures were found for the titania samples, for which the X-ray diffractograms showed to be formed by anatase and rutile phases. On the other hand, an amorphous phase was found in the silica sample. A highly ordered hexagonal structure of 1D cylindrical channels was also observed for this material. Loaded PH showed a good stability inside the used materials as observed by spectroscopy analysis. The adsorption and desorption of PH are faster in nanostructured TiO 2 tubes than in mesoporous silica matrix.

  7. Role of fission gas release in reactor licensing

    International Nuclear Information System (INIS)

    1975-11-01

    The release of fission gases from oxide pellets to the fuel rod internal voidage (gap) is reviewed with regard to the required safety analysis in reactor licensing. Significant analyzed effects are described, prominent gas release models are reviewed, and various methods used in the licensing process are summarized. The report thus serves as a guide to a large body of literature including company reports and government documents. A discussion of the state of the art of gas release analysis is presented

  8. Controlled release of D-glucose from starch granules containing 29% free D-glucose and Eudragit L100-55 as a binding and coating agent.

    Science.gov (United States)

    Kim, Yeon-Kye; Mukerjea, Rupendra; Robyt, John F

    2010-05-27

    Waxy maize starch (100% amylopectin) granules were modified by reaction of the granules with glucoamylase in a minimum amount of water to give 29% (w/w) D-glucose inside the granules [Kim, Y.-K.; Robyt, J. F. Carbohydr. Res.1999, 318, 129-134]. These granules were made into beads by dropping an ethanol slurry of starch and different amounts of Eudragit L100-55 in a constant ratio of 100:1 from a pipette onto Whatman 3MM filter paper. The starch beads were air dried and then repeatedly sprayed 0-12 times with 2.0% (w/v) Eudragit L100-55 in ethanol, with drying between each spraying, to coat the surface of the starch beads, giving different amounts of Eudragit L100-55 coating. Seven different kinds of beads, with different amounts of Eudragit L100-55 binding and coating agent, were obtained. The rates of release of D-glucose into water from the seven kinds of beads were inversely proportional to the amount of binding and coating agent. Bead type I, which was without any binding and coating gave a fast 100% release of D-glucose in 30 min. Beads II and III also gave a fast 100% release in 60 min and 90 min, respectively. Bead IV gave a near linear release of 97% D-glucose in 150 min; Bead V gave a 50% release in 120 min followed by the remaining 50% in 60 min; and Beads VI and VII gave a slow release of 10% and 4%, respectively, from 0 to 120 min, followed by a rapid 100% release from 120 to 180 min. (c) 2010 Elsevier Ltd. All rights reserved.

  9. Sulfur Release during Alternative fuels Combustion in Cement Rotary Kilns

    DEFF Research Database (Denmark)

    Cortada Mut, Maria del Mar

    fuel with the bed material, heating up of a particle, 5 iv devolatilization, char combustion, the reactions between CaSO 4 and the different reducing agents, and the oxidation of the volatiles gases in the free board. The main reducing agents are CO, CH 4 and H 2 , which are introduced under the bed...... are of high importance for SO 2 release because it is shown that introducing the same total amount of gas, the highest reducing agent concentration fo r a short period released a higher total SO 2 amount compared to the lowest concentration during a long period. A mathematical reaction based model...... but the effect of sulfur content in the bed cannot be predicted. Further development regarding particle motion according to the rotational speed may be needed. Furthermore, a model for predicting the tendency of build-ups for a kiln system is developed based on the prediction of SO 3 and Cl concentrations...

  10. Elucidating the Role of Carbon Sources on Abiotic and Biotic Release of Arsenic into Cambodian Aquifers

    Science.gov (United States)

    Koeneke, M.

    2017-12-01

    Arsenic (As) is a naturally occurring contaminant in Cambodia that has been contaminating well-water sources of millions of people. Commonly, studies look into the biotic factors that cause the arsenic to be released from aquifer sediments to groundwater. However, abiotic release of As from sediments, though little studied, may also play key roles in As contamination of well water. The goal of this research is to quantitatively compare organic-carbon mediated abiotic and biotic release of arsenic from sediments to groundwater. Batch anaerobic incubation experiments under abiotic (sodium azide used to immobilize microbes) and biotic conditions were conducted using Cambodian aquifer sediments, four different organic carbon sources (sodium lactate, sodium citrate, sodium oxalate, and humic acid), and six different carbon concentrations (0, 1, 2.5, 5, 10, 25mg C/L). Dissolved arsenic, iron(Fe), and manganese(Mn) concentrations in the treatments were measured 112 days . In addition, sediment and solution carbon solution was measured . Collectively, these show how different carbon sources, different carbon concentrations, and how abiotic and biotic factors impact the release of arsenic from Cambodian sediments into aquifers. Overall, an introduction of organic carbon to the soil increases the amount of As released from the sediment. The biotic + abiotic and abiotic conditions seemed to play a minimal role in the amount of As released. Dissolved species analysis showed us that 100% of the As was As(V), Our ICP-MS results vary due to the heterogeneity of samples, but when high levels are Fe are seen in solution, we also see high levels of As. We also see higher As concentrations when there is a smaller amount of Mn in solution.

  11. Hypsometric amplification and routing moderation of Greenland ice sheet meltwater release

    Directory of Open Access Journals (Sweden)

    D. van As

    2017-06-01

    Full Text Available Concurrent ice sheet surface runoff and proglacial discharge monitoring are essential for understanding Greenland ice sheet meltwater release. We use an updated, well-constrained river discharge time series from the Watson River in southwest Greenland, with an accurate, observation-based ice sheet surface mass balance model of the  ∼  12 000 km2 ice sheet area feeding the river. For the 2006–2015 decade, we find a large range of a factor of 3 in interannual variability in discharge. The amount of discharge is amplified  ∼  56 % by the ice sheet's hypsometry, i.e., area increase with elevation. A good match between river discharge and ice sheet surface meltwater production is found after introducing elevation-dependent transit delays that moderate diurnal variability in meltwater release by a factor of 10–20. The routing lag time increases with ice sheet elevation and attains values in excess of 1 week for the upper reaches of the runoff area at  ∼  1800 m above sea level. These multi-day routing delays ensure that the highest proglacial discharge levels and thus overbank flooding events are more likely to occur after multi-day melt episodes. Finally, for the Watson River ice sheet catchment, we find no evidence of meltwater storage in or release from the en- and subglacial environments in quantities exceeding our methodological uncertainty, based on the good match between ice sheet runoff and proglacial discharge.

  12. An integrated device for magnetically-driven drug release and in situ quantitative measurements: Design, fabrication and testing

    Energy Technology Data Exchange (ETDEWEB)

    Bruvera, I.J. [Aragon Institute of Nanoscience (INA), University of Zaragoza, 50018 (Spain); Hernández, R.; Mijangos, C. [Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid (Spain); Goya, G.F., E-mail: goya@unizar.es [Aragon Institute of Nanoscience (INA), University of Zaragoza, 50018 (Spain); Condensed Matter Physics Department, Science Faculty, University of Zaragoza, 50009 (Spain)

    2015-03-01

    We have developed a device capable of remote triggering and in situ quantification of therapeutic drugs, based on magnetically-responsive hydrogels of poly (N-isopropylacrylamide) and alginate (PNiPAAm). The heating efficiency of these hydrogels measured by their specific power absorption (SPA) values showed that the values between 100 and 300 W/g of the material were high enough to reach the lower critical solution temperature (LCST) of the polymeric matrix within few minutes. The drug release through application of AC magnetic fields could be controlled by time-modulated field pulses in order to deliver the desired amount of drug. Using B12 vitamin as a concept drug, the device was calibrated to measure amounts of drug released as small as 25(2)×10{sup −9} g, demonstrating the potential of this device for very precise quantitative control of drug release. - Highlights: • A device for magnetically driven drug release was developed and constructed. • Thermally responsive PNiPAAm and Fe3O4 nanoparticles were usedas drug reservoir. • The device allowed repetitive, remote and precisely controlled drug release. • By in situ spectrometry we could detect released drug quantities as small as 25 ng. • Released drug was controlled through magnetic ac field parameters H, f and time.

  13. An integrated device for magnetically-driven drug release and in situ quantitative measurements: Design, fabrication and testing

    International Nuclear Information System (INIS)

    Bruvera, I.J.; Hernández, R.; Mijangos, C.; Goya, G.F.

    2015-01-01

    We have developed a device capable of remote triggering and in situ quantification of therapeutic drugs, based on magnetically-responsive hydrogels of poly (N-isopropylacrylamide) and alginate (PNiPAAm). The heating efficiency of these hydrogels measured by their specific power absorption (SPA) values showed that the values between 100 and 300 W/g of the material were high enough to reach the lower critical solution temperature (LCST) of the polymeric matrix within few minutes. The drug release through application of AC magnetic fields could be controlled by time-modulated field pulses in order to deliver the desired amount of drug. Using B12 vitamin as a concept drug, the device was calibrated to measure amounts of drug released as small as 25(2)×10 −9 g, demonstrating the potential of this device for very precise quantitative control of drug release. - Highlights: • A device for magnetically driven drug release was developed and constructed. • Thermally responsive PNiPAAm and Fe3O4 nanoparticles were usedas drug reservoir. • The device allowed repetitive, remote and precisely controlled drug release. • By in situ spectrometry we could detect released drug quantities as small as 25 ng. • Released drug was controlled through magnetic ac field parameters H, f and time

  14. 3H-histamine release from human leukocytes

    International Nuclear Information System (INIS)

    Stahl Skov, P.; Norn, S.; Weeke, B.

    1979-01-01

    A rapid, simple, and inexpensive method for large scale screening of patients suspected of type I allergy has been developed. The method is based on in vitro incorporation of 3 H-histamine in the leukocytes of the patient, whereafter release of labelled histamine is measured after provocation of the cells with the suspected allergen. The new method was compared with the conventional basophil histamine release technique by in vitro provocation of six asthmatic patients under suspicion of type I allergy against animal dander, house dust, and mite, and an almost identical release of histamine was observed in both assays. (author)

  15. Predicting hydrocarbon release from soil

    International Nuclear Information System (INIS)

    Poppendieck, D.; Loehr, R.C.

    2002-01-01

    'Full text:' The remediation of hazardous chemicals from soils can be a lengthy and costly process. As a result, recent regulatory initiatives have focused on risk-based corrective action (RBCA) approaches. Such approaches attempt to identify the amount of chemical that can be left at a site with contaminated soil and still be protective of human health and the environment. For hydrocarbons in soils to pose risk to human heath and the environment, the hydrocarbons must be released from the soil and accessible to microorganisms, earthworms, or other higher level organisms. The sorption of hydrocarbons to soil can reduce the availability of the hydrocarbon to receptors. Typically in soils and sediments, there is an initial fast release of a hydrocarbon from the soil to the aqueous phase followed by a slower release of the remaining hydrocarbon to the aqueous phase. The rate and extent of slow release can influence aqueous hydrocarbon concentrations and the fate and transport of hydrocarbons in the subsurface. Once the fast fraction of the chemical has been removed from the soil, the remaining fraction of a chemical may desorb at a rate that natural mechanisms can attenuate the released hydrocarbon. Hence, active remediation may be needed only until the fast fraction has been removed. However, the fast fraction is a soil and chemical specific parameter. This presentation will present a tier I type protocol that has been developed to quickly estimate the fraction of hydrocarbons that are readily released from the soil matrix to the aqueous phase. Previous research in our laboratory and elsewhere has used long-term desorption (four months) studies to determine the readily released fraction. This research shows that a single short-term (less than two weeks) batch extraction procedure provides a good estimate of the fast released fraction derived from long-term experiments. This procedure can be used as a tool to rapidly evaluate the release and bioavailability of

  16. Diclofenac salts, part 6: release from lipid microspheres.

    Science.gov (United States)

    Fini, Adamo; Cavallari, Cristina; Rabasco Alvarez, Antonio M; Rodriguez, Marisa Gonzalez

    2011-08-01

    The release of diclofenac (20%, w/w) was studied from lipidic solid dispersions using three different chemical forms (acid, sodium salt, and pyrrolidine ethanol salt) and two different lipid carriers (Compritol 888 ATO or Carnauba wax) either free or together with varying amounts (10%-30%, w/w) of stearic acid. Microspheres were prepared by ultrasound-assisted atomization of the molten dispersions and analyzed by scanning electron microscopy, differential scanning calorimetry, and hot stage microscopy. The effects of different formulations on the resulting drug release profiles as a function of pH were studied and the results were discussed. The formulation of the 18 systems and the chemical form of the drug were found to strongly affect the mode of the drug release. The solubility of the chemical forms in the lipid mixture is in the following order: pyrrolidine ethanol salt ≫ acid > sodium salt (according to the solubility parameters), and the nature of the systems thus obtained ranges from a matrix, for mutually soluble drug/carrier pairs, to a microcapsule, for pairs wherein mutual solubility is poor. Drug release from microspheres prepared by pure lipids was primarily controlled by diffusion, whereas the release from microspheres containing stearic acid was diffusion/erosion controlled at pH 7.4. Copyright © 2011 Wiley-Liss, Inc.

  17. Tritium transport and release from lithium ceramic breeder materials

    International Nuclear Information System (INIS)

    Johnson, C.E.; Kopasz, J.P.; Tam, S.W.

    1994-01-01

    In an operating fusion reactor,, the tritium breeding blanket will reach a condition in which the tritium release rate equals the production rate. The tritium release rate must be fast enough that the tritium inventory in the blanket does not become excessive. Slow tritium release will result in a large tritium inventory, which is unacceptable from both economic and safety viewpoints As a consequence, considerable effort has been devoted to understanding the tritium release mechanism from ceramic breeders and beryllium neutron multipliers through theoretical, laboratory, and in-reactor studies. This information is being applied to the development of models for predicting tritium release for various blanket operating conditions

  18. Poly(dimethylsiloxane) coatings for controlled drug release--polymer modifications.

    Science.gov (United States)

    Schulze Nahrup, J; Gao, Z M; Mark, J E; Sakr, A

    2004-02-11

    Modifications of endhydroxylated poly(dimethylsiloxane) (PDMS) formulations were studied for their ability to be applied onto tablet cores in a spray-coating process and to control drug release in zero-order fashion. Modifications of the crosslinker from the most commonly used tetraethylorthosilicate (TEOS) to the trifunctional 3-(2,3-epoxypropoxy)propyltrimethoxysilane (SIG) and a 1:1 mixture of the two were undertaken. Addition of methylpolysiloxane-copolymers were studied. Lactose, microcrystalline cellulose (MCC) and polyethylene glycol 8000 (PEG) were the channeling agents applied. The effects on dispersion properties were characterized by particle size distribution and viscosity. Mechanical properties of resulting free films were studied to determine applicability in a pan-coating process. Release of hydrochlorothiazide (marker drug) was studied from tablets coated in a lab-size conventional coating pan. All dispersions were found suitable for a spray-coating process. Preparation of free films showed that copolymer addition was not possible due to great decline in mechanical properties. Tablets coated with formulations containing PEG were most suitable to control drug release, at only 5% coating weight. Constant release rates could be achieved for formulations with up to 25% PEG; higher amounts resulted in a non-linear release pattern. Upon adding 50% PEG, a drug release of 63% over 24 h could be achieved.

  19. Radioactive releases into the environment under accidental conditions

    International Nuclear Information System (INIS)

    Beninson, D.

    1976-01-01

    Although accidents involving the release of radioactive materials and the unplanned exposure of people can occur at any stage of the nuclear fuel cycle, most attention has been focused on reactor accidents. Although no power reactor accidents involving exposure of the public have yet occured, it should be recognized that the probability of such accidental releases cannot be reduced to zero. Since the inventory of radioactive materials in power reactors is very large, it is usual to postulate, for safety assessments, that a release of fission products takes place in spite of all protective measures. This postulated release is of importance for reactor siting and for preparing emergency plans. (HP) [de

  20. Unusual amount of (-)-mesquitol from the heartwood of Prosopis juliflora.

    Science.gov (United States)

    Sirmah, Peter; Dumarçay, Stéphane; Masson, Eric; Gérardin, Philippe

    2009-01-01

    A large amount of flavonoid has been extracted and isolated from the heartwood of Prosopis juliflora, an exogenous wood species of Kenya. Structural and physicochemical elucidation based on FTIR, (1)H and (13)C NMR, GC-MS and HPLC analysis clearly demonstrated the presence of (-)-mesquitol as the sole compound without any noticeable impurities. The product was able to slow down oxidation of methyl linoleate induced by AIBN. The important amount and high purity of (-)-mesquitol present in the acetonic extract of P. juliflora could therefore be of valuable interest as a potential source of antioxidants from a renewable origin.

  1. Extended latanoprost release from commercial contact lenses: in vitro studies using corneal models.

    Directory of Open Access Journals (Sweden)

    Saman Mohammadi

    Full Text Available In this study, we compared, for the first time, the release of a 432 kDa prostaglandin F2a analogue drug, Latanoprost, from commercially available contact lenses using in vitro models with corneal epithelial cells. Conventional polyHEMA-based and silicone hydrogel soft contact lenses were soaked in drug solution (131 μg = ml solution in phosphate buffered saline. The drug release from the contact lens material and its diffusion through three in vitro models was studied. The three in vitro models consisted of a polyethylene terephthalate (PET membrane without corneal epithelial cells, a PET membrane with a monolayer of human corneal epithelial cells (HCEC, and a PET membrane with stratified HCEC. In the cell-based in vitro corneal epithelium models, a zero order release was obtained with the silicone hydrogel materials (linear for the duration of the experiment whereby, after 48 hours, between 4 to 6 μg of latanoprost (an amount well within the range of the prescribed daily dose for glaucoma patients was released. In the absence of cells, a significantly lower amount of drug, between 0.3 to 0.5 μg, was released, (p <0:001. The difference observed in release from the hydrogel lens materials in the presence and absence of cells emphasizes the importance of using an in vitro corneal model that is more representative of the physiological conditions in the eye to more adequately characterize ophthalmic drug delivery materials. Our results demonstrate how in vitro models with corneal epithelial cells may allow better prediction of in vivo release. It also highlights the potential of drug-soaked silicone hydrogel contact lens materials for drug delivery purposes.

  2. Conditional release of materials from decommissioning process into the environment in the form of steel railway tracks

    International Nuclear Information System (INIS)

    Tatransky, Peter; Necas, Vladimir

    2009-01-01

    This work points to the possibilities of conditional release of materials from the process of decommissioning the nuclear unit from the operation. According to the valid legislation, materials which do not meet the condition of direct-unconditional release into the environment, should be modified and processed into the matrix designed for the final disposal in the storing place. However there exists a group of materials which activity is on the borderline of the limit of releasing into the environment and it is possible to release them conditionally. The matter of conditional release is that notable amount of materials, mainly metals, is usually contaminated only by radionuclids with relatively short time of half decay. These materials are suitable to use for a specific industrial purpose where the longtime fixation of shortly living radionuclids is expected in one place. This work deals with the conditional release of metals into the form of steel railway tracks. It describes the (working) groups of workers working with the steel railway tracks and defines in the numbers the critical group and its critical individual. For critical individual it dimensions the amounts of materials, which are possible to be released conditionally from one double-unit of the plant of the type VVER 440 V-230 which operation was ended on the regular basis. According to the calculations in the software VISIPLAN and OMEGA there is defined a number of released steel in such way that the internationally recommended rate of maximal effective dose for critical individual-10 μSv/year [IAEA, 2008. Managing low radioactivity material from the decommissioning of nuclear facility. Technical reports series no. 462] is not extended. In the final part there are compared the estimates of the costs of the decommissioning process with the application of conditional release and without it, which is directly reflected in the amount of saved costs and number of containers for surface disposal.

  3. Dynamic evaluation of environmental impact due to tritium accidental release from the fusion reactor

    International Nuclear Information System (INIS)

    Nie, Baojie; Ni, Muyi; Jiang, Jieqiong; Wu, Yican

    2015-01-01

    As one of the key safety issues of fusion reactors, tritium environmental impact of fusion accidents has attracted great attention. In this work, the dynamic tritium concentrations in the air and human body were evaluated on the time scale based on accidental release scenarios under the extreme environmental conditions. The radiation dose through various exposure pathways was assessed to find out the potential relationships among them. Based on this work, the limits of HT and HTO release amount for arbitrary accidents were proposed for the fusion reactor according to dose limit of ITER. The dynamic results aim to give practical guidance for establishment of fusion emergency standard and design of fusion tritium system. - Highlights: • Dynamic tritium concentration in the air and human body evaluated on the time scale. • Different intake forms and relevant radiation dose assessed to find out the potential relationships. • HT and HTO release amount limits for arbitrary accidents proposed for the fusion reactor according to dose limit

  4. CT and angiographic analysis of posterior communicating artery aneurysms: What factors influence the amount of subarachnoid blood?

    International Nuclear Information System (INIS)

    Kim, Young Min; Jung, Kun Sik; Rho, Myung Ho; Choi, Pil Youb; Sung, Young Soon; Kwon, Jae Soo; Lee, Sang Wook

    1998-01-01

    To determine how clinical and angiographic factors relate to the amount of subarachnoid blood detected by computerized tomography in patients with a ruptured aneurysm. Between January 1996 and December 1997, 22 patients with a posterior communicating artery aneurysm were retrospectively evaluated. Oval(three of four cases), funnel(both cases), and daughter-sac (four of five cases) types of aneurysmal sac were found among the 13 patients with a large amount of subarachnoid blood;eight of these had a past history of hyertension or diabetes. Seven of eleven cases of cylindricaltype aneurysmal sac were found among the 9 patients with a small amount of sularachnoid blood;eight of these had no past history of hypertension or diabetes. The average S/N ratio (ratio of maximum sac length to neck diameter) of patients with a small amount of blood was higher than that of patients with a large amount of blood(2.72 vs 2.07). Although many factors influence the amount of subarachnoid blood in an aneurysmal rupture, we found that a large amount of blood was frequently present in the oval, funnel and daughter sac types of aneurysm, when S/N ratio was low, and when an underlying disease such as hypertension or diabetes was present. Conversely, a small amount of blood was present in the cylindrical type, when S/N ratio was high, and where there was no underlying disease.=20

  5. Canadian pollutant releases and transfers : NPRI data 1998

    International Nuclear Information System (INIS)

    2001-03-01

    A large, two-sided fold-out poster showing pollution hotspots throughout Canada, has been released by the Canadian Institute for Environmental Law and Policy (CIELAP). The poster is based on the maps and tables of the National Pollutant Release Inventory (NPRI) 1998. It presents the top on-site releases and off-site transfers of pollutants by facilities across Canada, and provides a summary of releases, transfers and recycling of pollutants by province. The map depicts the facilities with the five largest quantities of individual pollutants released to each medium, i. e. water, air, land, underground. The crude oil and gas, other utilities, primary metal, paper and chemical industrial sectors are responsible for the largest on-site releases, while the business services, fabricated metal. primary metal and chemical industrial sectors account for the largest off-site transfers. Twenty-five of the 176 substances whose releases and transfers are reported under the NPRI are classified as 'toxic' or 'carcinogenic'. tabs., maps

  6. Radionuclide releases to the atmosphere from Hanford Operations, 1944--1972. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Heeb, C.M.

    1994-05-01

    The purpose of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation dose that individuals could have received as a result of radionuclide emissions since 1944 from the Hanford Site. The first step in determining dose is to estimate the amount and timing of radionuclide releases to air and water. This report provides the air release information.

  7. Widespread release of old carbon across the Siberian Arctic echoed by its large rivers

    Directory of Open Access Journals (Sweden)

    Ö. Gustafsson

    2011-06-01

    Full Text Available Over decadal-centennial timescales, only a few mechanisms in the carbon-climate system could cause a massive net redistribution of carbon from land and ocean systems to the atmosphere in response to climate warming. The largest such climate-vulnerable carbon pool is the old organic carbon (OC stored in Arctic permafrost (perennially frozen soils. Climate warming, both predicted and now observed to be the strongest globally in the Eurasian Arctic and Alaska, causes thaw-release of old permafrost carbon from local tundra sites. However, a central challenge for the assessment of the general vulnerability of this old OC pool is to deduce any signal integrating its release over larger scales. Here we examine radiocarbon measurements of molecular soil markers exported by the five Great Russian-Arctic Rivers (Ob, Yenisey, Lena, Indigirka and Kolyma, employed as natural integrators of carbon release processes in their watersheds. The signals held in estuarine surface sediments revealed that average radiocarbon ages of n-alkanes increased east-to-west from 6400 yr BP in Kolyma to 11 400 yr BP in Ob. This is consistent with westwards trends of both warmer climate and more degraded organic matter as indicated by the ratio of high molecular weight (HMW n-alkanoic acids to HMW n-alkanes. The dynamics of Siberian permafrost can thus be probed via the molecular-radiocarbon signal as carried by Arctic rivers. Old permafrost carbon is at present vulnerable to mobilization over continental scales. Climate-induced changes in the radiocarbon fingerprint of released permafrost carbon will likely depend on changes in both permafrost coverage and Arctic soil hydraulics.

  8. Reporting releases of hazardous substances under CERCLA and EPCRA

    International Nuclear Information System (INIS)

    Dailey, R.

    1990-04-01

    Several federal environmental laws requires that ''release of hazardous substances to the environment'' above certain threshold amounts -- Reportable Quantities or RQs -- be reported. Current and proposed regulations under these statutes are unclear and make full compliance difficult. Nevertheless, failure to comply could result in civil or criminal penalties. In response to questions raised by several DOE Field Elements, this Information Brief is part of a series that will provide updated information on this and other CERCLA issues. The Environmental Guidance Division (EH-231) has responded to those questions relating the reporting of releases for which EPA has a clearly articulated position. EPA's position on other questions raised by Field Elements has been equivocal; DOE is working with EPA to resolve these outstanding issues. Additional information briefs on reporting releases will be issued as a clear position is defined

  9. Engineered collagen hydrogels for the sustained release of biomolecules and imaging agents: promoting the growth of human gingival cells.

