WorldWideScience

Sample records for heat sterilization time

  1. Heat sterilization times of five hardwood species

    Science.gov (United States)

    William T. Simpson; Xiping Wang; John W. Forsman; John R. Erickson

    2005-01-01

    Heat sterilization of lumber, timbers, and pallets is currently used to kill insects, thus preventing their transfer between countries in international trade. An important factor in this treatment is the time required for the center of any wood configuration to reach the temperature necessary to kill the insect. This study explored the effect of size (1-, 1.5-, and 2.0...

  2. Thermal sterilization of heat-sensitive products using high-temperature short-time sterilization.

    Science.gov (United States)

    Mann, A; Kiefer, M; Leuenberger, H

    2001-03-01

    High-temperature short-time (HTST) sterilization with a continuous-flow sterilizer, developed for this study, was evaluated. The evaluation was performed with respect to (a) the chemical degradation of two heat-sensitive drugs in HTST range (140-160 degrees C) and (b) the microbiological effect of HTST sterilization. Degradation kinetics of two heat-sensitive drugs showed that a high peak temperature sterilization process resulted in less chemical degradation for the same microbiological effect than a low peak temperature process. Both drugs investigated could be sterilized with acceptable degradation at HTST conditions. For the evaluation of the microbiological effect, Bacillus stearothermophilus ATCC 7953 spores were used as indicator bacteria. Indicator spore kinetics (D(T), z value, k, and E(a)), were determined in the HTST range. A comparison between the Bigelow model (z value concept) and the Arrhenius model, used to describe the temperature coefficient of the microbial inactivation, demonstrated that the Bigelow model is more accurate in prediction of D(T) values in the HTST range. The temperature coefficient decreased with increasing temperature. The influence of Ca(2+) ions and pH value on the heat resistance of the indicator spores, which is known under typical sterilization conditions, did not change under HTST conditions.

  3. Effect of wet bulb depression on heat sterilization time of slash pine lumber

    Science.gov (United States)

    William T. Simpson

    For international trade, heat sterilization of wood products is often required to prevent the spread of insects and pathogens. Application of heat sterilization requires estimates of the time necessary to heat the center of the wood configuration to the temperature required to kill the insect or other pest. The nature of the heating medium was found to have a...

  4. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  5. Heat sterilization time of ponderosa pine and Douglas-fir boards and square timbers

    Science.gov (United States)

    William T. Simpson; Xiping Wang; Steve Verrill

    2003-01-01

    To prevent the unintentional transfer of insects and pathogens during world trade, wood products are often heat sterilized. The general requirement is that the center of the wood configuration be held at 133°F (56°C) for 30 min. However, many factors can affect the time required to reach this temperature. This study explored several of these factors, including...

  6. PRINCIPLES OF HEAT STERILIZATION IN DENTAL PRACTICE

    African Journals Online (AJOL)

    PRINCIPLES OF HEAT STERILIZATION. IN DENTAL PRACTICE. W.H. van Palenstein Helderman. Department of Community and Preventive Dentistry,. Faculty of Dentistry, Muhimbili University College of Health Sciences,. Dar es Salaam, Tanzania. Introduction. Sterilization is defined as the destruction of all forms of life ...

  7. Gamma irradiation and heat treatment for sterilization of Mushroom Spent Compost (MSC)

    International Nuclear Information System (INIS)

    Rosnani Abdul Rashid; Hassan Hamdani Mutaat; Foziah Ali; Zainab Harun; Hoe, P.C.K.; Mohd Meswan Maskom; Khairuddin Abdul Rahim

    2016-01-01

    Mushroom spent compost (MSC) refers to substrate residue from mushroom cultivation. MSC can be used as a material to improve soil properties for farming. MSC is also suitable as a carrier or substrate to hold beneficial microorganisms in bio fertilizer products. The carrier for bio fertilizer products must be sterilized completely before inoculating with bacteria inoculum. In this study, the effects of gamma irradiation and heat on sterilization of MSC were evaluated by microbial enumeration technique. The MSC was packed into polyethylene bags. The packed MSC were irradiated at different doses of 0 (control), 10, 20, 30, 40, 50 kGy, and heat sterilized at different autoclaving time of 0 (control), 15, 30, 45 and 60 minutes, separately. The irradiated and autoclaved samples were enumerated for viable colonies. The results showed that MSC was completely sterilized by gamma irradiation at the dose of 30 kGy whilst sterilization by heat required 30 minute autoclaving time. (author)

  8. Influence of heat sterilization on the organoleptic quality of spices

    NARCIS (Netherlands)

    Maarse, H.; Nijssen, L.M.; Nowak, M.

    1982-01-01

    Heat sterilization and storage of food products containing spices often results in a change of their organoleptic quality. Our knowledge about the stability of individual spices, however, is low. Therefore the heat stability of 8 different spices most frequently used has been investigated: cinnamon,

  9. Synergistic effects of heat and irradiation treatment (thermoradiation) in the sterilization of medical products

    International Nuclear Information System (INIS)

    Trauth, C.A. Jr.; Sivinski, H.D.

    1975-01-01

    This paper describes a generic class of sterilization processes is which properly chosen combinations of radiation and heat synergistically inactivate many bacteria and viruses. Treatments with optimal combinations are shown to offer the possibility of using lower total doses and lower temperatures than would be required separately for sterilization. This results from easier elimination of heat-labile, radioresistant organisms and radiolabile, heat-resistant organisms, and from synergistic inactivation of organisms which are both radioresistant and heat resistant. These processes depend upon temperature, dose-rate, and time in fairly complex ways; therefore, an analytical framework in which they can be defined is also presented. (author)

  10. Sterilization techniques without heating (ultraviolet ray, radiation and ozone)

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1991-01-01

    The recent demand of consumers for processed foods is characterized by the intention for health and nature, besides, the demand for low sweetness, salt reduction, no additive and freshness becomes strong. In view of the control of microorganisms in products, all these become the negative factors. Accordingly, in order to overcome them, it is urgently desired to develop new technology or to improve conventional methods. As to heating sterilization, the uniform temperature treatment to the inside of foods is difficult, and it cannot be applied to perishables. The high temperature sterilization above 120degC causes the change in nutrition composition and physical properties. Ultraviolet ray and ozone can be used for the sterilization of food surface and powder and liquid foods. Radiation treatment can be applied to packed foods and frozen foods as well as food surface. The principle and the fields of application of ultraviolet ray sterilization, radiation sterilization and ozone sterilization are reported. In the mechanism of these methods, the action to DNA and oxidation are common. (K.I.)

  11. Validation of the sterilization process for radiopharmaceuticals and materials with humid heat

    International Nuclear Information System (INIS)

    Robles, Anita; Moore, Mariel; Morote, Mario; Guevara, Buenaventura; Castro, Delcy; Paragulla, Wilson; Martinez, Ramos; Ocana, Elias; Novoa, Carlos

    2014-01-01

    A validation protocol has been designed and applied for the sterilization process of radiopharmaceuticals and materials, with humid heat for sodium pertechnetate Tc-99m injection solution (placebo) and materials, in compliance with good manufacturing practices for pharmaceutical products. The sterilization cycle set for each load is developed, according to the following parameters: 121 o C ± 1 o C (temperature), 15 ± 0.5 psi (pressure) and an exposure time of 20 and 15 minutes, respectively. The results in the penetration test with load, F0 values were higher than 20 minutes at 121 o C and for the biological challenge by biological indicators (Bacillus stearothermophilus) was negative in colder spots, in three consecutive runs. The sterilization process for each load and equipment has been validated to meet the established acceptance criteria. (authors).

  12. Chemical and biological evaluation of the nutritive value of heat-sterilized and radappertized feed mixtures

    International Nuclear Information System (INIS)

    Kooij, J.G. van

    1979-01-01

    In an attempt to develop a procedure for wholesomeness testing of irradiated food, which considers the use of irradiation as a physical process, large-scale feeding tests in pigs were carried out. Basic criteria of this procedure are the testing of wholly irradiated diets and the comparison of irradiation with another physical process, viz. heat treatment. The results of the biological evaluation of the protein showed, that protein quality of sow feed was not noticeably affected by either treatment, while protein quality of creep and hog feed was more adversely affected by heat than by irradiation. Heat-sterilized feeds always demonstrated the lowest values for lysine availability. Feed-borne vitamin E appeared very sensitive to irradiation. Losses of vitamins A, B 1 , B 6 and folic acid were in the order of 20% due to irradiation with 5 Mrad. Losses in heat-sterilized feeds were about 40% for vitamins A, B 1 and B 6 . Prior to heating, sow and creep feeds were fortified with vitamins A, B 1 and B 6 , and hog feed with vitamin A. Hogs on heat-sterilized feed showed a 10% increased feed conversion, indicating a less favourable growth than the pigs on untreated or on irradiated feed. The mean body-weight of piglets at 49 days on heat-sterilized feed was approx. 10% lower (significant at p<0.05) than the body-weight of piglets on either untreated or radappertized creep feed. Body-weight gain values of piglets on heat-sterilized creep feed are markedly lower than those of piglets on either untreated or radappertized creep feeds during that part of the lactation period when the young pigs consume considerable quantities of solid feed. Piglets and hogs on heat-sterilized feeds demonstrated an increased sensitivity to stress conditions

  13. Peracetic Acid: A Practical Agent for Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds

    Science.gov (United States)

    Yoganarasimha, Suyog; Trahan, William R.; Best, Al M.; Bowlin, Gary L.; Kitten, Todd O.; Moon, Peter C.

    2014-01-01

    Advanced biomaterials and sophisticated processing technologies aim at fabricating tissue-engineering scaffolds that can predictably interact within a biological environment at the cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed before clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam, and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone, a low melting polymer, and employing spores of Bacillus atrophaeus as biological indicators, we compared ethylene oxide, autoclaving and 80% ethanol to a known chemical sterilant, peracetic acid (PAA), for their ability to sterilize as well as their effects on scaffold properties. PAA diluted in 20% ethanol to 1000 ppm or above sterilized electrospun scaffolds in 15 min at room temperature while maintaining nano-architecture and mechanical properties. Scaffolds treated with PAA at 5000 ppm were rendered hydrophilic, with contact angles reduced to 0°. Therefore, PAA can provide economical, rapid, and effective sterilization of heat-sensitive polymeric electrospun scaffolds that are used in tissue engineering. PMID:24341350

  14. Combined effect of heat sterilization and ionizing radiation on folacin in canned food

    International Nuclear Information System (INIS)

    Hozova, B.; Sorman, L.

    1986-01-01

    The results are reported of a study in folacin changes following heat sterilization at reduced intensity combined with irradiation of model food products, such as pickled cauliflower and beef in gravy. The folacin content in cauliflower was found to vary with the intensity of heat sterilization; no significant effect was observed of varying radiation doses. With respect to beef in gravy, the study confirmed the suitability of the combined preservation process in view of the higher folacin retention in the given food type. (author). 3 tabs., 14 refs

  15. Natural convection heating of liquids, with reference to sterilization of canned food

    NARCIS (Netherlands)

    Hiddink, J.

    1975-01-01

    In a model system the physical transport phenomena that occur during the sterilization of a canned liquid food were investigated. Flow phenomena and heat transfer were studied experimentally as well as theoretically. Experiments on flow patterns and temperature profiles revealed a boundary

  16. Deformation of HyFlex CM instruments and their shape recovery following heat sterilization.

    Science.gov (United States)

    Alfoqom Alazemi, M; Bryant, S T; Dummer, P M H

    2015-06-01

    To assess the deformation of HyFlex CM instruments (Coltene Whaledent) when used in two instrumentation sequences and to assess their shape recovery after heat sterilization. Simulated root canals with four different shapes were prepared with HyFlex CM instruments using a single-length technique (n = 40) or a crown down technique (n = 40). Pre-preparation, post-preparation and post-sterilization standardized images of each instrument were recorded. Assessment of instrument deformation and their subsequent shape recovery was carried out visually and by comparing the digitised images. Data analysis was carried out using chi-square tests. None of the 400 instruments fractured. Visual assessment of instruments post-preparation revealed that 30.5% had unwound and 0.5% had reverse winding. Following sterilization 8.5% remained unwound and 0.5% remained with reverse winding. When assessing instrument shape using digital images, 35.25% were unwound post-preparation, which reduced to 11% post-sterilization. Nine size 25, 0.08 instruments deformed, but none fully regained their original shape after sterilization; however, other sizes of deformed instruments did regain their shape (P recovery. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  17. Comparison of heat stability of goat milk subjected to ultra-high temperature and in-container sterilization.

    Science.gov (United States)

    Chen, B Y; Grandison, A S; Lewis, M J

    2012-03-01

    Goat milk with and without stabilizing salt was subjected to in-container and UHT sterilization. Heat stability was assessed by measuring the amount of sediment in the milk. Without stabilizing salts, goat milk usually produced less sediment when subjected to in-container sterilization compared with UHT processing. Addition of stabilizing salts up to 12.8mM resulted in a progressive increase in sediment for in-container sterilization. In contrast, adding stabilizing salts at 6.4mM initially reduced sediment formation in UHT-treated milk but addition of stabilizing salts at 12.8mM increased sediment formation. Adding stabilizing salts to goat milk increased pH, decreased ionic calcium, and increased ethanol stability. Adding up to 2mM calcium chloride increased sediment formation more after UHT treatment than after in-container sterilization. These results suggest that no single mechanism or set of reactions causes milk to produce sediment during heating and that the favored pathway is different for UHT and in-container sterilization processes. Poor heat stability could be induced both by increasing ionic calcium and by decreasing it. Ethanol stability is not a good indicator of heat stability for in-container sterilization, but it may be for UHT sterilization, if milk does not enter the region of poor heat stability found at low concentrations of ionic calcium. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. Two-dimensional heat flow analysis applied to heat sterilization of ponderosa pine and Douglas-fir square timbers

    Science.gov (United States)

    William T. Simpson

    2004-01-01

    Equations for a two-dimensional finite difference heat flow analysis were developed and applied to ponderosa pine and Douglas-fir square timbers to calculate the time required to heat the center of the squares to target temperature. The squares were solid piled, which made their surfaces inaccessible to the heating air, and thus surface temperatures failed to attain...

  19. Heat sterilization of ash (Fraxinus spp.) firewood : heat-treating options, temperature monitoring and thermal verification

    Science.gov (United States)

    Xiping Wang; Richard Bergman; T. Mace

    2010-01-01

    Because of the potential risk associated with moving emerald ash borer (EAB)-infested firewood, the interstate movement of all hardwood firewood in the USA is currently restricted under the Federal quarantine. Communities and firewood producers are now faced with decisions on how to treat their firewood for interstate commerce. The new US Federal regulations for heat...

  20. The effects of inbreeding and heat stress on male sterility in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Pedersen, Louise Dybdahl; Pedersen, Asger Roer; Bijlsma, Kuke

    2011-01-01

    in benign and stressful environments using Drosophila melanogaster as a model organism. Male sterility was compared in 21 inbred lines and five non-inbred control lines at 25.0 and 29.0 °C. The effect of inbreeding on sterility was significant only at 29.0 °C. This stress-induced increase in sterility...

  1. Effects of ZnO nanoparticles and microwave heating on the sterilization and product quality of vacuum-packaged Caixin.

    Science.gov (United States)

    Liu, Qian; Zhang, Min; Fang, Zhong-xiang; Rong, Xiao-hong

    2014-09-01

    The sterilization of vacuum-packaged Caixin (Brassica chinensis L.), which is a green-leafy vegetable and also a low-acid food, remains a difficult problem. In this study, effects of ZnO nanoparticles and microwave heating on the sterilization and product quality of vacuum-packaged Caixin were investigated. Addition of ZnO nanoparticle suspension at 0.01-0.02 g kg(-1) reduced the number of bacterial colonies. The antibacterial activity was enhanced with the increased amount of ZnO nanoparticles. Microwave heating (915 and 2450 MHz) was used to sterilize Caixin samples. Samples had good product quality (better greenness, chroma and hue angle values, lower browning index and acceptable texture) and the lowest total colony number under the microwave heating condition of 400 W 150 s (2450 MHz). The best sterilization condition was observed under 2450 MHz microwave (400 W 150 s) heating combined with 0.02 g kg(-1) ZnO nanoparticle addition, which led to a total colony number of <1 log CFU g(-1) in Caixin samples within 7 days. © 2014 Society of Chemical Industry.

  2. Heat or gamma irradiation sterilization affects the hypocholesterolemic effect of guar gum in axenic and heteroxenic rats

    International Nuclear Information System (INIS)

    Alvarez-Leite, J.I.; Vieira, E.C.; Andrieux, C.

    1994-01-01

    Twenty-two axenic (germ free) or thirty heteroxenic (axenic colonized with human flora) 2.5-3.5 months old female Fisher rats were fed for four weeks either a hypercholesterolemic (hyper) diet or a hyper diet containing 5% guar gum (GG) sterilized by heat or gamma radiation. Axenic s rat fed the irradiated GG diet had had high cholesterolemia than their counterparts fed in autoclave diet (4.50 vs 2.29 mmol/l), whereas the method of sterilization had no effect on plasma cholesterol on axenic hyper or heteroxenic animals fed (7.35 vs 6.51 mg/dl). The levels of hepatic esterified cholesterol were higher in heteroxenic animals fed the irradiated GG diet than in their counterparts fed the autoclave GG diet (5.65 vs 3.57 mmol/g tissue). The composition of volatile fatty acids in the cecal contents of heteroxenic rats was dependent on the method of sterilization regardless of the presence of fiber: the levels of butyrate were 2.88 and 0,85 μmol/g for rats fed the autoclave and irradiated diets, respectively. Gamma radiation abolished the cholesterol-lowering effect of guar gum, whereas sterilization by heat preserved this effect. The hypocholesterolemic effect of guar was reduced by gamma irradiation sterilization and was probably mediated by qualitative changes in the intestinal microflora which interfered with bile acid absorption. (author)

  3. Sterilization processes. Meeting the demands of today's health care technology.

    Science.gov (United States)

    Crow, S

    1993-09-01

    Universal Precautions dictate sterilization for all invasive equipment that break the blood barrier; however, current methods of sterilization, such as steam and ethylene oxide gas (ETO), are not compatible with many of the delicate, heat-sensitive surgical instruments used in modern health care. In addition, traditional sterilization methods are often too time consuming for practical use in the operating room. Clearly, new sterilization processes need to be developed. In this article, the criteria modern sterilization processes must meet and how some manufacturers plan to meet this challenge are discussed. In addition, the pros and cons of using peracetic acid (the newest sterilization process currently available) are examined.

  4. Postpartum Sterilization

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ052 CONTRACEPTION Postpartum Sterilization • What is sterilization? • What is postpartum sterilization? • How is postpartum sterilization performed? • What kind of anesthesia is used for postpartum sterilization? • How ...

  5. Plasma Sterilization: New Epoch in Medical Textiles

    Science.gov (United States)

    Senthilkumar, P.; Arun, N.; Vigneswaran, C.

    2015-04-01

    Clothing is perceived to be second skin to the human body since it is in close contact with the human skin most of the times. In hospitals, use of textile materials in different forms and sterilization of these materials is an essential requirement for preventing spread of germs. The need for appropriate disinfection and sterilization techniques is of paramount importance. There has been a continuous demand for novel sterilization techniques appropriate for use on various textile materials as the existing sterilization techniques suffer from various technical and economical drawbacks. Plasma sterilization is the alternative method, which is friendlier and more effective on the wide spectrum of prokaryotic and eukaryotic microorganisms. Basically, the main inactivation factors for cells exposed to plasma are heat, UV radiation and various reactive species. Plasma exposure can kill micro-organisms on a surface in addition to removing adsorbed monolayer of surface contaminants. Advantages of plasma surface treatment are removal of contaminants from the surface, change in the surface energy and sterilization of the surface. Plasma sterilization aims to kill and/or remove all micro-organisms which may cause infection of humans or animals, or which can cause spoilage of foods or other goods. This review paper emphasizes necessity for sterilization, essentials of sterilization, mechanism of plasma sterilization and the parameters influencing it.

  6. Antioxidant and Antiproliferative Activities of Heated Sterilized Pepsin Hydrolysate Derived from Half-Fin Anchovy (Setipinna taty

    Directory of Open Access Journals (Sweden)

    Dongfeng Wang

    2011-06-01

    Full Text Available In this paper we studied the antioxidant and antiproliferative activities of the heated pepsin hydrolysate from a marine fish half-fin anchovy (HAHp-H. Furthermore, we compared the chemical profiles including the amino acid composition, the browning intensity, the IR and UV-visible spectra, and the molecular weight distribution between the half-fin anchovy pepsin hydrolysate (HAHp and HAHp-H. Results showed that heat sterilization on HAHp improved the 1,1-diphenyl-2-picryl-hydrazil (DPPH radical-scavenging activity and reducing power. In addition, the antiproliferative activities were all increased for HAHp-H on DU-145 human prostate cancer cell line, 1299 human lung cancer cell line and 109 human esophagus cancer cell line. The contents of free amino acid and reducing sugar of HAHp-H were decreased (P < 0.05. However, hydrophobic amino acid residues and the browning intensity of HAHp-H were increased. FT-IR spectroscopy indicated that amide I and amide III bands of HAHp-H were slightly modified, whereas band intensity of amide II was reduced dramatically. Thermal sterilization resulted in the increased fractions of HAHp-H with molecular weight of 3000–5000 Da and below 500 Da. The enhanced antioxidant and antiproliferative activities of HAHp-H might be attributed to the Maillard reaction.

  7. The relative nutritive value of irradiated spray-dried blood powder and heat-sterilized blood meal as measured in combination with whey protein

    International Nuclear Information System (INIS)

    Downes, T.E.H.; Nourse, L.D.; Siebrits, F.K.; Hastings, J.W.

    1987-01-01

    A method of processing blood meal in which nutritive value of the protein is preserved is described, since appreciable losses occur in the nutritive value of the protein when prepared by heat sterilization with drying at atmospheric pressure in steam jacketed vessels. Blood was spray dried and irradiated at an intensity of 10 kGy. Collectively the heat of spray drying and irradiation was effective in killing both the virus plaque-forming units and the bacteria, thus producing a commercially acceptable sterile product of higher nutritive value. The relative nutritive values (RNV) of 50:50 protein were 0,56 for whey protein concentrate plus heat-sterilized blood meal and 0.90 for whey protein concentrate plus irradiated spray-dried blood powder. Whey protein concentrate used as a control has a RNV of 1,0

  8. Priming of innate antimycobacterial immunity by heat-killed Listeria monocytogenes induces sterilizing response in the adult zebrafish tuberculosis model

    Directory of Open Access Journals (Sweden)

    Hanna Luukinen

    2018-01-01

    Full Text Available Mycobacterium tuberculosis remains one of the most problematic infectious agents, owing to its highly developed mechanisms to evade host immune responses combined with the increasing emergence of antibiotic resistance. Host-directed therapies aiming to optimize immune responses to improve bacterial eradication or to limit excessive inflammation are a new strategy for the treatment of tuberculosis. In this study, we have established a zebrafish-Mycobacterium marinum natural host-pathogen model system to study induced protective immune responses in mycobacterial infection. We show that priming adult zebrafish with heat-killed Listeria monocytogenes (HKLm at 1 day prior to M. marinum infection leads to significantly decreased mycobacterial loads in the infected zebrafish. Using rag1−/− fish, we show that the protective immunity conferred by HKLm priming can be induced through innate immunity alone. At 24 h post-infection, HKLm priming leads to a significant increase in the expression levels of macrophage-expressed gene 1 (mpeg1, tumor necrosis factor α (tnfa and nitric oxide synthase 2b (nos2b, whereas superoxide dismutase 2 (sod2 expression is downregulated, implying that HKLm priming increases the number of macrophages and boosts intracellular killing mechanisms. The protective effects of HKLm are abolished when the injected material is pretreated with nucleases or proteinase K. Importantly, HKLm priming significantly increases the frequency of clearance of M. marinum infection by evoking sterilizing immunity (25 vs 3.7%, P=0.0021. In this study, immune priming is successfully used to induce sterilizing immunity against mycobacterial infection. This model provides a promising new platform for elucidating the mechanisms underlying sterilizing immunity and to develop host-directed treatment or prevention strategies against tuberculosis. This article has an associated First Person interview with the first author of the paper.

  9. EPR STUDIES OF THERMALLY STERILIZED VASELINUM ALBUM.

    Science.gov (United States)

    Ramos, Paweł; Pilawa, Barbara

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy was used for examination of free radicals in thermally treated vaselinum album (VA). Thermal treatment in hot air as sterilization process was tested. Conditions of thermal sterilization were chosen according to the pharmaceutical norms. Vaselinum album was heated at the following conditions (T--temperature, t--time): T = 160°C and t = 120 min, T = 170°C and t = 60 min and T = 180°C and t = 30 min. The aim of this work was to determine concentration and free radical properties of thermally sterilized VA. EPR analysis for VA was done 15 min after sterilization. EPR measurements were done at room temperature. EPR spectra were recorded in the range of microwave power of 2.2-70 mW. g-Factor, amplitudes (A) and line width (ΔBpp) of the spectra were determined. The shape of the EPR spectra was analyzed. Free radical concentration (N) in the heated samples was determined. EPR spectra were not obtained for the non heated VA. EPR spectra were detected for all thermally sterilized samples. The spectra revealed complex character, their asymmetry depends on microwave power. The lowest free radicals concentration was found for the VA sterilized at 180°C during 30 min. EPR spectroscopy is proposed as the method useful for optimization of sterilization process of drugs.

  10. Hysteroscopic Sterilization

    Science.gov (United States)

    ... sterilization? Sterilization is a permanent form of birth control. What is tubal sterilization? Sterilization procedures for women are ... is quicker than from other types of sterilization. What are the risks of ... on for birth control. • There is a risk of injury to the ...

  11. Experimental Modeling of Sterilization Effects for Atmospheric Entry Heating on Microorganisms

    Science.gov (United States)

    Schubert, Wayne W.; Spry, James A.; Ronney, Paul D.; Pandian, Nathan R.; Welder, Eric

    2012-01-01

    The objective of this research was to design, build, and test an experimental apparatus for studying the parameters of atmospheric entry heating, and the inactivation of temperature-resistant bacterial spores. The apparatus is capable of controlled, rapid heating of sample coupons to temperatures of 200 to 350 C and above. The vacuum chamber permits operation under vacuum or special atmospheric gas mixtures.

  12. Food packaging and radiation sterilization

    International Nuclear Information System (INIS)

    Kawamura, Yoko

    1998-01-01

    Radiation sterilization has several merits that it is a positively effective sterilization method, it can be used to sterilize low heat-resistant containers and high gas barrier films, and there is no possibility of residual chemicals being left in the packages. It has been commercially used in 'Bag in a Box' and some food containers. The γ ray and an electron beam are commonly used in radiation sterilization. The γ ray can sterilize large size containers and containers with complex shapes or sealed containers due to its strong transmission capability. However, since the equipment tends to be large and expensive, it is generally used in off production lines. On the other hand, it is possible to install and electron beam system on food production lines since the food can be processed in a short time due to its high beam coefficient and its ease of maintenance, even though an electron beam has limited usage such as sterilizing relatively thin materials and surface sterilization due to the weak transmission. A typical sterilization dose is approximately 10-30 kGy. Direct effects impacting packaging materials, particularly plastics, include scission of polymer links, cross-linkage between polymers, and generating radiolysis products such as hydrogen, methane, aliphatic hydrocarbons, etc. Furthermore, under the existence of oxygen, the oxygen radicals generated by the radiation will oxidize and peroxidize polymer chains and will generate alcohol and carbonyl groups, which shear polymer links, and generate oxygen containing low molecular compounds. As a result, degradation of physical strength such as elongation and seal strength, generating foreign odor, and an increase in global migration values shown in an elution test are sometimes evident. The food packages have different shapes, materials, additives, number of microorganisms and purpose. Therefor the effects of radiation, the optimum dose and so on must be investigated on the individual package. (J.P.N.)

  13. Evaluation of Penicillium digitatum sterilization using non-equilibrium atmospheric pressure plasma by terahertz time-domain spectroscopy

    Science.gov (United States)

    Hiraoka, Takehiro; Ebizuka, Noboru; Takeda, Keigo; Ohta, Takayuki; Kondo, Hiroki; Ishikawa, Kenji; Kawase, Kodo; Ito, Masafumi; Sekine, Makoto; Hori, Masaru

    2011-10-01

    Recently, the plasma sterilization has attracted much attention as a new sterilization technique that takes the place of spraying agricultural chemicals. The conventional methods for sterilization evaluation, was demanded to culture the samples for several days after plasma treatment. Then, we focused on Terahertz time-domain spectroscopy (THz-TDS). At the THz region, vibrational modes of biological molecules and fingerprint spectra of biologically-relevant molecules were also observed. In this study, our purpose was measurement of the fingerprint spectrum of the Penicillium digitatum (PD) spore and establishment of sterilization method by THz-TDS. The sample was 40mg/ml PD spore suspensions which dropped on cover glass. The atmospheric pressure plasma generated under the conditions which Ar gas flow was 3slm, and alternating voltage of 6kV was applied. The samples were exposed the plasma from 10mm distance for 10 minutes. We could obtain the fingerprint spectrum of the PD spore from 0.5 to 0.9THz. This result indicated the possibility of in-situ evaluation for PD sterilization using THz-TDS.

  14. Sterilization of space hardware.

    Science.gov (United States)

    Pflug, I. J.

    1971-01-01

    Discussion of various techniques of sterilization of space flight hardware using either destructive heating or the action of chemicals. Factors considered in the dry-heat destruction of microorganisms include the effects of microbial water content, temperature, the physicochemical properties of the microorganism and adjacent support, and nature of the surrounding gas atmosphere. Dry-heat destruction rates of microorganisms on the surface, between mated surface areas, or buried in the solid material of space vehicle hardware are reviewed, along with alternative dry-heat sterilization cycles, thermodynamic considerations, and considerations of final sterilization-process design. Discussed sterilization chemicals include ethylene oxide, formaldehyde, methyl bromide, dimethyl sulfoxide, peracetic acid, and beta-propiolactone.

  15. Numerical analysis of heat transfer of canned liquid foods containing fibers or particles during sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.Z.; Sakai, N.; Hanzawa, T. [Tokyo Univ. of Fisheries, Tokyo (Japan). Dept. of Food Science and Tech.

    2000-10-01

    The velocity profile, temperature distribution, and the slowest heating point of a canned liquid food containing fibers or particles were calculated numerically by using fundamental equations that take account of the effect of free convection in the can at an unsteady state under the assumption of imaginary fluid with apparent physical properties. To check these calculated results, the temperature distribution in the can was measured experimentally under the same operating conditions as those of the theoretical analysis. The calculated results agree closely with the experimental ones. Adaptable ranges of present numerical analysis and the positional characteristics of the slowest heating point are shown. (author)

  16. Evaluation of steam sterilization conditions for [18F]fludeoxyglucose

    International Nuclear Information System (INIS)

    Santos, Priscilla F.; Nascimento, Leonardo T.; Valente, Eduardo S.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z.

    2011-01-01

    [ 18 F]Flu deoxyglucose ( 18 FDG) is the most commonly used radiopharmaceutical for positron emission tomography. Sterile filtration of the final product into sterile vials using 0.22 μm filter membrane is usually adopted for 18 FDG. However, Good Manufacturing Practice (GMP) guidelines recommend heat sterilization as the method of choice to ensure sterility of pharmaceutical preparations. The aim of this study was to essay different steam sterilization conditions in order to choose the best one for 18 FDG. Three different sterilization conditions were essayed. The first one at 121 deg C for 15 minutes, the second one at 135 deg C for 3.5 minutes and the third one at 133 deg C for 2 minutes. 18 FDG pH-formulation was kept around 6.0. At the end of autoclave cycles, 18 FDG sterility was evaluated by direct inoculation of 18 FDG in culture media and radiochemical purity was determined by TLC and HPLC. Results demonstrated that all essayed conditions were able to ensure 18 FDG sterility, but caused a decrease in radiochemical purity of 18 FDG. Autoclave cycle at 133 deg C for 2 minutes was the best essayed condition for 18 FDG terminal sterilization, once it provided the greater radiochemical purity value and took less time. 18 FDG was able to meet specifications after autoclave cycles, what supports the application of steam sterilization in routine 18 FDG production, in compliance with GMP. (author)

  17. Trends in sterilization since the introduction of Essure hysteroscopic sterilization.

    Science.gov (United States)

    Shavell, Valerie I; Abdallah, Mazen E; Shade, George H; Diamond, Michael P; Berman, Jay M

    2009-01-01

    To investigate trends in sterilization in women at the Detroit Medical Center, Michigan (DMC), since the introduction of Essure hysteroscopic sterilization. Retrospective study (Canadian Task Force classification II-2). Outpatient surgery center and university teaching hospitals. Women who underwent interval sterilization procedures at the DMC (Hutzel Women's Hospital, Sinai-Grace Hospital, and the Berry Center) and postpartum sterilization procedures at Hutzel Women's Hospital between January 1, 2002, and December 31, 2007. Permanent sterilization procedures including minilaparotomy tubal ligation, laparoscopic sterilization, Essure hysteroscopic sterilization, and postpartum tubal ligation performed at the time of cesarean section or after vaginal delivery. In all, 5509 permanent sterilization procedures were performed in the 6 years between January 1, 2002, and December 31, 2007, at the DMC facilities analyzed: 2484 interval sterilization procedures at Hutzel Women's Hospital, Sinai-Grace Hospital, and the Berry Center, and 3025 postpartum tubal ligations at Hutzel Women's Hospital. From 2002 through 2007, the decrease in laparoscopic sterilizations from 97.9% to 48.5% of all interval sterilization procedures corresponded significantly with the increase in Essure hysteroscopic sterilizations from 0.0% to 51.3% (p Essure hysteroscopic sterilizations increased significantly from 0.0% to 51.3% of all procedures. Since the approval of Essure hysteroscopic sterilization in November 2002, this minimally invasive method of hysteroscopic sterilization has increased in popularity at the DMC.

  18. NEW MODES OF HIGH STIR STERILIZATION OF CANNED «COMPOTE CHERRY» USING PRE HEATING OF FRUIT IN BANKS HOT WATER

    Directory of Open Access Journals (Sweden)

    M. M. Achmedova

    2013-01-01

    Full Text Available Conducted to determine the effect of increasing the temperature of the product prior to sealing the jars for the duration of modes of heat sterilization.It is revealed that the use of pre-heating the fruit in the banks before sealing provides the possibility of increasing the initial temperature of the syrup poured into the banks, increasing the initial temperature of the product, reducing the duration of the cooking process, and therebyimproving the quality of the finished product.

  19. Colony formation by sublethally heat-injured Zygosaccharomyces rouxii as affected by solutes in the recovery medium and procedure for sterilizing medium.

    Science.gov (United States)

    Golden, D A; Beuchat, L R

    1990-01-01

    Recovery and colony formation by healthy and sublethally heat-injured cells of Zygosaccharomyces rouxii as influenced by the procedure for sterilizing recovery media (YM agar [YMA], wort agar, cornmeal agar, and oatmeal agar) were investigated. Media were supplemented with various concentrations of glucose, sucrose, glycerol, or sorbitol and sterilized by autoclaving (110 degrees C, 15 min) and by repeated treatment with steam (100 degrees C). An increase in sensitivity was observed when heat-injured cells were plated on glucose-supplemented YMA at an aw of 0.880 compared with aws of 0.933 and 0.998. Colonies which developed from unheated and heated cells on YMA at aws of 0.998 and 0.933 generally exceeded 0.5 mm in diameter within 3.5 to 4 days of incubation at 25 degrees C, whereas colonies formed on YMA at an aw of 0.880 typically did not exceed 0.5 mm in diameter until after 5.5 to 6.5 days of incubation. The number of colonies exceeding 0.5 mm in diameter which were formed by heat-injured cells on YMA at an aw of 0.880 was 2 to 3 logs less than the total number of colonies detected, i.e., on YMA at an aw of 0.933 and using no limits of exclusion based on colony diameter. A substantial portion of cells which survived heat treatment were sublethally injured as evidenced by increased sensitivity to a suboptimum aw (0.880). In no instance was recovery of Z. rouxii significantly affected by medium sterilization procedure when glucose or sorbitol was used as the aw-suppressing solute.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2403251

  20. Colony formation by sublethally heat-injured Zygosaccharomyces rouxii as affected by solutes in the recovery medium and procedure for sterilizing medium.

    Science.gov (United States)

    Golden, D A; Beuchat, L R

    1990-08-01

    Recovery and colony formation by healthy and sublethally heat-injured cells of Zygosaccharomyces rouxii as influenced by the procedure for sterilizing recovery media (YM agar [YMA], wort agar, cornmeal agar, and oatmeal agar) were investigated. Media were supplemented with various concentrations of glucose, sucrose, glycerol, or sorbitol and sterilized by autoclaving (110 degrees C, 15 min) and by repeated treatment with steam (100 degrees C). An increase in sensitivity was observed when heat-injured cells were plated on glucose-supplemented YMA at an aw of 0.880 compared with aws of 0.933 and 0.998. Colonies which developed from unheated and heated cells on YMA at aws of 0.998 and 0.933 generally exceeded 0.5 mm in diameter within 3.5 to 4 days of incubation at 25 degrees C, whereas colonies formed on YMA at an aw of 0.880 typically did not exceed 0.5 mm in diameter until after 5.5 to 6.5 days of incubation. The number of colonies exceeding 0.5 mm in diameter which were formed by heat-injured cells on YMA at an aw of 0.880 was 2 to 3 logs less than the total number of colonies detected, i.e., on YMA at an aw of 0.933 and using no limits of exclusion based on colony diameter. A substantial portion of cells which survived heat treatment were sublethally injured as evidenced by increased sensitivity to a suboptimum aw (0.880). In no instance was recovery of Z. rouxii significantly affected by medium sterilization procedure when glucose or sorbitol was used as the aw-suppressing solute.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Reversibility of female sterilization.

    Science.gov (United States)

    Siegler, A M; Hulka, J; Peretz, A

    1985-04-01

    The discussion considers the current status of reversibility of sterilization in the US and describes clinical and experimental efforts for developing techniques designed for reversibility. It focuses on regret following sterilization, reversal potential of current sterilization techniques, patient selection, current reversal techniques, results of sterilization procedures, experimental approaches to reversal of current techniques of sterilization, and sterilization procedures devised for reversibility, in humans and in animals. Request is the 1st stage of reversal, but a request for sterilization reversal (SR) does not always mean regret for a decision made at the time. Frequently it is a wish to restore fertility because life circumstances have changed after a sterilization that was ppropriate at the time it was performed. Schwyhart and Kutner reviewed 22 studies published between 1949-69 in which they found that the percentage of patients regretting the procedure ranged from 1.3-15%. Requests for reversal remain low in most countries, but if sterilization becomes a more popular method of contraception, requests will also increase. The ideal operation considered as a reversaible method of sterilization should include an easy, reliable outpatient method of tubal occlusion with miniml risk or patient discomfort that subsequently could be reversed without the need for a major surgical intervention. Endoscopic methods have progressed toward the 1st objective. A recent search of the literature uncovered few series of SR of more than 50 cases. The 767 operations found were analyzed with regard to pregnancy outcome. The precent of live births varied from 74-78.8%, and the occurance of tubal pregnancies ranged from 1.7-6.5%. All of the confounding variables in patient selection and small numbers of reported procedures preclude any conclusion about the different techniques or the number of operations that give a surgeon a level of expertise. Few authors classify their

  2. Radiation sterilization

    International Nuclear Information System (INIS)

    Jacobs, G.P.

    1989-01-01

    In view of the application of ionizing radiation to sterilize pharmaceutical products, and the particular advantages of using this mode of sterilization for powders for injection, which cannot be sterilized by more conventional methods, it is important to recognise the possibility of modification of radiation response of bacteria when in close contact with various drug powders. For this study, bacterial spores, which lend themselves to dessication, and which can be dried onto an inert powder matrix, were chosen as the test system. The results of this work indicate that the additives tested have a modest protective effect on the spores. However, when considering a bacterial inactivation for sterilization purposes of between six and ten orders of magnitude, that is, a desired sterility assurance level of an expected maximum probability of a product item being non-sterile of 10 -6 , then the slight protective effect observed in this study approaches insignificance

  3. Radiation sterilization of some pharmaceutical preparations and medical products

    International Nuclear Information System (INIS)

    Tashmetov, M.Yu.; Makhkamov, Sh.M.; Urinov, Sh.S.; Turaev, A.S.; Sultanov, M.S.; Inagomov, Kh.S.

    2006-01-01

    Full text: In connection with intensive development of pharmacology and medical techniques, use of the products contacting to blood, with the internal environment of an organism, with wound surface, with mucous membranes and skin there were high requirements to sterility of pharmaceutical preparations and medical products. Traditional methods of sterilization (heat treatment, gas processing and processing the ferry) have some restrictions in application, and not insufficient degree of sterilization required for pharmaceutical preparations and medical products. Thermal processing can lead to degradation of structure (medicine), mechanical changes and loss of medical properties. Besides, it is impossible to carry out sterilization of many pharmaceutical preparations by a method of heat treatment. Sterilization of products in packing is very complicated, because sterilization temperature of packing and a product is different. Gas processing is basically applied to sterilization of medical products (syringes, bandage, cotton wools, etc.). However, the degree of sterility is low, because of rather low ability and heterogeneity of sterilizing substance. Sterilization in packing represents special difficulty and demands additional charges related with delivery of the purified gas from abroad. Last years alongside with known technological methods of sterilization of medical products and pharmaceutical preparations radiating methods of processing have found wide application. Use of electronic bunches with the moderate energy and various isotopes became a basis for formation and development of a new direction in the medicine, called by 'radiation sterilization'. The radiation technology is highly harmless and economic, not polluting substance and surrounding space. Unlike the specified traditional methods, radiating processing of products by the isotope 60 Co, radiating the gamma quantum, has unique opportunities - high penetrability in substance, providing uniformity of

  4. Sterile neutrino

    International Nuclear Information System (INIS)

    Anon.

    2007-01-01

    Paper deals with the information on the occurrence of the fields of the sterile neutrinos (the righthanded ones) mixed with the normal neutrinos (the lefthanded ones). Both the Max Plank Radioastronomy Institute and the Los Angeles University assumes that the occurrence of the keV mass sterile neutrinos may explain the dark matter nature, the fast rotation of the observed pulsars and the reionization processes. The issues associated with the possibility to record the sterile neutrinos were analyzed in the course of the Sterile Neutrinos in Astrophysics and Cosmology Workshop (Crans Montana, March 2006 [ru

  5. Materials Surfaces and sterility

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.

    2001-04-01

    A question of great interest in sterile and clean room technology is how can we devise a standard for the guarantee of sterility? Sterility is of widespread importance: it gives the life-time of our daily milk or yogurt, dominates the nature of food packing, and determines the feasibility of the miniaturization of biotechnology plants. All these phenomena are based on the principle of bioadhesion. Bioadhesion is also the basis of the biomimetic material technologies, like the attachment of selected protein layers that can be used for nanomasking. (orig.)

  6. High-Temperature-Short-Time (HTST) sterilization of liquid food with solid particles; HTST steriliseren van vloeibare levensmiddelen met vaste deeltjes

    Energy Technology Data Exchange (ETDEWEB)

    Boon, F

    2000-11-01

    As part of a sectoral study for the Association of the Dutch Vegetable and Fruit Processing Industry (VIGEF) a project started on the Factory 2005 concept. Options to improve the product quality of canned vegetables and fruit are investigated. One of the options is to reduce the heat during the sterilization process by applying the HTST method (high-temperature-short-time). Two processes are compared: the Gierschner process and the Stork Steripart process. [Dutch] Binnen de VIGEF (Vereniging van de Nederlandse Groenten- en Fruitverwerkende Industrie) is een project gestart in samenwerking met TNO dat zich richt op de fabriek 2005. Onderzoek wordt gedaan naar de mogelijkheden om de productkwaliteit van geconserveerde groenten en fruit te verbeteren. Het richt zich o.a. op de mogelijkheden om de hitte-intensiteit tijdens de sterilisatie te verlagen door te steriliseren volgens de HTST methode (high-temperature-short-time). Motivatie voor de ontwikkeling van HTST processen is primair kwaliteitsverbetering met gelijke microbiele veiligheid (t.o.v. het conventionele proces). Er worden 2 processen vergeleken: het Gierschner proces en het Stork Steripart proces.

  7. Evaluation of steam sterilization conditions for [{sup 18}F]fludeoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Priscilla F.; Nascimento, Leonardo T.; Valente, Eduardo S.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: somafe@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2011-07-01

    [{sup 18}F]Flu deoxyglucose ({sup 18}FDG) is the most commonly used radiopharmaceutical for positron emission tomography. Sterile filtration of the final product into sterile vials using 0.22 {mu}m filter membrane is usually adopted for {sup 18}FDG. However, Good Manufacturing Practice (GMP) guidelines recommend heat sterilization as the method of choice to ensure sterility of pharmaceutical preparations. The aim of this study was to essay different steam sterilization conditions in order to choose the best one for {sup 18}FDG. Three different sterilization conditions were essayed. The first one at 121 deg C for 15 minutes, the second one at 135 deg C for 3.5 minutes and the third one at 133 deg C for 2 minutes. {sup 18}FDG pH-formulation was kept around 6.0. At the end of autoclave cycles, {sup 18}FDG sterility was evaluated by direct inoculation of {sup 18}FDG in culture media and radiochemical purity was determined by TLC and HPLC. Results demonstrated that all essayed conditions were able to ensure {sup 18}FDG sterility, but caused a decrease in radiochemical purity of {sup 18}FDG. Autoclave cycle at 133 deg C for 2 minutes was the best essayed condition for {sup 18}FDG terminal sterilization, once it provided the greater radiochemical purity value and took less time. {sup 18}FDG was able to meet specifications after autoclave cycles, what supports the application of steam sterilization in routine {sup 18}FDG production, in compliance with GMP. (author)

  8. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    Directory of Open Access Journals (Sweden)

    Yanfeng Liu

    2017-10-01

    Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

  9. Heat conduction errors and time lag in cryogenic thermometer installations

    Science.gov (United States)

    Warshawsky, I.

    1973-01-01

    Installation practices are recommended that will increase rate of heat exchange between the thermometric sensing element and the cryogenic fluid and that will reduce the rate of undesired heat transfer to higher-temperature objects. Formulas and numerical data are given that help to estimate the magnitude of heat-conduction errors and of time lag in response.

  10. Effect of Different Sterilization Methods on the Extracted Oil from Oil Palm Fruit

    International Nuclear Information System (INIS)

    Hasimah Kasmin; Hasimah Kasmin; Roila Awang; Azwan Mat Lazim

    2015-01-01

    Sterilization is important process during the processing of oil palm fruits in order to produce crude palm oil (CPO). This process can be carried out using steam (conventional method), dry heating or wet heating method. In this study, the effectiveness of the dry heating and wet heating method for sterilization and solvent extraction were carried out. The sterilization time of these two methods were varied at 30, 60 and 90 min in order to determine their effectiveness on the oil extraction and their quality. Results showed that, at 30 min of sterilization, the wet heating produced a higher percentage of oil extraction compared to the conventional and dry heating, with average of 27.65 %, 19.01 % and 20.21 % respectively. In comparison with the conventional method, both sterilization methods gave better FFA and DOBI results. This can be seen where the average of free fatty acid (FFA) content for proposed sterilization method was between 0.37 % to 0.93 % while, average deterioration of bleach ability index (DOBI) was from 4.89 to 6.12. The average carotene content was in agreement with the conventional method at a range of 644.64 ppm to 764.80 ppm. (author)

  11. Sterilization in Finland: from eugenics to contraception.

    Science.gov (United States)

    Hemminki, E; Rasimus, A; Forssas, E

    1997-12-01

    The purpose of this paper was to describe the transition of sterilization in Finland from an eugenic tool to a contraceptive. Historical data were drawn from earlier reports in Finnish. Numbers of and reasons for sterilizations since 1950 were collected from nationwide sterilization statistics. Prevalence, characteristics of sterilized women, and women's satisfaction with sterilizations were studied from a 1994 nationwide survey (74% response rate). Logistic regression was used for adjustments. In the first half of the 20th century, eugenic ideology had influence in Finland as in other parts of Europe, and the 1935 and 1950 sterilization laws had an eugenic spirit. Regardless of this, the numbers of eugenic sterilizations remained low, and in practice, family planning was the main reason for sterilization. Nonetheless, prior to 1970 not all sterilizations were freely chosen, because sterilizations were sometimes used as a precondition for abortion. Female sterilizations showed remarkable fluctuation over time. Male sterilizations have been rare. The reasons stipulated by the law did not explain the numbers of sterilizations. In a 1994 survey, 9% of Finnish women reported they were using sterilization as their current contraceptive method (n = 189). Compared to women using other contraceptive methods, sterilized women were older, had had more births and pregnancies, and came from lower social classes. Sterilized women were satisfied with their sterilization, but there were women (8.5%) who regretted it. In conclusion, sterilizations have been and are likely to continue to be an important family planning method in Finland. The extreme gender ratio suggests a need for promoting male sterilizations, and women's expressed regrets suggest consideration of a higher age limit.

  12. Choice of sterilizing/disinfecting agent: determination of the Decimal ReductionTime (D-Value

    Directory of Open Access Journals (Sweden)

    Priscila Gava Mazzola

    2009-12-01

    Full Text Available Efforts to diminish the transmission of infections include programs in which disinfectants play a crucial role. Hospital surfaces and medical devices are potential sources of cross contamination, and each instrument, surface or area in a health care unit can be responsible for spread of infection. The decimal reduction time was used to study and compare the behavior of selected strains of microorganisms. The highest D-values for various bacteria were obtained for the following solutions: (i 0.1% sodium dichloroisocyanurate (pH 7.0 - E. coli and A. calcoaceticus (D = 5.9 min; (ii sodium hypochlorite (pH 7.0 at 0.025% for B. stearothermophilus (D = 24 min, E. coli and E. cloacae (D = 7.5 min; at 0.05% for B. stearothermophilus (D = 9.4 min and E. coli (D = 6.1 min. The suspension studies were an indication of the disinfectant efficacy on a surface. The data in this study reflect the formulations used and may vary from product to product. The expected effectiveness from the studied formulations shows that the tested agents can be recommended for surface disinfection as stated in present guidelines and emphasize the importance and need to develop routine and novel programs to evaluate product utility.Esforços para diminuir o risco de transmissões de infecções incluem programas nos quais os desinfetantes desempenham papel crucial. As superfícies de materiais médico-hospitalares, se não estiverem diretamente ligados à transmissão de doenças, podem contribuir, potencialmente, para uma contaminação cruzada secundária. Cada instrumento ou superfície do estabelecimento do ambiente de saúde que entra em contato com um paciente é um disseminador potencial de infecção. Para estudar e comparar o comportamento dos microrganismos selecionados foram realizados ensaios de determinação do tempo de redução decimal. Os maiores valores D determinados, foram: (i 0,1% dicloroisocianurato de sódio (NaDCC (pH 7.0 - E. coli e A. calcoaceticus (D = 5

  13. The Effect of Two Different Sterilization Methods on The Surface Topography and Microbial Contamination of Different Types of Endodontic Files

    International Nuclear Information System (INIS)

    Yousri, H.R.M.

    2014-01-01

    Sterilization is an integral part of the dental field. Sterilization should be used for instruments, surgical gloves and other items that come in direct contact with the blood stream or normally sterile tissues. Because sterilization is a process, not a single event, all components must be carried out correctly for sterilization to occur. To be effective, sterilization requires time, contact, temperature and with steam sterilization, high pressure. The effectiveness of any method of sterilization is also dependent upon four other factors: The type of microorganism present, the number of microorganisms present, the amount and type of organic material that protects the microorganisms and the number of cracks and crevices on an instrument that might harbor microorganisms. The most commonly used and standard methods of sterilization is the steam under pressure method using the autoclaves. However, it's not free from drawbacks; where it is not suitable for the heat sensitive equipment's such as the plastics, rubber. Also repeated autoclaving can cause pitting and dulling of cutting edges of instruments which might affect their clinical performance. Another alternative method of sterilization is by gamma rays which have been introduced for the sterilization of heat sensitive equipment's. Therefore conducting a study to investigate the effect of repeated sterilization cycles by either steam under pressure or gamma radiation on the surface topography of root canal enlarging instruments was thought to be valuable. The null hypothesis tested is that there is no difference in the effect of repeated sterilization by either steam under pressure or gamma radiation on the surface topography of root canal enlarging instruments

  14. Male and female sterility in Zambia

    Directory of Open Access Journals (Sweden)

    Athena Pantazis

    2014-02-01

    Full Text Available Background: Population measures of sterility are traditionally constructed for women, despite fertility and sterility being conditions of the couple. Estimates of male sterility provide insight into population-level sterility, and complement estimates based solely on women. Objective: This study seeks to estimate male sterility for the Gwembe Tonga of Zambia using male birth histories collected by the Gwembe Tonga Research Project from 1957 to 1995, while providing context by estimating female sterility for the Gwembe Tonga, as well as female sterility in all of Zambia, from Zambian DHS data (1992, 1997, 2001-02, and 2007. Methods: Sterility is measured using the Larson-Menken subsequently infertile indicator. Estimates are produced using discrete time event history analysis. Results: The odds of sterility were higher for women than men, though women's odds of sterility were only 1.5 times that of men's in the middle reproductive years. The odds of sterility increased steadily with age for both men and women, and across all datasets. However, women's sterility increased much more sharply with age than men's did, and women's odds of sterility were higher than men's at all reproductive ages.

  15. Processing of baby food using pressure-assisted thermal sterilization (PATS) and comparison with thermal treatment

    Science.gov (United States)

    Wang, Yubin; Ismail, Marliya; Farid, Mohammed

    2017-10-01

    Currently baby food is sterilized using retort processing that gives an extended shelf life. However, this type of heat processing leads to reduction of organoleptic and nutrition value. Alternatively, the combination of pressure and heat could be used to achieve sterilization at reduced temperatures. This study investigates the potential of pressure-assisted thermal sterilization (PATS) technology for baby food sterilization. Here, baby food (apple puree), inoculated with Bacillus subtilis spores was treated using PATS at different operating temperatures, pressures and times and was compared with thermal only treatment. The results revealed that the decimal reduction time of B. subtilis in PATS treatment was lower than that of thermal only treatment. At a similar spore inactivation, the retention of ascorbic acid of PATS-treated sample was higher than that of thermally treated sample. The results indicated that PATS could be a potential technology for baby food processing while minimizing quality deterioration.

  16. Optimal time-point for 68Ga-PSMA-11 PET/CT imaging in assessment of prostate cancer: feasibility of sterile cold-kit tracer preparation?

    Science.gov (United States)

    Beheshti, Mohsen; Paymani, Zeinab; Brilhante, Joana; Geinitz, Hans; Gehring, Daniela; Leopoldseder, Thomas; Wouters, Ludovic; Pirich, Christian; Loidl, Wolfgang; Langsteger, Werner

    2018-07-01

    In this prospective study, we evaluated the optimal time-point for 68 Ga-PSMA-11 PET/CT acquisition in the assessment of prostate cancer. We also examined, for the first time the feasibility of tracer production using a PSMA-11 sterile cold-kit in the clinical workflow of PET/CT centres. Fifty prostate cancer patients (25 staging, 25 biochemical recurrence) were enrolled in this study. All patients received an intravenous dose of 2.0 MBq/kg body weight 68 Ga-PSMA-11 prepared using a sterile cold kit (ANMI SA, Liege, Belgium), followed by an early (20 min after injection) semi-whole-body PET/CT scan and a standard-delay (100 min after injection) abdominopelvic PET/CT scan. The detection rates with 68 Ga-PSMA-11 were compared between the two acquisitions. The pattern of physiological background activity and tumour to background ratio were also analysed. The total preparation time was reduced to 5 min using the PSMA-11 sterile cold kit, which improved the final radionuclide activity by about 30% per single 68 Ge/ 68 Ga generator elution. Overall, 158 pathological lesions were analysed in 45 patients (90%) suggestive of malignancy on both (early and standard-delay) 68 Ga-PSMA PET/CT images. There was a significant (p PET/CT imaging seems to provide a detection rate comparable with that of standard-delay imaging. Furthermore, the shorter preparation time using the 68 Ga-PSMA-11 sterile cold kit and promising value of early PET/CT scanning could allow tailoring of imaging protocols which may reduce the costs and improve the time efficiency in PET/CT centres.

  17. Frictional Heating with Time-Dependent Specific Power of Friction

    Directory of Open Access Journals (Sweden)

    Topczewska Katarzyna

    2017-06-01

    Full Text Available In this paper analytical solutions of the thermal problems of friction were received. The appropriate boundary-value problems of heat conduction were formulated and solved for a homogeneous semi–space (a brake disc heated on its free surface by frictional heat fluxes with different and time-dependent intensities. Solutions were obtained in dimensionless form using Duhamel's theorem. Based on received solutions, evolution and spatial distribution of the dimensionless temperature were analyzed using numerical methods. The numerical results allowed to determine influence of the time distribution of friction power on the spatio-temporal temperature distribution in brake disc.

  18. Real-time modeling of heat distributions

    Science.gov (United States)

    Hamann, Hendrik F.; Li, Hongfei; Yarlanki, Srinivas

    2018-01-02

    Techniques for real-time modeling temperature distributions based on streaming sensor data are provided. In one aspect, a method for creating a three-dimensional temperature distribution model for a room having a floor and a ceiling is provided. The method includes the following steps. A ceiling temperature distribution in the room is determined. A floor temperature distribution in the room is determined. An interpolation between the ceiling temperature distribution and the floor temperature distribution is used to obtain the three-dimensional temperature distribution model for the room.

  19. Glass bead sterilizer comprehensively defeats hot air oven in orthodontic clinic

    Directory of Open Access Journals (Sweden)

    Sanjeev Vasudev Jakati

    2015-01-01

    Full Text Available Background: It is necessary to ′try in′ several bands before the correct one is selected. A possible concern with re-using such bands is the lack of cross-infection control. Aim and Objectives: To determine whether such bands could be successfully decontaminated with Glass bead sterilization so that they could be re-used without a cross-infection risk. Materials: Custom made molar bands were taken and buccal tubes,lingual sheath and lingual cleat were welded under strict aseptic conditions. Methods: Samples were divided into 2 groups i.e. A and B, based on mode for sterilization. Sterilized attachments were placed in each of 2 conical flask. The bacteria spores were inoculated into both flask under strict aseptic conditions. Bacteria Bacillus subtillis and Staphylococcus albus species were allowed to multiply in individual flasks filled with BHI broth for 24 hours. Bands from 1st group were placed in a glass bead sterilizer. For the 2 nd group i.e. hot air oven group, all bands were placed together. After sterilization bands were removed and placed in freshly sterilized 500ml conical flask containing BHI broth for 24 hours in the incubator. The following day randomly 4 attachments were selected from each group and streaked on blood agar culture plates. Results: After sterilization and on further incubation in BHI broth for 24 and 48 hrs. Respectively no growth was seen. Conclusion: 1 hr. of Hot Air Oven sterilization (excluding pre sterilization heat up time and post sterilization cooling time at 190°C is as effective as 3 min of Chair side Glass Bead sterilization.

  20. Pain Associated With Hysteroscopic Sterilization

    Science.gov (United States)

    Levy, Jenna; Childers, Meredith E.

    2007-01-01

    Background and Objectives: The safety and efficacy of female hysteroscopic sterilization using the Essure system has been well documented. Given the marked differences in the execution of hysteroscopic and laparoscopic sterilization, the objective of this study was to assess the experience of pain postprocedure between the 2. Secondary end-points included postoperative pain medication, time to return to normal activities, postprocedure bleeding, and patient satisfaction. Methods: Twenty cases each of laparoscopic sterilization (LS) and hysteroscopic sterilization (HS) were performed. Patients were surveyed regarding their experience of pain immediately postoperatively, 1 week, and 4 weeks post-procedure. Results: The average pain score immediately postprocedure was significantly lower among HS patients than among LS patients (t=−8.17, P<.0001). One-week post-procedure, none of the patients in the HS group reported any pain, while the average pain score among the LS patients was 2.65 (t =−9.67, P<.0001). Four weeks post-procedure, women in the HS group continued to report no pain, 35% of the LS group continued to report some pain (t=−3.04, P=.004). Conclusions: Hysteroscopic sterilization offers a minimally invasive, less painful, equally efficacious modality for sterilization than laparoscopic sterilization and should be available to all women seeking permanent birth control. PMID:17651558

  1. Sterilization by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Adir Jose; Mansano, Ronaldo Domingues; Andreoli Pinto, Terezinha de Jesus; Ruas, Ronaldo; Silva Zambon, Luis da; Silva, Monica Valero da; Verdonck, Patrick Bernard

    2004-07-31

    The use of polymeric medical devices has stimulated the development of new sterilization methods. The traditional techniques rely on ethylene oxide, but there are many questions concerning the carcinogenic properties of the ethylene oxide residues adsorbed on the materials after processing. Another common technique is the gamma irradiation process, but it is costly, its safe operation requires an isolated site and it also affects the bulk properties of the polymers. The use of a gas plasma is an elegant alternative sterilization technique. The plasma promotes an efficient inactivation of the micro-organisms, minimises the damage to the materials and presents very little danger for personnel and the environment. Pure oxygen reactive ion etching type of plasmas were applied to inactivate a biologic indicator, the Bacillus stearothermophilus, to confirm the efficiency of this process. The sterilization processes took a short time, in a few minutes the mortality was complete. In situ analysis of the micro-organisms' inactivating time was possible using emission spectrophotometry. The increase in the intensity of the 777.5 nm oxygen line shows the end of the oxidation of the biologic materials. The results were also observed and corroborated by scanning electron microscopy.

  2. Time-Dependent Natural Convection Couette Flow of Heat ...

    African Journals Online (AJOL)

    Time-Dependent Natural Convection Couette Flow of Heat Generating/Absorbing Fluid between Vertical Parallel Plates Filled With Porous Material. ... The numerical simulation conducted for some saturated liquids reveled that at t ≥ Pr the steady and unsteady state velocities (as well as the temperature of the fluid) ...

  3. Experimental Investigation of Heat Transfer during Night-Time Ventilation

    DEFF Research Database (Denmark)

    Artmann, Nikolai; Jensen, Rasmus Lund; Manz, H.

    2010-01-01

    is the heat transfer at the internal room surfaces. Increased convection is expected due to high air flow rates and the possibility of a cold air jet flowing along the ceiling, but the magnitude of these effects is hard to predict. In order to improve the predictability, heat transfer during night......-time ventilation in case of mixing and displacement ventilation has been investigated in a full scale test room. The results show that for low air flow rates displacement ventilation is more efficient than mixing ventilation. For higher air flow rates the air jet flowing along the ceiling has a significant effect...

