Sample records for photomagnetisme sous irradiation

  1. Comprhension de l'origine de l'volution sous irradiation de la tnacit des verres nuclaires

    E-print Network

    Paris-Sud XI, Université de

    Compréhension de l'origine de l'évolution sous irradiation de la ténacité des verres nucléaires Thè Bousquet, Virginie Ansault pour leur aide lors de la fabrication des verres, François Augereau pour les mesures des modules élastiques des verres, Laurent Cormier pour les simulations de Reverse Monte Carlo

  2. Hématome sous-capsulaire du foie

    Microsoft Academic Search

    P. Hohlfeld; W. Sanzeni

    1994-01-01

    Conclusion  Dans tous les cas, les patientes prsentant des douleurs abdominales irradiant dans l'paule, un choc, une ascite massive\\u000a ou un panchement pleural devraient subir une chographie pour exclure le diagnostic d'hmatome sous-capsulaire. Avant l'accouchement\\u000a il est prfrable d'associer une csarienne au traitement chirurgical de l'hmatome. Dans le post-partum, si l'hmatome nst\\u000a pas rompu et si l'tat de la patiente le

  3. Martyne Perrot Le monde sous globe

    E-print Network

    Paris-Sud XI, Université de

    « enfance du monde » : celle que construisirent, en le parcourant, des voyageurs illustres comme Marco Polo s'invente à chaque pas. Si Marco Polo réunit ses récits de voyage sous le titre Le Livre des mer

  4. Sous la direction de Pierre-Henri Gouyon

    E-print Network

    Sous la direction de Pierre-Henri Gouyon et Hélène Leriche l'environnement AUX ORIGINES DE Préface scientifique de Pierre-Henri Gouyon et Hélène Leriche Sous la direction éditoriale de Alexandrine Civard-Racinais Préface de Hubert Reeves Postface de Nicolas Hulot #12;4 LES DIRECTEURS SCIENTIFIQUES Pierre-Henri Gouyon

  5. Approche cognitive pour la planification de trajectoire sous

    E-print Network

    Paris-Sud XI, Université de

    Approche cognitive pour la planification de trajectoire sous contraintes TH`ESE pr´esent´ee et approche cognitive pour la planification de trajectoire sous contraintes. Elle repose en premier lieu sur'exploration produit par DKP progresse dans l'environnement. De plus, les comportements sont appliqués en fonction de

  6. Research of solar simulator irradiance non-uniformity measurement

    Microsoft Academic Search

    Yafei Yuan; Yiqiang Yang; Zhang Ya

    2011-01-01

    The irradiance non-uniformity on test plane of a large area pulsed solar simulator is critical for space solar array electrical characteristic measurement, because it is one of the main error souse of the measurement. Presently, the most commonly used irradiance non-uniformity measurement methods are \\

  7. SOUS-VIDE PROCESSED FOODS: SAFETY HAZARDS AND CONTROL OF MICROBIAL RISKS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concerns have been expressed about the public-health risks associated with sous-vide processed foods because the mild heat treatment applied to such foods to retain the organoleptic attributes may not be adequate to ensure proper destruction of pathogenic and spoilage organisms. The safety of sous-v...

  8. UNIVERSIT DE MONTPELLIER II Mmoires partages d'alignements sous-phrastiques bilingues

    E-print Network

    Paris-Sud XI, Université de

    UNIVERSITÉ DE MONTPELLIER II Mémoires partagées d'alignements sous-phrastiques bilingues par Johan intitulée: Mémoires partagées d'alignements sous-phrastiques bilingues présentée par: Johan Segura a été . . . . 117 4.1.2 Une correspondance bilingue entre SSTC : la S-SSTC . . . . . 122 4.2 Les structures

  9. Composes inter-halogenes sous pression: etude des transformations structurales dans le monobromure d'iode sous forme dense

    NASA Astrophysics Data System (ADS)

    Bouchard, Alexandre

    La famille des composes halogenes et inter-halogenes representent des solides moleculaires adoptant des phases denses communes avec des solides moleculaires diatomiques comme l'azote et l'hydrogene. Parmi les transformations structurales et electroniques induites sous haute pression et observees dans ces solides, on note, entre autres, la dissociation moleculaire et la metallisation. De plus, l'etude des phases denses de l'iode a permis recemment l'observation d'une structure cristalline possedant une modulation dite incommensurable, c'est-a-dire une modulation possedant une periodicite differente de celle de la structure cristalline, jetant ainsi une lumiere nouvelle sur le processus de dissociation moleculaire dans les solides halogenes. Dans ce memoire, on propose d'etudier les changements structuraux dans monobromure d'iode (IBr), un compose inter-halogene possedant des proprietes structurales semblables a celles de deux composes halogenes, soit l'iode (I 2) et le brome (Br2) sous leur forme solide. Des experiences de diffraction des rayons X de poudres en utilisant un rayonnement synchrotron ont ete realisees a temperature ambiante sur l'IBr en variant la pression jusqu'aux environs de 60 GPa. La nature chimique particuliere du compose IBr a necessite la mise au point de techniques de chargement d'echantillon destinees a preserver l'integrite chimique de la substance utilisee. On rapporte egalement l'observation d'une phase de l'IBr presentant une modulation incommensurable. Les phases observees dans l'IBr permettent d'etablir des paralleles avec les phases denses rapportees dans I2 et Br2 par le biais d'un modele phenomenologique decrivant la sequence structurale des solides halogenes sous forme condensee.

  10. 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

  11. 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

  12. ETUDE DE LA STABILITE D'ECHANTILLONS D'EAU CONTAMINES EN PESTICIDES SOUS DIFFERENTES CONDITIONS

    E-print Network

    Boyer, Edmond

    1 ETUDE DE LA STABILITE D'ECHANTILLONS D'EAU CONTAMINES EN PESTICIDES SOUS DIFFERENTES CONDITIONS recherche, le prélèvement et la conservation des échantillons d'eaux en vue du dosage des pesticides à l contaminés par 22 pesticides. Différentes modalités de conservation ont été testées. Parallèlement, les

  13. Ocanographie / Oceanography Bathymay : la structure sous-marine de Mayotte rvle par l'imagerie multifaisceaux

    E-print Network

    Boyer, Edmond

    Océanographie / Oceanography 1/24 Bathymay : la structure sous-marine de Mayotte révélée par l 338 (2006) 1240-1249" DOI : 10.1016/j.crte.2006.07.010 #12;Océanographie / Oceanography 2/24 Résumé La hal-00870100,version1-28Oct2013 #12;Océanographie / Oceanography 3/24 Abridged English version

  14. Les TIC dans les TPE : un investissement sous contraintes socio-conomiques et surtout individuelles.

    E-print Network

    Paris-Sud XI, Université de

    Les TIC dans les TPE : un investissement sous contraintes socio- économiques et surtout'une enquête réalisée auprès des entreprises artisanales de Bretagne sur leurs relations aux TIC (enquête par le non-équipement) en objets TIC dans ces TPE. Après avoir pré- senté une typologie des ces

  15. Sous la direction de Stphane Frioux et milie-Anne Ppy

    E-print Network

    Paris-Sud XI, Université de

    Sous la direction de Stéphane Frioux et Émilie-Anne Pépy Postface d'André Micoud L'animal sauvage entre nuisance et patrimoine ENS ÉDITIONS #12;#12;SOCIÉTÉS, ESPACES, TEMPS L'animal sauvage entre-Alpes Éléments de catalogage avant publication L'animal sauvage entre nuisance et patrimoine. France, xvie

  16. Comptes Rendus des JNC 17 -Poitiers 2011 Modlisation du comportement de composite matrice cramique sous

    E-print Network

    Boyer, Edmond

    composites oxidize, causing premature failure of the material. However, the creation of a self-healing matrixComptes Rendus des JNC 17 - Poitiers 2011 1 Modélisation du comportement de composite à matrice céramique sous sollicitation de fatigue Modeling of ceramic matrix composite behavior under fatigue loading

  17. Sous Zone 3 : Les gravures rupestres de lAdrar des Iforas

    E-print Network

    Paris-Sud XI, Université de

    Sous Zone 3 : Mali Les gravures rupestres de l·Adrar des Iforas Christian DUPUY Archéologue, Chargé, France) 1. Historique des recherches : Les premières mentions de la présence de gravures rupestres dans l, remontent à 1908 : elles sont dues au Capitaine Cortier. Les gravures de la région vont ensuite

  18. Caractrisation des sous-dynamiques et applications (cole CIMPA Bobo-Dioulaso)

    E-print Network

    Sablik, Mathieu

    -shift de type fini (SFT ) il existe un ensemble fini de motifs F tel que T = T(A,d,F) M. Sablik (LATP]) . Remarque : Par définition, on a: ClFT(FS) = SFT M. Sablik (LATP) Caractérisation des sous { , }Z les blocs de ont une longueur paire} Ainsi SFT ClFact(SFT) M. Sablik (LATP) Caractérisation des

  19. SPARATION DU RaD ET DU RaE PAR VAPORATION SOUS VIDE DES OXYDES

    E-print Network

    Boyer, Edmond

    recevoir 0,2 cm3 environ de solution, dans un circuit comprenant un potentiomètre, une batterie de 4 volts moins d'un centi- mètre, est placée une fine membrane de formvar aluminé sous-tendue par un anneau d'aluminium

  20. 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

  1. Amorphization of ?-Quartz under Irradiation

    NASA Astrophysics Data System (ADS)

    Douillard, L.; Duraud, J. P.

    1996-12-01

    The course of radiation induced damage produced in ?-quartz by neutrons, ions, electrons or photons — commonly known as metamictization — has been re-analyzed by careful comparison of available experimental data. Specific interest was devoted to confront experimental metamict state features with current structural models. It comes out that the metamict state of irradiated quartz should exhibit some structural characteristics of the modulated structure proposed for vitreous silica. The metamictization process is consistent with a structural relaxation process of a highly defective quartz matrix. According to this new point defect analysis, structural relaxation should be triggered by a critical concentration of oxygen vacancy point defects likely to significantly lower the connectivity of the SiO{2} network. Various experimental results are interpreted by incorporating the influence of the SiO{2} crystalline polymorph and the influence of the nature of the irradiating particle to the point defect model. Nous avons étudié les modifications de propriétés et de structures de monocristaux de quartz ?, consécutives à une irradiation sévère par des neutrons, des ions, des électrons ou des photons. Ce phénomène d'altération du quartz sous irradiation porte le nom de métamictisation. Notre travail exploite les recoupements de travaux antérieurs. Une attention particulière a été portée à la confrontation entre les données structurales expérimentales disponibles sur l'état métamicte du quartz et les modèles structuraux proposés. L'état métamicte du quartz présente ainsi les caractéristiques structurales du modèle de structure modulée, avancé pour décrire la structure de la silice thermique. Le mécanisme de métamictisation procéderait par relaxation de la matrice cristalline fortement endommagée. Ce phénomène de relaxation serait initié par l'apparition de concentration critique de défauts ponctuels de type lacunes d'oxygène responsables d'une forte augmentation des degrés de liberté des tétraèdres élémentaires SiO{4} au sein du crystal. Ce modèle de défaut ponctuel permet, par la prise en compte de la nature de la forme cristalline du dioxyde de silicium et la nature du projectile utilisé, de rendre compte de l'essentiel des donnés expérimentales.

  2. Irradiated foods

    MedlinePLUS

    ... and 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 for the control of insects on wheat and in certain spices and seasonings.

  3. Irradiation Information

    NSDL National Science Digital Library

    The Food Safety Consortium (FSC) is a federally created consortium consisting of researchers from the University of Arkansas, Iowa State University and Kansas State University. The FSC conducts research in poultry, beef, and pork production. This site contains summary articles from the FDA, the Washington Times, the Los Angeles Times, the Chicago Tribune, and newsletter articles from the FSC. Previously approved for use on poultry and fruits and vegetables in the US, irradiation can kill disease-causing bacteria like Salmonella and Escherichia coli 0157:H7 (discussed in the Scout Report for Science and Engineering's In the News section, September 17, 1997), and molds and funguses that cause rot. With recent US Food and Drug Administration (FDA) approval, irradiation can now be used to process red meat (e.g., beef, pork, lamb, and byproducts). The process involves exposing food to a source of radiation such as gamma rays from radioactive cobalt 60, cesium 137, or x-rays. No radioactive material is added to the product, and the technique is routinely used on grains and spices, as well as for sterilizing disposable medical devices. In spite of a number of tests conducted over the last 30 years substantiating its safety, irradiation has not gained widespread public acceptance in the US. This is largely due to the public's general fear of processes utilizing radiation. Supporters of the technology claim that it will virtually eliminate food-borne illness in the US, while skeptics feel that technology such as steam treatment can accomplish adequate sterilization without the purported risks and public concern associated with irradiation.

  4. REGIONES EMERGENTES EN URUGUAY, SUB-REGIN PLATA-MERCOSUR (NOUVEAUX TERRITOIRES EN URUGUAY, SOUS-RGION

    E-print Network

    1 REGIONES EMERGENTES EN URUGUAY, SUB-REGI�N PLATA- MERCOSUR (NOUVEAUX TERRITOIRES EN URUGUAY, SOUS, Uruguay halshs-00960472,version1-10Jun2014 Author manuscript, published in "1ère Conférence continuidad institucional del acuerdo del MERCOSUR como tal, sobre todo por la tensión entre Uruguay y

  5. Hesperis-Tamuda, Vol. XLV, (2010), pp. 75-88 LA PATRIMONIALISATION DE L'ARCHITECTURE PRODUITE SOUS

    E-print Network

    Boyer, Edmond

    2010-01-01

    Hesperis-Tamuda, Vol. XLV, (2010), pp. 75-88 LA PATRIMONIALISATION DE L'ARCHITECTURE PRODUITE SOUS présent article se propose d'engager une réflexion sur la patrimonialisation de l'architecture du XXe souhaiterions engager une étude sur le patrimoine en situation coloniale et postcoloniale - que l'on pourrait

  6. Attention : sous embargo Syndrome de Lynch : la biologie structurale en soutien de l'aide au diagnostic

    E-print Network

    van Tiggelen, Bart

    Attention : sous embargo Syndrome de Lynch : la biologie structurale en soutien de l'aide au syndrome de Lynch, une prédisposition génétique atomique de MLH1 permettra de mieux comprendre les syndrome de Lynch est une affection et du rectum. On estime que trois gènes appelés MLH1, MSH2 et MSH6, en

  7. Safer Food with Irradiation 

    E-print Network

    Thompson, Britta; Vestal, Andy; Van Laanen, Peggy

    2003-01-21

    This publication answers questions about food irradiation and how it helps prevent foodborne illnesses. Included are explanations of how irradiation works and its benefits. Irradiation is a safe method of preserving food quality and ensuring its...

  8. Analysis of the Seismicity Induced by Massive Fluid Injection in the HDR Geothermal Site of Soultz-sous-Forets (France)

    Microsoft Academic Search

    N. Cuenot; C. Dorbath; H. Haessler; L. Dorbath

    2002-01-01

    In july 2000 a stimulation experiment was performed at the Hot Dry Rock geothermal site of Soultz-sous-Forets (Alsace, France). During one week, a total of 23000 m3 of fluids were injected at 30, 40 and 50 l\\/s in a hot, fractured granitic massif at 5 km depth in order to enhance the fracture network. Induced microseismic events were recorded by

  9. The Enhanced Geothermal System of Soultz-sous-Forêts: A study of the relationships between fracture zones and calcite content

    Microsoft Academic Search

    Ronan L. Hébert; Béatrice Ledésert; Danièle Bartier; Chrystel Dezayes; Albert Genter; Céline Grall

    2010-01-01

    The Enhanced Geothermal System (EGS) of Soultz-sous-Forêts (France) is made of three boreholes (GPK2, GPK3 and GPK4). The hydraulic connection between the wells, which is crucial to get an efficient geothermal exchanger, may be unfortunately hindered by the more or less complete sealing of fractures by hydrothermal neoformed minerals. This paper takes over the recent work of the authors that

  10. Memoire de stage de DEA realise sous la direction de Patrick Cousot Laboratoire d'Informatique de l'ENS

    E-print Network

    Miné, Antoine

    M´emoire de stage de DEA r´ealis´e sous la direction de Patrick Cousot Laboratoire d fin de p, on a : +x + y 12 -x - y -12 Antoine Min´e - Soutenance de DEA, 18 septembre 2000 2 #12`edres; les invariants sont de la forme 1x1 + · · · + nxn c. Antoine Min´e - Soutenance de DEA, 18 septembre

  11. STRESS STATE AT SOULTZ-SOUS-FORÊTS TO 5 KM DEPTH FROM WELLBORE FAILURE AND HYDRAULIC OBSERVATIONS

    Microsoft Academic Search

    Benoît Valley; Keith F. Evans

    2007-01-01

    Observations of breakouts and drilling-induced tension fractures (DITFs) in two 5 km deep boreholes of the European Enhanced Geothermal Project of Soultz-sous-Forêts, France have been combined with the analysis of pressure data from stimulation tests in all 3 deep wells to obtained a description of the state of stress in the granite down to 5 km depth. The orientation of

  12. Modeling the non-standard behaviors observed during the tracer test at Soultz-sous-Forêts (France)

    Microsoft Academic Search

    S. S. Gentier; T. Tran Ngoc; X. Rachez; M. Peter-Borie; C. Souque

    2009-01-01

    Tracer test is largely used to understand hydraulic processes in geothermal fields. In the framework of the European Enhanced Geothermal System (EGS) project, a deep geothermal exchanger is in progress at Soultz-sous-Forêt (Alsace - northeast of France). The triplet is constituted by an injection well (GPK3) and two production wells (GPK2 and GPK4) drilled at a 5 km depth within

  13. 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

  14. 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.

  15. Évolution de leucémies myéloïdes chroniques sous nilotinib après échec a l'imatinib

    PubMed Central

    Sawadogo, Salifo; Hien, Francis Michel; Ouédraogo, Macaire Sampawendé; Drabo, Youssouf Joseph

    2014-01-01

    C'est une étude observationnelle prospective ouverte: quatre leucémies myéloïdes chroniques résistant ou intolérant à l'Imatinib ont été traitées par le Nilotinib. Elles ont été incluses dans le programme GIPAP et suivies selon les recommandations de “European LeukemiaNet”. Trois ont un score de Sokal de haut risque et une de bas risque. Deux étaient hypertendues. Mises sous Nilotinib, il y a eu deux rémissions cytogénétiques complètes et deux échecs. Le traitement a été interrompu chez les deux rémissions complètes, l'un pour effet secondaire du Nilotinib et l'autre pour changement de pays. Les deux échecs sont dus à des résistances. Le Nilotinib réduisant la fréquence des mutations des leucémies myéloïdes chroniques à haut risque et risque intermédiaire, il serait judicieux d'utiliser ce produit en première intention dans ces cas - ci pour réduire la charge des examens complémentaires. Les pays à bas revenu confrontés à des problèmes de survie ont besoin de la solidarité mondiale pour prendre en charge les leucémies myéloïdes chroniques. PMID:25419280

  16. Nasopharyngeal Radium Irradiation (NRI)

    MedlinePLUS

    ... CDC to assess the health risks associated with nasopharyngeal radium irradiation. This treatment was an accepted medical ... a workshop on "The Public Health Response to Nasopharyngeal Radium Irradiation." It brought together a diverse group ...

  17. 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.

  18. 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 local surface displacement in natural, in stimulation and production states of the geothermal plants. GNSS and INSAR are two spatial geodetic methods with millimeter accuracy. The GNSS provides information about the absolute 3D displacement at some point location. And the INSAR method gives high spatial (meters) information of relative displacement.

  19. L'innovation dans les services publics Aprs une longue phase de mconnaissance et de sous-estimation, la question de l'innovation

    E-print Network

    Paris-Sud XI, Université de

    Faridah DJELLAL Faïz GALLOUJ L'innovation dans les services publics Après une longue phase de méconnaissance et de sous-estimation, la question de l'innovation dans les services est désormais prise au cas de l'innovation dans les services publics. L'objectif de cet article est de proposer une relecture

  20. Beaujouan, J. ; Aubert, S. ; Coutarel, F. Formateur-animateur : un rle sous-estim et outiller dans la conception de dispositifs de formation.

    E-print Network

    Paris-Sud XI, Université de

    Beaujouan, J. ; Aubert, S. ; Coutarel, F. Formateur-animateur : un rôle sous-estimé et à outiller contre- perçage sur avion. J. Beaujouan1 , S. Aubert2 , F. Coutarel3 1,3 Maître de Conférences en formation à et par la pratique par le service Ergonomie d'un constructeur aéronautique (par exemple, Aubert

  1. Un isomorphisme motivique entre deux vari#t#s homog#nes projectives sous l'action d'un groupe de

    E-print Network

    Un isomorphisme motivique entre deux vari#t#s homog#nes projectives sous l est d'#tudier X (ff1) et X (ff2), les vari#t* *#s homog#nes pro- jectives associ#es # chacune#t#s homog#nes projectives . . . . . . . . . . . . . . . . . . . * *. . . . . . . 7 3.2 Foncteurs

  2. La jeunesse arabe et les nouveaux rseaux de la mondialisation : de la sous-culture globalise la contre-culture rvolutionnaire ?

    E-print Network

    Paris-Sud XI, Université de

    La jeunesse arabe et les nouveaux réseaux de la mondialisation : de la sous-culture globalisée à la.gonzalez@ifporient.org http://cpa.hypotheses.org La jeunesse arabe n'est pas difficile à trouver : la rue est son premier du spectacle de foules denses et surtout jeunes, le monde arabe, c'est d'abord la découverte de

  3. Le syndrome de Down, plus communment connu sous l'appellation de trisomie 21 s'accompagne trs souvent de pathologies que l'on

    E-print Network

    Rochaix, Jean-David

    Le syndrome de Down, plus communément connu sous l'appellation de «trisomie 21» s'accompagne très les personnes atteintes d'un syndrome de Down. L'étude ciblée et spécifique du chromosome 21 a révélé toute la population. La cardiopathie est un trouble fréquent du syndrome de Down. Si la présence d

  4. Installation de la distribution linux Ubuntu sous Windows La procdure dcrite dans ce document permet d'installer la distribution Ubuntu depuis un systme

    E-print Network

    Spiga, Aymeric

    V 1.1 1/3 Installation de la distribution linux Ubuntu sous Windows La procédure décrite dans ce document permet d'installer la distribution Ubuntu depuis un système Windows XP sans partitionnement ni préparation d'aucune sorte de son ordinateur. La désinstallation se fait aussi simplement que l'installation

  5. Soultz-sous-Forêts - What can inverse simulations contribute to the knowledge of hydro-geothermal system at the European EGS demonstration site?

    Microsoft Academic Search

    C. Kosack; V. Rath

    2009-01-01

    The European Enhanced Geothermal System (EGS) research project is located at Soultz-sous-Forêts at the western border of the Rhine rift valley. Three wells were drilled into the deep reservoir (4000 - 5000 m) within the granitic basement. Hydraulic stimulations produced additional mechanically damaged zones in the vicinity of the wells. In July 2005, a tracer was injected into the injector

  6. COMMUNIQU DE PRESSE NATIONAL I PARIS I 11 DECEMBRE 2013 ATTENTION ! Sous embargo jusqu'au 11/12/2013, 19H

    E-print Network

    Arleo, Angelo

    , sous l'effet du rayonnement solaire, à un réchauffement du climat terrestre à l'échelle des temps système solaire, il y a 4,5 milliards d'années, la luminosité du Soleil était égale à 70 % de sa valeur l'effet d'une augmentation très forte du flux solaire induisant l'évaporation de l'eau liquide dans

  7. Actes de l'atelier, 22-23 janvier 2001, Montpellier, France 11 L'irrigation aborde sous l'angle de la gestion

    E-print Network

    Paris-Sud XI, Université de

    Actes de l'atelier, 22-23 janvier 2001, Montpellier, France 11 L'irrigation abordée sous l'angle de parties prenantes Thierry RUF Ird, UrO44 Dynamiques sociales de l'irrigation, BP 5045, 34032 Montpellier comprendre la gestion communautaire de l'irrigation. Nous nous référons à deux réunions scientifiques

  8. 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 électromécaniques et thermiques. La procédure est gérée par une méthode d'optimisation déterministe de type Programmation Quadratique Séquentielle. Elle intègre l'influence du convertisseur au moyen de deux spécificités : la première consiste à évaluer les fonctions du problème d'optimisation sur la base du module d'analyse pluridisciplinaire ; la deuxième permet de contrôler l'évolution du dimensionnement au travers de variables d'optimisation dont la liste inclut les consignes de la commande en courant du convertisseur. Les difficultés d'optimisation liées au mode de fonctionnement discret du convertisseur sont discutées au regard du calcul de la sensibilité du couple électromagnétique envers la consigne de courant du convertisseur ; une méthode est proposée pour assurer la robustesse de la procédure en présence du convertisseur. L'application porte sur le dimensionnement d'un moteur à aimants permanents de type “brushless trapézoïdal" destiné à la traction d'un scooter électrique ; l'évolution de la structure optimale avec le degré de complexité du module d'analyse est mise en évidence.

  9. Safer Food with Irradiation (Spanish) 

    E-print Network

    Thompson, Britta; Vestal, Andy; Van Laanen, Peggy

    2003-01-21

    This publication answers questions about food irradiation and how it helps prevent foodborne illnesses. Included are explanations of how irradiation works and its benefits. Irradiation is a safe method of preserving food quality and ensuring its...

  10. 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.

  11. 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 régime thermique transitoire; l'influence des paramètres de commande du convertisseur est examinée.

  12. Irradiation-Induced Nanostructures

    SciTech Connect

    Birtcher, R.C.; Ewing, R.C.; Matzke, Hj.; Meldrum, A.; Newcomer, P.P.; Wang, L.M.; Wang, S.X.; Weber, W.J.

    1999-08-09

    This paper summarizes the results of the studies of the irradiation-induced formation of nanostructures, where the injected interstitials from the source of irradiation are not major components of the nanophase. This phenomena has been observed by in situ transmission electron microscopy (TEM) in a number of intermetallic compounds and ceramics during high-energy electron or ion irradiations when the ions completely penetrate through the specimen. Beginning with single crystals, electron or ion irradiation in a certain temperature range may result in nanostructures composed of amorphous domains and nanocrystals with either the original composition and crystal structure or new nanophases formed by decomposition of the target material. The phenomenon has also been observed in natural materials which have suffered irradiation from the decay of constituent radioactive elements and in nuclear reactor fuels which have been irradiated by fission neutrons and other fission products. The mechanisms involved in the process of this nanophase formation are discussed in terms of the evolution of displacement cascades, radiation-induced defect accumulation, radiation-induced segregation and phase decomposition, as well as the competition between irradiation-induced amorphization and recrystallization.