    Science.gov (United States)

    Choi, Jonghoon; Park, Hoyoung; Kim, Taeho; Jeong, Yoon; Oh, Myoung Hwan; Hyeon, Taeghwan; Gilad, Assaf A; Lee, Kwan Hyi

    2014-01-01

    We present here the in vitro release profiles of either fluorescently labeled biomolecules or computed tomography contrast nanoagents from engineered collagen hydrogels under physiological conditions. The collagen constructs were designed as potential biocompatible inserts into wounded human gingiva. The collagen hydrogels were fabricated under a variety of conditions in order to optimize the release profile of biomolecules and nanoparticles for the desired duration and amount. The collagen constructs containing biomolecules/nanoconstructs were incubated under physiological conditions (ie, 37°C and 5% CO2) for 24 hours, and the release profile was tuned from 20% to 70% of initially loaded materials by varying the gelation conditions of the collagen constructs. The amounts of released biomolecules and nanoparticles were quantified respectively by measuring the intensity of fluorescence and X-ray scattering. The collagen hydrogel we fabricated may serve as an efficient platform for the controlled release of biomolecules and imaging agents in human gingiva to facilitate the regeneration of oral tissues.

  10. Validation of software releases for CMS

    International Nuclear Information System (INIS)

    Gutsche, Oliver

    2010-01-01

    The CMS software stack currently consists of more than 2 Million lines of code developed by over 250 authors with a new version being released every week. CMS has setup a validation process for quality assurance which enables the developers to compare the performance of a release to previous releases and references. The validation process provides the developers with reconstructed datasets of real data and MC samples. The samples span the whole range of detector effects and important physics signatures to benchmark the performance of the software. They are used to investigate interdependency effects of all CMS software components and to find and fix bugs. The release validation process described here is an integral part of CMS software development and contributes significantly to ensure stable production and analysis. It represents a sizable contribution to the overall MC production of CMS. Its success emphasizes the importance of a streamlined release validation process for projects with a large code basis and significant number of developers and can function as a model for future projects.

  11. Containment response and radiological release for a TMLB' accident sequence in a large dry containment

    International Nuclear Information System (INIS)

    Gasser, R.D.; Bieniarz, P.P.; Tills, J.L.

    1987-01-01

    An analysis has been performed for the Bellefonte Pressurized Water Reactor (PWR) Unit 1 to determine the containment loading and the radiological releases into the environment from a station blackout accident. A number of issues have been addressed in this analysis, which include the effects of direct heating on containment loading and the effects of fission product heating and natural convection on releases from the primary system. The results indicate that direct heating, which involves more than about 50% of the core, may fail the Bellefonte containment, but natural convection in the Reactor Coolant System (RCS) may lead to overheating and failure of the primary system piping before core slump, thus, eliminating or mitigating direct heating. Releases from the primary system are significantly increased before vessel breach, due to natural circulation, and after vessel breach, due to reevolution of retained fission products by fission product heating of RCS structures. (orig.)

  12. Hyperinsulinemia is associated with increased soluble insulin receptors release from hepatocytes

    Directory of Open Access Journals (Sweden)

    Marcia eHiriart

    2014-06-01

    Full Text Available It has been generally assumed that insulin circulates freely in blood. However it can also interact with plasma proteins. Insulin receptors are located in the membrane of target cells and consist of an alpha and beta subunits with a tyrosine kinase cytoplasmic domain. The ectodomain, called soluble insulin receptor (SIR has been found elevated in patients with diabetes mellitus. We explored if insulin binds to SIRs in circulation under physiological conditions and hypothesize that this SIR may be released by hepatocytes in response to high insulin concentrations. The presence of SIR in rat and human plasmas and the culture medium of hepatocytes was explored using Western blot analysis. A purification protocol was performed to isolated SIR using affinity, gel filtration and ion exchange chromatographies. A modified reverse hemolytic plaque assay was used to measure SIR release from cultured hepatocytes. Incubation with 1 nmol l-1 insulin induces the release of the insulin receptor ectodomains from normal rat hepatocytes. This effect can be partially prevented by blocking protease activity. Furthermore, plasma levels of SIR were higher in a model of metabolic syndrome, where rats are hyperinsulinemic. We also found increased SIR levels in hyperinsulinemic humans. SIR may be an important regulator of the amount of free insulin in circulation. In hyperinsulinemia the amount of this soluble receptor increases, this could lead to higher amounts of insulin bound to this receptor, rather than free insulin, which is the biologically active form of the hormone. This observation could enlighten the mechanisms of insulin resistance.

  13. Release of chlorine from biomass at gasification conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerkman, E.; Stroemberg, B. [TPS Termiska Processer AB, Nykoeping (Sweden)

    1997-05-01

    The objective of the project was to investigate the influence of different gasifying atmospheres on the release of chlorine from biomass during gasification conditions. Furthermore, the purpose was also to try and identify the formed chloro compounds. The results showed that O{sub 2}, H{sub 2}O and CO{sub 2} had negligible effect on the chlorine release at temperatures under 700 deg C. At temperatures above 800 deg C the reactivity towards CO{sub 2} increased and could be seen as higher chlorine release and less solid residue. No chloro organic compounds (aliphatic one to six carbons or aromatic one to two rings) could be detected in the tar or the fuel gas produced during pyrolysis/gasifying. On the other hand, comparable amounts of chlorinated benzenes were found in the cooling section during combustion of lucerne and of synthetic waste, indicating that oxygen is essential for chlorination reactions. 11 refs, 4 figs, 1 tab

  14. Release of chlorine from biomass at gasification conditions

    International Nuclear Information System (INIS)

    Bjoerkman, E.; Stroemberg, B.

    1997-05-01

    The objective of the project was to investigate the influence of different gasifying atmospheres on the release of chlorine from biomass during gasification conditions. Furthermore, the purpose was also to try and identify the formed chloro compounds. The results showed that O 2 , H 2 O and CO 2 had negligible effect on the chlorine release at temperatures under 700 deg C. At temperatures above 800 deg C the reactivity towards CO 2 increased and could be seen as higher chlorine release and less solid residue. No chloro organic compounds (aliphatic one to six carbons or aromatic one to two rings) could be detected in the tar or the fuel gas produced during pyrolysis/gasifying. On the other hand, comparable amounts of chlorinated benzenes were found in the cooling section during combustion of lucerne and of synthetic waste, indicating that oxygen is essential for chlorination reactions. 11 refs, 4 figs, 1 tab

  15. Quality evaluation of extemporaneous delayed-release liquid formulations of lansoprazole.

    Science.gov (United States)

    Melkoumov, Alexandre; Soukrati, Amina; Elkin, Igor; Forest, Jean-Marc; Hildgen, Patrice; Leclair, Grégoire

    2011-11-01

    The quality attributes of extemporaneous delayed-release liquid formulations of lansoprazole for oral administration were evaluated. A novel liquid formulation (3 mg/mL) of Prevacid FasTab in an Ora-Blend vehicle was prepared and compared with the Prevacid FasTab 30 mg and Prevacid-sodium bicarbonate 1 M formulation (3 mg/mL). The latter formulation was combined with hydrochloric acid 0.1 N, and the remaining lansoprazole content was assayed by high-performance liquid chromatography (HPLC). A batch of delayed-release liquid formulation was prepared to evaluate content uniformity. For content assay, three samples were prepared for each evaluated condition and each sample was analyzed in triplicate by HPLC. The lansoprazole in the sodium bicarbonate formulation was extensively degraded by quantities of hydrochloric acid 0.1 N in excess of 100 mL. Storage time and temperature had a significant effect on lansoprazole stability in the Ora-Blend formulation. The drug remained stable for seven days when the formulation was stored at 4.5-5.5 °C, but storage at 21-22 °C or the reduction of pH with citric acid accelerated lansoprazole degradation. The amount of lansoprazole released from the Ora-Blend formulation during the buffer stage of the dissolution test decreased with increases in formulation storage time, in formulation storage temperature, and in the amount of lansoprazole released and degraded during the acid stage of the test. An extemporaneous formulation consisting of lansoprazole microgranules in Ora-Blend maintained acceptable quality attributes when stored for three days at 4.5-5.5 °C.

  16. In-pile observation of gas release from sodium-joint carbide pins irradiated in Osiris

    International Nuclear Information System (INIS)

    Colin, M.; Faugere, J.L.; Rouault, J.

    1978-01-01

    Gas release is studied in three sodium-joint carbide pins irradiated in the reactor Osiris at a nominal linear power of 900 W/cm to burn-ups ranging from 4 to 13%. The overall activity, stable gases and radioactive gases are measured. It is found that most of the gas is released in busts, that the release of stable gases speeds up sharply after an incubation time, that the initial bursts are very large and that for each mode of release observed and for each class of nuclide the radioactive gases follow a law R/B=A/lambda.n. An attempt is made to interpret the results in terms of either the formation of gas bubbles in the sodium joint, the existence of a large bubble above the fissile column or the simultaneous release of a large number of smaller bubbles [fr

  17. Release of corrosion products from construction materials containing cobalt. Pt.2: Inconel X750

    International Nuclear Information System (INIS)

    Falk, I.

    1978-02-01

    This report describes experimental work aimed at determining the release rate for corrosion products from 18Cr8Ni steel and Inconel X750 in BWR environments. For test purposes these environments were simulated in a high pressure loop, where irradiated samples of the materials were exposed for 720 hours. The amounts of released products were determined using gamma spectrometric analysis. The results show that the release from Inconel X750 is higher than that from 18Cr8Ni steel. The release calculated from Co58 measurements is 7 times higher and from Co60 measurements it is 1.5 times higher. Both the filtered and the deposited fractions of the released corrosion products exhibit the same relative concentrations of Co58 and Co60. (author)

  18. Comparison of in vitro histamine release by ionic and nonionic radiographyic contrast media

    International Nuclear Information System (INIS)

    Faraj, B.A.; Martin, L.G.

    1989-01-01

    This paper discusses a study whose results showed that in 53 hospitalized patients undergoing cardiovascular catheterization, incubation of their blood samples with varying concentrations of an ionic contrast medium (Angiovist-370, 60--631 mM) induced a significant (P < .005) amount of histamine release from whole blood (3.5%--10%), as compared with the histamine release following incubation with a nonionic contrast medium. Data suggest that the use of nonionic contrast media may induce minimal histamine release and thereby involve less patient risk from the histamine-mediated allergic and hemodynamic side effects associated with radiographic contrast media procedures

  19. Multiscale numerical modeling of Ce3+-inhibitor release from novel corrosion protection coatings

    International Nuclear Information System (INIS)

    Trenado, Carlos; Wittmar, Matthias; Veith, Michael; Strauss, Daniel J; Rosero-Navarro, Nataly C; Aparicio, Mario; Durán, Alicia; Castro, Yolanda

    2011-01-01

    A novel hybrid sol–gel coating has recently been introduced as an alternative to high toxic chromate-based corrosion protection systems. In this paper, we propose a multiscale computational model to estimate the amount and time scale of inhibitor release of the active corrosion protection coating. Moreover, we study the release rate under the influence of parameters such as porosity and viscosity, which have recently been implicated in the stability of the coating. Numerical simulations obtained with the model predicted experimental release tests and recent findings on the compromise between inhibitor concentration and the stability of the coating

  20. Counterion release from a discretely charged surface in an electrolyte: Monte Carlo simulation study

    International Nuclear Information System (INIS)

    Hernández-Contreras, M

    2015-01-01

    Monte Carlo simulations allowed us to determine the amount of released electric charges from a discretely charged surface in 1:1 aqueous electrolyte solution as a function of surface charge density. Within the restricted primitive model and for a fixed concentration of 0.1 M bulk electrolyte in solution, there is an increase in the number of released counterions per unit surface area as the strength of the surface charge is enhanced. A similar behaviour of the number of released counterions was also found through the use of mean field and liquid theory methods

  1. Quantification of the release of inorganic elements from biofuels

    DEFF Research Database (Denmark)

    Frandsen, Flemming; van Lith, Simone Cornelia; Korbee, Rob

    2007-01-01

    -scale and pilot-scale fixed-bed release data. In conclusion, it is recommended to perform the described lab-scale tests in order to obtain reliable quantitative data on the release of inorganic elements under grate-firing or suspension-firing conditions. Advanced fuel characterization by use of chemical......, the results from the lab-scale fixed-bed release tests were compared to pilot-scale mass balance tests. While large differences were seen between the lab-scale release data and the release information obtained by the fuel characterization techniques, a good correlation was found between the lab...... elements are thermodynamically stable as a function of temperature. This information is needed for the interpretation of the lab-scale release data. Thus, for the purpose of modeling ash or aerosol formation, fuel characterization methods should be combined with lab-scale release measurements. Pilot...

  2. Synthesis and characterization of superabsorbent polymer prepared by radiation-induced graft copolymerization of acrylamide onto carboxymethyl cellulose for controlled release of agrochemicals

    International Nuclear Information System (INIS)

    Hemvichian, Kasinee; Chanthawong, Auraruk; Suwanmala, Phiriyatorn

    2014-01-01

    Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N′-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO 3 ) as an agrochemical model and its potential for controlled release of KNO 3 was studied. The amount of released KNO 3 was analyzed by an inductively coupled plasma mass spectrometry (ICP–MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190 g/g of dry gel. - Highlights: • SAP was synthesized by radiation-induced grafting of AM onto CMC. • The synthesized SAP exhibited a maximum swelling ratio of 190 g/g. • The potential of SAP for controlled release of KNO 3 was studied. • The amount of KNO 3 released increased with increasing loading percentage of SAP. • SAP's swelling ratio decreased as the ionic strength of the medium increased

  3. Controlled release studies of calcium alginate hydrogels

    International Nuclear Information System (INIS)

    Rendevski, S.; Andonovski, A.; Mahmudi, N.

    2012-01-01

    Controlled release of substances in many cases may be achieved from calcium alginate hydrogels. In this research, the time dependence of the mass of released model substance bovine serum albumin (BSA) from calcium alginate spherical hydrogels of three different types (G/M ratio) have been investigated. The hydrogels were prepared with the drop-wise method of sodium alginate aqueous solutions with concentration of 0.02 g/cm 3 with 0.01 g/cm 3 BSA and a gelling water bath of chitosan in 0.2 M CH 3 COOH/0.4 M CH 3 COONa with added 0.2 M CaCl 2 .The hydrogel structures were characterized by dynamic light scattering and scanning electron microscopy. The controlled release studies were conducted by UV-Vis spectrophotometry of the released medium with p H=7 at 37 °C. The results showed that the model of osmotic pumping is the dominant mechanism of the release. Also, large dependences of the release profile on the homogeneity of the hydrogels were found. (Author)

  4. Comparison of nickel and chromium ions released from stainless steel and NiTi wires after immersion in Oral B®, Orthokin® and artificial saliva.

    Science.gov (United States)

    Jamilian, Abdolreza; Moghaddas, Omid; Toopchi, Shabnam; Perillo, Letizia

    2014-07-01

    Oral environment of the mouth is a suitable place for biodegradation of alloys used in orthodontic wires. The toxicity of these alloys namely nickel and chromium has concerned the researchers about the release of these ions from orthodontic wires and brackets. The aim of this study was to measure the levels of nickel and chromium ions released from 0.018" stainless steel (SS) and NiTi wires after immersion in three solutions. One hundred and forty-four round NiTi and 144 round SS archwires with the diameters of 0.018" were immersed in Oral B®, Orthokin® and artificial saliva. The amounts of nickel and chromium ions released were measured after 1, 6, 24 hours and 7 days. Two way repeated ANOVA showed that the amount of chromium and nickel significantly increased in all solutions during all time intervals (p nickel ions were released more in NiTi wire in all solutions compared with SS wire. The lowest increase rate was also seen in artificial saliva. There is general consensus in literature that even very little amounts of nickel and chromium are dangerous for human body specially when absorbed orally; therefore, knowing the precise amount of these ions released from different wires when immersed in different mouthwashes is of high priority.

  5. A radiolabel release microassay for phagocytic killing of Candida albicans

    International Nuclear Information System (INIS)

    Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P.; Puccetti, P.

    1982-01-01

    The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans. (Auth.)

  6. Effect for Recovery of the Containment Spray System to the Release of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Mi Ro [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    In the perspective of the amount of Cs-137, the mass of Cs-137 correspondent with the 100TBq is calculated as 32g. However, during the severe accident, if the containment has been failed, it is generally expected that the mass of Cs-137 released to the environment is more than 1kg for most accident sequences So, the review and improvement of the PSA model in order to reduce containment failure frequency should be needed. Actually, the current PSA model is known to be constructed by the conservative assumptions, especially in the view point of Level 2 PSA model. Therefore, it is necessary to find this conservatism and to improve the Model using the reasonable assumptions. All of the domestic operating nuclear power plants are required to prepare the Accident Management Plan within 3 years and this Accident Management Plan should have to meet the New Safety Goal including the requirement that the sum of the accident frequency that the release of the radioactive nuclide Cs-137 to the environment exceeds the 100TBq should be less than 1.0E-6/RY. The containment spray system is the only facility that mitigates the containment over-pressurization in the operating nuclear power plants, such as Westinghouse type or OPR1000 type. In this study, the effects of the containment spray system recovery on the amount of Cesium released to the environment were analyzed. If the recovery of the containment spray system can be applied to the PSA model, it is expected that the containment failure frequency and also the amount of cesium released to the environment can be greatly reduced.

  7. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 4: Hatteras abyssal red clay

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.L.

    1982-07-01

    A study in which neutron-activated 347 stainless steel was exposed to surficial sediment from a site in the Hatteras Abyssal Plain of the Northwest Atlantic Ocean is described. This sediment consists of approx. 20% CaCO/sub 3/, which could lead to the formation of calcareous scale on the metal surface and reduce the corrosion rate. The distribution of indigenous metals among different chemical fractions shows that extractable Cr, Mn, Fe, Co, and Zn were associated with amorphous Mn and Fe oxides. Most of the remaining extractable Cr, and about a third of the extractable Cu appear to have been weakly complexed. Major fractions (25 to 36%) of extractable Mn, Co and Ni were present as adsorbed cations. Organic complexation appears to account for a large amount of extractable Fe, Ni, Cu and Zn. Neutron-activated 347 stainless steel specimens were exposed to sediment slurry under aerobic and non-oxygenated conditions for a period of 94 days. The redox potential measurements for air-sparged and N/sub 2/, CO/sub 2/-sparged sediment slurries were +410 and +60 mv, respectively. The presence of 0/sub 2/ produced increased amounts of corrosion products. Chemical extraction showed that relatively labile substances constituted about 84% of the /sup 60/Co activity released in aerated sediment. Relatively labile substances constitute about 82% of the total /sup 60/Co activity released under non-oxygenated conditions. A large fraction of /sup 60/Co which was in the soluble or easily dissolved forms under non-oxygenated conditions appears to have been more strongly adsorbed to the sediment under aerated conditions.

  8. Preoperative Embolization Reduces the Risk of Cathecolamines Release at the Time of Surgical Excision of Large Pelvic Extra-Adrenal Sympathetic Paraganglioma

    Directory of Open Access Journals (Sweden)

    Nicola Di Daniele

    2012-01-01

    Full Text Available A 30-year-old woman with severe hypertension was admitted to the hospital with a history of headache, palpitations, and diaphoresis following sexual intercourse. Twenty-four hour urinary excretion of free catecholamines and metabolites was markedly increased as was serum chromogranin A. Computed tomography scan revealed a large mass in the left adnex site and magnetic resonance imaging confirmed the computer tomography finding, suggesting the presence of extra-adrenal sympathetic paraganglioma. I-metaiodobenzyl guanidine scintigram revealed an increased uptake in the same area. Transcatheter arterial embolization of the mass resulted in marked decreases in blood pressure and urinary excretion of free catecholamines and metabolites. Surgical excision of the mass was then accomplished without complication. Preoperative embolization is a useful and safe procedure which may reduce the risk of catecholamines release at the time of surgical excision in large pelvic extra-adrenal sympathetic paraganglioma.

  9. Inclusion of cefalexin in SBA-15 mesoporus material and release property

    International Nuclear Information System (INIS)

    Zhai, Qing-Zhou

    2012-01-01

    SBA-15 (Santa Barbara Amorphous-15) is a high ordered mesoporous material. It has the advantages of a non-toxic property, good hydrothermal stability and thermal stability, etc. Inside inner surface a lot of silanols exist. Pore diameter size is uniform and pore size distribution is narrow. This structural feature makes SBA-15 have a higher loading drug amount and be able to effectively extend the drug release cycle. In this paper, polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol was used as template and tetraethyl orthosilicate was used as silica source to prepare SBA-15 by hydrothermal synthesis method. Cefalexin was included in SBA-15 and the included cefalexin drug content was 158.72 mg/g. The composite materials were characterized by using chemical analysis, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared (IR) spectroscopy, and low temperature nitrogen adsorption–desorption. The results showed that cefalexin had been successfully included in host SBA-15 pore channels. Rational analyses of the release processes of cefalexin drug from the pores of SBA-15 to the simulated body fluid, simulated gastric juice and simulated intestinal fluid were made and sustained-release effects of the drug in complex system were studied. The results showed that in simulated body fluid within 1–5 h cefalexin was fast released and the cumulative release reached 50.00% at 5 h. In 15–20 h, the sustained release speed of cefalexin drug in the composite material decreased and the sustained-release cumulative amount reached 99.87% at 20 h. The release of cefalexin was basically complete. In simulated gastric fluid, composite material sustained-release ended at 4 h, the cumulative sustained release ratio reaching 26.10%. In simulated gastric fluid, the sustained-release was complete at 7 h, the cumulative sustained release ratio reaching 32.46%. The composite material of SBA-15 and cefalexin

  10. Tailorable Release of Small Molecules Utilizing Plant Viral Nanoparticles and Fibrous Matrix

    Science.gov (United States)

    Cao, Jing

    We have engineered Red clover necrotic mosaic virus (RCNMV) derived plant viral nanoparticles (PVNs) within a fibrous matrix to optimize its application for delivery and controlled release of active ingredients. RCNMV's structure and unique response to divalent cation depletion and re-addition enables the infusion of small molecules into its viral capsid through a pore formation mechanism. While this PVN technology shows a potential use in nano-scale therapeutic drug delivery, its inherent molecular dynamics to environmental stimuli places a constraint on its application and functionality as a vehicle for tailorable release of loading cargo. In this study, we enhance the understanding of the PVN technology by elucidating its mechanism for loading and triggered release of doxorubicin (Dox), a chemotherapeutic drug for breast cancer. Of critical importance is the methodology for manipulation of Dox's loading capacity and its binding location on either the exterior or interior of the virion capsid. The ability to control the active ingredient binding location provides an additional approach of tunable release from the PVN delivery vehicle besides its inherent pH- and ion- responsive release of loading cargo. The efficacious and controlled release strategy for agricultural active ingredients, such as nematicides, is also a large social need right now. Crop infestation of plant parasite nematodes causes in excess of 157 billion in worldwide crop damage annually. If an effective control strategy for these pests could be developed, it is estimated that the current market for effective nematicides is between 700 million and $1 billion each year worldwide. In this study, we report on the utilization of PVN technology to encapsulate the biological nematicide, abamectin (Abm), within the PVN's interior capsid (PVNAbm). Creating PVNAbm addresses Abm's issues of soil immobility while rendering a controlled release strategy for its bioavailability to root knot nematodes (RKNs

  11. Intermediate temperature heat release in an HCCI engine fueled by ethanol/n-heptane mixtures: An experimental and modeling study

    KAUST Repository

    Vuilleumier, David

    2014-03-01

    This study examines intermediate temperature heat release (ITHR) in homogeneous charge compression ignition (HCCI) engines using blends of ethanol and n-heptane. Experiments were performed over the range of 0-50% n-heptane liquid volume fractions, at equivalence ratios 0.4 and 0.5, and intake pressures from 1.4bar to 2.2bar. ITHR was induced in the mixtures containing predominantly ethanol through the addition of small amounts of n-heptane. After a critical threshold, additional n-heptane content yielded low temperature heat release (LTHR). A method for quantifying the amount of heat released during ITHR was developed by examining the second derivative of heat release, and this method was then used to identify trends in the engine data. The combustion process inside the engine was modeled using a single-zone HCCI model, and good qualitative agreement of pre-ignition pressure rise and heat release rate was found between experimental and modeling results using a detailed n-heptane/ethanol chemical kinetic model. The simulation results were used to identify the dominant reaction pathways contributing to ITHR, as well as to verify the chemical basis behind the quantification of the amount of ITHR in the experimental analysis. The dominant reaction pathways contributing to ITHR were found to be H-atom abstraction from n-heptane by OH and the addition of fuel radicals to O2. © 2013 The Combustion Institute.

  12. Intermediate temperature heat release in an HCCI engine fueled by ethanol/n-heptane mixtures: An experimental and modeling study

    KAUST Repository

    Vuilleumier, David; Kozarac, Darko; Mehl, Marco; Saxena, Samveg; Pitz, William J.; Dibble, Robert W.; Chen, Jyhyuan; Sarathy, Mani

    2014-01-01

    This study examines intermediate temperature heat release (ITHR) in homogeneous charge compression ignition (HCCI) engines using blends of ethanol and n-heptane. Experiments were performed over the range of 0-50% n-heptane liquid volume fractions, at equivalence ratios 0.4 and 0.5, and intake pressures from 1.4bar to 2.2bar. ITHR was induced in the mixtures containing predominantly ethanol through the addition of small amounts of n-heptane. After a critical threshold, additional n-heptane content yielded low temperature heat release (LTHR). A method for quantifying the amount of heat released during ITHR was developed by examining the second derivative of heat release, and this method was then used to identify trends in the engine data. The combustion process inside the engine was modeled using a single-zone HCCI model, and good qualitative agreement of pre-ignition pressure rise and heat release rate was found between experimental and modeling results using a detailed n-heptane/ethanol chemical kinetic model. The simulation results were used to identify the dominant reaction pathways contributing to ITHR, as well as to verify the chemical basis behind the quantification of the amount of ITHR in the experimental analysis. The dominant reaction pathways contributing to ITHR were found to be H-atom abstraction from n-heptane by OH and the addition of fuel radicals to O2. © 2013 The Combustion Institute.

