Science.gov

Sample records for photomagnetisme sous irradiation

  1. Caractérisation des dégradations de transistors MOS de puissance sous irradiations

    NASA Astrophysics Data System (ADS)

    Bendada, E.; Raïs, K.; Mialhe, P.

    1997-11-01

    The aim of this work is the characterization of D-MOS (HEXFET) structure before and after irradiations. An innovative method for device characterisation is experimented to quantify radiation effects. This study is based on the determination of importants parameters: series resitance, ideality factor, reverse recombination and reverse diffusion currents of the substrate-drain junction by the analysis of its current voltage characteristics. The form of I V characteristics of the substrate-drain junction with operating conditions is found dependent of defects induced by irradiations. It is shown that values of the series resistance, the ideality factor and the reverse recombination current increases with the gate voltage and with the dose absorbed. The reverse diffusion current is shown to be not albered by radiation exposures. Une nouvelle méthode de caractérisation de la dégradation sous irradiations des transistors à structure D-MOS de type HEXFET est proposée. Elle est basée sur l'analyse des propriétés de la diode substrat-drain en utilisant les méthodes bien établies de modélisation des jonctions p-n. La description des caractéristiques courant-tension à l'aide des modèles permettant de séparer les processus de diffusion et de recombinaison des porteurs, conduit à déterminer d'une manière simple des paramètres importants: résistance série, facteur de qualité, courant inverse de recombinaison et courant inverse de diffusion. La forme des caractéristiques courant-tension de la jonction avec les conditions de fonctionnement est trouvée dépendante des défauts induits par les irradiations. Il est montré que les valeurs de la résistance série, du facteur de qualité et du courant inverse de recombinaison augmentent avec la tension de grille et avec la dose absorbée. Le courant inverse de diffusion est non altéré par l'exposition aux radiations.

  2. Qualification sous irradiation du crayon cea: de la conception des composants a l'irradiation d'assemblages en reacteur de puissance

    NASA Astrophysics Data System (ADS)

    Marin, Jean-François; Pillet, Claude; François, Bernard; Morize, Pierre; Petitgrand, Sylvie; Atabek, Rose-Marie; Houdaille, Brigitte

    1982-04-01

    Cet article résume les principaux résultats obtenus au CEA au cours des dix dernières années dans la conception, la qualification et la fabrication des différents éléments originaux constitutifs d'un assemblage de réacteur à eau pressurisée, notamment: l'oxyde UO 2 obtenu par le procédé du Double Cycle Inverse, la gaine en zircaloy 4 recris talllsée, la grille à ressort papillon, la structure à grilles coulissantes. Les etudes et essais hors-pile de comportement thermomécanique du crayon et thermohydraulique des composants de l'assemblage, les irradiations paramétriques de crayons jusqu'à une combustion massique élevée, la validation à partir d'examens aprés irradiation des principaux modèles introduits dans les calculs de conception, enfin l'introduction en réacteur prototype, puis en réacteur de puissance d'assemblages comportant ces différents éléments, constituent les principales étapes de ce développement.

  3. La chirurgie du diaphragme sous aortique

    PubMed Central

    Moutakiallah, Younes; Maaroufi, Ilham; Aithoussa, Mahdi; Bamous, Mehdi; Abdou, Abdessamad; Atmani, Noureddine; Hatim, Abdedaïm; Amahzoune, Brahim; Bekkali, Youssef El; Boulahya, Abdelatif

    2016-01-01

    Le diaphragme sous aortique se caractérise par une certaine latence clinique et une faible morbi-mortalité. La chirurgie reste le traitement de choix malgré un réel risque de récurrence à long terme. Nous rapportons 18 patients opérés entre Avril 1994 et Mars 2011 pour diaphragme sous aortique d’âge moyen de 18,1±9,7 ans avec 11 patients de sexe masculin. Le diaphragme était de nature fibreuse chez 13 patients et fibro-musculaire chez 5 patients. Tous les patients ont été opérés par résection de diaphragme associée à une myectomie, une plastie aortique, une fermeture de communication interventriculaire et une ligature de canal artériel perméable respectivement chez 3, 3, 2 et 2 patients. La Mortalité opératoire était nulle et sans aucun cas de trouble de conduction postopératoire. Le suivi a duré en moyenne 44,3±36,8 mois sans aucun décès tardif. Deux patients ont présenté une récidive de diaphragme qui a nécessité une réopération avec bonne évolution. La tendance actuelle dans la chirurgie du diaphragme se fait vers des interventions précoces et des résections plus extensives. Cependant, le risque de récidive impose une surveillance échographique systématique et rapprochée. PMID:27516830

  4. Improvement of microbiological safety of sous-vide meals by gamma radiation

    NASA Astrophysics Data System (ADS)

    Farkas, J.; Polyák-Fehér, K.; Andrássy, É.; Mészáros, L.

    2002-03-01

    Experimental batches of smoked-cured pork in stewed beans sauce were inoculated with spores of psychrotrophic Bacillus cereus, more heat and radiation resistant than spores of non-proteolytic C. botulinum. After vacuum packaging, the meals were treated with combinations of pasteurizing heat treatments and gamma irradiation of 5 kGy. Prior and after treatments, and periodically during storage at 10°C, total aerobic and total anerobic viable cell counts, and selectively, the viable cell counts of B. cereus and sulphite-reducing clostridia have been determined. The effects of the treatment order as well as addition of nisin to enhance the preservative efficiency of the physical treatments were also studied. Heat-sensitization of bacterial spores surviving irradiation occurred. The quality-friendly sous-vide cooking in combination with this medium dose gamma irradiation and/or nisin addition increased considerably the microbiological safety and the keeping quality of the meals studied. However, approx. 40% loss of thiamin content occurred as an effect of combination treatments, and adverse sensorial effects may also limit the feasible radiation doses or the usable concentrations of nisin.

  5. Clostridium perfringens growth from spore inocula in sous-vide processed pork-based Mexican entrée.

    PubMed

    Miguel-Garcia, Denise Y; Juneja, Vijay K; Valenzuela-Melendrez, Martin; Díaz-Cinco, Martha E; Thippareddi, H; Aida Peña-Ramos, E

    2009-01-01

    The combined effect of Citricidal wih irradiation on Clostridium perfringens growth from spores in a sous-vide processed marinated pork meat Mexican entrée was investigated. Citricidal was added at 200 or 800 ppm after mixing pork meat with tomatillo sauce and inoculated with 3 log(10) CFU/g of C. perfringens spores. Samples were irradiated at either 0 or 2 kGy, heated to an internal temperature of 71 degrees C, and stored at 4 degrees C for 28 d, 15 degrees C for 45 d, and 25 degrees C for 26 h. To simulate the conditions that may occur during transportation, distribution, storage, or handling in supermarkets or by consumers, the effect of static temperature abuse on C. perfringens growth was assessed by transferring samples stored at 4 to 25 degrees C for 13 and 15 h. Total C. perfringens populations were determined by plating diluted samples on tryptose-sulfite-cycloserine agar. Growth was not observed up to 45 d of storage at 15 degrees C in samples supplemented with 800 ppm of Citricidal. At 25 degrees C, no significant differences (P > 0.05) on the lag phase duration due to antimicrobial treatments was observed. The temperature abuse of refrigerated products for up to 15 h did not lead to C. perfringens growth to high infective dose levels of 1 million cells required to cause food poisoning. The results suggest that 800 ppm Citricidal can have significant bacteriostatic activity against C. perfringens and may provide a degree of protection against this pathogen in sous-vide processed marinated pork meat Mexican entrée, under mild temperature abuse (

  6. Changes in Meat Quality Characteristics of the Sous-vide Cooked Chicken Breast during Refrigerated Storage

    PubMed Central

    2015-01-01

    This study was performed to investigate the changes in meat quality characteristics of the sous vide cooked chicken breast during refrigerated storage at 4℃ for 14 d between before and after sous-vide cooking. Cooking loss and shear force were significantly increased, whereas expressible drip was significantly decreased along with reduction in the water holding capacity in both of two groups. Redness of meat juice was significantly (p<0.05) increased during storage, and considerably increased in the refrigerated samples after sous-vide cooked at the 7 to 10 d. The thiobarbituric acid reactive substances (TBARS) was significantly increased and was higher in the refrigerator stored chicken breast samples after sous-vide cooking. The volatile basic nitrogen (VBN) value was significantly increased in both groups, but the VBN value of the stored raw meat sample before sous-vide cooking was increased at an early storage, while the VBN value of the stored sample after sous-vide cooking was increased gradually in this study. Total viable counts and coliform counts were significantly decreased during storage, and coliforms were not detected after 7 d of storage in both groups. Salmonella spp. was not detected during the whole studied period. The outcome of this research can provide preliminary data that could be used to apply for further study of chicken breast using sous-vide cooking method that could be attractive to consumers. PMID:26877635

  7. Photoconductivité et photoémission de diamant(s) sous irradiation XUV femtoseconde

    NASA Astrophysics Data System (ADS)

    Gaudin, J.; Geoffroy, G.; Guizard, S.; Esnouf, S.; Olevano, V.; Petite, G.; Klimentov, S. M.; Pivovarov, P. A.; Garnov, S. V.; Carre, B.; Martin, P.; Belsky, A.

    2005-06-01

    Nous décrivons une étude des propriétés de photoconductivité (PC) induite dans différents types de diamants (monocristaux de type IIa et couches CVD) par des impulsions femtosecondes XUV (jusqu'à l'harmonique 19 du laser titane/saphir). En complément de ces études, les spectres de photoémission de ces échantillons ont aussi été étudiés (harmoniques 13 à 27). En fonction de l'ordre de l'harmonique, on constate que le signal de PC augmente tout d'abord (harmoniques 9 à 13) puis diminue au delà. Si l'augmentation s'interprète aisément comme résultant de phénomènes de multiplication par collisions inélastiques, la diminution ultérieure n'a pas pour le moment d'explication. Les mesures de spectre de photoémission suggèrent un effet important de la relaxation par émission de plasmons. Enfin, nous avons réalisé le premier calcul ab-initio de la durée de vie des porteurs tenant compte des interactions électron-électron, à l'aide d'une approche de théorie quantique à plusieurs corps de type GW. Au voisinage du gap, on observe un comportement proche de celui d'un liquide de Fermi. A plus haute énergie on observe des déviations à ce comportement, provenant d'effets de structure de bande d'une part, et d'excitations de plasmons d'autre part.

  8. Mesures en continu de la redistribution de l'oxygène sous gradient thermique dans UO2+ x

    NASA Astrophysics Data System (ADS)

    Ducroux, R.; Fromont, M.; Baptiste, Ph. Jean; Pattoret, A.

    1980-09-01

    RésuméL'objet de ce travail est l'ètude hors-pile sous gradient thermique de la redistribution de l'oxygène dans UO2+x, de façon à expliquer ultèrieurement les profils O/U + Pu obtenus sur du combustible irradiè. Les gradients thermiques ont ètè obtenus à l'aide d'un four à image. La tache focale d'une surface de 0.5 cm2 est amenèe au sommet de l'èchantillon cylindrique d'oxyde dont la partie froide est au contact d'un four à environ 900°C; celui-ci permet de maintenir en conditions isothermes une minijauge à electrolyte solide (Th02-Y203) contenant une rèfèrence chimique Fe/FeO. La minijauge donne à tout instant l'activitè de l'oxygène à la partie froide des èchantillons. Elle a ètè testèe en mesurant les potentiels d'oxygène de diffèrents systèmes chimiques. Les expèriences ont ètè rèalisèes sous atmosphère d'argon purifiè par des pompes èlectrochimiques. Les èchantillons d'UO2+x sont soumis à un gradient thermique modeste de 300°C/cm environ pour limiter en partie chaude les phènomènes d'èvaporation. Après le suivi en continu de la fern les èchantillons sont trempés puis tronçonnès, le rapport O/U de chaque tranche ètant dèterminè. L'oxygène remonte le gradient thermique, de façon importante, bien que la durèe des recuits soit relativement courte et les tempèratures basses. La confrontation des rèsultats obtenus dans UO2+x, avec un calcul èlaborè sur la base de la thermodiffusion en phase solide pour l'oxygène, montre un accord très raisonnable.

  9. Development of Pangasius steaks by improved sous-vide technology and its process optimization.

    PubMed

    Kumari, Namita; Singh, Chongtham Baru; Kumar, Raushan; Martin Xavier, K A; Lekshmi, Manjusha; Venkateshwarlu, Gudipati; Balange, Amjad K

    2016-11-01

    The present study embarked on the objective of optimizing improved sous-vide processing condition for development of ready-to-cook Pangasius steaks with extended shelf-life using response surface methodology. For the development of improved sous-vide cooked product, Pangasius steaks were treated with additional hurdles in various combinations for optimization. Based on the study, suitable combination of chitosan and spices was selected which enhanced antimicrobial and oxidative stability of the product. The Box-Behnken experimental design with 15 trials per model was adopted for designing the experiment to know the effect of independent variables, namely chitosan concentration (X1), cooking time (X2) and cooking temperature (X3) on dependent variable i.e. TBARS value (Y1). From RSM generated model, the optimum condition for sous-vide processing of Pangasius steaks were 1.08% chitosan concentration, 70.93 °C of cooking temperature and 16.48 min for cooking time and predicted minimum value of multiple response optimal condition was Y = 0.855 mg MDA/Kg of fish. The high correlation coefficient (R(2) = 0.975) between the model and the experimental data showed that the model was able to efficiently predict processing condition for development of sous-vide processed Pangasius steaks. This research may help the processing industries and Pangasius fish farmer as it provides an alternative low cost technology for the proper utilization of Pangasius.

  10. Kyste hydatique sous cutané isolé: à propos d’un cas et revue de la literature

    PubMed Central

    Lemrhari, Bahija; Baha, Hasna; Azzouzi, Soufia; Chiheb, Soumyia

    2016-01-01

    La localisation sous cutanée, primitive et isolée, du kyste hydatique est exceptionnelle, même dans les pays où la maladie hydatique est endémique. Nous rapportons le cas d’une jeune patiente présentant un kyste hydatique sous cutané sans atteintes viscérales associées. PMID:27800067

  11. Une localisation exceptionnelle de la tuberculose vertébrale Mal de Pott sous-occipital

    PubMed Central

    Yahyaoui, Sana; Majdoub, Senda; Zaghouani, Houneida; Fradj, Hosni Ben; Bakir, Dejla; Bouajina, Elyes; Kraiem, Chakib

    2013-01-01

    Le mal de Pott est la forme la plus commune de la tuberculose osseuse touchant essentiellement le rachis dorso-lombaire. La localisation sous-occipitale reste exceptionnelle. Le diagnostic de cette entité est le plus souvent tardif ce qui expose à des complications graves. Les radiographies standard ne sont parlantes qu’à un stade tardif de la maladie, d'où l'intérêt de l'imagerie moderne notamment la tomodensitométrie (TDM) et l'imagerie par résonance magnétique (IRM) qui permettent un diagnostic précoce. Nous rapportons un nouveau cas de tuberculose sous-occipitale. Le diagnostic était posé sur l'imagerie en coupe et confirmé histologiquement à la biopsie transorale. Sont rappelés les aspects en imagerie de cette localisation particulière du mal de Pott. PMID:23819005

  12. [Food irradiation].

    PubMed

    Migdał, W

    1995-01-01

    A worldwide standard on food irradiation was adopted in 1983 by Codex Alimentarius Commission of the Joint Food Standard Programme of the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO). As a result, 41 countries have approved the use of irradiation for treating one or more food items and the number is increasing. Generally, irradiation is used to: food loses, food spoilage, disinfestation, safety and hygiene. The number of countries which use irradiation for processing food for commercial purposes has been increasing steadily from 19 in 1987 to 33 today. In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in Institute of Nuclear Chemistry and Technology. The plant is equipped with a small research accelerator Pilot (19MeV, 1 kW) and an industrial unit Elektronika (10MeV, 10 kW). On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permission for irradiation for: spices, garlic, onions, mushrooms, potatoes, dry mushrooms and vegetables.

  13. Tissue irradiator

    DOEpatents

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1975-12-16

    A tissue irradiator is provided for the in-vivo irradiation of body tissue. The irradiator comprises a radiation source material contained and completely encapsulated within vitreous carbon. An embodiment for use as an in- vivo blood irradiator comprises a cylindrical body having an axial bore therethrough. A radioisotope is contained within a first portion of vitreous carbon cylindrically surrounding the axial bore, and a containment portion of vitreous carbon surrounds the radioisotope containing portion, the two portions of vitreous carbon being integrally formed as a single unit. Connecting means are provided at each end of the cylindrical body to permit connections to blood- carrying vessels and to provide for passage of blood through the bore. In a preferred embodiment, the radioisotope is thulium-170 which is present in the irradiator in the form of thulium oxide. A method of producing the preferred blood irradiator is also provided, whereby nonradioactive thulium-169 is dispersed within a polyfurfuryl alcohol resin which is carbonized and fired to form the integral vitreous carbon body and the device is activated by neutron bombardment of the thulium-169 to produce the beta-emitting thulium-170.

  14. Irradiation subassembly

    DOEpatents

    Seim, O.S.; Filewicz, E.C.; Hutter, E.

    1973-10-23

    An irradiation subassembly for use in a nuclear reactor is described which includes a bundle of slender elongated irradiation -capsules or fuel elements enclosed by a coolant tube and having yieldable retaining liner between the irradiation capsules and the coolant tube. For a hexagonal bundle surrounded by a hexagonal tube the yieldable retaining liner may consist either of six segments corresponding to the six sides of the tube or three angular segments each corresponding in two adjacent sides of the tube. The sides of adjacent segments abut and are so cut that metal-tometal contact is retained when the volume enclosed by the retaining liner is varied and Springs are provided for urging the segments toward the center of the tube to hold the capsules in a closely packed configuration. (Official Gazette)

  15. Irradiated foods

    MedlinePlus

    ... it reduces the risk of food poisoning . Food irradiation is used in many countries. It was first approved in the U.S. to prevent sprouts on white potatoes, and to control insects on wheat and in certain spices and seasonings.

  16. Hypertriglycéridémie majeure sous tamoxifène

    PubMed Central

    Khabbal, Youssef; El Ouahabi, Hanane; Bensbaa, Salma; Agerd, Loubna; Brahmi, Sami; El Mesbahi, Omar; Ajdi, Farida

    2012-01-01

    Plusieurs agents pharmacologiques sont incriminés dans les hyperlipidémies. Le tamoxifène fournit un exemple de médicament hypertriglycéridémiant. Nous décrivons ici le cas ďune patiente atteinte de cancer du sein traitée par tamoxifène qui a présenté une hypertriglycéridémie sévère. Nous présentons aussi une brève revue de la littérature et discutons les mécanismes sous jacents aux effets hypertriglycéridémiants du tamoxifène. PMID:23396984

  17. Complication rare de la coloscopie chez un patient sous anticoagulant: hemopéritoine par rupture d'un hématome sous capsulaire de la rate, cas clinique

    PubMed Central

    Sbai, Hicham; Boukatta, Brahim; El Bouazzaoui, Abderahim; Youssfi, Mounia; Mellouki, Ihsane; Benajeh, Dafr Allah; Bobo, Meriem; Bohadouti, Hicham; Tizniti, Siham; Ibrahimi, Adil; Taleb, Khalid Ait; Kanjaa, Nabil

    2015-01-01

    La coloscopie à visée diagnostique et/ou thérapeutique est un examen invasif fréquemment pratiquée de nos jours. La perforation colique et l'hémorragie digestive en sont les principales complications. La survenue d'un hémopéritoine par rupture d'un hématome sous-capsulaire splénique est une complication extrêmement rare et potentiellement mortelle de la coloscopie. Un traumatisme splénique minime passé inaperçu et la prise d'anticoagulant en sont des facteurs favorisants. Nous présentons le cas d'une rupture d'un hématome sous-capsulaire de la rate après une coloscopie, survenue chez un patient de 70 ans porteur d'une valve mitrale mécanique sous acénocoumarol à dose hypocaogulante. La nécessité d'obtention d'une anti coagulation rapidement efficace et l'instabilité hémodynamique avaient justifiée la réalisation d'une splénectomie. L’évolution était favorable. A travers cette observation clinique nous discutons les mécanismes et les modalités de prise en charge devant cette complication. PMID:26523174

  18. Lipid oxidation stability of omega-3- and conjugated linoleic acid-enriched sous vide chicken meat.

    PubMed

    Narciso-Gaytán, C; Shin, D; Sams, A R; Keeton, J T; Miller, R K; Smith, S B; Sánchez-Plata, M X

    2011-02-01

    Lipid oxidation is known to occur rather rapidly in cooked chicken meat containing relatively high amounts of polyunsaturated fatty acids. To assess the lipid oxidation stability of sous vide chicken meat enriched with n-3 and conjugated linoleic acid (CLA) fatty acids, 624 Cobb × Ross broilers were raised during a 6-wk feeding period. The birds were fed diets containing CLA (50% cis-9, trans-11 and 50% trans-10, cis-12 isomers), flaxseed oil (FSO), or menhaden fish oil (MFO), each supplemented with 42 or 200 mg/kg of vitamin E (dl-α-tocopheryl acetate). Breast or thigh meat was vacuum-packed, cooked (74°C), cooled in ice water, and stored at 4.4°C for 0, 5, 10, 15, and 30 d. The lipid oxidation development of the meat was estimated by quantification of malonaldehyde (MDA) values, using the 2-thiobarbituric acid reactive substances analysis. Fatty acid, nonheme iron, moisture, and fat analyses were performed as well. Results showed that dietary CLA induced deposition of cis-9, trans-11 and trans-10, cis-12 CLA isomers, increased the proportion of saturated fatty acids, and decreased the proportions of monounsaturated and polyunsaturated fatty acids. Flaxseed oil induced higher deposition of C18:1, C18:2, C18:3, and C20:4 fatty acids, whereas MFO induced higher deposition of n-3 fatty acids, eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6; P < 0.05). Meat lipid oxidation stability was affected by the interaction of either dietary oil or vitamin E with storage day. Lower (P < 0.05) MDA values were found in the CLA treatment than in the MFO and FSO treatments. Lower (P < 0.05) MDA values were detected in meat samples from the 200 mg/kg of vitamin E than in meat samples from the 42 mg/kg of vitamin E. Nonheme iron values did not affect (P > 0.05) lipid oxidation development. In conclusion, dietary CLA, FSO, and MFO influenced the fatty acid composition of chicken muscle and the lipid oxidation stability of meat over the storage time. Supranutritional

  19. Hématome sous dural dorsal compliquant une anesthésie péridurale en chirurgie vasculaire

    PubMed Central

    Elahmadi, Brahim; Awab, Almahdi; El Moussaoui, Rachid; El Hijri, Ahmed; Azzouzi, Abderrahim; Alilou, Mustapha

    2014-01-01

    L'hématome péri médullaire est une complication rare, parfois invalidante de l'anesthésie péridurale. Il survient au décours d'une ponction difficile ou traumatique ou après une mauvaise gestion des anticoagulants. Son diagnostic est difficile parfois retardé. L'imagerie par résonance magnétique reste l'examen de choix. Le traitement est essentiellement chirurgical. Le pronostic dépend de l'importance de l'hématome et des lésions sous jacentes. Nous rapportons l'observation d'un hématome sous dural dorsal, compliquant une anesthésie péridurale en postopératoire d'un pontage aorto-bi fémoral, pour anévrysme de l'aorte abdominal sous rénale. PMID:25426189

  20. Integral modeling and financial impact of the geothermal situation and power plant at Soultz-sous-Forêts

    NASA Astrophysics Data System (ADS)

    Heidinger, Philipp

    2010-07-01

    The science about deep Enhanced Geothermal Systems (EGS) is still an emerging process and for further spreading economics is the key of the technology. To understand the financial situation, a program for economic evaluation was developed. This software (Euronaut) is completely modularized and considers all cash flows. Projects like an EGS are wrapped into tree-like structures. Based on the results which were gained at Soultz-sous-Forêts, two configurations were designed. The first EGS configuration consists of a simplified two well (doublet) system where the dependencies of all components (mainly the reservoir, wells, pumps and the heat-to-power conversion unit) are physically and economically linked together. The realization of these dependencies and their complex interactions enable a sensitivity analysis of the borehole depth and reservoir depth, respectively. As a result, depth dependent effective costs and revenues of an EGS plant with the geohydrological characteristics of Soultz-sous-Forêts are determined. As a future development, the second configuration will adapt the actual situation at Soultz-sous-Forêts with the individual features of all four wells (GPK1 - GPK4). Then, this model can be used for all kinds of sensitivity analyses to clarify the impact of certain components or to optimize the operation scheme; e.g. the flow rates.

  1. Phytosanitary Irradiation

    PubMed Central

    Hallman, Guy J.; Blackburn, Carl M.

    2016-01-01

    Phytosanitary treatments disinfest traded commodities of potential quarantine pests. Phytosanitary irradiation (PI) treatments use ionizing radiation to accomplish this, and, since their international commercial debut in 2004, the use of this technology has increased by ~10% annually. Generic PI treatments (one dose is used for a group of pests and/or commodities, although not all have been tested for efficacy) are used in virtually all commercial PI treatments, and new generic PI doses are proposed, such as 300 Gy, for all insects except pupae and adult Lepidoptera (moths). Fresh fruits and vegetables tolerate PI better than any other broadly used treatment. Advances that would help facilitate the use of PI include streamlining the approval process, making the technology more accessible to potential users, lowering doses and broadening their coverage, and solving potential issues related to factors that might affect efficacy. PMID:28231103

  2. Development of a convenience and safety chilled sous vide fish dish: Diversification of aquacultural products.

    PubMed

    Espinosa, M C; López, G; Díaz, P; Linares, M B; Garrido, M D

    2016-04-01

    The dynamic expansion of the ready-to-eat seabream sector in its adaptation to new lifestyles has led to the search for new presentation formats in seabream (Sparus aurata). Green sauce (olive oil, wine vinegar, garlic, fresh parsley, black pepper, basil and salt) and 60 ℃ of cooking temperature were chosen by the panellists for the sous vide cooking process. Seabream fillet and sauce were packaged in polypropylene trays, cooked, chilled and stored at 2 ℃. Microbiological (total viable counts,Enterobacteriaceae,lactic acid bacteria, anaerobic psychrotrophic, moulds and yeasts, Salmonella and Listeria monocytogenes), chemical (pH and TBARs) and sensory parameters were determined at 0, 7, 17, 34, 48 and 62 days. In the conditions used, the microbiological counts remained stable, and Salmonella and Listeria monocytogenes were absent. The acidic sauce had a positive effect on the pH of the product, and low TBARs were obtained throughout storage. The processing conditions used in the present study allowed a chilled ready-to-eat seabream product of consistently high quality up to 62 days of storage to be obtained, representing an expansion of the products offered by the aquacultural industry.

  3. Spoilage of sous vide cooked salmon (Salmo salar) stored under refrigeration.

    PubMed

    Díaz, P; Garrido, M D; Bañón, S

    2011-02-01

    The spoilage of Sous Vide 'SV' cooked salmon stored under refrigeration was studied. Samples were packaged under vacuum in polyamide-polypropylene pouches, cooked at an oven temperature/time of 80 (°)C/45 min, quickly chilled at 3 (°)C and stored at 2 (°)C for 0, 5 or 10 weeks for catering use. Microbial (aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae), physical-chemical (pH, water activity, TBARS, acidity, L*a*b* color, texture profile analysis and shear force) and sensory (appearance, odor, flavor, texture and overall quality) parameters were determined. SV processing prevented the growth of aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae. There were no relevant changes in pH, water activity, TBARS, CIELab color associated with cooked salmon spoilage. Instrumental texture data were contradictory. Slight decrease in lactic acid levels was found. In contrast, the SV cooked salmon suffered considerable sensory deterioration during its refrigerated storage, consisting of severe losses of cooked salmon odor and flavor, slight rancidity, discoloration associated with white precipitation, and moderates softness, and loss of chewiness and juiciness. No acidification, putrefaction or relevant rancidity was detected. The sensory spoilage preceded microbiological and physical-chemical spoilage, suggesting that microbiological quality alone may overestimate the shelf life of SV cooked salmon.

  4. Les tuméfactions sous mandibulaires: à propos de 42 cas et revue de la literature

    PubMed Central

    Darouassi, Youssef; Mliha Touati, Mohamed; Chihani, Mehdi; Nadour, Karim; Ammar, Haddou; Bouaity, Brahim

    2014-01-01

    Les tuméfactions de la région sous mandibulaire sont une entité pathologique fréquente, caractérisées par un tableau clinique et une démarche diagnostique stéréotypée, et une unicité presque constante au plan chirurgical. Notre travail est une étude rétrospective sur une période de 5 an d'une série consécutive de 42 cas de tuméfactions sous mandibulaires qui ont été colligés au service d'oto-rhino-laryngologie et de chirurgie cervico-faciale de l'hôpital militaire Avicenne de Marrakech. L’âge moyen des patients était de 41 ans. Une prédominance masculine a été retrouvée. Le tableau clinique a été dominé par la tuméfaction sous mandibulaire. Tous les patients ont bénéficié d'une échographie cervicale. La tomodensitométrie cervicale a été réalisée chez 7 patients. La première étiologie était la sous maxillite chronique lithiasique dans 39,02% des cas. Le traitement était chirurgical dans tous les cas. En comparant les résultats avec ceux rapportés dans la littérature, nous allons discuter les différents aspects diagnostiques et thérapeutiques des étiologies les plus fréquentes. Les tuméfactions de la région sous mandibulaire sont fréquentes, nécessitant une démarche diagnostique rigoureuse et une prise en charge thérapeutique adaptée. PMID:25469195

  5. La chirurgie coronaire sous circulation extra-corporelle chez le patient diabétique

    PubMed Central

    Moutakiallah, Younes; Benzaghmout, Khadija; Aithoussa, Mahdi; Atmani, Nourreddine; Amahzoune, Brahim; Hatim, Abdedaim; Drissi, Mohamed; Benyass, Aatif; ElBekkali, Youssef; Boulahya, Abdelatif

    2014-01-01

    Nous rapportons les résultats de la chirurgie coronaire chez une population de coronariens diabétiques opérés sous circulation extra-corporelle dans le service de chirurgie cardiaque de l'hôpital militaire d'instruction Mohammed V de Rabat. C'est une étude rétrospective menée entre Janvier 2008 et Février 2012 (4 ans), portant sur 103 patients diabétiques consécutifs opérés pour pontage coronaire. L’âge moyen des patients était de 61±8,7ans (37-82ans) avec un sexe ratio (H/F) de 3,9. Tous les patients diabétiques de type 2 et sous traitement anti-diabétique ont été inclus dans cette étude. La sténose du tronc commun gauche était présente chez 26,2% des patients et 53,4% étaient tritronculaires. Quatre-vingt patients (78,6%) étaient insulino-nécessitant, l'Euro-score moyen était de 1,63±1% et le nombre moyen de pontage de 2,3±0,7. Les durées moyennes de la circulation extra-corporelle et du clampage aortique étaient respectivement de 134,4 ± 42 min et 76 ± 28 min. La mortalité hospitalière était de 2 décès (1,9%), les durées moyennes de ventilation artificielle, du séjour en réanimation et du séjour postopératoire étaient respectivement de 7h (5-16h), 48h (42-52h) et 15,6 ± 8,6 jours. Les complications postopératoires étaient l'infarctus du myocarde, l'infection de paroi, la médiastinite et le bas débit cardiaque chez respectivement 1,9%, 10,7%, 3,9% et 1,9% des patients. Il ressort de notre étude, que les facteurs prédictifs d'infection post opératoire étaient la durée de ventilation artificielle (p = 0,002), la durée de la circulation extra-corporelle (p < 0,001) en plus du tabac (p = 0,004) et de l'obésité (p = 0,005). Les patients ont été contactés par téléphone ou lors de la consultation régulière de contrôle. Le taux de suivi a atteint 92,1% et la survie à 2 ans était de 98,9% des patients contrôlés avec une mortalité tardive de 1% avec un décès suite à un accident vasculaire c

  6. Time-dependent permeability anisotropy at the Soultz-sous-Forêts geothermal site, France

    NASA Astrophysics Data System (ADS)

    Heap, M. J.; Griffiths, L.; Wang, F.; Daval, D.; Gilg, H. A.; Baud, P.; Genter, A.; Schmittbuhl, J.

    2015-12-01

    Fluid circulation in geothermal reservoirs depends on the density, geometry, and hydraulic properties of fractures. The Soultz-sous-Forêts site located in the Upper Rhine Graben in Alsace, France, consists of a granitic reservoir overlain by a 1.4 km-thick sedimentary succession. Core analysis and borehole wall imagery collected from reconnaissance well EPS1 (2230 m depth) revealed an extensive fracture network throughout the granite and overlying sediments, including both open fractures and fractures filled through mineral precipitation (primarily quartz, barite, calcite, and galena). Here we present an experimental study that aims to quantify the impact of healed or partially-healed fractures on permeability anisotropy in the Triassic Buntsandstein sandstone (1000-1400 m). We targeted borehole samples that best represent the variability of these fractures. Forty cylindrical core samples (40 mm length and 20 mm diameter) were prepared such that they contain fractures either parallel or perpendicular to their axis. We also prepared samples of the intact host rock. Porosity and permeability were measured for each core, and thin sections were made to characterise the nature of the fractures and the precipitated minerals. The low permeability of the host rock (10-15 to 10-17 m2) can be explained by prevalent pore-filling clays. We found that fractures may present a conduit for or a barrier to flow, depending on the extent of healing and the nature of the filling. Crystal precipitation models, using borehole fluid composition and temperature data from Soultz, provide a timescale for crack healing. Our modelling shows that fractures that once represented effective conduits for flow may heal rapidly (on the order of months) and switch from providing conduits for flow to presenting barriers to flow, modifying the permeability anisotropy within these units. These data are important for understanding fluid flow and heat transfer within the reservoir.

  7. Fracture mapping in the Soultz-sous-Forêts geothermal field using microearthquake locations

    NASA Astrophysics Data System (ADS)

    Michelet, Sophie; ToksöZ, M. Nafi

    2007-07-01

    In 2003, a massive hydraulic fracturing experiment was carried out at the European Geothermal Hot Dry Rock site at Soultz-sous-Forêts, France. The 2 week injection of water generated a high level of microseismic activity, triggering about 90,000 microearthquakes during and after the fluid injection. Of these, 21,000 events, detected at all stations, were located individually with a grid search algorithm to characterize the extent of the seismic zones and ultimately of the fracture network. The accuracy of these initial locations was around 70 m, not sufficient to map detailed fracture patterns. A precise relocation effort was undertaken to reduce the location uncertainties using three different techniques: joint hypocenter determination (JHD), collapsing and multiplet analysis. The collapsing method was added to the JHD results to further consolidate the hypocenters. On the other hand, a multiplet analysis was performed on the initial data set for identifying microearthquakes with similar waveforms and hence relocating relatively the correlated events. The delays in traveltime were computed by wavelet analysis and the events were relocated using a grid search algorithm. We found 7463 events whose seismograms correlated with a correlation coefficient of 0.8 or higher, most of which were doublets. Multiplets are horizontal tube-like structures with lengths from a hundred to several hundred meters striking along the direction of the maximum compressive horizontal stress. We interpret these structures as the preferential paths where fluid flow is largely confined. This hypothesis is reinforced by the good correlation in depth between the events and the fluid outflows observed in the well. Therefore we believe that these relocated events highlight the zones where the permeability of the reservoir is increased.

  8. Use of Irradiated Foods

    NASA Technical Reports Server (NTRS)

    Brynjolfsson, A.

    1985-01-01

    The safety of irradiated foods is reviewed. Guidelines and regulations for processing irradiated foods are considered. The radiolytic products formed in food when it is irradiated and its wholesomeness is discussed. It is concluded that food irradiation processing is not a panacea for all problems in food processing but when properly used will serve the space station well.

  9. Tumeur sous scapulaire: élastofibrome dorsal bilatéral à propos d'un cas

    PubMed Central

    Dlimi, Meriem; Boukind, Samira; Elatiqi, Oumkeltoum; Elamrani, Driss; Benchamkha, Yassine; Ettalbi, Saloua

    2015-01-01

    L’élastofibrome dorsal est une tumeur bénigne rare des parties molles siégeant typiquement sous la pointe de la scapula. Nous rapportons notre observation; pour préciser les caractéristiques cliniques et paracliniques de ce type de tumeur ainsi que les modalités de prise en charge; cette entité gagnerait à être connue par tout praticien; pour permettre une attitude thérapeutique bien codifiée. PMID:26405479

  10. Geodetic monitoring strategy at the geothermal sites of Soultz-sous-Forêts and Rittershoffen (Upper Rhine Graben, France)

    NASA Astrophysics Data System (ADS)

    Heimlich, Christine; Masson, Frédéric; Gourmelen, Noël

    2014-05-01

    The European Cenozoic rift system, and in particular the Upper Rhine Graben offers a high potential of deep geothermal energy due to the well known geothermal anomaly and to the number of subsurface temperature data from oil exploration in the Upper Rhine Graben. One example is the Soultz-sous-Forêts Enhance Geothermal System (EGS) located in the French part of the Upper Rhine Graben. The Soultz-sous-Forêts EGS started in 1987 as a deep geothermal research site. The wells are drilled in naturally fractured and altered granites from 3200 to 5260 m depth located in the vicinity of quasi North-South faults. It is the first EGS site connected to the electric network, its electric production capacity is of 1.5MWe. A second EGS site, ECOGI, is in development near the village of Rittershoffen located at 7 km from Soultz-sous-Forêts. The objective of ECOGI is to produce 24MWth energy for an industrial use with a doublet configuration of wells at depths around 2500 and 3000 meters. Both EGS sites benefit of the natural circulation of geothermal water. Some challenges in geothermal power plant are to understand the long-term behavior of the geothermal system and the induced seismicity. In the Soultz-sous-Forêts plant, borehole measures give evidences of aseismic slip (Bailleux et al., 2013). And previous geodetic monitoring studies of other deep geothermal plants show subsidence and horizontal displacements due to geothermal exploitation (e.g. Massonnet et al., 1997; Nishijima et al., 2005; Fialko and Simons, 2000). The ability of geodesy tools to provide information about dynamic behaviour and the change in the local stress field around the geothermal site make them a suitable method to meet these challenges. Therefore, we establish a long-term geodetic monitoring system of the two geothermal sites. This work presents the monitoring strategy and the preliminary results. We install a network of continuous GNSS and INSAR data are in acquisition. Our aim is to monitor

  11. Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage

    PubMed Central

    Lim, Ki-Won

    2015-01-01

    Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (p<0.05). The percentage of myoglobin denaturation (PMD) of the CA groups was also increased according to the level of CA during storage. Total aerobic counts, Enterobacteriaceae counts, volatile basic nitrogen and thiobarbituric acid reactive substances (TBARS) were generally lower in the citric acid-treated samples than in untreated ones, indicating extended shelf life of the cooked chicken breast dipped in citric acid solution. The shear force of the 2CIT and 5CIT groups was significantly lower (p<0.05). The findings indicated positive effects in the physicochemical properties and storage ability of sous vide chicken breast at 2% and 5% citric acid concentrations. PMID:26761885

  12. Influence of Sous Vide and water immersion processing on polyacetylene content and instrumental color of parsnip (Pastinaca sativa) disks.

    PubMed

    Rawson, Ashish; Koidis, Anastasios; Rai, Dilip K; Tuohy, Maria; Brunton, Nigel

    2010-07-14

    The effect of blanching (95 +/- 3 degrees C) followed by sous vide (SV) processing (90 degrees C for 10 min) on levels of two polyacetylenes in parsnip disks immediately after processing and during chill storage was studied and compared with the effect of water immersion (WI) processing (70 degrees C for 2 min.). Blanching had the greatest influence on the retention of polyacetylenes in sous vide processed parsnip disks resulting in significant decreases of 24.5 and 24% of falcarinol (1) and falcarindiol (2) respectively (p < 0.05). Subsequent SV processing did not result in additional significant losses in polyacetylenes compared to blanched samples. Subsequent anaerobic storage of SV processed samples resulted in a significant decrease in 1 levels (p < 0.05) although no change in 2 levels was observed (p > 0.05). 1 levels in WI processed samples were significantly higher than in SV samples (p

  13. Commercial food irradiation

    SciTech Connect

    Black, E.F.; Libby, L.M.

    1983-06-01

    Food irradiation is discussed. Irradiation exposes food to gamma rays from a cobalt-60 or a cesium-137 source, or to high-energy electrons emitted by an electron accelerator. A major advantage is that food can be packaged either before or after treatment. FDA regulations with regard to irradiation are discussed. Comments on an 'Advance Notice' on irradiation, published by the FDA in 1981 are summarized.

  14. Welding irradiated stainless steel

    SciTech Connect

    Kanne, W.R. Jr.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

    1993-12-31

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials.

  15. Hématome sous capsulaire de foie compliquant une pré-éclampsie: à propos de 6 cas

    PubMed Central

    Mamouni, Nisrine; Derkaoui, Ali; Bougern, Hakima; Bouchikhi, Chehrazad; Chaara, Hikmat; Banani, Abdelaziz; Abdelilah, Melhouf Moulay

    2011-01-01

    L'hématome sous capsulaire du foie (HSCF) est une complication rare mais gravissime de la grossesse. Devant une symptomatologie clinique souvent non spécifique et un tableau biologique retardé, son diagnostic est basé essentiellement sur les moyens de l'imagerie (échographie, TDM, IRM). Son traitement est fonction de l'intégrité ou non de la capsule de Glisson. Nous rapportons les observations de 6 patientes, à travers une étude rétrospective s’étalant sur la période du Janvier 2005 à Octobre 2008, incluant tous les cas de preeclampsie colligés au service de gynécologie obstétrique du CHU Hassan II. Durant la période d’étude, L'incidence de l'hématome sous capsulaire de foie chez les patientes préeclamptiques admises durant la période d’étude est de 1,49 %. Aucune des patientes n'a benificié d'un suivi prénatal au sein de notre formation. La moyenne d’âge des patientes est de 37,6 ans avec des extrêmes allant de 33 à 45 ans. La gestité moyenne était de 4,8 avec une parité moyenne de 4,5.l'hematome sous capsulaire est survenu en post partum chez tous nos cas avec un délai moyen de 4 jours et des extrêmes allant de J0 et J10 du post partum .Toutes les patientes ont présenté un HELLP syndrome concomitant à la survenue de cette complication gravissime.Le diagnostic positif s'est basé sur les données échographiques dans 5 cas (hemoperitoine –HSCF).l’équipe a opté pour une abstention thérapeutique avec surveillance armée chez 2 cas et l'exploration chirurgicale a été indiquée chez quatre patientes en instabilité hemodynamique.Nous avons déploré deux cas de décès maternel. PMID:22145072

  16. Comminuting irradiated ferritic steel

    DOEpatents

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  17. Perspective on food irradiation

    SciTech Connect

    Not Available

    1987-02-01

    Recent US Food and Drug Administration approval of irradiation treatment for fruit, vegetables and pork has stimulated considerable discussion in the popular press on the safety and efficacy of irradiation processing of food. This perspective is designed to summarize the current scientific information available on this issue.

  18. MASSIVE LEAKAGE IRRADIATOR

    DOEpatents

    Wigner, E.P.; Szilard, L.; Christy, R.F.; Friedman, F.L.

    1961-05-30

    An irradiator designed to utilize the neutrons that leak out of a reactor around its periphery is described. It avoids wasting neutron energy and reduces interference with the core flux to a minimum. This is done by surrounding all or most of the core with removable segments of the material to be irradiated within a matrix of reflecting material.

  19. Irradiation Creep in Graphite

    SciTech Connect

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13

    An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

  20. The effects of sous-vide cooking parameters on texture and cell wall modifications in two apple cultivars: A response surface methodology approach.

    PubMed

    Ortiz, Abel; Le Meurlay, Dominique; Lara, Isabel; Symoneaux, Ronan; Madieta, Emmanuel; Mehinagic, Emira

    2017-03-01

    This work aimed at evaluating the effects of sous-vide cooking parameters, such as time and temperature and their interactions, on textural attributes of 'Mondial Gala' and 'Granny Smith' apple cultivars. For this, different response surface methodology-based models were developed. This methodology proved a suitable means for the assessment of changes in textural parameters and cell wall modifications during the processing of apples. 'Mondial Gala' fruit displayed better aptitude for the preservation of textural properties after high-temperature processing conditions and were therefore apparently more suited to sous-vide cooking than 'Granny Smith' apples. Pectin methylesterase activity levels in 'Mondial Gala' apples were enhanced at mild temperatures and pectins in this cultivar displayed a lower degree of methylation. Therefore, the establishment of calcium-mediated linkages between cell wall polymers might have been favoured in 'Mondial Gala' apples, thus reinforcing tissues and improving the preservation of textural attributes, in comparison to 'Granny Smith' samples.

  1. Plaie de l'artère sous-clavière gauche par un tournevis: à propos d'un cas

    PubMed Central

    Labsaili, Hicham; Makani, Said

    2014-01-01

    Nous rapportons le cas d'un patient présentant une plaie de l'artère sous-clavière gauche suite à un traumatisme par un tournevis. Il s'agit d'une lésion rare mais grave, qui entraine souvent des complications neurologiques et respiratoires pouvant être mortelles. Dans les pays en voie de développement, la chirurgie classique à ciel ouvert reste de premier recours. PMID:25400842

  2. Microbial, physical-chemical and sensory spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method.

    PubMed

    Díaz, Pedro; Nieto, Gema; Garrido, María Dolores; Bañón, Sancho

    2008-10-01

    The aim was to study spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method. Samples were packaged under vacuum into polyamide-polypropylene pouches, cooked at an oven temperature/time of 70°C/12h, chilled at 3°C and stored at 2°C for 0, 5 or 10 weeks. Microbial (psychrotrophs, lactic acid bacteria, Enterobacteriaceae, moulds and yeasts), physical-chemical (pH, water activity, TBARS, acidity, L(∗)a(∗)b(∗) colour, texture profile analysis and shear force) and sensory (appearance, odour, flavour, texture and acceptance) parameters were determined. The results showed that sensory spoilage preceded microbiological spoilage of sous vide pork loin. Counts bellow 1logcfu/g of psychrotrophs, anaerobic psychrotrophs, Enterobacteriaceae and lactic acid bacteria were detected in any control week, while moderate counts (2-3logcfu/g) of moulds and yeasts were found. Minor changes in water activity, lipid oxidation, CIELab colour, hardness, cohesiveness or gumminess were associated with spoilage of pork loin, only decreases of lactic acid, springiness and shear force were observed. The pork loin was unacceptable after 10 weeks. This loss of acceptance was mainly due to the deterioration of meaty flavour and odour, although the loss of appearance, juiciness and firmness also contributed. Moderate warmed-over and rancidity were detected. The sensory analysis was the most effective method for determining the shelf life of the sous vide pork-based dishes.

  3. Alaskan Commodities Irradiation Project

    SciTech Connect

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.; Das, D.K.; Lewis, C.E.; Workman, W.G.; Tumeo, M.A.; Hok, C.I.; Birklid, C.A.; Bennett, F.L.

    1988-12-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology. 40 refs., 50 figs., 53 tabs.

  4. 2-D Magnetotellurics at the geothermal site at Soultz-sous-Forêts: Resistivity distribution to about 3000 m depth

    NASA Astrophysics Data System (ADS)

    Geiermann, Johannes; Schill, Eva

    2010-07-01

    With the aim of investigating the possibilities of magnetotelluric methods for the exploration of potential Enhanced Geothermal System (EGS) sites in the Upper Rhine valley, a 2-D magnetotelluric (MT) survey has been carried out on a 13 km long profile across the thermal anomaly in the area of the geothermal power plant of Soultz-sous-Forêts in the winter 2007/08. Despite strong artificial noise, processing using remote referencing and Sutarno phase consistent smoothing revealed significant results from 10 out of 16 sites. Indication for 1-D structures was found in the shortest periods, 2-D effects in the periods up to 40 s, and 3-D effects in the long period range. Since 3-D effects were found in the longer periods, 2-D inversion was carried out for periods smaller than 40 s. The results of the inversion are consistent with the geology of the geothermal site and distinguish well the sediments from the granitic basement including the structures given by the faults. A conductive anomaly with a resistivity of about 3 Ωm has been found at a depth down to 2000 m in the area of the Soultz and Kutzenhausen faults, which is attributed to geothermal processes.

  5. Food irradiation in perspective

    NASA Astrophysics Data System (ADS)

    Henon, Y. M.

    1995-02-01

    Food irradiation already has a long history of hopes and disappointments. Nowhere in the world it plays the role that it should have, including in the much needed prevention of foodborne diseases. Irradiated food sold well wherever consumers were given a chance to buy them. Differences between national regulations do not allow the international trade of irradiated foods. While in many countries food irradiation is still illegal, in most others it is regulated as a food additive and based on the knowledge of the sixties. Until 1980, wholesomeness was the big issue. Then the "prerequisite" became detection methods. Large amounts of money have been spent to design and validate tests which, in fact, aim at enforcing unjustified restrictions on the use of the process. In spite of all the difficulties, it is believed that the efforts of various UN organizations and a growing legitimate demand for food safety should in the end lead to recognition and acceptance.

  6. [The irradiation process].

    PubMed

    Barillot, I; Chauvet, B; Hannoun Lévi, J M; Lisbona, A; Leroy, T; Mahé, M A

    2016-09-01

    The purpose of this article is to describe the regulatory framework of the radiotherapy practice in France, the external irradiation and brachytherapy process and the guidelines for patient follow-up.

  7. Total lymphoid irradiation

    SciTech Connect

    Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1983-05-01

    Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen.

  8. Blood irradiation: Rationale and technique

    SciTech Connect

    Lewis, M.C. )

    1990-01-01

    Upon request by the local American Red Cross, the Savannah Regional Center for Cancer Care irradiates whole blood or blood components to prevent post-transfusion graft-versus-host reaction in patients who have severely depressed immune systems. The rationale for blood irradiation, the total absorbed dose, the type of patients who require irradiated blood, and the regulations that apply to irradiated blood are presented. A method of irradiating blood using a linear accelerator is described.

  9. Effets Seebeck et Nernst dans les cuprates: Etude de la reconstruction de la surface de Fermi sous champ magnetique intense

    NASA Astrophysics Data System (ADS)

    Laliberte, Francis

    2010-06-01

    Ce memoire presente des mesures de transport thermoelectrique, les effets Seebeck et Nernst, dans une serie d'echantillons de supraconducteurs a haute temperature critique. Des resultats obtenus recemment au Laboratoire National des Champs Magnetiques Intenses a Grenoble sur La1.7Eu0.2Sr0.1 CuO4, La1.675Eu0.2Sr0.125CuO 4, La1.64Eu0.2Sr0.16CuO4, La1.74Eu0.1Sr0.16CuO4 et La 1.4Nd0.4Sr0.2CuO4 sont analyses. Une attention particuliere est accordee aux equations de la theorie semi-classique du transport et leur validite est verifiee. La procedure experimentale et les materiaux utilises pour concevoir les montages de mesures sont expliques en detail. Enfin, un chapitre est dedie a l'explication et l'interpretation des resultats de transport thermoelectrique sur YBa2Cu3O6+delta publies au cours de l'hiver 2010 dans les revues Nature et Physical Review Letters. Les donnees d'effet Seebeck dans les echantillons de La 1.8-x,Eu0.2SrxCuO 4, ou un changement de signe est observe, permettent de conclure a la presence d'une poche d'electrons dans la surface de Fermi qui domine le transport a basse temperature dans la region sous-dopee du diagramme de phase. Cette conclusion est similaire a celle obtenue par des mesures d'effet Hall dans YBa 2Cu3O6+delta et elle cadre bien dans un scenario de reconstruction de la surface de Fermi. Les donnees d'effet Nernst recueillies indiquent que la contribution des fluctuations supraconductrices est limitee a un modeste intervalle de temperature au-dessus de la temperature critique.

  10. ORNL irradiation creep facility

    SciTech Connect

    Reiley, T.C.; Auble, R.L.; Beckers, R.M.; Bloom, E.E.; Duncan, M.G.; Saltmarsh, M.J.; Shannon, R.H.

    1980-09-01

    A machine was developed at ORNL to measure the rates of elongation observed under irradiation in stressed materials. The source of radiation is a beam of 60 MeV alpha particles from the Oak Ridge Isochronous Cyclotron (ORIC). This choice allows experiments to be performed which simulate the effects of fast neutrons. A brief review of irradiation creep and experimental constraints associated with each measurement technique is given. Factors are presented which lead to the experimental choices made for the Irradiation Creep Facility (ICF). The ICF consists of a helium-filled chamber which houses a high-precision mechanical testing device. The specimen to be tested must be thermally stabilized with respect to the temperature fluctuations imposed by the particle beam which passes through the specimen. Electrical resistance of the specimen is the temperature control parameter chosen. Very high precision in length measurement and temperature control are required to detect the small elongation rates relevant to irradiation creep in the test periods available (approx. 1 day). The apparatus components and features required for the above are presented in some detail, along with the experimental procedures. The damage processes associated with light ions are discussed and displacement rates are calculated. Recent irradiation creep results are given, demonstrating the suitability of the apparatus for high resolution experiments. Also discussed is the suitability of the ICF for making high precision thermal creep measurements.

  11. FOOD IRRADIATION REACTOR

    DOEpatents

    Leyse, C.F.; Putnam, G.E.

    1961-05-01

    An irradiation apparatus is described. It comprises a pressure vessel, a neutronic reactor active portion having a substantially greater height than diameter in the pressure vessel, an annular tank surrounding and spaced from the pressure vessel containing an aqueous indium/sup 1//sup 1//sup 5/ sulfate solution of approximately 600 grams per liter concentration, means for circulating separate coolants through the active portion and the space between the annular tank and the pressure vessel, radiator means adapted to receive the materials to be irradiated, and means for flowing the indium/sup 1//sup 1//sup 5/ sulfate solution through the radiator means.

  12. Fuel or irradiation subassembly

    DOEpatents

    Seim, O.S.; Hutter, E.

    1975-12-23

    A subassembly for use in a nuclear reactor is described which incorporates a loose bundle of fuel or irradiation pins enclosed within an inner tube which in turn is enclosed within an outer coolant tube and includes a locking comb consisting of a head extending through one side of the inner sleeve and a plurality of teeth which extend through the other side of the inner sleeve while engaging annular undercut portions in the bottom portion of the fuel or irradiation pins to prevent movement of the pins.

  13. Irradiating insect pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a non-technical article focusing on phytosanitary uses of irradiation. In a series of interview questions, I present information on the scope of the invasive species problem and the contribution of international trade in agricultural products to the movement of invasive insects. This is foll...

  14. Update on meat irradiation

    SciTech Connect

    Olson, D.G.

    1997-12-01

    The irradiation of meat and poultry in the United States is intended to eliminate pathogenic bacteria from raw product, preferably after packaging to prevent recontamination. Irradiation will also increase the shelf life of raw meat and poultry products approximately two to three times the normal shelf life. Current clearances in the United States are for poultry (fresh or frozen) at doses from 1.5 to 3.0 kGy and for fresh pork at doses from 0.3 to 1.0 kGy. A petition for the clearance of all red meat was submitted to the Food and Drug Administration (FDA) in July 1994. The petition is for clearances of fresh meat at doses from 1.5 to 4.5 kGy and for frozen meat at {approximately}2.5 to 7.5 kGy. Clearance for red meat is expected before the end of 1997. There are 28 countries that have food irradiation clearances, of which 18 countries have clearances for meat or poultry. However, there are no uniform categories or approved doses for meat and poultry among the countries that could hamper international trade of irradiated meat and poultry.

  15. Phytosanitary applications of irradiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytosanitary treatments are used to disinfest agricultural commodities of quarantine pests so the commodities can be shipped across quarantine barriers to trade. Ionizing irradiation is a promising treatment that is increasing in use. Almost 19,000 tons of sweet potatoes and several fruits, plus ...

  16. Generic phytosanitary irradiation treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The history of the development of generic phytosanitary irradiation (PI) treatments is discussed beginning with its initial proposal in 1986. Generic PI treatments in use today are 150 Gy for all hosts of Tephritidae, 250 Gy for all arthropods on mango and papaya shipped from Australia to New Zeala...

  17. NSUF Irradiated Materials Library

    SciTech Connect

    Cole, James Irvin

    2015-09-01

    The Nuclear Science User Facilities has been in the process of establishing an innovative Irradiated Materials Library concept for maximizing the value of previous and on-going materials and nuclear fuels irradiation test campaigns, including utilization of real-world components retrieved from current and decommissioned reactors. When the ATR national scientific user facility was established in 2007 one of the goals of the program was to establish a library of irradiated samples for users to access and conduct research through competitively reviewed proposal process. As part of the initial effort, staff at the user facility identified legacy materials from previous programs that are still being stored in laboratories and hot-cell facilities at the INL. In addition other materials of interest were identified that are being stored outside the INL that the current owners have volunteered to enter into the library. Finally, over the course of the last several years, the ATR NSUF has irradiated more than 3500 specimens as part of NSUF competitively awarded research projects. The Logistics of managing this large inventory of highly radioactive poses unique challenges. This document will describe materials in the library, outline the policy for accessing these materials and put forth a strategy for making new additions to the library as well as establishing guidelines for minimum pedigree needed to be included in the library to limit the amount of material stored indefinitely without identified value.

  18. Food irradiation: Activities and potentialities

    NASA Astrophysics Data System (ADS)

    Doellstaedt, R.; Huebner, G.

    After the acceptance of food irradiation up to an overall average dose of 10 kGy recommended by the Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food in October 1980, the G.D.R. started a programme for the development of techniques for food irradiation. A special onion irradiator was designed and built as a pilot plant for studying technological and economic parameters of the irradiation of onions. The new principle of bulk-cargo irradiation allows the integration of this technology into the usual harvest technology for onions on the way from field to storage. Scientific and applied research work has been carried out in the past 3 yr on the irradiation of spices, potatoes, eviscerated chicken, animal feeds, fodder yeast, drugs and vaccines. In connection with the irradiation of eviscerated chicken, fodder yeast and animal feeds the basis of an antisalmonella programme has been discussed. Germ-count-reduced spices were employed for the production of test charges of preserves and tinned products. The results have led to the decision to design and build a new multipurpose irradiator for food irradiation. In order to cover the legal aspects of food irradiation the Ministry of Health issued regulations concerning the recommendation of irradiated food in the G.D.R.

  19. Physicochemical and microbiological changes during the refrigerated storage of lamb loins sous-vide cooked at different combinations of time and temperature.

    PubMed

    Roldán, Mar; Antequera, Teresa; Hernández, Alejandro; Ruiz, Jorge

    2015-10-01

    This study aimed to determine the influence of cooking temperature (either 60 ℃ or 80 ℃) and time (6 h or 24 h) on the physicochemical (weight loss, moisture content, instrumental color, instrumental texture, lipid and protein oxidation) and microbiological changes underwent by sous-vide cooked lamb loins during refrigerated storage for 30 days. There was a slight trend to decreasing weight losses in some of the cooking treatments, but only in samples cooked at 60 ℃ for 6 h it was paralleled with an increase in moisture content. The only noteworthy oxidative change was a marked decrease in conjugated dienes after two weeks of storage in samples cooked at 80 ℃ for 24 h. Neither instrumental texture nor color showed noticeable variations during the storage. Microbial population remained quite low during the whole refrigerated storage. Overall, most of the studied parameters showed only scarce changes throughout 30 days of refrigerated storage that most likely would not influence the quality of sous-vide cooked loin lambs.

  20. ELECTRON IRRADIATION OF SOLIDS

    DOEpatents

    Damask, A.C.

    1959-11-01

    A method is presented for altering physical properties of certain solids, such as enhancing the usefulness of solids, in which atomic interchange occurs through a vacancy mechanism, electron irradiation, and temperature control. In a centain class of metals, alloys, and semiconductors, diffusion or displacement of atoms occurs through a vacancy mechanism, i.e., an atom can only move when there exists a vacant atomic or lattice site in an adjacent position. In the process of the invention highenergy electron irradiation produces additional vacancies in a solid over those normally occurring at a given temperature and allows diffusion of the component atoms of the solid to proceed at temperatures at which it would not occur under thermal means alone in any reasonable length of time. The invention offers a precise way to increase the number of vacancies and thereby, to a controlled degree, change the physical properties of some materials, such as resistivity or hardness.

  1. BIOLOGICAL IRRADIATION FACILITY

    DOEpatents

    McCorkle, W.H.; Cern, H.S.

    1962-04-24

    A facility for irradiating biological specimens with neutrons is described. It includes a reactor wherein the core is off center in a reflector. A high-exposure room is located outside the reactor on the side nearest the core while a low-exposure room is located on the opposite side. Means for converting thermal neutrons to fast neutrons are movably disposed between the reactor core and the high and low-exposure rooms. (AEC)

  2. Surface segregation during irradiation

    SciTech Connect

    Rehn, L.E.; Lam, N.Q.

    1985-10-01

    Gibbsian adsorption is known to alter the surface composition of many alloys. During irradiation, four additional processes that affect the near-surface alloy composition become operative: preferential sputtering, displacement mixing, radiation-enhanced diffusion and radiation-induced segregation. Because of the mutual competition of these five processes, near-surface compositional changes in an irradiation environment can be extremely complex. Although ion-beam induced surface compositional changes were noted as long as fifty years ago, it is only during the past several years that individual mechanisms have been clearly identified. In this paper, a simple physical description of each of the processes is given, and selected examples of recent important progress are discussed. With the notable exception of preferential sputtering, it is shown that a reasonable qualitative understanding of the relative contributions from the individual processes under various irradiation conditions has been attained. However, considerably more effort will be required before a quantitative, predictive capability can be achieved. 29 refs., 8 figs.

  3. FDA perspective on food irradiation

    SciTech Connect

    Pauli, G.H.