  13. Gamma irradiation facilities

    NASA Astrophysics Data System (ADS)

    Tamura, Naoyuki

    A review is presented on the status and problem of gamma irradiation facilities for radiation processing. Requirements for the radioisotope source in the radiation processing and its comparison with electron accelerator are discussed. The gamma radioisotope source has speciality in the process of thicker products and source design, though it is inferior on the cost of radiation output. Problems on irradiation facilities such as storage and transportation of the source, the damage of materials used, and dosimetry are discussed. The gamma irradiation facilities for the radiation processing in Japan are introduced.

  14. 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.

  15. Blood irradiation: Rationale and technique

    SciTech Connect

    Lewis, M.C. (Savannah Regional Center for Cancer Care, Memorial Medical Center, GA (USA))

    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.

  16. Analysis of the Microseismicity Induced by Fluid Injections at the EGS Site of Soultz-sous-Forêts (Alsace, France): Implications for the Characterization of the Geothermal Reservoir Properties

    Microsoft Academic Search

    Nicolas Cuenot; Catherine Dorbath; Louis Dorbath

    2008-01-01

    In June\\/July 2000, a hydraulic stimulation experiment took place at the geothermal EGS site of Soultz-sous-Forêts (Alsace,\\u000a France) in order to enhance the permeability of the fractured granitic massif at 5 km depth. As it is well known that fluid\\u000a injections tend to induce microseismic events, a downhole and a surface seismological network have been installed to monitor\\u000a the seismic activity

  17. Source mechanisms of micro-earthquakes induced in hydraulic fracturing experiment at the HDR site Soultz-sous-Forêts (Alsace) in 2003 and their temporal and spatial variations

    Microsoft Academic Search

    J. Horálek; L. Dorbath; Z. Jechumtálová; J. Sílený

    2009-01-01

    We have investigated source mechanisms of microearthquakes induced in the 2003 hydrofracturing experiment in the GPK3 borehole of the Soultz-sous-Forêts Hot Dry Rock facility (located in the Rhine Graben) and their time and space distribution. During this massive hydrofatcturing a total of 34000m3 fluids with the wellhead pressure up to18 MPa were injected and about 5000 microearthquakes in the magnitude

  18. 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 realized with the thermodynamic and kinetic approaches that only differ in that the precipitation of the main minerals including quartz, calcite, and illites was treated thermodynamically and kinetically. The two approaches have other identical factors such as: all primary minerals are dissolved kinetically; other secondary minerals are formed at equilibrium. The modeling results showed that reaction pathways predicted by two approaches were slightly different. The difference was clearly indicated by the precipitation amount of quartz, calcite and illites, as well as the formation patterns of these minerals. Moreover, the difference in reaction pathways was also demonstrated by the activity diagrams, which presented th@unistra.fre relationship of various mineral groups. Altogether, the system stability fell in the stability zones of the main minerals such as calcite, illites. These findings highlighted the importance of the minerals like quartz, calcite, and illites. Our work further suggested that the kinetic approach would be more appropriate for the coupled thermo-hydro-chemical model in order to predict the long term evolution of the geothermal reservoir. This method can be applied with a great benefit to other geothermal reservoirs for a better understanding of the mineralogy evolution. References: Balderyou et al., Comptes Rendus Geoscience 335(4), 371-380; Dubois et al., Earth and Planetary Science 331(4), 303-309; Fritz et al., Comptes Rendus Geoscience 342(7-8), 653-667; Ledésert et al., Comptes Rendus Geoscience 342(7-8), 607-615; Ledésert et al., Journal of Volcanology and Geothermal Research 181(1-2), 106-114.

  19. 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.

  20. 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.

  1. Irradiation Stability of Carbon Nanotubes 

    E-print Network

    Aitkaliyeva, Assel

    2010-01-14

    Ion irradiation of carbon nanotubes is a tool that can be used to achieve modification of the structure. Irradiation stability of carbon nanotubes was studied by ion and electron bombardment of the samples. Different ion ...

  2. 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...

  3. Update on meat irradiation

    SciTech Connect

    Olson, D.G. [Iowa State Univ., Ames, IA (United States)

    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.

  4. Uniform high irradiance source

    NASA Technical Reports Server (NTRS)

    Lunde, A. R.; Fortini, A.; Buchele, D. R.

    1975-01-01

    New 50 Kw xenon short arc lamp mounted within elliptical collector provides irradiance levels up to 4.4 x 10 to the 7th power watts/sq m with non-uniformity ratio of 3.30. Energy mixer or light pipe between lamp source and target improves non-uniformity to required ratio.

  5. 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 ...

  6. Combination processes in food irradiation

    Microsoft Academic Search

    B. R. Thakur; R. K. Singh

    1995-01-01

    Irradiation is emerging as a potential method of food preservation. It is being used to extend the shelf life of raw and processed foods in many countries worldwide. Like all other methods of food preservation, irradiation has a number of limitations. Irradiation, when used alone, can cause the development of undesirable sensory and chemical changes in some foods, depending on

  7. Comparaison des effets des irradiations ?, X et UV dans les fibres optiques

    NASA Astrophysics Data System (ADS)

    Girard, S.; Ouerdane, Y.; Baggio, J.; Boukenter, A.; Meunier, J.-P.; Leray, J.-L.

    2005-06-01

    Les fibres optiques présentent de nombreux avantages incitant à les intégrer dans des applications devant résister aux environnements radiatifs associés aux domaines civil, spatial ou militaire. Cependant, leur exposition à un rayonnement entraîne la création de défauts ponctuels dans la silice amorphe pure ou dopée qui constitue les différentes parties de la fibre optique. Ces défauts causent, en particulier, une augmentation transitoire de l'atténuation linéique des fibres optiques responsable de la dégradation voire de la perte du signal propagé dans celles-ci. Dans cet article, nous comparons les effets de deux types d'irradiation: une impulsion X et une dose ? cumulée. Les effets de ces irradiations sont ensuite comparés avec ceux induits par une insolation ultraviolette (244 nm) sur les propriétés d'absorption des fibres optiques. Nous montrons qu'il existe des similitudes entre ces différentes excitations et qu'il est possible, sous certaines conditions, d'utiliser celles-ci afin d'évaluer la capacité de certaines fibres optiques à fonctionner dans un environnement nucléaire donné.

  8. Why the seismicity induced in Soultz-sous-Forêts and Gross Schoenebeck enhanced geothermal fields are so different? (Invited)

    NASA Astrophysics Data System (ADS)

    Gaucher, E.; Kohl, T.

    2013-12-01

    In enhanced geothermal systems, hydraulic fracturing and hydraulic stimulation are techniques used to increase the reservoir permeability. Their secondary effect, the induced seismicity, is a unique means to image the fault network created or reactivated by the operations. The interpretation of the results for this latter application is however limited by the capabilities of the seismic network and by our understanding of the involved physical processes. Here, we propose to highlight systematic behaviors of the seismicity induced in enhanced geothermal reservoirs. This is performed through the analysis of two EGS sites which appear to behave very differently in terms of induced seismicity: the Soultz-sous-Forêts (France) and the Gross Schoenebeck (Germany) fields. Several physics-based models have been tested for these fields and these observations should be used to calibrate them and the underlying physical assumptions. The Soultz-sous-Forêts (France) geothermal field is located in the Upper Rhine valley. Over the development of this EGS, four wells have been drilled into the granitic basement, up to 5 km depth, and eight major stimulations were carried out to create the heat exchanger. Several major observations based on the large induced seismicity database have been made and can apply on other EGS. Hence, it was noticed that a) the induced seismicity mainly occurs along planar features, b) during stimulation, the induced seismicity becomes stronger over time and this is still observed after shut-in. Most often, the largest magnitude microearthquake occurs following shut-in, c) over a certain overpressure threshold, seismicity can be induced and also a clear Kaiser effect can be observed for already stimulated volumes, d) the stimulation and the circulation periods induce different seismic responses. At Gross Schoenebeck (Germany), the Dethlingen sandstones and the underlying andesitic volcanic rocks of the Rotliegend formation of the North German Basin constitute the target reservoirs. Six major stimulations of the well doublet carried out around or deeper than 4.2 km created hydrofractures. The three seismically monitored operations highlighted very weak seismic responses in terms of energy and quantity. Only 78 microearthquakes were identified during the major operation which involved ~13,000 m3 of injected water and which is a volume comparable to that injected at Soultz. Such seismogenic behavior is consistent with the creation of hydrofractures and with a mechanism of dilatant shear. Interestingly, the strongest microearthquakes (Mw ? -1) occurred on a pre-existing fault and similar observations were already made in hydrofractured oil and gas reservoir. Seemingly, the sudden increase of the seismic moment of the microearthquakes and the decrease of the b-value are indicators of the reactivation of pre-existing fractures from the newly created one. As underlined by these case studies where fluid stimulation was always involved, the observation of induced seismicity may drastically change; and we will try to identify the reasons of these differences and propose directions to get better understanding.

  9. Identification of irradiated foods

    SciTech Connect

    Morehouse, K.M.

    1992-01-01

    A reliable method is needed to determine if foods have been irradiated and are in compliance with respect to the allowable absorbed radiation dose. Several approaches for the identification of irradiated foods are under development worldwide. These include measurement of o-tyrosine, radiolytically generated hydrocarbons from lipids and chemiluminescence or thermoluminescence, and the use of electron spin resonance (ESR) to measure free radicals trapped in calcified tissues. This paper describes the efforts being undertaken at the FDA to develop analytical procedures to monitor and identify foods that have been treated with ionizing radiation. In particular, it focuses on the use of an ESR approach to measure radiation-induced free radicals trapped in calcified tissues and the use of a capillary gas chromatography (GC)-based procedure to determine radiolytically generated hydrocarbons formed by the radiolysis of lipids in various foods.

  10. Detection of irradiated food

    Microsoft Academic Search

    W. G. Hein; T. J. Simat; H. Steinhart

    2000-01-01

    o-Tyrosine is proposed as a marker for the identification of irradiated protein-rich food. The disadvantages of most of the\\u000a published methods are insufficient selectivity and the relatively high values of o-tyrosine in unirradiated samples. A method for the analysis of non-protein-bound o-tyrosine in common shrimps is presented here. The procedure involves the homogenization of fresh shrimps followed by solvent\\u000a precipitation

  11. 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.

  12. 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

  13. 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

  14. The Enhanced Geothermal System of Soultz-sous-Forêts: A study of the relationships between fracture zones and calcite content

    NASA Astrophysics Data System (ADS)

    Hébert, Ronan L.; Ledésert, Béatrice; Bartier, Danièle; Dezayes, Chrystel; Genter, Albert; Grall, Céline

    2010-09-01

    The Enhanced Geothermal System (EGS) of Soultz-sous-Forêts (France) is made of three boreholes (GPK2, GPK3 and GPK4). The hydraulic connection between the wells, which is crucial to get an efficient geothermal exchanger, may be unfortunately hindered by the more or less complete sealing of fractures by hydrothermal neoformed minerals. This paper takes over the recent work of the authors that quantified the amounts of calcite on a random sampling within the three boreholes in order to assess the role of this mineral on the exchanger zone and in particular its influence on the permeability of the flow pathways. In the present study we focused the sampling on the fracture zones that have been identified as flow pathways. Now, all the three wells show high (above 10 wt.%) and moderate to low (between 2.0 and 7.0 wt.%) calcite anomalies. In GPK2, fracture zones with a high conductivity are characterized by high calcite content, and those with a low conductivity by low calcite content. The fracture zones of GPK3 show the opposite relationship: the most efficient flow pathways have a low calcite content, whilst the less conductive show a high calcite content. Fluid flow in GPK4 is mainly accommodated by the fracture zone at 4775 m MD that is not calcite rich. The other fracture zones of GPK4, which are interpreted with a similar and low conductivity, show low, moderate and high calcite contents. These data show clearly that GPK2 is different from GPK3 and GPK4, these two later being more comparable. It suggests that the fracture zones themselves may be of different type, and that the connectivity to the fracture network may be different too. This difference of behaviour is consistent with microseismicity data showing that GPK2 is characterized by a rather compact and well structured network of medium-scale fracture whereas GPK3 and GPK4 are altogether characterized by more localized and discrete fracture zones. Some issues remain such as the occurrence of calcite anomalies with no evident relationship with fracture zones, as well as the occurrence of identified flow pathways with no abnormal calcite content.

  15. Prophylactic neck irradiation

    SciTech Connect

    Rabuzzi, D.D.; Chung, C.T.; Sagerman, R.H.

    1980-08-01

    Treatment of subclinical cervical metastases from advanced squamous carcinomas of the nasopharynx, oropharynx, oral cavity, hypopharynx, and larynx remains contentious. Watchful waiting, elective neck surgery, and more recently, neck irradiation all have their advocates. The possibility of sterilization of the neck showing no clinical signs of metastasis has been especially appealing in concept. With this in mind, and by use of an external high-dose megavoltage technique, radiation therapy was used in 152 patients with clinically negative necks at the Upstate Medical Center from 1968 to 1977. Lymph node failures were extremely low (4%) when wide-field radiation ports were used and the primary lesion controlled.

  16. George Sand et le thtre de Nohant : l'intimit de la cration dramatique Tout au long de sa vie, George Sand s'intresse au thtre sous toutes ses formes

    E-print Network

    Paris-Sud XI, Université de

    1 George Sand et le théâtre de Nohant : l'intimité de la création dramatique Tout au long de sa vie, George Sand s'intéresse au théâtre sous toutes ses formes et en particulier à ses formes marginales questions esthétiques, philosophiques et psychologiques que s'est posées George Sand pendant toute sa vie 2

  17. D'une scne l'autre. Construction de l'obscnit dans les narrations factieuses la Renaissance , dans Obscnits Renaissantes, sous la dir. de H. Roberts G. Peureux et L. Wajeman, volume issu du Research network on

    E-print Network

    Paris-Sud XI, Université de

    Renaissance », dans Obscénités Renaissantes, sous la dir. de H. Roberts G. Peureux et L. Wajeman, volume issu du Research network on the notion of obscenity in Renaissance France (2007-2009), Genève, Droz, 2011, pp. 335-348 Résumé : les histoires comiques de la Renaissance recèlent souvent un contenu obscène

  18. Food Irradiation for Produce Safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A research priority for the produce industry is the development of an effective, safe and commercially applicable kill step. Irradiation is a nonthermal process that has been shown to inactivate human pathogens from fruits and vegetables. Irradiation treatment at 1.0 kGy can reduce the surface popul...

  19. Irradiation induced salivary gland neoplasia

    SciTech Connect

    Sener, S.F.; Scanlon, E.F.

    1980-03-01

    Twenty-six patients with a prior history of irradiation for benign conditions of the head and neck and salivary gland abnormalities are reported. All the patients had preoperative physical findings suggestive of tumor, not glandular infection. Forty-six per cent of the patients had one carcinoma and 11% had two carcinomas within the irradiated field. Eight of the 11 malignant tumors in these 26 patients were in the parotid gland. The nonmalignant salivary changes were similar to those previously reported in glands receiving therapeutic irradiation for carcinoma.

  20. [Cutaneous angiosarcoma after telecobalt irradiation].

    PubMed

    Laaff, H; Vibrans, U

    1992-10-01

    Cutaneous angiosarcomas are rare neoplasms. They occur most frequently on areas of skin exposed to sunlight in the elderly, or in long-standing lymphoedema (Stewart-Treves syndrome). Radiation is an important aetiological factor. With only 1 exception, the 34 published cases of cutaneous angiosarcoma on the trunk were caused by irradiation of internal tumours, occurring between 4 and 50 years after the irradiation treatment. The prognosis quoad vitam is poor. The tumours should be removed surgically. When they are inoperable, irradiation is an alternative therapeutic option. The aim of this paper is to show the histological differential diagnosis of cutaneous angiosarcomas and to demonstrate problems with the treatment. PMID:1428875

  1. Statistical criteria for characterizing irradiance time series

    Microsoft Academic Search

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

    2010-01-01

    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

  2. Sanitary safety of irradiated foods

    NASA Astrophysics Data System (ADS)

    Wolf, A.

    Consideration on the acceptability of the irradiation of food, especially from the toxicological point of view, is presented. The conditions of the potencial permission of the preservation of food by radiation in CSSR are briefly given.

  3. 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.

  4. 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.

  5. Lithium Irradiation Experiment

    SciTech Connect

    Leveling, A.F.; /Fermilab

    2000-08-22

    The subject of tritium production in the Antiproton Source Collection lens was raised in the mid-1980s during the design phase of the pbar source. Interest in it has recurred during development of the proton lens and in recent investigations to determine the feasibility of liquid lithium collection lenses for the pbar source and a muon collider project. Calculations for tritium and beryllium 7 production on lithium suffer from a lack of information on medium and high energy cross section data. In addition, knowledge of the energy spectrum within the target vault is based upon calculations. Knowledge of the low energy spectrum, important for tritium production on lithium, is limited, if not non-existent. For Collider Run II, effort is to be applied to improve the performance of the solid lithium lens. Historically, examination of failed lithium lenses has not been pursued because they have been fairly radioactive and because they are thought to contain significant quantities of the radionuclides tritium and beryllium 7. The development of methods to examine failed lithium lenses may be desirable so that the specific causes of failure can be discovered. From such studies, design improvements can be incorporated with the goal of achieving lens performances goals related to Collider Run II. The purpose of the lithium irradiation experiment is to determine the production rates of radioisotopes tritium and beryllium 7 within the lithium lens in its operating in its operating environment.

  6. (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.

  7. Consumer attitudes toward irradiated food

    SciTech Connect

    Conley, S. [USDA, Washington, DC (United States)

    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.

  8. before and after gamma irradiation

    NASA Astrophysics Data System (ADS)

    Habib, Zubida; Ikram, M.; Majid, Kowsar; Asokan, K.

    2014-09-01

    A series of samples of HoFe1- x Ni x O3 ( x = 0.0, 0.1, 0.3) were prepared using the solid-state reaction technique to understand the structural, dielectric and conductivity properties before and after gamma irradiation of accumulated dose of 625 KGy. The X-ray diffraction confirms that all the samples exist in single-phase orthorhombic structure having space group Pbnm. With increasing dopant Ni, the unit cell volume and lattice parameters undergo small change. X-ray analysis show change in the interplanar spacing and full width at half maximum values after gamma irradiation. The Raman spectra of the samples show modifications after gamma irradiation. It can be easily seen that after gamma irradiation intensity, peak width are completely altered by gamma-absorbed dose. Measurement of dielectric loss and dielectric constant at room temperature was performed before and after gamma irradiation in the frequency range of 20 Hz-1 MHz. It is observed that the value of dielectric constant decreases after irradiation. The ac conductivity is estimated from the dielectric constant and loss tangent. Exposure to gamma radiation results in substantial modification in the physical properties of the Ni-doped Ho-based orthoferrites.

  9. Restenosis after pulsed laser irradiation

    NASA Astrophysics Data System (ADS)

    Kvasnicka, Jan; Geschwind, Herbert J.; Nakamura, Fumitaka; Asada, Masakatsu; Levame, Micheline; Bousbaa, Hassan

    1993-06-01

    This study was designed to assess the depth and extent of chronic lesions induced by clinically relevant doses of excimer or Ho:YAG laser irradiation in an animal model of normal arterial wall. Normal iliac arteries of 14 male New Zealand rabbits were irradiated with excimer laser and 7 contralateral sites were irradiated with Ho:YAG laser. The lasers were coupled to a 1.4 and 1.5 mm multifiber wire guided catheter for excimer and Ho:YAG laser, respectively. The catheter was introduced through the carotid artery and positioned coaxially over the guide wire into the common iliac artery. After 28 days the irradiated sites were excised for light microscopy. Arterial wall lesions were assessed at the site of irradiation and at 30 mm antegrade to the site of intervention. (1) Excimer and Ho:YAG induce chronic arterial wall damage, which may result in accelerated restenosis. (2) Ho:YAG results in deeper and more extensive lesions than excimer. (3) Both lasers induce an initial vasodilation in the irradiated vessel which disappears at follow-up.

  10. Effect of microwave irradiation on TATB explosive

    Microsoft Academic Search

    Weifei Yu; Tonglai Zhang; Yigang Huang; Li Yang; Gang Li; Haibo Li; Jinshan Li; Hui Huang

    2009-01-01

    Finished TATB (1,3,5-triamino-2,4,6-trinitrobenzene) explosive safety under 800W microwave irradiation was experimented. No burning, deflagration and detonation were observed during 30-min continuous irradiation and no remarkable change were observed after irradiation according to HPLC, particles size analysis, and differential thermal analysis. Wet TATB sampled from synthesis line was irradiated with microwave vacuum method and irradiated TATB was measured to accord with

  11. Thse prpare dans le laboratoire LAGIS de l'cole Centrale de Lille et au LACS de l'cole Nationale d'Ingnieurs de Tunis, sous la direction des Professeurs P.Borne et M. Ksouri

    E-print Network

    Boyer, Edmond

    '�cole Nationale d'Ingénieurs de Tunis, sous la direction des Professeurs P.Borne et M. Ksouri �COLE CENTRALE DE LILLE UNIVERSIT� DE TUNIS EL MANAR �COLE NATIONALE D'ING�NIEURS DE TUNIS TH�SE Présentée en vue d'�cole Nationale d'Ingénieurs de Tunis Titre de la thèse : OPTIMISATION HEURISTIQUE POUR LA R�SOLUTION DU m

  12. Utilisation de la micromorphologie pour l'étude des relations trophiques dans le sol: la couche L d'un moder hydromorphe sous Pinus sylvestris (Forêt d'Orléans, France)

    Microsoft Academic Search

    J. F. Ponge

    1985-01-01

    Au cours d'investigations morphologiques dans la couche L d'un humus de type moder sous pin sylvestre, des différences notables concernant l'exploitation des ressources par les animaux du sol (particulièrement les vers Enchytréides, les Oribates, les Collemboles et les larves de Diptères) ont été trouvées entre les niveaux L1 et L2. Dans le premier niveau la mousse vivante est principalement consommée

  13. 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.

  14. Irradiation Resistance of Multicomponent Alloys

    NASA Astrophysics Data System (ADS)

    Egami, T.; Guo, W.; Rack, P. D.; Nagase, T.

    2014-01-01

    High-entropy alloys (HEAs) are characterized not only by high values of entropy but also by high atomic-level stresses originating from mixing of elements with different atomic sizes. Particle irradiation on solids produces atomic displacements and thermal spikes. The high atomic-level stresses in HEAs facilitate amorphization upon particle irradiation, followed by local melting and re-crystallization due to thermal spikes. We speculate that this process will leave much less defects in HEAs than in conventional alloys. For this reason, they may be excellent candidates as new nuclear materials. We discuss initial results of computer simulation on model binary alloys and an electron microscopy study on Zr-Hf-Nb alloys, which demonstrate extremely high irradiation resistance of these alloys against electron damage to support this speculation.

  15. Food Irradiation: What You Need to Know

    MedlinePLUS

    ... extend the shelf life of foods. Control of Insects – irradiation can be used to destroy insects in or on tropical fruits imported into the United States. Irradiation also decreases the need for other pest-control ...

  16. 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.

  17. 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. PMID:22112522

  18. Different behaviours of the seismic velocity field at Soultz-sous-Forêts revealed by 4-D seismic tomography: case study of GPK3 and GPK2 injection tests

    NASA Astrophysics Data System (ADS)

    Calò, Marco; Dorbath, Catherine

    2013-08-01

    The geothermal power plant of Soultz-sous-Forêts in Northeastern France consists of three boreholes (GPK2, GPK3, GPK4) reaching a depth of about 5 km. All the wells were stimulated through hydraulic injections. In this study, we present the results of a time-dependent (4-D) seismic tomography obtained with the P-wave arrival times of seismic events recorded in 2003 during the stimulation of the GPK3 well. The method combines double-difference tomography with the Weighted Average Model post-processing that corrects for parameter dependence effects. In light of additional processing of the continuous seismic records of 23 surface stations, some 4728 precisely located events were selected and separated into 13 subsets to examine periods defined with respect to the injection scheme. Particular attention is given to changes in injected flow rates, periods of stationary injection conditions, periods of dual stimulation with the GPK2 well and post-injection periods. Results confirm that significant structures crossing the well have controlled the evolution of the seismicity and have played a fundamental role in the distribution and amplitude of the seismic anomalies. Furthermore, the evolution of the seismic velocity field, together with the representation of the relocated seismicity, have been compared with the results of the 4-D tomography of the GPK2 well, which is located at only 600 m from the stimulated well.

  19. 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.

  20. KILLING SILKWORM COCOONS BY IRRADIATION

    Microsoft Academic Search

    Tsetskhladze

    1962-01-01

    The results of investigations of silkworm cocoon killing by irradiation ; are given. It is shown that the method is a very perspective one. Its ; industrial realization will give both increased raw silk yield and improved ; dynamometric characteristics of silk thread. (auth);

  1. Food irradiation: regulations and acceptance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food irradiation is an effective technology for reducing harmful pathogens and insect pests on meats, poultry, seafood and fruits and vegetables. Although it is one of the most extensively researched nonthermal food processing technologies, its commercial adoption remains relatively limited. Regulat...

  2. 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. PMID:17440329

  3. GAS TRANSMISSION IN IRRADIATED POLYETHYLENE

    Microsoft Academic Search

    Harris J. Bixler; Alan S. Michaels; Morris Salame

    1963-01-01

    The transmission of helium, nitrogen, methane, and propane was studied ; in samples of a high pressure, branched polyethylene (46% crystalline) irradiated ; to a dose in air of 10⁸ roentgens from a Co⁶° source. By using a ; time-lag apparatus the permeability, diffusion, and solubility constants were ; measured in the temperature range 0 to 55 nif- C. These

  4. Irradiation effects on graphite foam

    Microsoft Academic Search

    Nidia C. Gallego; Timothy D. Burchell; James W. Klett

    2006-01-01

    The solid state reactor is an advanced reactor concept that takes advantage of newly developed materials with enhanced heat transfer characteristics to provide an inherently safe, self-regulated heat source. High conductivity graphite foam, developed and produced at Oak Ridge National Laboratory, is being evaluated as a candidate material for the core of basic heat source modules.Irradiation studies at the Oak

  5. 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.