  13. Manufacturing Amorphous Solid Dispersions with a Tailored Amount of Crystallized API for Biopharmaceutical Testing.

    Science.gov (United States)

    Theil, Frank; Milsmann, Johanna; Anantharaman, Sankaran; van Lishaut, Holger

    2018-05-07

    The preparation of an amorphous solid dispersion (ASD) by dissolving a poorly water-soluble active pharmaceutical ingredient (API) in a polymer matrix can improve the bioavailability by orders of magnitude. Crystallization of the API in the ASD, though, is an inherent threat for bioavailability. Commonly, the impact of crystalline API on the drug release of the dosage form is studied with samples containing spiked crystallinity. These spiked samples possess implicit differences compared to native crystalline samples, regarding size and spatial distribution of the crystals as well as their molecular environment. In this study, we demonstrate that it is possible to grow defined amounts of crystalline API in solid dosage forms, which enables us to study the biopharmaceutical impact of actual crystallization. For this purpose, we studied the crystal growth in fenofibrate tablets over time under an elevated moisture using transmission Raman spectroscopy (TRS). As a nondestructive method to assess API crystallinity in ASD formulations, TRS enables the monitoring of crystal growth in individual dosage forms. Once the kinetic trace of the crystal growth for a certain environmental condition is determined, this method can be used to produce samples with defined amounts of crystallized API. To investigate the biopharmaceutical impact of crystallized API, non-QC dissolution methods were used, designed to identify differences between the various amounts of crystalline materials present. The drug release in the samples manufactured in this fashion was compared to that of samples with spiked crystallinity. In this study, we present for the first time a method for targeted crystallization of amorphous tablets to simulate crystallized ASDs. This methodology is a valuable tool to generate model systems for biopharmaceutical studies on the impact of crystallinity on the bioavailability.

  14. Elephant’s breast milk contains large amounts of glucosamine

    Science.gov (United States)

    TAKATSU, Zenta; TSUDA, Muneya; YAMADA, Akio; MATSUMOTO, Hiroshi; TAKAI, Akira; TAKEDA, Yasuhiro; TAKASE, Mitsunori

    2016-01-01

    Hand-reared elephant calves that are nursed with milk substitutes sometimes suffer bone fractures, probably due to problems associated with nutrition, exercise, sunshine levels and/or genetic factors. As we were expecting the birth of an Asian elephant (Elephas maximus), we analyzed elephant’s breast milk to improve the milk substitutes for elephant calves. Although there were few nutritional differences between conventional substitutes and elephant’s breast milk, we found a large unknown peak in the breast milk during high-performance liquid chromatography-based amino acid analysis and determined that it was glucosamine (GlcN) using liquid chromatography/mass spectrometry. We detected the following GlcN concentrations [mean ± SD] (mg/100 g) in milk hydrolysates produced by treating samples with 6M HCl for 24 hr at 110°C: four elephant’s breast milk samples: 516 ± 42, three cow’s milk mixtures: 4.0 ± 2.2, three mare’s milk samples: 12 ± 1.2 and two human milk samples: 38. The GlcN content of the elephant’s milk was 128, 43 and 14 times greater than those of the cow’s, mare’s and human milk, respectively. Then, we examined the degradation of GlcN during 0–24 hr hydrolyzation with HCl. We estimated that elephant’s milk contains >880 mg/100 g GlcN, which is similar to the levels of major amino acids in elephant’s milk. We concluded that a novel GlcN-containing milk substitute should be developed for elephant calves. The efficacy of GlcN supplements is disputed, and free GlcN is rare in bodily fluids; thus, the optimal molecular form of GlcN requires a further study. PMID:28049867

  15. Noble Gas Release Signal as a Precursor to Fracture

    Science.gov (United States)

    Bauer, S. J.; Lee, H.; Gardner, W. P.

    2017-12-01

    We present empirical results of rock strain, microfracturing, acoustic emissions, and noble gas release from laboratory triaxial experiments for a granite, basalt, shale and bedded rock salt. Noble gases are released and measured real-time during deformation using mass spectrometry. The gas release represents a precursive signal to macrofracture. Gas release is associated with increased acoustic emissions indicating that microfracturing is required to release gas and create pathways for the gas to be sensed. The gas released depends on initial gas content, pore structure and its evolution during deformation, the deformation amount, matrix permeability, deformation style and the stress/strain history. Gases are released from inter and intracrystalline sites; release rate increases as strain and microfracturing increases. The gas composition depends on lithology, geologic history and age, fluids present, and radioisotope concentrations that affect radiogenic noble gas isotope (e.g. 4He,40Ar) production. Noble gas emission and its relationship to crustal processes such as seismicity and volcanism, tectonic velocities, qualitative estimates of deep permeability, age dating of groundwater, and a signature of nuclear weapon detonation. Our result show that mechanical deformation of crustal materials is an important process controlling gas release from rocks and minerals, and should be considered in techniques which utilize gas release and/or accumulation. We propose using noble gas release to signal rock deformation in boreholes, mines and waste repositories. We postulate each rock exhibits a gas release signature which is microstructure, stress, strain, and/or permanent deformation dependent. Calibration of such relationships, for example relating gas release per rock unit volume to strain may be used to quantify rock deformation and develop predictive models.Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and

  16. Ibuprofen Release from Poly(ethyl cyanoacrylate Nanoparticles Prepared by Semicontinuous Heterophase Polymerization

    Directory of Open Access Journals (Sweden)

    J. A. Balleño

    2018-01-01

    Full Text Available Ibuprofen-loaded poly(ethyl cyanoacrylate nanoparticles were prepared by semicontinuous heterophase polymerization of ethyl cyanoacrylate in the presence of ibuprofen; different surfactant concentration, pH, and temperature were used. Particle size was measured by quasi-light scattering and transmission electron microscopy, while the amount of drug released was determined by UV spectroscopy. Nanoparticles with diameters between 10 and 58 nm, loaded with ibuprofen, were obtained. The smallest particles and the higher drug loading were obtained at the highest pH tested. The analysis of the release data showed that the drug release profiles correspond to the Weibull model. Moreover, it was found that most of the ibuprofen is released within the first 80–120 min; initially the release rate is slow, but then it increases to finally decrease. This behavior contrasts with the reported burst of drug concentration in the plasma after oral administration of IB.

  17. Comparative evaluation of fluoride release from PRG-composites and compomer on application of topical fluoride: An in-vitro study

    Directory of Open Access Journals (Sweden)

    Dhull K

    2009-03-01

    Full Text Available Aims and Objective: To determine the fluoride release from Giomer and Compomer, using different topical fluoride regimes, and to compare the amount of fluoride release from giomer with that of compomer. Materials and Method: Forty-eight specimens of each giomer and compomer were divided into four treatment groups, namely, control group, fluoridated dentifrice (500 ppm once daily group, fluoridated dentifrice (500 ppm twice daily group, fluoridated dentifrice (500 ppm once daily + fluoridated mouthwash (225 ppm group. Each specimen was suspended in demineralizing solution for six hours and remineralizing solution for 18 hours. Fluoride release was measured in both the demineralizing solution and remineralizing solution daily for seven days. Total daily fluoride release for each specimen was calculated by adding the amount released in the demineralizing solution to that released in remineralizing solution. Results and Conclusion: The fluoride release (ppm was found to be more in Giomer when compared to Compomer. The fluoride released from Giomer and Compomer was significantly greater in the acidic demineralizing solution than in the neutral remineralizing solution. It was found that increasing fluoride exposure significantly increased fluoride release from the giomer and compomer. It was found that the fluoride release from the subgroups of giomer and compomer was in the following order: fluoridated dentifrice twice daily > fluoridated dentifrice once daily + fluoridated mouthwash > fluoridated dentifrice once daily > control group. It was found that the giomer showed a greater fluoride uptake than the compomer.

  18. A large-scale radiometric micro-quantitative complement fixation test for serum antibody titration

    International Nuclear Information System (INIS)

    Bengali, Z.H.; Levine, P.H.; Das, S.R.

    1980-01-01

    A micro-quantitative complement fixation (CF) procedure based on 51 Cr release is described. The method employs 50% hemolysis as end point and the alternation equation to calculate the amount of complement involved in the hemolytic reaction. Compared to the conventional CF tests, the radiometric procedure described here is very precise and consistently reproducible. Also, since only 3 4-fold dilutions of sera are used for the titration of antibodies over a wide range of concentrations, the test is very concise and is economical to perform. Its format is amenable to automation and computerization. This radioimetric CF procedure is thus most useful for large-scale immunological research and epidemiological surveilance studies. (Auth.)

  19. Peptide secreted by human alveolar macrophages releases neutrophil granule contents

    International Nuclear Information System (INIS)

    MacArthur, C.K.; Miller, E.J.; Cohen, A.B.

    1987-01-01

    A monoclonal antibody was developed against an 8000-kDa enzyme-releasing peptide (ERP) released from human alveolar macrophages. ERP was isolated on an immunoaffinity column containing the antibody bound to staphylococcal protein A-Sepharose, and by autoradiography. Release of ERP from the macrophages is not changed by plastic adherence, phagocytosis, calcium ionophore, or phorbol esters. The peptide was not antigenically similar to interferon-γ, tumor necrosis factor, or interleukin lα or 1β. The release of constituents from azurophilic and specific granules was the main identified biologic function of ERP. ERP was a more effective secretagogue in the untreated neutrophils and f-met-leu-phe was more effective in the cytochalasin B-treated neutrophils. Absorption of ERP from macrophage-conditioned medium removed a small amount of the chemotactic activity; however, the immunopurified peptide was not chemotactic or chemokinetic for neutrophils, and at high concentrations, it suppressed base line chemokinesis. Treatment of washed macrophages with trypsin released active ERP of approximately the same m.w. of spontaneously secreted ERP. These studies showed that human alveolar macrophages release a peptide which is a secretagogue for human neutrophils under conditions which may be encountered in the lungs during certain disease states. Proteolytic enzymes which are free in the lungs may release the peptide and lead to the secretion of neutrophil enzymes

  20. Gastrin-releasing peptide in the porcine pancreas

    DEFF Research Database (Denmark)

    Holst, J J; Poulsen, Steen Seier

    1987-01-01

    to consist of one main form, namely the 27-amino acid peptide originally extracted from porcine stomach, and small amounts of a C-terminal fragment identical with the C-terminal 10-amino acid peptide. Gastrin-releasing peptide-like immunoreactivity released from the isolated perfused porcine pancreas during...... electrical vagal stimulation was shown by gel filtration to consist of the same two forms. By use of immunocytochemical techniques employing an antiserum directed against its N terminus, GRP was localized to varicose nerve fibers in close association with the exocrine tissue of the porcine pancreas...... in particular. Some fibers were found penetrating into pancreatic islets also. Immunoreactive nerve cell bodies as well as fibers were found within intrapancreatic ganglia. The potency of GRP in stimulating exocrine as well as endocrine secretion from the porcine pancreas, its presence in close contact...

  1. Detection of cold gas releases in space via low energy neutral atom imaging

    International Nuclear Information System (INIS)

    McComas, D.J.; Funsten, H.O.; Moore, K.R.; Scime, E.E.; Thomsen, M.F.

    1993-01-01

    Low energy neutral atoms (LENAs) are produced in space plasmas by charge exchange between the ambient magnetospheric plasma ions and cold neutral atoms. Under normal conditions these cold neutrals come from the terrestrial geocorona, a shroud of few-eV hydrogen atoms surrounding the Earth. As a consequence of this charge exchange, it has become possible to remotely image many regions of the magnetosphere for the first time utilizing recently developed LENA imaging technology. In addition to the natural hydrogen geocorona, conventional explosions and maneuvering thruster firings can also introduce large amounts of cold gas into the space environment. In this paper the authors examine whether such potentially clandestine activities could also be remotely observed for the first time via LENA imaging. First, they examine the fluxes of LENAs produced in the space environment from a conventional explosion. Then they review the present state of the art in the emerging field of LENA detection and imaging. Recent work has shown that LENAs can be imaged by first converting the neutrals to ions with ultra-thin (10s of angstrom) foils and then electrostatically analyzing these newly created ions to reject the large (> 10 10 cm -2 s -1 ) UV background to which the low energy detectors are sensitive. They conclude that the sensitivities for present LENA imager designs may be just adequate for detecting some man-made releases. With additional improvements in LENA detection capabilities, this technique could become an important new method for monitoring for conventional explosions, as well as other man-made neutral releases, in the space environment

  2. Sustained release of doxorubicin from zeolite-magnetite nanocomposites prepared by mechanical activation

    International Nuclear Information System (INIS)

    Arruebo, Manuel; Fernandez-Pacheco, Rodrigo; Irusta, Silvia; Arbiol, Jordi; Ibarra, M Ricardo; SantamarIa, Jesus

    2006-01-01

    Nanocomposites consisting of magnetite and FAU zeolite with a high surface area and adsorption capacity have been prepared by mechanical activation using high-energy milling at room temperature. FTIR results, as well as HRTEM, EFTEM, and XPS measurements, show that the resulting magnetic nanoparticles are covered by a thin aluminosilicate coating. A saturation magnetization as high as 16 emu g -1 and 94.2 Oe of coercivity were observed for the obtained composites. The main advantages of this synthesis procedure are (i) simplicity of the preparation procedure (ii) prevention of agglomeration of the magnetite nanoparticles to a large extent, and (iii) absence of free magnetite outside the zeolitic matrix. In addition, in vitro experiments revealed that the nanoparticles prepared were able to store and release substantial amounts of doxorubicin. In view of these advantages, these magnetic nanoparticles can be considered as potential candidates for drug-delivery applications

  3. Carbon dioxide degassing and thermal energy release at Vesuvio (Italy)

    Science.gov (United States)

    Frondini, F.; Chiodini, G.; Caliro, S.; Cardellini, C.; Granieri, D.

    2003-04-01

    At Vesuvio, basing on the data of the CO2 flux surveys carried out in April and May 2000, are discharged about 130 t d-1 of CO2 through soil diffuse degassing. In the crater area the distribution of the soil temperatures show a general correspondence between the CO2 flux anomalies and the high temperatures, suggesting that the heating of the soil is mainly due to the condensation of the rising volcanic-hydrothermal fluids. Considering that the original H2O/CO2 ratio of hydrothermal fluids is recorded by fumarolic effluents, the steam associated to the CO2 output has been computed and amount to is 475 t d-1. The energy produced by the steam condensation and cooling of the liquid phase is 1.26 1012 J d-1 (14.6 MW). The amounts of gas and energy released by Vesuvio are comparable to those released by other volcanic degassing areas of the world and their estimates, through periodical CO2 flux surveys, can constitute a powerful tool to monitor the activity of the volcano.

  4. Controlled release of metronidazole from composite poly-ε-caprolactone/alginate (PCL/alginate) rings for dental implants.

    Science.gov (United States)

    Lan, Shih-Feng; Kehinde, Timilehin; Zhang, Xiangming; Khajotia, Sharukh; Schmidtke, David W; Starly, Binil

    2013-06-01

    Dental implants provide support for dental crowns and bridges by serving as abutments for the replacement of missing teeth. To prevent bacterial accumulation and growth at the site of implantation, solutions such as systemic antibiotics and localized delivery of bactericidal agents are often employed. The objective of this study was to demonstrate a novel method of controlled localized delivery of antibacterial agents to an implant site using a biodegradable custom fabricated ring. The study involved incorporating a model antibacterial agent (metronidazole) into custom designed poly-ε-caprolactone/alginate (PCL/alginate) composite rings to produce the intended controlled release profile. The rings can be designed to fit around the body of any root form dental implants of various diameters, shapes and sizes. In vitro release studies indicate that pure (100%) alginate rings exhibited an expected burst release of metronidazole in the first few hours, whereas Alginate/PCL composite rings produced a medium burst release followed by a sustained release for a period greater than 4 weeks. By varying the PCL/alginate weight ratios, we have shown that we can control the amount of antibacterial agents released to provide the minimal inhibitory concentration (MIC) needed for adequate protection. The fabricated composite rings have achieved a 50% antibacterial agent release profile over the first 48 h and the remaining amount slowly released over the remainder of the study period. The PCL/alginate agent release characteristic fits the Ritger-Peppas model indicating a diffusion-based mechanism during the 30-day study period. The developed system demonstrates a controllable drug release profile and the potential for the ring to inhibit bacterial biofilm growth for the prevention of diseases such as peri-implantitis resulting from bacterial infection at the implant site. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Marine fouling release silicone/carbon nanotube nanocomposite coatings: on the importance of the nanotube dispersion state.

    Science.gov (United States)

    Beigbeder, Alexandre; Mincheva, Rosica; Pettitt, Michala E; Callow, Maureen E; Callow, James A; Claes, Michael; Dubois, Philippe

    2010-05-01

    The present work reports on the influence of the dispersion quality of multiwall carbon nanotubes (MWCNTs) in a silicone matrix on the marine fouling-release performance of the resulting nanocomposite coatings. A first set of coatings filled with different nanofiller contents was prepared by the dilution of a silicone/MWCNTs masterbatch within a hydrosilylation-curing polydimethylsiloxane resin. The fouling-release properties of the nanocomposite coatings were studied through laboratory assays with the marine alga (seaweed) Ulva, a common fouling species. As reported previously (see Ref. [19]), the addition of a small (0.05%) amount of carbon nanotubes substantially improves the fouling-release properties of the silicone matrix. This paper shows that this improvement is dependent on the amount of filler, with a maximum obtained with 0.1 wt% of multiwall carbon nanotubes (MWCNTs). The method of dispersion of carbon nanotubes in the silicone matrix is also shown to significantly (p = 0.05) influence the fouling-release properties of the coatings. Dispersing 0.1% MWCNTs using the masterbatch approach yielded coatings with circa 40% improved fouling-release properties over those where MWCNTs were dispersed directly in the polymeric matrix. This improvement is directly related to the state of nanofiller dispersion within the cross-linked silicone coating.

  6. Regenerated cellulose micro-nano fiber matrices for transdermal drug release

    International Nuclear Information System (INIS)

    Liu, Yue; Nguyen, Andrew; Allen, Alicia; Zoldan, Janet; Huang, Yuxiang; Chen, Jonathan Y.

    2017-01-01

    In this work, biobased fibrous membranes with micro- and nano-fibers are fabricated for use as drug delivery carries because of their biocompatibility, eco-friendly approach, and potential for scale-up. The cellulose micro-/nano-fiber (CMF) matrices were prepared by electrospinning of pulp in an ionic liquid, 1-butyl-3-methylimidazolium chloride. A model drug, ibuprofen (IBU), was loaded on the CMF matrices by a simple immersing method. The amount of IBU loading was about 6% based on the weight of cellulose membrane. The IBU-loaded CMF matrices were characterized by Fourier-transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. The test of ibuprofen release was carried out in an acetate buffer solution of pH 5.5 and examined by UV–Vis spectroscopy. Release profiles from the CMF matrices indicated that the drug release rate could be determined by a Fickian diffusion mechanism. - Highlights: • Cellulose micro-nano fiber matrix was prepared by dry-wet electrospinning. • Ibuprofen was loaded on the matrix by a simple immersing method. • The drug loaded matrix showed a biphasic release profile. • The drug release was determined by a Fickian diffusion mechanism.

  7. Regenerated cellulose micro-nano fiber matrices for transdermal drug release

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yue [School of Human Ecology, The University of Texas at Austin, Austin, TX (United States); Department of Chemistry, School of Science, Tianjin University, Tianjin (China); Nguyen, Andrew; Allen, Alicia; Zoldan, Janet [Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX (United States); Huang, Yuxiang [School of Human Ecology, The University of Texas at Austin, Austin, TX (United States); Chen, Jonathan Y., E-mail: jychen2@austin.utexas.edu [School of Human Ecology, The University of Texas at Austin, Austin, TX (United States)

    2017-05-01

    In this work, biobased fibrous membranes with micro- and nano-fibers are fabricated for use as drug delivery carries because of their biocompatibility, eco-friendly approach, and potential for scale-up. The cellulose micro-/nano-fiber (CMF) matrices were prepared by electrospinning of pulp in an ionic liquid, 1-butyl-3-methylimidazolium chloride. A model drug, ibuprofen (IBU), was loaded on the CMF matrices by a simple immersing method. The amount of IBU loading was about 6% based on the weight of cellulose membrane. The IBU-loaded CMF matrices were characterized by Fourier-transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. The test of ibuprofen release was carried out in an acetate buffer solution of pH 5.5 and examined by UV–Vis spectroscopy. Release profiles from the CMF matrices indicated that the drug release rate could be determined by a Fickian diffusion mechanism. - Highlights: • Cellulose micro-nano fiber matrix was prepared by dry-wet electrospinning. • Ibuprofen was loaded on the matrix by a simple immersing method. • The drug loaded matrix showed a biphasic release profile. • The drug release was determined by a Fickian diffusion mechanism.

  8. Piezo1 regulates mechanotransductive release of ATP from human RBCs.

    Science.gov (United States)

    Cinar, Eyup; Zhou, Sitong; DeCourcey, James; Wang, Yixuan; Waugh, Richard E; Wan, Jiandi

    2015-09-22

    Piezo proteins (Piezo1 and Piezo2) are recently identified mechanically activated cation channels in eukaryotic cells and associated with physiological responses to touch, pressure, and stretch. In particular, human RBCs express Piezo1 on their membranes, and mutations of Piezo1 have been linked to hereditary xerocytosis. To date, however, physiological functions of Piezo1 on normal RBCs remain poorly understood. Here, we show that Piezo1 regulates mechanotransductive release of ATP from human RBCs by controlling the shear-induced calcium (Ca(2+)) influx. We find that, in human RBCs treated with Piezo1 inhibitors or having mutant Piezo1 channels, the amounts of shear-induced ATP release and Ca(2+) influx decrease significantly. Remarkably, a critical extracellular Ca(2+) concentration is required to trigger significant ATP release, but membrane-associated ATP pools in RBCs also contribute to the release of ATP. Our results show how Piezo1 channels are likely to function in normal RBCs and suggest a previously unidentified mechanotransductive pathway in ATP release. Thus, we anticipate that the study will impact broadly on the research of red cells, cellular mechanosensing, and clinical studies related to red cell disorders and vascular disease.

  9. Revised Emergency Planning and Community Right-to-Know Act (EPCRA), Section 313, Toxic Chemical Release reporting for calendar year 1998

    International Nuclear Information System (INIS)

    Evans, R.A.

    2000-01-01

    This report contains forms which contain information on the physical location of the Y-12 Plant and the amount of lead that was released to the East Fork Poplar Creek and amounts transferred to landfills on-site as well as landfills in Texas and South Carolina. Amounts are given in pounds per year

  10. In situ release rates of Cu and Zn from commercial antifouling paints at different salinities.

    Science.gov (United States)

    Lagerström, Maria; Lindgren, J Fredrik; Holmqvist, Albin; Dahlström, Mia; Ytreberg, Erik

    2018-02-01

    Antifouling paints are environmentally risk assessed based on their biocidal release rates to the water phase. In situ release rates of copper (Cu) and zinc (Zn) were derived for five commercial paints in two recreational marinas with different salinities (5 and 14 PSU) using an X-Ray Fluorescence spectrometer (XRF). Salinity was found to significantly affect the Cu release, with twice the amount of Cu released at the higher salinity, while its influence on the Zn release was paint-specific. Site-specific release rates for water bodies with salinity gradients, e.g. the Baltic Sea, are therefore necessary for more realistic risk assessments of antifouling paints. Furthermore, the in situ release rates were up to 8 times higher than those generated using standardized laboratory or calculation methods. The environmental risk assessment repeated with the field release rates concludes that it is questionable whether the studied products should be allowed on the Swedish market. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. [The use of natural and synthetic hydrophilic polymers in the formulation of metformin hydrochloride tablets with different profile release].

    Science.gov (United States)

    Kołodziejczyk, Michał Krzysztof; Kołodziejska, Justyna; Zgoda, Marian Mikołaj

    2012-01-01

    -dissolving of a tablet, is conducive to the reduction of gastrointestinal side effects and better tolerance of the therapeutic product by a patient. The study on pharmaceutical availability indicated relevant kinetic differences between tested therapeutic products. They are particularly visible between standard formulations and the one with prolonged release (Glucophage XR500). Its release profile bears features of kinetics similar to zero-order reactions. Tested therapeutic products contain a large amount of the biologically active substance in relation to the content of excipients. A higher content of excipients in a single tablet mass distinguishes Siofor in comparison with Glucophage i Metformax. The excipients used in the formulations of tested preparations are comparable. A higher percentage of binding agents (HPMC, PVP) is observed, but there is a lack of typical disintegrants which results in a longer disintegration time up to 15 minutes. Siofor disintegrates at the same time as Formetic, but longer than Glucophage i Metformax. Considering the large content of the active substance and pharmacological properties of metformin hydrochloride, such a disintegration might have beneficial consequences, because the amount of the free active substance in the gastrointestinal tract will increase over the longer time period what will reduce the level of gastrointestinal side effects. The release profiles of metformin hydrochloride from tested therapeutic products are comparable. The Glucophage XR 500 formulation with the release kinetics of metformin hydrochloride similar to the zero-order kinetics is completely different from the others. The above is confirmed by the mathematical analysis of release profiles of metformin hydrochloride from tested preparations where equations of lines describing the release profile are characterized by similar values of correlation coefficients.

  12. Synthesis and characterization of emamectin-benzoate slow-release microspheres with different surfactants.

    Science.gov (United States)

    Wang, Yan; Wang, Anqi; Wang, Chunxin; Cui, Bo; Sun, Changjiao; Zhao, Xiang; Zeng, Zhanghua; Shen, Yue; Gao, Fei; Liu, Guoqiang; Cui, Haixin

    2017-10-06

    Pesticide slow-release formulations provide a way to increase the efficiency of active components by reducing the amount of pesticide that needs to be applied. Slow-release formulations also increase the stability and prolong the control effect of photosensitive pesticides. Surfactants are an indispensable part of pesticide formulations, and the choice of surfactant can strongly affect formulation performance. In this study, emamectin-benzoate (EMB) slow-release microspheres were prepared by the microemulsion polymerization method. We explored the effect of different surfactants on the particle size and dispersity of EMB in slow-release microspheres. The results indicated that the samples had uniform spherical shapes with an average diameter of 320.5 ±5.24 nm and good dispersity in the optimal formulation with the polymeric stabilizer polyvinyl alcohol (PVA) and composite non-ionic surfactant polyoxyethylene castor oil (EL-40). The optimal EMB pesticide slow-release microspheres had excellent anti-photolysis performance, stability, controlled release properties, and good leaf distribution. These results demonstrated that EMB slow-release microspheres are an attractive candidate for improving pesticide efficacy and prolonging the control effect of EMB in the environment.