    1994-12-31

    The Center for Food Safety and Applied Nutrition (CFSAN) monitors the safety of food irradiation. A few limited uses are regulated, and occasionally CFSAN receives a petition for a new use. Despite extensive studies (more than 400) showing the safety of food irradiation, a cloud of suspicion continues to hang over this issue in the mind of the public. People perceive food irradiation and direct body irradiation as having similar implications. Food irradiation is banned in two states in the United States. Food is irradiated for the following purposes: delay of ripening, prevention of sprouting, eradication of pests and sterilization, and allowing commodities to be stored unrefrigerated for long periods of time. The dosage depends on the purpose of the irradiation. Radiolytic products are formed during irradiation and during storage afterward. Most of these products are also formed during conventional preservation. In 1980, CFSAN, then the Bureau of Foods, introduced the term unique radiolytic products for compounds not identified in foods after conventional processing. Although the existence of URPs was never proven chemically, the term has caused anxiety. Irradiation of foods in the commercially useful range does not generate radioactivity above natural background. Because radiolytic products formed from beef, chicken, and pork are primarily the same, irradiated foods of similar food groups may be evaluated generically.

  4. Conduction sous champ électrique faible dans les liquides isolants. Influence de la distance inter-électrodes

    NASA Astrophysics Data System (ADS)

    Touchard, G.; Chaar, S. Ai; Watanabe, S.; Borzeix, J.

    1991-07-01

    This study relates the phenomena of electric conduction in a dielectric liquid under a weak electric field. In the first part the equations of the diffuse layer perturbed by a weak electric field are established. The solutions are then computed numerically. It appears that one of the most important parameter is the space charge density appearing on the electrodes. This quantity is determined by streaming current experiments. In the second part, the experimental equipment is presented as well as the experiments. The liquid used is n heptane with several additives for different concentrations. The conductivity is measured in terms of the distance between the electrodes, the application time of the electric field and the additives concentration. We notice a sudden slope variation of the conductivity for a value of the concentration. The confrontation between experiments in terms of electrodes distance and the theoretical predictions is rather good. Dans cette étude, nous analysons les phénomènes de conduction électrique dans un liquide diélectrique soumis à un champ électrique faible entre deux électrodes planes parallèles. La première partie est une étude théorique dans laquelle nous présentons tout d'abord les équations générales de la couche diffuse correspondant au cas de la conduction sous champ électrique faible. La complexité des équations ne nous permet pas d'obtenir des solutions analytiques, mais nécessite un traitement numérique. Nous mettons alors en évidence qu'un des paramètres très importants est la densité volumique de charge apparaissant sur les électrodes. Ce paramètre conditionne le phénomène et il sera nécessaire de le déterminer par la mesure des courants d'écoulement. Dans la deuxième partie, nous présentons le dispositif expérimental utilisé ainsi que les résultats obtenus. Les expériences ont été faites avec de I'n heptane contenant un certain nombre d'additifs à des concentrations variables. La

  5. Dimensionnement des actionneurs électriques alimentés à fréquence variable sous faible tension

    NASA Astrophysics Data System (ADS)

    Biedinger, J.-M.; Vilain, J.-P.

    1999-09-01

    In Part I we present a multidisciplinary analysis model for the prediction of functional connections between the design variables and the electromagnetical, electrical and thermal performances of a brushless permanent magnet motor. In this paper we have elaborated a design methodology for electrical motors supplied from a variable-frequency low-voltage source. The objective is to take into account the influence of the inverter's dynamics from the beginning of the design, for the same reasons as we do for electromechanical and thermal constraints. The procedure is based on a Sequential Quadratic Programming optimization method. Two techniques are used to take into account the influence of the inverter: the first one develops the performance analysis with the multidisciplinary model; the second one considers the inverter's current reference as a supplementary optimization variable for the control of the design. Optimization difficulties linked to the chopping of the converter are discuted in connection with a sensitivity analysis of the torque, with respect to the inverter's current reference; a method is proposed to enhance the performances of the algorithm. The method has been applied to the design of a permanent magnet brushless DC motor used in the propulsion system of an electrical scooter; evolution of the design with the complexity level of analysis model is evidenced. Dans une première partie nous avons développé un modèle d'analyse pluridisciplinaire qui établissait les dépendances fonctionnelles entre les variables de conception et les performances magnéto-électro-thermiques d'un moteur brushless à aimants permanents. Dans cet article nous décrivons une procédure de dimensionnement adaptée à la conception de la machine alimentée à fréquence variable sous faible tension. L'objectif est d'intégrer la dynamique du convertisseur électronique dès la phase initiale du dimensionnement, au même titre que les spécifications

  6. Replacement of 137Cs irradiators with x-ray irradiators.

    PubMed

    Dodd, Brian; Vetter, Richard J

    2009-02-01

    Self-shielded 137Cs irradiators have been used for many years to irradiate blood products to prevent graft vs. host disease and to irradiate cells and small animals in research. A report by the National Academy of Sciences recommends that careful consideration be given to replacement of 137Cs irradiators with x-ray irradiators. Several manufacturers and users of x-ray irradiators were contacted to determine costs of replacing and maintaining 137Cs irradiators with x-ray units and to assess users' experience with x-ray irradiators. Purchase costs of x-ray units are similar to 137Cs irradiators, but maintenance costs are significantly higher if annual service contracts are used. Performance of the two irradiator types appears to be equivalent, but in some cases x-ray irradiations may need to be performed in multiple configurations to achieve adequate uniformity in dose. No literature reports were found that evaluated the biological effectiveness of x rays vs. 137Cs gamma rays; therefore, a careful study should be conducted to determine the biological effectiveness of x rays vs. 137Cs gamma rays for biological responses relevant to transfusion medicine and immunological research. Throughput may be problematic for large transfusion medicine programs, and back-up plans may be necessary in case the x-ray unit needs to be taken out of service for extended maintenance. Disposition of a 137Cs irradiator will add to the cost of replacement with an x-ray unit, but disposal may be possible through the U.S. Department of Energy's Off-Site Source Recovery Program.

  7. Hématome sous-capsulaire du foie rompu compliquant une stéatose hépatique aiguë gravidique

    PubMed Central

    Doumiri, Mouhssine; Elombila, Marie; Oudghiri, Nezha; Saoud, Anas Tazi

    2014-01-01

    L'hématome sous-capsulaire du foie est une complication rare de la grossesse, survenant le plus souvent dans le cadre d'une pré éclampsie ou d'un HELLP syndrome (Hemolysis, Elevated Liver enzymes, and Low Platelets Syndrome). Rare sont les cas décris au cours d'une stéatose hépatique aiguë gravidique. Nous rapportons le cas d'une parturiente de 33 ans, multipare, sans antécédents, admise aux urgences au terme d'une grossesse à 37 semaines d'aménorrhées, pour pré éclampsie compliquée d'une stéatose hépatique aiguë gravidique. L’échographie hépatique réalisée à l'admission était sans anomalie. Une césarienne a été réalisée en urgence devant une souffrance fœtale aiguë, au cours de laquelle a été mise en évidence une rupture de l'hématome sous capsulaire du foie s'accompagnant d'un état de choc hémorragique. La prise en charge a consisté à une polytransfusion et packing perihépatique. Le retrait du packing n'a été réalisé qu'au quatrième jour, après stabilisation clinicobiologique et régression de l'encéphalopathie hépatique. L’évolution en réanimation a été favorable avec sortie de la patiente au vingtième jour. La rupture de l'hématome sous-capsulaire du foie est extrêmement dangereuse et à haut risque materno-fœtal. L'association à la stéatose hépatique aggrave le pronostic. PMID:25667700

  8. Craniospinal irradiation techniques

    SciTech Connect

    Scarlatescu, Ioana Avram, Calin N.; Virag, Vasile

    2015-12-07

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  9. Irradiation of northwest agricultural products

    NASA Astrophysics Data System (ADS)

    Eakin, D. E.; Tingey, G. I.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect ocntrol procedures are developed and followed. Due to the recognized potential benefits of irradiation, this program was conducted to evaluate the benefits of using irradiation on Northwest agricultural products. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  10. Food irradiation and the consumer

    NASA Astrophysics Data System (ADS)

    A Thomas, P.

    The poster presents a review of research work undertaken on the perception and understanding that consumers have of food irradiation. Food irradiation is not a revolutionary new food processing technique, in fact it is probably one of the most investigated methods presently available. Many countries such as Belgium, France, Denmark, Italy, Spain, the Netherlands and the United States of America permit food irradiation. In Britain it is presently banned although this is currently under review. Awareness of food irradiation by the general public in Britain, although not extensively researched would appear to be increasing, especially in the light of recent media coverage. New quantitative and qualitative work indicates that the general public are concerned about the safety and effectiveness of food irradiation. Research has shown that a large proportion of consumers in Britain, if given the opportunity to purchase irradiated food, would not do so. Further exploration into this response revealed the fact that consumers are confused over what food irradiation is. In addition, there is concern over the detection of irradiated food. The views presented in this paper, of the consumer reaction to irradiated food are of great importance to those involved in the food industry and industries allied to it, which are ultimately dependent on the consumer for their commercial survival.

  11. Description matricielle de l'anisotropie de la transition inter-sous-bande d'une structure à multi-puits quantiques

    NASA Astrophysics Data System (ADS)

    Boucher, Y. G.; Le Rouzo, J.; Ribet, I.; Haïdar, R.; Guérineau, N.

    2006-10-01

    Dans un puits quantique, les transitions radiatives inter-sous-bande sont telles que seule la composante du champ électrique parallèle à l'axe de croissance est affectée. Cette spécificité confère à l'absorption un caractère foncièrement anisotrope. Nous établissons la matrice de transfert d'une structure à multi-puits quantiques en assimilant chaque puits à une couche mince anisotrope uniaxe. À l'anisotropie intrinsèque (règles de sélection) se superpose une anisotropie structurelle (biréfringence de forme). Les symétries du système permettent néanmoins de découpler les états de polarisation (s) et (p).

  12. Thyroïdectomies pratiquées sous anesthésie locale au Centre Hospitalier Universitaire d'Antananarivo

    PubMed Central

    Razafindrakoto, Rex Mario; Razafindranaivo, Mananjara Nandrianina; Valisoa, Herimalalaniaina Angelo; Schammirah, Mahamad Rojovolaarivony; Randriamboavonjy, Rado

    2015-01-01

    Menée le plus souvent sous anesthésie générale, la chirurgie thyroïdienne peut aussi être pratiquée sous anesthésie régionale ou sous anesthésie locale. Notre objectif a été de rapporter l'expérience du Centre Hospitalier Universitaire d'Antananarivo sur l'anesthésie locale dans les thyroïdectomies. La drogue employée dans notre protocole anesthésique a été le fentanyl, administré en intraveineuse directe, associé à une infiltration sous-cutanée de lidocaïne suivant la ligne d'incision. Le/la patient(e) n'a pas été intubé(e), l'oxygène étant délivré au niveau des cavités nasales. Ont été étudiés le type de chirurgie thyroïdienne, la durée de l'intervention, la satisfaction des patient(e)s vis-à-vis de la qualité de l'anesthésie, et le coût de l'intervention. Sur 567 thyroïdectomies effectuées, 51,68% (n= 293) ont été des lobo-isthmectomies gauches, 44,44% (n= 252) des lobo-isthmectomies droites, 2,82% (n= 16) des thyroïdectomies subtotales ou totales, 1,06% (n= six) des totalisations pour carcinomes thyroïdiens. La durée des interventions a varié de 30 à 90 minutes. Un total de 83,95% (n= 476) des patient(e)s a été très satisfait de la qualité de l'anesthésie et 15,87% autres (n= 90) satisfait. Les suites opératoires ont été bonnes dans la majorité des cas. Le coût d'une thyroïdectomie a été évalué à 100- 150 dollars américains. L'anesthésie locale utilisée dans les thyroïdectomies effectuées au Centre Hospitalier Universitaire d'Antananarivo est simple, rapide, d'un coût moyen, et permet d'alarmer précocement le chirurgien en cas de lésion d'un nerf laryngé inférieur. PMID:26587128

  13. Food irradiation and sterilization

    NASA Astrophysics Data System (ADS)

    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.

  14. Wholesomeness of irradiated food

    NASA Astrophysics Data System (ADS)

    Ehlermann, Dieter A. E.

    2016-12-01

    Just with the emergence of the idea to treat food by ionizing radiation, the concerns were voiced whether it would be safe to consume such food. Now, we look back on more than hundred years of research into the 'wholesomeness', a terminology developed during those efforts. This review will cover the many questions which had been raised, explaining the most relevant ones in some detail; it will also give place to the concerns and elucidate their scientific relevance and background. There has never been any other method of food processing studied in such depth and in such detail as food irradiation. The conclusion based on science is: Consumption of any food treated at any high dose is safe, as long as the food remains palatable. This conclusion has been adopted by WHO, also by international and national bodies. Finally, this finding has also been adopted by Codex Alimentarius in 2003, the international standard for food. However, this conclusion has not been adopted and included at its full extent in most national regulations. As the literature about wholesomeness of irradiated food is abundant, this review will use only a few, most relevant references, which will guide the reader to further reading.

  15. Safety Evaluation of Sous Vide-Processed Products with Respect to Nonproteolytic Clostridium botulinum by Use of Challenge Studies and Predictive Microbiological Models

    PubMed Central

    Hyytiä-Trees, Eija; Skyttä, Eija; Mokkila, Mirja; Kinnunen, Arvo; Lindström, Miia; Lähteenmäki, Liisa; Ahvenainen, Raija; Korkeala, Hannu

    2000-01-01

    Sixteen different types of sous vide-processed products were evaluated for safety with respect to nonproteolytic group II Clostridium botulinum by using challenge tests with low (2.0-log-CFU/kg) and high (5.3-log-CFU/kg) inocula and two currently available predictive microbiological models, Food MicroModel (FMM) and Pathogen Modeling Program (PMP). After thermal processing, the products were stored at 4 and 8°C and examined for the presence of botulinal spores and neurotoxin on the sell-by date and 7 days after the sell-by date. Most of the thermal processes were found to be inadequate for eliminating spores, even in low-inoculum samples. Only 2 of the 16 products were found to be negative for botulinal spores and neurotoxin at both sampling times. Two products at the high inoculum level showed toxigenesis during storage at 8°C, one of them at the sell-by date. The predictions generated by both the FMM thermal death model and the FMM and PMP growth models were found to be inconsistent with the observed results in a majority of the challenges. The inaccurate predictions were caused by the limited number and range of the controlling factors in the models. Based on this study, it was concluded that the safety of sous vide products needs to be carefully evaluated product by product. Time-temperature combinations used in thermal treatments should be reevaluated to increase the efficiency of processing, and the use of additional antibotulinal hurdles, such as biopreservatives, should be assessed. PMID:10618228

  16. Commercial implementation of food irradiation

    NASA Astrophysics Data System (ADS)

    Welt, M. A.

    In July 1981, the first specifically designed multi-purpose irradiation facility for food irradiation was put into service by the Radiation Technology, Inc. subsidiary Process Technology, Inc. in West Memphis, Arkansas. The operational experience gained, resulted in an enhanced design which was put into commercial service in Haw River, North Carolina, by another subsidiary, Process Technology (N.C.), Inc. in October 1983. These facilities have enabled the food industry to assess the commercial viability of food irradiation. Further impetus towards commercialization of food irradiation was gained in March 1981 with the filing in the Federal Register, by the FDA, of an Advanced Proposed Notice of Rulemaking for Food Irradiation. Two years later in July 1983, the FDA approved the first food additive regulation involving food irradiation in nineteen years, when they approved the Radiation Technology, Inc. petition calling for the sanitization of spices, onion powder and garlic powder at a maximum dosage of 10 kGy. Since obtaining the spice irradiation approval, the FDA has accepted four additional petitions for filing in the Federal Register. One of the petitions which extended spice irradiation to include insect disinfestation has issued into a regulation while the remaining petitions covering the sanitization of herbs, spice blends, vegetable seasonings and dry powdery enzymes as well as the petition to irradiate hog carcasses and pork products for trichinae control at 1 kGy, are expected to issue either before the end of 1984 or early in 1985. More recently, food irradiation advocates in the United States received another vote of confidence by the announcement that a joint venture food irradiation facility to be constructed in Hawaii by Radiation Technology, is backed by a contractual committment for the processing of 40 million pounds of produce per year. Another step was taken when the Port of Salem, New Jersey announced that the Radiation Technology Model RT-4104

  17. Pallet irradiators for food processing

    NASA Astrophysics Data System (ADS)

    McKinnon, R. G.; Chu, R. D. H.

    This paper looks at the various design concepts for the irradiation processing of food products, with particular emphasis on handling the products on pallets. Pallets appear to offer the most attractive method for handling foods from many considerations. Products are transported on pallets. Warehouse space is commonly designed for pallet storage and, if products are already palletized before and after irradiation, then labour could be saved by irradiating on pallets. This is also an advantage for equipment operation since a larger carrier volume means lower operation speeds. Different pallet irradiator design concepts are examined and their suitability for several applications are discussed. For example, low product holdup for fast turn around will be a consideration for those operating an irradiation "service" business; others may require a very large source where efficiency is the primary requirement and this will not be consistent with low holdup. The radiation performance characteristics and processing costs of these machines are discussed.

  18. Phytosanitary irradiation - Development and application

    NASA Astrophysics Data System (ADS)

    Hallman, Guy J.; Loaharanu, Paisan

    2016-12-01

    Phytosanitary irradiation, the use of ionizing radiation to disinfest traded agricultural commodities of regulated pests, is a growing use of food irradiation that has great continued potential for increase in commercial application. In 2015 approximately 25,000 t of fresh fruits and vegetables were irradiated globally for phytosanitary purposes. Phytosanitary irradiation has resulted in a paradigm shift in phytosanitation in that the final burden of proof of efficacy of the treatment has shifted from no live pests upon inspection at a port of entry (as for all previous phytosanitary treatments) to total dependence on certification that the treatment for target pests is based on adequate science and is commercially conducted and protected from post-treatment infestation. In this regard phytosanitary irradiation is managed more like a hazard analysis and critical control point (HACCP) approach more consistent with food safety than phytosanitation. Thus, phytosanitary irradiation offers a more complete and rigorous methodology for safeguarding than other phytosanitary measures. The role of different organizations in achieving commercial application of phytosanitary irradiation is discussed as well as future issues and applications, including new generic doses.

  19. New facility for post irradiation examination of neutron irradiated beryllium

    SciTech Connect

    Ishitsuka, Etsuo; Kawamura, Hiroshi

    1995-09-01

    Beryllium is expected as a neutron multiplier and plasma facing materials in the fusion reactor, and the neutron irradiation data on properties of beryllium up to 800{degrees}C need for the engineering design. The acquisition of data on the tritium behavior, swelling, thermal and mechanical properties are first priority in ITER design. Facility for the post irradiation examination of neutron irradiated beryllium was constructed in the hot laboratory of Japan Materials Testing Reactor to get the engineering design data mentioned above. This facility consist of the four glove boxes, dry air supplier, tritium monitoring and removal system, storage box of neutron irradiated samples. Beryllium handling are restricted by the amount of tritium;7.4 GBq/day and {sup 60}Co;7.4 MBq/day.

  20. Proton irradiation of simple gas mixtures: Influence of irradiation parameters

    NASA Technical Reports Server (NTRS)

    Sack, Norbert J.; Schuster, R.; Hofmann, A.

    1990-01-01

    In order to get information about the influence of irradiation parameters on radiolysis processes of astrophysical interest, methane gas targets were irradiated with 6.5 MeV protons at a pressure of 1 bar and room temperature. Yields of higher hydrocarbons like ethane or propane were found by analysis of irradiated gas samples using gas chromatography. The handling of the proton beam was of great experimental importance for determining the irradiation parameters. In a series of experiments current density of the proton beam and total absorbed energy were shown to have a large influence on the yields of produced hydrocarbons. Mechanistic interpretations of the results are given and conclusions are drawn with regard to the chemistry and the simulation of various astrophysical systems.

  1. Les facteurs prédictifs de morbimortalité chez les patients sous ballon de contre pulsion intra-aortique en chirurgie cardiaque

    PubMed Central

    Elahmadi, Brahim; Motiaa, Youssef; Hatim, Abdedaim Elghadbane; Atmani, Noureddine; Moutakillah, Younes; Wahid, Fouad Amal; Elbekkali, Youssef; Houssa, Mahdi Ait; Razine, Rachid; Boulahya, Abdelatif; Drissi, Mohammed

    2015-01-01

    Le ballon de contre pulsion intra-aortique (BCPIA) est fréquemment utilisé en chirurgie cardiaque, comme moyen d'assistance circulatoire en cas de bas débit cardiaque. Il est d'intérêt clinique de déterminer les facteurs pronostiques chez les patients porteurs d'un BCPIA en chirurgie cardiaque, et qui restent un sujet rarement élucidé dans la littérature. L'objectif de notre travail est de déterminer les facteurs prédictifs de morbi-mortalité chez les patients sous ballon de contre pulsion intraortique en périopératoire d'une chirurgie cardiaque. Il s'agit d'une étude rétrospective portant sur l'ensemble des patients opérés en chirurgie cardiaque sous circulation extracorporelle, et ayant bénéficiés de la mise en place d'un ballon de contre pulsion intra-aortique en périopératoire, au service de chirurgie cardiovasculaire de l'Hôpital Militaire Mohamed V de Rabat, entre le mois de janvier 2005 et le mois d'aout 20014. Soixante dix patients ont été inclus dans notre étude. En analyse univariée l'âge, la dyspnée de stade III et IV, l'insuffisance cardiaque, la présence d'un infarctus du myocarde, d'une coronaropathie mono et bitronculaire, les anomalies du doppler de trons supra-aortique et du membre inférieur, le caractère urgent de la chirurgie, la durée de la circulation extracorporelle, l'instabilité hémodynamique postopératoire, le saignement et l'insuffisance rénale postopératoire étaient statistiquement associés à une mortalité postopératoire élevée. La dyskinésie préopératoire et la sortie de circulation extracorporelle sous drogues étaient associées à une morbidité globale élevée. En analyse multi variée, seule l'âge, constituait un facteur de risque indépendant de mortalité dans notre série avec un Odds Ratio (OR): 1,89 ; un Intervalle de Confiance (IC) 95% de (1,52-4,97) et un p =0,045. Au terme de notre étude, le taux de mortalité était de 48,57% et de morbidité globale était de 87,1%. Il

  2. Incidence des accidents vasculaires cérébraux chez les patients VIH positifs sous traitement antirétroviral au long court

    PubMed Central

    Mapoure, Yacouba Njankouo; Nkongni, Ines Nepetsoun; Luma, Henry Namme; Ngahane, Bertrand Hugo Mbtachou; Barla, Esther; Ngwane, Samuel; Mouelle, Albert Soné; Njamnshi, Alfred Kongnyu

    2016-01-01

    Introduction Avec l'introduction de la trithérapie dans les années 1996, la morbidité et la mortalité liées à l'infection par le VIH a nettement diminué. Concomitamment avec ce succès clinique, plusieurs changements métaboliques incluant diabète, hypertension artérielle, dyslipidémie et lipodystrophie ont été observés, ceux-ci étant des pourvoyeurs d'accidents vasculaires cérébraux. L'objectif de ce travail était de déterminer l'incidence des accidents vasculaires cérébraux chez les patients VIH positifs sous traitement antirétroviral au long court. Méthodes Il s'agissait d'une étude de cohorte rétrospective, menée dans le Centre de Traitement Agrée de l'Hôpital Général de Douala (HGD), avec un recueil des données sur 10 ans allant de Mai 2001 à avril 2010, portant sur les patients VIH positifs adultes sous traitement antirétroviral depuis au moins 6 mois. Les patients étaient suivis selon le protocole national de prise en charge du Cameroun. La survenue d'un AVC a été déterminée par la méthode Kaplan-Meyer tandis que les facteurs associés à la survenue d'un AVC ont été recherché par le test de Khi-2. Le seuil de signification statistique était fixé à 0,05. Résultats 307 patients étaient inclus dont 62,4% de sexe féminin, et l’âge moyen était de 40,1 ± 9,9 ans. L'incidence des AVC était de 1,7% sur 72 mois de suivi sans différence significative entre les femmes et les hommes (P= 0,76). Le taux d'incidence calculé était de 0,3 pour 100 personnes années. Dans 85,7% des cas il s'agissait d'un AVC ischémique. Le délai moyen de survenue d'un AVC était de 33,4 mois. Les facteurs associés à la survenue d'un AVC étaient: les patients ayant initié leur traitement au stade III et IV de l'OMS et le taux de CD4 > 100/mm3 à l'initiation du traitement antirétroviral. Conclusion L'incidence des AVC chez les patients VIH positifs sous traitement antirétroviral est similaire à celle rapportée ant

  3. Thermodynamic and kinetic modeling of mineralogical evolution in the Soultz-sous-Forêts geothermal system: insights into the reaction pathways

    NASA Astrophysics Data System (ADS)

    Van Ngo, Viet; Lucas, Yann; Clément, Alain; Fritz, Bertrand

    2015-04-01

    The energy production from hot fractured rocks has been investigated at the Soultz-sous-Forêts EGS (Alsace, France) from nearly three decades. Three wells have been drilled up to the depth of about 5000 m in which two wells are served as the fluid production and the third as a fluid re-injection. The circulation of geothermal fluids through the fractured reservoir leads to a strong chemical nonequilibrium of the solid and aqueous phases, which potentially cause changes in porosity, permeability, and flow pathways of the geothermal reservoir. Numerous experimental and modeling studies (e.g., Dubois et al., 2000; Baldeyrou et al., 2003; Ledésert et al., 2009; Fritz et al., 2010; Ledésert et al., 2010) carried out within the framework of the Soultz-sous-Forêts system have reported that quartz, calcite and illites are formed as the major secondary phases in the main fractures. Some contributions among the above publications further indicated that calcite plays an important role in the reduction of permeability of the fractured zones and illites are considered as a characteristic product of the hydrothermal vein alteration. Therefore, it is important to predict the evolution of minerals (especially for quartz, calcite, and illites), which may potentially modify the transport properties of the geothermal reservoir (e.g., Ledésert et al., 2009; Fritz et al., 2010). Understanding the changes in mineralogy in the fractured zones is also useful to choose the reagents in order to improve the permeability of the geothermal reservoir via the chemical stimulation. The overall objectives of the current study are to (i) investigate the long-term evolution of mineralogy in the geothermal Soultz-sous-Forêts Enhanced Geothermal System (EGS), (ii) establish the relationship between different mineral groups, (iii) study the reaction pathways, and (iv) compare the thermodynamic and kinetic approaches. The numerical calculations carried out using the KINDIS numerical code were

  4. (Irradiation creep of graphite)

    SciTech Connect

    Kennedy, C.R.

    1990-12-21

    The traveler attended the Conference, International Symposium on Carbon, to present an invited paper, Irradiation Creep of Graphite,'' and chair one of the technical sessions. There were many papers of particular interest to ORNL and HTGR technology presented by the Japanese since they do not have a particular technology embargo and are quite open in describing their work and results. In particular, a paper describing the failure of Minor's law to predict the fatigue life of graphite was presented. Although the conference had an international flavor, it was dominated by the Japanese. This was primarily a result of geography; however, the work presented by the Japanese illustrated an internal program that is very comprehensive. This conference, a result of this program, was better than all other carbon conferences attended by the traveler. This conference emphasizes the need for US participation in international conferences in order to stay abreast of the rapidly expanding HTGR and graphite technology throughout the world. The United States is no longer a leader in some emerging technologies. The traveler was surprised by the Japanese position in their HTGR development. Their reactor is licensed and the major problem in their graphite program is how to eliminate it with the least perturbation now that most of the work has been done.

  5. Generic phytosanitary irradiation treatments

    NASA Astrophysics Data System (ADS)

    Hallman, Guy J.

    2012-07-01

    The history of the development of generic phytosanitary irradiation (PI) treatments is discussed beginning with its initial proposal in 1986. Generic PI treatments in use today are 150 Gy for all hosts of Tephritidae, 250 Gy for all arthropods on mango and papaya shipped from Australia to New Zealand, 300 Gy for all arthropods on mango shipped from Australia to Malaysia, 350 Gy for all arthropods on lychee shipped from Australia to New Zealand and 400 Gy for all hosts of insects other than pupae and adult Lepidoptera shipped to the United States. Efforts to develop additional generic PI treatments and reduce the dose for the 400 Gy treatment are ongoing with a broad based 5-year, 12-nation cooperative research project coordinated by the joint Food and Agricultural Organization/International Atomic Energy Agency Program on Nuclear Techniques in Food and Agriculture. Key groups identified for further development of generic PI treatments are Lepidoptera (eggs and larvae), mealybugs and scale insects. A dose of 250 Gy may suffice for these three groups plus others, such as thrips, weevils and whiteflies.

  6. Irradiation of Northwest agricultural products

    SciTech Connect

    Eakin, D.E.; Tingey, G.L.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  7. Irradiation pretreatment for coal desulfurization

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.

    1979-01-01

    Process using highly-penetrating nuclear radiation (Beta and Gamma radiation) from nuclear power plant radioactive waste to irradiate coal prior to conventional desulfurization procedures increases total extraction of sulfur.

  8. Investigation of fluid flow paths within granitic batholiths: the Soultz-sous-Forêts 'Enhanced Geothermal System' and the Catalan Coastal Ranges examples

    NASA Astrophysics Data System (ADS)

    Place, Joachim; Geraud, Yves; Diraison, Marc; Le Garzic, Edouard; Sausse, Judith

    2010-05-01

    Geothermal exploitation of deep and hot rocks at industrial scale requires an accurate assessment of the available resource. In particular, temperature, porosity, connected porosity, fluids path, permeability, rock volume attainable by drainage, have to be constrained to forecast the potential of an area, and to further manage the heat resource during exploitation. We will present our work devoted to structural controls on fluid circulations in deep granitic basements. The first example is the current Soultz-sous-Forêts EGS being developed for over 20 years in the hot granite of the Upper Rhine Graben. Depth levels of naturally flowing deformation zones are known at well positions, but the fluid flow paths between the boreholes are still poorly understood. Our new developments of Vertical Seismic Profiling methods provide mapping of these permeable structures between the boreholes in 3D, below the sedimentary filling of the graben in the 1500-3500 depth range. As typical hercynian strike directions are identified, this study demonstrates the major role of inherited structures in the control of fluid flow paths. 3D representation with gOcad allows to build a reservoir model from various data. Such 3D approach is of major importance to identify the structural relations between the faults populations, especially their intersections and connectivity. The second example is also located within the European Cenozoic Rift System. Outcropping granites of the Catalan Coastal Ranges allow to access their structures in 3D with a comprehensive set of methods. Multi-scalar fractures have been identified from Digital Elevation Model to field analysis. Carbonate fillings are observed in fractures of specific orientations. They illustrate old fluid flow paths occurring in natural conditions. Conditions of their emplacement are provided by geochemical signatures. The geometry of the veins (orientations and connections) and their distribution illustrate how a rock mass volume can be

  9. Effect of Grapefruit Seed Extract on Thermal Inactivation of Listeria monocytogenes during Sous-Vide Processing of Two Marinated Mexican Meat Entrées.

    PubMed

    Valenzuela-Melendres, Martin; Peña-Ramos, E Aida; Juneja, Vijay K; Camou, Juan Pedro; Cumplido-Barbeitia, German

    2016-07-01

    D- and z-values for Listeria monocytogenes were obtained for two Mexican meat entrées: pork meat marinated in tomatillo (green tomato) sauce (PTS) and beef marinated in a red chili sauce (BRCS), with addition of 0, 200, and 800 ppm of grapefruit seed extract (GSE). Meat samples inoculated with L. monocytogenes were packaged in sterile bags, immersed in a water bath, and held at 55, 57.5, 60, and 62.5°C for different periods of time. Depending upon the temperature, D-values at 0 ppm of GSE ranged from 26.19 to 2.03 min in BRCS and 26.41 to 0.8 min in PTS. Adding 800 ppm of GSE to BRCS thermally treated at 55 and 62.5°C significantly decreased inactivation time by 35%. A reduction in time of 25.9, 10.6, and 40.1% at 55, 57.5, and 60°C, respectively, was observed in PTS with 800 ppm of GSE. The z-values of L. monocytogenes were not significantly affected by GSE addition; average z-values were 7.25 and 5.09°C for BRCS and PTS, respectively. Estimated thermal lethality for a 7-D log reduction of L. monocytogenes under commercial-size sous-vide conditions at a reference temperature of 55°C was reached at 78 and 71 min for BRCS without and with 800 ppm of GSE, respectively. For PTS, 7-D reduction was attained at 69 and 61 min without and with addition of 800 ppm of GSE, respectively. Supplementing both Mexican meat entrées (BRCS and PTS) with 800 ppm of GSE rendered L. monocytogenes cells more sensitive to the lethal effect of heat. The results of this study will assist the retail food industry in designing acceptance limits on critical control points pertaining to cooking regimes to effectively eliminate L. monocytogenes in BRCS and PTS sous-vide processed Mexican meat entrées.

  10. Cinétique de la troponine Ic et valeurs seuils pour le diagnostic d'infarctus du myocarde après chirurgie cardiaque sous circulation extracorporelle

    PubMed Central

    Kallel, Samy; Jarraya, Anwar; Ellouze, Maged; Frikha, Imed; Karoui, Abbdelhamid

    2012-01-01

    Introduction L'objectif de ce travail était d’étudier la cinétique de la Troponine Ic (TnIc) après chirurgie cardiaque sous circulation extracorporelle (CEC) et établir des valeurs seuils de TnIc pour le diagnostic d'infarctus du myocarde (IDM) post opératoire. Il s'agissait d'une étude prospective type cohorte observationnelle. Méthodes Nous avons inclus 37 patients âgés de plus de 18 ans proposés pour chirurgie valvulaire ou pontage aorto coronarien sous CEC. Nous avons suivi la cinétique de TnIc par des dosages immunoenzymatique sur mini-vidas® avant et après la CEC, à H4 et H12 postopératoire puis tous les jours les 4 premiers jours. Le cutoff pour le diagnostic d'IDM post opératoire a été défini comme la valeur moyenne de troponine + deux déviations standards des patients indemnes de complications cardiaques. Résultats Les valeurs de TnIc en préopératoire étaient toutes inférieures au seuil de détection de la méthode de dosage (<0,01µg/l). Les valeurs de TnIc augmentent en postopératoire immédiat pour atteindre un maximum à H4 puis diminuent progressivement pour se normaliser après 4 à 5 jours. Les valeurs seuils ont été déterminées pour H0, H4,H12, H24, H48, H72, H96 et ont été respectivement 1.36, 2.58, 3.1, 3.23, 2.13, 1.53, 1.17 pour la chirurgie coronaire et 3.75, 5.39, 4.22, 3.41, 1.65, 1.3 1.19 pour la chirurgie valvulaire. Conclusion La connaissance de la cinétique de TnIc lors de chirurgie cardiaque non compliquée et la fixation de valeur seuil ou Cutoff permet aux cliniciens de distinguer entre dommage myocardique secondaire à la chirurgie et IDM. PMID:23396754

  11. Slag recycling of irradiated vanadium

    SciTech Connect

    Gorman, Patrick K.

    1995-04-05

    An experimental inductoslag apparatus to recycle irradiated vanadium was fabricated and tested. An experimental electroslag apparatus was also used to test possible slags. The testing was carried out with slag materials that were fabricated along with impurity bearing vanadium samples. Results obtained include computer simulated thermochemical calculations and experimentally determined removal efficiencies of the transmutation impurities. Analyses of the samples before and after testing were carried out to determine if the slag did indeed remove the transmutation impurities from the irradiated vanadium.

  12. Consumer attitudes toward irradiated food

    SciTech Connect

    Conley, S.

    1994-12-31

    Throughout history, new methods of food preservation have been met with skepticism and fear. Such processes as pasteurization and canning were denounced as being dangerous, detrimental to nutrients, or an excuse for dirty products. Now comes irradiation, and activists argue against this new process for the same reasons. Publicly, the perception is that consumers, distrustful of nuclear power, will never buy or accept irradiated food.

  13. Calculating Irradiance For Photosynthesis In The Ocean

    NASA Technical Reports Server (NTRS)

    Collins, Donald J.; Davis, Curtiss O.; Booth, C. Rockwell; Kiefer, Dale A.; Stallings, Casson

    1990-01-01

    Mathematical model predicts available and usable irradiances. Yields estimates of irradiance available for photosynthesis (Epar) and irradiance usable for photosynthesis (Epur) as functions of depth in ocean. Describes Epur and Epar in terms of spectral parameters measured remotely (from satellites or airplanes). These irradiances useful in studies of photosynthetic productivity of phytoplankton in euphotic layer.

  14. Irradiance-dependent UVB Photocarcinogenesis

    PubMed Central

    Lan, Cheng-Che E.; Wu, Ching-Shuang; Huang, Shu-Mei; Wu, Chin-Han; Lai, Hsiao-Chi; Peng, Yu-Ting; Hou, Pao-Sheng; Yang, Hui-Jun; Chen, Gwo-Shing

    2016-01-01

    Ultraviolet B (UVB) radiation from the sun may lead to photocarcinogenesis of the skin. Sunscreens were used to protect the skin by reducing UVB irradiance, but sunscreen use did not reduce sunburn episodes. It was shown that UVB-induced erythema depends on surface exposure but not irradiance of UVB. We previously showed that irradiance plays a critical role in UVB-induced cell differentiation. This study investigated the impact of irradiance on UVB-induced photocarcinogenesis. For hairless mice receiving equivalent exposure of UVB radiation, the low irradiance (LI) UVB treated mice showed more rapid tumor development, larger tumor burden, and more keratinocytes harboring mutant p53 in the epidermis as compared to their high irradiance (HI) UVB treated counterpart. Mechanistically, using cell models, we demonstrated that LI UVB radiation allowed more keratinocytes harboring DNA damages to enter cell cycle via ERK-related signaling as compared to its HI UVB counterpart. These results indicated that at equivalent exposure, UVB radiation at LI has higher photocarcinogenic potential as compared to its HI counterpart. Since erythema is the observed sunburn at moderate doses and use of sunscreen was not found to associate with reduced sunburn episodes, the biological significance of sunburn with or without sunscreen use warrants further investigation. PMID:27869214

  15. Computing Solar EUV Irradiance Variability

    NASA Astrophysics Data System (ADS)

    Warren, H. P.

    2014-12-01

    The solar EUV irradiance plays a central role in determining the state of the Earth's upper atmosphere. The EUV irradiance at the shortest wavelengths, which is highly variable over time scales from seconds to decades, is particularly important for many aspects of space weather. Systematic spectrally resolved observations at the shortest EUV wavelengths, however, have been rare and there is a need to develop a methodology for estimating and forecasting the solar irradiance at all EUV wavelengths from sparse data sets. In this presentation we report on our efforts to use AIA DEM calculations to estimate the solar EUV irradiance at wavelength below 450 Å, where the emission is predominately optically thin. To validate our AIA DEM calculations we have performed extensive comparisons with simultaneous observations from the EVE instrument on SDO and the EIS instrument on Hinode and find that with the proper constraints we can generally reproduce the results obtained with detailed spectroscopic observations. Using a proxy for solar activity derived from photospheric magnetic field measurements we extend our model calculations to previous solar cycles and discuss how the model can be used to forecast EUV irradiance variability over short time scales. Finally, we speculate on what is needed to further develop semi-empirical and physical models for use in understanding the solar spectral irradiance at these wavelengths.

  16. Targeted cytoplasmic irradiation and autophagy.

    PubMed

    Wu, Jinhua; Zhang, Bo; Wuu, Yen-Ruh; Davidson, Mercy M; Hei, Tom K

    2017-03-01

    The effect of ionizing irradiation on cytoplasmic organelles is often underestimated because the general dogma considers direct DNA damage in the nuclei to be the primary cause of radiation induced toxicity. Using a precision microbeam irradiator, we examined the changes in mitochondrial dynamics and functions triggered by targeted cytoplasmic irradiation with α-particles. Mitochondrial dysfunction induced by targeted cytoplasmic irradiation led to activation of autophagy, which degraded dysfunctional mitochondria in order to maintain cellular energy homeostasis. The activation of autophagy was cytoplasmic irradiation-specific and was not detected in nuclear irradiated cells. This autophagic process was oxyradical-dependent and required the activity of the mitochondrial fission protein dynamin related protein 1 (DRP1). The resultant mitochondrial fission induced phosphorylation of AMP activated protein kinase (AMPK) which leads to further activation of the extracellular signal-related kinase (ERK) 1/2 with concomitant inhibition of the mammalian target of rapamycin (mTOR) to initiate autophagy. Inhibition of autophagy resulted in delayed DNA damage repair and decreased cell viability, which supports the cytoprotective function of autophagy. Our results reveal a novel mechanism in which dysfunctional mitochondria are degraded by autophagy in an attempt to protect cells from toxic effects of targeted cytoplasmic radiation.

  17. Une complication exceptionnelle de la pose d'une voie veineuse centrale jugulaire interne: pneumothorax, pneumo médiastin et retro pneumopéritoine et emphysème sous cutané géant

    PubMed Central

    Belkouch, Ahmed; Sirbou, Rachid; Zidouh, Saad; Chouaib, Naoufal; Rafai, Mostafa; Belyamani, Lahcen

    2015-01-01

    L'association: pneumothorax, pneumo médiastin, retro pneumopéritoine et emphysème sous cutané est connue de longue date comme complication de l'intubation et la ventilation mécanique, de l'endoscopie digestive ou de la chirurgie laparoscopique. En dehors de ce contexte, elle demeure inhabituelle surtout dans le cadre de La pose de voies veineuses centrales puisque le risque encouru est celui d'une brèche pleurale avec pneumothorax, il est surtout lié à la mise en place d'un cathéter central sous-clavier plus que lors de la pose d'une voie centrale par voie jugulaire. Nous rapportons le cas d'une patiente qui a souffert d'un pneumothorax associé à, un pneumo médiastin, un rétro pneumopéritoine et un emphysème sous cutané géant, suite à une tentative de catéthérisation de la veine jugulaire interne par voie postérieure. L'intérêt de cette observation réside dans la rareté exceptionnelle de cette association chez une patiente en ventilation spontanée et dans le mécanisme physiopathologique qu'elle suggère. PMID:26140069

  18. Irradiation hardening of pure tungsten exposed to neutron irradiation

    DOE PAGES

    Hu, Xunxiang; Koyanagi, Takaaki; Fukuda, Makoto; ...

    2016-08-26

    In this paper, pure tungsten samples have been neutron irradiated in HFIR at 90–850 °C to 0.03–2.2 dpa. A dispersed barrier hardening model informed by the available microstructure data has been used to predict the hardness. Comparison of the model predictions and the measured Vickers hardness reveals the dominant hardening contribution at various irradiation conditions. For tungsten samples irradiated in HFIR, the results indicate that voids and dislocation loops contributed to the hardness increase in the low dose region (<0.3 dpa), while the formation of intermetallic second phase precipitation, resulting from transmutation, dominates the radiation-induced strengthening beginning with a relativelymore » modest dose (>0.6 dpa). Finally, the precipitate contribution is most pronounced for the HFIR irradiations, whereas the radiation-induced defect cluster microstructure can rationalize the entirety of the hardness increase observed in tungsten irradiated in the fast neutron spectrum of Joyo and the mixed neutron spectrum of JMTR.« less

  19. Irradiation hardening of pure tungsten exposed to neutron irradiation

    SciTech Connect

    Hu, Xunxiang; Koyanagi, Takaaki; Fukuda, Makoto; Kumar, N. A. P. Kiran; Snead, Lance L.; Wirth, Brian D.; Katoh, Yutai

    2016-08-26

    In this paper, pure tungsten samples have been neutron irradiated in HFIR at 90–850 °C to 0.03–2.2 dpa. A dispersed barrier hardening model informed by the available microstructure data has been used to predict the hardness. Comparison of the model predictions and the measured Vickers hardness reveals the dominant hardening contribution at various irradiation conditions. For tungsten samples irradiated in HFIR, the results indicate that voids and dislocation loops contributed to the hardness increase in the low dose region (<0.3 dpa), while the formation of intermetallic second phase precipitation, resulting from transmutation, dominates the radiation-induced strengthening beginning with a relatively modest dose (>0.6 dpa). Finally, the precipitate contribution is most pronounced for the HFIR irradiations, whereas the radiation-induced defect cluster microstructure can rationalize the entirety of the hardness increase observed in tungsten irradiated in the fast neutron spectrum of Joyo and the mixed neutron spectrum of JMTR.

  20. Physico-chemical, textural and structural characteristics of sous-vide cooked pork cheeks as affected by vacuum, cooking temperature, and cooking time.

    PubMed

    Sánchez Del Pulgar, José; Gázquez, Antonio; Ruiz-Carrascal, Jorge

    2012-03-01

    This paper describes the influence of different factors on sous-vide cooked pork. Pork cheeks were cooked at different combinations of temperature (60°C or 80°C), time (5 or 12h) and vacuum (vacuum or air packaged). Weight losses were lower and moisture content higher in samples cooked for a shorter time (P=0.054) and at a lower temperature (P<0.001). Samples cooked at 60°C showed more lightness (L*) and redness (a*) (P<0.001). Lipid oxidation showed an interaction between cooking time and temperature (P=0.007), with higher TBARs values for samples cooked for 12h at 60°C and lower for those cooked for 12h at 80°C. Samples cooked at 80°C for 12h showed lower (P<0.05) values for most textural parameters than all the other types of samples. Vacuum packaging showed no influence on any of the studied variables. For the treatments evaluated, cooking temperature×time combination seems to be more important than vacuum packaging in the textural and colour parameters of pork cheeks.

  1. Effect of whey protein concentrate and sodium chloride concentrations on the odour profile of sous vide cooked whole-muscle beef from Argentina.

    PubMed

    Grigioni, G; Langman, L; Szerman, N; Irurueta, M; Vaudagna, S R

    2008-07-01

    Semitendinosus muscles added with whey protein concentrate (WPC) and sodium chloride (NaCl) were submitted to sous vide cooking. Four enhancement treatments and a control were tested: 0.875% WPC (w/w)+0.625% NaCl, 2.625% WPC+0.625% NaCl, 0.875% WPC+1.875% NaCl, 2.625% WPC+1.875% NaCl, and control (non-injected muscles). Odour analyses were carried out with an electronic nose (EN) system. EN data were evaluated applying Principal Component Analysis, Linear Discriminant Analysis and Partial Least Squares algorithm. EN was able to discriminate the odour profiles of cooked enhanced beef as a function of the amount of WPC added. No significant differences in odour profiles were observed regarding NaCl concentration. These results agreed with those obtained when odour profiles were analysed in WPC dispersions. The reported results support the applicability of EN methodology for analysing the impact of processing parameters on beef odour profiles.

  2. Diagnostic X de la zone proche injecteur d'un jet cryogénique d'azote sous haute pression

    NASA Astrophysics Data System (ADS)

    Métay, B.; Robert, E.; Viladrosa, R.; Cachoncinlle, C.; Pouvesle, J. M.; Mayer, W.; Schneider, G.

    2003-06-01

    Une source impulsionnelle de rayons X, compacte produisant des photons d'énergie comprise entre 5 et 50keV, a été spécialement conçue au GREMI afin de pouvoir caractériser l'écoulement proche d'injecteurs cryogéniques (20premiers mm) sur l'installations M51 du DLR à Lampoldhausen à des pressions comprises entre 10 et 60bars et des températures allant de 100 à 130K. Pour la première fois, des radiographies d'un jet cryogénique d'azote pur sous haute pression en sortie d'injecteur ont été réalisées sans ajout de traceur. Les données obtenues (cônes d'expansion, densité) ont pu être comparées à celles mesurées par d'autres systèmes (ombroscopie, thermocouple) et présentent la radiographie comme particulièrement sensible et bien adaptée à ce genre de problématique.

  3. Using numerical analysis to develop and evaluate the method of high temperature sous-vide to soften carrot texture in different-sized packages.

    PubMed

    Hong, Yoon-Ki; Uhm, Joo-Tae; Yoon, Won Byong

    2014-04-01

    The high-temperature sous-vide (HTSV) method was developed to prepare carrots with a soft texture at the appropriate degree of pasteurization. The effect of heating conditions, such as temperature and time, was investigated on various package sizes. Heating temperatures of 70, 80, and 90 °C and heating times of 10 and 20 min were used to evaluate the HTSV method. A 3-dimensional conduction model and numerical simulations were used to estimate the temperature distribution and the rate of heat transfer to samples with various geometries. Four different-sized packages were prepared by stacking carrot sticks of identical size (9.6 × 9.6 × 90 mm) in a row. The sizes of the packages used were as follows: (1) 9.6 × 86.4 × 90, (2) 19.2 × 163.2 × 90, (3) 28.8 × 86.4 × 90, and (4) 38.4 × 86.4 × 90 mm. Although only a moderate change in color (L*, a*, and b*) was observed following HTSV cooking, there was a significant decrease in carrot hardness. The geometry of the package and the heating conditions significantly influenced the degree of pasteurization and the final texture of the carrots. Numerical simulations successfully described the effect of geometry on samples at different heating conditions.

  4. Can faults become barriers for deep fluid circulation? Insights from high-resolution seismic VSP tomography at the Soultz-sous-Forêts geothermal site

    NASA Astrophysics Data System (ADS)

    Calò, Marco; Dorbath, Catherine; Lubrano Lavadera, Paul

    2016-09-01

    Vertical Seismic Profile (VSP) surveys are generally used for modelling converted phases of the seismic body waves propagating in the medium allowing the detection of waves interpreted as reflections on steeply dipping reflecting structures such as faults, abrupt lateral changes of lithology, and fractures. At the Enhanced Geothermal System geothermal field of Soultz-sous-Forêts the analysis of data recorded during a VSP experiment allowed describing the presence of at least two structures near the wells. Here we show how seismic tomography method can be applied to the VSP data to reconstruct the 3-D shape of structures in the volume surrounding the geothermal wells. The three-dimensional P wave velocity model obtained shows positive velocity anomalies associated with the main faults observed by the VSP analysis and negative anomalies in the regions affected by massive hydraulic stimulations performed in the past. This pattern can be explained as a different response of the rock volume to the fluid injections where regions marked by relative pre-existing high permeability were less affected by the hydraulic stimulations. This difference in permeability produced regions that could work as barriers for fluid diffusion through the reservoir. Comparisons of our high resolved model with the location of the induced seismicity and with another model obtained using seismic noise correlation give evidence of the presence of these structures and may explain the poor connection between the wells GPK4 and GPK2-GPK3 system.

  5. Effect of the addition of conventional additives and whey proteins concentrates on technological parameters, physicochemical properties, microstructure and sensory attributes of sous vide cooked beef muscles.

    PubMed

    Szerman, N; Gonzalez, C B; Sancho, A M; Grigioni, G; Carduza, F; Vaudagna, S R

    2012-03-01

    Beef muscles submitted to four enhancement treatments (1.88% whey protein concentrate (WPC)+1.25% sodium chloride (NaCl); 1.88% modified whey protein concentrate (MWPC)+1.25%NaCl; 0.25% sodium tripolyphosphate (STPP)+1.25%NaCl; 1.25%NaCl) and a control treatment (non-injected muscles) were sous vide cooked. Muscles with STPP+NaCl presented a significantly higher total yield (106.5%) in comparison to those with WPC/MWPC+NaCl (94.7% and 92.9%, respectively), NaCl alone (84.8%) or controls (72.1%). Muscles with STPP+NaCl presented significantly lower shear force values than control ones; also, WPC/MWPC+NaCl added muscles presented similar values than those from the other treatments. After cooking, muscles with STPP+NaCl or WPC/MWPC+NaCl depicted compacted and uniform microstructures. Muscles with STPP+NaCl showed a pink colour, meanwhile other treatment muscles presented colours between pinkish-grey and grey-brown. STPP+NaCl added samples presented the highest values of global tenderness and juiciness. The addition of STPP+NaCl had a better performance than WPC/MWPC+NaCl. However, the addition of WPC/MWPC+NaCl improved total yield in comparison to NaCl added or control ones.

  6. Le lymphangiome kystique du plancher buccal étendu a la région sous mandibulaire de l’adulte

    PubMed Central

    Ali, Elboukhari; Karim, Nador; Hicham, Attifi; Mohamed, Zalagh

    2016-01-01

    Les lymphangiomes kystiques sont des lésions congénitales bénignes prédominantes nettement au niveau de la région de la tête et du cou plus particulièrement dans le triangle cervical postérieur. Ces malformations des vaisseaux lymphatiques sont fréquemment diagnostiquées chez l'enfant. Nous rapportons le cas clinique d'un lymphangiome kystique du plancher buccal ayant survenu chez un adulte de 28 ans et qui s'est étendu progressivement vers la région sous mandibulaire gauche. La tumeur suspecté cliniquement a été bien exploré à la tomodensitométrie. Le traitement a consisté en une exérèse complète par voie endobuccale avec étude histologique qui a confirmé le diagnostic d'un lymphangiome kystique macroscopique. Le suivi à quatre ans n'a montré aucune récidive. PMID:27795797

  7. Interdiffusion de puits quantiques controlee par irradiation laser excimere pour l'integration de composants photoniques

    NASA Astrophysics Data System (ADS)

    Genest, Jonathan

    L'integration de composants discrets sur un systeme unique, tel une puce electronique, augmente les performances totales du systeme, fait apparaitre de nouvelles fonctionnalites et diminue les couts associes a la fabrication des dispositifs. Ces ameliorations, appliquees au secteur de la microelectronique, sont grandement responsables des avancements importants qu'ont connus les technologies de l'information et des communications au cours des dernieres annees. Puisque la fabrication de circuits photoniques integres necessite l'integration de structures ayant des bandes interdites differentes a partir d'une meme puce semiconductrice, leur niveau d'integration est bien inferieur que celui atteint pour un microprocesseur standard. Parmi les techniques ayant le potentiel de fabriquer des circuits photoniques integres monolithiquement, l'interdiffusion de puits quantique post-expitaxial controlee spatialement augmente la bande interdite d'une heterostructure semiconductrice a l'interieur de regions definies. Le processus d'interdiffusion, active thermiquement, est accelere par la diffusion d'impuretes et de defauts ponctuels tels que les lacunes et les interstitiels. L'hypothese de depart de mes travaux de doctorat suppose que la radiation laser ultra-violette module la diffusion et la generation de defauts ponctuels dans les heterostructures reposant sur les technologies a base de GaAs et d'InP et, consequemment, controle spatialement l'interdiffusion de puits quantiques. Nous avons demontre que lorsque appliquee sur des heterostructures a base de GaAs, l'irradiation laser excimere l'interdiffusion en favorisant la croissance d'un stresseur de surface qui empeche la diffusion des defauts ponctuels vers les puits quantiques. Nous avons souligne l'influence de la vapeur d'eau physisorbee sur la croissance du stresseur et avons determine la resolution spatiale de la technique. Dans les heterostructures basees sur les technologies InP, meme sous le seuil d'ablation, l

  8. Irradiation damage to the lung

    SciTech Connect

    Fennessy, J.J.

    1987-07-01

    While some degree of injury to normal, non-tumor-bearing, intrathoracic structures always occurs following irradiation for cure or palliation of neoplastic disease, clinical expression of this injury is uncommon. However, under certain circumstances, clinical manifestations may be severe and life threatening. Acute radiographic manifestations of pulmonary injury usually appear either synchronous with or, more typically, seven to ten days after the onset of the clinical syndrome. The acute signs of edema and slight volume loss within the irradiated zone are nonspecific except for their temporal and spatial relationship to the irradiation of the patient. Resolution of the acute changes is followed by pulmonary cicatrization, which is almost always stable within one year after completion of therapy. Change in postirradiation scarring following stabilization of the reaction must always be assumed to be due to some other process. While the radiograph primarily reveals pulmonary injury, all tissues, including the heart and major vessels, are susceptible, and the radiologist must recognize that any change within the thorax of a patient who has undergone thoracic irradiation may be a complication of that treatment. Differentiation of irradiation injury from residual or recurrent tumor, drug reaction, or opportunistic infection may be difficult and at times impossible.

  9. Food irradiation: Public opinion surveys

    SciTech Connect

    Kerr, S.D.

    1987-01-01

    The Canadian government are discussing the legislation, regulations and practical protocol necessary for the commercialization of food irradiation. Food industry marketing, public relations and media expertise will be needed to successfully introduce this new processing choice to retailers and consumers. Consumer research to date including consumer opinion studies and market trials conducted in the Netherlands, United States, South Africa and Canada will be explored for signposts to successful approaches to the introduction of irradiated foods to retailers and consumers. Research has indicated that the terms used to describe irradiation and information designed to reduce consumer fears will be important marketing tools. Marketers will be challenged to promote old foods, which look the same to consumers, in a new light. Simple like or dislike or intention to buy surveys will not be effective tools. Consumer fears must be identified and effectively handled to support a receptive climate for irradiated food products. A cooperative government, industry, health professional, consumer association and retailer effort will be necessary for the successful introduction of irradiated foods into the marketplace. Grocery Products Manufacturers of Canada is a national trade association of more than 150 major companies engaged in the manufacture of food, non-alcoholic beverages and array of other national-brand consumer items sold through retail outlets.

  10. Neutron irradiation of beryllium pebbles

    SciTech Connect

    Gelles, D.S.; Ermi, R.M.; Tsai, H.

    1998-03-01

    Seven subcapsules from the FFTF/MOTA 2B irradiation experiment containing 97 or 100% dense sintered beryllium cylindrical specimens in depleted lithium have been opened and the specimens retrieved for postirradiation examination. Irradiation conditions included 370 C to 1.6 {times} 10{sup 22} n/cm{sup 2}, 425 C to 4.8 {times} 10{sup 22} n/cm{sup 2}, and 550 C to 5.0 {times} 10{sup 22} n/cm{sup 2}. TEM specimens contained in these capsules were also retrieved, but many were broken. Density measurements of the cylindrical specimens showed as much as 1.59% swelling following irradiation at 500 C in 100% dense beryllium. Beryllium at 97% density generally gave slightly lower swelling values.

  11. Fracture surfaces of irradiated composites

    NASA Technical Reports Server (NTRS)

    Milkovich, Scott M.; Sykes, George F., Jr.; Herakovich, Carl T.

    1987-01-01

    Electron microscopy was used to analyze the fracture surfaces of T300/934 graphite/epoxy unidirectional off-axis tensile coupons which were subjected to 1.0-MeV electron radiation at a rate of 50 Mrad/h for a total dose of 10 Grad. Fracture surfaces from irradiated and nonirradiated specimens tested at 116 K, room temperature, and 394 K were analyzed to assess the influence of radiation and temperature on the mode of failure and variations in constituent material as a function of environmental exposure. Micrographs of fracture surfaces indicate that irradiated specimens are more brittle than nonirradiated specimens at low temperatures. However, at elevated temperatures the irradiated specimens exhibit significantly more plasticity than nonirradiated specimens.

  12. Effects of irradiation on PVC compounds

    NASA Astrophysics Data System (ADS)

    Bataille, P.; Ulkem, I.; Schreiber, H. P.

    1995-11-01

    PVC compounds containing CaCO 3 filler and plasticizers were prepared with or without a trifunctional acrylic crosslinking agent and irradiated by 60Co γ-rays under air or nitrogen atmosphere. The samples without crosslinking agent did not respond to irradiation. The mechanical properties of the other samples such as tensile strength, yield strength and % elongation showed a great sensitivity to irradiation. Lower values of Young's modulus were observed for samples irradiated in air compared with samples irradiated in nitrogen indicating the effect of atmosphere in the range of irradiation studied.

  13. Healing in the irradiated wound

    SciTech Connect

    Miller, S.H.; Rudolph, R. )

    1990-07-01

    Poor or nonhealing of irradiated wounds has been attributed to progressive obliterative endarteritis. Permanently damaged fibroblasts may also play an important part in poor healing. Regardless of the cause, the key to management of irradiated skin is careful attention to prevent its breakdown and conservative, but adequate, treatment when wounds are minor. When wounds become larger and are painful, complete excision of the wound or ulcer is called for and coverage should be provided by a well-vascularized nonparasitic distant flap.16 references.

  14. Modeling Solar Lyman Alpha Irradiance

    NASA Technical Reports Server (NTRS)

    Pap, J.; Hudson, H. S.; Rottman, G. J.; Willson, R. C.; Donnelly, R. F.; London, J.

    1990-01-01

    Solar Lyman alpha irradiance is estimated from various solar indices using linear regression analyses. Models developed with multiple linear regression analysis, including daily values and 81-day running means of solar indices, predict reasonably well both the short- and long-term variations observed in Lyman alpha. It is shown that the full disk equivalent width of the He line at 1083 nm offers the best proxy for Lyman alpha, and that the total irradiance corrected for sunspot effect also has a high correlation with Lyman alpha.

  15. Long-lived interaction between hydrothermal and magmatic fluids in the Soultz-sous-Forêts granitic system (Rhine Graben, France)

    NASA Astrophysics Data System (ADS)

    Gardien, Véronique; Rabinowicz, Michel; Vigneresse, Jean-Louis; Dubois, Michel; Boulvais, Philippe; Martini, Rossana

    2016-03-01

    The 5 km deep drilling at Soultz-sous-Forêts samples a granitic intrusion under its sedimentary cover. Core samples at different depths allow study of the evolving conditions of fluid-rock interaction, from the syn-tectonic emplacement of Hercynian granites at depth until post-cooling history and alteration close to the surface. Hydrogen, carbon and oxygen isotope compositions of CO2 and H2O have been measured in fluid inclusions trapped in magmatic quartz within samples collected along the drill core. Early Fluid Inclusions Assemblage (FIA) contains aqueous carbonic fluids whereas the latest FIA are H2O-rich. In the early FIA, the amount of CO2 and the δ13C value both decrease with depth, revealing two distinct sources of carbon, one likely derived from sedimentary carbonates (δ13C = - 2‰ V-PDB) and another from the continental crust (δ13C = - 9‰ V-PDB). The carbon isotope composition of bulk granites indicates a third carbon source of organic derivation (δ13C = - 20‰ V-PDB). Using a δD - δ18O plot, we argue that the water trapped in quartz grains is mainly of meteoric origin somewhat mixed with magmatic water. The emplacement of the Soultz-sous-Forêts granite pluton occurred in a North 030-040° wrench zone. After consolidation of the granite mush at 600 °C, sinistral shear (γ 1) concentrated the final leucocratic melt in vertical planes oriented along (σ1, σ2). Crystallization of this residual leucocratic melt occurred while shearing was still active. At a temperature of 550 °C, crystallization ended with the formation of vertical quartz veins spaced about 5 mm, and exhibiting a width of several cm. The quartz veins form a connected network of a few kilometers in height, generated during hydrothermal contraction of the intrusion. Quartz crystallization led to the exsolution of 30% by volume of the aqueous fluid. As quartz grains were the latest solid phase still plastic, shearing localized inside the connected quartz network. Aqueous fluid was

  16. Estimating the permeability distribution and its uncertainty at the EGS demonstration reservoir Soultz-sous-Forêts using the ensemble Kalman filter

    NASA Astrophysics Data System (ADS)

    Vogt, C.; Marquart, G.; Kosack, C.; Wolf, A.; Clauser, C.