  4. A gauge invariant theory for time dependent heat current

    International Nuclear Information System (INIS)

    Chen, Jian; ShangGuan, Minhui; Wang, Jian

    2015-01-01

    In this work, we develop a general gauge-invariant theory for AC heat current through multi-probe systems. Using the non-equilibrium Green’s function, a general expression for time-dependent electrothermal admittance is obtained where we include the internal potential due to the Coulomb interaction explicitly. We show that the gauge-invariant condition is satisfied for heat current if the self-consistent Coulomb interaction is considered. It is known that the Onsager relation holds for dynamic charge conductance. We show in this work that the Onsager relation for electrothermal admittance is violated, except for a special case of a quantum dot system with a single energy level. We apply our theory to a nano capacitor where the Coulomb interaction plays an essential role. We find that, to the first order in frequency, the heat current is related to the electrochemical capacitance as well as the phase accumulated in the scattering event. (paper)

  5. Performance of discrete heat engines and heat pumps in finite time

    Science.gov (United States)

    Feldmann; Kosloff

    2000-05-01

    The performance in finite time of a discrete heat engine with internal friction is analyzed. The working fluid of the engine is composed of an ensemble of noninteracting two level systems. External work is applied by changing the external field and thus the internal energy levels. The friction induces a minimal cycle time. The power output of the engine is optimized with respect to time allocation between the contact time with the hot and cold baths as well as the adiabats. The engine's performance is also optimized with respect to the external fields. By reversing the cycle of operation a heat pump is constructed. The performance of the engine as a heat pump is also optimized. By varying the time allocation between the adiabats and the contact time with the reservoir a universal behavior can be identified. The optimal performance of the engine when the cold bath is approaching absolute zero is studied. It is found that the optimal cooling rate converges linearly to zero when the temperature approaches absolute zero.

  6. An experimental study on sterilized barium sulfate (BaSO4) for vertebroplasty

    International Nuclear Information System (INIS)

    Chen Long; Ni Caifang; Ding Yi; Wang Yijin

    2005-01-01

    Objective: To search the proper sterilization method of barium for vertebroplasty. Methods: Perfusion agents were classified into two groups with ratio of powder/liquid(g/ml) as 3:2, and the percentage of BsSO 4 in powder was 20%. The barium powder in one group was sterilized by dry-heat and by ethylene oxide in the other. The barium powder of each group was germicultured and the polymerization time, CT value, strength and stiffness were measured respectively including 6 samples. Two independent-samples t text was used for analysis. Results: The germiculture in each group was negative. The difference in polmerization time and CT value of each group were not significant (P>0.05), while the strength and stiffness were significantly different (P<0.05). Conclusions: Sterilized effects of two groups were satisfied but the dry-heat barium sulfate is superior, more suitable for vertebroplasty. (authors)

  7. keV-Scale sterile neutrino sensitivity estimation with time-of-flight spectroscopy in KATRIN using self-consistent approximate Monte Carlo

    Science.gov (United States)

    Steinbrink, Nicholas M. N.; Behrens, Jan D.; Mertens, Susanne; Ranitzsch, Philipp C.-O.; Weinheimer, Christian

    2018-03-01

    We investigate the sensitivity of the Karlsruhe Tritium Neutrino Experiment (KATRIN) to keV-scale sterile neutrinos, which are promising dark matter candidates. Since the active-sterile mixing would lead to a second component in the tritium β-spectrum with a weak relative intensity of order sin ^2θ ≲ 10^{-6}, additional experimental strategies are required to extract this small signature and to eliminate systematics. A possible strategy is to run the experiment in an alternative time-of-flight (TOF) mode, yielding differential TOF spectra in contrast to the integrating standard mode. In order to estimate the sensitivity from a reduced sample size, a new analysis method, called self-consistent approximate Monte Carlo (SCAMC), has been developed. The simulations show that an ideal TOF mode would be able to achieve a statistical sensitivity of sin ^2θ ˜ 5 × 10^{-9} at one σ , improving the standard mode by approximately a factor two. This relative benefit grows significantly if additional exemplary systematics are considered. A possible implementation of the TOF mode with existing hardware, called gated filtering, is investigated, which, however, comes at the price of a reduced average signal rate.

  8. Identification by real-time PCR with SYBR Green of Leishmania spp. and Serratia marcescens in canine 'sterile' cutaneous nodular lesions.

    Science.gov (United States)

    Cornegliani, Luisa; Corona, Antonio; Vercelli, Antonella; Roccabianca, Paola

    2015-06-01

    Noninfectious, non-neoplastic, nodular to diffuse, so-called 'sterile' granulomatous/pyogranulomatous skin lesions (SGPSLs) are infrequently identified in dogs and may represent a diagnostic challenge. Their correct identification is based on history, histopathology and absence of intralesional foreign bodies and micro-organisms. The aim of this study was to investigate the presence of Leishmania spp., Mycobacterium spp., Serratia marcescens and Nocardia spp. by real-time PCR in canine nodular skin lesions histologically diagnosed as putatively sterile. Formalin-fixed skin biopsies were collected from 40 dogs. All samples were associated with an SGPSL diagnosis characterized by multifocal, nodular to diffuse, periadnexal and perifollicular pyogranulomas/granulomas. Neither micro-organisms nor foreign bodies were detected with haematoxylin and eosin staining, under polarized light. Further analyses included periodic acid Schiff, Ziehl-Neelsen, Fite Faraco, Giemsa and Gram histochemical stains; anti-Bacillus Calmette-Guérin (BCG) and Leishmania spp. immunohistochemistry; and real-time PCR analysis for Leishmania spp., Mycobacterium spp., S. marcescens and Nocardia spp. Special stains and BCG/immunohistochemistry were negative in all samples. Real-time PCR was positive for Leishmania spp. in four of 40 biopsies and for S. marcescens in two of 40 samples. Real-time PCR for Mycobacterium spp. and Nocardia spp. was negative. No correlation between real-time PCR positivity and a specific histological pattern was identified. Leishmania spp. have been previously identified as possible agents of certain SGPSLs, while the involvement of S. marcescens has not been investigated previously. According to our findings, Serratia spp. should be included in the list of agents possibly associated with a subgroup of granulomatous/pyogranulomatous skin lesions in dogs. © 2015 ESVD and ACVD.

  9. Time development of a blast wave with shock heated electrons

    International Nuclear Information System (INIS)

    Edgar, R.J.; Cox, D.P.

    1983-01-01

    Accurate approximations are presented for the time development of both edge conditions and internal structures of a blast wave with shock heated electrons, and equal ion and electron temperatures at the shock. The cases considered evolve in cavities with power law ambient densities (including the uniform ambient density case) and have negligible external pressure. Account is taken of possible saturation of the thermal conduction flux. The structures evolve smoothly to the adiabatic structures

  10. Birth planning and sterilization in China.

    Science.gov (United States)

    Short, S E; Linmao, M; Wentao, Y

    2000-11-01

    Sterilization is the most prevalent method of contraception in China. Approximately half of all women of reproductive age report that they or their husbands are sterilized. Using data from the China Health and Nutrition Survey we describe patterns of sterilization in eight Chinese provinces. With a discrete-time event history model we investigate the link between characteristics of local birth planning policy and the risk of sterilization. After controlling for parity, the risk of sterilization is highest in communities where birth planning policy is least strong as measured by exceptions to the one-child policy. These results suggest that couples with more flexibility in family building may have less control over contraceptive method use. Other factors affecting the risk of sterilization are a woman's age, parity, and whether or not she has a son. Our results emphasize the importance of taking into account multiple dimensions of reproductive behaviour when assessing one-child policy changes.

  11. Radiation sterilization: an industrial process

    International Nuclear Information System (INIS)

    Ley, F.J.

    1975-01-01

    A new dimension has been added to the use of radiation in the medical field with the introduction of radiation as a sterilizing agent. Its use in diagnosis through radioactive tracers or X-rays and in therapy administered with the most sophisticated of electrical machines or radioisotope units, is familiar in the hospital world, being well established therein. In contrast, the application of radiation sterilization is in industry where the installation of large radiation sources is already commonplace in many countries. The beginnings in the early 1950's centered on the Van de Graaff machine and linear accelerators and the pioneering efforts of Ethicon Inc. here in the United States must be recognized. However, although sterilization with electron beams is still current practice in a number of plants, the use of gamma rays from cobalt-60 is preferred. The first steps in this direction were taken by the U.K.A.E.A. which, in common with similar organizations elsewhere, was attempting to exploit the tremendous potential for cobalt-60 production arising through the rapid construction of nuclear reactors. The first full-scale commercial gamma plant was commissioned in the U.K. in 1960. It reached a loading of 500,000 curies before its demolition after twelve years of operation. The process gained rapid acceptance within industry and approval by health authorities because it provided a ''cold'' sterilization method combining the property of lethal effect with penetration. Its immediate impact occurred in the introduction of disposable products making it possible, for example, to use heat-labile plastics and new packaging materials and package designs. Certainly, the technique has proved complementary to sterilization methods based on heat and to the use of chemical agents, in particular ethylene oxide gas

  12. Gamma-sterilization

    International Nuclear Information System (INIS)

    Lindgren, E.

    1974-01-01

    The author makes a survey of his experience in sterilization and sterility control of medical products. At present three different methods are used, steamsterilization, gassterilizing and gammasterilizing. The investments and costs for gamma radiation is presented and a comparison of the costs for gamma- and gassterilization including sterility control is made. (M.S.)

  13. ISO radiation sterilization standards

    International Nuclear Information System (INIS)

    Lambert, Byron J.; Hansen, Joyce M.

    1998-01-01

    This presentation provides an overview of the current status of the ISO radiation sterilization standards. The ISO standards are voluntary standards which detail both the validation and routine control of the sterilization process. ISO 11137 was approved in 1994 and published in 1995. When reviewing the standard you will note that less than 20% of the standard is devoted to requirements and the remainder is guidance on how to comply with the requirements. Future standards developments in radiation sterilization are being focused on providing additional guidance. The guidance that is currently provided in informative annexes of ISO 11137 includes: device/packaging materials, dose setting methods, and dosimeters and dose measurement, currently, there are four Technical Reports being developed to provide additional guidance: 1. AAMI Draft TIR, 'Radiation Sterilization Material Qualification' 2. ISO TR 13409-1996, 'Sterilization of health care products - Radiation sterilization - Substantiation of 25 kGy as a sterilization dose for small or infrequent production batches' 3. ISO Draft TR, 'Sterilization of health care products - Radiation sterilization Selection of a sterilization dose for a single production batch' 4. ISO Draft TR, 'Sterilization of health care products - Radiation sterilization-Product Families, Plans for Sampling and Frequency of Dose Audits'

  14. Radiation sterilization of medical products- current trends and future prospects

    International Nuclear Information System (INIS)

    Sharma, G.

    1997-01-01

    In medical practice use of sterile pharmaceuticals and single use disposable medical devices is steadily increasing. Sterile pharmaceuticals like injections and ophthalmic ointments are required for therapy. Medical devices are employed for diagnostic, drug administration or corrective purposes, and as implants for temporary, short term or long term residence in the human system. All these products are made available in sterile form by treating them to a suitable process of sterilization i.e. dry/wet heat, ethylene oxide (EtO) gas or ionizing radiation. In this paper current trends and future prospects of radiation sterilization of medical products are given in detail. 9 refs., 7 tabs

  15. Time-resolved explosion of intense-laser-heated clusters.

    Science.gov (United States)

    Kim, K Y; Alexeev, I; Parra, E; Milchberg, H M

    2003-01-17

    We investigate the femtosecond explosive dynamics of intense laser-heated argon clusters by measuring the cluster complex transient polarizability. The time evolution of the polarizability is characteristic of competition in the optical response between supercritical and subcritical density regions of the expanding cluster. The results are consistent with time-resolved Rayleigh scattering measurements, and bear out the predictions of a recent laser-cluster interaction model [H. M. Milchberg, S. J. McNaught, and E. Parra, Phys. Rev. E 64, 056402 (2001)

  16. Time-resolved explosion of intense-laser-heated clusters

    International Nuclear Information System (INIS)

    Kim, K.Y.; Alexeev, I.; Parra, E.; Milchberg, H.M.

    2003-01-01

    We investigate the femtosecond explosive dynamics of intense laser-heated argon clusters by measuring the cluster complex transient polarizability. The time evolution of the polarizability is characteristic of competition in the optical response between supercritical and subcritical density regions of the expanding cluster. The results are consistent with time-resolved Rayleigh scattering measurements, and bear out the predictions of a recent laser-cluster interaction model [H. M. Milchberg, S. J. McNaught, and E. Parra, Phys. Rev. E 64, 056402 (2001)

  17. Tubal Sterilization

    Science.gov (United States)

    ... me? Are there other forms of permanent birth control? What if I want to reverse the procedure later ... time for me to have the procedure done? What are the risks involved with the ... Birth Control Methods U.S. Food and Drug Administration, Birth Control: ...

  18. Use of sodC versus ctrA for real-time polymerase chain reaction-based detection of Neisseria meningitidis in sterile body fluids

    Directory of Open Access Journals (Sweden)

    Fábio Takenori Higa

    2013-04-01

    Full Text Available We evaluated the use of a newly described sodC-based real-time-polymerase chain reaction (RT-PCR assay for detecting Neisseria meningitidis in normally sterile sites, such as cerebrospinal fluid and serum. The sodC-based RT-PCR assay has an advantage over ctrA for detecting nongroupable N. meningitidis isolates, which are commonly present in asymptomatic pharyngeal carriage. However, in our study, sodC-based RT-PCR was 7.5% less sensitive than ctrA. Given the public health impact of possible false-negative results due to the use of the sodC target gene alone, sodC-based RT-PCR for the diagnosis of meningococcal meningitis should be used with caution.

  19. Hydrodynamic time scales for intense laser-heated clusters

    International Nuclear Information System (INIS)

    Parra, Enrique; Alexeev, Ilya; Fan, Jingyun; Kim, Kiong Y.; McNaught, Stuart J.; Milchberg, Howard M.

    2003-01-01

    Measurements are presented of x-ray (>1.5 keV) and extreme ultraviolet (EUV, λ equal to 2-44 nm) emission from argon clusters irradiated with constant-energy (50 mJ), variable-width laser pulses ranging from 100 fs to 10 ns. The results for clusters can be understood in terms of two time scales: a short time scale for optimal resonant absorption at the critical-density layer in the expanding plasma, and a longer time scale for the plasma to drop below critical density. We present a one-dimensional hydrodynamic model of the intense laser-cluster interaction in which the laser field is treated self-consistently. We find that nonuniform expansion of the heated material results in long-time resonance of the laser field at the critical-density plasma layer. These simulations explain the dependence of generation efficiency on laser pulse width

  20. Methods of sterilization and monitoring of sterilization across selected dental practices in karachi, pakistan

    International Nuclear Information System (INIS)

    Ahmed, H.

    2015-01-01

    To assess methods of sterilization in dental practices in Karachi and secondly to investigate methods of monitoring sterilization in dental practices in Karachi, Pakistan. Study Design: Cross-sectional, descriptive study. Place and Duration of Study: Dental colleges, hospitals and private clinics of Karachi, Pakistan, from January to March 2013. Methodology: A total of 251 questionnaires were obtained. Descriptive statistics were computed and differences between groups were assessed through chi-square test using Statistical Package for the Social Sciences (SPSS) version 16.0. P-value < 0.05 was taken as statistically significant. Results: Autoclave, used by 155 (61.8%) dentists was the most common method of sterilization followed by more than one method, 65 (25.9%); dry heat, 24 (9.6%); and cold sterilization, 7 (2.8%). Majority of dentists, 126 (50.1%), never monitored sterilization and those who did monitored mostly monthly. Statistically significant difference was found amongst the three groups of dentists monitoring sterilization (p=0.09) and methods of sterilization (p < 0.01). Conclusion: Statistically significant difference was found in infection control practices of specialists, postgraduate trainees and general dentists regarding method of monitoring sterilization with majority of dentists never monitoring sterilization. (author)

  1. Ozone--the latest advance in sterilization of medical devices.

    Science.gov (United States)

    Murphy, Lorna

    2006-06-01

    How many times have procedures in your operating rooms been delayed because the instruments needed were still in the sterilizer? As Perioperative nurses you are likely to be quite familiar with the constant pressure to ensure that scarce instrumentation is available when needed. In 2003, a Canadian company developed a unique sterilization process employing ozone as the sterilizing agent. This technology is a safe, rapid and economical alternative to other low temperature sterilization modalities and may relieve some of the pressure experienced when instruments in short supply are in high demand. This article will discuss the principles of the sterilizer and the cycle and will explore the advantages of using this sterilization technology.

  2. Finite element solution of two dimensional time dependent heat equation

    International Nuclear Information System (INIS)

    Maaz

    1999-01-01

    A Microsoft Windows based computer code, named FHEAT, has been developed for solving two dimensional heat problems in Cartesian and Cylindrical geometries. The programming language is Microsoft Visual Basic 3.0. The code makes use of Finite element formulation for spatial domain and Finite difference formulation for time domain. Presently the code is capable of solving two dimensional steady state and transient problems in xy- and rz-geometries. The code is capable excepting both triangular and rectangular elements. Validation and benchmarking was done against hand calculations and published results. (author)

  3. Safety and efficacy of hysteroscopic sterilization compared with laparoscopic sterilization: an observational cohort study

    Science.gov (United States)

    Mao, Jialin; Pfeifer, Samantha; Schlegel, Peter

    2015-01-01

    Objective To compare the safety and efficacy of hysteroscopic sterilization with the “Essure” device with laparoscopic sterilization in a large, all-inclusive, state cohort. Design Population based cohort study. Settings Outpatient interventional setting in New York State. Participants Women undergoing interval sterilization procedure, including hysteroscopic sterilization with Essure device and laparoscopic surgery, between 2005 and 2013. Main outcomes measures Safety events within 30 days of procedures; unintended pregnancies and reoperations within one year of procedures. Mixed model accounting for hospital clustering was used to compare 30 day and 1 year outcomes, adjusting for patient characteristics and other confounders. Time to reoperation was evaluated using frailty model for time to event analysis. Results We identified 8048 patients undergoing hysteroscopic sterilization and 44 278 undergoing laparoscopic sterilization between 2005 and 2013 in New York State. There was a significant increase in the use of hysteroscopic procedures during this period, while use of laparoscopic sterilization decreased. Patients undergoing hysteroscopic sterilization were older than those undergoing laparoscopic sterilization and were more likely to have a history of pelvic inflammatory disease (10.3% v 7.2%, P<0.01), major abdominal surgery (9.4% v 7.9%, P<0.01), and cesarean section (23.2% v 15.4%, P<0.01). At one year after surgery, hysteroscopic sterilization was not associated with a higher risk of unintended pregnancy (odds ratio 0.84 (95% CI 0.63 to 1.12)) but was associated with a substantially increased risk of reoperation (odds ratio 10.16 (7.47 to 13.81)) compared with laparoscopic sterilization. Conclusions Patients undergoing hysteroscopic sterilization have a similar risk of unintended pregnancy but a more than 10-fold higher risk of undergoing reoperation compared with patients undergoing laparoscopic sterilization. Benefits and risks of both procedures

  4. Evaluation of Effects of Sterilization on Mechanical Properties of Orthodontic Wires

    Directory of Open Access Journals (Sweden)

    Sridhar Kannan

    2012-01-01

    Results: Dry heat sterilization, autoclave, 2% glutaraldehyde solution had no effect on ultimate tensile strength, 0.1% yield strength, modulus of elasticity and percentage elongation of stainless steel and elgiloy wires. Tensile strength and yield strength of Nitinol and b-titanium wires together with percentage elongation of b-titanium wires significantly increased following dry heat sterilization and autoclave. No detrimental effects on properties of wires were observed. These sterilization procedures could be safely recommended for sterilization of orthodontic wires.

  5. Radiosterilization and gas sterilization

    International Nuclear Information System (INIS)

    Schultz, H.A.; Gruenewald, T.

    1987-01-01

    The book presents a survey of the principles of cold sterilization by radiation or gas, and also of the problems involved. The reader who has to do with sterilization of some kind or other, as e.g. sterilization of medicaments, medical supplies, medical device, drugs, grafts, or food, will find comprehensive information on the various available methods and their effects, as well as on monitoring procedures and techniques, together with proposals for efficient documentation and validation of partial sterilization processes. The introduction summarizes the potentials of sterilization by radiation, and the subsequent by radiation, and the subsequent chapters explain the specific applicabilities of radiosterilization along with the most important criteria for evaluating the sterilizing efficiency. The information on the legal situation and requirements takes into account the second amendment of the Medical Preparations Act. With 38 figs., 14 tabs [de

  6. Inherited sterility in insects

    International Nuclear Information System (INIS)

    Carpenter, J.E.; Marec, F.; Bloem, S.

    2005-01-01

    The unique genetic phenomena responsible for inherited sterility (IS) in Lepidoptera and some other arthropods, as compared with full sterility, provide advantages for pest control. Lepidopteran females are usually more sensitive to radiation than males of the same species. This allows the radiation dose to be adjusted to suit programme requirements. When partially sterile males mate with wild females, the radiation-induced deleterious effects are inherited by the F 1 generation. As a result, egg hatch is reduced and the resulting offspring are both highly sterile and predominately male. Compared with the high radiation required to achieve full sterility in Lepidoptera, the lower dose of radiation used to induce F 1 sterility increases the quality and competitiveness of the released insects as measured by improved dispersal after release, increased mating ability, and superior sperm competition. F 1 sterile progeny produced in the field enhance the efficacy of released partially sterile males, and improve compatibility with other pest control strategies. In addition, F 1 sterile progeny can be used to increase the production of natural enemies, and to study the potential host and geographical ranges of exotic lepidopteran pests. (author)

  7. Integration of the time-dependent heat equation in the fuel rod performance program IAMBUS

    International Nuclear Information System (INIS)

    West, G.

    1982-01-01

    An iterative numerical method for integration of the time-dependent heat equation is described. No presuppositions are made for the dependency of the thermal conductivity and heat capacity on space, time and temperature. (orig.) [de

  8. Device and Container for Reheating and Sterilization

    Science.gov (United States)

    Sastry, Sudhir K.; Heskitt, Brian F.; Jun, Soojin; Marcy, Joseph E.; Mahna, Ritesh

    2012-01-01

    Long-duration space missions require the development of improved foods and novel packages that do not represent a significant disposal issue. In addition, it would also be desirable if rapid heating technologies could be used on Earth as well, to improve food quality during a sterilization process. For this purpose, a package equipped with electrodes was developed that will enable rapid reheating of contents via ohmic heating to serving temperature during space vehicle transit. Further, the package is designed with a resealing feature, which enables the package, once used, to contain and sterilize waste, including human waste for storage prior to jettison during a long-duration mission. Ohmic heating is a technology that has been investigated on and off for over a century. Literature indicates that foods processed by ohmic heating are of superior quality to their conventionally processed counterparts. This is due to the speed and uniformity of ohmic heating, which minimizes exposure of sensitive materials to high temperatures. In principle, the material may be heated rapidly to sterilization conditions, cooled rapidly, and stored. The ohmic heating device herein is incorporated within a package. While this by itself is not novel, a reusable feature also was developed with the intent that waste may be stored and re-sterilized within the packages. These would then serve a useful function after their use in food processing and storage. The enclosure should be designed to minimize mass (and for NASA's purposes, Equivalent System Mass, or ESM), while enabling the sterilization function. It should also be electrically insulating. For this reason, Ultem high-strength, machinable electrical insulator was used.

  9. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  10. Food irradiation and sterilization

    International Nuclear Information System (INIS)

    Josephson, E.S.

    1981-01-01

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25 to 70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning in achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70 to 80 0 C (bacon to 53 0 C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurrence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40 0 C to -20 0 C). Radappertized foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for 'wholesomeness' (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effects of radappertization on the 'wholesomeness' characteristics of these foods. (author)

  11. Changes in the timing, length and heating degree days of the heating season in central heating zone of China

    Science.gov (United States)

    Shen, Xiangjin; Liu, Binhui

    2016-01-01

    Climate change affects the demand for energy consumption, especially for heating and cooling buildings. Using daily mean temperature (Tmean) data, this study analyzed the spatiotemporal changes of the starting date for heating (HS), ending date for heating (HE), length (HL) and heating degree day (HDD) of the heating season in central heating zone of China. Over China’s central heating zone, regional average HS has become later by 0.97 day per decade and HE has become earlier by 1.49 days per decade during 1960–2011, resulting in a decline of HL (−2.47 days/decade). Regional averaged HDD decreased significantly by 63.22 °C/decade, which implies a decreasing energy demand for heating over the central heating zone of China. Spatially, there are generally larger energy-saving rate in the south, due to low average HDD during the heating season. Over China’s central heating zone, Tmean had a greater effect on HL in warm localities and a greater effect on HDD in cold localities. We project that the sensitivity of HL (HDD) to temperature change will increase (decrease) in a warmer climate. These opposite sensitivities should be considered when we want to predict the effects of climate change on heating energy consumption in China in the future. PMID:27651063

  12. Modular ionizing sterilizer (MIS)

    International Nuclear Information System (INIS)

    Freijo, Jose L.

    1999-01-01

    A transportable device designed to sterilize medical material and wastes by gamma irradiation is described. The sterilizer is formed by three modules: one of the modules contains the gamma source and can be removed to transport and transfer the source, the other modules are designed to introduce and draw out the materials to be irradiated

  13. Application of EPR spectroscopy to examine free radicals evolution during storage of the thermally sterilized Ungentum ophthalmicum.

    Science.gov (United States)

    Ramos, Paweł; Pilawa, Barbara

    2016-06-24

    Free radicals formed during thermal sterilization of the Ungentum ophthalmicum were examined by an X-band EPR spectroscopy. The influence of storage time (15 min; 1, 2 and 3 days after heating) on free radical properties and concentrations in this sample was determined. Thermal sterilization was done according to the pharmaceutical norms. The first-derivative EPR spectra with g-values about 2 were measured with magnetic modulation of 100 kHz in the range of microwave power 2.2-70 mW. The changes of amplitudes (A) and linewidths (ΔB pp ) with microwave powers were evaluated. Free radicals in concentration ∼10 17 spin/g were formed during heating of the tested Ungentum. Free radical concentration decreased with increase in storage time, and reached values ∼10 17 spin/g after 3 days from sterilization. The tested U. ophthalmicum should not be sterilized at a temperature of 160 °C because of the free radicals formation, or it should be used 3 days after heating, when free radicals were considerably quenched. Free radical properties remain unchanged during storage of the Ungentum. The EPR lines of the U. ophthalmicum were homogeneously broadened and their linewidths (ΔB pp ) increased with increase in microwave power. EPR spectroscopy is useful to examine free radicals to optimize sterilization process and storage conditions of ophthalmologic samples.

  14. Soil heat flux and day time surface energy balance closure

    Indian Academy of Sciences (India)

    Soil heat flux; surface energy balance; Bowen's ratio; sensible and latent ... The energy storage term for the soil layer 0–0.05 m is calculated and the ground heat ... When a new method that accounts for both soil thermal conduction and soil ...

  15. [Sterilization and eugenics].

    Science.gov (United States)

    Shasha, Shaul M

    2011-04-01

    The term "eugenics" was coined by Francis Galton in 1883 and was defined as the science of the improvement of the human race by better breeding. "Positive eugenics" referred to methods of encouraging the "most fit" to reproduce more often, while "negative eugenics" was related to ways of discouraging or preventing the "less fit" from reproducing by birth control and sterilization. Many western countries adopted eugenics programs including Britain, Canada, Norway, Australia, Switzerland and others. In Sweden more then 62,000 "unfits" were forcibly sterilized. Many states in the U.S.A. had adopted marriage laws with eugenics criteria including forced sterilization. Approximately 64,000 individuals were sterilized. Eugenics considerations also lay behind the adoption of the Immigration Restriction Act of 1924. The Largest plan on eugenics was adopted by the Nazi regime in Germany. Hundreds of thousands of people, who were viewed as being "unfit", were forcibly sterilized by different methods: Surgical sterilization or castration with severe complications and high mortality rates. X-ray irradiation. The method was suggested by Brack, and tested by Schuman using prisoners in Block No. 10 in Auschwitz and Birkenau. Experiments were also performed by Brack on prisoners using the "window method". "Klauberg method"--injection of irritating materials into the uterus. Experiments were conducted using the plant Caladium Seguinum which was believed to have sterilization and castration properties.

  16. Sterilization of solutions for parenterals products. Problem analysis

    Directory of Open Access Journals (Sweden)

    Yanelys Montes-González

    2017-09-01

    Full Text Available The solutions for the formulation of parenteral products must be sterile before the aseptic formulation process. For this reason, different methods of sterilization referred in the literature are analyzed. Thermodynamic criteria that rule the sterilization are presented. Furthermore, previous experiences in the sterilization of solutions for the formulation of parental products in an autoclave are analyzed, that take large time of processing and only low volumes of solution can be handled. Using jacketed stirred tanks for the sterilization may solve the problem and, therefore, criteria for the design of the later that allow to process high volumes of solution for the formulation of parenteral products are shown.

  17. [Legal statutes on sterilization].

    Science.gov (United States)

    Zupancic, K

    1980-01-01

    Sterilization in Yugoslavia is no population policy measure. Decision about the birth of children is free, a private problem of any individual, a basic right guaranteed by the Constitution. However, according to certain laws in Slovenia and Croatia, sterilization is allowed as a family planning method in persons over 35 year old. Only exceptionally can sterilization be applied in persons younger than 35 years: according to the Slovenian law, in cases when a person lacks the capacity of reasoning and also when there are medical indications, and according to the Croatian law, when there are medical and eugenic reasons (if the child is supposed to be born with negative congenital properties).

  18. Phenology, sterility and inheritance of two environment genic male sterile (EGMS) lines for hybrid rice.

    Science.gov (United States)

    El-Namaky, R; van Oort, P A J

    2017-12-01

    There is still limited quantitative understanding of how environmental factors affect sterility of Environment-conditioned genic male sterility (EGMS) lines. A model was developed for this purpose and tested based on experimental data from Ndiaye (Senegal) in 2013-2015. For the two EGMS lines tested here, it was not clear if one or more recessive gene(s) were causing male sterility. This was tested by studying sterility segregation of the F2 populations. Daylength (photoperiod) and minimum temperatures during the period from panicle initiation to flowering had significant effects on male sterility. Results clearly showed that only one recessive gene was involved in causing male sterility. The model was applied to determine the set of sowing dates of two different EGMS lines such that both would flower at the same time the pollen would be completely sterile. In the same time the local popular variety (Sahel 108, the male pollen donor) being sufficiently fertile to produce the hybrid seeds. The model was applied to investigate the viability of the two line breeding system in the same location with climate change (+2oC) and in two other potential locations: in M'Be in Ivory Coast and in the Nile delta in Egypt. Apart from giving new insights in the relation between environment and EGMS, this study shows that these insights can be used to assess safe sowing windows and assess the suitability of sterility and fertility period of different environments for a two line hybrid rice production system.

  19. Sterilization by gamma irradiation

    International Nuclear Information System (INIS)

    Reyes Frias, L.

    1992-01-01

    Since 1980 the National Institute of Nuclear Research counts with an Industrial Gamma Irradiator, for the sterilization of raw materials and finished products. Through several means has been promoted the use of this technology as alternative to conventional methods of sterilization as well as steam treatment and ethylene oxide. As a result of the made promotion this irradiator has come to its saturation limit being the sterilization irradiation one of the main services that National Institute of Nuclear Research offers to producer enterprises of disposable materials of medical use also of raw materials for the elaboration of cosmetic products and pharmaceuticals as well as dehydrated foods. It is presented the trend to the sterilization service by irradiation showed by the compilation data in a survey made by potential customers. (Author)

  20. An Analytical Solution for Transient Heat Conduction in a Composite Slab with Time-Dependent Heat Transfer Coefficient

    Directory of Open Access Journals (Sweden)

    Ryoichi Chiba

    2018-01-01

    Full Text Available An analytical solution is derived for one-dimensional transient heat conduction in a composite slab consisting of n layers, whose heat transfer coefficient on an external boundary is an arbitrary function of time. The composite slab, which has thermal contact resistance at n-1 interfaces, as well as an arbitrary initial temperature distribution and internal heat generation, convectively exchanges heat at the external boundaries with two different time-varying surroundings. To obtain the analytical solution, the shifting function method is first used, which yields new partial differential equations under conventional types of external boundary conditions. The solution for the derived differential equations is then obtained by means of an orthogonal expansion technique. Numerical calculations are performed for two composite slabs, whose heat transfer coefficient on the heated surface is either an exponential or a trigonometric function of time. The numerical results demonstrate the effects of temporal variations in the heat transfer coefficient on the transient temperature field of composite slabs.

  1. Seeking sterile neutrinos in Finslerian cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Deng [Nankai University, Theoretical Physics Division, Chern Institute of Mathematics, Tianjin (China); Meng, Xin-He [Nankai University, Department of Physics, Tianjin (China)

    2017-11-15

    For the first time, to search for sterile neutrinos in the framework of Finler geometry, we constrain four cosmological models using the most stringent constraint we can provide so far. We find that the Finslerian massless sterile neutrino model can, respectively, give a better cosmological fit to data and alleviate the current H{sub 0} tension more effectively than the other three models. For the Finslerian massless sterile neutrino model, we obtain the constraint N{sub eff} = 3.237{sup +0.092}{sub -0.185}, which is consistent with ΔN{sub eff} > 0 at the 1.03σ confidence level (CL). This gives a very weak hint of massless sterile neutrinos and may imply the non-existence of massless sterile neutrinos in the Finslerian cosmological setting. For the Finslerian massive sterile neutrino model, we obtain the constraints N{sub eff} = 3.143{sup +0.064}{sub -0.066}, which favors ΔN{sub eff} > 0 at the 1.47σ CL, and m{sub ν,sterile}{sup eff} < 0.121 eV at the 2σ CL which is much tighter than the Planck results. This very tight restriction appears to indicate the massive sterile neutrinos are also non-existent in the Finslerian scenarios. Consequently, one may conclude that the sterile neutrinos are possibly non-existent in the Finslerian universe. Our results are compatible with the recent results of the neutrino oscillation experiments implemented by the Daya Bay and MINOS collaborations and the cosmic ray one carried out by the IceCube collaboration. (orig.)

  2. Radiation sterilization of medical devices

    International Nuclear Information System (INIS)

    Kaluska, I.; Stuglik, Z.

    1996-01-01

    Overview of sterilization methods of medical devices has been given, with the special stress put on radiation sterilization. A typical validation program for radiation sterilization has been shown and also a comparison of European and ISO standards concerning radiation sterilization has been discussed. (author). 13 refs, 1 fig., 2 tabs

  3. Auditing radiation sterilization facilities

    Science.gov (United States)

    Beck, Jeffrey A.

    The diversity of radiation sterilization systems available today places renewed emphasis on the need for thorough Quality Assurance audits of these facilities. Evaluating compliance with Good Manufacturing Practices is an obvious requirement, but an effective audit must also evaluate installation and performance qualification programs (validation_, and process control and monitoring procedures in detail. The present paper describes general standards that radiation sterilization operations should meet in each of these key areas, and provides basic guidance for conducting QA audits of these facilities.

  4. Analytical and numerical treatment of the heat conduction equation obtained via time-fractional distributed-order heat conduction law

    Science.gov (United States)

    Želi, Velibor; Zorica, Dušan

    2018-02-01

    Generalization of the heat conduction equation is obtained by considering the system of equations consisting of the energy balance equation and fractional-order constitutive heat conduction law, assumed in the form of the distributed-order Cattaneo type. The Cauchy problem for system of energy balance equation and constitutive heat conduction law is treated analytically through Fourier and Laplace integral transform methods, as well as numerically by the method of finite differences through Adams-Bashforth and Grünwald-Letnikov schemes for approximation derivatives in temporal domain and leap frog scheme for spatial derivatives. Numerical examples, showing time evolution of temperature and heat flux spatial profiles, demonstrate applicability and good agreement of both methods in cases of multi-term and power-type distributed-order heat conduction laws.

  5. Radiation sterilization of medical products

    International Nuclear Information System (INIS)

    Khurshid, S.J.; Hussain, A.M.

    1989-01-01

    Radiation sterilization is the best method of sterilization, essentially for single use medical and surgical products. Pakistan has established a commercial gamma irradiation plant for this purpose. This article overviews the advantages and benefits of radiation sterilization to stimulate the interest of industrialists and the users in this technology. This technology can give a better medical care in the country and the growing demand can only be met by bulk sterilization. The radiation sterilized medical products can also compete well with the products sterilized by other methods in the international market, gamma sterilization is accepted internationally and if adopted it can boost our export of medical products. (author)

  6. Radiation sterilization of livestock feeds

    International Nuclear Information System (INIS)

    Kawashima, Koji

    1984-01-01

    The radiation sterilization of livestock feeds is not much used presently because the process is not known well, and the cost is relatively high. However, its effect of sterilization is absolute, the radiation-sterilized feeds are safe in both nutrition and toxicity, and do not affect the appetite of livestocks, and the radiation energy required is small. In the future, as in the sterilization of medical supplies, feed radiation sterilization plants should be established, to stabilize livestock industry and to contribute to the health control of experimental animals. The following matters are described: radiation, comparison between radiation sterilization and other sterilization methods, the practice of feed radiation sterilization, the adverse effects of radiation sterilization, economic aspect, and the situation of feed radiation sterilization in various countries. (Mori, K.)

  7. Long-time tails of the heat-conductivity time correlation functions for a magnetized plasma - a kinetic theory approach

    NARCIS (Netherlands)

    Schoolderman, A.J.; Suttorp, L.G.

    1989-01-01

    The long-time behaviour of the longitudinal and the transverse heat conductivity time correlation functions for a magnetized one-component plasma is studied by means of kinetic theory. To that end these correlation functions, which are defined as the inverse Laplace transforms of the dynamic heat

  8. Production of a sterile species: Quantum kinetics

    Science.gov (United States)

    Boyanovsky, D.; Ho, C. M.

    2007-10-01

    Production of a sterile species is studied within an effective model of active-sterile neutrino mixing in a medium in thermal equilibrium. The quantum kinetic equations for the distribution functions and coherences are obtained from two independent methods: the effective action and the quantum master equation. The decoherence time scale for active-sterile oscillations is τdec=2/Γaa, but the evolution of the distribution functions is determined by the two different time scales associated with the damping rates of the quasiparticle modes in the medium: Γ1=Γaacos⁡2θm; Γ2=Γaasin⁡2θm where Γaa is the interaction rate of the active species in the absence of mixing and θm the mixing angle in the medium. These two time scales are widely different away from Mikheyev-Smirnov-Wolfenstein resonances and preclude the kinetic description of active-sterile production in terms of a simple rate equation. We give the complete set of quantum kinetic equations for the active and sterile populations and coherences and discuss in detail the various approximations. A generalization of the active-sterile transition probability in a medium is provided via the quantum master equation. We derive explicitly the usual quantum kinetic equations in terms of the “polarization vector” and show their equivalence to those obtained from the quantum master equation and effective action.

  9. Observations on female sterilization in Chile.

    Science.gov (United States)

    Menanteau-Horta, D

    1982-01-01

    Prior to 1976, voluntary female sterilization was 1 of the regular family planning services offered in Chile. After that the Ministry of Public Health declared that it could not be considered a fertility regulation activity and could thus be performed only for health reasons. Between 1971-75, there was almost a 6-fold increase in the number of sterilizations performed at the Valdivia Regional Hospital, with a rise to 2400 procedures. Such an unprecedented increase in voluntary sterilization prompted this study. The results are based on a 1976 survey of women sterilized between 1971-75 at the Valdivia Regional Hospital. Personal interviews were conducted. The number of voluntary sterilizations there during the aforementioned period showed a sustained upward trend; the number of births increased only moderately during that time. The data on sterilization in the Valdivia area is compared to that collected by the Santiago study. Age, marital status, place of origin or residence, education, and religion were compared. Socioeconomic and occupational data were also examined. 9 of 10 women in Valdivia were from low-income families. This agrees closely with the Santiago data. About 1/4 of the women in both samples were employed outside the home. Also in both samples, about 1/2 of the spouses of sterilized women were blue collar workers; only 1/5 or less were white collar, and very few were professionals. About 52% in Valdivia and 45% in Santiago had borne 7 or more viable offspring. The average number of spontaneous abortions was also similar. A significantly higher percentage (P0.01) of Valdivia women used contraceptives. There are some general trends apparent in both groups as to the reasons for sterilization; most were prompted by difficult socioeconomic conditions. 37.9% of the Santiago women felt their families were complete and 27.3% of the other group cited the same reason. Other reasons were medical, failure of contraception, problems with spouse, and other. Medical

  10. Searching for Sterile Neutrinos with MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Timmons, Ashley [Manchester U.

    2016-01-01

    This document presents the latest results for a 3+1 sterile neutrino search using the $10.56 \\times 10^{20}$ protons-on-target data set taken from 2005 - 2012. By searching for oscillations driven by a large mass splitting, MINOS is sensitive to the existence of sterile neutrinos through any energy dependent deviations using a charged current sample, as well as looking at any relative deficit between neutral current events between the far and near detectors. This document will discuss the novel analysis that enabled a search for sterile neutrinos setting a limit in the previously unexplored regions in the parameter space $\\{\\Delta m^{2}_{41}, \\sin^2\\theta_{24}\\}$. The results presented can be compared to the parameter space suggested by LSND and MiniBooNE and complements other previous experimental searches for sterile neutrinos in the electron neutrino appearance channel.

  11. Influence of time presetting procedure for rapid local heat;.ng on brazing temperature conditions

    International Nuclear Information System (INIS)

    Lezhnin, G.P.; Tul'skikh, V.E.

    1985-01-01

    Correlation of known and suggested presetting procedures for heating period during induction brazing was conducted. It is shown that brazing time must be established considering heat propagation during heating in order to obtain the assigned joint temperature regardless of heating rate change. Methods for temperature calculation in assigned zones of the joint are suggested. The suggested presetting procedure for heating time was applied for induction vacuum brazing of a tube of 12Kh18N10T steel to a pipe connection of VT20 alloy

  12. Standardized Method for High-throughput Sterilization of Arabidopsis Seeds.

    Science.gov (United States)

    Lindsey, Benson E; Rivero, Luz; Calhoun, Chistopher S; Grotewold, Erich; Brkljacic, Jelena

    2017-10-17

    Arabidopsis thaliana (Arabidopsis) seedlings often need to be grown on sterile media. This requires prior seed sterilization to prevent the growth of microbial contaminants present on the seed surface. Currently, Arabidopsis seeds are sterilized using two distinct sterilization techniques in conditions that differ slightly between labs and have not been standardized, often resulting in only partially effective sterilization or in excessive seed mortality. Most of these methods are also not easily scalable to a large number of seed lines of diverse genotypes. As technologies for high-throughput analysis of Arabidopsis continue to proliferate, standardized techniques for sterilizing large numbers of seeds of different genotypes are becoming essential for conducting these types of experiments. The response of a number of Arabidopsis lines to two different sterilization techniques was evaluated based on seed germination rate and the level of seed contamination with microbes and other pathogens. The treatments included different concentrations of sterilizing agents and times of exposure, combined to determine optimal conditions for Arabidopsis seed sterilization. Optimized protocols have been developed for two different sterilization methods: bleach (liquid-phase) and chlorine (Cl2) gas (vapor-phase), both resulting in high seed germination rates and minimal microbial contamination. The utility of these protocols was illustrated through the testing of both wild type and mutant seeds with a range of germination potentials. Our results show that seeds can be effectively sterilized using either method without excessive seed mortality, although detrimental effects of sterilization were observed for seeds with lower than optimal germination potential. In addition, an equation was developed to enable researchers to apply the standardized chlorine gas sterilization conditions to airtight containers of different sizes. The protocols described here allow easy, efficient, and

  13. Release of bound residues of atrazine from soils through autoclaving and gamma radiation sterilization

    International Nuclear Information System (INIS)

    Nakagawa, L.E.; Andréa, M.M.

    1997-01-01

    The sterilization methods are particularly important to study the influence of microorganisms on the pesticide dissipation in soils. This study, conducted in the laboratories of the Instituto Biológico of São Paulo in august 1996, tested the influence of two methods of soil sterilization - moist heat (autoclaving) and γ radiation - on the release of nonextractable or bound residues. It was studied, as example, bound residues of the herbicide atrazine in two types of soil (gley humic and dark red latosol). In the soil samples submitted to the moist heat sterilization, the recovery of the previously bound residues as reextractable residues was 5.6 and 5.9 times higher than in the control soils, not submitted to any sterilization process. Therefore, the method itself released the residues, indicating that the autoclaving is not the most appropriate method for studies on the influence of microorganisms on the release of bound residues. Otherwise, the γ radiation did not modify the residues recovery when compared to the controls. (author) [pt

  14. Male sterility in chestnuts

    International Nuclear Information System (INIS)

    Omura, Mitsuo; Akihama, Tomoya

    1982-01-01

    A tentative plan was proposed for chestnuts based on their pollination system, male sterility and restoration. The studies on the male sterility of 1,063 cultivars and clones suggested that there were three types of male sterility. The first type (S-1) was characterized by antherless florets. In the second type (S-2), the catkins fell before anthesis, and the third type (S-3) appeared to develop normally in gross floral morphology, but the pollen grains were abnormal in shape and did not have germinating power. In an interspecific hybrid clone CS which belonged to S-1, fertility was restored in an open pollinated progeny. The use of CS and CSO-3 with its restored fertility, permitted the planning of breeding the chestnut hybrid cultivars propagated by seeds. The inbred clones with either male sterility or restorer genes are first bred mainly by back crossing with parents with favorable pollen. The clones are selected individually for early bearing, wasp and disease resistance, and restoration. Then, the hybrid seedling lines between male sterile and restorer inbreds are evaluated for homogenity in nut characters and tree habits. Next, the hybrid seedling lines selected will be examined for crop yield, vigor and cross compatibility. The superior seedling lines are finally selected, and the parental inbreds are grafted to be propagated for seed production orchards. (Kaihara, S.)

  15. Online, real-time corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.

    2005-01-01

    The corrosion control in district heating systems is today performed primarily with control of the water quality. The corrosion rate is kept low by assuring low dissolved oxygen concentration, high pH and low conductivity. Corrosion failures can occur, e.g. as a result of unknown oxygen ingress, ......, precipitation of deposits or crevices. The authors describe methods used for on-line monitoring of corrosion, cover the complications and the main results of a Nordic project.......The corrosion control in district heating systems is today performed primarily with control of the water quality. The corrosion rate is kept low by assuring low dissolved oxygen concentration, high pH and low conductivity. Corrosion failures can occur, e.g. as a result of unknown oxygen ingress...

  16. Audits of radiation sterilization facilities

    International Nuclear Information System (INIS)

    Kelkar, Prabhakar M.

    2001-01-01

    Johnson and Johnson is the world leader in sterilization science and technology. A special group of scientists and technologists are engaged in the development of new methods of sterilization, worldwide monitoring of sterilization processes, equipment and approvals for all types of sterilization processes. Kilmer Conference in the alternate year for the benefit of all those involved in improvement in sterilization science is held. Cobalt-60 gamma radiation for sterilization of medical products on commercial scale is used. This kind of mammoth task can only be achieved through systematic method of planning, auditing, expert review and approval of facilities

  17. Sterility induction in tsetse

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, C F [London School of Hygiene and Tropical Medicine (UK); Langley, P A [Bristol Univ. (UK)

    1982-01-01

    The first laboratory and field experiments on genetic control were with tsetse flies, and they made use of the sterility in crosses and hybrids between closely related species of the Glossina morsitans complex. Backcrosses indicate that there are two separate sterility mechanisms involved: (a) genetic incompatibility between a mother and the products of alien genes in the embryo or larva in the uterus; (b) inability of hybrid males to inseminate due to incompatibility of their X-chromosomes with an alien Y or autosomes. The two largest sterile male release programmes have been in Tanzania and Upper Volta, and have used irradiation at the pupal or adult stage, respectively, for the production of sterility. Male tsetse are remarkably resistant to radiosterilization and, with the doses required to induce dominant lethals in more than 95% of sperms, premature senescence and lethargic behaviour of the males tends to result. With G. morsitans irradiated at the puparial stage these effects can be alleviated by the use of a nitrogen atmosphere during irradiation. If the puparia are then transferred to air at 11/sup 0/C for transport to the release site, immediate emergence occurs on re-warming after arrival. This advantageous procedure was used for the releases in Tanzania. In addition to dominant lethals, irradiation also produces chromosome translocations which cause inherited partial sterility. A homozygous translocation line was selected but this example did not have sufficient fitness to be used in a mass rearing programme. Chemosterilants can be applied by pupal dipping, adult contact with deposits or in aerosols. Studies are now in progress on their use in association with odour-baited traps or pheromone-baited decoys as a means of sterilizing the wild population and thus avoiding the costly and difficult process of mass rearing tsetse.

  18. Time-dependent photon heat transport through a mesoscopic Josephson device

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wen-Ting; Zhao, Hong-Kang, E-mail: zhaohonk@bit.edu.cn

    2017-02-15

    The time-oscillating photon heat current through a dc voltage biased mesoscopic Josephson Junction (MJJ) has been investigated by employing the nonequilibrium Green’s function approach. The Landauer-like formula of photon heat current has been derived in both of the Fourier space and its time-oscillating versions, where Coulomb interaction, self inductance, and magnetic flux take effective roles. Nonlinear behaviors are exhibited in the photon heat current due to the quantum nature of MJJ and applied external dc voltage. The magnitude of heat current decreases with increasing the external bias voltage, and subtle oscillation structures appear as the superposition of different photon heat branches. The overall period of heat current with respect to time is not affected by Coulomb interaction, however, the magnitude and phase of it vary considerably by changing the Coulomb interaction. - Highlights: • The time-oscillating photon heat current through a mesoscopic Josephson Junction has been investigated. • The Landauer-like formula of photon heat current has been derived by the nonequilibrium Green’s function approach. • Nonlinear behaviors are exhibited in the photon heat current resulting from the self inductance and Coulomb interaction. • The oscillation structure of heat current is composed of the superposition of oscillations with different periods.

  19. Time-dependent photon heat transport through a mesoscopic Josephson device

    International Nuclear Information System (INIS)

    Lu, Wen-Ting; Zhao, Hong-Kang

    2017-01-01

    The time-oscillating photon heat current through a dc voltage biased mesoscopic Josephson Junction (MJJ) has been investigated by employing the nonequilibrium Green’s function approach. The Landauer-like formula of photon heat current has been derived in both of the Fourier space and its time-oscillating versions, where Coulomb interaction, self inductance, and magnetic flux take effective roles. Nonlinear behaviors are exhibited in the photon heat current due to the quantum nature of MJJ and applied external dc voltage. The magnitude of heat current decreases with increasing the external bias voltage, and subtle oscillation structures appear as the superposition of different photon heat branches. The overall period of heat current with respect to time is not affected by Coulomb interaction, however, the magnitude and phase of it vary considerably by changing the Coulomb interaction. - Highlights: • The time-oscillating photon heat current through a mesoscopic Josephson Junction has been investigated. • The Landauer-like formula of photon heat current has been derived by the nonequilibrium Green’s function approach. • Nonlinear behaviors are exhibited in the photon heat current resulting from the self inductance and Coulomb interaction. • The oscillation structure of heat current is composed of the superposition of oscillations with different periods.

  20. Effect of two viscosity models on lethality estimation in sterilization of liquid canned foods.

    Science.gov (United States)

    Calderón-Alvarado, M P; Alvarado-Orozco, J M; Herrera-Hernández, E C; Martínez-González, G M; Miranda-López, R; Jiménez-Islas, H

    2016-09-01

    A numerical study on 2D natural convection in cylindrical cavities during the sterilization of liquid foods was performed. The mathematical model was established on momentum and energy balances and predicts both the heating dynamics of the slowest heating zone (SHZ) and the lethal rate achieved in homogeneous liquid canned foods. Two sophistication levels were proposed in viscosity modelling: 1) considering average viscosity and 2) using an Arrhenius-type model to include the effect of temperature on viscosity. The remaining thermodynamic properties were kept constant. The governing equations were spatially discretized via orthogonal collocation (OC) with mesh size of 25 × 25. Computational simulations were performed using proximate and thermodynamic data for carrot-orange soup, broccoli-cheddar soup, tomato puree, and cream-style corn. Flow patterns, isothermals, heating dynamics of the SHZ, and the sterilization rate achieved for the cases studied were compared for both viscosity models. The dynamics of coldest point and the lethal rate F0 in all food fluids studied were approximately equal in both cases, although the second sophistication level is closer to physical behavior. The model accuracy was compared favorably with reported sterilization time for cream-style corn packed at 303 × 406 can size, predicting 66 min versus an experimental time of 68 min at retort temperature of 121.1 ℃. © The Author(s) 2016.

  1. Proposed Philippine radiation-sterilization plant, and a survey of market potential

    International Nuclear Information System (INIS)

    Singson, C.C.; Ibe, L.D.

    1975-01-01

    The paper deals with a study to assess the market potential of radiation sterilization in the Philippines. A market survey conducted with the technical assistance of an IAEA expert from India shows that most of the pharmaceutical industries engaged in the manufacture of medical products unanimously agree that there is an urgent need for a centralized radiation sterilization plant to meet the demands of sterilization of most of their products and packaging materials. The authorities of the government and some of the private hospitals surveyed are also very keen for the establishment of a sterilization facility since most modern medical products and devices are made of heat-sensitive thermoplastics which cannot be heat or steam sterilized. Availability of sterile products will help improve the public health standards of the population. The scope of the utilization of a radiation-sterilization facility in Diliman Quezon City is also discussed. (author)

  2. Learning control for batch thermal sterilization of canned foods.

    Science.gov (United States)

    Syafiie, S; Tadeo, F; Villafin, M; Alonso, A A

    2011-01-01

    A control technique based on Reinforcement Learning is proposed for the thermal sterilization of canned foods. The proposed controller has the objective of ensuring a given degree of sterilization during Heating (by providing a minimum temperature inside the cans during a given time) and then a smooth Cooling, avoiding sudden pressure variations. For this, three automatic control valves are manipulated by the controller: a valve that regulates the admission of steam during Heating, and a valve that regulate the admission of air, together with a bleeder valve, during Cooling. As dynamical models of this kind of processes are too complex and involve many uncertainties, controllers based on learning are proposed. Thus, based on the control objectives and the constraints on input and output variables, the proposed controllers learn the most adequate control actions by looking up a certain matrix that contains the state-action mapping, starting from a preselected state-action space. This state-action matrix is constantly updated based on the performance obtained with the applied control actions. Experimental results at laboratory scale show the advantages of the proposed technique for this kind of processes. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  3. MINOS Sterile Neutrino Search

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, David Jason [Univ. College London, Bloomsbury (United Kingdom)

    2009-02-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the v μ→ Vτ transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling ~2.5 x 1020 protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.

  4. Thermal In-Pouch Microwave Sterilization

    Science.gov (United States)

    2012-01-09

    straints for heat-sterilized ( retort ) packaging materials. Table 1: Functional Contributions of Materials in Foil Laminations MATERIAL FUNCTIONS...shelf life of the packaged entree items through temperature and humidity changes typically seen throughout the extended shelf life of the items. 15...Barber Industrial Ct.. Villa Rica. GA 30180. Final Scientific Report Light Barrier for Non-Foil Packaging Contract No. W911QY-08-C-0132 Thermal In

  5. Methodology for estimation of time-dependent surface heat flux due to cryogen spray cooling.

    Science.gov (United States)

    Tunnell, James W; Torres, Jorge H; Anvari, Bahman

    2002-01-01

    Cryogen spray cooling (CSC) is an effective technique to protect the epidermis during cutaneous laser therapies. Spraying a cryogen onto the skin surface creates a time-varying heat flux, effectively cooling the skin during and following the cryogen spurt. In previous studies mathematical models were developed to predict the human skin temperature profiles during the cryogen spraying time. However, no studies have accounted for the additional cooling due to residual cryogen left on the skin surface following the spurt termination. We formulate and solve an inverse heat conduction (IHC) problem to predict the time-varying surface heat flux both during and following a cryogen spurt. The IHC formulation uses measured temperature profiles from within a medium to estimate the surface heat flux. We implement a one-dimensional sequential function specification method (SFSM) to estimate the surface heat flux from internal temperatures measured within an in vitro model in response to a cryogen spurt. Solution accuracy and experimental errors are examined using simulated temperature data. Heat flux following spurt termination appears substantial; however, it is less than that during the spraying time. The estimated time-varying heat flux can subsequently be used in forward heat conduction models to estimate temperature profiles in skin during and following a cryogen spurt and predict appropriate timing for onset of the laser pulse.

  6. Effect of energetic ion loss on ICRF heating efficiency and energy confinement time in heliotrons

    International Nuclear Information System (INIS)

    Murakami, S.; Nakajima, N.; Okamoto, M.; Nuehrenberg, J.

    1999-06-01

    ICRF heating efficiency and the global energy confinement time during ICRF heating are investigated including the effect of energetic ion loss in heliotrons. The approximate formula of ICRF heating efficiency is derived using the results based on Monte Carlo simulations. The global energy confinement time including energetic ion effect can be expressed in terms of ICRF heating power, plasma density, and magnetic field strength in heliotrons. Our results in the CHS plasma show the systematic decrement of the global energy confinement time due to the energetic ion loss from the assumed energy confinement scaling law, which is consistent with the experimental observations. Also we apply our model to the ICRF minority heating in the LHD plasma in two cases of typical magnetic configurations. The clear increment of the global energy confinement time due to the stored energy of energetic tail ions is obtained in the 'orbit improved' configuration, while the decrement is observed in the 'standard' configuration. (author)

  7. Finite-Time Thermoeconomic Optimization of a Solar-Driven Heat Engine Model

    Directory of Open Access Journals (Sweden)

    Fernando Angulo-Brown

    2011-01-01

    Full Text Available In the present paper, the thermoeconomic optimization of an irreversible solar-driven heat engine model has been carried out by using finite-time/finite-size thermodynamic theory. In our study we take into account losses due to heat transfer across finite time temperature differences, heat leakage between thermal reservoirs and internal irreversibilities in terms of a parameter which comes from the Clausius inequality. In the considered heat engine model, the heat transfer from the hot reservoir to the working fluid is assumed to be Dulong-Petit type and the heat transfer to the cold reservoir is assumed of the Newtonian type. In this work, the optimum performance and two design parameters have been investigated under two objective functions: the power output per unit total cost and the ecological function per unit total cost. The effects of the technical and economical parameters on the thermoeconomic performance have been also discussed under the aforementioned two criteria of performance.

  8. Precooling With Crushed Ice: As Effective as Heat Acclimation at Improving Cycling Time-Trial Performance in the Heat.

    Science.gov (United States)

    Zimmermann, Matthew; Landers, Grant; Wallman, Karen; Kent, Georgina

    2018-02-01

    This study compared the effects of precooling (ice ingestion) and heat-acclimation training on cycling time-trial (CTT) performance in the heat. Fifteen male cyclists/triathletes completed two 800-kJ CTTs in the heat, with a 12-d training program in between. Initially, all participants consumed 7 g/kg of water (22°C) in 30 min before completing an 800-kJ CTT in hot, humid conditions (pre-CTT) (35°C, 50% relative humidity [RH]). Participants were then split into 2 groups, with the precooling group (n = 7) training in thermoneutral conditions and then undergoing precooling with ice ingestion (7 g/kg, 1°C) prior to the final CTT (post-CTT) and the heat-acclimation group (n = 8) training in hot conditions (35°C, 50% RH) and consuming water (7 g/kg) prior to post-CTT. After training in both conditions, improvement in CTT time was deemed a likely positive benefit (precooling -166 ± 133 s, heat acclimation -105 ± 62 s), with this result being similar between conditions (d = 0.22, -0.68-1.08 90% confidence interval [CI]). Core temperature for post-CTT was lower in precooling than in heat acclimation from 20 min into the precooling period until the 100-kJ mark of the CTT (d > 0.98). Sweat onset occurred later in precooling (250 ± 100 s) than in heat acclimation (180 ± 80 s) for post-CTT (d = 0.65, -0.30-1.50 90% CI). Thermal sensation was lower at the end of the precooling period prior to post-CTT for the precooling trial than with heat acclimation (d = 1.24, 0.90-1.58 90% CI). Precooling with ice ingestion offers an alternative method of improving endurance-cycling performance in hot conditions if heat acclimation cannot be attained.

  9. Inverse heat transfer analysis of a functionally graded fin to estimate time-dependent base heat flux and temperature distributions

    International Nuclear Information System (INIS)

    Lee, Haw-Long; Chang, Win-Jin; Chen, Wen-Lih; Yang, Yu-Ching

    2012-01-01

    Highlights: ► Time-dependent base heat flux of a functionally graded fin is inversely estimated. ► An inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied. ► The distributions of temperature in the fin are determined as well. ► The influence of measurement error and measurement location upon the precision of the estimated results is also investigated. - Abstract: In this study, an inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied to estimate the unknown time-dependent base heat flux of a functionally graded fin from the knowledge of temperature measurements taken within the fin. Subsequently, the distributions of temperature in the fin can be determined as well. It is assumed that no prior information is available on the functional form of the unknown base heat flux; hence the procedure is classified as the function estimation in inverse calculation. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The influence of measurement errors and measurement location upon the precision of the estimated results is also investigated. Results show that an excellent estimation on the time-dependent base heat flux and temperature distributions can be obtained for the test case considered in this study.

  10. Time-evolution of photon heat current through series coupled two mesoscopic Josephson junction devices

    Science.gov (United States)

    Lu, Wen-Ting; Zhao, Hong-Kang; Wang, Jian

    2018-03-01

    Photon heat current tunneling through a series coupled two mesoscopic Josephson junction (MJJ) system biased by dc voltages has been investigated by employing the nonequilibrium Green’s function approach. The time-oscillating photon heat current is contributed by the superposition of different current branches associated with the frequencies of MJJs ω j (j = 1, 2). Nonlinear behaviors are exhibited to be induced by the self-inductance, Coulomb interaction, and interference effect relating to the coherent transport of Cooper pairs in the MJJs. Time-oscillating pumping photon heat current is generated in the absence of temperature difference, while it becomes zero after time-average. The combination of ω j and Coulomb interactions in the MJJs determines the concrete heat current configuration. As the external and intrinsic frequencies ω j and ω 0 of MJJs match some specific combinations, resonant photon heat current exhibits sinusoidal behaviors with large amplitudes. Symmetric and asymmetric evolutions versus time t with respect to ω 1 t and ω 2 t are controlled by the applied dc voltages of V 1 and V 2. The dc photon heat current formula is a special case of the general time-dependent heat current formula when the bias voltages are settled to zero. The Aharonov-Bohm effect has been investigated, and versatile oscillation structures of photon heat current can be achieved by tuning the magnetic fluxes threading through separating MJJs.