  13. An In-Vitro Study on the Release of Fluoride from Two Restorative Materials and Their Rechargeability after Exposure to Daily 1000 ppm Fluoride

    Directory of Open Access Journals (Sweden)

    A. Kowsari

    2005-09-01

    Full Text Available Statement of Problem: Since the fluoride releases from materials with the property of releasing fluoride are decreasing gradually, it seems that probably the material rechargeability is more important than their long-term fluoride release.Purpose: the objective of this study was to asses the fluoride release and rechargeability of 2 types of fluoride releasing restorative materials, a resin modified glass ionomer(Vitremer and a compomer (Compoglass F, after exposure to daily NaF solutionscontaining 1000 ppm F, for 1 minute.Materials and Methods: Twelve discs ( 8 mm ×2 mm of each of the materials were fabricated, and divided into 2 groups (test and control. All discs were stored in 4 mL artificial saliva at 37°C. In group 1 (N=6, the specimens were immersed in artificialsaliva which was changed daily for 25 days. In group 2 (N=6, in addition to receiving the same treatment as group 1, the specimens were immersed in NaF solution (1000ppm F, ph=6.9 for 1 minute before daily saliva change. A potentiometer was used to determine the amount of fluoride released on days 1, 2, 3, 5, 10, 15, 20 and 25, after the daily saliva change, in all study groups. Data were analyzed by the t-student test after confirmation of the equality of variances by Leven’s test.Results: Both materials continued releasing fluoride throughout the whole study period. For each material, the release was highest on day one. During the first 3 days,glass ionomer released significantly higher amounts of fluoride as compared to compomer (p0.05. After exposure to NaF solution, none of the materials showed statistically significant rechargeability (p>0.05 and the amount of fluoride-releasecontinued to drop during the study period in similar patterns for both the test and the control groups.Conclusion: It may be concluded that rechargeability of glass ionomer and compomer,using daily neutral fluoride mouth rinses and toothpastes does not occur in reliable amounts.

  14. Colloid electrochemistry of conducting polymer: towards potential-induced in-situ drug release

    International Nuclear Information System (INIS)

    Sankoh, Supannee; Vagin, Mikhail Yu.; Sekretaryova, Alina N.; Thavarungkul, Panote; Kanatharana, Proespichaya; Mak, Wing Cheung

    2017-01-01

    Highlights: • Pulsed electrode potential induced an in-situ drug release from dispersion of conducting polymer microcapsules. • Fast detection of the released drug within the colloid microenvironment. • Improved the efficiency of localized drug release at the electrode interface. - Abstract: Over the past decades, controlled drug delivery system remains as one of the most important area in medicine for various diseases. We have developed a new electrochemically controlled drug release system by combining colloid electrochemistry and electro-responsive microcapsules. The pulsed electrode potential modulation led to the appearance of two processes available for the time-resolved registration in colloid microenvironment: change of the electronic charge of microparticles (from 0.5 ms to 0.1 s) followed by the drug release associated with ionic equilibration (1–10 s). The dynamic electrochemical measurements allow the distinction of drug release associated with ionic relaxation and the change of electronic charge of conducting polymer colloid microparticles. The amount of released drug (methylene blue) could be controlled by modulating the applied potential. Our study demonstrated a surface-potential driven controlled drug release of dispersion of conducting polymer carrier at the electrode interfaces, while the bulk colloids dispersion away from the electrode remains as a reservoir to improve the efficiency of localized drug release. The developed new methodology creates a model platform for the investigations of surface potential-induced in-situ electrochemical drug release mechanism.

  15. Antifouling coating with controllable and sustained silver release for long-term inhibition of infection and encrustation in urinary catheters.

    Science.gov (United States)

    Wang, Rong; Neoh, Koon Gee; Kang, En-Tang; Tambyah, Paul Anantharajah; Chiong, Edmund

    2015-04-01

    Urinary tract infections constitute a large proportion of nosocomial infections, and the urinary catheter is the most important predisposing factor. Encrustation induced by urease-producing uropathogens like Proteus mirabilis causes further complications. In the present work, a strategy for controllable and sustained release of silver over several weeks has been developed for combating bacterial infection and encrustation in urinary devices. Silver nanoparticles (AgNPs) were first immobilized on polydopamine (PDA) pre-treated silicone catheter surface and this was followed by another PDA coating. The number of AgNP-PDA bilayers could be manipulated to control the amount of silver loaded and its subsequent release. Poly(sulfobetaine methacrylate-co-acrylamide) was then grafted to provide an antifouling outer layer, and to ensure free diffusion of Ag from the surface. The micron-scale combination of an antifouling coating with AgNP-PDA bilayers reduced colonization of the urinary catheter by uropathogens by approximately two orders of magnitude. With one and two AgNP-PDA bilayers, the coated catheter could resist encrustation for 12 and 45 days, respectively, compared with approximately 6 days with the Dover™ silver-coated catheter. Such anti-infective and anti-encrustation catheters can potentially have a large impact on reducing patient morbidity and healthcare expenditure. © 2014 Wiley Periodicals, Inc.

  16. Clostridium butyricum MIYAIRI 588 shows antitumor effects by enhancing the release of TRAIL from neutrophils through MMP-8.

    Science.gov (United States)

    Shinnoh, Masahide; Horinaka, Mano; Yasuda, Takashi; Yoshikawa, Sae; Morita, Mie; Yamada, Takeshi; Miki, Tsuneharu; Sakai, Toshiyuki

    2013-03-01

    Bacillus Calmette-Guérin (BCG) intravesical therapy against superficial bladder cancer is one of the most successful immunotherapies in cancer, though the precise mechanism has not been clarified. Recent studies have demonstrated urinary tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) levels to be higher in BCG-responsive patients than non-responders and shown that polymorphonuclear neutrophils (PMNs) migrating to the bladder after BCG instillation release large amounts of TRAIL. To establish a safer and more effective intravesical therapy than BCG, we examined whether other bacteria induced similar effects. We stimulated PMNs or peripheral blood mononuclear cells (PBMCs) with BCG or other bacteria, and then aliquots of the culture supernatants or cell lysates were assayed for TRAIL. We examined the signaling pathway regulating the release of TRAIL from PMNs and evaluated the antitumor effects of BCG or other bacteria in vitro and in vivo. We have found that Clostridium butyricum MIYAIRI 588 (CBM588) induces the release of endogenous TRAIL from PMNs as well as BCG. In addition, we have shown that matrix metalloproteinase 8 (MMP-8) is one of the key factors responsible for the release. Interestingly, TLR2/4 signaling pathway has been suggested to be important for the release of TRAIL by MMP-8. CBM588 has been proven to be as effective as BCG against cancer cells by inducing apoptosis in vivo as well as in vitro. Taken together, these results strongly suggest that CBM588 is promising for a safer and more effective therapy against bladder cancer.

  17. Release of nitrogen precursors from coal and biomass residues in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    P. Abelha; I. Gulyurtlu; I. Cabrita [Instituto Nacional de Engenharia, Lisbon (Portugal)

    2008-01-15

    This work was undertaken with the aim of quantifying the relative amounts of NH{sub 3} and HCN released from different residues during their devolatilization under fluidized bed conditions. The results were compared with data collected for bituminous coals of different origin. The relation between amounts of HCN and NH{sub 3} released and the levels of NOX and N{sub 2}O formed during cocombustion was also addressed. The partitioning of nitrogen between volatiles and char was also quantified. The pyrolysis studies were undertaken in a small fluidized bed reactor of 80 mm of ID and 500 mm high using an inert atmosphere (N{sub 2}). The HCN and NH{sub 3} were quantified by bubbling the pyrolysis gases in absorbing solutions which were subsequently analyzed with selective electrodes. The combustion studies were carried out on a pilot installation. The fluidized bed combustor is square in cross section with each side being 300 mm long. There is secondary air supply to the freeboard at different heights to deal with high volatile fuels as almost all waste materials are. The temperatures in the bed and in the freeboard and that of the flue gases leaving the reactor were continuously monitored. The results obtained suggest that, while coal releases nitrogen mostly as HCN, residues like RDF and sewage sludge give out fuel-N in greater quantities as NH{sub 3}. Residues at fluidized bed combustion (FBC) temperatures release more than 80% of the fuel-N with the volatiles. The NH{sub 3} evolved during pyrolysis acted as a reducing agent on NOX emissions. The presence of calcium significantly reduces the emission of N{sub 2}O probably by interfering with HCN chemistry. With high amounts of residues in the fuel mixture, the relative importance of char on the nitrogen chemistry substantially decreases. By using cocombustion, it is possible to reduce fuel-N conversion to NOX and N{sub 2}O, by tuning the amounts of coal and residue in the mixture. 29 refs., 18 figs., 3 tabs.

  18. Large scale rock slope release planes imaged by differential ground based InSAR at Randa, Switzerland

    Science.gov (United States)

    Gischig, V.; Loew, S.; Kos, A.; Raetzo, H.

    2009-04-01

    instability most probably correlate with faults which were mapped on the surface or can be seen on the DTM. Inside the moving rock mass several discrete structures can be identified along which active movements take place. In this contribution we discuss the ability of GB-DInSAR to detect release planes and active fractures of large scale landslides in fractured rock masses, which is not possible with any other method in inaccessible terrain. The identification of such structures provides essential information for kinematic analysis and the understanding of failure mechanisms in fractured rock masses.

  19. Release of mannoproteins during Saccharomyces cerevisiae autolysis induced by Pulsed Electric Field

    Directory of Open Access Journals (Sweden)

    Juan Manuel Martínez

    2016-09-01

    Full Text Available The potential of the application of PEF to induce accelerate autolysis of a commercial strain of Sacharomyces cerevisiae for winemaking use was evaluated. The influence of PEF treatments of different intensity (5-25 kV/cm for 30-240 µs on cell viability, cytoplasmic membrane permeabilization, release of mannoproteins and compounds absorbing at 260 and 280 nm has been investigated.After 8 days of incubation at 25 ºC the Abs600 of the suspension containing the control cells was kept constant while the Abs600 of the suspension containing the cells treated by PEF decreased. The measurement of the absorbance at 260 and 280 nm revealed no release of UV absorbing material from untreated cells after 8 days of incubation but the amount of UV absorbing material released drastically increased in the samples that contained cells treated by PEF after the same storage period. After 18 days of storage the amount of mannoproteins released from the untreated cell was negligible. Conversely, mannoprotein concentration increased linearly for the samples containing cells of S. cerevisiae treated by PEF. After 18 days of incubation the concentration of mannoproteins in the supernatant increased 4.2 times for the samples containing cells treated by PEF at 15 and 25 kV/cm for 45 and 150 µs.Results obtained in this study indicates that PEF could be used in winemaking to accelerate the sur lie aging or to obtain mannoproteins from yeast cultures to be used in winemaking.

  20. Estimation of Recurrence Interval of Large Earthquakes on the Central Longmen Shan Fault Zone Based on Seismic Moment Accumulation/Release Model

    Directory of Open Access Journals (Sweden)

    Junjie Ren

    2013-01-01

    Full Text Available Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing seismic hazard. The 2008 Wenchuan earthquake (Mw 7.9 occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF and the Guanxian-Jiangyou fault (GJF. However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-seismic trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS and Interferometric Synthetic Aperture Radar (InSAR data and construct a characteristic seismic moment accumulation/release model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7 ± 0.3 × 1017 N m/yr, and a recurrence interval of 3900 ± 400 yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for seismic hazard analysis in the Longmen Shan region.

  1. Estimation of recurrence interval of large earthquakes on the central Longmen Shan fault zone based on seismic moment accumulation/release model.

    Science.gov (United States)

    Ren, Junjie; Zhang, Shimin

    2013-01-01

    Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing seismic hazard. The 2008 Wenchuan earthquake (Mw 7.9) occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF) and the Guanxian-Jiangyou fault (GJF). However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-seismic trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data and construct a characteristic seismic moment accumulation/release model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7 ± 0.3) × 10¹⁷ N m/yr, and a recurrence interval of 3900 ± 400 yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for seismic hazard analysis in the Longmen Shan region.

  2. Gastrointestinal absorption of large amounts of plutonium. Effect of valency state on transfer

    International Nuclear Information System (INIS)

    Lataillade, G.; Duserre, C.; Metivier, H.; Madic, C.; CEA Centre d'Etudes Nucleaires de Fontenay-aux-Roses, 92

    1989-01-01

    The gastrointestinal absorption of Pu, ingested in valency state III, IV, V or VI was studied in baboons. For each state, the absorption of Pu from masses ranging from 1 to 7 mg per kg of body weight was compared with that from masses ranging from 5 to 45 μg per kg of body weight. The mass ingested did not affect the gastrointestinal absorption of Pu(IV) or PU(VI), but for Pu(V) and to a lesser extent Pu(III), absorption clearly increased about 150-fold and 7-fold respectively, when large masses of Pu were ingested. When small masses were ingested, the valency state did not affect absorption. The increased Pu absorption observed after ingestion of large masses of Pu(V) or (III) might be due to the weak hydrolysis of these valency states. (author)

  3. Data-based method for creating electricity use load profiles using large amount of customer-specific hourly measured electricity use data

    International Nuclear Information System (INIS)

    Raesaenen, Teemu; Voukantsis, Dimitrios; Niska, Harri; Karatzas, Kostas; Kolehmainen, Mikko

    2010-01-01

    The recent technological developments monitoring the electricity use of small customers provides with a whole new view to develop electricity distribution systems, customer-specific services and to increase energy efficiency. The analysis of customer load profile and load estimation is an important and popular area of electricity distribution technology and management. In this paper, we present an efficient methodology, based on self-organizing maps (SOM) and clustering methods (K-means and hierarchical clustering), capable of handling large amounts of time-series data in the context of electricity load management research. The proposed methodology was applied on a dataset consisting of hourly measured electricity use data, for 3989 small customers located in Northern-Savo, Finland. Information for the hourly electricity use, for a large numbers of small customers, has been made available only recently. Therefore, this paper presents the first results of making use of these data. The individual customers were classified into user groups based on their electricity use profile. On this basis, new, data-based load curves were calculated for each of these user groups. The new user groups as well as the new-estimated load curves were compared with the existing ones, which were calculated by the electricity company, on the basis of a customer classification scheme and their annual demand for electricity. The index of agreement statistics were used to quantify the agreement between the estimated and observed electricity use. The results indicate that there is a clear improvement when using data-based estimations, while the new-estimated load curves can be utilized directly by existing electricity power systems for more accurate load estimates.

  4. Data-based method for creating electricity use load profiles using large amount of customer-specific hourly measured electricity use data

    Energy Technology Data Exchange (ETDEWEB)

    Raesaenen, Teemu; Niska, Harri; Kolehmainen, Mikko [Department of Environmental Sciences, University of Eastern Finland P.O. Box 1627, FIN-70211 Kuopio (Finland); Voukantsis, Dimitrios; Karatzas, Kostas [Department of Mechanical Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2010-11-15

    The recent technological developments monitoring the electricity use of small customers provides with a whole new view to develop electricity distribution systems, customer-specific services and to increase energy efficiency. The analysis of customer load profile and load estimation is an important and popular area of electricity distribution technology and management. In this paper, we present an efficient methodology, based on self-organizing maps (SOM) and clustering methods (K-means and hierarchical clustering), capable of handling large amounts of time-series data in the context of electricity load management research. The proposed methodology was applied on a dataset consisting of hourly measured electricity use data, for 3989 small customers located in Northern-Savo, Finland. Information for the hourly electricity use, for a large numbers of small customers, has been made available only recently. Therefore, this paper presents the first results of making use of these data. The individual customers were classified into user groups based on their electricity use profile. On this basis, new, data-based load curves were calculated for each of these user groups. The new user groups as well as the new-estimated load curves were compared with the existing ones, which were calculated by the electricity company, on the basis of a customer classification scheme and their annual demand for electricity. The index of agreement statistics were used to quantify the agreement between the estimated and observed electricity use. The results indicate that there is a clear improvement when using data-based estimations, while the new-estimated load curves can be utilized directly by existing electricity power systems for more accurate load estimates. (author)

  5. Use of fibrin sealants for the localized, controlled release of cefazolin

    Science.gov (United States)

    Tredwell, Stephen; Jackson, John K.; Hamilton, Donald; Lee, Vivian; Burt, Helen M.

    2006-01-01

    Background Fibrin sealants are used increasingly in surgery to reduce bleeding and improve wound healing. They have great potential as biocompatible, biodegradable drug delivery systems, because the sealant may adhere to the target tissue and allow controlled release of the drug over an extended period. We investigated the encapsulation, stability and controlled release of erythromycin and cefazolin from Beriplast fibrin sealants (Aventis Behring Canada). Methods Drug-loaded clots were cast in glass vials and allowed to set. We observed the clots for drug precipitation and aggregation, and we assessed the effect of drug encapsulation on clot strength. Drug stability and release from the clots in phosphate buffered saline (PBS) was quantified by ultraviolet and visible violet absorbance spectroscopy and high-performance liquid chromatography. Results Erythromycin was found to release slowly from the fibrin clots over the first 2 hours but then degrade rapidly. Cefazolin was found to be very stable in clots in PBS (97% stable at 2 d and 93% stable at 5 d). The drug released in a controlled manner over 2 days, with most being released during the first day. The dose of drug released could be varied by changing the amount placed in the thrombin solution. Clot thickness had no effect on the rate of cefazolin release. Conclusion Overall, the 2-day release profile and the excellent stability of the drug suggest that cefazolin-loaded fibrin sealants may offer an effective route of postoperative antibiotic delivery. PMID:17152573

  6. Solubility and fluoride release in ionomers and compomers.

    Science.gov (United States)

    Bertacchini, S M; Abate, P F; Blank, A; Baglieto, M F; Macchi, R L

    1999-03-01

    The degree of solubility and the fluoride release of glass-ionomer cements and "compomers" were determined as a function of time. Three conventional glass-ionomer cements, three hybrid ionomers, and two compomers were included in the study. Disk-shaped specimens were prepared and immersed in a lactic acid solution. Solubility was evaluated from determinations of loss of mass as a function of time. To evaluate fluoride release, similar specimens were immersed in 50 mL of deionized water to which 50 mL of buffer solution was added. A fluoride ion detector was used to read the concentration of fluoride ion in the overall solution at different times after immersion. Material and time factors had a significant influence on results. The compomers showed less corrosion and fluoride release than the ionomers. Some correlation was found between solubility and fluoride leakage values. Components of both the ionomers and compomers that were studied can dissolve in water. The materials leak fluoride ions in amounts that differ according to the characteristics of the individual products.

  7. Estimation of erosion amount by geochemical characteristic in the Horonobe area, northern Hokkaido

    International Nuclear Information System (INIS)

    Takahashi, Kazuharu; Niizato, Tadafumi; Yasue, Ken-ichi; Ishii, Eiichi

    2005-08-01

    This article presents the results of the estimated amount of erosion and uplifting based on mineralogy and organic geochemical characters of the Neogene siliceous rock (Wakkanai and Koetoi Formations) in Horonobe. As a result of the transformational change of silica minerals, it was clarified that the erosion amount was about 0.66 [m ky -1 ] or more at the large uplift site, and about 0.21 [m ky -1 ] or more at the small uplift site at Hokushin region, Horonobe area. In this case of the correlation with the palaeo-geothermal temperature and the sterane/sterene ratio, the ratio is effective measure to estimate the burial depth and erosion amount. We think that the estimation of the amount of erosion and uplifting became possible in high resolution by the organic geochemical character. (author)

  8. Laboratory for Large Data Research

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The Laboratory for Large Data Research (LDR) addresses a critical need to rapidly prototype shared, unified access to large amounts of data across both the...

  9. Combined gelatin-chondroitin sulfate hydrogels for controlled release of cationic antibacterial proteins

    NARCIS (Netherlands)

    Kuijpers, A. J.; Engbers, G. H. M.; Meyvis, T. K. L.; de Smedt, S. S. C.; Demeester, J.; Krijgsveld, J.; Zaat, S. A. J.; Dankert, J.; Feijen, J.

    2000-01-01

    Chemically cross-linked gelatin-chondroitin sulfate (ChS) hydrogels were prepared for the controlled release of small cationic proteins. The amount of chondroitin sulfate in the gelatin gels varied between 0 and 20 wt %. The chemical cross-link density, the degree of swelling, and the rheological

  10. Controlled release of phenytoin for epilepsy treatment from titania and silica based materials

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Tessy, E-mail: tessy3@prodigy.net.mx [Universidad Autonoma Metropolitana-Xochimilco. Departamento de Microbiologia. Calzada del Hueso 1100, Col. Villa Quietud, Coyoacan, C.P. 04960, Mexico D.F. Mexico (Mexico); Instituto Nacional de Neurologia y Neurocirugia ' MVS' . Laboratorio de Nanotecnologia. Av. Insurgentes Sur 3877, Col. La Fama, Tlalpan, 14269, Mexico, D.F. Mexico (Mexico); Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, LA 70118 (United States); Ortiz, Emma [Instituto Nacional de Neurologia y Neurocirugia ' MVS' . Laboratorio de Nanotecnologia. Av. Insurgentes Sur 3877, Col. La Fama, Tlalpan, 14269, Mexico, D.F. Mexico (Mexico); Meza, Doraliz [Universidad Autonoma Metropolitana-Iztapalapa, Departamento de Quimica, Av. San Rafael Atlixco 186, A.P. 55-534, Mexico D.F., C.P. 09340 (Mexico); Basaldella, Elena [CIC-CINDECA - Universidad Nacional de La Plata - Calle 47 No 257 - La Plata (Argentina); Bokhimi, Xim; Magana, Carlos [Instituto de fisica, UNAM. Circuito de la Investigacion s/n. C.U. Mexico D.F. 01000 (Mexico); Sepulveda, Antonio; Rodriguez, Francisco; Ruiz, Javier [Departamento de Quimica Inorganica, Universidad de Alicante. Apartado 99, E-03080 Alicante, Espana Spain (Spain)

    2011-04-15

    Research highlights: {yields} Template technique was used to obtain well ordered nanostructured materials: SBA-15 and titania tubes. {yields} Phenytoin (PH), a drug used in epilepsy treatment, was loaded in these materials to used como PH release. {yields} Loaded PH showed a good stability inside the used materials as observed by spectroscopy analysis. {yields} The load-release PH are faster in nanostructured TiO2 tubes than in mesoporous silica matrix. {yields} There is an inverse effect of the surface area of the structured materials on the amount of released PH. - Abstract: Template technique was used to obtain well ordered nanostructured materials: mesoporous silica and nanostructured titania tubes. This technique permits the synthesis of solids with controlled mesoporosity, where a large variety of molecules that have therapeutic activity can be hosted and further released to specific sites. In this work phenytoin (PH), a drug used in epilepsy treatment, was loaded in ordered mesoporous silica (SBA 15) and nanostructured titania tubes (TiO{sub 2}). The pure materials and those containing PH were characterized by X-ray diffraction, FTIR spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and N{sub 2} adsorption-desorption at 77 K. In order to determine the loading capacity of the antiepileptic drug on these silica- and titania-based materials, the loading and release of PH was investigated using UV-vis spectroscopy. Tubular structures were found for the titania samples, for which the X-ray diffractograms showed to be formed by anatase and rutile phases. On the other hand, an amorphous phase was found in the silica sample. A highly ordered hexagonal structure of 1D cylindrical channels was also observed for this material. Loaded PH showed a good stability inside the used materials as observed by spectroscopy analysis. The adsorption and desorption of PH are faster in nanostructured TiO{sub 2} tubes than in mesoporous silica

  11. Air exposure and sample storage time influence on hydrogen release from tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Moshkunov, K.A., E-mail: moshkunov@gmail.co [National Research Nuclear University ' MEPhI' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation); Schmid, K.; Mayer, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Kurnaev, V.A.; Gasparyan, Yu.M. [National Research Nuclear University ' MEPhI' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation)

    2010-09-30

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D{sub 2}O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of {approx}300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  12. Air exposure and sample storage time influence on hydrogen release from tungsten

    International Nuclear Information System (INIS)

    Moshkunov, K.A.; Schmid, K.; Mayer, M.; Kurnaev, V.A.; Gasparyan, Yu.M.

    2010-01-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2 O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ∼300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  13. Air exposure and sample storage time influence on hydrogen release from tungsten

    Science.gov (United States)

    Moshkunov, K. A.; Schmid, K.; Mayer, M.; Kurnaev, V. A.; Gasparyan, Yu. M.

    2010-09-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ˜300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  14. The minimization of radioactive releases to the sea from the Tokai Reprocessing Plant

    International Nuclear Information System (INIS)

    Sugiyama, T.; Yoshikawa, K.; Ishii, T.