    2012-08-01

    We present an estimation of the permeability fields of the reservoir at the Enhanced Geothermal System (EGS) at Soultz-sous-Forêts, France, based on the data assimilation technique Ensemble Kalman Filter (EnKF). To this end, we assimilate data from a tracer circulation experiment performed in 2005. Using a 3-D numerical simulation of fluid transport and chemical tracer dispersion, we advance the tracer in time and control the concentration. With the EnKF we obtain reliable fits for concentration data recorded in both existing production boreholes, GPK2 and GPK4. As an alternative to discrete fracture networks, our heterogeneous equivalent porous medium approach thus can also characterize the hydraulically fractured zone of the engineered geothermal system. We present best estimates for permeabilities (10-14 m2-10-12 m2for the fracture zone) and the corresponding uncertainty which is about one order of magnitude. After comparing our results to results from a massive Monte Carlo and from a gradient-based Bayesian approach, it becomes clear that only the EnKF of this three approaches is able to fit concentrations at GPK2 and GPK4 simultaneously. Based on the EnKF estimates obtained, a long-term performance prediction including an uncertainty analysis for the reservoir (as it was in 2005) yields no thermal breakthrough in the system within at least 50 years of operation. Our study demonstrates the efficiency of the EnKF when estimating the permeability distribution in an EGS reservoir even with sparse data available.

  17. Élaboration d'un bronze Cu-8%Sn fritté sous pression et l'étude de son aptitude à l'absorption

    NASA Astrophysics Data System (ADS)

    Loucif, K.; Keraghel, F.; Alem, S.

    2005-05-01

    L'introduction des píeces miniatures dans le domaine de l'informatique et la microélectronique nécessite une grande précision et un environnement propre. D'autre part, la conservation d'énergie exige des pièces légères et une bonne longévité. Pour résoudre ces problèmes, des pièces autolubrifiées ont été proposées. En effet, plusieurs disciplines peuvent s'ingérer pour élaborer ces pièces: la métallurgie des poudres pour produire des pièces poreuses, la tribologie pour caractériser la pièce en fonctionnement et la mécanique des fluides pour évaluer le comportement échantillon -lubrifiant.
Dans ce présent travail, nous présentons l'évolution de la densité des échantillons élaborés en fonction de: la température d'élaboration, la pression de compactage, et le temps de maintien et l'évolution de l'absorption des lubrifiants par un alliage Cu-8% Sn fritté sous pression. Les lubrifiants choisis sont l'eau et une huile de machine à usage domestique et leur aptitude à l'autolubrification.

  18. Hair dosimetry following neutron irradiation.

    PubMed

    Lebaron-Jacobs, L; Gaillard-Lecanu, E; Briot, F; Distinguin, S; Boisson, P; Exmelin, L; Racine, Y; Berard, P; Flüry-Herard, A; Miele, A; Fottorino, R

    2007-05-01

    Use of hair as a biological dosimeter of neutron exposure was proposed a few years ago. To date, the (32)S(n,p)(32)P reaction in hair with a threshold of 2.5 MeV is the best choice to determine the fast neutron dose using body activation. This information is essential with regards to the heterogeneity of the neutron transfer to the organism. This is a very important parameter for individual dose reconstruction from the surface to the deeper tissues. This evaluation is essential to the adapted management of irradiated victims by specialized medical staff. Comparison exercises between clinical biochemistry laboratories from French sites (the CEA and COGEMA) and from the IRSN were carried out to validate the measurement of (32)P activity in hair and to improve the techniques used to perform this examination. Hair was placed on a phantom and was irradiated at different doses in the SILENE reactor (Valduc, France). Different parameters were tested: variation of hair type, minimum weight of hair sample, hair wash before measurement, delivery period of results, and different irradiation configurations. The results obtained in these comparison exercises by the different laboratories showed an excellent correlation. This allowed the assessment of a dose-activity relationship and confirmed the feasibility and the interest of (32)P measurement in hair following fast neutron irradiation.

  19. Irradiation enhancement of biomass conversion

    NASA Astrophysics Data System (ADS)

    Smith, G. S.; Kiesling, H. E.; Galyean, M. L.; Bader, J. R.

    The vast supply of cellulosic agricultural residues and industrial by-products that is produced each year is a prospective resource of biomass suitable for conversion to useful products such as feedstock for the chemicals industry and feedstuffs for the livestock industry. Conversions of such biomass is poor at present, and utilization is inefficient, because of physio-chemical barriers to biological degradation and (or) anti-quality components such as toxicants that restrict biological usages. Improvements in biodegradability of ligno-cellulosic materials have been accomplished by gamma-ray and electron-beam irradiation at intermediate dosage (˜ 50 Mrad; .5 MGy); but applications of the technology have been hampered by questionable interpretations of results. Recent research with organic wastes such as sewage sludge and straw suggests opportunity for important applications of irradiation technology in enhancement of biomass conversion. Data from experiments using irradiated straw as feed for ruminants are presented and discussed in relation to research on prospective usage of sewage products as feed for ruminants. Findings are discussed in regard to prospective applications in industrial fermentation processes. Possible usage of irradiation technology for destruction of toxicants in exotic plants is considered in regard to prospective new feedstuffs.

  20. Irradiance Variability of the Sun

    NASA Technical Reports Server (NTRS)

    Froehlich, Claus

    1990-01-01

    Direct measurements of the solar constant--the total irradiance at mean Sun-Earth distance--during the last ten years from satellites show variations over time scales from minutes to years and decades. At high frequencies the spectral power is determined by granulation, super- and mesogranulation. In the 5-minute range, moreover, it is dominated by power from the solar p-mode oscillations. Their power and frequencies change with time, yielding information about changes in the convection zone. During periods of several hours, the power is steadily increasing and may be partly due to solar gravity modes. The most important variance is in the range from days to several months and is related to the photospheric features of solar activity, decrease of the irradiance during the appearance of sunspots, and increasing by faculae and the magnetic network. Long-term modulation by the 11-year activity cycle are observed conclusively with the irradiance being higher during solar maximum. All these variations can be explained--at least qualitatively--by their manifestation on the photosphere. For the long-term changes, the simultaneous changes of the frequencies of solar p-mode oscillations suggest a more global origin of the variations. Indeed, it seems that the observed irradiance modulation is a true luminosity change with the magnetic cycle of the Sun.

  1. Microstructural processes in irradiated materials

    NASA Astrophysics Data System (ADS)

    Byun, Thak Sang; Morgan, Dane; Jiao, Zhijie; Almer, Jonathan; Brown, Donald

    2016-04-01

    These proceedings contain the papers presented at two symposia, the Microstructural Processes in Irradiated Materials (MPIM) and Characterization of Nuclear Reactor Materials and Components with Neutron and Synchrotron Radiation, held in the TMS 2015, 144th Annual Meeting & Exhibition at Walt Disney World, Orlando, Florida, USA on March 15-19, 2015.

  2. Food Irradiation Research and Technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food Irradiation is a safe and effective U.S. Food and Drug Administration (FDA) approved process that can be used to disinfest or delay the maturation of fruits and vegetables, improve the microbiological safety of shellfish, eggs, raw meat and poultry, spices, and seeds used for sprouting. FDA ap...

  3. Food irradiation research and technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food Irradiation is a safe and effective U.S. Food and Drug Administration (FDA) approved process that can be used to disinfest or delay the maturation of fruits and vegetables, improve the microbiological safety of shellfish, eggs, raw meat and poultry, spices, and seeds used for sprouting. FDA ap...

  4. Internal irradiation for cystic craniopharyngioma

    SciTech Connect

    Kobayashi, T.; Kageyama, N.; Ohara, K.

    1981-12-01

    The authors report the results of internal irradiation with labeled chromic phosphate (32P) and gold-198 (198Au) colloid in eight cases of cystic craniopharyngiomas. They used a newly developed dosimetric formula, by which the radiation dose at the cyst wall and at any point far from the radioactive source can be calculated. Ten courses of irradiation in eight patients were carried out by injection of either 32P or 198Au colloid into the cyst through an Ommaya drainage system that had been placed at craniotomy. Follow-up studies ranging from 13 to 156 months revealed that all cysts were effectively treated, with elimination of fluid or collapse of the cyst. This was confirmed by Conray cystography and/or computerized tomography. Not only the dose delivered to the wall but also the thickness of the cyst wall and the location of the cyst are important factors in planning internal irradiation. A safe and adequate dose to the cyst wall could range between 9000 to 30,000 rads for craniopharyngioma. This treatment is suitable for large cysts that are thought to be difficult to remove radically, recurrent cysts resistant to previous treatment, or multiple cysts. Internal irradiation may also be applicable in other cystic intracranial tumors if dosimetry is calculated accurately.

  5. Statistical criteria for characterizing irradiance time series.

    SciTech Connect

    Stein, Joshua S.; Ellis, Abraham; Hansen, Clifford W.

    2010-10-01

    We propose and examine several statistical criteria for characterizing time series of solar irradiance. Time series of irradiance are used in analyses that seek to quantify the performance of photovoltaic (PV) power systems over time. Time series of irradiance are either measured or are simulated using models. Simulations of irradiance are often calibrated to or generated from statistics for observed irradiance and simulations are validated by comparing the simulation output to the observed irradiance. Criteria used in this comparison should derive from the context of the analyses in which the simulated irradiance is to be used. We examine three statistics that characterize time series and their use as criteria for comparing time series. We demonstrate these statistics using observed irradiance data recorded in August 2007 in Las Vegas, Nevada, and in June 2009 in Albuquerque, New Mexico.

  6. Ultrasonic Transducer Irradiation Test Results

    SciTech Connect

    Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert; Chien, Hual-Te; Kohse, Gordon; Tittmann, Bernhard; Reinhardt, Brian; Rempe, Joy

    2015-02-01

    Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric

  7. Biological effects of ultraviolet irradiation on bees

    SciTech Connect

    Es`kov, E.K.

    1995-09-01

    The influence of natural solar and artificial ultraviolet irradiation on developing bees was studied. Lethal exposures to irradiation at different stages of development were determined. The influence of irradiation on the variability of the morphometric features of bees was revealed. 5 refs., 1 fig.

  8. Schedule and status of irradiation experiments

    SciTech Connect

    Rowcliffe, A.F.; Grossbeck, M.L.

    1997-04-01

    To provide an updated summary of the status of irradiation experiments for the neutron-interactive materials program. The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has two irradiation experiments in reactor; and 8 experiments in the planning or design stages. Postirradiation examination and testing is in progress on 18 experiments.

  9. Migration intra-vésicale d’une bandelette sous urétrale type TVT: à propos d’un cas et revue de la littérature

    PubMed Central

    Kallat, Adil; Diaby, Oumar; Valizadeh, Ali; Agel, Jean; Erb, Claude

    2016-01-01

    Les techniques de soutènement sous urétral par bandelette synthétique constituent le gold standard actuel pour la prise en charge de l’incontinence urinaire d’effort. Nous rapportant le cas d’une patiente de 60 ans, ayant comme antécédents une incontinence urinaire d’effort traitée par une bandelette sous urétrale type TVT (Tension free Vaginal Tape) en 2008. La cystoscopie per opératoire était normale. Six ans plus tard la patiente a présenté des infections urinaires à répétition, à Escherichia Coli, rebelles à toute antibiothérapie adaptée. Une échographie a été réalisée ayant objectivé un calcul intra vésical faisant 2.5cm de grand axe, par ailleurs le résidu post mictionnel était nul. La fibroscopie a objectivé une bandelette en intra-vésical avec une grosse calcification autour. Notre patiente a bénéficié d’un traitement conservateur qui consisté à une section endoscopique de la portion intra vésicale de la bandelette avec préservation de la portion sous urétrale, par ailleurs le calcul a été fragmenté par le lithoclaste. Sur le plan fonctionnel, notre patiente est toujours continente. PMID:28154638

  10. Complexation des acides aminés basiques arginine, histidine et lysine avec l'ADN plasmidique en solution aqueuse : participation à la capture de radicaux sous irradiation X à 1,5 keV

    NASA Astrophysics Data System (ADS)

    Tariq Khalil, Talat; Taillefumier, Baptiste; Boulanouar, Omar; Mavon, Christophe; Fromm, Michel

    2016-09-01

    L'environnement chimique de l'ADN en situation biologique est complexe notam-ment en raison de la présence d'histones, protéines nucléaires, associées en quantité approximativement égales à l'ADN pour former la chromatine. Les histones possèdent de nombreux radicaux basiques arginine et lysine chargés positivement et dont la majorité se trouve sur les chaînes émergentes, l'ADN présente quant à lui des charges négatives sur ses groupements phosphates localisés tout au long de la double hélice. Dans cette étude, la complexité de la structure de la chromatine nucléaire est dans un premier temps mimée en solution aqueuse par la formation de complexes entre un ADN plasmidique sonde et les trois acides aminés basiques, Arg, His, Lys, qui, mis à part His, sont protonés au pH physiologique. Ces acides aminés libres en solution sont réputés être des capteurs efficaces de radicaux libres, notamment pour le radical hydroxyle, conférant ainsi un pouvoir protecteur vis-à-vis des effets indirects sur l'ADN en situation d'exposition aux rayonnements ionisants. A concentration fixée, les capacités de capture des acides aminés libres, σ, pour le radical hydroxyle sont typiquement les suivantes σHis ≈σArg > σLys (σLys ≈ 0,1 × σArg). Nous avons mesuré les taux de cassures simple brin par plasmide et par Gray (χ) lors d'expositions de solutions aqueuses de complexes [acide aminé - ADN plasmidique] aux rayons X ultra-mous (1,5 keV). A concentrations égales, les trois acides aminés complexés et présents en large excès ne manifestent pas une capacité de protection de l'ADN proportionnelle à leur capacité de capture libre et en solution ; on trouve en effet des taux de cassures dans l'ordre suivant χHis > χArg > χLys (χLys ≈ 0,01 χArg). Après avoir détaillé le mode opératoire de ces mesures, nous analyserons sur des bases bibliographiques, les modes spécifiques d'interaction des acides aminés basiques avec l'ADN. La spécificité des liaisons de l'arginine avec l'ADN et plus particulièrement sa propension à être un ligand bidentate qui se lie aux bases (principalement G) de l'ADN nous permet d'expliquer les taux de cassures simple brin particulièrement élevés observés avec Arg. Un mécanisme de transfert de radical intermoléculaire est suggéré pour Arg. Un raisonnement globalement similaire peut être tenu pour la lysine. Pour l'histidine, nous suggérons quelques voies possibles qui conduiraient à expliquer les taux de cassure anormalement élevés observés, mais cela demandera des expériences complémentaires.

  11. Laser irradiation to produce amorphous pharmaceuticals.

    PubMed

    Titapiwatanakun, Varin; Tankul, Junlathip; Basit, Abdul W; Gaisford, Simon

    2016-11-30

    Using a high-power CO2 laser to irradiate powder beds, it was possible to induce phase transformation to the amorphous state. Irradiation of a model drug, indometacin, resulted in formation of a glass. Varying the settings of the laser (power and raster speed) was shown to change the physicochemical properties of the glasses produced and all irradiated glasses were found to be more stable than a reference glass produced by melt-quenching. Irradiation of a powder blend of paracetamol and polyvinylpyrrolidone K30 was found to produce a solid amorphous dispersion. The results suggest that laser-irradiation might be a useful method for making amorphous pharmaceuticals.

  12. Food irradiation development in Pakistan

    NASA Astrophysics Data System (ADS)

    Khan, I.

    The large scale trials were held to extend the storage life of potatoes, onions and dry fruits by gamma radiation. It was concluded that radiation preservation of potatoes and onions was much cheaper as compared to conventional methods. A dose of 1 kGy can control the insects in dry fruits and nuts. The consumers' acceptability and market testing performed during the last four years are also conducive to the commercialization of the technology in this country. The Government of Pakistan has accorded clearance for the irradiation of some food items like potatoes, onions, garlic and spices for human consumption. The Pakistan Radiation Services (PARAS), the commercial irradiator (200 Kci) at Lahore, has already started functioning in April, 1987. It is planned to start large scale sterilization of spices by gamma radiation in PARAS shortly.

  13. Particular applications of food irradiation fresh produce

    NASA Astrophysics Data System (ADS)

    Prakash, Anuradha

    2016-12-01

    On fresh fruits and vegetables, irradiation at low and medium dose levels can effectively reduce microbial counts which can enhance safety, inhibit sprouting to extend shelf-life, and eliminate or sterilize insect pests which can serve to facilitate trade between countries. At the dose levels used for these purposes, the impact on quality is negligible. Despite the fact that regulations in many countries allow the use of irradiation for fresh produce, the technology remains under-utilized, even in the light of an increase in produce related disease outbreaks and the economic benefits of extended shelf life and reduced food waste. Putative concerns about consumer acceptance particularly for produce that is labeled as irradiated have deterred many companies from using irradiation and retailers to carry irradiated produce. This section highlights the commercial use of irradiation for fresh produce, other than phytosanitary irradiation which is covered in supplementary sections.

  14. Blood Irradiator Interactive Tool Beta Version

    SciTech Connect

    Howington, John; Potter, Charles; DeGroff, Tavias; Best, Derek

    2016-04-15

    The “Blood Irradiator Interactive Tool” compares a typical Cs-137 Blood Irradiator with that of the capabilities of an average X-ray Irradiator. It is designed to inform the user about the potential capabilities that an average X-ray Irradiator could offer them. Specifically the tool compares the amount of blood bags that can be irradiated by the users’ machine with that of the average X-ray capability. It also forcasts the amount of blood that can be irradiated on yearly basis for both the users’ machine and an average X-ray Device. The Average X-ray capabilities are taken from the three X-ray devices currently on the market: The RS 3400 Rad Source X-ray Blood Irradiator and both the 2.0L and 3.5 L versions of the Best Theratronis Raycell MK2

  15. Future Satellite Observations of Solar Irradiance

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; Rottman, G.; Woods, T.; Lawrence, G.; Harder, J.; McClintock, W.; Kopp, G.

    2003-01-01

    Required solar irradiance measurements for climate studies include those now being made by the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) onboard the SORCE satellite, part of the Earth Observing System fleet of NASA satellites. Equivalent or better measures of Total Solar Irradiance (TSI) and Spectral Solar Irradiance (SSI, 200 to 2000 nm) are planned for the post-2010 satellites of the National Polar-orbiting Operational Environmental Satellite System ("OESS). The design life of SORCE is 5 years, so a "Solar Irradiance Gap Filler" EOS mission is being planned for launch in the 2007 time frame, to include the same TSI and SSI measurements. Besides avoiding any gap, overlap of the data sources is also necessary for determination of possible multi-decadal trends in solar irradiance. We discuss these requirements and the impacts of data gaps, and data overlaps, that may occur in the monitoring of the critical solar radiative forcing.

  16. Microstructure evolution in irradiated materials

    SciTech Connect

    Caturla, M

    1999-11-30

    Study the interaction of defects produced during irradiation or deformation of a metal with the microstructure of that particular material, such as dislocations and grain boundaries. In particular we will study the interaction of dislocation with interstitial loops and stacking fault tetrahedral, and the production of displacement cascades close to dislocations and grain boundaries. The data obtained from these simulations will be used as input to diffusion models and dislocation dynamics models.

  17. RERTR-8 Irradiation Summary Report

    SciTech Connect

    D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-8, was designed to test monolithic mini-fuel plates fabricated via hot isostatic pressing (HIP), the effect of molybdenum (Mo) content on the monolithic fuel behavior, and the efficiency of ternary additions to dispersion fuel particles on the interaction layer behavior at higher burnup. The following report summarizes the life of the RERTR-8 experiment through end of irradiation, including as-run neutronic analysis, thermal analysis and hydraulic testing results.

  18. RERTR-6 Irradiation Summary Report

    SciTech Connect

    D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-6 was designed to evaluate several modified fuel designs that were proposed to address the possibility of breakaway swelling due to porosity within the (U. Mo) Al interaction product observed in the full-size plate tests performed in Russia and France1. The following report summarizes the life of the RERTR-6 experiment through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.

  19. Microstructural processes in irradiated materials

    SciTech Connect

    Byun, Thak Sang; Morgan, Dane; Jiao, Zhijie; Almer, Jonathan; Brown, Donald

    2016-04-01

    This is an editorial article (preface) for the publication of symposium papers in the Journal of Nuclear materials: These proceedings contain the papers presented at two symposia, the Microstructural Processes in Irradiated Materials (MPIM) and Characterization of Nuclear Reactor Materials and Components with Neutron and Synchrotron Radiation, held in the TMS 2015, 144th Annual Meeting & Exhibition at Walt Disney World, Orlando, Florida, USA on March 15–19, 2015.

  20. FFTF utilization for irradiation testing

    SciTech Connect

    Corrigan, D.C.; Julyk, L.J.; Hoth, C.W.; McGuire, J.C.; Sloan, W.R.

    1980-01-01

    FFTF utilization for irradiation testing is beginning. Two Fuels Open Test Assemblies and one Vibration Open Test Assembly, both containing in-core contact instrumentation, are installed in the reactor. These assemblies will be used to confirm plant design performance predictions. Some 100 additional experiments are currently planned to follow these three. This will result in an average core loading of about 50 test assemblies throughout the early FFTF operating cycles.

  1. Radical Irradiation of Extracranial Oligometastases

    PubMed Central

    Salama, Joseph K.; Milano, Michael T.

    2014-01-01

    Advances in radiotherapy planning and delivery have been used to treat patients with limited metastatic disease. With these techniques, high rates of treated metastasis control and low toxicity have been reported. Some patients have long disease-free intervals after radiotherapy similar to those seen after surgical resection. Ongoing studies will determine the benefit of these irradiation techniques to treat limited metastases, identify appropriate candidates, and assist in integrating these treatments into management strategies for specific diseases. PMID:25113765

  2. Licensing a new industrial irradiator.

    PubMed

    Bates, Nicolas K; Entwistle, Frederick B

    2010-02-01

    After nearly three decades of medical product sterilization, 3M launched a major new project to build and license an irradiator facility. 3M Corporate Health Physics was responsible for the licensing aspect of this project. The licensing process consisted of six amendments, over 30 submissions to the U.S. Nuclear Regulatory Commission (U.S. NRC) and four U.S. NRC site visits. It took approximately 22 months to complete. The six license amendments are reviewed and several of the submissions are discussed. These include 3M's response to the U.S. NRC's interest in the shielding calculations used for the bioshield, the development of a protocol of radiation safety system test methods, and an analysis to show that a dropped cask during loading operations would not fall on sealed sources. A number of lessons were learned during the course of licensing the new irradiator. Among these were the importance of understanding the U.S. NRC license reviewer's perspective, the need to thoroughly review the irradiator manufacturer's licensing package during project negotiations, the benefits of leaving the Health Physics Office and meeting with the non-health physicists involved in the project, and the necessity of maintaining the solid relationships that already existed with the site Radiation Safety Officer and Sterilization Engineer.

  3. Seismic response of the fractured and faulted granite of Soultz-sous-Forêts (France) to 5 km deep massive water injections

    NASA Astrophysics Data System (ADS)

    Dorbath, Louis; Cuenot, Nicolas; Genter, Albert; Frogneux, Michel

    2009-05-01

    The European Enhanced Geothermal System (EGS, formerly Hot Dry Rock, HDR) programme of Soultz-sous-Forêts is organized around three wells drilled to a depth of about 5000 m. Hydraulic stimulations were performed in the wells in 2000 (GPK2 well), 2003 (GPK3 well) and 2004 and 2005 (GPK4 well). The stimulation of GPK2 induced more than 700 seismic events with a magnitude greater than 1.0. The seismicity depicts a dense, homogeneous cloud, without any apparent structure. Medium-size earthquakes represent more than 80 per cent of the cumulative seismic moment. The b-value of the Gutenberg and Richter law is larger than 1.2. The injectivity has been increased by a factor 20. These characteristics indicate that the stimulation reactivated a 3-D dense network of fractures. The stimulation of GPK3 induced only about 250 events with a magnitude greater than 1.0 but with a greater proportion of large events, up to 2.9. The hypocentres form clear structures identified as large faults, the b-value is about 0.9 and the large events (M > 2.0) account for the greater part of the cumulative seismic moment. The injectivity of the well, which was already high before the stimulation, remained unchanged. The stimulation of GPK4 was achieved in two stages. This stimulation produced even less induced events, making the interpretation difficult. The differences between the seismic response of GPK2 and GPK3 are due to the presence of large faults cut by GPK3 or in its close vicinity and reached by the injected water. Once a seismic event occurs on a fault, a sequence of earthquakes is triggered and the seismicity behaves, for a large part, independent of the injected flow rate. The stimulations also show some evidence that creeping could be a major source of deformation, if not the main one. The future EGS programme will have to drill wells in zones free of large faults to avoid poor hydraulic performance and inconvenience to the population.

  4. Velocity structures of Geothermal sites: A comparative study between different tomography techniques on the EGS-Soultz-sous-Forêts Site (France)

    NASA Astrophysics Data System (ADS)

    Calo', M. C.; Dorbath, C.

    2009-12-01

    One major goal of monitoring seismicity accompanying hydraulic fracturing of a reservoir is to recover the seismic velocity field in and around the geothermal site. In many cases the seismicity induced by the hydraulic stimulations allows us to roughly describe the velocity anomalies close to the hypocentral location, but only during the time period of the stimulation. Several studies have shown that the 4D (time dependent) seismic tomographies are very useful to illustrate and study the temporal variation of the seismic velocities conditioned by injected fluids. Nevertheless in geothermal fields local earthquake tomography (LET) is often inadequate to study the seismic velocities during the inter-injection periods, due to the lack of seismicity. In July 2000 an injection test that lasted 15 days performed at the Enhanced Geothermal System (EGS) site of Soultz-sous-Forêts (Alsace, France) produced about 7200 micro-earthquakes with Duration Magnitude ranging from -0.9 to 2.5. the earthquakes were located by down hole and surface seismic stations. We present here a comparison between three tomographic studies, 1) the “traditional” seismic tomography of Cuneot et al., 2008, 2) a Double Difference tomography using the TomoDD code of Zhang and Thurber (2003) and, 3) the models obtained by applying the Weighted Average Model method (WAM, Calo’ et al., 2009). the velocity models were obtained using the same dataset recorded during the stimulation. The WAM technique produces a more reliable reconstruction of the structures around and above the cluster of earthquakes, as demonstrated by the distribution of the velocity standard deviations. Although the velocity distributions obtained by the three tomographic approaches are qualitatively similar, the WAM results correlate better with independent data such the fracturing directions measured in the down-holes, the location of the clustered seimsicity) than those of the traditional and DD tomographies. To overcome the

  5. Transition de phase quantique de type verrouillage-deverrouillage dans les canaux lineaires coherents des phases en rayures dans les doubles puits quantiques sous champ magnetique perpendiculaire

    NASA Astrophysics Data System (ADS)

    Faribault, Alexandre

    groupe de renormalisation perturbatif des couplages Josephson generaux permet alors de conclure si la phase deverrouillee peut etre stable lorsque l'on traite les fluctuations quantiques qui ne sont pas incluses dans l'approximation GRPA. Ces calculs nous permettent de conclure que la phase en rayures coherentes dans les doubles puits quantiques sous champ magnetique perpendiculaire est telle que les canaux coherents demeurent toujours verrouilles et ce, peu importe la valeur de la distance inter-puits. On envisage par contre que l'ajout d'un biais electrostatique pourrait permettre de modifier les proprietes du double puits de facon telle qu'une phase en rayures deverrouillees puisse etre stabilisee par les fluctuations quantiques.

  6. Texturation à froid sous contraintes triaxiales de phase à haute T_c de Bi(Pb)SrCaCuO préréagie

    NASA Astrophysics Data System (ADS)

    Langlois, P.; Massat, H.; Suryanarayanan, R.

    1994-11-01

    The alignment of grains in isostatically precompacted samples of prereacted Bi{1,8}Pb{0,4}Sr{2,0}Ca{2,2}Cu{3,0}O{10,3 + x} powder has been achieved by compressive plastic deformation under isostatic pressure at room temperature. Isostatic pressures were in the range 0.1 to 1 GPa and deformation rates were led up to 57 %. Prior to sintering, X-ray diffraction measurements corroborate an expected high- T_c phase purity of nearly 85 % and indicate that the as-deformed samples have been textured with the (c-axes parallel to the pressing direction whilst a.c. susceptibility measurements ascertain a high transition temperature around 107 K. Intergranular connection does not occur until sintering at 850 ^{circ}C for 80 h and measurements indicate then that the texture has been retained. Superconducting properties themselves show sensitivity to texture through anisotropy-related distinctive irreversibility lines. L'alignement de grains de poudre Bi{1,8}Pb{0,4}Sr{2,0}Ca{2,2}Cu{3,0}O{10,3 + x} préréagie a été réalisé par déformation plastique à température ambiante d'échantillons précompactés isostatiquement et comprimés sous pression isostatique, la gamme des pressions isostatiques allant de 0,1 à 1 GPa et les taux de déformation atteignant 57 %. Les mesures de diffraction de rayons X corroborent la pureté de phase à haute T_c proche de 85 % attendue et indiquent que les échantillons ainsi déformés ont été texturés avec les plans ab perpendiculaires à la direction de compression. Les mesures de susceptibilité alternative avèrent une température élevée de transition à environ 107 K mais la connexion intergranulaire n'est assurée qu'après un frittage à 850 ^{circ}C pendant 80 h dont on vérifie qu'il conserve la texture. Enfin, la sensibilité des propriétés supraconductrices à la texturation est évaluée par le biais de lignes d'irréversibilité distinctes en fonction de l'anisotropie.

  7. Status of Post Irradiation Examination of FCAB and FCAT Irradiation Capsules

    SciTech Connect

    Field, Kevin G.; Yamamoto, Yukinori; Howard, Richard H.

    2016-09-29

    A series of irradiation programs are ongoing to address the need for determining the radiation tolerance of FeCrAl alloys. These irradiation programs, deemed the FCAT and FCAB irradiation programs, use the High Flux Isotope Reactor (HFIR) to irradiate second generation wrought FeCrAl alloys and early-generation powder-metallurgy (PM) oxide dispersion-strengthened (ODS) FeCrAl alloys. Irradiations have been or are being performed at temperatures of 200°C, 330°C, and 550°C from doses of 1.8 dpa up to 16 dpa. Preliminary post-irradiation examination (PIE) on low dose (<2 dpa) irradiation capsules of tensile specimens has been performed. Analysis of co-irradiated SiC thermometry have shown reasonable matching between the nominal irradiation temperatures and the target irradiation temperatures. Room temperature tensile tests have shown typical radiation-induced hardening and embrittlement at irradiations of 200°C and 330°C, but a propensity for softening when irradiated to 550°C for the wrought alloys. The PM-ODS FeCrAl specimens showed less hardening compared to the wrought alloys. Future PIE includes high temperature tensile tests on the low dose irradiation capsules as well as the determination of reference fracture toughness transition temperature, To, in alloys irradiated to 7 dpa and higher.

  8. Pontage fémoro-fémoral croisé avec tunnulisation périnéale sous-scrotale pour une infection grave du triangle de scarpa

    PubMed Central

    Mrad, Melek Ben; Miri, Rim; Kaouel, Karim; Derbel, Bilel; Tarzi, Mariem; Ghedira, Faker; Kalfat, Tawfik; Mizouni, Hbiba; Khayati, Adel

    2015-01-01

    Nous décrivons dans cet article une technique de revascularisation des patients ayant une infection de prothèse vasculaire sus-crurale au niveau dutriangle de scarpa, et qui minimise le risque d'infection récurrente du greffon. Cette technique consiste en un pontage fémoro-fémoral croisé avec un tunnel périnéal sous-cutané loin du scarpa infecté que le tunnel classique sus-pubiensous-cutané ne permet pas. Nous rapportons le cas d'un patient âgé de 52 ans, artéritique, multi-opérés, admis pour infection du scarpa droit sur un pontage fémoro-fémoral prothétique perméable, le patient a eu une explantation de ce pontage et une revascularisation par un pontage périnéal sous-scrotal veineux loin du site infectieux; l’évolution a été excellente et le pontage est encore perméable après deux ans de suivi. Le pontage fémoro-fémoral périnéal est une procédure exceptionnellement réalisée, mais qui peut constituer une vraie option thérapeutique de revascularisation chez les patients avec une infection du scarpa. PMID:26955419

  9. 2-alkylcyclobutanones as irradiation dose indicators in irradiated ground beef patties.

    PubMed

    Gadgil, Priyadarshini; Hachmeister, Kathleen A; Smith, J Scott; Kropf, Donald H

    2002-09-25

    Alkylcyclobutanones have been recognized as chemical markers of irradiated lipid-containing foods since 1970. They are important because they are produced solely as a result of irradiation and not any other processing method. This study investigated the formation of 2-dodecylcyclobutanone (2-DCB) and 2-tetradec-5'-enylcyclobutanone (2-TDCB) in irradiated ground beef patties from commercial and noncommercial sources. Patties were irradiated using a (60)C source (gamma-irradiation) and electron beam irradiation, at five targeted absorbed doses of 0.5, 1.0, 2.5, 5.0, and 7.0 kGy. Commercially available irradiated patties were also studied. A supercritical fluid extraction (SFE) procedure was optimized and used for the extraction and isolation of the alkylcyclobutanones. Samples can be used for extraction without a prior cleanup step, which makes this procedure rapid and convenient to use. Identification and quantitation of the cyclobutanones were done by gas chromatography-mass spectroscopy. 2-DCB was detected in all of the irradiated samples (including commercial patties), and its concentration increased linearly with the irradiation dose. Electron beam irradiation produced a greater amount of 2-DCB compared to gamma-irradiation at dose levels >2.5 kGy. 2-TDCB was detected only at the two higher irradiation doses, whereas both marker compounds were not detected in the non-irradiated samples.

  10. Thermal analysis applied to irradiated propolis

    NASA Astrophysics Data System (ADS)

    Matsuda, Andrea Harumi; Machado, Luci Brocardo; del Mastro, Nélida Lucia

    2002-03-01

    Propolis is a resinous hive product, collected by bees. Raw propolis requires a decontamination procedure and irradiation appears as a promising technique for this purpose. The valuable properties of propolis for food and pharmaceutical industries have led to increasing interest in its technological behavior. Thermal analysis is a chemical analysis that gives information about changes on heating of great importance for technological applications. Ground propolis samples were 60Co gamma irradiated with 0 and 10 kGy. Thermogravimetry curves shown a similar multi-stage decomposition pattern for both irradiated and unirradiated samples up to 600°C. Similarly, through differential scanning calorimetry , a coincidence of melting point of irradiated and unirradiated samples was found. The results suggest that the irradiation process do not interfere on the thermal properties of propolis when irradiated up to 10 kGy.

  11. Methods for detection of irradiation of spices.

    PubMed

    Sjöberg, A M; Manninen, M; Härmälä, P; Pinnioja, S

    1990-02-01

    Three types of methods for the identification of irradiation of spices were tested as potential control methods. The methods were microbiological, combining a direct epifluorescent filter technique (DEFT) with a total aerobic plate count (APC), a chemiluminescence method and chemical gas-chromatographic (GC) and GC mass-spectrometric (MS) methods for analysis of volatile oils of spices isolated by steam distillation. Twelve samples of spices, mainly peppers, were analysed before and after gamma-irradiation with doses of 10 and 50 kGy. The chemiluminescence measurements were performed before the irradiation and 10 and 100 days after the irradiation. The best methods for control purposes were the microbiological (DEFT + APC) methods combined with chemiluminescence measurements. No differences were detected between the irradiated and non-irradiated samples with the chemical methods.

  12. HRB-22 irradiation phase test data report

    SciTech Connect

    Montgomery, F.C.; Acharya, R.T.; Baldwin, C.A.; Rittenhouse, P.L.; Thoms, K.R.; Wallace, R.L.

    1995-03-01

    Irradiation capsule HRB-22 was a test capsule containing advanced Japanese fuel for the High Temperature Test Reactor (HTTR). Its function was to obtain fuel performance data at HTTR operating temperatures in an accelerated irradiation environment. The irradiation was performed in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). The capsule was irradiated for 88.8 effective full power days in position RB-3B of the removable beryllium (RB) facility. The maximum fuel compact temperature was maintained at or below the allowable limit of 1300{degrees}C for a majority of the irradiation. This report presents the data collected during the irradiation test. Included are test thermocouple and gas flow data, the calculated maximum and volume average temperatures based on the measured graphite temperatures, measured gaseous fission product activity in the purge gas, and associated release rate-to-birth rate (R/B) results. Also included are quality assurance data obtained during the test.

  13. Early esophageal carcinoma treated with intracavitary irradiation

    SciTech Connect

    Hishikawa, Y.; Tanaka, S.; Miura, T.

    1985-08-01

    Five patients with early esophageal carcinoma were treated by 6-12 Gy of intracavitary irradiation following 50-60 Gy of external irradiation as a boost therapy. Surgery was not performed in these cases. None of the patients had local recurrence after radiation therapy, as demonstrated by esophagography and endoscopy. Three patients have been alive for 1-3 years 10 months. Esophageal ulceration induced by intracavitary irradiation has occurred in three of the five patients; however, intracavitary irradiation is still a beneficial treatment because of its efficacy in controlling local lesions and because radiation ulceration can eventually be cured. Intracavitary irradiation is recommended to follow external irradiation as a boost therapy for the treatment of early esophageal carcinoma.

  14. A new multipurpose gamma-irradiation facility

    NASA Astrophysics Data System (ADS)

    Huebner, G.

    In the past 3 yr much work has been done in the G.D.R. on food irradiation. The experiments have shown that this treatment gives favourable results in many products such as spices, onions, potatoes, chicken, animal feeds, fodder yeast, drugs and vaccines. Economic aspects of food irradiation require the effective use of an irradiation plant and cobalt-60. Therefore, a new multipurpose irradiation facility was developed, applicable as an onion irradiator with a capacity of about 15 ton/h and for the simultaneous irradiation of different products (spices, animal feed, chicken, etc.) in closed product ☐es with a size of 1.2 m x 1.0 m x 1.2 m. A microcomputer controls the transport of product ☐es around the gamma sources.

  15. Irradiation preservation of seafood: Literature review

    SciTech Connect

    Molton, P.M.

    1987-10-01

    The application of gamma-irradiation for extending the shelf life of seafood has been of interest for many years. This report reviews a number of studies on seafood irradiation conducted over the past several years. Topics covered include seafood irradiation techniques and dosages, species applicability and differences, the effects of packaging on seafood preservation, and changes in organoleptic acceptability as a result of irradiation. Particular attention is given to radiation effects (likely and unlikely) of concern to the public. These include the potential for generation of toxic chemical products, botulinum toxin production, and other health concerns. No scientifically defensible evidence of any kind was found for any harmful effect of irradiation of seafoods at the doses being considered (less than 300 krad), and all indications are that irradiation is an acceptable and needed additional tool for seafood preservation. 49 refs., 14 figs., 14 tabs.

  16. EPR Investigation of Irradiated Curry Powder

    SciTech Connect

    Duliu, O. G.; Ali, S. I.; Georgescu, R.

    2007-04-23

    Gamma-ray irradiated curry powder, a well priced oriental spice was investigated in order to establish the ability of EPR to detect the presence and time stability of free irradiation free-radicals. Accordingly, curry powder aliquots were irradiated with gradually increasing absorbed doses up to 11.3 kGy. The EPR spectra of all irradiated samples show the presence of al last two different species of free radicals, whose concentration increased monotonously with the absorbed doses. A 100 deg. C isothermal annealing of irradiated samples has shown a differential reduction of amplitude of various components of the initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after more than one year storage at room temperature, all of them being very useful in establishing the existence of any previous irradiation treatment.

  17. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2014-07-30

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  18. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2013-12-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  19. Ion irradiation of astrophysical ices

    NASA Astrophysics Data System (ADS)

    Palumbo, M. E.; Baratta, G. A.; Fulvio, D.; Garozzo, M.; Gomis, O.; Leto, G.; Spinella, F.; Strazzulla, G.

    2008-02-01

    Ices, silicates and carbonaceous materials have been detected in several astrophysical environments such as interstellar molecular clouds, comets, and planetary surfaces. These solids are continuously exposed to ion irradiation and UV photolysis. Our knowledge on the properties of solids and molecules and on the modification induced by fast ions (keV-MeV) and UV photons is mainly based on laboratory experiments and on the comparison of experimental results with observations. Here we will give a few examples of the role of laboratory experiments to our understanding of the physical and chemical properties of ices in space.

  20. Thymus irradiation for myasthenia gravis

    SciTech Connect

    Currier, R.D.; Routh, A.; Hickman, B.T.; Douglas, M.A.

    1983-01-01

    Twenty-eight patients with progressive myasthenia gravis without thymoma received treatment of 3000 rads (30 Gy) to the anterior mediastinum, and a followup was conducted for five to 18 years. Twenty-four patients had generalized myasthenia, and four had ocular myasthenia gravis. Twenty patients with generalized myasthenia survived the several month post-treatment period and improved, but four died during that period. The improvement lasted a median of 1.5 years, and older patients had longer remissions than younger patients. The four patients who had ocular myasthenia did not change after treatment. Mediastinal irradiation produces a temporary remission in generalized myasthenia.

  1. Food irradiation and airline catering

    SciTech Connect

    Preston, F.S.

    1988-04-01

    Food poisoning from contaminated airline food can produce serious consequences for airline crew and passengers and can hazard flight. While irradiation of certain foodstuffs has been practised in a number of countries for some years, application of the process has not been made to complete meals. This paper considers the advantages, technical considerations, costs and possible application to airline meals. In addition, the need to educate the public in the advantages of the process in the wake of incidents such as Chernobyl is discussed.

  2. Electron spin resonance identification of irradiated fruits

    NASA Astrophysics Data System (ADS)

    Raffi, Jacques J.; Agnel, Jean-Pierre L.

    The electron spin resonance spectrum of achenes, pips, stalks and stones from irradiated fruits (strawberry, raspberry, red currant, bilberry, apple, pear, fig, french prune, kiwi, water-melon and cherry) always displays, just after γ-treatment, a weak triplet ( aH≈30 G) due to a cellulose radical; its left line (lower field) can be used as an identification test of irradiation, at least for strawberries, rapsberries, red currants or bilberries irradiated in order to improve their storage time.

  3. Food irradiation facilities: Requirements and technical aspects

    NASA Astrophysics Data System (ADS)

    Mittendorfer, Josef

    2016-12-01

    This survey presents some aspects and requirement for food irradiation facilities. Topics like radiation source, dose ranges and dose rate are discussed, together with logistics and operational considerations

  4. Aqueous marker penetration into ion irradiated polyimide

    NASA Astrophysics Data System (ADS)

    Fink, D.; Müller, M.; Petrov, A.; Klett, R.; Palmetshofer, L.; Hnatowicz, V.; Vacik, J.; Cervena, J.; Chadderton, L. T.

    2002-05-01

    The penetration of aqueous 6Li + markers into low energy ion irradiated polyimide (PI) foils was examined by the neutron depth profiling technique in combination with a modified tomographic approach. The ion irradiation always leads to an enhancement in marker uptake. After irradiation at low fluence the marker profiles follow the nuclear damage distribution even in three dimensions. At elevated fluences saturation in the marker uptake is clearly seen. The polymer's penetrant uptake can be described well by regular diffusion, with nuclear damage centres acting as saturable traps. These observations are strikingly different from the marker penetration into high-energy heavy-ion irradiated PI.

  5. Free radical kinetics on irradiated fennel

    NASA Astrophysics Data System (ADS)

    Yamaoki, Rumi; Kimura, Shojiro; Ohta, Masatoshi

    2008-09-01

    Herein, an electron spin resonance study on the behavior of organic radicals in fennel before and after irradiation is reported. The spectrum of irradiated fennel composed of the spectrum component derived from the un-irradiated sample (near g=2.005) and the spectra components derived from carbohydrates. The time decay of intensity spectral components was well explained by first-order kinetics with a variety of rate constants. Especially, the signal at near g=2.02 ascribed to stable cellulose-derivative components is expected to be a good indicator in the identification of irradiated plant samples.

  6. Analytical screening studies on irradiated food packaging.

    PubMed

    Driffield, M; Bradley, E L; Leon, I; Lister, L; Speck, D R; Castle, L; Potter, E L J

    2014-01-01

    Foods may be irradiated in their final packaging and this process may affect the composition of the packaging and in turn affect the migration of substances into food. Headspace and liquid injection GC-MS and HPLC with time-of-flight MS have been used to identify and estimate levels of radiolytic products in irradiated finished plastic packaging materials. Fifteen retail packaging materials were studied. Investigations were carried out into the effect of different irradiation types (gamma and electron beam), irradiation doses (1, 3, 7 and 10 kGy) and dose rates (5 kGy s(-1) for electron beam and 0.4 and 1.85 kGy h(-1) for gamma) on the radiolytic products. Any differences seen in comparing the two ionising radiation types were attributed largely to the very different dose rates; for electron beam a 10 kGy dose was delivered in just 2 s whereas using gamma it took 5.4 h. Differences were also seen when comparing the same samples irradiated at different doses. Some substances were not affected by irradiation, others decreased in concentration and others were formed upon increasing doses of irradiation. These results confirm that irradiation-induced changes do occur in substances with the potential to migrate and that the safety of the finished packaging material following irradiation should be assessed.

  7. The irradiation effects on zirconium alloys

    NASA Astrophysics Data System (ADS)

    Negut, Gh.; Ancuta, M.; Radu, V.; Ionescu, S.; Stefan, V.; Uta, O.; Prisecaru, I.; Danila, N.

    2007-05-01

    Pressure tube samples were irradiated under helium atmosphere in the TRIGA Steady State Research and Material Test Reactor of the Romanian Institute for Nuclear Research (INR). These samples are made of the Zr-2.5%Nb alloy used as structural material for the CANDU Romanian power reactors. After irradiation, mechanical tests were performed in the Post Irradiation Examination Laboratory (PIEL) to study the influence of irradiation on zirconium alloys mechanical behaviour. The tensile test results were used for structural integrity assessment. Results of the tests are presented. The paper presents, also, pressure tube structural integrity assessment.

  8. Study of irradiation creep of vanadium alloys

    SciTech Connect

    Tsai, H.; Strain, R.V.; Smith, D.L.

    1997-08-01

    Thin-wall tubing was produced from the 832665 (500 kg) heat of V-4 wt.% Cr-4 wt.% Ti to study its irradiation creep behavior. The specimens, in the form of pressurized capsules, were irradiated in Advanced Test Reactor and High Flux Isotope Reactor experiments (ATR-A1 and HFIR RB-12J, respectively). The ATR-A1 irradiation has been completed and specimens from it will soon be available for postirradiation examination. The RB-12J irradiation is not yet complete.

  9. Healing burns using atmospheric pressure plasma irradiation

    NASA Astrophysics Data System (ADS)

    Hirata, Takamichi; Kishimoto, Takumi; Tsutsui, Chihiro; Kanai, Takao; Mori, Akira

    2014-01-01

    An experiment testing the effects of plasma irradiation with an atmospheric-pressure plasma (APP) reactor on rats given burns showed no evidence of electric shock injuries upon pathology inspection of the irradiated skin surface. In fact, the observed evidence of healing and improvement of the burns suggested healing effects from plasma irradiation. The quantities of neovascular vessels in the living tissues at 7 days were 9.2 ± 0.77 mm-2 without treatment and 18.4 ± 2.9 mm-2 after plasma irradiation.

  10. Food irradiation: Key research needs

    SciTech Connect

    Morehouse, K.M. )

    1993-01-01

    Treatment of foods with ionizing radiation reduces microbial infection and insect infestations, inhibits sprouting, and delays maturation, thereby extending the shelf life of foods. The treatment of different types of foods with ionizing radiation for specific purposes is accepted in several countries, although it is prohibited in others. The US Food and Drug Administration has established regulations to allow the treatment of several different foods with ionizing radiation and has received petitions for the approval of radiation treatment of additional foods. When carried out according to established good manufacturing practices, food irradiation yields safe, wholesome foods. The irradiated product may be often chemically or microbiologically [open quotes]safer[close quotes] than the nonirradiated product. This paper presents several areas of scientific research in which more information would facilitate the expansion of this technology and points out major areas of concern. The question of the public acceptance of foods that have been treated with ionizing radiation is discussed only briefly in order to make the presentation complete.

  11. Stochastic Estimates of the Permeability Field of the Soultz-sous-Forêts Geothermal Reservoir - Comparison of Bayesian Inversion, MC Geostatistics, and EnKF Assimilation

    NASA Astrophysics Data System (ADS)

    Kosack, Christian; Vogt, Christian; Rath, Volker; Marquart, Gabriele

    2010-05-01

    The knowledge of the permeability distribution at depth is of primary concern for any geothermal reservoir engineering. However, permeability might change over orders of magnitude even for a single rock type and is additionally controlled by tectonic or engineered fracturing of the rocks. During reservoir exploration pumping tests are regularly performed where tracer marked water is pumped in one borehole and retrieved at one or a few others. At the European Enhanced Geothermal System (EGS) test site at Soultz-sous-Forêts three wells had been drilled in the granitic bedrock down to 4 to 5 km and were hydraulically stimulated to enhance the hydraulic connectivity between the wells. In July 2005, a tracer circulation test was carried out in order to estimate the changes of the hydraulic properties. Therefore a tracer was injected into the well GPK3 for 19 hours at a rate of 0.015 m3 s-1 and a concentration of 0.389 mol m-3. Tracer concentration was measured in the production wells over the following 5 months, while the produced water was re-injected into GPK3. This experiment demonstrated a good hydraulic connection between GPK3 and one of the production wells, GPK2, while a very low connectivity was observed in the other one, GPK4. We tested three different approaches simulating the pumping experiment with the numerical simulator shemat_suite in a simplified 3D model of the site in order to study their respective potential to estimate a reliable permeability distribution for the Soultz reservoir: A full-physics gradient-based Bayesian inversion, a massive Monte Carlo approach with geostatistic analysis, and an Ensemble-Kalman-Filter (EnKF) assimilation. A common feature in all models is a high permeability zone which acts as main flow area and transports most of the tracer. It is assumed to be associated with the fault zone cutting through the boreholes GPK2 and GPK3. With the Bayesian Inversion we were able to estimate a parameter set consisting of porosity

  12. A SU-8 dish for cell irradiation

    NASA Astrophysics Data System (ADS)

    Arteaga-Marrero, N.; Auzelyte, V.; Olsson, M. G.; Pallon, J.

    2007-10-01

    The objective of the CELLION project is radiation research at low doses. The main cell responses to low dose irradiation are bystander effects, genomic instability and adaptive responses. In order to study these effects it is convenient to make the cells addressable in space and time through locking the cell position. A new alternative dish has been developed for irradiation procedures at the Lund Nuclear Probe. The versatile dish can be used both to cultivate and to hold the cells during the irradiation procedure. The irradiation dish is made of an epoxy-based photopolymer named SU-8 chosen by its flexibility, non-toxicity and biological compatibility to cell attachment. It has been fabricated using a UV lithographic technique. The irradiation dish forms a 2 × 2 mm 2 grid which contains 400 squares. Each square has 80 μm side and is separated from neighbouring ones by 20 μm wide walls. The location of each square is marked by a row letter and column number patterned outside the grid. The Cell Irradiation Facility at the Lund Nuclear Probe utilizes protons to irradiate living cells. A post-cell detection set up is used to control the applied dose, detecting the number of protons after passing through the targeted cell. The transmission requirement is fulfilled by our new irradiation dish. So far, the dish has been used to perform non-targeted irradiation of Hepatoma cells. The cells attach and grow easily on the SU-8 surface. In addition, the irradiation procedure can be performed routinely and faster since the cells are incubated and irradiated in the same surface.

  13. Correlation of irradiation data using activation fluences and irradiation temperature.

    NASA Technical Reports Server (NTRS)

    Lynch, J. H.

    1972-01-01

    A new method of correlating radiation damage data is tested using actual measured data taken from the open literature. This method, the activation fluence method, was found to be as accurate as other contemporary models with which it was compared. The new method also has several advantages over the other methods. The method employs a new entity, the activation fluence (time-integrated specific activation rate), as the independent variables in a regression model. Temperature at which the irradiation takes place is also a variable. Although the method was tested for a specific type of damage (change in nil-ductility transition temperature for A302-B steel) it has no inherent restrictions and is limited only by the imagination of the user.

  14. Prévalence, facteurs associés et prédisposant au syndrome métabolique chez les personnes vivants avec le VIH sous traitement antirétroviral à Porto-Novo en 2014

    PubMed Central

    Adébayo, Alassani; Albert, Dovonou Comlan; Ericie, Sossou; Angelo, Attinsounon Cossi; Jules, Gninkoun; Armand, Wanvoegbe; Séraphin, Ahoui; Léopold, Codjo; Gabriel, Ade

    2015-01-01

    Introduction Le syndrome métabolique est associé aux maladies cardiovasculaires. L'infection au VIH est devenue aujourd'hui une maladie chronique. L'objectif de cette étude est de déterminer la prévalence, les facteurs associés et prédisposant au syndrome métabolique chez les patients infectés par le VIH sous traitement antirétroviral. Méthodes Il s'est agi d'une étude transversale, descriptive et analytique. La population d’étude est constituée des patients vivant avec le VIH sous antirétroviral suivis au Centre Hospitalier Universitaire de l'Ouémé-Plateau. Le syndrome métabolique a été défini selon les critères de la Fédération Internationale du Diabète. Résultats La population était constituée de 244 patients. La prévalence du syndrome métabolique était de 18,03% avec une prédominance féminine (74,6%). La moyenne d’âge était de 40,7 ± 9,71 ans. Les facteurs associés au syndrome métabolique étaient le sexe féminin, la sédentarité, l'antécédent d'HTA, le surpoids, l'apport énergétique élevé, l'apport lipidique élevé, la consommation d'alcool, la consommation de tabac et l'hypercholestérolémie. Les facteurs prédisposant au syndrome métabolique étaient la présence de l'HTA, le tour de taille élevé, l'hyperglycémie, l'hypocholestérolémie HDL et l'hypertriglycéridémie. Conclusion Le syndrome métabolique est fréquent chez les patients infectés par le VIH sous traitement antirétroviral. Une prévention prenant en compte les facteurs associés et prédisposant s'avère nécessaire. PMID:26966492

  15. Cherry Irradiation Studies. 1984 annual report

    SciTech Connect

    Eakin, D.E.; Hungate, F.P.; Tingey, G.L.; Olsen, K.L.; Fountain, J.B.; Burditt, A.K. Jr.; Moffit, H.R.; Johnson, D.A.; Lunden, J.D.

    1985-04-01

    Fresh cherries, cherry fruit fly larvae, and codling moth larvae were irradiated using the PNL cobalt-60 facility to determine the efficacy of irradiation treatment for insect disinfestation and potential shelf life extension. Irradiation is an effective disinfestation treatment with no significant degradation of fruit at doses well above those required for quarantine treatment. Sufficient codling moth control was achieved at projected doses of less than 25 krad; cherry fruit fly control, at projected doses of less than 15 krad. Dose levels up to 60 krad did not adversely affect cherry quality factors tested. Irradiation above 60 krad reduced the firmness of cherries but had no significant impact on other quality factors tested. Irradiation of cherries below 80 krad did not result in any significant differences in sensory evaluations (appearance, flavor, and firmness) in tests conducted at OSU. Irradiation up to 200 krad at a temperature of about 25/sup 0/C (77/sup 0/F) did not measurably extend shelf life. Irradiation at 500 krad at 25/sup 0/C (77/sup 0/F) increased mold and rotting of cherries tested. There is no apparent advantage of irradiation over low-temperature fumigation.

  16. Reprocessing technology development for irradiated beryllium

    SciTech Connect

    Kawamura, H.; Sakamoto, N.; Tatenuma, K.

    1995-09-01

    At present, beryllium is under consideration as a main candidate material for neutron multiplier and plasma facing material in a fusion reactor. Therefore, it is necessary to develop the beryllium reprocessing technology for effective resource use. And, we have proposed reprocessing technology development on irradiated beryllium used in a fusion reactor. The preliminary reprocessing tests were performed using un-irradiated and irradiated beryllium. At first, we performed beryllium separation tests using un-irradiated beryllium specimens. Un-irradiated beryllium with beryllium oxide which is a main impurity and some other impurities were heat-treated under chlorine gas flow diluted with Ar gas. As the results high purity beryllium chloride was obtained in high yield. And it appeared that beryllium oxide and some other impurities were removed as the unreactive matter, and the other chloride impurities were separated by the difference of sublimation temperature on beryllium chloride. Next, we performed some kinds of beryllium purification tests from beryllium chloride. And, metallic beryllium could be recovered from beryllium chloride by the reduction with dry process. In addition, as the results of separation and purification tests using irradiated beryllium specimens, it appeared that separation efficiency of Co-60 from beryllium was above 96%. It is considered that about 4% Co-60 was carried from irradiated beryllium specimen in the form of cobalt chloride. And removal efficiency of tritium from irradiated beryllium was above 95%.

  17. Proton irradiation study of GFR candidate ceramics

    NASA Astrophysics Data System (ADS)

    Gan, Jian; Yang, Yong; Dickson, Clayton; Allen, Todd

    2009-06-01

    This work investigated the microstructural response of SiC, ZrC and ZrN irradiated with 2.6 MeV protons at 800 °C to a fluence of 2.75 × 10 19 protons/cm 2, corresponding to 0.71-1.8 displacement per atom (dpa), depending on the material. The change of lattice constant evaluated using HOLZ patterns is not observed. In comparison to Kr ion irradiation at 800 °C to 10 dpa from the previous studies, the proton irradiated ZrC and ZrN at 1.8 dpa show less irradiation damage to the lattice structure. The proton irradiated ZrC exhibits faulted loops which are not observed in the Kr ion irradiated sample. ZrN shows the least microstructural change from proton irradiation. The microstructure of 6H-SiC irradiated to 0.71 dpa consists of black dot defects at high density.

  18. A Retailer's Experience with Irradiated Foods

    SciTech Connect

    James P. Corrigan

    2000-11-12

    A food irradiation success story comes from Northbrook, Illinois, where Carrot Top, Inc., has been routinely carrying irradiated food for more than 7 yr. This paper presents the experiences of Carrot Top during those years, details the marketing approaches used, and summarizes the resulting sales figures.

  19. Schedule and status of irradiation experiments

    SciTech Connect

    Rowcliffe, A.F.; Grossbeck, M.L.; Robertson, J.P.

    1998-09-01

    The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has one irradiation experiment in reactor and five experiments in the design or construction stages. Postirradiation examination and testing is in progress on ten experiments.

  20. Electron irradiation of dry food products

    NASA Astrophysics Data System (ADS)

    Grünewald, Th.

    The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10∗∗4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50°C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the iradiation field in a closed conveyor system.

  1. Schedule and status of irradiation experiments

    SciTech Connect

    Rowcliffe, A.F.; Grossbeck, M.L.; Robertson, J.P.

    1998-03-01

    The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has four irradiation experiments in reactor, and five experiments in the design or construction stages. Postirradiation examination and testing is in progress on ten experiments.

  2. Electron Spin Relaxation in Irradiated Solids.

    DTIC Science & Technology

    1996-03-01

    the development and use of ELDOR techniques to study the spectral diffusion in irradiated L-alanine and other irradiated organic solids. Pulsed STELDOR...and pulsed two-frequency ELDOR methods were developed and the details of the implementation is reported. The assignment of relaxation times that gave

  3. Immune reactivity after high-dose irradiation

    SciTech Connect

    Gassmann, W.; Wottge, H.U.; von Kolzynski, M.; Mueller-Ruchholtz, W.

    1986-03-01

    Immune reactivity after total-body irradiation was investigated in rats using skin graft rejection as the indicator system. After sublethal irradiation with 10.5 Gy (approximately 50% lethality/6 weeks) the rejection of major histocompatibility complex allogeneic skin grafts was delayed significantly compared with nonirradiated control animals (28 versus 6.5 days). In contrast, skin grafts were rejected after 7.5 days in sublethally irradiated animals and 7 days in lethally irradiated animals if additional skin donor type alloantigens--namely, irradiated bone marrow cells--were given i.v. either simultaneously or with a delay of not more than 24 hr after the above conditioning regimen. These reactions were alloantigen-specific. They were observed in six different strain combinations with varying donors and recipients. Starting on day 2 after irradiation, i.v. injection of bone marrow gradually lost its effectivity and skin grafts were no longer rejected with uniform rapidity; skin donor marrow given on days 4 or 8 did not accelerate skin graft rejection at all. These data show that for approximately 1-2 days after high-dose total-body irradiation rats are still capable of starting a vigorous immune reaction against i.v.-injected alloantigens. The phenomenon of impaired rejection of skin grafted immediately after high-dose irradiation appears to result from the poor accessibility of skin graft alloantigens during the early postirradiation phase when vascularization of the grafted skin is insufficient.

  4. Passive SiC irradiation temperature monitor

    SciTech Connect

    Youngblood, G.E.

    1996-04-01

    A new, improved passive irradiation temperature monitoring method was examined after an irradiation test at 627{degrees}C. The method is based on the analysis of thermal diffusivity changes during postirradiation annealing of polycrystalline SiC. Based on results from this test, several advantages for using this new method rather than a method based on length or lattice parameter changes are given.