  11. Influence of the Microwave Heating Time on the Self-Healing Properties of Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Jose Norambuena-Contreras

    2017-10-01

    Full Text Available This paper aims to evaluate the influence of the microwave heating time on the self-healing properties of fibre-reinforced asphalt mixtures. To this purpose, self-healing properties of dense asphalt mixtures with four different percentages of steel wool fibres were evaluated as the three-point bending strength before and after healing via microwave heating at four different heating times. Furthermore, the thermal behaviour of asphalt mixtures during microwave heating was also evaluated. With the aim of quantifying the efficiency of the repair process, ten damage-healing cycles were done in the test samples. In addition, self-healing results were compared with the fibre spatial distribution inside asphalt samples evaluated by CT-scans. Crack-size change on asphalt samples during healing cycles was also evaluated through optical microscopy. It was found that the heating time is the most influential variable on the healing level reached by the asphalt mixtures tested by microwave radiation. CT-Scans results proved that fibre spatial distribution into the asphalt mixtures play an important role in the asphalt healing level. Finally, it was concluded that 40 s was the optimum heating time to reach the highest healing levels with the lowest damage on the asphalt samples, and that heating times over 30 s can seal the cracks, thus achieving the self-healing of asphalt mixtures via microwave heating.

  12. Time differentiated nuclear resonance spectroscopy coupled with pulsed laser heating in diamond anvil cells

    Energy Technology Data Exchange (ETDEWEB)

    Kupenko, I., E-mail: kupenko@esrf.fr; Strohm, C. [Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth (Germany); ESRF-The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9 (France); McCammon, C.; Cerantola, V.; Petitgirard, S.; Dubrovinsky, L. [Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth (Germany); Glazyrin, K. [Photon Science, DESY, D-22607 Hamburg (Germany); Vasiukov, D.; Aprilis, G. [Laboratory of Crystallography, Material Physics and Technology at Extreme Conditions, Universität Bayreuth, D-95440 Bayreuth (Germany); Chumakov, A. I.; Rüffer, R. [ESRF-The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9 (France)

    2015-11-15

    Developments in pulsed laser heating applied to nuclear resonance techniques are presented together with their applications to studies of geophysically relevant materials. Continuous laser heating in diamond anvil cells is a widely used method to generate extreme temperatures at static high pressure conditions in order to study the structure and properties of materials found in deep planetary interiors. The pulsed laser heating technique has advantages over continuous heating, including prevention of the spreading of heated sample and/or the pressure medium and, thus, a better stability of the heating process. Time differentiated data acquisition coupled with pulsed laser heating in diamond anvil cells was successfully tested at the Nuclear Resonance beamline (ID18) of the European Synchrotron Radiation Facility. We show examples applying the method to investigation of an assemblage containing ε-Fe, FeO, and Fe{sub 3}C using synchrotron Mössbauer source spectroscopy, FeCO{sub 3} using nuclear inelastic scattering, and Fe{sub 2}O{sub 3} using nuclear forward scattering. These examples demonstrate the applicability of pulsed laser heating in diamond anvil cells to spectroscopic techniques with long data acquisition times, because it enables stable pulsed heating with data collection at specific time intervals that are synchronized with laser pulses.

  13. Revisiting cosmological bounds on sterile neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, Aaron C. [Institute for Particle Physics Phenomenology (IPPP), Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Martínez, Enrique Fernández [Departamento and Instituto de Física Teórica (IFT), UAM/CSIC, Universidad Autonoma de Madrid, C/ Nicolás Cabrera 13-15, E-28049 Cantoblanco, Madrid (Spain); Hernández, Pilar; Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Lattanzi, Massimiliano, E-mail: aaron.vincent@durham.ac.uk, E-mail: enrique.fernandez-martinez@uam.es, E-mail: m.pilar.hernandez@uv.es, E-mail: omena@ific.uv.es, E-mail: lattanzi@fe.infn.it [Dipartimento di Fisica e Science della Terra, Università di Ferrara and INFN, sezione di Ferrara, Polo Scientifico e Tecnologico, Edificio C Via Saragat, 1, I-44122 Ferrara (Italy)

    2015-04-01

    We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R{sub CMB} and the sound horizon r{sub s} from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin{sup 2}θ ∼< 0.026 (m{sub s}/eV){sup −2}.

  14. Full-scale and time-scale heating experiments at Stripa: preliminary results

    International Nuclear Information System (INIS)

    Cook, N.G.W.; Hood, Michael; California Univ., Berkeley

    1978-01-01

    Two full-scale heating experiments and a time-scale heating experiment have recently been started in granite 340 meters below surface. The purpose of the full-scale heating experiments is to assess the near-field effects of thermal loading for the design of an underground repository of nuclear wastes. That of the time-scale heating experiments is to obtain field data of the interaction between heaters and its effect on the rock mass during a period of about two years, which corresponds to about twenty years of full-scale operation. Geological features of the rock around each experiment have been mapped carefully, and temperatures, stresses and displacements induced in the rock by heating have been calculated in advance of the experiments. Some 800 different measurements are recorded at frequent intervals by a computer system situated underground. These data can be compared at any time with predictions made earlier on video display units underground

  15. Modeling heat dominated electric breakdown in air, with adaptivity to electron or ion time scales

    NARCIS (Netherlands)

    Agnihotri, A.; Hundsdorfer, W.; Ebert, U.

    2017-01-01

    We model heat dominated electrical breakdown in air in a short planar gap. We couple the discharge dynamics in fluid approximation with the hydrodynamic motion of the air heated by the discharge. To be computationally efficient, we derive a reduced model on the ion time scale, and we switch between

  16. Optimization of solar-powered Stirling heat engine with finite-time thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Yaqi, Li [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Xi' an Research Institute of Hi-Tech, Xi' an, Shaanxi 710025 (China); Yaling, He; Weiwei, Wang [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2011-01-15

    A mathematical model for the overall thermal efficiency of the solar-powered high temperature differential dish-Stirling engine with finite-rate heat transfer, regenerative heat losses, conductive thermal bridging losses and finite regeneration processes time is developed. The model takes into consideration the effect of the absorber temperature and the concentrating ratio on the thermal efficiency; radiation and convection heat transfer between the absorber and the working fluid as well as convection heat transfer between the heat sink and the working fluid. The results show that the optimized absorber temperature and concentrating ratio are at about 1100 K and 1300, respectively. The thermal efficiency at optimized condition is about 34%, which is not far away from the corresponding Carnot efficiency at about 50%. Hence, the present analysis provides a new theoretical guidance for designing dish collectors and operating the Stirling heat engine system. (author)

  17. MR imaging of ''sterilized'' lymphoma

    International Nuclear Information System (INIS)

    Zerhouni, E.A.; Fishman, E.K.; Jones, R.; Siegelman, S.S.; Soulen, R.L.

    1986-01-01

    Residual masses are commonly observed after effective therapy in patients with lymphoma. These masses may be sterile but their presence poses a management problem, inasmuch as there is no adequate means of distinguishing sterile from active masses. The potential role of MR imaging in this context was evaluated by studying a group of 15 patients with stable, residual, presumably inactive masses (as determined from CT) and comparing the MR imaging findings in patients with newly diagnosed, untreated or recently treated lymphoma. All patients underwent an MR imaging examination consisting of one short repetition time (TR), short echo time (TE) (T1-weighted) sequence and one long TR, long TE(T2-weighted) sequence. The signal intensity of the masses was compared with that of fat in each patient, for each sequence. In selected patients, sequential examinations showed a progressive evolution toward the inactive pattern over a period of several weeks. Active and inactive disease are well depicted on T1-weighted sequences but are not distinguishable from each other. On T2-weighted sequences active disease is poorly demonstrated because the lesions are isointense with fat, whereas inactive masses remain clearly identifiable because they are of much lower signal intensity than fat

  18. Genetically conditioned male sterility

    International Nuclear Information System (INIS)

    Gottschalk, W.

    1976-01-01

    A survey is given of two different types of genetically controlled male sterility in higher plants. 'Functional' male sterility is due to the action of mutated genes causing a misdifferentiation of the growing points in different specific ways. Under the influence of the genes of this group either the stamens or the archespore tissues are not differentiated. In other mutants functionable male germ cells are produced but cannot be used for fertilizing the egg cells because the anthers remain closed or anthers and stigma become spatially separated from each other. Other genes of the group are responsible for the transformation of stamens into carpels, i.e. for a change of the hermaphrodite flower into a unisexually female one. A second type of male sterility is due to the action of ms genes influencing the course of micro-sporogenesis directly. They cause the breakdown of this process in a specific meiotic stage characteristic for each gene of the group. This breakdown is introduced by the degeneration of PMCs, microspores, or pollen grains preventing the production of male germ cells. The female sex organs remain uninfluenced. (author)

  19. Time-resolved x-ray laser induced photoelectron spectroscopy of isochoric heated copper

    International Nuclear Information System (INIS)

    Nelson, A.J.; Dunn, J.; Hunter, J.; Widmann, K.

    2005-01-01

    Time-resolved x-ray photoelectron spectroscopy is used to probe the nonsteady-state evolution of the valence band electronic structure of laser heated ultrathin (50 nm) copper. A metastable phase is studied using a 527 nm wavelength 400 fs laser pulse containing 0.1-2.5 mJ laser energy focused in a large 500x700 μm 2 spot to create heated conditions of 0.07-1.8x10 12 W cm -2 intensity. Valence band photoemission spectra are presented showing the changing occupancy of the Cu 3d level with heating are presented. These picosecond x-ray laser induced time-resolved photoemission spectra of laser-heated ultrathin Cu foil show dynamic changes in the electronic structure. The ultrafast nature of this technique lends itself to true single-state measurements of shocked and heated materials

  20. Practical problems in radiation sterilization of medical devices made from plasticized PVC

    International Nuclear Information System (INIS)

    Beenen, J.H.

    1990-01-01

    The following three methods for sterilizing medical devices made from plasticised PVC are used in the Netherlands. 1. sterilization by steam, steam-air or superheated water. 2. sterilization by electron beam or gamma irradiation. 3. ethylene oxide sterilization. IV-bags, blood bags and other bag types for similar applications made from plasticized PVC are mostly sterilized by steam-air or super heated water, especially when filled or partly filled containers are considered. More complicated products or products with components that cannot resist steam sterilization of 121 0 C are sterilized by ethylene oxide or irradiation. These last two methods also are favoured for sterilizing empty bags where sticking of the surfaces at the sterilization temperature creates a serious handicap. Moreover, steam sterilization may cause a permanent opacity of some plastics. However, we have to add that due to developments in formulations steam sterilization of empty bags is going to be of an increasing importance. proven carcinogenity of the gas ethylene oxide, difficult deaeration and retention of the gas in plasticized PVC has increased the demand for better radiation resistant plastics as an alternative for steam sterilization. (author)

  1. The Plasma Discharge System For Effective Sterilization Of Water And Solid Surfaces

    International Nuclear Information System (INIS)

    Senturk, K.

    2010-01-01

    The different areas such as medicine, surgery, food production need efficient sterilization system since they are directly related to human health. In this work a new plasma system is described in order to present its effectiveness in sterilization. This is a different method from conventional methods such as: chemicals and heat addition, UV irradiation etc. The developed plasma system produces cold plasma working under atmospheric pressure. To generate the plasma both AC and DC high voltage power supplies were used. The developed system is cheap and very effective for sterilization. The light emission for both AC and DC coronas for the plasmas were investigated to understand the nature of generated plasma ionization. Different parameters like temperature, voltage, application time were changed during the plasma application and the optimization for killing the micro-organisms were investigated. To understand the biological effect of plasma on the organisms comparisons were done by using the scanning electron microscope and absorption spectrometer. The plasma was applied on the bacteria like Escherichia coli, Bacillus subtilis, Streptococcus mutans , the yeasts such as Candida albicans, and green algae. The efficiency, the non toxic nature, the affordable price make this plasma discharge method a very efficient one for sterilization.

  2. Production of a sterile species via active-sterile mixing: An exactly solvable model

    Science.gov (United States)

    Boyanovsky, D.

    2007-11-01

    The production of a sterile species via active-sterile mixing in a thermal medium is studied in an exactly solvable model. The exact time evolution of the sterile distribution function is determined by the dispersion relations and damping rates Γ1,2 for the quasiparticle modes. These depend on γ˜=Γaa/2ΔE, with Γaa the interaction rate of the active species in absence of mixing and ΔE the oscillation frequency in the medium without damping. γ˜≪1, γ˜≫1 describe the weak and strong damping limits, respectively. For γ˜≪1, Γ1=Γaacos⁡2θm; Γ2=Γaasin⁡2θm where θm is the mixing angle in the medium and the sterile distribution function does not obey a simple rate equation. For γ˜≫1, Γ1=Γaa and Γ2=Γaasin⁡22θm/4γ˜2, is the sterile production rate. In this regime sterile production is suppressed and the oscillation frequency vanishes at an Mikheyev-Smirnov-Wolfenstein (MSW) resonance, with a breakdown of adiabaticity. These are consequences of quantum Zeno suppression. For active neutrinos with standard model interactions the strong damping limit is only available near an MSW resonance if sin⁡2θ≪αw with θ the vacuum mixing angle. The full set of quantum kinetic equations for sterile production for arbitrary γ˜ are obtained from the quantum master equation. Cosmological resonant sterile neutrino production is quantum Zeno suppressed relieving potential uncertainties associated with the QCD phase transition.

  3. Novel precooling strategy enhances time trial cycling in the heat.

    Science.gov (United States)

    Ross, Megan L R; Garvican, Laura A; Jeacocke, Nikki A; Laursen, Paul B; Abbiss, Chris R; Martin, David T; Burke, Louise M

    2011-01-01

    To develop and investigate the efficacy of a new precooling strategy combining external and internal techniques on the performance of a cycling time trial (TT) in a hot and humid environment. Eleven well-trained male cyclists undertook three trials of a laboratory-based cycling TT simulating the course characteristics of the Beijing Olympic Games event in a controlled hot and humid environment (32°C-35°C at 50%-60% relative humidity). The trials, separated by 3-7 d, were undertaken in a randomized crossover design and consisted of the following: 1) CON-no treatment apart from the ad libitum consumption of cold water (4°C), 2) STD COOL-whole-body immersion in cold (10°C) water for 10 min followed by wearing a cooling jacket, or 3) NEW COOL-combination of consumption of 14 g of ice slurry ("slushie") per kilogram body mass made from a commercial sports drink while applying iced towels. There was an observable effect on rectal temperature (T(rec)) before the commencement of the TT after both precooling techniques (STD COOL < NEW COOL < CON, P < 0.05), but pacing of the TT resulted in similar T(rec), HR, and RPE throughout the cycling protocol in all trials. NEW COOL was associated with a 3.0% increase in power (approximately 8 W) and a 1.3% improvement in performance time (approximately 1:06 min) compared with the CON trial, with the true likely effects ranging from a trivial to a large benefit. The effect of the STD COOL trial compared with the CON trial was "unclear." This new precooling strategy represents a practical and effective technique that could be used by athletes in preparation for endurance events undertaken in hot and humid conditions.

  4. Analytical Solution of Heat Conduction for Hollow Cylinders with Time-Dependent Boundary Condition and Time-Dependent Heat Transfer Coefficient

    Directory of Open Access Journals (Sweden)

    Te-Wen Tu

    2015-01-01

    Full Text Available An analytical solution for the heat transfer in hollow cylinders with time-dependent boundary condition and time-dependent heat transfer coefficient at different surfaces is developed for the first time. The methodology is an extension of the shifting function method. By dividing the Biot function into a constant plus a function and introducing two specially chosen shifting functions, the system is transformed into a partial differential equation with homogenous boundary conditions only. The transformed system is thus solved by series expansion theorem. Limiting cases of the solution are studied and numerical results are compared with those in the literature. The convergence rate of the present solution is fast and the analytical solution is simple and accurate. Also, the influence of physical parameters on the temperature distribution of a hollow cylinder along the radial direction is investigated.

  5. Temperature Effects on Free Radicals in Gamma-sterilized Beef

    Science.gov (United States)

    Pramanik, S. I.; Jahan, M. S.

    1999-11-01

    Gamma irradiation has become the method of choice for sterilizing frozen meat and their products to reduce levels of food-borne pathogens and to extend shelf life. In this report we have employed ESR technique for detection of free radicals in sterilized and non-sterilized dry beef without bone. We have also determined the heating effects on free radicals at temperatures 176^°C and 250^°C. Meat samples were dried in a food dehydrator at 60^°C and were packaged in dry N_2. They were then sterilized by γ-irradiation (2.5 MRad), ground into powder, and placed in ESR sample tubes. Non-sterilized powder samples were used as control. While all powder samples, sterilized or not, produced a broad single line in the ESR spectra with (Δ H_pp ~ 9 G) and g = 2.013, the radical concentration in the sterilized samples increased by a factor of five. Heat treatment at 176^°C produced similar radicals. But, when samples were heated 250^°C different radical species were formed which are characterized by narrow width (Δ H_pp ~ 6 G) and lower g-value (g =2.010). In contrast with previous work, where free radicals in chicken bones were reduced by heating [1], we observed an increase in concentration. Results of structural analyses of the radicals will be presented. Ref.[1]: Radiat. Phys. Chem., 49, 477-481, 1997. Work supported by Grants from the University of Memphis

  6. Blow-Up Time for Nonlinear Heat Equations with Transcendental Nonlinearity

    Directory of Open Access Journals (Sweden)

    Hee Chul Pak

    2012-01-01

    Full Text Available A blow-up time for nonlinear heat equations with transcendental nonlinearity is investigated. An upper bound of the first blow-up time is presented. It is pointed out that the upper bound of the first blow-up time depends on the support of the initial datum.

  7. Energy analysis in sterilization process of food

    International Nuclear Information System (INIS)

    Lee, Dong Sun; Pyun, Yu Ryang

    1986-01-01

    A procedure was developed for predicting energy consumption of batch type thermal processing of food. From mass and energy balance equations various energy usages or losses were estimated for steam sterilization of model food system in No.301-7 can (Φ74.1 x 113.0mm) at three different temperatures. Selected models were 5 % bentonite solution for conductive food and tap water for convective food. Total steam or energy consumption was higher at 110 deg C than at two other higher temperatures (121 deg C and 130 deg C). High energy consumption at low sterilization temperature was mainly due to high bleeding steam energy and convective and radiative heat losses. Thermal energy efficiency was also disscussed. (Author)

  8. Radiation sterilization of pharmaceuticals and polymers

    International Nuclear Information System (INIS)

    Gopal, N.G.S.

    1978-01-01

    Radiation, in the form of high energy electrons as well as gamma radiation, has featured in the last 15 yr as a promising sterilization agent for many heat sensitive and ethylene oxide incompatible pharmaceuticals and polymers of medical usage. This article deals with (i) a comparison of the various methods of sterilization and their shortcomings, (ii) modes of interaction of radiation with matter, (iii) the types of radiation sources in common use, (iv) dosimetry, (v) dose rate effect, (vi) a literature survey of the radiation effect on pharmaceuticals in solid form as well as in aqueous solution and on polymers in the form of plastic medical products and (vii) the evaluation of the irradiated products. The effect of dose rate on the stability of these materials is emphasized. Either very little work has been done on the dose rate effect or the published information is scanty. The literature survey covers the recent period of 5 to 6 years. (author)

  9. Surgical sterilization of free-ranging wolves.

    Science.gov (United States)

    Spence, C E; Kenyon, J E; Smith, D R; Hayes, R D; Baer, A M

    1999-02-01

    The objective of the study was to determine whether surgical sterilization of both males and females in wolf pairs alters basic wolf social and territorial behaviors. Wolves were located from the air by snow-tracking methods and were tranquilizer-darted from a helicopter. Surgeries were performed either in a tent at the capture site or in a heated building in a nearby village. Six vasectomies and seven uterine horn ligations were performed in January and February of 1996 and 1997. Two females died: one likely related to the capture procedure, the other of a peritonitis unrelated to the surgery. One wolf had a litter. None of the wolves have shown changes in behavioral patterns. Surgical sterilization can be effective, but other, less invasive, fertility control techniques should be investigated.

  10. CAN LARGE TIME DELAYS OBSERVED IN LIGHT CURVES OF CORONAL LOOPS BE EXPLAINED IN IMPULSIVE HEATING?

    International Nuclear Information System (INIS)

    Lionello, Roberto; Linker, Jon A.; Mikić, Zoran; Alexander, Caroline E.; Winebarger, Amy R.

    2016-01-01

    The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delay is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored

  11. Effect of sterilization process on surface characteristics and biocompatibility of pure Mg and MgCa alloys

    International Nuclear Information System (INIS)

    Liu, X.L.; Zhou, W.R.; Wu, Y.H.; Cheng, Y.; Zheng, Y.F.

    2013-01-01

    The aim of this work was to investigate the effect of various sterilization methods on surface characteristics and biocompatibility of MgCa alloy, with pure Mg as a comparison, including steam autoclave sterilization (SA), ethylene oxide steam sterilization (EO), glutaraldehyde sterilization (GD), dry heat sterilization (DH) and Co60 γ ray radiation sterilization (R) technologies. The surface characterizations were performed by environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, water contact angle and surface free energy measurement, whereas the cytotoxicity and hemocompatibility were evaluated by cellular adhesive experiment, platelet adhesion and hemolysis test. The results showed that the five sterilization processes caused more changes on the surface of MgCa alloy than that on the surface of pure Mg. The GD sterilization caused the most obvious changes on the surface of the pure Mg, and the SA sterilization made the largest alteration on the MgCa alloy surface. The GD and DH sterilization processes could cause increases on surface free energy for both pure Mg and MgCa alloys, while the other three sterilization processes reduced the surface free energy. The DH and GD sterilization processes caused the least alteration on the cell adhesion on pure Mg surface, whereas the EO sterilization performed the greatest impact on the cell adhesion on the Mg–Ca alloy surface. The hemolysis percentage of pure Mg and MgCa alloys were reduced by SA sterilization, meanwhile the other four sterilization processes increased their hemolysis percentages significantly, especially for the EO sterilization. - Highlights: • The effect of sterilization on surface chemistry and biocompatibility was studied. • Sterilization caused more surface changes on MgCa alloy than pure Mg. • Co60 γ ray radiation is the most appropriate sterilization process

  12. Design, Construction and Evaluation of a Dry Solar Sterilizer

    International Nuclear Information System (INIS)

    Hernández Fereira, Arcelio A.

    2017-01-01

    The objective of the work was the search of an alternative for sterilization using solar energy. For such purposes, a dry solar sterilizer of 4276 cm3 capacity was designed, constructed and evaluated. Potential users would be rural medical posts in areas without electricity, health posts in military units under field conditions, and experimental microbiology stations. The evaluation included the determination of the energy efficiency of the sterilizer, the economic evaluation against other variants and the biological safety assessment. The developed equipment reached the sterilization temperature for levels of the direct component of the solar radiation higher than 300 W/m2 in 14 minutes, corresponding to an average heating rate of 13 0C/minute, higher than that of an electric furnace. Its energy efficiency with direct solar radiation of 310.5 W/m2 was 53.79%. The equipment is of easy construction, simple operation and very low cost. (author)

  13. Validation of radiation sterilization process

    International Nuclear Information System (INIS)

    Kaluska, I.

    2007-01-01

    The standards for quality management systems recognize that, for certain processes used in manufacturing, the effectiveness of the process cannot be fully verified by subsequent inspection and testing of the product. Sterilization is an example of such a process. For this reason, sterilization processes are validated for use, the performance of sterilization process is monitored routinely and the equipment is maintained according to ISO 13 485. Different aspects of this norm are presented

  14. Effect of Heating Time on Hardness Properties of Laser Clad Gray Cast Iron Surface

    Science.gov (United States)

    Norhafzan, B.; Aqida, S. N.; Mifthal, F.; Zulhishamuddin, A. R.; Ismail, I.

    2018-03-01

    This paper presents effect of heating time on cladded gray cast iron. In this study, the effect of heating time on cladded gray cast iron and melted gray cast iron were analysed. The gray cast iron sample were added with mixed Mo-Cr powder using laser cladding technique. The mixed Mo and Cr powder was pre-placed on gray cast iron surface. Modified layer were sectioned using diamond blade cutter and polish using SiC abrasive paper before heated. Sample was heated in furnace for 15, 30 and 45 minutes at 650 °C and cool down in room temperature. Metallographic study was conduct using inverted microscope while surface hardness properties were tested using Wilson hardness test with Vickers scale. Results for metallographic study showed graphite flakes within matrix of pearlite. The surface hardness for modified layer decreased when increased heating time process. These findings are significant to structure stability of laser cladded gray cast iron with different heating times.

  15. Isothermal calorimeter for measurements of time-dependent heat generation rate in individual supercapacitor electrodes

    Science.gov (United States)

    Munteshari, Obaidallah; Lau, Jonathan; Krishnan, Atindra; Dunn, Bruce; Pilon, Laurent

    2018-01-01

    Heat generation in electric double layer capacitors (EDLCs) may lead to temperature rise and reduce their lifetime and performance. This study aims to measure the time-dependent heat generation rate in individual carbon electrode of EDLCs under various charging conditions. First, the design, fabrication, and validation of an isothermal calorimeter are presented. The calorimeter consisted of two thermoelectric heat flux sensors connected to a data acquisition system, two identical and cold plates fed with a circulating coolant, and an electrochemical test section connected to a potentiostat/galvanostat system. The EDLC cells consisted of two identical activated carbon electrodes and a separator immersed in an electrolyte. Measurements were performed on three cells with different electrolytes under galvanostatic cycling for different current density and polarity. The measured time-averaged irreversible heat generation rate was in excellent agreement with predictions for Joule heating. The reversible heat generation rate in the positive electrode was exothermic during charging and endothermic during discharging. By contrast, the negative electrode featured both exothermic and endothermic heat generation during both charging and discharging. The results of this study can be used to validate existing thermal models, to develop thermal management strategies, and to gain insight into physicochemical phenomena taking place during operation.

  16. Sterilizing insects with ionizing radiation

    International Nuclear Information System (INIS)

    Bakri, A.; Mehta, K.; Lance, D.R.

    2005-01-01

    Exposure to ionizing radiation is currently the method of choice for rendering insects reproductively sterile for area-wide integrated pest management (AW-IPM) programmes that integrate the sterile insect technique (SIT). Gamma radiation from isotopic sources (cobalt-60 or caesium-137) is most often used, but high-energy electrons and X-rays are other practical options. Insect irradiation is safe and reliable when established safety and quality-assurance guidelines are followed. The key processing parameter is absorbed dose, which must be tightly controlled to ensure that treated insects are sufficiently sterile in their reproductive cells and yet able to compete for mates with wild insects. To that end, accurate dosimetry (measurement of absorbed dose) is critical. Irradiation data generated since the 1950s, covering over 300 arthropod species, indicate that the dose needed for sterilization of arthropods varies from less than 5 Gy for blaberid cockroaches to 300 Gy or more for some arctiid and pyralid moths. Factors such as oxygen level, and insect age and stage during irradiation, and many others, influence both the absorbed dose required for sterilization and the viability of irradiated insects. Consideration of these factors in the design of irradiation protocols can help to find a balance between the sterility and competitiveness of insects produced for programmes that release sterile insects. Many programmes apply 'precautionary' radiation doses to increase the security margin of sterilization, but this overdosing often lowers competitiveness to the point where the overall induced sterility in the wild population is reduced significantly. (author)

  17. Post-sterilization autonomy among young mothers in South India.

    Science.gov (United States)

    Pallikadavath, Saseendran; Rajan, Irudaya; Singh, Abhishek; Ogollah, Reuben; Page, Samantha

    2015-01-01

    This study examined the post-sterilization autonomy of women in south India in the context of early sterilization and low fertility. Quantitative data were taken from the third round of the National Family Health Survey (NFHS-3) carried out in 2005-06, and qualitative data from one village each in Kerala and Tamil Nadu during 2010-11. The incident rate ratios and thematic analysis showed that among currently married women under the age of 30 years, those who had been sterilized had significantly higher autonomy in household decision-making and freedom of mobility compared with women who had never used any modern family planning method. Early age at sterilization and low fertility enables women to achieve the social status that is generally attained at later stages in the life-cycle. Policies to capitalize on women's autonomy and free time resulting from early sterilization and low fertility should be adopted in south India.

  18. Influence of microwave sterilization on the cutting capacity of carbide burs.

    Science.gov (United States)

    Fais, Laiza Maria Grassi; Pinelli, Lígia Antunes Pereira; Adabo, Gelson Luis; Silva, Regina Helena Barbosa Tavares da; Marcelo, Caroline Canhizares; Guaglianoni, Dalton Geraldo

    2009-01-01

    This study compared the cutting capacity of carbide burs sterilized with microwaves and traditional sterilization methods. Sixty burs were divided into 5 groups according to the sterilization methods: dry heat (G1), autoclave (G2), microwave irradiation (G3), glutaraldehyde (G4) or control - no sterilization (G5). The burs were used to cut glass plates in a cutting machine set for twelve 2.5-min periods and, after each period, they were sterilized (except G5) following the protocol established for each group. The cutting capacity of the burs was determined by a weight-loss method. Data were analyzed statistically by Kruskal-Wallis and Dunn's test. The means of the cutting amount performed by each group after the 12 periods were G1 = 0.2167 +/- 0.0627 g; G2 = 0.2077 +/- 0.0231 g; G3 = 0.1980 +/- 0.0326 g; G4 = 0.1203 +/- 0.0459 g; G5 = 0.2642 +/- 0.0359 g. There were statistically significant differences among the groups (p<0.05); only dry heat sterilization was similar to the control. Sterilization by dry heat was the method that least affected the cutting capacity of the carbide burs and microwave sterilization was not better than traditional sterilization methods.

  19. Influence of microwave sterilization on the cutting capacity of carbide burs

    Directory of Open Access Journals (Sweden)

    Laiza Maria Grassi Fais

    2009-12-01

    Full Text Available OBJECTIVE: This study compared the cutting capacity of carbide burs sterilized with microwaves and traditional sterilization methods. MATERIAL AND METHODS: Sixty burs were divided into 5 groups according to the sterilization methods: dry heat (G1, autoclave (G2, microwave irradiation (G3, glutaraldehyde (G4 or control - no sterilization (G5. The burs were used to cut glass plates in a cutting machine set for twelve 2.5-min periods and, after each period, they were sterilized (except G5 following the protocol established for each group. The cutting capacity of the burs was determined by a weight-loss method. Data were analyzed statistically by Kruskal-Wallis and Dunn's test. RESULTS: The means of the cutting amount performed by each group after the 12 periods were G1 = 0.2167 ± 0.0627 g; G2 = 0.2077 ± 0.0231 g; G3 = 0.1980 ± 0.0326 g; G4 = 0.1203 ± 0.0459 g; G5 = 0.2642 ± 0.0359 g. There were statistically significant differences among the groups (p<0.05; only dry heat sterilization was similar to the control. CONCLUSION: Sterilization by dry heat was the method that least affected the cutting capacity of the carbide burs and microwave sterilization was not better than traditional sterilization methods.

  20. Laparoscopic female sterilization.

    Science.gov (United States)

    Filshie, G M

    1989-09-01

    An overview of laparoscopic sterilization techniques from a historical and practical viewpoint includes instrumentation, operative techniques, mechanical occlusive devices, anesthesia, failure rates, morbidity and mortality. Laparoscope was first reported in 1893, but was developed simultaneously in France, Great Britain, Canada and the US in the 1960s. There are smaller laparoscopes for double-puncture procedures, and larger, single-puncture laparoscopes. To use a ring or clip, a much larger operating channel, up to 8 mm is needed. Insufflating gas may be CO2, which does not support combustion, but is more uncomfortable, NO2, which is also an anesthetic, and room air often used in developing countries. Unipolar electrocautery is now rarely used, in fact most third party payers do not allow it. Bipolar cautery, thermal coagulation and laser photocoagulation are safer methods. Falope rings, Hulka-Clemens, Filshie, Bleier, Weck and Tupla clips are described and illustrated. General anesthesia, usually a short acting agent with a muscle relaxant, causes 33% of the mortality of laparoscope, often due to cardiac arrest and arrhythmias, preventable with atropine. Local anesthesia is safer and cheaper and often used in developing countries. Failure rates of the various laparoscopic tubal sterilization methods are reviewed: most result from fistula formation. Mortality and morbidity can be caused by bowel damage, injury or infection, pre- existing pelvic infection, hemorrhage, gas embolism (avoidable by the saline drip test), and other rare events.

  1. [Determinants of sterilization among married couples in Korea].

    Science.gov (United States)

    Kim, Ju Hee; Chung, Woojin; Lee, Sunmi; Suh, Moonhee; Kang, Dae Ryong

    2007-11-01

    The purpose of this study was to examine the determinants of sterilization in South Korea. This study was based on the data from the Korea National Fertility Survey carried out in the year 2000 by the Korea Institute of Health and Social Affairs. The subjects of the analysis were 4,604 women and their husbands who were in their first marriage, in the age group of 15-49 years. The data were analyzed by multiple logistic regression analysis. Consistent with the findings of previous studies, the woman's age and the number of total children increased the likelihood of sterilization. In addition, the year of marriage had a strong positive association with sterilization. Interestingly, the number of surviving sons tended to increase the likelihood of sterilization, whereas the woman's education level and age at the time of marriage showed a negative association with sterilization. Religion, place of residence, son preference, and the husband's education level, age and type of occupation were not significant determinants of sterilization. The sex of previous children and lower level of education are distinct determinants of sterilization among women in South Korea. More studies are needed in order to determine the associations between sterilization rate and decreased fertility.

  2. [Affect regularity of medicinal species and heating time on flavonoids contents in Epimedium cut crude drug].

    Science.gov (United States)

    Sun, E; Chen, Ling-ling; Jia, Xiao-bin; Qian, Qian; Cui, Li

    2012-09-01

    To study the affect regularity of medicinal species and heating time on flavonoids contents in Epimedium cut crude drug. Setting processing temperature at 170 degrees C, 39 batches Epimedium cut crude drug of different species were heated for 0, 5, 10 minutes. The contents of epimedin A, B, C, icariin, Baohuoside I in different species of Epimedium were determined by HPLC. The variance analysis was used to study the effect of medicinal species and heating time on the contents change of five major flavonoids. The contents of Epimedin A, B, C were significantly impacted by medicinal species (P time (P time and species (P > 0.05). The medicinal species and heat processed time are two important influence factors on the flavonoids contents in Epimedium. The contents of Epimedin A, C are abundant in Epimedium pubescens, and the contents of Epimedin B, Baohuoside I are higher in Epimedium brevicornu. After heating, the contents of Epimedin A, B, C are decreased, and icariin, Baohuoside I are increased. This study provides scientific evidences for variety certification, optimizing processing technology, exploring processing mechanism and clinical rational administration.

  3. Estimate of the global-scale joule heating rates in the thermosphere due to time mean currents

    International Nuclear Information System (INIS)

    Roble, R.G.; Matsushita, S.

    1975-01-01

    An estimate of the global-scale joule heating rates in the thermosphere is made based on derived global equivalent overhead electric current systems in the dynamo region during geomagnetically quiet and disturbed periods. The equivalent total electric field distribution is calculated from Ohm's law. The global-scale joule heating rates are calculated for various monthly average periods in 1965. The calculated joule heating rates maximize at high latitudes in the early evening and postmidnight sectors. During geomagnetically quiet times the daytime joule heating rates are considerably lower than heating by solar EUV radiation. However, during geomagnetically disturbed periods the estimated joule heating rates increase by an order of magnitude and can locally exceed the solar EUV heating rates. The results show that joule heating is an important and at times the dominant energy source at high latitudes. However, the global mean joule heating rates calculated near solar minimum are generally small compared to the global mean solar EUV heating rates. (auth)

  4. TIME-DEPENDENT TURBULENT HEATING OF OPEN FLUX TUBES IN THE CHROMOSPHERE, CORONA, AND SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Woolsey, L. N.; Cranmer, S. R., E-mail: lwoolsey@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2015-10-01

    We investigate several key questions of plasma heating in open-field regions of the corona that connect to the solar wind. We present results for a model of Alfvén-wave-driven turbulence for three typical open magnetic field structures: a polar coronal hole, an open flux tube neighboring an equatorial streamer, and an open flux tube near a strong-field active region. We compare time-steady, one-dimensional turbulent heating models against fully time-dependent three-dimensional reduced-magnetohydrodynamic modeling of BRAID. We find that the time-steady results agree well with time-averaged results from BRAID. The time dependence allows us to investigate the variability of the magnetic fluctuations and of the heating in the corona. The high-frequency tail of the power spectrum of fluctuations forms a power law whose exponent varies with height, and we discuss the possible physical explanation for this behavior. The variability in the heating rate is bursty and nanoflare-like in nature, and we analyze the amount of energy lost via dissipative heating in transient events throughout the simulation. The average energy in these events is 10{sup 21.91} erg, within the “picoflare” range, and many events reach classical “nanoflare” energies. We also estimated the multithermal distribution of temperatures that would result from the heating-rate variability, and found good agreement with observed widths of coronal differential emission measure distributions. The results of the modeling presented in this paper provide compelling evidence that turbulent heating in the solar atmosphere by Alfvén waves accelerates the solar wind in open flux tubes.

  5. Real time plasma control experiments using the JET auxiliary plasma heating systems as the actuator

    International Nuclear Information System (INIS)

    Zornig, N.H.

    1999-01-01

    The role of the Real Time Power Control system (RTPC) in the Joint European Torus (JET) is described in depth. The modes of operation are discussed in detail and a number of successful experiments are described. These experiments prove that RTPC can be used for a wide range of experiments, including: (1) Feedback control of plasma parameters in real time using Ion Cyclotron Resonance Heating (ICRH) or Neutral Beam Heating (NBH) as the actuator in various JET operating regimes. It is demonstrated that in a multi-parameter space it is not sufficient to control one global plasma parameter in order to avoid performance limiting events. (2) Restricting neutron production and subsequent machine activation resulting from high performance pulses. (3) The simulation of α-particle heating effects in a DT-plasma in a D-only plasma. The heating properties of α-particles are simulated using ICRH-power, which is adjusted in real time. The simulation of α-particle heating in JET allows the effects of a change in isotopic mass to be separated from α-particle heating. However, the change in isotopic mass of the plasma ions appears to affect not only the global energy confinement time (τ E ) but also other parameters such as the electron temperature at the plasma edge. This also affects τ E , making it difficult to make a conclusive statement about any isotopic effect. (4) For future JET experiments a scheme has been designed which simulates the behaviour of a fusion reactor experimentally. The design parameters of the International Thermonuclear Experimental Reactor (ITER) are used. In the proposed scheme the most relevant dimensionless plasma parameters are similar in JET and ITER. It is also shown how the amount of heating may be simulated in real time by RTPC using the electron temperature and density as input parameters. The results of two demonstration experiments are presented. (author)

  6. EFFECT OF HEAT TREATMENT ON THE SURVIVAL OF ...

    African Journals Online (AJOL)

    BARTH EKWUEME

    seconds at temperatures ranging from 69OC to 73OC. E. coli O157:H7 ... inoculum was added to 90ml of sterile raw milk (heated in water bath ..... the high temperature short time (HTST) pasteurization technique .... I. The use of selective media.

  7. Investigating the combined effects of heat and lighting on students reaction time in laboratory condition

    Directory of Open Access Journals (Sweden)

    Zohre Mohebian

    2016-12-01

    Full Text Available Introduction: In many workplaces there is exposure to heat and light simultaneously. This study investigated the combined effect of heat and lighting on some cognitive performance, i.e. reaction time. Methodology: the present semi-experimental study was conducted 2015 on 33 healthy students (16 girls and 17 boys with a mean age of 22.1 in the thermal stress chamber. The reaction time parameter by the reaction time measurement device, after exposure to different heat surfaces (dry temperatures 22 °C and 37 °C and lighting surfaces (200, 500 and 1500 lux. Data were analyzed using ANOVA test in SPSS-20. Results: The results showed that the average simple, diagnostic, two-color selective, two-sound selective reaction times and reaction time error increased after combined exposure to heat and lighting and showed a significant difference (P<0.05. The maximum score of reaction time belong to temperature of 37 c° and lighting of 1500 lux, the minimum score of reaction time belong to temperature of 22 °c and lighting of 1500 lux.

  8. Effect of energetic ion loss on ICRF heating efficiency and energy confinement time in heliotrons

    International Nuclear Information System (INIS)

    Murakami, S.; Nakajima, N.; Okamoto, M.; Nuehrenberg, J.

    1999-01-01

    The ICRF heating efficiency and the global energy confinement time during ICRF heating are investigated, including the effect of energetic ion loss in heliotrons. The approximate formula of ICRF heating efficiency is derived using results based on Monte Carlo simulations (Murakami, S., et al., Fusion Eng. Des. 26 (1995) 209). The global energy confinement time including the energetic ion effect can be expressed in heliotrons in terms of ICRF heating power, plasma density and magnetic field strength. Results in plasmas at CHS show a systematic decrease of the global energy confinement time due to energetic ion loss from the assumed energy confinement scaling law, which is consistent with the experimental observations. The model is also applied to ICRF minority heating in LHD plasmas in two cases of typical magnetic configurations. A clear increase of the global energy confinement time due to the stored energy of energetic tail ions is obtained in the 'orbit improved' configuration, while a decrease is observed in the 'standard' configuration. (author)

  9. Time evolution simulation of heat removal in a small water tank by natural convection

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Carlos Alberto de, E-mail: carlos.freitas1950@hotmail.com [Instituto Federal do Rio de Janeiro (IFRJ), Nilopolis, RJ (Brazil); Jachic, Joao; Moreira, Maria de Lourdes, E-mail: jjachic@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    One of the cooling modes for any source of heat such as in a shutdown nuclear core is the natural convection. The design specifications of any cooling pool can only be done when the removal heat rate and the corresponding mass flow rate is reasonably established. In our simulation scheme, we assumed that the body forces acting in the cubic water cell are: the weight, the drag force and the integrated pressure forces on the horizontal surfaces, the viscosity shear forces on the vertical surfaces and also a special viscosity drag force due to the mass dislocation along a Bernoulli type current tube outside the motive region. For a suitable time step, the uprising convection velocity is determined by an implicit and also by an explicit solution algorithm. The resulting differential equation depends on updating specific mass, dynamic viscosity and constant pressure heat coefficient with the last known temperature in the cell that absorbed heat. Numerical calculation software was performed using MATLAB’s technical computing language and then applied for a heat generation plate simulating a spent fuel assembler from a shutdown nuclear core. The results show time evolution of convection, terminal velocity and water temperature distribution. Pool dimension as well as pool level decrement are also determined for various air exhausting system conditions and heat rate of the spent fuel plate being cooled. (author)

  10. Time evolution simulation of heat removal in a small water tank by natural convection

    International Nuclear Information System (INIS)

    Freitas, Carlos Alberto de; Jachic, Joao; Moreira, Maria de Lourdes

    2013-01-01

    One of the cooling modes for any source of heat such as in a shutdown nuclear core is the natural convection. The design specifications of any cooling pool can only be done when the removal heat rate and the corresponding mass flow rate is reasonably established. In our simulation scheme, we assumed that the body forces acting in the cubic water cell are: the weight, the drag force and the integrated pressure forces on the horizontal surfaces, the viscosity shear forces on the vertical surfaces and also a special viscosity drag force due to the mass dislocation along a Bernoulli type current tube outside the motive region. For a suitable time step, the uprising convection velocity is determined by an implicit and also by an explicit solution algorithm. The resulting differential equation depends on updating specific mass, dynamic viscosity and constant pressure heat coefficient with the last known temperature in the cell that absorbed heat. Numerical calculation software was performed using MATLAB’s technical computing language and then applied for a heat generation plate simulating a spent fuel assembler from a shutdown nuclear core. The results show time evolution of convection, terminal velocity and water temperature distribution. Pool dimension as well as pool level decrement are also determined for various air exhausting system conditions and heat rate of the spent fuel plate being cooled. (author)

  11. Transient local heat fluxes during the entire vapor bubble life time

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, P.; Fuchs, T; Wagner, E.; Schweizer, N. [Technische Universitaet Darmstadt (Germany). Technical Thermodynamics], e-mail: pstephan@ttd.tu-darmstadt.de

    2009-07-01

    Recent experimental and numerical investigations of the nucleate boiling heat transfer process at a single active nucleation site are presented and used for an evaluation of the local heat fluxes during the entire life time of a vapor bubble from its nucleation to the rise through the thermal boundary layer. In a special boiling cell, vapor bubbles are generated at a single nucleation site on a 20 {mu}m thin stainless steel heating foil. An infrared camera captures the temperature distribution at the wall with high temporal and spatial resolution. The bubble shape is recorded with a high-speed camera. Measurements were conducted with the pure fluids FC-84 and FC-3284 and with its binary mixtures. For pure fluids, up to 50-60% of the latent heat flows through the three-phase-contact line region. For mixtures, this ratio is clearly reduced. These observations are in agreement with the numerical model of the author's group. The fully transient model contains a multi scale approach ranging from the nanometer to the millimeter scale for the detailed description of the relevant local and global phenomena. It describes the transient heat and fluid flow during the entire periodic cycle of a growing, detaching and rising bubble including the waiting time between two successive bubbles from a single nucleation site. The detailed analysis of the computed transient temperature profiles in wall and fluid give accurate information about the heat supply, temporal energy storage and local evaporation rates. (author)

  12. Transient local heat fluxes during the entire vapor bubble life time

    International Nuclear Information System (INIS)

    Stephan, P.; Fuchs, T; Wagner, E.; Schweizer, N.

    2009-01-01

    Recent experimental and numerical investigations of the nucleate boiling heat transfer process at a single active nucleation site are presented and used for an evaluation of the local heat fluxes during the entire life time of a vapor bubble from its nucleation to the rise through the thermal boundary layer. In a special boiling cell, vapor bubbles are generated at a single nucleation site on a 20 μm thin stainless steel heating foil. An infrared camera captures the temperature distribution at the wall with high temporal and spatial resolution. The bubble shape is recorded with a high-speed camera. Measurements were conducted with the pure fluids FC-84 and FC-3284 and with its binary mixtures. For pure fluids, up to 50-60% of the latent heat flows through the three-phase-contact line region. For mixtures, this ratio is clearly reduced. These observations are in agreement with the numerical model of the author's group. The fully transient model contains a multi scale approach ranging from the nanometer to the millimeter scale for the detailed description of the relevant local and global phenomena. It describes the transient heat and fluid flow during the entire periodic cycle of a growing, detaching and rising bubble including the waiting time between two successive bubbles from a single nucleation site. The detailed analysis of the computed transient temperature profiles in wall and fluid give accurate information about the heat supply, temporal energy storage and local evaporation rates. (author)

  13. The nutritonal value of protein in radiation sterilized fish meal

    International Nuclear Information System (INIS)

    Harmuth-Hoene, A.E.; Partmann, W.

    1976-01-01

    Investigations of four samples of fish flour from various countries which had been sterilized by radiation (5 Mrad) did not show any evidence of radiation-induced changes in crude protein content as well as protein digestibility by enzymatic hydrolysis. Of the 16 amino acids studied only serine suffered a mean loss of 16% while the remaining amino acids showed only slight changes after irradiation. In all four samples we noticed a mean loss of 9% in available lysine. The sterilization of fish flour by irradiation does not diminish the nutritional value of fish protein to any significant extent and, should be given preference over sterilization by heat which reduces the protein quality of fumigation by heat which leaves residues. (orig.) [de

  14. Effect of heat treatment time on microstructure and electrical conductivity in LATP glass ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sonigra, Dhiren, E-mail: somans@iitb.ac.in, E-mail: ajit.kulkarni@iitb.ac.in; Soman, Swati, E-mail: somans@iitb.ac.in, E-mail: ajit.kulkarni@iitb.ac.in; Kulkarni, Ajit R., E-mail: somans@iitb.ac.in, E-mail: ajit.kulkarni@iitb.ac.in [Dept. of Metallurgical Engineering and Materials Science, IIT Bombay, Mumbai-400076 (India)

    2014-04-24

    Glass-ceramic is prepared by heat treatment of melt quenched 14Li{sub 2}O−9Al{sub 2}O{sub 3}−38TiO{sub 2}−39P{sub 2}O{sub 5} glass in the vicinity of crystallization temperature. Growth of ceramic phase is controlled by tuning heat treatment time at fixed temperature. Ceramic phase was identified to be LiTi{sub 2}(PO{sub 4}){sub 3} from X Ray Diffraction analysis. Microstructural evolution of this phase with hold time was observed under high resolution Scanning Electron Microscope. DC conductivity is observed to increase by 4-5 orders of magnitude in this glass-ceramic compared to parent glass. However, formation of pores and cracks with very large heat treatment time seem to hinder further increase of conductivity.

  15. Effects of particle size and heating time on thiobarbituric acid (TBA) test of soybean powder.

    Science.gov (United States)

    Lee, Youn-Ju; Yoon, Won-Byong

    2013-06-01

    Effects of particle size and heating time during TBA test on the thiobarbituric acid reactive substance (TBARS) of soybean (Glycine Max) powder were studied. Effects of processing variables involved in the pulverization of soybean, such as the temperature of soybean powder, the oxygen level in the vessel, and the pulverisation time, were investigated. The temperature of the soybean powder and the oxygen level had no significant influence on the TBARS (pTBA test significantly affected the TBARS. Change of TBARS during heating was well described by the fractional conversion first order kinetics model. A diffusion model was introduced to quantify the effect of particle size on TBARS. The major finding of this study was that the TBA test to estimate the level of the lipid oxidation directly from powders should consider the heating time and the mean particle sizes of the sample. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. The effect of heat preservation time on the electrochemical properties of LiFePO4

    Science.gov (United States)

    He, Rui; Zhang, Lihui; Bai, Xue; Liu, Zhenfa

    2017-12-01

    LiFePO4 was prepared via high temperature solid-state method at different heat preservation time. XRD and SEM was used to test the structure and morphology of LiFePO4. Land 2001 was used to test the electrochemical performance of LiFePO4. The results illustrated that well-crystallized LiFePO4 composite with homogeneous small particles was obtained by XRD and SEM. And the optimum heat preservation time was 4 hour. From charge/discharge test, it can be seen that at 0.2C, LiFePO4 has initial discharge capacities of 159.1mAh/g at the heat preservation time 4 hour. From the rate capacity, it can be seen that the discharge capacity was of optimum sample remains above 99% after 200 cycles.

  17. Apparatus for dynamic measurement of gases released from materials heated under programmed temperature-time control

    International Nuclear Information System (INIS)

    Early, J.W.; Abernathey, R.M.

    1982-04-01

    This apparatus, a prototype of one being constructed for hotcell examination of irradiated nuclear materials, measures dynamic release rates and integrated volumes of individual gases from materials heated under controlled temperature-time programs. It consists of an inductively heated vacuum furnace connected to a quadrupole mass spectrometer. A computerized control system with data acquisition provides scanning rates down to 1s and on-line tabular and graphic displays. Heating rates are up to 1300 0 C/min to a maximum temperature of 2000 0 C. The measurement range is about 10 -6 to 10 -2 torr-liter/s for H 2 , CH 4 , H 2 O, N 2 , and CO and 10 -8 to 10 -2 torr-liter/s for He, Kr, and Xe. Applications are described for measurements of Kr and Xe in mixed oxide fuel, various gases in UO 2 pellets, and He in 238 PuO 2 power and heat sources

  18. Time behaviours of visible lines in turbulently heated TRIAM-1 plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, N; Nakamura, K; Nakamura, Y; Itoh, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1981-08-01

    Spectroscopic studies were carried out on turbulently heated TRIAM-1 tokamak plasma. The temporal evolutions of the line radiance of visible lines were measured and two types of time behaviours of the line radiance were identified. The observed remarkable reduction of the line radiance of visible lines which have low ionization potential and are localized in the skin-layer due to the application of a pulsed electric-field for turbulent heating is attributed to the strong plasma heating in the peripherical region. Spatial profiles of neutrals and ions which are related to these lines are calculated, and the temporal variations of these profiles caused by the application of the heating pulse are discussed.

  19. The effects of sterilization on the tensile strength of orthodontic wires.

    Science.gov (United States)

    Staggers, J A; Margeson, D

    1993-01-01

    The purpose of this study was to evaluate the effect of sterilization on the tensile strength of 0.016" beta-titanium, nickel titanium and stainless steel wires. Three common methods of sterilization--autoclaving, dry heat and ethylene oxide--were evaluated in three test trials involving zero, one and five sterilization cycles. For each of the test trials, five pieces each of 0.016" TMA, 0.016" Sentalloy and 0.016" Tru-chrome stainless steel wires were sterilized using a standard autoclave. Five other pieces of each of the same wires were sterilized in a dryclave, while an additional five pieces of each of the three wire types were sterilized using ethylene oxide. The ultimate tensile strengths of the wires were then determined using an Instron Universal Testing Machine. The data were compared for statistical differences using analysis of variance. The results showed that dry heat sterilization significantly increased the tensile strength of TMA wires after one cycle, but not after five cycles. Autoclaving and ethylene oxide sterilization did not significantly alter the tensile strength of TMA wires. Dry heat and autoclave sterilization also significantly increased the tensile strength of Sentalloy wires, but the mean strength after five sterilization cycles was not significantly different than after one cycle. Ethylene oxide sterilization of Sentalloy wires did not significantly alter the tensile strengths of that wire. There were no significant differences in the tensile strengths of the stainless steel wires following zero, one or five cycles for any of the sterilization methods.

  20. Electrolytic silver ion cell sterilizes water supply

    Science.gov (United States)

    Albright, C. F.; Gillerman, J. B.

    1968-01-01

    Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water.

  1. Sterilization of Microorganisms by Ozone and Ultrasound

    Science.gov (United States)

    Krasnyj, V. V.; Klosovskij, A. V.; Panasko, T. A.; Shvets, O. M.; Semenova, O. T.; Taran, V. S.; Tereshin, V. I.

    2008-03-01

    The results of recent experimental methods of sterilization of microorganisms with the use of ozone and ultrasound are presented. The main aim was to optimize the process of sterilization in water solution taking into account the ozone concentration, the power of ultrasonic emitter and the temperature of water. In the present work, the ultrasonic cavitation with simultaneous ozone generation has been used. The high ozone concentration in water solution was achieved by two-barrier glow discharge generated at atmospheric pressure and a cooling thermo-electric module. Such a sterilizer consists of ozone generator in a shape of flat electrodes covered with dielectric material and a high-voltage pulsed power supply of 250 W. The sterilization camera was equipped with ultrasonic source operated at 100 W. The experiments on the inactivation of bacteria of the Bacillus Cereus type were carried out in the distilled water saturated by ozone. The ozone concentration in the aqueous solution was 10 mg/1, whereas the ozone concentration at the output of ozone generator was 30 mg/1. The complete inactivation of spores took 15 min. Selection of the temperature of water, the ozone concentrations and ultrasonic power allowed to determine the time necessary for destroying the row of microorganisms.

  2. USING CENTER HOLE HEAT TRANSFER TO REDUCE FORMATION TIMES FOR CERAMIC WASTE FORMS FROM PYROPROCESSING

    International Nuclear Information System (INIS)

    Kenneth J. Bateman; Charles W. Solbrig

    2006-01-01

    The waste produced from processing spent fuel from the EBR II reactor must be processed into a waste form suitable for long term storage in Yucca Mountain. The method chosen produces zeolite granules mixed with glass frit, which must then be converted into a solid. This is accomplished by loading it into a can and heating to 900 C in a furnace regulated at 915 C. During heatup to 900 C, the zeolite and glass frit react and consolidate to produce a sodalite monolith. The resultant ceramic waste form (CWF) is then cooled. The waste is 52 cm in diameter and initially 300 cm long but consolidates to 150 cm long during the heating process. After cooling it is then inserted in a 5-DHLW/DOE SNF Long Canister. Without intervention, the waste takes 82 hours to heat up to 900 C in a furnace designed to geometrically fit the cylindrical waste form. This paper investigates the reduction in heating times possible with four different methods of additional heating through a center hole. The hole size is kept small to maximize the amount of CWF that is processed in a single run. A hole radius of 1.82 cm was selected which removes only 1% of the CWF. A reference computation was done with a specified inner hole surface temperature of 915 C to provide a benchmark for the amount of improvement which can be made. It showed that the heatup time can potentially be reduced to 43 hours with center hole heating. The first method, simply pouring high temperature liquid aluminum into the hole, did not produce any noticeable effect on reducing heat up times. The second method, flowing liquid aluminum through the hole, works well as long as the velocity is high enough (2.5 cm/sec) to prevent solidification of the aluminum during the initial front movement of the aluminum into the center hole. The velocity can be reduced to 1 cm/sec after the initial front has traversed the ceramic. This procedure reduces the formation time to near that of the reference case. The third method, flowing a gas

  3. Thermalizing Sterile Neutrino Dark Matter.

    Science.gov (United States)

    Hansen, Rasmus S L; Vogl, Stefan

    2017-12-22

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  4. Thermalizing Sterile Neutrino Dark Matter

    Science.gov (United States)

    Hansen, Rasmus S. L.; Vogl, Stefan

    2017-12-01

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  5. Sterile Endophthalmitis after Intravitreal Injections

    Directory of Open Access Journals (Sweden)

    Joaquín Marticorena

    2012-01-01

    Full Text Available Sterile endophthalmitis appears as an infrequent complication of intravitreal injections and seems to develop mainly in the context of the off-label use of drugs that have not been conceived for intravitreous administration. The aetiology of sterile endophthalmitis, independently of the administered drug, remains uncertain and a multifactorial origin cannot be discarded. Sterile inflammation secondary both to intravitreal triamcinolone acetonide and to intravitreal bevacizumab share many characteristics such as the acute and painless vision loss present in the big majority of the cases. Dense vitreous opacity is a common factor, while anterior segment inflammation appears to be mild to moderate. In eyes with sterile endophthalmitis, visual acuity improves progressively as the intraocular inflammation reduces without any specific treatment. If by any chance the ophthalmologist is not convinced by the sterile origin of the inflammation, this complication must be treated as an acute endophthalmitis because of the devastating visual prognosis of this intraocular infection in the absence of therapy.

  6. Surgical sterilization of free-ranging wolves.

    OpenAIRE

    Spence, C E; Kenyon, J E; Smith, D R; Hayes, R D; Baer, A M

    1999-01-01

    The objective of the study was to determine whether surgical sterilization of both males and females in wolf pairs alters basic wolf social and territorial behaviors. Wolves were located from the air by snow-tracking methods and were tranquilizer-darted from a helicopter. Surgeries were performed either in a tent at the capture site or in a heated building in a nearby village. Six vasectomies and seven uterine horn ligations were performed in January and February of 1996 and 1997. Two females...

  7. Method and apparatus for real-time measurement of fuel gas compositions and heating values

    Science.gov (United States)

    Zelepouga, Serguei; Pratapas, John M.; Saveliev, Alexei V.; Jangale, Vilas V.

    2016-03-22

    An exemplary embodiment can be an apparatus for real-time, in situ measurement of gas compositions and heating values. The apparatus includes a near infrared sensor for measuring concentrations of hydrocarbons and carbon dioxide, a mid infrared sensor for measuring concentrations of carbon monoxide and a semiconductor based sensor for measuring concentrations of hydrogen gas. A data processor having a computer program for reducing the effects of cross-sensitivities of the sensors to components other than target components of the sensors is also included. Also provided are corresponding or associated methods for real-time, in situ determination of a composition and heating value of a fuel gas.

  8. Fission track retention in minerals as a function of heating time during isothermal experiments

    International Nuclear Information System (INIS)

    Burchart, J.; Butkiewicz, T.; Dakowski, M.; Galazka-Friedman, J.

    1979-01-01

    The linear dependence of track retention on logarithm of heating time (at constant temperature) has been verified by statistical analysis of data on isothermal annealing of apatite. The other functions proposed (rho/rho 0 as a linearly decreasing function of exp t or t) fit the experimental data only within a limited range of heating times, where the shapes of all three are experimentally hard to resolve. The logarithmic relationship implies a memory of tracks for thermal events and creates a basis for methods of age corrections. (author)

  9. Evaluation of focused ultrasound algorithms: Issues for reducing pre-focal heating and treatment time.

    Science.gov (United States)

    Yiannakou, Marinos; Trimikliniotis, Michael; Yiallouras, Christos; Damianou, Christakis

    2016-02-01

    Due to the heating in the pre-focal field the delay between successive movements in high intensity focused ultrasound (HIFU) are sometimes as long as 60s, resulting to treatment time in the order of 2-3h. Because there is generally a requirement to reduce treatment time, we were motivated to explore alternative transducer motion algorithms in order to reduce pre-focal heating and treatment time. A 1 MHz single element transducer with 4 cm diameter and 10 cm focal length was used. A simulation model was developed that estimates the temperature, thermal dose and lesion development in the pre-focal field. The simulated temperature history that was combined with the motion algorithms produced thermal maps in the pre-focal region. Polyacrylimde gel phantom was used to evaluate the induced pre-focal heating for each motion algorithm used, and also was used to assess the accuracy of the simulation model. Three out of the six algorithms having successive steps close to each other, exhibited severe heating in the pre-focal field. Minimal heating was produced with the algorithms having successive steps apart from each other (square, square spiral and random). The last three algorithms were improved further (with small cost in time), thus eliminating completely the pre-focal heating and reducing substantially the treatment time as compared to traditional algorithms. Out of the six algorithms, 3 were successful in eliminating the pre-focal heating completely. Because these 3 algorithms required no delay between successive movements (except in the last part of the motion), the treatment time was reduced by 93%. Therefore, it will be possible in the future, to achieve treatment time of focused ultrasound therapies shorter than 30 min. The rate of ablated volume achieved with one of the proposed algorithms was 71 cm(3)/h. The intention of this pilot study was to demonstrate that the navigation algorithms play the most important role in reducing pre-focal heating. By evaluating in

  10. Conditional sterility in plants

    Science.gov (United States)

    Meagher, Richard B.; McKinney, Elizabeth; Kim, Tehryung

    2010-02-23

    The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

  11. The Sterile Insect Technique

    International Nuclear Information System (INIS)

    Kiragu, J.

    2006-01-01

    Insect pests have caused an increasing problem in agriculture and human health through crop losses and disease transmission to man and livestock. Intervention to ensure food security and human health has relied on Integrated Pest Management (IPM) strategies to keep the pests population below economic injury levels. IPM integrate a variety of methods, but there has been over-reliance on chemical control following the discovery of insecticidal properties of DDT. It is now realized that, maintaining pest populations at controlled levels is unsustainable and eradication options is now being considered. Although the Sterile Insect Technique(SIT) could be used for insect suppression, it is gaining favour in the elimination (eradication) of the target pest population through Areawide-based IPM (Author)

  12. Sterile neutrino dark matter

    CERN Document Server

    Merle, Alexander

    2017-01-01

    This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.