    1996-01-01

    The Tokai Reprocessing Plant (TRP) started hot operation in September 1977. The total amount of about 790 tU of spent fuel, generated in Japan, has been successfully reprocessed as of December 1994. Low-level liquid wastes have been treated safely with the low-level waste treatment process. The design of TRP was based on foreign technology. In the early stage of designing, the radioactivity released to the sea was estimated at approximately 2.6 TBq/day (70 Ci/day) for beta activity (except for tritium). Later, PNC added an evaporator to the process to reduce the level down to 1/100, i.e. 9.6 TBq/year (260 Ci/year) or 2.6 x 10 -2 TBq/day (0.7 Ci/day). In addition, under the supervision of the government, PNC started R and D to further decrease the radioactivity released to the sea in terms of ALARA. Aiming at reducing the activity from 9.6 TBq/year (260 Ci/year) to 1/10 of that value (i.e. 26 Ci/year), the release reduction technology development facility was added. This facility was incorporated into the low-level waste treatment process in 1980, before starting the regular operation of TRP. Since the fuel reprocessing commenced, total radioactivity discharged to the sea has been 1.9 x 10 -2 TBq (0.51 Ci) for beta activity, as of December 1994. Before incorporating the release reduction technology development facility, the yearly level was 3.7 x 10 -3 - 7.4 x 10 -3 TBq (0.1 - 0.2 Ci). After incorporation of the facility, radioactivity released to the sea was greatly decreased to non-detection levels in recent years, in spite of increasing annual reprocessing amounts. Although serious equipment failures have occurred such as the acid recovery evaporator and the dissolvers, there was no influence on radioactivity released to the sea. (author)

  15. Competitive interactions and controlled release of a natural antioxidant from halloysite nanotubes.

    Science.gov (United States)

    Hári, József; Gyürki, Ádám; Sárközi, Márk; Földes, Enikő; Pukánszky, Béla

    2016-01-15

    Halloysite nanotubes used as potential carrier material for a controlled release stabilizer in polyethylene were thoroughly characterized with several techniques including the measurement of specific surface area, pore volume and surface energy. The high surface energy of the halloysite results in the strong bonding of the additive to the surface. Dissolution experiments carried out with eight different solvents for the determination of the effect of solvent characteristics on the amount of irreversibly bonded quercetin proved that adsorption and dissolution depend on competitive interactions prevailing in the system. Solvents with low polarity dissolve only surplus quercetin adsorbed in multilayers. Polyethylene is a very apolar polymer forming weak interactions with every substance; quercetin dissolves into it from the halloysite surface only above a critical surface coverage. Stabilization experiments confirmed that strong adhesion prevents dissolution and results in limited stabilization efficiency. At larger adsorbed amounts better stability and extended effect were measured indicating dissolution and controlled release. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Effect of surface water on tritium release behavior from Li4SiO4

    International Nuclear Information System (INIS)

    Hanada, T.; Fukada, S.; Nishikawa, M.; Suematsu, K.; Yamashita, N.; Kanazawa, T.

    2010-01-01

    The tritium release model to represent the release behavior of bred tritium from solid breeder materials has been developed by the blanket group of Kyushu University. It has been found that water is released to the purge gas from solid breeder materials and that this water affects the tritium release behavior. In this study, the amount of surface water released from Li 4 SiO 4 is quantified by the experiment. In addition, the tritium release behavior from Li 4 SiO 4 are estimated based on the tritium release model using parameters obtained in our studies under conditions of commercial reactor operation and ITER test blanket module operation. The effect of the surface water on tritium release behavior is discussed from the obtained results. Moreover, the tritium inventory of Li 4 SiO 4 is discussed based on calculation under the unsteady state condition. Further, the effects of grain size and temperature on distribution of tritium inventory under the steady state condition are evaluated, and the optimal grain size is discussed from the view point of tritium release from Li 4 SiO 4 .

  17. Preparation of hydroxypropyl cyclosophoraose/dextran microspheres for the controlled release of ciprofloxacin

    International Nuclear Information System (INIS)

    Lee, Benel; Jeong, Da Ham; Joo, Sang Woo; Choi, Jae Min; Jung, Seung Ho; Cho, Eun Na; Lee, Jae Yung; Park, Se Yeon

    2016-01-01

    Hydroxypropyl cyclosophoraose/dextran (HPCys/dextran) microspheres were prepared using an emulsion polymerization method for use as drug carriers to achieve the controlled release of a poorly water-soluble antibacterial drug, ciprofloxacin (CFX). Cyclosophoraoses are cyclic (1 → 2)-β-d-glucans isolated from the Rhizobium species. Characteristics of HPCys/dextran microspheres were investigated using Fourier transform infrared analysis, solid-state 13C nuclear magnetic resonance spectroscopy, and field emission scanning electron microscopy. The amount of CFX released from these microspheres at pH 7.4 (intestinal phase pH) was about two times higher than that released at pH 1.2 (gastric phase pH). Furthermore, HPCys/dextran microspheres did not show any toxicity in human embryonic kidney cells. We propose that HPCys/dextran microspheres could be used as an effective pH-dependent release system for poorly water-soluble drugs such as CFX

  18. Preparation of hydroxypropyl cyclosophoraose/dextran microspheres for the controlled release of ciprofloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Benel; Jeong, Da Ham; Joo, Sang Woo; Choi, Jae Min; Jung, Seung Ho; Cho, Eun Na [Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul (Korea, Republic of); Lee, Jae Yung [Dept. Biological Science, Mokpo National University, Mokpo (Korea, Republic of); Park, Se Yeon [Dept. Applied Chemistry, Dongduk Women' s University, Seoul (Korea, Republic of)

    2016-12-15

    Hydroxypropyl cyclosophoraose/dextran (HPCys/dextran) microspheres were prepared using an emulsion polymerization method for use as drug carriers to achieve the controlled release of a poorly water-soluble antibacterial drug, ciprofloxacin (CFX). Cyclosophoraoses are cyclic (1 → 2)-β-d-glucans isolated from the Rhizobium species. Characteristics of HPCys/dextran microspheres were investigated using Fourier transform infrared analysis, solid-state 13C nuclear magnetic resonance spectroscopy, and field emission scanning electron microscopy. The amount of CFX released from these microspheres at pH 7.4 (intestinal phase pH) was about two times higher than that released at pH 1.2 (gastric phase pH). Furthermore, HPCys/dextran microspheres did not show any toxicity in human embryonic kidney cells. We propose that HPCys/dextran microspheres could be used as an effective pH-dependent release system for poorly water-soluble drugs such as CFX.

  19. Interaction between fed and gastric media (ensure Plus) and different hypromellose based caffeine controlled release tablets; comparison and mechanistic study of caffeine release in fed and fasted media versus water using USP dissolution apparatus 3

    DEFF Research Database (Denmark)

    Franek, Frans; Holm, Per; Larsen, Frank

    2014-01-01

    , which decreases erosion rate in 100 mPa s viscosity tablets, swelling in 15,000 mPa s viscosity tablets and caffeine release from both tablets. This observed interaction between Ensure Plus® and the HPMC tablets may translate into decreased drug release rate in the fed stomach, which may decrease...... using factorial designed experiments. Furthermore, the mechanism of release in Ensure Plus®, a nutrition drink similar in composition to the FDA standard meal, was investigated by studying tablet swelling using texture analysis. Altering dip speed has negligible effect on release and erosion rates...... the amount of drug available for absorption in the small intestine and thus reduce systemic drug exposure and maximum plasma concentration....

  20. Participation of irradiated Anopheles arabiensis males in swarms following field release in Sudan

    International Nuclear Information System (INIS)

    Ageep, Tellal B; Alsharif, Bashir; Ahmed, Ayman; Salih, Elwaleed HO; Ahmed, Fayez TA; El Sayed, Badria B; Damiens, David; Gilles, Jeremie RL; Lees, Rosemary S; Diabaté, Abdoulaye

    2015-01-01

    BACKGROUND: The success of the SIT depends on the; release of large numbers of sterile males, which are able to; compete for mates with the wild male population within the; target area. The processes of colonisation, mass production; and irradiation may reduce the competitiveness of sterile; males through genetic selection, loss of natural traits and; somatic damage. In this context, the capacity of released; sterile Anopheles arabiensis males to survive, disperse and; participate in swarms occurring at varying distances from; the release site was studied using mark-release-recapture; techniques.; METHODS: In order to assess their participation in; swarms, irradiated and marked laboratory-reared male; mosquitoes were released 50, 100 or 200 m from the; known site of a large swarm on three consecutive nights.; Males were collected from this large swarm on subsequent; nights. Over the three days a total of 8,100 males were released.; Mean distance travelled (MDT), daily probability of; survival and estimated population size were calculated; from the recapture data. An effect of male age at the time; of release on these parameters was observed.; RESULTS: Five per cent of the males released over three; days were recaptured. In two-, three- and four-day-old; males, MDT was 118, 178 and 170 m, and the daily survival; probability 0.95, 0.90 and 0.75, respectively. From the; recapture data on the first day following each release, the; Lincoln index gives an estimation of 32,546 males in the; natural population.; DISCUSSION: Sterile An. arabiensis males released into; the field were able to find and participate in existing; swarms, and possibly even initiate swarms. The survival; probability decreased with the age of male on release but; the swarm participation and the distance travelled by older; males seemed higher than for younger males. The inclusion; of a pre-release period may thus be beneficial to male competitiveness; and increase the attractiveness of adult sexing

  1. Requirements for controlling a repository's releases of carbon-14 dioxide; the high costs and negligible benefits

    International Nuclear Information System (INIS)

    Park, U Sun; Pflum, C.G.

    1990-01-01

    A repository excavated within the unsaturated zone may release carbon (C)-14 dioxide in amounts that exceed limits imposed by the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC). The release would not threaten the general population, but may expose some hypothetical maximally exposed individual to 0.0005 millirems/year. Yet a repository's releases of C-14 dioxide are strictly regulated, perhaps unintentionally. The EPA and NRC regulations could force the Department of Energy to design and fabricate an expensive 10,000-year waste package solely for the sake of controlling releases of C-14 dioxide. This paper argues that the repository regulations should exempt releases of C-14 dioxide or at least impose more equitable limits. 21 refs., 1 tab

  2. Increasing potassium (K release from K-containing minerals in the presence of insoluble phosphate by bacteria

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Sarikhani

    2016-03-01

    Full Text Available Introduction: Phosphorus and potassium are major essential macronutrients for biological growth and development. Application of soil microorganisms is one approach to enhance crop growth. Some bacteria are efficient in releasing K and solubilizing P from mineral sources but their behavior was not studied more in presence together. Materials and methods: In this study the ability of seven bacterial strains, including Pseudomonas putida P13, P. putida Tabriz, P. fluorescens Tabriz, P. fluorescens Chao, Pantoea agglomerans P5, Azotobacter sp. and Bacillus megaterium JK3 to release mineral K from muscovite and biotite with application of insoluble (Ca3(PO42 or soluble (Na2HPO4 P-sources was investigated. Nutrient Broth was used to prepare an overnight culture of bacteria to inoculate in Aleksandrov medium, which was used to study the dissolution of silicate minerals. It should be mentioned that Aleksandrov medium was used to determine the amount of released P from tricalcium phosphate (TCP while muscovite was added to the medium as a sole source of potassium. Concentration of P was determined spectrophotometrically by ammonium-vanadate-molybdate method and K was determined by flame photometry. Results: The insoluble P-source led to a significantly increased released K into assay medium (66%, and the net release of K from the biotite was significantly enhanced. Among bacterial strains, the highest mean of released K was observed with P. putida P13 which released more K (27% than the control. The amounts of released K from micas in the presence of insoluble and soluble phosphate by P. putida P13 were 8.25 and 4.87 mg/g, respectively. Discussion and conclusion: Application of insoluble phosphate could increase K release from mica minerals. The enhanced releasing of mineral K might be attributed to the release of organic acids from the bacteria, a mechanism which plays a pivotal role in solubilizing phosphate from inorganic source of phosphate.

  3. Effect of Nisin's Controlled Release on Microbial Growth as Modeled for Micrococcus luteus.

    Science.gov (United States)

    Balasubramanian, Aishwarya; Lee, Dong Sun; Chikindas, Michael L; Yam, Kit L

    2011-06-01

    The need for safe food products has motivated food scientists and industry to find novel technologies for antimicrobial delivery for improving food safety and quality. Controlled release packaging is a novel technology that uses the package to deliver antimicrobials in a controlled manner and sustain antimicrobial stress on the targeted microorganism over the required shelf life. This work studied the effect of controlled release of nisin to inhibit growth of Micrococcus luteus (a model microorganism) using a computerized syringe pump system to mimic the release of nisin from packaging films which was characterized by an initially fast rate and a slower rate as time progressed. The results show that controlled release of nisin was strikingly more effective than instantly added ("formulated") nisin. While instant addition experiments achieved microbial inhibition only at the beginning, controlled release experiments achieved complete microbial inhibition for a longer time, even when as little as 15% of the amount of nisin was used as compared to instant addition.

  4. Dilaton field released under collision of dilatonic black holes with Gauss-Bonnet term

    Energy Technology Data Exchange (ETDEWEB)

    Gwak, Bogeun [Sejong University, Department of Physics and Astronomy, Seoul (Korea, Republic of); Ro, Daeho [POSTECH, Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk (Korea, Republic of)

    2017-08-15

    We investigate the upper limit of the gravitational radiation released upon the collision of two dilatonic black holes by analyzing the Gauss-Bonnet term. Dilatonic black holes have a dilaton hair coupled with this term. Using the laws of thermodynamics, the upper limit of the radiation is obtained, which reflected the effects of the dilaton hair. The amount of radiation released is greater than that emitted by a Schwarzschild black hole due to the contribution from the dilaton hair. In the collision, most of the dilaton hair can be released through radiation, where the energy radiated by the dilaton hair is maximized when the horizon of one black hole is minimized for a fixed second black hole. (orig.)

  5. Overview study of LNG release prevention and control systems

    Energy Technology Data Exchange (ETDEWEB)

    Pelto, P.J.; Baker, E.G.; Holter, G.M.; Powers, T.B.

    1982-03-01

    The liquefied natural gas (LNG) industry employs a variety of release prevention and control techniques to reduce the likelihood and the consequences of accidental LNG releases. A study of the effectiveness of these release prevention and control systems is being performed. Reference descriptions for the basic types of LNG facilities were developed. Then an overview study was performed to identify areas that merit subsequent and more detailed analyses. The specific objectives were to characterize the LNG facilities of interest and their release prevention and control systems, identify possible weak links and research needs, and provide an analytical framework for subsequent detailed analyses. The LNG facilities analyzed include a reference export terminal, marine vessel, import terminal, peakshaving facility, truck tanker, and satellite facility. A reference description for these facilities, a preliminary hazards analysis (PHA), and a list of representative release scenarios are included. The reference facility descriptions outline basic process flows, plant layouts, and safety features. The PHA identifies the important release prevention operations. Representative release scenarios provide a format for discussing potential initiating events, effects of the release prevention and control systems, information needs, and potential design changes. These scenarios range from relatively frequent but low consequence releases to unlikely but large releases and are the principal basis for the next stage of analysis.

  6. Study of BSA protein adsorption/release on hydroxyapatite nanoparticles

    Science.gov (United States)

    Swain, Sanjaya Kumar; Sarkar, Debasish

    2013-12-01

    Three different spherical, rod and fibrous morphologies of hydroxyapatite (HA) nanoparticles have been prepared through control over the processing parameters like temperature, pH and Ca:P ratio. Protein adsorption/release with respect to HA nanoparticle morphologies are investigated using model protein bovine serum albumin (BSA). BSA adsorption on HA nanoparticles follows Langmuir adsorption isotherm. Thermal analysis and FT-IR spectrum confirms the BSA adhesion and retention of their secondary structure. High surface area with high Ca:P ratio nanorod adsorbs relatively more amount (28 mg BSA/gm of nanorod HA) of BSA within 48 h in comparison with counterpart fibroid and spherical morphologies. Slow and steady BSA release (75 wt% of adsorbed BSA in 96 h) from nanorod HA is found as futuristic drug delivery media.

  7. Improvement in energy release properties of boron-based propellant by oxidant coating

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Daolun; Liu, Jianzhong, E-mail: jzliu@zju.edu.cn; Chen, Binghong; Zhou, Junhu; Cen, Kefa

    2016-08-20

    Highlights: • NH{sub 4}ClO{sub 4}, KNO{sub 3}, KClO{sub 4} and HMX coated B were used to prepare propellant samples. • FTIR, XRD and SEM were used for the microstructure analysis of the prepared B. • Thermal oxidation and combustion characteristics of the propellants were studied. • HMX coating was the most beneficial to the energy release of the samples. - Abstract: The energy release properties of a propellant can be improved by coating boron (B) particles with oxidants. In the study, B was coated with four different oxidants, namely, NH{sub 4}ClO{sub 4}, KNO{sub 3}, LiClO{sub 4}, and cyclotetramethylenetetranitramine (HMX), and the corresponding propellant samples were prepared. First, the structural and morphological analyses of the pretreated B were carried out. Then, the thermal analysis and laser ignition experiments of the propellant samples were carried out. Coating with NH{sub 4}ClO{sub 4} showed a better performance than mechanical mixing with the same component. Coating with KNO{sub 3} efficiently improved the ignition characteristics of the samples. Coating with LiClO{sub 4} was the most beneficial in reducing the degree of difficulty of B oxidation. Coating with HMX was the most beneficial in the heat release of the samples. The KNO{sub 3}-coated sample had a very high combustion intensity in the beginning, but then it rapidly became weak. Large amounts of sparks were ejected during the combustion of the LiClO{sub 4}-coated sample. The HMX-coated sample had the longest self-sustaining combustion time (4332 ms) and the highest average combustion temperature (1163.92 °C).

  8. Investigation of Released Cadmium and Lead from Different Colors of Over Glaze Designs to Food Stuff in Different Conditions

    Directory of Open Access Journals (Sweden)

    H. Hashemi-Moghaddam

    2012-03-01

    Full Text Available In this paper, leaching of lead and cadmium was investigated from porcelain over glaze designs between different colors.  Also the effect of microwave heating was considered on leaching of lead and cadmium.  Dishes were selected with a decor with the dominant color of gray, red, yellow, blue, and dark blue. Amounts of cadmium and lead which leached from the container by acetic acid and orange juice were measured according to the standard ASTM C738.  The results showed that especially in the red and dark blue colors cadmium and lead could be released easily by either acetic acid or orange juice, and these amounts were much higher than the permissible standard amount. Also microwave heating could enhance releasing of lead and cadmium from decorated dinnerware. 

  9. Studies on Fragrance Delivery from Inorganic Nanocontainers: Encapsulation, Release and Modeling Studies

    Science.gov (United States)

    Ghodke, Shailesh Adinath; Sonawane, Shirish Hari; Bhanvase, Bharat Apparao; Mishra, Satyendra; Joshi, Kalpana Shrikant

    2015-04-01

    The present work deals with encapsulation of fragrance molecule in inorganic nanocontainers substrate and investigation of its prolonged release at different pH condition. The nanocontainers used were aluminosilicate clay (Halloysite) having cylindrical shape with outside diameter in the range of 30-50 nm, 15 nm lumen and length equal to 800 ± 300 nm. Rosewater absolute was used as a sample fragrance for loading in nanocontainer and delivery purpose. The fragrance loaded nanocontainers were coated with a thin layer of polyelectrolyte i.e. Polyacrylic Acid (PAA). The structural characteristics of prepared nanocontainers were determined by using Fourier Transform Intra-red Spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA) and UV spectroscopy analysis. Release of fragrance molecules in the aqueous medium was monitored for 24 h. The fragrance release was found to be responsive as the amount of fragrance release increases with increase in pH value from 3 to 7. Fragrance release has been studied by using various permeation kinetic models such as zero order, first order, Hixson-Crowell, Higuchi, Korsmeyer-Peppas and Hopfenberg models. Korsemyer-Peppas shows the best fit (R2 = 0.9544) compared to other kinetic model for the release of fragrance from nanocontainers.

  10. In vitro release of metformin hydrochloride from sodium alginate/polyvinyl alcohol hydrogels.

    Science.gov (United States)

    Martínez-Gómez, Fabián; Guerrero, Juan; Matsuhiro, Betty; Pavez, Jorge

    2017-01-02

    Hydrogels, based on polysaccharides have found a number of applications as drug delivery carriers. In this work, hydrogels of full characterized sodium alginate (Mn 87,400g/mol) and commercial poly(vinyl alcohol) (PVA) sensitive to pH and temperature stimuli were obtained using a simple, controlled, green, low cost method based on freeze-thaw cycles. Stable hydrogels of sodium alginate/PVA with 0.5:1.5 and 1.0:1.0w/v concentrations showed very good swelling ratio values in distilled water (14 and 20g/g, respectively). Encapsulation and release of metformin hydrochloride in hydrogels of 1.0:1.0w/v sodium alginate/PVA was followed by UV spectroscopy. The hydrogel released a very low amount of metformin hydrochloride at pH 1.2; the highest release value (55%) was obtained after 6h at pH 8.0. Also, the release of metformin hydrochloride was studied by 1 H NMR spectroscopy, the temporal evolution of methyl group signals of metformin showed 30% of drug release after 3h. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Modelling of motorway tunnels scenario for utilization of conditionally released radioactive materials

    International Nuclear Information System (INIS)

    Hrncir, Tomas; Panik, Michal; Necas, Vladimir

    2011-01-01

    Considerable amount of solid radioactive waste with radioactivity slightly above the limits for unconditional release is generated during the decommissioning of the nuclear installations. Conditional release deals with precisely this type of materials with activity slightly above limits in order to save considerable financial resources, which would be otherwise spend on treatment, conditioning and disposal of these materials at appropriate repository. The basic principles of conditional release as well as possibilities of reusing of the conditionally released materials are described. One of these possibilities of the reusing was chosen and application proposal of conditional release of metal waste - steel reinforcement in the concrete, which could be used for construction of motorway tunnels, was created. The computer code Visiplan 4.0 3D ALARA planning tool software was used for the calculation of effective individual dose for personnel constructing the tunnel and for critical group related to scenario. Particular models for individual scenarios of conditional release have been developed within the scope of this software code. The aim of the paper is to determine a level of the radioactivity of conditional released materials to avoid over exceeding the value of annual individual effective dose 10μSv/year established by international recommendations. (author)

  12. Quantification of nanoparticle release from polymer nanocomposite coatings due to environmental stressing.

    Science.gov (United States)

    Kim, Yeon Seok; Davis, Rick; Uddin, Nasir; Nyden, Marc; Rabb, Savelas A

    2016-01-01

    Certain engineered nanoparticles (ENP) reduce the flammability of components used in soft furnishings (mattresses and upholstered furniture). However, because of the ENP's small size and ability to interact with biological molecules, these fire retardant ENPs may pose a health and environmental risks, if they are released sometime during the life cycle of the soft furnishing. Quantifying the released amount of these ENPs under normal end-use circumstances provides a basis for assessing their potential health and environmental impact. In this article, we report on efforts to identify suitable methodologies for quantifying the release of carbon nanofibers, carbon nanotubes, and sodium montmorillonites from coatings applied to the surfaces of barrier fabric and polyurethane foam. The ENPs released in simulated chewing and mechanical stressing experiments were collected in aqueous solution and quantified using Ultraviolet-Visible and inductively coupled plasma-optical emission spectroscopy. The microstructures of the released ENPs were characterized using scanning electron microscopy. The reported methodology and results provide important milestones to estimate the impact and toxicity of the ENP release during the life cycle of the nanocomposites. To our knowledge, this is the first study of ENP release from the soft furnishing coating, something that can be important application area for fire safety.

  13. Synthesis and characterization of superabsorbent polymer prepared by radiation-induced graft copolymerization of acrylamide onto carboxymethyl cellulose for controlled release of agrochemicals

    Science.gov (United States)

    Hemvichian, Kasinee; Chanthawong, Auraruk; Suwanmala, Phiriyatorn

    2014-10-01

    Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N‧-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO3) as an agrochemical model and its potential for controlled release of KNO3 was studied. The amount of released KNO3 was analyzed by an inductively coupled plasma mass spectrometry (ICP-MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190 g/g of dry gel.

  14. Artificial saliva effect on toxic substances release from acrylic resins

    Directory of Open Access Journals (Sweden)

    Kostić Milena

    2015-01-01

    Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

  15. In-reactor measurements of thermo mechanical behaviour and fission gas release of water reactor fuel

    International Nuclear Information System (INIS)

    Kolstad, E.; Vitanza, C.

    1983-01-01

    the fuel performance during and after a power ramp can be investigated by direct in-pile measurements related to the thermal, mechanical and fission gas release behaviour. The thermal response is examined by thermocouples placed at the centre of the fuel. Such measurements allow the determination of thermal feedback effects induced by the simultaneous liberation of fission gases. The thermal feedback effect is also being separately studied out-of-pile in a specially designed rod where the fission gas release is simulated by injecting xenon in known quantities at different axial positions within the rod. Investigations on the mechanical behaviour are based on axial and diametral cladding deformation measurements. This enables the determination of the amount of local cladding strain and ridging during ramping, the extent of relaxation during the holding time and the amount of residual (plastic) deformation. Gap width measurements are also performed in operating fuel rods using a cladding deflection technique. Fission gas release data are obtained, besides from post-irradiation puncturing, by continuous measurements of the rod internal pressure. This type of measurement leads to the description of the kinetics of the fission gas release process at different powers. The data tend to indicate that the time-dependent release can be reasonably well described by simple diffusion. The paper describes measuring techniques developed and currently in use in Halden, and presents and discusses selected experimental results obtained during various power ramps and transients. (author)

  16. Identification of the algal dimethyl sulfide-releasing enzyme: A missing link in the marine sulfur cycle

    Science.gov (United States)

    Alcolombri, Uria; Ben-Dor, Shifra; Feldmesser, Ester; Levin, Yishai; Tawfik, Dan S.; Vardi, Assaf

    2015-06-01

    Algal blooms produce large amounts of dimethyl sulfide (DMS), a volatile with a diverse signaling role in marine food webs that is emitted to the atmosphere, where it can affect cloud formation. The algal enzymes responsible for forming DMS from dimethylsulfoniopropionate (DMSP) remain unidentified despite their critical role in the global sulfur cycle. We identified and characterized Alma1, a DMSP lyase from the bloom-forming algae Emiliania huxleyi. Alma1 is a tetrameric, redox-sensitive enzyme of the aspartate racemase superfamily. Recombinant Alma1 exhibits biochemical features identical to the DMSP lyase in E. huxleyi, and DMS released by various E. huxleyi isolates correlates with their Alma1 levels. Sequence homology searches suggest that Alma1 represents a gene family present in major, globally distributed phytoplankton taxa and in other marine organisms.

  17. Simultaneous measurement of hormone release and secretagogue binding by individual pituitary cells

    International Nuclear Information System (INIS)

    Smith, P.F.; Neill, J.D.