  6. SORCE Solar Irradiance Data Products

    NASA Astrophysics Data System (ADS)

    Lindholm, D. M.; Pankratz, C. K.; Knapp, B. G.; Meisner, R.; Fontenla, J.; Harder, J. W.; McClintock, W. E.; Kopp, G.; Snow, M.; Woods, T. N.

    2007-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado manages the SOlar Radiation and Climate Experiment (SORCE) Science Data System. This data processing system routinely produces Total Solar Irradiance (TSI) and Spectral Solar Irradiance (SSI) data products, which are formulated using measurements from the four primary instruments on board the SORCE spacecraft. The TIM instrument provides measurements of the TSI, whereas the SIM, SOLSTICE, and XPS instruments collectively provide measurements of the solar irradiance spectrum from 1 nm to 2400 nm (excluding 31-115nm, which is measured by the SEE instrument on NASA's TIMED mission). The SORCE Science Data System utilizes raw spacecraft and instrument telemetry, calibration data, and other ancillary information to produce a variety of solar irradiance data products that have been corrected for all known instrumental and operational factors. Since launch of the SORCE spacecraft in January 2003, science processing algorithms have continued to mature, and "Level 3" data products (time-averaged and/or spectrally resampled onto uniform wavelength scales) are routinely being produced and delivered to the public via the SORCE web site, and are archived at the Goddard Earth Sciences (GES) Data and Information Services Center (DISC, formerly DAAC). This poster provides an overview of the SORCE data processing system, summarizes the present state of the processing algorithms and future plans, describes the quality of the current SORCE data products, and provides details on how to access SORCE science data.

  7. EXPERIMENTAL ANTHRAX INFECTION IN IRRADIATED ANIMALS

    Microsoft Academic Search

    A. P. Krasilnikov; N. A. Izraitel

    1959-01-01

    ABS>The experiments were staged on white mice. The following was ; studied: the natural resistance of irradiated animals to experimental infection, ; with B. anthraois in dependence to the terms of infection following irradiation, ; the doses oi irradiation and the site of introduction of the infectious matter; ; the time of the onset and the duration of bacteremia and

  8. Irradiation-induced phenomena in carbon

    E-print Network

    Krasheninnikov, Arkady V.

    Chapter 1 Irradiation-induced phenomena in carbon nanotubes To appear in "Chemistry of Carbon@acclab.helsinki.fi 1 #12;2CHAPTER 1. IRRADIATION-INDUCED PHENOMENA IN CARBON NANOTUBES #12;Contents 1 Irradiation-induced phenomena in carbon nanotubes 1 1.1 Introduction

  9. Food irradiation: research and technology, preface

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many interesting and exciting developments have occurred in the field of food irradiation since the publication of the first edition of Food Irradiation: Research and Technology in 2006. The 2nd edition of the book reviews our latest knowledge on food irradiation, highlights the current developments...

  10. Effects of mediastinal irradiation on oesophageal function

    Microsoft Academic Search

    E Yeoh; R H Holloway; A Russo; M Tippett; H Bermingham; B Chatterton; M Horowitz

    1996-01-01

    Although it is well recognised that oesophageal symptoms are common during therapeutic mediastinal irradiation of intrathoracic malignant diseases, the effects of mediastinal irradiation on oesophageal function are poorly defined. To clarify the pathogenesis of these sequelae a prospective study was performed to document comprehensively the effects of mediastinal irradiation on oesophageal function. Oesophageal symptoms, barium swallow, endoscopy, and combined radionuclide

  11. Effect of microwave irradiation on TATB explosive.

    PubMed

    Yu, Weifei; Zhang, Tonglai; Huang, Yigang; Yang, Li; Li, Gang; Li, Haibo; Li, Jinshan; Huang, Hui

    2009-09-15

    Finished TATB (1,3,5-triamino-2,4,6-trinitrobenzene) explosive safety under 800W microwave irradiation was experimented. No burning, deflagration and detonation were observed during 30-min continuous irradiation and no remarkable change were observed after irradiation according to HPLC, particles size analysis, and differential thermal analysis. Wet TATB sampled from synthesis line was irradiated with microwave vacuum method and irradiated TATB was measured to accord with military standard specifications including appearance, moisture and volatile, chloride content, HPLC, mean particle size, DTA exothermic peak, ash, acetone soluble content, PH value, etc. Microwave vacuum desiccation was deemed laborsaving, energy-efficient, and practicable compared to conventional processing method. PMID:19324496

  12. Design of YCF-1 mobile ? irradiator

    NASA Astrophysics Data System (ADS)

    Hehu, Zhang; Chuanzhen, Wang

    1993-07-01

    YCF-1 Mobile irradiator is designed by BINE of China. It has been put into running in YanJi city of Jilin province. It is able to be moved to border and distance places and area lumped and spreading out of agricultural products to service. It can play a important role in demonstration and extending irradiation technology in food irradiation, disinfestation, sterilization and quarantine, etc. This paper describes the features and design considerations of mobile irradiator. This irradiator adopted Cesium-137 source. The design capacity of loading source is 9.25PBq (250kCi), A half-time of Cs- 137 is 30.2 years long, exchanging source is not needed utilization rate of energy is higher, and the shielding is thinner, The Weight is lighter, The dose rate on the surface of it is 0.0025mSv/h in accordance with national standard. The internal size of irradiation room is 1800×1800×900mm (L×W×H), The sheilding of irradiation room is a steel shell filled with lead. The thickness of lead is 18cm. The irradiator is installed on a special flat truck. The size of the truck is 7000×3400×4200mm (L×W×H). The weight of irradiator is more than 80 150kw. The main components and parts of irradiator are: source, source racks and hoist, irradiation chamber, storage source chamber, the product's transport system, dose monitoring system, ventilation system and safety interlock system, etc.

  13. GTL-1 Irradiation Summary Report

    SciTech Connect

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

    2012-01-01

    The primary objective of the Gas Test Loop (GTL-1) miniplate experiment is to confirm acceptable performance of high-density (i.e., 4.8 g-U/cm3) U3Si2/Al dispersion fuel plates clad in Al-6061 and irradiated under the relatively aggressive Booster Fast Flux Loop (BFFL) booster fuel conditions, namely a peak plate surface heat flux of 450 W/cm2. As secondary objectives, several design and fabrication variations were included in the test matrix that may have the potential to improve the high-heat flux, high-temperature performance of the base fuel plate design.1, 2 The following report summarizes the life of the GTL-1 experiment through end of irradiation, including as-run neutronic analysis, thermal analysis and hydraulic testing results.

  14. Notes on irradiation of neodymium

    Microsoft Academic Search

    1966-01-01

    The fission product, promethium-147, would be much more desirable as a heat-producing radioisotope if it were not in such short supply. C.A. Rohrmann`s chart ``Characteristics of Radioisotopic Heat Sources`` lists the annual availability of Pm-147 as 5-5 kw, corresponding to about 17 kg. Hence, consideration has been given to irradiation of neodymium-146 in order to augment the supply of Pm-147,

  15. Recovery in neutron irradiated tungsten

    Microsoft Academic Search

    M. S. Anand; B. M. Pande; R. P. Agarwala

    1978-01-01

    The recovery of defects in partially and well annealed tungsten has been studied using electrical resistivity technique. The irradiation was carried out at reactor ambient temperature (?343 K) to a fluence of 10 n\\/m. Isochronal annealing studies of the defects show two stages centred around 0.17Tm and 0.31Tm referred to as Stage III and Stage V respectively. Stage III shows

  16. 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. PMID:20065665

  17. Irradiation performance of nitride fuels

    SciTech Connect

    Matthews, R.B.

    1993-01-01

    The properties and advantages of nitride fuels are well documented in the literature. Basically the high thermal conductivity and uranium density of nitride fuels permit high power density, good breeding ratios, low reactivity swings, and large diameter pins compared to oxides. Nitrides are compatible with cladding alloys and liquid metal coolants, thereby reducing fuel/cladding chemical interactions and permitting the use of sodium-bonded pins and the operation of breached pins. Recent analyses done under similar operating conditions show that - compared to metal - fuels mixed nitrides operate at lower temperatures, produce less cladding strain, have greater margins to failure, result in lower transient temperatures, and have lower sodium void reactivity. Uranium nitride fuel pellet fabrication processes were demonstrated during the SP-100 program, and irradiated nitride fuels can be reprocessed by the PUREX process. Irradiation performance data suggest that nitrides have low fission gas release and swelling rates thereby permitting favorable pin designs and long lifetime. The objective of this report is to summarize the available nitride irradiation performance data base and to recommend optimum nitride characteristics for use in advanced liquid metal reactors.

  18. SORCE Solar Irradiance Data Products

    NASA Astrophysics Data System (ADS)

    Pankratz, C. K.; Knapp, B. G.; Fontenla, J. M.; Rottman, G. J.; Woods, T. N.; Harder, J. W.; Kopp, G.; McClintock, W. E.; Snow, M.

    2005-05-01

    The SORCE Science Data System produces Total Solar Irradiance (TSI) and Spectral Solar Irradiance (SSI) data products on a daily basis, which are formulated using measurements from the four primary instruments on board the SORCE spacecraft. The TIM instrument provides measurements of the TSI, whereas the SIM, SOLSTICE, and XPS instruments collectively provide measurements of the solar irradiance spectrum from 1 nm to 3000 nm (excluding 31-115nm, which is covered by the TIMED SEE experiment). The Science Data System utilizes raw spacecraft and instrument telemetry, calibration data, and other ancillary information to produce a variety of data products that have been corrected for all known instrumental and operational factors. Since launch of the SORCE spacecraft in January 2003, science processing algorithms have continued to mature, and "Level 3" data products are routinely being produced and delivered to the public via the SORCE web site and the Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC). This poster provides an overview of the SORCE data processing system, summarizes the present state of the processing algorithms and the quality of the current SORCE data products, and provides details on how to access SORCE science data.

  19. SORCE Solar Irradiance Data Products

    NASA Astrophysics Data System (ADS)

    Pankratz, C. K.; Knapp, B. G.; Fontenla, J. M.; Rottman, G. J.; Woods, T. N.; Harder, J. W.; Kopp, G.; McClintock, W. E.; Snow, M.

    2005-12-01

    The SORCE Science Data System produces Total Solar Irradiance (TSI) and Spectral Solar Irradiance (SSI) data products on a daily basis, which are formulated using measurements from the four primary instruments on board the SORCE spacecraft. The TIM instrument provides measurements of the TSI, whereas the SIM, SOLSTICE, and XPS instruments collectively provide measurements of the solar irradiance spectrum from 1 nm to 2700 nm (excluding 31-115 nm, which is measured by the TIMED SEE experiment). The Science Data System utilizes raw spacecraft and instrument telemetry, calibration data, and other ancillary information to produce a variety of data products that have been corrected for all known instrumental and operational factors. Since launch of the SORCE spacecraft in January 2003, science processing algorithms have continued to mature, and "Level 3" data products are routinely being produced and delivered to the public via the SORCE web site and the Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC). This poster provides an overview of the SORCE data processing system, summarizes the present state of the processing algorithms and future plans, describes the quality of the current SORCE data products, and provides details on how to access SORCE science data. The NPOESS TSIS instrument package will also include TIM and SIM instruments, having direct flight heritage from the SORCE mission, and will produce data products similar to those produced by the existing SORCE Science Data System.

  20. Analysis of the Microseismicity Induced by Fluid Injections at the EGS Site of Soultz-sous-Forêts (Alsace, France): Implications for the Characterization of the Geothermal Reservoir Properties

    NASA Astrophysics Data System (ADS)

    Cuenot, Nicolas; Dorbath, Catherine; Dorbath, Louis

    2008-05-01

    In June/July 2000, a hydraulic stimulation experiment took place at the geothermal EGS site of Soultz-sous-Forêts (Alsace, France) in order to enhance the permeability of the fractured granitic massif at 5 km depth. As it is well known that fluid injections tend to induce microseismic events, a downhole and a surface seismological network have been installed to monitor the seismic activity during the stimulation test. 23400 m3 of fluid have been injected in the rock volume through the open-hole section (4400 m 5000 m) of the well GPK2 at increasing rates of 30 l.s-1, 40 l.s-1 and then 50 l.s-1. More than 7200 microseismic events in the magnitude range 0.9 to 2.6 have been precisely located through a simultaneous inversion of the seismic velocity structure and location parameters. The analysis of the behavior of the seismicity relative to the hydraulic parameters gives important information about the geothermal reservoir. It appears that the evolution of the seismicity strongly depends on the variations of the injection rate: An increase or a decrease leads to changes of the velocity structure, the number and magnitude of microseismic events. This involves different hydro-mechanical processes between the fluid flow and the fracture planes, which will control the final shape of the microseismic cloud. Moreover, the study of the variations of the b-value with time suggests that the stimulation experiment produces a large proportion of small earthquakes, but records of events of magnitude higher than 2 indicate that fluid injection could reactivate structures whose dimensions allow the generation of such earthquakes.

  1. Aseismic motions associated with fluid injections. The case study of the stimulation of GPK2 well at Soultz-sous-Forêts, France

    NASA Astrophysics Data System (ADS)

    Calo, M.; Cornet, H.; Dorbath, C.

    2012-12-01

    Relationship between seismic and aseismic slips is a fundamental challenge for understanding and controling induced seismicity. In 2000, a large water injection has been conducted in granite through a 5-km-deep borehole at the Enhanced Geothermal System (EGS) site of Soultz-sous-Forêts, in the Upper Rhine Graben (France). The microseismicity induced during the hydraulic stimulation was used by Calo' et al. (2011) to carry out a time-dependent P-waves seismic tomography of the stimulated region. Vp anomalies observed during stationary injection conditions are interpreted by the authors as being caused by effective stress variations linked to fluid diffusion, while the fast changes observed concomitantly to changes in flow rate are considered to be caused by non-seismic motions. We present a mechanical model of the stress field variations compatible with the seismic velocities observed during the hydraulic stimulation. The modeling is performed considering a fresh fracture region defined by the seismological information (the seismic cluster). The shear zone is loaded by pore pressure variations following the wellhead pressure trend recorded during the injection test. Results show that the variation of the maximum differential stress (?1 - ?3), in such conditions, reproduces patterns that match well the observed seismic velocity anomalies. Results from laboratory measurements are used for converting the calculated stress field variations into corresponding seismic velocities in order to compare the observed seismic velocities variations with those computed with the model. The proposed model suggests that time-dependent seismic tomography may provide a useful tool for observing the occurrence of large-scale aseismic slips during massive fluid injections.

  2. Proton Irradiation Study of GFR Candidate Ceramics

    SciTech Connect

    Jian Gan; Yong Yang; Clayton Dickson; Todd Allen

    2009-05-01

    This work investigated the microstructural response of ZrC, ZrN, TiN, and SiC irradiated with 2.6 MeV protons at 800ºC to a single dose in the range of 1.5 to 3.0 displacement per atom (dpa), depending on the material. The change of lattice constant evaluated using HOLZ patterns is not observed and is small when measured using XRD for the irradiated samples up to 1.5 dpa for 6H-SiC, and up to 3.0 dpa for ZrC and ZrN. In comparison to Kr ion irradiation at 800ºC to 10 dpa from the previous studies, the proton-irradiated ceramics at 3.0 dpa show less irradiation damage to the lattice structure. The irradiated ZrC exhibits faulted loops which are not observed in the Kr ion irradiated sample. The irradiated ZrN shows the least microstructural change from proton irradiation. The microstructure of 6H-SiC irradiated to 3.0 dpa consists of a black dot defect type at high density.

  3. 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. PMID:12236709

  4. Evolution of active regions and irradiance variations

    NASA Astrophysics Data System (ADS)

    Baranyi, Tünde; Pap, Judit M.

    Total solar irradiance have been measured now for more than three decades. These observations demonstrate the total irradiance changes on time scales from minutes to years and decades. Considerable efforts have been put forward to understand the physical origin of irradiance variations and model the observed changes using measures of sunspots and faculae. Using the Photometric Sunspot Index developed from the area and contrast of sunspots and full disk indices for describing the effect of faculae models have been developed with linear regression analysis. However these models are limited because of the non-linearity between irradiance variations and activity indices and that variations in total irradiance cannot be accounted for by a simple combination of area and position of sunspots. In this paper we present new findings which show that the effect of sunspots on total irradiance strongly depends on their type in the Zurich classification system as well as on their evolution.

  5. 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.

  6. 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.

  7. Irradiation response of ODS Eurofer97 steel

    Microsoft Academic Search

    N. V. Luzginova; H. S. Nolles; P. ten Pierick; T. Bakker; R. K. Mutnuru; M. Jong; D. T. Blagoeva

    Oxide dispersion strengthened (ODS) Eurofer97 steel (EU batch, 0.3wt.% of Y2O3 particles), produced by mechanical alloying followed by hot rolling, is irradiated in the High Flux Reactor in Petten, The Netherlands at three different irradiation temperatures (300, 450 and 550°C) up to nominal doses of 1dpa and 3dpa. The effect of neutron irradiation on the mechanical properties of ODS Eurofer97

  8. Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells.

    PubMed

    Hino, Mizuki; Hamada, Nobuyuki; Tajika, Yuki; Funayama, Tomoo; Morimura, Yoshihiro; Sakashita, Tetsuya; Yokota, Yuichiro; Fukamoto, Kana; Mutou, Yasuko; Kobayashi, Yasuhiko; Yorifuji, Hiroshi

    2010-01-01

    Autophagy is one of the major processes involved in the degradation of intracellular materials. Here, we examined the potential impact of heavy ion irradiation on the induction of autophagy in irradiated C2C12 mouse myoblasts and their non-targeted bystander cells. In irradiated cells, ultrastructural analysis revealed the accumulation of autophagic structures at various stages of autophagy (i.e. phagophores, autophagosomes and autolysosomes) within 20 min after irradiation. Multivesicular bodies (MVBs) and autolysosomes containing MVBs (amphisomes) were also observed. Heavy ion irradiation increased the staining of microtubule-associated protein 1 light chain 3 and LysoTracker Red (LTR). Such enhanced staining was suppressed by an autophagy inhibitor 3-methyladenine. In addition to irradiated cells, bystander cells were also positive with LTR staining. Altogether, these results suggest that heavy ion irradiation induces autophagy not only in irradiated myoblasts but also in their bystander cells. PMID:20685830

  9. Grafting of styrene into pre-irradiated fluoropolymer films: Influence of base material and irradiation temperature

    NASA Astrophysics Data System (ADS)

    Lappan, Uwe; Geißler, Uwe; Gohs, Uwe; Uhlmann, Steffi

    2010-10-01

    In this study, the influence of irradiation temperature on mechanical properties of three fluoropolymers and on grafting of styrene into the polymers by the pre-irradiation method was investigated. Electron paramagnetic resonance spectroscopy and infrared spectroscopy were used to characterize the irradiated polymers regarding trapped radical species and changes in the chemical structure, respectively. For poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) the irradiation temperature was found to be an important factor for tensile strength and elongation at break of the pre-irradiated film. No strong effect of irradiation temperature on the mechanical properties was noticed for poly(tetrafluoroethylene-co-ethylene) (ETFE); however the yield of grafting drops at high irradiation temperatures. Finally, mechanical properties of poly(tetrafluoroethylene) (PTFE) were found to be dramatically altered, even if the film was irradiated at elevated temperature.

  10. 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. PMID:24215551

  11. ISO 21348 - Process for determining solar irradiances

    NASA Astrophysics Data System (ADS)

    Tobiska, W.; Nusinov, A.

    A new international standard is being published by the International Standards Organization ISO The document ISO 21348 Space Environment natural and artificial -- Process for determining solar irradiances describes the process for representing solar irradiances We report on the content of the final version of this new standard Because solar irradiance measurements and modeling are constantly evolving through improved instrumentation measurement techniques and modeling capabilities the new standard has been written as a process-based standard to encourage development in solar irradiance determination The standard covers all representations of solar irradiances and is applicable to measurements reference spectra empirical models physics-based models as well as solar proxies and indices The purpose of the standard is to provide a common specification for all solar irradiances for use by space systems materials and environment users A solar irradiance product or specification is compliant with the standard if four criteria are followed First solar irradiances are reported at the minimum in SI units of Watts per square meter corrected to 1 AU Second the method of determining irradiances is documented for data collection processing archiving validation accuracy precision methodology and algorithm information Where applicable a description of proxies and independent data sets used in the derivation of empirical models including the rationale for proxy selection and the mathematical formulation for numerical models is

  12. 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.

  13. Irradiation effects in ferritic steels

    NASA Astrophysics Data System (ADS)

    Lechtenberg, Thomas

    1985-08-01

    Since 1979 the Alloy Development for Irradiation Performance (ADIP) task funded by the US Department of Energy has been studying the 2-12Cr class of ferritic steels to establish the feasibility of using them in fusion reactor first wall/breeding blanket (FW/B) applications. The advantages of ferritic steels include superior swelling resistance, low thermal stresses compared to austenitic stainless steels, attractive mechanical properties up to 600°C. and service histories exceeding 100 000 h. These steels are commonly used in a range of microstructural conditions which include ferritic, martensitic. tempered martensitic, bainitic etc. Throughout this paper where the term "ferritic" is used it should be taken to mean any of these microstructures. The ADIP task is studying several candidate alloy systems including 12Cr-1MoWV (HT-9), modified 9Cr-1MoVNb, and dual-phased steels such as EM-12 and 2 {1}/{4}Cr-Mo. These materials are ferromagnetic (FM), body centered cubic (bcc), and contain chromium additions between 2 and 12 wt% and molybdenum additions usually below 2%. The perceived issues associated with the application of this class of steel to fusion reactors are the increase in the ductile-brittle transition temperature (DBTT) with neutron damage, the compatibility of these steels with liquid metals and solid breeding materials, and their weldability. The ferromagnetic character of these steels can also be important in reactor design. It is the purpose of this paper to review the current understanding of these bcc steels and the effects of irradiation. The major points of discussion will be irradiation-induced or -enhanced dimensional changes such as swelling and creep, mechanical properties such as tensile strength and various measurements of toughness, and activation by neutron interactions with structural materials.

  14. 3D cartography of space charges induced by UV irradiation

    Microsoft Academic Search

    A. Petre; D. Mary; C. D. Pham; L. Berquez

    2007-01-01

    UV irradiation produces irreversible damages in the dielectric insulators. Irradiation sources are numerous: partial discharges, parasitic discharges (environmental) or ambient light. The most known effect of irradiation is yellowing indicating an advanced material damage. We already have shown that before yellowing, space charges appear close to the irradiated surface, and increase with the irradiation time. In order to investigate more

  15. Irradiation of Food, Current Legislation Framework, and Detection of Irradiated Foods

    Microsoft Academic Search

    Rayna Stefanova; Nikola V. Vasilev; Stefan L. Spassov

    2010-01-01

    The review covers description of food irradiation process, the current status of global legislation background in the field\\u000a of irradiated foodstuffs, and the state of detection methods up-to-date available based on physical, chemical, biological,\\u000a and microbiological changes in irradiated foods. Special emphasis was put on European Standards for the detection of irradiated\\u000a foods adopted by the European Committee for Standardization,

  16. 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.

  17. Effect of re-irradiation by neutrons on mechanical properties of un-irradiated/irradiated SS316LN weldments

    NASA Astrophysics Data System (ADS)

    Tsuchiya, K.; Shimizu, M.; Kawamura, H.; Kalinin, G.

    2008-02-01

    Stainless steel of type SS316LN-IG (ITER Grade) is used for the branch pipeline connecting of the module coolant system and for other structures of ITER. One of the most important requirements for the branch pipeline connection is to recover various defects by welding. In the present study, characteristics of irradiated weldments were evaluated. SS316LN-IG specimens irradiated to helium contents of 3 and 10 appm He were prepared by the first neutron irradiation. Thereafter, the SS316LN-IG specimens with three different combinations of un-irradiation and irradiation were welded by a tungsten inert-gas (TIG) welding method. These weldments were re-irradiated at 150 °C up to a fast neutron fluence of about 7.5 × 10 24 n/m 2 ( E > 1 MeV). Tensile tests of the weldments and the base material were carried out at 20 and 150 °C after the re-irradiation. The results of the comparison before and after the re-irradiation showed that tensile properties of all weldment specimens with the different combinations were almost the same as those of the base materials.

  18. Updates to ISO 21348 (determining solar irradiances)

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent

    2012-07-01

    The ISO 21348 (Determining Solar Irradiances) International Standard is going through a document update. A consensus solar spectrum, solar indices/proxies descriptions, solar model descriptions, and solar measurement descriptions are among the Annexes that are proposed to the standard. These topics will be reviewed and described. The International Standards Organization (ISO) published IS 21348 in 2007 after 7 years of development by the international scientific community. In ISO, documents are reviewed on a regular basis and reaffirmed, updated, or deleted according to the votes of national delegations represented in ISO. IS 21348 provides guidelines for specifying the process of determining solar irradiances. Solar irradiances are reported through products such as measurement sets, reference spectra, empirical models, theoretical models and solar irradiance proxies or indices. These products are used in scientific and engineering applications to characterize within the natural space environment solar irradiances that are relevant to space systems and materials. Examples of applications using input solar irradiance energy include the determination of atmospheric densities for spacecraft orbit determination, attitude control and re-entry calculations, as well as for debris mitigation and collision avoidance activity. Direct and indirect pressure from solar irradiance upon spacecraft surfaces also affects attitude control separately from atmospheric density effects. Solar irradiances are used to provide inputs for a) calculations of ionospheric parameters, b) photon-induced radiation effects, and c) radiative transfer modeling of planetary atmospheres. Input solar irradiance energy is used to characterize material properties related to spacecraft thermal control, including surface temperatures, reflectivity, absorption and degradation. Solar energy applications requiring a standard process for determining solar irradiance energy include i) solar cell power simulation, ii) material degradation, and iii) the development of lamps and filters for terrestrial solar simulators. A solar irradiance product certifies compliance with this process-based standard by following compliance criteria that are described in this International Standard.

  19. 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 ?m side and is separated from neighbouring ones by 20 ?m 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.

  20. Spectroscopic analysis of irradiated erythrocytes

    NASA Astrophysics Data System (ADS)

    Selim, Nabila S.; Desouky, Omar S.; Ismail, Nagla M.; Dakrory, Amira Z.