  13. Multi-time-scale heat transfer modeling of turbid tissues exposed to short-pulsed irradiations.

    Science.gov (United States)

    Kim, Kyunghan; Guo, Zhixiong

    2007-05-01

    A combined hyperbolic radiation and conduction heat transfer model is developed to simulate multi-time-scale heat transfer in turbid tissues exposed to short-pulsed irradiations. An initial temperature response of a tissue to an ultrashort pulse irradiation is analyzed by the volume-average method in combination with the transient discrete ordinates method for modeling the ultrafast radiation heat transfer. This response is found to reach pseudo steady state within 1 ns for the considered tissues. The single pulse result is then utilized to obtain the temperature response to pulse train irradiation at the microsecond/millisecond time scales. After that, the temperature field is predicted by the hyperbolic heat conduction model which is solved by the MacCormack's scheme with error terms correction. Finally, the hyperbolic conduction is compared with the traditional parabolic heat diffusion model. It is found that the maximum local temperatures are larger in the hyperbolic prediction than the parabolic prediction. In the modeled dermis tissue, a 7% non-dimensional temperature increase is found. After about 10 thermal relaxation times, thermal waves fade away and the predictions between the hyperbolic and parabolic models are consistent.

  14. Effects of Sterilization Cycles on PEEK for Medical Device Application

    Science.gov (United States)

    Yap, Wai Teng; Foo, Soo Leong; Lee, Teck Kheng

    2018-01-01

    The effects of the sterilization process have been studied on medical grade thermoplastic polyetheretherketone (PEEK). For a reusable medical device, material reliability is an important parameter to decide its lifetime, as it will be subjected to the continuous steam sterilization process. A spring nature, clip component was selected out of a newly designed medical device (patented) to perform this reliability study. This clip component was sterilized for a predetermined number of cycles (2, 4, 6, 8, 10, 20…100) at 121 °C for 30 min. A significant decrease of ~20% in the compression force of the spring was observed after 30 cycles, and a ~6% decrease in the lateral dimension of the clip was observed after 50 cycles. No further significant change in the compression force or dimension was observed for the subsequent sterilization cycles. Vickers hardness and differential scanning calorimetry (DSC) techniques were used to characterize the effects of sterilization. DSC results exhibited no significant change in the degree of cure and melting behavior of PEEK before and after the sterilization. Hardness measurement exhibited an increase of ~49% in hardness after just 20 cycles. When an unsterilized sample was heated for repetitive cycles without the presence of moisture (121 °C, 10 and 20 cycles), only ~7% of the maximum change in hardness was observed. PMID:29466289

  15. Effects of Sterilization Cycles on PEEK for Medical Device Application.

    Science.gov (United States)

    Kumar, Amit; Yap, Wai Teng; Foo, Soo Leong; Lee, Teck Kheng

    2018-02-21

    The effects of the sterilization process have been studied on medical grade thermoplastic polyetheretherketone (PEEK). For a reusable medical device, material reliability is an important parameter to decide its lifetime, as it will be subjected to the continuous steam sterilization process. A spring nature, clip component was selected out of a newly designed medical device (patented) to perform this reliability study. This clip component was sterilized for a predetermined number of cycles (2, 4, 6, 8, 10, 20…100) at 121 °C for 30 min. A significant decrease of ~20% in the compression force of the spring was observed after 30 cycles, and a ~6% decrease in the lateral dimension of the clip was observed after 50 cycles. No further significant change in the compression force or dimension was observed for the subsequent sterilization cycles. Vickers hardness and differential scanning calorimetry (DSC) techniques were used to characterize the effects of sterilization. DSC results exhibited no significant change in the degree of cure and melting behavior of PEEK before and after the sterilization. Hardness measurement exhibited an increase of ~49% in hardness after just 20 cycles. When an unsterilized sample was heated for repetitive cycles without the presence of moisture (121 °C, 10 and 20 cycles), only ~7% of the maximum change in hardness was observed.

  16. A real-time heat strain risk classifier using heart rate and skin temperature

    International Nuclear Information System (INIS)

    Buller, Mark J; Latzka, William A; Yokota, Miyo; Tharion, William J; Moran, Daniel S

    2008-01-01

    Heat injury is a real concern to workers engaged in physically demanding tasks in high heat strain environments. Several real-time physiological monitoring systems exist that can provide indices of heat strain, e.g. physiological strain index (PSI), and provide alerts to medical personnel. However, these systems depend on core temperature measurement using expensive, ingestible thermometer pills. Seeking a better solution, we suggest the use of a model which can identify the probability that individuals are 'at risk' from heat injury using non-invasive measures. The intent is for the system to identify individuals who need monitoring more closely or who should apply heat strain mitigation strategies. We generated a model that can identify 'at risk' (PSI ≥ 7.5) workers from measures of heart rate and chest skin temperature. The model was built using data from six previously published exercise studies in which some subjects wore chemical protective equipment. The model has an overall classification error rate of 10% with one false negative error (2.7%), and outperforms an earlier model and a least squares regression model with classification errors of 21% and 14%, respectively. Additionally, the model allows the classification criteria to be adjusted based on the task and acceptable level of risk. We conclude that the model could be a valuable part of a multi-faceted heat strain management system. (note)

  17. On Time Domain Analysis of Photoplethysmogram Signals for Monitoring Heat Stress

    Directory of Open Access Journals (Sweden)

    Mohamed Elgendi

    2015-09-01

    Full Text Available There are a limited number of studies on heat stress dynamics during exercise using the photoplethysmogram (PPG and its second derivative (APG. However, we investigate the most suitable index from short PPG signal recordings for heat stress assessment. The APG waveform consists of a, b, c and d waves in systole and an e wave in diastole. Our preliminary results indicate that the use of the energy of aa area, derived from PPG signals measured from emergency responders in tropical conditions, is promising in determining the heat stress level using 20-s recordings. After examining 14 time domain features using leave-one-out cross-validation, we found that the aa energy extracted from PPG signals is the most informative feature for classifying heat-stressed subjects, with an overall accuracy of 79%. Moreover, the combination of the aa energy with the traditional heart rate variability index of heat stress (i.e., the square root of the mean of the squares of the successive aa intervals improved the heat stress detection to an overall accuracy of 83%.

  18. Laparoscopic tubal sterilization reversal and fertility outcomes

    Directory of Open Access Journals (Sweden)

    K Jayakrishnan

    2011-01-01

    Full Text Available Purpose: The purpose of the study was two-fold. Firstly it was to assess the suitability for tubal recanalization and factors predicting successful laparoscopic recanalization. Secondly, it was to analyze the fertility outcomes and factors affecting the pregnancy rate following laparoscopic tubal recanalization. Materials and Methods: A retrospective chart review of prospectively followed-up 29 women at a tertiary care center seeking tubal sterilization reversal between May 2005 and February 2010 were included. Results: In 14 (48.3% women unilateral tubes were suitable and in only 3 women (10.3% bilateral tubes were suitable. All cases with laparoscopic tubal sterilization were suitable, whereas all cases with fimbriectomy were unsuitable for recanalization. In 6 (20.7% cases salphingostomy was performed as an alternative procedure to tubal reanastomosis. The overall pregnancy rate was 58.8%. In cases with sterilization by Pomeroy′s method, 4 out of 10 (40% conceived, whereas for laparoscopic tubal ligation cases 6 out of 7 (85.7% conceived (P=0.32. None of the patients with final tubal length <5 cm conceived (P=0.03. Comparing the age at recanalization, in women ≤30 years, 71.4% conceived, as compared with 50% when age of women was more than 30 years (P=0.37. Conclusions: The important factors determining the success of recanalization are technique of sterilization and the remaining length of the tube after recanalization. The gynecologist must use an effective technique of sterilization to minimize the failure rates, but at the same time, which causes minimal trauma, and aim at preserving the length of the tube so that reversal is more likely to be successful, should the patient′s circumstances change.

  19. Effect of ohmic heating of soymilk on urease inactivation and kinetic analysis in holding time.

    Science.gov (United States)

    Li, Fa-De; Chen, Chen; Ren, Jie; Wang, Ranran; Wu, Peng

    2015-02-01

    To verify the effect of the ohmic heating on the urease activity in the soymilk, the ohmic heating methods with the different electrical field conditions (the frequency and the voltage ranging from 50 to 10 kHz and from 160 to 220 V, respectively) were employed. The results showed that if the value of the urease activity measured with the quantitative spectrophotometry method was lower than 16.8 IU, the urease activity measured with the qualitative method was negative. The urease activity of the sample ohmically heated was significantly lower than that of the sample conventionally heated (P urease inactivation. In addition, the inactivation kinetics of the urease in the soymilk could be described with a biphasic model during holding time at a target temperature. Thus, it was concluded that the urease in the soymilk would contain 2 isoenzymes, one is the thermolabile fraction, the other the thermostable fraction, and that the thermostable isoenzyme could not be completely inactivated when the holding time increased, whether the soymilk was cooked with the conventional method or with the ohmic heating method. Therefore, the electric field had no effect on the inactivation of the thermostable isoenzyme of the urease. © 2015 Institute of Food Technologists®

  20. Study on nonstationary convective heat transfer in annular channels and rod bundles in conditions of arbitrary variation of heat duty in time and length

    International Nuclear Information System (INIS)

    Kuznetsov, Yu.N.; Kalinin, E.I.; Naumov, M.A.

    1980-01-01

    The effect of variability of heat duty on the characteristics of heat exchange in ring channels and rod bundles is investigated with analytical methods. The plotting of calculation formulae for non-stationary heat exchange in an annular channel at a jump of heat duty is carried out on the basis of the method of the effect function. The formulae obtained permit to accomplish technical calculations of the processes of non-stationary heat exchange in annular channels in the case of any alterations of thermal duty in time, at any moment of time, for any channel cross section (including the entrance heat section) in a wide range of geometric and regime parameters of the turbulent current of a coolant. According to preliminary estimates, calculation results differ from the results oi a numerical solution less than 5%. The approach considered permits to transfer the data on the non-stationary heat exchange in annular channels in the case of changing the heat duty in time, in the case of a non-stationary heat exchange in longitudinally flown not very dense and infinite rod bundles

  1. Sterile neutrinos as the origin of dark and baryonic matter.

    Science.gov (United States)

    Canetti, Laurent; Drewes, Marco; Shaposhnikov, Mikhail

    2013-02-08

    We demonstrate for the first time that three sterile neutrinos alone can simultaneously explain neutrino oscillations, the observed dark matter, and the baryon asymmetry of the Universe without new physics above the Fermi scale. The key new point of our analysis is leptogenesis after sphaleron freeze-out, which leads to resonant dark matter production, evading thus the constraints on sterile neutrino dark matter from structure formation and x-ray searches. We identify the range of sterile neutrino properties that is consistent with all known constraints. We find a domain of parameters where the new particles can be found with present day experimental techniques, using upgrades to existing experimental facilities.

  2. Bacterial spores survive treatment with commercial sterilants and disinfectants.

    Science.gov (United States)

    Sagripanti, J L; Bonifacino, A

    1999-09-01

    This study compared the activity of commercial liquid sterilants and disinfectants on Bacillus subtilis spores deposited on three types of devices made of noncorrodible, corrodible, or polymeric material. Products like Renalin, Exspor, Wavicide-01, Cidexplus, and cupric ascorbate were tested under conditions specified for liquid sterilization. These products, at the shorter times indicated for disinfection, and popular disinfectants, like Clorox, Cavicide, and Lysol were also studied. Data obtained with a sensitive and quantitative test suggest that commercial liquid sterilants and disinfectants are less effective on contaminated surfaces than generally acknowledged.

  3. Delayed pulsar kicks from the emission of sterile neutrinos

    International Nuclear Information System (INIS)

    Kusenko, Alexander; Mandal, Bhabani Prasad; Mukherjee, Alok

    2008-01-01

    The observed velocities of pulsars suggest the possibility that sterile neutrinos with mass of several keV are emitted from a cooling neutron star. The same sterile neutrinos could constitute all or part of cosmological dark matter. The neutrino-driven kicks can exhibit delays depending on the mass and the mixing angle, which can be compared with the pulsar data. We discuss the allowed ranges of sterile neutrino parameters, consistent with the latest cosmological and x-ray bounds, which can explain the pulsar kicks for different delay times

  4. The processing technology of bread crumbs sterilization by irradiation

    International Nuclear Information System (INIS)

    Zhu Jiating; Li Zhengkui; Zhao Yongfu; Zhang Weidong; Jin Jie; Wu Lei; Wang Xinghai

    2003-01-01

    The processing technology of bread crumbs sterilization by irradiation was studied. The results demonstrated that dose heterogeneity had osculatory connection with pile height and turning, sterilization effect had positive correlation with the irradiation dose and negative correlation with colour. Compared with the CK, the content of crud protein, fat, carbohydrate, microelement and amino acid in irradiated bread crumbs had no obvious change. It is recommended that the range of best sterilization dose be 6-10 kGy and the shelf time of bread crumbs be extended to one year

  5. Effect of solution heat treatment time on a rheocast Al-Zn-Mg-Cu alloy

    CSIR Research Space (South Africa)

    Mazibuko, NE

    2011-06-01

    Full Text Available During rheo-high pressure die casting (R-HPDC) of Al-Zn-Mg-Cu alloys a coarse eutectic phase is formed. This eutectic phase is difficult to take into solution because of its size and it would require longer solution heat treatment times...

  6. Heat conduction in a plate-type fuel element with time-dependent boundary conditions

    International Nuclear Information System (INIS)

    Faya, A.J.G.; Maiorino, J.R.

    1981-01-01

    A method for the solution of boundary-value problems with variable boundary conditions is applied to solve a heat conduction problem in a plate-type fuel element with time dependent film coefficient. The numerical results show the feasibility of the method in the solution of this class of problems. (Author) [pt

  7. Real time control of EC heating & current drive systems on TCV

    NARCIS (Netherlands)

    Paley, J.I.; Felici, F.; Curchod, L.; Coda, S.; Goodman, T.P.

    2009-01-01

    The ability to control, in real time, the electron cyclotron heating & current drive systems for the control of MHD instabilities is particularly important for large tokamaks operating at high performance. Several algorithms have been developed and tested on TCV to explore possible control

  8. Existence of a time-dependent heat flux-related ponderomotive effect

    International Nuclear Information System (INIS)

    Schamel, H.; Sack, C.

    1980-01-01

    The existence of a new ponderomotive effect associated with high-frequency waves is pointed out. It originates when time-dependency, mean velocities, or divergent heat fluxes are involved and it supplements the two effects known previously, namely, the ponderomotive force and fake heating. Two proofs are presented; the first is obtained by establishing the momentum equations generalized by including radiation effects and the second by solving the quasi-linear-type diffusion equation explicitly. For a time-dependent wave packet the solution exhibits a new contribution in terms of an integral over previous states. Owing to this term, the plasma has a memory which leads to a breaking of the time symmetry of the plasma response. The range, influenced by the localized wave packet, expands during the course of time due to streamers emanating from the wave active region. Perturbations, among which is the heat flux, are carried to remote positions and, consequently, the region accessible to wave heating is increased. The density dip appears to be less pronounced at the center, and its generation and decay are delayed. The analysis includes a self-consistent action of high-frequency waves as well as the case of traveling wave packets. In order to establish the existence of this new effect, the analytical results are compared with recent microwave experiments. The possibility of generating fast particles by this new ponderomotive effect is emphasized

  9. Validation of an intermediate heat exchanger model for real time analysis

    International Nuclear Information System (INIS)

    Tzanos, C.P.

    1986-11-01

    A new method was presented for LMFBR intermediate heat exchanger (IHX) analysis in real time for purposes of continuous on-line data validation, plant state verification and fault identification. For the validation of this methodology the EBR-II IHX transient during Test 8A was analyzed. This paper presents the results of this analysis

  10. Ad-libitum drinking and performance during a 40-km cycling time trial in the heat

    NARCIS (Netherlands)

    Berkulo, M.A.R.; Bol, S.; Levels, K.; Lamberts, R.P.; Daanen, H.A.M.; Noakes, T.D.

    2015-01-01

    The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and

  11. Ad-libitum drinking and performance during a 40-km cycling time trial in the heat

    NARCIS (Netherlands)

    Berkulo, M.A.R.; Bol, S.; Levels, K.; Lamberts, R.P.; Daanen, H.A.M.; Noakes, T.D.

    2016-01-01

    The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and

  12. Validation of the sterile manufacture of the AAEC MARK III molybdenum-99/techtnetium-99m generator

    International Nuclear Information System (INIS)

    Saunders, M.T.; Drummond, C.M.; Harrison, M.A.

    1982-07-01

    The Mark II molybdenum-99/technetium-99m generator now supplied to hospitals by the Australian Atomic Energy Commission is a non-sterile elution system. The Mark III version will be supplied as a sterile elution system. A validation study has been undertaken to assess the capability of the new production facility, to evaluate up-to-date procedures for manufacturing sterile generators and to demonstrate that a sterile radionuclide generator can be made. Generator manufacturing procedures and a time study of the validation are described. Microbiological methods for monitoring in-process aspects of manufacture, disinfectant efficacy and generator sterility are defined

  13. AN INVESTIGATION OF TIME LAG MAPS USING THREE-DIMENSIONAL SIMULATIONS OF HIGHLY STRATIFIED HEATING

    Energy Technology Data Exchange (ETDEWEB)

    Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Lionello, Roberto; Downs, Cooper; Mikić, Zoran; Linker, Jon [Predictive Science, Inc., 9990 Mesa Rim Rd., Ste. 170, San Diego, CA 92121-2910 (United States); Mok, Yung, E-mail: amy.r.winebarger@nasa.gov, E-mail: lionel@predsci.com, E-mail: cdowns@predsci.com, E-mail: mikicz@predsci.com, E-mail: linkerj@predsci.com, E-mail: ymok@uci.edu [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

    2016-11-10

    The location and frequency of coronal energy release provide a significant constraint on the coronal heating mechanism. The evolution of the intensity observed in coronal structures found from time lag analysis of Atmospheric Imaging Assembly (AIA) data has been used to argue that heating must occur sporadically. Recently, we have demonstrated that quasi-steady, highly stratified (footpoint) heating can produce results qualitatively consistent with the evolution of observed coronal structures. The goals of this paper are to demonstrate that time lag analysis of 3D simulations of footpoint heating are qualitatively consistent with time lag analysis of observations and to use the 3D simulations to further understand whether time lag analysis is a useful tool in defining the evolution of coronal structures. We find the time lag maps generated from simulated data are consistent with the observed time lag maps. We next investigate several example points. In some cases, the calculated time lag reflects the evolution of a unique loop along the line of sight, though there may be additional evolving structures along the line of sight. We confirm that using the multi-peak AIA channels can produce time lags that are difficult to interpret. We suggest using a different high temperature channel, such as an X-ray channel. Finally, we find that multiple evolving structures along the line of sight can produce time lags that do not represent the physical properties of any structure along the line of sight, although the cross-correlation coefficient of the lightcurves is high. Considering the projected geometry of the loops may reduce some of the line-of-sight confusion.

  14. Timing of Histologic Progression from Chorio-Deciduitis to Chorio-Deciduo-Amnionitis in the Setting of Preterm Labor and Preterm Premature Rupture of Membranes with Sterile Amniotic Fluid.

    Science.gov (United States)

    Park, Chan-Wook; Park, Joong Shin; Norwitz, Errol R; Moon, Kyung Chul; Jun, Jong Kwan; Yoon, Bo Hyun

    2015-01-01

    Histologic chorio-deciduitis and chorio-deciduo-amnionitis (amnionitis) in extra-placental membranes are known to represent the early and advanced stages of ascending intra-uterine infection. However, there are no data in humans about the time required for chorio-deciduitis to develop and for chorio-deciduitis without amnionitis to progress to chorio-deciduitis with amnionitis, and the effect of prolongation of pregnancy on the development of chorio-deciduitis and amnionitis in patients with preterm labor and intact membranes (PTL) and preterm premature rupture of membranes (preterm-PROM). We examined these issues in this study. The study population consisted of 289 women who delivered preterm (133 cases with PTL, and 156 cases with preterm-PROM) and who had sterile amniotic fluid (AF) defined as a negative AF culture and the absence of inflammation as evidenced by a matrix metalloproteinase-8 (MMP-8) level membranes (i.e., inflammation-free extra-placental membranes, choroi-deciduitis only, and chorio-deciduitis with amnionitis) in patients with PTL and preterm-PROM. Amniocentesis-to-delivery interval was longer in cases of chorio-deciduitis with amnionitis than in cases of chorio-deciduitis only in both PTL (median [interquartile-range (IQR)]; 645.4 [319.5] vs. 113.9 [526.9] hours; P = 0.005) and preterm-PROM (131.3 [135.4] vs. 95.2 [140.5] hours; Pmembranes. Moreover, prolongation of pregnancy is an independent predictor of the development of both chorio-deciduitis and amnionitis in cases of PTL with sterile AF.

  15. Sterile neutrinos as dark matter

    International Nuclear Information System (INIS)

    Dodelson, S.; Widrow, L.M.

    1994-01-01

    The simplest model that can accommodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed (sterile) neutrinos. We consider a single generation of neutrinos with a Dirac mass μ and a Majorana mass M for the right-handed component. If M much-gt μ (standard hot dark matter corresponds to M=0), then sterile neutrinos are produced via oscillations in the early Universe with energy density independent of M. However, M is crucial in determining the large scale structure of the Universe; for M∼100 eV, sterile neutrinos make an excellent warm dark matter candidate

  16. Crystallite size variation of TiO_2 samples depending time heat treatment

    International Nuclear Information System (INIS)

    Galante, A.G.M.; Paula, F.R. de; Montanhera, M.A.; Pereira, E.A.; Spada, E.R.

    2016-01-01

    Titanium dioxide (TiO_2) is an oxide semiconductor that may be found in mixed phase or in distinct phases: brookite, anatase and rutile. In this work was carried out the study of the residence time influence at a given temperature in the TiO_2 powder physical properties. After the powder synthesis, the samples were divided and heat treated at 650 °C with a ramp up to 3 °C/min and a residence time ranging from 0 to 20 hours and subsequently characterized by x-ray diffraction. Analyzing the obtained diffraction patterns, it was observed that, from 5-hour residence time, began the two-distinct phase coexistence: anatase and rutile. It also calculated the average crystallite size of each sample. The results showed an increase in average crystallite size with increasing residence time of the heat treatment. (author)

  17. Male gametophytic sterility. 1 - Gametic sterilities and deletions in petunia

    Energy Technology Data Exchange (ETDEWEB)

    Cornu, A.; Maizonnier, D. (Station d' Amelioration des Plantes de l' I.N.R.A., Dijon (France))

    1982-01-01

    Terminal deletions induced by ionizing radiations in Petunia are not sexually transmitted. Cytogenetic study of plants with a heterozygous deletion and their progenies shows that this lack of transmission is accompanied by a gametic semi-sterility due to the fact that gametes carrying the deleted chromosome are not viable. The interest of such a male sterility with a gametophytic determinism for the study of sporophyte-gametophyte relationships is underlined.

  18. Integral transform method for solving time fractional systems and fractional heat equation

    Directory of Open Access Journals (Sweden)

    Arman Aghili

    2014-01-01

    Full Text Available In the present paper, time fractional partial differential equation is considered, where the fractional derivative is defined in the Caputo sense. Laplace transform method has been applied to obtain an exact solution. The authors solved certain homogeneous and nonhomogeneous time fractional heat equations using integral transform. Transform method is a powerful tool for solving fractional singular Integro - differential equations and PDEs. The result reveals that the transform method is very convenient and effective.

  19. Sterile neutrinos in the early universe

    Energy Technology Data Exchange (ETDEWEB)

    Malaney, R.A. (Lawrence Livermore National Lab., CA (USA)); Fuller, G.M. (California Univ., San Diego, La Jolla, CA (USA). Dept. of Physics)

    1990-11-14

    We discuss the role played by right-handed sterile neutrinos in the early universe. We show how well known {sup 4}He constraint on the number of relativistic degrees of freedom at early times limits the equilibration of the right handed neutrino sea with the background plasma. We discuss how this allows interesting constraints to be placed on neutrino properties. In particular, a new limit on the Dirac mass of the neutrino is presented. 12 refs.

  20. Time-varying Entry Heating Profile Replication with a Rotating Arc Jet Test Article

    Science.gov (United States)

    Grinstead, Jay Henderson; Venkatapathy, Ethiraj; Noyes, Eric A.; Mach, Jeffrey J.; Empey, Daniel M.; White, Todd R.

    2014-01-01

    A new approach for arc jet testing of thermal protection materials at conditions approximating the time-varying conditions of atmospheric entry was developed and demonstrated. The approach relies upon the spatial variation of heat flux and pressure over a cylindrical test model. By slowly rotating a cylindrical arc jet test model during exposure to an arc jet stream, each point on the test model will experience constantly changing applied heat flux. The predicted temporal profile of heat flux at a point on a vehicle can be replicated by rotating the cylinder at a prescribed speed and direction. An electromechanical test model mechanism was designed, built, and operated during an arc jet test to demonstrate the technique.

  1. Pressure-assisted thermal sterilization of soup

    Science.gov (United States)

    Shibeshi, Kidane; Farid, Mohammed M.

    2010-12-01

    The overall efficiency of an existing scale-up pressure-assisted thermal sterilization (PATS) unit was investigated with regards to inactivation of Geobacillus stearothermophilus spores suspended in pumpkin soup. The PATS unit is a double pipe heat exchanger in which the soup is pumped into its inner high pressure tube and constrained by two high pressure valves, while steam is continuously passed through the annular region to heat the content. The technology is based on pressure generation by thermal expansion of the liquid in an enclosure. In this work, the addition of an air line to push the treated liquid food out of the existing PATS unit has improved the overall quality of the treated samples, as evidenced by achieving higher log reduction of the spores. Compared with thermal processing, the application of PATS shows the potential for lowering the thermal treatment temperature, offering improved food quality.

  2. Portable Decontamination and Sterilization System

    National Research Council Canada - National Science Library

    Bell, William; Smerjac, Suzanne; Smith, Bryan

    2004-01-01

    TDA Research, Inc., (TDA) is developing a portable system to generate chlorine dioxide, which can be used for biodecontamination of small items and to sterilize medical and dental instruments in austere environments...

  3. Documentation requirements for radiation sterilization

    DEFF Research Database (Denmark)

    Miller, A.

    1995-01-01

    Several standards are recently approved or are under development by the standard organizations ISO and CEN in the field of radiation sterilization. Particularly in Europe these standards define new requirements on some issues and on other issues they emphasize the necessary documentation for appr......Several standards are recently approved or are under development by the standard organizations ISO and CEN in the field of radiation sterilization. Particularly in Europe these standards define new requirements on some issues and on other issues they emphasize the necessary documentation...... for approval of radiation sterilized products. The impact of these standards on the radiation sterilization is discussed, with special attention given to a few special issues, mainly traceability and uncertainty of measurement results....

  4. Steam sterilization does not require saturated steam

    NARCIS (Netherlands)

    van Doornmalen Gomez Hoyos, J. P.C.M.; Paunovic, A.; Kopinga, K.

    2017-01-01

    The most commonly applied method to sterilize re-usable medical devices in hospitals is steam sterilization. The essential conditions for steam sterilization are derived from sterilization in water. Microbiological experiments in aqueous solutions have been used to calculate various time–temperature

  5. Bacterial Spores Survive Treatment with Commercial Sterilants and Disinfectants

    OpenAIRE

    Sagripanti, Jose-Luis; Bonifacino, Aylin

    1999-01-01

    This study compared the activity of commercial liquid sterilants and disinfectants on Bacillus subtilis spores deposited on three types of devices made of noncorrodible, corrodible, or polymeric material. Products like Renalin, Exspor, Wavicide-01, Cidexplus, and cupric ascorbate were tested under conditions specified for liquid sterilization. These products, at the shorter times indicated for disinfection, and popular disinfectants, like Clorox, Cavicide, and Lysol were also studied. Data ob...

  6. Radiation sterilization of skin allograft

    Science.gov (United States)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-07-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6. The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2. The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  7. Radiation sterilization of skin allograft

    International Nuclear Information System (INIS)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-01-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6 . The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2 . The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  8. Time-dependent mixed convection heat transfer from a sphere in a micro-gravity environment

    International Nuclear Information System (INIS)

    Hommel, M.J.

    1987-01-01

    A fundamental problem of interest for crystal growth in micro-gravity applications involves the mixed convection heat transfer from a sphere in a uniform flow of fluid at a differing temperature. Under the combined influence of the imposed free stream as well as an induced buoyancy force due to thermal expansion of the fluid, the heat transfer from the sphere will be different from that of either the pure forced convection flow or the pure free convection flow. For the present study, the method of matched asymptotic expansions is applied to the laminar flow problem of an impulsively heated, impulsively started sphere in an originally quiescent fluid. Time series expansions are developed for the dependent variables by acknowledging the existence of two district regions: one, an inner region, near the sphere, in which viscous effects are significant; and two, an outer region in which the fluid may be treated as inviscid. The time series expansions are developed in terms of the Reynolds number and Richardson number (Buoyancy Parameter), and the relevant heat transfer and drag coefficients are calculated and plotted

  9. Shock compression and flash-heating of molecular adsorbates on the picosecond time scale

    Science.gov (United States)

    Berg, Christopher Michael

    An ultrafast nonlinear coherent laser spectroscopy termed broadband multiplex vibrational sum-frequency generation (SFG) with nonresonant suppression was employed to monitor vibrational transitions of molecular adsorbates on metallic substrates during laser-driven shock compression and flash-heating. Adsorbates were in the form of well-ordered self-assembled monolayers (SAMs) and included molecular explosive simulants, such as nitroaromatics, and long chain-length alkanethiols. Based on reflectance measurements of the metallic substrates, femtosecond flash-heating pulses were capable of producing large-amplitude temperature jumps with DeltaT = 500 K. Laser-driven shock compression of SAMs produced pressures up to 2 GPa, where 1 GPa ≈ 1 x 104 atm. Shock pressures were estimated via comparison with frequency shifts observed in the monolayer vibrational transitions during hydrostatic pressure measurements in a SiC anvil cell. Molecular dynamics during flash-heating and shock loading were probed with vibrational SFG spectroscopy with picosecond temporal resolution and sub-nanometer spatial resolution. Flash-heating studies of 4-nitrobenzenethiolate (NBT) on Au provided insight into effects from hot-electron excitation of the molecular adsorbates at early pump-probe delay times. At longer delay times, effects from the excitation of SAM lattice modes and lower-energy NBT vibrations were shown. In addition, flash-heating studies of alkanethiolates demonstrated chain disordering behaviors as well as interface thermal conductances across the Au-SAM junction, which was of specific interest within the context of molecular electronics. Shock compression studies of molecular explosive simulants, such as 4-nitrobenzoate (NBA), demonstrated the proficiency of this technique to observe shock-induced molecular dynamics, in this case orientational dynamics, on the picosecond time scale. Results validated the utilization of these refined shock loading techniques to probe the shock

  10. Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

    Science.gov (United States)

    He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

    2011-08-01

    The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

  11. A novel steam explosion sterilization improving solid-state fermentation performance.

    Science.gov (United States)

    Zhao, Zhi-Min; Wang, Lan; Chen, Hong-Zhang

    2015-09-01

    Traditional sterilization of solid medium (SM) requires lengthy time, degrades nutrients, and even sterilizes inadequately compared with that of liquid medium due to its low thermal conductivity. A novel sterilization strategy, high-temperature and short-time steam explosion (SE), was exploited for SM sterilization in this study. Results showed that SE conditions for complete sterilization were 172 °C for 2 min and 128 °C for 5 min. Glucose and xylose contents in medium after SE sterilization increased by 157% and 93% respectively compared with those after conventional sterilization (121 °C, 20 min) while fermentation inhibitors were not detected. FTIR spectra revealed that the mild SE conditions helped to release monosaccharides from the polysaccharides. Bacillus subtilis fermentation productivity on medium after SE sterilization was 3.83 times of that after conventional sterilization. Therefore, SE shortened sterilization time and improved SM nutrition, which facilitated fermentability of SM and should promote economy of solid-state fermentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Real-Time Personalized Monitoring to Estimate Occupational Heat Stress in Ambient Assisted Working

    Directory of Open Access Journals (Sweden)

    Pablo Pancardo

    2015-07-01

    Full Text Available Ambient Assisted Working (AAW is a discipline aiming to provide comfort and safety in the workplace through customization and technology. Workers’ comfort may be compromised in many labor situations, including those depending on environmental conditions, like extremely hot weather conduces to heat stress. Occupational heat stress (OHS happens when a worker is in an uninterrupted physical activity and in a hot environment. OHS can produce strain on the body, which leads to discomfort and eventually to heat illness and even death. Related ISO standards contain methods to estimate OHS and to ensure the safety and health of workers, but they are subjective, impersonal, performed a posteriori and even invasive. This paper focuses on the design and development of real-time personalized monitoring for a more effective and objective estimation of OHS, taking into account the individual user profile, fusing data from environmental and unobtrusive body sensors. Formulas employed in this work were taken from different domains and joined in the method that we propose. It is based on calculations that enable continuous surveillance of physical activity performance in a comfortable and healthy manner. In this proposal, we found that OHS can be estimated by satisfying the following criteria: objective, personalized, in situ, in real time, just in time and in an unobtrusive way. This enables timely notice for workers to make decisions based on objective information to control OHS.

  13. Steam sterilization costs: a guide for the central service manager.

    Science.gov (United States)

    O'Shaughnessy, K L

    1993-07-01

    The Nassau County Medical Center CS department, East Meadow, New York, was faced with a staff layoff and an increased workload. With some hard thinking and strong staff support, new processes/systems were designed to save time and money. These included outsourcing the sterilization of "easy" trays, instituting a case cart program and developing custom packs. In order to determine where savings could be had, it was first important to examine current costs. By breaking the costs of sterilization processing down into an average cost per load, a formula was developed that helped determine many additional cost comparisons for the department. For example, the cost analysis formula could be used by CS departments to determine the cost-effectiveness of off-site sterilization, to compare using disposable vs. reusable items and to determine costs for EtO sterilization and aeration.

  14. Time course of primary and secondary hyperalgesia after heat injury to the skin

    DEFF Research Database (Denmark)

    Møiniche, S; Dahl, J B; Kehlet, H

    1993-01-01

    the injury in any volunteer. These findings suggest post-injury development of secondary hyperalgesia to be a dynamic process, closely related in time to a peripheral nociceptive input, with reversal to normal when the peripheral lesion disappears. These observations may be relevant to the concept of "pre......We have examined the time course of, and relationship between, primary and secondary hyperalgesia after thermal injury to the skin in humans. Burn injuries (15 x 25 mm rectangular thermode, 49 degrees C, 5 min) were produced in eight healthy, unmedicated male volunteers, on the medial side...... of the right calf, on two occasions at least 8 days apart. Heat pain detection thresholds (HPDT), heat pain tolerance (HPT), mechanical pain detection threshold (MPDT) and the intensity of burn-injury induced erythema (skin erythema index, SEI) were assessed inside the burn injury. HPT was assessed only in one...

  15. Impact of Air Distribution on Heat Transfer during Night-Time Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Artmann, Nikolai; Jensen, Rasmus Lund

    2009-01-01

    Passive cooling by night-time ventilation is seen as a promising approach for energy efficient cooling of buildings. However, uncertainties in prediction of cooling potential and consequenses for thermal comfort restrain architects and engineers from applying this technique. Heat transfer...... at internal room surfaces determines the performance of night-time ventilation. In order to improve predictability, heat transfer mechanism in case of either mixing or displacement ventilation has been investigated in a full scale test room with an exposed ceiling as the dominating thermal mass. The influence...... of air distribution principle, air flow rate and inlet air temperature were investigated. Results show that for low air flow rates displacement ventilation is more efficient than mixing ventilation. For higher airflow rates the air jet flowing along the ceiling has a significant effect, and mixing...

  16. Real-time simulation of thermal stresses and creep in plates subjected to transient heat input

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri; Jacobsen, Torben Krogsdal; Hansen, P.N.

    1997-01-01

    -difference approach. It applies a general formulation which takes into account nonconstant material properties (e.g. temperature, material, or time dependency), heat-transfer coefficients, and creep. The temperature calculation applies a one-dimensional numerical model, whereas the stress analysis is semi......This paper presents a novel numerical technique for solving the temperature and stress fields in a plate subjected to arbitrarily varying transient boundary conditions (transient temperature and heat-flux variations) on a surface. The numerical method is based on the control-volume finite......-two-dimensional. Both plane stress and plane strain conditions are considered as extreme cases. It is shown that, by using the developed numerical technique, very fast real-time simulations can be performed. The method has proved its applicability in e.g. high-pressure die-casting, and applications to this industrial...

  17. Precooling and Warm-Up Effects on Time Trial Cycling During Heat Stress.

    Science.gov (United States)

    Al-Horani, Ramzi A; Wingo, Jonathan E; Ng, Jason; Bishop, Phillip; Richardson, Mark

    2018-02-01

    Heat stress limits endurance exercise performance. Combining precooling and warm-up prior to endurance exercise in the heat may exploit the benefits of both strategies while avoiding the potential negative consequences of each. This study tested the hypothesis that precooling combined with warm-up improves time trial cycling performance in the heat relative to either treatment alone. Nine healthy men completed three 16.1-km time trials in 33°C after: 1) precooling (ice slurry and ice vest) alone (PREC); 2) warm-up alone (WU); or 3) PREC plus WU (COMBO). Tre was lower after PREC compared to WU throughout exercise and lower than COMBO for the first 12 km; COMBO was lower than WU for the first 4 km. Tsk during PREC was lower than COMBO and WU for the first 8 km, and lower in COMBO than WU for the first 4 km. PREC lowered pre-exercise heart rate relative to COMBO and WU (68 ± 10, 106 ± 12, 101 ± 13 bpm, respectively), but it increased similarly during exercise. Local sweat rate (SR) was lower in PREC (0.1 ± 0.1 mg · cm-2 · min-1) than COMBO (0.5 ± 0.2 mg · cm-2 · min-1) and WU (0.6 ± 0.2 mg · cm-2 · min-1) for the first 4 km. Treatments did not differentially affect performance (PREC = 31.9 ± 1.9 min, COMBO = 32.6 ± 2.7 min, WU = 33.1 ± 2.9 min). We conclude precooling alone or with warm-up mitigated thermal strain during exercise, but did not significantly improve 16.1-km cycling time trial performance.Al-horani RA, Wingo JE, Ng J, Bishop P, Richardson M. Precooling and warm-up effects on time trial cycling during heat stress. Aerosp Med Hum Perform. 2018; 89(2):87-93.

  18. Sterilization of Exopolysaccharides Produced by Deep-Sea Bacteria: Impact on Their Stability and Degradation

    Directory of Open Access Journals (Sweden)

    Sylvia Colliec-Jouault

    2011-02-01

    Full Text Available Polysaccharides are highly heat-sensitive macromolecules, so high temperature treatments are greatly destructive and cause considerable damage, such as a great decrease in both viscosity and molecular weight of the polymer. The technical feasibility of the production of exopolysaccharides by deep-sea bacteria Vibrio diabolicus and Alteromonas infernus was previously demonstrated using a bioproduct manufacturing process. The objective of this study was to determine which sterilization method, other than heat sterilization, was the most appropriate for these marine exopolysaccharides and was in accordance with bioprocess engineering requirements. Chemical sterilization using low-temperature ethylene oxide and a mixture of ionized gases (plasmas was compared to the sterilization methods using gamma and beta radiations. The changes to both the physical and chemical properties of the sterilized exopolysaccharides were analyzed. The use of ethylene oxide can be recommended for the sterilization of polysaccharides as a weak effect on both rheological and structural properties was observed. This low-temperature gas sterilizing process is very efficient, giving a good Sterility Assurance Level (SAL, and is also well suited to large-scale compound manufacturing in the pharmaceutical industry.

  19. Effect of sterilization on the properties of CDHA-OCP-beta-TCP biomaterial

    Directory of Open Access Journals (Sweden)

    Loreley Morejón-Alonso

    2007-03-01

    Full Text Available The effect of the method of sterilization on the physical, chemical and mechanical properties of a new bone repairing material was studied. The material was obtained by thermal hydrolysis of beta-tricalcium phosphate/orthophosphoric acid cement and was composed of calcium deficient hydroxyapatite, octacalcium phosphate (OCP, and beta-tricalcium phosphate. Partial decomposition of the OCP was observed after sterilization for the three methods. Decomposition increased to the following sequence of sterilization methods: ethylene oxide; autoclaving; dry oven. On the other hand, mechanical strength decreased with regard to non sterilized material in the sterilization sequence: ethylene oxide; dry oven; autoclaving. The compressive strength was 8.5 ± 1.0; 9.0 ± 1.2; 8.2 ± 0.8 and 6.5 ± 1.0 MPa, whereas diametral tensile strength was 2.1 ± 0.3; 2.5 ± 0.1; 1.9 ± 0.9 and 1.6 ± 0.3 for the material sterilized by ethylene oxide, dry oven, and autoclaving, respectively. Several compositional and microstuctural changes were detected after dry heat and autoclave sterilization. Ethylene oxide sterilization had lesser effect on the chemical composition and strength than dry heat and autoclaving.

  20. Genomic networks of hybrid sterility.

    Directory of Open Access Journals (Sweden)

    Leslie M Turner

    2014-02-01

    Full Text Available Hybrid dysfunction, a common feature of reproductive barriers between species, is often caused by negative epistasis between loci ("Dobzhansky-Muller incompatibilities". The nature and complexity of hybrid incompatibilities remain poorly understood because identifying interacting loci that affect complex phenotypes is difficult. With subspecies in the early stages of speciation, an array of genetic tools, and detailed knowledge of reproductive biology, house mice (Mus musculus provide a model system for dissecting hybrid incompatibilities. Male hybrids between M. musculus subspecies often show reduced fertility. Previous studies identified loci and several X chromosome-autosome interactions that contribute to sterility. To characterize the genetic basis of hybrid sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL. Many trans eQTL cluster into eleven 'hotspots,' seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL-but not cis eQTL-were substantially lower when mapping was restricted to a 'fertile' subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. The integrated mapping approach we employed is

  1. Genomic networks of hybrid sterility.

    Science.gov (United States)

    Turner, Leslie M; White, Michael A; Tautz, Diethard; Payseur, Bret A

    2014-02-01

    Hybrid dysfunction, a common feature of reproductive barriers between species, is often caused by negative epistasis between loci ("Dobzhansky-Muller incompatibilities"). The nature and complexity of hybrid incompatibilities remain poorly understood because identifying interacting loci that affect complex phenotypes is difficult. With subspecies in the early stages of speciation, an array of genetic tools, and detailed knowledge of reproductive biology, house mice (Mus musculus) provide a model system for dissecting hybrid incompatibilities. Male hybrids between M. musculus subspecies often show reduced fertility. Previous studies identified loci and several X chromosome-autosome interactions that contribute to sterility. To characterize the genetic basis of hybrid sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven 'hotspots,' seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL-but not cis eQTL-were substantially lower when mapping was restricted to a 'fertile' subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. The integrated mapping approach we employed is applicable in a broad

  2. Finite time thermodynamic analysis and optimization of solar-dish Stirling heat engine with regenerative losses

    Directory of Open Access Journals (Sweden)

    Sharma Arjun

    2011-01-01

    Full Text Available The present study investigates the performance of the solar-driven Stirling engine system to maximize the power output and thermal efficiency using the non-linearized heat loss model of the solar dish collector and the irreversible cycle model of the Stirling engine. Finite time thermodynamic analysis has been done for combined system to calculate the finite-rate heat transfer, internal heat losses in the regenerator, conductive thermal bridging losses and finite regeneration process time. The results indicate that exergy efficiency of dish system increases as the effectiveness of regenerator increases but decreases with increase in regenerative time coefficient. It is also found that optimal range of collector temperature and corresponding concentrating ratio are 1000 K~1400 K and 1100~1400, respectively in order to get maximum value of exergy efficiency. It is reported that the exergy efficiency of this dish system can reach the maximum value when operating temperature and concentrating ratio are 1150 K and 1300, respectively.

  3. Water-Stressed Loquat Trees Need More Time and Heat to Ripen Their Fruits

    Directory of Open Access Journals (Sweden)

    Julián Cuevas

    2018-06-01

    Full Text Available To determine if water-stressed trees need more time and heat to mature their fruits, we compared chronological and thermal time from bloom to harvest among control fully-irrigated ‘Algerie’ loquat trees and trees suffering prior-to-bloom deficit irrigation (DI. Heat requirement calculation was performed using the double sine method with a lower threshold temperature of 3 °C. The results show that the greater the blooming advancement achieved by DI, the longer the period to mature the fruits. Such a pattern indicates that the longer duration for bloom-harvest period under DI is due to a displacement of the reproductive phenology to cooler dates. However, some effects of DI on heat requirements for ripening persist, indicating a slower fruit development in some, but not all, DI treatments. The differences in fruit development rate between fully-irrigated and water-stressed trees were established during the phase of rapid fruit growth. The comparison of water stress effects on sink (flower size and seed number and source (leaf number and size, gas exchange and mineral and carbohydrate nutrition of DI treatments seems to indicate that the amount of stored reserves in the leaves to sustain early fruit development is the most plausible reason behind the increase in thermal time between bloom and harvest in water-stressed loquats.

  4. Influence of variable heat transfer coefficient of fireworks and crackers on thermal explosion critical ambient temperature and time to ignition

    Directory of Open Access Journals (Sweden)

    Guo Zerong

    2016-01-01

    Full Text Available To study the effect of variable heat transfer coefficient of fireworks and crackers on thermal explosion critical ambient temperature and time to ignition, considering the heat transfer coefficient as the power function of temperature, mathematical thermal explosion steady state and unsteady-state model of finite cylindrical fireworks and crackers with complex shell structures are established based on two-dimensional steady state thermal explosion theory. The influence of variable heat transfer coefficient on thermal explosion critical ambient temperature and time to ignition are analyzed. When heat transfer coefficient is changing with temperature and in the condition of natural convection heat transfer, critical ambient temperature lessen, thermal explosion time to ignition shorten. If ambient temperature is close to critical ambient temperature, the influence of variable heat transfer coefficient on time to ignition become large. For firework with inner barrel in example analysis, the critical ambient temperature of propellant is 463.88 K and the time to ignition is 4054.9s at 466 K, 0.26 K and 450.8s less than without considering the change of heat transfer coefficient respectively. The calculation results show that the influence of variable heat transfer coefficient on thermal explosion time to ignition is greater in this example. Therefore, the effect of variable heat transfer coefficient should be considered into thermal safety evaluation of fireworks to reduce potential safety hazard.

  5. Effect of heating strategies on whey protein denaturation--Revisited by liquid chromatography quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Akkerman, M; Rauh, V M; Christensen, M; Johansen, L B; Hammershøj, M; Larsen, L B

    2016-01-01

    Previous standards in the area of effect of heat treatment processes on milk protein denaturation were based primarily on laboratory-scale analysis and determination of denaturation degrees by, for example, electrophoresis. In this study, whey protein denaturation was revisited by pilot-scale heating strategies and liquid chromatography quadrupole time-of-flight mass spectrometer (LC/MC Q-TOF) analysis. Skim milk was heat treated by the use of 3 heating strategies, namely plate heat exchanger (PHE), tubular heat exchanger (THE), and direct steam injection (DSI), under various heating temperatures (T) and holding times. The effect of heating strategy on the degree of denaturation of β-lactoglobulin and α-lactalbumin was determined using LC/MC Q-TOF of pH 4.5-soluble whey proteins. Furthermore, effect of heating strategy on the rennet-induced coagulation properties was studied by oscillatory rheometry. In addition, rennet-induced coagulation of heat-treated micellar casein concentrate subjected to PHE was studied. For skim milk, the whey protein denaturation increased significantly as T and holding time increased, regardless of heating method. High denaturation degrees were obtained for T >100°C using PHE and THE, whereas DSI resulted in significantly lower denaturation degrees, compared with PHE and THE. Rennet coagulation properties were impaired by increased T and holding time regardless of heating method, although DSI resulted in less impairment compared with PHE and THE. No significant difference was found between THE and PHE for effect on rennet coagulation time, whereas the curd firming rate was significantly larger for THE compared with PHE. Micellar casein concentrate possessed improved rennet coagulation properties compared with skim milk receiving equal heat treatment. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Augmenting performance feedback does not affect 4 km cycling time-trials in the heat.

    Science.gov (United States)

    Waldron, Mark; Villerius, Vincent; Murphy, Aron

    2015-01-01

    We compared the effects of (1) accurate and (2) surreptitiously augmented performance feedback on power output and physiological responses to a 4000 m time-trial in the heat. Nine cyclists completed a baseline (BaseL) 4000 m time-trial in ambient temperatures of 30°C, followed by two further 4000 m time-trials at the same temperature, randomly assigning the participants to an accurate (ACC; accurate feedback of baseline) or deceived (DEC; 2% increase above baseline) feedback group. The total power output (PO) and aerobic (Paer) and anaerobic (Pan) contributions were determined at 0.4 km stages during the time-trials, alongside measurements of rectal (Trec) and skin (Tskin) temperatures. There were no differences (P > 0.05) in any of the variables between BaseL, ACC and DEC, despite increases (P 0.05) between feedback condition and time-trial stage. Providing surreptitiously augmented performance feedback to well-trained cyclists did not alter their performance or physiological responses to a 4000 m time-trial in a hot environment. The assumed influence of augmented performance feedback was nullified in the heat, perhaps reflecting a central down-regulation of exercise intensity in response to an increased body temperature.

  7. Counselling women considering or seeking sterilization.

    Science.gov (United States)

    Jackson, T

    1980-12-01

    The view of counseling as assessment and advice-giving places unrealistic and unnecessary stresses on both counselor and client. The counselor-doctor feels responsible for client's subsequent happiness in life and feels guilty if his advice leads to future unhappiness for her. The client feels powerless in the decision-making process and has less incentive to take full responsibility for the direction of her life. A review of studies of emotional adjustment to sterilization revealed a lack of clearly defined goals for preoperative counseling and the failure to test in any way the effect of different models of counseling on client outcome. Issues which might be raised with a woman considering sterilization may be grouped into 4: 1) the woman's life situation; 2) her reasons for considering sterilization; 3) timing; and 4) ambivalence. Counselors should be prepared for and comfortable with the expression of emotion in counseling sessions. Counselors who themselves are unable to cope with expression of intense emotion will send conflicting messages to clients, both giving permission for and disapproving of exploration of certain levels of feeling. The concept of 'regret' as an outcome measure should be refined.

  8. [Essure--a novel method of sterilization].

    Science.gov (United States)

    Revel, Ariel; Nadjary, Michel; Shushan, Asher

    2008-02-01

    Essure hysteroscopic sterilization is a minimally invasive, outpatient approach to female sterilization, which avoids the possible complications of laparoscopic sterilization. This procedure has been available since 2003 in both Europe and North America. We present our experience of the first 12 cases of the procedure performed in Israel. Women who have completed their family planning were offered to consider Essure as their permanent contraception. The procedure was performed without anesthesia by the vaginoscopic technique at the hospital's outpatient clinic. Patients completed a questionnaire and were discharged immediately following the procedure. A follow-up checkup was completed after three months including three dimensional sonography, abdominal X-ray and occasional hysterosalpingogram. Twelve patients participated in the pilot group at Hadassah. The average age was 40 years (34-45) and the average number of children was 5 (4-8). The average time for the procedure was under 8 minutes. Periostial adhesions required adhesiolysis prior to insertion of the device in one patient. All patients resumed their normal activity on the same day. Our patient satisfaction survey revealed that the procedure was associated with high satisfaction levels. Sonographic and radiographic studies confirmed the good placement of the device. The Essure procedure was well tolerated by patients. The limitation is probably going to be the price of Essure, as this procedure is not covered by the 'health basket' in Israel.

  9. Study on blood compatibility of the radiation sterilized disposable burette transfusion apparatus

    International Nuclear Information System (INIS)

    Chen Guochong; Liu Wen; Liu Qingfang

    2011-01-01

    The blood compatibility of the radiation sterilized disposable burette transfusion apparatus was investigated to provide evidence for the safety of radiation sterilized medical devices. The initial bacteria burden of the disposable burette transfusion apparatus was examined according to the ISO11737 standard, and the whole blood clotting time, prothrombin time, partial thromboplastin time and hemolysis rate of the samples were determined. There was no significant difference between the radiation sterilized samples and negative controls on WBCT, PT and PTT (p>0.05). Haemolysis test showed that the haemolysis rate of the sample sterilized by irradiation was 1.38%, which was coincidence with the criteria of the medical devices. After sterilization by irradiation, disposable burette transfusion apparatus show good blood compatibility, which could be considered that radiation sterilization is a biologically safe method for the medical apparatus. (authors)

  10. Sewage sterilization through gamma radiation

    International Nuclear Information System (INIS)

    Vieira, D.V.; Teixeira, W.M.S.; Silva, F.C.A. da

    2017-01-01

    Lack of sewage treatment and adequate sanitation conditions can contribute to the proliferation of numerous parasitic and infectious diseases in addition to water degradation. Approximately fifty types of infections can be transmitted from a sick to a healthy person through different pathways involving human excreta. Untreated sewage can contaminate water, food, hands, soil, etc. Epidemics of certain diseases such as typhoid, cholera, dysenteries, etc., and countless cases of worms are responsible for high mortality rates in third world countries. In the work the different techniques of sewage treatment by disinfestation and sterilization were analyzed, highlighting the use and the advantages of the gamma radiation as well as the aspects of the radiological protection involved. The technique of sewage sterilization using gamma radiation is a method of controlling bacteria and microorganisms. It is estimated that more than 200 large irradiators are in operation worldwide, of which 5 are in Brazil, for general sterilization use. These facilities use a large amount of radioactive material, in the order of millions of Becquerel, for sterilization with high doses of radiation, which can generate lethal doses in a few minutes. These industrial facilities use Cobalt-60, being classified by the International Atomic Energy Agency - IAEA as Category 1 of high risk, and must possess a high level of radiological protection to carry out the sterilization, standing out the defense in depth. Specific legislation on radiological protection should be drafted for safe work and avoid future radiation accidents

  11. Radiation: A means of sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, R N [International Atomic Energy Agency, Division of Life Sciences, Radiation Biology Section, Vienna (Austria)

    1975-12-15

    The sterilization of medical products by ionizing radiation is a well-established industrial process in a number of technologically advanced countries. It is indeed encouraging to note the rate of growth experienced during the past fifteen years. Starting with the first commercial plant in the early sixties in the USA there are to date more than sixty large facilities of this kind located in USA, Canada, Australia and the countries of Europe including USSR. The geographical distribution of these sterilization plants is rather unbalanced. In this respect Europe is far ahead of the other continents of the world, with about 65% of all sterilization plants, followed by North and South America with 17%, Asia with 8%, Australia and New Zealand with 9% and Africa with only 1%. During the last 10 years the IAEA has actively contributed to the development of radiation sterilization practices and technology in the Member States, with particular emphasis on the developing countries. Such promotional efforts have been made by (a) supporting co-ordinated research to accumulate relevant technical information, (b) organizing scientific meetings and training courses, (c) providing technical expertise in the form of fellowships and expert services, (d) providing technical assistance to conduct market surveys and economic feasibility assessment, (e) scientific publications, including technical manuals and proceedings reports, and (f) assistance in the formulation of an international 'Code of Practice' for standardization of the manufacturing practices for radiation sterilized medical products to meet the specified requirements of the various national Pharmacopoeias and of the international consumer market.

  12. Analysis of the dual phase lag bio-heat transfer equation with constant and time-dependent heat flux conditions on skin surface

    Directory of Open Access Journals (Sweden)

    Ziaei Poor Hamed

    2016-01-01

    Full Text Available This article focuses on temperature response of skin tissue due to time-dependent surface heat fluxes. Analytical solution is constructed for DPL bio-heat transfer equation with constant, periodic and pulse train heat flux conditions on skin surface. Separation of variables and Duhamel’s theorem for a skin tissue as a finite domain are employed. The transient temperature responses for constant and time-dependent boundary conditions are obtained and discussed. The results show that there is major discrepancy between the predicted temperature of parabolic (Pennes bio-heat transfer, hyperbolic (thermal wave and DPL bio-heat transfer models when high heat flux accidents on the skin surface with a short duration or propagation speed of thermal wave is finite. The results illustrate that the DPL model reduces to the hyperbolic model when τT approaches zero and the classic Fourier model when both thermal relaxations approach zero. However for τq = τT the DPL model anticipates different temperature distribution with that predicted by the Pennes model. Such discrepancy is due to the blood perfusion term in energy equation. It is in contrast to results from the literature for pure conduction material, where the DPL model approaches the Fourier heat conduction model when τq = τT . The burn injury is also investigated.

  13. Prospects of radiation sterilization of medical devices

    International Nuclear Information System (INIS)

    Hosobuchi, Kazunari

    1992-01-01

    Since radiation sterilization was first introduced in the United States in 1956 in the field of disposable medical devices, it has become an indispensable technique for sterilization because of the following reasons: (1) introduction into dialyzers, (2) introduction in medical device makers, (3) development of disposable medical devices associated with developing both high molecular chemistry and cool sterilization, (4) rationality of sterilization process, and (5) problems of sterilization with ethylene oxide gas. To promote the further development of radiation sterilization, the following items are considered necessary: (1) an increase in the number of facilities for radiation sterilization, (2) recommendation of the international standardization of sterilization method, (3) decrease in radiation doses associated with sterilization, (4) development of electron accelerators and bremsstrahlung equipments for radiation sources, and (5) simplification of sterilization process management. Factors precluding the development of radiation sterilization are: (1) development of other methods than radiation sterilization, (2) development of technique for sterile products, (3) high facility cost, (4) high irradiation cost, (5) benefits and limits of sterilization markets, and (6) influences of materials. (N.K.)

  14. Modelling, simulation and dynamic analysis of the time delay model of the recuperative heat exchanger

    Directory of Open Access Journals (Sweden)

    Debeljković Dragutin Lj.

    2016-01-01

    Full Text Available The heat exchangers are frequently used as constructive elements in various plants and their dynamics is very important. Their operation is usually controlled by manipulating inlet fluid temperatures or mass flow rates. On the basis of the accepted and critically clarified assumptions, a linearized mathematical model of the cross-flow heat exchanger has been derived, taking into account the wall dynamics. The model is based on the fundamental law of energy conservation, covers all heat accumulation storages in the process, and leads to the set of partial differential equations (PDE, which solution is not possible in closed form. In order to overcome this problem the approach based on physical discretization was applied with associated time delay on the positions where it was necessary and unavoidable. This is quite new approach, which represent the further extension of previous results which did not include significant time delay existing in the working media. Simulation results, were derived, showing progress in building such a model suitable for further treatment from the position of analysis as well as the needs for control synthesis problem.

  15. Development of atmospheric pressure plasma needle jet for sterilization applications

    Science.gov (United States)

    Elfa, Rizan Rizon; Ahmad, Mohd Khairul; Soon, Chin Fhong; Sahdan, Mohd Zainizan; Lias, Jais; Wibowo, Kusnanto Mukti; Bakar, Ahmad Shuhaimi Abu; Arshad, Mohd Khairuddin Md; Hashim, Uda; Nayan, Nafarizal

    2017-09-01

    Inactivation of bacteria or sterilization has been a major issue in the medical field, especially regarding of human safety, whereby, in a huge scenario fatality can be caused by hazardous bacteria. Often, E-coli as gram-negative bacteria are selected as a key indicator of proper sterilization process as E-coli is tough and dormant bacteria. The technology in sterilization has moved on from chemical, wet and irradiation sterilization to a high promising device such as atmospheric pressure plasma needle jet (APPNJ). It has been reported that atmospheric pressure plasma has provided bundle of advantages over earlier sterilization process. The APPNJ is developed in our lab using high frequency and high voltage neon transformer power supply connected to copper needle and copper sheet electrodes. The gas discharge is Ar gas flowing at 40 L/min through a quartz glass tube. The E-coli bacteria are self-cultured from waste water and then treated with APPNJ. The treatment processes are run into two difference gaps between the plasma orifice and sample with various treatment times. Only 40s is required by direct treatment to achieve 100% killing of E-coli. On the other hand, indirect treatment has inactivated 50% of the E-coli in 40s. In this study, direct and indirect effect of APPNJ to the E-coli can be observed which can be utilized into sterilization of bio-compatible material applications.

  16. Remodeling of ACL Allografts is Inhibited by Peracetic Acid Sterilization

    Science.gov (United States)

    Gonnermann, Johannes; Kamp, Julia; Przybilla, Dorothea; Pruss, Axel

    2008-01-01

    Sterilization of allografts for anterior cruciate ligament (ACL) reconstruction has become an important prerequisite to prevent disease transmission. However, current sterilization techniques impair the biological or mechanical properties of such treated grafts. Peracetic acid (PAA) has been successfully used to sterilize bone allografts without these disadvantages and does not impair the mechanical properties of soft tissue grafts in vitro. We asked whether PAA sterilization would influence recellularization, restoration of crimp length and pattern, and revascularization of ACL grafts during early healing. We used an in vivo sheep model for open ACL reconstruction. We also correlated the histologic findings with the restoration of anteroposterior stability and structural properties during load-to-failure testing. PAA slowed remodeling activity at 6 and 12 weeks compared to nonsterilized allografts and autografts. The mechanical properties of PAA grafts were also reduced compared to these control groups at both time points. We conclude PAA sterilization currently should not be used to sterilize soft tissue grafts typically used in ACL reconstruction. PMID:18491201

  17. [Proposal of a costing method for the provision of sterilization in a public hospital].

    Science.gov (United States)

    Bauler, S; Combe, C; Piallat, M; Laurencin, C; Hida, H

    2011-07-01

    To refine the billing to institutions whose operations of sterilization are outsourced, a sterilization cost approach was developed. The aim of the study is to determine the value of a sterilization unit (one point "S") evolving according to investments, quantities processed, types of instrumentation or packaging. The time of preparation has been selected from all sub-processes of sterilization to determine the value of one point S. The time of preparation of sterilized large and small containers and pouches were raised. The reference time corresponds to one bag (equal to one point S). Simultaneously, the annual operating cost of sterilization was defined and divided into several areas of expenditure: employees, equipments and building depreciation, supplies, and maintenance. A total of 136 crossing times of containers were measured. Time to prepare a pouch has been estimated at one minute (one S). A small container represents four S and a large container represents 10S. By dividing the operating cost of sterilization by the total number of points of sterilization over a given period, the cost of one S can be determined. This method differs from traditional costing method in sterilizing services, considering each item of expenditure. This point S will be the base for billing of subcontracts to other institutions. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  18. Effect of the time window on the heat-conduction information filtering model

    Science.gov (United States)

    Guo, Qiang; Song, Wen-Jun; Hou, Lei; Zhang, Yi-Lu; Liu, Jian-Guo

    2014-05-01

    Recommendation systems have been proposed to filter out the potential tastes and preferences of the normal users online, however, the physics of the time window effect on the performance is missing, which is critical for saving the memory and decreasing the computation complexity. In this paper, by gradually expanding the time window, we investigate the impact of the time window on the heat-conduction information filtering model with ten similarity measures. The experimental results on the benchmark dataset Netflix indicate that by only using approximately 11.11% recent rating records, the accuracy could be improved by an average of 33.16% and the diversity could be improved by 30.62%. In addition, the recommendation performance on the dataset MovieLens could be preserved by only considering approximately 10.91% recent records. Under the circumstance of improving the recommendation performance, our discoveries possess significant practical value by largely reducing the computational time and shortening the data storage space.