    1987-01-01

    The quantitative relationship between receptor binding and hormone secretion at the single-cell level was investigated in the present study by combining a reverse hemolytic plaque assay for measurement of luteinizing hormone (LH) secretion from individual pituitary cells with an autoradiographic assay of 125 I-labeled gonadontropin-releasing hormone (GnRH) agonist binding to the same cells. In the plaque assay, LH secretion induces complement-mediated lysis of the LH-antibody-coated erythrocytes around the gonadotropes, resulting in areas of lysis (plaques). LH release from individual gonadotropes was quantified by comparing radioimmunoassayable LH release to hemolytic area in similarly treated cohort groups of cells; plaque area was linearly related to the amount of LH secreted. Receptor autoradiography was performed using 125 I-labeled GnRH-A (a superagonist analog of GnRH) both as the ligand and as the stimulant for LH release in the plaque assay. The grains appeared to represent specific and high-affinity receptors for GnRH because (i) no pituitary cells other than gonadotropes bound the labeled ligand and (ii) grain development was progressively inhibited by coincubation with increasing doses of unlabeled GnRH-A. The authors conclude that GnRH receptor number for any individual gonadotrope is a weak determinant of the amount of LH it can secrete; nevertheless, full occupancy of all its GnRH receptors is required for any gonadotrope to reach its full LH-secretory capacity. Apparently the levels of other factors comprising the steps along the secretory pathway determine the secretory capacity of an individual cell

  18. Pre-Release Consumption of Methyl Eugenol Increases the Mating Competitiveness of Sterile Males of the Oriental Fruit Fly, Bactrocera dorsalis, in Large Field Enclosures

    Science.gov (United States)

    Shelly, Todd E.; Edu, James; McInnis, Donald

    2010-01-01

    The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1–4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost

  19. Simulating the Fate and Transport of an Acid Mine Drainage Release

    Science.gov (United States)

    On August 5, 2015, approximately 3 million gallons of acid mine drainage were released from the Gold King Mine into Cement Creek in the San Juan River watershed (CO, NM, UT). The release further mobilized additional metals, which resulted in a large mass of solids and dissolved m...

  20. Influence of bracket-slot design on the forces released by superelastic nickel-titanium alignment wires in different deflection configurations.

    Science.gov (United States)

    Nucera, Riccardo; Gatto, Elda; Borsellino, Chiara; Aceto, Pasquale; Fabiano, Francesca; Matarese, Giovanni; Perillo, Letizia; Cordasco, Giancarlo

    2014-05-01

    To evaluate how different bracket-slot design characteristics affect the forces released by superelastic nickel-titanium (NiTi) alignment wires at different amounts of wire deflection. A three-bracket bending and a classic-three point bending testing apparatus were used to investigate the load-deflection properties of one superelastic 0.014-inch NiTi alignment wire in different experimental conditions. The selected NiTi archwire was tested in association with three bracket systems: (1) conventional twin brackets with a 0.018-inch slot, (2) a self-ligating bracket with a 0.018-inch slot, and (3) a self-ligating bracket with a 0.022-inch slot. Wire specimens were deflected at 2 mm and 4 mm. Use of a 0.018-inch slot bracket system, in comparison with use of a 0.022-inch system, increases the force exerted by the superelastic NiTi wires at a 2-mm deflection. Use of a self-ligating bracket system increases the force released by NiTi wires in comparison with the conventional ligated bracket system. NiTi wires deflected to a different maximum deflection (2 mm and 4 mm) release different forces at the same unloading data point (1.5 mm). Bracket design, type of experimental test, and amount of wire deflection significantly affected the amount of forces released by superelastic NiTi wires (Pwire's load during alignment.

  1. Amounts of NPK removed from soil in harvested coffee berries as ...

    African Journals Online (AJOL)

    Monthly samples of ripened improved robusta coffee berries from compact and large growth forms from three locations, which are representative of the main ecological zones where coffee is grown in Ghana, were taken for 3 years. The pulp and parchment and beans were analysed for N, P and K contents. The amounts of ...

  2. Synthesis of copolymers suitable for the storage and slow release of reactants. Cases of copper salts for intra-uterine devices

    International Nuclear Information System (INIS)

    Gaussens, Gilbert; Duchemin-Berthet, Jeanne.

    1976-01-01

    This research has been carried out to determine whether a grafted poly(ethylene-vinyl acetate) matrix could be prepared which would release useful amounts of copper salts when used in intra-uterine devices. Intra-uterine devices were prepared by grafting hydroxyethyl acrylate onto ethylene-vinylacetate copolymers (EVA). The kinetics of the grafting reaction were studied. The grafting reaction was initiated by cobalt 60 gamma rays using the simultaneous method. The conditions of copper salts absorption by the grafted copolymers were selected. The average quantity of copper salts released daily from the intra-uterine device was meaured as a function of grafting ratio and the amount of copper salt initially incorporated in the grafted polymeric matrix. In vitro experiments samples showed constant release rates during a period of 18 months

  3. Predator response to releases of American shad larvae in the Susquehanna River basin

    Science.gov (United States)

    Johnson, James H.; Ringler, N.H.

    1998-01-01

    Predation on American shad (Alosa sapidissima) larvae within the first two hours of release was examined from 1989 to 1992 on 31 occasions at stocking sites in the Susquehanna River basin. Twenty-two fish species consumed shad larvae; the dominant predators were spotfin shiner (Cyprinella spiloptera), mimic shiner (Notropis volucellus) and juvenile smallmouth bass (Micropterus dolomieu). The number of shad larvae found in predator stomachs ranged from 0 to 900. Mortality of shad larvae at the stocking site was usually less than 2%. The greatest mortality (9.6%) occurred at the highest stocking level (1.5 million larvae). Highly variable predation rates and release levels of shad insufficient to achieve predator satiation hindered the ability to determine a specific type of functional response of predators. Predator numbers increased with stocking density, indicating short-term aggregation at the release site. Because of practical problems associated with releasing the large numbers of larvae that would be required to satiate predators, routine stocking at these levels is probably unreasonable. Releases of 400,000 to 700,000 larvae may reduce predation by offsetting depensatory mechanisms that operate on small releases and the effects of increased predation due to predator aggregation on large releases. Night stocking may reduce predation on larval shad at the release site.

  4. Development and evaluation of sustained release losartan potassium matrix tablet using kollidon SR as release retardant

    Directory of Open Access Journals (Sweden)

    Shahid Sarwar

    2012-12-01

    Full Text Available The present study was undertaken to develop sustained release (SR matrix tablets of losartan potassium, an angiotensin-II antagonist for the treatment of hypertension. The tablets were prepared by direct compression method, along with Kollidon SR as release retardant polymer. The amount of losartan potassium remains fixed (100 mg for all the three formulations whereas the amounts of Kollidon SR were 250 mg, 225 mg, and 200 mg for F-1, F-2, and F-3 respectively. The evaluation involves three stages: the micromeritic properties evaluation of granules, physical property studies of tablets, and in-vitro release kinetics studies. The USP apparatus type II was selected to perform the dissolution test, and the dissolution medium was 900 mL phosphate buffer pH 6.8. The test was carried out at 75 rpm, and the temperature was maintained at 37 ºC ± 0.5 ºC. The release kinetics was analyzed using several kinetics models. Higher polymeric content in the matrix decreased the release rate of drug. At lower polymeric level, the rate and extent of drug release were enhanced. All the formulations followed Higuchi release kinetics where the Regression co-efficient (R² values are 0.958, 0.944, and 0.920 for F-1, F-2, and F-3 respectively, and they exhibited diffusion dominated drug release. Statistically significant (PO presente estudo foi realizado para desenvolver (SR matriz de comprimidos de liberação sustentada de losartana, um antagonista da angiotensina II, para o tratamento da hipertensão arterial. Os comprimidos foram preparados pelo método de compressão direta com Kollidon SR como polímero de liberação lenta. A quantidade de losartana potássica permanece fixa (100 mg para todas as três formulações enquanto que as quantidades de Kollidon SR foram de 250 mg, 225 mg e 200 mg para F-1, F-2 e F-3, respectivamente. A avaliação envolve três etapas- propriedades micromeríticas dos grânulos, estudo das propriedades físicas dos comprimidos e

  5. Prolactin, thyrotropin, and growth hormone release during stress associated with parachute jumping.

    Science.gov (United States)

    Noel, G L; Dimond, R C; Earll, J M; Frantz, A G

    1976-05-01

    Prolactin, growth hormone, and thyrotropin (TSH) release during the stress of parachute jumping has been evaluated in 14 male subjects. Subjects were studied at several times before and immediately after their first military parachute jump. All three hormones had risen significantly 1 to 14 min after the jump, compared to mean levels measured immediately beforehand. Earlier studies of physical exercise by ourselves and others would suggest that emotional stress played a role in producing changes of this magnitude. We conclude that prolactin, TSH, and growth hormone are released in physiologically significant amounts in association with the stress of parachute jumping.

  6. Environmental pH-controlled loading and release of protein on mesoporous hydroxyapatite nanoparticles for bone tissue engineering.

    Science.gov (United States)

    Zhang, Ning; Gao, Tianlin; Wang, Yu; Wang, Zongliang; Zhang, Peibiao; Liu, Jianguo

    2015-01-01

    To explore the controlled delivery of protein drugs in micro-environment established by osteoblasts or osteoclasts, the loading/release properties of bovine serum albumin (BSA) depending on pH environment were assessed. The adsorption amounts over mesoporous hydroxyapatite (MHA) or hydroxyapatite (HA) decreased as the pH increased, negatively correlating with zeta-potential values. The adsorption behavior over MHA fits well with the Freundlich and Langmuir models at different pHs. The results suggest that the adsorbed amount of protein on MHA or HA depended on the pH of protein solution. MHA adsorbed BSA at basic pH (MHApH 8.4) exhibited a different release kinetics compared with those in acid and neutral environments (MHApH 4.7 and MHApH 7.4), indicating that the release of protein could be regulated by environmental pH at which MHAs adsorb protein. MHApH 8.4 showed a sustained release for 6h before a gradual release when immersing in acidic environment, which is 2h longer than that in neutral environment. This suggests that MHApH 8.4 showed a more sustained release in acidic environment, which can be established by osteoclasts. The variation of adsorption strength between protein and MHA may be responsible for these behaviors. Our findings may be very useful for the development of MHA applications on both bone repair and protein delivery. Copyright © 2014. Published by Elsevier B.V.

  7. The Role of Organic Acids on the Release of Phosphorus and Zinc in a Calcareous Soil

    Directory of Open Access Journals (Sweden)

    Sareh Nezami

    2017-02-01

    Full Text Available Introduction: Phosphorus (P and zinc (Zn fixation by soil minerals and their precipitation is one of the major constraints for crop production in calcareous soils. Recent Studies show that root exudates are effective for the extraction of the large amounts of nutrients in calcareous soils. A part of the root exudations are Low Molecular Weight Organic Acids (LMWOAs. LMWOAs are involved in the nutrients availability and uptake by plants, nutrients detoxification, minerals weathering and microbial proliferation in the soil. At nutrients deficiency conditions citric and oxalic acids are released by plants root in large quantities and increase nutrient solubility like P, Zn, Fe, Mn and Cu in the rhizosphere. These components are the large portion of the carbon source in the soil after exudations are mineralized by microorganisms, quickly. In addition, soil surface sorption can affect their half-life and other behaviors in the soil. In order to study the effect of oxalic and citric organic acids on the extraction of phosphorus and zinc from a calcareous soil, an experiment was conducted. Materials and Methods: Studied soil was calcareous and had P and Zn deficiency. Soil sample was collected from A horizon (0-30 cm of Damavand region. 3 g of dried soil sample was extracted with 30 ml of oxalic and citric acids extraction solutions at different concentrations (0.1, 1 and 10 mM and different time periods (10, 60, 180 and 360 minutes on an orbital shaker at 200 rev min-1.The soil extracts then centrifuged for 10 minutes (16000g. After filtering, the pH of the extractions was recorded and then phosphorus, calcium and zinc amounts were determined. Soil extraction with distilled water was used as control. Each treatment was performed in 3 replications. Statistical analysis was performed with ANOVA test followed by the Bonferroni method significant level adjustments due to multiple comparisons. Results and Discussion: The results of variance analysis showed

  8. Building an Efficient Model for Afterburn Energy Release

    Energy Technology Data Exchange (ETDEWEB)

    Alves, S; Kuhl, A; Najjar, F; Tringe, J; McMichael, L; Glascoe, L

    2012-02-03

    Many explosives will release additional energy after detonation as the detonation products mix with the ambient environment. This additional energy release, referred to as afterburn, is due to combustion of undetonated fuel with ambient oxygen. While the detonation energy release occurs on a time scale of microseconds, the afterburn energy release occurs on a time scale of milliseconds with a potentially varying energy release rate depending upon the local temperature and pressure. This afterburn energy release is not accounted for in typical equations of state, such as the Jones-Wilkins-Lee (JWL) model, used for modeling the detonation of explosives. Here we construct a straightforward and efficient approach, based on experiments and theory, to account for this additional energy release in a way that is tractable for large finite element fluid-structure problems. Barometric calorimeter experiments have been executed in both nitrogen and air environments to investigate the characteristics of afterburn for C-4 and other materials. These tests, which provide pressure time histories, along with theoretical and analytical solutions provide an engineering basis for modeling afterburn with numerical hydrocodes. It is toward this end that we have constructed a modified JWL equation of state to account for afterburn effects on the response of structures to blast. The modified equation of state includes a two phase afterburn energy release to represent variations in the energy release rate and an afterburn energy cutoff to account for partial reaction of the undetonated fuel.

  9. Combustion heat release effects on asymmetric vortex shedding from bluff bodies

    Science.gov (United States)

    Cross, Caleb Nathaniel

    2011-07-01

    reduced the temperature of the recirculating gases further, resulting in large (i.e., near-unity) products-to-reactants density ratios in the near-wake. When the fuel was introduced upstream of the bluff body, the BVK heat release dynamics significantly decreased in amplitude. In this case the fuel was, in all likelihood, fully evaporated and well-mixed with the air prior to burning, resulting in greater amounts of fuel entrainment and subsequent heat release in the near-wake than in the close-coupled fuel injection case. In addition, the heat release was distributed more uniformly across the combustor span, which led to stronger density gradients across the near-wake reaction zone than in close-coupled-fuelled flames due to a lack of reactants entrainment into the recirculation zone. This enhanced the damping of vorticity due to dilatation, which inhibited the formation and shedding of the large-scale, coherent vortices. When the local density gradient was large enough, the BVK instability was completely suppressed. A parallel, linear stability analysis was performed in order to further understand the influence of the near-wake combustion process heat release upon the wake instability characteristics. The results of this analysis indicate that the products-to-reactants density and velocity ratios in the near-wake are the primary parameters controlling the onset of local absolute instability (a necessary condition for the global, BVK instability) in reacting wakes. Upon comparing these results to the measured data, absolute instability was predicted for all operating conditions in which relatively high-amplitude BVK heat release dynamics were observed. This was the case for close-coupled fuel injection at all global equivalence ratios, as well as upstream fuel injection at lean equivalence ratios, due to the low temperature rise across the reacting shear layers in these cases. Only upstream fuel injection at near stoichiometric fuel-air ratios resulted in local products

  10. The effect of loading solution and dissolution media on release of Diclofenac from ion exchange resins

    Directory of Open Access Journals (Sweden)

    "Atyabi F

    2002-07-01

    Full Text Available Drugs can be loaded on ion exchange resins in order to control their release. Loading of diclofenac sodium on the resin beads not only sustain its release but also reduce its gastrointestinal mucosal injury. In this study the effect of loading solution and concentration of diclofenac in loading solution on total amount of drug loaded on the resin beads (Amberlite IRA-900 and the release characteristic of drug in different media were examined. Results showed that diclofenac resin complex did not release their drug content in simulated gastric fluid but released it in simulated intestinal fluid independent of exposure time in acidic conditions. The effect of a number of parameters such as ionic strength and pH on the release characteristic of drug - resin complexes were also examined. Results showed that although ionic strength is an important factor, drug release is more affected by the pH of the media. NO ABSTRACT

  11. Boreal Forests Sequester Large Amounts of Mercury over Millennial Time Scales in the Absence of Wildfire.

    Science.gov (United States)

    Giesler, Reiner; Clemmensen, Karina E; Wardle, David A; Klaminder, Jonatan; Bindler, Richard

    2017-03-07

    Alterations in fire activity due to climate change and fire suppression may have profound effects on the balance between storage and release of carbon (C) and associated volatile elements. Stored soil mercury (Hg) is known to volatilize due to wildfires and this could substantially affect the land-air exchange of Hg; conversely the absence of fires and human disturbance may increase the time period over which Hg is sequestered. Here we show for a wildfire chronosequence spanning over more than 5000 years in boreal forest in northern Sweden that belowground inventories of total Hg are strongly related to soil humus C accumulation (R 2 = 0.94, p millennial time scales in the prolonged absence of fire.

  12. Limited contribution of permafrost carbon to methane release from thawing peatlands

    Science.gov (United States)

    Cooper, Mark D. A.; Estop-Aragonés, Cristian; Fisher, James P.; Thierry, Aaron; Garnett, Mark H.; Charman, Dan J.; Murton, Julian B.; Phoenix, Gareth K.; Treharne, Rachael; Kokelj, Steve V.; Wolfe, Stephen A.; Lewkowicz, Antoni G.; Williams, Mathew; Hartley, Iain P.

    2017-07-01

    Models predict that thaw of permafrost soils at northern high latitudes will release tens of billions of tonnes of carbon (C) to the atmosphere by 2100 (refs ,,). The effect on the Earth’s climate depends strongly on the proportion of this C that is released as the more powerful greenhouse gas methane (CH4), rather than carbon dioxide (CO2) (refs ,); even if CH4 emissions represent just 2% of the C release, they would contribute approximately one-quarter of the climate forcing. In northern peatlands, thaw of ice-rich permafrost causes surface subsidence (thermokarst) and water-logging, exposing substantial stores (tens of kilograms of C per square meter, ref. ) of previously frozen organic matter to anaerobic conditions, and generating ideal conditions for permafrost-derived CH4 release. Here we show that, contrary to expectations, although substantial CH4 fluxes (>20 g CH4 m-2 yr-1) were recorded from thawing peatlands in northern Canada, only a small amount was derived from previously frozen C (effect of permafrost thaw on CH4 emissions from northern peatlands.

  13. Release Mathematical Model of Active Agent from Packaging Material into Food

    Directory of Open Access Journals (Sweden)

    Xiuling Huang

    2013-01-01

    Full Text Available Active packaging is an innovative packaging technology by which active compounds are released from the package to enhance the quality and microbial safety for a wide range of foods. The problem of active ingredient release through the bilayer packaging food system is studied from a theoretical viewpoint. A release model is built to provide predictions of concentration and amount of active ingredient. The equations are built based on Fickian diffusion, and numerical solutions are obtained through finite difference. Different diffusion coefficients DP and DC of active ingredient in different packaging layers, partition coefficient kCP at the interface of outer layer and inner layer, partition coefficient kFC at the interface of inner layer and food, and mass transfer coefficient hm at the interface of inner layer and food are considered in the model. The effects of kCP, thicknesses of outer layer and inner layer, CP0, DP, DC, kFC, and hm on the release are discussed. Corresponding conclusions and analysis are given.

  14. Experiments to quantify airborne release from packages with dispersible radioactive materials under accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Martens, R.; Lange, F. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50667 Koeln (Germany); Koch, W.; Nolte, O. [Fraunhofer-Institut fuer Toxikologie und Experimentelle Medizin (ITEM), Nikolai-Fuchs-Str.1, 30625 Hannover (Germany)

    2005-07-01

    For transport or handling accidents involving packages with radioactive materials and the assessment of potential radiological consequences, for the review of current requirements of the IAEA Transport Regulations, and for their possible further development reliable release data following mechanical impact are required. Within this context a research project was carried out which extends the basis for a well-founded examination of the contemporary system of requirements of 'Low Specific Activity' (LSA)-type materials and allows for its further development where appropriate. This project comprises a prior system-analytical examination and an experimental programme aiming at improving the general physical understanding of the release process as well as the quantity and the characteristics of airborne released material for non-fixed dispersible LSA-II material upon mechanical impact. Impaction experiments applying small, medium and real sized specimens of different dispersible materials revealed that the release behaviour of dispersible powders strongly depends upon material properties, e.g. particle size distribution and cohesion forces. The highest experimentally determined release fraction of respirable mass (AED < 10 {mu}m) amounted to about 2 % and was obtained for 2 kg of un-contained easily dispersible pulverized fly ash (PFA). For larger un-contained PFA specimen the release fraction decreases. However, packaging containing powdery material substantially reduces the airborne release fraction. The measured airborne release fractions for a 200 l drum with Type A certificate containing PFA were about a factor of 50 to 100 lower than for un-contained material. For a drop height of 9 m the airborne release fraction amounted to about 4 x 10{sup -5}. This value should be applicable for most of transport and handling accidents with mechanical impact. For a metal container of Type IP-2 or better which contains powder masses of 100 kg or more this release

  15. [3H]Dopamine accumulation and release from striatal slices in young, mature and senescent rats

    International Nuclear Information System (INIS)

    Thompson, J.M.

    1981-01-01

    Examinations of [ 3 H]dopamine ([ 3 H]DA) release following KCl or amphetamine administration in striatal slices from young (7 month), mature (12 month) and senescent (24 month) Wistar rats showed no age-related changes. Further, the amount of [ 3 H]DA accumulated in the striatal slices showed no changes with age. Thus, previously reported age-related deficits in motor behavior (i.e. rotational) are not produced by changes in striatal DA accumulation or release. (Auth.)

  16. Deformation-induced release of ATP from erythrocytes in a poly(dimethylsiloxane)-based microchip with channels that mimic resistance vessels.

    Science.gov (United States)

    Price, Alexander K; Fischer, David J; Martin, R Scott; Spence, Dana M

    2004-08-15

    The ability of nitric oxide to relax smooth muscle cells surrounding resistance vessels in vivo is well documented. Here, we describe a series of studies designed to quantify amounts of adenosine triphosphate (ATP), a known stimulus of NO production in endothelial cells, released from erythrocytes that are mechanically deformed as these cells traverse microbore channels in lithographically patterned microchips. Results indicate that micromolar amounts of ATP are released from erythrocytes flowing through channels having cross sectional dimensions of 60 x 38 micron (2.22 +/- 0.50 microM ATP). Microscopic images indicate that erythrocytes, when being pumped through the microchip channels, migrate toward the center of the channels, leaving a cell-free or skimming layer at the walls of the channel, a profile known to exist in circulatory vessels in vivo. A comparison of the amounts of ATP released from RBCs mechanically deformed in microbore tubing (2.54 +/- 0.15 microM) vs a microchip (2.59 +/- 0.32 microM) suggests that channels in microchips may serve as functional biomimics of the microvasculature. Control studies involving diamide, a membrane-stiffening agent, suggest that the RBC-derived ATP is not due to cell lysis but rather physical deformation.

  17. Release of DNA from polyelectrolyte multilayers fabricated using 'charge-shifting' cationic polymers: tunable temporal control and sequential, multi-agent release.

    Science.gov (United States)

    Sun, Bin; Lynn, David M

    2010-11-20

    We report an approach to the design of multilayered polyelectrolyte thin films (or 'polyelectrolyte multilayers', PEMs) that can be used to provide tunable control over the release of plasmid DNA (or multiple different DNA constructs) from film-coated surfaces. Our approach is based upon methods for the layer-by-layer assembly of DNA-containing thin films, and exploits the properties of a new class of cationic 'charge-shifting' polymers (amine functionalized polymers that undergo gradual changes in net charge upon side chain ester hydrolysis) to provide control over the rates at which these films erode and release DNA. We synthesized two 'charge-shifting' polymers (polymers 1 and 2) containing different side chain structures by ring-opening reactions of poly(2-alkenyl azlactone)s with two different tertiary amine functionalized alcohols (3-dimethylamino-1-propanol and 2-dimethylaminoethanol, respectively). Subsequent characterization revealed large changes in the rates of side chain ester hydrolysis for these two polymers; whereas the half-life for the hydrolysis of the esters in polymer 1 was ~200 days, the half-life for polymer 2 was ~6 days. We demonstrate that these large differences in side chain hydrolysis make possible the design of PEMs that erode and promote the surface-mediated release of DNA either rapidly (e.g., over ~3 days for films fabricated using polymer 2) or slowly (e.g., over ~1 month for films fabricated using polymer 1). We demonstrate further that it is possible to design films with release profiles that are intermediate to these two extremes by fabricating films using solutions containing different mixtures of these two polymers. This approach can thus expand the usefulness of these two polymers and achieve a broader range of DNA release profiles without the need to synthesize polymers with new structures or properties. Finally, we demonstrate that polymers 1 and 2 can be used to fabricate multilayered films with hierarchical structures that

  18. Observations on 3He release from ErT2 films

    International Nuclear Information System (INIS)

    Venhaus, T.J.; Poths, J.

    2004-01-01

    We have loaded thin (500nm) films of erbium to a stoichiometry of ErT 2 , and have been observing their 3 He release characteristics. The films are stored in vacuum-tight metal vessels and the headspace helium is analyzed after accumulation for times ranging from a day to several months. Analysis is performed with very high sensitivity using a static noble gas mass spectrometer. For the first several years, 3 He release is a fairly constant function of helium generation, and does not depend on the substrate or the amount of helium accumulated in the film. We find a somewhat higher helium release (up to 3%) at very early times, decreasing over 6 months to a fairly consistent value (0.8%). This observation is consistent with a bubble nucleation and growth mechanism. The very early release behavior does not appear to be dependent upon the presence or growth of surface oxide layers. We also observed that, despite the very low vapor pressure of ErT 2 , our vacuum system became contaminated with low levels of tritium, representing perhaps a few ppm of the tritium in a sample.

  19. Nanostructured Diclofenac Sodium Releasing Material

    Science.gov (United States)

    Nikkola, L.; Vapalahti, K.; Harlin, A.; Seppälä, J.; Ashammakhi, N.