  5. AGR-1 Post Irradiation Examination Final Report

    SciTech Connect

    Demkowicz, Paul Andrew

    2015-08-01

    The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building

  6. Production of modified starches by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kang, Il-Jun; Byun, Myung-Woo; Yook, Hong-Sun; Bae, Chun-Ho; Lee, Hyun-Soo; Kwon, Joong-Ho; Chung, Cha-Kwon

    1999-04-01

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch.

  7. Characterisation and disintegration properties of irradiated starch.

    PubMed

    De Kerf, M; Mondelaers, W; Lahorte, P; Vervaet, C; Remon, J P

    2001-06-19

    Irradiation treatment could provide a quick and simple way to modify the physical, chemical and pharmaceutical properties of biopolymers such as starch. Corn, potato and drum dried corn starch were exposed to X-ray and electron beam (e-beam) irradiation treatment at doses of 10, 50 and 100 kGy. The disintegration properties of these starches were compared using alpha-lactose monohydrate tablets containing 5% (w/w) starch as disintegrant. Starch solubility increased, while its swelling capacity decreased with increasing irradiation dose. The irradiation treatment caused fragmentation of the amylopectin fraction. Irradiation modified the different starches thoroughly, showing remarkable differences in disintegration properties after X-ray treatment and e-beam modification. The e-beam modification resulted in significantly higher disintegration times of the tablets.

  8. Effect of Laser Irradiation on Enzyme Activity

    NASA Astrophysics Data System (ADS)

    Murakami, Satoshi; Kashii, Masafumi; Kitano, Hiroshi; Adachi, Hiroaki; Takano, Kazufumi; Matsumura, Hiroyoshi; Inoue, Tsuyoshi; Mori, Yusuke; Doi, Masaaki; Sugamoto, Kazuomi; Yoshikawa, Hideki; Sasaki, Takatomo

    2005-11-01

    We previously developed a protein crystallization technique using a femtosecond laser and protein crystal processing and detaching techniques using a pulsed UV laser. In this study, we examine the effect of laser irradiation on protein integrity. After several kinds of laser were irradiated on part of a solution of glycerol-6-phosphate dehydrogenase from Leuconostoc mesenteroides, we measured the enzyme activity. Femtosecond and deep-UV laser irradiations have little influence on the whole enzyme activity, whereas the enzyme lost its activity upon high-power near-infrared laser irradiation at a wavelength of 1547 nm. These results suggest that suitable laser irradiation has no remarkable destructive influence on protein crystallization or crystal processing.

  9. Cost effective alternative to low irradiance measurements

    NASA Technical Reports Server (NTRS)

    Oleary, Scott T.

    1988-01-01

    Martin Marietta's Space Simulation Laboratory (SSL) has a Thermal Environment Simulator (TES) with 56 individually controlled heater zones. The TES has a temperature range of approximately minus 129 C to plus 149 C. Because of the ability of TES to provide complex irradiance distributions, it is necessary to be able to measure a wide range of irradiance levels. SSL currently uses ambient temperature controlled radiometers with the capacity to measure sink irradiance levels of approximately 42.6 mw/sq cm, sink temperature equals 21 C and up. These radiometers could not be used to accurately measure the lower irradiance levels of the TES. Therefore, it was necessary to obtain a radiometer or develop techniques which could be used to measure lower irradiance levels.

  10. ATF Neutron Irradiation Program Technical Plan

    SciTech Connect

    Geringer, J. W.; Katoh, Yutai

    2016-03-01

    The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post-irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.

  11. Relief of vasospasm by intravascular ultraviolet irradiation

    NASA Astrophysics Data System (ADS)

    Nakai, Kanji; Morimoto, Yuji; Ito, Hirotaka; Kominami, Kimito; Matsuo, Hirotaka; Arai, Tsunenori; Kikuchi, Makoto

    1998-05-01

    We investigated the photovasorelaxation with intravascular transluminal irradiation using in vivo model. A 2.5 Fr. catheter was inserted in the femoral artery of a rabbit under anesthesia. A 400 micrometers diameter quartz fiber was inserted through the catheter. The catheter was withdrawn from the distal end to the proximal end of the exposed femoral artery without laser irradiation in order to observe the mechanical dilation by the procedure. The femoral artery lumen was irradiated by a Helium-Cadmium(He-Cd) laser (wavelength; 325 nm) with 8 mW through the fiber during 30 s. We carried out that the laser irradiation produced vasorelaxation (185% on the average) compared with mechanical vasodilation (150% on the average) with angiography. The results suggest that intravascular transluminal irradiation with low-power UV laser might be applicable to the relief of acute arterial vasospasm.

  12. Modeling of Irradiation Hardening of Polycrystalline Materials

    SciTech Connect

    Li, Dongsheng; Zbib, Hussein M.; Garmestani, Hamid; Sun, Xin; Khaleel, Mohammad A.

    2011-09-14

    High energy particle irradiation of structural polycrystalline materials usually produces irradiation hardening and embrittlement. The development of predict capability for the influence of irradiation on mechanical behavior is very important in materials design for next generation reactors. In this work a multiscale approach was implemented to predict irradiation hardening of body centered cubic (bcc) alpha-iron. The effect of defect density, texture and grain boundary was investigated. In the microscale, dislocation dynamics models were used to predict the critical resolved shear stress from the evolution of local dislocation and defects. In the macroscale, a viscoplastic self-consistent model was applied to predict the irradiation hardening in samples with changes in texture and grain boundary. This multiscale modeling can guide performance evaluation of structural materials used in next generation nuclear reactors.

  13. Li + grafting of ion irradiated polyethylene

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Rybka, V.; Vacík, J.; Hnatowicz, V.; Öchsner, R.; Ryssel, H.

    1999-02-01

    Foils of oriented polyethylene (PE) were irradiated with 63 keV Ar + and 155 keV Xe + ions to different fluences at room temperature and then doped from water solution of LiCl. The as irradiated and irradiated plus doped samples were examined by IR, EPR and neutron depth profiling (NDP) technique. The sheet resistance was also measured by the standard two points method. After Li salt doping of ion modified layer of PE, a reaction between degraded macromolecules and Li occur and thus a new chemical structure C-Li + is formed. Owing to the presence of these cations on the polymer chain, the irradiated plus doped layer exhibits higher electric conductivity compared to as-irradiated ones.

  14. Microbiological decontamination of natural honey by irradiation

    NASA Astrophysics Data System (ADS)

    Migdał, W.; Owczarczyk, H. B.; K ȩdzia, B.; Hołderna-K ȩdzia, E.; Madajczyk, D.

    2000-03-01

    Degree of microbiological decontamination, organoleptic and physico-chemical properties of natural honeys were investigated after radiation treatment. Seven kinds of honeys were irradiated with the beams of 10 MeV electrons from a 10 kW linear accelerator "Elektronika 10-10" at the dose 10 kGy. It was shown, that after irradiation, the total count of aerobic and anaerobic bacteria and moulds decrease by 99%. The antibiotic value in investigated honeys increased in turn from 1.67 to 2.67 after irradiation. Such factors and parameters of investigated honeys as their consistency, content of water and saccharose, acidity, the diastase and 5-HMF values were not changed significantly after irradiation. Decontamination by irradiation is a process which allows us to obtain high microbiological purity of honeys. It is especially needed, when honeys are used in surgical treatment of injuries and in nutrition of babies with food deficiency.

  15. ESR spectroscopic properties of irradiated gum Arabic.

    PubMed

    Leonor, S J; Gómez, J A; Kinoshita, A; Calandreli, I; Tfouni, E; Baffa, O

    2013-12-01

    Electron spin resonance (ESR) spectra of irradiated gum Arabic with doses between 0.5 and 5 kGy were studied. A linear relationship between the absorbed dose and the intensities of the ESR spectra was observed. ESR spectra of irradiated gum Arabic showed a decay of relative concentrations of free radicals originated by radiation and the production of at least two species of free radicals with half-times: 3.3 and 125.4 h. The results of spectral simulations for these radical groups were giso=2.0046; A=1.2 mT and gx=gy=2.0062, gz=2.0025. Hydration and dehydration of irradiated gum Arabic returns the ESR spectrum to its initial state before irradiation. The results show that ESR can be used as simple and reliable method to detect irradiated gum Arabic up to 60 days after initial radiation with doses on the order of 5 kGy.

  16. Tensile properties of irradiated surveillance coupons

    SciTech Connect

    Huang, F.H.; Blackburn, L.D.

    1994-06-01

    Tensile testing of austenitic steel and superalloy samples irradiated in the HMO 13 assembly was performed in support of the Fast Flux Test Facility (FFTF) Surveillance Program. Postirradiation yield stress, ultimate tensile stress, uniform elongation, total elongation, and reduction in area of 304 stainless steel (SS), 308 SS weld, 316 SS, A286, In718, and In718 weld were determined. Results showed the strength of austenitic steels increased while the ductility decreased as a result of irradiation. Low irradiation exposure produced little property change in In718. Overall, the tensile properties of HMO 13 surveillance coupons showed a lower magnitude of irradiation-induced property change than was expected based on earlier studies. Results from these tests gave no indications of unexpectedly severe irradiation damage to FFTF components.

  17. RERTR-7 Irradiation Summary Report

    SciTech Connect

    D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-7A, was designed to test several modified fuel designs to target fission densities representative of a peak low enriched uranium (LEU) burnup in excess of 90% U-235 at peak experiment power sufficient to generate a peak surface heat flux of approximately 300 W/cm2. The RERTR-7B experiment was designed as a high power test of 'second generation' dispersion fuels at peak experiment power sufficient to generate a surface heat flux on the order of 230 W/cm2.1 The following report summarizes the life of the RERTR-7A and RERTR-7B experiments through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.

  18. Variability of solar ultraviolet irradiance

    NASA Technical Reports Server (NTRS)

    Pap, J. M.; Donnelly, R. F.; Hudson, H. S.; Rottman, G. J.; Willson, R. C.

    1991-01-01

    A model of solar Lyman alpha irradiance developed by multiple linear regression analysis, including the daily values and 81-day running means of the full disk equivalent width of the Helium line at 1083 nm, predicts reasonably well both the short- and long-term variations observed in Lyman alpha. In contrast, Lyman alpha models calculated from the 10.7-cm radio flux overestimate the observed variations in the rising portion and maximum period of solar cycle, and underestimates them during solar minimum. Models are shown of Lyman alpha based on the He-line equivalent width and 10.7-cm radio flux for those time intervals when no satellite observations exist, namely back to 1974 and after April 1989, when the measurements of the Solar Mesosphere Satellite were terminated.

  19. AFIP-3 Irradiation Summary Report

    SciTech Connect

    Danielle M Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-05-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-3 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-3 experiment was fabricated by hot isostatic pressing (HIP) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-3 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  20. AFIP-3 Irradiation Summary Report

    SciTech Connect

    Danielle M Perez

    2011-04-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-3 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-3 experiment was fabricated by hot isostatic pressing (HIP) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-3 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  1. AFIP-3 Irradiation Summary Report

    SciTech Connect

    Danielle M Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2012-03-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-3 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-3 experiment was fabricated by hot isostatic pressing (HIP) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-3 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  2. RERTR-10 Irradiation Summary Report

    SciTech Connect

    D. M. Perez

    2011-05-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-10 was designed to further test the effectiveness of modified fuel/clad interfaces in monolithic fuel plates. The experiment was conducted in two campaigns: RERTR-10A and RERTR-10B. The fuel plates tested in RERTR-10A were all fabricated by Hot Isostatic Pressing (HIP) and were designed to evaluate the effect of various Si levels in the interlayer and the thickness of the Zr interlayer (0.001”) using 0.010” and 0.020” nominal foil thicknesses. The fuel plates in RERTR-10B were fabricated by Friction Bonding (FB) with two different thickness Si layers and Nb and Zr diffusion barriers.1 The following report summarizes the life of the RERTR-10A/B experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

  3. Irradiation creep of dispersion strengthened copper alloy

    SciTech Connect

    Pokrovsky, A.S.; Barabash, V.R.; Fabritsiev, S.A.

    1997-04-01

    Dispersion strengthened copper alloys are under consideration as reference materials for the ITER plasma facing components. Irradiation creep is one of the parameters which must be assessed because of its importance for the lifetime prediction of these components. In this study the irradiation creep of a dispersion strengthened copper (DS) alloy has been investigated. The alloy selected for evaluation, MAGT-0.2, which contains 0.2 wt.% Al{sub 2}O{sub 3}, is very similar to the GlidCop{trademark} alloy referred to as Al20. Irradiation creep was investigated using HE pressurized tubes. The tubes were machined from rod stock, then stainless steel caps were brazed onto the end of each tube. The creep specimens were pressurized by use of ultra-pure He and the stainless steel caps subsequently sealed by laser welding. These specimens were irradiated in reactor water in the core position of the SM-2 reactors to a fluence level of 4.5-7.1 x 10{sup 21} n/cm{sup 2} (E>0.1 MeV), which corresponds to {approx}3-5 dpa. The irradiation temperature ranged from 60-90{degrees}C, which yielded calculated hoop stresses from 39-117 MPa. A mechanical micrometer system was used to measure the outer diameter of the specimens before and after irradiation, with an accuracy of {+-}0.001 mm. The irradiation creep was calculated based on the change in the diameter. Comparison of pre- and post-irradiation diameter measurements indicates that irradiation induced creep is indeed observed in this alloy at low temperatures, with a creep rate as high as {approx}2 x 10{sup {minus}9}s{sup {minus}1}. These results are compared with available data for irradiation creep for stainless steels, pure copper, and for thermal creep of copper alloys.

  4. Historical Variations in Solar UV Irradiance

    NASA Astrophysics Data System (ADS)

    DeLand, M. T.

    2011-12-01

    Satellite measurements of solar UV variability have been made by at least fifteen different instruments since 1978. While it is difficult to keep a single UV irradiance instrument operating throughout a complete solar cycle, many of these instruments (Nimbus-7 SBUV, SME, NOAA-9 SBUV/2, NOAA-11 SBUV/2, UARS SUSIM, UARS SOLSTICE) were able to observe both maximum and minimum irradiance levels during either rising or declining phases of solar activity. Comparisons of these published results for solar cycles 21, 22, and 23 show consistent solar cycle irradiance changes at key wavelengths for terrestrial effects (e.g. 205 nm, 240 nm) within instrumental uncertainties. All historical data sets also show the same relative spectral dependence in the ultraviolet for both short-term (rotational) and long-term (solar cycle) variations. Empirical solar irradiance models that employ multiple proxy data sets to represent spectral irradiance produce long-term solar UV variations that are in good agreement with merged observational data through 2005. Recent UV irradiance data from the SORCE mission covering the declining phase of Cycle 23 present a different picture of long-term solar variations, with significantly larger temporal changes and different spectral dependence. We present comparisons of the SORCE irradiance data with previous solar UV observations and current model predictions. Scaling factors for use with solar UV proxy indexes have been derived from SORCE SIM and SORCE SOLSTICE data during 2004-2005. These scale factors, based on short-term irradiance variations, agree very well with results derived from concurrent NOAA-17 SBUV/2 and UARS SUSIM measurements. The 2004-2005 scale factors are consistent with previously derived scale factors that produce calculated long-term irradiance changes in good agreement with observations. The SORCE long-term solar UV irradiance results, corresponding to the early part of the mission, are consistent with undercorrection of

  5. Parameterization of Solar Global Uv Irradiation

    NASA Astrophysics Data System (ADS)

    Feister, U.; Jaekel, E.; Gericke, K.

    Daily doses of solar global UV-B, UV-A, and erythemal irradiation have been param- eterized to be calculated from pyranometer data of global and diffuse irradiation as well as from atmospheric column ozone measured at Potsdam (52 N, 107 m asl). The method has been validated against independent data of measured UV irradiation. A gain of information is provided by use of the parameterization for the three UV compo- nents (UV-B, UV-A and erythemal) referring to average values of UV irradiation. Ap- plying the method to UV irradiation measured at the mountain site Hohenpeissenberg (48 N, 977 m asl) shows that the parameterization even holds under completely differ- ent climatic conditions. On a long-term average (1953 - 2000), parameterized annual UV irradiation values are by 15 % (UV-A) and 21 % (UV-B), respectively, higher at Hohenpeissenberg, than they are at Potsdam. Using measured input data from 27 Ger- man weather stations, the method has been also applied to estimate the spatial distribu- tion of UV irradiation across Germany. Daily global and diffuse irradiation measured at Potsdam (1937 -2000) as well as atmospheric column ozone measured at Potsdam between1964 - 2000 have been used to derive long-term estimates of daily and annual totals of UV irradiation that include the effects of changes in cloudiness, in aerosols and, at least for the period 1964 to 2000, also in atmospheric ozone. It is shown that the extremely low ozone values observed mainly after the volcanic eruptions of Mt. Pinatubo in 1991 have substantially enhanced UV-B irradiation in the first half of the 90ies of the last century. The non-linear long-term changes between 1968 and 2000 amount to +4% ...+5% for annual global and UV-A irradiation mainly due to changing cloudiness, and +14% ... +15% for UV-B and erythemal irradiation due to both chang- ing cloudiness and decreasing column ozone. Estimates of long-term changes in UV irradiation derived from data measured at other German sites are

  6. AGR-1 Irradiation Experiment Test Plan

    SciTech Connect

    John T. Maki

    2009-10-01

    This document presents the current state of planning for the AGR-1 irradiation experiment, the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel process development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment will be irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). The test will contain six independently controlled and monitored capsules. Each capsule will contain a single type, or variant, of the AGR coated fuel. The irradiation is planned for about 700 effective full power days (approximately 2.4 calendar years) with a time-averaged, volume-average temperature of approximately 1050 °C. Average fuel burnup, for the entire test, will be greater than 17.7 % FIMA, and the fuel will experience fast neutron fluences between 2.4 and 4.5 x 1025 n/m2 (E>0.18 MeV).

  7. [Near infrared light irradiator using halogen lamp].

    PubMed

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  8. AGC-1 Post Irradiation Examination Status

    SciTech Connect

    David Swank

    2011-09-01

    The Next Generation Nuclear Plant (NGNP) Graphite R&D program is currently measuring irradiated material property changes in several grades of nuclear graphite for predicting their behavior and operating performance within the core of new Very High Temperature Reactor (VHTR) designs. The Advanced Graphite Creep (AGC) experiment consisting of six irradiation capsules will generate this irradiated graphite performance data for NGNP reactor operating conditions. All six AGC capsules in the experiment will be irradiated in the Advanced Test Reactor (ATR), disassembled in the Hot Fuel Examination Facility (HFEF), and examined at the INL Research Center (IRC) or Oak Ridge National Laboratory (ORNL). This is the first in a series of status reports on the progress of the AGC experiment. As the first capsule, AGC1 was irradiated from September 2009 to January 2011 to a maximum dose level of 6-7 dpa. The capsule was removed from ATR and transferred to the HFEF in April 2011 where the capsule was disassembled and test specimens extracted from the capsules. The first irradiated samples from AGC1 were shipped to the IRC in July 2011and initial post irradiation examination (PIE) activities were begun on the first 37 samples received. PIE activities continue for the remainder of the AGC1 specimen as they are received at the IRC.

  9. The Next Spaceflight Solar Irradiance Sensor: TSIS

    NASA Astrophysics Data System (ADS)

    Kopp, Greg; Pilewskie, Peter; Richard, Erik

    2016-05-01

    The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

  10. Irradiation exposure modulates central opioid functions

    SciTech Connect

    Dougherty, P.M.; Dafny, N.

    1987-11-01

    Exposure to low doses of gamma irradiation results in the modification of both the antinociceptive properties of morphine and the severity of naloxone-precipitated withdrawal in morphine-dependent rats. To better define the interactions between gamma irradiation and these opiate-mediated phenomena, dose-response studies were undertaken of the effect of irradiation on morphine-induced antinociception, and on the naloxone-precipitated withdrawal syndrome of morphine-dependent rats. In addition, electrophysiologic studies were conducted in rats after irradiation exposure and morphine treatment correlating with the behavioral studies. The observations obtained demonstrated that the antinociceptive effects of morphine as well as naloxone-precipitated withdrawal were modified in a dose-dependent manner by irradiation exposure. In addition, irradiation-induced changes in the evoked responses obtained from four different brain regions demonstrated transient alterations in both baseline and morphine-treated responses that may reflect the alterations observed in the behavioral paradigms. These results suggest that the effects of irradiation on opiate activities resulted from physiologic alterations of central endogenous opioid systems due to alterations manifested within peripheral targets.

  11. Rheological changes in irradiated chicken eggs

    NASA Astrophysics Data System (ADS)

    Ferreira, Lúcia F. S.; Del Mastro, Nélida L.

    1998-06-01

    Pathogenic bacteria may cause foodborne illnesses. Humans may introduce pathogens into foods during production, processing, distribution and or preparation. Some of these microorganisms are able to survive conventional preservation treatments. Heat pasteurization, which is a well established and satisfactory means of decontamination/disinfection of liquid foods, cannot efficiently achieve a similar objective for solid foods. Extensive work carried out worldwide has shown that irradiation is efficient in eradicating foodborne pathogens like Salmonella spp. that can contaminate poultry products. In this work Co-60 gamma irradiation was applied to samples of industrial powder white, yolk and whole egg at doses between 0 and 25 kGy. Samples were rehydrated and the viscosity measured in a Brookfield viscosimeter, model DV III at 5, 15 and 25°C. The rheological behaviour among the various kinds of samples were markedly different. Irradiation with doses up to 5 kGy, known to reduced bacterial contamination to non-detectable levels, showed almost no variation of viscosity of irradiated egg white samples. On the other hand, whole or yolk egg samples showed some changes in rheological properties depending on the dose level, showing the predominance of whether polimerization or degradation as a result of the irradiation. Additionally, irradiation of yolk egg powder reduced yolk color as a function of the irradiation exposure implemented. The importance of these results are discussed in terms of possible industrial applications.

  12. Influence of microwave irradiation on enzyme kinetics

    NASA Astrophysics Data System (ADS)

    Pavelkić, V. M.; Stanisavljev, D. R.; Gopčević, K. R.; Beljanski, M. V.

    2009-09-01

    The in vitro effect of 2.45 GHz microwave irradiation on porcine pepsin activity under controlled temperature and absorbed microwave power via kinetic parameters was evaluated. Kinetic study with respect of time of irradiation demonstrated the existence of an inactivation effect of microwaves at pH 2 on pepsin molecule. Bovine serum albumin (BSA)-bromphenol blue (BPB) complex was used as substrate for the assay of pepsin by kinetic method. Depending on absorbed microwave dose, the degree of caused inactivation varies from 39.11 to 45.91% for 5 and 20 min of pepsin MW irradiation, respectively. The V maxapp and K mapp were calculated for low (5 min of MW irradiation) and higher specific absorbed dose (20 min of MW irradiation), as well as for untreated enzyme, from double reciprocal Lineweaver-Burk plot. The effect of microwaves on substrate (BSA-BPB complex) was also investigated. For reaction performed with MW irradiated substrate for 5 min the reaction rate was decreased for 15.15%, while for 20 min of substrate irradiation reaction rate was decreased for 25.52% compared to the control reaction.

  13. Rapid detection of irradiated frozen hamburgers

    NASA Astrophysics Data System (ADS)

    Delincée, Henry

    2002-03-01

    DNA comet assay can be employed as a rapid and inexpensive screening test to check whether frozen ground beef patties (hamburgers) have been irradiated as a means to increase their safety by eliminating pathogenic bacteria, e.g. E. coli O157:H7. Such a detection procedure will provide an additional check on compliance with existing regulations, e.g. enforcement of labelling and rules in international trade. Frozen ready prepared hamburgers from the market place were `electron irradiated' with doses of 0, 1.3, 2.7, 4.5 and 7.2kGy covering the range of potential commercial irradiation. DNA fragmentation in the hamburgers was made visible within a few hours using the comet assay, and non-irradiated hamburgers could be easily discerned from the irradiated ones. Even after 9 months of frozen storage, irradiated hamburgers could be identified. Since DNA fragmentation may also occur with other food processes (e.g. temperature abuse), positive screening tests shall be confirmed using a validated method to specifically prove an irradiation treatment, e.g. EN 1784 or EN 1785.

  14. Microstructure evolution during helium irradiation and post-irradiation annealing in a nanostructured reduced activation steel

    NASA Astrophysics Data System (ADS)

    Liu, W. B.; Ji, Y. Z.; Tan, P. K.; Zhang, C.; He, C. H.; Yang, Z. G.

    2016-10-01

    Severe plastic deformation, intense single-beam He-ion irradiation and post-irradiation annealing were performed on a nanostructured reduced activation ferritic/martensitic (RAFM) steel to investigate the effect of grain boundaries (GBs) on its microstructure evolution during these processes. A surface layer with a depth-dependent nanocrystalline (NC) microstructure was prepared in the RAFM steel using surface mechanical attrition treatment (SMAT). Microstructure evolution after helium (He) irradiation (24.8 dpa) at room temperature and after post-irradiation annealing was investigated using Transmission Electron Microscopy (TEM). Experimental observation shows that GBs play an important role during both the irradiation and the post-irradiation annealing process. He bubbles are preferentially trapped at GBs/interfaces during irradiation and cavities with large sizes are also preferentially trapped at GBs/interfaces during post-irradiation annealing, but void denuded zones (VDZs) near GBs could not be unambiguously observed. Compared with cavities at GBs and within larger grains, cavities with smaller size and higher density are found in smaller grains. The average size of cavities increases rapidly with the increase of time during post-irradiation annealing at 823 K. Cavities with a large size are observed just after annealing for 5 min, although many of the cavities with small sizes also exist after annealing for 240 min. The potential mechanism of cavity growth behavior during post-irradiation annealing is also discussed.

  15. Influences of Microwave Irradiation on Environment

    NASA Astrophysics Data System (ADS)

    Murakami, H.; Abe, Y.; Iwata, T.; Kudo, I.; Saito, K.; Okuda, T.

    2004-12-01

    An experimental facility to evaluate the long-duration influence of microwave to environment, a so-called long duration microwave exposure facility (LDMEF), was constructed in Tsukuba in 1994, and so far irradiation tests on plants accumulated over 40,000 hours have been conducted with the aid of 2.45 GHz magnetron. The LDMEF consists of a pair of outdoor electromagnetically isolated areas, one under the influence of microwave irradiation with a 500 W magnetron and one without microwave irradiation. The growth rates of plants in both areas were compared and evaluated with the experimental data for the temperature distribution in the soil and power distribution of microwave. Although any appreciable influence of microwave was not noticed in the power density less than 10 mW/cm2 , the experimental results showed a significant growth rate enhancement when the power density became over 10 mW/cm2 . However, the growth was rather depressed when the power density increased over 15 mW/cm2 . These effects are well explained by the temperature and moisture in the soil which are also under an appreciable influence of microwave irradiation [1,2]. In this context, we newly constructed an indoor irradiation facility, in which the growth conditions of plants under a constant soil temperature can be maintained. In addition, irradiation with a 5.8 GHz magnetron will be conducted in the new facility. In parallel to a series of indoor and outdoor irradiation tests on plants, the influence of microwave irradiation on the growth pattern of albino mouse will be conducted. This experiment will be the first experimental evaluation for the influence of microwave irradiation on animals.

  16. Etude du comportement et de la modélisation viscoplastique du zircaloy 4recristallisé sous chargements monotones et cycliques uni et multiaxes

    NASA Astrophysics Data System (ADS)

    Delobelle, P.; Robinet, P.

    1994-08-01

    The results of experiment performed on a recrystallized zircaloy 4 alloy in the intermediate temperature domain 20 leqslant T leqslant 400 ^{circ}C are presented. To characterize the anisotropy, especially at 350 ^{circ}C, the tests were made under both monotonic and cyclic uni- and bidirectional loadings, i.e. tension-compression, tension-torsion and tension-internal pressure tests. The different anisotropy coefficients and especially R^p = \\varepsilon^p_{θθ} /\\varepsilon^ p _ {{^-_-}{^-_-} } seem to be temperature independent. An important feature of the behavior of this alloy in the neighbourhood of 300 ^{circ}C is attributed to the dislocations-point defects interactions (dynamic strain aging), phenomena often observed in the solid solutions. For the 2D cyclic non proportional loadings it is shown that a weak supplementary hardening appears, which is a function of the degree of the phase lag. We propose to particularize and to apply a unified viscoplastic model with internal variables to the considered alloy, as the model as already been developed and identified elsewhere for other isotropic materials. From a general point of view the introduction of the anisotropy in the model is made by four tensors of rank 4 ; [ M] is assigned to the flow directions, [ N] to the linear parts of the kinematical hardening variables and [ Q] , [ R] respectively to the dynamic and static recoveries of these tensorial variables. This phenomenological formulation leads to a correct representation of the set of the experimental results presented at 350 ^{circ}C, which provides an a posteriori confirmation of the formalism used. On étudie, entre 20 et 400 ^{circ}C, à l'aide d'essais sous chargements multiaxiaux monotones et cycliques (traction, torsion et pression interne) les propriétés viscoplastiques anisotropes de tube de zircaloy 4 recristallisé. A la température de 350 ^{circ}C, l'anisotropie a été quantifiée de façon détaillée. Les quelques résultats obtenus

  17. Infrared spectroscopy study of irradiated PVDF

    SciTech Connect

    Chappa, Veronica; Grosso, Mariela del; Garcia Bermudez, Gerardo; Behar, Moni

    2007-10-26

    The effects induced by 1 MeV/amu ion irradiations were compared to those induced by 4-12 MeV/amu irradiations. Structural analysis with infrared spectroscopy (FTIR) was carried out on PVDF irradiated using C and He beams with different fluences. From these spectra it was observed, as a function of fluence, an overall destruction of the polymer, amorphization of the crystalline regions and the creation of in-chain unsaturations. The track dimensions were determined using a previously developed Monte Carlo simulation code and these results were compared to a semiempirical model.

  18. Laser Irradiated Growth of Protein Crystal

    NASA Astrophysics Data System (ADS)

    Adachi, Hiroaki; Takano, Kazufumi; Hosokawa, Youichiroh; Inoue, Tsuyoshi; Mori, Yusuke; Matsumura, Hiroyoshi; Yoshimura, Masashi; Tsunaka, Yasuo; Morikawa, Masaaki; Kanaya, Shigenori; Masuhara, Hiroshi; Kai, Yasushi; Sasaki, Takatomo

    2003-07-01

    We succeeded in the first ever generation of protein crystals by laser irradiation. We call this process Laser Irradiated Growth Technique (LIGHT). Effective crystallization was confirmed by applying an intense femtosecond laser. The crystallization period was dramatically shortened by LIGHT. In addition, protein crystals were obtained by LIGHT from normally uncrystallized conditions. These results indicate that intense femtosecond laser irradiation generates crystal nuclei; protein crystals can then be grown from the nuclei that act as seeds in a supersaturated solution. The nuclei formation is possible primarily due to nonlinear nucleation processes of an intense femtosecond laser with a peak intensity of over a gigawatt (GW).

  19. Total body calcium analysis. [neutron irradiation

    NASA Technical Reports Server (NTRS)

    Lewellen, T. K.; Nelp, W. B.

    1974-01-01

    A technique to quantitate total body calcium in humans is developed. Total body neutron irradiation is utilized to produce argon 37. The radio argon, which diffuses into the blood stream and is excreted through the lungs, is recovered from the exhaled breath and counted inside a proportional detector. Emphasis is placed on: (1) measurement of the rate of excretion of radio argon following total body neutron irradiation; (2) the development of the radio argon collection, purification, and counting systems; and (3) development of a patient irradiation facility using a 14 MeV neutron generator. Results and applications are discussed in detail.

  20. Hyperparathyroidism following head and neck irradiation

    SciTech Connect

    Rao, S.D.; Frame, B.; Miller, M.J.; Kleerskoper, M.; Block, M.A.; Parfitt, A.M.

    1980-02-01

    A history of head and neck irradiation in childhood or adolescence was found in 22 of 130 patients with primary hyperparathyroidism compared with only 12 of 400 control patients. Among 200 patients with a known history of childhood irradiation, biochemical or surgical evidence of hyperparathyroidism was found in ten, a prevalence of 5%. This is at least 30 times the prevalence of hyperparathyroidism in the general population. The data indicate that head and neck irradiation should be regarded as an important risk factor in the subsequent development of hyperparathyroidism.

  1. Gamma-ray irradiated polymer optical waveguides

    SciTech Connect

    Lai, C.-C.; Wei, T.-Y.; Chang, C.-Y.; Wang, W.-S.; Wei, Y.-Y.

    2008-01-14

    Optical waveguides fabricated by gamma-ray irradiation on polymer through a gold mask are presented. The gamma-ray induced index change is found almost linearly dependent on the dose of the irradiation. And the measured propagation losses are low enough for practical application. Due to the high penetrability of gamma ray, uniform refractive index change in depth can be easily achieved. Moreover, due to large-area printing, the uniformity of waveguide made by gamma-ray irradiation is much better than that by e-beam direct writing.

  2. Processing Irradiated Beryllium For Disposal

    SciTech Connect

    T. J. Tranter; R. D. Tillotson; N. R. Mann; G. R. Longhurst

    2005-11-01

    The purpose of this research was to develop a process for decontaminating irradiated beryllium that will allow it to be disposed of through normal radwaste channels. Thus, the primary objectives of this ongoing study are to remove the transuranic (TRU) isotopes to less than 100 nCi/g and remove {sup 60}Co, and {sup 137}Cs, to levels that will allow the beryllium to be contact handled. One possible approach that appears to have the most promise is aqueous dissolution and separation of the isotopes by selected solvent extraction followed by precipitation, resulting in a granular form for the beryllium that may be fixed to prevent it from becoming respirable and therefore hazardous. Beryllium metal was dissolved in nitric and fluorboric acids. Isotopes of {sup 241}Am, {sup 239}Pu, {sup 85}Sr, and {sup 137}Cs were then added to make a surrogate beryllium waste solution. A series of batch contacts was performed with the spiked simulant using chlorinated cobalt dicarbollide (CCD) and polyethylene glycol diluted with sulfone to extract the isotopes of Cs and Sr. Another series of batch contacts was performed using a combination of octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in tributyl phosphate (TBP) diluted with dodecane for extracting the isotopes of Pu and Am. The results indicate that greater than 99.9% removal can be achieved for each isotope with only three contact stages.

  3. Surface Irradiances Consistent With CERES-Derived Top-of-Atmosphere Shortwave and Longwave Irradiances

    NASA Technical Reports Server (NTRS)

    Kato, Seiji; Loeb, Norman G.; Rose, Fred G.; Doelling, David R.; Rutan, David A.; Caldwell, Thomas E.; Yu, Lisan; Weller, Robert A.

    2013-01-01

    The estimate of surface irradiance on a global scale is possible through radiative transfer calculations using satellite-retrieved surface, cloud, and aerosol properties as input. Computed top-of-atmosphere (TOA) irradiances, however, do not necessarily agree with observation-based values, for example, from the Clouds and the Earth's Radiant Energy System (CERES). This paper presents amethod to determine surface irradiances using observational constraints of TOA irradiance from CERES. A Lagrange multiplier procedure is used to objectively adjust inputs based on their uncertainties such that the computed TOA irradiance is consistent with CERES-derived irradiance to within the uncertainty. These input adjustments are then used to determine surface irradiance adjustments. Observations by the Atmospheric Infrared Sounder (AIRS), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), CloudSat, andModerate Resolution Imaging Spectroradiometer (MODIS) that are a part of the NASA A-Train constellation provide the uncertainty estimates. A comparison with surface observations from a number of sites shows that the bias [root-mean-square (RMS) difference] between computed and observed monthlymean irradiances calculated with 10 years of data is 4.7 (13.3) W/sq m for downward shortwave and 22.5 (7.1) W/sq m for downward longwave irradiances over ocean and 21.7 (7.8) W m22 for downward shortwave and 21.0 (7.6) W/sq m for downward longwave irradiances over land. The bias andRMS error for the downward longwave and shortwave irradiances over ocean are decreased from those without constraint. Similarly, the bias and RMS error for downward longwave over land improves, although the constraint does not improve downward shortwave over land. This study demonstrates how synergetic use of multiple instruments (CERES,MODIS, CALIPSO, CloudSat, AIRS, and geostationary satellites) improves the accuracy of surface irradiance computations.

  4. Irradiated foods: current trends and technologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Additional demands on keeping food safe and palatable through longer distribution chains have led industry executives to reconsider irradiation and other technologies as viable processing alternatives for many foods. Other intervention technologies (precision thermal, UV, and novel sanitizer formula...

  5. He-Ne laser extravascular irradiation therapy

    NASA Astrophysics Data System (ADS)

    Chen, Rong; Chen, Huifang; Xie, Shusen; Chen, Yanjiao; Zhang, Yanrong

    2000-10-01

    Based on the study of tissue optics related with the laser irradiation blood therapy, a new treatment method, extravascular low-level laser irradiation therapy (ELLLI) is developed. The veins of 30 patients with cerebrovascular disease combined with diabetes, asthma were treated by He-Ne laser (632.8nm, 25mW) which was delivered by an optics fiber. The fiber was outside the patient's skin and the laser irradiated on the blood vessel perpendicularly. The therapy time was 60 minutes each time and about 7-10 times a course of the treatment. The values of blood sugar, blood- fat and hemorrheology were measured as the effective indexes. After the treatment the effective indexes and the symptoms of the patients were all improved. With the advantages of simplicity and safety (no medical infection), laser extravascular irradiation therapy is likely to be a new medical method for heart brain and other diseases.

  6. Laser irradiation of carbon-tungsten materials

    NASA Astrophysics Data System (ADS)

    Marcu, A.; Avotina, L.; Marin, A.; Lungu, C. P.; Grigorescu, C. E. A.; Demitri, N.; Ursescu, D.; Porosnicu, C.; Osiceanu, P.; Kizane, G.; Grigoriu, C.

    2014-09-01

    Carbon-tungsten layers deposited on graphite by thermionic vacuum arc (TVA) were directly irradiated with a femtosecond terawatt laser. The morphological and structural changes produced in the irradiated area by different numbers of pulses were systematically explored, both along the spots and in their depths. Although micro-Raman and Synchrotron-x-ray diffraction investigations have shown no carbide formation, they have shown the unexpected presence of embedded nano-diamonds in the areas irradiated with high fluencies. Scanning electron microscopy images show a cumulative effect of the laser pulses on the morphology through the ablation process. The micro-Raman spatial mapping signalled an increased percentage of sp3 carbon bonding in the areas irradiated with laser fluencies around the ablation threshold. In-depth x-ray photoelectron spectroscopy investigations suggested a weak cumulative effect on the percentage increase of the sp2-sp3 transitions with the number of laser pulses just for nanometric layer thicknesses.

  7. Neoplasia in fast neutron-irradiated beagles

    SciTech Connect

    Bradley, E.W.; Zook; B.C.; Casarett, G.W.

    1981-09-01

    One hundred fifty-one beagle dogs were irradiated with either photons or fast neutrons (15 MeV) to one of three dose-limiting normal tissues - spinal cord, lung, or brain. The radiation was given in four fractions per week for 5 weeks (spinal cord), 6 weeks (lung), 7 weeks (brain) to total doses encompassing those given clinically for cancer management. To date, no nonirradiated dogs or photon-irradiated dogs have developed neoplasms within the irradiated field. Of the neutron-irradiated dogs at risk, the incidence of neoplasia was 15%. The latent period for radiation-induced cancers has varied from 1 to 4 1/2 years at this time in the study.

  8. Neoplasia in fast neutron-irradiated beagles

    SciTech Connect

    Bradley, E.W.; Zook, B.C.; Casarett, G.W.; Deye, J.A.; Adoff, L.M.; Rogers, C.C.

    1981-09-01

    One hundred fifty-one beagle dogs were irradiated with either photons or fast neutrons (15 MeV) to one of three dose-limiting normal tissues--spinal cord, lung, or brain. The radiation was given in four fractions per week for 5 weeks (spinal cord), 6 weeks (lung), or 7 weeks (brain) to total doses encompassing those given clinically for cancer management. To date, no nonirradiated dogs or photon-irradiated dogs have developed any neoplasms. Seven dogs receiving fast neutrons have developed 9 neoplasms within the irradiated field. Of the neutron-irradiated dogs at risk, the incidence of neoplasia was 15%. The latent period for radiation-induced cancers has varied from 1 to 4 1/2 years at this time in the study.

  9. Irradiated Shellfish: Identification by Photostimulated Luminescence

    PubMed Central

    Di Schiavi, Maria Teresa; Falconi, Grazia; Verità, Francesca Della; Cavallina, Roberta

    2014-01-01

    The irradiation of food is a technology used in the industry to prevent the deterioration of foodstuff in some countries. The European Community legislation states that each Member State must carry out annual checks on the products during commercialisation. The Istituto Zooprofilattico Sperimentale delle regioni Lazio e Toscana (Rome, Italy) has developed and validated the screening method of photostimulated luminescence UNI EN 13751:2009 to identify irradiated shellfish. A total of 30 tests of shellfish samples, consisting of 22 certified as irradiated and 8 not-irradiated samples, were performed. The validation procedure was based on sensitivity and specificity; the compatibility between the screening method and the reference standard EN 13751:2009 was evaluated. Data were processed: 100% sensitivity and 100% specificity were obtained. Results obtained in our laboratory were perfectly compatible with the reference standard. For this reason, the method has been validated and proved to be suitable for its intended use. PMID:27800335

  10. Antioxidant tolerance of kidney after irradiation.

    PubMed

    Bukan, Neslihan; Güney, Yildiz; Hiçsönmez, Ayşe; Bilgihan, Ayşe

    2003-03-01

    Different doses of irradiation were performed in which group 1 (non-irradiated), group 2 (8 Gy/single dose/whole body) and group 3 (15 Gy/single dose/whole body) were formed of guinea pigs. After 24 hr of radiation exposure the levels of lipid peroxidation product, malondialdehyde, (MDA), glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured in the whole kidney. The MDA content increased in animals irradiated with 8 and 15 Gy. And group 3 showed an increase the level of MDA. GSH contents of kidney in group 2 and 3 increased. The activity of SOD decreased markedly in group 3 when compared with control group. The activity of GSH-Px decreased significantly in group 2 and group 3 in comparison to controls. It may be concluded that a high dose of ionizing irradiation cause excessive oxidative stress in kidney.

  11. IRRADIATION METHOD OF CONVERTING ORGANIC COMPOUNDS

    DOEpatents

    Allen, A.O.; Caffrey, J.M. Jr.

    1960-10-11

    A method is given for changing the distribution of organic compounds from that produced by the irradiation of bulk alkane hydrocarbons. This method consists of depositing an alkane hydrocarbon on the surface of a substrate material and irradiating with gamma radiation at a dose rate of more than 100,000 rads. The substrate material may be a metal, metal salts, metal oxides, or carbons having a surface area in excess of 1 m/sup 2//g. The hydrocarbons are deposited in layers of from 0.1 to 10 monolayers on the surfaces of these substrates and irradiated. The product yields are found to vary from those which result from the irradiation of bulk hydrocarbons in that there is an increase in the quantity of branched hydrocarbons.

  12. Hardness Evolution of Gamma-Irradiated Polyoxymethylene

    NASA Astrophysics Data System (ADS)

    Hung, Chuan-Hao; Harmon, Julie P.; Lee, Sanboh

    2016-12-01

    This study focuses on analyzing hardness evolution in gamma-irradiated polyoxymethylene (POM) exposed to elevated temperatures after irradiation. Hardness increases with increasing annealing temperature and time, but decreases with increasing gamma ray dose. Hardness changes are attributed to defects generated in the microstructure and molecular structure. Gamma irradiation causes a decrease in the glass transition temperature, melting point, and extent of crystallinity. The kinetics of defects resulting in hardness changes follow a first-order structure relaxation. The rate constant adheres to an Arrhenius equation, and the corresponding activation energy decreases with increasing dose due to chain scission during gamma irradiation. The structure relaxation of POM has a lower energy barrier in crystalline regions than in amorphous ones. The hardness evolution in POM is an endothermic process due to the semi-crystalline nature of this polymer.

  13. Thermoluminescence properties of irradiated chickpea and corn

    NASA Astrophysics Data System (ADS)

    Necmeddin Yazici, A.; Bedir, Metin; Bozkurt, Halil; Bozkurt, Hüseyin

    2008-02-01

    A study was carried out to establish a detection method for irradiated chickpea and corn by thermoluminescence (TL) method. The leguminous were packed in polyethylene bags and then the packets were irradiated at room temperature at different doses by 60Co gamma source at 1, 4, 8 and 10 kGy. Minerals extracted from the leguminous were deposited onto a clean aluminum disc and TL intensities of the minerals were measured by TL. It was observed that the extracted samples from both leguminous exhibit good TL Intensity and the TL intensity of glow curves of them increased proportionally to irradiation doses. The TL glow curve of both irradiated leguminous presents a single broad peak below 400 °C. The TL trapping parameters glow peaks were estimated by the additive dose (AD), Tm(Ea)-Tstop and computerized glow curve deconvolution (CGCD) methods. The fading characteristics of glow curves were also recorded up to 6 months.

  14. Food Irradiation: Is It Safe and Wholesome?

    ERIC Educational Resources Information Center

    Rebus, Shirley

    1990-01-01

    Addresses some of the major issues of food irradiation with respect to safety and wholesomeness, including formation of radiolytic products, effects on nutrients, prevention of food-borne illness, development of radiation-resistant bacteria, and formation of afaltoxins. (Author)

  15. Total lymphoid irradiation in alloimmunity and autoimmunity

    SciTech Connect

    Strober, S.

    1987-12-01

    Total lymphoid irradiation has been used as an immunosuppressive regimen in autoimmune disease and organ transplantation. The rationale for its use originated from studies of patients with Hodgkin disease, in whom this radiotherapy regimen was noted to induce profound and long-lasting immune suppression and yet was well tolerated, with few long-term side effects. Total lymphoid irradiation is a unique immunosuppressive regimen that produces a selective (and long-lasting) reduction in the number and function of helper T cells and certain subsets of B cells. Conventional immunosuppressive drugs show little selectivity, and their effects are short-lived. The most important aspect of total lymphoid irradiation is the potential for achieving transplantation tolerance and permanent remissions in autoimmune disease in laboratory animals. Attempts are being made to achieve similar goals in humans given total lymphoid irradiation, so that immunosuppressive drugs can be ultimately withdrawn from transplant recipients and patients with lupus nephritis. 28 references.

  16. Polymer Morphological Change Induced by Terahertz Irradiation.

    PubMed

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-07

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced "softly," without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10-20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm(2), which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  17. Food Irradiation Update and Cost Analysis

    DTIC Science & Technology

    1991-11-01

    poultry 3kGy Control Salrnl’..a products and other bacteria Fresh fruits and vegetables ikGy Inhibit growth and maturation Wheat, rice, barley, fruit...to the chilled non-irradiated product. Strawberries are frequently attacked by the fungi Botrytis cinerea Pers. ex Fr., or "gray mold", which can...Low dose irradiation delays ripening or mold growth , and therefore extends the shelf life of some fruits and vegetables. Apples, cherries, peaches

  18. Neutron Irradiation Resistance of RAFM Steels

    SciTech Connect

    Gaganidze, Ermile; Dafferner, Bernhard; Aktaa, Jarir

    2008-07-01

    The neutron irradiation resistance of the reduced-activation ferritic/martensitic (RAFM) steel EUROFER97 and international reference steels (F82H-mod, OPTIFER-Ia, GA3X and MANET-I) have been investigated after irradiation in the Petten High Flux Reactor up to 16.3 dpa at different irradiation temperatures (250-450 deg. C). The embrittlement behavior and hardening are investigated by instrumented Charpy-V tests with sub-size specimens. Neutron irradiation-induced embrittlement and hardening of EUROFER97 was studied under different heat treatment conditions. Embrittlement and hardening of as-delivered EUROFER97 steel are comparable to those of reference steels. Heat treatment of EUROFER97 at a higher austenitizing temperature substantially improves the embrittlement behaviour at low irradiation temperatures. Analysis of embrittlement vs. hardening behavior of RAFM steels within a proper model in terms of the parameter C={delta}DBTT/{delta}{sigma} indicates hardening-dominated embrittlement at irradiation temperatures below 350 deg. C with 0.17 {<=} C {<=} 0.53 deg. C/MPa. Scattering of C at irradiation temperatures above 400 deg. C indicates non hardening embrittlement. A role of He in a process of embrittlement is investigated in EUROFER97 based steels, that are doped with different contents of natural B and the separated {sup 10}B-isotope (0.008-0.112 wt.%). Testing on small scale fracture mechanical specimens for determination of quasi-static fracture toughness will be also presented in a view of future irradiation campaigns. (authors)

  19. Gamma irradiation effects in W films

    SciTech Connect

    Claro, Luiz H.; Santos, Ingrid A.; Silva, Cassia F.

    2013-05-06

    Using the van Der Pauw methodology, the surface resistivity of irradiated tungsten films deposited on Silicon substrate was measured. The films were exposed to {gamma} radiation using a isotopic {sup 60}Co source in three irradiation stages attaining 40.35 kGy in total dose. The obtained results for superficial resistivity display a time annealing features and their values are proportional to the total dose.

  20. Brain fibronectin expression in prenatally irradiated mice

    SciTech Connect

    Meznarich, H.K.; McCoy, L.S.; Bale, T.L.; Stiegler, G.L.; Sikov, M.R. )

    1993-01-01

    Activation of gene transcription by radiation has been recently demonstrated in vivo. However, little is known on the specificity of these alterations on gene transcription. Prenatal irradiation is a known teratogen that affects the developing mammalian central nervous system (CNS). Altered neuronal migration has been suggested as a mechanism for abnormal development of prenatally irradiated brains. Fibronectin (FN), an extracellular glycoprotein, is essential for neural crest cell migration and neural cell growth. In addition, elevated levels of FN have been found in the extracellular matrix of irradiated lung. To test whether brain FN is affected by radiation, either FN level in insoluble matrix fraction or expression of FN mRNA was examined pre- and postnatally after irradiation. Mice (CD1), at 13 d of gestation (DG), served either as controls or were irradiated with 14 DG, 17 DG, or 5,6, or 14 d postnatal. Brain and liver were collected from offspring and analyzed for either total FN protein levels or relative mRNAs for FN and tubulin. Results of prenatal irradiation on reduction of postnatal brain weight relative to whole are comparable to that reported by others. Insoluble matrix fraction (IMF) per gram of brain, liver, lung, and heart weight was not significantly different either between control and irradiated groups or between postnatal stages, suggesting that radiation did not affect the IMF. However, total amounts of FN in brain IMF at 17 DG were significantly different (p < .02) between normal (1.66 [+-] 0.80 [mu]g) and irradiated brains (0.58 [+-] 0.22 [mu]g). FN mRNA was detectable at 13, 14, and 17 DG, but was not detectable at 6 and 14 d postnatal, indicating that FN mRNA is developmentally regulated. 41 refs., 4 figs., 3 tabs.

  1. Irradiance analyzer for high power lasers

    SciTech Connect

    Conrad, R.W.

    1981-04-07

    An irradiance analysis system which includes an array of square rods that are joined together and have a flat entrance end and a polished flat exit end through which visible light is transmitted to a fresnel lens and focused to a particular area where the image focused is photographed so that when the various frames are developed they can be analyzed in a conventional film densitometer to yield quantative data on the temporal variation of laser beam irradiance distributions.

  2. Preserved irradiated homologous cartilage for orbital reconstruction

    SciTech Connect

    Linberg, J.V.; Anderson, R.L.; Edwards, J.J.; Panje, W.R.; Bardach, J.

    1980-07-01

    Human costal cartilage is an excellent implant material for orbital and periorbital reconstruction because of its light weight, strength, homogeneous consistency and the ease with which it can be carved. Its use has been limited by the necessity of a separate surgical procedure to obtain the material. Preserved irradiated homologous cartilage has been shown to have almost all the autogenous cartilage and is convenient to use. Preserved irradiated homologous cartilage transplants do not elicit rejection reactions, resist infection and rarely undergo absorption.

  3. Van de Graaff Irradiation of Materials

    SciTech Connect

    Quigley, Kevin; Chemerisov, Sergey; Tkac, Peter; Vandegrift, George F.

    2016-10-01

    Through irradiations using our 3 MeV Van de Graaf accelerator, Argonne is testing the radiation stability of components of equipment that are being used to dispense molybdenum solutions for use as feeds to 99mTc generators and in the 99mTc generators themselves. Components have been irradiated by both a direct electron beam and photons generated from a tungsten convertor.

  4. Food Irradiation | RadTown USA | US EPA

    EPA Pesticide Factsheets

    2016-02-23

    Using radiation to kill bacteria and other pathogens in food is called food irradiation. Irradiating food kills bacteria and molds that can make people sick. Irradiation does not remove toxins that are already in food. The high energy of the radiation breaks chemical bonds to stop bacteria and other pathogens from multiplying. Irradiation does not make food radioactive.

  5. Irradiation of municipal sludge for agricultural use

    NASA Astrophysics Data System (ADS)

    Ahlstrom, Scott B.

    Research has demonstrated that irradiation is an effective means for reducing pathogens in sewage sludge to levels where sludge reuse in public areas meets criteria for protection of the public health. Complementary research has demonstrated the value of the irradiated sludge in both agronomic and animal science applications. The benefits of sludge application to cropland are well documented. The irradiation process does not increase the extractability and plant uptake of a broad range of nutrients and heavy metals from sludge-amended soils. However, it does eliminate the hazards associated with pathogen contamination when applying sludge to agricultural land. Irradiated sludge has also been evaluated as a supplemental foodstuff for cattle and sheep. The data indicate that products derived from raw sewage may have a substantial nutritive value for ruminant animals. Irradiation of sewage sludge is a practical means of sludge disinfection. Where a highly disinfected sludge is required, it should be considered as a viable sludge management alternative. Evaluation of sludge irradiation technology and its associated costs must be done with consideration of other sludge treatment processes to develop an acceptable sludge management system.

  6. Total lymphoid irradiation and discordant cardiac xenografts

    SciTech Connect

    Kaplan, E.; Dresdale, A.R.; Diehl, J.T.; Katzen, N.A.; Aronovitz, M.J.; Konstam, M.A.; Payne, D.D.; Cleveland, R.J. )

    1990-01-01

    Total lymphoid irradiation can prolong concordant cardiac xenografts. The effects of total lymphoid irradiation in a discordant xenograft model (guinea pig to rat) were studied with and without adjuvant pharmacologic immunosuppression. Inbred Lewis rats were randomly allocated to one of four groups. Group 1 (n = 6) served as a control group and rats received no immunosuppression. Group 2 (n = 5) received triple-drug therapy that consisted of intraperitoneal azathioprine (2 mg/kg), cyclosporine (20 mg/kg), and methylprednisolone (1 mg/kg) for 1 week before transplantation. Group 3 animals (n = 5) received 15 Gy of total lymphoid irradiation in 12 divided doses over a 3-week period. Group 4 (n = 6) received both triple-drug therapy and total lymphoid irradiation as described for groups 2 and 3. Complement-dependent cytotoxicity assay was performed to determine if a correlation between complement-dependent cytotoxicity and rejection-free interval existed. Rejection was defined as cessation of graft pulsation and was confirmed by histologic test results. Only groups 1 and 2 showed a difference in survival (group 1, 6.9 +/- 1.0 minutes; group 2, 14.2 +/- 2.7 minutes, p = 0.02). Although total lymphoid irradiation did decrease complement-dependent cytotoxicity, linear regression revealed no correlation between complement-dependent cytotoxicity and graft survival (coefficient of correlation, 0.30). Unlike concordant cardiac xenografts, total lymphoid irradiation with or without triple-drug therapy does not prolong graft survival.

  7. [Light irradiator for various chronic pain].

    PubMed

    Ide, Yasuo

    2014-07-01

    Effects of light upon human tissue are divided into irreversible effects and reversible effects. Irreversible effects can be called as high level laser therapy (HLLT), and reversible effects can be called as low level light therapy (LLLT). Light irradiators for chronic pain act under principle of LLLT. Laser diode, halogen lamp and xenon lamp are used as light sources for light irradiator for various chronic pain. These days, light emitting diode (LED) is used as light source for light irradiator for various kinds of pain. Light irradiators are now divided into portable light weight low power machine and heavy weight, high power machine. In the dental area Nd : YAG laser is using as HLLT tool. But, now there are many reports about Nd : YAG laser used as anesthetic machine. In these reports, topical anesthetic effects of Nd : YAG laser are immediate and with fewer side effects compared with topical anesthetic agents. These effects are explained as LLLT. Halogen lamp and xenon lamp type irradiators were also introduced. MEDILASER SOFT PULSE10, an laser diode type irradiator was withdrawn from the market.

  8. Irradiated Nuclear Fuel Management: Resource Versus Waste

    SciTech Connect

    Nash, Kenneth L.; Lumetta, Gregg J.; Vienna, John D.

    2013-01-01

    Management of irradiated fuel is an important component of commercial nuclear power production. Although it is broadly agreed that the disposition of some fraction of the fuel in geological repositories will be necessary, there is a range of options that can be considered that affect exactly what fraction of material will be disposed in that manner. Furthermore, until geological repositories are available to accept commercial irradiated fuel, these materials must be safely stored. Temporary storage of irradiated fuel has traditionally been conducted in storage pools, and this is still true for freshly discharged fuel. Criticality control technologies have led to greater efficiencies in packing of irradiated fuel into storage pools. With continued delays in establishing permanent repositories, utilities have begun to move some of the irradiated fuel inventory into dry storage. Fuel cycle options being considered worldwide include the once-through fuel cycle, limited recycle in which U and Pu are recycled back to power reactors as mixed oxide fuel, and advance partitioning and transmutation schemes designed to reduce the long term hazards associated with geological disposal from millions of years to a few hundred years. Each of these options introduces specific challenges in terms of the waste forms required to safely immobilize the hazardous components of irradiated fuel.

  9. Dosimetry Formalism and Implementation of a Homogenous Irradiation Protocol to Improve the Accuracy of Small Animal Whole-Body Irradiation Using a 137Cs Irradiator.

    PubMed

    Brodin, N Patrik; Chen, Yong; Yaparpalvi, Ravindra; Guha, Chandan; Tomé, Wolfgang A

    2016-02-01

    Shielded Cs irradiators are routinely used in pre-clinical radiation research to perform in vitro or in vivo investigations. Without appropriate dosimetry and irradiation protocols in place, there can be large uncertainty in the delivered dose of radiation between irradiated subjects that could lead to inaccurate and possibly misleading results. Here, a dosimetric evaluation of the JL Shepard Mark I-68A Cs irradiator and an irradiation technique for whole-body irradiation of small animals that allows one to limit the between subject variation in delivered dose to ±3% are provided. Mathematical simulation techniques and Gafchromic EBT film were used to describe the region within the irradiation cavity with homogeneous dose distribution (100% ± 5%), the dosimetric impact of varying source-to-subject distance, and the variation in attenuation thickness due to turntable rotation. Furthermore, an irradiation protocol and dosimetry formalism that allows calculation of irradiation time for whole-body irradiation of small animals is proposed that is designed to ensure a more consistent dose delivery between irradiated subjects. To compare this protocol with the conventional irradiation protocol suggested by the vendor, high-resolution film dosimetry measurements evaluating the dose difference between irradiation subjects and the dose distribution throughout subjects was performed using phantoms resembling small animals. Based on these results, there can be considerable variation in the delivered dose of > ± 5% using the conventional irradiation protocol for whole-body irradiation doses below 5 Gy. Using the proposed irradiation protocol this variability can be reduced to within ±3% and the dosimetry formalism allows for more accurate calculation of the irradiation time in relation to the intended prescription dose.

  10. Etude de la microstructure d'un acier 316 titane apres vieillissement et apres irradiation aux neutrons

    NASA Astrophysics Data System (ADS)

    Brun, G.; Le Naour, J.; Vouillon, M.

    1981-10-01

    La précipitation qui se produit lors de vieillissements de longue durée entre 450 et 700°C dans un acier 316 Ti soit hypertrempé soit écroui, a été étudiée en couplant les techniques de microscopic électronique et de microanalyse X. Pour les cas expérimentaux étudiés, les résultats obtenus montrent que la composition des carbures M 23C 6 et des phases σ, Laves et χ est peu sensible aux conditions de vieillissement et dépend également peu de l'état structural initial. Leur teneur en éléments principaux de l'alliage est d'ailleurs voisine de celle des phases précipitées dans l'acier non stabilisé. Excepté les carbures de type M 6C, toutes ces phases ont une teneur en nickel inférieure à celle de la matrice. Les premiers rérultats obtenus sur des matériaux irradiés aux neutrons montrent que la précipitation sous flux est différente de celle qui se produit dans l'acier vieilli. Les phases γ' et G ainsi que les carbures riches en nickel ont été observés. L'attention a été attirée sur le fait qu'il n'y a pas de corrélation simple entre la vitesse de gonflement et la teneuer résiduelle en nickel de la matrice.

  11. A Solar Irradiance Climate Data Record

    NASA Astrophysics Data System (ADS)

    Coddington, O.; Lean, J. L.; Pilewskie, P.; Snow, M.; Lindholm, D.

    2016-08-01

    We present a new climate data record for total solar irradiance and solar spectral irradiance between 1610 and the present day with associated wavelength and time-dependent uncertainties and quarterly updates. The data record, which is part of the National Oceanic and Atmospheric Administration’s (NOAA) Climate Data Record (CDR) program, provides a robust, sustainable, and scientifically defensible record of solar irradiance that is of sufficient length, consistency, and continuity for use in studies of climate variability and climate change on multiple time scales and for user groups spanning climate modeling, remote sensing, and natural resource and renewable energy industries. The data record, jointly developed by the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP) and the Naval Research Laboratory (NRL), is constructed from solar irradiance models that determine the changes with respect to quiet sun conditions when facular brightening and sunspot darkening features are present on the solar disk where the magnitude of the changes in irradiance are determined from the linear regression of a proxy magnesium (Mg) II index and sunspot area indices against the approximately decade-long solar irradiance measurements of the Solar Radiation and Climate Experiment (SORCE). To promote long-term data usage and sharing for a broad range of users, the source code, the dataset itself, and supporting documentation are archived at NOAA's National Centers for Environmental Information (NCEI). In the future, the dataset will also be available through the LASP Interactive Solar Irradiance Data Center (LISIRD) for user-specified time periods and spectral ranges of interest.