  19. Experimental Investigation of the Heat Transfer in a Room using Night-Time Coling by Mixing Ventilation

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Nørgaard, Jesper; Daniels, Ole

    2011-01-01

    of full-scale measurements. The efficiency of night-time ventilation depends on the outdoor temperature and the heat transfer between the room air and the building constructions. In a full-scale test room the heat transfer was investigated during 12 hour of discharging by night-time ventilation. Three...... areas and the convective heat transfer coefficient ranged between 5 and 30 W/m2. The ratio of convective to total heat flow from the ceiling depends on the air change rate, ranging from approximately 40% at the low air change rates to approximately 70% at the high air change rate. Even though radiation......For many years focus has been on reducing the energy need for heating in buildings. This has lead to buildings with low energy demands for heating but often at the expense of the need for cooling of the building. In order to design buildings with low or zero energy need energy efficient strategies...

  20. Radiation sterilization of hydrocortisone acetate

    International Nuclear Information System (INIS)

    Charef, A.; Boussaha, A.

    1989-09-01

    The feasibility of using high energy ionizing radiation for the sterilization of hydrocortisone acetate was investigated. Hydrocortisone acetate in the form of powder was exposed to different dose levels of gamma radiation using a Cobalt-60 source. The irradiated samples were examined by various physico-chemical techniques in order to detect possible radiolysis products. It was of interest to know if one could insure sterility and retain biological properties of the drug by suitable choice of radiation dose. The results showed that a 10 KGy radiation dose causes no change in the physico-chemical properties of the drug and is sufficient to obtain contaminant-free product

  1. Plasma Sterilizer with Ultrasonic Cavitation

    International Nuclear Information System (INIS)

    Krasnyj, V.V.; Klosovsky, A.V.; Panasko, T.A.; Shvets, O.M.; Semenova, O.T.; Taran, V.S.; Tereshin, V.I.

    2006-01-01

    A sterilizer consists of ozone generator based on a barrier glow discharge with the flat electrodes covered with dielectric with a high-voltage pulsed power supply of up to 250 W (1). The sterilization camera is equipped with ultrasonic source with the power of 100 W. The experiments on the inactivation of bacteria of the Bacillus Cereus type were carried out in the distilled water saturated by ozone. Ozone concentration in the aqueous solution was 6 mg/liter with ozone concentration at the output of ozone generator 30 mg/liter. The complete inactivation of spores took 15 min

  2. Liquid-Metal/Water Direct Contact Heat Exchange: Flow Visualization, Flow Stability, and Heat Transfer Using Real-Time X-Ray Imaging

    International Nuclear Information System (INIS)

    Abdulla, Sherif H.; Liu Xin; Anderson, Mark H.; Bonazza, Riccardo; Corradini, Michael L.; Cho, Dae; Page, Richard

    2005-01-01

    Advanced reactor system designs are being considered with liquid-metal cooling connected to a steam power cycle. In addition, current reactor safety systems are considering auxiliary cooling schemes that assure ex-vessel debris coolability utilizing direct water injection into molten material pools to achieve core quenching and eventual coolability. The phenomenon common in both applications is direct contact heat exchange. The current study focuses on detailed measurements of liquid-metal/water direct contact heat exchange that is directly applicable to improvements in effective heat transfer in devices that are being considered for both of these purposes.In this study, a test facility was designed at the University of Wisconsin-Madison to map the operating range of liquid-metal/water direct contact heat exchange. The test section (184-cm height, 45.75-cm width, and 10-cm depth) is a rectangular slice of a larger heat exchange device. This apparatus was used not only to provide measurements of integral thermal performance (i.e., volumetric heat transfer coefficient), but also local heat transfer coefficients in a bubbly flow regime with X-ray imaging based on measured parameters such as bubble formation time, bubble rise velocity, and bubble diameters.To determine these local heat transfer coefficients, a complete methodology of the X-ray radiography for two-phase flow measurement has been developed. With this methodology, a high-energy X-ray imaging system is optimized for our heat exchange experiments. With this real-time, large-area, high-energy X-ray imaging system, the two-phase flow was quantitatively visualized. An efficient image processing strategy was developed by combining several optimal digital image-processing algorithms into a software computational tool written in MATLAB called T-XIP. Time-dependent heat transfer-related variables such as bubble volumes and velocities, were determined. Finally, an error analysis associated with these measurements

  3. Sterilization of Turmeric by Atmospheric Pressure Dielectric Barrier Discharge Plasma

    International Nuclear Information System (INIS)

    Salarieh Setareh; Dorranian Davoud

    2013-01-01

    In this study atmospheric pressure dielectric barrier discharge (DBD) plasma has been employed for sterilizing dry turmeric powders. A 6 kV, 6 kHz frequency generator was used to generate plasma with Ar, Ar/O 2 , He, and He/O 2 gases between the 5 mm gap of two quartz covered electrodes. The complete sterilization time of samples due to plasma treatment was measured. The most important contaminant of turmeric is bacillus subtilis. The results show that the shortest sterilization time of 15 min is achieved by exposing the samples to Ar/O 2 plasma. Survival curves of samples are exponential functions of time and the addition of oxygen to plasma leads to a significant increase of the absolute value of time constant of the curves. Magnitudes of protein and DNA in treated samples were increased to a similar value for all samples. Taste, color, and solubility of samples were not changed after the plasma treatment

  4. Sterilization of Turmeric by Atmospheric Pressure Dielectric Barrier Discharge Plasma

    Science.gov (United States)

    Setareh, Salarieh; Davoud, Dorranian

    2013-11-01

    In this study atmospheric pressure dielectric barrier discharge (DBD) plasma has been employed for sterilizing dry turmeric powders. A 6 kV, 6 kHz frequency generator was used to generate plasma with Ar, Ar/O2, He, and He/O2 gases between the 5 mm gap of two quartz covered electrodes. The complete sterilization time of samples due to plasma treatment was measured. The most important contaminant of turmeric is bacillus subtilis. The results show that the shortest sterilization time of 15 min is achieved by exposing the samples to Ar/O2 plasma. Survival curves of samples are exponential functions of time and the addition of oxygen to plasma leads to a significant increase of the absolute value of time constant of the curves. Magnitudes of protein and DNA in treated samples were increased to a similar value for all samples. Taste, color, and solubility of samples were not changed after the plasma treatment.

  5. Is carbon / CO2 taxes implementation timely for electricity and heat generation in Romania ?

    International Nuclear Information System (INIS)

    Tutuianu, O.; Fulger, E.D.; Vieru, A.; Feher, M.

    1996-01-01

    Lately, carbon / CO 2 taxes are very much discussed in Europe and in many countries of the world as economic and financial instruments for reducing the CO 2 emissions. Some countries have already introduced such taxes while in other countries or international organisations they are under study, especially concerning the moment, the way of implementation and the amount of taxes. CO 2 emissions in Romania, in absolute and specific values (per capita, per kWh equivalent) are lower than in other countries. This can be justified by the low level of electricity and heat output owing to the recent economic restructuring and by the energy sector characteristics: natural gas major contribution, hydroelectric power, cogeneration and nuclear power implementation. We can also mention, as a positive factor, the CO 2 absorption potential of the Romanian forests. Carbon / CO 2 taxes introduction has severe economic and social impact, such as: domestic coal extraction blockage, increase in the electricity and heat prices, decrease of Romanian export products competitiveness and reduction of population standard of living. Therefore, the authors are considering that carbon / CO 2 taxes introduction is not timely by the year 2000 for the Romanian electricity and heat generation. (author). 3 figs. 2 tabs. 10 refs

  6. Suitability of peracetic acid for sterilization of media for mycoplasma cultures.

    Science.gov (United States)

    Wutzler, P; Sprössig, M; Peterseim, H

    1975-01-01

    The utility of peracetic acid for sterilization of serum and yeast extract additions to mycoplasma medium was studied by culturing six Mycoplasma species. Culture media containing additions that had been sterilized with peracetic acid proved to be as good as filtered components. The use of 0.05 to 0.1% peracetic acid is recommended to sterilize the serum and yeast extract additions since savings in time and equipment can be accomplished. PMID:1100656

  7. Time resolved spectra in the infrared absorption and emission from shock heated hydrocarbons. [in interstellar medium

    Science.gov (United States)

    Bauer, S. H.; Borchardt, D. B.

    1990-01-01

    The wavelength range of a previously constructed multichannel fast recording spectrometer was extended to the mid-infrared. With the initial configuration, light intensities were recorded simultaneously with a silicon-diode array simultaneously at 20 adjacent wavelengths, each with a 20-micron time resolution. For studies in the infrared, the silicon diodes were replaced by a 20-element PbSe array of similar dimensions, cooled by a three-stage thermoelectric device. It is proposed that infrared emissions could be due to shock-heated low molecular-weight hydrocarbons. The full Swan band system appeared in time-integrated emission spectra from shock-heated C2H2; no soot was generated. At low resolution, the profiles on the high-frequency side of the black body maximum show no distinctive features. These could be fitted to Planck curves, with temperatures that declined with time from an initial high that was intermediate between T5 (no conversion) and T5(eq).

  8. Life time test of a partial model of HTGR helium-helium heat exchanger

    International Nuclear Information System (INIS)

    Kitagawa, Masaki; Hattori, Hiroshi; Ohtomo, Akira; Teramae, Tetsuo; Hamanaka, Junichi; Itoh, Mitsuyoshi; Urabe, Shigemi

    1984-01-01

    Authors had proposed a design guide for the HTGR components and applied it to the design and construction of the 1.5 Mwt helium heat exchanger test loop for the nuclear steel making under the financial support of the Japanese Ministry of International Trade and Industry. In order to assure that the design method covers all the conceivable failure mode and has enough safety margin, a series of life time tests of partial model may be needed. For this project, three types of model tests were performed. A life time test of a partial model of the center manifold pipe and eight heat exchanger tubes were described in this report. A damage criterion with a set of material constants and a simplified method for stress-strain analysis for stub tube under three dimensional load were newly developed and used to predict the lives of each tube. The predicted lives were compared with the experimental lives and good agreement was found between the two. The life time test model was evaluated according to the proposed design guide and it was found that the guide has a safety factor of approximately 200 in life for this particular model. (author)

  9. Study on neutron diffusion and time dependence heat ina fluidized bed nuclear reactor

    International Nuclear Information System (INIS)

    Vilhena, M.T. de.

    1988-01-01

    The purpose of this work is to model the neutron diffusion and heat transfer for a Fluidized Bed Nuclear Reactor and its solution by Laplace Transform Technique with numerical inversion using Fourier Series. Also Gaussian quadrature and residues techniques were applied for numerical inversion. The neutron transport, diffusion, and point Kinetic equation for this nuclear reactor concept are developed. A matricial and Taylor Series methods are proposed for the solution of the point Kinetic equation which is a time scale problem of Stiff type

  10. Devolatilization kinetics of woody biomass at short residence times and high heating rates and peak temperatures

    DEFF Research Database (Denmark)

    Johansen, Joakim M.; Gadsbøll, Rasmus; Thomsen, Jesper

    2016-01-01

    This work combines experimental and computational fluid dynamics (CFD) results to derive global kinetics for biomass (pine wood) devolatilization during heating rates on the order of 105Ks-1, bulk flow peak temperatures between 1405 and 1667K, and particle residence times below 0.1s. Experiments......Jmol-1. The accuracy of the derived global kinetics was supported by comparing predictions to experimental results from a 15kW furnace. The work emphasizes the importance of characterizing the temperature history of the biomass particles when deriving pyrolysis kinetics. The present results indicate...

  11. Electric space heating scheduling for real-time explicit power control in active distribution networks

    DEFF Research Database (Denmark)

    Costanzo, Giuseppe Tommaso; Bernstein, Andrey; Chamorro, Lorenzo Reyes

    2015-01-01

    This paper presents a systematic approach for abstracting the flexibility of a building space heating system and using it within a composable framework for real-time explicit power control of microgrids and, more in general, active distribution networks. In particular, the proposed approach...... is developed within the context of a previously defined microgrid control framework, called COMMELEC, conceived for the explicit and real-time control of these specific networks. The designed control algorithm is totally independent from the need of a building model and allows exploiting the intrinsic thermal...... inertia for real-time control. The paper first discusses the general approach, then it proves its validity via dedicated simulations performed on specific case study composed by the CIGRE LV microgrid benchmark proposed by the Cigré TF C6.04.02....

  12. Real-time protection of the Ohmic heating coil force limits in DIII-D

    International Nuclear Information System (INIS)

    Broesch, J.D.; Scoville, J.T.; Hyatt, A.W.; Coon, R.M.

    1997-11-01

    The maximum safe operating limits of the DIII-D tokamak are determined by the force produced in the ohmic heating coil and the toroidal field coil during a plasma pulse. This force is directly proportional to the product of the current in the coils. Historically, the current limits for each coil were set statically before each pulse without regard for the time varying nature of the currents. In order to allow the full time-dependent capability of the ohmic coil to be used, a system was developed for monitoring the product of the currents dynamically and making appropriate adjustments in real time. This paper discusses the purpose, implementation, and results of this work

  13. Full-scale and time-scale heating experiments at Stripa: preliminary results. Technical project report No. 11

    International Nuclear Information System (INIS)

    Cook, N.G.W.; Hood, M.

    1978-12-01

    Two full-scale heating experiments and a time-scale heating experiment have recently been started in granite 340 meters below surface. The purpose of the full-scale heating experiments is to assess the near-field effects of thermal loading for the design of an underground repository of nuclear wastes. That of the time-scale heating experiments is to obtain field data of the interaction between heaters and its effect on the rock mass during a period of about two years, which corresponds to about twenty years of full-scale operation. Geological features of the rock around each experiment have been mapped carefully, and temperatures, stresses and displacements induced in the rock by heating have been calculated in advance of the experiments. Some 800 different measurements are recorded at frequent intervals by a computer system situated underground. These data can be compared at any time with predictions made earlier on video display units underground

  14. Application of thermal sterilization regimes simulation for improvement of canned foods quality factors

    Directory of Open Access Journals (Sweden)

    Stolyanov A.V.

    2015-03-01

    Full Text Available Results of comparison of optimization methods of thermal sterilization temperature-time regimes have been described. It has been shown that due to simulation the final canned foods’ quality factors are significantly improved, sterilization process time is decreased and energy consumption is reduced without sacrificing actual final lethality value

  15. Establishment of a sterilization dose

    International Nuclear Information System (INIS)

    Kaluska, I.

    2007-01-01

    Factors that impact on product bioburden (population of diable microorganisms on or in product and/or sterile barrier system) are: Raw materials, components, product design and size, manufacturing process, manufacturing equipment, manufacturing environment and manufacturing location. Presented lecture describes all these factors in details

  16. Sterile neutrino constraints from cosmology

    DEFF Research Database (Denmark)

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.

    2012-01-01

    The presence of light particles beyond the standard model's three neutrino species can profoundly impact the physics of decoupling and primordial nucleosynthesis. I review the observational signatures of extra light species, present constraints from recent data, and discuss the implications of po...... of possible sterile neutrinos with O(eV)-masses for cosmology....

  17. Sterile Neutrino Search with MINOS

    International Nuclear Information System (INIS)

    Devan, Alena V.

    2015-01-01

    MINOS, Main Injector Neutrino Oscillation Search, is a long-baseline neutrino oscillation experiment in the NuMI muon neutrino beam at the Fermi National Accelerator Laboratory in Batavia, IL. It consists of two detectors, a near detector positioned 1 km from the source of the beam and a far detector 734 km away in Minnesota. MINOS is primarily designed to observe muon neutrino disappearance resulting from three flavor oscillations. The Standard Model of Particle Physics predicts that neutrinos oscillate between three active flavors as they propagate through space. This means that a muon-type neutrino has a certain probability to later interact as a different type of neutrino. In the standard picture, the neutrino oscillation probabilities depend only on three neutrino flavors and two mass splittings, Δm 2 . An anomaly was observed by the LSND and MiniBooNE experiments that suggests the existence of a fourth, sterile neutrino flavor that does not interact through any of the known Standard Model interactions. Oscillations into a theoretical sterile flavor may be observed by a deficit in neutral current interactions in the MINOS detectors. A distortion in the charged current energy spectrum might also be visible if oscillations into the sterile flavor are driven by a large mass-squared difference, Δm s 2 ~ 1 eV 2 . The results of the 2013 sterile neutrino search are presented here.

  18. Sterility test by radiometric technique

    International Nuclear Information System (INIS)

    Faruq, Muhammad

    1980-01-01

    Sterility test of pharmaceuticals can be carried out by the application of pharmacopoeia and radiometric technique. In Indonesia the application of pharmacopoeia technique is carried out through liquid germination for aerobacteria and for fungus and yeast. Radiometric technique is applied to autotrop and heterotrop bacteria. (SMN)

  19. Sterile Neutrino Search with MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Devan, Alena V. [College of William and Mary, Williamsburg, VA (United States)

    2015-08-01

    MINOS, Main Injector Neutrino Oscillation Search, is a long-baseline neutrino oscillation experiment in the NuMI muon neutrino beam at the Fermi National Accelerator Laboratory in Batavia, IL. It consists of two detectors, a near detector positioned 1 km from the source of the beam and a far detector 734 km away in Minnesota. MINOS is primarily designed to observe muon neutrino disappearance resulting from three flavor oscillations. The Standard Model of Particle Physics predicts that neutrinos oscillate between three active flavors as they propagate through space. This means that a muon-type neutrino has a certain probability to later interact as a different type of neutrino. In the standard picture, the neutrino oscillation probabilities depend only on three neutrino flavors and two mass splittings, Δm2. An anomaly was observed by the LSND and MiniBooNE experiments that suggests the existence of a fourth, sterile neutrino flavor that does not interact through any of the known Standard Model interactions. Oscillations into a theoretical sterile flavor may be observed by a deficit in neutral current interactions in the MINOS detectors. A distortion in the charged current energy spectrum might also be visible if oscillations into the sterile flavor are driven by a large mass-squared difference, ms2 ~ 1 eV2. The results of the 2013 sterile neutrino search are presented here.

  20. Predicting outgrowth and inactivation of Clostridium perfringens in meat products during low temperature long time heat treatment

    DEFF Research Database (Denmark)

    Duan, Zhi; Holst Hansen, Terese; Hansen, Tina Beck

    OBJECTIVE Sous-vide cooking and molecular gastronomy has started a wave of experimenting with Low Temperature Long Time (LTLT) heat treatments. Heat treatments, at temperatures as low as 50°C, have been suggested by celebrity chefs. LTLT treatments often take hours to reach to the final core...

  1. Sterilization can change properties of bioceramics

    International Nuclear Information System (INIS)

    Willmann, G.

    2003-01-01

    Bioceramics made of bioinert alumina or zirconia and bioactive hydroxyapatite are well established implant materials. Implants have to be cleaned and sterilized. When sterilized some bioceramics change their color. This may effect their properties. No decrease of mechanical strength is observed when sterilizing alumina and the novel ceramic biocomposite AMC (Alumina Matrix Composite) with steam or Co 60 Gamma irradiation. When sterilizing Y-TZP zirconia with steam a decrease of strength is observed. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [de

  2. An ecological time-series study of heat-related mortality in three European cities

    Directory of Open Access Journals (Sweden)

    Russo Antonio

    2008-01-01

    Full Text Available Abstract Background Europe has experienced warmer summers in the past two decades and there is a need to describe the determinants of heat-related mortality to better inform public health activities during hot weather. We investigated the effect of high temperatures on daily mortality in three cities in Europe (Budapest, London, and Milan, using a standard approach. Methods An ecological time-series study of daily mortality was conducted in three cities using Poisson generalized linear models allowing for over-dispersion. Secular trends in mortality and seasonal confounding factors were controlled for using cubic smoothing splines of time. Heat exposure was modelled using average values of the temperature measure on the same day as death (lag 0 and the day before (lag 1. The heat effect was quantified assuming a linear increase in risk above a cut-point for each city. Socio-economic status indicators and census data were linked with mortality data for stratified analyses. Results The risk of heat-related death increased with age, and females had a greater risk than males in age groups ≥65 years in London and Milan. The relative risks of mortality (per °C above the heat cut-point by gender and age were: (i Male 1.10 (95%CI: 1.07–1.12 and Female 1.07 (1.05–1.10 for 75–84 years, (ii M 1.10 (1.06–1.14 and F 1.08 (1.06–1.11 for ≥85 years in Budapest (≥24°C; (i M 1.03 (1.01–1.04 and F 1.07 (1.05–1.09, (ii M 1.05 (1.03–1.07 and F 1.08 (1.07–1.10 in London (≥20°C; and (i M 1.08 (1.03–1.14 and F 1.20 (1.15–1.26, (ii M 1.18 (1.11–1.26 and F 1.19 (1.15–1.24 in Milan (≥26°C. Mortality from external causes increases at higher temperatures as well as that from respiratory and cardiovascular disease. There was no clear evidence of effect modification by socio-economic status in either Budapest or London, but there was a seemingly higher risk for affluent non-elderly adults in Milan. Conclusion We found broadly consistent

  3. Sterile searches with Liquid Argon at FNAL

    CERN Document Server

    Raselli, Gian Luca

    2017-01-01

    A new Short Baseline Neutrino (SBN) experiment is in preparation at FNAL to definitely prove or exclude the existence of non-standard neutrino oscillations into sterile states. The program foresees the deployment along the Booster Neutrino Beam (BNB) of three detectors, all based on the liquid-argon time projection chamber technique. This technology has been taken to full maturity with ICARUS T600, which will act as far detector after the completion of the overhauling at CERN and its transportation to FNAL. The program foresees the data taking for three years.

  4. [Preliminary Study of Lonicera hypoglauca on Germination Conditions of Sand Culture Seeds and Sterilization Method of Sand Culture Seedling Sterilization].

    Science.gov (United States)

    Tan, Mu-xiu; Zeng, Wen-wen; Wei, Peng-xiao; Mo, Qiao-cheng; Pu, Zu-ning; Cen, Xiu-fen; Shi, Feng-hua

    2015-05-01

    To explore the germination conditions of Lonicera hypoglauca sand culture seeds and the effects of sand culture seedlings sterilization. 0.1% HgCl2 with different sterilization time, different illumination time and temperature culture condition were adopted to study the germination conditions of sand culture seeds. Different sterilization treatments and different hardening-seedling days were used to test the sterilization effect of sand culture seedlings. The sterilization effect of the combination of 75% ethanol 30 s + 0.1% HgCl2 5 min on Lonicera hypoglauca seeds was the optimum,with the average pollution rate of 15.56%, and the average germination rate reached 51.11%. The combination of varied temperature-room temperature under light for 12 h/d was the best, with the average germination rate peaked at 75.49%, and the average germination potential reached 68.36%. The treatment of detergent liquor scrub-tap water wash on the part above the hypocotyl, which was sand cultured under the opening condition and had no root, showed the best sterilization effect, with the average pollution rate was zero, and the average survival rate peaked at 100.00%. The sterilization effect of sand culture seedlings, which was disinfected after cleaning by detergent liquor scrub-tap water wash after hardening-seeding for 30 days, was the best, with the average pollution rate of 50.00%, and the average survival rate of 100.00%. The best sterilization effect is the combination of 75% ethanol 30 s + 0.1% HgCl2 5 min; Lighting for 12 h/d of varied temperature-room temperature is regarded as the optimum culture condition. The treatment of detergent liquor scrub-tap water wash treatment on the part above the hypocotyl,which is sand cultured under the opening condition and had no root, shows the best sterilization effect. For the sand culture seedlings, before inoculated in subculture medium, should be hardening-seedling for some days and sterilized after detergent liquor scrub-tap water wash.

  5. Practices of radiation sterilization of medical products and pharmaceutical preparations: egyptian experience

    International Nuclear Information System (INIS)

    Roushdy, H.M.

    1992-01-01

    Radiation sterilization involves the application of sufficient ionizing energy furnished by either x-rays, gamma-rays or accelerated electron beams, to render an article free of viable micro-organisms. The method offers a number of advantages which makes it an attractive choice in a number of situations: It is a suitable means of sterilizing many many materials.. Radiation causes no significant temperature rise, thus permits sterilization of heat-sensitive drugs and low melting-point plastics. It is certainly the best, and often the only method of sterilizing biological tissues and preparations of biological origin. due to its high penetrating ability, gamma-radiation reaches all parts of the object to be sterilized. The radiation sterilized products are not subjected to touching or exposure to the outside environment except by the and users. The chemical reactivity of radiation is relatively low as compared with the highly reactive gases. Radiation can be easily adapted for continuous processing as compared with batch operations currently in use with gas sterilization. The radiation process is the most reliable of all competing sterilization methods due to the obsolete certainty that the radiation source emits radiation of known energy and power

  6. Practices of radiation sterilization of medical products and pharmaceutical preparations: egyptian experience

    Energy Technology Data Exchange (ETDEWEB)

    Roushdy, H M

    1993-12-31

    Radiation sterilization involves the application of sufficient ionizing energy furnished by either x-rays, gamma-rays or accelerated electron beams, to render an article free of viable micro-organisms. The method offers a number of advantages which makes it an attractive choice in a number of situations: It is a suitable means of sterilizing many many materials.. Radiation causes no significant temperature rise, thus permits sterilization of heat-sensitive drugs and low melting-point plastics. It is certainly the best, and often the only method of sterilizing biological tissues and preparations of biological origin. due to its high penetrating ability, gamma-radiation reaches all parts of the object to be sterilized. The radiation sterilized products are not subjected to touching or exposure to the outside environment except by the and users. The chemical reactivity of radiation is relatively low as compared with the highly reactive gases. Radiation can be easily adapted for continuous processing as compared with batch operations currently in use with gas sterilization. The radiation process is the most reliable of all competing sterilization methods due to the obsolete certainty that the radiation source emits radiation of known energy and power.

  7. Timing Effects of Heat-Stress on Plant Ecophysiological Characteristics and Growth.

    Science.gov (United States)

    Wang, Dan; Heckathorn, Scott A; Mainali, Kumar; Tripathee, Rajan

    2016-01-01

    Heat-waves with higher intensity and frequency and longer durations are expected in the future due to global warming, which could have dramatic impacts in agriculture, economy and ecology. This field study examined how plant responded to heat-stress (HS) treatment at different timing in naturally occurring vegetation. HS treatment (5 days at 40.5°C) were applied to 12 1 m 2 plots in restored prairie vegetation dominated by a warm-season C 4 grass, Andropogon gerardii , and a warm-season C 3 forb, Solidago canadensis , at different growing stages. During and after each heat stress (HS) treatment, temperature were monitored for air, canopy, and soil; net CO 2 assimilation ( A net ), quantum yield of photosystem II (Φ PSII ), stomatal conductance ( g s ), and internal CO 2 level ( C i ), specific leaf area (SLA), and chlorophyll content of the dominant species were measured. One week after the last HS treatment, all plots were harvested and the biomass of above-ground tissue and flower weight of the two dominant species were determined. HS decreased physiological performance and growth for both species, with S. canadensis being affected more than A. gerardii , indicated by negative HS effect on both physiological and growth responses for S. canadensis . There were significant timing effect of HS on the two species, with greater reductions in the net photosynthetic rate and productivity occurred when HS was applied at later-growing season. The reduction in aboveground productivity in S. canadensis but not A. gerardii could have important implications for plant community structure by increasing the competitive advantage of A. gerardii in this grassland. The present experiment showed that HS, though ephemeral, may promote long-term effects on plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when more frequent and severe HS occur in the future.

  8. The possibility of gamma ray sterilization by using ITU TRIGA Mark II reactor

    International Nuclear Information System (INIS)

    Bilge, A.N.; Tugrul, B.; Yavuz, H.

    1988-01-01

    Gamma rays are one of the effective method for sterilization which is preferred for a long time. Generally Co-60 radioisotope sources betatrons or accelerators are used for the sterilization. In this work, it was aimed to find the possibilities of the sterilization by gamma rays obtained in ITU TRIGA Mark-II radial tube. Radiation dosages are measured in the radial tube and several medical products are irradiated. Irradiation is arranged according to the desired dosages. Irradiated sterilized goods (mainly medical products) tested and checked at the Governmental Medical Health Center and results compared with literature. It can be seen that this kind of irradiation is a good tool for sterilization. Unfortunately, because of the stability of the radial tube and impracticality of the system it is rather difficult to compete with industrial system using Co-60 and accelerators. Nevertheless, this type of irradiation is also applicable for the purpose of the sterilization by using ITU TRIGA Mark II. (author)

  9. Sterile Neutrinos in Cold Climates

    International Nuclear Information System (INIS)

    Jones, Benjamin J.P.

    2015-01-01

    Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system; test-stand measurements of liquid argon optical properties with dissolved impurities; optimization of wavelength-shifting coatings for liquid argon scintillation light detection; testing and deployment of high-voltage surge arrestors to protect TPC field cages; and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin 2 2θ 24 ≤ 0.02 at m 2 ~ 0.3 eV 2 , and the LSND and MiniBooNE allowed regions are excluded at

  10. Reionization in sterile neutrino cosmologies

    Science.gov (United States)

    Bose, Sownak; Frenk, Carlos S.; Hou, Jun; Lacey, Cedric G.; Lovell, Mark R.

    2016-12-01

    We investigate the process of reionization in a model in which the dark matter is a warm elementary particle such as a sterile neutrino. We focus on models that are consistent with the dark matter decay interpretation of the recently detected line at 3.5 keV in the X-ray spectra of galaxies and clusters. In warm dark matter models, the primordial spectrum of density perturbations has a cut-off on the scale of dwarf galaxies. Structure formation therefore begins later than in the standard cold dark matter (CDM) model and very few objects form below the cut-off mass scale. To calculate the number of ionizing photons, we use the Durham semi-analytic model of galaxy formation, GALFORM. We find that even the most extreme 7 keV sterile neutrino we consider is able to reionize the Universe early enough to be compatible with the bounds on the epoch of reionization from Planck. This, perhaps surprising, result arises from the rapid build-up of high redshift galaxies in the sterile neutrino models which is also reflected in a faster evolution of their far-UV luminosity function between 10 > z > 7 than in CDM. The dominant sources of ionizing photons are systematically more massive in the sterile neutrino models than in CDM. As a consistency check on the models, we calculate the present-day luminosity function of satellites of Milky Way-like galaxies. When the satellites recently discovered in the Dark Energy Survey are taken into account, strong constraints are placed on viable sterile neutrino models.

  11. Time and spatial heat transfer performance around an isothermally heated sphere placed in a uniform, downwardly directed flow (in relation to the enhancement of latent heat storage rate in a spherical capsule)

    International Nuclear Information System (INIS)

    Koizumi, H.

    2004-01-01

    The aim of this study is to reveal the temporal and spatial heat transfer performance of an isothermally heated sphere placed in a uniform, downwardly directed flow using a micro-foil heat flow sensor (HFS). A HFS, whose response time is about 0.02 s, was pasted on the surface of a heated copper sphere. Experiments were carried out using air with a Grashof number of 3.3 x 10 5 and with several Reynolds numbers (Re) up to 1800. Three flow patterns appeared: a chaotic flow at Re<240; a two-dimensional steady separated flow at 240 ≤ Re<500, and a three-dimensional unsteady separated flow at Re ≥ 500. In addition, the instantaneous and time-averaged heat transfer performance around the sphere in each of the three regions was clarified. Next, enhancement of the latent heat storage rate of a solid phase change material (PCM) in a spherical capsule was performed. The flow around the spherical capsule, in which the solid PCM was filled and placed in a heated, upwardly directed flow, is the approximate adverse flow phenomenon around the heated sphere which was placed in a downwardly directed flow. In other words, the buoyant flow and the forced flow are in the opposite directions in these two cases. Tests of latent heat storage were run for two Reynolds numbers which represented different flow characteristics in the heat transfer experiments, Re=150 and 1800. Furthermore, copper plates were inserted into the solid PCM, of which thermal conductivity was considerably low, to enhance the latent heat storage rate for the two Reynolds number flows

  12. Effect of caffeine on cycling time-trial performance in the heat.

    Science.gov (United States)

    Pitchford, Nathan W; Fell, James W; Leveritt, Michael D; Desbrow, Ben; Shing, Cecilia M

    2014-07-01

    The purpose of this investigation was to determine whether a moderate dose of caffeine would improve a laboratory simulated cycling time-trial in the heat. Nine well-trained male subjects (VO2max 64.4±6.8mLmin(-1)kg(-1), peak power output 378±40W) completed one familiarisation and two experimental laboratory simulated cycling time-trials in environmental conditions of 35°C and 25% RH 90min after consuming either caffeine (3mgkg(-1) BW) or placebo, in a double blind, cross-over study. Time-trial performance was faster in the caffeine trial compared with the placebo trial (mean±SD, 3806±359s versus 4079±333s, p=0.06, 90%CI 42-500s, 86% likelihood of benefit, d=-0.79). Caffeine ingestion was associated with small to moderate increases in average heart rate (p=0.178, d=0.39), VO2 (p=0.154, d=0.45), respiratory exchange ratio (p=0.292, d=0.35) and core temperature (p=0.616, d=0.22) when compared to placebo, however, these were not statistically significant. Average RPE during the caffeine supplemented time-trial was not significantly different from placebo (p=0.41, d=-0.13). Caffeine supplementation at 3mgkg(-1) BW resulted in a worthwhile improvement in cycling time-trial performance in the heat. Double-blind cross-over study. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  13. Compodock, a new device for sterile docking

    NARCIS (Netherlands)

    van der Meer, P. F.; Biekart, F. T.; Pietersz, R. N.; Rebers, S. P.; Reesink, H. W.

    2000-01-01

    BACKGROUND: A new device for sterile docking, the Compodock (Fresenius NPBI Transfusion Technology), was developed for connecting PVC tubing for medical use while maintaining sterility. STUDY DESIGN AND METHODS: Sterility of the connections was assessed by welding tubing with a heavy exterior

  14. Propagation of a laser beam in a time-varying waveguide. [plasma heating for controlled fusion

    Science.gov (United States)

    Chapman, J. M.; Kevorkian, J.

    1978-01-01

    The propagation of an axisymmetric laser beam in a plasma column having a radially parabolic electron density distribution is reported. For the case of an axially uniform waveguide it is found that the basic characteristics of alternating focusing and defocusing beams are maintained. However, the intensity distribution is changed at the foci and outer-beam regions. The features of paraxial beam propagation are discussed with reference to axially varying waveguides. Laser plasma coupling is considered noting the case where laser heating produces a density distribution radially parabolic near the axis and the energy absorbed over the focal length of the plasma is small. It is found that: (1) beam-propagation stability is governed by the relative magnitude of the density fluctuations existing in the axial variation of the waveguides due to laser heating, and (2) for beam propagation in a time-varying waveguide, the global instability of the propagation is a function of the initial fluctuation growth rate as compared to the initial time rate of change in the radial curvature of the waveguide.

  15. The application of complex network time series analysis in turbulent heated jets

    International Nuclear Information System (INIS)

    Charakopoulos, A. K.; Karakasidis, T. E.; Liakopoulos, A.; Papanicolaou, P. N.

    2014-01-01

    In the present study, we applied the methodology of the complex network-based time series analysis to experimental temperature time series from a vertical turbulent heated jet. More specifically, we approach the hydrodynamic problem of discriminating time series corresponding to various regions relative to the jet axis, i.e., time series corresponding to regions that are close to the jet axis from time series originating at regions with a different dynamical regime based on the constructed network properties. Applying the transformation phase space method (k nearest neighbors) and also the visibility algorithm, we transformed time series into networks and evaluated the topological properties of the networks such as degree distribution, average path length, diameter, modularity, and clustering coefficient. The results show that the complex network approach allows distinguishing, identifying, and exploring in detail various dynamical regions of the jet flow, and associate it to the corresponding physical behavior. In addition, in order to reject the hypothesis that the studied networks originate from a stochastic process, we generated random network and we compared their statistical properties with that originating from the experimental data. As far as the efficiency of the two methods for network construction is concerned, we conclude that both methodologies lead to network properties that present almost the same qualitative behavior and allow us to reveal the underlying system dynamics

  16. Exponential Stability of the Monotubular Heat Exchanger Equation with Time Delay in Boundary Observation

    Directory of Open Access Journals (Sweden)

    Xue-Lian Jin

    2017-01-01

    Full Text Available The exponential stability of the monotubular heat exchanger equation with boundary observation possessing a time delay and inner control was investigated. Firstly, the close-loop system was translated into an abstract Cauchy problem in the suitable state space. A uniformly bounded C0-semigroup generated by the close-loop system, which implies that the unique solution of the system exists, was shown. Secondly, the spectrum configuration of the closed-loop system was analyzed and the eventual differentiability and the eventual compactness of the semigroup were shown by the resolvent estimates on some resolvent sets. This implies that the spectrum-determined growth assumption holds. Finally, a sufficient condition, which is related to the physical parameters in the system and is independent of the time delay, of the exponential stability of the closed-loop system was given.

  17. Application of artificial neural network to predict the optimal start time for heating system in building

    International Nuclear Information System (INIS)

    Yang, In-Ho; Yeo, Myoung-Souk; Kim, Kwang-Woo

    2003-01-01

    The artificial neural network (ANN) approach is a generic technique for mapping non-linear relationships between inputs and outputs without knowing the details of these relationships. This paper presents an application of the ANN in a building control system. The objective of this study is to develop an optimized ANN model to determine the optimal start time for a heating system in a building. For this, programs for predicting the room air temperature and the learning of the ANN model based on back propagation learning were developed, and learning data for various building conditions were collected through program simulation for predicting the room air temperature using systems of experimental design. Then, the optimized ANN model was presented through learning of the ANN, and its performance to determine the optimal start time was evaluated

  18. The effects of heating temperatures and time on deformation energy and oil yield of sunflower bulk seeds in compression loading

    Science.gov (United States)

    Kabutey, A.; Herak, D.; Sigalingging, R.; Demirel, C.

    2018-02-01

    The deformation energy (J) and percentage oil yield (%) of sunflower bulk seeds under the influence of heat treatment temperatures and heating time were examined in compression test using the universal compression testing machine and vessel diameter of 60 mm with a plunger. The heat treatment temperatures were between 40 and 100 °C and the heating time at specific temperatures of 40 and 100 °C ranged from 15 to 75 minutes. The bulk sunflower seeds were measured at a pressing height of 60 mm and pressed at a maximum force of 100 kN and speed of 5 mm/min. Based on the compression results, the deformation energy and oil yield increased along with increasing heat treatment temperatures. The results were statistically significant (p 0.05).

  19. Practical aspects during sterilization validation for medical devices at IRASM Microbiological Laboratory

    International Nuclear Information System (INIS)

    Trandafir, L.; Ene, M.; Alexandru, M.; Constantin, M.; Ionita, A.; Zorila, F.; Moise, I.V.

    2011-01-01

    Complete text of publication follows. The state of being free of living microorganisms is called sterility. The sterility state can be achieved by different means of sterilization. In practice the results of the process cannot be fully verified by tests, so the efficacy of the sterilization process must be validated. ISO 11137 established regulations for setting or substantiating the dose for achieving the desired sterility assurance level. The validation studies can be designed in particular for different types of product. Each product needs distinct protocol for bioburden determination and sterility testing. During time, the Microbiological Laboratories from Multipurpose Irradiation Center deals with different types of products, mainly for VD max 25 method. When it comes to microbiological evaluation the most challenging was cotton gauze. Special situation for establishing the sterilization validation method appears in cases of cotton, packed in large quantities. VD max 25 method can not be applied for items with average bioburden more than 1000 CFU / pack, no matter which is the weight of the package. This is a method limitation and implies increased costs for manufacturer, when choosing other method. For microbiological tests, culture condition should be selected in both cases the bioburden and sterility testing. These are time and money consuming. The costs can be reduced if taking into account some aspects. Reason for performing the bacteriostasis-fungistasis just for sterility testing will be given. The present study puts forward aspects during the validation studies for medical devices (cotton wool, cotton gauze, surgical sutures, dental screws), at IRASM Microbiological Laboratory.

  20. The Effect of Sterilization on Size and Shape of Fat Globules in Model Processed Cheese Samples

    Directory of Open Access Journals (Sweden)

    B. Tremlová

    2006-01-01

    Full Text Available Model cheese samples from 4 independent productions were heat sterilized (117 °C, 20 minutes after the melting process and packing with an aim to prolong their durability. The objective of the study was to assess changes in the size and shape of fat globules due to heat sterilization by using image analysis methods. The study included a selection of suitable methods of preparation mounts, taking microphotographs and making overlays for automatic processing of photographs by image analyser, ascertaining parameters to determine the size and shape of fat globules and statistical analysis of results obtained. The results of the experiment suggest that changes in shape of fat globules due to heat sterilization are not unequivocal. We found that the size of fat globules was significantly increased (p < 0.01 due to heat sterilization (117 °C, 20 min, and the shares of small fat globules (up to 500 μm2, or 100 μm2 in the samples of heat sterilized processed cheese were decreased. The results imply that the image analysis method is very useful when assessing the effect of technological process on the quality of processed cheese quality.

  1. Histopathologic changes in fallopian tubes subsequent to sterilization procedures.

    Science.gov (United States)

    Stock, R J

    1983-01-01

    Longitudinal serial and serial step sections of fallopian tubes from more than 100 patients, subsequent to tubal sterilization procedures, were examined. Thirteen of these patients had pregnancies following their sterilizations. The histologic findings at the previous surgical sites were compatible with what would be expected for a normal healing process. Evidence for a unique tubal epithelial process, as suggested by the terms "endosalpingiosis" or "recanalization," was lacking. Likewise, the author found no evidence of tuboperitoneal fistula formation and/or the subsequent occurrence of pregnancy secondary to localized endometriosis. The histologic notations of proximal luminal dilatation, plical attenuation, chronic inflammatory infiltrates with pseudopolyp formation, and the findings of plical thickening in the distal segment of remaining tube after an interruption type of procedure seem to be associated with the length of time from the sterilization procedure. These may be factors related to the apparent reduced success rate, with time, of microsurgical reanastomotic procedures.

  2. Radiosterilization or sterilization by steam. Procedures for sterilization of spices

    International Nuclear Information System (INIS)

    Warmbold, J.

    1994-01-01

    The article compares two different methods for the sterilization of spices, namely radiosterilization and sterilization with steam. The first method applies ionizing radiation which can alter the chemical composition of the products. Tests have shown, however, that radiation doses up to 10 kGy will not induce the formation of carcinogenic agents in the foodstuffs, or of toxic substances, and thus are a wholesome method of preservation. Any modifications of taste, color or smell, or loss of vitamins, can be avoided by proper dose control and standard irradiation conditions. Sterilization by steam is a method achieving substantial suppression of the formation of germs, aerobic spores, yeasts, mould, and gramnegative germs, while preserving in most cases the essential oils. It may result in sensoric alterations, i.e affect the color, smell or taste, but in general the spices thus treated preserved their characteristic properties. The method is a good alternative to radiosterilization. The article adds some concluding information on mandatory labelling of irradiated food imported from third countries

  3. EFFECT OF MICROWAVE POWER ON SHAPE OF EPR SPECTRA--APPLICATION TO EXAMINATION OF COMPLEX FREE RADICAL SYSTEM IN THERMALLY STERILIZED ACIDUM BORICUM.

    Science.gov (United States)

    Ramos, Paweł; Pieprzyca, Małgorzata; Pilawa, Barbara

    2016-01-01

    Complex free radical system in thermally sterilized acidum boricum (AB) was studied. Acidum boricum was sterilized at temperatures and times given by pharmaceutical norms: 160 degrees C and 120 min, 170 degrees C and 60 min and 180 degrees C and 30 min. The advanced spectroscopic tests were performed. The EPR spectra of free radicals were measured as the first derivatives with microwaves of 9.3 GHz frequency and magnetic modulation of 100 kHz. The Polish X-band electron paramagnetic resonance spectrometer of Radiopan (Poznań) was used. EPR lines were not observed for the nonheated AB. The broad EPR asymmetric lines were obtained for all the heated AB samples. The influence of microwave power in the range of 2.2-70 mW on the shape of EPR spectra of the heated drug samples was tested. The following asymmetry parameters: A1/A2, A1-A2, B1/B2, and B1-B2, were analyzed. The changes of these parameters with microwave power were observed. The strong dependence of shape and its parameters on microwave power proved the complex character of free radical system in thermally sterilized AB. Changes of microwave power during the detection of EPR spectra indicated complex character of free radicals in AB sterilized in hot air under all the tested conditions. Thermolysis, interactions between free radicals and interactions of free radicals with oxygen may be responsible for the complex free radicals system in thermally treated AB. Usefulness of continuous microwave saturation of EPR lines and shape analysis to examine free radicals in thermally sterilized drugs was confirmed.

  4. A preliminary evaluation of a reusable digital sterilization indicator prototype.

    Science.gov (United States)

    Puttaiah, R; Griggs, J; D'Onofrio, M

    2014-09-01

    in an autoclave. In this study, the final batch of the DS1922F prototype data logger was found to be robust in withstanding the challenge of 600 autoclave cycles, with a mean lifetime of more than 450 cycles, multiple times more than prescribed number of cycles. Instrument reprocessing is among the important aspects of infection control. While stringent procedures are followed in instrument reprocessing within the clinic in assuring patient safety, regular use of sterilization process indicators and periodic biological validation of the sterilizer's performance is necessary. Chemical indicators for use in Autoclaves provide information on whether the particular cycle's parameters were achieved but do not provide at what specific point in time or temperature the failure occurred. Data loggers and associated reader software as the tested prototype in this evaluation (DS1922F), are designed to provide continuous information on time and temperature of the prescribed cycle. Data loggers provide immediate information on the process as opposed to Biological Indicators that take from days to a week in obtaining a confirmatory result. Further, many countries do not have the sterilization monitoring service infrastructure to meet the demands of the end users. In the absence of sterilization monitoring services, use of digital data loggers for each sterilization cycle is more pragmatic.

  5. Association of Finite-Time Thermodynamics and a Bond-Graph Approach for Modeling an Endoreversible Heat Engine

    Directory of Open Access Journals (Sweden)

    Michel Feidt

    2012-03-01

    Full Text Available In recent decades, the approach known as Finite-Time Thermodynamics has provided a fruitful theoretical framework for the optimization of heat engines operating between a heat source (at temperature and a heat sink (at temperature . The aim of this paper is to propose a more complete approach based on the association of Finite-Time Thermodynamics and the Bond-Graph approach for modeling endoreversible heat engines. This approach makes it possible for example to find in a simple way the characteristics of the optimal operating point at which the maximum mechanical power of the endoreversible heat engine is obtained with entropy flow rate as control variable. Furthermore it provides the analytical expressions of the optimal operating point of an irreversible heat engine where the energy conversion is accompanied by irreversibilities related to internal heat transfer and heat dissipation phenomena. This original approach, applied to an analysis of the performance of a thermoelectric generator, will be the object of a future publication.

  6. Citrate-capped gold nanoparticle electrophoretic heat production in response to a time-varying radiofrequency electric-field.

    Science.gov (United States)

    Corr, Stuart J; Raoof, Mustafa; Mackeyev, Yuri; Phounsavath, Sophia; Cheney, Matthew A; Cisneros, Brandon T; Shur, Michael; Gozin, Michael; McNally, Patrick J; Wilson, Lon J; Curley, Steven A

    2012-11-15

    The evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radiofrequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol which allows for highly-stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ≤ 10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area, and severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz to 3 GHz, as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia.

  7. Preparatory selection of sterilization regime for canned Natural Atlantic Mackerel with oil based on developed mathematical models of the process

    Directory of Open Access Journals (Sweden)

    Maslov A. A.

    2016-12-01

    Full Text Available Definition of preparatory parameters for sterilization regime of canned "Natural Atlantic Mackerel with Oil" is the aim of current study. PRSC software developed at the department of automation and computer engineering is used for preparatory selection. To determine the parameters of process model, in laboratory autoclave AVK-30M the pre-trial process of sterilization and cooling in water with backpressure of canned "Natural Atlantic Mackerel with Oil" in can N 3 has been performed. Gathering information about the temperature in the autoclave sterilization chamber and the can with product has been carried out using Ellab TrackSense PRO loggers. Due to the obtained information three transfer functions for the product model have been identified: in the least heated area of autoclave, the average heated and the most heated. In PRSC programme temporary temperature dependences in the sterilization chamber have been built using this information. The model of sterilization process of canned "Natural Atlantic Mackerel with Oil" has been received after the pre-trial process. Then in the automatic mode the sterilization regime of canned "Natural Atlantic Mackerel with Oil" has been selected using the value of actual effect close to normative sterilizing effect (5.9 conditional minutes. Furthermore, in this study step-mode sterilization of canned "Natural Atlantic Mackerel with Oil" has been selected. Utilization of step-mode sterilization with the maximum temperature equal to 125 °C in the sterilization chamber allows reduce process duration by 10 %. However, the application of this regime in practice requires additional research. Using the described approach based on the developed mathematical models of the process allows receive optimal step and variable canned food sterilization regimes with high energy efficiency and product quality.

  8. Heat Generation on Implant Surface During Abutment Preparation at Different Elapsed Time Intervals.

    Science.gov (United States)

    Al-Keraidis, Abdullah; Aleisa, Khalil; Al-Dwairi, Ziad Nawaf; Al-Tahawi, Hamdi; Hsu, Ming-Lun; Lynch, Edward; Özcan, Mutlu

    2017-10-01

    The purpose of this study was to evaluate heat generation at the implant surface caused by abutment preparation using a diamond bur in a high-speed dental turbine in vitro at 2 different water-coolant temperatures. Thirty-two titanium-alloy abutments were connected to a titanium-alloy implant embedded in an acrylic resin placed within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each). Group 1: the temperature was maintained at 20 ± 1°C; and group 2: the temperature was maintained at 32 ± 1°C. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute. The temperature of the heat generated from abutment preparation was recorded and measured at 3 distinct time intervals. Water-coolant temperature (20°C vs 32°C) had a statistically significant effect on the implant's temperature change during preparation of the abutment (P water-coolant temperature of 20 ± 1°C during preparation of the implant abutment decreased the temperature recorded at the implant surface to 34.46°C, whereas the coolant temperature of 32 ± 1°C increased the implant surface temperature to 40.94°C.

  9. Time resolved spectra in the infrared absorption and emission from shock heated hydrocarbons

    Science.gov (United States)

    Bauer, S. H.; Borchardt, D. B.

    1990-07-01

    We have extended the wavelength range of our previously constructed multichannel, fast recording spectrometer to the mid-infrared. With the initial configuration, using a silicon-diode (photovoltaic) array, we recorded light intensities simultaneously at 20 adjacent wavelengths, each with 20 μs time resolution. For studies in the infrared the silicon diodes are replaced by a 20 element PbSe (photoconducting) array of similar dimensions (1×4 mm/element), cooled by a three-stage thermoelectric device. These elements have useful sensitivities over 1.0-6.7 μm. Three interchangeable gratings in a 1/4 m monochromator cover the following spectral ranges: 1.0-2.5 μm (resolution 33.6 cm-1) 2.5-4.5 μm (16.8 cm-1) 4.0-6.5 μm (16.7 cm-1). Incorporated in the new housing there are individually controlled bias-power sources for each detector, two stages of analogue amplification and a 20-line parallel output to the previously constructed digitizer, and record/hold computer. The immediate application of this system is the study of emission and absorption spectra of shock heated hydrocarbons-C2H2, C4H4 and C6H6-which are possible precursors of species that generate infrared emissions in the interstellar medium. It has been recently proposed that these radiations are due to PAH that emit in the infrared upon relaxation from highly excited states. However, it is possible that such emissions could be due to shock-heated low molecular-weight hydrocarbons, which are known to be present in significant abundances, ejected into the interstellar medium during stellar outer atmospheric eruptions. The full Swan band system appeared in time-integrated emission spectra from shock heated C2H2 (1% in Ar; T5eq~=2500K) no soot was generated. At low resolution the profiles on the high frequency side of the black body maximum show no distinctive features. These could be fitted to Planck curves, with temperatures that declined with time from an initial high that was intermediate between T5 (no

  10. Female Sterilization and Poor Mental Health: Rates and Relatedness among American Indian and Alaska Native Women.

    Science.gov (United States)

    Cackler, Christina J J; Shapiro, Valerie B; Lahiff, Maureen

    2016-01-01

    To describe the reproductive and mental health of American Indian and Alaska Native (AI/AN) women, an understudied population. Data from the 2004 Behavioral Risk Factor Surveillance System survey were analyzed to determine the 1) prevalence of female sterilization among a nationally representative sample of reproductive age AI/AN women and 2) the association of female sterilization and poor mental health among AI/AN women compared with non-Hispanic White, non-Hispanic Black, and Hispanic women. Nearly 25% of AI/AN women reported female sterilization, a prevalence higher than the comparison racial/ethnic groups (p women reporting female sterilization had nearly 2.5 times the odds of poor mental health compared with AI/AN women not reporting female sterilization (p = .001). The same magnitude of relationship between female sterilization and poor mental health was not found for non-Hispanic White, non-Hispanic Black, and Hispanic women. The prevalence of female sterilization is greater among AI/AN women compared with non-Hispanic White, non-Hispanic Black, and Hispanic women, and AI/AN women reporting female sterilization have higher odds of reporting poor mental health. Common cultural experiences, such as a shared ancestral history of forced sterilizations, may be relevant, and could be considered when providing reproductive and mental health services to AI/AN women. Copyright © 2016 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

  11. Dosimetry for electron beam sterilization

    International Nuclear Information System (INIS)

    Miller, A.

    2007-01-01

    According to ISO 11137-1 (sect 4.3.4) dosimetry used in the development, validation and routine control of the sterilization process shall have measurement traceability to national or international standards and shall have a known level of uncertainty. It can only be obtained through calibration of the dosimeters. In presented lecture different types of dosimeter systems for electron beams (calorimeters, radiochromic film dosimeters, alanine / EPR) and their calibration are described

  12. Spread ability of diamondblack moth (Plutella xylotella L) steriled by irradiation

    International Nuclear Information System (INIS)

    Yang Rongxin; Fang Julian; Xia Darong; Chu Jiming; Feng Chunsheng

    1990-01-01

    The spread ability of the radiation steriled diamondblack moth (DBM) is reported. It shows that the 94.2% of DBM is spread in 40 m duration of 10 days and a few of moths are 120 m. It indicates that the spread of steriled DBM is definitely time limit, the spread area is withinca. 700 m 2 in the first three days

  13. Mirror model for sterile neutrinos

    International Nuclear Information System (INIS)

    Berezinsky, Veniamin; Narayan, Mohan; Vissani, Francesco

    2003-01-01

    Sterile neutrinos are studied as subdominant contribution to solar neutrino physics. The mirror-matter neutrinos are considered as sterile neutrinos. We use the symmetric mirror model with gravitational communication between mirror and visible sectors. This communication term provides mixing between visible and mirror neutrinos with the basic scale μ=v EW 2 /M Pl =2.5x10 -6 eV, where v EW =174 GeV is the vacuum expectation value of the standard electroweak group and M Pl is the Planckian mass. It is demonstrated that each mass eigenstate of active neutrinos splits into two states separated by small Δm 2 . Unsuppressed oscillations between active and sterile neutrinos (ν a ↔ν s ) occur only in transitions between each of these close pairs ('windows'). These oscillations are characterized by very small Δm 2 and can suppress the flux and distort spectrum of pp-neutrinos in detectable way. The other observable effect is anomalous seasonal variation of neutrino flux, which appears in LMA solution. The considered subdominant neutrino oscillations ν a ↔ν s can reveal itself as big effects in observations of supernova neutrinos and high-energy (HE) neutrinos. In the case of HE neutrinos they can provide a very large diffuse flux of active neutrinos unconstrained by the e-m cascade upper limit

  14. Relation between time-temperature transformation and continuous heating transformation diagrams of metallic glassy alloys

    International Nuclear Information System (INIS)

    Louzguine-Luzgin, Dmitri V.; Inoue, Akihisa

    2005-01-01

    The time-temperature transformation (TTT) diagrams for the onset of devitrification of the Ge-Ni-La and Cu-Hf-Ti glassy alloys were calculated from the isothermal differential calorimetry data using an Arrhenius equation. The continuous heating transformation (CHT) diagrams for the onset of devitrification of the glassy alloys were subsequently recalculated from TTT diagrams. The recalculation method used for conversion of the TTT into CHT diagrams produces reasonable results and is not sensitive to the type of the devitrification reaction (polymorphous or primary transformation). The diagrams allow to perform a comparison of the stabilities of glassy alloys on a long-term scale. The relationship between these diagrams is discussed

  15. Real-time control of focused ultrasound heating based on rapid MR thermometry.

    Science.gov (United States)

    Vimeux, F C; De Zwart, J A; Palussiére, J; Fawaz, R; Delalande, C; Canioni, P; Grenier, N; Moonen, C T

    1999-03-01

    Real-time control of the heating procedure is essential for hyperthermia applications of focused ultrasound (FUS). The objective of this study is to demonstrate the feasibility of MRI-controlled FUS. An automatic control system was developed using a dedicated interface between the MR system control computer and the FUS wave generator. Two algorithms were used to regulate FUS power to maintain the focal point temperature at a desired level. Automatic control of FUS power level was demonstrated ex vivo at three target temperature levels (increase of 5 degrees C, 10 degrees C, and 30 degrees C above room temperature) during 30-minute hyperthermic periods. Preliminary in vivo results on rat leg muscle confirm that necrosis estimate, calculated on-line during FUS sonication, allows prediction of tissue damage. CONCLUSIONS. The feasibility of fully automatic FUS control based on MRI thermometry has been demonstrated.

  16. Displaced vertex searches for sterile neutrinos at future lepton colliders

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805 München (Germany); Cazzato, Eros; Fischer, Oliver [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland)

    2016-12-02

    We investigate the sensitivity of future lepton colliders to displaced vertices from the decays of long-lived heavy (almost sterile) neutrinos with electroweak scale masses and detectable time of flight. As future lepton colliders we consider the FCC-ee, the CEPC, and the ILC, searching at the Z-pole and at the center-of-mass energies of 240, 350 and 500 GeV. For a realistic discussion of the detector response to the displaced vertex signal and the Standard Model background we consider the ILC’s Silicon Detector (SiD) as benchmark for the future lepton collider detectors. We find that displaced vertices constitute a powerful search channel for sterile neutrinos, sensitive to squared active-sterile mixing angles as small as 10{sup −11}.

  17. Economical aspects of radiation sterilization with electron beam

    International Nuclear Information System (INIS)

    Zimek, Z.; Kaluska, I.

    1998-01-01

    Radiation sterilization has been introduced in Poland in the early seventies. Since then continuous progress is observed in quantity of sterilized products. The commercial irradiation facility was built in 1993 to fulfill growing demands for radiation service. The real costs of running this plant were shown. The share of the cost of investment and the cost of maintenance and spare parts in accelerator exploitation, as well as the cost of one hour accelerator exploitation against time of one year accelerator exploitation were taken into account

  18. Sterile Neutrinos in Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Benjamin J.P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-09-01

    Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system; test-stand measurements of liquid argon optical properties with dissolved impurities; optimization of wavelength-shifting coatings for liquid argon scintillation light detection; testing and deployment of high-voltage surge arrestors to protect TPC field cages; and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin224 ≤ 0.02 at m2 ~ 0.3 eV2, and the LSND and Mini

  19. Acute acetaminophen (paracetamol) ingestion improves time to exhaustion during exercise in the heat.

    Science.gov (United States)

    Mauger, Alexis R; Taylor, Lee; Harding, Christopher; Wright, Benjamin; Foster, Josh; Castle, Paul C

    2014-01-01

    Acetaminophen (paracetamol) is a commonly used over-the-counter analgesic and antipyretic and has previously been shown to improve exercise performance through a reduction in perceived pain. This study sought to establish whether its antipyretic action may also improve exercise capacity in the heat by moderating the increase in core temperature. On separate days, 11 recreationally active participants completed two experimental time-to-exhaustion trials on a cycle ergometer in hot conditions (30°C, 50% relative humidity) after ingesting a placebo control or an oral dose of acetaminophen in a randomized, double-blind design. Following acetaminophen ingestion, participants cycled for a significantly longer period of time (acetaminophen, 23 ± 15 min versus placebo, 19 ± 13 min; P = 0.005; 95% confidence interval = 90-379 s), and this was accompanied by significantly lower core (-0.15°C), skin (-0.47°C) and body temperatures (0.19°C; P 0.05). This is the first study to demonstrate that an acute dose of acetaminophen can improve cycling capacity in hot conditions, and that this may be due to the observed reduction in core, skin and body temperature and the subjective perception of thermal comfort. These findings suggest that acetaminophen may reduce the thermoregulatory strain elicited from exercise, thus improving time to exhaustion.

  20. Sterilization of ready to eat meals destined to immunocompromised by irradiation

    International Nuclear Information System (INIS)

    Berhouma, Hiba

    2011-01-01

    Immunocompromised patients who have a dysfunction in one or more components of the immune system must follow a diet low in bacteria. Several methods are used to obtain this type of system such as pasteurization (65-10 degree), wet sterilization (120 degree - 140 degree UHT) or dry ( 180 degree), heating in the oven convection ((250 degree) and radappertization). In Tunisia, the CNGMO uses sterilization in a forced air oven 120 degree for 20 min. Of high radiation doses 5, 10 and 15 KGy were used in this study to achieve sterilization of Couscous. The dose of 5 KGy improves the bacteriological quality (reduce the microbial load of 2048 to 1 log CFU/g) of this dish while preserving the organoleptic qualities. The comparison sample irradiated 5 KGy and the heat-treated seems to be very close during the various tests. except that the heat-treated has a high oxidation state (TBARS value of 7900.90 mg / kg).

  1. Theoretical analysis of oscillatory terms in lattice heat-current time correlation functions and their contributions to thermal conductivity

    Science.gov (United States)

    Pereverzev, Andrey; Sewell, Tommy

    2018-03-01

    Lattice heat-current time correlation functions for insulators and semiconductors obtained using molecular dynamics (MD) simulations exhibit features of both pure exponential decay and oscillatory-exponential decay. For some materials the oscillatory terms contribute significantly to the lattice heat conductivity calculated from the correlation functions. However, the origin of the oscillatory terms is not well understood, and their contribution to the heat conductivity is accounted for by fitting them to empirical functions. Here, a translationally invariant expression for the heat current in terms of creation and annihilation operators is derived. By using this full phonon-picture definition of the heat current and applying the relaxation-time approximation we explain, at least in part, the origin of the oscillatory terms in the lattice heat-current correlation function. We discuss the relationship between the crystal Hamiltonian and the magnitude of the oscillatory terms. A solvable one-dimensional model is used to illustrate the potential importance of terms that are omitted in the commonly used phonon-picture expression for the heat current. While the derivations are fully quantum mechanical, classical-limit expressions are provided that enable direct contact with classical quantities obtainable from MD.