    2008-02-01

    Various techniques have been developed to produce second generation biomaterials for tissue repair. These include extrusion, molding, salt leaching, spinning etc, but success in regenerating tissues has been limited. It is important to develop porous material, yet with a fibrous structure for it to be biomimetic. To mimic biological tissues, the extra-cellular matrix usually contains fibers in nano scale. To produce nanostructures, self-assembly or electrospinning can be used. Adding a drug release function to such a material may advance applications further for use in controlled tissue repair. This turns the resulting device into a multifunctional porous, fibrous structure to support cells and drug releasing properties in order to control tissue reactions. A bioabsorbable poly(ɛ-caprolactone-co-D,L lactide) 95/5 (PCL) was made into diluted solution using a solvent, to which was added 2w-% of diclofenac sodium (DS). Nano-fibers were made by electrospinning onto substrate. Microstructure of the resulting nanomat was studied using SEM and drug release profiles with UV/VIS spectroscopy. Thickness of the electrospun nanomat was about 2 mm. SEM analysis showed that polymeric nano-fibers containing drug particles form a highly interconnected porous nano structure. Average diameter of the nano-fibers was 130 nm. There was a high burst peak in drug release, which decreased to low levels after one day. The used polymer has slow a degradation rate and though the nanomat was highly porous with a large surface area, drug release rate is slow. It is feasible to develop a nano-fibrous porous structure of bioabsorbable polymer, which is loaded with test drug. Drug release is targeted at improving the properties of biomaterial for use in controlled tissue repair and regeneration.

  20. Chronic cigarette smoking enhances spontaneous release of tumour necrosis factor-α from alveolar macrophages of rats

    Directory of Open Access Journals (Sweden)

    G. P. Pessina

    1993-01-01

    Full Text Available Some biological effects of chronic cigarette smoking (two cigarettes for 2 h, daily for 4 months in rats were evaluated. During the smoking period, body weight of smoker rats was always significantly lower than that of control rats. Immediately after the last smoking session the carboxyhaemoglobin concentration in the blood was about 8.5% and the polymorphonuclear cells in the bronchoalveolar fluid increased significantly. At the same time, enzymatic analyses on the supernatants of bronchoalveolar fluid revealed a significant increase of β-glucuronidase in the smoker group. Alveolar macrophages, collected 0, 8 and 24 h after the last smoking session, significantly increased the generation of superoxide anion and, after incubation for 24 h at 37° C in a humidified atmosphere, released significantly high amounts of TNF-α. When challenged with lipopolysaccharide, alveolar macrophages of smoker rats released much more TNF-α but, in such a case, TNF-α release was about one half of that observed in the control group. Peritoneal macrophages of both control and smoker rats were unable either to generate high levels of superoxide anion or to release significant amounts of TNF-α. The results clearly demonstrated the activated state of alveolar macrophages and the resting state of peritoneal macrophages.

  1. Application of Metal-Organic Framework Nano-MIL-100(Fe) for Sustainable Release of Doxycycline and Tetracycline.

    Science.gov (United States)

    Taherzade, Seyed Dariush; Soleimannejad, Janet; Tarlani, Aliakbar

    2017-08-06

    Nanostructures of MIL-100 were synthesized and used as a drug delivery platform for two members of the Tetracycline family. Doxycycline monohydrate (DOX) and Tetracycline hydrochloride (TC) were loaded separately on nano-MIL-100 (nanoparticles of drug@carrier were abbreviated as DOX@MIL-100 and TC@MIL-100). Characterizations were carried out using FT-IR, XRD, BET, DLS, and SEM. The FT-IR spectra revealed that the drugs were loaded into the framework of the carrier. The XRD patterns of DOX@MIL-100 and TC@MIL-100 indicated that no free DOX or TC were present. It could be concluded that the drugs are well dispersed into the pores of nano-MIL-100. The microporosity of the carrier was confirmed by BJH data. BET analysis showed a reduction in the free surface for both DOX@MIL-100 and TC@MIL-100. The release of TC and DOX was investigated, and it was revealed that MIL-100 mediated the drug solubility in water, which in turn resulted in a decrease in the release rate of TC (accelerating in DOX case) without lowering the total amount of released drug. After 48 h, 96 percent of the TC was sustain released, which is an unprecedented amount in comparison with other methods.

  2. Fluoride release and recharge abilities of contemporary fluoride-containing restorative materials and dental adhesives.

    Science.gov (United States)

    Dionysopoulos, Dimitrios; Koliniotou-Koumpia, Eugenia; Helvatzoglou-Antoniades, Maria; Kotsanos, Nikolaos

    2013-01-01

    The aim of this study was to evaluate the fluoride release of five fluoride-releasing restorative materials and three dental adhesives, before and after NaF solution treatment. Five restorative materials (Fuji IX GP, GC Corp.; Ketac N100, 3M ESPE; Dyract Extra, Dentsply; Beautifil II, Shofu Inc.; Wave, SDI) and three dental adhesives (Stae, SDI; Fluorobond II - Shofu Inc.; Prime & Bond NT, Dentsply) were investigated before and after NaF solution treatment. A fluoride ion-selective electrode was to measure fluoride concentrations. During the 86-day period before NaF solution treatment, Fuji IX GP released the highest amount of fluoride among the restorative materials while Prime & Bond NT was the highest among the dental adhesives. After NaF solution treatment, Fuji IX GP again ranked the highest in fluoride release among the restorative materials while Fluorobond II ranked the highest among dental adhesives. It was concluded that the compositions and setting mechanisms of fluoride-containing dental materials influenced their fluoride release and recharge abilities.

  3. Pebble fabrication and tritium release properties of an advanced tritium breeder

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Tsuyoshi, E-mail: hoshino.tsuyoshi@jaea.go.jp [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuch, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Edao, Yuki [Tritium Technology Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-4 Shirakata, Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kawamura, Yoshinori [Blanket Technology Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Ochiai, Kentaro [BA Project Coordination Group, Department of Fusion Power Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuch, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan)

    2016-11-01

    Highlights: • Li{sub 2}TiO{sub 3} with excess Li (Li{sub 2+x}TiO{sub 3+y}) pebble as an advanced tritium breeders was fabricated using emulsion method. • Grain size of Li{sub 2+x}TiO{sub 3+y} pebbles was controlled to be less than 5 μm. • Li{sub 2+x}TiO{sub 3+y} pebbles exhibited good tritium release properties similar to that of Li{sub 2}TiO{sub 3} pebbles. - Abstract: Li{sub 2}TiO{sub 3} with excess Li (Li{sub 2+x}TiO{sub 3+y}) has been developed as an advanced tritium breeder. With respect to the tritium release characteristics of the blanket, the optimum grain size after sintering was less than 5 μm. Therefore, an emulsion method was developed to fabricate pebbles with this target grain size. The predominant factor affecting grain growth was assumed to be the presence of binder in the gel particles; this remaining binder was hypothesized to react with the excess Li, thereby generating Li{sub 2}CO{sub 3}, which promotes grain growth. To inhibit the generation of Li{sub 2}CO{sub 3}, calcined Li{sub 2+x}TiO{sub 3+y} pebbles were sintered under vacuum and subsequently under a 1% H{sub 2}–He atmosphere. The average grain size of the sintered Li{sub 2+x}TiO{sub 3+y} pebbles was less than 5 μm. Furthermore, the tritium release properties of Li{sub 2+x}TiO{sub 3+y} pebbles were evaluated, and deuterium–tritium (DT) neutron irradiation experiments were performed at the Fusion Neutronics Source facility in the Japan Atomic Energy Agency. To remove the tritium produced by neutron irradiation, 1% H{sub 2}–He purge gas was passed through the Li{sub 2+x}TiO{sub 3+y} pebbles. The Li{sub 2+x}TiO{sub 3+y} pebbles exhibited good tritium release properties, similar to those of Li{sub 2}TiO{sub 3} pebbles. In particular, the released amount of tritiated hydrogen gas for easier tritium handling was greater than the released amount of tritiated water.

  4. Release of indigenous gases from LWR fuel and the reaction kinetics with Zircaloy cladding

    International Nuclear Information System (INIS)

    Beyer, C.E.; Hann, C.R.

    1977-04-01

    The objective of this study was to evaluate the open literature data to estimate: the rate of gaseous impurity release from oxide fuel, the amount and composition of the gaseous impurities, and their subsequent rate of reaction with the fuel or Zircaloy

  5. Numerical simulation of radioisotope's dependency on containment performance for large dry PWR containment under severe accidents

    International Nuclear Information System (INIS)

    Mehboob, Khurram; Xinrong, Cao; Ahmed, Raheel; Ali, Majid

    2013-01-01

    Highlights: • Calculation and comparison of activity of BURN-UP code with ORIGEN2 code. • Development of SASTC computer code. • Radioisotopes dependency on containment ESFs. • Mitigation in atmospheric release with ESFs operation. • Variation in radioisotopes source term with spray flow and pH value. -- Abstract: During the core melt accidents large amount of fission products can be released into the containment building. These fission products escape into the environment to contribute in accident source term. The mitigation in environmental release is demanded for such radiological consequences. Thus, countermeasures to source term, mitigations of release of radioactivity have been studied for 1000 MWe PWR reactor. The procedure of study is divided into five steps: (1) calculation and verification of core inventory, evaluated by BURN-UP code, (2) containment modeling based on radioactivity removal factors, (3) selection of potential accidents initiates the severe accident, (4) calculation of release of radioactivity, (5) study the dependency of release of radioactivity on containment engineering safety features (ESFs) inducing mitigation. Loss of coolant accident (LOCA), small break LOCA and flow blockage accidents (FBA) are selected as initiating accidents. The mitigation effect of ESFs on source term has been studied against ESFs performance. Parametric study of release of radioactivity has been carried out by modeling and simulating the containment parameters in MATLAB, which takes BURN-UP outcomes as input along with the probabilistic data. The dependency of iodine and aerosol source term on boric and caustic acid spray has been determined. The variation in source term mitigation with the variation of containment spray flow rate and pH values have been studied. The variation in containment retention factor (CRF) has also been studied with the ESF performance. A rapid decrease in source term is observed with the increase in pH value

  6. Use of tritium and sources

    International Nuclear Information System (INIS)

    Noguchi, Hiroshi

    1997-01-01

    There are many kinds of tritium, sources in the environment. The maximum inventory of them is the nuclear tests, although the atmospheric nuclear test has not been carried out since 1981. So that the inventory originated from them will decrease. By the latest data in 1989, the total amount of released tritium was about 24 PBq/yr by the use of atomic energy in the world. The maximum source was the heavy water moderated reactors, for example, CANDU reactor. In the future, large amount of tritium inventory may be the fusion reactor. The test of JET (Joint European Torus) released about 600 GBq of tritium until March in 1992. 80-90% of them were tritium water (HTO). The amount of tritium released from industries and medicine are limited. Although ITER has a large amount of tritium inventory, the amount of release is seemed not to be larger than other nuclear power facility. (S.Y.)

  7. Barrier and operational risk analysis of hydrocarbon releases (BORA-Release)

    International Nuclear Information System (INIS)

    Sklet, Snorre; Vinnem, Jan Erik; Aven, Terje

    2006-01-01

    This paper presents results from a case study carried out on an offshore oil and gas production platform with the purpose to apply and test BORA-Release, a method for barrier and operational risk analysis of hydrocarbon releases. A description of the BORA-Release method is given in Part I of the paper. BORA-Release is applied to express the platform specific hydrocarbon release frequencies for three release scenarios for selected systems and activities on the platform. The case study demonstrated that the BORA-Release method is a useful tool for analysing the effect on the release frequency of safety barriers introduced to prevent hydrocarbon releases, and to study the effect on the barrier performance of platform specific conditions of technical, human, operational, and organisational risk influencing factors (RIFs). BORA-Release may also be used to analyse the effect on the release frequency of risk reducing measures

  8. The effect of additives on release and in vitro skin retention of flavonoids from emulsion and gel semisolid formulations.

    Science.gov (United States)

    Dyja, R; Jankowski, A

    2017-08-01

    To assess the effect of two different additives (propylene glycol (PG) and polyethylene glycol 400 (PEG 400)) on release and in vitro skin retention of quercetin and chrysin from semisolid bases (amphiphilic creams and acidic carbomer gels). For obtaining semisolid formulations, flavonoids were pre-dissolved in the liquid (PG or PEG 400) or directly suspended in the semisolid base. Three chrysin formulations ('cream 0', 'PG-cream' and 'PEG 400-cream') and five quercetin formulations ('cream 0', 'PG cream', 'PEG 400 cream', 'gel 0' and 'PG gel') were prepared. The release studies were carried out in Franz diffusion cells by means of a cellulose membrane. The porcine ear skin was used in in vitro skin retention studies. The dissolution was a prerequisite to increase the release rates of tested flavonoids from obtained semisolid formulations. The cumulative amount of chrysin released after 6 h from 'PEG 400 cream' containing partly dissolved form of that flavonoid was higher than that from 'cream 0' or 'PG cream' containing its suspended form. The formulations containing quercetin dissolved in PG ('PG cream', 'PG gel') or PEG 400 ('PEG 400 cream') exhibited higher release rates of that flavonoid than corresponding semisolid suspensions ('cream 0' or 'gel 0'). The effects of both liquid additives (PG and PEG 400) on the cumulative amount of quercetin released after 6 h were comparable. However, there was no correlation between the release rate and the skin retention. The amounts of the flavonoids found in the skin were strongly affected by the type of the used solvent. While PG increased the skin retention of both flavonoids, PEG 400 had no effect on chrysin skin retention and delayed quercetin skin absorption. The proper choice of the solvent added to the semisolid base is crucial for enhanced skin delivery of the tested flavonoids. PG is more efficient absorption promoter than PEG 400 of both chrysin and quercetin. © 2017 Society of Cosmetic Scientists and the Soci

  9. An Investigation on Metallic Ion Release from Four Dental Casting Alloys

    Directory of Open Access Journals (Sweden)

    F. Nejatidanesh

    2005-12-01

    Full Text Available Statement of Problem: Element release from dental casting alloys into the oral environment is of clinical concern and is considered to be a potential health problem to all patients.Purpose: The aim of this study was to investigate the metallic ion release of four base metal alloys.Materials and Methods: Two Ni-Cr (Minalux and Supercast and two Co-Cr alloys (Minalia and Wironit were examined. Nine specimens of each type were prepared in 13×11×1.4 mm dimensions and each of the four alloys (3 specimens per group were conditioned in artificial saliva at 37 c for one, three and seven days.The conditioning media were analyzed for element-release using Inductive CoupledPlasma Atomic Emission Spectrophotometer (ICPAES. Collected data were statistically analyzed using ANOVA and Duncan multiple range test (P< 0.05.Results: The greatest amount of element release was seen after seven days (134.9 ppb Supercast, 159.2 ppb Minalux, 197.2 ppb Minalia, and 230.2 ppb Wironit. There was a significant difference between the released elements from the alloys after the three conditioning times (p<0.001.Conclusion: Element release from the studied alloys is proportional to the conditioning time. The Ni-Cr alloys tested in this investigation were more resistant to corrosion as compared to the Co-Cr alloys in artificial saliva. Supercast had the highest corrosion resistance.

  10. Nanostructural control of the release of macromolecules from silica sol–gels

    Science.gov (United States)

    Radin, Shula; Bhattacharyya, Sanjib; Ducheyne, Paul

    2013-01-01

    The therapeutic use of biological molecules such as growth factors and monoclonal antibodies is challenging in view of their limited half-life in vivo. This has elicited the interest in delivery materials that can protect these molecules until released over extended periods of time. Although previous studies have shown controlled release of biologically functional BMP-2 and TGF-β from silica sol–gels, more versatile release conditions are desirable. This study focuses on the relationship between room temperature processed silica sol–gel synthesis conditions and the nanopore size and size distribution of the sol–gels. Furthermore, the effect on release of large molecules with a size up to 70 kDa is determined. Dextran, a hydrophilic polysaccharide, was selected as a large model molecule at molecular sizes of 10, 40 and 70 kDa, as it enabled us to determine a size effect uniquely without possible confounding chemical effects arising from the various molecules used. Previously, acid catalysis was performed at a pH value of 1.8 below the isoelectric point of silica. Herein the silica synthesis was pursued using acid catalysis at either pH 1.8 or 3.05 first, followed by catalysis at higher values by adding base. This results in a mesoporous structure with an abundance of pores around 3.5 nm. The data show that all molecular sizes can be released in a controlled manner. The data also reveal a unique in vivo approach to enable release of large biological molecules: the use more labile sol–gel structures by acid catalyzing above the pH value of the isoelectric point of silica; upon immersion in a physiological fluid the pores expand to reach an average size of 3.5 nm, thereby facilitating molecular out-diffusion. PMID:23643607

  11. Influence of Nanomaterial Compatibilization Strategies on Polyamide Nanocomposites Properties and Nanomaterial Release during the Use Phase.

    Science.gov (United States)

    Fernández-Rosas, Elisabet; Vilar, Gemma; Janer, Gemma; González-Gálvez, David; Puntes, Victor; Jamier, Vincent; Aubouy, Laurent; Vázquez-Campos, Socorro

    2016-03-01

    The incorporation of small amounts of nanofillers in polymeric matrices has enabled new applications in several industrial sectors. The nanofiller dispersion can be improved by modifying the nanomaterial (NM) surface or predispersing the NMs to enhance compatibility. This study evaluates the effect of these compatibilization strategies on migration/release of the nanofiller and transformation of polyamide-6 (PA6), a thermoplastic polymer widely used in industry during simulated outdoors use. Two nanocomposites (NCs) containing SiO2 nanoparticles (NPs) with different surface properties and two multiwalled carbon nanotube (MWCNT) NCs obtained by different addition methods were produced and characterized, before and after accelerated wet aging conditions. Octyl-modified SiO2 NPs, though initially more aggregated than uncoated SiO2 NPs, reduced PA6 hydrolysis and, consequently, NM release. Although no clear differences in dispersion were observed between the two types of MWCNT NCs (masterbatch vs direct addition) after manufacture, the use of the MWCNT masterbatch reduced PA6 degradation during aging, preventing MWCNT accumulation on the surface and further release or potential exposure by direct contact. The amounts of NM released were lower for MWCNTs (36 and 108 mg/m(2)) than for SiO2 NPs (167 and 730 mg/m(2)), being lower in those samples where the NC was designed to improve the nanofiller-matrix interaction. Hence, this study shows that optimal compatibilization between NM and matrix can improve NC performance, reducing polymer degradation and exposure and/or release of the nanofiller.

  12. Influence of the reagent concentration of the colorimetric copper determination with sodium diethyl dithiocarbamate (abbreviated: D.D.C.) and its importance for the determination of copper in the presence of large amounts of iron

    NARCIS (Netherlands)

    Karsten, P.; Rademaker, S.C.; Walraven, J.J.

    1950-01-01

    From a research about the influence of the reagent concentration on the copper determination with sodium di-ethyl-di-thio-carbamate in the presence of large amounts of iron some insight was gained into factors which had never been examined so far and which were found to have great influence on the

  13. Controlled drug release from bifunctionalized mesoporous silica

    Science.gov (United States)

    Xu, Wujun; Gao, Qiang; Xu, Yao; Wu, Dong; Sun, Yuhan; Shen, Wanling; Deng, Feng

    2008-10-01

    Serial of trimethylsilyl-carboxyl bifunctionalized SBA-15 (TMS/COOH/SBA-15) have been studied as carriers for controlled release of drug famotidine (Famo). To load Famo with large capacity, SBA-15 with high content of carboxyl groups was successfully synthesized by one-pot synthesis under the assistance of KCl. The mesostructure of carboxyl functionalized SBA-15 (COOH/SBA-15) could still be kept even though the content of carboxyl groups was up to 57.2%. Increasing carboxyl content could effectively enhance the loading capacity of Famo. Compared with pure SBA-15, into which Famo could be hardly adsorbed, the largest drug loading capacity of COOH/SBA-15 could achieve 396.9 mg/g. The release of Famo from mesoporous silica was studied in simulated intestine fluid (SIF, pH=7.4). For COOH/SBA-15, the release rate of Famo decreased with narrowing pore size. After grafting TMS groups on the surface of COOH/SBA-15 with hexamethyldisilazane, the release of Famo was greatly delayed with the increasing content of TMS groups.

  14. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 2. Sequim Bay clayey silt

    International Nuclear Information System (INIS)

    Schmidt, R.L.

    1982-04-01

    This report describes laboratory experiments in which neutron-activated 347 stainless steel specimens were exposed to clayey silt from Sequim Bay, Washington. The properties and trace metal geochemistry of the sediment and the amounts of corrosion products that were released under oxic and reduced conditions and their distribution among different chemical fractions of the sediment are discussed. The distributions of Cr, Mn, Fe, Ni and Cu among different chemical forms in the Sequim Bay sediment show that DTPA removed <10% of extractable Cr, Fe and Mn, approx. 20% of extractable Ni and approx. 30% of extractable Cu. The inorganic fraction (material soluble in 2.5% acetic acid) accounted for approx. 30% of total extractable Mn and approx. 10% or less of Cr, Fe, Ni and Cu. Major portions of Cr and Cu, and a large amount of Fe were in the organic fraction. Extractable Mn, Fe and Ni were associated with hydrous oxides likely as coatings on the mineral substrate of the sediment. No Co was detectable in any of the extracts

  15. Square Wave Voltammetry: An Alternative Technique to Determinate Piroxicam Release Profiles from Nanostructured Lipid Carriers.

    Science.gov (United States)

    Otarola, Jessica; Garrido, Mariano; Correa, N Mariano; Molina, Patricia G

    2016-08-04

    A new, simple, and fast electrochemical (EC) method has been developed to determine the release profile of piroxicam, a nonsteroidal anti-inflammatory drug, loaded in a drug delivery system based on nanostructured lipid carriers (NLCs). For the first time, the samples were analyzed by using square wave voltammetry, a sensitive EC technique. The piroxicam EC responses allow us to propose a model that explains the experimental results and to subsequently determine the amount of drug loaded into the NLCs formulation as a function of time. In vitro drug release studies showed prolonged drug release (up to 5 days), releasing 60 % of the incorporated drug. The proposed method is a promising and stable alternative for the study of different drug delivery systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Ion release from orthodontic brackets in 3 mouthwashes: an in-vitro study.

    Science.gov (United States)

    Danaei, Shahla Momeni; Safavi, Afsaneh; Roeinpeikar, S M Mehdi; Oshagh, Morteza; Iranpour, Shiva; Omidkhoda, Maryam; Omidekhoda, Maryam

    2011-06-01

    Stainless steel orthodontic brackets can release metal ions into the saliva. Fluoridated mouthwashes are often recommended to orthodontic patients to reduce the risk of white-spot lesions around their brackets. However, little information is available regarding the effect of different mouthwashes in ion release of orthodontic brackets. The purpose of this study was to measure the amount of metal ion release from orthodontic brackets when kept in different mouthwashes. One hundred sixty stainless steel brackets (0.022-in, 3M Unitek, Monrovia, Calif) were divided randomly into 4 equal groups and immersed in Oral B (Procter & Gamble, Weybridge, United Kingdom), chlorhexidine (Shahdaru Labratories, Tehran, Iran), and Persica (Poursina Pharmaceutical Laboratories, Tehran, Iran) mouthwashes and distilled deionized water and incubated at 37°C for 45 days. Nickel, chromium, iron, copper, and manganese released from the orthodontic brackets were measured with an inductively coupled plasma spectrometer. For statistical analysis, 1-way analysis of variance (ANOVA) and the Duncan multiple-range tests were used. The results showed that ion release in deionized water was significantly (P 0.05) in nickel, chromium, iron, and copper ion release in the Oral B and Persica mouthwashes. The level of manganese release was significantly different in all 4 groups. If ion release is a concern, Oral B and Persica mouthwashes might be better options than chlorhexidine for orthodontic patients with stainless steel brackets. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  17. LAVA: Large scale Automated Vulnerability Addition

    Science.gov (United States)

    2016-05-23

    LAVA: Large-scale Automated Vulnerability Addition Brendan Dolan -Gavitt∗, Patrick Hulin†, Tim Leek†, Fredrich Ulrich†, Ryan Whelan† (Authors listed...released, and thus rapidly become stale. We can expect tools to have been trained to detect bugs that have been released. Given the commercial price tag...low TCN) and dead (low liveness) program data is a powerful one for vulnera- bility injection. The DUAs it identifies are internal program quantities

  18. Inorganically modified diatomite as a potential prolonged-release drug carrier.

    Science.gov (United States)

    Janićijević, Jelena; Krajišnik, Danina; Calija, Bojan; Dobričić, Vladimir; Daković, Aleksandra; Krstić, Jugoslav; Marković, Marija; Milić, Jela

    2014-09-01

    Inorganic modification of diatomite was performed with the precipitation product of partially neutralized aluminum sulfate solution at three different mass ratios. The starting and the modified diatomites were characterized by SEM-EDS, FTIR, thermal analysis and zeta potential measurements and evaluated for drug loading capacity in adsorption batch experiments using diclofenac sodium (DS) as a model drug. In vitro drug release studies were performed in phosphate buffer pH6.8 from comprimates containing: the drug adsorbed onto the selected modified diatomite sample (DAMD), physical mixture of the drug with the selected modified diatomite sample (PMDMD) and physical mixture of the drug with the starting diatomite (PMDD). In vivo acute toxicity testing of the modified diatomite samples was performed on mice. High adsorbent loading of the selected modified diatomite sample (~250mg/g in 2h) enabled the preparation of comprimates containing adsorbed DS in the amount near to its therapeutic dose. Drug release studies demonstrated prolonged release of DS over a period of 8h from both DAMD comprimates (18% after 8h) and PMDMD comprimates (45% after 8h). The release kinetics for DAMD and PMDMD comprimates fitted well with Korsmeyer-Peppas and Bhaskar models, indicating that the release mechanism was a combination of non-Fickian diffusion and ion exchange process. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Atmospheric Dispersion Modeling of the February 2014 Waste Isolation Pilot Plant Release

    Energy Technology Data Exchange (ETDEWEB)

    Nasstrom, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Piggott, Tom [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lobaugh, Megan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tai, Lydia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pobanz, Brenda [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yu, Kristen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-22

    This report presents the results of a simulation of the atmospheric dispersion and deposition of radioactivity released from the Waste Isolation Pilot Plant (WIPP) site in New Mexico in February 2014. These simulations were made by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL), and supersede NARAC simulation results published in a previous WIPP report (WIPP, 2014). The results presented in this report use additional, more detailed data from WIPP on the specific radionuclides released, radioactivity release amounts and release times. Compared to the previous NARAC simulations, the new simulation results in this report are based on more detailed modeling of the winds, turbulence, and particle dry deposition. In addition, the initial plume rise from the exhaust vent was considered in the new simulations, but not in the previous NARAC simulations. The new model results show some small differences compared to previous results, but do not change the conclusions in the WIPP (2014) report. Presented are the data and assumptions used in these model simulations, as well as the model-predicted dose and deposition on and near the WIPP site. A comparison of predicted and measured radionuclide-specific air concentrations is also presented.