    2011-12-01

    The aim of the present work is to study the effect of gamma radiation on the lipid part of the erythrocyte membrane, and to test the efficiency of lipoic acid as a radioprotector. This effect was evaluated using electron paramagnetic resonance (EPR), and Fourier transform infrared (FT-IR) spectroscopy. The results showed an increase in the number of spin density by 14%, 22% and 65% after exposure to 25, 50 and 100 Gy respectively; whereas there was a decline in the obtained density after incubation with lipoic acid by a factor of approximately 32%. The FT-IR spectra of the irradiated erythrocytes samples showed a marked decrease in the intensity of all characteristic peaks, which increased as the irradiation dose increased. The second-derivative of these spectra, allow the conformationally sensitive membrane acyl chain methylene stretching modes to be separated from the protein (mostly hemoglobin) vibrations that dominate the spectra of intact cells. The 2850 cm -1 band showed changes in the band shape and position after exposure to 50 and 100 Gy. Therefore it can be concluded that the band at 2850 cm -1 only is useful in monitoring the radiation effect of the lipids cell membrane intact cells.

  1. 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

    On peut creer un gaz electronique bidimensionnel en utilisant le potentiel de confinement d'une couche mince d'un semiconducteur dans un substrat fait d'une autre semiconducteur de gap plus eleve. L'ajout d'un champ magnetique perpendiculaire au plan de confinement modifie de facon drastique les proprietes du gaz electronique. Pour des densites et des valeurs du champ magnetique adequatement choisies, on obtient un etat fondamental en onde de densite de charge. Dans un systeme compose de deux de ces gaz bidimensionnels suffisamment rapproches l'un de l'autre, on prevoit theoriquement l'existence d'un etat fondamental compose d'une onde de densite de charge dans chacun des puits et d'une serie de regions lineaires ou l'on a une delocalisation coherente des electrons entre les deux puits. Dans cette these, on etudie le comportement a temperature nulle de cet etat fondamental en rayures coherentes. L'etude numerique des modes collectifs de ces phases laisse croire qu'un deverrouillage des canaux coherents est envisageable dans ce systeme. Afin d'etudier cette possibilite, nous construisons d'abord un modele effectif de canaux quasi-unidimensionnels couples qui permettent de reproduire correctement les excitations collectives a basse energie de la phase en rayures coherentes du double puits quantique. Dans un systeme de coordonnees adequatement choisi, ces excitations peuvent etre decrites par des ondes de pseudospin. Les parametres de ce modele effectif simple peuvent etre extraits des calculs des fonctions de reponse realises dans l'approximation Hartree-Fock dependante du temps (appelee aussi Generalized Random Phase Approximation). On constate l'efficacite de ce modele a decrire la dynamique basse energie du systeme pour une certaine plage de distances inter-puits. En retirant de ce modele les contributions a l'hamiltonien provenant des couplages de type Josephson entre les canaux, on obtient alors un systeme ou les canaux sont deverrouilles. Un traitement en 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.

  2. Calcimetry as a useful tool for a better knowledge of flow pathways in the Soultz-sous-Forêts Enhanced Geothermal System

    NASA Astrophysics Data System (ADS)

    Ledésert, Béatrice; Hébert, Ronan L.; Grall, Céline; Genter, Albert; Dezayes, Chrystel; Bartier, Danièle; Gérard, André

    2009-03-01

    The Soultz-sous-Forêts granite located in the Rhine graben (France) has been chosen for the European Enhanced Geothermal System (EGS). Three wells have been drilled to a minimum depth of 5000 m in order to reach a temperature of 200 °C. At Soultz, the main fracture network in the basement is orientated approximately N-S with moderate to steep dip. Its geometrical relationship with the in situ stress field suits fluid circulation, hence the EGS project. However, fractures are firmly sealed due to natural fluids (fossil and/or possibly present). The main sealing minerals, as identified during previous studies, are clay minerals, calcite and quartz. However, some fractured zones remain permeable due to the high porosity developed in the wall rocks through hydrothermal alteration. A circulation test was carried out from July to December 2005 to test the performance of the Soultz geothermal reservoir. This test showed a significant difference in the production rate between the two outflow wells (GPK2 and GPK4). In order to improve the fluid circulation within the underground heat exchanger, chemical stimulations have been scheduled. In this framework, quantifying the calcite content of the granite provides a basis for identifying the calcite-rich zones as well as choosing the most suitable chemical stimulation. Measurement of calcite ponderal concentration was carried out in the cutting samples of the 3 deep wells (GPK2, GPK3, GPK4) between 4000 and 5000 m depth using manocalcimetry. Based on detailed measurements in the 3 wells, this study shows that calcite is not only a very common and ubiquitous hydrothermal mineral but that its content seems to be also spatially correlated with most of the fracture zones bearing natural flow. The conductivity of these natural flow pathways seems anti-correlated with the calcite content. Calcimetry has proved to be an easy, efficient and low-cost method for a better knowledge of hydrothermal sealing of the Soultz reservoir. This method can be applied with great benefit to all types of basement reservoirs (oil, gas, water, heat) overlain by sedimentary rocks for a better understanding of the fracture network permeability.

  3. Soultz-sous-Forêts - What can inverse simulations contribute to the knowledge of hydro-geothermal system at the European EGS demonstration site?

    NASA Astrophysics Data System (ADS)

    Kosack, C.; Rath, V.

    2009-04-01

    The European Enhanced Geothermal System (EGS) research project is located at Soultz-sous-Forêts at the western border of the Rhine rift valley. Three wells were drilled into the deep reservoir (4000 - 5000 m) within the granitic basement. Hydraulic stimulations produced additional mechanically damaged zones in the vicinity of the wells. In July 2005, a tracer was injected into the injector 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, but only a very low connectivity was observed in the other one. In the following we concentrate on the high productivity connection between GPK3 and GPK2. Based on general knowledge of the geological setup we constructed simplified three-dimensional heterogeneous models in order to explain the tracer concentration observed in GPK2 during this experiment. To quantify porosity, permeability, and dispersivity of predefined property zones, we applied a full-physics Bayesian inversion. Numerical experiments with different models show that an excellent fit can be obtained with several models of different complexities and parameterizations. Rough estimates indicate that less than 4 parameters may be estimated from tracer data alone. As expected, a high-permeability low-porosity zone (main fracture) is required in all models, though the numerical value depends on the spatial extent of the zone and the properties of the immediate surrounding rocks. Most of the tracer is transported near the main flow zone, and an additional circulation path of large spatial extent is not required by the data. Though explaining tracer concentrations equally well, all these models will imply a different behavior of bottom hole pressures and temperatures, which were not available for inversion. Additionally, there is considerable uncertainty in details of the experimental setup. To move from these conceptual studies to model identification and calibration, independent constraints on model geometry are necessary, as well as more observed data. We will present new results based on a more complete data set, including bottom hole pressures, temperatures and pumping schedules. To take into account the high salinity of the reservoir fluids an appropriate model for thermophysical properties was implemented in the inverse code.

  4. Numerical modeling of the impact of temperature on the behavior of minerals in the Soultz-sous-Forêts enhanced geothermal system

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    Operation of the enhanced geothermal system (EGS) requires to re-inject fluid, after heat exchange at the surface to the energy production, into the geothermal reservoir. This cold re-injected fluid can cause a strong disequilibrium with the fluid and granitic rock within the geothermal reservoir and then implies the possible dissolution/precipitation of minerals. The hydrothermal alterations include the transformation of plagioclase, biotite and K-feldspar and the precipitation of various secondary minerals. The major sealing phases observed in the main fracture zones are quartz, calcite, and clay minerals. These mineralogical transformations may modify the porosity, permeability and fluid pathways of the geothermal reservoir. In the Soultz-sous-Forêts EGS (Alsace, France), the hydraulic connection between the injection well and the production well is quite poor. Therefore, understanding the impact of changes in temperature, which are caused by the re-injected fluid, on the behavior of minerals (especially for the main newly-formed minerals such as quartz, calcite and clay minerals) is a critical preliminary step for the long-term prediction of their evolution. The approach used in the present work is typically based on a geochemical code, called THERMA, which enables to calculate the changes in equilibrium constants of all primary and secondary minerals and aqueous species as a function of temperature. Our model accounted for a wide range of different mineral groups in order to make sure a large freedom for the numerical calculations. The modeling results showed that when the temperature of geothermal reservoir is cooled down, quartz, calcite, illites, galena and pyrite have tendency towards equilibrium state, which indicates that they are precipitated under the geothermal conditions. In contrast, other minerals including plagioclase, K-feldspar and biotite remained unsaturated. These behaviors of minerals were further illustrated by the Khorzinsky stability diagrams, which are based on the activities of different species such as H4SiO4, Ca2+, Mg2+, and Al3+ and take into account partial CO2 pressure,. The modeling results further suggested that we should pay a special attention to the main minerals (e.g., quartz, calcite and illites) when studying the changes in porosity and permeability of the geothermal reservoir. This study was preparing a simulation of water-rock interaction processes related to these temperature conditions.

  5. Electroluminescence analysis of neutron irradiation of JFETs

    Microsoft Academic Search

    A. Ahaitouf; M. Lahbabi; M. Fliyou; E. Abarkan; A. Hoffmann; J. P. Charles

    2001-01-01

    Electroluminescence (EL) measurements are used as a sensitive technique for the study of fast neutron irradiation of silicon n-channel JFET overlaid by a passivation oxide layer. By theoretical simulations, it is demonstrated that neutron irradiation result in two effects: an increase of the refractive index of the passivation oxide and the introduction of deep level traps which reduce the emitted

  6. Brain fibronectin expression in prenatally irradiated mice

    Microsoft Academic Search

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

    1993-01-01

    Activation of gene transcription by radiation has been recently demonstrated in vitro. 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

  7. Identification of irradiated apples for phytosanitary purposes

    NASA Astrophysics Data System (ADS)

    Horak, Celina I.; Di Giorgio, Marina; Kairiyama, Eulogia

    2009-07-01

    The irradiation treatment of fresh fruits and vegetables for phytosanitary purposes is a satisfactory alternative method to others like fumigation and cold and hot treatments. Its use is increasing in several countries, and at present its approval is under revision by the National Regulatory Authorities. To verify the control process, apart from irradiation and dosimetry certificates, National Authorities require complementary evidence to show the efficacy of this treatment, especially when the documentation is not clear. The irradiation of fresh fruits produces single and double fragmentation in the DNA molecule, which can be measured using the microgel electrophoresis of individual cell (comet assay). The purpose of this work was to evaluate if it is possible to identify the irradiated apples for phytosanitary purposes from the others that were not treated. The possibility to estimate the absorbed dose was also evaluated. The methodology was carried out on the cell suspension obtained from irradiated seed cells with incremental doses (100, 200 and 300 Gy). The irradiation treatment for phytosanitary purposes to avoid emergency of codling moth ( Cydia pomonella) is 200 Gy. The fragmentation produced in the irradiated samples was proportional with the incremental doses applied. These results show that with this methodology it can be determined if the apple was irradiated or not. This comet assay is a simple, economical and interesting method that can be used, in case of necessity, by the National Authorities.

  8. HAPO irradiation of capsules containing UOâ specimens

    Microsoft Academic Search

    H. W. Newkirk; M. K. Millhollen; D. W. Brite

    1958-01-01

    A knowledge of the effect of reactor irradiation on the properties of UOâ is relevant to the design and evaluation of UOâ fuel elements for the PRTR. Of particular interest is the effect of reactor irradiation on the thermal conductivity of sintered UOâ and the type, mechanism, and extent of radiation damage in sintered UOâ. In the latter case the

  9. SIPS: Solar Irradiance Prediction System Stefan Achleitner

    E-print Network

    Cerpa, Alberto E.

    SIPS: Solar Irradiance Prediction System Stefan Achleitner Computer Science and Engineering the variability and dynamics are the largest. We propose SIPS, Solar Irradiance Prediction System, a novel sensing-scaling capacities of renewable energy sources such as wind and solar. However, variability and uncertainty in power

  10. Irradiation-induced phenomena in carbon nanomaterials

    Microsoft Academic Search

    Arkady Krasheninnikov

    2008-01-01

    The irradiation of solids with energetic particles such as electrons or ions is associated with disorder, normally an undesirable phenomenon. However, recent experiments [for an overview, see A.V Krasheninnikov, F. Banhart, Nature Materials, 6 (2007) 723] on bombardment of carbon nanostructures with energetic particles demonstrate that irradiation can have beneficial effects and that electron or ion beams may serve as

  11. Effect of gamma-irradiation on ripening papaya pectin

    Microsoft Academic Search

    Min Zhao; James Moy; Robert E. Paull

    1996-01-01

    Papaya (Carica papaya, L., var. Sunset) at three initial ripeness stages were irradiated with 0.25, 0.50, 0.75, 1.0, or 1.5 kGy gamma-irradiation and pectin changes during ripening determined. A significant linear relationship was found between irradiation dose and firmness immediately after irradiation. Irradiation had no effect on fruit skin or flesh color of papaya fruit irradiated at the 5 to

  12. High energy heavy ion irradiation in semiconductors

    NASA Astrophysics Data System (ADS)

    Srivastava, P. C.; Pandey, S. P.; Sinha, O. P.; Avasthi, D. K.; Asokan, K.

    Pd/n-Si and Pd/n-GaAs devices have been irradiated from high energy (˜100 MeV) heavy ions of Au 7+ (gold) and Si 7+ (silicon) to study the irradiation effects in these junction devices on semiconductor substrates. The devices have been characterized from I-V and C-V studies for electronic flow characterization. It has been found that the devices become high resistive on the irradiation and the substrates change the conductivity type from n- to p- on the irradiation of fluence of ˜10 12-10 13 ions/cm 2. The change in conductivity type has been understood as a result of creation of deep acceptors on the irradiation.

  13. Significance of primary irradiation creep in graphite

    NASA Astrophysics Data System (ADS)

    Erasmus, Christiaan; Kok, Schalk; Hindley, Michael P.

    2013-05-01

    Traditionally primary irradiation creep is introduced into graphite analysis by applying the appropriate amount of creep strain to the model at the initial time-step. This is valid for graphite components that are subjected to high fast neutron flux fields and constant stress fields, but it does not allow for the effect of movement of stress locations around a graphite component during life, nor does it allow primary creep to be applied rate-dependently to graphite components subject to lower fast neutron flux. This paper shows that a differential form of primary irradiation creep in graphite combined with the secondary creep formulation proposed by Kennedy et al. performs well when predicting creep behaviour in experimental samples. The significance of primary irradiation creep in particular in regions with lower flux is investigated. It is shown that in low flux regions with a realistic operating lifetime primary irradiation creep is significant and is larger than secondary irradiation creep.

  14. Effects of irradiation on mandibular scintigraphy

    SciTech Connect

    Aitasalo, K.; Ruotsalainen, P.

    1985-11-01

    Technetium-99m methylene diphosphonate (Sn) scintigraphy with computer analysis was used to investigate alterations in the pathophysiology of the normal mandible and the pathologic mandible during and after irradiation. Slight but significant elevations of uptake levels were recorded as an early effect of irradiation. The elevations correlated with the duration of treatment and normalized over a follow-up period of 6 to 12 mo. Increased mandibular metabolism was found during irradiation and in osteomyelitis and osteoradionecrosis of the mandible. Scintigraphy with computer analysis proved a simple and valid method in the evaluation of early irradiation damage and pathophysiologic conditions of the mandible. The method can also be used to predict whether the irradiation damage will become irreversible.

  15. 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.

  16. Decontamination of pancreatin powder by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kairiyama, Eulogia; Narvaiz, Patricia

    1997-03-01

    Dehydrated pancreatin, packed in polyethylene bags, was gamma irradiated with doses of 5, 10, 15 and 20 kGy. Control and irradiated samples were stored at 19 ± 4 C and 70 ± 10% RH during 14 months. Microbiological and chemical tests were performed. Samples irradiated with 5 kGy showed two log cycles reduction of sporulated and aerobic mesophilic bacteria, and one log cycle reduction of moulds and yeasts, which fulfilled the microbiological requirements. This situation was maintained throughout the storage period. The irradiation did not significantly affect water content, fat, and total volatile basic nitrogen. Protease and amylase activities decreased with storage time and radiation dose. However, irradiation with 5 and 10 kGy caused no significant alteration on either of these activities as compared with control samples.

  17. Application of multi-irradiation facilities

    NASA Astrophysics Data System (ADS)

    Trocellier, P.; Serruys, Y.; Miro, S.; Bordas, E.; Pellegrino, S.; Vaubaillon, S.; Ruault, M. O.; Henry, S.; Kaïtasov, O.

    2008-06-01

    Multiple ion beam facilities have been used for nearly 30 years to simulate the irradiation effects of neutrons on relevant nuclear materials. Simultaneous ion beam irradiation allow the study of structural damage and foreign atoms accumulation in a broad range of parameters (projected range, temperature, dose rate, fluence, nuclear over electronic stopping power ratio) coupled with characterization of the investigated material. First, a review is given on the multi-irradiation facilities in operation worldwide. Then, the progress report of the Joint Accelerators for Nanosciences and NUclear Simulation project (JANNUS) is presented. In the third part of this paper, the main planned activity fields using JANNUS will be discussed i.e. the study of irradiation behaviour of nuclear materials, the controlled modification of materials properties by ion beam irradiation/implantation and the teaching of ion beam interactions with solids, ion beam physics and ion beam analysis.

  18. The LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Pankratz, C. K.; Lindholm, D. M.; Snow, M.; Knapp, B.; Woodraska, D.; Templeman, B.; Woods, T. N.; Eparvier, F. G.; Fontenla, J.; Harder, J.; McClintock, W. E.

    2007-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) has been making space-based measurements of solar irradiance for many decades, and thus has established an extensive catalog of past and ongoing space- based solar irradiance measurements. In order to maximize the accessibility and usability of solar irradiance data and information from multiple missions, LASP is developing the LASP Interactive Solar IRradiance Datacenter (LISIRD) to better serve the needs of researchers, educators, and the general public. This data center is providing interactive and direct access to a comprehensive set of solar spectral irradiance measurements from the soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as state-of-the-art measurements of Total Solar Irradiance (TSI). LASP researchers are also responsible for an extensive set of solar irradiance models and historical solar irradiance reconstructions, which will also be accessible via this data center over time. LISIRD currently provides access to solar irradiance data sets from the SORCE, TIMED-SEE, UARS-SOLSTICE, and SME instruments, spanning 1981 to the present, as well as a Lyman Alpha composite that is available from 1947 to the present. LISIRD also provides data products of interest to the space weather community, whose needs demand high time cadence and near real-time data delivery. This poster provides an overview of the LISIRD system, summarizes the data sets currently available, describes future plans and capabilities, and provides details on how to access solar irradiance data through LISIRD's various interfaces.

  19. Irradiation applications for homeland security

    NASA Astrophysics Data System (ADS)

    Desrosiers, Marc F.

    2004-09-01

    In October 2001, first-class mail laced with anthrax was sent to political and media targets resulting in several deaths, illnesses, significant mail-service disruption, and economic loss. The White House Office of Science and Technology Policy established a technical task force on mail decontamination that included three key agencies: National Institute of Standards and Technology with responsibility for radiation dosimetry and coordinating and performing experiments at industrial accelerator facilities; the Armed Forces Radiobiology Research Institute with responsibility for radiobiology; and the US Postal Service with responsibility for radiation-processing quality assurance and quality control. An overview of the anthrax attack decontamination events will be presented as well as expectations for growth in this area and the prospects of other homeland security areas where irradiation technology can be applied.

  20. AFIP-2 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-2 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-2 experiment was fabricated by friction bond (FB) 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-2 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. The safety analyses performed for AFIP-2 are summarized in Table 5 of the following report.

  1. 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.

  2. AFIP-2 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-2 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-2 experiment was fabricated by friction bond (FB) 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-2 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. The safety analyses performed for AFIP-2 are summarized in Table 5 of the following report.

  3. AFIP-1 Irradiation Summary Report

    SciTech Connect

    D. 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-1 was designed to demonstrate the performance of second-generation dispersion fuels at a prototypic scale with a length of 21.5 inches (54.6 cm), width of 2.25 inches (5.75 cm) and a thickness of 0.050 inch (0.13 cm). The experiment was fabricated using commercially standard practices at BWX Technology, Inc. (BWXT). The U-7Mo fuel particles were supplied by the Korean Atomic Energy Research Institute (KAERI) using equipment intended for commercial supply. Two fuel plates were tested that incorporated two different matrix compositions, Al-2Si and Al-4043.1 The following report summarizes the life of the AFIP-1 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

  4. 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.

  5. 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.

  6. Irradiation growth in zirconium and its alloys

    NASA Astrophysics Data System (ADS)

    Rogerson, A.

    1988-10-01

    The UKAEA Northern Research Laboratories (Risley) have recently completed an underlying research study on irradiation growth in zirconium and its alloys. During this study, irradiation growth measurements have been made on a range of well-characterized single-crystal and polycrystalline iodide zirconium, commercial alloys Zircaloy-2 and Zr-2.5 wt% Nb, and high-purity zirconium-tin alloys in different metallurgical conditions following irradiation in the DIDO reactor at AERE Harwell. Irradiations were performed in three rigs operating at irradiation temperatures between 353 and 673 K. An important feature of the experimental programme was the capability to perform repeat length measurements on individual growth specimens at intervals during their irradiation programme. This facility has allowed accurate monitoring of the growth phenomenon and changes in growth behaviour induced by the combined effects of irradiation temperature and accumulated fast neutron dose over large dose ranges. This paper reviews the main experimental results from this programme and discusses them in terms of current understanding of the growth process. Thus, it has been observed that, in annealed Zircaloy-2 at temperatures between 553 and 673 K, a transition from saturating growth to accelerating growth rates occurs with increasing dose. The dose above which this "growth breakaway" takes place is seen to be inversely dependent on irradiation temperature in mis temperature range. The well-documented difference in growth behaviour between annealed and cold-worked Zircaloy-2 observed at relatively low irradiation temperatures, in which cold-worked material grows at a high linear rate over large dose ranges, is not observed at 673 K. Comparison is made with reported results on similar material irradiated in other irradiation facilities. The growth data are interpreted in terms of recent theories regarding the development during fast neutron irradiation of a cold-worked microstructure consisting of < a>- and < c>-type dislocations. Irradiation growth behaviour of annealed polycrystalline iodide zirconium between 353 and 673 K contrasts strongly with that in annealed Zircaloy-2 with low irradiation growth rates being observed over a large dose and temperature range. The influence of key irradiation parameters on the growth process have been examined in a series of studies initiated as part of a collaborative programme with AECL Chalk River Nuclear Labs. Final results from the studies on annealed and deformed single-crystal zirconium are reported here. They show that growth saturates rapidly at low dose in annealed single-crystal material irradiated at 353 and 553 K but that a gradual increase in growth strain is observed on irradiation to high dose at 553 K. Single-crystal specimens heavily swaged prior to irradiation at 353 K and given different pre-irradiation heat-treatments exhibit high near-linear or accelerating growth rates. These growth data are interpreted in terms of the importance of grain boundaries and twin boundaries as sinks for point defects which allow point defect separation and hence growth to continue to high dose. Finally, the results of growth experiments performed on Zr-0.1% Sn and Zr-1.5% Sn alloys at 353 and 553 K are reviewed. These experiments confirm the important role played by alloying additions and impurities on the growth process in zirconium and Zircaloy-2.

  7. 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.

  8. Urban tree influences on ultraviolet irradiance

    NASA Astrophysics Data System (ADS)

    Heisler, Gordon M.; Grant, Richard H.; Gao, Wei

    2002-01-01

    Many of the effects of ultraviolet radiation (UVR) on people and their environment--damage to various materials, survival of insects and microbial pathogens, growth of vegetation, and adverse or beneficial effects on human health--are modified by the presence of trees. Human epidemiological investigations generally consider exposure as given by indices of UVR irradiance on horizontal surfaces in the open. Though many people are exposed to UVR while reclining at a beach or swimming pool, thus experiencing irradiance on essentially horizontal surfaces in the open, exposure to UVR during daily routines in urban areas may also be important in affecting human health. Tree influences on UVR irradiance, particularly in the UVB, can differ substantially from influences on the visible portion of the solar spectrum. Trees greatly reduce UVB irradiance in their shade when they obscure both the sun and sky. Where trees obscure the sun but leave much of the sky in view, UVB irradiance will be greater than suggested by the visible shadow. In small sunny areas near trees that block much of the sky from view, UVB irradiance is reduced substantially, whereas visible irradiance may be nearly as great or slightly greater than in the open.

  9. 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).

  10. Food irradiation: Technology transfer to developing countries

    NASA Astrophysics Data System (ADS)

    Kunstadt, Peter

    This paper discusses Nordion's experiences to-date with the Food Irradiation Project in Thailand (1987-1990). This project will enable the Government of Thailand and the Thai food industry to benefit from established Canadian technology in food irradiation. It includes the design and the construction in Thailand of a multipurpose irradiation facility, similar to the Canadian Irradiation Centre. In addition Canada provides the services, for extended periods of time, of construction and installation management and experts in facility operation, maintenance and training. The Technology Transfer component is a major part of the overall Thai Food Irradiation Project. Its purpose is to familiarize Thai government and industry personnel with Canadian requirements in food regulations and distribution and to conduct market and consumer tests of selected Thai irradiated food products in Canada, once the products have Canadian regulatory approval. On completion of this project, Thailand will have the necessary facility, equipment and training to continue to provide leadership in food irradiation research, as well as scientific and technical support to food industries not only in Thailand by also in the ASEAN region.

  11. Influence of irradiation on stored platelets

    SciTech Connect

    Moroff, G.; George, V.M.; Siegl, A.M.; Luban, N.L.

    1986-09-01

    Platelet concentrates intended for transfusion to immunosuppressed patients are irradiated to minimize transfusion-induced graft-versus-host disease. Because few reports describe how irradiation influences stored platelets, the authors studied whether 5000 rad of gamma irradiation, the maximum dose currently used clinically, altered platelets in vitro. Platelet concentrates were stored for either 1 day or 5 days in plastic (PL 732) containers before gamma irradiation. One unit of a pair of identical platelet concentrates was irradiated; the second unit served as a control. Irradiation did not alter platelet morphology, mean platelet volume, expression of platelet-factor-3 activity, response to hypotonic stress, extent of discharge of lactate dehydrogenase, release of beta-thromboglobulin, formation of thromboxane B2, nor the ability to undergo synergistic aggregation. The lack of any substantial change was observed whether the platelet concentrates were stored initially for either 1 day or 5 days. These results suggest that stored platelets are not altered deleteriously by irradiation with 5000 rad.

  12. 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.

  13. Raman spectroscopy of C-irradiated graphite

    SciTech Connect

    Hembree, D.M. Jr.; Pedraza, D.F.; Romanoski, G.R.; Withrow, S.P.; Annis, B.K.