  2. Effects of Time, Heat, and Oxygen on K Basin Sludge Agglomeration, Strength, and Solids Volume

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Sinkov, Sergey I.; Schmidt, Andrew J.; Daniel, Richard C.; Burns, Carolyn A.

    2011-01-04

    Sludge disposition will be managed in two phases under the K Basin Sludge Treatment Project. The first phase is to retrieve the sludge that currently resides in engineered containers in the K West (KW) Basin pool at ~10 to 18°C. The second phase is to retrieve the sludge from interim storage in the sludge transport and storage containers (STSCs) and treat and package it in preparation for eventual shipment to the Waste Isolation Pilot Plant. The work described in this report was conducted to gain insight into how sludge may change during long-term containerized storage in the STSCs. To accelerate potential physical and chemical changes, the tests were performed at temperatures and oxygen partial pressures significantly greater than those expected in the T Plant canyon cells where the STSCs will be stored. Tests were conducted to determine the effects of 50°C oxygenated water exposure on settled quiescent uraninite (UO2) slurry and a full simulant of KW containerized sludge to determine the effects of oxygen and heat on the composition and mechanical properties of sludge. Shear-strength measurements by vane rheometry also were conducted for UO2 slurry, mixtures of UO2 and metaschoepite (UO3•2H2O), and for simulated KW containerized sludge. The results from these tests and related previous tests are compared to determine whether the settled solids in the K Basin sludge materials change in volume because of oxidation of UO2 by dissolved atmospheric oxygen to form metaschoepite. The test results also are compared to determine if heating or other factors alter sludge volumes and to determine the effects of sludge composition and settling times on sludge shear strength. It has been estimated that the sludge volume will increase with time because of a uranium metal → uraninite → metaschoepite oxidation sequence. This increase could increase the number of containers required for storage and increase overall costs of sludge management activities. However, the volume

  3. Effects of Time, Heat, and Oxygen on K Basin Sludge Agglomeration, Strength, and Solids Volume

    International Nuclear Information System (INIS)

    Delegard, Calvin H.; Sinkov, Sergey I.; Schmidt, Andrew J.; Daniel, Richard C.; Burns, Carolyn A.

    2011-01-01

    Sludge disposition will be managed in two phases under the K Basin Sludge Treatment Project. The first phase is to retrieve the sludge that currently resides in engineered containers in the K West (KW) Basin pool at ∼10 to 18 C. The second phase is to retrieve the sludge from interim storage in the sludge transport and storage containers (STSCs) and treat and package it in preparation for eventual shipment to the Waste Isolation Pilot Plant. The work described in this report was conducted to gain insight into how sludge may change during long-term containerized storage in the STSCs. To accelerate potential physical and chemical changes, the tests were performed at temperatures and oxygen partial pressures significantly greater than those expected in the T Plant canyon cells where the STSCs will be stored. Tests were conducted to determine the effects of 50 C oxygenated water exposure on settled quiescent uraninite (UO 2 ) slurry and a full simulant of KW containerized sludge to determine the effects of oxygen and heat on the composition and mechanical properties of sludge. Shear-strength measurements by vane rheometry also were conducted for UO 2 slurry, mixtures of UO2 and metaschoepite (UO 3 · 2H 2 O), and for simulated KW containerized sludge. The results from these tests and related previous tests are compared to determine whether the settled solids in the K Basin sludge materials change in volume because of oxidation of UO2 by dissolved atmospheric oxygen to form metaschoepite. The test results also are compared to determine if heating or other factors alter sludge volumes and to determine the effects of sludge composition and settling times on sludge shear strength. It has been estimated that the sludge volume will increase with time because of a uranium metal → uraninite → metaschoepite oxidation sequence. This increase could increase the number of containers required for storage and increase overall costs of sludge management activities. However, the

  4. Regret following female sterilization in Slovenia.

    Science.gov (United States)

    Becner, Anja; Turkanović, Anela Bečić; But, Igor

    2015-07-01

    To estimate the regret rate and risk factors for regret among women who have undergone sterilization. A retrospective study was conducted among all women who underwent a sterilization procedure at the University Medical Center Maribor, Maribor, Slovenia, in 2008-2012. Identified women were contacted and asked to complete an online questionnaire assessing regret and symptoms associated with depression. Among 714 identified women, 308 (43.1%) completed the questionnaire. Four (1.3%) participants reported regret, and 9 (2.9%) reported that they would not opt for sterilization again, all of whom had post-sterilization problems. Such problems were significantly associated with participants reporting that they would not opt for sterilization again (P=0.003). Additionally, women who would not choose sterilization again had significantly higher scores on the depressive scale used than did those who would undergo sterilization again (P=0.028). Few women report regret after tubal sterilization in Slovenia. However, an additional consultation on post-sterilization problems and depressive disorder before sterilization might minimize the risk of regret. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Women plan condom use after sterilization.

    Science.gov (United States)

    1998-12-01

    Sexual sterilization is highly effective in preventing pregnancy, but it does not protect against sexually transmitted diseases (STDs). People who accept sterilization as their method of family planning therefore need to be encouraged to protect themselves against HIV/AIDS and STDs even after they have been sterilized. Since women return less often to family planning providers following their sterilization procedure, they need to be advised to protect themselves against HIV and STDs before the sterilization is performed. 42% of the 2782 women who underwent tubal sterilizations at the Baylor College of Medicine in Houston during 1991-96 indicated their intention in a cross-sectional study to use condoms after sterilization. 20% of all respondents, aged 18-51 years, had a known risk factor for HIV, and almost 25% reported regular condom use for contraception or disease protection during the 3 months before sterilization. Planned condom use increased from 32% in 1991 to 51% in 1996, irrespective of age, marital status, or ethnic background. Of the 646 women who used condoms before being sterilized, almost half indicated no plans to do so after the procedure. The following factors were associated with condom use: relatively younger age, black ethnicity, unmarried status, history of previous STD, no steady partner, having a higher number of previous sex partners, past use of condoms to prevent disease transmission, and lack of partner involvement in the decision to undergo sterilization.

  6. Disinfection/sterilization of extracted teeth for dental student use.

    Science.gov (United States)

    Dominici, J T; Eleazer, P D; Clark, S J; Staat, R H; Scheetz, J P

    2001-11-01

    Extracted human teeth are used in many preclinical courses. While there has been no report of disease transmission with extracted teeth, sterilization of teeth used in the teaching laboratory should be a concern. The purpose of this study was to determine the effectiveness of different sterilization/disinfection methods of extracted human teeth using Bacillus stearothermophilus, a bacteria resistant to heat and frequently used to test sterilizers. In this study, 110 extracted molars with no carious lesions were collected and stored in buffered saline. An endodontic occlusal access preparation was cut into the pulp chamber of each tooth. Pulp tissue in the chamber was removed with a broach. Approximately 1 x 10(5) B. stearothermophilus endospores in culture medium were injected into the pulp chamber, sealed with Cavit G, and then placed in sterile saline for twelve hours. Ten teeth were placed into each of eleven groups. Seven groups were immersed for one week in one of the following solutions: a) sterile saline (control group), b) 5.25% NaOCl, c) 2.6% NaOCl, d) 1% NaOCl, e) 10% buffered formalin, f) 2% gluteraldehyde, g) 0.28% quaternary ammonium. Four additional groups were treated by h) 10% formalin for two days, i) 10% formalin for four days, j) autoclaving at 240 degrees F and 20 psi for twenty minutes, and k) autoclaving at 240 degrees F and twenty psi for forty minutes. Each tooth was then aseptically split and placed in an individual test tube with growth medium. Samples were examined for evidence of growth (turbidity) at forty-eight hours. Only autoclaving for forty minutes at 240 degrees F and 20 psi or soaking in 10 percent formalin for one week were 100 percent effective in preventing growth. A chi-square analysis of the data indicates these two methods were significantly better than all other methods (p<0.001).

  7. Comparison of Sterile and Clean Dressing Techniques in Post ...

    African Journals Online (AJOL)

    Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, ... Chinese hospital, and to compare their impact on wound healing and the cost of the ... up to the time of their discharge. Results: Twelve (18.5 %) patients out of those who received sterile or clean .... identified using automated means [13,14].

  8. Radiation sterilization of enzyme hybrids with biodegradable polymers

    International Nuclear Information System (INIS)

    Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

    2002-01-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate 'hybrid' biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of 60 Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification

  9. Bacterial growth on Mueller Hinton medium sterilized by. gamma. -radiation

    Energy Technology Data Exchange (ETDEWEB)

    Eisenberg, E. (Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center); Bogokowsky, B.; Altmann, G. (Sheba Medical Center, Tel Hashomer (Israel); Tel Aviv Univ. (Israel). Medical School)

    1981-12-01

    The possibility of radiosterilization of culture media for the cultivation of bacteria was investigated. Mueller Hinton agar, a medium widely used for the propagation of some fastidious pathogenic bacteria, was sterilized with 1.0 and 1.5 Mrad doses of ..gamma..-radiation. Bacteria belonging to seven different species grew as well on the radiosterilized medium as on medium sterilized by heat in a conventional way. Reduction in colony size was observed on the radiosterilized medium with Staphylococcus aureus and Shigella boydii. Neisseria meningitidis, the most fastidious bacterium tested, did not grow at all. The addition of small amounts of catalase corrected the deleterious radiation effect and all bacteria tested could be successfully grown on irradiated Mueller Hinton agar supplemented with up to 11 Keil units catalase per liter medium.

  10. Influence of lactic acid and post-treatment recovery time on the heat resistance of Listeria monocytogenes.

    Science.gov (United States)

    Omori, Yasuo; Miake, Kiyotaka; Nakamura, Hiromi; Kage-Nakadai, Eriko; Nishikawa, Yoshikazu

    2017-09-18

    The aim of this study was to evaluate the effect of lactic acid (LA) with and without organic material at various post-treatment recovery times on the heat resistance of Listeria monocytogenes (Lm). LA decreased Lm numbers; however, the effect was remarkably attenuated by the presence of organic matter. Five strains of Lm were treated with LA and the listericidal effects were compared. The effect of LA varied depending on the strain, with ≥3.0% (w/w) LA required to kill the Lm strains in a short time. The heat resistance of Lm treated with LA was examined with respect to the time interval between the acid treatment and the subsequent manufacturing step. The heat resistance of Lm was shown to significantly increase during the post-treatment period. Heat tolerance (D value) increased up to 3.4-fold compared with the non-treated control bacteria. RNA sequencing and RT-PCR analyses suggested that several stress chaperones, proteins controlled by RecA and associated with high-temperature survival, were involved in the mechanism of enhanced heat resistance. These results are applicable to manufacturers when LA and heat treatment methods are utilized for the effective control of Lm in foods. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Time-of-day effects of exposure to solar radiation on thermoregulation during outdoor exercise in the heat.

    Science.gov (United States)

    Otani, Hidenori; Goto, Takayuki; Goto, Heita; Shirato, Minayuki

    2017-01-01

    High solar radiation has been recognised as a contributing factor to exertional heat-related illness in individuals exercising outdoors in the heat. Although solar radiation intensity has been known to have similar time-of-day variation as body temperature, the relationship between fluctuations in solar radiation associated with diurnal change in the angle of sunlight and thermoregulatory responses in individuals exercising outdoors in a hot environment remains largely unknown. The present study therefore investigated the time-of-day effects of variations in solar radiation associated with changing solar elevation angle on thermoregulatory responses during moderate-intensity outdoor exercise in the heat of summer. Eight healthy, high school baseball players, heat-acclimatised male volunteers completed a 3-h outdoor baseball trainings under the clear sky in the heat. The trainings were commenced at 0900 h in AM trial and at 1600 h in PM trial each on a separate day. Solar radiation and solar elevation angle during exercise continued to increase in AM (672-1107 W/m 2 and 44-69°) and decrease in PM (717-0 W/m 2 and 34-0°) and were higher on AM than on PM (both P  0.05). Tympanic temperature measured by an infrared tympanic thermometer and mean skin temperature were higher in AM than PM at 120 and 180 min (P  0.05). The current study demonstrates a greater thermoregulatory strain in the morning than in the afternoon resulting from a higher body temperature and heart rate in relation to an increase in environmental heat stress with rising solar radiation and solar elevation angle during moderate-intensity outdoor exercise in the heat. This response is associated with a lesser net heat loss at the skin and a greater body heat gain from the sun in the morning compared with the afternoon.

  12. Experimental research on the ultimate strength of hard aluminium alloy 2017 subjected to short-time radioactive heating

    International Nuclear Information System (INIS)

    Dafang, Wu; Yuewu, Wang; Bing, Pan; Meng, Mu; Lin, Zhu

    2012-01-01

    Highlights: ► Ultimate strength at transient heating is critical to security design of missiles. ► We measure the ultimate strength of alloy 2017 subjected to transient heating. ► Experimental results at transient heating are lacking in strength design handbook. ► Ultimate strength of alloy 2017 experimented is much higher than handbook value. ► The results provide a new method for optimal design of high-speed flight vehicles. -- Abstract: Alloy 2017 (Al–Cu–Mg) is a hard aluminium alloy strengthened by heat treatment. Because of its higher strength, finer weldability and ductility, hard aluminium alloy 2017 has been widely used in the field of aeronautics and astronautics. However, the ultimate strength and other characteristic mechanical parameters of aluminium alloy 2017 in a transient heating environment are still unclear, as these key mechanical parameters are lacking in the existing strength design handbook. The experimental characterisation of these critical parameters of aluminium alloy 2017 is undoubtedly meaningful for reliably estimating life span of and improving safety in designing high-speed flight vehicles. In this paper, the high-temperature ultimate strength, loading time and other mechanical properties of hard aluminium alloy 2017 under different transient heating temperatures and loading conditions are investigated by combining a transient aerodynamic heating simulation system and a material testing machine. The experimental results reveal that the ultimate strength and loading capability of aluminium alloy 2017 subjected to transient thermal heating are much higher than those tested in a long-time stable high-temperature environment. The research of this work not only provides a substantial basis for the loading capability improvement and optimal design of aerospace materials and structures subject to transient heating but also presents a new research direction with a practical application value.

  13. Time-Dependent Heat Conduction Problems Solved by an Integral-Equation Approach

    International Nuclear Information System (INIS)

    Oberaigner, E.R.; Leindl, M.; Antretter, T.

    2010-01-01

    Full text: A classical task of mathematical physics is the formulation and solution of a time dependent thermoelastic problem. In this work we develop an algorithm for solving the time-dependent heat conduction equation c p ρ∂ t T-kT, ii =0 in an analytical, exact fashion for a two-component domain. By the Green's function approach the formal solution of the problem is obtained. As an intermediate result an integral-equation for the temperature history at the domain interface is formulated which can be solved analytically. This method is applied to a classical engineering problem, i.e. to a special case of a Stefan-Problem. The Green's function approach in conjunction with the integral-equation method is very useful in cases were strong discontinuities or jumps occur. The initial conditions and the system parameters of the investigated problem give rise to two jumps in the temperature field. Purely numerical solutions are obtained by using the FEM (finite element method) and the FDM (finite difference method) and compared with the analytical approach. At the domain boundary the analytical solution and the FEM-solution are in good agreement, but the FDM results show a signicant smearing effect. (author)

  14. Advances on the time differential three-phase-lag heat conduction model and major open issues

    Science.gov (United States)

    D'Apice, Ciro; Zampoli, Vittorio

    2017-07-01

    The main purpose of this short contribution is to summarize the recent achievements concerning the so-called time differential three-phase-lag heat conduction model, contextually focusing attention on some of the numerous open problems associated with such an attractive theory. After having briefly recalled the origin of the model at issue, the restrictions upon the delay times and the constitutive tensors able to make it thermodynamically consistent are recalled. Under these hypotheses, the investigation of the well-posedness issue has already provided important results in terms of uniqueness and continuous dependence of the solutions (even related to the thermoelastic case), as well as in terms of existence of a domain of influence of the assigned data in connection with the thermoelastic model. Finally, some of the main problems currently object of investigation are recalled, including the very challenging issues about the different possible choices of Taylor series expansion orders for the constitutive equation, the interaction of the model with energy processes that take place on the nanoscale, with multi-porous materials and with biological systems.

  15. Reason behind wet pack after steam sterilization and its consequences: An overview from Central Sterile Supply Department of a cancer center in eastern India.

    Science.gov (United States)

    Basu, Debabrata

    Wet pack after steam sterilization process that means there are surely obtain millions of microorganisms that can breed and multiply rapidly and objects are unsterile and can never be used for further procedure. There are many reasons behind the wet pack occurrences after autoclaving like poor quality of wrapping materials, faulty valves of rigid container, faulty loading and packaging technique, poor steam quality, sterilizer malfunction and may be design related problems in CSSD sterile storage area. Cause of wet pack after steam sterilization processes may occur severe problems because of wasted time and effort, increased work load, increased cost, potentially contaminated instruments, infection risk to the patient, poor patient outcomes and delayed or cancellation of procedures. But such wet pack scenario can be avoided by various methods by using good steam (water) quality, performing periodic maintenance of the Autoclaves, avoidance of sterilizer overloading, allowing adequate post sterilization time to cool down the materials to room temperature, using good quality wrapping materials, properly maintain temperature and humidity of sterile storage area etc. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  16. Harmonic oscillator in heat bath: Exact simulation of time-lapse-recorded data and exact analytical benchmark statistics

    DEFF Research Database (Denmark)

    Nørrelykke, Simon F; Flyvbjerg, Henrik

    2011-01-01

    The stochastic dynamics of the damped harmonic oscillator in a heat bath is simulated with an algorithm that is exact for time steps of arbitrary size. Exact analytical results are given for correlation functions and power spectra in the form they acquire when computed from experimental time...

  17. Model business plan for a sterile insect production facility

    International Nuclear Information System (INIS)

    2008-01-01

    For over 50 years the sterile insect technique (SIT) is a pest control strategy which has been used for eradication, and more recently for suppression, containment and prevention, of unwanted insect pest populations. Examples of successful applications of SIT, almost always applied in conjunction with other control methods in an area-wide integrated approach, are available from around the world. The development and application of SIT has relied overwhelmingly on public or donor initiative and funding throughout its history, although the private sector has always been involved as participants, cooperators or partners in funding. The demand for SIT, and therefore the market for sterile insects, has increased in recent years. This increase coincides with the introduction of new pests through the expansion of global trade and, at the same time, widespread pressure to find alternatives to pesticides. Recent improvements in the technology supporting SIT facilitate its application and suggest lower costs can be achieved. The conditions are therefore met for a greater commercialization of the technique to bring it in line with other pest control approaches that are fully integrated into a market approach. Several challenges arise, however, in pursuing sterile insect production as a commercial venture, ranging from intellectual property protection to pricing of the product. Routine insurance requirements, for instance, are complicated by the biological aspects of the business. This report is aimed at facilitating private sector involvement in the production of sterile insects for use in pest control. It provides guidelines and tools to support the development of specific business plans for a new SIT venture. By providing an international perspective on such issues as initial capital costs and recurring operational expenditures for a sterile insect facility, it may be used to evaluate the feasibility of proceeding with the construction or expansion of a sterile insect

  18. Sterilization of heparinized cuprophan hemodialysis membranes

    OpenAIRE

    ten Hoopen, Hermina W.M.; Hinrichs, W.L.J.; Hinrichs, W.L.J.; Engbers, G.H.M.; Feijen, Jan

    1996-01-01

    The effects of sterilization of dry heparinized Cuprophan hemodialysis membranes by means of ethylene oxide (EtO) exposure, gamma irradiation, or steam on the anticoagulant activity and chemical characteristics of immobilized heparin and the permeability of the membrane were investigated. Sterilization did not result in a release of heparin or heparin fragments from heparinized Cuprophan. Sterilization of heparinized Cuprophan by means of EtO exposure and gamma irradiation induced a slight, i...

  19. EB surface sterilization of food material

    International Nuclear Information System (INIS)

    Kaneko, H.; Mizutani, A.; Kato, K.; Nishikimi, T.; Taniguchi, S.

    2001-01-01

    In this paper, we introduce a food irradiation with low energetic, lower than 300keV, electrons (so-called SOFT ELECTRON) as a rather new method of food sterilization. It is also a physical sterilization method, and free from the problems mentioned above. Low energetic electrons have small penetration power (50-200micron) through raw materials, and by selecting a proper energy of electrons we can sterilize only the surfaces or skins of target materials

  20. Cryoradiation sterilization - contemporary state and outlook

    International Nuclear Information System (INIS)

    Talrose, V.L.

    1995-01-01

    The new approach of radiation sterilization -cryoradiosterilization with programmed freezing - was developed for pharmaceutical solutions. Both scientific and technical problems are solved, the results are discussed. Programmed freezing of vials with the drug's solutions provides the high stability of soluted components with biological activity at sterilizing irradiation without significant change of sterilization doses. Physical, chemical, biological and pharmacological properties of a lot of drug solutions for injection satisfy official requirements after cryoradiation sterilization treatment. This method seems to be especially important for the protein systems which could be infected by dangerous viruses (VIH, hepatitis B): blood plasma, diagnostic sera, protein preparations manufactured from donor's blood, etc. (Author)

  1. Probabilistic model for sterilization of food

    International Nuclear Information System (INIS)

    Chepurko, V.V.; Malinovskij, O.V.

    1986-01-01

    The probabilistic model for radiation sterilization is proposed based on the followng suppositions: (1) initial contamination of a volume unit of the sterilized product m is described by the distribution of the probabilities q(m), (2) inactivation of the population from m of microorganisms is approximated by Bernoulli test scheme, and (3) contamination of unit of the sterilized product is independent. The possibility of approximation q(m) by Poisson distribution is demonstrated. The diagrams are presented permitting to evaluate the dose which provides the defined reliability of sterilization of food for chicken-gnotobionts

  2. Sterile neutrino dark matter with supersymmetry

    Science.gov (United States)

    Shakya, Bibhushan; Wells, James D.

    2017-08-01

    Sterile neutrino dark matter, a popular alternative to the WIMP paradigm, has generally been studied in non-supersymmetric setups. If the underlying theory is supersymmetric, we find that several interesting and novel dark matter features can arise. In particular, in scenarios of freeze-in production of sterile neutrino dark matter, its superpartner, the sterile sneutrino, can play a crucial role in early Universe cosmology as the dominant source of cold, warm, or hot dark matter, or of a subdominant relativistic population of sterile neutrinos that can contribute to the effective number of relativistic degrees of freedom Neff during big bang nucleosynthesis.

  3. Currently available devices for female sterilization.

    Science.gov (United States)

    Chapman, Lynne; Magos, Adam

    2005-09-01

    Sterilization is now the method of family planning most commonly used in the world. Over the last 150 years, research has evolved in the search for the ideal method of female sterilization. The procedure should ideally have high efficacy, be readily accessible and be personally and culturally acceptable. The method should be simple, quick, easily learned and be able to be performed in an outpatient setting without general anesthesia. The most common and effective method for sterilization has, thus far, been via the laparoscopic route. Hysteroscopic sterilization, however, potentially fulfills many of these ideal criteria, but until recently has remained more of a concept than a reality.

  4. Genetic basis of the sterile insect technique

    International Nuclear Information System (INIS)

    Robinson, A.S.

    2014-01-01

    The use of the sterile insect technique for insect control relies on the introduction of sterility in the females of the wild population. This sterility is produced following the mating of these females with released males carrying, in their sperm, dominant lethal mutations that have been induced by ionizing radiation. As well as radiation-induced sterility, natural mechanisms can be recruited, especially the use of hybrid sterility. Radiation is usually one of the last procedures that insects undergo before leaving mass-rearing facilities for release in the field. It is essential that the dosimetry of the radiation source be checked to ensure that all the insects receive the required minimum dose. A dose should be chosen that maximizes the level of introduced sterility in the wild females in the field. Irradiation in nitrogen can provide protection against the detrimental somatic effects of radiation. Currently, the development of molecular methods to sterilize pest insects in the field, by the release of fertile insects carrying trans genes, is very much in vogue. It is concluded that using a physical process, such as radiation, will always have significant advantages over genetic and other methods of sterilization for the large-scale application of the sterile insect technique. (author)

  5. NMR-Based Metabonomic Investigation of Heat Stress in Myotubes Reveals a Time-Dependent Change in the Metabolites

    DEFF Research Database (Denmark)

    Straadt, Ida K; Young, Jette F; Bross, Peter

    2010-01-01

    NMR-based metabonomics was applied to elucidate the time-dependent stress responses in mouse myotubes after heat exposure of either 42 or 45 degrees C for 1 h. Principal component analysis (PCA) revealed that the gradual time-dependent changes in metabolites contributing to the clustering...... and separation of the control samples from the different time points after heat stress primarily are in the metabolites glucose, leucine, lysine, phenylalanine, creatine, glutamine, and acetate. In addition, PC scores revealed a maximum change in metabolite composition 4 h after the stress exposure; thereafter......, samples returned toward control samples, however, without reaching the control samples even 10 h after stress. The results also indicate that the myotubes efficiently regulate the pH level by release of lactate to the culture medium at a heat stress level of 42 degrees C, which is a temperature level...

  6. Energy dashboard for real-time evaluation of a heat pump assisted solar thermal system

    Science.gov (United States)

    Lotz, David Allen

    The emergence of net-zero energy buildings, buildings that generate at least as much energy as they consume, has lead to greater use of renewable energy sources such as solar thermal energy. One example is a heat pump assisted solar thermal system, which uses solar thermal collectors with an electrical heat pump backup to supply space heating and domestic hot water. The complexity of such a system can be somewhat problematic for monitoring and maintaining a high level of performance. Therefore, an energy dashboard was developed to provide comprehensive and user friendly performance metrics for a solar heat pump system. Once developed, the energy dashboard was tested over a two-week period in order to determine the functionality of the dashboard program as well as the performance of the heating system itself. The results showed the importance of a user friendly display and how each metric could be used to better maintain and evaluate an energy system. In particular, Energy Factor (EF), which is the ratio of output energy (collected energy) to input energy (consumed energy), was a key metric for summarizing the performance of the heating system. Furthermore, the average EF of the solar heat pump system was 2.29, indicating an efficiency significantly higher than traditional electrical heating systems.

  7. Soil heat flux and day time surface energy balance closure at ...

    Indian Academy of Sciences (India)

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were ... mate source of energy for all physical and bio- logical processes ... May) account for major thunderstorm activity in the state and winter ...

  8. Effect of microwave heat-treatment time on the properties of activated carbons as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    He, X.; Wang, T.; Long, S.; Zhang, X.; Zheng, M. [Anhui Univ. of Technology, Ma' aushan (China). School of Chemistry and Chemical Engineering, Anhui Key Lab of Coal Clean Conversion and Utilization

    2010-07-01

    A microwave-assisted heating technique was used to prepare activated carbons (ACs) from petroleum coke with potassium hydroxide (KOH) as an activating agent. The aim of the study was to investigate the effect of heat treatment time on AC properties at 3, 5, and 7 minutes with a microwave power rate of 700 W. The structure and electrochemical performance of the microwave ACs were then compared with commercially prepared ACs. The study showed that the specific capacitance, equivalent series resistance and energy density of the AC electrodes decreased, while the cycle performance of the AC electrodes was improved. The specific capacitance and energy density of the ACs treated with microwave heat at 3 and 7 minutes was higher than rates observed in commercially-prepared ACs. Results showed that the microwave heat treatment method is an efficient means of obtaining stable ACs for use in supercapacitors. 3 refs., 1 tab., 1 fig.

  9. The Effects of Heat Stress on Selective Attention and Reaction Time among Workers of a Hot Industry: Application of Computerized Version of Stroop Test

    Directory of Open Access Journals (Sweden)

    F. Golbabaei

    2015-04-01

    .Conclusion: According to the findings in present study, heat stress causes an increase in reaction time and a decrease in selective attention. Thus, heat can be assumed as a stressor in hot work environments and the heat should be taken into account while design of job and tasks which needed selective attention or reaction time.

  10. Sterilization of collagen scaffolds designed for peripheral nerve regeneration: Effect on microstructure, degradation and cellular colonization

    International Nuclear Information System (INIS)

    Monaco, Graziana; Cholas, Rahmatullah; Salvatore, Luca; Madaghiele, Marta; Sannino, Alessandro

    2017-01-01

    In this study we investigated the impact of three different sterilization methods, dry heat (DHS), ethylene oxide (EtO) and electron beam radiation (β), on the properties of cylindrical collagen scaffolds with longitudinally oriented pore channels, specifically designed for peripheral nerve regeneration. Scanning electron microscopy, mechanical testing, quantification of primary amines, differential scanning calorimetry and enzymatic degradation were performed to analyze possible structural and chemical changes induced by the sterilization. Moreover, in vitro proliferation and infiltration of the rat Schwann cell line RSC96 within the scaffolds was evaluated, up to 10 days of culture. No major differences in morphology and compressive stiffness were observed among scaffolds sterilized by the different methods, as all samples showed approximately the same structure and stiffness as the unsterilized control. Proliferation, infiltration, distribution and morphology of RSC96 cells within the scaffolds were also comparable throughout the duration of the cell culture study, regardless of the sterilization treatment. However, we found a slight increase of chemical crosslinking upon sterilization (EtO < DHS < β), together with an enhanced resistance to denaturation of the EtO treated scaffolds and a significantly accelerated enzymatic degradation of the β sterilized scaffolds. The results demonstrated that β irradiation impaired the scaffold properties to a greater extent, whereas EtO exposure appeared as the most suitable method for the sterilization of the proposed scaffolds. - Highlights: • Production of longitudinally oriented collagen scaffolds for nerve regeneration • Control of pore structure and crosslinking • Impact of terminal sterilization on the scaffold properties • Proliferation and infiltration of Schwann cells within the sterilized scaffolds

  11. Sterilization of collagen scaffolds designed for peripheral nerve regeneration: Effect on microstructure, degradation and cellular colonization

    Energy Technology Data Exchange (ETDEWEB)

    Monaco, Graziana [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy); Dhitech Scarl – Distretto Tecnologico High Tech, Via per Monteroni, 73100 Lecce (Italy); Cholas, Rahmatullah; Salvatore, Luca [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy); Madaghiele, Marta, E-mail: marta.madaghiele@unisalento.it [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy); Sannino, Alessandro [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy)

    2017-02-01

    In this study we investigated the impact of three different sterilization methods, dry heat (DHS), ethylene oxide (EtO) and electron beam radiation (β), on the properties of cylindrical collagen scaffolds with longitudinally oriented pore channels, specifically designed for peripheral nerve regeneration. Scanning electron microscopy, mechanical testing, quantification of primary amines, differential scanning calorimetry and enzymatic degradation were performed to analyze possible structural and chemical changes induced by the sterilization. Moreover, in vitro proliferation and infiltration of the rat Schwann cell line RSC96 within the scaffolds was evaluated, up to 10 days of culture. No major differences in morphology and compressive stiffness were observed among scaffolds sterilized by the different methods, as all samples showed approximately the same structure and stiffness as the unsterilized control. Proliferation, infiltration, distribution and morphology of RSC96 cells within the scaffolds were also comparable throughout the duration of the cell culture study, regardless of the sterilization treatment. However, we found a slight increase of chemical crosslinking upon sterilization (EtO < DHS < β), together with an enhanced resistance to denaturation of the EtO treated scaffolds and a significantly accelerated enzymatic degradation of the β sterilized scaffolds. The results demonstrated that β irradiation impaired the scaffold properties to a greater extent, whereas EtO exposure appeared as the most suitable method for the sterilization of the proposed scaffolds. - Highlights: • Production of longitudinally oriented collagen scaffolds for nerve regeneration • Control of pore structure and crosslinking • Impact of terminal sterilization on the scaffold properties • Proliferation and infiltration of Schwann cells within the sterilized scaffolds.

  12. Quality comparison of continuous steam sterilization segmented-flow aseptic processing versus conventional canning of whole and sliced mushrooms.

    Science.gov (United States)

    Anderson, N M; Walker, P N

    2011-08-01

    This study was carried out to investigate segmented-flow aseptic processing of particle foods. A pilot-scale continuous steam sterilization unit capable of producing shelf stable aseptically processed whole and sliced mushrooms was developed. The system utilized pressurized steam as the heating medium to achieve high temperature-short time processing conditions with high and uniform heat transfer that will enable static temperature penetration studies for process development. Segmented-flow technology produced a narrower residence time distribution than pipe-flow aseptic processing; thus, whole and sliced mushrooms were processed only as long as needed to achieve the target F₀  = 7.0 min and were not overcooked. Continuous steam sterilization segmented-flow aseptic processing produced shelf stable aseptically processed mushrooms of superior quality to conventionally canned mushrooms. When compared to conventionally canned mushrooms, aseptically processed yield (weight basis) increased 6.1% (SD = 2.9%) and 6.6% (SD = 2.2%), whiteness (L) improved 3.1% (SD = 1.9%) and 4.7% (SD = 0.7%), color difference (ΔE) improved 6.0% (SD = 1.3%) and 8.5% (SD = 1.5%), and texture improved 3.9% (SD = 1.7%) and 4.6% (SD = 4.2%), for whole and sliced mushrooms, respectively. Segmented-flow aseptic processing eliminated a separate blanching step, eliminated the unnecessary packaging of water and promoted the use of bag-in-box and other versatile aseptic packaging methods. Segmented-flow aseptic processing is capable of producing shelf stable aseptically processed particle foods of superior quality to a conventionally canned product. This unique continuous steam sterilization process eliminates the need for a separate blanching step, reduces or eliminates the need for a liquid carrier, and promotes the use of bag-in-box and other versatile aseptic packaging methods. © 2011 Institute of Food Technologists®

  13. Non-equilibrium effects of core-cooling and time-dependent internal heating on mantle flush events

    Directory of Open Access Journals (Sweden)

    D. A. Yuen

    1995-01-01

    Full Text Available We have examined the non-equilibrium effects of core-cooling and time-dependent internal-heating on the thermal evolution of the Earth's mantle and on mantle flush events caused by the two major phase transitions. Both two- and three-dimensional models have been employed. The mantle viscosity responds to the secular cooling through changes in the averaged temperature field. A viscosity which decreases algebraically with the average temperature has been considered. The time-dependent internal-heating is prescribed to decrease exponentially with a single decay time. We have studied the thermal histories with initial Rayleigh numbers between 2 x 107 and 108 . Flush events, driven by the non-equilibrium forcings, are much more dramatic than those produced by the equilibrium boundary conditions and constant internal heating. Multiple flush events are found under non-equilibrium conditions in which there is very little internal heating or very fast decay rates of internal-heating. Otherwise, the flush events take place in a relatively continuous fashion. Prior to massive flush events small-scale percolative structures appear in the 3D temperature fields. Time-dependent signatures, such as the surface heat flux, also exhibits high frequency oscillatory patterns prior to massive flush events. These two observations suggest that the flush event may be a self-organized critical phenomenon. The Nusselt number as a function of the time-varying Ra does not follow the Nusselt vs. Rayleigh number power-law relationship based on equilibrium (constant temperature boundary conditions. Instead Nu(t may vary non-monotonically with time because of the mantle flush events. Convective processes in the mantle operate quite differently under non-equilibrium conditions from its behaviour under the usual equilibrium situations.

  14. Implication of sterile fermions in particle physics and cosmology

    International Nuclear Information System (INIS)

    Lucente, M.

    2015-01-01

    The Ph.D. thesis work summarised in this manuscript was dedicated to studying several aspects of the phenomenology of Standard Model (SM) extensions by sterile fermions, in particular their impact for particle and astro-particle physics. An important part of the work is dedicated to a class of SM extensions which allow to explain the smallness of the observed neutrino masses (as well as their mixings) by linking them to the breaking of total lepton number, in the framework of the so-called Inverse seesaw mechanism (ISS). The work described in the thesis addresses the role of these sterile states in providing a satisfactory explanation to 3 open observational problems of the SM: the generation of neutrino masses and mixings, a viable dark matter candidate, and the dynamical generation of the baryon asymmetry of the Universe. We identified the minimal ISS realisation accounting for the observed neutrino data while at the same time complying with all available experimental and observational constraints. This study was based on a perturbative approach to the diagonalization of the neutrino mass matrix, which allowed to identify the number of states associated with the different mass scales. Our study revealed that, depending on the number of additional sterile fermion fields, the ISS can accommodate both a 3-flavour mixing scheme and a 3+more mixing scheme. The potential role of these sterile states as dark matter (DM) candidates led us to carry a dedicated study of the viability of the sterile fermion dark matter hypothesis in a minimal ISS realisation (in which the SM is extended by 2 right-handed neutrinos and 3 additional sterile fermion fields). The degeneracy in the sterile neutrino mass spectrum - which is characteristic of low scale seesaw models with approximate lepton number conservation - can play a relevant role in cosmology, since it allows us to explain the observed baryon asymmetry of the Universe via lepto-genesis. We identified different lepton number

  15. Timing in administration of a heat-killed Lactobacillus casei preparation for radioprotection in mice

    International Nuclear Information System (INIS)

    Tsuneoka, Kazuko; Ishihara, Hiroshi; Dimchev, A.B.; Shikita, Mikio; Nomoto, Koji; Yokokura, Teruo.

    1994-01-01

    A single subcutaneous injection of a preparation of heat-killed Lactobacillus casei (LC 9018), given before or after irradiation, significantly increased the survival rate of mice that had received 8.5-Gy 137 Cs whole-body γ-irradiation. A similar radioprotective effect was observed when LC 9018 was administered within the period from 2 days before irradiation to 9 h after irradiation, the pre-irradiation treatment being slightly better than the post-irradiation treatment. Increases in the weight of the spleen and in the number of endogenous spleen colonies on days 8 and 12 after irradiation suggested that the radioprotective effect was based on enhanced recovery of hematopoietic tissues. The activity of macrophage colony-stimulating factor (M-CSF) in serum was rapidly increased by the treatment and was maintained at the elevated level for 13 days. At the same time, an increased level of M-CSF mRNA was detected in the livers of the treated mice. However, LC 9018 failed to save the lives of mice when administered 3 days after irradiation, although it increased serum M-CSF as effectively as noted above. The small advantage of the pre-irradiation over the post-irradiation treatment was not explained by the increases of metallothionein in the hematopoietic tissues of the treated mice. (author)

  16. Sterility among female lizards (Uta stansburiana) exposed to continuous γ irradiation

    International Nuclear Information System (INIS)

    Turner, F.B.; Medica, P.A.

    1977-01-01

    A natural population of the lizard Uta stansburiana occupying a fenced 9-ha area in southern Nevada was exposed to essentially continuous γ irradiation from an arificial source between February 1964 and September 1973. Tissue doses were estimated using implanted lithium fluoride microdosimeters. Females became sterile as early as 11 months of age, but many were still fertile at ages of 20 months and a very few may have reproduced at 32 months. Dosimetry showed some females to be sterile after accumulated doses of around 500 rad, while others may have required 1000 or more rad. One female estimated to have received over 1200 rad was still reproductive. Irradiated females may pass through a state of half sterility, during which time they possess one functional ovary. Female U. stansburiana are sterilized at lower doses than the sterilizing dose (1500 rad) previously suggested for the leopard lizard, Crotaphytus wislizenii

  17. [Evaluation of the influence of sterilization method on the stability of carboxymethyl cellulose wound dressing].

    Science.gov (United States)

    Muselík, Jan; Wojnarová, Lenka; Masteiková, Ruta; Sopuch, Tomáš

    2013-04-01

    Carboxymethyl cellulose, especially its sodium salt, is a versatile pharmaceutical excipient. From a therapeutic point of view, sodium salt of carboxymethyl cellulose is used in the production of modern wound dressings to allow moist wound healing. Wound dressings must be sterile and stable throughout their shelf life and have to be able to withstand different temperature conditions. At the present time, a number of sterilization methods are available. In the case of polymeric materials, the selected sterilization process must not induce any changes in the polymer structure, such as polymer chains cleavage, changes in cross-linking, etc. This paper evaluates the influence of different sterilization methods (γ-radiation, β-radiation, ethylene oxide) on the stability of carboxymethyl cellulose and the results of long-term and accelerated stability testing. Evaluation of samples was performed using size-exclusion chromatography. The obtained results showed that ethylene oxide sterilization was the least aggressive variant of the sterilization methods tested. When the γ-radiation sterilization was used, the changes in the size of the carboxymethyl cellulose molecule occurred. In the course of accelerated and long term stability studies, no further degradation changes were observed, and thus sterilized samples are suitable for long term storage.

  18. Monitoring cow activity and rumination time for an early detection of heat stress in dairy cow

    Science.gov (United States)

    Abeni, Fabio; Galli, Andrea

    2017-03-01

    The aim of this study was to explore the use of cow activity and rumination time by precision livestock farming tools as early alert for heat stress (HS) detection. A total of 58 Italian Friesian cows were involved in this study during summer 2015. Based on the temperature humidity index (THI), two different conditions were compared on 16 primiparous and 11 multiparous, to be representative of three lactation phases: early (15-84 DIM), around peak (85-154 DIM), and plateau (155-224 DIM). A separate dataset for the assessment of the variance partition included all the cows in the herd from June 7 to July 16. The rumination time (RT2h, min/2 h) and activity index (AI2h, bouts/2 h) were summarized every 2-h interval. The raw data were used to calculate the following variables: total daily RT (RTt), daytime RT (RTd), nighttime RT (RTn), total daily AI (AIt), daytime AI (AId), and nighttime AI (AIn). Either AIt and AId increased, whereas RTt, RTd, and RTn decreased with higher THI in all the three phases. The highest decrease was recorded for RTd and ranged from 49 % (early) to 45 % (plateau). The contribution of the cow within lactation phase was above 60 % of the total variance for AI traits and a share from 33.9 % (for RTt) to 54.8 % (RTn) for RT traits. These observations must be extended to different feeding managements and different animal genetics to assess if different thresholds could be identified to set an early alert system for the farmer.

  19. Methane potential of sterilized solid slaughterhouse wastes.

    Science.gov (United States)

    Pitk, Peep; Kaparaju, Prasad; Vilu, Raivo

    2012-07-01

    The aim of the current study was to determine chemical composition and methane potential of Category 2 and 3 solid slaughterhouse wastes rendering products (SSHWRP) viz. melt, decanter sludge, meat and bone meal (MBM), technical fat and flotation sludge from wastewater treatment. Chemical analyses showed that SSHWRP were high in protein and lipids with total solids (TS) content of 96-99%. Methane yields of the SSHWRP were between 390 and 978 m(3) CH(4)/t volatile solids (VS)(added). Based on batch experiments, anaerobic digestion of SSHWRP from the dry rendering process could recover 4.6 times more primary energy than the energy required for the rendering process. Estonia has technological capacity to sterilize all the produced Category 2 and 3 solid slaughterhouse wastes (SSHW) and if separated from Category 1 animal by-products (ABP), it could be further utilized as energy rich input material for anaerobic digestion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Twenty years of radiation sterilization in Croatia

    Science.gov (United States)

    Ražem, Dus̆an

    2004-09-01

    The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m 3 kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m 3 kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made.

  1. Twenty years of radiation sterilization in Croatia

    International Nuclear Information System (INIS)

    Razem, Dusan

    2004-01-01

    The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m 3 kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m 3 kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made

  2. Gamma sterilization of disposable medical products (DMP's)

    International Nuclear Information System (INIS)

    Brinston, R.M.

    1990-01-01

    Ten million cubic meters (361 million cubic feet) of disposable medical products (DMP) and related health care items are estimated to be sterilized in the world. In this paper, current conditions and perspectives of gamma sterilization is discussed in comparison with ethylene oxide gas and electron beams. Of the total sterilization estimates for DMP, 2.8 million cubic meters (99 million cubic feet) are sterilized with gamma radiation, with a market share of 27%. Gamma radiation is becoming increased from both general market growth and the introduction of new products, as well as the conversion of product from ethylene oxide gas to cobalt-60. Regulatory pressures, legal considerations, and increasing publicity surrounding ethylene oxide usage are encouraging manufactures to switch to gamma radiation. Gamma's performance features include: no temperature change during the sterilization, high penetration, even through hermetically sealed packages, no residues, and no post-sterilization treatment or quarantine period. Gamma sterilization is economically beneficial in large volumes of product. Cost saving to the end user of gamma sterilization has meant lower minimum dose levels than 25 KGy. Despite of an increasingly accepted gamma radiation, there are still four factors to be considered, including cobalt-60 availability, price, transportation, and disposal. The price of cobalt-60 is based on neutron cost. In the future, cobalt-60 price is expected to be flat and enables gamma processing to become even more competitive with other sterilization methods. Gamma radiation using cobalt-60 has been proven as a safe, effective, and cost-competitive sterilization method for treating DMP and related health care items. It's wide use and many processing advantages will continue to make it a preferred sterilization method. (N.K.)

  3. Estimation of non-linear continuous time models for the heat exchange dynamics of building integrated photovoltaic modules

    DEFF Research Database (Denmark)

    Jimenez, M.J.; Madsen, Henrik; Bloem, J.J.

    2008-01-01

    This paper focuses on a method for linear or non-linear continuous time modelling of physical systems using discrete time data. This approach facilitates a more appropriate modelling of more realistic non-linear systems. Particularly concerning advanced building components, convective and radiati...... that a description of the non-linear heat transfer is essential. The resulting model is a non-linear first order stochastic differential equation for the heat transfer of the PV component....... heat interchanges are non-linear effects and represent significant contributions in a variety of components such as photovoltaic integrated facades or roofs and those using these effects as passive cooling strategies, etc. Since models are approximations of the physical system and data is encumbered...

  4. Estimation of heat rejection based on the air conditioner use time and its mitigation from buildings in Taipei City

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Chun-Ming; Aramaki, Toshiya; Hanaki, Keisuke [The University of Tokyo, Bunkyo-ku, Tokyo (Japan). Department of Urban Engineering

    2007-09-15

    The main work in the research focuses on the analysis and mitigation of the anthropogenic heat discharged from buildings, which is one of the main reasons leading to the heat island effect. The residential and commercial buildings, divided into 10 categories, with HVAC systems were analyzed by the building energy program, EnergyPlus. With the help of GIS, the heat rejection of all the residential and commercial buildings in DaAn Ward of Taipei City were evaluated, in which the spatial data and diurnal variation of the heat rejection were described by 3-h time periods. Furthermore, the effect of mitigation strategies was discussed. The first strategy was to change the wall/roof material of building envelope. The second and third strategies, from the viewpoint of energy saving, were to change the temperature setting of air conditioners and to turn off the lighting and equipment when not in use. The fourth strategy was to use a better efficiency of the cooling systems. Finally, the evaluation of installing the water-cooled cooling system, which discharges heat in the form of sensible and latent heat, was also included. (author)

  5. On board short-time high temperature heat treatment of ballast water: a field trial under operational conditions.

    Science.gov (United States)

    Quilez-Badia, Gemma; McCollin, Tracy; Josefsen, Kjell D; Vourdachas, Anthony; Gill, Margaret E; Mesbahi, Ehsan; Frid, Chris L J

    2008-01-01

    A ballast water short-time high temperature heat treatment technique was applied on board a car-carrier during a voyage from Egypt to Belgium. Ballast water from three tanks was subjected for a few seconds to temperatures ranging from 55 degrees C to 80 degrees C. The water was heated using the vessel's heat exchanger steam and a second heat exchanger was used to pre-heat and cool down the water. The treatment was effective at causing mortality of bacteria, phytoplankton and zooplankton. The International Maritime Organization (IMO) standard was not agreed before this study was carried out, but comparing our results gives a broad indication that the IMO standard would have been met in some of the tests for the zooplankton, in all the tests for the phytoplankton; and probably on most occasions for the bacteria. Passing the water through the pump increased the kill rate but increasing the temperature above 55 degrees C did not improve the heat treatment's efficacy.

  6. Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities.

    Science.gov (United States)

    Davis, Robert E; Hondula, David M; Patel, Anjali P

    2016-06-01

    Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat-mortality relationships. We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature-mortality relationships were associated with maximum temperature, although mean temperature results were comparable. There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature-mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum

  7. Factors Related to Intention to Undergo Female Sterilization Among Married Women in Rural Kathmandu, Nepal.

    Science.gov (United States)

    Dhungana, Adhish; Nanthamongkolchai, Sutham; Pitikultang, Supachai

    2016-03-01

    Sterilization is most widely used fertility regulation method in Nepal. However, prevalence of uptake of female sterilization in central hilly region is less than the national average. The objective of the study was to explore the number and factors related to intention of married women to undergo female sterilization in rural Kathmandu which lies within central hilly region. This is a community based cross-sectional survey research conducted in rural area of Kathmandu valley. Two hundred and forty currently married women with at least one child of any age were interviewed using a structured pre-tested questionnaire. More than four-fifth of the respondents intended to undergo sterilization. Almost two-third of them wanted to limit their family size by taking this option. More than one-third of women not-intending to undergo sterilization feared weakness after sterilization. Age of the respondents, duration of marriage, and number of living children were significantly associated with intention to undergo sterilization. 15-24 years age group were six times more likely to have the intention for sterilization (OR 6.79, CI 2.28-20.19) compared to age 35 years and above group. Mothers with less than 3 living children are about three times more likely to have the intention to undergo sterilization (OR 2.87, CI 1.3-6.33) compared to women with more than 2 living children. Women married for 6 to 10 years were three times more likely to have the intention (OR 3.0, CI 1.09-8.27). However, gender of the living children was not associated with intention to undergo sterilization. There were significant numbers of women intending to undergo sterilization. Age of the mother, number of living children and the duration of marriage were found to be significantly influencing the intention to undergo sterilization. However, as intention refers to future plan, the respondents' intention may change over time. The national family planning program also needs to identify the key factors in

  8. Research of tare hydrodynamic behaviour at sterilization of canned fish

    Directory of Open Access Journals (Sweden)

    Alexeev G. V.

    2016-09-01

    Full Text Available The paper is devoted to research on improving the equipment that ensures the absolute safety of mineral nutrients in the production of sterilized canned fish. The results of experimental study of hydrodynamic characteristics moving sterilized jars of canned fish of different sizes under the influence of circulating gas-liquid heat-carrying medium in the capacity have been presented. Some experimental setup with organized top-down and bottom-up flows in it modeling a sterilizer (autoclave has been proposed for the research. The experiments have been performed in the superficial gas velocity ranging from 0.03 m/s to 0.15 m/s corresponding to stable operation of the apparatus. Cans drag coefficient in the flow of heat-carrying medium has been determined by two methods for two heat-carrying media – pure glycerol and water solutions in experiments on precipitation and air – cans when blowing in the wind tunnel. The significant difference in the rates of cans upstream and downstream is reliably established, and therefore it has been proposed to use for the cans' motion characterization the indicator averaged over the two specified rates and called cans circulation speed. An empirical equation describing the dependence of the cans circulation rate from the superficial gas velocity has been obtained. Based on the analysis of studies some empirical dependencies on calculation of the drag coefficients of various types of packaging in the range of Reynolds criterion values from 1 to 4 000 have been offered. The necessity of using the qualifying factor for calculating the real drag on the results of the experiment has been determined.

  9. Effect of chopping time and heating on 1 H nuclear magnetic resonance and rheological behavior of meat batter matrix.

    Science.gov (United States)

    Zhou, Fen; Dong, Hui; Shao, Jun-Hua; Zhang, Jun-Long; Liu, Deng-Yong

    2018-04-01

    The effect of chopping time and heating on physicochemical properties of meat batters was investigated by low-field nuclear magnetic resonance and rheology technology. Cooking loss and L* increased while texture profile analysis index decreased between chopping 5 and 6 min. The relaxation time T 21 (bound water) and its peak area ratio decreased, while the ratio of T 22 peak area (immobilized water) in raw meat batters gradually increased with the extension of chopping time. However, T 22 was opposite after being heated and a new component T 23 (free water) appeared (T 2i is the spin - spin relaxation time for the ith component.). The initial damping factor (Tan δ) gradually decreased and there were significant difference between 4 and 5 min of chopping time. There were significantly positive correlations between the ratio of peak area of T 22 and chopping time, the storage modulus (G'), cooking loss, and L*, respectively. Continued chopping time could improve the peak area proportion of T 22 in raw meat batters. Further, the higher the peak area proportion of T 22 in raw meat batters, the cooking loss of heated meat gel was higher. Also, the stronger the mobility of immobilized water in meat batter, the higher the L* of the fresh meat batters. Thus, it is revealed that the physicochemical properties of meat batter are significantly influenced by chopping time which further affects the water holding capacity and the texture of emulsification gel. © 2017 Japanese Society of Animal Science.

  10. Eugenics and Involuntary Sterilization: 1907-2015.

    Science.gov (United States)

    Reilly, Philip R

    2015-01-01

    In England during the late nineteenth century, intellectuals, especially Francis Galton, called for a variety of eugenic policies aimed at ensuring the health of the human species. In the United States, members of the Progressive movement embraced eugenic ideas, especially immigration restriction and sterilization. Indiana enacted the first eugenic sterilization law in 1907, and the US Supreme Court upheld such laws in 1927. State programs targeted institutionalized, mentally disabled women. Beginning in the late 1930s, proponents rationalized involuntary sterilization as protecting vulnerable women from unwanted pregnancy. By World War II, programs in the United States had sterilized approximately 60,000 persons. After the horrific revelations concerning Nazi eugenics (German Hereditary Health Courts approved at least 400,000 sterilization operations in less than a decade), eugenic sterilization programs in the United States declined rapidly. Simplistic eugenic thinking has faded, but coerced sterilization remains widespread, especially in China and India. In many parts of the world, involuntary sterilization is still intermittently used against minority groups.

  11. Cosmology seeking friendship with sterile neutrinos

    DEFF Research Database (Denmark)

    Hamann, Jan; Hannestad, Steen; Raffelt, G.G.

    2011-01-01

    Precision cosmology and big-bang nucleosynthesis mildly favour extra radiation in the universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We present bounds on the common mass scale ms and effective number Ns of thermally excited sterile ...

  12. Current Sterilization Protocols-An Orthodontic Perspective

    Directory of Open Access Journals (Sweden)

    Abraham Vinod Korath

    2010-01-01

    Part I of this article focuses on the working principles of various methods of sterilization with an appraisalof their effects on orthodontic instruments. Additionally,contributory factors of instrument damage is enumerated to emphasis the importance of adhering to precise protocols and manufacturer recommendations as well as in alleviating some misconceptions about sterilization induced instrument damage.

  13. Light Sterile Neutrinos: A White Paper

    DEFF Research Database (Denmark)

    Abazajian, K. N.; Acero, M. A.; Agarwalla, S. K.

    2012-01-01

    This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.......This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data....

  14. Male sterile mutant in Vigna radiata

    International Nuclear Information System (INIS)

    Pande, Kalpana; Raghuvanshi, S.S.

    1987-01-01

    Single and combined treatment of γ-rays and 0.25 per cent EMS were tried on Vigna radiata variety K851. A male sterile mutant was isolated in M 2 generation. Experiments indicated male sterility to be recessive and monogenic in nature. 6 figures. (author)

  15. Sodium hypochlorite sterilization of culture medium in ...

    African Journals Online (AJOL)

    With the purpose of finding an alternative to thermal sterilization, this research aimed at assessing the efficiency and ideal concentration of sodium hypochlorite for sterilization of culture media and glassware used during rooting of micropropagated Gerbera hybrida cv. Essandre. Two experiments were carried out. In the first ...

  16. Timing effects of heat-stress on plant physiological characteristics and growth: a field study with prairie vegetation

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2016-11-01

    Full Text Available More intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic agricultural, economic and ecological impacts. This field study examined how plant responded to heat-stress (HS treatment at different timing in naturally-occurring vegetation. HS treatment (5 days at 40.5 ºC were applied to 12 1m2 plots in restored prairie vegetation dominated by Andropogon gerardii (warm-season C4 grass and Solidago canadensis (warm-season C3 forb at different growing stages. During and after HS, air, canopy, and soil temperature were monitored; net CO2 assimilation (Pn, quantum yield of photosystem II (ФPSII, stomatal conductance (gs, and internal CO2 level (Ci of the dominant species were measured. One week after the last HS treatment, all plots were harvested and the biomass of above-ground tissue and flower weight of the two dominant species was determined. HS decreased physiological performance and growth for both species, with S. canadensis being affected more than A. gerardii, indicated by negative heat stress effect on both physiological and growth responses. There were significant timing effect of heat stress on the two species, with greater reductions in the photosynthesis and productivity occurred when heat stress was applied at later-growing season. The reduction in aboveground productivity in S. canadensis but not A. gerardii could have important implications for plant community structure by increasing the competitive advantage of A. gerardii in this grassland. The present experiment showed that heat stress, though ephemeral, may promote long-term effects on plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when more frequent and severe heat stress occur in the future.

  17. [Characteristics and follow-up of sterilized women].

    Science.gov (United States)

    Molina, R; López, I

    1982-02-01

    In order to gain insight into the characteristics of sterilized women evaluating at the same time the effects of sterilization, 70 patients who underwent sterilization in an Obstetrics Unit were studied. The clinical records were analyzed and a questionnaire comprising general knowledge, attitudes, and conduct was applied. Women over 30 and with a parity of 4 or more predominated. There was a low frequency of abortions reported but this information is not reliable. The educational level was lower than the average for the Metropolitan Region and pointed to a more precocious initiation in sexual relationships than was found in a previous similar study. Religion proved to be no obstacle for sterilization nor was attendance to church subsequently diminished. A negative moral feeling towards the operation nearly disappeared following surgery. The fear of sexual dissatisfaction in husbands decreased following surgery and a similar effect was seen with regard to negative self-image. There were no changes in marital relations nor in their satisfaction. (author's modified)

  18. Sterilization Effect of Wet Oxygen Plasma in the Bubbling Method.

    Science.gov (United States)

    Tamazawa, Kaoru; Shintani, Hideharu; Tamazawa, Yoshinori; Shimauchi, Hidetoshi

    2015-01-01

    A new low-temperature sterilization method to replace the ethylene oxide gas sterilization is needed. Strong bactericidal effects of OH and O2H radicals are well known. The purpose of this study was to evaluate the sterilization effect of wet oxygen ("O2+H2O") plasma in the bubbling method, confirming the effect of humidity. Sterility assurance was confirmed by using a biological indicator (Geobacillus stearothermophilus ATCC7953, Namsa, USA). One hundred and eight samples (10(5) spores/carrier) were divided into three groups of 36 in each for treatment with a different type of gas (O2, O2+H2O, Air+H2O). Plasma processing was conducted using a plasma ashing apparatus (13.56 MHz, PACK-3(®), Y. A. C., Japan) under various gas pressures (13, 25, 50 Pa) and gas flows (50, 100, 200 sccm). Fixed plasma treatment parameters were power at 150 W, temperature of 60 ℃, treatment time of 10 min. The samples after treatment were incubated in trypticase soy broth at 58 ℃ for 72 h. The negative culture rate in the "O2+H2O" group was significantly (Mantel-Haenszel procedure, pbubbling method which is the method of introducing vapor into the chamber. The bubbling method seems able to generate OH and O2H radicals in a stable way.

  19. Radiation sterilization of medical products in the Philippines

    Science.gov (United States)

    Singson, C.; Carmona, C.; de Guzman, Z.; Barrun, W.; Lanuza, L.

    This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. Hence, the materials used were directly obtained from local manufacturers. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. These studies indicated that radiation sterilization is technically feasible for locally manufactured medical products.

  20. Genetics and evolution of hybrid male sterility in house mice.

    Science.gov (United States)

    White, Michael A; Stubbings, Maria; Dumont, Beth L; Payseur, Bret A

    2012-07-01

    Comparative genetic mapping provides insights into the evolution of the reproductive barriers that separate closely related species. This approach has been used to document the accumulation of reproductive incompatibilities over time, but has only been applied to a few taxa. House mice offer a powerful system to reconstruct the evolution of reproductive isolation between multiple subspecies pairs. However, studies of the primary reproductive barrier in house mice-hybrid male sterility-have been restricted to a single subspecies pair: Mus musculus musculus and Mus musculus domesticus. To provide a more complete characterization of reproductive isolation in house mice, we conducted an F(2) intercross between wild-derived inbred strains from Mus musculus castaneus and M. m. domesticus. We identified autosomal and X-linked QTL associated with a range of hybrid male sterility phenotypes, including testis weight, sperm density, and sperm morphology. The pseudoautosomal region (PAR) was strongly associated with hybrid sterility phenotypes when heterozygous. We compared QTL found in this cross with QTL identified in a previous F(2) intercross between M. m. musculus and M. m. domesticus and found three shared autosomal QTL. Most QTL were not shared, demonstrating that the genetic basis of hybrid male sterility largely differs between these closely related subspecies pairs. These results lay the groundwork for identifying genes responsible for the early stages of speciation in house mice.

  1. Analytical Solution of the Hyperbolic Heat Conduction Equation for Moving Semi-Infinite Medium under the Effect of Time-Dependent Laser Heat Source

    Directory of Open Access Journals (Sweden)

    R. T. Al-Khairy

    2009-01-01

    source, whose capacity is given by (,=((1−− while the semi-infinite body has insulated boundary. The solution is obtained by Laplace transforms method, and the discussion of solutions for different time characteristics of heat sources capacity (constant, instantaneous, and exponential is presented. The effect of absorption coefficients on the temperature profiles is examined in detail. It is found that the closed form solution derived from the present study reduces to the previously obtained analytical solution when the medium velocity is set to zero in the closed form solution.

  2. International Standards for Radiation Sterilization of Medical Devices

    International Nuclear Information System (INIS)

    Miller, A.