  12. Removal of carbon-14 from irradiated graphite

    NASA Astrophysics Data System (ADS)

    Dunzik-Gougar, Mary Lou; Smith, Tara E.

    2014-08-01

    Approximately 250,000 tonnes of irradiated graphite waste exists worldwide and that quantity is expected to increase with decommissioning of Generation II reactors and deployment of Generation IV gas-cooled, graphite moderated reactors. This situation indicates the need for a graphite waste management strategy. On of the isotopes of great concern for long-term disposal of irradiated graphite is carbon-14 (14C), with a half-life of 5730 years. Study of irradiated graphite from some nuclear reactors indicates 14C is concentrated on the outer 5 mm of the graphite structure. The aim of the research presented here is to develop a practical method by which 14C can be removed. In parallel with these efforts, the same irradiated graphite material is being characterized to identify the chemical form of 14C in irradiated graphite. A nuclear-grade graphite, NBG-18, and a high-surface-area graphite foam, POCOFoam®, were exposed to liquid nitrogen (to increase the quantity of 14C precursor) and neutron-irradiated (1013 neutrons/cm2/s). During post-irradiation thermal treatment, graphite samples were heated in the presence of an inert carrier gas (with or without the addition of an oxidant gas), which carries off gaseous products released during treatment. Graphite gasification occurs via interaction with adsorbed oxygen complexes. Experiments in argon only were performed at 900 °C and 1400 °C to evaluate the selective removal of 14C. Thermal treatment also was performed with the addition of 3 and 5 vol% oxygen at temperatures 700 °C and 1400 °C. Thermal treatment experiments were evaluated for the effective selective removal of 14C. Lower temperatures and oxygen levels correlated to more efficient 14C removal.

  13. Preservation of food products by irradiation

    SciTech Connect

    McGivney, W.T.

    1988-01-01

    The use of irradiation to preserve food has the potential to significantly enhance our capacity to maximize the quality and quantity of the food we consume. In a world in which distribution of food occurs across continents and in which malnourished populations are in dire need of basic food products, any safe, effective, and efficient means of preserving food is more than welcome. Irradiation, as a method for food preservation, has been studied for more than 30 years. This discussion focuses on this most recent method for the preservation of food with particular emphasis on its effects on the safety, nutritive, and aesthetic values of the food preserved by irradiation. The use of ionizing radiation as a method to preserve foods is one that has been demonstrated to be effective for a variety of food classes. Irradiation offers a means to decontaminate, disinfest, and retard the spoilage of the food supply. At the same time, it appears that the wholesomeness of these food products is maintained. Nutritive value can be sustained by use of effective doses of radiation. Concerns over the safety of irradiated food are rooted in questions regarding the potential induction of radioactivity, harmful radiolytic products, and pathogenic radiation-resistant or mutant strains of microorganisms. Research findings have allayed concerns over safety. However, more research is necessary to conclusively resolve these safety issues. Food irradiation is a promising technology that has and will contribute to our ability to feed the people of this world. This technology is but one of many available ways to preserve our greatest natural resource, the food supply. Enhancement of the ability to preserve food by irradiation will facilitate the distribution of food from fertile developed regions to the malnourished peoples of underdeveloped countries. 21 references.

  14. The treatment of extensively burned patients and {beta} irradiational injury skin burn patients with irradiated pigskin

    SciTech Connect

    Tang Zhong Yi; Lu Xing An; Jing Ling; Qi Qiang

    1994-12-31

    Obvious therapeutic effects achieved by the covering of irradiation sterilized pigskin on burn wounds, escarectomized 3rd degree burn wounds and {beta} injured burns are introduced. The article introduces also the manufacture processes of irradiated pigskins and the selection of surgical treatments of various burns.

  15. Quality of gamma ray-irradiated iceberg lettuce and treatments to minimize irradiation-induced disorders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation of Iceberg lettuce was recently approved by the FDA to enhance microbial safety and to extend shelf-life at doses up to 4 kGy. However, the radiation tolerance of whole head lettuce is unclear. The present study was conducted to investigate the effects of irradiation on the quality of he...

  16. Profil de l'hémogramme chez les enfants paludéens de 0 à 5 ans sous quinine, cas de la République Démocratique du Congo

    PubMed Central

    Kabamba, Arsène Tshikongo; Lukumwena, Zet Kalala; Longanga, Albert Otshudi

    2014-01-01

    Le paludisme constitue un des problèmes de santé publique majeur en République Démocratique du Congo (RDC) à cause d'une part des risques d’épidémies dans certaines zones du pays et d'autre part à cause du nombre des malades et des décès qu'il provoque. Cette étude expose les aspects hématologiques liés à la prise de la quinine au cours du paludisme grave chez l'enfant. Pour ce faire, les prises de sang ont été effectuées à deux groupes d'enfants, dans différents centres hospitaliers de Lubumbashi: le premier groupe est constitué d'enfants gravement impaludés et sous traitement à la quinine; tandis que le second groupe, composé d'enfants impaludés aussi mais sans traitement à la quinine et sert de groupe témoin. Ces prélèvements ont été analysés pour une exploration de l'hémogramme par un dosage sérique des paramètres hématologiques ci-après: les globules rouges, l'hémoglobine, l'hématocrite et le volume globulaire moyen. Les résultats obtenus montrent une différence statistiquement significative entre les deux groupes d'enfants examinés. En effet, dans la majorité des cas, une augmentation des taux plasmatiques des paramètres hématologiques analysés a été observée dans le groupe d'enfants impaludés sous traitement à la quinine, traduisant ainsi l'apport de la quinine sur la stabilisation de l'hémogramme au cours d'un paludisme grave chez l'enfant de moins de cinq ans. PMID:25722768

  17. Place du traitement chirurgical sous circulation extracorporelle à cœur battant dans les cancers du rein avec envahissement cave supra-diaphragmatique: à propos de sept cas

    PubMed Central

    Lahyani, Mounir; Karmouni, Tarik; Elkhader, Khalid; Koutani, Abdellatif; Andaloussi, Ahmed Ibn Attya

    2014-01-01

    Ce travail vise à analyser les résultats de la néphrectomie avec thrombectomie atrio-cave sous circulation extracorporelle (CEC) chez sept patients ayant un cancer du rein avec envahissement cave supra-diaphragmatique et de discuter les indications opératoires. Sept patients, six hommes et une femme dont l’âge varie entre 46ans et 65ans, ont été opérés d'un cancer du rein avec extension atrio-cave. L’écho-doppler a toujours permis la mise en évidence de l'extension veineuse mais la limite supérieure du thrombus était formellement identifiée par l'examen tomodensitométrique quatre fois, et par la résonance magnétique nucléaire dans tous les cas. Tous les patients ont été opérés sous CEC à cœur battant en normothermie. Un seul décès postopératoire est survenu. La durée du séjour en réanimation a été de 4,5 jours. Cinq patients ont eu à distance une dissémination métastatique. Cinq malades ont eu une médiane de survie de 11,5 mois (de 7 à16). Un malade a subi une métastasectomie pulmonaire 6 mois après la néphrectomie. L'exérèse des thrombi atrio-caves a été facilitée par la CEC avec une mortalité et une morbidité postopératoires acceptables mais les résultats à distance ont été décevants. Cette intervention ne peut être proposée qu'aux patients n'ayant aucune extension locorégionale et générale décelable, ce qui souligne l'importance des examens morphologiques préopératoires. PMID:25995777

  18. Dimensionnement des actionneurs électriques alimentés à fréquence variable sous faible tension: I. Analyse du problème couplé magnétique, thermique, électrique

    NASA Astrophysics Data System (ADS)

    Biedinger, J.-M.; Vilain, J.-P.

    1998-07-01

    In this paper, the autors present a model for the multidisciplinary operation analysis of a variable frequency electrical drive, in the case of low voltage supply. This model takes into account the coupling between the electromagnetic, thermal and electrical phenomena. It allows to evaluate the performances under permanent or transient thermal conditions, as we can find in the working cycles of electrical vehicles with on board energy supply. This model is a part of an optimal design procedure, which will be described in an other article. For this reason, this paper is devoted to explain the dependences between the design variables and the performances. The proposed model is applied to a permanent magnet brushless DC motor. The performances are evaluated for the S1 and S2 duty-cycling operations. The influence of the driving parameters of the converter is also examined. L'objectif de cet article est de présenter la synthèse d'un modèle d'analyse pluridisciplinaire adapté à la caractérisation des performances d'un entraînement électrique alimenté à fréquence variable sous faible tension. Le modèle prend en compte le couplage entre les phénomènes électromagnétique, thermique et électrique. Il permet d'étudier le fonctionnement sous les conditions de régime thermique permanent ou transitoire qui interviennent dans la définition des cycles de travail des engins de traction à énergie embarquée. Ce modèle d'analyse constitue un élément d'une procédure de dimensionnement optimal qui sera développée dans un article séparé; aussi l'exposé est-il conduit en explicitant les dépendances fonctionnelles entre les paramètres de dimensionnement et les performances. La procédure d'analyse est appliquée à l'étude d'un moteur à aimants permanents périphériques alimenté suivant le mode “brushless trapézoïdal"; les performances sont évaluées pour deux types de cycle de travail: le cycle S1 en régime permanent, et le cycle S2 en r

  19. Irradiation response on mechanical properties of neutron irradiated F82H

    NASA Astrophysics Data System (ADS)

    Shiba, K.; Suzuki, M.; Hishinuma, A.

    1996-10-01

    Tensile and Charpy impact properties of neutron irradiated F82H (Fe8Cr2WVTa) with and without boron have been investigated to obtain the basic irradiation response on mechanical properties in low damage regime less than 1 dpa at the temperature ranging from 300° to 590°C. Boron-doped steel was used for the helium effect due to (n, α) reaction. Typical irradiation hardening was observed at 300°C. The irradiation above 520°C did not reveal increase in yield stress, but the specimen irradiated at 590°C showed some reduction in elongation in room temperature tensile testing. Slight difference in the tensile properties between boron-doped and boron-free were observed at 590°C. No changes in ductile brittle transition temperature (DBTT) occurred at a temperature between 335° and 460°C by Charpy impact testing.

  20. The influence of Gamma Irradiation on flavonoïds content during storage of irradiated clementina

    NASA Astrophysics Data System (ADS)

    Oufedjikh, H.; Mahrouz, M.; Lacroix, M.; Amiot, M. J.; Taccini, M.

    1998-06-01

    The influence of Gamma irradiation on content of some important flavonoïds (flavonones glycosides and polymethoxylated flavones) was evaluated during storage of Moroccan clementina treated at a mean dose of 0.3 kGy and stored three months at 3'C. Results shows that at day one, gamma irradiation induced degradation of small quantities of these flavonoïds, however after 14 days of storage, the content of these compounds was significantly higher (p≤0.05) in irradiated samples. Irradiation stimulated biosynthesis of flavonoïds after 14 days of storage. Hesperidin was the major flavanones compounds in clementines. Nobiletin and Heptamethoxyflavone were the major polymethoxylated flavones in clementines. Our study demonstrated that the content of these compounds was significantly higher (p≤0.05) in irradiated samples.

  1. The volume effect in irradiated mouse colorectum

    NASA Astrophysics Data System (ADS)

    Skwarchuk, Mark William

    1997-11-01

    Damage of the colorectum is the dose-limiting normal tissue complication following radiotherapy of prostate and cervical cancers. One approach for decreasing complications is to physically reduce the treatment volume. Mathematical models have been previously developed to describe the change in associated toxicity with a change in irradiated volume, i.e. the 'volume effect', for serial-type normal tissues including the colorectum. The first goal of this thesis was to test the hypothesis that there would not be a threshold length in the development of obstruction after irradiation of mouse colorectum, as predicted by the Probability model of the volume effect. The second goal was to examine if there were differences in the threshold and in the incidence of colorectal obstruction after irradiation of two mouse strains, C57B1/6 (C57) and C3Hf/Kam (C3H), previously found to be fibrosis-prone and-resistant, respectively, after lung irradiation due, in part, to genetic differences. The hypothesis examined was that differences in incidence between strains were due to the differential expression of the fibrogenic cytokines TGF/beta and TNF/alpha. Various lengths of C57 and C3H mouse colorectum were irradiated and the incidence of colorectal obstruction was followed up to 15 months. A threshold length was observed for both mouse strains, in contradiction of model predictions. The mechanism of the threshold was epithelial regeneration after irradiation. C57 mice had significantly higher incidence of colorectal obstruction compared to C3H mice, especially at smaller irradiated lengths. Colorectal tissue was obtained at various times after irradiation and prepared for histology, immunohistochemistry and RNase protection assay for measurement of TGF/beta 1, 2, 3 and TNF/alpha mRNA. Distinct strain differences in the histological time of appearance and spatial locations of fibrosis were observed. However, there were no consistent strain difference in mRNA levels or

  2. Effects of irradiation on platelet function

    SciTech Connect

    Rock, G.; Adams, G.A.; Labow, R.S.

    1988-09-01

    Current medical practice involves the irradiation of blood components, including platelet concentrates, before their administration to patients with severe immunosuppression. The authors studied the effect of irradiation on in vitro platelet function and the leaching of plasticizers from the bag, both immediately and after 5 days of storage. The platelet count, white cell count, pH, glucose, lactate, platelet aggregation and release reaction, and serotonin uptake were not altered by the irradiation of random-donor or apheresis units with 2000 rads carried out at 0 and 24 hours and 5 days after collection. The leaching of di(2-ethylhexyl)phthalate from the plastic bags followed by the conversion to mono(2-ethylhexyl)phthalate was not increased by irradiation. Therefore, it is possible to irradiate platelet concentrates on the day of collection and subsequently store them for at least 5 days while maintaining in vitro function. This procedure could have considerable benefit for blood banks involved in the provision of many platelet products.

  3. Measurement of Diameter Changes during Irradiation Testing

    SciTech Connect

    Davis, K. L.; Knudson, D. L.; Crepeau, J. C.; Solstad, S.

    2015-03-01

    New materials are being considered for fuel, cladding, and structures in advanced and existing nuclear reactors. Such materials can experience significant dimensional and physical changes during irradiation. Currently in the US, such changes are measured by repeatedly irradiating a specimen for a specified period of time and then removing it from the reactor for evaluation. The time and labor to remove, examine, and return irradiated samples for each measurement makes this approach very expensive. In addition, such techniques provide limited data and handling may disturb the phenomena of interest. In-pile detection of changes in geometry is sorely needed to understand real-time behavior during irradiation testing of fuels and materials in high flux US Material and Test Reactors (MTRs). This paper presents development results of an advanced Linear Variable Differential Transformer-based test rig capable of detecting real-time changes in diameter of fuel rods or material samples during irradiation in US MTRs. This test rig is being developed at the Idaho National Laboratory and will provide experimenters with a unique capability to measure diameter changes associated with fuel and cladding swelling, pellet-clad interaction, and crud buildup.

  4. Disinfestation of different cereal products by irradiation

    NASA Astrophysics Data System (ADS)

    Kovács, E.; Kiss, I.; Boros, A.; Horváth, Ny.; Tóth, J.; Gyulai, P.; Szalma, Á.

    The sensitivity of overlineTribolium confusum - small flour beetle - to radiation was studied in a dose range of 0-0.8 kGy. We found that the insect egg was the most sensitive to radiation, then larvae and pupae followed it. 0.2 kGy dose of irradiation kills these forms or their further development is inhibited. Imagoes do not immediately die after 0.8 kGy dose of irradiation; the young imagoes are more sensitive to radiation than the aged ones. 0.4 kGy average dose of irradiation is a suitable protection against overlineTribolium confusum. Disinfestation experiments were performed with wheat-germ and wheat-bran and parallelly the most important ingredients of the two products were analysed. The vitamin E content and the rate of lipid-oxidation of wheat germ were determined. The vitamin E content decreased after radiation treatment, however, during storage of at least 6 months, it remained at a level specified by food quality standards (higher than 10 mg%). Carbohydrate content of wheat-bran (water soluble carbohydrate content, crude-fibre and dietary fibre content) did not change at all. Storability of radiation disinfested wheat-germ was 8 months, wheat-bran 3-4 months. On the base of the results 2-2 tons of wheat-germ and wheat-bran were irradiated and trial marked in 1985. In 1986 the irradiation of 10 tons of wheat-germ is planned.

  5. Infrared Irradiation: Toward Green Chemistry, a Review

    PubMed Central

    Escobedo, René; Miranda, René; Martínez, Joel

    2016-01-01

    This review provides a comprehensive overview of where infrared irradiation has been employed, mainly as regards activating green mode for natural products extractions, as well as to favor a reaction, highlighting its actual importance. It is also underlined that infrared irradiation heating has been around for a long time; however, only in the last eighteen years have many of its advantages been applied to satisfy a wide range of chemical processes, natural products extractions, and for the promotion of many kinds of reactions. In addition, it is brought to light that near infrared irradiation is more efficient than middle and far infrared irradiations, being easily controllable and with the quality of a fast responding heat source. Thus, the main objective of this review is to offer infrared irradiation as an alternative clean energy source to activate reactions, in addition to favor the selective extraction of natural products, all of which is within the Green Chemistry protocol. Some recent results from our laboratory are also included. PMID:27023535

  6. Carotid artery disease following external cervical irradiation

    SciTech Connect

    Elerding, S.C.; Fernandez, R.N.; Grotta, J.C.; Lindberg, R.D.; Causay, L.C.; McMurtrey, M.J.

    1981-01-01

    A retrospective study of 910 patients surviving at least five years after cervical irradiation for Hodgkin's disease, non-Hodgkin's lymphoma, or primary head an neck neoplasms showed the incidence of stroke following cervical irradiation was 63 of 910 patients (6.3%) during a mean period of observation of nine years. This represents a trend toward an increased risk for this population observed over the same period of time (p . 0.39). A prospective study of 118 similar patients currently living five years after cervical radiotherapy was performed to determine the incidence of carotid artery disease occurring as a consequence of neck irradiation. Abnormal carotid phonangiograms (CPA) were found in 25% of the patients and abnormal oculoplethysmographs (OPG) were found in 17%. These studies represent significant carotid lesions that are not expected in such a population. It is concluded that the carotid stenoses demonstrated are most likely a consequence of prior irradiation. Patients that are five-year survivors of cervical irradiation should have noninvasive vascular laboratory studies performed as part of their routine follow-up examinations in order to detect these carotid lesions while they are occult.

  7. Carotid artery disease following external cervical irradiation

    SciTech Connect

    Elerding, S.C.; Fernandez, R.N.; Grotta, J.C.; Lindberg, R.D.; Causay, L.C.; McMurtrey, M.J.

    1981-11-01

    A retrospective study of 910 patients surviving at least five years after cervical irradiation for Hodgkin's disease, non-Hodgkin's lymphoma, or primary head and neck neoplasms showed the incidence of stroke following cervical irradiation was 63 of 910 patients (6.3%) during a mean period of observation of nine years. This represents a trend toward an increased risk for this population over the expected incidence of 38 strokes for a matched population observed over the same period of time (p = 0.39). A prospective study of 118 similar patients currently living five years after cervical radiotherapy was performed to determine the incidence of carotid artery disease occurring as a consequence of neck irradiation. Abnormal carotid phonoangiograms (CPA) were found in 25% of the patients and abnormal oculoplethysmographs (OPG) were found in 17%. These studies represent significant carotid lesions that are not expected in such a population. It is concluded that the carotid stenoses demonstrated are most likely a consequence of prior irradiation. Patients that are five-year survivors of cervical irradiation should have noninvasive vascular laboratory studies performed as part of their routine follow-up examinations in order to detect these carotid lesions while they are occult.

  8. The LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Snow, M.; Woods, T. N.; Eparvier, F. G.; Fontenla, J.; Harder, J.; McClintock, W. E.; Pankratz, C.; Richard, E.; Windnagel, A.; Woodraska, D.

    2005-12-01

    LASP has created an online resource for combined solar irradiance datasets from the SORCE, TIMED, UARS, and SME missions. The LASP Interactive Solar IRradiance Datacenter (LISIRD) not only provides unified access to the individual datasets, but also combines them for ease of use by scientists, educators, and the general public. In particular, LISIRD makes available composite spectra and time series. The TIMED SEE, SORCE SOLSTICE, and SORCE SIM instruments produce spectra that together cover the solar spectrum from 1 to 2700 nm. Through the LISIRD interface, the user can get data that bridges the various missions in both wavelength and time. LISIRD also hosts data products of interest to the space weather community. They have slightly different needs than the atmospheric modelers that are the typical users of irradiance data. For space weather applications, high time cadence and near real-time data delivery are key. For these users, we make our observations available shortly after spacecraft contact, and append the observations to a single data file which they can retrieve using anonymous ftp every few hours. The third component of LISIRD is the Solar Physical Radiation Model (SPRM) results of Fontenla et al. It provides a model of current solar activity, the synthetic spectral irradiance, and tools that permit one to model the solar activity source of the spectral irradiance variations.

  9. Infrared Irradiation: Toward Green Chemistry, a Review.

    PubMed

    Escobedo, René; Miranda, René; Martínez, Joel

    2016-03-26

    This review provides a comprehensive overview of where infrared irradiation has been employed, mainly as regards activating green mode for natural products extractions, as well as to favor a reaction, highlighting its actual importance. It is also underlined that infrared irradiation heating has been around for a long time; however, only in the last eighteen years have many of its advantages been applied to satisfy a wide range of chemical processes, natural products extractions, and for the promotion of many kinds of reactions. In addition, it is brought to light that near infrared irradiation is more efficient than middle and far infrared irradiations, being easily controllable and with the quality of a fast responding heat source. Thus, the main objective of this review is to offer infrared irradiation as an alternative clean energy source to activate reactions, in addition to favor the selective extraction of natural products, all of which is within the Green Chemistry protocol. Some recent results from our laboratory are also included.

  10. Cobalt-60 gamma irradiation of shrimp

    SciTech Connect

    Sullivan, N.L.B.

    1993-01-01

    Meta- and ortho-tyrosine were measured using high performance liquid chromatography (HPLC) in conjunction with electrochemical detection in shrimp irradiated using cobalt-60 gamma radiation in the absorbed dose range 0.8 to 6.0 kGy, in nonirradiated shrimp, and in bovine serum albumin (BSA) irradiated in dilute aqueous solution at 25.0 kGy. Ortho-tyrosine was measured in nonirradiated BSA. Para-, meta-, and ortho-tyrosine was measured using HPLC in conjunction with uv-absorption detection in dilute aqueous solutions of phenylalanine irradiated in the absorbed dose range 16.0 to 195.0 kGy. The measured yields of tyrosine isomers were approximately linear as a function of absorbed dose in shrimp, and in irradiated solutions of phenylalanine up to 37.0 kGy. The occurrence of meta- and ortho-tyrosine, which had formerly been considered unique radiolytic products, has not previously been reported in nonirradiated shrimp or BSA. The conventional hydrolyzation and analytical techniques used in the present study to measure meta- and ortho-tyrosine may provide the basis for a method to detect and determine the dose used in food irradiation.

  11. Ion irradiation effects on metallic nanocrystals

    SciTech Connect

    Kluth, P.; Johannessen, B.; Giulian, R.; Schnohr, C.S.; Foran, G.J.; Cookson, D.J.; Byrne, A.P.; Ridgway, M.C.

    2008-04-02

    We have investigated structural and morphological properties of metallic nanocrystals (NCs) exposed to ion irradiation. NCs were characterized by transmission electron microscopy in combination with advanced synchrotron-based analytical techniques, in particular X-ray absorption spectroscopy and small-angle X-ray scattering. A number of different effects were observed depending on the irradiation conditions. At energies where nuclear stopping is predominant, structural disorder/amorphization followed by inverse Ostwald ripening/dissolution due to ion beam mixing was observed for Au and Cu NCs embedded in SiO{sub 2}. The ion-irradiation-induced crystalline to amorphous transition in the NCs, which cannot be achieved in the corresponding bulk metals, was attributed to their initially higher structural energy as compared to bulk material and possibly preferential nucleation of the amorphous phase at the NC/SiO{sub 2} interface. At very high irradiation energies (swift heavy ion irradiation), where the energy loss is nearly entirely due to electronic stopping, a size-dependent shape transformation of the NCs from spheres to rod like shapes was apparent in Au NCs. Our preliminary results are in good agreement with considerations on melting of the NCs in the ion track as one mechanism involved in the shape transformation.

  12. Neoplasms in young dogs after perinatal irradiation

    SciTech Connect

    Benjamin, S.A.; Lee, A.C.; Angleton, G.M.; Saunders, W.J.; Miller, G.K.; Williams, J.S.; Brewster, R.D.; Long, R.I.

    1986-08-01

    For a study of the life-time effects of irradiation during development, 1,680 beagles were given single, whole-body exposures to /sup 60/Co gamma-radiation at one of three prenatal (preimplantation, embryonic, and fetal) or at one of three postnatal (neonatal, juvenile, and young adult) ages. Mean doses were 0, 0.16, or 0.83 Gy. For comparison with data on childhood cancer after prenatal irradiation, examination was made of tumors occurring in young dogs in this life-span experiment. Up to 4 years of age, 18 dogs had neoplasms diagnosed, 2 of these being in controls. Four dogs that were irradiated in the perinatal (late fetal or neonatal) period died of cancers prior to 2 years of age. This risk was of significant increase compared to the risks for other experimental groups and for the canine population in general. Overall, 71% (5 of 7) of all cancers and 56% (10 of 18) of all benign and malignant neoplasms seen in the first 4 years of life occurred in 29% (480 of 1680) of the dogs irradiated in the perinatal period. These data suggest an increased risk for neoplasia after perinatal irradiation in dogs.

  13. RESTORATION INDUCED BY CATALASE IN IRRADIATED MICROORGANISMS

    PubMed Central

    Latarjet, Raymond; Caldas, Luis Renato

    1952-01-01

    1. E. coli, strain K-12, and B. megatherium 899, irradiated in strict but still undefined physiological conditions with certain heavy doses of ultraviolet light, are efficiently restored by catalase, which acts on or fixes itself upon the bacteria in a few minutes. This restoration (C. R.), different from photorestoration, is aided by a little visible light. 2. At 37° the restorability lasts for about 2 hours after UV irradiation; the restored cells begin to divide at the same time as the normal survivors. 3. C. R. is not produced after x-irradiation. 4. B. megatherium Mox and E. coli, strain B/r show little C. R.; E. coli strain B shows none. None of these three strains is lysogenic, whereas the two preceding catalase-restorable strains are. 5. Phage production in the system "K-12 infected with T2 phage" is restored by catalase after UV irradiation, whereas phage production in the system "infected B" is not. 6. With K-12, catalase does not prevent the growth of phage and the lysis induced by UV irradiation (Lwoff's phenomenon). 7. Hypotheses are discussed concerning: (a) the chemical nature of this action of catalase; (b) a possible relation between C. R. and lysogenicity of the sensitive bacteria; (c) the consequences of such chemical restorations on the general problem of cell radiosensitivity. PMID:14898028

  14. The effect of gamma irradiation on injectable human amnion collagen

    SciTech Connect

    Liu, B.C.; Harrell, R.; Davis, R.H.; Dresden, M.H.; Spira, M. )

    1989-08-01

    The effect of gamma irradiation on the physicochemical properties of injectable human amnion collagen was investigated. Pepsin-extracted human amnion collagen was purified, reconstituted, and irradiated with varying doses of gamma irradiation (0.25 Mrads to 2.5 Mrads). Gamma irradiation had a significant impact on the physical characteristics of the collagen. The neutral solubility of collagen in PBS at 45{degrees}C was decreased from 100% for the nonirradiated control sample to 16% for the 2.5 Mrads irradiated sample. SDS polyacrylamide gel electrophoresis also demonstrated the dose-dependent effect of gamma irradiation on collagen cross-links. Electron microscopic observation revealed that even at low irradiation dose (0.25 Mrads), collagen fibril diameter increased. The average diameter was 50 nm for nonirradiated control fibrils, while 4.4% of the irradiated collagen fibrils had a diameter greater than 100 nm. Irradiated collagen showed little evidence of damage. Well-preserved cross-striations were found in collagen fibrils at all doses of irradiation. Native amnion collagen irradiated with gamma rays demonstrated a slight increase in resistance to collagenase degradation compared with nonirradiated native collagen samples. Increased resistance to collagenase did not correlate with increasing irradiation dose. After 30 min of incubation at 37{degrees}C, both irradiated and nonirradiated collagen was completely digested by collagenase. However, gamma-irradiated collagen did become more sensitive to hydrolysis by trypsin. The higher the irradiation doses used, the greater sensitivity to trypsin was observed. At 0.25 Mrads irradiation only a slight increase was found. No marked differences in amino acid composition were noted among the high dose irradiated, low dose irradiated and control amnion collagen.

  15. Irradiation creep of vanadium-base alloys

    SciTech Connect

    Tsai, H.; Billone, M.C.; Strain, R.V.; Smith, D.L.; Matsui, H.

    1998-03-01

    A study of irradiation creep in vanadium-base alloys is underway with experiments in the Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR) in the United States. Test specimens are thin-wall sealed tubes with internal pressure loading. The results from the initial ATR irradiation at low temperature (200--300 C) to a neutron damage level of 4.7 dpa show creep rates ranging from {approx}0 to 1.2 {times} 10{sup {minus}5}/dpa/MPa for a 500-kg heat of V-4Cr-4Ti alloy. These rates were generally lower than reported from a previous experiment in BR-10. Because both the attained neutron damage levels and the creep strains were low in the present study, however, these creep rates should be regarded as only preliminary. Substantially more testing is required before a data base on irradiation creep of vanadium alloys can be developed and used with confidence.

  16. Horizontal modular dry irradiated fuel storage system

    DOEpatents

    Fischer, Larry E.; McInnes, Ian D.; Massey, John V.

    1988-01-01

    A horizontal, modular, dry, irradiated fuel storage system (10) includes a thin-walled canister (12) for containing irradiated fuel assemblies (20), which canister (12) can be positioned in a transfer cask (14) and transported in a horizontal manner from a fuel storage pool (18), to an intermediate-term storage facility. The storage system (10) includes a plurality of dry storage modules (26) which accept the canister (12) from the transfer cask (14) and provide for appropriate shielding about the canister (12). Each module (26) also provides for air cooling of the canister (12) to remove the decay heat of the irradiated fuel assemblies (20). The modules (26) can be interlocked so that each module (26) gains additional shielding from the next adjacent module (26). Hydraulic rams (30) are provided for inserting and removing the canisters (12) from the modules (26).

  17. Status of food irradiation in the world

    NASA Astrophysics Data System (ADS)

    Kume, Tamikazu; Furuta, Masakazu; Todoriki, Setsuko; Uenoyama, Naoki; Kobayashi, Yasuhiko

    2009-03-01

    The status of food irradiation in the world in 2005 was investigated using published data, a questionnaire survey and direct visits. The results showed that the quantity of irradiated foods in the world in 2005 was 405,000 ton and comprised 1,86,000 ton (46%) for disinfection of spices and dry vegetables, 82,000 ton (20%) for disinfestation of grains and fruits, 32,000 ton (8%) for disinfection of meat and fish, 88,000 ton (22%) for sprout inhibition of garlic and potato, and 17,000 ton (4%) of other food items that included health foods, mushroom, honey, etc. Commercial food irradiation is increasing significantly in Asia, but decreasing in EU.

  18. Dosimetry procedures for an industrial irradiation plant

    NASA Astrophysics Data System (ADS)

    Grahn, Ch.

    Accurate and reliable dosimetry procedures constitute a very important part of process control and quality assurance at a radiation processing plant. γ-Dose measurements were made on the GBS 84 irradiator for food and other products on pallets or in containers. Chemical dosimeters wre exposed in the facility under conditions of the typical plant operation. The choice of the dosimeter systems employed was based on the experience in chemical dosimetry gained over several years. Dose uniformity information was obtained in air, spices, bulbs, feeds, cosmetics, plastics and surgical goods. Most products currently irradiated require dose uniformity which can be efficiently provided by pallet or box irradiators like GBS 84. The radiation performance characteristics and some dosimetry procedures are discussed.

  19. Enucleation versus plaque irradiation for choroidal melanoma

    SciTech Connect

    Straatsma, B.R.; Fine, S.L.; Earle, J.D.; Hawkins, B.S.; Diener-West, M.; McLaughlin, J.A.

    1988-07-01

    The Collaborative Ocular Melanoma Study (COMS) is an international, multicenter-controlled study. The organization includes an Executive Committee, Steering Committee, 6 Central Units, 32 Clinical Centers, and a Data and Safety Monitoring Committee. Scientifically, the COMS consists of (1) a randomized trial of patients with medium choroidal melanoma treated with enucleation versus iodine-125 plaque irradiation, (2) a randomized trial of patients with large choroidal melanoma treated with enucleation versus preenucleation external beam irradiation and enucleation, and (3) a prospective observational study of patients with small choroidal melanoma to determine whether a randomized trial of treatment is appropriate. In design and conduct of the COMS, special consideration is given to biostatistics and sample size considerations, iodine-125 plaque irradiation of choroidal melanoma, and coordinated ocular melanoma research. Recruitment is in progress. However, the pool of eligible patients is limited and the COMS needs the continued support and cooperation of ophthalmologists throughout the United States and Canada.

  20. Neutrophil myeloperoxidase destruction by ultraviolet irradiation

    SciTech Connect

    Hanker, J.; Giammara, B.; Strauss, G.

    1988-01-01

    The peroxidase activity of enriched leukocyte preparations on coverslips was determined cytochemically with a newly developed method. The techniques utilizes diaminobenzidine medium and cupric nitrate intensification and is suitable for analysis with light microscopy, SEM, and TEM. Blood specimens from control individuals were studied with and without in vitro UV irradiation and compared with those from psoriasis patients exposed therapeutically to various types of UV in phototherapy. All UV irradiated samples showed diminished neutrophil myeloperoxidase (MP) activity although that of the principal eosinophil peroxidase was unaffected. The SEMs supported the contention that decreased neutrophil MP activity might be related to UV induced degranulation. It is believed to be possible, eventually, to equate the observed MP degranulation effect after UV irradiation with diminished ability to fight bacterial infections.

  1. Effects of Laser Irradiation on Peripheral Nerve

    NASA Astrophysics Data System (ADS)

    Baxter, G. D.; Chow, R.; Armati, P.; Bjordal, J. M.; Laakso, L.

    2009-06-01

    A literature review was undertaken to determine the electrophysiological effects of Laser Irradiation (LI) on peripheral mammalian nerves, as a means of elucidating the potential mechanisms underlying pain relief associated with laser therapy. Relevant computerized databases and reference lists were searched, and experts consulted for further articles. A total of 38 studies, comprising 82 separate experiments were identified. In human studies, all types of LI (red and infrared, pulsed and cw) slowed nerve conduction velocity, and reduced compound action potential of irradiated nerves. In animal studies, infrared LI suppressed conduction velocity, as well as noxious stimulation evoked potential. This review thus indicates the potential of laser irradiation to inhibit activity in peripheral nerves, and highlights one potential mechanism of action for laser-mediated pain relief.

  2. Irradiated homologous costal cartilage for augmentation rhinoplasty

    SciTech Connect

    Lefkovits, G. )

    1990-10-01

    Although the ideal reconstructive material for augmentation rhinoplasty continues to challenge plastic surgeons, there exists no report in the literature that confines the use of irradiated homologous costal cartilage, first reported by Dingman and Grabb in 1961, to dorsal nasal augmentation. The purpose of this paper is to present a retrospective analysis of the author's experience using irradiated homologous costal cartilage in augmentation rhinoplasty. Twenty-seven dorsal nasal augmentations were performed in 24 patients between 16 and 49 years of age with a follow-up ranging from 1 to 27 months. Good-to-excellent results were achieved in 83.3% (20 of 24). Poor results requiring revision were found in 16.7% (4 of 24). Complication rates included 7.4% infection (2 of 27) and 14.8% warping (4 of 27). The resorption rate was zero. These results compare favorably with other forms of nasal augmentation. Advantages and disadvantages of irradiated homologous costal cartilage are discussed.

  3. Slow ion irradiation of sugar: astrobiological implications

    NASA Astrophysics Data System (ADS)

    Tuleta, M.; Gabla, L.; Wickramasinghe, N. C.

    2009-10-01

    As a result of irradiation by slow hydrogen and argon ions of saccharose, humic films having a fractal nature were produced. The use of hydrogen ions simulated roughly the interaction of low-energy solar wind protons with interplanetary dust grains which, in addition to organic and mineral dust, may include clumps of viable bacteria. The type of film generated by this experimental procedure could play a role in shielding the interior of micron-sized clumps from damaging ultraviolet and low-energy cosmic ray irradiation. We argue that such films may have played a role in processes that led to the initial origin of life, and following the emergence of life the same types of films (as, for instance, in biofilms surrounding cells) may have been modified by irradiation to offer protection to viable cells in the interior.

  4. Irradiation properties of T0 chopper components

    NASA Astrophysics Data System (ADS)

    Itoh, Shinichi; Ueno, Kenji; Ohkubo, Ryuji; Sagehashi, Hidenori; Funahashi, Yoshisato; Yokoo, Tetsuya

    2011-10-01

    We investigated the irradiation properties of the components of a T0 chopper. The organic materials in the rotor bearing grease, the magnetic fluids in seals, and the rubber in the timing belt, as well as the semiconductor materials in the rotation sensor and motor encoder, were all irradiated with high-energy γ-rays up to 100 kGy. No significant damage that shortens the lifetime of a T0 chopper was observed for the mechanical components. However, the semiconductor components were damaged by the irradiation. For the rotation sensor system detecting the rotor phase, the signal from a marker on the rotor shaft was transmitted outside the shielding by an optical fiber with radiation-proofing and the electrical circuits were removed from the beamline shielding. The lifetime of the motor encoder possibly meets the requirement for the maintenance period of the T0 chopper.

  5. Health risk assessment of irradiated topaz

    SciTech Connect

    Nelson, J.W.; Baum, J.W.

    1993-01-01

    Irradiated topaz gemstones are currently processed for color improvement by subjecting clear stones to neutron or high-energy electron irradiations, which leads to activation of trace elements in the stones. Assessment of the risk to consumers required the identification and quantification of the resultant radionuclides and the attendant exposure. Representative stones from Brazil, India, Nigeria, Sri Lanka were irradiated and analyzed for gamma ray and beta particle emissions, using sodium iodide and germanium spectrometers; and Geiger-Muller, plastic and liquid scintillation, autoradiography, and thermoluminescent-dosimetry measurement techniques. Based on these studies and other information derived from published literature, dose and related risk estimates were made for typical user conditions. New criteria and methods for routine assays for acceptable release, based on gross beta and gross photon emissions from the stones, were also developed.

  6. BPX insulation irradiation program test results

    SciTech Connect

    McManamy, T.J. ); Kanemoto, G. ); Snook, P.G. . Plasma Physics Lab.)

    1991-01-01

    The toroidal field coil insulation for the Burning Plasma Experiment (BPX) is expected to receive a radiation dose of nearly 10{sup 10} rad and to withstand significant mechanical stresses. An irradiation test program was performed at the Idaho National Engineering Laboratory (INEL) using the Advanced Technology Reactor (ATR) for irradiations to doses on the order of 3 {times} 10{sup 10} rad. The flexure and shear strength with compression of commercially procured sheet material were reported earlier. A second series of tests has been performed to slightly higher dose levels with vacuum impregnated materials, glass strand material, and Spaulrad-S sheet samples. Vacuum impregnation with a Shell 9405 resin and 9470 hardener was used to produce bonded copper squares and flexure samples of both pure resin and resin with S-glass. A new test fixture was developed to test the bonded samples in shear without applied compression. The Spaulrad-S flexure samples demonstrated a loss of strength with irradiation, similar to previous results. The pure resin lost nearly all flexibility, while the S-glass-reinforced samples retained between 30% and 40% of the initial flexure strength. The S-glass strands showed a 30% loss of strength at the higher dose level when tested in tension. The bonded copper squares had a low room-temperature shear strength of approximately 17 MPa before irradiation, which was unchanged in the irradiated samples. Shear testing of unirradiated bonded copper squares with ten different types of surface treatment revealed that the low shear strength resulted from the polyurethane primer used. In the later series of test, the epoxy-based primers and DZ-80 from Ciba-Geigy did much better, with shear strengths on the order of 40 MPa. These samples also demonstrated a resistance to cryogenic shock. One irradiated bonded sample was tested up 10 210 MPa in compression, the limit of the test fixture, without failure.

  7. Studies on potato irradiation in the G.D.R.

    NASA Astrophysics Data System (ADS)

    Luther, Th.; Hübner, G.; Grahn, Ch.; Döllstädt, R.

    The studies of potato irradiation have been conducted in the framework of the National Food Irradiation Research Project for 4 years. Although in the G.D.R. the use of chemical sprout inhibitors is allowed, potato irradiation can be an alternative technique for potato processing. Before irradiation a wound healing period of approx. 2 weeks is absolutely necessary to protect the potatoes from Fusarium. The method that presents the minimum risk of damage is irradiation in containers. Economic evaluations for the irradiation of potatoes are also made.

  8. [Pelvic irradiation in prostate cancer: what place for what volumes?].

    PubMed

    Chapet, O; Enachescu, C; Lorchel, F

    2013-10-01

    External beam radiotherapy alone is a standard treatment for prostate cancer. According to clinical, histological and biological characteristics of the tumour, lymph node irradiation can be done in combination with irradiation of the prostate. The completion of pelvic irradiation remains controversial and may cause complications by increasing volumes of irradiated healthy tissues. The accuracy of the delineation of lymph node becomes an important issue. This article proposes to take on the characteristics of the pelvic lymph node drainage of the prostate, to review the literature on pelvic irradiation and the definition of volumes to be irradiated.

  9. Enhancement of Irradiation Capability of the Experimental Fast Reactor Joyo

    NASA Astrophysics Data System (ADS)

    Maeda, Shigetaka; Serine, Takashi; Aoyama, Takafumi; Suzuki, Soju

    2009-08-01

    The experimental fast reactor Joyo is the first sodium-cooled fast reactor in Japan. One of its primary missions is to perform irradiation tests of fuel and structural materials to support the development of fast reactors. The MK-III high performance core upgrade to enhance the irradiation testing capabilities was completed in 2003. In order to expand Joyo's capabilities for innovative irradiation testing applications, neutron spectrum tailoring, lower irradiation temperature, movable sample devices and fast neutron beam holes are being considered. This program responds to existing irradiation needs and aims to further expand capabilities for a variety of irradiation tests.

  10. Electron irradiation of modern solar cells

    NASA Technical Reports Server (NTRS)

    Anspaugh, B. E.; Miyahira, T. F.

    1977-01-01

    A number of modern solar cell types representing 1976 technology (as well as some older types) were irradiated with 1 MeV electrons (and a limited number with 2 MeV electrons and 10 MeV protons). After irradiation, the cells were annealed, with I-V curves measured under AMO at 30 C. The purpose was to provide data to be incorporated in the revision of the solar cell radiation handbook. Cell resistivities ranged from 2 to 20 ohm-cm, and cell thickness from 0.05 to 0.46 mm. Cell types examined were conventional, shallow junction, back surface field (BSF), textured, and textured with BSF.

  11. Quantum dot intermixing using excimer laser irradiation

    SciTech Connect

    Djie, H. S.; Ooi, B. S; Gunawan, O.

    2006-08-21

    The authors report a spatial control of the band gap in InGaAs/GaAs quantum dots (QDs) using the combined effects of pulsed excimer laser irradiation and impurity-free dielectric cap induced intermixing technique. A large band gap shift of up to 180 meV has been obtained under laser irradiation of 480 mJ/cm{sup 2} and 150 pulses to the SiO{sub 2} capped shallow QD structure, while the nonirradiated SiO{sub 2} and Si{sub x}N{sub y} capped QDs only exhibit band gap shifts of 18 and 91 meV, respectively.

  12. Schistosoma mansoni: cercarial responses to irradiance changes

    SciTech Connect

    Saladin, K.S.

    1982-02-01

    Cercariae of Schistosoma mansoni alternate between active swimming and passive drifting. They began swimming in response to either an increase or decrease in irradiance experienced during the passive phase. The number of cercariae reacting to a shadow was proportional to the magnitude of the stimulus. The shadow response may be mediated by the cercaria's ciliary receptors. About half as many cercariae reacted to an irradiance increase as to an equivalent decrease. This report is the first quantitative study of photosensory stimulus-response relationships in schistosome cercariae.

  13. Vanadium irradiation at ATR - neutronics aspects

    SciTech Connect

    Gomes, I.C.; Smith, D.L.

    1995-04-01

    Calculations were performed to estimate damage and transmutation rates in vanadium irradiated in the ATR (Advanced Test Reactor) located in Idaho. The main focuses of the study are to evaluate the transmutation of vanadium to chromium and to explore ways to design the irradiation experiment to avoid excessive transmutation. It was found that the A-hole of ATR produces damage rate of {approximately} 0.2%/dpa of vanadium to chromium. A thermal neutron filter can be incorporated into the design to reduce the vanadium-to-chromium transmutation rate to low levels. A filter 1-2 mm thick of gadolinium or hafnium can be used.

  14. Separation of sodium-22 from irradiated targets

    DOEpatents

    Taylor, Wayne A.; Jamriska, David

    1996-01-01

    A process for selective separation of sodium-22 from an irradiated target including dissolving an irradiated target to form a first solution, contacting the first solution with hydrated antimony pentoxide to selectively separate sodium-22 from the first solution, separating the hydrated antimony pentoxide including the separated sodium-22 from the first solution, dissolving the hydrated antimony pentoxide including the separated sodium-22 in a mineral acid to form a second solution, and, separating the antimony from the sodium-22 in the second solution.

  15. Effects of gamma irradiation on deteriorated paper

    NASA Astrophysics Data System (ADS)

    Bicchieri, Marina; Monti, Michela; Piantanida, Giovanna; Sodo, Armida

    2016-08-01

    Even though gamma radiation application, also at the minimum dosage required for disinfection, causes depolymerization and degradation of the paper substrate, recently published papers seemed, instead, to suggest that γ-rays application could be envisaged in some conditions for Cultural Heritage original documents and books. In some of the published papers, the possible application of γ-rays was evaluated mainly by using mechanical tests that scarcely reflect the chemical modifications induced in the cellulosic support. In the present article the effect of low dosage γ-irradiation on cellulosic substrates was studied and monitored applying different techniques: colorimetry, spectroscopic measurements, carbonyl content and average viscometric degree of polymerization. Two different papers were investigated, a non-sized, non-filled cotton paper, and a commercial permanent paper. To simulate a real deteriorated document, which could need γ-rays irradiation, some samples were submitted to a hydrolysis treatment. We developed a treatment based on the exposition of paper to hydrochloric acid vapors, avoiding any contact of the samples with water. This method induces a degradation similar to that observed on original documents. The samples were then irradiated with 3 kGy γ-rays at a 5258 Gy/h rate. The aforementioned analyses were performed on the samples just irradiated and after artificial ageing. All tests showed negative effects of gamma irradiation on paper. Non-irradiated paper preserves better its appearance and chemical properties both in the short term and after ageing, while the irradiated samples show appreciable color change and higher oxidation extent. Since the Istituto centrale restauro e conservazione patrimonio archivistico e librario is responsible for the choice of all restoration treatments that could be applied on library and archival materials under the protection of the Italian State (http://www.icpal.beniculturali.it/allegati/DM-7

  16. Bonding of dopants to irradiated polymers

    NASA Astrophysics Data System (ADS)

    Fink, D.; Klett, R.; Hnatowicz, V.; Vacik, J.; Mathis, C.; Omichi, H.; Hosoi, F.; Chadderton, L. T.; Wang, L.

    1996-08-01

    Latent tracks are formed in polyimide, polypropylene and polyethylene by irradiation with 0.5 to 3 GeV heavy ions. They are then doped with aqueous LiCl, organo- {Li}/{THF}, or {C60}/{THF} solutions for well-defined periods after the irradiation. Subsequently, the excess of non-trapped Li dopant fraction is washed out. The remaining lithium-doped polymer zones along the latent ion tracks are studied here. The depth distribution of the bonding efficiency, as determined by neutron depth profiling, points out an electronic nature of the bonding process.

  17. Irradiated versus fumigated spices in sausage.

    PubMed

    Bolander, C R; Toma, R B; Davis, R M; Medora, N P

    1995-11-01

    The efficacy of gamma radiation and ethylene oxide fumigation as decontaminating treatments for spices used in sausages was compared. Microbial loads of sausages containing irradiated, fumigated or non-treated spices were examined over three intervals of time. No significant differences between microbial loads of Mexican sausages containing irradiated spices (10 kGy) verses ethylene oxide-treated spices were found. Mexican sausages containing treated spices had significantly lower yeast, mould and spore counts than control sausages. After 8 weeks of storage, only the microbial loads of control sausages suggested spoilage. No discernable differences in treatment efficacy were noted with respect to yeast, mould and spore counts in Italian sausages.

  18. Neutron Spectrum Measurements from Irradiations at NCERC

    SciTech Connect

    Jackman, Kevin Richard; Mosby, Michelle A.; Bredeweg, Todd Allen; Hutchens, Gregory Joe; White, Morgan Curtis

    2015-04-15

    Several irradiations have been conducted on assemblies (COMET/ZEUS and Flattop) at the National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS). Configurations of the assemblies and irradiated materials changed between experiments. Different metallic foils were analyzed using the radioactivation method by gamma-ray spectrometry to understand/characterize the neutron spectra. Results of MCNP calculations are shown. It was concluded that MCNP simulated spectra agree with experimental measurements, with the caveats that some data are limited by statistics at low-energies and some activation foils have low activities.

  19. The effects of sunspots on solar irradiance

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.; Silva, S.; Woodard, M.; Willson, R. C.

    1982-01-01

    It is pointed out that the darkness of a sunspot on the visible hemisphere of the sun will reduce the solar irradiance on the earth. Approaches are discussed for obtaining a crude estimate of the irradiance deficit produced by sunspots and of the total luminosity reduction for the whole global population of sunspots. Attention is given to a photometric sunspot index, a global measure of spot flux deficit, and models for the compensating flux excess. A model is shown for extrapolating visible-hemisphere spot areas to the invisible hemisphere. As an illustration, this extrapolation is used to calculate a very simple model for the reradiation necessary to balance the flux deficit.

  20. Irradiation of meat products, chicken and use of irradiated spices for sausages

    NASA Astrophysics Data System (ADS)

    Kiss, I. F.; Beczner, J.; Zachariev, Gy.; Kovács, S.

    The shelf-life of packed minced meat has been increased at least threefold at 4°C by applying a 2 kGy dose. Results have been confirmed by detailed quatitative microbiological examinations. Sensory evaluations show no significant difference between the unirradiated samples. The optimal average dose was 4 kGy for packed-frosen chicken. The number of mesophilic aerobic microbes was reduced by 2, that of psychrotolerant by 2-3 and that of Enterbacteriaceae by 3-4 orders of magnitude by 4 kGy. S. aureus and Salmonella could not be detected in the irradiated samples. In sensory evaluations there was no significant difference between untreated and irradiated samples. In 1984-1985 5100 kg irradiated chickens were marketed labelled as radiation treated. Irradiated spices (5 kGy) were used in the production of sausages (heat-treated and non-heat-treated) under industrial conditions. The microbiological contamination of irradiated spices was lower than that of ethylene oxide treated ones. The cell count in products made with irradiated spices was lower than in those made with unirradiated spices. The sausages proved to be of very good quality. In accordance with the permission, products were marketed and because of the low ratio of spices there was no need to declare them as using irradiated spices.

  1. Determination of irradiation dose and distinguishing between irradiated and non irradiated fish meat by real-time PCR.

    PubMed

    Şakalar, Ergün; Mol, Sühendan

    2015-09-01

    In this study, the effects of gamma irradiation on the DNA of fish (Oncorhynchus mykiss) by real-time PCR were studied. Fish (O. mykiss) were exposed to radiation doses of 0.250, 0.500, 1, 3, 5, 7, and 9 kGy in a gamma cell. Primers were designed for regions with different lengths of both nuclear and mitochondrial DNA, and each primer was used to amplify the DNA from irradiated samples. The amplicon curves for mitochondrial and nuclear DNA, and the correlations among the curves, were obtained. The Ct values for a 519 bp region of the 18S RNA gene on nuclear DNA correlated appropriately. Radiation doses applied to the fillets were estimated using the standard curve data obtained from the correlation values, and the DNA damage caused by each dose was calculated. As a consequence, a molecular methodology to analyze irradiated fish meat qualitatively and also for the estimation of administered dose was developed. This method allowed analysis of irradiated fish, which had been stored for up to 3 months with a dose limit of approximately 0.5 kGy.

  2. Combustible caramel pour reacteurs de recherche: Experience acquise en fabrication, controles et irradiation du coeur d'osiris

    NASA Astrophysics Data System (ADS)

    de Contenson, Ghislain; Foulquier, Henri; Trotabas, Maria; Vignesoult, Nicole; Cerles, Jean-Marie; Delafosse, Jacques

    1982-04-01

    L'un des aboutissements des différentes actions menées en France concernant la conception, la fabrication et le développement des combustibles nucléaires a été la mise au point par le CEA d'un combustible de type plaque (combustible CARAMEL) susceptible d'être adapté a différentes catégories de réacteurs à eau (réacteur de puissance, propulsion navale, chauffage urbain, pile de recherche). Ces travaux ont été couronnés par la réalisation de tout un coeur et des recharges du réacteur de recherche à hautes performances, Osiris, à Saclay. L'ancien combustible en alliage U Al fortement enrichi a eté remplacé par un combustible caramel de faible enrichissement (7%), non proliférant. Ce nouveau coeur fonctionne avec satisfaction, depuis janvier 1980. Après une brève description des caractéristiques du combustible caramel et de ses principaux avantages, on présente sa fabrication ainsi que l'ensemble des contrôles de qualité auxquels il est soumis. Le programme de qualification ainsi que les principaux résultáts qui en ont été tirés sont exposés. On décrit également le programme de suivi du combustible en pile dont le but est de s'assurer du bon comportement du combustible sous irradiation. Le bon fonctionnement d'Osiris, qui a terminé 11 cycles d'irradiation le 21 avril 1981, a permis de montrer le bien fondé des choix effectués et l'excellent comportement de l'élément combustible dans les conditions pourtant sévères d'un réacteur de recherche à hautes performances.

  3. Understanding the Irradiation Behavior of Zirconium Carbide

    SciTech Connect

    Motta, Arthur; Sridharan, Kumar; Morgan, Dane; Szlufarska, Izabela

    2013-10-11

    Zirconium carbide (ZrC) is being considered for utilization in high-temperature gas-cooled reactor fuels in deep-burn TRISO fuel. Zirconium carbide possesses a cubic B1-type crystal structure with a high melting point, exceptional hardness, and good thermal and electrical conductivities. The use of ZrC as part of the TRISO fuel requires a thorough understanding of its irradiation response. However, the radiation effects on ZrC are still poorly understood. The majority of the existing research is focused on the radiation damage phenomena at higher temperatures (>450{degree}C) where many fundamental aspects of defect production and kinetics cannot be easily distinguished. Little is known about basic defect formation, clustering, and evolution of ZrC under irradiation, although some atomistic simulation and phenomenological studies have been performed. Such detailed information is needed to construct a model describing the microstructural evolution in fast-neutron irradiated materials that will be of great technological importance for the development of ZrC-based fuel. The goal of the proposed project is to gain fundamental understanding of the radiation-induced defect formation in zirconium carbide and irradiation response by using a combination of state-of-the-art experimental methods and atomistic modeling. This project will combine (1) in situ ion irradiation at a specialized facility at a national laboratory, (2) controlled temperature proton irradiation on bulk samples, and (3) atomistic modeling to gain a fundamental understanding of defect formation in ZrC. The proposed project will cover the irradiation temperatures from cryogenic temperature to as high as 800{degree}C, and dose ranges from 0.1 to 100 dpa. The examination of this wide range of temperatures and doses allows us to obtain an experimental data set that can be effectively used to exercise and benchmark the computer calculations of defect properties. Combining the examination of radiation

  4. Polymer Morphological Change Induced by Terahertz Irradiation

    PubMed Central

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-01-01

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10−20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules. PMID:27272984

  5. Minimizing material damage using low temperature irradiation

    NASA Astrophysics Data System (ADS)

    Craven, E.; Hasanain, F.; Winters, M.

    2012-08-01

    Scientific advancements in healthcare driven both by technological breakthroughs and an aging and increasingly obese population have lead to a changing medical device market. Complex products and devices are being developed to meet the demands of leading edge medical procedures. Specialized materials in these medical devices, including pharmaceuticals and biologics as well as exotic polymers present a challenge for radiation sterilization as many of these components cannot withstand conventional irradiation methods. The irradiation of materials at dry ice temperatures has emerged as a technique that can be used to decrease the radiation sensitivity of materials. The purpose of this study is to examine the effect of low temperature irradiation on a variety of polymer materials, and over a range of temperatures from 0 °C down to -80 °C. The effectiveness of microbial kill is also investigated under each of these conditions. The results of the study show that the effect of low temperature irradiation is material dependent and can alter the balance between crosslinking and chain scission of the polymer. Low temperatures also increase the dose required to achieve an equivalent microbiological kill, therefore dose setting exercises must be performed under the environmental conditions of use.

  6. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5...

  7. Monitoring pathogens from irradiated agriculture products

    NASA Astrophysics Data System (ADS)

    Butterweck, Joseph S.

    The final food and environmental safety assessment of agriculture product irradiation can only be determined by product history. Product history will be used for future research and development, regulations, commercial practices and implementation of agriculture and food irradiation on a regional basis. The commercial irradiator treats large varieties and amounts of products that are used in various environments. It, in time, will generate a large data base of product history. Field product monitoring begins when food irradiation progresses from the pilot/demonstration phase to the commercial phase. At that time, it is important that there be in place a monitoring system to collect and analyze field data. The systems managers, public health authorities and exotic disease specialists will use this information to assess the reduction of food pathogens on the populace and the environment. The common sources of monitoring data are as follows: 1) Host Monitoring a) Medical Diagnosis b) Autopsy c) Serology Surveys 2) Environmental Monitoring a) Sentinel b) Pest Surveys/Microbial Counts c) Sanitary Inspections 3) Food Industries Quality Assurance Monitoring a) End Product Inspection b) Complaints c) Continual Use of the Product

  8. Amphytrion: Example of a high capacity irradiator

    NASA Astrophysics Data System (ADS)

    Keraron(SGN-France), Y.; Santos(Amphytrion-France), P. L.

    SGN recently built a pallet irradiator for the AMPHYTRION Company which incorporates new technological features. After a short review of the design criteria, the major mechanical equipment is described (source-holder, conveyor, automatic warehouse system), together with the ventilation/air conditioning system and the control/management architecture. Information is given on the new technical aspects and the performance of the facility.

  9. Microwave Irradiation on Halloysite-Polypropylene Nanocomposites

    NASA Astrophysics Data System (ADS)

    Espino, Omar; Yust, Brian; Chipara, Dorina; Ajayan, Pullickel; Chipara, Alin; Chipara, Mircea; Utrgv Collaboration; Rice Collaboration

    Halloysite is an unique cyllindrical nanoclay characterized by poor electrical and thermal conductivity, which may become the filler of choice for the reinforcement of polymeric matrix, where electrical or thermal insulation are required. The main limits in the use of halloysite as replacement for carbon nanotube (CNT) are: 1. Smaller aspect ratio as halloysites are typically shorter than CNTs. 2. Smaller Young modulus of halloysites compared with CNTs. 3. Reduced thermal stability due to the loss of water upon heating. A research on halloysite dispersed within isotactic polypropylene is reported. To improve the interface between the halloysite and the polymeric matrix a microwave irradiation step has been considered. The local heating of the halloysite nanotubes is mediated by the absorbed/structural water content of the nanoclay. Nanocomposites loaded by various amounts of halloysite ranging from 0 % to 20 % wt. have been prepared by melt mixing by using a Haake RheoMixer. The as obtained nanocomposites have been subjected to microwave irradiation at 75 W in an Anton Paar Monowave 300 system and various irradiation times ranging from 5, 10, 15, 30, 45, and 60 minutes. The effect of microwave irradiation has been studied by Raman and FTIR spectroscopy

  10. Studies of Solar EUV Irradiance from SOHO

    NASA Technical Reports Server (NTRS)

    Floyd, Linton

    2002-01-01

    The Extreme Ultraviolet (EUV) irradiance central and first order channel time series (COC and FOC) from the Solar EUV Monitor aboard the Solar and Heliospheric observatory (SOHO) issued in early 2002 covering the time period 1/1/96-31/1201 were analyzed in terms of other solar measurements and indices. A significant solar proton effect in the first order irradiance was found and characterized. When this effect is removed, the two irradiance time series are almost perfectly correlated. Earlier studies have shown good correlation between the FOC and the Hall core-to-wing ratio and likewise, it was the strongest component of the COC. Analysis of the FOC showed dependence on the F10.7 radio flux. Analysis of the CDC signals showed additional dependences on F10.7 and the GOES x-ray fluxes. The SEM FOC was also well correlated with thein 30.4 nm channel of the SOHO EUV Imaging Telescope (EIT). The irradiance derived from all four EIT channels (30.4 nm, 17.1 nm, 28.4 nm, and 19.5 nm) showed better correlation with MgII than F10.7.

  11. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5...

  12. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5...

  13. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5...

  14. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... purification system designed to be capable of maintaining the water during normal operation at a conductivity..., irradiator pools must either: (1) Have a water-tight stainless steel liner or a liner metallurgically... water level that could allow water to drain out of the pool. Pipes that have intakes more than 0.5...

  15. Fluorescence anisotropy of UV-irradiated viruses.

    PubMed

    Hörer, O L

    1989-01-01

    The steady-state fluorescence anisotropy measurements on influenza and parainfluenza viruses, showed no changes in the microviscosity of the viral membranes after exposure to UV-irradiation, when a fluorescent probe was used, but the intrinsic fluorescence of viral proteins presented, under the same experimental conditions, a significant difference of anisotropy behaviour in the two viruses used.