    1994-09-01

    Highly oriented pyrolytic graphite samples were irradiated with C{sup +} ions at 35 keV in a direction normal to the basal plane and subsequently annealed up to 1373 K. Substantial surface topography changes were observed at fluences of 5 {times} 10{sup 18} ions/m{sup 2} and higher using scanning electron and atomic force microscopies. Intricate networks of surface cracks and ridges developed after high dose implantation. A systematic study of the irradiation effects was conducted using Raman spectroscopy. Microstructural changes in irradiated regions were first detected at a dose of 1 {times} 10{sup 17} ions/m{sup 2} through the appearance of the Raman D-line at {approx}1360 cm{sup {minus}1}. The intensity of this line increases while that of the Raman G-line at 1580 cm{sup {minus}1} decreases as the irradiation dose is increased or the irradiation temperature is decreased. After irradiation at 280K to a fluence of 5 {times} 10{sup 19} ions/m{sup 2} or higher the first order spectrum exhibits one single line at a wavelength intermediate between the D- and G-lines. Damage recovery upon thermal annealing depends not only on the initial damage state but also on the annealing temperature sequence. Samples irradiated to a damage level where two distinct Raman peaks are no longer resolvable exhibited upon direct annealing at a high temperature two distinct Raman lines. By contrast, pre-annealing these highly irradiated specimens at lower temperatures produced less pronounced changes in the Raman spectra. Pre-annealing appears to stabilize damage structures that are more resistant to high-temperature annealing than those induced by irradiation.

  14. The Total Irradiance Monitor (TIM): Instrument Design

    NASA Astrophysics Data System (ADS)

    Kopp, Greg; Lawrence, George

    2005-08-01

    The Total Irradiance Monitor (TIM) instrument is designed to measure total solar irradiance with an absolute accuracy of 100 parts per million. Four electrical substitution radiometers behind precision apertures measure input radiant power while providing redundancy. Duty cycling the use of the radiometers tracks degradation of the nickel-phosphorous absorptive black radiometer interiors caused by solar exposure. Phase sensitive detection at the shutter frequency reduces noise and simplifies the estimate of the radiometer's equivalence ratio. An as-designed uncertainty budget estimates the instrument's accuracy goal. The TIM measurement equation defines the conversion from measured signal to solar irradiance.

  15. Infrared spectroscopy study of irradiated PVDF

    SciTech Connect

    Chappa, Veronica [U.A. Fisica, CNEA, and CONICET, Bs. As. (Argentina); Grosso, Mariela del [U.A. Fisica, CNEA, and GCMM-UTN-FRG Pacheco (Argentina); Garcia Bermudez, Gerardo [U.A. Fisica, CNEA, CONICET, and Escuela de Ciencia y Tecnologia, UNSAM (Argentina); Behar, Moni [Instituto de Fisica, Universidade Federal do Rio Grande do Sul (Brazil)

    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.

  16. Solar Cycle Variation in Solar Irradiance

    NASA Astrophysics Data System (ADS)

    Yeo, K. L.; Krivova, N. A.; Solanki, S. K.

    2014-12-01

    The correlation between solar irradiance and the 11-year solar activity cycle is evident in the body of measurements made from space, which extend over the past four decades. Models relating variation in solar irradiance to photospheric magnetism have made significant progress in explaining most of the apparent trends in these observations. There are, however, persistent discrepancies between different measurements and models in terms of the absolute radiometry, secular variation and the spectral dependence of the solar cycle variability. We present an overview of solar irradiance measurements and models, and discuss the key challenges in reconciling the divergence between the two.

  17. Irradiation Is it Consumer-Friendly?

    NSDL National Science Digital Library

    Swamy Anantheswaran

    2000-01-01

    “Leo Altamari,” CEO of Kutztown Meat Packing Corporation, has just come back from his Monday morning staff meeting, where the major agenda item was a discussion about the irradiation of meat products.  Leo must decide whether his company should pursue meat irradiation, weighing the expense of the technology and the wariness of many consumers, even though research has shown it to be an effective means of eliminating E. coli contamination in meat products.  Developed for an introductory food science course, the case introduces students to consumer perceptions and beliefs about food irradiation and teaches them how the food industry evaluates new processing technologies from a business perspective.

  18. Some wholesomeness studies on irradiated Iraqi dates

    NASA Astrophysics Data System (ADS)

    Al Rawi, A. M.; Hamoudi, H. I.

    Iraqi dates (Zahdi and Khestawi) were irradiated at different dose levels (0-1500 krad) to extend their shelf-lives. Samples irradiated at 150 krad showed no change in the behaviour studies of tested Swiss albino mice. Fungi were found to have a constant rate of growth on the syrup irradiated dates. Chemical products such as malondialdhyde, deoxy sugars, acids and reducing sugars were quantified. In conclusion, 150 krad is a convinient dose to extend the shelf-lives of the tested dates and is therefore recommended.

  19. Oxygen intake in ion irradiated fullerene films

    NASA Astrophysics Data System (ADS)

    Kumar, Amit; Khan, S. A.; Kumar, Manvendra; Agarwal, D. C.; Singh, Fouran; Tripathi, A.; Govind; Shivaprasad, S. M.; Salomon, J.; Pichon, L.; Pivin, J. C.; Avasthi, D. K.

    2008-04-01

    The present work reports the change in the oxygen content in energetic ion irradiated fullerene films. The oxygen contents in irradiated films have been studied using on-line elastic recoil detection analysis (ERDA) and off-line X-ray photo electron emission (XPS) and nuclear reaction analysis (NRA) techniques. The XPS and NRA techniques show that the oxygen content increases with ion fluence, whereas on-line ERDA measurements reveal that the oxygen content decreases with ion fluence. These experiments give clear evidence that oxygen content in irradiated films increases after exposure to the atmospheric oxygen.

  20. 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.

  1. Swelling in reactor-conditioned nickel-ion irradiated nimonic PE16. [Neutron irradiation and nickel-ion irradiation

    SciTech Connect

    Bajaj, R.; Diamond, S.; Chickering, R.W.; Bleiberg, M.L.

    1981-01-01

    Nimonic PE16 solution treated and aged and neutron irradiated at three temperatures to a fluence up to 5.9 X 10/sup 22/ n/cm/sup 2/ was bombarded to an additional nominal nickel ion dose of 150 displacements per atom (dpa) at various temperatures. The swelling determined by transmission electron microscopy is described and comparisons are made with results obtained from ion bombardments of virgin material and high-fluence neutron irradiated material.

  2. 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, permeability, and dispersivity which produces a nearly perfect fit to the measured tracer data. The models used for the inversion are simplified to the main geologic elements of the geothermal reservoir and consist of only 2 to 4 regions of constant properties. Optimal a-posteriori parameter estimates will be complemented by an analysis of parameter dependencies and uncertainties as a by-product of the nonlinear inversion. With both ensemble methods a cell-wise discrete spatial distribution of the permeability can be retrieved. For MC approach we produced a large number of system realizations with permeability distributions randomly picked from a bimodal histogram of the enhanced zone and the surrounding. The main fracture area is modelled by assuming a high permeability and an anisotropic correlation length. After forward simulation of the tracer experiment, the successful realizations are selected and further grouped to study principal features of the permeability distribution. Similar to the MC approach, the EnKF is based on a forward propagation of an ensemble of realizations. At successive instants in time, different kinds of data as tracer concentration, bottom hole pressure, and permeability in various drill holes are collected in one data vector and used to update (assimilate) the system variables to improve the match between observation and simulation leading to a convergence of the ensemble. We studied the performance and spatial resolution of the EnKF procedure for a 3D test model which is based on the borehole locations and tracer experiment of the Soultz geothermal reservoir. We used all available information to condition the pressure field and to estimate the permeability. Already after a few assimilation steps the ensemble average permeability shows coarse features of the expected permeability field. However, any estimates of smaller scale permeability variations turn out to be very sensitive to the (potentially unknown) correlation lengths.

  3. Embrittlement of irradiated F82H in the absence of irradiation hardening

    Microsoft Academic Search

    R. L. Klueh; K. Shiba; M. A. Sokolov

    2009-01-01

    Neutron irradiation of 7–12% Cr ferritic\\/martensitic steels below 425–450°C produces microstructural defects and precipitation that cause an increase in yield stress. This irradiation hardening causes embrittlement, which is observed in a Charpy impact or fracture toughness test as an increase in the ductile-brittle transition temperature. Based on observations that show little change in strength in steels irradiated above 425–450°C, the

  4. Embrittlernent of irradiated F82H in the absence of irradiation hardening

    Microsoft Academic Search

    Ronald L Klueh; Kiyoyuki Shiba; Mikhail A Sokolov

    2009-01-01

    Neutron irradiation of 7-12% Cr ferritic\\/martensitic steels below 425-450 C produces microstructural defects and precipitation that cause an increase in yield stress. This irradiation hardening causes embrittlement, which is observed in a Charpy impact or fracture toughness test as an increase in the ductile-brittle transition temperature. Based on observations that show little change in strength in steels irradiated above 425-450

  5. Swelling in previously neutron-irradiated commercial Fe-Cr-Ni based alloys under electron irradiation

    NASA Astrophysics Data System (ADS)

    Gelles, D. S.; Thomas, L. E.; Laidler, J. J.

    1982-08-01

    In order to avoid the artifacts which result because void swelling and precipitate stability are not accelerated to the same degree during radiation damage simulation experiments, a series of electron irradiation experiments were performed on commercial alloy specimens which were first irradiated in-reactor. This procedure is intended to establish a microstructure typical of in-reactor behavior which is then irradiated at accelerated rates in order to provide prediction of behavior to high fluence in-reactor on a reduced time scale. Neutron-irradiated specimens of fully-aged and solution treated Nimonic ? PE16, 20% cold-worked AISI 310 stainless steel and aged A-286 were electron irradiated at 500-700°C in the HVEM to determine the effect of reactor-conditioning on the simulation of void swelling at high neutron fluences. For aged PE16 it was found that the swelling behavior under electron irradiation was unaffected by prior neutron irradiation. Specimens from four different reactor temperature/fluence conditions showed the same temperature-dependent swelling rates in the HVEM irradiations. The swelling behavior of aged PE16. A-286 and cold-worked 310 was also consistent with previous results on specimens which were not previously neutron irradiated. However, reactor conditioning did alter the swelling response of solution-treated PE16 under electron irradiation, and this effect is attributed to the irradiaton-enhanced precipitation of ?' which occurs in-reactor. It is concluded that void and dislocation substructures generated in-reactor exert only second order control over void swelling during electron irradiation. Reactor conditioning expriments can be better described as temperature change experiments, providing that the alloy in question remains stable during neutron irradiation.

  6. Validation of gamma irradiator controls for quality and regulatory compliance

    Microsoft Academic Search

    Rorry B. Harding; Francis J. A. Pinteric

    1995-01-01

    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

  7. Production test IP614-A: Irradiation of thorium target elements

    Microsoft Academic Search

    K. L. Hladek; L. E. Kusler

    1963-01-01

    Limited irradiations of thorium target elements have been conducted at HAPO during the past ten years but large-scale irradiations have not been attempted. An obstacle encountered in thorium irradiation programs has been the formation of U-232, which is undesirable because of intense gamma radiation. Further study of the problem indicates that by employing certain restrictions during irradiation of the thorium

  8. UV Microspot Irradiator at Columbia University

    PubMed Central

    Bigelow, Alan W.; Ponnaiya, Brian; Targoff, Kimara L.; Brenner, David J.

    2013-01-01

    The Radiological Research Accelerator Facility (RARAF) at Columbia University has recently added a UV microspot irradiator to a microbeam irradiation platform. This UV microspot irradiator applies multiphoton excitation at the focal point of an incident laser as the source for cell damage, and with this approach, a single cell within a 3D sample can be targeted and exposed to damaging UV. The UV microspot’s ability to impart cellular damage within 3D is an advantage over all other microbeam techniques, which instead impart damage to numerous cells along microbeam tracks. This short communication is an overview and a description of the UV microspot including the following applications and demonstrations of selective damage to live single cell targets: DNA damage foci formation, patterned irradiation, photoactivation, targeting of mitochondria, and targeting of individual cardiomyocytes in the live zebrafish embryo. PMID:23708525

  9. 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)

  10. 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.

  11. 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.

  12. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...pool water level is below the normal low water level or above the normal high water level. (e) Irradiator pools must be equipped with a purification system designed to be capable of maintaining the water during normal operation at a...

  13. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...pool water level is below the normal low water level or above the normal high water level. (e) Irradiator pools must be equipped with a purification system designed to be capable of maintaining the water during normal operation at a...

  14. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...pool water level is below the normal low water level or above the normal high water level. (e) Irradiator pools must be equipped with a purification system designed to be capable of maintaining the water during normal operation at a...

  15. 10 CFR 36.33 - Irradiator pools.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...pool water level is below the normal low water level or above the normal high water level. (e) Irradiator pools must be equipped with a purification system designed to be capable of maintaining the water during normal operation at a...

  16. Selective irradiation of the vascular endothelium

    E-print Network

    Schuller, Bradley W

    2007-01-01

    We developed a unique methodology to selectively irradiate the vascular endothelium in vivo to better understand the role of vascular damage in causing normal tissue radiation side-effects.The relationship between vascular ...

  17. Correlations of solar cycle 22 UV irradiance

    NASA Technical Reports Server (NTRS)

    Floyd, L.; Brueckner, G.; Crane, P.; Prinz, D.; Herring, L.

    1997-01-01

    The solar ultraviolet spectral irradiance monitor (SUSIM) onboard the upper atmosphere research satellite (UARS) is an absolutely calibrated UV spectrometer which has measured the solar spectral irradiance over the wavelengths 115 nm to 410 nm since October 1991. This data set now extends for about six years from near the peak of solar cycle 22, through its minimum, to the initial rise associated with solar cycle 23. Generally, the time series of UV spectral irradiances obtained shows behavior similar to that of other solar activity indices. The conditions on the sun, which can in result in dominant 13.5-day periodicity, are analyzed and illustrated. It is found that any combination of presence or absence of dominant 13.5-day in UV irradiance and solar wind velocity is possible depending entirely on the particular surface distribution and orientation of solar active regions.

  18. Cantilever beam stress measurements during ion irradiation

    SciTech Connect

    Sambeek, A.I. Van; Averback, R.S. [Univ. of Illinois, Urbana, IL (United States). Dept. of Materials Science and Engineering

    1996-12-31

    In-situ stress measurements on single crystal MgO and Al{sub 2}O{sub 3} have been performed during ion irradiation. A cantilevered beam sample arrangement was used, with the stress in the implanted layer determined form the deflection of the sample as measured by the change in capacitance between the free end of the sample and a reference electrode. Point defect concentrations are obtained by dividing the volume strain by the defect relaxation volume, with saturation values of 0.8 to 1.2% obtained for 1.0 MeV Ne, Ar and Kr irradiations. Defect production is sublinear with dose, with an efficiency of less than 25% compared to Kinchin-Pease predictions. Ionization induced annealing is evaluated with 1.0 MeV He and 1.0 MeV H irradiations following heavy ion irradiation.

  19. a Study of Stress Relaxation Rate in Un-Irradiated and Neutron-Irradiated Stainless Steel

    NASA Astrophysics Data System (ADS)

    Ghauri, I. M.; Afzal, Naveed; Zyrek, N. A.

    Stress relaxation rate in un-irradiated and neutron-irradiated 303 stainless steel was investigated at room temperature. The specimens were exposed to 100 mC, Ra-Be neutron source of continuous energy 2-12 MeV for a period ranging from 4 to 16 days. The tensile deformation of the specimens was carried out using a Universal Testing Machine at 300 K. During the deformation, straining was frequently interrupted by arresting the cross head to observe stress relaxation at fixed load. Stress relaxation rate, s, was found to be stress dependent i.e. it increased with increasing stress levels ?0 both in un-irradiated and irradiated specimens, however the rate was lower in irradiated specimens than those of un-irradiated ones. A further decrease in s was observed with increase in exposure time. The experiential decrease in the relaxation rate in irradiated specimens is ascribed to strong interaction of glide dislocations with radiation induced defects. The activation energy for the movement of dislocations was found to be higher in irradiated specimens as compared with the un-irradiated ones.

  20. Patterning magnetic films by ion beam irradiation

    Microsoft Academic Search

    B. D. Terris; D. Weller; L. Folks; J. E. E. Baglin; A. J. Kellock; H. Rothuizen; P. Vettiger

    2000-01-01

    We have used ion beam irradiation through a silicon stencil mask to alter the magnetic properties of Co\\/Pt multilayer and FePt chemically-ordered superlattice films. In both systems, ion irradiation disorders the as-grown films which results in a reduction of the magnetic anisotropy. Regularly spaced micrometer-sized regions of magnetically altered material have been produced over areas of a square millimeter. These

  1. The Total Irradiance Monitor (TIM): Instrument Design

    Microsoft Academic Search

    Greg Kopp; George Lawrence

    2005-01-01

    The Total Irradiance Monitor (TIM) instrument is designed to measure total solar irradiance with an absolute accuracy of 100\\u000a parts per million. Four electrical substitution radiometers behind precision apertures measure input radiant power while providing\\u000a redundancy. Duty cycling the use of the radiometers tracks degradation of the nickel-phosphorous absorptive black radiometer\\u000a interiors caused by solar exposure. Phase sensitive detection at

  2. The Total Irradiance Monitor (TIM): Instrument Design

    Microsoft Academic Search

    Greg Kopp; George Lawrence

    The Total Irradiance Monitor (TIM) instrument is designed to measure total solar irradiance with an absolute accuracy of 100\\u000a parts per million. Four electrical substitution radiometers behind precision apertures measure input radiant power while providing\\u000a redundancy. Duty cycling the use of the radiometers tracks degradation of the nickel-phosphorous absorptive black radiometer\\u000a interiors caused by solar exposure. Phase sensitive detection at

  3. IRRADIATION DAMAGE STUDIES IN SOLID TARGETS

    Microsoft Academic Search

    N. Simos; H. Kirk; J. O Conor; L. Mausner; N. Mokhov

    In an effort to address the limitations on high-power accelerator target performance prompted by the elevated dose levels and the associated irradiation damage, an experimental study has been conducted to explore interesting new alloys and composites under the influence of protons and neutrons. Material irradiations were performed using the 200-MeV protons of the BNL Linac operating with an effective power

  4. FTIR analysis of microwave irradiated polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Acharya, N. K.; Prajapati, A. N.

    2010-06-01

    Polymer nanocomposites were prepared in the form of thin films of 30?m by using solution cast method. The samples were prepared with silver nanoparticles and TiO2 nanopowder and dispersed in polycarbonate. These composite polymer films were irradiated by various doses of microwaves at 100 to 750 W for 10 minutes in commercial microwave oven. The FTIR spectra were taken for various samples and compared. The results show the effect of microwave irradiation on polymer nanocomposites.

  5. Splenic irradiation in chronic myeloid leukemia.

    PubMed

    Hukku, S; Baboo, H A; Venkataratnam, S; Vidyasagar, M S; Patel, N L

    1983-01-01

    Results of splenic irradiation as the initial and only method of treatment are reported in 25 patients with chronic myeloid leukemia. Peripheral remission was induced in all the patients. Induction was achieved after a short period of 11 to 30 days in the majority of the patients, the longest period being 40 days. Several patients were in remission 9 months after treatment. The results are compared with those obtained by chemotherapy. Some advantages of splenic irradiation over chemotherapy are emphasized. PMID:6305140

  6. Temperature distribution in tissue during laser irradiation

    Microsoft Academic Search

    J. Eichler; J. Knof; H. Lenz; J. Salk; G. Schäfer

    1978-01-01

    Summary During irradiation with an Ar+- and Kr+-laser the temperature rise in living and dead tissue was measured in various depths. The contribution of the blood flow to the heat transport during irradiation was found to be small. The influence of the different depths of penetration and backscattering at the blue-green Ar+- and the red Kr+-radiation was investigated. The measurements

  7. Fission gas retention in irradiated metallic fuel

    Microsoft Academic Search

    G. R. Fenske; E. E. Gruber; J. M. Kramer

    1987-01-01

    Theoretical calculations and experimental measurements of the quantity of retained fission gas in irradiated metallic fuel (U-5Fs) are presented. The calculations utilize the Booth method to model the steady-state release of gases from fuel grains and a simplified grain-boundary gas model to predict the gas release from intergranular regions. The quantity of gas retained in as-irradiated fuel was determined by

  8. Electron irradiation of solid nitrous oxide

    NASA Astrophysics Data System (ADS)

    Sivaraman, B.; Ptasinska, S.; Jheeta, S.; Mason, N. J.

    2008-07-01

    We report the results of chemical processing induced by 1 keV electron irradiation of a solid N 2O ice sample formed at 25 K. Ozone and several oxides of nitrogen (NO 2, N 2O 2, N 2O 3, N 2O 4 and N 2O 5) were observed to form during the irradiation period. Such reactions have important implications for the ice chemistry of outer solar system planets/satellites and interstellar ices.

  9. NUCLEAR IRRADIATION EFFECTS ON FERROMAGNETIC CORE MATERIALS

    Microsoft Academic Search

    R. S. Sery; D. I. Gordon

    1958-01-01

    Effects of nuclear irradiation on the magnetic properties of 14 ; representative core materials were investigated. Measurements before, during, ; and after irradiation were made at a flux level of about 10¹² neutrons\\/ cm\\/; sup 2\\/ sec and for a total integrated neutron flux of ~ 10¹⁸ nvt. The fast ; flux (E) 1 ev) was about 10¹¹ n\\/cm² sec

  10. 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.

  11. The effects of irradiation on blood components

    SciTech Connect

    Button, L.N.; DeWolf, W.C.; Newburger, P.E.; Jacobson, M.S.; Kevy, S.V.

    1981-01-01

    The functional properties of formed elements of whole blood were studied following irradiation doses of 500 to 20,000 rads. Irradiated lymphocytes retained only 1.5 per cent of their 3H thymidine uptake after a 5,000-rad exposure and none after 7,500 rads. Red blood cells stored for 21 days and then irradiated with 5,000 rads had the same survival as nonirradiated controls. In contrast, 5,000 rads reduced platelet yields. However, transfused irradiated platelets produced the expected increases in platelet counts and controlled hemostasis in thrombocytopenic patients. After 5,000 rads, granulocytes had normal bacterial killing capacity, chemotactic mobility, and normal superoxide production after high-dose stimulation. Nitroblue tetrazolium reduction and ingestion stimulated by complement opsonized oil droplets were not diminished by 5,000- and 10,000-rad irradiation. The functional qualities of cellular blood components other than lymphocytes are not compromised by 5,000 rads. This irradiation dose may be an effective means of controlling incidence of graft-vs-host disease in immunosuppressed patients.

  12. 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...

  13. Irradiation eradication and pathogen reduction. Ceasing cesium irradiation of blood products

    Microsoft Academic Search

    P D Mintz; G Wehrli

    2009-01-01

    The irradiation of cellular blood components to prevent transfusion-associated (TA)-GVHD is an established practice in the developed world. Susceptible patients include those who are immunosuppressed, fetuses, very premature neonates and patients who have an increased likelihood of possessing one HLA haplotype for which the blood component donor is homozygous. Problems and challenges associated with blood component irradiation include transfusion delay,

  14. Tolerance of bile duct to intraoperative irradiation

    SciTech Connect

    Sindelar, W.F.; Tepper, J.; Travis, E.L.

    1982-09-01

    In order to determine the effects of intraoperative radiation therapy of the bile duct and surrounding tissues, seven adult dogs were subjected to laparotomy and intraoperative irradiation with 11 MeV electrons. Two animals were treated at each dose level of 2000, 3000, and 4500 rads. A single dog which received a laparotomy and sham irradiation served as a control. The irradiation field consisted of a 5 cm diameter circle encompassing the extrahepatic bile duct, portal vein, hepatic artery, and lateral duodenal wall. The animals were followed clinically for mor than 18 months after treatment, and autopsies were performed on dogs that died to assess radiation-induced complications or tissue damage. All dogs developed fibrosis and mural thickening of the common duct, which appeared by 6 weeks following irradiation and which was dose-related, being mild at low doses and more severe at high doses. Hepatic changes were seen as early as 6 weeks after irradiation, consisting of periportal inflammation and fibrosis. The hepatic changes appeared earliest at the highest doses. Frank biliary cirrhosis eventually developed at all dose levels. Duodenal fibrosis appeared in the irradiation portal, being most severe at the highest doses and in some animals resulting in duodenal obstruction. No changes were observed in irradiated portions of portal vein and hepatic artery at any dose level. It was concluded that intraoperative radiation therapy delivered to the region of the common duct leads to ductal fibrosis, partial biliary obstruction with secondary hepatic changes, and duodenal fibrosis if bowel wall is included in the field. Clinical use of intraoperative radiation therapy to the bile duct in humans may require routine use of biliary and duodenal bypass to prevent obstructive complications.

  15. Embrittlernent of irradiated F82H in the absence of irradiation hardening

    SciTech Connect

    Klueh, Ronald L [ORNL; Shiba, Kiyoyuki [ORNL; Sokolov, Mikhail A [ORNL

    2009-01-01

    Neutron irradiation of 7-12% Cr ferritic/martensitic steels below 425-450 C produces microstructural defects and precipitation that cause an increase in yield stress. This irradiation hardening causes embrittlement, which is observed in a Charpy impact or fracture toughness test as an increase in the ductile-brittle transition temperature. Based on observations that show little change in strength in steels irradiated above 425-450 C, the general conclusion has been that no embrittlement occurs above these temperatures. In a recent study of F82H steel, significant embrittlement was observed after irradiation at 500 C. This embrittlement is apparently due to irradiation-accelerated Laves-phase precipitation. Observations of the embrittlement in the absence of hardening has been examined and analyzed with thermal-aging studies and computational thermodynamics calculations to illuminate and understand the effect.

  16. Multiscale modeling of nanofoams under irradiation

    NASA Astrophysics Data System (ADS)

    Bringa, E. M.; Rodriguez-Nieva, J.; Monk, J. D.; Caro, J. A.; Loeffler, M. J.; Cassidy, T. A.; Johnson, R. E.; Baragiola, R. A.; Farkas, D.