  20. Optimization of Melatonin Dissolution from Extended Release Matrices Using Artificial Neural Networking.

    Science.gov (United States)

    Martarelli, D; Casettari, L; Shalaby, K S; Soliman, M E; Cespi, M; Bonacucina, G; Fagioli, L; Perinelli, D R; Lam, J K W; Palmieri, G F

    2016-01-01

    Efficacy of melatonin in treating sleep disorders has been demonstrated in numerous studies. Being with short half-life, melatonin needs to be formulated in extended-release tablets to prevent the fast drop of its plasma concentration. However, an attempt to mimic melatonin natural plasma levels during night time is challenging. In this work, Artificial Neural Networks (ANNs) were used to optimize melatonin release from hydrophilic polymer matrices. Twenty-seven different tablet formulations with different amounts of hydroxypropyl methylcellulose, xanthan gum and Carbopol®974P NF were prepared and subjected to drug release studies. Using dissolution test data as inputs for ANN designed by Visual Basic programming language, the ideal number of neurons in the hidden layer was determined trial and error methodology to guarantee the best performance of constructed ANN. Results showed that the ANN with nine neurons in the hidden layer had the best results. ANN was examined to check its predictability and then used to determine the best formula that can mimic the release of melatonin from a marketed brand using similarity fit factor. This work shows the possibility of using ANN to optimize the composition of prolonged-release melatonin tablets having dissolution profile desired.

  1. In vitro atrazine-exposure inhibits human natural killer cell lytic granule release

    International Nuclear Information System (INIS)

    Rowe, Alexander M.; Brundage, Kathleen M.; Barnett, John B.

    2007-01-01

    The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine exposure. These assays demonstrated no significant decrease in the level of target cell binding. However, the levels of NK intracellular lytic protein retained and the amount of lytic protein released were assessed following a 4-h incubation with K562 target cells. The relative level of intracellular lytic protein was 25-50% higher, and the amount of lytic protein released was 55-65% less in atrazine-treated cells than vehicle-treated cells following incubation with the target cells. These results indicate that ATR exposure inhibits the ability of NK cells to lyse target cells by blocking lytic granule release without affecting the ability of the NK cell to form stable conjugates with target cells

  2. Nitrate uptake and nitrite release by tomato roots in response to anoxia.

    Science.gov (United States)

    Morard, Philippe; Silvestre, Jérôme; Lacoste, Ludovic; Caumes, Edith; Lamaze, Thierry

    2004-07-01

    Excised root systems of tomato plants (early fruiting stage, 2nd flush) were subjected to a gradual transition from normoxia to anoxia by seating the hydroponic root medium while aeration was stopped. Oxygen level in the medium and respiration rate decreased and reached very low values after 12 h of treatment, indicating that the tissues were anoxic thereafter. Nitrate loss from the nutrient solution was strongly stimulated by anoxia (after 26 h) concomitantly with a release of nitrite starting only after 16 h of treatment. This effect was not observed in the absence of roots or in the presence of tungstate, but occurred with whole plants or with sterile in vitro cultured root tissues. These results indicate that biochemical processes in the root involve nitrate reductase. NR activity assayed in tomato roots increased during anoxia. This phenomenon appeared in intact plants and in root tissues of detopped plants. The stimulating effect of oxygen deprivation on nitrate uptake was specific; anoxia simultaneously entailed a release of orthophosphate, sulfate, and potassium by the roots. Anoxia enhanced nitrate reduction by root tissues, and nitrite ions were released into xylem sap and into medium culture. In terms of the overall balance, the amount of nitrite recovered represented only half of the amount of nitrate utilized. Nitrite reduction into nitric oxide and perhaps into nitrogen gas could account for this discrepancy. These results appear to be the first report of an increase in nitrate uptake by plant roots under anoxia of tomato at the early fruiting stage, and the rates of nitrite release in nutrient medium by the asphyxiated roots are the fastest yet reported.

  3. Toxic chemical release inventory reporting form R and instructions. Revised 1992 version. Section 313 of the Emergency Planning and Community Right-to-Know Act

    International Nuclear Information System (INIS)

    1993-01-01

    Reporting is required to provide the public with information on the releases of listed toxic chemicals in their communities and to provide EPA with release information to assist the Agency in determining the need for future regulations. Facilities must report the quantities of both routine and accidental releases of listed toxic chemicals, as well as the maximum amount of the listed toxic chemical on-site during the calendar year and the amount contained in wastes transferred off-site. These instructions supplement and elaborate on the requirements in the reporting rule (40 CFR Part 372). Together with the reporting rule, they constitute the reporting requirements. All references in these instructions are to sections in the reporting rule unless otherwise indicated

  4. Expression of the capacity to release [3H]norepinephrine by neural crest cultures

    International Nuclear Information System (INIS)

    Maxwell, G.D.; Sietz, P.D.

    1983-01-01

    Cultures of trunk neural crest cells from quail embryos were tested for their ability to release [ 3 H]norepinephrine [( 3 H]NE) in response to depolarization. After 7 days in vitro, exposure of the cultures to either the alkaloid veratridine or 40 mM K+ results in the evoked release of [ 3 H]NE. The release evoked by veratridine is blocked in the presence of tetrodotoxin. The release evoked by increased K+ is blocked by the calcium antagonist cobalt. Release in response to the nicotinic cholinergic agonist 1,1-dimethyl-4-phenylpiperazine was also observed. The amount of evoked release is highly correlated with the number of histochemically demonstrable catecholamine-containing cells in a given culture. Autoradiography reveals that the radioactivity taken up by these cultures is located in a subpopulation of cells whose morphology resembles that of the histochemically detectable catecholamine-containing cell population. Whereas capacity for the release of [ 3 H] NE is readily detectable after 7 days in vitro, it is detectable only with difficulty after 4 days in vitro. There is a greater than 6-fold increase in uptake capacity over the period of 4 to 7 days in vitro. These results demonstrate that neural crest cultures grown without their normal synaptic inputs or targets can exhibit the capacity for stimulus secretion coupling characteristic of synaptic neurotransmitter release

  5. Controlled release effervescent buccal discs of buspirone hydrochloride: in vitro and in vivo evaluation studies.

    Science.gov (United States)

    Jaipal, A; Pandey, M M; Charde, S Y; Sadhu, N; Srinivas, A; Prasad, R G

    2016-01-01

    In the present study controlled release effervescent buccal discs of buspirone hydrochloride (BS) were designed using HPMC as rate controlling and bioadhesive polymer by direct compression method. Sodium bicarbonate and citric acid were used in varying amounts as effervescence forming agents. Carbon dioxide evolved due to reaction of sodium bicarbonate and citric acid was explored for its potential as buccal permeation enhancer. The designed buccal discs were evaluated for physical characteristics and in vitro drug release studies. Bioadhesive behavior of designed buccal discs was assessed using texture analyzer. In vivo animal studies were performed in rabbits to study bioavailability of BS in the designed buccal discs and to establish permeation enhancement ability of carbon dioxide. It was observed that effervescent buccal discs have faster drug release compared to non-effervescent buccal discs in vitro and effervescent buccal discs demonstrated significant increase in bioavailability of drug when compared to non-effervescent formulation. Hence, effervescent buccal discs can be used as an alternative to improve the drug permeation resulting in better bioavailability. However, the amount of acid and base used for generation of carbon dioxide should be selected with care as this may damage the integrity of bioadhesive dosage form.

  6. Mechanical energy release in CABRI-2 experiments with Viggen-4 fuel pins

    International Nuclear Information System (INIS)

    Wolff, J.

    1993-07-01

    The results of mechanical energy release evaluations in CABRI-2 experiments with Viggen-4 fuel pins (12 atom % burnup) are described. In general the experience gained by the CABRI-1 experiments is confirmed. Those physical phenomena are enhanced which are influenced by the release of fission products. Especially the late blow-out of pressurized fission gases from the lower test pin plenum led to large flow variations. The corresponding mechanical power releases are low

  7. Saturation transfer EPR (ST-EPR) for dating biocarbonates containing large amount of Mn2+: separation of SO3- and CO2- lines and geochronology of Brazilian fish fossil

    International Nuclear Information System (INIS)

    Sastry, M.D.; Andrade, M.B.; Watanabe, Shigueo

    2003-01-01

    A method using saturation transfer EPR (ST-EPR) is shown to be feasible for detecting EPR signal of radiation-induced defects in biocarbonates containing large amount of Mn 2+ . The ST-EPR measurements conducted at room temperature on fish fossil of Brazilian origin, enabled the identification of CO 2 - and SO 3 - radical ions, by partially suppressing the intense signal from Mn 2+ when the signal are detected 90 deg. out of phase with magnetic field modulating signal and at high microwave power (50 mW). Using these signals the age of fish fossil is estimated to be (36±5) Ma

  8. Controlled release of cytokines using silk-biomaterials for macrophage polarization.

    Science.gov (United States)

    Reeves, Andrew R D; Spiller, Kara L; Freytes, Donald O; Vunjak-Novakovic, Gordana; Kaplan, David L

    2015-12-01

    Polarization of macrophages into an inflammatory (M1) or anti-inflammatory (M2) phenotype is important for clearing pathogens and wound repair, however chronic activation of either type of macrophage has been implicated in several diseases. Methods to locally control the polarization of macrophages is of great interest for biomedical implants and tissue engineering. To that end, silk protein was used to form biopolymer films that release either IFN-γ or IL-4 to control the polarization of macrophages. Modulation of the solubility of the silk films through regulation of β-sheet (crystalline) content enabled a short-term release (4-8 h) of either cytokine, with smaller amounts released out to 24 h. Altering the solubility of the films was accomplished by varying the time that the films were exposed to water vapor. The released IFN-γ or IL-4 induced polarization of THP-1 derived macrophages into the M1 or M2 phenotypes, respectively. The silk biomaterials were able to release enough IFN-γ or IL-4 to repolarize the macrophage from M1 to M2 and vice versa, demonstrating the well-established plasticity of macrophages. High β-sheet content films that are not soluble and do not release the trapped cytokines were also able to polarize macrophages that adhered to the surface through degradation of the silk protein. Chemically conjugating IFN-γ to silk films through disulfide bonds allowed for longer-term release to 10 days. The release of covalently attached IFN-γ from the films was also able to polarize M1 macrophages in vitro. Thus, the strategy described here offers new approaches to utilizing biomaterials for directing the polarization of macrophages. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Validation of basophil histamine release against the autologous serum skin test and outcome of serum-induced basophil histamine release studies in a large population of chronic urticaria patients

    DEFF Research Database (Denmark)

    Platzer, M H; Grattan, C E H; Poulsen, Lars K.

    2005-01-01

    the immunoglobulin E (IgE) or the high affinity IgE receptor (FcepsilonRI) and serum-induced histamine release (HR) from basophils and mast cells. We have examined the correlation between the ASST and a new basophil histamine-releasing assay (the HR-Urtikaria test) in a group of well-characterized CU patients...... and subsequently determined the frequency of HR-Urticaria-positive sera from a larger population of CU patients....

  10. Experimental investigation of methane release from hydrate formation in sandstone through both hydrate dissociation and CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Husebo, J.; Graue, A.; Kvamme, B. [Bergen Univ., Bergen (Norway). Dept. of Physics and Technology; Stevens, J.; Howard, J.J. [ConocoPhillips, Ponca City, OK (United States); Baldwin, B.A. [Green Country Petrophysics LLC, Dewey, OK (United States)

    2008-07-01

    Large amounts of natural gas trapped in hydrate reservoirs are found in Arctic regions and in deep offshore locations around the world. Natural gas production from hydrate deposits offer significant potential for future energy needs. However, research is needed in order to propose potential production schemes for natural gas hydrates. Natural gas molecules can be freed from hydrate structured cages by depressurization, by heating and by exposing the hydrate to a substance that will form a thermodynamically more stable hydrate structure. This paper provided a comparison of two approaches for releasing methane from methane hydrate in porous sandstone. The study scope covered the dissociation rate of methane hydrate in porous media through depressurization, and also referred to previous work done on producing methane from hydrates in sandstone while sequestering carbon dioxide (CO{sub 2}). The study was conducted in a laboratory setting. The paper discussed the experimental design which included the placing of a pressure- and temperature-controlled sample holder inside the bore of a magnetic resonance imager. The experimental procedures were then outlined, with reference to hydrate formation; carbon dioxide sequestration; hydrate dissociation experiments with constant volume; and hydrate dissociation experiments at constant pressure. The constant volume experiments demonstrated that in order to dissociate a large amount of hydrate, the initial depressurization had to be significantly lower than the hydrate stability pressure. 9 refs., 9 figs.

  11. pH-Sensitive Amphiphilic Block-Copolymers for Transport and Controlled Release of Oxygen

    KAUST Repository

    Patil, Yogesh Raghunath

    2017-05-31

    Saturated fluorocarbons, their derivatives and emulsions are capable of dissolving anomalously high amounts of oxygen and other gases. The mechanistic aspects of this remarkable effect remain to be explored experimentally. Here, the synthesis of a library of amphiphilic fluorous block-copolymers incorporating different fluorinated monomers is described, and the capacity of these copolymers for oxygen transport in water is systematically investigated. The structure of the fluorous monomer employed was found to have a profound effect on both the oxygen-carrying capacity and the gas release kinetics of the polymer emulsions. Furthermore, the release of O2 from the polymer dispersions could be triggered by changing the pH of the solution. This is the first example of a polymer-based system for controlled release of a non-polar, non-covalently entrapped respiratory gas.

  12. pH-Sensitive Amphiphilic Block-Copolymers for Transport and Controlled Release of Oxygen

    KAUST Repository

    Patil, Yogesh Raghunath; Almahdali, Sarah; Vu, Khanh B.; Zapsas, Georgios; Hadjichristidis, Nikolaos; Rodionov, Valentin

    2017-01-01

    Saturated fluorocarbons, their derivatives and emulsions are capable of dissolving anomalously high amounts of oxygen and other gases. The mechanistic aspects of this remarkable effect remain to be explored experimentally. Here, the synthesis of a library of amphiphilic fluorous block-copolymers incorporating different fluorinated monomers is described, and the capacity of these copolymers for oxygen transport in water is systematically investigated. The structure of the fluorous monomer employed was found to have a profound effect on both the oxygen-carrying capacity and the gas release kinetics of the polymer emulsions. Furthermore, the release of O2 from the polymer dispersions could be triggered by changing the pH of the solution. This is the first example of a polymer-based system for controlled release of a non-polar, non-covalently entrapped respiratory gas.

  13. Atmospheric modeling of Mars CH4 subsurface clathrates releases mimicking SAM and 2003 Earth-based detections

    Science.gov (United States)

    Pla-García, J.; Rafkin, S. C.

    2017-12-01

    The aim of this work is to establish the amount of mixing during all martian seasons to test whether CH4 releases inside or outside of Gale crater are consistent with MSL-SAM observations. Several modeling scenarios were configured, including instantaneous and steady releases, both inside and outside the crater. A simulation to mimic the 2003 Earth-based detections (Mumma et al. 2009 or M09) was also performed. In the instantaneous release inside Gale experiments, Ls270 was shown to be the faster mixing season when air within and outside the crater was well mixed: all tracer mass inside the crater is diluted after just 8 hours. The mixing of near surface crater air with the external environment in the rest of the year is potentially rapid but slower than Ls270.In the instantaneous release outside Gale (NW) experiment, in just 12 hours the CH4 that makes it to the MSL landing location is diluted by six orders of magnitude. The timescale of mixing in MRAMS experiments is on the order of 1 sol regardless of season. The duration of the CH4 peak observed by SAM is 100 sols. Therefore there is a steady release inside the crater, or there is a very large magnitude steady release outside the crater. In the steady release Gale experiments, CH4 flux rate from ground is 1.8 kg m-2 s-1 (derived from Gloesener et al. 2017 clathrates fluxes) and it is not predictive. In these experiments, 200 times lower CH4 values detected by SAM are modeled around MSL location. There are CH4 concentration variations of orders of magnitude depending on the hour, so timing of SAM measurements is important. With a larger (but further away) outside crater release area compared to inside, similar CH4 values around MSL are modeled, so distance to source is important. In the steady experiments mimicking M09 detection release area, only 12 times lower CH4 values detected by SAM are modeled around MSL. The highest value in the M09 modeled scenario (0.6 ppbv) is reached in Ls270. This value is the

  14. Development of a mechanistic model for release of radionuclides from spent fuel in brines: Salt Repository Project

    International Nuclear Information System (INIS)

    Reimus, P.W.; Windisch, C.F.

    1988-03-01

    At present there are no comprehensive mechanistic models describing the release of radionuclides from spent fuel in brine environments. This report provides a comprehensive review of the various factors that can affect radionuclide release from spent fuel, suggests a modeling approach, and discusses proposed experiments for obtaining a better mechanistic understanding of the radionuclide release processes. Factors affecting radionuclide release include the amount, location, and disposition of radionuclides in the fuel and environmental factors such as redox potential, pH, the presence of complexing anions, temperature, and radiolysis. It is concluded that a model describing the release of radionuclides from spent fuel should contain separate terms for release from the gap, grain boundaries, and grains of the fuel. Possible functional forms for these terms are discussed in the report. Experiments for assessing their validity and obtaining key model parameters are proposed. 71 refs., 4 figs., 6 tabs

  15. Controlled Aloin Release from Crosslinked Polyacrylamide Hydrogels: Effects of Mesh Size, Electric Field Strength and a Conductive Polymer

    Directory of Open Access Journals (Sweden)

    Anuvat Sirivat

    2013-10-01

    Full Text Available The aim of this paper is to investigate the effects of hydrogel mesh size, a conductive polymer, and electric field strength on controlled drug delivery phenomena using drug-loaded polyacrylamide hydrogels prepared at various crosslinking ratios both with and without a conductive polymer system. Poly(p-phenylene vinylene, PPV, as the model conductive polymer, was used to study its ability to control aloin released from aloin-doped poly(p-phenylene vinylene/polyacrylamide hydrogel (aloin-doped PPV/PAAM. In the passive release, the diffusion of aloin from five aloin-doped PPV/PAAM hydrogel systems each was delayed ranging from during the first three hours to during the first 14 h due to the ionic interaction between the anionic drug and PPV. After the delayed periods, aloin could diffuse continuously into the buffer solution through the PAAM matrix. The amount of aloin released from the aloin-doped PPV/PAAM rose with increasing electric field strength as a result of the three mechanisms: the expansion of PPV chains inside the hydrogel, iontophoresis, and the electroporation of the matrix pore size, combined. Furthermore, the conductive polymer and the electric field could be used in combination to regulate the amount of release drug to a desired level, to control the release rate, and to switch the drug delivery on/off.

  16. Systemic levels of metallic ions released from orthodontic mini-implants.

    Science.gov (United States)

    de Morais, Liliane Siqueira; Serra, Glaucio Guimarães; Albuquerque Palermo, Elisabete Fernandes; Andrade, Leonardo Rodrigues; Müller, Carlos Alberto; Meyers, Marc André; Elias, Carlos Nelson

    2009-04-01

    Orthodontic mini-implants are a potential source of metallic ions to the human body because of the corrosion of titanium (Ti) alloy in body fluids. The purpose of this study was to gauge the concentration of Ti, aluminum (Al), and vanadium (V), as a function of time, in the kidneys, livers, and lungs of rabbits that had Ti-6Al-4V alloy orthodontic mini-implants placed in their tibia. Twenty-three New Zealand rabbits were randomly divided into 4 groups: control, 1 week, 4 weeks, and 12 weeks. Four orthodontic mini-implants were placed in the left proximal tibia of 18 rabbits. Five control rabbits had no orthodontic mini-implants. After 1, 4, and 12 weeks, the rabbits were killed, and the selected tissues were extracted and prepared for analysis by graphite furnace atomic absorption spectrophotometry. Low amounts of Ti, Al, and V were detectable in the 1-week, 4-weeks, and 12-weeks groups, confirming that release of these metals from the mini-implants occurs, with diffusion and accumulation in remote organs. Despite the tendency of ion release when using the Ti alloy as orthodontic mini-implants, the amounts of metals detected were significantly below the average intake of these elements through food and drink and did not reach toxic concentrations.

  17. Investigation of some factors affecting on release of radon-222 from phosphogypsum waste associated with phosphate ore processing.

    Science.gov (United States)

    Hilal, M A; El Afifi, E M; Nayl, A A

    2015-07-01

    The aim of this study is oriented to investigate the influence of some physicochemical factors such as radium distribution, grain size, moisture content and chemical constituents on releases of radon-222 from the accumulated phosphogypsum (PG) waste. The emanation fraction, activity concentration in the pore and the surface exhalation rate of radon-222 in the bulk PG waste are 34.5 ± 0.3%, 238.6 ± 7.8 kBq m(-3) and 213 ± 6.9 mBq m(-2) s(-1), respectively. These values were varied and enhanced slightly in the fine grain sizes (F1 factor of 1.05 folds compared to the bulk residue. It was also found that release of radon from residue PG waste was controlled positively by radium (Ra-226), calcium (CaSO4) and strontium (SrO). About 67% of radon release attributed to the grain size below 0.5 mm, while 33% due to the large grain size above 0.5 mm. The emanation fraction of Rn-222 is increased with moisture content and the maximum emanation is ∼43% of moisture of 3-8%. It reduced slowly with the continuous increase in moisture till 20%. Due to PG waste in situ can be enhancing the background to the surround workers and/or public. Therefore, the environmental negative impacts due to release of Rn-222 can be minimized by legislation to restrict its civil uses, or increasing its moisture to ∼10%, or by the particle size separation of the fine fraction containing the high levels of Ra-226 followed by a suitable chemical treatment or disposal; whereas the low release amount can be diluted and used in cement industry, roads or dam construction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Calcium release rates from tooth enamel treated with dentifrices containing whitening agents and abrasives.

    Science.gov (United States)

    Araujo, Danilo Barral; Silva, Luciana Rodrigues; de Araujo, Roberto Paulo Correia

    2010-01-01

    Tooth whitening agents containing hydrogen peroxide and carbamide peroxide are used frequently in esthetic dental procedures. However, lesions on the enamel surface have been attributed to the action of these products. Using conventional procedures for separating and isolating biological structures, powdered enamel was obtained and treated with hydrogen peroxide, carbamide peroxide, and sodium bicarbonate, ingredients typically found in dentifrices. The enamel was exposed to different pH levels, and atomic emission spectrometry was used to determine calcium release rates. As the pH level increased, the rate of calcium release from enamel treated with dentifrices containing whitening agents decreased. Carbamide peroxide produced the lowest amount of decalcification, while sodium bicarbonate produced the highest release rates at all pH levels.

  19. Carbon dioxide diffuse emission and thermal energy release from hydrothermal systems at Copahue-Caviahue Volcanic Complex (Argentina)

    Science.gov (United States)

    Chiodini, Giovanni; Cardellini, Carlo; Lamberti, María Clara; Agusto, Mariano; Caselli, Alberto; Liccioli, Caterina; Tamburello, Giancarlo; Tassi, Franco; Vaselli, Orlando; Caliro, Stefano

    2015-10-01

    The north-western sector of Caviahue caldera (Argentina), close to the active volcanic system of Copahue, is characterized by the presence of several hydrothermal sites that host numerous fumarolic emissions, anomalous soil diffuse degassing of CO2 and hot soils. In March 2014, measurements of soil CO2 fluxes in 5 of these sites (namely, Las Máquinas, Las Maquinitas I, Las Maquinitas II, Anfiteatro, and Termas de Copahue) allowed an estimation that 165 t of deeply derived CO2 is daily released. The gas source is likely related to a relatively shallow geothermal reservoir containing a single vapor phase as also suggested by both the geochemical data from the 3 deep wells drilled in the 1980s and gas geoindicators applied to the fumarolic discharges. Gas equilibria within the H-C-O gas system indicate the presence of a large, probably unique, single phase vapor zone at 200-210 °C feeding the hydrothermal manifestations of Las Máquinas, Las Maquinitas I and II and Termas de Copahue. A natural thermal release of 107 MW was computed by using CO2 as a tracer of the original vapor phase. The magmatic signature of the incondensable fumarolic gases, the wide expanse of the hydrothermal areas and the remarkable high amount of gas and heat released by fluid expulsion seem to be compatible with an active magmatic intrusion beneath this portion of the Caviahue caldera.

  20. Liquid-Phase Heat-Release Rates of the Systems Hydrazine-Nitric Acid and Unsymmetrical Dimethylhydrazine-Nitric Acid

    Science.gov (United States)

    Somogyi, Dezso; Feiler, Charles E.

    1960-01-01

    The initial rates of heat release produced by the reactions of hydrazine and unsymmetrical dimethylhydrazine with nitric acid were determined in a bomb calorimeter under conditions of forced mixing. Fuel-oxidant weight ratio and injection velocity were varied. The rate of heat release apparently depended on the interfacial area between the propellants. Above a narrow range of injection velocities representing a critical amount of interfacial area, the rates reached a maximum and were almost constant with injection velocity. The maximum rate for hydrazine was about 70 percent greater than that for unsymmetrical dimethylhydrazine. The total heat released did not vary with mixture ratio over the range studied.