  16. SOLVENT FREE CHEMICAL TRANSFORMATION USING MICROWAVE IRRADIATION

    EPA Science Inventory

    Microwave-expedited solvent-free synthetic processes will be described that involve the exposure of neat reactants to microwave (MW) irradiation in the presence of supported reagents or catalysts on mineral oxides. Recent developments will be presented on the synthetic utility o...

  17. Sucrose synthesis in gamma irradiated sweet potato

    SciTech Connect

    Ailouni, S.; Hamdy, M.K.; Toledo, R.T.

    1987-01-01

    Effect of ..cap alpha..-irradiation carbohydrate metabolism was examined to elucidate mechanism of sucrose accumulation in sweet potato (SP). Enzymes examined were: ..beta..-amylase, phosphorylase, phosphoglucomutase, phosphoglucose isomerase, sucrose phosphate synthetase and sucrose synthetase. Irradiated SP (Red Jewell) sucrose was synthesized to yield 10.7% after 4 d PI. Activities of sugar synthesizing enzymes in irradiated SP were enhanced to different degrees using 100-200 Krad and 3 d PI at 24/sup 0/C. Phosphorylase and phosphoglucomutases specific activities reached 2.4 and 1.8 folds, respectively compared to control SP. ..beta..-amylase, phosphoglucose isomerase, sucrose synthetase and sucrose phosphate synthetase were also affected to yield 1.2, 1.3, 1.3 and 1.2 folds, respectively compared to controls. It is believed that amylase hydrolyzed starch to glucose which is converted to fructose by phosphoglucose isomerase. Sucrose is then formed by sucrose phosphate synthetase and/or sucrose synthetase leading to its accumulation. The irradiated SP was used for alcohol fermentation leading to 500 gal. of 200 proof ethanol/acre (from 500-600 bushels tuber/acre).

  18. Localized comedo formation after cobalt irradiation

    SciTech Connect

    Myskowski, P.L.; Safai, B.

    1981-10-01

    Following Cobalt-60 irradiation for a left frontotemporal tumor, a 61-year-old woman developed comedones on the forehead. These changes responded to conventional acne therapy with retinoic acid. Multiple acneigenic factors were implicated in the pathogenesis of her lesions.

  19. Hyperparathyroidism After Irradiation for Childhood Malignancy

    SciTech Connect

    McMullen, Todd; Bodie, Greg; Gill, Anthony; Ihre-Lundgren, Catharina; Shun, Albert; Bergin, Mary; Stevens, Graham; Delbridge, Leigh

    2009-03-15

    Purpose: To examine the occurrence of hyperparathyroidism in a cohort of patients undergoing combined parathyroid and thyroid surgery after previous head-and-neck irradiation for childhood malignancy. Methods and Materials: This is a retrospective cohort study for the years 1996 to 2007. The study group comprised patients undergoing surgery in University of Sydney Endocrine Surgical Unit who had received previous head-and-neck irradiation in childhood and who were identified as having pathologic thyroid and parathyroid characteristics. Results: A total of 53 patients were identified in whom head-and-neck irradiation for the treatment of childhood malignancy had been documented. In each of the cases, thyroid disease was the primary reason for referral for surgery. Five of these patients (10%) were found to exhibit coexisting hyperparathyroidism. The latency period for hyperparathyroidism was less than 20 years in 4 of the 5 cases. There were four conventional parathyroid adenomas and one parathyroid lipoadenoma. All patients exhibited a significant decrease in postoperative calcium levels after surgery. Conclusions: To our knowledge, this is the first study to document the significant risk of hyperparathyroidism after radiation exposure for childhood malignancy. The timeframe for development of disease is much shorter than that published for individuals who have undergone irradiation for benign diseases. High doses of therapeutic radiation at a young age make childhood survivors of malignancy at especially high risk for developing hyperparathyroidism.

  20. New pallet irradiation for Gammaster International

    NASA Astrophysics Data System (ADS)

    Möhlmann, Mr. J. H. F.

    1993-07-01

    State of the art technology offers many opportunities to improve production process with ionizing radiation. Also the requirements to this process become more and more stringent; who was aware of the ISO-9000 Standards? Now it is a necessary concept? Internal and external audits, in particular by Regulatory Bodies such as the FDA and DHSS/MCA, are necessary and commonplace requirements when operating in the Healthcare and Pharmaceutical sectors. Efficiency is a major requirement for industry and also for our radiation business. With all the above mentioned items in mind, Gammaster International B.V. in close cooperation with Nordion International Inc. has developed and built a new type Pallet Irradiator. In this new concept, our 22 years experience in gamma processing and the expertise gained in 10 years of operation of pallet irradiators was incorporated. For this irradiator Gammaster International designed and built a new process control console, incorporating state of the art technology such as: - A well-balanced safety system - A control panel, with status indication for all essential operating and safety parameters - Advances warning for necessary maintenance work - Automatic timer-setting control in addition to an automatic timer setting modification - Clear indication of the position of the product inside the unit and its status - Fully automatic product information generated when the product leaves the irradiation unit - Visual process control with the help of a color monitor - Incremental dose-control - Fault identification

  1. Continuous wave laser irradiation of explosives

    SciTech Connect

    McGrane, Shawn D.; Moore, David S.

    2010-12-01

    Quantitative measurements of the levels of continuous wave (CW) laser light that can be safely applied to bare explosives during contact operations were obtained at 532 nm, 785 nm, and 1550 nm wavelengths. A thermal camera was used to record the temperature of explosive pressed pellets and single crystals while they were irradiated using a measured laser power and laser spot size. A visible light image of the sample surface was obtained before and after the laser irradiation. Laser irradiation thresholds were obtained for the onset of any visible change to the explosive sample and for the onset of any visible chemical reaction. Deflagration to detonation transitions were not observed using any of these CW laser wavelengths on single crystals or pressed pellets in the unconfined geometry tested. Except for the photochemistry of DAAF, TATB and PBX 9502, all reactions appeared to be thermal using a 532 nm wavelength laser. For a 1550 nm wavelength laser, no photochemistry was evident, but the laser power thresholds for thermal damage in some of the materials were significantly lower than for the 532 nm laser wavelength. No reactions were observed in any of the studied explosives using the available 300 mW laser at 785 nm wavelength. Tables of laser irradiance damage and reaction thresholds are presented for pressed pellets of PBX9501, PBX9502, Composition B, HMX, TATB, RDX, DAAF, PETN, and TNT and single crystals of RDX, HMX, and PETN for each of the laser wavelengths.

  2. Polymer Morphological Change Induced by Terahertz Irradiation

    NASA Astrophysics Data System (ADS)

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-01

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10‑20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  3. X-ray irradiation of yeast cells

    NASA Astrophysics Data System (ADS)

    Masini, Alessandra; Batani, Dimitri; Previdi, Fabio; Conti, Aldo; Pisani, Francesca; Botto, Cesare; Bortolotto, Fulvia; Torsiello, Flavia; Turcu, I. C. Edmond; Allott, Ric M.; Lisi, Nicola; Milani, Marziale; Costato, Michele; Pozzi, Achille; Koenig, Michel

    1997-10-01

    Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers. Teflon stripes were chosen as targets for the UV laser, emitting X-rays at about 0.9 keV, characterized by a very large decay exponent in biological matter. X-ray doses to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. After irradiation, the selective damage to metabolic activity at the membrane level was measured by monitoring CO2 production with pressure silicon detectors. Preliminary results gave evidence of pressure reduction for irradiated samples and non-linear response to doses. Also metabolic oscillations were evidenced in cell suspensions and it was shown that X-ray irradiation changed the oscillation frequency.

  4. Nanoscale Morphology Evolution Under Ion Irradiation

    SciTech Connect

    Aziz, Michael J.

    2014-11-10

    We showed that the half-century-old paradigm of morphological instability under irradiation due to the curvature-dependence of the sputter yield, can account neither for the phase diagram nor the amplification or decay rates that we measure in the simplest possible experimental system -- an elemental semiconductor with an amorphous surface under noble-gas ion irradiation; We showed that a model of pattern formation based on the impact-induced redistribution of atoms that do not get sputtered away explains our experimental observations; We developed a first-principles, parameter-free approach for predicting morphology evolution, starting with molecular dynamics simulations of single ion impacts, lasting picoseconds, and upscaling through a rigorous crater-function formalism to develop a partial differential equation that predicts morphology evolution on time scales more than twelve orders of magnitude longer than can be covered by the molecular dynamics; We performed the first quantitative comparison of the contributions to morphological instability from sputter removal and from impact-induced redistribution of atoms that are removed, and showed that the former is negligible compared to the latter; We established a new paradigm for impact-induced morphology evolution based on crater functions that incorporate both redistribution and sputter effects; and We developed a model of nanopore closure by irradiation-induced stress and irradiationenhanced fluidity, for the near-surface irradiation regime in which nuclear stopping predominates, and showed that it explains many aspects of pore closure kinetics that we measure experimentally.

  5. Irradiation Processing Department monthly report, June 1962

    SciTech Connect

    Not Available

    1992-07-13

    This document details activities of the Irradiation Processing Department during the month of June, 1962. A general summary is included at the start of the report, after which the report is divided into the following sections: Research and Engineering Operations; Production and Reactor Operations; Facilities Engineering Operation; and NPR Project.

  6. High accuracy diffuse horizontal irradiance measurements without a shadowband

    SciTech Connect

    Schlemmer, J.A; Michalsky, J.J.

    1995-12-31

    The standard method for measuring diffuse horizontal irradiance uses a fixed shadowband to block direct solar radiation. This method requires a correction for the excess skylight blocked by the band, and this correction varies with sky conditions. Alternately, diffuse horizontal irradiance may be calculated from total horizontal and direct normal irradiance. This method is in error because of angular (cosine) response of the total horizontal pyranometer to direct beam irradiance. This paper describes an improved calculation of diffuse horizontal irradiance from total horizontal and direct normal irradiance using a predetermination of the angular response of the total horizontal pyranometer. We compare these diffuse horizontal irradiance calculations with measurements made with a shading-disk pyranometer that shields direct irradiance using a tracking disk. Results indicate significant improvement in most cases. Remaining disagreement most likely arises from undetected tracking errors and instrument leveling.

  7. Food irradiation: Standards, regulations and world-wide trade

    NASA Astrophysics Data System (ADS)

    Roberts, Peter B.

    2016-12-01

    There is an established framework of international standards for food irradiation covering human health, plant protection, labelling, dose delivery, quality assurance and facility management. Approximately 60 countries permit irradiation of one or more food or food classes. National regulations are briefly reviewed. Decontamination of spices, herbs and condiments remains the single largest application of irradiation. However, in recent years the market for irradiated fresh and processed meat has become firmly established in several countries including China and the USA. At least 10 countries have recently established bi-lateral agreements for trade in irradiated fresh fruits and vegetables using phytosanitary irradiation. Irradiated fresh produce volumes now exceed 20,000 t per year. Rationalization and greater consistency in labelling regulations would be advantageous to the future growth of applications of food irradiation.

  8. Neutron irradiation of Am-241 effectively produces curium

    NASA Technical Reports Server (NTRS)

    Anderson, R. W.; Milstead, J.; Stewart, D. C.

    1967-01-01

    Computer study was made on the production of multicurie amounts of highly alpha-active curium 242 from americium 241 irradiation. The information available includes curium 242 yields, curium composition, irradiation data, and production techniques and safeguards.

  9. The present situation of the irradiation application industry and irradiation facilities in Japan

    NASA Astrophysics Data System (ADS)

    Mizusawa, K.; Baba, T.

    2003-08-01

    The irradiation application industry and irradiation facilities in Japan have been making slow but steady progress for the past 2-3 years. Beside conventional applications, new ones such as carbon fibers and membrane filters have come into the market. There are a lot of new applications about to emerge. PE tubing, already is in the European market, is being evaluated by end users in Japan. Cleaning of dioxin in exhaust gas was successfully tested at a pilot plant. Cross-linked PTFE and polyamide are waiting customers' evaluations as an engineering plastic. Surface cross-linking of artificial polycarbonate teeth has yielded remarkable experimental results. Cross-linking of polycaprolactone will be useful for biodegradable products. Being aware of the future growth of irradiation industry, contract service providers opened new facilities or increased their capability. Beside in-house facilities, there are now three Co-60 facilities and nine EB facilities available for contract irradiation in Japan.

  10. Electrokinetic and surface chemical characterizations of an irradiated microfiltration polysulfone membrane: comparison of two irradiation doses.

    PubMed

    de Lara, R; Benavente, J

    2007-06-15

    The effect of ionizing radiation on the surface and electrokinetic characteristic parameters for a porous membrane of pore size 0.2 mum is determined and correlated with the irradiation dose (10 and 80 J/kg). Changes in NaCl permeability and membrane system electrical resistance determined from diffusion and impedance spectroscopy measurements are consistent with the increase of membrane pore radii/porosity, in agreement with SEM micrographs and reported results. Low irradiation dose seems to clean the membrane surface of impurities, according to XPS results, but the increase of irradiation doses could affect surface roughness. Due to the relatively high pore radius, ion transport numbers are practically independent of radiation and dose, but irradiation slightly modifies the membrane solution interface by increasing its weakly electronegative character, which could be of interest in the ultrafiltration of proteins or macromolecules.

  11. Calibration of the Odyssey Photosynthetic Irradiance Recorder for Absolute Irradiance Measures

    EPA Science Inventory

    Researchers are increasingly interested in measuring hotosynthetically active radiation (PAR) because of its importance in determining the structure and function of lotic ecosystems. The Odyssey Photosynthetic Irradiance Recorder is an affordable PAR meter gaining popularity am...

  12. Optical imaging of irradiated and non-irradiated hearts (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Bolin, Stephanie; Chen, Guanchu; Medhora, Meetha M.; Camara, Amadou K. S.; Ranji, Mahsa

    2016-03-01

    Objective: In this study, the metabolic state of the heart tissue is studied in a rodent model of ischemia and reperfusion (IR) in rats exposed to irradiation injury using a cryofluorescence imaging technique. Mitochondrial metabolic state is evaluated by autofluorescence of mitochondrial metabolic coenzymes NADH and FAD. The redox ratio (NADH/FAD) is used as a biochemical/metabolic marker of oxidative stress, before, during and after IR. Materials and methods: Hearts were extracted from non-irradiated (control) and irradiated rats (Irr) given 15 Gy whole thorax irradiation rats (WTI). After 35 days, before the onset of radiation pneumonitis, these two groups of hearts were subjected to one of three treatments; Time control (TC; hearts perfused for the duration of the protocol without ischemia or IR), 25 minutes ischemia with no reperfusion and 25 minutes ischemia followed by 60 minutes reperfusion (IR). Hearts were removed from the Langendorff perfusion system and immediately snap frozen in liquid N2 to preserve the metabolic state after injury; 3-dimensional (3D) cryo-fluorescent imager was used to obtain in fixed time NADH and FAD fluorescence images and their distribution across the entire ventricles. In this study, a 30-μm axial resolution was used resulting in 550 cross-section images per heart. The 3D images of the redox ratio and their respective histograms were calculated in the six groups of hearts. Results: We compared the mean values of the redox ratio in each group, which demonstrate a reduced mitochondrial redox state in both irradiated and non-irradiated ischemic hearts and an oxidized mitochondrial redox state for both irradiated and non-irradiated ischemia-reperfusion hearts compared to control hearts. For non-irradiated hearts, ischemia and IR injuries resulted respectively in 61% increase and 54% decrease in redox ratio when compared with TC. For irradiated hearts, ischemia and IR injuries resulted respectively in 90% increase and 50% decrease

  13. IRRADIATION EFFECTS ON THE PHYSICAL CHARACTERISTICS OF SEWAGE SLUDGE

    SciTech Connect

    Lee, M-J.; Lee, J-K.; Yoo, D-H.; Ho, K.

    2004-10-05

    The radiation effects on the physical characteristic of the sewage sludge were studied in order to obtain information which will be used for study on the enhancement of the sludge's dewaterability. Water contents, capillary suction time, zeta potential, irradiation dose, sludge acidity, total solid concentration, sludge particle size and microbiology before and after irradiation were investigated. Irradiation gave an effect on physical characteristics sludge. Water content in sludge cake could be reduced by irradiation at the dose of 10kGy.

  14. Ionospheric Change and Solar EUV Irradiance

    NASA Astrophysics Data System (ADS)

    Sojka, J. J.; David, M.; Jensen, J. B.; Schunk, R. W.

    2011-12-01

    The ionosphere has been quantitatively monitored for the past six solar cycles. The past few years of observations are showing trends that differ from the prior cycles! Our good statistical relationships between the solar radio flux index at 10.7 cm, the solar EUV Irradiance, and the ionospheric F-layer peak density are showing indications of divergence! Present day discussion of the Sun-Earth entering a Dalton Minimum would suggest change is occurring in the Sun, as the driver, followed by the Earth, as the receptor. The dayside ionosphere is driven by the solar EUV Irradiance. But different components of this spectrum affect the ionospheric layers differently. For a first time the continuous high cadence EUV spectra from the SDO EVE instrument enable ionospheric scientists the opportunity to evaluate solar EUV variability as a driver of ionospheric variability. A definitive understanding of which spectral components are responsible for the E- and F-layers of the ionosphere will enable assessments of how over 50 years of ionospheric observations, the solar EUV Irradiance has changed. If indeed the evidence suggesting the Sun-Earth system is entering a Dalton Minimum periods is correct, then the comprehensive EVE solar EUV Irradiance data base combined with the ongoing ionospheric data bases will provide a most fortuitous fiduciary reference baseline for Sun-Earth dependencies. Using the EVE EUV Irradiances, a physics based ionospheric model (TDIM), and 50 plus years of ionospheric observation from Wallops Island (Virginia) the above Sun-Earth ionospheric relationship will be reported on.

  15. Experimental plan for irradiation experiment HRB-21

    SciTech Connect

    Goodin, D. T.; Kania, M. J.; Patton, B. W.

    1989-04-01

    Irradiation experiment HRB-21 is the first in a series of test capsules that are designed to provide a fuel-performance data base to be used for the validation of modular high-temperature gas-cooled reactor (MHTGR) coated-particle fuel performance models under MHTGR normal operating conditions and specific licensing basis events. Capsule HRB-21 will contain an advanced TRISO-P UCO/ThO{sub 2} - coated-particle fuel system with demonstrated low defective-particle fraction ({le}5 {times} 10{sup {minus}5}) and a heavy metal-contamination fraction ({le}1 {times} 10{sup {minus}5}) that meets MHTGR quality specifications. The coated particles and fuel compacts were fabricated in laboratory-scale facilities using MHTGR reference procedures at General Atomics (GA). Nearly 150,000 fissile and fertile particles will be irradiated in capsule HRB-21 at a mean volumetric fuel temperature of 975{degree}C and will achieve a peak fissile burnup of 26% fissions per initial metal atom (FIMA) while accumulating a fast neutron fluence of about 4.5 {times} 10{sup 25} neutrons/m{sup 2}. This experiment is a cooperative effort between the US Department of Energy (DOE) and the Japan Atomic Energy Research Institute (JAERI). The participants are the Oak Ridge National Laboratory (ORNL), GA, and the Tokai Research Establishment. Capsule HRB-21 will contain the US MHTGR fuel specimens, and a companion capsule, HRB-22, will contain the JAERI fuel. The irradiation will take place in the removable beryllium reflector facility of the High Flux Isotope Reactor (HFIR) at ORNL. The performance of the fuel during irradiation will be closely monitored through on-line fission gas release measurements. Detailed postirradiation examination and conduction cooldown simulation testing will be performed on the irradiated fuel compacts from both the HRB-21 and HRB-22 capsules. 5 refs., 9 figs., 6 tabs.

  16. Updated Results of Ultrasonic Transducer Irradiation Test

    SciTech Connect

    Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert; Chien, Hual-Te; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon; Rempe, Joy; Villard, J.F.

    2015-07-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10{sup 21} n/cm{sup 2}. A multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET-ASI) program also provided initial support for this effort. This irradiation, which started in February 2014, is an instrumented lead test and real-time transducer performance data are collected along with temperature and neutron and gamma flux data. The irradiation is ongoing and will continue to approximately mid-2015. To date, very encouraging results have been attained as several transducers continue to operate under irradiation. (authors)

  17. Biodegradation of selected UV-irradiated and non-irradiated polycyclic aromatic hydrocarbons (PAHs).

    PubMed

    Lehto, Kirsi-Maarit; Puhakka, Jaakko A; Lemmetyinen, Helge

    2003-08-01

    Biodegradation of UV-irradiated anthracene, pyrene, benz[a]anthracene, and dibenz[a,h]anthracene was compared to that of the non-irradiated samples, individually and in synthetic mixtures with enrichment cultures. Combined treatment was repeated for individual anthracene and for the PAH mixture with Sphingomonas sp. strain EPA 505 and Sphingomonas yanoikuyae. Enrichment culture studies were performed on the PAH mixtures in the presence of the main photoproduct of anthracene, pure 9,10-anthracenedione. Photochemically pretreated creosote solutions were also subjected to biodegradation and the results were compared to those of the non-irradiated solutions. The primary interest was on 16 polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by European Union (EU) and the United States Environmental Protection Agency (USEPA). Irradiation accelerated the biodegradation onset for anthracene, pyrene, and benz[a]anthracene when they were treated individually. The biodegradation of irradiated pyrene started with no lag phase and was complete by 122 h whereas biodegradation of the non-irradiated sample had a lag of 280 h and resulted in complete degradation by 720 h. Biodegradation of PAHs was accelerated in synthetic mixtures, especially in the presence of pure 9,10-anthracenedione. In general, irradiation had no effect on the biodegradation of PAHs incubated in synthetic mixtures or with pure cultures. Under current experimental conditions, the UV-irradiation invariably reduced the biodegradation of PAHs in creosote. Based on the results of the present and previous photochemical-biological studies of PAHs, the influence of the photochemical pretreatment on the biodegradation is highly dependent on the compounds being treated and other process parameters.

  18. Phytosanitary irradiation and fresh fruit quality: Cultivar and maturity effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is an effective quarantine treatment for global trade of fresh produce. Variation in cultivars and maturity stages can impact the tolerance of fresh fruits to irradiation for the purposes of quarantine security. Tolerance thresholds for irradiated fruit are lacking for a large number of ...

  19. Food irradiation regulatory development in the U.S.

    NASA Astrophysics Data System (ADS)

    Miller, Sandford A.; Coleman, Eugene C.

    The Food and Drug Administration's involvement in food irradiation dates back more than thirty years. The agency has been involved with the wholesomeness testing of the irradiated foods from both nutritional and toxicological standpoints. Knowledge about the nutritional and toxicological aspects of irradiated foods is fundamental in the development of a regulatory strategy for assuring the safe use of such foods.

  20. Coincidence doppler broadening study in electron-irradiated polyurethane

    NASA Astrophysics Data System (ADS)

    Yang, D. J.; Zhang, J. D.; Leung, J. K. C.; Beling, C. D.; Liu, L. B.

    2007-06-01

    Coincidence doppler broadening measurements on electron-irradiated polyurethanes were performed in the presence of air. It is shown that, after a certain electron irradiation, the momentum density distributions of annihilation electrons have obvious changes for the high crosslinking polyurethane, but no significant changes have been observed for the low crosslinking polyurethane. The results were performed to analyse by irradiation crosslinking and degradation principles.

  1. Response of neutron-irradiated RPV steels to thermal annealing

    SciTech Connect

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1997-03-01

    One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels.

  2. Soluble irradiation targets and methods for the production of radiorhenium

    SciTech Connect

    Vanderhevden, J.L.E.; Su, F.M.; Ehrhardt, G.J.

    1992-09-08

    This patent describes a method of producing a rhenium-188 radionuclide generator. It comprises irradiating a water soluble irradiation target selected from the group consisting of sodium tungstate and lithium tungstate, reacting the irradiated target with an aqueous zirconium solution to obtain an insoluble zirconium tungstate gel, and disposing the zirconium tungstate in an elutable container to obtain the rhenium-188 radionuclide generator.

  3. Irradiation creep of various ferritic alloys irradiated {approximately}400 C in the PFR and FFTF reactors

    SciTech Connect

    Toloczko, M.B.; Garner, F.A.; Eiholzer, C.R.

    1998-03-01

    Three ferritic alloys were irradiated in two fast reactors to doses of 50 dpa or more at temperatures near 400 C. One martensitic alloy, HT9, was irradiated in both the FFTF and PFR reactors. PFR is the Prototype Fast Reactor in Dourneay, Scotland, and FFTF is the Fast Flux Test Facility in Richland, WA. D57 is a developmental alloy that was irradiated in PFR only, and MA957 is a Y{sub 2}O{sub 3} dispersion-hardened ferritic alloy that was irradiated only in FFTF. These alloys exhibited little or no void swelling at {approximately}400 C. Depending on the alloy starting condition, these steels develop a variety of non-creep strains early in the irradiation that are associated with phase changes. Each of these alloys creeps at a rate that is significantly lower than that of austenitic steels irradiated in the same experiments. The creep compliance for ferritic alloys in general appears to be {approximately}0.5 {times} 10{sup {minus}6} MPa{sup {minus}1} dpa{sup {minus}1}, independent of both composition and starting state. The addition of Y{sub 2}O{sub 3} as a dispersoid does not appear to change the creep behavior.

  4. Detection of low amount of irradiated ingredients in non-irradiated precooked meals

    NASA Astrophysics Data System (ADS)

    Marchioni, Eric; Horvatovich, Peter; Ndiaye, Bara; Miesch, Michel; Hasselmann, Claude

    2002-03-01

    The application of the European Standards for the detection of irradiated food by thermoluminescence of silicates, electron-spin resonance spectroscopy of bones or gas chromatography-mass spectrometry of 2-alkylcyclobutanones does not allow the detection of irradiated ingredients included in small quantity in the matrix of a food which has not been irradiated, but which could be subjected to various processing technologies such as cooking, freezing or storage. The use of an enzymatic food hydrolysis carried out at moderated temperature, for the extraction of the food-contaminating silicate minerals and bone fragments, followed by a purification of the extracts by a high-density aqueous solution of sodium polytungstate, allows a simultaneous detection of weak inclusions (0.1% m:m) of irradiated spices and mechanically deboned turkey meat (MRM) included in various precooked foods. Moreover, the use of a supercritical fluid extraction procedure for the 2-alkylcyclobutanones or an additional purification step of the lipid extracts made it possible to lower the detection limit of the 2-alkylcyclobutanones radiation-induced from triglycerides. Using gas chromatography-mass spectrometry, down to 0.5% (m:m) of irradiated MRM included in non-irradiated chicken quenelles could be detected.

  5. Sensitivity of ultrasonic nonlinearity to irradiated, annealed, and re-irradiated microstructure changes in RPV steels

    SciTech Connect

    Matlack, Katie; Kim, J-Y.; Wall, J.J.; Jacobs, L.J.; Sokolov, Mikhail A

    2014-05-01

    The planned life extension of nuclear reactors throughout the US and abroad will cause reactor vessel and internals materials to be exposed to more neutron irradiation than was originally intended. A nondestructive evaluation (NDE) method to monitor radiation damage would enable safe and cost-effective continued operation of nuclear reactors. Radiation damage in reactor pressure vessel (RPV) steels causes microstructural changes that leave the material in an embrittled state. Nonlinear ultrasound is an NDE technique quantified by the measurable acoustic nonlinearity parameter, which is sensitive to microstructural changes in metallic materials such as dislocations, precipitates and their combinations. Recent research has demonstrated the sensitivity of the acoustic nonlinearity parameter to increasing neutron fluence in representative RPV steels. The current work considers nonlinear ultrasonic experiments conducted on similar RPV steel samples that had a combination of irradiation, annealing, re-irradiation, and/or re-annealing to a total neutron fluence of 0.5 5 1019 n/cm2 (E > 1 MeV) at an irradiation temperature of 290 C. The acoustic nonlinearity parameter generally increased with increasing neutron fluence, and consistently decreased from the irradiated to the annealed state over different levels of neutron fluence. Results of the measured acoustic nonlinearity parameter are compared with those from previous measurements on other RPV steel samples. This comprehensive set of results illustrates the dependence of the measured acoustic nonlinearity parameter on neutron fluence, material composition, irradiation temperature and annealing.

  6. Effect of low-level laser irradiating point on immunity

    NASA Astrophysics Data System (ADS)

    Cai, ChangSong; Qi, Qiong-fang; Xin, Jiang

    1993-03-01

    This paper reports that cellular immune function was observed when He-Ne laser was used to irradiate `zusanli' point in rats using various power, time, and periods. The indicator was a lymphocyte transformation test (LTT) by MTT colorimetric analysis. The best irradiating condition was determined, the effect and both virtues and defects of the laser were compared with those of electropuncture. The results show (1) LTT was enhanced in the group of laser irradiating point, but LTT was not enhanced in non-point (t' test, P < 0.01). (2) Lower power -- 2 mW or 5 mW of irradiating for 15 - 20 min, was better; 10 mW or 20 mW of irradiating for 10 - 15 min was suitable. Prolonged irradiating time did not enhance the immune function of the rats. On the contrary, immune function was inhibited. (3) A 7-day period of irradiating was best (once a day, 10 mW for 10 min). Enhanced LTT was not seen when irradiation days were added (SNK, P > 0.05). (4) Laser irradiation point and electropuncture were compared with vehicle control, LTT in the former two groups was enhanced significantly (ANOVA, P < 0.01), and laser irradiating point and electropuncture had the same effect (SNK, P > 0.05). The data suggest that laser irradiating point was able to enhance cell immunity and the enhancement of LTT had a point specific characteristic. The best condition of laser irradiating point was 2 mW for 15 - 20 min, and 10 mW or 20 mW for 10 - 15 min. The best period was 7-day irradiation. The results show laser irradiating the point may activate the main and collateral channels system, then modify the immune function of the body. Our observations provide experimental evidence for proper clinical application of laser irradiating points. The paper theoretically discusses and analyzes the experiment results in detail.

  7. Advanced Numerical Model for Irradiated Concrete

    SciTech Connect

    Giorla, Alain B.

    2015-03-01

    In this report, we establish a numerical model for concrete exposed to irradiation to address these three critical points. The model accounts for creep in the cement paste and its coupling with damage, temperature and relative humidity. The shift in failure mode with the loading rate is also properly represented. The numerical model for creep has been validated and calibrated against different experiments in the literature [Wittmann, 1970, Le Roy, 1995]. Results from a simplified model are shown to showcase the ability of numerical homogenization to simulate irradiation effects in concrete. In future works, the complete model will be applied to the analysis of the irradiation experiments of Elleuch et al. [1972] and Kelly et al. [1969]. This requires a careful examination of the experimental environmental conditions as in both cases certain critical information are missing, including the relative humidity history. A sensitivity analysis will be conducted to provide lower and upper bounds of the concrete expansion under irradiation, and check if the scatter in the simulated results matches the one found in experiments. The numerical and experimental results will be compared in terms of expansion and loss of mechanical stiffness and strength. Both effects should be captured accordingly by the model to validate it. Once the model has been validated on these two experiments, it can be applied to simulate concrete from nuclear power plants. To do so, the materials used in these concrete must be as well characterized as possible. The main parameters required are the mechanical properties of each constituent in the concrete (aggregates, cement paste), namely the elastic modulus, the creep properties, the tensile and compressive strength, the thermal expansion coefficient, and the drying shrinkage. These can be either measured experimentally, estimated from the initial composition in the case of cement paste, or back-calculated from mechanical tests on concrete. If some

  8. Planarian immobilization, partial irradiation, and tissue transplantation.

    PubMed

    Guedelhoefer, Otto C; Sánchez Alvarado, Alejandro

    2012-08-06

    The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology. Planarian regeneration of any missing or damaged tissues is made possible by adult stem cells termed neoblasts. Although these stem cells have been definitively shown to be pluripotent and singularly capable of reconstituting an entire animal, the heterogeneity within the stem cell population and the dynamics of their cellular behaviors remain largely unresolved. Due to the large number and wide distribution of stem cells throughout the planarian body plan, advanced methods for manipulating subpopulations of stem cells for molecular and functional study in vivo are needed. Tissue transplantation and partial irradiation are two methods by which a subpopulation of planarian stem cells can be isolated for further study. Each technique has distinct advantages. Tissue transplantation allows for the introduction of stem cells, into a naïve host, that are either inherently genetically distinct or have been previously treated pharmacologically. Alternatively, partial irradiation allows for the isolation of stem cells within a host, juxtaposed to tissue devoid of stem cells, without the introduction of a wound or any breech in tissue integrity. Using these two methods, one can investigate the cell autonomous and non-autonomous factors that control stem cell functions, such as proliferation, differentiation, and migration. Both tissue transplantation and partial irradiation have been used historically in defining many of the questions about planarian regeneration that remain under study today. However, these techniques have remained underused due to the laborious and inconsistent nature of previous methods. The protocols presented here represent a large step forward in decreasing the time and effort necessary to reproducibly generate large numbers of grafted or partially irradiated animals with efficacies approaching 100 percent. We cover the

  9. Planarian Immobilization, Partial Irradiation, and Tissue Transplantation

    PubMed Central

    Guedelhoefer IV, Otto C.; Sánchez Alvarado, Alejandro

    2012-01-01

    The planarian, a freshwater flatworm, has proven to be a powerful system for dissecting metazoan regeneration and stem cell biology1,2. Planarian regeneration of any missing or damaged tissues is made possible by adult stem cells termed neoblasts3. Although these stem cells have been definitively shown to be pluripotent and singularly capable of reconstituting an entire animal4, the heterogeneity within the stem cell population and the dynamics of their cellular behaviors remain largely unresolved. Due to the large number and wide distribution of stem cells throughout the planarian body plan, advanced methods for manipulating subpopulations of stem cells for molecular and functional study in vivo are needed. Tissue transplantation and partial irradiation are two methods by which a subpopulation of planarian stem cells can be isolated for further study. Each technique has distinct advantages. Tissue transplantation allows for the introduction of stem cells, into a naïve host, that are either inherently genetically distinct or have been previously treated pharmacologically. Alternatively, partial irradiation allows for the isolation of stem cells within a host, juxtaposed to tissue devoid of stem cells, without the introduction of a wound or any breech in tissue integrity. Using these two methods, one can investigate the cell autonomous and non-autonomous factors that control stem cell functions, such as proliferation, differentiation, and migration. Both tissue transplantation5,6 and partial irradiation7 have been used historically in defining many of the questions about planarian regeneration that remain under study today. However, these techniques have remained underused due to the laborious and inconsistent nature of previous methods. The protocols presented here represent a large step forward in decreasing the time and effort necessary to reproducibly generate large numbers of grafted or partially irradiated animals with efficacies approaching 100 percent. We

  10. A study on preparation of glucoamylase by irradiation

    NASA Astrophysics Data System (ADS)

    Ruyan, Chen; Junming, Lan; Youqi, Yan; Can, Tao; Shijie, Li; Liangbi, Song

    1993-10-01

    A study on preparation of industrial glucoamylase irradiated by 60Co gamma-ray showed that an abvious change took place in the extraviolet absorption spectrum and the pH - value of the enzyme solution and the activity of the enzyme preparation was much more resistant to irradiation than that of microbes contained in the preparation. The result indicates that irradiated glucoamylase preparation is not only favourable to activity preservation but also is improved in the hygienic quality of products. A comparison of the various properties of irradiated enzyme preparation with those of unirradiated one has proved that irradiation does not change the normal application of glucoamylase preparation.

  11. Application of gamma irradiation for inhibition of food allergy

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Lee, Ju-Woon; Yook, Hong-Sun; Jo, Cheorun; Kim, Hee-Yun

    2002-03-01

    This study was carried out to evaluate the application of food irradiation technology as a method for reducing food allergy. Milk β-lactoglobulin, chicken egg albumin, and shrimp tropomyosin were used as model food allergens for experiments on allergenic and molecular properties by gamma irradiation. The amount of intact allergens in an irradiated solution was reduced by gamma irradiation depending upon the dose. These results showed that epitopes on the allergens were structurally altered by radiation treatment and that the irradiation technology can be applied to reduce allergenicity of allergic foods.

  12. Mechanical properties of UV irradiated rat tail tendon (RTT) collagen.

    PubMed

    Sionkowska, Alina; Wess, Tim

    2004-04-01

    The mechanical properties of RTT collagen tendon before and after UV irradiation have been investigated by mechanical testing (Instron). Air-dried tendon were submitted to treatment with UV irradiation (wavelength 254 nm) for different time intervals. The changes in such mechanical properties as breaking strength and percentage elongation have been investigated. The results have shown, that the mechanical properties of the tendon were greatly affected by time of UV irradiation. Ultimate tensile strength and ultimate percentage elongation decreased after UV irradiation of the tendon. Increasing UV irradiation leads to a decrease in Young's modulus of the tendon.

  13. Food irradiation in the UK and the European Directive

    NASA Astrophysics Data System (ADS)

    Woolston, John

    2000-03-01

    Food irradiation in the UK has been authorised since the early 1990s. In principle it is possible to irradiate a wide range of foods for a variety of purposes. In practice food irradiation is virtually non-existent. The structure of food retailing in the UK, a continual stream of food safety scares and a developing public 'crisis of confidence' in the food producer/supply chain have combined to make the future for food irradiation look bleak. The new European Directive on Food Irradiation is unlikely to alter this outlook.

  14. Influence of gamma ray irradiation on metakaolin based sodium geopolymer

    NASA Astrophysics Data System (ADS)

    Lambertin, D.; Boher, C.; Dannoux-Papin, A.; Galliez, K.; Rooses, A.; Frizon, F.

    2013-11-01

    Effects of gamma irradiation on metakaolin based Na-geopolymer have been investigated by external irradiation. The experiments were carried out in a gamma irradiator with 60Co sources up to 1000 kGy. Various Na-geopolymer with three H2O/Na2O ratios have been studied in terms of hydrogen radiolytic yield. The results show that hydrogen production increases linearly with water content. Gamma irradiation effects on Na-geopolymer microstructure have been investigated with porosity measurements and X-ray pair distribution function analysis. A change of pore size distribution and a structural relaxation have been found after gamma ray irradiation.

  15. Irradiation creep and swelling of various austenitic alloys irradiated in PFR and FFTF

    SciTech Connect

    Garner, F.A.; Toloczko, M.B.

    1996-10-01

    In order to use data from surrogate neutron spectra for fusion applications, it is necessary to analyze the impact of environmental differences on property development. This is of particular importance in the study of irradiation creep and its interactions with void swelling, especially with respect to the difficulty of separation of creep strains from various non-creep strains. As part of an on-going creep data rescue and analysis effort, the current study focuses on comparative irradiations conducted on identical gas-pressurized tubes produced and constructed in the United States from austenitic steels (20% CW 316 and 20% CW D9), but irradiated in either the Prototype Fast Reactor (PFR) in the United Kingdom or the Fast Flux Test Facility in the United States. In PFR, Demountable Subassemblies (DMSA) serving as heat pipes were used without active temperature control. In FFTF the specimens were irradiated with active ({+-}{degrees}5C) temperature control. Whereas the FFTF irradiations involved a series of successive side-by-side irradiation, measurement and reinsertion of the same series of tubes, the PFR experiment utilized simultaneous irradiation at two axial positions in the heat pipe to achieve different fluences at different flux levels. The smaller size of the DMSA also necessitated a separation of the tubes at a given flux level into two groups (low-stress and high-stress) at slightly different axial positions, where the flux between the two groups varied {le}10%. Of particular interest in this study was the potential impact of the two types of separation on the derivation of creep coefficients.

  16. [Dosimetric comparison of external partial breast irradiation with whole breast irradiation and partial breast brachytherapy].

    PubMed

    Bodács, István; Polgár, Csaba; Major, Tibor

    2014-06-01

    Different techniques exist for the delivery of radiotherapy after breast conserving surgery. The conventional method is whole breast irradiation. However, in selected patients partial breast irradiation can be performed, either with external beams or brachytherapy. In the current study three irradiation techniques are compared regarding dosimetric aspects. Treatment plans of thirty women treated with external beam conformal partial breast irradiation (CONF) were evaluated using dose-volume histograms. For the same patients whole breast irradiation plans (WBI) were made and compared with the CONF ones. Breast and lung of both sides, and heart at left sided lesions were contoured as organs at risk. After this, dose plans of another thirty patients treated with interstitial brachytherapy (IBT) were analyzed and compared with the CONF plans. According to our results the 90% isodose curve covered at least 97% of the target volume at all three techniques, and this value was 100% for CONF. The maximal dose within target volume was 106% in CONF and 115% in WBI plans. Volume of ipsilateral breast receiving the prescribed dose was 66%, 15% and 13% in the WBI, CONF and IBT plans, respectively. The dose to the contralateral breast was less for CONF compared to WBI. Volume of the ipsilateral lung receiving 30% of the prescribed dose was 15%, 8% and 1%, the maximal dose was 105%, 94% and 47% in the WBI, CONF and IBT plans, respectively. In the same order the maximal dose to the heart was 82%, 49% and 25%, while the dose irradiated to 5% of the heart volume was 27%, 19% and 14% at left sided lesions. Regarding target coverage, the conformal technique was the best, and the dose was more homogeneous than at WBI. With respect to dose to organs at risk the partial breast irradiation techniques were much more favorable than WBI, and the lowest doses occurred in the IBT treatment plans.

  17. Post-irradiation stability of polyvinyl chloride at sterilizing doses

    NASA Astrophysics Data System (ADS)

    Naimian, F.; Katbab, A. A.; Nazokdast, H.

    1994-12-01

    Post-irradiation stability of plasticized PVC irradiated by 60Co gamma ray at sterilizing doses has been studied. Effects of irradiation upon chemical structure, mechanical properties and rheological behaviour of samples contained different amounts of Di(2-ethylhexyl)phthalate as plasticizer have been investigated. Formation of conjugated double bonds, carbonyl and hydroxyl groups have been followed by UV and FTIR spectrometers up to 6 months after irradiation. FTIR spectra of irradiated samples showed no significant changes in carbonyl and hydroxyl groups even 6 months after irradiation. However, changes in UV-visible spectra was observed for the irradiated samples up to 6 months post-irradiation. This has been attributed to the formation of polyenes which leads to the discoloration of this polymer. Despite a certain degree of discoloration, it appears that the mechanical properties of PVC are not affected by irradiation at sterilizing doses. No change in the melt viscosity of the irradiated PVC samples with post-irradiation was observed, which is in consistent with the IR results.

  18. Gamma irradiation influence on physical properties of milk proteins

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Salmieri, S.; Lacroix, M.; Tien, C. Le

    2004-09-01

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling.

  19. Microarchitecture of irradiated bone: comparison with healthy bone

    NASA Astrophysics Data System (ADS)

    Bléry, Pauline; Amouriq, Yves; Guédon, Jeanpierre; Pilet, Paul; Normand, Nicolas; Durand, Nicolas; Espitalier, Florent; Arlicot, Aurore; Malard, Olivier; Weiss, Pierre

    2012-03-01

    The squamous cell carcinomas of the upper aero-digestive tract represent about ten percent of cancers. External radiation therapy leads to esthetic and functional consequences, and to a decrease of the bone mechanical abilities. For these patients, the oral prosthetic rehabilitation, including possibilities of dental implant placement, is difficult. The effects of radiotherapy on bone microarchitecture parameters are not well known. Thus, the purpose of this study is to assess the effects of external radiation on bone micro architecture in an experimental model of 25 rats using micro CT. 15 rats were irradiated on the hind limbs by a single dose of 20 Grays, and 10 rats were non irradiated. Images of irradiated and healthy bone were compared. Bone microarchitecture parameters (including trabecular thickness, trabecular number, trabecular separation, connectivity density and tissue and bone volume) between irradiated and non-irradiated bones were calculated and compared using a Mann and Whitney test. After 7 and 12 weeks, images of irradiated and healthy bone are different. Differences on the irradiated and the healthy bone populations exhibit a statistical significance. Trabecular number, connectivity density and closed porosity are less important on irradiated bone. Trabecular thickness and separation increase for irradiated bone. These parameters indicate a decrease of irradiated bone properties. Finally, the external irradiation induces changes on the bone micro architecture. This knowledge is of prime importance for better oral prosthetic rehabilitation, including implant placement.

  20. Mechanical properties for irradiated face-centred cubic nanocrystalline metals.

    PubMed

    Xiao, X Z; Song, D K; Chu, H J; Xue, J M; Duan, H L

    2015-05-08

    In this paper, a self-consistent plasticity theory is proposed to model the mechanical behaviours of irradiated face-centred cubic nanocrystalline metals. At the grain level, a tensorial crystal model with both irradiation and grain size effects is applied for the grain interior (GI), whereas both grain boundary (GB) sliding with irradiation effect and GB diffusion are considered in modelling the behaviours of GBs. The elastic-viscoplastic self-consistent method with considering grain size distribution is developed to transit the microscopic behaviour of individual grains to the macroscopic properties of nanocrystals (NCs). The proposed theory is applied to model the mechanical properties of irradiated NC copper, and the feasibility and efficiency have been validated by comparing with experimental data. Numerical results show that: (i) irradiation-induced defects can lead to irradiation hardening in the GIs, but the hardening effect decreases with the grain size due to the increasing absorption of defects by GBs. Meanwhile, the absorbed defects would make the GBs softer than the unirradiated case. (ii) There exists a critical grain size for irradiated NC metals, which separates the grain size into the irradiation hardening dominant region (above the critical size) and irradiation softening dominant region (below the critical size). (iii) The distribution of grain size has a significant influence on the mechanical behaviours of both irradiated and unirradiated NCs. The proposed model can offer a valid theoretical foundation to study the irradiation effect on NC materials.

  1. Fractionated total body irradiation for metastatic neuroblastoma

    SciTech Connect

    Kun, L.E.; Casper, J.T.; Kline, R.W.; Piaskowski, V.D.

    1981-11-01

    Twelve patients over one year old with neuroblastoma (NBL) metastatic to bone and bone marrow entered a study of adjuvant low-dose, fractionated total body irradiation (TBI). Six children who achieved a ''complete clinical response'' following chemotherapy (cyclophosphamide and adriamycin) and surgical resection of the abdominal primary received TBI (10 rad/fraction to totals of 100-120 rad/10-12 fx/12-25 days). Two children received concurrent local irradiation for residual abdominal tumor. The intervals from cessation of chemotherapy to documented progression ranged from 2-16 months, not substatially different from patients receiving similar chemotherapy and surgery without TBI. Three additional children with progressive NBL received similar TBI (80-120 rad/8-12 fx) without objective response.

  2. Laryngeal acinic cell carcinoma following thyroid irradiation

    SciTech Connect

    Reibel, J.F.; McLean, W.C.; Cantrell, R.W.

    1981-01-01

    Only three examples of acinic cell carcinoma of the larynx or trachea are found in the recent literature. A case of acinic cell carcinoma of the subglottic larynx and trachea was diagnosed and treated at the University of Virginia Medical Center. To our knowledge this is the first such case with a prior history of radiation to the neck. The patient is a 56-year-old woman who was irradiated for hyperthyroidism 46 years ago. When seen she also had parathyroid hyperplasia and multiple thyroid adenomas, conditions that frequently follow irradiation of the thyroid in children. These findings in this case support the concept that radiation may be responsible for inducing this tumor, which otherwise rarely occurs in this location. The use of electron microscopy was extremely useful in the diagnosis of this tumor. She was treated with total laryngectomy and right neck dissection and is now free of disease one year after surgery.

  3. Spectral measurements of asymmetrically irradiated capsule backlighters

    NASA Astrophysics Data System (ADS)

    Keiter, P. A.; Drake, R. P.

    2016-11-01

    Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies [J. F. Hansen et al., Rev. Sci. Instrum. 79, 013504 (2008)]. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of 2-13 keV and time-resolved spectra over the photon energy range of 2-3 keV. We will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

  4. Spectral measurements of asymmetrically irradiated capsule backlighters

    DOE PAGES

    Keiter, P. A.; Drake, R. P.

    2016-09-09

    Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of ~2-13 keV and time-resolved spectra over the photon energy range of ~2-3 keV. Lastly, we will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

  5. Membrane Protein Crystallization Using Laser Irradiation

    NASA Astrophysics Data System (ADS)

    Adachi, Hiroaki; Murakami, Satoshi; Niino, Ai; Matsumura, Hiroyoshi; Takano, Kazufumi; Inoue, Tsuyoshi; Mori, Yusuke; Yamaguchi, Akihito; Sasaki, Takatomo

    2004-10-01

    We demonstrate the crystallization of a membrane protein using femtosecond laser irradiation. This method, which we call the laser irradiated growth technique (LIGHT), is useful for producing AcrB crystals in a solution of low supersaturation range. LIGHT is characterized by reduced nucleation times. This feature is important for crystallizing membrane proteins because of their labile properties when solubilized as protein-detergent micelles. Using LIGHT, high-quality crystals of a membrane transporter protein, AcrB, were obtained. The resulting crystals were found to be of sufficiently high resolution for X-ray diffraction. The results reported here indicate that LIGHT is a powerful tool for membrane protein crystallization, as well as for the growth of soluble proteins.

  6. Neutron irradiation induced amorphization of silicon carbide

    SciTech Connect

    Snead, L.L.; Hay, J.C.

    1998-09-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 {times} 10{sup 25} n/m{sup 2}. Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density ({minus}10.8%), elastic modulus as measured using a nanoindentation technique ({minus}45%), hardness as measured by nanoindentation ({minus}45%), and standard Vickers hardness ({minus}24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C.

  7. Titanium implants in irradiated dog mandibles

    SciTech Connect

    Schweiger, J.W. )

    1989-08-01

    The use of osseointegrated titanium implants has been a great benefit to selected cancer patients who otherwise would not be able to wear conventional and/or maxillofacial prostheses. Cognizant of the risk of osteoradionecrosis, we used an animal model to seek experimental evidence for successful osseointegration in bone irradiated to tumoricidal levels. Five healthy male beagle dogs received 60 gray to a previously edentulated and healed area of the right hemimandible. The left hemimandible was kept as a nonirradiated control. After 9 months, titanium implants were placed and allowed an additional 5 1/2 months to osseointegrate. At that time, block specimens were obtained, radiographed, photographed, and analyzed histologically. Although statistical significance cannot be attached to the results, osseointegration was achieved in half of the irradiated specimens.

  8. UVA system for human cornea irradiation

    NASA Astrophysics Data System (ADS)

    Pereira, Fernando R. A.; Stefani, Mario; Otoboni, José A.; Richter, Eduardo H.; Rossi, Giuliano; Mota, Alessandro D.; Ventura, Liliane

    2009-02-01

    According to recent studies, an increase in corneal stiffness is a promising alternative for avoiding ectasias and for stagnating keratoconus of grades 1 and 2. The clinical treatment consists essentially of instilling Riboflavin (vitamin B2), in the cornea and then irradiating the corneal tissue, with UVA (365nm) radiation at 3mW/cm2 for 30min. This procedure provides collagen cross-linking in the corneal surface, increasing its stiffness. This work presents a system for UVA irradiation of the corneas at a peak wavelength of 365nm with adjustable power up to 5mW. The system has closed loop electronics to control the emitted power with 20% precision from the sated power output. The system is a prototype for performing corneal cross-linking and has been clinically tested. The closed loop electronics is a differential from the equipments available on the market.

  9. Sublethal irradiation promotes invasiveness of neuroblastoma cells

    SciTech Connect

    Schweigerer, Lothar; Rave-Fraenk, Margret; Schmidberger, Heinz; Hecht, Monica . E-mail: monica.hecht@med.uni-goettingen.de

    2005-05-13

    Neuroblastoma is the most frequent extracranial solid tumour of childhood. Despite multiple clinical efforts, clinical outcome has remained poor. Neuroblastoma is considered to be radiosensitive, but some clinical studies including the German trial NB90 failed to show a clinical benefit of radiation therapy. The mechanisms underlying this apparent discrepancy are still unclear. We have therefore investigated the effects of radiation on neuroblastoma cell behaviour in vitro. We show that sublethal doses of irradiation up-regulated the expression of the hepatocyte growth factor (HGF) and its receptor c-Met in some neuroblastoma cell lines. The increase in HGF/c-Met expression was correlated with enhanced invasiveness and activation of proteases degrading the extracellular matrix. Thus, irradiation at sublethal doses may promote the metastatic dissemination of neuroblastoma cells through activating the HGF/c-Met pathway and triggering matrix degradation.

  10. Nanohardness and brittleness of irradiated spinel ceramics

    NASA Astrophysics Data System (ADS)

    Jagielski, J.; Aubert, P.; Maciejak, O.; Piatkowska, A.; Labdi, S.; Jozwik-Biala, I.; Jozwik, P.; Wajler, A.

    2012-09-01

    The influence of the size of crystalline regions on mechanical properties of irradiated oxides has been studied using magnesium aluminate spinel MgAl2O4. The samples characterized by different dimensions of crystalline domains, from sintered ceramics with grains of few micrometers in size up to single crystals, were used in the experiments. The samples were irradiated at room temperature with 320 keV Ar2+ ions up to fluences reaching 5 × 1016 cm-2. Nanomechanical properties were measured by using a nanoindentation technique and the resistance to crack formation by measurement of the total crack lengths made by Vickers indenter. The results revealed: correlation of nanohardness with accumulated damage, radiation-induced hardness increase in grain-boundary region and significant improvement of material resistance to crack formation.

  11. Stress relaxation of vitreous silica on irradiation

    SciTech Connect

    Primak, W.

    1982-11-01

    The radiation-induced stress relaxation which is observed on ion bombardment of vitreous silica is described as a viscoelastic behavior in which the apparent viscosity is reduced to approx.10/sup 14/ Poise during irradiation and then increases rapidly by 4 or 5 orders of magnitude on cessation or interruption of irradiation. The bombarded layer appears to possess a viscosity approx.10/sup 19/ Poise, lower than would be expected for normal vitreous silica. On electron bombardment the viscosity is also reduced, but not as greatly as an ion bombardment, yet sufficiently to result in the whole radiation-induced volume contraction being realized perpendicularly to the surface, as has been found for ion bombardment. The maximum elastic stored energy which can be realized is but a fraction of a calorie per gram, hence the reported values of 200 cal/g would seem to be associated with the fragmentation of the network responsible for the reduced viscosity.

  12. Stored energy in irradiated silicon carbide

    SciTech Connect

    Snead, L.L.; Burchell, T.D.

    1997-04-01

    This report presents a short review of the phenomenon of Wigner stored energy release from irradiated graphite and discusses it in relation to neutron irradiation of silicon carbide. A single published work in the area of stored energy release in SiC is reviewed and the results are discussed. It appears from this previous work that because the combination of the comparatively high specific heat of SiC and distribution in activation energies for recombining defects, the stored energy release of SiC should only be a problem at temperatures lower than those considered for fusion devices. The conclusion of this preliminary review is that the stored energy release in SiC will not be sufficient to cause catastrophic heating in fusion reactor components, though further study would be desirable.

  13. Prospects for Irradiation in Cellulosic Ethanol Production

    PubMed Central

    Saini, Anita; Aggarwal, Neeraj K.; Sharma, Anuja; Yadav, Anita

    2015-01-01

    Second generation bioethanol production technology relies on lignocellulosic biomass composed of hemicelluloses, celluloses, and lignin components. Cellulose and hemicellulose are sources of fermentable sugars. But the structural characteristics of lignocelluloses pose hindrance to the conversion of these sugar polysaccharides into ethanol. The process of ethanol production, therefore, involves an expensive and energy intensive step of pretreatment, which reduces the recalcitrance of lignocellulose and makes feedstock more susceptible to saccharification. Various physical, chemical, biological, or combined methods are employed to pretreat lignocelluloses. Irradiation is one of the common and promising physical methods of pretreatment, which involves ultrasonic waves, microwaves, γ-rays, and electron beam. Irradiation is also known to enhance the effect of saccharification. This review explains the role of different radiations in the production of cellulosic ethanol. PMID:26839707

  14. Quantification of biologically effective environmental UV irradiance

    NASA Astrophysics Data System (ADS)

    Horneck, G.

    To determine the impact of environmental UV radiation on human health and ecosystems demands monitoring systems that weight the spectral irradiance according to the biological responses under consideration. In general, there are three different approaches to quantify a biologically effective solar irradiance: (i) weighted spectroradiometry where the biologically weighted radiometric quantities are derived from spectral data by multiplication with an action spectrum of a relevant photobiological reaction, e.g. erythema, DNA damage, skin cancer, reduced productivity of terrestrial plants and aquatic foodweb; (ii) wavelength integrating chemical-based or physical dosimetric systems with spectral sensitivities similar to a biological response curve; and (iii) biological dosimeters that directly weight the incident UV components of sunlight in relation to the effectiveness of the different wavelengths and to interactions between them. Most biological dosimeters, such as bacteria, bacteriophages, or biomolecules, are based on the UV sensitivity of DNA. If precisely characterized, biological dosimeters are applicable as field and personal dosimeters.

  15. Solar Irradiance, Plage and SOHO UV Images

    NASA Astrophysics Data System (ADS)

    Lopresto, James C.; Manross, Kevin

    1996-05-01

    Calcium K and H alpha plage and sunspot area have been monitored using Big Bear Observatory images on the INTERNET since November of 1992. The purpose of the project is to determine the correlation of changing plage area and solar irradiance changes. We also monitor changes in the K2 spec- tral index provided daily from Sacramento Peak. With the recent launching of the SOHO satellite, we are able to monitor the plage in the He II 304 Angstroms UV image. This image is near the top of the chromosphere nar or just under the transition region. The images show limb brightening as expected. Since it is widely believed that short time scale changes in the UV may be the dominant cause for low amplitude solar irradiance changes, the comparison of the "plage" ara in these UV images to those in conventional visible images should prove instructive.

  16. Cadmium Nanowire Formation Induced by Ion Irradiation

    SciTech Connect

    Jiang, Weilin; Weber, William J.; Wang, Chong M.; Young, James S.; Boatner, Lynn A.; Lian, Jie; Wang, Lumin; Ewing, Rodney C.

    2005-07-04

    One-dimensional nanostructures, such as nanowires, of semiconductors and metals are of great technological interest due to their potential for many advanced technology applications. Utilization of these materials versus their bulk counterparts will not only allow for device miniaturisation, but also may improve device performance or create new functions. Here we report a novel method for the synthesis of crystalline Cd-nanowires without involving either templates or a “seeded” structure. Ion irradiation at low temperatures (≤ 295 K) has been used to induce material decomposition and phase segregation in a cadmium niobate pyrochlore (Cd2Nb2O7) wafer. During the formation and rupture of the gas-filled blisters in the material, soft metallic Cd is extruded/extracted as nanowires through pores in the exfoliated layer. The entire process may be readily controlled by changing the ion irradiation conditions (e.g., ion species, dose and energy) with minimal thermal constraints.

  17. Long-term effects of orbital irradiation

    SciTech Connect

    Guyuron, B.; Dagys, A.P.; Munro, I.R.

    1987-11-01

    This retrospective study is a review of 18 patients who received radiotherapy to the orbit between the ages of 1 month and 10 years. Patients were followed for 7-21 years in an attempt to define the effects of orbital irradiation on a growing child. None of the patients in the study was spared injurious effects on soft tissue or bone, but soft tissue appeared to be more vulnerable to radiation than bone. Orbital irradiation caused soft tissue deficits of the upper face in 100% of the patients. Sixty-seven percent of patients had soft tissue deformities of the midface, and 13% had soft tissue deformities of the lower face. Bony deficits were found in the upper face in 67% of the patients, the midface in 50%, and the lower face in 6%. This study found no correlation between age and time of radiotherapy on the effects of facial growth.

  18. Raman spectroscopy of ion-irradiated astrophysically relevant materials

    NASA Astrophysics Data System (ADS)

    Baratta, G. A.; Brunetto, R.; Leto, G.; Palumbo, M. E.; Spinella, F.; Strazzulla, G.

    Solid objects in space (interstellar grains, comets, interplanetary dust particles, etc.) are continuously exposed to energetic processes, such as cosmic ion irradiation, that influence their evolution. In this paper we present an experimental study, carried out by Raman spectroscopy, of the effects induced by ion irradiation on frozen ices and refractory materials. If the irradiated ice mixture contains a relevant amount of carbon atoms, the ice is converted into an organic residue (stable at room temperature), which at high irradiation dose evolves toward a hydrogenated amorphous carbon. Here we show that material similar to that produced in the laboratory by ion irradiation of frozen ice mixtures and refractory materials can be formed in space by cosmic ion irradiation. This finding has been recently confirmed by the Stardust mission, which revealed in some of the cometary particles collected in space and returned to earth carbonaceous materials that have been processed by cosmic ion irradiation.

  19. Identification of gamma-irradiated papaya, melon and watermelon

    NASA Astrophysics Data System (ADS)

    Marín-Huachaca, Nélida S.; Mancini-Filho, Jorge; Delincée, Henry; Villavicencio, Anna Lúcia C. H.

    2004-09-01

    Ionizing radiation can be used to control spoilage microorganisms and to increase the shelf life of fresh fruits and vegetables in replacement for the treatment with chemical fumigants. In order to enforce labelling regulations, methods for detecting the irradiation treatment directly in the produce are required. Recently, a number of detection methods for irradiated food have been adopted by the Codex Comission. A rapid screening method for qualitative detection of irradiation is the DNA Comet Assay. The applicability of the DNA Comet Assay for distinguishing irradiated papaya, melon, and watermelon was evaluated. The samples were treated in a 60Co facility at dose levels of 0.0, 0.5, 0.75, and 1.0kGy. The irradiated samples showed typical DNA fragmentation whereas cells from non-irradiated ones appeared intact. In addition to the DNA Comet Assay also the half-embryo test was applied in melon and watermelon to detect the irradiation treatment.

  20. Low Dose Food Irradiation at Natick

    DTIC Science & Technology

    1977-06-01

    activity, titratable acidity, pH, ash, protein, and moisture content), dough and baking characteristics (bread scores, rheological and alpha-amylase...on the vitamin content in the irradiated flour or in the bread made from the 1 3See footnote 5 15 flour (Tables 10,11). Farinographs, dough ...sometimes sour , replaced it. The appearance of the nonirradiated chicken showed no discoloration up to about 8 days in storage, after which a dull

  1. Post irradiation examination of thermal reactor fuels

    NASA Astrophysics Data System (ADS)

    Sah, D. N.; Viswanathan, U. K.; Ramadasan, E.; Unnikrishnan, K.; Anantharaman, S.