    2012-02-01

    Nanoscale porosity appears in solids under a number of conditions: radiation damage in nuclear reactors, initial stages of ductile failure, in astro-materials, etc. Using molecular dynamics (MD) simulations, we analyze the radiation damage and surface modification of materials with various nanoscale porosities, where experimental techniques can be difficult to use and interpret. We consider (a) irradiation with ions with energies in the range 1-25 keV, of interest for fusion and fission energy applications; (b) swift heavy ion irradiation, with energies up to few GeV, relevant for track formation and interstellar grain evolution. We find that irradiation effects have larger spatial extent than for full-density solids and include the production of point-defects and twins which change the mechanical properties of the samples. We use our MD results as input for a Monte Carlo (MC) code to calculate sputtering yields from nanofoams of different geometries under different irradiation conditions. We also use our MD results to build models which predict possible radiation endurance under intense irradiation.

  17. 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.

  18. Endocrine deficit after fractionated total body irradiation.

    PubMed

    Ogilvy-Stuart, A L; Clark, D J; Wallace, W H; Gibson, B E; Stevens, R F; Shalet, S M; Donaldson, M D

    1992-09-01

    Endocrine function was assessed in 31 children (17 boys) after fractionated total body irradiation used in the preparative regimen for bone marrow transplantation. Endocrine dysfunction was present in 25 children. Fifteen of 29 had growth hormone insufficiency 0.9-4.9 years after total body irradiation, yet only three of the 15 had received previous cranial irradiation. Five of 30 had thyroid dysfunction: two with a low thyroxine and raised thyroid stimulating hormone (TSH) concentration and three with a raised TSH and normal thyroxine concentration. Thus the incidence of thyroid dysfunction (16%) is much lower than that reported after single fraction total body irradiation (39-59%). In only two children were abnormalities of the hypothalamic-pituitary-adrenal axis demonstrated. The majority of pubertal children assessed (n = 15) showed evidence of gonadal damage. All the pubertal girls (n = 5) had ovarian failure, although there was evidence of recovery of ovarian function in one girl. All seven boys in late puberty showed evidence of damage to the germinal epithelium, and two of three in early puberty had raised follicle stimulating hormone concentrations. Despite the use of a fractionated total body irradiation regimen, endocrine morbidity is substantial and children undergoing such procedures will require long term endocrine review and management. PMID:1417055

  19. Review of recent irradiation-creep results

    SciTech Connect

    Coghlan, W.A.

    1982-05-01

    Materials deform faster under stress in the presence of irradiation by a process known as irradiation creep. This phenomenon is important to reactor design and has been the subject of a large number of experimental and theoretical investigations. The purpose of this work is to review the recent experimental results to obtain a summary of these results and to determine those research areas that require additional information. The investigations have been classified into four subgroups based on the different experimental methods used. These four are: (1) irradiation creep using stress relaxation methods, (2) creep measurements using pressurized tubes, (3) irradiation creep from constant applied load, and (4) irradiation creep experiments using accelerated particles. The similarity and the differences of the results from these methods are discussed and a summary of important results and suggested areas for research is presented. In brief, the important results relate to the dependence of creep on swelling, temperature, stress state and alloying additions. In each of these areas new results have been presented and new questions have arisen which require further research to answer. 65 references.

  20. 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. (ASRP); (ANSTO); (ANU)

    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.

  1. Effect of neutron irradiation on vanadium alloys

    SciTech Connect

    Braski, D.N.

    1986-01-01

    Neutron-irradiated vanadium alloys were evaluated for their susceptibility to irradiation hardening, helium embrittlement, swelling, and residual radioactivity, and the results were compared with those for the austenitic and ferritic stainless steels. The VANSTAR-7 and V-15Cr-5Ti alloys showed the greatest hardening between 400 and 600/sup 0/C while V-3Ti-1Si and V-20Ti had lower values that were comparable to those of ferritic steels. The V-15Cr-5Ti and VANSTAR-7 alloys were susceptible to helium embrittlement caused by the combination of weakened grain boundaries and irradiation-hardened grain matrices. Specimen fractures were entirely intergranular in the most severe instances of embrittlement. The V-3Ti-1Si and V-20Ti alloys were more resistant to helium embrittlement. Except for VANSTAR-7 irradiated to 40 dpa at 520/sup 0/C, all of the vanadium alloys exhibited low swelling that was similar to the ferritic steels. Swelling was greater in specimens that were preimplanted with helium using the tritium trick. The vanadium alloys clearly exhibit lower residual radioactivity after irradiation than the ferrous alloys.

  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. 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.

  4. Laboratory for Characterization of Irradiated Graphite

    SciTech Connect

    Karen A. Moore

    2010-03-01

    The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center (IRC). The CCL was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite and ceramic composite research and development activities. The research is in support of the Advanced Graphite Creep (AGC) experiment — a major material irradiation experiment within the NGNP Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials.

  5. Heavy ion irradiation of crystalline water ice

    E-print Network

    Dartois, E; Boduch, P; Brunetto, R; Chabot, M; Domaracka, A; Ding, J J; Kamalou, O; Lv, X Y; Rothard, H; da Silveira, E F; Thomas, J C

    2015-01-01

    Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic ...

  6. Raman spectroscopy of ion irradiated amorphous carbons

    NASA Astrophysics Data System (ADS)

    Baratta, G. A.; Arena, M. M.; Strazzulla, G.; Colangeli, L.; Mennella, V.; Bussoletti, E.

    1996-08-01

    We have studied, by "in situ" Raman spectroscopy, the modifications induced by 3 keV He + ions on thin amorphous carbon grain deposits. Previous results obtained with our experimental apparatus show that in the case of carbon-containing frozen targets (such as benzene and butane) for doses greater than about 100 eV/mol, ion irradiation induces the formation of an hydrogenated amorphous carbon. In this paper, the bombarded material is already an amorphous carbon with a relatively high order degree. In this case ion irradiation progressively decreases the order degree in the amorphous carbon. This result is in agreement with analogous ion irradiation experiments carried out on highly ordered pyrolitic graphite crystals. These studies are important to understand physical characteristics and evolution of refractory carbon grains in astrophysical environments.

  7. 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.

  8. Horizontal modular dry irradiated fuel storage system

    DOEpatents

    Fischer, Larry E. (Los Gatos, CA); McInnes, Ian D. (San Jose, CA); Massey, John V. (San Jose, CA)

    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).

  9. Ion irradiation of preceramic polymer thin films

    SciTech Connect

    Pivin, J.C. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, Orsay (France); Colombo, P.; Tonidandel, M. [Univ. di Padova (Italy)

    1996-07-01

    Thin films of two preceramic polymers, namely polycarbosilane (PCS) and a silicone resin (SR350), were deposited on Si substrates. Instead of employing conventional annealing at high temperatures in an inert atmosphere, ion irradiation was used to achieve the polymer-to-ceramic conversion. A detailed investigation of the changes in the composition, chemical structure, and hardness was performed by means of ion bean analysis (Rutherford backscattering spectrometry, nuclear reaction analysis, and elastic recoil detection analysis), FTIR, Raman and nanoindentation, respectively. This processing method yielded amorphous Si-C and Si-O-C coatings possessing high hardness and density. Compared to films heat-treated under vacuum at 1,000 C, ion-irradiated ones exhibited a similar hydrogen content, a lower oxygen contamination, and a higher carbon content. Annealing at 1,000 C of previously irradiated films resulted in coatings still possessing a high carbon content and a high hardness.

  10. Phototoxicity testing by online irradiation and HPLC.

    PubMed

    Schröder, Sven; Surmann, J P

    2006-11-01

    A high-performance liquid chromatography (HPLC) system was developed for the determination of drug photostability and phototoxicity based on an automated column-switching system with aqueous online UV-A irradiation and hyphenated organic separation of the drug and its photoproducts. The photoreactor is built with an poly(ethylene-co-tetrafluoroethylene) (ETFE) reaction coil knitted around a UV-A light source. The chromatographic separation was performed with two special C18 columns, which are also suitable for using with pure water as eluent. Degradation of chlorpromazine (CPZ) by ultraviolet light was investigated at pH 7 and pH 3. Furthermore chlorpromazine was irradiated in the presence of guanosine-5-monophosphate (GMP) in pH 7 buffered solution, leading to a new photoproduct. In the pH 3 irradiation studies of CPZ and GMP, no reaction was detected between the molecules. PMID:17058072

  11. 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. ?-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.

  12. 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.

  13. BPX insulation irradiation program test results

    SciTech Connect

    McManamy, T.J. (Oak Ridge National Lab., TN (United States)); Kanemoto, G. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Snook, P.G. (Princeton Univ., NJ (United States). 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.

  14. Irradiation Pressure Effects in Close Binary Systems

    E-print Network

    Sam Phillips; Philipp Podsiadlowski

    2001-09-19

    We present a method for the calculation of the effects of external irradiation on the geometrical shape of the secondary in a close binary containing a compact star, the source of the radiation, and a normal companion star, where we include the possibility of shadowing by an accretion disc. The model is based on a simple modification of the standard Roche binary potential in which the radiation-pressure force is parameterised using the ratio of the radiation to the gravitational force. We have constructed numerical solutions of approximate 3-dimensional irradiated equipotential surfaces to demonstrate the main geometrical effects of external radiation pressure. For systems in which the inner Lagrangian point is irradiated directly and for sufficiently high irradiation fluxes, the critical condition for which the secondary fills its tidal lobe changes from an inner to an outer critical configuration, where the critical equipotential surface connects to one of the outer rather than the inner Lagrangian point. Such a situation may apply to evaporating binary pulsar systems (e.g. PSR 1957+20), stars orbiting supermassive black holes in AGN and some high-mass X-ray binaries (including Centaurus X-3). For systems containing an accretion disc, which shadows the inner Lagrangian point from the external irradiation, the presence of significant radiation pressure causes a non-axisymmetric deformation of the stellar surface. We have calculated modified Roche potentials to determine the main effects on the optical lightcurves and radial velocity curves for typical binary parameters. Compared to previous studies, the inclusion of irradiation-pressure effects results in changes in the derived system parameters (e.g. component masses, radial velocities) that may be as high as 30 per cent.

  15. Dyeing of ?-irradiated cotton with natural flavonoid dye extracted from irradiated onion shells (Allium cepa) powder

    NASA Astrophysics Data System (ADS)

    Rehman, Fazal-ur; Adeel, Shahid; Shahid, Muhammad; Bhatti, Ijaz Ahmad; Nasir, Faiza; Akhtar, Nasim; Ahmad, Zulfiqar

    2013-11-01

    Powder of Onion shells as a source of natural flavonoid dye (Quercetin) and cotton fabrics were exposed to absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. Irradiated and un-irradiated dye powder was used for extraction of quercetin as well as antibacterial, hemolytic and antioxidant activities were also determined to observe the effect of radiation. Furthermore, color strength and colourfastness of irradiated fabrics were improved by using pre and post-mordants such as alum and iron. It is found that 4 kGy is the optimal absorbed dose for extraction of natural quercetin extracted from onion shells while maximum color strength and acceptable fastness properties are obtained on dyeing of irradiated fabric at 60 °C keeping M:L of 1:30 using 10% alum as pre-mordant and 6% alum as post-mordant. Gamma irradiation has not only improved the color strength of the dye using irradiated cotton but also that of colourfastness properties.

  16. Irradiation effects studies of NERVA materials

    NASA Technical Reports Server (NTRS)

    Demastry, J. A.; Merrick, T. P.

    1972-01-01

    Several materials used in the NERVA project were irradiated at cryogenic temperatures to neutron fluences between 10 to the 17th and 10 to the 19th power newtons per square centimeter. Tensile properties were determined over a temperature range to evaluate the effects of irradiation on the material properties. The expected radiation damage typical of other materials was observed. A general increase in strength and decrease in ductility occurred. The effects at liquid nitrogen temperatures are more pronounced since radiation induced defects are not annealed out.

  17. Irradiation time (h) [IPU]/[IPU]0

    E-print Network

    Boyer, Edmond

    With NaN3 With 2-propanol 19% 0% 12% 6% OH OH OH OH OH OH OH OH OH OH OH OH OH OH O OH OH O OH OHOH O O OH0.2 0.4 0.6 0.8 1 0 2 4 6 8 Irradiation time (h) [IPU]/[IPU]0 Purified water Suwannee South Platte 0.2 0.4 0.6 0.8 1 0 2 4 6 8 Irradiation time (h) [E2]/[E2]0 Purified water Pinail Suwannee South

  18. Heavy-Section Steel Irradiation Program

    SciTech Connect

    Rosseel, T.M.

    2000-04-01

    Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents that have the potential for major contamination release. Because the RPV is the only key safety-related component of the plant for which a redundant backup system does not exist, it is imperative to fully understand the degree of irradiation-induced degradation of the RPV's fracture resistance that occurs during service. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established.

  19. Separation of sodium-22 from irradiated targets

    DOEpatents

    Taylor, Wayne A. (Los Alamos, NM); Jamriska, David (Los Alamos, NM)

    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.

  20. Magnetism in disordered graphene and irradiated graphite.

    PubMed

    Yazyev, Oleg V

    2008-07-18

    The magnetic properties of disordered graphene and irradiated graphite are systematically studied using a combination of mean-field Hubbard model and first-principles calculations. By considering large-scale disordered models of graphene, I conclude that only single-atom defects can induce ferromagnetism in graphene-based materials. The preserved stacking order of graphene layers is shown to be another necessary condition for achieving a finite net magnetic moment of irradiated graphite. Ab initio calculations of hydrogen binding and diffusion and of interstitial-vacancy recombination further confirm the crucial role of stacking order in pi-electron ferromagnetism of proton-bombarded graphite. PMID:18764285

  1. Radiostability of pharmaceuticals under different irradiation conditions

    NASA Astrophysics Data System (ADS)

    Crucq, Anne-Sophie; Deridder, Véronique; Tilquin, Bernard

    2005-02-01

    In this paper, the products studied are cefazolin, glucagon and dobutamine HCl. The radioresistance of pharmaceuticals may depend on the conditions of irradiation. The best is to irradiate the drugs in solid state and the chemical transformations can be reduced also by lowering the temperature of the liquid. In solid state, the dose rate has no influence on the decomposition for the selected molecules and it should be noted that drug excipients selected for bioavailability reasons are not always radioprotectors. These results are important from a technical point of view in pharmaceutical industry.

  2. The puridec range of gamma irradiation plants

    NASA Astrophysics Data System (ADS)

    Reuter, G. W.

    1995-02-01

    In 1992 Amersham International plc. and NUKEM GmbH agreed to cooperate in the field of industrial gamma irradiation plants. Consequently the brand "PURIDEC" was founded, to handle the common business worldwide. Amersham Int. plc. has been a leading company in manufacturing and transport of Co60 sources for more than 30 years while NUKEM looks back to three decades of experience in engineering and realization of nuclear plants and installations. Based on this vast experience a range of industrial irradiation plants has been developed that satisfies the individual demands of our customers. This paper gives an overview of PURIDEC's range of plants including those with dry and twin pool source storage.

  3. FMIT - the fusion materials irradiation test facility

    SciTech Connect

    Liska, D.J.

    1980-01-01

    A joint effort by the Hanford Engineering Development Laboratory (HEDL) and Los Alamos Scientific Laboratory (LASL) has produced a preliminary design for a Fusion Materials Irradiation Test Facility (FMIT) that uses a high-power linear accelerator to fire a deuteron beam into a high-speed jet of molten lithium. The result is a continuous energy spectrum of neutrons with a 14-MeV average energy which can irradiate material samples to projected end-of-life levels in about 3 years, with a total accumulated fluence of 10/sup 21/ to 10/sup 22/ n/cm/sup 2/.

  4. Evaluation of CERES surface irradiance products

    NASA Astrophysics Data System (ADS)

    Kato, S.; Loeb, N. G.; Rose, F. G.; Rutan, D. A.; Doelling, D.; Radkevich, A.; Ham, S. H.

    2014-12-01

    Understanding the surface radiation budget is important for several reasons. At the global and large temporal scales, it should balance with the sum of surface latent and sensible heat fluxes and ocean heating. At regional scales, it is an indispensable boundary condition for ocean or snow models or any other models that need energy input to the surface. NASA's Clouds and the Earth's Radiant Energy System (CERES) project provides surface irradiance data products for a range of temporal and spatial scales computed using a radiative transfer model initialized using satellite-derived cloud and aerosol properties. Other inputs to the radiative transfer model include temperature and humidity profiles from NASA Global Modeling and Assimilation Office's (GMAO) reanalysis. The CERES team uses more than 80 surface observation sites located over land and ocean to evaluate computed irradiances. When computed monthly 1° by 1° gridded mean downward irradiances are compared with 10 years of observed irradiances, the bias averaged over all land and ocean sites are, respectively, -1.7 Wm-2 and 4.7 Wm-2 for shortwave and -1.0 Wm-2 and -2.0 Wm-2 for longwave. The shortwave agreement is significantly better than other satellite-based surface irradiance products. One of reasons for the better agreement is careful treatment of diurnal cycle of clouds by merging 3-hourly geostationary satellite-derived cloud properties. In addition, computed surface irradiance variability shows a remarkable agreement with observed variability. However, these data sets have their shortcomings. The uncertainty in nighttime surface longwave irradiance over polar regions is larger than that of other regions primarily due to the difficulty of cloud detection and large uncertainties in skin temperature and near-surface temperature and humidity. The large uncertainty in polar region surface irradiances hampers, for example, investigation of surface radiation budget changes in response to changes in sea ice extent. In this presentation, we present an evaluation of the current CERES products and discuss ways these products can be improved in the future.

  5. Evaluation of 2-dodecylcyclobutanone as an irradiation dose indicator in fresh irradiated ground beef.

    PubMed

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

    2005-03-23

    Alkylcyclobutanones (2-ACBs) are radiolytic products formed when fatty acids are irradiated. These cyclobutanones are unique irradiation byproducts and therefore may serve as indicators of irradiation exposure. As only limited information exists about 2-ACB formation in retail meat products, reliable methods that can quantify 2-ACBs and thus estimate irradiation dose in commercial meat products are desired. The cyclobutanone studied in this experiment was 2-dodecylcyclobutanone (2-DCB), which is formed from palmitic acid. The formation of 2-DCB was evaluated in fresh irradiated ground beef patties at two fat levels. Patties containing 15% and 25% fat were irradiated by electron beam at 1.0, 2.0, 3.0, and 4.5 kGy. Commercially available 1-lb irradiated ground beef chubs with different fat levels were analyzed in order to estimate dose absorbed by these samples. The 2-DCB was extracted using supercritical fluid extraction (SFE) and analyzed by gas chromatography-mass spectroscopy (GC-MS) and was detected in all the irradiated samples. The concentration of 2-DCB increased linearly with dose with R2 = 0.9646 for 25% fat samples and R2 = 0.9444 for 15% fat samples. Further, there was no significant difference in 2-DCB concentrations between the two fat levels. The estimated doses applied to the commercial samples ranged between 1.38 and 1.55 kGy, values consistent with doses normally used in the industry (1.0-2.0 kGy). Our results show that 2-DCB can be used to monitor fresh irradiated beef and approximate the absorbed dose. PMID:15769109

  6. Post irradiation tensile and fatigue behavior of austenitic PCA stainless steels irradiated in HFIR

    NASA Astrophysics Data System (ADS)

    Tanaka, M. P.; Hamada, S.; Hishinuma, A.; Grossbeck, M. L.

    1988-07-01

    Mechanical properties were determined on solution annealed (SA) and cold worked (CW) JPCA (Ti-modified austenitic stainless steel) irradiated in the High Flux Isotope Reactor (HFIR) at temperatures ranging from 300 to 600°C. The irradiation produced damage levels from 16 to 56 dpa and helium concentration from 1020 to 4100 appm. The improved stability of MC precipitates which formed in the matrix during irradiation prevent loss of ductility at 500°C and below. Application of solution annealed JPCA is recommended for structural components of fusion reactors to be operated at 500°C and below.

  7. 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 (ZrC) 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-induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.

  8. 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.

  9. The effects of irradiation on Beijing roast duck

    NASA Astrophysics Data System (ADS)

    Weiguo, Wang; Yongbao, Gu; Fengmei, Li; Ruiying, Zhou

    The irradiation technique combined with freezing has been used to control the microorganisms in Beijing roast duck. 60Co was chosen as the ?-ray source. The average absorbed dose was 2 kGy. After irradiation, the microbe counts reached the tolerable level. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamins etc. Preliminary indications are that irradiated frozen Beijing roast duck is wholesome.

  10. Soft magnetic materials—17 years after electron irradiation

    Microsoft Academic Search

    R. S. Sery

    1987-01-01

    During the period 1963–1966 about 175 flat ring samples of Supermalloy, Unimag, Mumetal, 65 Ni-Fe, and pure iron were irradiated with electrons. Energies and integrated fluxes varied from 0.5 to 2.0 MeV and (0.2–1.0)×1017e\\/cm2, respectively. Some samples were irradiated in the Earth’s magnetic field and the rest were irradiated with applied circumferential fields of 0.22 Oe. Temperatures of irradiation varied

  11. 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.

  12. Mantle irradiation of the major salivary glands

    SciTech Connect

    Kaplan, P.

    1985-11-01

    Radiation given to the mantle field for treatment of Hodgkin's disease impinges on the submandibular and parotid glands at levels that have been both measured and calculated to be the complete tumor dose. This dosage is above the level of irradiation that has been shown to cause partial or complete loss of salivary gland function.

  13. Water hydraulic polymer components under irradiation

    Microsoft Academic Search

    Teresa Hernández; Eric R. Hodgson

    2007-01-01

    Polymers will be used as different sealing and glide components in the hydraulic remote handling systems for lifting and moving activities in ITER. The degradation of the polymer materials does not depend only on the radiation dose but also on the irradiation environment, and for remote handling hydraulic applications the components have to work in high humidity or water. In

  14. Susceptibility of irradiated steels to hydrogen embrittlement

    NASA Technical Reports Server (NTRS)

    Rossin, A. D.

    1968-01-01

    Investigation determined whether irradiated pressure-vessel steels 4340 and 212-B are susceptible to hydrogen embrittlement and to catastrophic failure. Hydrogen-charging conditions which completely embrittled 4340 steel had negligible effect on 212-B steel in tensile and delayed-failure tests.

  15. Irradiation studies of astrophysical ice analogues

    NASA Astrophysics Data System (ADS)

    Holton, Philip D.

    In this thesis the formation of molecular species in cold icy mantles, typical of those in the interstellar medium (ISM) has been studied. The construction of an ultra high vacuum system for the formation and containment of these astrophysical ice analogues is described. The method of preparation of these ices is detailed and analysis methodologies are discussed. VUV spectra of molecular ices (e.g. SO2, CH3NH2, OCS) measured on the UV1 beam line of the Astrid Synchrotron facility at the University of Aarhus in Denmark, are presented. Molecular synthesis (e.g. CO3, CO, H2CO3) induced by ion irradiated CO2/H 2O ices using facilities at Queens University Belfast are also reported. In particular this thesis focuses on the irradiation studies of the binary ice mixture of Methylamine (CH3NH2) and Carbon Dioxide (CO2). The results of irradiation of CH3NH2 and CO2 binary ice mixtures by ultraviolet photons, and electrons are presented. The apparent production of the amino acid - glycine - in our irradiated samples is discussed together with possible production processes.

  16. Possibility for irradiated beryllium at CERN

    E-print Network

    McDonald, Kirk

    possibilities exists at CERN to obtain irradiated beryllium for testing: beam windows, and in particular 6 sec. (fast extraction) SPS primary targets, used for secondary beam production for test beams-line, just in front of the CNGS target shielding assembly March 2011 before start-up (after 1.434*1020 POT

  17. DUGWAY FOOD IRRADIATOR USES 8 MTR ELEMENTS

    Microsoft Academic Search

    C. J. Christensen; A. Jacobsen; Q. Klinger; G. Abel

    1957-01-01

    Eight spent MTR fuel elements are the radintion source in the Dugway ; high-level gamma irradiation facility, designed especially for canned-food ; processing. The system will accept any can up to the No. 10 size and deliver a ; specified uniform radiation dose between 25,000 and 10⁷ r. Variation in ; total dose is limited to a few per cent.

  18. 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.

  19. Extrasolar Giant Planets under Strong Stellar Irradiation

    Microsoft Academic Search

    S. Seager; D. D. Sasselov

    1998-01-01

    We investigate irradiation of extrasolar giant planets (EGPs) by treating the radiative transfer in detail, so that the flux from the parent star interacts with all relevant depths of the planetary atmosphere with no need for a preassumed albedo. Rayleigh scattering (in dust-free models) increases the EGP's flux by orders of magnitude shortward of the Ca II H and K

  20. Charge accumulation in dielectrics irradiated by protons

    SciTech Connect

    Boev, S.G.; Paderin, V.A.

    1987-11-01

    A phenomenological analysis of the electric charging of dielectrics irradiated by accelerated protons is performed. It is shown that the energy of the particles and their range in the material affect the accumulation of volume charge. The results of an experimental study of the charging of a number of dielectrics with different structures and properties are presented.

  1. Low energy electron irradiation of an apple 

    E-print Network

    Brescia, Giovanni Batista

    2002-01-01

    is the need to achieve a uniform dose over the entire surface of convoluted shapes. The main goal of this research was to calculate the dose distribution produced by low energy electron irradiation of a typical complex shape, an apple, using Monte Carlo...

  2. Ion irradiation-induced anisotropic plastic deformation

    E-print Network

    Polman, Albert

    .3 This thesis 14 2 Anisotropic plastic deformation of colloidal silica particles under 4 MeV Xe ion irradiation-dimensional colloidal crystals, nanolithography 109 9.4 Photonic crystals of shape-anisotropic colloidal silica in silica glasses 95 8.1 Introduction 96 8.2 Experimental 96 8.3 Results and analysis 98 8.4 Discussion 101

  3. Urban tree influences on ultraviolet irradiance

    Microsoft Academic Search

    Gordon M. Heisler; Richard H. Grant; Wei Gao

    2002-01-01

    Many of the effects of ultraviolet radiation (UVR) on people and their environment--damage to various materials, survival of insects and microbial pathogens, growth of vegetation, and adverse or beneficial effects on human health-are modified by the pxesence of trees. Human epidemiological investigations generally consider exposure as given by indices of WR irradiance on horizontal surfaces in the open. Though many

  4. Urban tree influences on ultraviolet irradiance

    Microsoft Academic Search

    Gordon M. Heisler; Richard H. Grant; Wei Gao

    2002-01-01

    Many of the effects of ultraviolet radiation (UVR) on people and their environment--damage to various materials, survival of insects and microbial pathogens, growth of vegetation, and adverse or beneficial effects on human health--are modified by the presence of trees. Human epidemiological investigations generally consider exposure as given by indices of UVR irradiance on horizontal surfaces in the open. Though many

  5. 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...