    2007-01-01

    For a terminally sterilized medical device to be designated '' STERILE '', probability of finding the viable micro-organisms in the device shall be equal to or less than 1 x 10 -6 (EN 556-1:2001: Sterilization of medical devices - Requirements for medical devices to be designated '' STERILE '' - Part 1: Requirements for terminally sterilized medical devices). Author presents the main legal aspects of the international standards for radiation sterilization of medical devices

  3. Microbiological evaluation of the steam sterilization of assembled laparoscopic instruments.

    Science.gov (United States)

    Camargo, Tamara Carolina de; Graziano, Kazuko Uchikawa; Almeida, Alda Graciele Claudio Dos Santos; Suzuki, Karina; Silva, Cely Barreto da; Pinto, Flávia Morais Gomes

    2016-11-21

    assess the safety of steam sterilization of assembled laparoscopic instruments with challenge contamination. a laboratory experimental study, using as test samples trocars and laparoscopic graspers. Geobacillus stearothermophillus ATCC-7953 was used, with a microbial population of 106UFC/Filter paper substrate, removed from the biological indicator. Three of them were introduced into each instrument at the time of assembly, and sterilized at pressurized saturated steam, 134oC for 5 minutes. After sterilization, the instrument was disassembled and each filter paper substrate was inoculated in soybean casein culture and incubated at 56oC for 21 days. In case of absence of growth, they were subjected to heat shock of 80oC, for 20 minutes and re-incubated for 72 hours. Sample size: 185 graspers and 185 trocars, with 95% power. We paired the experiments with comparative negative control groups (5 graspers and 5 trocars with challenge contamination, sterilized disassembled) and positive control (30 filter paper supports, unsterilized), subject to the same incubation procedures. there was no microbial growth in experimental and negative control. The results of the positive control were satisfactory. this study provided strong scientific evidence to support the safety of steam sterilizing of the assembled laparoscopic instrument. avaliar a segurança da esterilização a vapor, do instrumental laparoscópico montado com desafio da contaminação. estudo experimental laboratorial, cujo corpo de prova foram trocarte e pinça laparoscópica. Utilizou-se esporos Geobacillus stearothermophillus ATCC-7953, com população microbiana de 106UFC/suporte de papel filtro, removidos do indicador biológico. Três deles foram introduzidos no interior de cada instrumento, no momento da montagem, sendo esterilizados a vapor saturado sob pressão, 134oC por 5 minutos. Depois da esterilização, o instrumental foi desmontado, e cada suporte de papel filtro foi inoculado em meio de cultura

  4. Effect of sterilization procedures on properties of plasma polymers relevant to biomedical applications

    International Nuclear Information System (INIS)

    Artemenko, A.; Kylián, O.; Choukourov, A.; Gordeev, I.; Petr, M.; Vandrovcová, M.; Polonskyi, O.; Bačáková, L.; Slavinska, D.; Biederman, H.

    2012-01-01

    This study is focused on the evaluation of resistance of plasma polymers toward common sterilization techniques, i.e. property important for possible use of such materials in biomedical applications. Three kinds of plasma polymers having different bioadhesive natures were studied: plasma polymerized poly(ethylene oxide), fluorocarbon plasma polymers, and nitrogen-rich plasma polymers. These plasma polymers were subjected to dry heat, autoclave and UV radiation treatment. Their physical, chemical and bioresponsive properties were determined by means of different techniques (ellipsometry, atomic force microscopy, wettability measurements, X-ray photoelectron spectroscopy and biological tests with osteoblast-like cells MG63). The results clearly show that properties of thin films of plasma polymers may be significantly altered by a sterilization process. Moreover, observed changes induced by selected sterilization methods were found to depend strongly on the sterilized plasma polymer. - Highlights: ► Effect of common sterilization methods on three kinds of plasma polymers is studied. ► Physical, chemical and bioresponsive properties of plasma polymers are analyzed. ► Changes induced by sterilization depend strongly on type of the plasma polymer.

  5. Morphological and chemical changes of dentin after applying different sterilization methods

    Directory of Open Access Journals (Sweden)

    Cláudio Antonio Talge Carvalho

    Full Text Available Aim The present study evaluated the morphological and chemical changes of dentin produced by different sterilization methods, using scanning electron microscopy (SEM and energy-dispersive X-ray spectrometry (EDS analysis. Material and method Five human teeth were sectioned into 4 samples, each divided into 3 specimens. The specimens were separated into sterilization groups, as follows: wet heat under pressure; cobalt 60 gamma radiation; and control (without sterilization. After sterilization, the 60 specimens were analyzed by SEM under 3 magnifications: 1500X, 5000X, and 10000X. The images were analyzed by 3 calibrated examiners, who assigned scores according to the changes observed in the dentinal tubules: 0 = no morphological change; 1, 2 and 3 = slight, medium and complete obliteration of the dentinal tubules. The chemical composition of dentin was assessed by EDS, with 15 kV incidence and 1 μm penetration. Result The data obtained were submitted to the statistical tests of Kruskall-Wallis and ANOVA. It was observed that both sterilization methods – with autoclave and with cobalt 60 gamma radiation – produced no significant changes to the morphology of the dentinal tubules or to the chemical composition of dentin. Conclusion Both methods may thus be used to sterilize teeth for research conducted in vitro.

  6. Effect of sterilization procedures on properties of plasma polymers relevant to biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Artemenko, A. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Kylian, O., E-mail: ondrej.kylian@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Choukourov, A.; Gordeev, I.; Petr, M. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Vandrovcova, M. [Institute of Physiology, Academy of Sciences of the Czech Republic, Department of Growth and Differentiation of Cell Populations, Videnska 1083, 142 20, Prague 4 (Czech Republic); Polonskyi, O. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Bacakova, L. [Institute of Physiology, Academy of Sciences of the Czech Republic, Department of Growth and Differentiation of Cell Populations, Videnska 1083, 142 20, Prague 4 (Czech Republic); Slavinska, D.; Biederman, H. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic)

    2012-10-01

    This study is focused on the evaluation of resistance of plasma polymers toward common sterilization techniques, i.e. property important for possible use of such materials in biomedical applications. Three kinds of plasma polymers having different bioadhesive natures were studied: plasma polymerized poly(ethylene oxide), fluorocarbon plasma polymers, and nitrogen-rich plasma polymers. These plasma polymers were subjected to dry heat, autoclave and UV radiation treatment. Their physical, chemical and bioresponsive properties were determined by means of different techniques (ellipsometry, atomic force microscopy, wettability measurements, X-ray photoelectron spectroscopy and biological tests with osteoblast-like cells MG63). The results clearly show that properties of thin films of plasma polymers may be significantly altered by a sterilization process. Moreover, observed changes induced by selected sterilization methods were found to depend strongly on the sterilized plasma polymer. - Highlights: Black-Right-Pointing-Pointer Effect of common sterilization methods on three kinds of plasma polymers is studied. Black-Right-Pointing-Pointer Physical, chemical and bioresponsive properties of plasma polymers are analyzed. Black-Right-Pointing-Pointer Changes induced by sterilization depend strongly on type of the plasma polymer.

  7. Use of miniature magnetic sensors for real-time control of the induction heating process

    Science.gov (United States)

    Bentley, Anthony E.; Kelley, John Bruce; Zutavern, Fred J.

    2002-01-01

    A method of monitoring the process of induction heating a workpiece. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, B.sub.sat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can also be used to measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).

  8. Effects of Ohmic Heating on Microbial Counts and Denaturatiuon of Proteins in Milk

    OpenAIRE

    SUN, Huixian; KAWAMURA, Shuso; HIMOTO, Jun-ichi; ITOH, Kazuhiko; WADA, Tatsuhiko; KIMURA, Toshinori

    2008-01-01

    The aim of this study was to compare the inactivation effects of ohmic heating (internal heating by electric current) and conventional heating (external heating by hot water) on viable aerobes and Streptococcus thermophilus 2646 in milk under identical temperature history conditions. The effects of the two treatments on quality of milk were also compared by assessing degrees of protein denaturation in raw and sterilized milk (raw milk being sterilized by ohmic heating or conventional heating)...

  9. Identifcation of a Linear COntinuous Time Stochastic Model of the Heat Dynamics of a Greenhouse

    DEFF Research Database (Denmark)

    Nielsen, Bjarne; Madsen, Henrik

    1998-01-01

    The purpose of this paper is to describe the basis for improving the control of air temperature and heat supply in greenhouses using a method which controls the energy supply by a model-based prediction of the air temperature in the greenhouse. Controllers of this type are the minimum variance co...... controller, the generalized predictive controller and the proportional-integral-plus(PIP) controller. Prediction-based controllers have proved to be powerful in controlling the supply temperature in a distinct heating system....

  10. Acute sterile endophthalmitis following intravitreal bevacizumab: case series

    Science.gov (United States)

    Orozco-Hernández, Axel; Ortega-Larrocea, Ximena; Sánchez-Bermúdez, Gustavo; García-Aguirre, Gerardo; Cantón, Virgilio Morales; Velez-Montoya, Raul

    2014-01-01

    Background Since the ophthalmological community adopted the use of intravitreal bevacizumab as an accepted off-label treatment for neovascular diseases, the amount of knowledge regarding its effects and properties has been increasing continually. In the last few years, there have been an increasing number of reports about sterile intraocular inflammation and intraocular pressure elevations after intravitreal bevacizumab. In the following case series, we describe the clinical presentation and outcomes of ten consecutive cases of patients developing mild-to-severe sterile intraocular inflammation after intravitreal bevacizumab and their management. Methods This report presents a retrospective case series. We reviewed the medical records of ten consecutive patients from a group of 46, in whom repackaged bevacizumab in individual aliquots from two vials from the same batch were used. All surgical procedures were performed using standard sterile techniques in the operating room. At each follow-up visit, patients underwent a complete ophthalmological examination including visual acuity assessment, intraocular pressure, biomicroscopy, and posterior fundus examination. Results Ten patients presented sterile endophthalmitis with an onset time of 3.5±1.95 days. The clinical characteristics were mild pain, slight visual loss, conjunctival hyperemia, and various degrees of intraocular inflammation with microhypopyon. All cultures were negative. All patients were managed with topical steroids and antibiotics, except two, in whom, due to severe vitreous cells, intravitreal antibiotics were used. Three patients showed a transient elevation of intraocular pressure. Only 50% of the patients regained a visual acuity equal or better to the baseline visual acuity on file. Conclusion The increasing number of intravitreal injections of bevacizumab applied every day, due to its widespread acceptance, might be one reason why the number of cases of sterile endophthalmitis is rising. Fast

  11. Steam sterilization and automatic dispensing of [{sup 18}F]fludeoxyglucose (FDG) for injection

    Energy Technology Data Exchange (ETDEWEB)

    Karwath, Pascal [Department of Nuclear Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany) and MC-Pharma GmbH (MCP), Bonn (Germany); Sartor, Johannes [MC-Pharma GmbH (MCP), Bonn (Germany); Gries, Wolfgang [MC-Pharma GmbH (MCP), Bonn (Germany); Wodarski, Christine [MC-Pharma GmbH (MCP), Bonn (Germany); Dittmar, Claus [MC-Pharma GmbH (MCP), Bonn (Germany); Biersack, Hans J [Department of Nuclear Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany); Guhlke, Stefan [Department of Nuclear Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany) and MC-Pharma GmbH (MCP), Bonn (Germany)

    2005-04-01

    For the purpose of implementing steam sterilization of 2-[{sup 18}F]FDG (FDG) in the final container into routine production, we have validated and established a fully automated dispensing and sterilization system, thereby considerably reducing the radiation burden to the personnel. Methods: The commercially available system combines aseptic dispensing of the product solution under a miniaturized laminar flow unit with subsequent steam sterilization, realized by heating of the product in the final containers by an autoclave included in the dispensing unit, thus incorporating current pharmaceutical manufacturing standards for the production of parental radiopharmaceuticals. The efficiency of the used sterilization cycle, the stability of FDG under the conditions of sterilization and the stability of the final product towards radiolysis was investigated with respect to various pH-formulations. Results: The system was found to be fully valid for filling of vials in a laminar flow class A (US-class 100) environment and for sterilization of FDG in the final container. The pH for sterilizing FDG solutions must be slightly acidic to avoid decomposition. A pH of 5.5 appears to be optimal and gives FDG of very high radiochemical purity ({approx}99%). In addition, radiolysis of FDG in solutions of high activity concentration was significantly lower at pH 5.5 than at neutral pH. Conclusion: Terminal sterilization enables the production of FDG in full compliance with GMP-regulations even in Class C or D (US class 10,000 or 100,000) laboratories.

  12. Steam sterilization and automatic dispensing of [18F]fludeoxyglucose (FDG) for injection

    International Nuclear Information System (INIS)

    Karwath, Pascal; Sartor, Johannes; Gries, Wolfgang; Wodarski, Christine; Dittmar, Claus; Biersack, Hans J.; Guhlke, Stefan

    2005-01-01

    For the purpose of implementing steam sterilization of 2-[ 18 F]FDG (FDG) in the final container into routine production, we have validated and established a fully automated dispensing and sterilization system, thereby considerably reducing the radiation burden to the personnel. Methods: The commercially available system combines aseptic dispensing of the product solution under a miniaturized laminar flow unit with subsequent steam sterilization, realized by heating of the product in the final containers by an autoclave included in the dispensing unit, thus incorporating current pharmaceutical manufacturing standards for the production of parental radiopharmaceuticals. The efficiency of the used sterilization cycle, the stability of FDG under the conditions of sterilization and the stability of the final product towards radiolysis was investigated with respect to various pH-formulations. Results: The system was found to be fully valid for filling of vials in a laminar flow class A (US-class 100) environment and for sterilization of FDG in the final container. The pH for sterilizing FDG solutions must be slightly acidic to avoid decomposition. A pH of 5.5 appears to be optimal and gives FDG of very high radiochemical purity (∼99%). In addition, radiolysis of FDG in solutions of high activity concentration was significantly lower at pH 5.5 than at neutral pH. Conclusion: Terminal sterilization enables the production of FDG in full compliance with GMP-regulations even in Class C or D (US class 10,000 or 100,000) laboratories

  13. Feasibility Study of Aseptic Homogenization: Affecting Homogenization Steps on Quality of Sterilized Coconut Milk

    Directory of Open Access Journals (Sweden)

    Phungamngoen Chanthima

    2016-01-01

    Full Text Available Coconut milk is one of the most important protein-rich food sources available today. Separation of an emulsion into an aqueous phase and cream phase is commonly occurred and this leads an unacceptably physical defect of either fresh or processed coconut milk. Since homogenization steps are known to affect the stability of coconut milk. This work was aimed to study the effect of homogenization steps on quality of coconut milk. The samples were subject to high speed homogenization in the range of 5000-15000 rpm under sterilize temperatures at 120-140 °C for 15 min. The result showed that emulsion stability increase with increasing speed of homogenization. The lower fat particles were generated and easy to disperse in continuous phase lead to high stability. On the other hand, the stability of coconut milk decreased, fat globule increased, L value decreased and b value increased when the high sterilization temperature was applied. Homogenization after heating led to higher stability than homogenization before heating due to the reduced particle size of coconut milk after aggregation during sterilization process. The results implied that homogenization after sterilization process might play an important role on the quality of the sterilized coconut milk.

  14. The possibilities of sterilization of media and medium ingredients by ionizing gamma radiation

    International Nuclear Information System (INIS)

    Pogany, I.

    1979-01-01

    The thermoshock originated from sterilization by heat can occasionally destroy the media to such an extent that the growth can start only at dilutions 2 to 3 power less than in control media sterilized by glass filtration. There are some ingredients which could be produced by an aseptic procedure only - e.g. egg yolk extract - as they are not sterilizable by filtration or heat. Solid and liquid culture media prepared from natural substances and ingredients such as serum or egg yolk extract, etc. can successfully be sterilized by 1 Mrad integrated dose in 500 ml volume irrespective of dispension. In the culture media prepared with substances from natural sources it was impossible to demonstrate any radiochemical destroying effect using colony counting method, and these media were so sensitive as if they had been sterilized by glass filtration. With these substances sterilization by irradiation proved to be an applicable method in industry. Radiochemical effect was demonstrable in two cases only: the phenol-red indicator has decolorized and after a long period of storage it showed inclination to recombine, and potassium-tellurite has been precipitated owing to the above mentioned dose of irradiation. (author)

  15. Stability and biocompatibility of photothermal gold nanorods after lyophilization and sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Leyre [Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), C/ Mariano Esquillor, R and D Building, University of Zaragoza, 50018 Zaragoza (Spain); Cebrian, Virginia [CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Zaragoza (Spain); Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); Martin-Saavedra, Francisco [Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Zaragoza (Spain); Arruebo, Manuel, E-mail: arruebom@unizar.es [Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), C/ Mariano Esquillor, R and D Building, University of Zaragoza, 50018 Zaragoza (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Zaragoza (Spain); Vilaboa, Nuria [Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Zaragoza (Spain); Santamaria, Jesus, E-mail: Jesus.Santamaria@unizar.es [Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), C/ Mariano Esquillor, R and D Building, University of Zaragoza, 50018 Zaragoza (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Zaragoza (Spain)

    2013-10-15

    Graphical abstract: - Highlights: • Morphological changes are observed for CTABr capped gold nanorods over time. • Polystyrenesulfonate (PSS) and polyethyleneglycol (PEG) coated nanorods are stable. • Re-suspendible and sterilizable colloids are prepared using those capping agents. • Those materials are efficient heat sinks potentially used in photothermal therapy. - Abstract: Suspensions in phosphate buffered saline (PBS) of gold nanorods stabilized with cetyltrimethyl ammonium chloride (CTABr), polystyrenesulfonate (PSS) and methyl-polyethyleneglycol-thiol (m-PEG-SH) have been prepared and the evolution of their colloidal stability and plasmonic response over time has been evaluated. Their performance after lyophilization, alcoholic sterilization and resuspension has also been characterized. Sub-cytotoxic doses on HeLa cells were calculated for the three surface functionalizations used. Their heating efficiency at different exposure times was also evaluated after being irradiated with near infrared light. The best results were obtained for m-PEG-SH stabilized rods, which were not only stable, sterilizable and lyophilizable, but also biocompatible at all doses tested, showing potential as a stable, re-suspendible and biocompatible hyperthermic agent.

  16. Stability and biocompatibility of photothermal gold nanorods after lyophilization and sterilization

    International Nuclear Information System (INIS)

    Gomez, Leyre; Cebrian, Virginia; Martin-Saavedra, Francisco; Arruebo, Manuel; Vilaboa, Nuria; Santamaria, Jesus

    2013-01-01

    Graphical abstract: - Highlights: • Morphological changes are observed for CTABr capped gold nanorods over time. • Polystyrenesulfonate (PSS) and polyethyleneglycol (PEG) coated nanorods are stable. • Re-suspendible and sterilizable colloids are prepared using those capping agents. • Those materials are efficient heat sinks potentially used in photothermal therapy. - Abstract: Suspensions in phosphate buffered saline (PBS) of gold nanorods stabilized with cetyltrimethyl ammonium chloride (CTABr), polystyrenesulfonate (PSS) and methyl-polyethyleneglycol-thiol (m-PEG-SH) have been prepared and the evolution of their colloidal stability and plasmonic response over time has been evaluated. Their performance after lyophilization, alcoholic sterilization and resuspension has also been characterized. Sub-cytotoxic doses on HeLa cells were calculated for the three surface functionalizations used. Their heating efficiency at different exposure times was also evaluated after being irradiated with near infrared light. The best results were obtained for m-PEG-SH stabilized rods, which were not only stable, sterilizable and lyophilizable, but also biocompatible at all doses tested, showing potential as a stable, re-suspendible and biocompatible hyperthermic agent

  17. Influence of Actively Controlled Heat Release Timing on the Performance and Operational Characteristics of a Rotary Valve, Acoustically Resonant Pulse Combustor

    KAUST Repository

    Lisanti, Joel; Roberts, William L.

    2017-01-01

    The influence of heat release timing on the performance and operational characteristics of a rotary valve, acoustically resonant pulse combustor is investigated both experimentally and numerically. Simulation results are obtained by solving the quasi-1D Navier-Stokes equations with forced volumetric heat addition. Experimental efforts modify heat release timing through modulated fuel injection and modification of the fluid dynamic mixing. Results indicate that the heat release timing has a profound effect on the operation and efficiency of the pulse combustor and that this timing can be difficult to control experimentally.

  18. Influence of Actively Controlled Heat Release Timing on the Performance and Operational Characteristics of a Rotary Valve, Acoustically Resonant Pulse Combustor

    KAUST Repository

    Lisanti, Joel

    2017-01-05

    The influence of heat release timing on the performance and operational characteristics of a rotary valve, acoustically resonant pulse combustor is investigated both experimentally and numerically. Simulation results are obtained by solving the quasi-1D Navier-Stokes equations with forced volumetric heat addition. Experimental efforts modify heat release timing through modulated fuel injection and modification of the fluid dynamic mixing. Results indicate that the heat release timing has a profound effect on the operation and efficiency of the pulse combustor and that this timing can be difficult to control experimentally.

  19. Forced sterilization of women as discrimination.

    Science.gov (United States)

    Patel, Priti

    2017-01-01

    There has been a long history of subjecting marginalized women to forced and coerced sterilization. In recent years, the practice has been documented in countries in North and South America, Europe, Asia, and Africa. It has targeted women who are ethnic and racial minorities, women with disabilities, women living with HIV, and poor women. A handful of courts have issued decisions on the recent forced sterilization of marginalized women finding that such actions violate the women's rights. However, they have all failed to address the women's claims of discrimination. The failure to acknowledge that forced sterilization is at its core a violation of the prohibition of discrimination undermines efforts to eradicate the practice. It further fails to recognize that coerced and forced sterilization fundamentally seeks to deny women deemed as "unworthy" the ability to procreate. Four key principles outlined in the human rights in patient care framework highlight the importance of a finding that the prohibition of discrimination was violated in cases of forced sterilization: the need to highlight the vulnerability of marginalized populations to discrimination in health care settings; the importance of the rights of medical providers; the role of the state in addressing systemic human rights violations in health care settings; and the application of human rights to patient care. Based on these principles, it is clear that finding a violation of the prohibition of discrimination in forced sterilization cases is critical in addressing the systemic nature of the practice, acknowledging the marginalization of specific groups and effectively ending forced sterilization through addressing the underlying purpose of the practice. If litigators, non-governmental organizations and judicial officers are mindful of these principles when dealing with cases of forced sterilization, it is likely that they will be better able to eradicate forced sterilization.

  20. Genetic basis of the sterile insect technique

    International Nuclear Information System (INIS)

    Robinson, A.S.

    2005-01-01

    The use of the sterile insect technique (SIT) for insect control relies on the introduction of sterility in the females of the wild population. This sterility is produced following the mating of these females with released males carrying, in their sperm, dominant lethal mutations that have been induced by ionizing radiation. The reasons why the SIT can only be effective when the induced sterility in the released males is in the form of dominant lethal mutations, and not some form of sperm inactivation, are discussed, together with the relationship of dominant lethal mutations to dose, sex, developmental stage and the particular species. The combination of genetic sterility with that induced by radiation is also discussed in relation to the use of genetic sexing strains of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) in area-wide integrated pest management (AW-IPM) programmes that integrate the SIT. A case is made to lower the radiation dose used in such programmes so as to produce a more competitive sterile insect. Increased competitiveness can also be achieved by using different radiation environments. As well as radiation-induced sterility, natural mechanisms can be recruited, especially the use of hybrid sterility exemplified by a successful field trial with tsetse flies Glossina spp. in the 1940s. Genetic transformation will make some impact on the SIT, especially regarding the introduction of markers for released flies, and the construction of genetic sexing strains. It is concluded that using a physical process, such as radiation, will always have significant advantages over genetic and other methods of sterilization for the large-scale application of the SIT. (author)

  1. Testing the time-scale dependence of delayed interactions: A heat wave during the egg stage shapes how a pesticide interacts with a successive heat wave in the larval stage.

    Science.gov (United States)

    Janssens, Lizanne; Tüzün, Nedim; Stoks, Robby

    2017-11-01

    Under global change organisms are exposed to multiple, potentially interacting stressors. Especially interactions between successive stressors are poorly understood and recently suggested to depend on their timing of exposure. We particularly need studies assessing the impact of exposure to relevant stressors at various life stages and how these interact. We investigated the single and combined impacts of a heat wave (mild [25 °C] and extreme [30 °C]) during the egg stage, followed by successive exposure to esfenvalerate (ESF) and a heat wave during the larval stage in damselflies. Each stressor caused mortality. The egg heat wave and larval ESF exposure had delayed effects on survival, growth and lipid peroxidation (MDA). This resulted in deviations from the prediction that stressors separated by a long time interval would not interact: the egg heat wave modulated the interaction between the stressors in the larval stage. Firstly, ESF caused delayed mortality only in larvae that had been exposed to the extreme egg heat wave and this strongly depended upon the larval heat wave treatment. Secondly, ESF only increased MDA in larvae not exposed to the egg heat wave. We found little support for the prediction that when there is limited time between stressors, synergistic interactions should occur. The intermediate ESF concentration only caused delayed mortality when combined with the larval heat wave, and the lowest ESF concentrations only increased oxidative damage when followed by the mild larval heat wave. Survival selection mitigated the interaction patterns between successive stressors that are individually lethal, and therefore should be included in a predictive framework for the time-scale dependence of the outcome of multistressor studies with pollutants. The egg heat wave shaping the interaction pattern between successive pesticide exposure and a larval heat wave highlights the connectivity between the concepts of 'heat-induced pesticide sensitivity' and

  2. Inheritance of sterility in Dysdercus koenigii F. (Hemiptera: Pyrrhocoridae)

    International Nuclear Information System (INIS)

    Harwalkar, M.R.; Rahalkar, G.W.

    1979-01-01

    It has been suggested that for the control of Lepidopterous populations, release of fully competitive partially sterile males would be more advantageous than the release of completely sterile males. This suggestion is based on the fact, elucidated in many studies, that partially sterilized males mated to normal females produce totally sterile or partially sterile progeny. In Hemiptera too, F 1 progeny of partially sterile males has been shown to inherit sterility. Individual impact of sterility inherited by either sex of the F 1 progeny on population growth has been studied in an hemipteran insect Dysdercus koenigii. A dose of 7 krad induces near-complete sterility in males. When males irradiated with substerilizing doses of 1,2 and 3 krad were crossed with normal females, F 1 progeny of both sexes was partially sterile : the female being more sterile than the males. When the F 1 progeny was intercrossed, there was enhanced reduction in progeny production. (auth.)

  3. Effect of Stabilization Heat Treatment on Time-Dependent Polarization Losses in Sintered Nd-Fe-B Permanent Magnets

    Directory of Open Access Journals (Sweden)

    Tuominen S.

    2013-01-01

    Full Text Available Some companies in the motor and generator industry utilizing sintered NdFeB magnets have adopted pre-ageing heat treatment in order to improve the stability of the magnets. The parameters of this stabilization heat treatment are based mainly on assumptions rather than on any published research results. In this work, the effects of pre-ageing treatment on the time-dependent polarization losses of two different types of commercial sintered NdFeB magnets were studied. The material showing the squarer J(H curve did not benefit from the pre-ageing treatment, since it seems to be stable under a certain critical temperature. In contrast, a stabilizing effect was observed in the material showing rounder J(H curve. After the stabilization heat treatment, the polarization of the magnets was found to be at lower level, but unchanged over a certain period of time. The length of this period depends on the temperature and the duration of the pre-ageing treatment. In addition, our analysis reveals that the stabilization heat treatment performed in an open circuit condition does not stabilize the magnet uniformly.

  4. Radiation sterilization facility for melon fly

    International Nuclear Information System (INIS)

    Danno, A.

    1985-01-01

    The melon fly (Dacus cucurbitae Coquillett) has been observed in Amami Island since l975. Kagoshima Prefecture has had a melon fly eradication project underway since 1979. A mass-fearing facility and a radiation sterilization facility were constructed in Naze in March of l98l. In the early stages of the project, sterile insects were produced at the rate of 4 x l0/sup 6/ pupae/week. In the later stages, the activity of the project was enlarged by tenfold. The conditions for design of the radiation sterilization facility, which has been developed with a central control system for automated irradiation, are examined from an engineering standpoint

  5. Cosmology seeking friendship with sterile neutrinos

    International Nuclear Information System (INIS)

    Hamann, J.; Hannestad, S.; Raffelt, G.G.; Tamborra, I.; Wong, Y.Y.Y.

    2011-01-01

    Precision cosmology and big-bang nucleosynthesis mildly favour extra radiation in the universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We present bounds on the common mass scale ms and effective number Ns of thermally excited sterile neutrino states from the most recent cosmological data. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if ms is in the sub-eV range.

  6. Spore-Forming Bacteria that Resist Sterilization

    Science.gov (United States)

    LaDuc, Myron; Venkateswaran, Kasthuri

    2003-01-01

    A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

  7. Study on the simulation time increments for solar DHW heating systems; Taiyonetsu kyuto simulation ni okeru keisan jikan kankaku no kento

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M; Udagawa, M [Kogakuin University, Tokyo (Japan)

    1997-11-25

    Calculation time intervals effective in simulating solar DHW systems were discussed, taking into account water temperature in a heat storage tank and calorific power in supplied hot water. The discussion was given on a direct heat collecting system in which heat passes through a heat collector from the bottom of the heat storage tank and returns to the center of the tank, and an indirect heat collecting system which has a heat exchanger built inside the heat storage tank at its bottom. The calculation was performed with time intervals of one to sixty minutes and five to forty-five layer divisions. The following results were obtained: because the calorific power of the hot water supplied is underestimated in the calculation if the calorific power of one hot water supply is extremely large, the calculation time intervals must be reduced to 1 to 15 minutes; cumulative calorific power of the hot water supply was found to show little variation if the number of division is greater than fifteen; and the daily cumulative effective heat collection amount shows very little variation due to the calculation time intervals, but errors from the measured value have decreased as the smaller the number of layer division in the direct heat collecting system, and as the greater the number of division in the indirect heat collecting system. 4 refs., 9 figs., 2 tabs.

  8. Microscope sterility during spine surgery.

    Science.gov (United States)

    Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

    2012-04-01

    Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact

  9. Inferring near surface soil temperature time series from different land uses to quantify the variation of heat fluxes into a shallow aquifer in Austria

    Science.gov (United States)

    Kupfersberger, Hans; Rock, Gerhard; Draxler, Johannes C.

    2017-09-01

    Different land uses exert a strong spatially distributed and temporal varying signal of heat fluxes from the surface in or out of the ground. In this paper we show an approach to quantify the heat fluxes into a groundwater body differentiating between near surface soil temperatures under grass, forest, asphalt, agriculture and surface water bodies and heat fluxes from subsurface structures like heated basements or sewage pipes. Based on observed time series of near surface soil temperatures we establish individual parameters (e.g. shift, moving average) of a simple empirical function that relates air temperature to soil temperature. This procedure is useful since air temperature time series are readily available and the complex energy flux processes at the soil atmosphere interface do not need to be described in detail. To quantify the heat flux from heated subsurface structures that have lesser depths to the groundwater table the 1D heat conduction module SoilTemp is developed. Based on soil temperature time series observed at different depths in a research lysimeter heat conduction and heat storage capacity values are calibrated disregarding their dependence on the water content. With SoilTemp the strong interaction between time series of groundwater temperature and groundwater level, near surface soil temperatures and the basement temperatures in heated buildings could be evaluated showing the dynamic nature of thermal gradients. The heat fluxes from urban areas are calculated considering the land use patterns within a spatial unit by mixing the heat fluxes from basements with those under grass and asphalt. The heat fluxes from sewage pipes and of sewage leakage are shown to be negligible for evaluated pipe diameters and sewage discharges. The developed methodology will allow to parameterize the upper boundary of heat transport models and to differentiate between the heat fluxes from different surface usages and their dynamics into the subsurface.

  10. Monitoring sterile and wild insects in area-wide integrated pest management programmes

    International Nuclear Information System (INIS)

    Vreysen, M.J.B.

    2005-01-01

    Insect pest control programmes, which integrate the release of sterile insects, can be efficient only if the released insects have an optimal biological quality. Frequent monitoring of the quality of reared insects after being released in the field is an important but often neglected component of area-wide integrated pest management (AW-IPM) programmes that integrate the sterile insect technique (SIT). Parameters of sterile insects, which should be monitored regularly, are sexual competitiveness of the released insects, and related components, e.g. survival, mobility, dispersal characteristics, and spatial occupation of the habitat. A well-balanced monitoring programme will, at any given time, provide essential feedback on the progress being made. This information is prerequisite to efficient implementation of the release and cost-efficient use of sterile insects. The type of monitoring to be done will be determined largely by the particular biology of the target insect species. The most important parameter in relation to the release of sterile insects is the rate of sterility induced in the wild insect pest population; it will provide the best evidence that any observed changes, e.g. in the density of the target insect, are caused by the release of sterile insects. (author)

  11. Retrospective cost analysis comparing Essure hysteroscopic sterilization and laparoscopic bilateral tubal coagulation.

    Science.gov (United States)

    Hopkins, Matthew R; Creedon, Douglas J; Wagie, Amy E; Williams, Arthur R; Famuyide, Abimbola O

    2007-01-01

    To compare the institutional cost of permanent female sterilization by Essure hysteroscopic sterilization and laparoscopic bilateral coagulation. Retrospective cohort study (Canadian Task Force classification II-2). Midwestern academic medical center. Women of reproductive age who elected for permanent contraception by the Essure method (n = 43) or by laparoscopic tubal coagulation (n = 44) during the time frame studied. Placement of the Essure inserts according to the manufacturer's instructions or laparoscopic tubal sterilization using bipolar forceps according to standard techniques of open or closed laparoscopy. Cost-center data for the institutional cost of the procedure was abstracted for each patient included in the study. In addition, demographic data and procedural information were obtained and compared for the patient populations. The Essure system of hysteroscopic sterilization had a significantly decreased cost compared with laparoscopic tubal sterilization when both procedures were performed in an operating room setting. The decrease per patient in institutional cost was 180 dollars (p = .038). This included the cost of the confirmatory hysterosalpingogram 3 months after Essure placement and the cost of laparoscopic tubal occlusion by Filshie clip if the Essure micro-inserts could not be placed. The majority of the cost was related to hospital costs as opposed to physician costs. The Essure procedure had higher costs for disposable equipment (p Essure hysteroscopic sterilization had significant cost savings compared with laparoscopic tubal sterilization (p = .038). We believe that our data represent the minimum of potential savings using this approach, and future developments will only increase the cost difference found in our study.

  12. Looking for Holes in Sterile Wrapping: How Accurate Are We?

    Science.gov (United States)

    Rashidifard, Christopher H; Mayassi, Hani A; Bush, Chelsea M; Opalacz, Brian M; Richardson, Mark W; Muccino, Paul M; DiPasquale, Thomas G

    2018-05-01

    Defects in sterile surgical wrapping are identified by the presence of holes through which light can be seen. However, it is unknown how reliably the human eye can detect these defects. The purpose of this study was to determine (1) how often holes in sterile packaging of various sizes could be detected; and (2) whether differences in lighting, experience level of the observer, or time spent inspecting the packaging were associated with improved likelihood of detection of holes in sterile packaging. Thirty participants (10 surgical technicians, 13 operating room nurses, seven orthopaedic surgery residents) inspected sterile sheets for perforations under ambient operating room (OR) lighting and then again with a standard powered OR lamp in addition to ambient lighting. There were no additional criteria for eligibility other than willingness to participate. Each sheet contained one of nine defect sizes with four sheets allocated to each defect size. Ten wraps were controls with no defects. Participants were allowed as much time as necessary for inspection. Holes ≥ 2.5 mm were detected more often than holes ≤ 2 mm (87% [832 of 960] versus 7% [82 of 1200]; odds ratio, 88.6 [95% confidence interval, 66.2-118.6]; p < 0.001). There was no difference in detection accuracy between OR lamp and ambient lightning nor experience level. There was no correlation between inspection time and detection accuracy. Defects ≤ 2 mm were not reliably detected with respect to lighting, time, or level of experience. Future research is warranted to determine defect sizes that are clinically meaningful. Level II, diagnostic study.

  13. [Microcontroller temperature regulator MPT110 for drying-sterilizing cabinets].

    Science.gov (United States)

    Kostin, N N; Gavrishchuk, V I; Zelepukin, S A; Shkulepa, V M; Zharov, E N

    2002-01-01

    The paper describes a MPT-110 temperature microcontroller developed by the closed joint-stock company "OPLEKS" (Orel, Russia) and the results of comparative tests performed in the @IIICC-80 drying sterilizing cabinet. The use of the MPT-110 controller is shown to improve the quality of control and to shorten the times that is taken for the cabinet to reach the preset temperature point.

  14. Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes.

    Science.gov (United States)

    Winter, S; Smith, A; Lappin, D; McDonagh, G; Kirk, B

    2017-12-01

    Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organizations still advocate non-vacuum sterilization processes for these devices. To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations. Measurements at different positions within air turbines were undertaken with thermocouples and data loggers. Two examples of widely used UK benchtop steam sterilizers were tested: a non-vacuum benchtop sterilizer (Little Sister 3; Eschmann, Lancing, UK) and a vacuum benchtop sterilizer (Lisa; W&H, Bürmoos, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate. A total of 140 measurements inside dental handpiece lumens were recorded. The non-vacuum process failed (time range: 0-150 s) to reliably achieve sterilization temperatures within the time limit specified by the international standard (15 s equilibration time). The measurement point at the base of the handpiece failed in all test runs (N = 9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases. Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces, and the base of the handpiece is the site most likely to fail. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  15. Factors associated with sterilization use among women leaving a U.S. jail: a mixed methods study.

    Science.gov (United States)

    Ramaswamy, Megha; Kelly, Patricia J

    2014-07-31

    Despite the high rates of reported sterilization use among women who have spent time in correctional facilities, little is known about the context in which women in this population choose this option. The objective of our study was to use both quantitative and qualitative methods to understand factors associated with sterilization use among women leaving a U.S. jail. We administered a cross-sectional survey with 102 jailed women who were participating in a study about contraceptive use after release from jail, and then conducted semi-structured interviews with 29 of those women after their release from jail. We used logistic regression and analytic induction to assess factors associated with self-reported sterilization use. In our cross-sectional survey, one-third of our sample reported a history of sterilization use. Controlling for age and past pregnancies, the only factor associated with sterilization use was physical abuse history before age 16. In semi-structured interviews, we found that women's primary motivation for sterilization was the desire to limit childbearing permanently, in some cases where other contraceptive methods had failed them. The decision for sterilization was generally supported by family, partners, and providers. Many women who opted for sterilization expressed financial concern about supporting children and/or reported family histories of sterilization. The decision to use the permanent method of sterilization as a contraceptive method is a complex one. Results from this study suggest that while explicit coercion may not be a factor in women's choice for sterilization, interpersonal relationship histories, negative experiences with contraceptives, and structural constraints, such as financial concerns and ongoing criminal justice involvement, seem to influence sterilization use among the vulnerable group of women with criminal justice histories. Public health programs that connect women to reproductive health services should acknowledge

  16. The basic principles of the application of sterile insect technique for area-wide insect pest control

    International Nuclear Information System (INIS)

    Singgih Sutrisno

    2006-01-01

    Sterile Insect Technique (SIT) is a new insect pest control technique, potential, and compatible to other techniques. This technique includes irradiation of insect colony in the laboratory using gamma, n, or x-rays and then release them in the field periodically to obtain the increase of sterility probability level from the first generation to the dependence as the result the decrease of the fertility level in the field. The effect the release of sterile insects ( 9:1 ratio to the male indigenous and reproductive potential every single female of each generation reproduce 5 females ) to the insect reduction population model is conceptually discussed. From one million of the female parental decrease to be 26, 316; 1,907; 10; and 0 insects at the first, second, third, and the forth progeny respectively. Then if sterile insect technique integrated with chemical technique (insecticide) 90% kill, it will be much more effective compared to the application sterile insect technique only. From the number of one million population of insects will decrease to be 2,632; 189; and 0 insects at the first, second, and the third progeny respectively. In the Lepidoptera insects was found a phenomenon of inherited sterility. According to Knipling (1970) the inherited sterility in the first offspring caused by chromosome translocation in the gamete . In the individual of heterozygote will be die and in the homozygotes is still alive. Interspecific hybrid sterility first time was found by Laster (1972) from a cross between males Heliothis virescens (F) and females Heliothis subflexa Guenee. Male moths of the first offspring from the cross between H. virescens and H. subflexa is sterile and the females still remain fertile. If the female moths of the first offspring back crossed with male H. virescens the phenomenon of sterility always found will same situation as mention earlier the male offspring is sterile and the females is fertile ( the male F2 will be sterile and the females will

  17. Time-temperature characteristics of the various heat-affected zones in HT-9 weldments

    International Nuclear Information System (INIS)

    Foulds, J.R.

    1984-01-01

    Temperatures at different distances from the fusion boundary were measured during GTA weld depositing MTS-4 filler wire on 9.52-mm (3/8 in.) thick HT-9 plate. Peak temperature measurements indicate each of the heat-affected regions to be austenitized. An exponential expression has been used to describe the cooling curves as a function of peak temperature (or distance) from the fusion boundary

  18. Combined electrochemical, heat generation, and thermal model for large prismatic lithium-ion batteries in real-time applications

    Science.gov (United States)

    Farag, Mohammed; Sweity, Haitham; Fleckenstein, Matthias; Habibi, Saeid

    2017-08-01

    Real-time prediction of the battery's core temperature and terminal voltage is very crucial for an accurate battery management system. In this paper, a combined electrochemical, heat generation, and thermal model is developed for large prismatic cells. The proposed model consists of three sub-models, an electrochemical model, heat generation model, and thermal model which are coupled together in an iterative fashion through physicochemical temperature dependent parameters. The proposed parameterization cycles identify the sub-models' parameters separately by exciting the battery under isothermal and non-isothermal operating conditions. The proposed combined model structure shows accurate terminal voltage and core temperature prediction at various operating conditions while maintaining a simple mathematical structure, making it ideal for real-time BMS applications. Finally, the model is validated against both isothermal and non-isothermal drive cycles, covering a broad range of C-rates, and temperature ranges [-25 °C to 45 °C].

  19. Gamma-ray irradiation, autoclave and ethylene oxide sterilization to thermosetting polyurethane: sterilization to polyurethane

    International Nuclear Information System (INIS)

    Hirata, Noriko; Matsumoto, Ken-Ichi; Inishita, Takashi; Takenaka, Yoshinori; Suma, Yasunori; Shintani, Hideharu; National Inst. of Health Sciences, Tokyo

    1995-01-01

    Thermosetting polyurethane (PU) is widely used in a large variety of medical devices. 4,4'-methylenedianiline (MDA) was produced from PU by sterilization and it was studied for the relationship between urethane components or polymer characteristics and formation of MDA upon sterilization, using the commercially available dialyzers fabricated with different combination of isocyanate and polyol. We confirmed that the molecular-weight of polyol influenced the production of MDA upon sterilization. (author)

  20. A review: radiation sterilization of pharmaceuticals

    International Nuclear Information System (INIS)

    Jacobs, G.P.

    1985-01-01

    The literature on the effects of γ-radiation on drugs, relevant to their sterilization or decontamination, is reviewed. This literature survey essentially covers the past 7 yr, although relevant reports not covered in previous reviews have been included. (author)

  1. Radiation sterilization of animal farm sewage

    International Nuclear Information System (INIS)

    Rosiak, J.; Perkowski, J.; Pekala, W.

    1984-01-01

    Influence of irradiation on organisms appearing in farm sewage has been discussed. Practical examples of employing the radiation to sterilization of municipal wastes and liquid sewage from the industrial swine farms have been presented. (author)

  2. Determination of sterilizing dose of lincocine drug

    International Nuclear Information System (INIS)

    Adawi, M.A.; Shamma, M.; Al-Mousa, A.

    1998-01-01

    There are too many antibiotics that have been studied on their dry solid state to determine their safe sterilizing dose by decreasing their bio burden in order to reach the sterility assurance level (SAL) needed. The sterilizing radiating dose of lincocine was determined according to information about their bio burden and radiating sensitivity at the sterility assurance level 10-6. The study of bio burden has shown that the contamination was fungal (Pemicillium sp.) and by applying the same tests to the raw materials of lincocine it came out that the cause of contamination was bad storage and that the radiating dose required to decrease the bio burden was 5.5 kGy. (author)

  3. Numerical simulation of time fractional dual-phase-lag model of heat transfer within skin tissue during thermal therapy.

    Science.gov (United States)

    Kumar, Dinesh; Rai, K N

    2017-07-01

    In this paper, we investigated the thermal behavior in living biological tissues using time fractional dual-phase-lag bioheat transfer (DPLBHT) model subjected to Dirichelt boundary condition in presence of metabolic and electromagnetic heat sources during thermal therapy. We solved this bioheat transfer model using finite element Legendre wavelet Galerkin method (FELWGM) with help of block pulse function in sense of Caputo fractional order derivative. We compared the obtained results from FELWGM and exact method in a specific case, and found a high accuracy. Results are interpreted in the form of standard and anomalous cases for taking different order of time fractional DPLBHT model. The time to achieve hyperthermia position is discussed in both cases as standard and time fractional order derivative. The success of thermal therapy in the treatment of metastatic cancerous cell depends on time fractional order derivative to precise prediction and control of temperature. The effect of variability of parameters such as time fractional derivative, lagging times, blood perfusion coefficient, metabolic heat source and transmitted power on dimensionless temperature distribution in skin tissue is discussed in detail. The physiological parameters has been estimated, corresponding to the value of fractional order derivative for hyperthermia treatment therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Improved quantification accuracy for duplex real-time PCR detection of genetically modified soybean and maize in heat processed foods

    Directory of Open Access Journals (Sweden)

    CHENG Fang

    2013-04-01

    Full Text Available Real-time PCR technique has been widely used in quantitative GMO detection in recent years.The accuracy of GMOs quantification based on the real-time PCR methods is still a difficult problem,especially for the quantification of high processed samples.To develop the suitable and accurate real-time PCR system for high processed GM samples,we made ameliorations to several real-time PCR parameters,including re-designed shorter target DNA fragment,similar lengths of amplified endogenous and exogenous gene targets,similar GC contents and melting temperatures of PCR primers and TaqMan probes.Also,one Heat-Treatment Processing Model (HTPM was established using soybean flour samples containing GM soybean GTS 40-3-2 to validate the effectiveness of the improved real-time PCR system.Tested results showed that the quantitative bias of GM content in heat processed samples were lowered using the new PCR system.The improved duplex real-time PCR was further validated using processed foods derived from GM soybean,and more accurate GM content values in these foods was also achieved.These results demonstrated that the improved duplex real-time PCR would be quite suitable in quantitative detection of high processed food products.

  5. On the Coupling Time of the Heat-Bath Process for the Fortuin-Kasteleyn Random-Cluster Model

    Science.gov (United States)

    Collevecchio, Andrea; Elçi, Eren Metin; Garoni, Timothy M.; Weigel, Martin

    2018-01-01

    We consider the coupling from the past implementation of the random-cluster heat-bath process, and study its random running time, or coupling time. We focus on hypercubic lattices embedded on tori, in dimensions one to three, with cluster fugacity at least one. We make a number of conjectures regarding the asymptotic behaviour of the coupling time, motivated by rigorous results in one dimension and Monte Carlo simulations in dimensions two and three. Amongst our findings, we observe that, for generic parameter values, the distribution of the appropriately standardized coupling time converges to a Gumbel distribution, and that the standard deviation of the coupling time is asymptotic to an explicit universal constant multiple of the relaxation time. Perhaps surprisingly, we observe these results to hold both off criticality, where the coupling time closely mimics the coupon collector's problem, and also at the critical point, provided the cluster fugacity is below the value at which the transition becomes discontinuous. Finally, we consider analogous questions for the single-spin Ising heat-bath process.

  6. A comparison of two efficient nonlinear heat conduction methodologies using a two-dimensional time-dependent benchmark problem

    International Nuclear Information System (INIS)

    Wilson, G.L.; Rydin, R.A.; Orivuori, S.

    1988-01-01

    Two highly efficient nonlinear time-dependent heat conduction methodologies, the nonlinear time-dependent nodal integral technique (NTDNT) and IVOHEAT are compared using one- and two-dimensional time-dependent benchmark problems. The NTDNT is completely based on newly developed time-dependent nodal integral methods, whereas IVOHEAT is based on finite elements in space and Crank-Nicholson finite differences in time. IVOHEAT contains the geometric flexibility of the finite element approach, whereas the nodal integral method is constrained at present to Cartesian geometry. For test problems where both methods are equally applicable, the nodal integral method is approximately six times more efficient per dimension than IVOHEAT when a comparable overall accuracy is chosen. This translates to a factor of 200 for a three-dimensional problem having relatively homogeneous regions, and to a smaller advantage as the degree of heterogeneity increases

  7. 21 CFR 522.1862 - Sterile pralidoxime chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sterile pralidoxime chloride. 522.1862 Section 522....1862 Sterile pralidoxime chloride. (a) Chemical name. 2-Formyl-1-methylpyridinium chloride oxime. (b) Specifications. Sterile pralidoxime chloride is packaged in vials. Each vial contains 1 gram of sterile...

  8. Sterilization of instruments in solar ovens

    Energy Technology Data Exchange (ETDEWEB)

    Fjendbo Joergensen, A. [Odense Univ. Hospital, Dept. of Infectious Diseases, Odense (Denmark); Noehr, K. [Odense Technical College, Dept. of Metal, Odense (Denmark); Boisen, F. [The Danish Veterinary and Food Administration Funen, Dept. of Microbiology, Odense (Denmark)

    2000-07-01

    The sterilization of instruments in rural health clinics in less developed countries is an increasing problem because chemical methods can no longer be recommended and wood fuel is becoming more and more scarce. Thus, it seemed obvious to try to utilize solar energy for sterilization purposes. A solar oven was designed and manufactured using local materials and simple tools. The solar oven was tested by physical, chemical, and microbiological methods. A mathematical model for the sterilization effect was developed and programmed into a microprocessor that was connected to a thermocouple. The microprocessor switches on a green light when the sterilization is completed. After successful testing, the oven was built into the west-facing wall of a rural health clinic and used daily for sterilization. The oven was able to generate temperatures above 180 deg. C. On all days with direct sunlight the oven fulfilled the international recommendations for hot air sterilization because no growth could be detected from any of the test bacteria spores. The chemical indicators Brownes tubes types 3 and 5 also changed colours. The solar oven was easy to use for the clinic staff, but during the seasons with low sun position (in Tanzania, December and June) it was difficult to achieve a high enough temperature for sterilization. Therefore, if the method is to be used throughout the year the oven must be moved to collect the sun's rays from several directions, or the clinic must have more than one solar oven facing in different directions. We conclude that the solar oven is a realistic method for sterilization of instruments. (au)

  9. Radiation sterilization of potato starch and Sedonik

    International Nuclear Information System (INIS)

    Tashmetov, M.Yu.; Ismatov, N.B.; Saidov, R.P. et al.

    2016-01-01

    The raw material of pharmaceutical preparations potato starch and sedative means of Sedonik are sterilized at the electron's accelerator Electronics U-003. It is established that at 20.3 kGy absorbed dose and electron's energy 3 - 5 MeV the results of microbiological analysis showed sterility of potato starch and Sedonik and correspondence of their physical-optical properties to the requirements of normative documents. (authors)

  10. Effect of heat shock and recovery temperature on variability of single cell lag time of Cronobacter turicensis.

    Science.gov (United States)

    Xu, Y Zh; Métris, A; Stasinopoulos, D M; Forsythe, S J; Sutherland, J P

    2015-02-01

    The effect of heat stress and subsequent recovery temperature on the individual cellular lag of Cronobacter turicensis was analysed using optical density measurements. Low numbers of cells were obtained through serial dilution and the time to reach an optical density of 0.035 was determined. Assuming the lag of a single cell follows a shifted Gamma distribution with a fixed shape parameter, the effect of recovery temperature on the individual lag of untreated and sublethally heat treated cells of Cr. turicensis were modelled. It was found that the shift parameter (Tshift) increased asymptotically as the temperature decreased while the logarithm of the scale parameter (θ) decreased linearly with recovery temperature. To test the validity of the model in food, growth of low numbers of untreated and heat treated Cr. turicensis in artificially contaminated infant first milk was measured experimentally and compared with predictions obtained by Monte Carlo simulations. Although the model for untreated cells slightly underestimated the actual growth in first milk at low temperatures, the model for heat treated cells was in agreement with the data derived from the challenge tests and provides a basis for reliable quantitative microbiological risk assessments for Cronobacter spp. in infant milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Effects of Pressure, Temperature, Treatment Time, and Storage on Rheological, Textural, and Structural Properties of Heat-Induced Chickpea Gels

    Directory of Open Access Journals (Sweden)

    María Dolores Alvarez

    2015-04-01

    Full Text Available Pressure-induced gelatinization of chickpea flour (CF was studied in combination with subsequent temperature-induced gelatinization. CF slurries (with 1:5 flour-to-water ratio and CF in powder form were treated with high hydrostatic pressure (HHP, temperature (T, and treatment time (t at three levels (200, 400, 600 MPa; 10, 25, 50 °C; 5, 15, 25 min. In order to investigate the effect of storage (S, half of the HHP-treated CF slurries were immediately analyzed for changes in oscillatory rheological properties under isothermal heating at 75 °C for 15 min followed by cooling to 25 °C. The other half of the HHP-treated CF slurries were refrigerated (at 4 °C for one week and subsequently analyzed for changes in oscillatory properties under the same heating conditions as the unrefrigerated samples. HHP-treated CF in powder form was analyzed for changes in textural properties of heat-induced CF gels under isothermal heating at 90 °C for 5 min and subsequent cooling to 25 °C. Structural changes during gelatinization were investigated using microscopy. Pressure had a more significant effect on rheological and textural properties, followed by T and treatment t (in that order. Gel aging in HHP-treated CF slurries during storage was supported by rheological measurements.

  12. Application of radiation sterilization to bone allografts

    International Nuclear Information System (INIS)

    Li Youchen; Li Baoxing; Sun Shiquan

    2003-01-01

    With prominent features of high penetration, no temperature increases, no harm residues and easy dose control, radiation sterilization technology is widely used in the sterilization of bone allografts. During the radiation sterilization of bone allografts, the irradiation dose should be optimized to ensure sterilization of grafts and preservation of biological properties of bone. The immunogenicity of allografts is decreased by irradiation. IAEA devoted great efforts to generalization of the radiation sterilization of tissue allografts in developing countries since 1986. Tissue Bank of China Institute for Radiation Protection (CIRP) was initially established in 1988 with the support of IAEA, afterwards restructured into Shanxi Provincial Tissue Bank (SPTB). The SPTB, as the first manufacturer of the irradiated bone allografts in the country, was granted production license by the State Food and Drug Administration of China. The SPTB sponsored IAEA/RCA Training Courses, National Symposium on Bone Grafting, and National Training Course on Bone Banking. Technique of radiation sterilization for bone grafts has become popularized in China after these activities. (authors)

  13. Improving the sterile sperm identification method for its implementation in the area-wide sterile insect technique program against Ceratitis capitata (Diptera: Tephritidae) in Spain

    International Nuclear Information System (INIS)

    Juan-Blasco, M.; Urbaneja, A.; San Andrés, V.; Sabater-Muñoz, B.; Castañera, P.

    2014-01-01

    The success of sterile males in area-wide sterile insect technique (aw-SIT) programs against Ceratitis capitata (Wiedemann) is currently measured by using indirect methods as the wild: sterile male ratio captured in monitoring traps. In the past decade, molecular techniques have been used to improve these methods. The development of a polymerase chain reaction-restriction fragment-length polymorphism- based method to identify the transfer of sterile sperm to wild females, the target of SIT, was considered a significant step in this direction. This method relies on identification of sperm by detecting the presence of Y chromosomes in spermathecae DNA extract complemented by the identification of the genetic origin of this sperm: Vienna-8 males or wild haplotype. However, the application of this protocol to aw-SIT programs is limited by handling time and personnel cost. The objective of this work was to obtain a high-throughput protocol to facilitate the routine measurement in a pest population of sterile sperm presence in wild females. The polymerase chain reactionrestriction fragment-length polymorphism markers previously developed were validated in Mediterranean fruit by samples collected from various locations worldwide. A laboratory protocol previously published was modified to allow for the analysis of more samples at the same time. Preservation methods and preservation times commonly used for Mediterranean fruit by female samples were assessed for their influence on the correct molecular detection of sterile sperm. This high-throughput methodology, as well as the results of sample management presented here, provide a robust, efficient, fast, and economical sterile sperm identification method ready to be used in all Mediterranean fruit by SIT programs. (author)

  14. Voluntary sterilization in Serbia: Unmet need?

    Directory of Open Access Journals (Sweden)

    Rašević Mirjana M.

    2002-01-01

    Full Text Available Is voluntary sterilization as a birth control method accepted in Serbia? This is certainly a question that is being imposed for research, regardless of the fact that voluntary sterilization is neither accessible nor promoted. Most importantly because there is no understanding in the social nor political sphere for legalization of voluntary sterilization as a form of birth control, apart from the clear necessity for this, first, step. They are: the recognition that voluntary sterilization is an efficient and safe birth control method, respectability of basic human as well as sexual and reproductive rights, spreading of sterilization as a form of birth control among population of both developed and developing countries and an epidemic diffusion of repeated induced abortions in Serbia. Thus individual recognition of the advantages of relying on voluntary sterilization, in a non-encouraging atmosphere, certainly represents one more argument to enable couples to prevent conception by sterilization. Since it was impossible to carry out a representative research among the population of men and women who are at risk for conception, an attempt was made to obtain a reply to the set question among women who decided to induce abortion. It was done out of at least two reasons. The first being that women with induced abortion in their reproductive history were the target group for voluntary sterilization. The second reason was based on the assumption that bringing a decision on induced abortion is preceded by the reconsideration of an earlier adopted strategy regarding children, giving birth and contraception and thus its rational component is revealed more and therefore more easily measurable. The research was carried out in the University Clinic of Obstetrics and Gynecology 'Narodni front' in Belgrade from January 21st o March 1st 2002, and included 296 women. By comparing the social and demographic characteristics of the female respondents, as well as

  15. A novel plasma source for sterilization of living tissues

    International Nuclear Information System (INIS)

    Martines, E; Zuin, M; Cavazzana, R; Gazza, E; Serianni, G; Spagnolo, S; Spolaore, M; Leonardi, A; Deligianni, V; Brun, P; Aragona, M; Castagliuolo, I; Brun, P

    2009-01-01

    A source for the production of low-power plasmas at atmospheric pressure, to be used for the nondamaging sterilization of living tissues, is presented. The source, powered by radiofrequency and working with a helium flow, has a specific configuration, studied to prevent the formation of electric arcs dangerous to living matter. It is capable of killing different types of bacteria with a decimal reduction time of 1-2 min; on the contrary, human cells such as conjunctival fibroblasts were found to be almost unharmed by the plasma. A high concentration of OH radicals, likely to be the origin of the sterilizing effect, is detected through their UV emission lines. The effect of the UV and the OH radicals on the fibroblasts was analysed and no significant effects were detected.

  16. Real-time appraisal of the spatially distributed heat related health risk and energy demand of cities

    Science.gov (United States)

    Keramitsoglou, Iphigenia; Kiranoudis, Chris T.; Sismanidis, Panagiotis

    2016-08-01

    The Urban Heat Island (UHI) is an adverse environmental effect of urbanization that increases the energy demand of cities, impacts the human health, and intensifies and prolongs heatwave events. To facilitate the study of UHIs the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens (IAASARS/NOA) has developed an operational real-time system that exploits remote sensing image data from Meteosat Second Generation - Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) and generates high spatiotemporal land surface temperature (LST) and 2 m air temperature (TA) time series. These datasets form the basis for the generation of higher value products and services related to energy demand and heat-related health issues. These products are the heatwave hazard (HZ); the HUMIDEX (i.e. an index that describes the temperature felt by an individual exposed to heat and humidity); and the cooling degrees (CD; i.e. a measure that reflects the energy needed to cool a building). The spatiotemporal characteristics of HZ, HUMIDEX and CD are unique (1 km/5 min) and enable the appraisal of the spatially distributed heat related health risk and energy demand of cities. In this paper, the real time generation of the high spatiotemporal HZ, HUMIDEX and CD products is discussed. In addition, a case study corresponding to Athens' September 2015 heatwave is presented so as to demonstrate their capabilities. The overall aim of the system is to provide high quality data to several different end users, such as health responders, and energy suppliers. The urban thermal monitoring web service is available at http://snf-652558.vm.okeanos.grnet.gr/treasure/portal/info.html.

  17. Unsteady axisymmetric flow and heat transfer over time-dependent radially stretching sheet

    Directory of Open Access Journals (Sweden)

    Azeem Shahzad

    2017-03-01

    Full Text Available This article address the boundary layer flow and heat transfer of unsteady and incompressible viscous fluid over an unsteady stretching permeable surface. First of all modeled nonlinear partial differential equations are transformed to a system of ordinary differential equations by using similarity transformations. Analytic solution of the reduced problem is constructed by using homotopy analysis method (HAM. To validate the constructed series solution a numerical counterpart is developed using shooting algorithm based on Runge-Kutta method. Both schemes are in an excellent agreement. The effects of the pertinent parameters on the velocity and energy profile are shown graphically and examined in detail.

  18. Early puerperal laparoscopic sterilization--a new technique.

    Directory of Open Access Journals (Sweden)

    Parulekar S

    1985-07-01

    Full Text Available This paper describes the results of 23 cases of puerperal laparoscopic sterilization performed within 72 hours of delivery. A new method was employed to avoid injury to the uterine fundus and to make the tubes more accessible. Before insertion of the Veress needle, the anterior and posterior lips of the cervix were held with forceps and Hulka′s uterine manipulator was introduced into the uterine cavity. The uterus was pulled down toward the introitus by applying traction to the sponge-holding forceps. Pneumoperitoneum of 3-4 liters was induced through use of a Veress needle, followed by introduction of a Storz single puncture operative laparoscope through an incision in the lower umbilical fold. Tubal occlusion was achieved with silastic bands. The average time required for sterilization from induction of general anesthesia was 6 minutes. There was no instance of injury to the uterine fundus, nor were there any cases of uterine perforation, injury to other pelvic structures, laceration of the cervix, or puerperal sepsis. At the time of follow-up 15 days after the procedure, all patients were in satisfactory condition. It is concluded that this method can enhance postpartum family planning programs. Since it can be carried out within the 1st 48 hours after delivery, the routine hospital stay of 3 days does not have to be prolonged as a result of sterilization.

  19. Approximate series solution of multi-dimensional, time fractional-order (heat-like) diffusion equations using FRDTM.

    Science.gov (United States)

    Singh, Brajesh K; Srivastava, Vineet K

    2015-04-01

    The main goal of this paper is to present a new approximate series solution of the multi-dimensional (heat-like) diffusion equation with time-fractional derivative in Caputo form using a semi-analytical approach: fractional-order reduced differential transform method (FRDTM). The efficiency of FRDTM is confirmed by considering four test problems of the multi-dimensional time fractional-order diffusion equation. FRDTM is a very efficient, effective and powerful mathematical tool which provides exact or very close approximate solutions for a wide range of real-world problems arising in engineering and natural sciences, modelled in terms of differential equations.