    2008-12-01

    The post irradiation examination (PIE) facility at the Bhabha Atomic Research Centre (BARC) has been in operation for more than three decades. Over these years this facility has been utilized for examination of experimental fuel pins and fuels from commercial power reactors operating in India. In a program to assess the performance of (U,Pu)O 2 MOX fuel prior to its introduction in commercial reactors, three experimental MOX fuel clusters irradiated in the pressurized water loop (PWL) of CIRUS up to burnup of 16 000 MWd/tU were examined. Fission gas release from these pins was measured by puncture test. Some of these fuel pins in the cluster contained controlled porosity pellets, low temperature sintered (LTS) pellets, large grain size pellets and annular pellets. PIE has also been carried out on natural UO 2 fuel bundles from Indian PHWRs, which included two high burnup (˜15 000 MWd/tU) bundles. Salient investigations carried out consisted of visual examination, leak testing, axial gamma scanning, fission gas analysis, microstructural examination of fuel and cladding, β, γ autoradiography of the fuel cross-section and fuel central temperature estimation from restructuring. A ThO 2 fuel bundle irradiated in Kakrapar Atomic Power Station (KAPS) up to a nominal fuel burnup of ˜11 000 MWd/tTh was also examined to evaluate its in-pile performance. The performance of the BWR fuel pins of Tarapur Atomic Power Stations (TAPS) was earlier assessed by carrying out PIE on 18 fuel elements selected from eight fuel assemblies irradiated in the two reactors. The burnup of these fuel elements varied from 5000 to 29 000 MWd/tU. This paper provides a brief review of some of the fuels examined and the results obtained on the performance of natural UO 2, enriched UO 2, MOX, and ThO 2 fuels.

  2. Total lymphoid irradiation for multiple sclerosis

    SciTech Connect

    Devereux, C.K.; Vidaver, R.; Hafstein, M.P.; Zito, G.; Troiano, R.; Dowling, P.C.; Cook, S.D.

    1988-01-01

    Although chemical immunosuppression has been shown to benefit patients with chronic progressive multiple sclerosis (MS), it appears that chemotherapy has an appreciable oncogenic potential in patients with multiple sclerosis. Accordingly, we developed a modified total lymphoid irradiation (TLI) regimen designed to reduce toxicity and applied it to a randomized double blind trial of TLI or sham irradiation in MS. Standard TLI regimens were modified to reduce dose to 1,980 rad, lowering the superior mantle margin to midway between the thyroid cartilage and angle of the mandible (to avert xerostomia) and the lower margin of the mantle field to the inferior margin of L1 (to reduce gastrointestinal toxicity by dividing abdominal radiation between mantle and inverted Y), limiting spinal cord dose to 1,000 rad by custom-made spine blocks in the mantle and upper 2 cm of inverted Y fields, and also protecting the left kidney even if part of the spleen were shielded. Clinical efficacy was documented by the less frequent functional scale deterioration of 20 TLI treated patients with chronic progressive MS compared to to 20 sham-irradiated progressive MS patients after 12 months (16% versus 55%, p less than 0.03), 18 months (28% versus 63%, p less than 0.03), and 24 months (44% versus 74%, N.S.). Therapeutic benefit during 3 years follow-up was related to the reduction in lymphocyte count 3 months post-irradiation (p less than 0.02). Toxicity was generally mild and transient, with no instance of xerostomia, pericarditis, herpes zoster, or need to terminate treatment in TLI patients. However, menopause was induced in 2 patients and staphylococcal pneumonia in one.

  3. Adjustable compensators for whole-brain irradiation.

    PubMed

    Lerch, I A; Newall, J

    1979-02-01

    A compensator for use in irradiating the whole brain with parellel opposed lateral fields was made from a stack of thin tempered aluminum plates. This configuration gives a wide latitude of degrees of compensation and can accommodate a broad range of head sizes. Dosimetry studies indicate that overcompensation may be desirable to reduce the dose to the mid-coronal plane of the skull and scalp without seriously affecting the dose uniformity in the treatment volume.

  4. Surface changes of implants after laser irradiation

    NASA Astrophysics Data System (ADS)

    Rechmann, Peter; Sadegh, Hamid M. M.; Goldin, Dan S.; Hennig, Thomas

    1999-05-01

    Periimplantitis is one of the major factors for the loss of dental implants. Due to the minor defense ability of the tissue surrounding the implant compared to natural teeth treatment of periimplantitis in the early stage is very important. Reducing bacteria with a laser might be the most successful step in therapy of periimplantitis. Aim of the study was to observe changes in surface morphology of seven different implants after irradiation with three different lasers. Two kinds of flat round samles were prepared by the manufacturers either identical to the body surface or to the cervical area of the corresponding implants. The samples were irradiated using different power settings. The lasers used were a CO2 laser (Uni Laser 450P, ASAH Medico Denmark; fiber guided, wavelength 10.6 μm, max. average power 8.3 W, "soft-pulse" and cw) an Er:YAG laser (KaVo Key Laser II, wavelength 2.94 μm, pulse duration 250-500μs, pulse energy 60-500 mJ, pulse repetition rate 1-15 Hz, focus diameter 620 μm, air-water cooling; Biberach, Germany; a frequency doubled Alexandrite laser (laboratory prototype, q-switched, fiber guided, wavelength 377 nm, pulse duration 1 μs, pulse repetition rate 30 Hz, water cooling). After irradiation the implant surfaces were investigated with a Scanning Electron Microscope. Ablation thresholds were determined. After CO2 laser irradiation no changes in surface morphology were observed whereas using the pulsed Er:YAG laser or frequency doubled Alexandrite laser even at low energies loss of integrity or melting of the surface was observed. The changes in surface morphology seem to depend very strongly on the type of surface coating.

  5. Metal fuel manufacturing and irradiation performance

    SciTech Connect

    Pedersen, D.R.; Walters, L.C.

    1992-01-01

    The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

  6. Metal fuel manufacturing and irradiation performance

    SciTech Connect

    Pedersen, D.R.; Walters, L.C.

    1992-06-01

    The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

  7. Antitumor Immunity Induced after α Irradiation123

    PubMed Central

    Gorin, Jean-Baptiste; Ménager, Jérémie; Gouard, Sébastien; Maurel, Catherine; Guilloux, Yannick; Faivre-Chauvet, Alain; Morgenstern, Alfred; Bruchertseifer, Frank; Chérel, Michel; Davodeau, François; Gaschet, Joëlle

    2014-01-01

    Radioimmunotherapy (RIT) is a therapeutic modality that allows delivering of ionizing radiation directly to targeted cancer cells. Conventional RIT uses β-emitting radioisotopes, but recently, a growing interest has emerged for the clinical development of α particles. α emitters are ideal for killing isolated or small clusters of tumor cells, thanks to their specific characteristics (high linear energy transfer and short path in the tissue), and their effect is less dependent on dose rate, tissue oxygenation, or cell cycle status than γ and X rays. Several studies have been performed to describe α emitter radiobiology and cell death mechanisms induced after α irradiation. But so far, no investigation has been undertaken to analyze the impact of α particles on the immune system, when several studies have shown that external irradiation, using γ and X rays, can foster an antitumor immune response. Therefore, we decided to evaluate the immunogenicity of murine adenocarcinoma MC-38 after bismuth-213 (213Bi) irradiation using a vaccination approach. In vivo studies performed in immunocompetent C57Bl/6 mice induced a protective antitumor response that is mediated by tumor-specific T cells. The molecular mechanisms potentially involved in the activation of adaptative immunity were also investigated by in vitro studies. We observed that 213Bi-treated MC-38 cells release “danger signals” and activate dendritic cells. Our results demonstrate that α irradiation can stimulate adaptive immunity, elicits an efficient antitumor protection, and therefore is an immunogenic cell death inducer, which provides an attractive complement to its direct cytolytic effect on tumor cells. PMID:24862758

  8. Histologic changes in previously irradiated thyroid glands

    SciTech Connect

    Valdiserri, R.O.; Borochovitz, D.

    1980-03-01

    Thyroid tissue from 90 patients with a history of therapeutic irradiation to the head and neck in childhood and adolescence was examined microscopically. In addition to the well-known observation that these individuals have an increased incidence of primary thyroid carcinoma, it was also demonstrated that they have an increased incidence of benign histologic changes. These changes represent a spectrum from nonspecific hyperplastic lesions to benign neoplasis and thyroidltis.

  9. Electron Irradiation of Light Emitting Diodes.

    DTIC Science & Technology

    1984-12-01

    the present experiment were fabricated by liquid phase epitaxy (LPE) or vapor phase epitaxy (VPE). Millea and Aukerman [Ref. 5 and 6] studied electron...neutron induced damage. They and Millea and Aukerman [Ref. 6] observed the absence of bias induced recovery in neutron irradiated LEDs. This is in...Herrick, D., J. Applied Phys., 41, 3783, 1970. 4. Stanley, A.G., IEEE Trans. Nucl. Sci., NS-17, 239, 1970. 5. Millea, M.F., and Aukerman , L.W., J

  10. Mechanical Cutting of Irradiated Reactor Internal Components

    SciTech Connect

    Anderson, M.G.; Fennema, J.A.

    2007-07-01

    This paper discusses the use of mechanical cutting methods to volume reduce and package irradiated reactor internal components. The recent completion of the removal of the Reactor Vessel Internals (RVI) from within the Sacramento Municipal Utility District's (SMUD) Rancho Seco Nuclear Power Plant demonstrates that unlike previous methods used for similar projects, mechanical cutting minimizes exposure to workers, costly water cleanup, and excessive secondary waste generation. (authors)

  11. Optical Properties of Irradiated Topaz Crystals

    NASA Astrophysics Data System (ADS)

    Skvortsova, V.; Mironova-Ulmane, N.; Trinkler, L.

    2015-04-01

    The results of an investigation of UV-Visible absorption and photoluminescence spectra of colorless topaz before and after neutron irradiation, natural blue topaz from Ukraine, and yellow topaz are presented. We assume that the absorption band ∼ 620 nm and broad emission band 300-700 nm in topaz crystals are associated with exchange interaction between a radiation defect (anion vacancies, which capture one or two electrons) and impurity ions Cr3+, Fe3+ and Mn2+.

  12. Irradiation Products On Dwarf Planet Makemake

    NASA Astrophysics Data System (ADS)

    Brown, M. E.; Schaller, E. L.; Blake, G. A.

    2015-03-01

    The dark, reddish tinged surfaces of icy bodies in the outer solar system are usually attributed to the long term irradiation of simple hydrocarbons leading to the breaking of C-H bonds, loss of hydrogen, and the production of long carbon chains. While the simple hydrocarbon methane is stable and detected on the most massive bodies in the Kuiper Belt, evidence of active irradiation chemistry is scant except for the presence of ethane on methane-rich Makemake and the possible detections of ethane on more methane-poor Pluto and Quaoar. We have obtained deep high signal-to-noise spectra of Makemake from 1.4 to 2.5 μm in an attempt to trace the radiation chemistry in the outer solar system beyond the initial ethane formation. We present the first astrophysical detection of solid ethylene and evidence for acetylene and high-mass alkanes—all expected products of the continued irradiation of methane, and use these species to map the chemical pathway from methane to long-chain hydrocarbons.

  13. Advanced lymphosarcoma treated by total body irradiation.

    PubMed Central

    Chaffey, J. T.; Rosenthal, D. S.; Pinkus, F.; Hellman, S.

    1975-01-01

    Twenty-five cases of clinical Stage III and Stage IV lymphosarcoma primarily treated by total body irradiation (TBI) are reported. Fifteen cases demonstrated nodular histology and 10 demonstrated diffuse histology by the Rappaport criteria. Treatments were 15 rad given twice weekly, calculated to midpelvis, to a total dose of 150 rad. Toxicity was confined to thrombocytopenia, one-third of patients requiring interruptions in the treatment course to allow platelet count recovery. Five patients had additional local irradiation. Complete responses were seen in 80% of patients and partial responses in 20%. Sixteen patients (64%) have been in continuous, unmaintained remission since treatments for variable periods to 39 months. Of 9 patients with clinically recurrent disease, 3 received further TBI and are in remission, 3 are in remission on chemotherapy, one patient has died, failing on all therapy, and 2 have not been treated. One patient died of pneumonia at 12 months, without clinical evidence of disease. Overall, actuarial survival is 87% at 2 years and compares well with survival in a sequential combination drug treated group of patients matched for age, sex, and histology, though differences are not statistically significant in these small groups. Total body irradiation is an effective systemic agent in the management of advanced lymphosarcoma and should be considered in treating this disease. PMID:810155

  14. Irradiation Environment of the Materials Test Station

    SciTech Connect

    Pitcher, Eric John

    2012-06-21

    Conceptual design of the proposed Materials Test Station (MTS) at the Los Alamos Neutron Science Center (LANSCE) is now complete. The principal mission is the irradiation testing of advanced fuels and materials for fast-spectrum nuclear reactor applications. The neutron spectrum in the fuel irradiation region of MTS is sufficiently close to that of fast reactor that MTS can match the fast reactor fuel centerline temperature and temperature profile across a fuel pellet. This is an important characteristic since temperature and temperature gradients drive many phenomena related to fuel performance, such as phase stability, stoichiometry, and fission product transport. The MTS irradiation environment is also suitable in many respects for fusion materials testing. In particular, the rate of helium production relative to atomic displacements at the peak flux position in MTS matches well that of fusion reactor first wall. Nuclear transmutation of the elemental composition of the fusion alloy EUROFER97 in MTS is similar to that expected in the first wall of a fusion reactor.

  15. Electron Irradiation of Interstellar Ice Analogues

    NASA Astrophysics Data System (ADS)

    Nair, B. G.; Mason, N. J.

    2011-05-01

    Molecular synthesis in the Universe primarily occurs in the icy mantles on dust grains in dense interstellar dust clouds. The interaction of photons, electrons and cosmic rays with these ice mantles triggers complex chemical synthesis leading to the formation of complex molecules. Such molecular reactions can only be understood by systematic laboratory studies. In our experiments astrophysical environments are recreated in the laboratory using an ultra high vacuum chamber (UHV) capable of reaching pressures of the order of 10 -10 mBar containing a liquid helium cryostat capable of attaining a temperature of 20 K. Ice films are deposited on a ZnSe substrate (cooled by cryostat) by background deposition and irradiated with electrons of 1KeV energy. Chemical changes induced by electron irradiation were monitored by an infrared spectrometer. By varying the temperature, we also investigate the temperature dependence on the kinetics of the reactions. In this poster we will present the first results of electron irradiation of simple organic molecules like formamide (HCONH2) and allyl alcohol (CH2CHCH2OH).

  16. Local brain heavy ion irradiation induced Immunosuppression

    NASA Astrophysics Data System (ADS)

    Lei, Runhong; Deng, Yulin; Huiyang Zhu, Bitlife.; Zhao, Tuo; Wang, Hailong; Yu, Yingqi; Ma, Hong; Wang, Xiao; Zhuang, Fengyuan; Qing, Hong

    Purpose: To investigate the long term effect of acute local brain heavy ion irradiation on the peripheral immune system in rat model. Methodology: Only the brain of adult male Wistar rats were radiated by heavy ions at the dose of 15 Gy. One, two and three months after irradiation, thymus and spleen were analyzed by four ways. Tunel assay was performed to evaluate the percentage of apoptotic cells in thymus and spleen, level of Inflammatory cytokines (IL-2, IL-6, SSAO, and TNF-α) was detected by ELISA assay, the differentiation of thymus T lymphocyte subsets were measured by flow cytometry and the relative expression levels of genes related to thymus immune cell development were measured by using quantitative real-time PCR. Results: Thymus and spleen showed significant atrophy from one month to three months after irradiation. A high level of apoptosis in thymus and spleen were obtained and the latter was more vulnerable, also, high level of inflammatory cytokines were found. Genes (c-kit, Rag1, Rag2 and Sca1) related to thymus lymphocytes’ development were down-regulated. Conclusion: Local area radiation in the rat brain would cause the immunosuppression, especially, the losing of cell-mediated immune functions. In this model, radiation caused inflammation and then induced apoptosis of cells in the immune organs, which contributed to immunosuppression.

  17. Irradiation response and stability of nanoporous materials

    SciTech Connect

    Fu, Engang; Wang, Yongqiang; Serrano De Caro, Magdalena; Caro, Jose A.; Zepeda-Ruiz, L; Bringa, E.; Nastasi, Mike; Baldwin, Jon K.

    2012-08-28

    Nanoporous materials consist of a regular organic or inorganic framework supporting a regular, porous structure. Pores are by definition roughly in the nanometre range, that is between 0.2 nm and 100 nm. Nanoporous materials can be subdivided into 3 categories (IUPAC): (1) Microporous materials - 0.2-2 nm; (2) Mesoporous materials - 2-50 nm; and (3) Macroporous materials - 50-1000 nm. np-Au foams were successfully synthesized by de-alloying process. np-Au foams remain porous structure after Ne ion irradiation to 1 dpa. Stacking Fault Tetrahedra (SFTs) were observed in RT irradiated np-Au foams under the highest and intermediate fluxes, but not under the lowest flux. SFTs were not observed in LNT irradiated np-Au foams under all fluxes. The vacancy diffusivity in Au at RT is high enough so that the vacancies have enough time to agglomerate and then collapse to form SFTs. The high ion flux creates more damage per unit time; vacancies don't have enough time to diffuse or recombine. As a result, SFTs were formed at high ion fluxes.

  18. Polyethylene terephthalate degradation under reactor neutron irradiation

    NASA Astrophysics Data System (ADS)

    Chikaoui, K.; Izerrouken, M.; Djebara, M.; Abdesselam, M.

    2017-01-01

    This paper is devoted to study the defects generated by reactor neutron in polyethylene terephthalate (PET) films. The explored fast neutron fluence ranges from 2.02×1016 to 2.07×1018 n cm-2. The induced damages were investigated using ultraviolet-visible spectrophotometry (UV-vis), Fourier Transform Infrared spectrometry (FTIR) and X-ray diffraction (XRD). The UV-vis spectra show important changes indicating the degradation of the chemical structure and the creation of new chromophores. FTIR spectra reveal that the intensities of the different absorption bands decrease linearly under fast neutron irradiation. The internal reference band at 1410 cm-1 is used to follow the overall damage during irradiation. The 1342 cm-1 band corresponding to CH2 wagging of trans conformation of crystalline phase show a sharpe linear decrease as the fast neutrons fluence goes up. The creation of the monosubstituted benzene, investigated using the 1610 cm-1 band. It shows a linear increase with fast neutron fluence. It is found from XRD analysis that the diffraction peak (100) intensity is drastically reduced after irradiation at 2.02×1016 n cm-2.

  19. Recycling of irradiated high-density polyethylene

    NASA Astrophysics Data System (ADS)

    Navratil, J.; Manas, M.; Mizera, A.; Bednarik, M.; Stanek, M.; Danek, M.

    2015-01-01

    Radiation crosslinking of high-density polyethylene (HDPE) is a well-recognized modification of improving basic material characteristics. This research paper deals with the utilization of electron beam irradiated HDPE (HDPEx) after the end of its lifetime. Powder of recycled HDPEx (irradiation dose 165 kGy) was used as a filler into powder of virgin low-density polyethylene (LDPE) in concentrations ranging from 10% to 60%. The effect of the filler on processability and mechanical behavior of the resulting mixtures was investigated. The results indicate that the processability, as well as mechanical behavior, highly depends on the amount of the filler. Melt flow index dropped from 13.7 to 0.8 g/10 min comparing the lowest and the highest concentration; however, the higher shear rate the lower difference between each concentration. Toughness and hardness, on the other hand, grew with increasing addition of the recycled HDPEx. Elastic modulus increased from 254 to 450 MPa and material hardness increased from 53 to 59 ShD. These results indicate resolving the problem of further recycling of irradiated polymer materials while taking advantage of the improved mechanical properties.

  20. Hydrogen retention in ion irradiated steels

    SciTech Connect

    Hunn, J.D.; Lewis, M.B.; Lee, E.H.

    1998-11-01

    In the future 1--5 MW Spallation Neutron Source, target radiation damage will be accompanied by high levels of hydrogen and helium transmutation products. The authors have recently carried out investigations using simultaneous Fe/He,H multiple-ion implantations into 316 LN stainless steel between 50 and 350 C to simulate the type of radiation damage expected in spallation neutron sources. Hydrogen and helium were injected at appropriate energy and rate, while displacement damage was introduced by nuclear stopping of 3.5 MeV Fe{sup +}, 1 {micro}m below the surface. Nanoindentation measurements showed a cumulative increase in hardness as a result of hydrogen and helium injection over and above the hardness increase due to the displacement damage alone. TEM investigation indicated the presence of small bubbles of the injected gases in the irradiated area. In the current experiment, the retention of hydrogen in irradiated steel was studied in order to better understand its contribution to the observed hardening. To achieve this, the deuterium isotope ({sup 2}H) was injected in place of natural hydrogen ({sup 1}H) during the implantation. Trapped deuterium was then profiled, at room temperature, using the high cross-section nuclear resonance reaction with {sup 3}He. Results showed a surprisingly high concentration of deuterium to be retained in the irradiated steel at low temperature, especially in the presence of helium. There is indication that hydrogen retention at spallation neutron source relevant target temperatures may reach as high as 10%.

  1. The spectral irradiance of the moon

    USGS Publications Warehouse

    Kieffer, H.H.; Stone, T.C.

    2005-01-01

    Images of the Moon at 32 wavelengths from 350 to 2450 nm have been obtained from a dedicated observatory during the bright half of each month over a period of several years. The ultimate goal is to develop a spectral radiance model of the Moon with an angular resolution and radiometric accuracy appropriate for calibration of Earth-orbiting spacecraft. An empirical model of irradiance has been developed that treats phase and libration explicitly, with absolute scale founded on the spectra of the star Vega and returned Apollo samples. A selected set of 190 standard stars are observed regularly to provide nightly extinction correction and long-term calibration of the observations. The extinction model is wavelength-coupled and based on the absorption coefficients of a number of gases and aerosols. The empirical irradiance model has the same form at each wavelength, with 18 coefficients, eight of which are constant across wavelength, for a total of 328 coefficients. Over 1000 lunar observations are fitted at each wavelength; the average residual is less than 1%. The irradiance model is actively being used in lunar calibration of several spacecraft instruments and can track sensor response changes at the 0.1% level. ?? 2005. The American Astronomical Society. All rights reserved.

  2. Blue LED irradiation to hydration of skin

    NASA Astrophysics Data System (ADS)

    Menezes, Priscila F. C.; Requena, Michelle B.; Lizarelli, Rosane F., Z.; Bagnato, Vanderlei S.

    2015-06-01

    Blue LED system irradiation shows many important properties on skin as: bacterial decontamination, degradation of endogenous skin chromophores and biostimulation. In this clinical study we prove that the blue light improves the skin hydration. In the literature none authors reports this biological property on skin. Then this study aims to discuss the role of blue light in the skin hydration. Twenty patients were selected to this study with age between 25-35 years old and phototype I, II and III. A defined area from forearm was pre determined (A = 4.0 cm2). The study was randomized in two treatment groups using one blue light device (power of 5.3mW and irradiance of 10.8mW/cm2). The first treatment group was irradiated with 3J/cm2 (277seconds) and the second with 6J/cm2 (555 seconds). The skin hydration evaluations were done using a corneometer. The measurements were collected in 7, 14, 21 and 30 days, during the treatment. Statistical test of ANOVA, Tukey and T-Student were applied considering 5% of significance. In conclusion, both doses were able to improve the skin hydration; however, 6J/cm2 has kept this hydration for 30 days.

  3. NOTE: Validation of blood product irradiation doses

    NASA Astrophysics Data System (ADS)

    Cheung, T.; Butson, M.; Yu, P. K. N.

    2001-10-01

    Dosimetry of blood irradiation using x-ray beams on a medical linear accelerator has been studied to evaluate the accuracy of a diode detector and the delivery achievable. Variations in applied doses for a standard dual field 6 MV x-ray are measured with a commercial diode detector. Results show that the diode detector measured applied in vitro doses to within 5.4% (2 standard deviations (2 SD)) of those calculated with a collapsed-cone convolution treatment-planning computer for a sample of 100 blood irradiations. Experiments involving the packing procedure of the blood products in the blood box were performed. It was found that a large proportion of the variation in the predicted and measured dose was due to the compacting of the scatter material at the base of the blood box (over a 6 month period) producing a higher density below the blood than originally scanned; hence an overall reduction of delivered dose was observed. The diode measurements (which provide an immediate printout) are recommended in conjunction with a film dosimeter such as radiochromic film, which still provides a back-up dose monitor and a visual reminder that the blood has been irradiated. It is also recommended that the blood box be completely evacuated of all scatter material every month and the base be carefully repacked to provide uniform scatter material.

  4. Validation of blood product irradiation doses.

    PubMed

    Cheung, T; Butson, M; Yu, P K

    2001-10-01

    Dosimetry of blood irradiation using x-ray beams on a medical linear accelerator has been studied to evaluate the accuracy of a diode detector and the delivery achievable. Variations in applied doses for a standard dual field 6 MV x-ray are measured with a commercial diode detector. Results show that the diode detector measured applied in vitro doses to within 5.4% (2 standard deviations (2 SD)) of those calculated with a collapsed-cone convolution treatment-planning computer for a sample of 100 blood irradiations. Experiments involving the packing procedure of the blood products in the blood box were performed. It was found that a large proportion of the variation in the predicted and measured dose was due to the compacting of the scatter material at the base of the blood box (over a 6 month period) producing a higher density below the blood than originally scanned; hence an overall reduction of delivered dose was observed. The diode measurements (which provide an immediate printout) are recommended in conjunction with a film dosimeter such as radiochromic film, which still provides a back-up dose monitor and a visual reminder that the blood has been irradiated. It is also recommended that the blood box be completely evacuated of all scatter material every month and the base be carefully repacked to provide uniform scatter material.

  5. Protein Quality of Irradiated Brazilian Beans

    NASA Astrophysics Data System (ADS)

    Delincée, Henry; Villavicencio, Anna-Lucia C. H.; Mancini-Filho, Jorge

    1998-06-01

    Beans are a major source of dietary protein in Brazil. However, high losses due to insect infestation occur after each harvest. To combat these losses, radiation processing of beans offers promise as an alternative to chemical treatment, provided the nutritional quality of beans is not impaired by the radiation treatment. Conflicting results have been published about the effect of radiation on the biological value of legume proteins. Therefore, two varieties of Brazilian beans were studied: 1) Phaseolus vulgaris L., var. carioca and 2) Vigna unguiculata (L.) Walp, var. macaçar. The beans were irradiated with doses of 0, 0.5, 1.0, 2.5, 5.0 and 10 kGy. Since irradiated beans will be consumed after appropriate storage, the beans under study were stored for 6 months at ambient temperature. Protein quality was measured by a biological assay employing the nitrogen balance approach in weanling rats. The animals were fed with optimally cooked beans, which were the only source of protein (˜10%). Nitrogen contents of legumes, diets, animal urine and faeces were determined by Kjeldahl analysis. The indices for apparent protein quality: net protein utilisation, digestibility and biological value were not influenced by irradiation. Thus, radiation treatment of Brazilian beans offers considerable promise as an effective insect disinfection process, without impairing the biological quality of the valuable bean protein.

  6. Upgrade to the Birmingham Irradiation Facility

    NASA Astrophysics Data System (ADS)

    Dervan, P.; French, R.; Hodgson, P.; Marin-Reyes, H.; Parker, K.; Wilson, J.; Baca, M.

    2015-10-01

    The Birmingham Irradiation Facility was developed in 2013 at the University of Birmingham using the Medical Physics MC40 cyclotron. It can achieve High Luminosity LHC (HL-LHC) fluences of 1015 (1 MeV neutron equivalent (neq)) cm-2 in 80 s with proton beam currents of 1 μA and so can evaluate effectively the performance and durability of detector technologies and new components to be used for the HL-LHC. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis Cartesian robot scanning system. In 2014 the cooling system and cold box were upgraded from a recirculating glycol chiller system to a liquid nitrogen evaporative system. The new cooling system achieves a stable temperature of -50 °C in 30 min and aims to maintain sub-0 °C temperatures on the sensors during irradiations. This paper reviews the design, development, commissioning and performance of the new cooling system.

  7. Hodgkin's disease: thyroid dysfunction following external irradiation

    SciTech Connect

    Tamura, K.; Shimaoka, K.

    1981-01-01

    The thyroid gland is commonly included in the field of radiation therapy for patients with malignant lymphoma and with head and neck tumors. The radiation dose for malignant diseases varies considerably depending on the purpose of treatment and the institutional policies. A substantial number of these patients are developing subclinical and clinical hypothyroidism. The risk of developing hypothyroidism after a moderate radiation dose of 2000 to 4500 rads has been reported to be 10 to 20 percent. In addition, subclinical hypothyroidism is induced further in one third of the patients. There are also suggestions that external irradiation of the thyroid gland in patients with malignant lymphomas, as well as internal irradiation with radioiodine of the normal and hyperthyroid human thyroid glands, would induce elevations of serum antithyroid autoantibody titers. However, only a few cases of Graves disease following irradiation to the thyroid gland have been reported. We encountered a young woman who received radiation therapy to the mantle field for her Hodgkin's disease and developed hypothyroxinemia without overt signs and symptoms of hypothyroidism, followed by appearance of nodular goiter and then full-blown Graves disease.

  8. Multivariate Analysis of Solar Spectral Irradiance Measurements

    NASA Technical Reports Server (NTRS)

    Pilewskie, P.; Rabbette, M.

    2001-01-01

    Principal component analysis is used to characterize approximately 7000 downwelling solar irradiance spectra retrieved at the Southern Great Plains site during an Atmospheric Radiation Measurement (ARM) shortwave intensive operating period. This analysis technique has proven to be very effective in reducing a large set of variables into a much smaller set of independent variables while retaining the information content. It is used to determine the minimum number of parameters necessary to characterize atmospheric spectral irradiance or the dimensionality of atmospheric variability. It was found that well over 99% of the spectral information was contained in the first six mutually orthogonal linear combinations of the observed variables (flux at various wavelengths). Rotation of the principal components was effective in separating various components by their independent physical influences. The majority of the variability in the downwelling solar irradiance (380-1000 nm) was explained by the following fundamental atmospheric parameters (in order of their importance): cloud scattering, water vapor absorption, molecular scattering, and ozone absorption. In contrast to what has been proposed as a resolution to a clear-sky absorption anomaly, no unexpected gaseous absorption signature was found in any of the significant components.

  9. Analyzing UV-B narrowband solar irradiance: comparison with erythemal and vitamin D production irradiances.

    PubMed

    Sola, Yolanda; Lorente, Jerónimo; Ossó, Albert

    2012-12-05

    The heliotherapy and the phototherapy are mainly focused on taking benefit of the therapeutic effects of the ultraviolet (UV) irradiance on different skin diseases. The use of UV-B narrowband lamps, with emissions centered at 311 nm, has spread out among the dermatologist community because of its high therapeutic effect in comparison with its low erythema dose. For cloudless sun exposure, the balance of solar erythemal and solar narrowband (NB)-equivalent irradiances depends on several factors such as the solar zenith angle (SZA), the total ozone column (TOC) and the altitude. For SZA below 55°, the ratio of solar UV-B narrowband and erythemal irradiances increases with the SZA whereas the ratio of vitamin D production and erythemal irradiances decreases with the SZA with the maximum around midday. Furthermore, the solar NB ratio also increases with the TOC because the shorter wavelengths of the erythemal action spectrum are more affected by the ozone absorption processes. Considering the daily variations of the ratio between narrowband and erythemal irradiance, sun exposures avoiding midday hours are recommended in order to prevent negative side-effects. However to accumulate great NB doses and sufficient vitamin D in winter months is difficult because the time exposures may be longer than the day duration.

  10. METAPHIX-1 non destructive post irradiation examinations in the irradiated elements cell at Phenix

    SciTech Connect

    Breton, Laurent; Masson, M.; Garces, E.; Desjardins, S.; Fontaine, B.; Lacroix, B.; Martella, T.; Loubet, L.; Ohta, H.; Yokoo, T.; Ougier, M.; Glatz, J.P.

    2007-07-01

    Central Research Institute of Electric Power Industry (CRIEPI) has been developing minor actinide (MA) transmutation technology in homogeneous loading mode by use of metal fuel fast reactors in cooperation with Institute for Transuranium Elements (ITU) and Commissariat a l'Energie Atomique (CEA). Fast reactor metal fuel pins of Uranium- Plutonium-Zirconium (U-Pu-Zr) alloy containing 2 wt% MAs and 2 wt% rare earth elements (REs), 5 wt% MAs, and 5 wt% MAs and 5 wt% REs were irradiated in the PHENIX French fast reactor as METAPHIX experiments. In these METAPHIX experiments, three rigs each consisting of three metal fuel experimental pins and sixteen oxide fuel driver pins were irradiated. The target burnup of the three rigs is 2.4 at%, 7 at% and 11 at% which corresponds to 120, 360 and 600 equivalent full power days (EFPD) in terms of irradiation periods, respectively. The low burnup rig of 2.4 at%, METAPHIX-1, was discharged from the core in August 2004. After cooling, the non-destructive post irradiation examinations (PIEs) of the rig (visual examination, measurement of rig length and deformation) and of the metal fuel pins (visual examination, measurement of pin length and deformation, {gamma}-spectrometry and neutron radiography) were conducted in the Irradiated Elements Cell (IEC) at PHENIX. (authors)

  11. Plant responses to UV-B irradiation are modified by UV-A irradiation

    SciTech Connect

    Middleton, E.M.; Teramura, A.H. Univ. of Maryland, College Park )

    1993-06-01

    The increasing UV-B radiation (0.28-0.32 [mu]m) reaching the earth's surface is an important concern. Plant response in artificial UV-B irradiation studies has been difficult to assess, especially regarding photosynthetic pigments, because the fluorescent lamps also produce UV-A (0.32-0.40[mu]m) radiation which is involved with blue light in pigment synthesis. Both UV-A and UV-B irradiances were controlled in two glasshouse experiments conducted under relatively high PPFD (> 1300[mu]mol m[sup [minus]2] s[sup [minus]1]) at two biologically effective daily UV-B irradiances (10.7 and 14.1 kJ m[sup [minus]2]); UV-A irradiances were matched in Controls ([approximately]5, 9 kJ m[sup [minus]2]). Normal, chlorophyll-deficient, and flavonoid-deficient isolines of soybean cultivar, Clark, were utilized. Many growth/ pigment variables exhibited a statistically significant interaction between light quality and quantity: in general, UV-A radiation moderated the damaging effects of UV-B radiation. Regression analyses demonstrated that a single negative function related photosynthetic efficiency to carotenoid Content (r[sup 2] =0.73, P[le]0.001), implying a [open quotes]cost[close quotes] in maintaining carotenoids for photoprotection. A stomatal limitation to photosynthesis was verified and carotenoid content was correlated with UV-B absorbing compound levels, in UV-B irradiated plants.

  12. Survival after total body irradiation: Effects of irradiation of exteriorized small intestine. (Reannouncement with new availability information)

    SciTech Connect

    Vriesendorp, H.M.; Vigneulle, R.M.; Kitto, G.; Pelky, T.; Taylor, P.

    1993-12-31

    Rats receiving lethal irradiation to their exteriorized small intestine with pulsed 18 MVp bremsstrahlung radiation live about 4 days longer than rats receiving a dose of total-body irradiation (TBI) causing intestinal death. The LD50 for intestinal irradiation is approximately 6 Gy higher than the LD50 for intestinal death after TBI. Survival time after exteriorized intestinal irradiation can be decreased, by adding abdominal irradiation. Adding thoracic or pelvic irradiation does not alter survival time. Shielding of large intestine improves survival after irradiation of the rest of the abdomen while the small intestine is also shielded. The kinetics of histological changes in small intestinal tissues implicate the release of humoral factors after irradiation of the abdomen. Radiation injury develops faster in the first (proximal) 40 cm of the small intestine and is expressed predominantly as shortening in villus height. In the last (distal) 40 cm of the small intestine, the most pronounced radiation effect is a decrease in the number of crypts per millimeter. Irradiation (20 Gy) of the proximal small intestine causes 92 % mortality (median survival 10 days). Irradiation (20 Gy) of the distal small intestine causes 27% mortality (median survival > 30 days). In addition to depletion of crypt stem cells in the small intestine, other issues (humoral factors, irradiated subsection of the small intestine and shielding of the large intestine) appear to influence radiation-induced intestinal mortality.

  13. Methods for routine control of irradiated food: Determination of the irradiation status of shellfish by thermoluminescence analysis

    NASA Astrophysics Data System (ADS)

    Schreiber, G. A.; Hoffmann, A.; Helle, N.; Bögl, K. W.

    1994-06-01

    In some countries, clearance has been given for treating certain types of shellfish by ionizing radiation in order to increase the shelf-life and to reduce health hazards which might be caused by contaminating microorganisms. In the present study, thermoluminescence (TL) analysis was used to examine the irradiation status of shellfish products purchased from local suppliers. For analysis minerals were isolated from the guts of the animals. Although on none of the examined products an irradiation treatment prior to analysis could be shown, the results obtained on non-irradiated and irradiated products have revealed that irradiation within the commercially used dose range can clearly be detected. Already first glow TL intensities of minerald indicated irradiation treatments. Normalized TL signals of non-irradiated and irradiated samples were clearly separated. By calculation of differences of TL intensities and TL signals between non-irradiated and irradiated samples in dependency of integration temperature an optimized integration area for glow curves was determined. The result of this study agree well with results obtained by two large-scale intercomparisons between food control laboratories to detect irradiation treatment of spices and herbal products as well as of fruit and vegetables by TL analysis of contaminating minerals.

  14. The spectral irradiance traceability chain at PTB

    SciTech Connect

    Sperfeld, P.; Pape, S.; Nevas, S.

    2013-05-10

    Spectral irradiance is a fundamental radiometric unit. Its application to measurement results requires qualified traceability to basic units of the international system of units (Systeme international d'unites, SI). The Physikalisch-Technische Bundesanstalt (PTB) is amongst other national metrological institutes (NMIs) responsible for the realization, maintenance and dissemination of various radiometric and photometric units based on and traceable to national standards. The unit of spectral irradiance is realized and represented by a blackbody-radiator as the national primary standard of the PTB. Based on Planck's radiation law, the irradiance is calculated and realized for any wavelength taking into account the exact knowledge of the radiation temperature and the geometrical parameters. Using a double-monochromator-based spectroradiometer system, secondary standard lamps can be calibrated by direct comparison to the blackbody-radiator (substitution method). These secondary standard lamps are then used at the PTB to calibrate standard lamps of customers. The customers themselves use these so-called transfer standards to calibrate their working standard lamps. These working standards are then used to calibrate own spectroradiometers or sources. This rather complex calibration chain is a common procedural method that for the customers generally leads to satisfying measurement results on site. Nevertheless, the standard lamps in use have to fulfill highest requirements concerning stability and reproducibility. Only this allows achieving comparably low transfer measurement uncertainties, which occur at each calibration step. Thus, the PTB is constantly investigating the improvement and further development of transfer standards and measurement methods for various spectral regions. The realization and dissemination of the spectral irradiance using the blackbody-radiator at the PTB is accomplished with worldwide approved minimized measurement uncertainties confirmed by

  15. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS

    SciTech Connect

    Clark, E.

    2011-09-22

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Polymeric materials become damaged by exposure over time to ionizing radiation. Despite the limited lifetime, polymers have unique engineering material properties and polymers continue to be used in tritium handling systems. In tritium handling systems, polymers are employed mainly in joining applications such as valve sealing surfaces (eg. Stem tips, valve packing, and O-rings). Because of the continued need to employ polymers in tritium systems, over the past several years, programs at the Savannah River National Laboratory have been studying the effect of tritium on various polymers of interest. In these studies, samples of materials of interest to the SRS Tritium Facilities (ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, Teflon{reg_sign}), Vespel{reg_sign} polyimide, and the elastomer

  16. The spectral irradiance traceability chain at PTB

    NASA Astrophysics Data System (ADS)

    Sperfeld, P.; Pape, S.; Nevas, S.

    2013-05-01

    Spectral irradiance is a fundamental radiometric unit. Its application to measurement results requires qualified traceability to basic units of the international system of units (Système international d'unités, SI). The Physikalisch-Technische Bundesanstalt (PTB) is amongst other national metrological institutes (NMIs) responsible for the realization, maintenance and dissemination of various radiometric and photometric units based on and traceable to national standards. The unit of spectral irradiance is realized and represented by a blackbody-radiator as the national primary standard of the PTB. Based on Planck's radiation law, the irradiance is calculated and realized for any wavelength taking into account the exact knowledge of the radiation temperature and the geometrical parameters. Using a double-monochromator-based spectroradiometer system, secondary standard lamps can be calibrated by direct comparison to the blackbody-radiator (substitution method). These secondary standard lamps are then used at the PTB to calibrate standard lamps of customers. The customers themselves use these so-called transfer standards to calibrate their working standard lamps. These working standards are then used to calibrate own spectroradiometers or sources. This rather complex calibration chain is a common procedural method that for the customers generally leads to satisfying measurement results on site. Nevertheless, the standard lamps in use have to fulfill highest requirements concerning stability and reproducibility. Only this allows achieving comparably low transfer measurement uncertainties, which occur at each calibration step. Thus, the PTB is constantly investigating the improvement and further development of transfer standards and measurement methods for various spectral regions. The realization and dissemination of the spectral irradiance using the blackbody-radiator at the PTB is accomplished with worldwide approved minimized measurement uncertainties confirmed by

  17. Evaluation of various procedures transposing global tilted irradiance to horizontal surface irradiance

    NASA Astrophysics Data System (ADS)

    Housmans, Caroline; Bertrand, Cédric

    2017-02-01

    Many transposition models have been proposed in the literature to convert solar irradiance on the horizontal plane to that on a tilted plane. The inverse process, i.e. the conversion from tilted to horizontal is investigated here based upon seven months of in-plane global solar irradiance measurements recorded on the roof of the Royal Meteorological Institute of Belgium's radiation tower in Uccle (Longitude 4.35° E, Latitude 50.79° N). Up to three pyranometers mounted on inclined planes of different tilts and orientations were involved in the inverse transposition process. Our results indicate that (1) the tilt to horizontal irradiance conversion is improved when measurements from more than one tilted pyranometer are considered (i.e. by using a multi-pyranometer approach) and (2) the improvement from using an isotropic model to anisotropic models in the inverse transposition problem is not significant.

  18. Preliminary analysis of irradiation effects on CLAM after low dose neutron irradiation

    NASA Astrophysics Data System (ADS)

    Peng, Lei; Huang, Qunying; Li, Chunjing; Liu, Shaojun

    2009-04-01

    To investigate the irradiation effects on a new version of reduced activation ferritic/martensitic steels (RAFMs) i.e. China Low Activation Martensitic steel (CLAM), neutron irradiation experiments has been being carried out under wide collaboration in China and overseas. In this paper, the mechanical properties of CLAM heats 0603A, 0408B, and 0408D were investigated before and after neutron irradiation to ˜0.02 dpa at 250 °C. The test results showed that ultimate strength and yield stress of CLAM HEAT 0603A increased about 10-30 MPa and ductile to brittle transition temperature (DBTT) shift was about 5 °C. For CLAM heats 0408B and 0408D, ultimate strength and yield stress increased about 80-150 MPa.

  19. Gamma irradiation treatment of cereal grains for chick diets

    SciTech Connect

    Campbell, G.L.; Classen, H.L.; Ballance, G.M.

    1986-04-01

    Wheat (W), triticale (T), hulled barley (HB), hull-less barley (HLB), hulled oats (HO), and hull-less oats (HLO) were gamma irradiated (/sup 60/Co) at 0, 3, 6 and 9 Mrad to study the effect of irradiation on the nutritional value of cereal grains for chicks. A significant curvilinear relationship between radiation dose and 3-wk body weight of chicks fed irradiated cereals was noted for T, HB, HLB, HO and HLO. Chicks fed W or T showed no effect or lower body weight, respectively, while body weights of chicks fed barley or oat samples were higher with irradiation. The improvement tended to be maximal at the 6 Mrad level. Irradiation significantly improved the gain-to-feed ratio for chicks fed either HO or HLO. Apparent fat retention and tibia ash were higher in chicks fed irradiated HLO than in those fed untreated HLO. In a second experiment chick body weight, apparent amino acid and fat retention, tibia ash, and gain-to-feed ratios were lower in chicks fed autoclaved (121 degrees C for 20 min) barley than in those fed untreated barley. Irradiation (6 Mrad) subsequent to autoclaving barley samples eliminated these effects. Irradiation appears to benefit cereals containing soluble or mucilagenous fiber types as typified by beta-glucan of barley and oats. These fibers appear prone to irradiation-induced depolymerization, as suggested by increased beta-glucan solubility and reduced extract viscosity for irradiated barley and oat samples.

  20. Physicochemical and sensory properties of irradiated dry-cured ham

    NASA Astrophysics Data System (ADS)

    Jin, Sang-Keun; Kim, Chul-Wook; Chung, Ki-Hwa; Jo, Kwang-Keun; Jeong, Jin-Yeon; Hur, In-Chul; Jung, Eun-Young; Joo, Seon-Tea; Yang, Han-Sul

    2012-02-01

    To determine the effect of different irradiation doses on ready-to-eat (RTE) dry-cured shoulder hams, physicochemical and sensory attributes were analyzed during 8 weeks of refrigerated storage. The results show that irradiation reduced the redness value and increased the 2-thiobarbituric acid-reactive substance (TBARS) value as well as the irradiation aroma during storage. However, ham samples irradiated with 2.5 and 5.0 kGy did not show significant changes in lightness values compared to the control sample during 8 weeks of storage. TBARS values were lower in the sample irradiated with 2.5 kGy than in the other irradiated samples. The total plate counts of the 5.0 kGy-irradiated samples were not measured after 0 weeks. Sensory panels found that the 2.5- and 5.0 kGy-irradiated samples had better overall acceptability scores than the other irradiated samples. It was concluded that treatments with lower levels of irradiation (≤5.0 kGy) can enhance the microbial safety and sensory acceptance of dry-cured shoulder hams.

  1. Evaluation of Neutron Irradiated Silicon Carbide and Silicon Carbide Composites

    SciTech Connect

    Newsome G, Snead L, Hinoki T, Katoh Y, Peters D

    2007-03-26

    The effects of fast neutron irradiation on SiC and SiC composites have been studied. The materials used were chemical vapor deposition (CVD) SiC and SiC/SiC composites reinforced with either Hi-Nicalon{trademark} Type-S, Hi-Nicalon{trademark} or Sylramic{trademark} fibers fabricated by chemical vapor infiltration. Statistically significant numbers of flexural samples were irradiated up to 4.6 x 10{sup 25} n/m{sup 2} (E>0.1 MeV) at 300, 500 and 800 C in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Dimensions and weights of the flexural bars were measured before and after the neutron irradiation. Mechanical properties were evaluated by four point flexural testing. Volume increase was seen for all bend bars following neutron irradiation. Magnitude of swelling depended on irradiation temperature and material, while it was nearly independent of irradiation fluence over the fluence range studied. Flexural strength of CVD SiC increased following irradiation depending on irradiation temperature. Over the temperature range studied, no significant degradation in mechanical properties was seen for composites fabricated with Hi-Nicalon{trademark} Type-S, while composites reinforced with Hi-Nicalon{trademark} or Sylramic fibers showed significant degradation. The effects of irradiation on the Weibull failure statistics are also presented suggesting a reduction in the Weibull modulus upon irradiation. The cause of this potential reduction is not known.

  2. Effect of Electron Beam Irradiation on Tensile Strength of Polypropylene

    NASA Astrophysics Data System (ADS)

    Yamada, Hiroshi; Ikeda, Masayuki; Shimbo, Minoru; Miyano, Yasushi

    In this paper, the effects of the intensity of electron beam and the variation with time after irradiation of electron beam on the tensile strength of the polypropylene (PP), which is widely used as medicine containers, were investigated. PP with and without colorants were used first and samples irradiated under various intensity of EB. A tensile test on the irradiated samples with elapsed time after the irradiation of the electron beam was carried out. The effects of those factors on the tensile strength were discussed. The following results were obtained (1) The tensile strength of PP decreased due to the influence of the electron beam irradiation, however the rate of the decrease in strength was small compared with the original one. Furthermore, the rate of the decrease in strength was very small owing to the variation with time after the EB irradiation. (2) The tensile rupture strength of PP increased and the rupture strain owing to the influence of the electron beam irradiation compared with the original one. In addition, these rupture strength increased and the rupture strain decreased along with time after the irradiation of the electron beam. (3) The tensile rupture strain energy of PP decreased owing to the influence of the electron beam irradiation compared with the original one. In addition, the strain energy decreases with time after the irradiation of the electron beam. Moreover, the strength characteristics of PP with colorants received greater influence of electron beam compared with the one without colorants.

  3. Bystander responses in low dose irradiated cells treated with plasma from gamma irradiated blood

    NASA Astrophysics Data System (ADS)

    Acheva, A.; Georgieva, R.; Rupova, I.; Boteva, R.; Lyng, F.

    2008-02-01

    There are two specific low-dose radiation-induced responses that have been the focus of radiobiologists' interest in recent years. These are the bystander effect in non-irradiated cells and the adaptive response to a challenge dose after prior low dose irradiation. In the present study we have investigated if plasma from irradiated blood can act as a 'challenge dose' on low dose irradiated reporter epithelial cells (HaCaT cell line). The main aim was to evaluate the overall effect of low dose irradiation (0.05 Gy) of reporter cells and the influence of bystander factors in plasma from 0.5 Gy gamma irradiated blood on these cells. The effects were estimated by clonogenic survival of the reporter cells. We also investigated the involvement of reactive oxygen species (ROS) as potential factors involved in the bystander signaling. Calcium fluxes and mitochondrial membrane potential (MMP) depolarization were also examined as a marker for initiation of apoptosis in the reporter cells. The results show that there are large individual differences in the production of bystander effects and adaptive responses between different donors. These may be due to the specific composition of the donor plasma. The observed effects generally could be divided into two groups: adaptive responses and additive effects. ROS appeared to be involved in the responses of the low dose pretreated reporter cells. In all cases there was a significant decrease in MMP which may be an early event in the apoptotic process. Calcium signaling also appeared to be involved in triggering apoptosis in the low dose pretreated reporter cells. The heterogeneity of the bystander responses makes them difficult to be modulated for medical uses. Specific plasma characteristics that cause these large differences in the responses would need to be identified to make them useful for radiotherapy.

  4. Effect of gamma irradiation on Korean traditional multicolored paintwork

    NASA Astrophysics Data System (ADS)

    Yoon, Minchul; Kim, Dae-Woon; Choi, Jong-il; Chung, Yong-Jae; Kang, Dai-Ill; Hoon Kim, Gwang; Son, Kwang-Tae; Park, Hae-Jun; Lee, Ju-Woon

    2015-10-01

    Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d'Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.

  5. Post-irradiation-examination of irradiated fuel outside the hot cell

    SciTech Connect

    Dawn E. Janney; Adam B. Robinson; Thomas P. O'Holleran; R. Paul Lind; Marc Babcock; Laurence C. Brower; Julie Jacobs; Pamela K. Hoggan

    2007-09-01

    Because of their high radioactivity, irradiated fuels are commonly examined in a hot cell. However, the Idaho National Laboratory (INL) has recently investigated irradiated U-Mo-Al metallic fuel from the Reduced Enrichment for Research and Test Reactors (RERTR) project using a conventional unshielded scanning electron microscope outside a hot cell. This examination was possible because of a two-step sample-preparation approach in which a small volume of fuel was isolated in a hot cell and shielding was introduced during later stages of sample preparation. The resulting sample contained numerous sample-preparation artifacts but allowed analysis of microstructures from selected areas.

  6. Development of microstructure and irradiation hardening of Zircaloy during low dose neutron irradiation at nominally 358 C

    SciTech Connect

    Cockeram, Brian V; Smith, Richard W; Leonard, Keith J; Byun, Thak Sang; Snead, Lance Lewis

    2011-01-01

    Wrought Zircaloy-2 and Zircaloy-4 were neutron irradiated at nominally 358 C in the high flux isotope reactor (HFIR) at relatively low neutron fluences between 5.8 1022 and 2.9 1025 n/m2 (E > 1 MeV). The irradiation hardening and change in microstructure were characterized following irradiation using tensile testing and examinations of microstructure using Analytical Electron Microscopy (AEM). Small increments of dose (0.0058, 0.11, 0.55, 1.08, and 2.93 1025 n/m2) were used in the range where the saturation of irradiation hardening is typically observed so that the role of microstructure evolution and hai loop formation on irradiation hardening could be correlated. An incubation dose between 5.8 1023 and 1.1 1024 n/m2 was needed for loop nucleation to occur that resulted in irradiation hardening. Increases in yield strength were consistent with previous results in this temperature regime, and as expected less irradiation hardening and lower hai loop number density values than those generally reported in literature for irradiations at 260 326 C were observed. Unlike previous lower temperature data, there is evidence in this study that the irradiation hardening can decrease with dose over certain ranges of fluence. Irradiation induced voids were observed in very low numbers in the Zircaloy-2 materials at the highest fluence.

  7. Formation of hazardous by-products resulting from the irradiation of natural organic matter: comparison between UV and VUV irradiation.

    PubMed

    Buchanan, W; Roddick, F; Porter, N

    2006-05-01

    The use of ultraviolet (UV) or vacuum ultraviolet (VUV) photo-oxidation followed by biological treatment for the removal of natural organic matter (NOM) in drinking water is a potential water treatment technique under investigation. This paper reports on the trihalomethane formation potential (THMFP), the haloacetic acid formation potential (HAAFP), and formation of nitrite and peroxide following both UV and VUV irradiation of NOM prior to biological treatment. The total THMFP was found to decrease with increasing UV and VUV irradiation dose, although there was a linear increase in bromoform formation. Determination of the THMFP of NOM fractions obtained after irradiation, showed that the hydrophobic fraction was dominated by chlorinated species which accounted for the majority of the total THMFP, while bromoform was observed only in the hydrophilic fraction of NOM. VUV irradiation reduced the HAAFP with increasing dose, in contrast, UV irradiation had a limited effect on the overall HAAFP. Following UV or VUV irradiation, the chlorinated species accounted for the majority of HAAFP; however, significant formation of brominated haloacetic acid (HAA) was observed. The nitrate concentration of the untreated water directly influenced the concentration of nitrite produced as a consequence of UV and VUV irradiation. Hydrogen peroxide formation was greater during VUV irradiation than during UV irradiation. Samples exposed to various doses of UV or VUV irradiation (up to 138 J cm(-2)) were deemed non-cytotoxic (African green monkey kidney cells) and non-mutagenic (Ames test).

  8. NANOSTRUCTURE PATTERNING UNDER ENERGETIC PARTICLE BEAM IRRADIATION

    SciTech Connect

    Wang, Lumin; Lu, Wei

    2013-01-31

    Energetic ion bombardment can lead to the development of complex and diverse nanostructures on or beneath the material surface through induced self-organization processes. These self-organized structures have received particular interest recently as promising candidates as simple, inexpensive, and large area patterns, whose optical, electronic and magnetic properties are different from those in the bulk materials [1-5]. Compared to the low mass efficiency production rate of lithographic methods, these self-organized approaches display new routes for the fabrication of nanostructures over large areas in a short processing time at the nanoscale, beyond the limits of lithography [1,4]. Although it is believed that surface nanostructure formation is based on the morphological instability of the sputtered surface, driven by a kinetic balance between roughening and smoothing actions [6,7], the fundamental mechanisms and experimental conditions for the formation of these nanostructures has still not been well established, the formation of the 3-D naopatterns beneath the irradiated surface especially needs more exploration. During the last funding period, we have focused our efforts on irradiation-induced nanostructures in a broad range of materials. These structures have been studied primarily through in situ electron microscopy during electron or ion irradiation. In particular, we have performed studies on 3-D void/bubble lattices (in metals and CaF2), embedded sponge-like porous structure with uniform nanofibers in irradiated semiconductors (Ge, GaSb, and InSb), 2-D highly ordered pattern of nanodroplets (on the surface of GaAs), hexagonally ordered nanoholes (on the surface of Ge), and 1-D highly ordered ripple and periodic arrays (of Cu nanoparticles) [3,8-11]. The amazing common feature in those nanopatterns is the uniformity of the size of nanoelements (nanoripples, nanodots, nanovoids or nanofibers) and the distance separating them. Our research focuses on the

  9. Physicochemical and structural characteristics of rice starch modified by irradiation.

    PubMed

    Polesi, Luís Fernando; Sarmento, Silene Bruder Silveira; Moraes, Jaqueline de; Franco, Célia Maria Landi; Canniatti-Brazaca, Solange Guidolin

    2016-01-15

    This work evaluated the physicochemical and structural properties of rice starch of the cultivars IAC 202 and IRGA 417 modified by irradiation. Starch samples were irradiated by (60)Co in doses 1, 2 and 5kGy, on a rate of 0.4kGy/h. A control not irradiated was used for comparison. The granule morphology and A-type X-ray diffraction pattern were not altered by irradiation. There was an increase in amylose content, carboxyl content and acidity with irradiation. Gamma radiation did not affect the thermal properties of IAC202, but increased gelatinization temperature of IRGA417, in the higher dose (5kGy). The number of long chains of amylopectin was reduced and short chains were increased for IAC202, whereas for IRGA 417, the opposite was observed, probably due to cross-linking of starch chains. Starches had their physicochemical and structural properties modified by irradiation differently.

  10. Safety evaluation of irradiated foods in China: A condensed report

    SciTech Connect

    Yin, D. )

    1989-03-01

    Eight trials, with 439 human volunteers who consumed irradiated foods including rice, potatoes, mushrooms, peanuts, and Chinese sausages, as well as diets composed of multiple irradiated foods (irradiated at dosages of 0.2 to 8 kGy) that accounted for 60-66% of the entire diet, were carried out for 2-3 months according to a unified protocol. No adverse effects on body weight, blood pressure, ECG, hematology, blood enzyme activities, serum lipids or blood or urine 17-hydroxycortisol contents and no chromosomal aberration of peripheral blood lymphocytes were found. It is especially worthwhile to note that there was no change in the polyploidy after consumption of irradiated diets. On the basis of these results and a comprehensive analysis of the physical and chemical characteristics of irradiated foods, temporary hygienic standards for irradiated rice, potatoes, onions, garlic, Chinese sausages, peanuts, and mushrooms were promulgated by the Chinese Ministry of Public Health.

  11. Spectral properties of ion irradiated carbon rich solids

    NASA Astrophysics Data System (ADS)

    Strazzulla, G.; Baratta, G.; Brunetto, R.; Garozzo, M.; Kanuchova, Z.

    2009-04-01

    Carbon rich solid materials have been studied before, during, and after ion irradiation (3-400 keV ions) by in situ reflectance spectroscopy (from UV to IR). Frozen hydrocarbons (benzene, methane, butane, acetylene, etc., also mixed with water ice) have been irradiated at low temperature with fast ions. Irradiation causes the formation of many molecular species and of a long chain polymer like material (organic refractory residue). The process mimics what occurs in space because of cosmic ion irradiation of the icy surfaces of some objects in the Solar System. Other irradiated materials include natural bitumens (Asphaltite, kerite) and polymers (i.e. polystyrene). Upon irradiation the originally transparent polymer samples are converted in a material that, already at low doses, strongly absorbs in the UV. Such materials could mimic a kind of organic material (i.e. a spectrally neutral one) freshly exposed at the surface of minor objects in the Solar System because of meteoritic impact.

  12. Solar irradiance measurements - Minimum through maximum solar activity

    NASA Technical Reports Server (NTRS)

    Lee, R. B., III; Gibson, M. A.; Shivakumar, N.; Wilson, R.; Kyle, H. L.; Mecherikunnel, A. T.

    1991-01-01

    The Earth Radiation Budget Satellite (ERBS) and the NOAA-9 spacecraft solar monitors were used to measure the total solar irradiance during the period October 1984 to December 1989. Decreasing trends in the irradiance measurements were observed as sunspot activity decreased to minimum levels in 1986; after 1986, increasing trends were observed as sunspot activity increased. The magnitude of the irradiance variability was found to be approximately 0.1 percent between sunspot minimum and maximum (late 1989). When compared with the 1984 to 1989 indices of solar magnetic activity, the irradiance trends appear to be in phase with the 11-year sunspot cycle. Both irradiance series yielded 1,365/sq Wm as the mean value of the solar irradiance, normalized to the mean earth/sun distance. The monitors are electrical substitution, active-cavity radiometers with estimated measurement precisions and accuracies of less than 0.02 and 0.2 percent, respectively.

  13. Performance of single crystalline silicon solar cell with irradiance

    NASA Astrophysics Data System (ADS)

    Chander, Subhash; Purohit, A.; Nehra, Anshu; Nehra, S. P.; Dhaka, M. S.

    2015-06-01

    In this paper, the effect of irradiance on the performance parameters of single crystalline silicon solar cell is undertaken. The experiment was carried out employing solar cell simulator with varying irradiance in the range 115-550W/m2 at constant cell temperature 25°C. The results show that the short circuit current is found to be increased linearly with irradiance and the open circuit voltage is increased slightly. The fill factor, maximum power and cell efficiency are also found to be increased with irradiance. The efficiency is increased linearly at lower irradiance while slightly increased at higher. The results revealed that the irradiance has a dominant effect on the performance parameters. The results are in good agreement with the available literature.