  6. Enhancement effect of irradiation by methotrexate

    SciTech Connect

    Shehata, W.M.; Meyer, R.L.

    1980-09-15

    Three cases are described in which complications developed which were believed to be due to the enhancement effect of irradiation by methotrexate during the course of therapy for lung, kidney, and bladder cancer. These included esophageal and large bowel complications. In two of these cases, the patients improved with conservative therapy.

  7. Hyperparathyroidism After Irradiation for Childhood Malignancy

    SciTech Connect

    McMullen, Todd; Bodie, Greg [University of Sydney Endocrine Surgical Unit, Sydney, NSW (Australia); Gill, Anthony [Department of Anatomical Pathology, Royal North Shore Hospital and University of Sydney, Sydney, NSW (Australia); Ihre-Lundgren, Catharina [University of Sydney Endocrine Surgical Unit, Sydney, NSW (Australia); Shun, Albert [Department of Surgery, Children's Hospital at Westmead, Sydney (Australia); Bergin, Mary [Late Effects Oncology Clinic, Children's Hospital at Westmead, Sydney (Australia); Stevens, Graham [Oncology Service, Auckland Hospital, Auckland (New Zealand); Delbridge, Leigh [University of Sydney Endocrine Surgical Unit, Sydney, NSW (Australia)], E-mail: leighd@med.usyd.edu.au

    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.

  8. The irradiation laboratory at ?KD semiconductors Praha

    NASA Astrophysics Data System (ADS)

    Klisky, Vladimir

    1990-04-01

    An electron linac radiation source used to produce bulk defects in semiconductor power devices (SPDs) is described. Such defects serve to regulate the turn-off time and forward voltage drop of SPD devices. The irradiation facility, techniques, parameters of the electron beam and dosimetry are described.

  9. Computing exact shadow irradiance using splines

    Microsoft Academic Search

    Michael M. Stark; Elaine Cohen; Tom Lyche; Richard F. Riesenfeld

    1999-01-01

    We present a solution to the general problem of characterizing shad- ows in scenes involving a uniform polygonal area emitter and a polygonal occluder in arbitrary position by manifesting shadow irradiance as a spline function. Studying generalized prism-like constructions generated by the emitter and the occluder in a four- dimensional (shadow) space reveals a simpler intrinsic structure of the shadow

  10. 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.

  11. Irradiation effects on fuels for space reactors

    SciTech Connect

    Ranken, W.A.; Cronenberg, A.W.

    1984-01-01

    A review of irradiation-induced swelling and gas release experience is presented here for the three principal fuels UO/sub 2/, UC, and UN. The primary advantage of UC and UN over UO/sub 2/ is higher thermal conductivity and attendant lower fuel temperature at equivalent pellet diameter and power density, while UO/sub 2/ offers the distinct benefit of well-known irradiation performance. Irradiation test results indicate that at equivalent burnup, temperature, and porosity conditions, UC experiences higher swelling than UO/sub 2/ or UN. Fission gas swelling becomes important at fuel temperatures above 1320 K for UC, and at somewhat higher temperatures for UO/sub 2/ and UN. Evidence exists that at equivalent fuel temperatures and burnups, high density UO/sub 2/ and UN experience comparable swelling behavior; however, differences in thermal conductivity influence overall irradiation performance. The low conductivity of UO/sub 2/ results in higher thermal gradients which contribute to fuel microcracking and gas release. As a result UO/sub 2/ exhibits higher fractional gas release than UN, at least or burnups up to about 3%.

  12. Studies of Solar EUV Irradiance from SOHO

    NASA Astrophysics Data System (ADS)

    Floyd, Linton

    2002-06-01

    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.

  13. 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.

  14. Dynamic nuclear polarization of irradiated targets

    Microsoft Academic Search

    M. L. Seely; A. Amittay; M. R. Bergstrom; S. K. Dhawan; V. W. Hughes; R. F. Oppenheim; K. P. Schueler; P. A. Souder; K. Kondo; S. Miyashita; K. Morimoto; S. J. St. Lorant; Y.-N. Guo; A. Winnacker

    1983-01-01

    We have irradiated and studied dynamic nuclear polarization in ammonia, deuterated ammonia, butanol, borane ammonia, methylamine, ethane and lithium borohydride in order to test these substances for potential use as polarized target materials. These studies were conducted using a polarized target system operating at a temperature of 1K and a magnetic field of 5T. The target system was set up

  15. Migration and sensory evaluation of irradiated polymers

    Microsoft Academic Search

    Niels H Stoffers; Jozef P. H Linssen; Roland Franz; Frank Welle

    2004-01-01

    The effects on ionising irradiation on polymer additives, monomers and polymers themselves have been investigated. Changes of initial concentrations of certain additives and monomers, a change in their specific migration as well as sensory changes of the polymers were examined. Polymer stabilizers such as Irganox 1076 and Irgafos 168 used in polyethylene were found to be degraded by ionising radiation.

  16. New irradiation geometry for microbeam radiation therapy

    Microsoft Academic Search

    E. Bräuer-Krisch; H. Requardt; P. Régnard; S. Corde; E. Siegbahn; G. LeDuc; T. Brochard; H. Blattmann; J. Laissue; A. Bravin

    2005-01-01

    Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a

  17. Fast flux irradiation program in the United States

    Microsoft Academic Search

    J. M. Simmons; J. E. Fox

    1973-01-01

    The USAEC fast flux irradiation program supporting the development of ; fuels and other reactor materials for use in demonstration and commercial fast ; breeder reactors is described. The fast flux irradiation experiments conducted ; during a recent 15month period are discussed. Summaries are given for the ; irradiation experiments containing mixed-oxide fuels, advanced fuels, cladding ; and structural materials,

  18. ENGINEERING SIGNIFICANCE OF IRRADIATION EFFECTS IN STRUCTURAL METALS

    Microsoft Academic Search

    Fleischmann

    1962-01-01

    S>The engineering significance of irradiation effects in structural ; materials is best discussed by the use of the true stress-strain diagram. The ; effects of irradiation are shown for stainless steel, carbon steel, copper, and ; nickel. When the irradiation effects are evaluated, the designer and ; metallurgist can take the necessary action to assure reliability of reactor ; components.

  19. Destabilization of olivine by 10kV electron irradiation

    Microsoft Academic Search

    L. Lemelle; L. Beaunier; S. Borensztajn; M. Fialin; F. Guyot

    2003-01-01

    Mineral phases in the interplanetary medium are subjected to the solar wind irradiation. Irradiation induces fractional volatilization of chemical elements in silicates; if large scale directional flow occurs, such as predicted by numerous models in the early solar system, then large scale chemical fractionnations occur. Electron irradiation experiments were performed using a 30 keV electron beam on single crystals of

  20. Creation of a composite solar ultraviolet irradiance data set

    Microsoft Academic Search

    Matthew T. DeLand; Richard P. Cebula

    2008-01-01

    Characterization of long-term solar ultraviolet (UV) irradiance variations is important for understanding the radiative forcing of Earth's atmosphere. Extending such a characterization to multidecadal timescales requires the merging of multiple satellite data sets. Currently available irradiance data sets show both absolute offsets and time-dependent differences that vary between spectral ranges. We have created a composite spectral UV irradiance data set

  1. Surface modification of magnetic metal nanoparticles through irradiation graft polymerization

    Microsoft Academic Search

    Min Zhi Rong; Ming Qiu Zhang; Hong Bing Wang; Han Min Zeng

    2002-01-01

    To tailor the interfacial interaction in magnetic metal nanoparticles filled polymer composites, the surfaces of iron, cobalt and nickel nanoparticles were grafted by irradiation polymerization. In the current report, effects of grafting conditions, including irradiation atmosphere, irradiation dose and monomer concentration, on the grafting reaction are presented. The interaction between the nanoparticles and the grafted polymer was studied by thermal

  2. Relationships of photosynthetically active radiation and shortwave irradiance

    Microsoft Academic Search

    G. Papaioannou; N. Papanikolaou; D. Retalis

    1993-01-01

    Hourly measurements of solar irradiance in the wave band excluding photosynthetically active radiation (PAR) and solar irradiance (SI) were made over a 12-month period at the National Observatory of Athens, for obtaining the ratios of PAR to SI. These irradiance ratios exhibit dependence on sky conditions, with slightly larger values being observed under “cloudy” skies and seasonal variations, attributable to

  3. Irradiation Applications in Vegetables and Fruits: A Review

    Microsoft Academic Search

    Ioannis S. Arvanitoyannis; Alexandros Ch. Stratakos; Panagiotis Tsarouhas

    2009-01-01

    There is an increasing trend both in advanced countries and many developing countries to centrally process fresh fruits and vegetables, properly packaged, for distribution and marketing. Irradiation technology proved to be effective in reducing post-harvest losses, and controlling the stored product insects and the microorganisms. Gamma irradiation was employed to restrain potato sprouting and kill pests in grain. Irradiation proved

  4. Compensation of scintillator sensitivity loss due to irradiation damage

    E-print Network

    Paris-Sud XI, Université de

    Compensation of scintillator sensitivity loss due to irradiation damage François GUILLET, 91192 Gif-sur-Yvette, France Irradiation damage can decrease sensitivity of imaging devices during variation is irradiation damage which indeed occurs on the camera considered in this study. This paper

  5. Effects of Chlorhexidine and Fluoride on Irradiated Enamel and Dentin

    Microsoft Academic Search

    C. J. Soares; N. A. Neiva; P. B. F. Soares; P. Dechichi; V. R. Novais; L. Z. Naves; M. R. Marques

    2011-01-01

    The effectiveness of mouthwash protocols in preventing gamma irradiation therapy damage to the ultimate tensile strength (UTS) of enamel and dentin is unknown. It was hypothesized that the use of chlorhexidine and fluoride mouthwash would maintain the UTS of dental structures. One hundred and twenty teeth were divided into 2 groups: irradiated (subjected to 60 Gy of gamma irradiation in

  6. Effects of fast neutron irradiation on zirconium carbide

    NASA Astrophysics Data System (ADS)

    Snead, Lance L.; Katoh, Yutai; Kondo, Sosuke

    2010-04-01

    High-purity zone refined zirconium carbide has been fast neutron irradiated in the dose and temperature range of 1-10 × 10 25 N/m 2 ( E > 0.1 MeV) and 635-1480 °C, respectively. Non-irradiated and as-irradiated properties were measured including the lattice parameter, hardness and elastic modulus as determined through nano-indentation, thermal conductivity, and indentation fracture toughness. The effects of neutron irradiation on the microstructure were also determined though using transmission electron microscopy. The general finding of this paper, limited to this particular zone refined ZrC of nominal C/Zr ratio of 0.93, is that this ceramic is quite stable under neutron irradiation in the temperature and dose range studied. Measurement of lattice parameter before and after irradiation indicated a lack of significant crystalline strain due to irradiation. Only modest changes were observed in the mechanical properties of hardness, elastic modulus, and indentation fracture toughness. The thermal conductivity underwent a slight reduction near 1000 °C irradiation, though was essentially unchanged for 1300-1480 °C irradiation. Transmission electron microscopy revealed black-spot-type defects (likely Frank or other small loops) for irradiation at 670 °C, maturing to faulted Frank loops at 1280 °C. As the irradiation temperature increased from 1280 °C to the highest irradiation temperature, of 1496 °C, a transition to prismatic loops occurs.

  7. Large Animal Irradiation J. Daniel Bourland, PhD

    E-print Network

    Large Animal Irradiation J. Daniel Bourland, PhD Professor Department of Radiation Oncology · Summary #12;Irradiation Issues same as for humans · Animal size (nominal L x W x H) · Photon energy (to: Total Body Irradiation dose escalation study · 15 animals, matched by sex, weight · Animal handling

  8. Inferring Total and Spectral Solar Irradiance From Sunspot Areas Only

    Microsoft Academic Search

    D. G. Preminger; S. R. Walton

    2004-01-01

    We show that daily sunspot area can be used in simple models to reconstruct daily variations in total or spectral solar irradiance. The models assume that all solar irradiance fluctuations can be traced back to the emergence of sunspots on the solar disk. Cotemporal data for irradiance and sunspot area are analysed to extract a detailed impulse response function that

  9. Progress of food irradiation in the United States

    NASA Astrophysics Data System (ADS)

    Derr, D. D.; Engeljohn, D. L.; Griffin, R. L.

    1995-02-01

    Irradiated foods have not yet made a significant impact in the United States marketplace. What progress has occurred to facilitate their commercialization? Irradiated produce has been sold in small quantities since 1992 and irradiated poultry was introduced in the marketplace in 1993. Federal inspection of irradiated commodities has settled into a regular routine. What must occur to further expand irradiated foods in the marketplace? Petitions to permit irradiation of red meats and seafood are being considered by the Food and Drug Administration (FDA) and a petition to permit the irradiation of shell eggs is being prepared for submission to FDA. In addition, the U.S. Department of Agriculture (USDA) has accelerated efforts to develop the policies and regulatory structure needed to facilitate the approval of new irradiation treatments for imported plant products regulated by quarantine. When will greater commercialization occur? More positive coverage to food irradiation in recent months by both the trade and popular press indicates a change in attitude towards irradiated foods by both consumers and the food industry. Finally, actual consumer response to available irradiated foods casts a favorable light on the potential for increased marketing of value-added irradiated foods.

  10. Radical Production by Infrared A Irradiation in Human Tissue

    Microsoft Academic Search

    M. E. Darvin; S. Haag; M. Meinke; L. Zastrow; W. Sterry; J. Lademann

    2010-01-01

    The influence of the ultraviolet (UV) irradiation of the sun on the formation of free radicals in human skin is well investigated. Up to now, only small amounts of data are available stating that infrared (IR) irradiation can produce free radicals in the skin. In the present study, the formation of free radicals in human skin, subsequent to IRA irradiation

  11. Irradiation embrittlement of LWR pressure vessel steels: Final report

    Microsoft Academic Search

    G. R. Odette; G. E. Lucas

    1989-01-01

    This program was conducted to generate an extensive bank of irradiated and aged pressure vessel steels, to test them for the effects of irradiation on mechanical properties, and to analyze the data in support of the development of a comprehensive relationship between pressure vessel steel embrittlement and both irradiation and material variables. Over 100 alloys were prepared which had variations

  12. Sample Targeting During Single-Particle Single-Cell Irradiation

    E-print Network

    Bigelow, Alan W.

    of stained cells be irradiated with a certain number of particles, including only one. An overview to this stage and records their position. During irradiation cell images are acquired again but through a 40Sample Targeting During Single-Particle Single-Cell Irradiation A.W. Bigelowa , G. Randers

  13. Summary Pinus taeda L. stomata respond slowly to changes in irradiance. Because incident irradiance on a leaf varies

    E-print Network

    Teskey, Robert O.

    Summary Pinus taeda L. stomata respond slowly to changes in irradiance. Because incident irradiance, and as foliage moves within the canopy. The length of time necessary for stomata to equilibrate to changes

  14. Irradiation-induced hardening mechanism of ion irradiated JLF-1 to high fluences

    Microsoft Academic Search

    H. Ogiwara; A. Kohyama; H. Tanigawa; H. Sakasegawa

    2006-01-01

    Reduced-activation ferritic\\/martensitic steels, RAFs, are leading candidates for blanket and first wall of fusion reactors, and effects of displacement damage and helium production on mechanical properties and microstructures are important subjects. The objective of this work is to clarify radiation hardening mechanism by means of ion irradiation and nano indentation. JLF-1 (9Cr–2W–V, Ta) steel was irradiated to 60dpa at 693,

  15. a Study of Stress Relaxation Rate in Un-Irradiated and Neutron-Irradiated Stainless Steel

    Microsoft Academic Search

    I. M. Ghauri; Naveed Afzal; N. A. Zyrek

    2007-01-01

    Stress relaxation rate in un-irradiated and neutron-irradiated 303 stainless steel was investigated at room temperature. The specimens were exposed to 100 mC, Ra-Be neutron source of continuous energy 2-12 MeV for a period ranging from 4 to 16 days. The tensile deformation of the specimens was carried out using a Universal Testing Machine at 300 K. During the deformation, straining

  16. Gamma-ray irradiation and post-irradiation responses of high dose range RADFETs

    Microsoft Academic Search

    A. Jaksic; G. Ristic; M. Pejovic; A. Mohammadzadeh; C. Sudre

    2001-01-01

    Gamma-ray irradiation and post-irradiation responses have been studied for the two types of radiation sensitive p-channel MOSFETs (RADFETs) from different manufacturers. In addition to, in dosimetric applications standard, threshold voltage measurements at a single specified current, transistor I-V and charge-pumping characteristics have been monitored. This has been shown to be useful in providing a more detailed insight into processes that

  17. Experimental plan for irradiation experiment HRB-21

    SciTech Connect

    Goodin, D. T. [General Atomics, San Diego, CA (United States); Kania, M. J.; Patton, B. W. [Oak Ridge National Lab., TN (United States)

    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.

  18. Aliphatic/aromatic systems under irradiation: influence of the irradiation temperature and of the molecular organization.

    PubMed

    Ferry, M; Bessy, E; Harris, H; Lutz, P J; Ramillon, J-M; Ngono-Ravache, Y; Balanzat, E

    2013-11-21

    With the aim of understanding the electronic excitation, charge or reactive species transfers occurring during irradiation, we studied the role of the aromatic content on ethylene/styrene random copolymers (PES) and on cyclohexane/benzene glasses (amorphous organic solids). Radiation-induced modifications were monitored in situ, at the molecular level, using Fourier transform infrared spectroscopy (FTIR). Irradiations were performed under a vacuum, and thanks to in situ measurements, oxidation was avoided. We followed both the C?C bond creation in the aliphatic moiety and the destruction of the aromatic moiety. The influence of the irradiation temperature was investigated by irradiating samples at room temperature and at 11 K. At such a low temperature, long-range migration hardly occurs and its influence is considerably reduced or could even vanish. Therefore, low temperature irradiation gives insight on the relative influence of reactive species transport and electronic excitation and charge transport. We found that the effect of lowering the PES irradiation temperature from room temperature to 11 K is small, indicating a minor role for the reactive species transport. Moreover, the two chosen systems allow the examination of the relative magnitude of intra- and intermolecular transfers. We demonstrate that, under conditions where reactive species are almost frozen, intermolecular transfers are very efficient. PMID:24168676

  19. Irradiation temperature dependence of production efficiency of lattice defects in some neutron-irradiated oxides

    NASA Astrophysics Data System (ADS)

    Okada, Moritami; Atobe, Kozo; Nakagawa, Masuo

    2004-11-01

    Temperature dependence of production efficiency of irradiation-induced defects in neutron-irradiated oxides has been investigated. Some oxide single crystals, MgO, ?-Al2O3 (sapphire) and TiO2 (rutile), were irradiated at several controlled temperatures, 10, 20, 50, 100, 150 and 200 K, using the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL), and at ambient temperature (?370 K) in the same facility. Irradiation temperature dependence of production efficiency of a 1 ?m band in TiO2 differs greatly from that of anion vacancy (F-type centers) in MgO and ?-Al2O3. Results for MgO and ?-Al2O3 show steep negative gradients from 10 to 370 K, whereas that for TiO2 includes a valley between 40 and 60 K and a hump at about 130 K, and then disappear at about 200 K. In MgO and ?-Al2O3, this behavior can be explained by the recombination of Frenkel pairs, which is activated at higher temperature. In TiO2, in addition to the recombination mechanism, a covalent bonding property is thought to be exerted strong influence, and it is suggested that a disappearance of the 1 ?m band at above 200 K is due to the recombination process of Frenkel pairs which is caused by the irradiation-induced crystallization.

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

    SciTech Connect

    Matlack, Katie [Georgia Institute of Technology, Atlanta; Kim, J-Y. [Georgia Institute of Technology, Atlanta; Wall, J.J. [Electric Power Research Institute (EPRI); Jacobs, L.J. [Georgia Institute of Technology, Atlanta; Sokolov, Mikhail A [ORNL

    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.

  1. Advances in the Hopkinson bar testing of irradiated/non-irradiated nuclear materials and large specimens.

    PubMed

    Albertini, Carlo; Cadoni, Ezio; Solomos, George

    2014-05-13

    A brief review of the technological advances of the Hopkinson bar technique in tension for the study of irradiated/non-irradiated nuclear materials and the development of this technology for large specimens is presented. Comparisons are made of the dynamic behaviour of non-irradiated and irradiated materials previously subjected to creep, low cycle fatigue and irradiation (2, 10 and 30 displacements per atom). In particular, complete results of the effect of irradiation on the dynamic mechanical properties of AISI304L steel, tested at 20, 400 and 550°C are presented. These high strain rate tests have been performed with a modified Hopkinson bar (MHB), installed inside a hot cell. Examples of testing large nuclear steel specimens with a very large Hopkinson bar are also shown. The results overall demonstrate the capability of the MHB to efficiently reproduce the material stress conditions in case of accidental internal and external dynamic loadings in nuclear reactors, thus contributing to the important process of their structural assessment. PMID:24711490

  2. In situ transmission electron microscope studies of irradiation-induced and irradiation-enhanced phase changes

    SciTech Connect

    Allen, C.W.

    1991-01-01

    Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing TEMs have been performed for several decades, involving irradiation-induced and irradiation-enhanced, microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact: (1) The availability of TEM specimen holders in which specimen temperature can be controlled in the range 10--2200 K; and (2) the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes, including the current state of in situ ion beam capability internationally, and presents two case studies involving in situ experiments performed in an HVEM to illustrate the dynamics of such an approach in materials research.

  3. In situ transmission electron microscope studies of irradiation-induced and irradiation-enhanced phase changes

    SciTech Connect

    Allen, C.W.

    1991-12-31

    Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing TEMs have been performed for several decades, involving irradiation-induced and irradiation-enhanced, microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact: (1) The availability of TEM specimen holders in which specimen temperature can be controlled in the range 10--2200 K; and (2) the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes, including the current state of in situ ion beam capability internationally, and presents two case studies involving in situ experiments performed in an HVEM to illustrate the dynamics of such an approach in materials research.

  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. Gas-cooled fast breeder reactor steady-state irradiation testing program

    Microsoft Academic Search

    R. T. Acharya; R. J. Campana; S. Langer

    1980-01-01

    The requirements for the gas-cooled fast breeder reactor irradiation program are specified, and an irradiation program plan which satisfies these requirements is presented. The irradiation program plan consists of three parts and includes a schedule and a preliminary cost estimate: (1) a steady-state irradiation program, (2) irradiations in support of the design basis transient test program, and (3) irradiations in

  6. Impact of Irradiation on Fish and Seafood Shelf Life: A Comprehensive Review of Applications and Irradiation Detection

    Microsoft Academic Search

    Ioannis S. Arvanitoyannis; Alexandros Stratakos; Elena Mente

    2008-01-01

    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

  7. Future radiation sources and identification of irradiated foods

    SciTech Connect

    Brynjolfsson, A. (International Facility for Food Irradiation Technology, Wageningen (Netherlands))

    1989-07-01

    Two major questions regarding irradiation that are raised today are: (1) Which sources should be used for irradiating food and (2) How can irradiated foods be identified This article considers both questions. After briefly mentioning a few of the historical stepping stones in the development of radiation sources, present and future radiation sources are discussed. Next the changes in foods caused by irradiation are considered. These changes are extremely small-so minor in fact that it is difficult to detect if the food has been irradiated. Still, these are several detection methods available, and this article describes them.

  8. Electron beam irradiation effects on ethylene-tetrafluoroethylene copolymer films

    NASA Astrophysics Data System (ADS)

    Nasef, Mohamed Mahmoud; Saidi, Hamdani; Dahlan, Khairul Zaman M.

    2003-12-01

    The effects of electron beam irradiation on ethylene-tetrafluoroethylene copolymer (ETFE) films were studied. Samples were irradiated in air at room temperature by a universal electron beam accelerator for doses ranging from 100 to 1200 kGy. Irradiated samples were investigated with respect to their chemical structure, thermal characteristics, crystallinity and mechanical properties using FTIR, differential scanning calorimeter (DSC) and universal mechanical tester. The interaction of electron irradiation with ETFE films was found to induce dose-dependent changes in all the investigated properties. A mechanism for electron-induced reactions is proposed to explain the structure-property behaviour of irradiated ETFE films.

  9. 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 ?-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.

  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. Effects of stress on microstructural evolution during irradiation

    SciTech Connect

    Gelles, D.S. [Pacific Northwest Lab., Richland, VA (United States)

    1992-12-31

    Many theories have been postulated to describe irradiation creep but few have been supported with microstructural evidence. The purpose of this paper is to review microstructural studies of the effects of stress during irradiation in order to assess the validity of the available irradiation creep theories. Microstructural studies based on high voltage electron, ion, proton and neutron irradiation will be described, with major emphasis placed on interpreting behavior demonstrated in austenitic steels. Special attention will be given to work on fast neutron irradiated Nimonic PE16, a precipitation strengthened superalloy.

  12. Effects of stress on microstructural evolution during irradiation

    NASA Astrophysics Data System (ADS)

    Gelles, D. S.

    1993-10-01

    Many theories have been postulated to describe irradiation creep but few have been supported with microstructural evidence. The purpose of this paper is to review microstructural studies of the effects of stress during irradiation to assess the validity of the available irradiation creep theories. Microstructural studies based on high-voltage electron, ion, proton and neutron irradiation are described, with major emphasis placed on interpreting behavior demonstrated in austenitic steels. Special attention is given to work on fast-neutron-irradiated Nimonic PE16, a precipitation-strengthened superalloy.

  13. Gamma irradiation influence on physical properties of milk proteins

    NASA Astrophysics Data System (ADS)

    Cie?la, 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 ?-sheets, in particular from increase of ?-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.