  20. The influence of sterilization on nitrogen-included ultrananocrystalline diamond for biomedical applications

    International Nuclear Information System (INIS)

    Tong, Wei; Tran, Phong A.; Turnley, Ann M.; Aramesh, Morteza; Prawer, Steven; Brandt, Milan; Fox, Kate

    2016-01-01

    Diamond has shown great potential in different biomedical applications, but the effects of sterilization on its properties have not been investigated. Here, we studied the influence of five sterilization techniques (solvent cleaning, oxygen plasma, UV irradiation, autoclave and hydrogen peroxide) on nitrogen-included ultrananocrystalline diamond. The chemical modification of the diamond surface was evaluated using X-ray photoelectron spectroscopy and water contact angle measurements. Different degrees of surface oxidation and selective sp 2 bonded carbon etching were found following all sterilization techniques, resulting in an increase of hydrophilicity. Higher viabilities of in vitro mouse 3T3 fibroblasts and rat cortical neuron cells were observed on oxygen plasma, autoclave and hydrogen peroxide sterilized diamond, which correlated with their higher hydrophilicity. By examination of apatite formation in simulated body fluid, in vivo bioactivity was predicted to be best on those surfaces which have been oxygen plasma treated and lowest on those which have been exposed to UV irradiation. The charge injection properties were also altered by the sterilization process and there appears to be a correlation between these changes and the degree of oxygen termination of the surface. We find that the modification brought by autoclave, oxygen plasma and hydrogen peroxide were most consistent with the use of N-UNCD in biological applications as compared to samples sterilized by solvent cleaning or UV exposure or indeed non-sterilized. A two-step process of sterilization by hydrogen peroxide following oxygen plasma treatment was then suggested. However, the final choice of sterilization technique will depend on the intended end application. - Highlights: • We test for the first time the effect of 5 sterilization techniques on nitrogen included ultrananocrystalline diamond. • Different degrees of surface oxidation and selective sp 2 bonded carbon etching were found to

  1. The influence of sterilization on nitrogen-included ultrananocrystalline diamond for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Wei [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Tran, Phong A. [Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria (Australia); Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland (Australia); Turnley, Ann M. [Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria (Australia); Aramesh, Morteza [School of Physics, University of Melbourne, Parkville, Victoria (Australia); School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland (Australia); Prawer, Steven [School of Physics, University of Melbourne, Parkville, Victoria (Australia); Brandt, Milan [Centre for Additive Manufacturing, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, Victoria (Australia); Fox, Kate, E-mail: kate.fox@rmit.edu.au [Centre for Additive Manufacturing, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, Victoria (Australia)

    2016-04-01

    Diamond has shown great potential in different biomedical applications, but the effects of sterilization on its properties have not been investigated. Here, we studied the influence of five sterilization techniques (solvent cleaning, oxygen plasma, UV irradiation, autoclave and hydrogen peroxide) on nitrogen-included ultrananocrystalline diamond. The chemical modification of the diamond surface was evaluated using X-ray photoelectron spectroscopy and water contact angle measurements. Different degrees of surface oxidation and selective sp{sup 2} bonded carbon etching were found following all sterilization techniques, resulting in an increase of hydrophilicity. Higher viabilities of in vitro mouse 3T3 fibroblasts and rat cortical neuron cells were observed on oxygen plasma, autoclave and hydrogen peroxide sterilized diamond, which correlated with their higher hydrophilicity. By examination of apatite formation in simulated body fluid, in vivo bioactivity was predicted to be best on those surfaces which have been oxygen plasma treated and lowest on those which have been exposed to UV irradiation. The charge injection properties were also altered by the sterilization process and there appears to be a correlation between these changes and the degree of oxygen termination of the surface. We find that the modification brought by autoclave, oxygen plasma and hydrogen peroxide were most consistent with the use of N-UNCD in biological applications as compared to samples sterilized by solvent cleaning or UV exposure or indeed non-sterilized. A two-step process of sterilization by hydrogen peroxide following oxygen plasma treatment was then suggested. However, the final choice of sterilization technique will depend on the intended end application. - Highlights: • We test for the first time the effect of 5 sterilization techniques on nitrogen included ultrananocrystalline diamond. • Different degrees of surface oxidation and selective sp{sup 2} bonded carbon etching were

  2. Power generation efficiency of an SOFC-PEFC combined system with time shift utilization of SOFC exhaust heat

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Shin' ya [Power Engineering Lab., Department of Electrical and Electronic Engineering, Kitami Institute of Technology, 165 Kouen-cho, Kitami, Hokkaido 0908507 (Japan)

    2010-01-15

    A microgrid, with little environmental impact, is developed by introducing a combined SOFC (solid oxide fuel cell) and PEFC (proton exchange membrane fuel cell) system. Although the SOFC requires a higher operation temperature compared to the PEFC, the power generation efficiency of the SOFC is higher. However, if high temperature exhaust heat may be used effectively, a system with higher total power generation efficiency can be built. Therefore, this paper investigates the operation of a SOFC-PEFC combined system, with time shift operation of reformed gas, into a microgrid with 30 houses in Sapporo, Japan. The SOFC is designed to correspond to base load operation, and the exhaust heat of the SOFC is used for production of reformed gas. This reformed gas is used for the production of electricity for the PEFC, corresponding to fluctuation load of the next day. Accordingly, the reformed gas is used with a time shift operation. In this paper, the relation between operation method, power generation efficiency, and amount of heat storage of the SOFC-PEFC combined system to the difference in power load pattern was investigated. The average power generation efficiency of the system can be maintained at nearly 48% on a representative day in February (winter season) and August (summer season). (author)

  3. Effect of heat-induced pain stimuli on pulse transit time and pulse wave amplitude in healthy volunteers.

    Science.gov (United States)

    van Velzen, Marit H N; Loeve, Arjo J; Kortekaas, Minke C; Niehof, Sjoerd P; Mik, Egbert G; Stolker, Robert J

    2016-01-01

    Pain is commonly assessed subjectively by interpretations of patient behaviour and/or reports from patients. When this is impossible the availability of a quantitative objective pain assessment tool based on objective physiological parameters would greatly benefit clinical practice and research beside the standard self-report tests. Vasoconstriction is one of the physiological responses to pain. The aim of this study was to investigate whether pulse transit time (PTT) and pulse wave amplitude (PWA) decrease in response to this vasoconstriction when caused by heat-induced pain. The PTT and PWA were measured in healthy volunteers, on both index fingers using photoplethysmography and electrocardiography. Each subject received 3 heat-induced pain stimuli using a Temperature-Sensory Analyzer thermode block to apply a controlled, increasing temperature from 32.0 °C to 50.0 °C to the skin. After reaching 50.0 °C, the thermode was immediately cooled down to 32.0 °C. The study population was divided into 2 groups with a time-interval between the stimuli 20s or 60s. The results showed a significant (p  Heat-induced pain causes a decrease of PTT and PWA. Consequently, it is expected that, in the future, PTT and PWA may be applied as objective indicators of pain, either beside the standard self-report test, or when self-report testing is impossible.

  4. The Effect of Air Plasma on Sterilization of Escherichia coli in Dielectric Barrier Discharge

    International Nuclear Information System (INIS)

    Hu Miao; Guo Yun

    2012-01-01

    In this work, a Dielectric Barrier Discharge (DBD) air plasma was used to sterilize Escherichia coli (E. coli) on the surface of medical Polyethylene Terephthalate (PET) film. The leakage of cellular DNA and protein by optical absorbance measurement at 260 nm and 280 nm, together with transmission electron microscopy (TEM) about cell morphology were performed after sterilization to analyse inactivation mechanisms. The results indicated that the DBD air plasma was very effective in E. coli sterilization. The plasma germicidal efficiency depended on the plasma treatment time, the air-gap distance, and the applied voltage. Within 5 min of plasma treatment, the germicidal efficiency against E. coli could reach 99.99%. An etching action on cell membranes by electrons, ions and radicals is the primary mechanism for DBD air plasma sterilization, which leads to the effusion of cellular contents (DNA and protein) and bacterial death. (plasma technology)

  5. Determination of the sterile release rate for stopping growing age-structured populations

    International Nuclear Information System (INIS)

    Barclay, Hugh John

    2016-01-01

    A freely-growing age-structured population was modelled for growth and control by sterile male releases. Equilibrium populations yield critical sterile male release rates that would hold the population at equilibrium. It is shown here that these rates may be different from the release rates required to stop a growing population and bring it to an equilibrium. A computer simulation was constructed of this population and a parameter sensitivity analysis graphed the effects on the required sterile male release rate of fertility, mating delay in adult females, net juvenile survivorship, three adult survivorship curves, the time spent in the juvenile stages, and total life span. The adult survivorship curves had the greatest effect on the required sterile release rate for population elimination. The required release rate was also determined for Ceratitis capitata (Wiedemann) using survivorship and fertility data from a laboratory strain. The concepts of over-flooding ratio and release ratio were discussed and quantified for the cases above. (author)

  6. Evaluation of two disinfection/sterilization methods on silicon rubber-based composite finishing instruments.

    Science.gov (United States)

    Lacerda, Vánia A; Pereira, Leandro O; Hirata JUNIOR, Raphael; Perez, Cesar R

    2015-12-01

    To evaluate the effectiveness of disinfection/sterilization methods and their effects on polishing capacity, micomorphology, and composition of two different composite fiishing and polishing instruments. Two brands of finishing and polishing instruments (Jiffy and Optimize), were analyzed. For the antimicrobial test, 60 points (30 of each brand) were used for polishing composite restorations and submitted to three different groups of disinfection/sterilization methods: none (control), autoclaving, and immersion in peracetic acid for 60 minutes. The in vitro tests were performed to evaluate the polishing performance on resin composite disks (Amelogen) using a 3D scanner (Talyscan) and to evaluate the effects on the points' surface composition (XRF) and micromorphology (MEV) after completing a polishing and sterilizing routine five times. Both sterilization/disinfection methods were efficient against oral cultivable organisms and no deleterious modification was observed to point surface.

  7. Infection rate of toxoplasma gondii and age distribution in female patients with sterility

    International Nuclear Information System (INIS)

    Li Shuhong; Dai Pei; Cui Liming; Zong Shan; Zuo Wenjing

    2006-01-01

    Objective: To discuss the relationship between the infection of Toxoplasma gondii and female sterility. Methods: Toxoplasma gondii serum antibody were determined in 882 women with sterility (experimental group) and 107 normal bearing women (control group) by using ELISA. At the same time the differences of the infection with Toxoplasma gondii between the ages of the sterility women were analyzed. Results: The positive rate in experimental group was 15.87% (140/882), the positive rate in control group was 5.61% (6/107), remarkable difference was found between two groups (P<0.01). The infection rate in the different age groups (20-24, 25-29, 30-34, 35-39 and ≥40) is 5.63%, 15.24%, 17.91%, 19.44% and 15.38%. Conclusion: Toxoplasma gondii infection may be one of the factors which can cause sterility, and the infection rates at different ages have no instinct differences. (authors)

  8. [Paper on sterilization in the family planning programs of Colombia: a national debate].

    Science.gov (United States)

    Rizo, A; Roper, L

    1986-01-01

    During 1984, family planning became the object of heated public debate in Colombia. In particular, considerable controversy surrounded the practice of sterilization. In Colombia in 1980, 49% of married women were practicing family planning. The main protagonist has been Profamilia, an IPPF affliate, which runs clinics and advisory services throughout Colombia. Sterilization is performed quite extensively on men of at least 28 years and women of 25 with 3 living children. Further activities of Profamilia include community distribution and social marketing programs. Many of the health facilities used are those of the Ministry of Public Health. The Minister of Health responded to criticism levelled by the Catholic church and others by instituting an investigation into alleged practices of mass sterilization. Profamilia declared publicy that sterilization was performed only under certain conditions, after waiting periods, and under no circumstances with coersion. Various groups including medical associations publicy supported Profamilia. Although recognizing the need for families to be limited in size, religious and other commentators suggested that sterilization was often presented as a solution to family ills, and that it represented foreign involvement in Colombian social policy. The opposing opinions were that church-supported natural family planning was not an effective enough strategy. The ministry has resolved to invoke more stringent screening of women desiring sterilization to include natural family planning in its programs, and to deal with international organizations only on the ministry level. The number of sterilizations has diminished. The controversy helped to expose political weaknesses of Profamilia's programs (e.g. the use of monetary incentives; lack of supervision).

  9. On the reconstruction of inclusions in a heat conductive body from dynamical boundary data over a finite time interval

    International Nuclear Information System (INIS)

    Ikehata, Masaru; Kawashita, Mishio

    2010-01-01

    The enclosure method was originally introduced for inverse problems concerning non-destructive evaluation governed by elliptic equations. It was developed as one of the useful approaches in inverse problems and applied for various equations. In this paper, an application of the enclosure method to an inverse initial boundary value problem for a parabolic equation with a discontinuous coefficient is given. A simple method to extract the depth of unknown inclusions in a heat conductive body from a single set of the temperature and heat flux on the boundary observed over a finite time interval is introduced. Other related results with infinitely many data are also reported. One of them gives the minimum radius of the open ball centred at a given point that contains the inclusions. The formula for the minimum radius is newly discovered

  10. A homemade high-resolution orthogonal-injection time-of-flight mass spectrometer with a heated capillary inlet

    International Nuclear Information System (INIS)

    Guo Changjuan; Huang Zhengxu; Gao Wei; Nian Huiqing; Chen Huayong; Dong Junguo; Shen Guoying; Fu Jiamo; Zhou Zhen

    2008-01-01

    We describe a homemade high-resolution orthogonal-injection time-of-flight (O-TOF) mass spectrometer combing a heated capillary inlet. The O-TOF uses a heated capillary tube combined with a radio-frequency only quadrupole (rf-only quadrupole) as an interface to help the ion transmission from the atmospheric pressure to the low-pressure regions. The principle, configuration of the O-TOF, and the performance of the instrument are introduced in this paper. With electrospray ion source, the performances of the mass resolution, the sensitivity, the mass range, and the mass accuracy are described. We also include our results obtained by coupling atmospheric pressure matrix-assisted laser deporption ionization with this instrument

  11. Twenty years of radiation sterilization in Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Razem, Dusan E-mail: razem@irb.hr

    2004-10-01

    The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m{sup 3} kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m{sup 3} kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made.

  12. Effect of short-term heat acclimation on endurance time and skin blood flow in trained athletes

    Directory of Open Access Journals (Sweden)

    Chen TI

    2013-06-01

    Full Text Available Tsung-I Chen,1,2 Pu-Hsi Tsai,3 Jui-Hsing Lin,4 Ning-Yuean Lee,5 Michael TC Liang61Graduate Institute of Sport Science, National Taiwan Sport University, Taoyuan, 2Center for Physical Education, Tzu Chi University, Hualien, 3Department of Sport and Leisure, National Quemoy University, Kinmen, 4Department of Physical Education, National Pingtung University of Education, Pingtung, 5College of Living Technology, Tainan University of Technology, Tainan, Taiwan; 6Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA, USABackground: To examine whether short-term, ie, five daily sessions, vigorous dynamic cycling exercise and heat exposure could achieve heat acclimation in trained athletes and the effect of heat acclimation on cutaneous blood flow in the active and nonactive limb.Methods: Fourteen male badminton and table tennis athletes (age = 19.6 ± 1.2 years were randomized into a heat acclimation (EXP, n = 7 or nonheat acclimation (CON, n = 7 group. For 5 consecutive days, the EXP group was trained using an upright leg cycle ergometer in a hot environment (38.4°C ± 0.4°C, while the CON group trained in a thermoneutral environment (24.1°C ± 0.3°C. For both groups, the training intensity and duration increased from a work rate of 10% below ventilatory threshold (VT and 25 minutes per session on day 1, to 10% above VT and 45 minutes per session on day 5. Subjects performed two incremental leg cycle exercise tests to exhaustion at baseline and post-training in both hot and thermoneutral conditions. Study outcome measurements include: maximum oxygen uptake (VO2max; exercise heart rate (HR; O2 pulse; exercise time to exhaustion (tmax; skin blood flow in the upper arm (SkBFa and quadriceps (SkBFq; and mean skin (Tsk.Results: The significant heat-acclimated outcome measurements obtained during high-intensity leg cycling exercise in the high ambient environment are: (1 56%–100% reduction in cutaneous

  13. Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene

    OpenAIRE

    Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

    2016-01-01

    Nuclear male sterility is common in flowering plants, but its application in hybrid breeding and seed production is limited because of the inability to propagate a pure male sterile line for commercial hybrid seed production. Here, we characterized a rice nuclear gene essential for sporophytic male fertility and constructed a male sterility system that can propagate the pure male sterile seeds on a large scale. This system is fundamentally advantageous over the current cytoplasmic male steril...

  14. Phenology, sterility and inheritance of two environment genic male sterile (EGMS) lines for hybrid rice

    NARCIS (Netherlands)

    El-Namaky, R.; Oort, van P.A.J.

    2017-01-01

    Background: There is still limited quantitative understanding of how environmental factors affect sterility of Environment-conditioned genic male sterility (EGMS) lines. A model was developed for this purpose and tested based on experimental data from Ndiaye (Senegal) in 2013-2015. For the two

  15. Extended stability of intravenous 0.9% sodium chloride solution after prolonged heating or cooling.

    Science.gov (United States)

    Puertos, Enrique

    2014-03-01

    The primary objective of this study was to evaluate the stability and sterility of an intravenous 0.9% sodium chloride solution that had been cooled or heated for an extended period of time. Fifteen sterile 1 L bags of 0.9% sodium chloride solution were randomly selected for this experiment. Five bags were refrigerated at an average temperature of 5.2°C, 5 bags were heated at an average temperature of 39.2°C, and 5 bags were stored at an average room temperature of 21.8°C to serve as controls. All samples were protected from light and stored for a period of 199 days prior to being assayed and analyzed for microbial and fungal growth. There was no clinically significant difference in the mean sodium values between the refrigerated samples, the heated samples, and the control group. There were no signs of microbial or fungal growth for the duration of the study. A sterile intravenous solution of 0.9% sodium chloride that was heated or cooled remained stable and showed no signs of microbial or fungal growth for a period of 199 days. This finding will allow hospitals and emergency medical technicians to significantly extend the expiration date assigned to these fluids and therefore obviate the need to change out these fluids every 28 days as recommended by the manufacturer.

  16. Predicting outgrowth and inactivation of Clostridium perfringens in meat products during low temperature long time heat treatment

    DEFF Research Database (Denmark)

    Duan, Zhi; Hansen, Terese Holst; Hansen, Tina Beck

    2016-01-01

    With low temperature long time (LTLT) cooking it can take hours for meat to reach a final core temperature above 53 °C and germination followed by growth of Clostridium perfringens is a concern. Available and new growth data in meats including 154 lag times (tlag), 224 maximum specific growth rates...... (μmax) and 25 maximum population densities (Nmax) were used to developed a model to predict growth of C. perfringens during the coming-up time of LTLT cooking. New data were generate in 26 challenge tests with chicken (pH 6.8) and pork (pH 5.6) at two different slowly increasing temperature (SIT...... the SIT profiles. Similar results were found for non-heated and heated spores in chicken, whereas in pork C. perfringens 790-94 increased less than 1 log CFU/g. At 53 °C C. perfringens 790-94 was log-linearly inactivated. Observed and predicted concentrations of C. perfringens, at the time when 53 °C (log...

  17. Time-resolved plasma spectroscopy of thin foils heated by a relativistic-intensity short-pulse laser

    International Nuclear Information System (INIS)

    Audebert, P.; Gauthier, J.-C.; Shepherd, R.; Fournier, K.B.; Price, D.; Lee, R.W.; Springer, P.; Peyrusse, O.; Klein, L.

    2002-01-01

    Time-resolved K-shell x-ray spectra are recorded from sub-100 nm aluminum foils irradiated by 150-fs laser pulses at relativistic intensities of Iλ 2 =2x10 18 W μm 2 /cm 2 . The thermal penetration depth is greater than the foil thickness in these targets so that uniform heating takes place at constant density before hydrodynamic motion occurs. The high-contrast, high-intensity laser pulse, broad spectral band, and short time resolution utilized in this experiment permit a simplified interpretation of the dynamical evolution of the radiating matter. The observed spectrum displays two distinct phases. At early time, ≤500 fs after detecting target emission, a broad quasicontinuous spectral feature with strong satellite emission from multiply excited levels is seen. At a later time, the He-like resonance line emission is dominant. The time-integrated data is in accord with previous studies with time resolution greater than 1 ps. The early time satellite emission is shown to be a signature of an initial large area, high density, low-temperature plasma created in the foil by fast electrons accelerated by the intense radiation field in the laser spot. We conclude that, because of this early time phenomenon and contrary to previous predictions, a short, high-intensity laser pulse incident on a thin foil does not create a uniform hot and dense plasma. The heating mechanism has been studied as a function of foil thickness, laser pulse length, and intensity. In addition, the spectra are found to be in broad agreement with a hydrodynamic expansion code postprocessed by a collisional-radiative model based on superconfiguration average rates and on the unresolved transition array formalism

  18. Genetic technologies to enhance the Sterile Insect Technique (SIT)

    International Nuclear Information System (INIS)

    Alphey, Luke; Baker, Pam; Condon, George C.; Condon, Kirsty C.; Dafa'alla, Tarig H.; Fu, Guoliang; Jin, Li; Labbe, Genevieve; Morrison, Neil M.; Nimmo, Derric D.; O'Connell, Sinead; Phillips, Caroline E.; Plackett, Andrew; Scaife, Sarah; Woods, Alexander; Burton, Rosemary S.; Epton, Matthew J.; Gong, Peng

    2006-01-01

    The Sterile Insect Technique (SIT) has been used very successfully against range of pest insects, including various tephritid fruit flies, several moths and a small number of livestock pests. However, modern genetics could potentially provide several improvements that would increase the cost-effectiveness of SIT, and extend the range of suitable species. These include improved identification of released individuals by incorporation of a stable, heritable, genetic marker; built-in sex separation (genetic sexing); reduction of the hazard posed by non-irradiated accidental releases from mass-rearing facility (fail-safe); elimination of the need for sterilization by irradiation (genetic sterilization). We discuss applications of these methods and the state of the art, at the time of this meeting, in developing suitable strains. We have demonstrated, in several key pest species, that the required strains can be constructed by introducing a repressible dominant lethal genetic system, a method known as RIDL(trade mark). Based on field experience with Medfly, incorporation of a genetic sexing system into SIT programs for other tephritids could potentially provide a very significant improvement in cost-effectiveness. We have now been able to make efficient female-lethal strains for Medfly. One advantage of our approach is that it should be possible rapidly to extend this technology to other fruit fly species; indeed we have recently been able also to make genetic sexing strains of Medfly (Anastrepha ludens). (author)

  19. Genetic technologies to enhance the Sterile Insect Technique (SIT)

    Energy Technology Data Exchange (ETDEWEB)

    Alphey, Luke; Baker, Pam; Condon, George C; Condon, Kirsty C; Dafa' alla, Tarig H; Fu, Guoliang; Jin, Li; Labbe, Genevieve; Morrison, Neil M; Nimmo, Derric D; O' Connell, Sinead; Phillips, Caroline E; Plackett, Andrew; Scaife, Sarah; Woods, Alexander [Oxitec Ltd., Oxford (United Kingdom); Burton, Rosemary S; Epton, Matthew J; Gong, Peng [University of Oxford (United Kingdom). Dept. of Zoology

    2006-07-01

    The Sterile Insect Technique (SIT) has been used very successfully against range of pest insects, including various tephritid fruit flies, several moths and a small number of livestock pests. However, modern genetics could potentially provide several improvements that would increase the cost-effectiveness of SIT, and extend the range of suitable species. These include improved identification of released individuals by incorporation of a stable, heritable, genetic marker; built-in sex separation (genetic sexing); reduction of the hazard posed by non-irradiated accidental releases from mass-rearing facility (fail-safe); elimination of the need for sterilization by irradiation (genetic sterilization). We discuss applications of these methods and the state of the art, at the time of this meeting, in developing suitable strains. We have demonstrated, in several key pest species, that the required strains can be constructed by introducing a repressible dominant lethal genetic system, a method known as RIDL(trade mark). Based on field experience with Medfly, incorporation of a genetic sexing system into SIT programs for other tephritids could potentially provide a very significant improvement in cost-effectiveness. We have now been able to make efficient female-lethal strains for Medfly. One advantage of our approach is that it should be possible rapidly to extend this technology to other fruit fly species; indeed we have recently been able also to make genetic sexing strains of Medfly (Anastrepha ludens). (author)

  20. Radiation sterilization of medical products in the Philippines

    International Nuclear Information System (INIS)

    Singson, C.; Carmona, C.; Guzman, Z. de; Barrun, W.; Lanuza, L.

    1983-01-01

    This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. (author)

  1. Radiation sterilization of medical products in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Singson, C; Carmona, C; Guzman, Z de; Barrun, W; Lanuza, L [Philippine Atomic Energy Commission, Diliman, Quezon City

    1983-01-01

    This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D/sub 10/ values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged.

  2. Axion-assisted production of sterile neutrino dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Berlin, Asher; Hooper, Dan

    2017-04-12

    Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line searches, however, have excluded the simplest of such models. In this letter, we propose a novel alternative to the standard scenario in which the mixing angle between the sterile and active neutrinos is a dynamical quantity, induced through interactions with a light axion-like field. As the energy density of the axion-like particles is diluted by Hubble expansion, the degree of mixing is reduced at late times, suppressing the decay rate and easily alleviating any tension with X-ray or gamma-ray constraints. We present a simple model which illustrates the phenomenology of this scenario, and also describe a framework in which the QCD axion is responsible for the production of sterile neutrinos in the early universe.

  3. Dose setting for radiation sterilization of dialyzers, (2)

    International Nuclear Information System (INIS)

    Kigawa, Akiko; Tateishi, Tsuneo; Iso, Katsuaki; Kimura, Toshio; Mamuro, Tetsuo; Misawa, Sho.

    1986-01-01

    It was found in the preceding study that the strain that showed the highest radiation resistance among the strains washed out of dializers not yet sterilzed was Bacillus megaterium and the D-value of its spore was about 40 percent higher than that of B. pumilus ATCC 27142 spore. In the present study, bundles of hollow fibers were inoculated with spores of both the B. megaterium and the B. pumilus and D-values of the spores were measured to be 0.24 7 and 0.16 9 Mrad, respectively. The dializer is consisted of several materials. Sterilization effect of gamma-ray irradiation is the least for hollow fibers, because they contain glycerin. It is concluded that 10 6 sterility assurance is achieved by setting the sterilization dose at 2.0 Mrad, about eight times of the D-value for the B. megaterium under the condition that the number of contaminants per product is less than 100. (author)

  4. Effectiveness of various sterilization methods of contaminated post-fitted molar band

    Directory of Open Access Journals (Sweden)

    Anggia Tridianti

    2013-06-01

    Full Text Available Background: Molar band as anchoring device may be contaminated during the fitting process. Thus, decontamination process is essential to prevent cross-infection between patients. Purpose: The objective of this research was to determine the amount of bacteria in molar band post-fitted on the patient teeth, after previously undergone pre-sterilization using alcohol and ultrasonic cleaning bath followed by sterilization using dry heat oven and steam autoclave, in order to find the best method in decontamination of post-fitted molar band. Methods: Four molar bands which already fitted on one patient then divided evenly into two groups. The first group was pre-sterilized using alcohol. One of the bands then sterilized using dry heat oven, while the other one was sterilized using steam autoclave. The second group was pre-sterilized using ultrasonic cleaning bath. One band from this group then sterilized using dry heat oven and the other was sterilized using steam autoclave. The next step was to immerse all the bands in a phosphate-buffered saline solution. Using micropipette, the solution was retrieved and dropped upon a petri dish containing Brain Heart Infusion broth. The dish was then stored in an incubator for 24 hours, prior to counting the number of bacteria existed. The same methods were used to the rest of the patients, with total 128 molar bands from 32 patients. Results: There was a profound difference in numbers of bacteria found between those methods of sterilization. However, there was a non significant difference between the two groups which were at the alcohol-steam autoclave group and at the ultrasonic cleaning bath-steam autoclave group. Conclusion: This study showed that steam autoclave is better than for sterilizing molar band, as it left the minimal amount of bacteria in post-fitted molar band.Latar belakang: Molar band merupakan suatu alat penjangkaran yang dapat mengalami kontaminasi selama proses fitting band, sehingga perlu

  5. 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)

  6. Gamma radiation sterilized amnion: use in ophthalmology

    International Nuclear Information System (INIS)

    Martinez P, M. E.; Leon T, Y.; Vazquez M, L.

    2010-10-01

    Amnion processed at the Radio sterilized Tissue Bank at the National Institute of Nuclear Research, sterilized with 60 Co gamma radiation, have been used in Mexico since 2005 either as a graft to replace the damaged ocular surface, or as a patch to prevent unwanted inflammatory reactions. Patients from the Hospital General de Mexico (HGM) and Instituto Mexicano del Seguro Social (IMSS), suffering diverse pathologies such as keratoconjunctivitis; recurrent pterygium associated with symblepharon; corneal neuro trophic ulcers, chemical and thermal burns, and corneal thinning s, had been successfully treated with irradiated amnion. In the HGM, a clinical prospective study on lesions of the ocular surface of 17 eyes from 15 patients, affected with the above mentioned pathologies, was successful in 88.2%. The results have proven to be excellent as much for cosmetic purposes as for functional ones. Without the treatment, the patients could have suffered a healing after-effect or loss of sight. At IMSS, a controlled clinical randomized trial with 108 eyes from 100 patients, affected with primary nasal pterygium, was performed in 2009. These eyes were treated with radio sterilized amnion and intraoperative mitomycin C to prevent recurrence after excision of the primary pterygium. The preliminary results do not shown adverse reaction, inflammation and pain were significantly reduced radio sterilized amnion also offer security because they do no express antigens HLA-A, B or Dr and the sterile irradiated tissue do not provoke rejection or transmit an infective disease. (Author)

  7. Gamma radiation sterilized amnion: use in ophthalmology

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Leon T, Y. [Hospital General Regional 220, IMSS, Paseo Tollocan No. 620, Col. Vertice, Toluca 50150, Estado de Mexico (Mexico); Vazquez M, L., E-mail: esther.martinez@inin.gob.m [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06720 Mexico D. F. (Mexico)

    2010-10-15

    Amnion processed at the Radio sterilized Tissue Bank at the National Institute of Nuclear Research, sterilized with {sup 60}Co gamma radiation, have been used in Mexico since 2005 either as a graft to replace the damaged ocular surface, or as a patch to prevent unwanted inflammatory reactions. Patients from the Hospital General de Mexico (HGM) and Instituto Mexicano del Seguro Social (IMSS), suffering diverse pathologies such as keratoconjunctivitis; recurrent pterygium associated with symblepharon; corneal neuro trophic ulcers, chemical and thermal burns, and corneal thinning s, had been successfully treated with irradiated amnion. In the HGM, a clinical prospective study on lesions of the ocular surface of 17 eyes from 15 patients, affected with the above mentioned pathologies, was successful in 88.2%. The results have proven to be excellent as much for cosmetic purposes as for functional ones. Without the treatment, the patients could have suffered a healing after-effect or loss of sight. At IMSS, a controlled clinical randomized trial with 108 eyes from 100 patients, affected with primary nasal pterygium, was performed in 2009. These eyes were treated with radio sterilized amnion and intraoperative mitomycin C to prevent recurrence after excision of the primary pterygium. The preliminary results do not shown adverse reaction, inflammation and pain were significantly reduced radio sterilized amnion also offer security because they do no express antigens HLA-A, B or Dr and the sterile irradiated tissue do not provoke rejection or transmit an infective disease. (Author)

  8. Sterilization and disinfection: the prevailing indifference

    International Nuclear Information System (INIS)

    Mirza, I.

    2007-01-01

    To evaluate the knowledge and attitude of health care professionals towards the process of sterilization and disinfection, and to check the adequacy of the reading material accessible to them. The study comprised of three components. In the first part, sections devoted to this subject in the popular books read by the students of operation theatre assistant course and students of diploma in general nursing were examined for adequacy and authenticity of information. In the second part, standard operating procedures were examined regarding sterilization of textile, rubber tubes of suction units and diathermy hand pieces of 20 operation theatres of three teaching hospital attached to undergraduate medical college of Punjab. In the third part of the study, working knowledge of 64 practicing operation theatre assistants and 57 practicing nurses was assessed through a questionnaire. It was found that popular books either did not contain the required information or the information provided was misleading or incorrect. Standard operating procedures for sterilization of selected items of all the operation theatres studied fell much below the standard of practice desired in the light of current knowledge and contemporary practices. Finally the working knowledge of the professionals studied was much below the bare minimum expected by the profession. There is a dire need for upgrading the knowledge and attitude of health care professionals regarding sterilization, besides improving the operation theatres sterilization procedures. (author)

  9. Optimal technology choice and investment timing: A stochastic model of industrial cogeneration vs. heat-only production

    International Nuclear Information System (INIS)

    Wickart, Marcel; Madlener, Reinhard

    2007-01-01

    In this paper we develop an economic model that explains the decision-making problem under uncertainty of an industrial firm that wants to invest in a process technology. More specifically, the decision is between making an irreversible investment in a combined heat-and-power production (cogeneration) system, or to invest in a conventional heat-only generation system (steam boiler) and to purchase all electricity from the grid. In our model we include the main economic and technical variables of the investment decision process. We also account for the risk and uncertainty inherent in volatile energy prices that can greatly affect the valuation of the investment project. The dynamic stochastic model presented allows us to simultaneously determine the optimal technology choice and investment timing. We apply the theoretical model and illustrate our main findings with a numerical example that is based on realistic cost values for industrial oil- or gas-fired cogeneration and heat-only generation in Switzerland. We also briefly discuss expected effects of a CO 2 tax on the investment decision

  10. Indoor Solar Thermal Energy Saving Time with Phase Change Material in a Horizontal Shell and Finned-Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    S. Paria

    2015-01-01

    Full Text Available An experimental as well as numerical investigation was conducted on the melting/solidification processes of a stationary phase change material (PCM in a shell around a finned-tube heat exchanger system. The PCM was stored in the horizontal annular space between a shell and finned-tube where distilled water was employed as the heat transfer fluid (HTF. The focus of this study was on the behavior of PCM for storage (charging or melting and removal (discharging or solidification, as well as the effect of flow rate on the charged and discharged solar thermal energy. The impact of the Reynolds number was determined and the results were compared with each other to reveal the changes in amount of stored thermal energy with the variation of heat transfer fluid flow rates. The results showed that, by increasing the Reynolds number from 1000 to 2000, the total melting time decreases by 58%. The process of solidification also will speed up with increasing Reynolds number in the discharging process. The results also indicated that the fluctuation of gradient temperature decreased and became smooth with increasing Reynolds number. As a result, by increasing the Reynolds number in the charging process, the theoretical efficiency rises.

  11. Indoor solar thermal energy saving time with phase change material in a horizontal shell and finned-tube heat exchanger.

    Science.gov (United States)

    Paria, S; Sarhan, A A D; Goodarzi, M S; Baradaran, S; Rahmanian, B; Yarmand, H; Alavi, M A; Kazi, S N; Metselaar, H S C

    2015-01-01

    An experimental as well as numerical investigation was conducted on the melting/solidification processes of a stationary phase change material (PCM) in a shell around a finned-tube heat exchanger system. The PCM was stored in the horizontal annular space between a shell and finned-tube where distilled water was employed as the heat transfer fluid (HTF). The focus of this study was on the behavior of PCM for storage (charging or melting) and removal (discharging or solidification), as well as the effect of flow rate on the charged and discharged solar thermal energy. The impact of the Reynolds number was determined and the results were compared with each other to reveal the changes in amount of stored thermal energy with the variation of heat transfer fluid flow rates. The results showed that, by increasing the Reynolds number from 1000 to 2000, the total melting time decreases by 58%. The process of solidification also will speed up with increasing Reynolds number in the discharging process. The results also indicated that the fluctuation of gradient temperature decreased and became smooth with increasing Reynolds number. As a result, by increasing the Reynolds number in the charging process, the theoretical efficiency rises.

  12. Laser-induced heating integrated with a microfluidic platform for real-time DNA replication and detection

    Science.gov (United States)

    Hung, Min-Sheng; Ho, Chia-Chin; Chen, Chih-Pin

    2016-08-01

    This study developed a microfluidic platform for replicating and detecting DNA in real time by integrating a laser and a microfluidic device composed of polydimethylsiloxane. The design of the microchannels consisted of a laser-heating area and a detection area. An infrared laser was used as the heating source for DNA replication, and the laser power was adjusted to heat the solutions directly. In addition, strong biotin-avidin binding was used to capture and detect the replicated products. The biotin on one end was bound to avidin and anchored to the surface of the microchannels, whereas the biotin on the other end was bound to the quantum dots (Qdots). The results showed that the fluorescent intensity of the Qdots bound to the replicated products in the detection area increased with the number of thermal cycles created by the laser. When the number of thermal cycles was ≥10, the fluorescent intensity of the Qdots was directly detectable on the surface of the microchannels. The proposed method is more sensitive than detection methods entailing gel electrophoresis.

  13. Heat transfer analytical models for the rapid determination of cooling time in crystalline thermoplastic injection molding and experimental validation

    Science.gov (United States)

    Didier, Delaunay; Baptiste, Pignon; Nicolas, Boyard; Vincent, Sobotka

    2018-05-01

    Heat transfer during the cooling of a thermoplastic injected part directly affects the solidification of the polymer and consequently the quality of the part in term of mechanical properties, geometric tolerance and surface aspect. This paper proposes to mold designers a methodology based on analytical models to provide quickly the time to reach the ejection temperature depending of the temperature and the position of cooling channels. The obtained cooling time is the first step of the thermal conception of the mold. The presented methodology is dedicated to the determination of solidification time of a semi-crystalline polymer slab. It allows the calculation of the crystallization time of the part and is based on the analytical solution of the Stefan problem in a semi-infinite medium. The crystallization is then considered as a phase change with an effective crystallization temperature, which is obtained from Fast Scanning Calorimetry (FSC) results. The crystallization time is then corrected to take the finite thickness of the part into account. To check the accuracy of such approach, the solidification time is calculated by solving the heat conduction equation coupled to the crystallization kinetics of the polymer. The impact of the nature of the contact between the polymer and the mold is evaluated. The thermal contact resistance (TCR) appears as significant parameter that needs to be taken into account in the cooling time calculation. The results of the simplified model including or not TCR are compared in the case of a polypropylene (PP) with experiments carried out with an instrumented mold. Then, the methodology is applied for a part made with PolyEtherEtherKetone (PEEK).

  14. Ionizing radiation for sterilization of medical products and biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S K; Raghevendrarao, M K [Bhabha Atomic Research Centre, Bombay (India). Library and Technical Information Section

    1975-10-01

    The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products.

  15. Effect of Dry Heat Pre-Treatment (Toasting) on the Cooking Time of ...

    African Journals Online (AJOL)

    The cooking time for IAR48 and IT89KD-288 cowpea varieties increased from 104.67 to 106.00 and 88.00 to 88.67 min, respectively. The results indicate that the cooking time of cowpea seeds can be reduced significantly on toasting, while maintaining their potential as functional agents in the food industry for nutrition and ...

  16. Electricity and combined heat and power from municipal solid waste; theoretically optimal investment decision time and emissions trading implications.

    Science.gov (United States)

    Tolis, Athanasios; Rentizelas, Athanasios; Aravossis, Konstantin; Tatsiopoulos, Ilias

    2010-11-01

    Waste management has become a great social concern for modern societies. Landfill emissions have been identified among the major contributors of global warming and climate changes with significant impact in national economies. The energy industry constitutes an additional greenhouse gas emitter, while at the same time it is characterized by significant costs and uncertain fuel prices. The above implications have triggered different policies and measures worldwide to address the management of municipal solid wastes on the one hand and the impacts from energy production on the other. Emerging methods of energy recovery from waste may address both concerns simultaneously. In this work a comparative study of co-generation investments based on municipal solid waste is presented, focusing on the evolution of their economical performance over time. A real-options algorithm has been adopted investigating different options of energy recovery from waste: incineration, gasification and landfill biogas exploitation. The financial contributors are identified and the impact of greenhouse gas trading is analysed in terms of financial yields, considering landfilling as the baseline scenario. The results indicate an advantage of combined heat and power over solely electricity production. Gasification, has failed in some European installations. Incineration on the other hand, proves to be more attractive than the competing alternatives, mainly due to its higher power production efficiency, lower investment costs and lower emission rates. Although these characteristics may not drastically change over time, either immediate or irreversible investment decisions might be reconsidered under the current selling prices of heat, power and CO(2) allowances.

  17. Gas flow characteristics of a time modulated APPJ: the effect of gas heating on flow dynamics

    International Nuclear Information System (INIS)

    Zhang, S; Sobota, A; Van Veldhuizen, E M; Bruggeman, P J

    2015-01-01

    This work investigates the flow dynamics of a radio-frequency (RF) non-equilibrium argon atmospheric pressure plasma jet. The RF power is at a frequency of 50 Hz or 20 kHz. Combined flow pattern visualizations (obtained by shadowgraphy) and gas temperature distributions (obtained by Rayleigh scattering) are used to study the formation of transient vortex structures in initial flow field shortly after the plasma is switched on and off in the case of 50 Hz modulation. The transient vortex structures correlate well with observed temperature differences. Experimental results of the fast modulated (20 kHz) plasma jet that does not induce changes of the gas temperature are also presented. The latter result suggests that momentum transfer by ions does not have dominant effect on the flow pattern close to the tube. It is argued that the increased gas temperature and corresponding gas velocity increase at the tube exit due to the plasma heating increases the admixing of surrounding air and reduces the effective potential core length. With increasing plasma power a reduction of the effective potential core length is observed with a minimum length for 5.6 W after which the length extends again. Possible mechanisms related to viscosity effects and ionic momentum transfer are discussed. (paper)

  18. Testosterone as a Bio marker for Rapid Detection of Male Sterility of the Mediterranean Fruit Fly, Ceratitis Capitata (Wied.)

    International Nuclear Information System (INIS)

    Shoman, A.A.; El-Arab, A.E.; Aly, M.S.A.

    2000-01-01

    A rapid biochemical method for the determination of the sterility in males of the fruit fly, Ceratitis Capitata (Wied.) was established utilizing testosterone as a bio marker. Pupae (2 days before emergence) were irradiated at 90 Gy using a 60 Co-gamma-cell, unit. Testosterone level, measured by radioimmunoassay (RIA), in addition to sterility in irradiated male flies were compared to their corresponding values of the untreated control group. The data obtained revealed a highly significant decrease in the testosterone level associated with a highly significant decrease in sterility. The decrease in the hormone level was recognized during the different time intervals (24-120 hours after adult emergence). This bio marker (Testosterone) could be adopted as a rapid monitor for measurements of medfly male sterility before release in the field in a sterile insect technique (SIT) program

  19. Heat transfer

    International Nuclear Information System (INIS)

    Saad, M.A.

    1985-01-01

    Heat transfer takes place between material systems as a result of a temperature difference. The transmission process involves energy conversions governed by the first and second laws of thermodynamics. The heat transfer proceeds from a high-temperature region to a low-temperature region, and because of the finite thermal potential, there is an increase in entropy. Thermodynamics, however, is concerned with equilibrium states, which includes thermal equilibrium, irrespective of the time necessary to attain these equilibrium states. But heat transfer is a result of thermal nonequilibrium conditions, therefore, the laws of thermodynamics alone cannot describe completely the heat transfer process. In practice, most engineering problems are concerned with the rate of heat transfer rather than the quantity of heat being transferred. Resort then is directed to the particular laws governing the transfer of heat. There are three distinct modes of heat transfer: conduction, convection, and radiation. Although these modes are discussed separately, all three types may occur simultaneously

  20. Comparison of steam sterilization conditions efficiency in the treatment of Infectious Health Care Waste.

    Science.gov (United States)

    Maamari, Olivia; Mouaffak, Lara; Kamel, Ramza; Brandam, Cedric; Lteif, Roger; Salameh, Dominique

    2016-03-01

    Many studies show that the treatment of Infectious Health Care Waste (IHCW) in steam sterilization devices at usual operating standards does not allow for proper treatment of Infectious Health Care Waste (IHCW). Including a grinding component before sterilization allows better waste sterilization, but any hard metal object in the waste can damage the shredder. The first objective of the study is to verify that efficient IHCW treatment can occur at standard operating parameters defined by the contact time-temperature couple in steam treatment systems without a pre-mixing/fragmenting or pre-shredding step. The second objective is to establish scientifically whether the standard operation conditions for a steam treatment system including a step of pre-mixing/fragmenting were sufficient to destroy the bacterial spores in IHCW known to be the most difficult to treat. Results show that for efficient sterilization of dialysis cartridges in a pilot 60L steam treatment system, the process would require more than 20 min at 144°C without a pre-mixing/fragmenting step. In a 720L steam treatment system including pre-mixing/fragmenting paddles, only 10 min at 144°C are required to sterilize IHCW proved to be sterilization challenges such as dialysis cartridges and diapers in normal conditions of rolling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Modelling the effects of the sterile insect technique applied to Eldana saccharina Walker in sugarcane

    Directory of Open Access Journals (Sweden)

    L Potgieter

    2012-12-01

    Full Text Available A mathematical model is formulated for the population dynamics of an Eldana saccharina Walker infestation of sugarcane under the influence of partially sterile released insects. The model describes the population growth of and interaction between normal and sterile E.saccharina moths in a temporally variable, but spatially homogeneous environment. The model consists of a deterministic system of difference equations subject to strictly positive initial data. The primary objective of this model is to determine suitable parameters in terms of which the above population growth and interaction may be quantified and according to which E.saccharina infestation levels and the associated sugarcane damage may be measured. Although many models have been formulated in the past describing the sterile insect technique, few of these models describe the technique for Lepidopteran species with more than one life stage and where F1-sterility is relevant. In addition, none of these models consider the technique when fully sterile females and partially sterile males are being released. The model formulated is also the first to describe the technique applied specifically to E.saccharina, and to consider the economic viability of applying the technique to this species. Pertinent decision support is provided to farm managers in terms of the best timing for releases, release ratios and release frequencies.

  2. Factors affecting the efficiency of the sterile insect release method for tsetse

    International Nuclear Information System (INIS)

    Curtis, C.F.

    1980-01-01

    Data are reviewed on the levels of sterility, survival and competitiveness of Glossina males after irradiation with various gamma-ray doses delivered in air or nitrogen. A simple population model helps in the choice of the optimum dose. Field studies of mating competitiveness require a measure of the ratio of sterile to fertile males and of sterile to fertile matings, and both ratio estimates will be subject to sampling error. Data on multiple mating of female Glossina are reviewed. There is some degree of precedence for sperm from the first mating but sterile sperm are fully competitive for fertilization and, following the early death of an embryo, the timing of the next ovulation is only advanced to a slight extent. Thus in an isolated population the occurrence or non-occurrence of female polygamy would be of almost no consequence. Where mated females were immigrating into the release area female polygamy would be advantageous. The low recovery potential of tsetse populations is the main reason for thinking them suitable for control by the introduction of sterility. In trying to measure this recovery potential it is important to distinguish it from natural seasonal increase. If natural population fluctuations are studied to detect density dependent effects it is important not to confuse cause with effect. Non-isolation of the 'target' population is almost certainly the most serious obstacle to practical application of the sterile insect release method, and a steady 'rolling forward' of the release area may be a possible solution. (author)

  3. Genetic architecture of male sterility and segregation distortion in Drosophila pseudoobscura Bogota-USA hybrids.

    Science.gov (United States)

    Phadnis, Nitin

    2011-11-01

    Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses of the genetic architecture underlying hybrid male sterility and segregation distortion between the Bogota and USA subspecies of Drosophila pseudoobscura. Previously, a single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both male sterility and segregation distortion in F(1) hybrids between these subspecies, requiring several interacting partner loci for full manifestation of hybrid phenomena. I map these partner loci separately on the Bogota X chromosome and USA autosomes using a combination of different mapping strategies. I find that hybrid sterility involves a single hybrid incompatibility of at least seven interacting partner genes that includes three large-effect loci. Segregation distortion involves three loci on the Bogota X chromosome and one locus on the autosomes. The genetic bases of hybrid sterility and segregation distortion are at least partially--but not completely--overlapping. My results lay the foundation for fine-mapping experiments to identify the complete set of genes that interact with Overdrive. While individual genes that cause hybrid sterility or inviability have been identified in a few cases, my analysis provides a comprehensive look at the genetic architecture of all components of a hybrid incompatibility underlying F(1) hybrid sterility. Such an analysis would likely be unfeasible for most species pairs due to their divergence time and emphasizes the importance of young species pairs such as the D. pseudoobscura subspecies studied here.

  4. Genetic Architecture of Male Sterility and Segregation Distortion in Drosophila pseudoobscura Bogota–USA Hybrids

    Science.gov (United States)

    Phadnis, Nitin

    2011-01-01

    Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses of the genetic architecture underlying hybrid male sterility and segregation distortion between the Bogota and USA subspecies of Drosophila pseudoobscura. Previously, a single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both male sterility and segregation distortion in F1 hybrids between these subspecies, requiring several interacting partner loci for full manifestation of hybrid phenomena. I map these partner loci separately on the Bogota X chromosome and USA autosomes using a combination of different mapping strategies. I find that hybrid sterility involves a single hybrid incompatibility of at least seven interacting partner genes that includes three large-effect loci. Segregation distortion involves three loci on the Bogota X chromosome and one locus on the autosomes. The genetic bases of hybrid sterility and segregation distortion are at least partially—but not completely—overlapping. My results lay the foundation for fine-mapping experiments to identify the complete set of genes that interact with Overdrive. While individual genes that cause hybrid sterility or inviability have been identified in a few cases, my analysis provides a comprehensive look at the genetic architecture of all components of a hybrid incompatibility underlying F1 hybrid sterility. Such an analysis would likely be unfeasible for most species pairs due to their divergence time and emphasizes the importance of young species pairs such as the D. pseudoobscura subspecies studied here. PMID:21900263

  5. Radiation Fusion Technology for Sewage Sterilization

    International Nuclear Information System (INIS)

    Lee, M. J.; Kim, T. H.; Ryu, S. H.; Jung, I. H.; Lee, O. M.; Kim, T. H.

    2011-01-01

    Environmental regulation for effluent of sewage and wastewater treatment plant is going to be reinforced in terms of ecology toxicity and number of E.coli from 2011. Besides, it has been known that UV technology is not enough to be a sterilization tool due to regrowth of E.coli even after treatment with UV. Therefore it needs a novel technology for both restriction of E.coli regrowth and treatment of toxic materials in order to meet the environmental regulation being enforced. Electron beam has unique capabilities on destruction of chemicals and sterilization of microbial. In this study, field study on destruction of antibiotics and endocrine disruptors, reduction ecological toxicity and E.Coli regrowth was carried out using by mobile electron beam accelerator. Experimental results showed that irradiation on effluent could effectively reduce not only ecology toxicity but regrowth of E.coli by destruction of chemicals and complete sterilization

  6. Mechanisms of male sterility in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Yasuo [Tsukuba Univ., Sakura, Ibaraki (Japan)

    1982-03-01

    The mechanisms causing male sterility in higher plants were classified into two major categories: genetic and non-genetic. The former was further divided into six classes: 1) Anomality in spindle mechanism during meiosis, 2) chromosomal anomality such as haploidy, polyploidy, aneuploidy, chromosome some deficiency, inversion and reciprocal translocation, 3) presence of male sterile genes, 4) cytoplasmic abnormality, 5) the combination of some specific cytoplasm with particular genes, and 6) infections of microorganisms or viruses. Each mechanism was briefly explained, and the methods for the maintenance of parent lines for heterosis breeding and hybrid seed production were described. The non-genetic male sterility was classified into four types, which are caused by 1) low or high temperature, 2) water deficiency, 3) application of chemicals, and 4) radiation, with a brief explanation given for each of them.

  7. Dosimetry requirements derived from the sterilization standards

    DEFF Research Database (Denmark)

    Miller, A.

    1998-01-01

    The main standards for radiation sterilization, ISO 11137 and EN 552, rest the documentation for the properly executed sterilization process on dosimetry. Both standards describe general requirements to the dosimetry system: The dose measurements must be traceable to national standards...... and documented uncertainty limits of the dose measurements can be used to specify process control limits. This is also useful, for example, when dose setting experiments are carried out according to the methods described in ISO 11137, where product samples shall be irradiated within narrow limits......., the uncertainty of the dose measurement and the environmental influences must be known. This paper discusses how to obtain and maintain traceability and how to document measurement uncertainty. The implications of these requirements in the process control of radiation sterilization are further discussed. Known...

  8. Mechanisms of male sterility in higher plants

    International Nuclear Information System (INIS)

    Ohta, Yasuo

    1982-01-01

    The mechanisms causing male sterility in higher plants were classified into two major categories: genetic and non-genetic. The former was further divided into six classes: 1) Anomality in spindle mechanism during meiosis, 2) chromosomal anomality such as haploidy, polyploidy, aneuploidy, chromosome some deficiency, inversion and reciprocal translocation, 3) presence of male sterile genes, 4) cytoplasmic abnormality, 5) the combination of some specific cytoplasm with particular genes, and 6) infections of microorganisms or viruses. Each mechanism was briefly explained, and the methods for the maintenance of parent lines for heterosis breeding and hybrid seed production were described. The non-genetic male sterility was classified into four types, which are caused by 1) low or high temperature, 2) water deficiency, 3) application of chemicals, and 4) radiation, with a brief explanation given for each of them. (Kaihara, S.)

  9. Contraceptive sterilization among Canadians, 1984-1995

    Directory of Open Access Journals (Sweden)

    Vijaya Krishnan

    2004-12-01

    Full Text Available Prior to early 1970s, traditional methods were the principal means of controlling the number and spacing of births. Today, an estimated 57 per cent of the world’s married women use contraceptives and half use modern methods such as medical sterilizations. Recent statistics suggest that Canada has the highest sterilization rate in the Western world. This paper presents findings of research examining sterilization trends in Canada with respect to changing patterns in the use of modern contraceptives, using data from the 1984 Canadian Fertility Survey (CFS and the 1995 General Social Survey (GSS. The main finding is that there is a decrease in the use of tubal ligation and an increase in the use of hysterectomy over the period 1984-1995. Less educated women are more likely to be in the forefront of modern methods of contraception.

  10. Exact solutions of time-fractional heat conduction equation by the fractional complex transform

    Directory of Open Access Journals (Sweden)

    Li Zheng-Biao

    2012-01-01

    Full Text Available The Fractional Complex Transform is extended to solve exactly time-fractional differential equations with the modified Riemann-Liouville derivative. How to incorporate suitable boundary/initial conditions is also discussed.

  11. Time-Separating Heating and Sensor Functions of Thermistors in Precision Thermal Control Applications

    Science.gov (United States)

    Cho, Hyung J.; Sukhatme, Kalyani G.; Mahoney, John C.; Penanen, Konstantin Penanen; Vargas, Rudolph, Jr.

    2010-01-01

    A method allows combining the functions of a heater and a thermometer in a single device, a thermistor, with minimal temperature read errors. Because thermistors typically have a much smaller thermal mass than the objects they monitor, the thermal time to equilibrate the thermometer to the temperature of the object is typically much shorter than the thermal time of the object to change its temperature in response to an external perturbation.

  12. Dynamic sterilization of titanium implants with ultraviolet light

    International Nuclear Information System (INIS)

    Singh, S.; Schaaf, N.G.

    1989-01-01

    All implantable devices must be sterile. However, autoclaves produce poor surface properties that jeopardize the integration process. The application of a modified ultraviolet light source has proven to enhance bioreactivity by controlling surface properties, but it lacks validation of its sterilization capabilities. Forty-eight titanium implants were contaminated with spores of the biological indicator Bacillus stearothermophilus and subjected to dynamic sterilization by ultraviolet light. Forty-seven of the implants were successfully sterilized, as indicated by not producing turbidity in a suitable growth medium. This sterilization technique only requires a 20-second exposure to achieve sterility

  13. A high-temperature furnace and a heating/drawing device designed for time-resolved X-ray diffraction measurements of polymer solids using imaging plates

    International Nuclear Information System (INIS)

    Murakami, Syozo; Tanno, Kiyomitsu; Tsuji, Masaki; Kohjiya, Shinzo

    1995-01-01

    For time-resolved X-ray diffraction measurements using the imaging plate system in the drawing and/or heating process of polymer solids, a high-temperature furnace for heat treatment and a heating/drawing device were newly designed and constructed. Then, to demonstrate their performance, some experimental results obtained in the drawing process of an extruded/blown film of high-density polyethylene at room temperature and in the crystallization process of an oriented amorphous film of poly(ethylene naphthalene-2,6-dicarboxylate) by heating were presented. Other experimental results obtained using them were also briefly cited. (author)

  14. Trace metals content (contaminants) as initial indicator in the quality of heat treated palm oil whole extract

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Fauzi, Noor Akhmazillah bt [Chemical and Bioprocess Department, Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia); Sarmidi, Mohd Roji [Chemical Engineering Pilot Plant, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2011-07-01

    An investigation was carried out on the effect of different sterilization time on the trace metals concentration of palm oil whole extract. Palm fruits were collected, cleaned and sterilized for 0, 20, 40 and 60 minutes. The kernels were then stripped from the sterilized fruits to get the pulp and later the pulp was pressed using small scale expeller. The resulting puree was centrifuge at 4000 rpm for 20 minutes. The palm oil whole extract were then collected and trace metals analysis was conducted using Inductively Couple Plasma-Mass Spectrometry (ICP-MS). The result showed that the highest yield was obtained at 40 minutes of sterilization with 19.9 {+-} 0.21 % (w/w). There was no significant different (p < 0.5) in total trace metals content between the degrees of the heat treatment. Na+ was found as the highest trace metals content in the extract with mean concentration ranging from 1.05 {+-} 0.03 ppm to 2.36 {+-} 0.01 ppm. 40 minutes of heating time was predicted to have good oil quality due to higher content in trace metals that inhibit the lipase enzyme activity.

  15. About the Sterilization of Chitosan Hydrogel Nanoparticles.

    Science.gov (United States)

    Galante, Raquel; Rediguieri, Carolina F; Kikuchi, Irene Satiko; Vasquez, Pablo A S; Colaço, Rogério; Serro, Ana Paula; Pinto, Terezinha J A

    2016-01-01

    In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP) associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility) with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS) hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation), a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP) hydrogel nanoparticles (CS-HNP), with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol). Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.

  16. About the Sterilization of Chitosan Hydrogel Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Raquel Galante

    Full Text Available In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation, a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP hydrogel nanoparticles (CS-HNP, with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol. Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.

  17. Induced mutant for male sterility in niger

    International Nuclear Information System (INIS)

    Sujatha, M.

    2001-01-01

    Full text: Niger (Guizotia abyssinica Cass.), an important oilseed crop of the family Compositae is highly cross-pollinated due to the twin mechanisms of protandry and incompatibility. Studies revealed the functional nature of protandry and the breakdown of incompatibility with alteration in temperature. It has very small flowers (disc florets) arranged in a capitulum that open on 3-4 consecutive days which pose problems in emasculation for cross-breeding. To induce mutations, seeds of variety 'IGP-76' were irradiated with γ-rays 200 to 1000 Gy. All seeds of M 1 plants were sown separately in individual plant-to progeny rows. The results of screening of M 2 segregating material indicated that γ-ray treatment was effective in induction of male sterility. Frequency of visible mutations were higher in sibbed progeny as compared to open pollinated population and male sterile plants were observed only in sibbed population (1000 Gy). Male sterile plants could easily be identified at the flowering stage by their altered floral morphology (disc florets transformed into ligulate ray florets) and complete absence or presence of a rudimentary anther column. Seeds were collected following sib-mating with the fertile counterparts. Progeny segregated in a ration of 3 normal : 1 male sterile. Further work on the mechanism of sterility, maintenance and linkage relationships with associated characters is under progress. This is the first report of induction of male sterility in niger through the use of physical mutagens. The availability of this mutant will be of great value for exploitation of heterosis on commercial basis. (author)

  18. The effect of methyl eugenol exposure on subsequent mating performance of sterile males of the oriental fruit fly, Bactrocera dorsalis

    International Nuclear Information System (INIS)

    Ji Qing'e; Guo Qingliang; Chen Jiahua

    2011-01-01

    The effect of methyl eugenol (ME) on the total times of mating, consecutive mating, mating competitiveness, multiple mating, and the incidence of wild female remating were studied in sterile males from a genetic sexing strain of Bactrocera dorsalis (Hendel). Male pupae were irradiated at dose of 100 Gy by 137 Cs at 2 d before emergence and the dose rate was 1.00 Gy/min. Sexually mature 10 day old sterile males were fed ME, while Non-ME-fed sterile males and normal wild males were used as control, and wild females as mating partners. The results showed that some ME-fed sterile males could mate continuously up to nine times, but the total times of consecutive mating and the mean value of continuous mating times were not significant (P > 0.05) compared with the control. The total mating times of ME-fed sterile males was 344.33 ± 12.55 and the mean value was 6.88 ± 0.25, but both have no significant difference compared with the control. The mating success rate of ME-fed and non-ME-fed sterile males mated with wild females were 44.67 ± 2.40% and 22.00 ± 2.31% separately. There were significant differences between them (t = -6.8, P = 0.002). The outcomes were that feeding on ME did not increase the frequency of multiple mating by sterile males, but significantly increased the mating competitiveness of sterile males against wild males. At the same time, sterile males fed ME did not significantly affect the remating of wild females 5 days after the initial mating, but increased the remating frequency of females 10 and 15 days after the initial mating. (authors)

  19. The effect of methyl eugenol exposure on subsequent mating performance of sterile males of the oriental fruit fly, bactrocera dorsalis

    International Nuclear Information System (INIS)

    Ji Qing'e; Guo Qingliang; Chen Jiaye

    2012-01-01

    The effect of methyl eugenol (ME) on the total times of mating, consecutive mating, mating competitiveness, multiple mating, and the incidence of wild female remating were studied in sterile males from a genetic sexing strain of Bactrocera dorsalis (Hendel). Male pupae were irradiated at dose of 100 Gy by 137 Cs at 2 d before emergence and the dose rate was 1.00 Gy/min. Sexually mature 10 day old sterile males were fed ME, while Non-ME-fed sterile males and normal wild males were used as control, and wild females as mating partners. The results showed that some ME-fed sterile males could mate continuously up to nine times, but the total times of consecutive mating and the mean value of continuous mating times were not significant (P> 0.05) compared with the control. The total mating times of ME-fed sterile males was 344.33±12.55 and the mean value was 6.88±0.25, but both have no significant difference compared with the control. The mating success rate of ME-fed and non- ME-fed sterile males mated with wild females were (44.67±2.40)% and (22.00±2.31)% separately. There were significant differences between them (t = -6.8, P = 0.002). The outcomes were that feeding on ME did not increase the frequency of multiple mating by sterile males, but significantly increased the mating competitiveness of sterile males against wild males. At the same time, sterile males fed ME did not significantly affect the remating of wild females 5 days after the initial mating, but increased the remating frequency of females 10 and 15 days after the initial mating. (authors)

  20. Mass-rearing for sterile insect release

    International Nuclear Information System (INIS)

    Parker, A.G.

    2005-01-01

    As the sterile insect technique (SIT) relies upon released sterile male insects efficiently competing with wild males to mate with wild females, it follows that mass-rearing of insects is one of the principal steps in the process. Mass-rearing for the SIT presents both problems and opportunities due to the increased scale involved compared with rearing insects for most other purposes. This chapter discusses facility design, environmental concerns, strain management, quality control, automation, diet, sex separation, marking, and storage in relation to rearing for the SIT. (author)