  14. Commercialization of food irradiation in the U.S.A.

    NASA Astrophysics Data System (ADS)

    Cottee, Jim; Kunstadt, Peter; Fraser, Frank

    1995-02-01

    Commercializing food irradiation in the United States has been a major marketing and business challenge. This paper begins by examining the situation before America's first food irradiator was established, in 1992. With the Vindicator irradiator in place, beneficial changes and market offerings took place, amidst perceived activist threats and disinterest from the food industry. Initial efforts to market irradiated foods were made by independents in the food business, as part of their attempts to differentiate themselves from large food companies and grocery chains. Special tactics were needed to launch products into sensitive and fearful market-places. The brisk sales of irradiated foods in small, initial markets, has been an unexpected success. This paper discusses the methods used to promote positive awareness of irradiated foods nationally, building on small local successes.

  15. Up-to-date status of food irradiation

    NASA Astrophysics Data System (ADS)

    Ahmed, Mainuddin

    1993-07-01

    The last decade has witnessed significant advancement of the acceptance of food irradiation processing. At present 37 countries have approved one or more food items for human consumption and 25 countries have commercialized this process. More developing countries are showing keen interest to introduce irradiation processing in order to reduce post-harvest food losses, to increase export potentials and to ensure safety of food to their people. Although progress towards acceptance of food irradiation by the industry is slow, actual market trials have shown that once consumers have understood this technology, they are willing to buy irradiated foods. This paper deals with the latest developments in the field of food irradiation with particular reference to legislation, consumer acceptance, commercialization and potential application in developing countries. This paper also deals with the role played by the International Organizations, aimed at facilitating the acceptance of food irradiation.

  16. Antioxidant Approaches to Management of Ionizing Irradiation Injury

    PubMed Central

    Greenberger, Joel; Kagan, Valerian; Bayir, Hulya; Wipf, Peter; Epperly, Michael

    2015-01-01

    Ionizing irradiation induces acute and chronic injury to tissues and organs. Applications of antioxidant therapies for the management of ionizing irradiation injury fall into three categories: (1) radiation counter measures against total or partial body irradiation; (2) normal tissue protection against acute organ specific ionizing irradiation injury; and (3) prevention of chronic/late radiation tissue and organ injury. The development of antioxidant therapies to ameliorate ionizing irradiation injury began with initial studies on gene therapy using Manganese Superoxide Dismutase (MnSOD) transgene approaches and evolved into applications of small molecule radiation protectors and mitigators. The understanding of the multiple steps in ionizing radiation-induced cellular, tissue, and organ injury, as well as total body effects is required to optimize the use of antioxidant therapies, and to sequence such approaches with targeted therapies for the multiple steps in the irradiation damage response. PMID:26785339

  17. Modeling and prediction of irradiation assisted stress corrosion cracking

    SciTech Connect

    Andresen, P.L.; Ford, F.P.

    1995-12-31

    Following an introduction to the phenomenology and consequences of irradiation assisted stress corrosion cracking (IASCC), the many common aspects of SCC response in unirradiated and irradiated environments is reviewed. From a secure basis of understanding and predictive modeling under unirradiated conditions, the effects of individual irradiation phenomena are identified and modeled. The individual effects of radiation on segregation, creep/stress relaxation, hardening, and radiolytic water chemistry are modeled based on the best available data, some from proprietary sources. Critical issues are addressed, such as the possibility that radiation produces very high corrosion potentials in crevices/cracks under irradiated conditions. A wide variety of irradiated laboratory data and field observations provides a basis for comparison with prediction and an optimism that, despite an imperfect understanding of irradiation phenomena, it is possible to develop predictive algorithms that characterize IASCC with reasonable accuracy and, from that, to develop an effective approach for life prediction.

  18. Thermal analysis of the FSP-1RR irradiation test

    SciTech Connect

    Webb, R.H.; Lyon, W.F. III

    1992-10-14

    The thermal analysis of four unirradiated fuel pins to be tested in the FSP-1RR fuels irradiation experiment was completed. This test is a follow-on experiment in the series of fuel pin irradiation tests conducted by the SP-100 Program in the Fast Flux Test Facility. One of the pins contains several meltwire temperature monitors within the fuel and the Li annulus. A post-irradiation examination will verify the accuracy of the pre-irradiation thermal analysis. The purpose of the pre-irradiation analysis was to determine the appropriate insulating gap gas compositions required to provide the design goal cladding operating temperatures and to ensure that the meltwire temperature ranges in the temperature monitored pin bracket peak irradiation temperatures. This paper discusses the methodology and summarizes the results of the analysis.

  19. Thermal analysis of the FSP-1RR irradiation test

    SciTech Connect

    Webb, R.H.; Lyon, W.F. III )

    1993-01-10

    The thermal analysis of four unirradiated fuel pins to be tested in the FSP-1RR fuels irradiation experiment was completed. This test is a follow-on experiment in the series of fuel pin irradiation tests conducted by the SP-100 Program in the Fast Flux Test Facility. One of the pins contains several meltwire temperature monitors within the fuel and the Li annulus. A post-irradiation examination will verify the accuracy of the pre-irradiation thermal analysis. The purpose of the pre-irradiation analysis was to determine the appropriate insulating gap gas compositions required to provide the design goal cladding operating temperatures and to ensure that the meltwire temperature ranges in the temperature monitored pin bracket peak irradiation temperatures. This paper discusses the methodology and summarizes the results of the analysis.

  20. Hydrodynamic Simulations of Unevenly Irradiated Jovian Planets

    NASA Astrophysics Data System (ADS)

    Langton, Jonathan; Laughlin, Gregory

    2008-02-01

    We employ a two-dimensional, grid-based hydrodynamic model to simulate upper atmospheric dynamics on extrasolar giant planets. The hydrodynamic equations of motion are integrated on a rotating, irradiated sphere using a pseudospectral algorithm. We use a two-frequency, two-stream approximation of radiative transfer to model the temperature forcing. This model is well suited to simulate the dynamics of the atmospheres of planets with high orbital eccentricity, which are subject to widely varying irradiation conditions. We identify six such planets, with eccentricities between e = 0.28 and e = 0.93 and semimajor axes from a = 0.0508 AU to a = 0.432 AU, as particularly interesting. For each, we determine the temperature profile and resulting infrared light curves in the 8 μm Spitzer band. Especially notable are the results for HD 80606b, which has the largest eccentricity (e = 0.9321) of any known planet, and HAT-P-2b, which transits its parent star, so that its physical properties are well constrained. Despite the varied orbital parameters, the atmospheric dynamics of these planets display a number of interesting common properties. In all cases, the atmospheric response is primarily driven by the intense irradiation at periastron. The resulting expansion of heated air produces high-velocity turbulent flow, including long-lived circumpolar vortices. In addition, a superrotating acoustic front develops on some planets; the strength of this disturbance depends on both the eccentricity and the temperature gradient from uneven heating. The specifics of the resulting infrared light curves depend strongly on the orbital geometry. We show, however, that the variations on HD 80606b and HAT-P-2b should be readily detectable at 4.5 and 8 μm using Spitzer. These two objects present the most attractive observational targets of all known high-e exoplanets.

  1. Protostellar chemistry dominated by external irradiation

    NASA Astrophysics Data System (ADS)

    Lindberg, Johan E.; Charnley, Steven B.; Jørgensen, Jes K.; Watanabe, Yoshimasa; Bisschop, Suzanne E.; Sakai, Nami; Yamamoto, Satoshi

    2015-08-01

    In their youngest stages, protostars are deeply enshrouded in envelopes of gas and dust, material that later accretes onto the central object and the protoplanetary disc. The chemical composition and excitation properties measured towards these envelopes provide valuable information about the current and previous irradiation environment of the forming protostar.We demonstrate the strengths of unbiased single-dish line surveys, which we use to study the chemical and physical properties of protostellar envelopes. We have performed line surveys of more than 50 sources in the nearby Corona Australis and Ophiuchus star-forming regions using the APEX telescope. Many of the Corona Australis sources are located near the intermediate-mass Herbig Be star R CrA, and we find that despite its moderate luminosity, the irradiation from this star enhances the H2CO temperatures of the nearby protostellar envelopes from 10 K to at least 30-40 K. This drastically elevated temperature should be of crucial importance to the chemistry of these envelopes, due to thermal evaporation of many key species from the dust grain surfaces.Towards R CrA-IRS7B, the most thoroughly investigated object in our study, we find that the chemistry differs greatly from other thoroughly investigated deeply embedded protostars (hot corinos and warm carbon-chain chemistry sources, WCCC). We find low abundances of complex organic molecules such as CH3OCH3 and CH3CN, but instead elevated abundances of CN and some carbon-chain species like HC3N and C2H, although not to the same level as towards typical WCCC sources. We interpret the observed chemical properties as a result of thermal evaporation of CO from the grain mantles and photo-dissociation reactions in the IRS7B envelope, both initiated by the irradiation from R CrA.

  2. A Simplified Shuttle Irradiation Facility for ATR

    SciTech Connect

    Palmer, Alma Joseph; Laflin, S. T.

    1999-09-01

    During the past fifteen years there has been a steady increase in the demand for radioisotopes in nuclear medicine and a corresponding decline in the number of reactors within the U.S. capable of producing them. The Advanced Test Reactor (ATR) is the largest operating test reactor in the U.S., but its isotope production capabilities have been limited by the lack of an installed isotope shuttle irradiation system. A concept for a simple “low cost” shuttle irradiation facility for ATR has been developed. Costs were reduced (in comparison to previous ATR designs) by using a shielded trough of water installed in an occupiable cubicle as a shielding and contamination control barrier for the send and receive station. This shielding concept also allows all control valves to be operated by hand and thus the need for an automatic control system was eliminated. It was determined that 4 – 5 ft of water would be adequate to shield the isotopes of interest while shuttles are transferred to a small carrier. An additional feature of the current design is a non-isolatable by-pass line, which provides a minimum coolant flow to the test region regardless of which control valves are opened or closed. This by-pass line allows the shuttle facility to be operated without bringing reactor coolant water into the cubicle except for send and receive operations. The irradiation position selected for this concept is a 1.5 inch “B” hole (B-11). This position provides neutron fluxes of approximately: 1.6 x 1014 (<0.5 eV) and 4.0 x 1013 (>0.8 MeV) n/cm2*sec.

  3. Early and Late Responses to Ion Irradiation

    NASA Astrophysics Data System (ADS)

    Schulte, Reinhard; Ling, Ted

    Early and late responses to ion beam therapy (IBT) are the result of complex interactions between host, dose volume, and radiobiological factors. Our understanding of these early and late tissue responses has improved greatly with the accumulation of laboratory and clinical experience with proton and heavy ion irradiation. With photon therapy becoming increasingly conformal, many concepts developed for 3D conformal radiotherapy and intensity modulated radiation therapy with photons are also applicable to IBT. This chapter reviews basic concepts and experimental data of early and late tissue responses to protons and ions.

  4. Nasopharyngeal radium irradiation: The lessons of history.

    PubMed

    Graamans, Kees

    2017-02-01

    In the Netherlands, nasopharyngeal radium irradiation was started in 1945. The indications included refractory symptoms of otitis media with effusion and other adenoid-related disorders after adenoidectomy. It was considered a safe and effective therapy. Its use decreased sharply in 1958, following a worldwide media avalanche around the dramatic events in the treatment of a 5-year-old child in Utrecht, enhancing the widespread fear of radioactivity. This case history illustrates the powerful role of the media in medical decision-making.

  5. DECONTAMINATION OF NEUTRON-IRRADIATED REACTOR FUEL

    DOEpatents

    Buyers, A.G.; Rosen, F.D.; Motta, E.E.

    1959-12-22

    A pyrometallurgical method of decontaminating neutronirradiated reactor fuel is presented. In accordance with the invention, neutron-irradiated reactor fuel may be decontaminated by countercurrently contacting the fuel with a bed of alkali and alkaine fluorides under an inert gas atmosphere and inductively melting the fuel and tracking the resulting descending molten fuel with induction heating as it passes through the bed. By this method, a large, continually fresh surface of salt is exposed to the descending molten fuel which enhances the efficiency of the scrubbing operation.

  6. Microstructural examination of irradiated vanadium alloys

    SciTech Connect

    Gelles, D.S.; Chung, H.M.

    1997-04-01

    Microstructural examination results are reported for a V-5Cr-5Ti unirradiated control specimens of heat BL-63 following annealing at 1050{degrees}C, and V-4Cr-4Ti heat BL-47 irradiated in three conditions from the DHCE experiment: at 425{degrees}C to 31 dpa and 0.39 appm He/dpa, at 600{degrees}C to 18 dpa and 0.54 appm He/dpa and at 600{degrees}C to 18 dpa and 4.17 appm He/dpa.

  7. Preoperative irradiation and cystectomy for bladder cancer.

    PubMed

    Smith, J A; Batata, M; Grabstald, H; Sogani, P C; Herr, H; Whitmore, W F

    1982-03-01

    Between 1971 and 1974, 101 patients at Memorial Sloan-Kettering Cancer Center underwent planned integrated treatment for bladder cancer with 2000 rads by megavoltage delivered to the whole pelvis over five consecutive days followed by radical cystectomy within a week. The overall five-year survival rate was 39%; the hospital mortality rate was 2%. In the pelvis alone tumor recurred in 9% of the patients. These results support other studies demonstrating the efficacy of this and other regimens of preoperative irradiation and cystectomy.

  8. Medical waste irradiation study. Final report

    SciTech Connect

    Adler, R.J.; Stein, J.; Nygard, J.

    1998-07-25

    The North Star Research Corporation Medical Waste project is described in this report, with details of design, construction, operation, and results to date. The project began with preliminary design of the accelerator. The initial design was for a single accelerator chamber with a vacuum tube cavity driver built into the chamber itself, rather than using a commercial tube separate from the RF accelerator. The authors believed that this would provide more adjustability and permit better coupling to be obtained. They did not have sufficient success with that approach, and finally completed the project using a DC accelerator with a unique new scanning system to irradiate the waste.

  9. Separation of transuranium elements from irradiated targets

    SciTech Connect

    Wham, R.M.; Benker, D.E.; Felker, L.K.; Chattin, F.R.

    1993-12-31

    Aluminum targets containing curium/americium oxide are irradiated to produce the transcurium actinides einsteinium, fermium, berkelium, and californium. Recovery of recycle curium/americium and the transcurium elements involves several chemical processing steps to selectively recover those elements and remove fission products. Chemical processing steps developed at the Radiochemical Engineering Development Center (REDC) include aluminum dejacketing, solvent extraction to remove bulk impurities, solvent extraction to remove plutonium, anion exchange to partition curium and transcurium elements from the rare earths, and a second anion exchange cycle to separate americium/curium from the transcurium elements.

  10. Inactivation of Microorganisms by Gamma Irradiation

    DTIC Science & Technology

    2005-12-01

    microorganismes pathogdniques devant etre utilis~s plus tard comme r~actifs d’antig~ nes . L’utilisation initiale d’organismes non pathog ~niques est une m~thode A...d’irradiations par expositions. Les procedures utilis6es pour effectuer ces travaux serviront plus tard A l’dtude de la stWrilisation des microorganismes pathog ...niques qui seront utilis~s plus tard comme r6actifs d’antig~ nes . L’utilisation initiale d’organismes non pathogdniques est une m~thode A faible risque

  11. The Total Solar Irradiance Climate Data Record

    NASA Astrophysics Data System (ADS)

    Dewitte, Steven; Nevens, Stijn

    2016-10-01

    We present the composite measurements of total solar irradiance (TSI) as measured by an ensemble of space instruments. The measurements of the individual instruments are put on a common absolute scale, and their quality is assessed by intercomparison. The composite time series is the average of all available measurements. From 1984 April to the present the TSI shows a variation in phase with the 11 yr solar cycle and no significant changes of the quiet-Sun level in between the three covered solar minima.

  12. Haemopoiesis in the Beagle Foetus after in utero Irradiation

    DTIC Science & Technology

    1983-01-01

    protein) as the source of erythropoietin ( EPO ). Cultures (2-5 x 104 nucleated liver or spleen cells per 01 ml, 5.0 x 104 nucleated marrow cells per 0.1...comparison with the other foetal tissues, the foetal liver appeared to experience greater radiation injury. For example, on day 44, the irradiated liver BFU... liver . However, unlike the irradiated spleen, the irradiated bone marrow had decreased BFU-E activity compared with the "- 1ues for the nonirradiated bone

  13. Thermal effects in IR-laser-irradiated living cells

    NASA Astrophysics Data System (ADS)

    Meier, Thomas H.; Rueck, Angelika C.; Scalfi-Happ, Claudia; Hug, Hubert; Schneider, Marion E.

    2003-10-01

    Irradiation of cell-layers with focussed 2.8 μm ir-laser allows to control the cell temperature from room temperature up to 100°C. Temperatures were calculated for a cell culture model and verified experimentally by thermal mapping of the cell-surrounding medium by means of thermochromic liquid crystals (TLC). Irradiation power and time were varied and associated biological effects like necrosis and apoptosis were observed with respect to the irradiation dosis.

  14. Solar Irradiance Variations on Active Region Time Scales

    NASA Technical Reports Server (NTRS)

    Labonte, B. J. (Editor); Chapman, G. A. (Editor); Hudson, H. S. (Editor); Willson, R. C. (Editor)

    1984-01-01

    The variations of the total solar irradiance is an important tool for studying the Sun, thanks to the development of very precise sensors such as the ACRIM instrument on board the Solar Maximum Mission. The largest variations of the total irradiance occur on time scales of a few days are caused by solar active regions, especially sunspots. Efforts were made to describe the active region effects on total and spectral irradiance.

  15. Checking ozone amounts by measurements of UV-irradiances

    NASA Technical Reports Server (NTRS)

    Seckmeyer, Gunther; Kettner, Christiane; Thiel, Stephen

    1994-01-01

    Absolute measurements of UV-irradiances in Germany and New Zealand are used to determine the total amounts of ozone. UV-irradiances measured and calculated for clear skies and for solar zenith angles less than 60 deg generally show a good accordance. The UVB-irradiances, however, show that the actual Dobson values are about 5 percent higher in Germany and about 3 percent higher in New Zealand compared to those obtained by our method. Possible reasons for these deviations are discussed.

  16. Thermally activated deformation of irradiated reactor pressure vessel steel

    NASA Astrophysics Data System (ADS)

    Böhmert, J.; Müller, G.

    2002-03-01

    Temperature and strain rate change tensile tests were performed on two VVER 1000-type reactor pressure vessel welds with different contents of nickel in unirradiated and irradiated conditions in order to determine the activation parameters of the contribution of the thermally activated deformation. There are no differences of the activation parameters in the unirradiated and the irradiated conditions as well as for the two different materials. This shows that irradiation hardening preferentially results from a friction hardening mechanism by long-range obstacles.

  17. Irradiation performance of full-length metallic IFR fuels

    SciTech Connect

    Tsai, H.; Neimark, L.A.

    1992-07-01

    An assembly irradiation of 169 full-length U-Pu-Zr metallic fuel pins was successfully completed in FFTF to a goal burnup of 10 at.%. All test fuel pins maintained their cladding integrity during the irradiation. Postirradiation examination showed minimal fuel/cladding mechanical interaction and excellent stability of the fuel column. Fission-gas release was normal and consistent with the existing data base from irradiation testing of shorter metallic fuel pins in EBR-II.

  18. ESR detection procedure of irradiated papaya containing high water content

    NASA Astrophysics Data System (ADS)

    Kikuchi, Masahiro; Shimoyama, Yuhei; Ukai, Mitsuko; Kobayashi, Yasuhiko

    2011-05-01

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the γ-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  19. Etats hémodynamiques et respiratoires des opérées de fistules obstétricales sous rachianesthésie au CHRR Manakara, Madagascar

    PubMed Central

    Martinetti, Andrianimaro Florelia; Franklin, Rabenjarison; Lalao, Randriamboavonjy Rado; Judicael, Harioly Nirina Marie Osé; Yvonne, Rasolonjatovo Tsiorintsoa; Andriambelo, Rajaonera Tovohery; Nicole, Rakotoarison Ratsaraharimanana Catherine; Enintsoa, Raveloson Nasolotsiry; Edwige, Ravaomanana

    2016-01-01

    L'objectif était d'évaluer les états hémodynamiques et respiratoires des opérées de fistules obstétricales et rapporter nos expériences sur la prise en charge de ces malades. Il s'agit d'une étude transversale descriptive effectuée au Bloc opératoire et Réanimation du CHRR Manakara allant du 20 au 30 aout 2013. Etaient incluses les patientes opérées de fistules obstétricales sous rachianesthésie. Nous avons exclu les patientes classées ASA >2 et celles ayant des tares cardio-vasculaires ou respiratoires. Après consultations préanesthésiques, et bilans préopératoires, nous avons administré chez les patientes 12,5mg de bupivacaïne adrénalinée 0,5% isobare en intrathécal. Elles étaient mises en position de Trendelenburg 5 minutes après l'injection du produit anesthésique et durant toute l'intervention. Le niveau sensitif, la pression artérielle, la fréquence cardiaque, la fréquence respiratoire et la saturation pulsée en oxygène (SpO2) étaient enregistrés pendant l'intervention. Nous avons retenues 57 malades. Le bloc sensitivomoteur était excellent pour toutes les malades. Un niveau métamérique supérieur à T6 était atteint chez 56,36% des malades. A part quelques épisodes d'hypertension artérielle et tachycardie, nous n'avons trouvé aucune difficulté respiratoire ni cardiovasculaire en rapport avec la position. Seuls, le niveau sensitif et la fréquence respiratoire présentaient une corrélation (p=0,01). Cette étude suggère que la position de Trendelenburg est réalisable au cours de la rachianesthésie en utilisant un produit anesthésique approprié, en faisant attention, notamment aux changements de position et en tenant compte de l'examen préanesthésique. PMID:28292102

  20. Irradiation dose detection of irradiated milk powder using visible and near-infrared spectroscopy and chemometrics.

    PubMed

    Kong, W W; Zhang, C; Liu, F; Gong, A P; He, Y

    2013-08-01

    The objective of this study was to examine the possibility of applying visible and near-infrared spectroscopy to the quantitative detection of irradiation dose of irradiated milk powder. A total of 150 samples were used: 100 for the calibration set and 50 for the validation set. The samples were irradiated at 5 different dose levels in the dose range 0 to 6.0 kGy. Six different pretreatment methods were compared. The prediction results of full spectra given by linear and nonlinear calibration methods suggested that Savitzky-Golay smoothing and first derivative were suitable pretreatment methods in this study. Regression coefficient analysis was applied to select effective wavelengths (EW). Less than 10 EW were selected and they were useful for portable detection instrument or sensor development. Partial least squares, extreme learning machine, and least squares support vector machine were used. The best prediction performance was achieved by the EW-extreme learning machine model with first-derivative spectra, and correlation coefficients=0.97 and root mean square error of prediction=0.844. This study provided a new approach for the fast detection of irradiation dose of milk powder. The results could be helpful for quality detection and safety monitoring of milk powder.

  1. Irradiation-induced effects of proton irradiation on zirconium carbides with different stoichiometries

    SciTech Connect

    Y. Huang; B.R. Maier; T.R. Allen

    2014-10-01

    Zirconium carbide (ZrC) is being considered for utilization in deep burn TRISO fuel particles for hightemperature, gas-cooled reactors. Zirconium carbide has a cubic B1 type crystal structure along with a very high melting point (3420 ?C), exceptional hardness and good thermal and electrical conductivities. Understanding the ZrC irradiation response is crucial for establishing ZrC as an alternative component in TRISO fuel. Until now, very few studies on irradiation effects on ZrC have been released and fundamental aspects of defect evolution and kinetics are not well understood although some atomistic simulations and phenomenological studies have been performed. This work was carried out to understand the damage evolution in float-zone refined ZrC with different stoichiometries. Proton irradiations at 800 ?C up to doses of 3 dpa were performed on ZrCx (where x ranges from 0.9 to 1.2) to investigate the damage evolution. The irradiation-induced defects, such as density of dislocation loops, at different stoichiometries and doses which were characterized by transmission electron microscopy (TEM) is presented and discussed.

  2. Emulation of reactor irradiation damage using ion beams

    SciTech Connect

    Was, G. S.; Jiao, Z.; Getto, E.; Sun, K.; Monterrosa, A. M.; Maloy, S. A.; Anderoglu, O.; Sencer, B. H.; Hackett, M.

    2014-06-14

    The continued operation of existing light water nuclear reactors and the development of advanced nuclear reactor depend heavily on understanding how damage by radiation to levels degrades materials that serve as the structural components in reactor cores. The first high dose ion irradiation experiments on a ferritic-martensitic steel showing that ion irradiation closely emulates the full radiation damage microstructure created in-reactor are described. Ferritic-martensitic alloy HT9 (heat 84425) in the form of a hexagonal fuel bundle duct (ACO-3) accumulated 155 dpa at an average temperature of 443°C in the Fast Flux Test Facility (FFTF). Using invariance theory as a guide, irradiation of the same heat was conducted using self-ions (Fe++) at 5 MeV at a temperature of 460°C and to a dose of 188 displacements per atom. The void swelling was nearly identical between the two irradiation and the size and density of precipitates and loops following ion irradiation are within a factor of two of those for neutron irradiation. The level of agreement across all of the principal microstructure changes between ion and reactor irradiation establishes the capability of tailoring ion irradiation to emulate the reactor-irradiated microstructure.

  3. Practical dosimetric aspects of blood and blood product irradiation

    SciTech Connect

    Fearon, T.C.; Luban, N.L.

    1986-09-01

    The method of choice to reduce susceptibility to transfusion-transmitted graft-versus-host disease is irradiation of allogenic blood and blood products for transfusion to immunosuppressed recipients. Optimal irradiation requires delivery of a known and homogeneous absorbed dose. The use of absorbed dose in air measured at the center of the irradiation volume without proper compensation for sample absorption can lead to approximately 20 percent underexposure. A lucite cylinder was used to provide the delivery of a homogeneous irradiation dose to blood products of different volumes by allowing rotation of the product.

  4. Rationale and recommendations for the irradiation of blood products

    SciTech Connect

    Pritchard, S.L.; Rogers, P.C.

    1987-01-01

    Blood products are often irradiated to prevent proliferation of lymphocytes which could cause graft-vs.-host disease in immunocompromised recipients. The effects of irradiation on the function of blood components is discussed. It is concluded that 1500 rad is sufficient to prevent lymphocyte proliferation and production of graft-vs.-host disease in vivo, although 10 to 20% of lymphocytes are still capable of proliferation in vitro after 1500 rad. Neutrophils and erythrocytes are extremely radioresistant and their function is unaffected by 1500 rad. There are limited data to suggest that platelet yields may be slightly reduced following irradiation. Guidelines for the use of irradiated blood products are suggested.61 references.

  5. Pretransfusion blood irradiation: Clinical rationale and dosimetric considerations

    SciTech Connect

    Masterson, M.E.; Febo, R. )

    1992-05-01

    The irradiation of blood before transfusion into immunosuppressed patients is an increasingly common technique used to prevent graft-versus-host disease. A technical procedure is described for the calibration of blood irradiators, including the determination of absolute dose rate and relative dose distribution over the blood volume. Results of dose rate measurements on commercially available irradiators indicate differences of +5% to {minus}13% with manufacturer-supplied calibrations and variations in the relative dose rate over the irradiation volume from 70% to 180%. The clinical implications of these findings and the need for accurate dosimetry are discussed.

  6. Consumer in-store response to irradiated papayas

    SciTech Connect

    Bruhn, C.M.; Noell, J.W.

    1987-09-01

    In this study, purchase behavior of California consumers in response to irradiated papayas is described. The papayas were shipped from Hawaii and irradiated in California under a permit by the Animal and Plant Health Inspection Service and approved by the California Department of Food and Agriculture. Results show that the superior appearance of the irradiated fruit appealed to consumers and that two-thirds or more of the people queried indicated that they would buy irradiated produce. It is noted that this marketing took place in a supportive environment with no protestors present. Informational material was available.

  7. Validation of gamma irradiator controls for quality and regulatory compliance

    NASA Astrophysics Data System (ADS)

    Harding, Rorry B.; Pinteric, Francis J. A.

    1995-09-01

    Since 1978 the U.S. Food and Drug Administration (FDA) has had both the legal authority and the Current Good Manufacturing Practice (CGMP) regulations in place to require irradiator owners who process medical devices to produce evidence of Irradiation Process Validation. One of the key components of Irradiation Process Validation is the validation of the irradiator controls. However, it is only recently that FDA audits have focused on this component of the process validation. What is Irradiator Control System Validation? What constitutes evidence of control? How do owners obtain evidence? What is the irradiator supplier's role in validation? How does the ISO 9000 Quality Standard relate to the FDA's CGMP requirement for evidence of Control System Validation? This paper presents answers to these questions based on the recent experiences of Nordion's engineering and product management staff who have worked with several US-based irradiator owners. This topic — Validation of Irradiator Controls — is a significant regulatory compliance and operations issue within the irradiator suppliers' and users' community.

  8. Effect of. gamma. -ray irradiation on alcohol production from corn

    SciTech Connect

    Han, Y.W.; Cho, Y.K.; Ciegler, A.

    1983-11-01

    Cracked corn was irradiated with ..gamma.. rays at 0-100 Mrad and the effects of the irradiation on sugar yield, susceptibility to enzymatic hydrolysis of starch, yeast growth, and alcohol production were studied. Gamma irradiation at 50 Mrad or greater produced a considerable amount of reducing sugar but little glucose. At lower dosages, ..gamma.. irradiation significantly increased the susceptibility of corn starch to enzymatic hydrolysis, but dosages of 50 Mrad or greater decomposed the starch molecules as indicated by the reduction in iodine uptake. About 12.5% reducing sugar was produced by amylase treatment of uncooked, irradiated corn. This amount exceeded the level of sugar produced from cooked (gelatinized) corn by the same enzyme treatment. The yeast numbers in submerged cultivation were lower on a corn substrate that was irradiated at 50 Mrad or greater compared to that on an unirradiated control. About the same level of alcohol was produced on uncooked, irradiated (10/sup 5/ - 10/sup 6/ rad) corn as from cooked (121 degrees C for 30 min) corn. Therefore, the conventional cooking process for gelatinization of starch prior to its saccharification can be eliminated by irradiation. Irradiation also eliminated the necessity of sterilization of the medium and reduced the viscosity of high levels of substrate in the fermentation broth. (Refs. 10).

  9. Iron release analyses from ferritin by visible light irradiation.

    PubMed

    Ohishi, Kentaro; Zhang, Xiao Mei; Moriwaki, Shinichi; Hiramitsu, Tadahisa; Matsugo, Seiichi

    2005-08-01

    We investigated the iron release from ferritin by irradiation from a white fluorescent light in the absence or presence of ADP. Irradiation of a ferritin solution at 17,000 lx in the absence of ADP slightly induces iron release from ferritin but only at acidic pH conditions (pH 5.0 or pH 6.0). Irradiation in the presence of ADP markedly enhances iron release from ferritin under the same conditions. In the absence of irradiation, the iron release from ferritin was low even in the presence of ADP. The induction of the iron release by irradiation in the presence of ADP was also affected by various factors such as irradiation dose and acidity, but not temperature (4-47 degrees C), oxygen concentration, or free radical generations during the irradiation. The iron release during the irradiation ceased to increase by turning off the light and was found to increase again after additional irradiation. These results suggest that visible light directly induces iron release from ferritin via the photoreduction of iron stored inside ferritin.

  10. 10 CFR 36.13 - Specific licenses for irradiators.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... organizational structure for managing the irradiator, specifically the radiation safety responsibilities and... responsibilities or authorities. In particular, the application must specify who, within the management...

  11. 10 CFR 36.13 - Specific licenses for irradiators.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... organizational structure for managing the irradiator, specifically the radiation safety responsibilities and... responsibilities or authorities. In particular, the application must specify who, within the management...

  12. Study on sterilization and storage of enzymatic preparations by irradiation

    NASA Astrophysics Data System (ADS)

    Dengyi, Xu; Guangzheng, Liu; Yunsen, Long; Xiaoping, Liu; Fengxin, Yi; Xiaqdong, Zhao

    1993-10-01

    Effects of irradiation with cobalt-60 γ-rays on sterilization, storage and enzymes activity of four kinds of biological enzymatic preparations, namely trypsin, pepsin, amylase and liquid carbohydrase, were investigated. The results showed that these enzymes have different sensitivity to irradiation, amylase being the most sensitive. The enzyme activity and enzyme effect of amylase were lowered with irradiation dose higher than 7 KGY. With irradiation doses between 7-10 KGY, enzyme activity of trypsin and pepsin were stable. Liquid carbohydrase can be stored more than half a year under a natural temperature with a stable enzyme activity without molding.

  13. Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Hun; Sung, Nak-Yun; Raghavendran, H. Balaji; Yoon, Yohan; Song, Beom-Seok; Choi, Jong-il; Yoo, Young-Choon; Byun, Myung-Woo; Hwang, Young-Jeong; Lee, Ju-Woon

    2009-07-01

    Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-α and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX ( P<0.05). In vivo study on the tumor mass inhibition, gamma-irradiated DOX showed a considerable inhibition of tumor mass and this effect was statistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.

  14. Health protection and food preservation by gamma irradiation

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Results of several major studies on food systems for space missions beginning with Apollo 12 through Apollo-Soyuz and investigations of the application of irradiation to food for manned space flight are reported. The study of flight food systems involved the application of radurization (pasteurizing levels) doses of gamma irradiation to flour and bread supplied by Pepperidge Farms in advance of the missions. All flights from Apollo 12 through 17 carried irradiated fresh bread. On Apollo 17, cooperation with Natick Laboratories permitted the introduction of a ham sandwich using irradiated bread and irradiated sterile ham. Investigations centered on irradiated bread were conducted during the course of these missions. Studies were applied to the concept of improving fresh bread from the point of view of mold inhibition. The studies considered how irradiation could best be applied at what levels and on a variety of bread types. Throughout the studies of the application of gamma irradiation the emphasis was placed upon using low levels of irradiation in the pasteurizing or radurizing doses--under a Megarad. The primary goal was to determine if a public health benefit could be demonstrated using radurization along with food preservation and food quality improvements. The public health benefit would be parallel to that of pasteurization of milk as a concept. Publications are included providing the details of these observations, one dealing with the flour characteristics and the other dealing with the influence on fresh bread types. These demonstrate the major findings noted during the period of the studies examining bread.

  15. Food irradiation in Hungary: commercial processing and development work

    NASA Astrophysics Data System (ADS)

    Kalman, B.; Szikra, L.; Ferencz, P.

    2000-03-01

    The result of an experiment with irradiated frozen poultry meat is presented. The purpose of the experiment was to prove the benefit of irradiation treatment for elimination of pathogenic bacteria such as Salmonella and Campylobacter. We found that an average dose of 4.5 kGy kills the bacteria in the meat. Agroster was involved in an EU project on the identification of irradiation treatment of spices and data from this project are presented. Commercial irradiation of spices has been used for more than 15 years in Hungary, proving the benefit of this technology

  16. Emulation of reactor irradiation damage using ion beams

    DOE PAGES

    Was, G. S.; Jiao, Z.; Getto, E.; ...

    2014-06-14

    The continued operation of existing light water nuclear reactors and the development of advanced nuclear reactor depend heavily on understanding how damage by radiation to levels degrades materials that serve as the structural components in reactor cores. The first high dose ion irradiation experiments on a ferritic-martensitic steel showing that ion irradiation closely emulates the full radiation damage microstructure created in-reactor are described. Ferritic-martensitic alloy HT9 (heat 84425) in the form of a hexagonal fuel bundle duct (ACO-3) accumulated 155 dpa at an average temperature of 443°C in the Fast Flux Test Facility (FFTF). Using invariance theory as a guide,more » irradiation of the same heat was conducted using self-ions (Fe++) at 5 MeV at a temperature of 460°C and to a dose of 188 displacements per atom. The void swelling was nearly identical between the two irradiation and the size and density of precipitates and loops following ion irradiation are within a factor of two of those for neutron irradiation. The level of agreement across all of the principal microstructure changes between ion and reactor irradiation establishes the capability of tailoring ion irradiation to emulate the reactor-irradiated microstructure.« less

  17. EPR study on gamma-irradiated fruits dehydrated via osmosis

    NASA Astrophysics Data System (ADS)

    Yordanov, N. D.; Aleksieva, K.

    2007-06-01

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit "sugar-like" EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  18. AGC-2 Specimen Post Irradiation Data Package Report

    SciTech Connect

    Windes, William Enoch; Swank, W. David; Rohrbaugh, David T.; Cottle, David L.

    2015-08-01

    This report documents results of the post-irradiation examination material property testing of the creep, control, and piggyback specimens from the irradiation creep capsule Advanced Graphite Creep (AGC)-2 are reported. This is the second of a series of six irradiation test trains planned as part of the AGC experiment to fully characterize the neutron irradiation effects and radiation creep behavior of current nuclear graphite grades. The AGC-2 capsule was irradiated in the Idaho National Laboratory Advanced Test Reactor at a nominal temperature of 600°C and to a peak dose of 5 dpa (displacements per atom). One-half of the creep specimens were subjected to mechanical stresses (an applied stress of either 13.8, 17.2, or 20.7 MPa) to induce irradiation creep. All post-irradiation testing and measurement results are reported with the exception of the irradiation mechanical strength testing, which is the last destructive testing stage of the irradiation testing program. Material property tests were conducted on specimens from 15 nuclear graphite grades using a similar loading configuration as the first AGC capsule (AGC-1) to provide easy comparison between the two capsules. However, AGC-2 contained an increased number of specimens (i.e., 487 total specimens irradiated) and replaced specimens of the minor grade 2020 with the newer grade 2114. The data reported include specimen dimensions for both stressed and unstressed specimens to establish the irradiation creep rates, mass and volume data necessary to derive density, elastic constants (Young’s modulus, shear modulus, and Poisson’s ratio) from ultrasonic time-of-flight velocity measurements, Young’s modulus from the fundamental frequency of vibration, electrical resistivity, and thermal diffusivity and thermal expansion data from 100–500°C. No data outliers were determined after all measurements were completed. A brief statistical analysis was performed on the irradiated data and a limited comparison between

  19. Irradiation Programs and Test Plans to Assess High-Fluence Irradiation Assisted Stress Corrosion Cracking Susceptibility.

    SciTech Connect

    Teysseyre, Sebastien

    2015-03-01

    . Irradiation assisted stress corrosion cracking (IASCC) is a known issue in current reactors. In a 60 year lifetime, reactor core internals may experience fluence levels up to 15 dpa for boiling water reactors (BWR) and 100+ dpa for pressurized water reactors (PWR). To support a safe operation of our fleet of reactors and maintain their economic viability it is important to be able to predict any evolution of material behaviors as reactors age and therefore fluence accumulated by reactor core component increases. For PWR reactors, the difficulty to predict high fluence behavior comes from the fact that there is not a consensus of the mechanism of IASCC and that little data is available. It is however possible to use the current state of knowledge on the evolution of irradiated microstructure and on the processes that influences IASCC to emit hypotheses. This report identifies several potential changes in microstructure and proposes to identify their potential impact of IASCC. The susceptibility of a component to high fluence IASCC is considered to not only depends on the intrinsic IASCC susceptibility of the component due to radiation effects on the material but to also be related to the evolution of the loading history of the material and interaction with the environment as total fluence increases. Single variation type experiments are proposed to be performed with materials that are representative of PWR condition and with materials irradiated in other conditions. To address the lack of IASCC propagation and initiation data generated with material irradiated in PWR condition, it is proposed to investigate the effect of spectrum and flux rate on the evolution of microstructure. A long term irradiation, aimed to generate a well-controlled irradiation history on a set on selected materials is also proposed for consideration. For BWR, the study of available data permitted to identify an area of concern for long term performance of component. The efficiency of

  20. Effect of helium on irradiation creep behavior of B-doped F82H irradiated in HFIR

    DOE PAGES

    Ando, M.; Nozawa, Takashi; Hirose, Takanori; ...

    2015-07-30

    The diameter of pressurized tubes of F82H and B-doped F82H irradiated up to similar to 6 dpa have been measured by a non-contacting laser profilometer. The irradiation creep strains of F82H irradiated at 573 and 673K were almost linearly dependent on the effective stress level for stresses below 260 MPa and 170 MPa, respectively. The creep strain of (BN)-B-10-F82H was similar to that of F82H IEA at each effective stress level except 294 MPa at 573K irradiation. For 673K irradiation, the creep strain of some (BN)-B-10-F82H tubes was larger than that of F82H tubes. However, the generation of similar tomore » 300 appm He did not cause a large difference in the irradiation creep behavior at 6 dpa.« less

  1. Impact of irradiation on fish and seafood shelf life: a comprehensive review of applications and irradiation detection.

    PubMed

    Arvanitoyannis, Ioannis S; Stratakos, Alexandros; Mente, Elena

    2009-01-01

    Irradiation is one of the most important and effective methods towards food preservation despite the consumer lack of trust and aversion towards this method. Irradiation effectiveness greatly depends on the dose provided to food. This review aims at summarizing all available information regarding the impact of irradiation dose on the shelf life and microflora and sensory and physical properties of fish, shellfish, molluscs, and crustaceans. The synergistic effect of irradiation in conjunction with other techniques such as salting, smoking, freezing, and vacuum packaging was also reported. Another issue covered within the frame of this review is the detection (comparison of methods in terms of their effectiveness and validity) of irradiated fish and seafood. The information related to fish and seafood irradiation and its detection is presented by means of 11 comprehensive tables and 9 figures.

  2. Effect of helium on irradiation creep behavior of B-doped F82H irradiated in HFIR

    SciTech Connect

    Ando, M.; Nozawa, Takashi; Hirose, Takanori; Tanigawa, H.; Wakai, E.; Stoller, Roger E; Myers, Janie

    2015-07-30

    The diameter of pressurized tubes of F82H and B-doped F82H irradiated up to similar to 6 dpa have been measured by a non-contacting laser profilometer. The irradiation creep strains of F82H irradiated at 573 and 673K were almost linearly dependent on the effective stress level for stresses below 260 MPa and 170 MPa, respectively. The creep strain of (BN)-B-10-F82H was similar to that of F82H IEA at each effective stress level except 294 MPa at 573K irradiation. For 673K irradiation, the creep strain of some (BN)-B-10-F82H tubes was larger than that of F82H tubes. However, the generation of similar to 300 appm He did not cause a large difference in the irradiation creep behavior at 6 dpa.

  3. Irradiation hardening of ODS ferritic steels under helium implantation and heavy-ion irradiation

    NASA Astrophysics Data System (ADS)

    Zhang, Hengqing; Zhang, Chonghong; Yang, Yitao; Meng, Yancheng; Jang, Jinsung; Kimura, Akihiko

    2014-12-01

    Irradiation hardening of ODS ferritic steels after multi-energy He-ion implantation, or after irradiation with energetic heavy ions including Xe and Bi-ions was investigated with nano-indentation technique. Three kinds of high-Cr ODS ferritic steels including the commercial MA956 (19Cr-3.5Al), the 16Cr-0.1Ti and the 16Cr-3.5Al-0.1Zr were used. Data of nano-hardness were analyzed with an approach based on Nix-Gao model. The depth profiles of nano-hardness can be understood by the indentation size effect (ISE) in specimens of MA956 implanted with multi-energy He-ions or irradiated with 328 MeV Xe ions, which produced a plateau damage profile in the near-surface region. However, the damage gradient overlaps the ISE in the specimens irradiated with 9.45 Bi ions. The dose dependence of the nano-hardness shows a rapid increase at low doses and a slowdown at higher doses. An 1/2-power law dependence on dpa level is obtained. The discrepancy in nano-hardness between the helium implantation and Xe-ion irradiation can be understood by using the average damage level instead of the peak dpa level. Helium-implantation to a high dose (7400 appm/0.5 dpa) causes an additional hardening, which is possibly attributed to the impediment of motion dislocations by helium bubbles formed in high concentration in specimens.

  4. Evolution of the nanostructure of VVER-1000 RPV materials under neutron irradiation and post irradiation annealing

    NASA Astrophysics Data System (ADS)

    Miller, M. K.; Chernobaeva, A. A.; Shtrombakh, Y. I.; Russell, K. F.; Nanstad, R. K.; Erak, D. Y.; Zabusov, O. O.

    2009-04-01

    A high nickel VVER-1000 (15Kh2NMFAA) base metal (1.34 wt% Ni, 0.47% Mn, 0.29% Si and 0.05% Cu), and a high nickel (12Kh2N2MAA) weld metal (1.77 wt% Ni, 0.74% Mn, 0.26% Si and 0.07% Cu) have been characterized by atom probe tomography to determine the changes in the microstructure during neutron irradiation to high fluences. The base metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 14.9 × 10 23 m -2 ( E > 0.5 MeV), and the weld metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 11.5 × 10 23 m -2 ( E > 0.5 MeV). High number densities of ˜2-nm-diameter Ni-, Si- and Mn-enriched nanoclusters were found in the neutron irradiated base and weld metals. No significant copper enrichment was associated with these nanoclusters and no copper-enriched precipitates were observed. The number densities of these nanoclusters correlate with the shifts in the ΔT 41 J ductile-to-brittle transition temperature. These nanoclusters were present after a post irradiation anneal of 2 h at 450 °C, but had dissolved into the matrix after 24 h at 450 °C. Phosphorus, nickel, silicon and to a lesser extent manganese were found to be segregated to the dislocations.

  5. Hafnium radioisotope recovery from irradiated tantalum

    DOEpatents

    Taylor, Wayne A.; Jamriska, David J.

    2001-01-01

    Hafnium is recovered from irradiated tantalum by: (a) contacting the irradiated tantalum with at least one acid to obtain a solution of dissolved tantalum; (b) combining an aqueous solution of a calcium compound with the solution of dissolved tantalum to obtain a third combined solution; (c) precipitating hafnium, lanthanide, and insoluble calcium complexes from the third combined solution to obtain a first precipitate; (d) contacting the first precipitate of hafnium, lanthanide and calcium complexes with at least one fluoride ion complexing agent to form a fourth solution; (e) selectively adsorbing lanthanides and calcium from the fourth solution by cationic exchange; (f) separating fluoride ion complexing agent product from hafnium in the fourth solution by adding an aqueous solution of ferric chloride to obtain a second precipitate containing the hafnium and iron; (g) dissolving the second precipitate containing the hafnium and iron in acid to obtain an acid solution of hafnium and iron; (h) selectively adsorbing the iron from the acid solution of hafnium and iron by anionic exchange; (i) drying the ion exchanged hafnium solution to obtain hafnium isotopes. Additionally, if needed to remove residue remaining after the product is dried, dissolution in acid followed by cation exchange, then anion exchange, is performed.

  6. Neutron irradiation induced amorphization of silicon carbide

    NASA Astrophysics Data System (ADS)

    Snead, L. L.; Hay, J. C.

    1999-07-01

    This paper provides the properties of bulk stoichiometric silicon carbide which has been amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60°C to a total fast neutron fluence of 2.6 × 10 25 n/m 2. Amorphization was seen in both materials as evidenced by TEM, electron diffraction and X-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (-10.8%), elastic modulus as measured using a nanoindentation technique (-45%), hardness as measured by nanoindentation (-45%), and standard Vickers hardness (-24%). Similar property changes are observed for the amorphized CVD SiC. Using measured thermal conductivity data for the CVD SiC sample, the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than ˜125°C.

  7. Heat profiles of laser-irradiated nails

    NASA Astrophysics Data System (ADS)

    Paasch, Uwe; Nenoff, Pietro; Seitz, Anna-Theresa; Wagner, Justinus A.; Kendler, Michael; Simon, Jan C.; Grunewald, Sonja

    2014-01-01

    Onychomycosis is a worldwide problem with no tendency for self-healing, and existing systemic treatments achieve disease-free nails in only 35 to 76% of cases. Recently, treatment of nail fungus with a near-infrared laser has been introduced. It is assumed that fungal eradication is mediated by local heat. To investigate if laser treatment has the potential to eradicate fungal hyphae and arthrospores, laser heat application and propagation needs to be studied in detail. This study aimed to measure nail temperatures using real-time videothermography during laser irradiation. Treatment was performed using 808- and 980-nm linear scanning diode lasers developed for hair removal, enabling contact-free homogeneous irradiation of a human nail plate in one pass. Average and peak temperatures increased pass by pass, while the laser beam moved along the nail plates. The achieved mean peak temperatures (808 nm: 74.1 to 112.4°C, 980 nm: 45.8 to 53.5°C), as well as the elevation of average temperatures (808 nm: 29.5 to 38.2°C, 980 nm: 27.1 to 32.6°C) were associated with pain that was equivalent to that of hair removal procedures and was not significantly different for various wavelengths. The linear scanning laser devices provide the benefits of contact-free homogeneous heating of the human nail while ensuring adequate temperature rises.

  8. Properties of polymers after cryogenic neutron irradiation

    NASA Astrophysics Data System (ADS)

    Tucker, D. S.; Clinard, F. W.; Hurley, G. F.; Fowler, J. D.

    1985-08-01

    Organic matrix insulation has been specified for use in fusion reactor superconducting coils due to lower material and fabrication costs compared to other forms of insulation. Glass fabric filled resins are prime candidates since they provide not only electrical insulation, but also the mechanical strength necessary to withstand the high magnetic forces present during coil operation. Two epoxy- and two polyimide-based fiber reinforced materials were irradiated to neutron fluences of 4.1 × 10 21n/m 2, E > 0.1 MeV at 4.2 K. Post-irradiation testing included flexural (3 pt. bend), as well as DC conductivity and dielectric breakdown strength. Measurements were made at 77 K and 300 K. Flexural strength was observed to decrease for the epoxy-based materials while the polyimide-based materials exhibited essentially no change in strength. Both DC conductivity and dielectric breakdown strength revealed little or no pattern of degradation at all levels of radiation exposure.

  9. Solar variability in irradiance and oscillations

    NASA Technical Reports Server (NTRS)

    Kuhn, Jeff R.

    1995-01-01

    The signature of the solar cycle appears in helioseismic frequencies and splittings. It is known that the changing outer superadiabatic region of the sun is responsible for this. The deeper solar-cycle mechanism from the surface changes, and, in particular, how magnetic fields perturb the global modes, the solar irradiance and the luminosity, is discussed. The irradiance and helioseismic changes are described. The interpretation of seismic and photometric data is discussed, considering current one-dimensional models and phenomenology. It is discussed how the long term solar-cycle luminosity effect could be caused by changes occurring near the base of the convection zone (CZ). It is shown that a thin toroidal flux sheath at the top of the radiative zone changed the thermal stratification immediately below the CZ over a solar-cycle timescale in two ways: the temperature of the magnetized fluid becomes hotter than the surrounding fluid, and the temperature gradient steepens above the magnetized region. The testing of CZ dynamics and extension of numerical experiments to global scales are considered.

  10. Heat profiles of laser-irradiated nails.

    PubMed

    Paasch, Uwe; Nenoff, Pietro; Seitz, Anna-Theresa; Wagner, Justinus A; Kendler, Michael; Simon, Jan C; Grunewald, Sonja

    2014-01-01

    Onychomycosis is a worldwide problem with no tendency for self-healing, and existing systemic treatments achieve disease-free nails in only 35 to 76% of cases. Recently, treatment of nail fungus with a near-infrared laser has been introduced. It is assumed that fungal eradication is mediated by local heat. To investigate if laser treatment has the potential to eradicate fungal hyphae and arthrospores, laser heat application and propagation needs to be studied in detail. This study aimed to measure nail temperatures using real-time videothermography during laser irradiation. Treatment was performed using 808- and 980-nm linear scanning diode lasers developed for hair removal, enabling contact-free homogeneous irradiation of a human nail plate in one pass. Average and peak temperatures increased pass by pass, while the laser beam moved along the nail plates. The achieved mean peak temperatures (808 nm: 74.1 to 112.4°C, 980 nm: 45.8 to 53.5°C), as well as the elevation of average temperatures (808 nm: 29.5 to 38.2°C, 980 nm: 27.1 to 32.6°C) were associated with pain that was equivalent to that of hair removal procedures and was not significantly different for various wavelengths. The linear scanning laser devices provide the benefits of contact-free homogeneous heating of the human nail while ensuring adequate temperature rises.

  11. Current status and regulation of food irradiation

    SciTech Connect

    Sivinski, J.S.

    1987-01-01

    It is estimated by the Food and Agricultural Organization (FAO) of the United Nations that 25 to 35 percent of world food production is lost through natural causes such a pests, microbes, and insects. In the ASEAN countries alone, postharvest losses of cereals are estimated at 30 percent, fruits and vegetables at 20 to 40 percent, and up to 50 percent for fish. Some products in Africa suffer postharvest losses as high as 50 percent. One of the best responses to the problem of world hunger is preservation of what has already been grown. If postharvest losses worldwide could be minimized, food supply gains could be made without allocation of additional resources. The problems of food production, processing and storage require a continuing search for effective, technically and economically feasible alternative methods of food preservation. Food irradiation is not a panacea for this problem, however. Alone, it cannot change conditions or solve the problems of world hunger, but it can become a factor in the improvement of conditions where improved human nutrition is an immediate need. Food irradiation has progressed steadily over the past 40 years in terms of research, development, and legislative or regulatory activities.

  12. Pterygia: Single-fraction postoperative beta irradiation

    SciTech Connect

    Beyer, D.C. )

    1991-02-01

    A retrospective evaluation was performed with records of 128 patients with 146 eyes that underwent applications of strontium-90 after pterygium excisions performed between 1982 and 1988. With a median follow-up of 13 months, 135 eyes were evaluable. Most pterygia (127 of 135) were treated with a single postoperative application of Sr-90 that delivered 3,000 cGy of beta radiation in one fraction. The actuarial freedom from relapse was 87%; all recurrences occurred within the first 18 months, and 46% of these within the first 3 months. Of the 13 recurrences, 10 have been re-treated with surgery and a second course of beta irradiation with excellent results. All eight eyes for which follow-up was available had no evidence of disease. The ultimate control rate was 96.3% for the series. Correlation of various treatment parameters, including age, bilaterality, prior recurrence, and interval from surgery to irradiation, was performed, and no statistically significant difference was seen. No serious complications have developed. Transient conjunctivitis and photophobia were almost universally seen, with five cases lasting beyond 5 months. The authors conclude that a single application of Sr-90 after surgery is effective and safe in managing pterygia.

  13. LWRS ATR Irradiation Testing Readiness Status

    SciTech Connect

    Kristine Barrett

    2012-09-01

    The Light Water Reactor Sustainability (LWRS) Program was established by the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of the current reactors. The LWRS Program is divided into four R&D Pathways: (1) Materials Aging and Degradation; (2) Advanced Light Water Reactor Nuclear Fuels; (3) Advanced Instrumentation, Information and Control Systems; and (4) Risk-Informed Safety Margin Characterization. This report describes an irradiation testing readiness analysis in preparation of LWRS experiments for irradiation testing at the Idaho National Laboratory (INL) Advanced Test Reactor (ATR) under Pathway (2). The focus of the Advanced LWR Nuclear Fuels Pathway is to improve the scientific knowledge basis for understanding and predicting fundamental performance of advanced nuclear fuel and cladding in nuclear power plants during both nominal and off-nominal conditions. This information will be applied in the design and development of high-performance, high burn-up fuels with improved safety, cladding integrity, and improved nuclear fuel cycle economics

  14. High temperature annealing of ion irradiated tungsten

    DOE PAGES

    Ferroni, Francesco; Yi, Xiaoou; Arakawa, Kazuto; ...

    2015-03-21

    In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500°C, 1014 W+/cm2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View the MathML source andmore » were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding Ea=1.34±0.2 eV for the 700–1100°C range.« less

  15. High temperature annealing of ion irradiated tungsten

    SciTech Connect

    Ferroni, Francesco; Yi, Xiaoou; Fitzgerald, Steven P.; Edmondson, Philip D.; Roberts, Steve G.

    2015-03-21

    In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500°C, 1014 W+/cm2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View the MathML source and were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding Ea=1.34±0.2 eV for the 700–1100°C range.

  16. A Simplified Shuttle Irradiation Facility for ATR

    SciTech Connect

    A. J. Palmer; S. T. Laflin

    1999-08-01

    During the past fifteen years there has been a steady increase in the demand for radioisotopes in nuclear medicine and a corresponding decline in the number of reactors within the U.S. capable of producing them. The Advanced Test Reactor (ATR) is the largest operating test reactor in the U.S., but its isotope production capabilities have been limited by the lack of an installed isotope shuttle irradiation system. A concept for a simple "low cost" shuttle irradiation facility for ATR has been developed. Cost were reduced (in comparison to previous ATR designs) by using a shielded trough of water installed in an occupiable cubicle as a shielding and contamination control barrier for the send and receive station. This shielding concept also allows all control valves to be operated by hand and thus the need for an automatic control system was eliminated. It was determined that 4-5 ft of water would be adequate to shield the isotopes of interest while shuttles are transferred to a small carrier. An additional feature of the current design is a non-isolatable by-pass line, which provides a minimum coolant flow to the test region regardless of which control valves are opened or closed. This by-pass line allows the shuttle facility to be operated without bringing reactor coolant water into the cubicle except for send and receive operations.

  17. Stereotaxic intracavitary irradiation for cystic craniopharyngiomas

    SciTech Connect

    Pollack, I.F.; Lunsford, L.D.; Slamovits, T.L.; Gumerman, L.W.; Levine, G.; Robinson, A.G.

    1988-02-01

    Stereotaxic intracavitary irradiation with instillation of phosphorus-32 (/sup 32/P) colloidal chromic phosphate was performed in nine patients with cystic craniopharyngiomas. Serial neurological, ophthalmological, neuroendocrinological, and radiological examinations were performed before and after treatment. Dosimetry was determined based on a computerized tomography (CT) estimation of tumor volume, and was calculated to provide a tumoricidal dose (200 to 300 Gy) to the cyst wall. The follow-up period ranged from 14 to 45 months (mean 27 months). After treatment, all nine patients showed improvement of symptoms and radiological evidence of cyst regression. Because of an expanding solid component producing recurrent symptoms, one patient required a craniotomy 14 months after isotope instillation. Three of five patients with impaired visual acuity before surgery had significant improvement in acuity after treatment. Preoperative visual field defects in eight patients improved in four after /sup 32/P therapy. Of seven patients with preoperative endocrine abnormalities, one individual showed almost complete normalization and another had improvement in endocrine function. Patients who exhibited residual neuroendocrine function before isotope instillation developed no significant deterioration in endocrine status during the follow-up period. The findings suggest that stereotaxic intracavitary irradiation is a safe and effective treatment which should be considered as the initial surgery for cystic craniopharyngiomas.

  18. Un carcinome épidermoïde du col utérin récidivant sous forme d'une métastase pulmonaire isolée: à propos d'un cas et revue de la literature

    PubMed Central

    Kanab, Rajae; El M'rabet, Fazoumed; Ameuraoui, Taoufiq; Sidibé, Fatoumata; Tizniti, Siham; Amarti, Afaf; Arifi, Samia; Mellas, Nawfal

    2015-01-01

    Les métastases pulmonaires du carcinome épidermoïde (CE) du col utérin sont rares. C'est un cancer à évolution locorégionale, rarement extra pelvienne, et qui est intimement lié à l'infection par HPV (humain papilloma virus). Nous rapportons un nouveau cas d'une patiente âgée de 40 ans, traitée pour CE du col utérin il y a 3 ans, traitées par RTH externe, curiethérapie et chirurgie et qui présente une récidive de sa maladie sous forme d'une masse pulmonaire isolée mimant un primitif pulmonaire. Le diagnostic a été posé par génotypage HPV sur le prélèvement biopsique de la masse pulmonaire. La patiente a été mise sous chimiothérapie type col utérin, avec une bonne réponse clinique et biologique. PMID:27022429

  19. Irradiated ready-to-eat spinach leaves: How information influences awareness towards irradiation treatment and consumer's purchase intention

    NASA Astrophysics Data System (ADS)

    Finten, G.; Garrido, J. I.; Agüero, M. V.; Jagus, R. J.

    2017-01-01

    This article aims to clarify and supply further information on food irradiation acceptance, with particular focus on Argentina and irradiated ready-to-eat (RTE) spinach leaves through an open web-online survey. Results showed that half of respondents did not know food irradiation, but the other half demonstrated uncertainty despite they declared they had knowledge about it; thus, confirming little awareness towards this technology. Respondents who believed in the misleading myth about food irradiation represented 39%, while roughly the same number was doubtful. On the other hand, after supplying informative material, respondents were positively influenced and an increase in acceptance by 90% was found. Finally, 42% of respondents were willing to consume/purchase irradiated RTE spinach leaves, and 35% remained doubtful. Respondents who did not exclude to accept irradiated spinach could be considered potential consumers if intensive campaigns about the benefits of food irradiation were carried out by reliable actors. If the Argentinean RTE market grew, following the world consumption trend towards these products, irradiated spinach leaves could be successfully introduced by making better efforts to inform consumers about food irradiation.

  20. Position of the American Dietetic Association: food irradiation.

    PubMed

    Wood, O B; Bruhn, C M

    2000-02-01

    Food irradiation has been identified a sa safe technology to reduce the risk of foodborne illness as part of high-quality food production, processing, handling, and preparation. Food irradiation's history of scientific research , evaluation, and testing spans more than 40 countries around the world and it has been endorsed or support by numerous national and international food and organizations and professional groups. Food irradiation utilizes a source of ionizing energy that passes through food to destroy harmful bacteria and other organism. Often referred to as "cold pasteurization," food irradiation offers negligible loss of nutrients or sensory qualities in food as it does not substantially raise the temperature of the food during processing. Food irradiation does not replace proper food production, processing, handling, or preparation, nor can it enhance the quality of or prevent contact with foodborne bacteria after irradiation. In the United States, manufacturers are required to identify irradiated food sold to consumers with an international symbol (Radura) and and terminology describing the process on product labels. In addiction, food irradiation facilities are thoroughly regulated and monitored for worker and environmental safety. Members of The American Dietetic Association (ADA) and other food, nutrition, and health professionals have a responsibility to educate consumers, food processors, manufacturers and retailers about the safety and application of the technology. When consumers are educated about food irradiation, many prefer irradiated products because of their increased safety. It is the position of ADA that food irradiation enhances the safety and quality of the food supply and helps protect consumers from foodborne illness. The ADA encourages the government, food manufactures, food commodity groups, and qualified food and nutrition professionals to work together to educate consumers about this additional food safety tool and make this choice