  14. Irradiation in Adulthood as a New Model of Schizophrenia

    PubMed Central

    Iwata, Yasuhide; Suzuki, Katsuaki; Wakuda, Tomoyasu; Seki, Norihito; Thanseem, Ismail; Matsuzaki, Hideo; Mamiya, Takayoshi; Ueki, Takatoshi; Mikawa, Sumiko; Sasaki, Takeshi; Suda, Shiro; Yamamoto, Shigeyuki; Tsuchiya, Kenji J.; Sugihara, Genichi; Nakamura, Kazuhiko; Sato, Kohji; Takei, Nori; Hashimoto, Kenji; Mori, Norio

    2008-01-01

    Background Epidemiological studies suggest that radiation exposure may be a potential risk factor for schizophrenia in adult humans. Here, we investigated whether adult irradiation in rats caused behavioral abnormalities relevant to schizophrenia. Methodology/Principal Findings A total dose of 15-Gy irradiation in six fractionations during 3 weeks was exposed to the forebrain including the subventricular zone (SVZ) and subgranular zone (SGZ) with male rats in the prone position. Behavioral, immunohistochemical, and neurochemical studies were performed three months after fractionated ionizing irradiation. Three months after fractionated ionizing irradiation, the total numbers of BrdU-positive cells in both the SVZ and SGZ zones of irradiated rats were significantly lower than those of control (sham-irradiated) rats. Hyperactivity after administration of the dopaminergic agonist methamphetamine, but not the N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine, was significantly enhanced in the irradiated rats although spontaneous locomotion in the irradiated rats was significantly lower than that of controls. Behavioral abnormalities including auditory sensory gating deficits, social interaction deficits, and working memory deficits were observed in the irradiated rats. Conclusion/Significance The present study suggests that irradiation in adulthood caused behavioral abnormalities relevant to schizophrenia, and that reduction of adult neurogenesis by irradiation may be associated with schizophrenia-like behaviors in rats. PMID:18509473

  15. 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.

  16. 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.

  17. 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.

  18. Germination test for identification of gamma-irradiated rice

    NASA Astrophysics Data System (ADS)

    Kawamura, Yoko; Suzuki, Naomi; Uchiyama, Sadao; Saito, Yukio

    Husked rice ( Oryza sativa L.) was used for the identification test of irradiation, since it grows faster than unhusked rice after 1 month of storage, and germination success is not affected by storage time and temperature. The critical dose that inhibited root elongation varied from 0.15 to 0.5kGy according to the rice cultivar. All cultivars tested exhibited similar reductions in root elongation after ?-irradiation of 0.5kGy or more. Most of the rice samples which were irradiated above 0.5kGy exhibited root growth of less than 10 mm after 3 days of incubation. The reduction was not affected so much by the presence of a husk at the time of irradiation. Storage periods of up to 12 months had little effect. This test can thus discriminate between irradiated and non-irradiated rice for 12 months or more after ?-irradiation.

  19. Proton irradiation energy dependence of defect formation in graphene

    NASA Astrophysics Data System (ADS)

    Lee, Sanggeun; Seo, Jungmok; Hong, Juree; Park, Seul Hyun; Lee, Joo-Hee; Min, Byung-Wook; Lee, Taeyoon

    2015-07-01

    Graphene transistors on SiO2/Si were irradiated with 5, 10, and 15 MeV protons at a dose rate of 2 × 1014 cm-2. The effect of proton irradiation on the structural defects and electrical characteristics of graphene was measured using Raman spectroscopy and electrical measurements. Raman spectra exhibited high intensity peaks induced by defects after 5 and 10 MeV proton irradiation, whereas no significant defect-induced peaks were observed after 15 MeV proton irradiation. The drain current of graphene transistors decreased and the Dirac point shifted after proton irradiation; however, a flattening in the Dirac point occurred after 15 MeV proton irradiation. The variations in characteristics were attributed to different types of graphene defects, which were closely related to the irradiation energy dependency of the transferred energy. Our observation results were in good agreement with the Bethe formula as well as the stopping and range of ions in matter simulation results.

  20. The problem of permissible doses of irradiation for biota

    SciTech Connect

    Korogodin, V.I. [Joint Institute for Nuclear Research, Moscow (Russian Federation)

    1995-07-01

    The dose of acute irradiation or of chronic irradiation under which the biota`s functioning is not disturbed is suggested as a permissible dose of irradiation for biota. On the basis of many separate experiments and observations, doses of chronic irradiation 1-3 gy/year are supposed to be permissible for higher plants and animals. The irradiation tolerance of microorganisms is considerably higher. The permissible doses of irradiation for the biota and for human beings are compared. The accepted maximum tolerance dose of irradiation of 10{sup -3} gy/year for humans is determined to be groundless. We propose substituting the term {open_quotes}permissible dose.{close_quotes} 28 refs., 3 figs.

  1. Neurite outgrowth on fluorinated polyimide film micropatterned by ion irradiation

    NASA Astrophysics Data System (ADS)

    Okuyama, Y.; Sato, M.; Nagaoka, S.; Kawakami, H.; Suzuki, Y.; Iwaki, M.

    2003-05-01

    In this study, we investigated neurite outgrowth on a fluorinated polyimide film micropatterned by ion irradiation. We used the fluorinated polyimide because of its excellent thermal and mechanical properties and biocompatibility. Rattus norvegicus chromaphin (PC12) cells were used for in vitro studies. The polyimide films were irradiated with He +, Ne + or Kr + at 1 × 10 14 ions/cm 2 using an ion-beam mask. The lines in the mask were 120 and 160 ?m wide and 120-160 ?m apart. PC12 cells were selectively adhered on the polyimide film micropatterned by Kr +-irradiation. However, the neurite length on the film irradiated by Kr + was shorter than that determined in the film irradiated by He +. On the other hand, neurite outgrowth on the polyimide film micropatterned by He +-irradiation was at least 100 ?m in length. This initial study indicated the enhanced outgrowth of PC12 cells on the fluorinated polyimide film micropatterned by ion irradiation.

  2. Gamma irradiation in a saturated tuff environment

    SciTech Connect

    Bates, J.K.; Oversby, V.M.

    1984-12-31

    The influence of gamma irradiation on the reaction of actinide doped SRL 165 and PNL 76-68 glasses in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The reaction, and subsequent actinide release, of both glasses depends on the dynamic interaction between radiolysis effects which cause the solution pH to become more acidic and glass reaction which drives the pH more basic. The use of large gamma irradiation dose rates to accelerate reactions that would occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons are made between the present results and data obtained by reacting the same or similar glasses using MCC-1 and NNWSI rock cup procedures. 11 references, 3 figures.

  3. EPR study of ?-irradiated cholesteryl methyl carbonate

    NASA Astrophysics Data System (ADS)

    Aras, Erdal; I?lek, Yasemin; Karata?, Ozgul; Abbass, Hind Kh; Birey, Mehmet; Kiliç, Ahmet

    2014-11-01

    The electron paramagnetic resonance (EPR) of ?-irradiated single crystals of cholesteryl methyl carbonate (C29H48O3) has been studied for different orientations of the crystals in a magnetic field. EPR spectra of cholesteryl methyl carbonate (C29H48O3irradiated by 60Co-? were recorded between 125 K and 300 K for different orientations of the crystal in the magnetic field. The spectra were found to be temperature independent. In C29H48O3 single crystal, the radiation damage centers caused by a 60Co-? source were determined as CH?3CH2CH radical. For CH?3CH2CH radical, a value of spectroscopic splitting factor g was calculated and experimentally results were supported by simulation program (WinEPR).

  4. Prediction of Irradiation Spectrum Effects in Pyrochlores

    NASA Astrophysics Data System (ADS)

    Uberuaga, B. P.; Jiang, C.; Stanek, C. R.; Sickafus, K. E.; Scott, C.; Smith, R.

    2014-09-01

    The formation energy of cation antisites in pyrochlores (A2B2O7) has been correlated with the susceptibility to amorphize under irradiation, and thus, density functional theory calculations of antisite energetics can provide insights into the radiation tolerance of pyrochlores. Here, we show that the formation energy of antisite pairs in titanate pyrochlores, as opposed to other families of pyrochlores (B = Zr, Hf, or Sn), exhibits a strong dependence on the separation distance between the antisites. Classical molecular dynamics simulations of collision cascades in Er2Ti2O7 show that the average separation of antisite pairs is a function of the primary knock-on atom energy that creates the collision cascades. Together, these results suggest that the radiation tolerance of titanate pyrochlores may be sensitive to the irradiation conditions and might be controllable via the appropriate selection of ion beam parameters.

  5. Prediction of Irradiation Spectrum Effects in Pyrochlores

    NASA Astrophysics Data System (ADS)

    Uberuaga, B. P.; Jiang, C.; Stanek, C. R.; Sickafus, K. E.; Scott, C.; Smith, R.

    2014-12-01

    The formation energy of cation antisites in pyrochlores (A2B2O7) has been correlated with the susceptibility to amorphize under irradiation, and thus, density functional theory calculations of antisite energetics can provide insights into the radiation tolerance of pyrochlores. Here, we show that the formation energy of antisite pairs in titanate pyrochlores, as opposed to other families of pyrochlores (B = Zr, Hf, or Sn), exhibits a strong dependence on the separation distance between the antisites. Classical molecular dynamics simulations of collision cascades in Er2Ti2O7 show that the average separation of antisite pairs is a function of the primary knock-on atom energy that creates the collision cascades. Together, these results suggest that the radiation tolerance of titanate pyrochlores may be sensitive to the irradiation conditions and might be controllable via the appropriate selection of ion beam parameters.

  6. New irradiation geometry for microbeam radiation therapy.

    PubMed

    Bräuer-Krisch, E; Requardt, H; Régnard, P; Corde, S; Siegbahn, E; LeDuc, G; Brochard, T; Blattmann, H; Laissue, J; Bravin, A

    2005-07-01

    Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumour area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumouricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumour in the paths of the arrays. PMID:15972983

  7. Stochastic biophysical modeling of irradiated cells

    E-print Network

    Fornalski, Krzysztof Wojciech

    2014-01-01

    The paper presents a computational stochastic model of virtual cells irradiation, based on Quasi-Markov Chain Monte Carlo method and using biophysical input. The model is based on a stochastic tree of probabilities for each cell of the entire colony. Biophysics of the cells is described by probabilities and probability distributions provided as the input. The adaptation of nucleation and catastrophe theories, well known in physics, yields sigmoidal relationships for carcinogenic risk as a function of the irradiation. Adaptive response and bystander effect, incorporated into the model, improves its application. The results show that behavior of virtual cells can be successfully modeled, e.g. cancer transformation, creation of mutations, radioadaptation or radiotherapy. The used methodology makes the model universal and practical for simulations of general processes. Potential biophysical curves and relationships are also widely discussed in the paper. However, the presented theoretical model does not describe ...

  8. 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.

  9. TEM study of neutron-irradiated iron

    SciTech Connect

    Horton, L.L.; Bentley, J.; Farrell, K.

    1981-01-01

    Results of a transmission electron microscopy study of the defect structure in iron neutron-irradiated to low fluences (less than or equal to 1 dpa) at temperatures of 455 to 1013/sup 0/K are presented. The dislocation microstructures coarsen with increasing irradiation temperature from decorated dislocations, through clusters of dislocation loops, to near-edge, interstitial dislocation loops with b = a<100>, and network segments. Significant cavity formation occurred only at 548 to 723/sup 0/K, with homogeneous distributions found only at 623 and 673/sup 0/K. The maximum swelling of 0.07% occurred at 673/sup 0/K. Large cavities had a truncated octahedral shape with (111) facets and (100) truncations. Damage halos were observed around boron-containing precipitates. The effects of interstitial impurities on microstructural development and the differences in the observed microstructures compared to those in refractory bcc metals are discussed. 8 figures, 6 tables.

  10. Polyethylene welding by pulsed visible laser irradiation

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Caridi, F.; Visco, A. M.; Campo, N.

    2011-01-01

    Laser welding of plastics is a relatively new process that induces locally a fast polymer heating. For most applications, the process involves directing a pulsed beam of visible light at the weld joint by going through one of the two parts. This is commonly referred to as “through transmission visible laser welding”. In this technique, the monochromatic visible light source uses a power ns pulsed laser in order to irradiate the joint through one part and the light is absorbed in the vicinity of the other part. In order to evaluate the mechanical resistance of the welded joint, mass quadrupole spectrometry, surface profilometry, microscopy techniques and mechanical shear tests were employed. The welding effect was investigated as a function of the laser irradiation time, nature of the polyethylene materials and temperature.

  11. 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.

  12. Exploiting geometrical irradiation possibilities in MRT application

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Requardt, H.; Régnard, P.; Corde, S.; Siegbahn, E. A.; LeDuc, G.; Blattmann, H.; Laissue, J.; Bravin, A.

    2005-08-01

    Microbeam Radiation Therapy (MRT) has the potential to treat infantile brain tumors when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of X-rays but provides unusual resistance to radioneurotoxicity, presumably from the rapid migration of regenerative endothelial cells from dose "valleys" into dose "peaks", i.e., into directly irradiated micro-slices of tissues. We will present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumor area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumoricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumor in the paths of the arrays.

  13. New irradiation geometry for microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Requardt, H.; Régnard, P.; Corde, S.; Siegbahn, E.; LeDuc, G.; Brochard, T.; Blattmann, H.; Laissue, J.; Bravin, A.

    2005-07-01

    Microbeam radiation therapy (MRT) has the potential to treat infantile brain tumours when other kinds of radiotherapy would be excessively toxic to the developing normal brain. MRT uses extraordinarily high doses of x-rays but provides unusual resistance to radioneurotoxicity, presumably from the migration of endothelial cells from 'valleys' into 'peaks', i.e., into directly irradiated microslices of tissues. We present a novel irradiation geometry which results in a tolerable valley dose for the normal tissue and a decreased peak-to-valley dose ratio (PVDR) in the tumour area by applying an innovative cross-firing technique. We propose an MRT technique to orthogonally crossfire two arrays of parallel, nonintersecting, mutually interspersed microbeams that produces tumouricidal doses with small PVDRs where the arrays meet and tolerable radiation doses to normal tissues between the microbeams proximal and distal to the tumour in the paths of the arrays.

  14. Quantification of biologically effective environmental UV irradiance.

    PubMed

    Horneck, G

    2000-01-01

    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. PMID:12038484

  15. 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.

  16. Kossel Line Studies of Irradiated Nickel Crystals

    Microsoft Academic Search

    R. E. Hanneman; R. E. Ogilvie; A. Modrzejewski

    1962-01-01

    Irradiation damage of nickel single crystals bombarded with 3 Mev electrons has been studied by Kossel line techniques. Changes of lattice parameter and x-ray line breadth were determined for crystals bombarded with integrated dosages of 1016, 1017, and 1018 electrons?cm2 at liquid nitrogen temperature. It is concluded that the formation of Frenkel defects in the lattice due to the electron

  17. Neutron irradiation of sapphire for compressive strengthening

    Microsoft Academic Search

    Thomas M Regan; Daniel C Harris; Rhonda M Stroud; John R White

    2002-01-01

    Sapphire suffers a dramatic loss of c-axis compression strength at elevated temperatures. Irradiation of sapphire with fission-spectrum neutrons to an exposure of ?1022 neutrons\\/m2 in the core of a 1 MW fission reactor increased the c-axis compression strength by a factor of ?3 at 600 °C. Strength was similarly improved when 99% of slow neutrons (?0.1 eV) were removed by

  18. 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 ?m, max. average power 8.3 W, "soft-pulse" and cw) an Er:YAG laser (KaVo Key Laser II, wavelength 2.94 ?m, pulse duration 250-500?s, pulse energy 60-500 mJ, pulse repetition rate 1-15 Hz, focus diameter 620 ?m, air-water cooling; Biberach, Germany; a frequency doubled Alexandrite laser (laboratory prototype, q-switched, fiber guided, wavelength 377 nm, pulse duration 1 ?s, 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.

  19. Nanolithography by tip-enhanced laser irradiation

    Microsoft Academic Search

    ZhiHong Mai; Yongfeng Lu; W. D. Song; W. K. Chim

    1999-01-01

    Recently, scanning probe lithography by applying an electric field between the tip and the sample has been shown to be a promising technique for nanofabrication. In this paper, we present a novel method of nanofabrication, namely, nanolithography by tip-enhanced laser irradiation. Based on the operation of the laser-assisted scanning tunneling microscope (STM), we established a nanolithography system using tip-enhanced laser

  20. WEBEXPIR: Windowless target electron beam experimental irradiation

    Microsoft Academic Search

    Marc Dierckx; Paul Schuurmans; Jan Heyse; Kris Rosseel; Katrien Van Tichelen; Benoit Nactergal; Dirk Vandeplassche; Thierry Aoust; Michel Abs; Arnaud Guertin; Jean-Michel Buhour; Arnaud Cadiou; Hamid Aït Abderrahim

    2008-01-01

    The windowless target electron beam experimental irradiation (WEBEXPIR) program was set-up as part of the MYRRHA\\/XT-ADS R&D effort on the spallation target design to investigate the interaction of a proton beam with a liquid lead–bismuth eutectic (LBE) free surface. In particular, possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on\\/off transient situations, as well

  1. Models of Irradiated Extrasolar Giant Planets

    E-print Network

    Adam Burrows; David Sudarsky

    2002-07-23

    We review some of the characteristics of irradiated extrasolar giant planets (EGPs), in anticipation of their direct detection from the ground and from space. Spectral measurements are the key to unlocking their structural and atmospheric characteristics and to determining the true differences between giant planets and brown dwarfs. In this spirit, the theoretical spectral and atmospheric calculations we summarize here are in support of the many searches for EGPs to be conducted in the coming decade by astronomers from around the world.

  2. Extracorporeal irradiation for malignant bone tumors

    Microsoft Academic Search

    Angela Hong; Graham Stevens; Paul Stalley; Susan Pendlebury; Verity Ahern; Anna Ralston; Edgar Estoesta; Ian Barrett

    2001-01-01

    Purpose: Extracorporeal irradiation (ECI) has been used selectively in the management of primary malignant bone tumors since 1996. We report our techniques for ECI and the short-term oncologic and orthopedic outcomes.Methods and Materials: Sixteen patients with primary malignant bone tumors were treated with ECI from 1996 to 2000. The median age was 14 years. The histologic diagnoses were Ewing’s sarcoma

  3. 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.

  4. 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.

  5. Percutaneous needle biopsy of the irradiated skeleton

    SciTech Connect

    Edeiken, B.; deSantos, L.A.

    1983-03-01

    Percutaneous needle biopsy was performed in 20 patients who had radiologic abnormalities after irradiation of the skeleton. The biopsies were performed to determine the nature of the bone changes and to differentiate radiation necrosis from metastases or local tumor extension. Eleven patients had tumors, two of which were radiation-induced sarcomas; nine patients did not show evidence of tumor. One patient had osteomyelitis rather than the suspected tumor. The value of percutaneous needle biopsy in the postirradiated skeleton is discussed.

  6. Online Irradiation Control by Means of PET

    NASA Astrophysics Data System (ADS)

    Fiedler, Fine; Kunath, Daniela; Priegnitz, Marlen; Enghardt, Wolfgang

    Positron emission tomography (PET) is a dedicated tool for quality assurance in IBT. By measuring the spatial distribution of positron emitters generated via nuclear interactions between projectiles and atomic nuclei of the tissue during the therapeutic irradiation, conclusions on the accuracy of the dose localization can be drawn. In the following, the physical background as well as the technical realization of PET is depicted. Furthermore, current PET installations for quality assurance of proton and IBT are presented.

  7. 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.

  8. 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).

  9. Magnetic phase formation in irradiated austenitic alloys

    SciTech Connect

    Gussev, Maxim N [ORNL] [ORNL; Busby, Jeremy T [ORNL] [ORNL; Tan, Lizhen [ORNL] [ORNL; Garner, Francis A. [Radiation Effects Consulting, Richland, WA] [Radiation Effects Consulting, Richland, WA

    2014-01-01

    Austenitic alloys are often observed to develop magnetic properties during irradiation, possibly associated with radiation-induced acceleration of the ferrite phase. Some of the parametric sensitivities of this phenomenon have been addressed using a series of alloys irradiated in the BOR-60 reactor at 593K. The rate of development of magnetic phase appears to be sensitive to alloy composition. To the first order, the largest sensitivities to accelerate ferrite formation, as explored in this experiment, are associated with silicon, carbon and manganese and chromium. Si, C, and Mn are thought to influence diffusion rates of point defects while Cr plays a prominent role in defining the chromium equivalent and therefore the amount of ferrite at equilibrium. Pre-irradiation cold working was found to accelerate ferrite formation, but it can play many roles including an effect on diffusion, but on the basis of these results the dominant role or roles of cold-work cannot be identified. Based on the data available, ferrite formation is most probably associated with diffusion.

  10. 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 ?m 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.

  11. 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.

  12. Irradiation Environment of the Materials Test Station

    SciTech Connect

    Pitcher, Eric John [Los Alamos National Laboratory

    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.

  13. Irradiation response and stability of nanoporous materials

    SciTech Connect

    Fu, Engang [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory; Serrano De Caro, Magdalena [Los Alamos National Laboratory; Caro, Jose A. [Los Alamos National Laboratory; Zepeda-Ruiz, L [Lawrence Livermore national Laboratory; Bringa, E. [CONICET, Universidad de Cuyo, Argentina; Nastasi, Mike [University of Nebraska, Lincoln, NE; Baldwin, Jon K. [Los Alamos National Laboratory

    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.

  14. Total scalp irradiation using helical tomotherapy

    SciTech Connect

    Orton, Nigel [Department of Human Oncology, University of Wisconsin, Madison, WI (United States)]. E-mail: nporton@facstaff.wisc.edu; Jaradat, Hazim [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Welsh, James [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Tome, Wolfgang [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States)

    2005-09-30

    Homogeneous irradiation of the scalp poses technical and dosimetric challenges due to the extensive, superficial, curved treatment volume. Conventional treatments on a linear accelerator use multiple matched electron fields or a combination of electron and photon fields. Problems with these techniques include dose heterogeneity in the target due to varying source-to-skin distance (SSD) and angle of beam incidence, significant dose to the brain, and the potential for overdose or underdose at match lines between the fields. Linac-based intensity-modulated radiation therapy (IMRT) plans have similar problems. This work presents treatment plans for total scalp irradiation on a helical tomotherapy machine. Helical tomotherapy is well-suited for scalp irradiation because it has the ability to deliver beamlets that are tangential to the scalp at all points. Helical tomotherapy also avoids problems associated with field matching and use of more than one modality. Tomotherapy treatment plans were generated and are compared to plans for treatment of the same patient on a linac. The resulting tomotherapy plans show more homogeneous target dose and improved critical structure dose when compared to state-of-the-art linac techniques. Target equivalent uniform dose (EUD) for the best tomotherapy plan was slightly higher than for the linac plan, while the volume of brain tissue receiving over 30 Gy was reduced by two thirds. Furthermore, the tomotherapy plan can be more reliably delivered than linac treatments, because the patient is aligned prior to each treatment based on megavoltage computed tomography (MVCT)

  15. Uses of irradiation for inactivation of microorganisms

    SciTech Connect

    Brynjolfsson, A.

    1988-01-01

    The lethal effects of radiation on microorganisms was noted soon after the discovery of X rays in 1895. In 1904, it was shown that vegetative bacteria are more sensitive than spores; however, no industrial applications could be made as the radiation sources were too expensive. In the mid-1950s, it became economical and practical to sterilize medical products, and ever since sterilization has been a growing industry. Radiation sterilization technology has made possible users of new materials, such as plastics. Food irradiation is about to take off. Just as there was a resistance to pasteurization of milk when it was first introduced, there will be resistance to radpasteurization. Irradiated foods have been proven safe beyond reasonable doubt. Safety has been established through two independent methods: (1) through the most extensive multigeneration animal feeding studies ever carried out, and (2) by analyzing the radiolytic products formed and the chemical changes that take place when food is irradiated. The possible toxicity of these products has been evaluated by an independent group of toxicologists, who based their evaluation on the results of exposure of these products in large quantities either to humans or to animals.

  16. 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. [Commissariat a l'Energie Atomique - CEA, Centrale Phenix, 30200 Bagnols Sur Ceze (France); Lacroix, B.; Martella, T.; Loubet, L. [Commissariat a l'Energie Atomique - CEA, Centre de Cadarache, 13108 Saint-Paul-Lez-Durance cedex (France); Ohta, H.; Yokoo, T. [Central Research Institute of Electric Power Industry - CRIEPI, 2-11-1 Iwado-kita, Komae, Tokyo 201-8511 (Japan); Ougier, M.; Glatz, J.P. [European Commission Joint Research, Institute for Transuranium Elements - JRC-ITU, Postfach 2340, D-76125 Karlsruhe (Germany)

    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)

  17. Solar Irradiance Data Products at the LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Ware Dewolfe, A.; Wilson, A.; Lindholm, D. M.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.

    2010-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) has developed the LASP Interactive Solar IRradiance Datacenter (LISIRD) to provide access to a comprehensive set of solar irradiance measurements. LISIRD has recently been updated to serve many new datasets and models, including data from SORCE, UARS-SOLSTICE, SME, and TIMED-SEE, and model data from the Flare Irradiance Spectral Model (FISM). The user interface emphasizes web-based interactive visualizations, allowing users to explore and compare this data before downloading it for analysis. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as wavelength-independent Total Solar Irradiance (TSI). Combined data from the SORCE, TIMED-SEE, UARS-SOLSTICE, and SME instruments provide continuous coverage from 1981 to the present, while Lyman-alpha measurements, FISM daily data, and TSI models date from the 1940s to the present. LISIRD will also host Glory TSI data as part of the SORCE data system. This poster provides an overview of the LISIRD system, summarizes the data sets currently available, describes future plans and capabilities, and provides details on how to access solar irradiance data through LISIRD’s interfaces.

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

    SciTech Connect

    Middleton, E.M.; Teramura, A.H. (NASA/Goddard Space Flight Center, Greenbelt, MD (United States) Univ. of Maryland, College Park (United States))

    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.

  19. Comparison of structural properties of pristine and gamma irradiated single-wall carbon nanotubes: Effects of medium and irradiation dose

    SciTech Connect

    Kleut, D. [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia)] [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia); Jovanovic, S., E-mail: svetlanajovanovic@vinca.rs [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia); Markovic, Z.; Kepic, D.; Tosic, D. [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia)] [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia); Romcevic, N. [Insitute of Physics, P.O.B. 68, University of Belgrade, 11001 Belgrade (Serbia)] [Insitute of Physics, P.O.B. 68, University of Belgrade, 11001 Belgrade (Serbia); Marinovic-Cincovic, M.; Dramicanin, M. [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia)] [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia); Holclajtner-Antunovic, I. [Faculty of Physical Chemistry, P.O.B. 47, University of Belgrade, 11158 Belgrade (Serbia)] [Faculty of Physical Chemistry, P.O.B. 47, University of Belgrade, 11158 Belgrade (Serbia); Pavlovic, V. [Faculty of Agriculture, P.O.B. 127, University of Belgrade, 11080 Belgrade (Serbia)] [Faculty of Agriculture, P.O.B. 127, University of Belgrade, 11080 Belgrade (Serbia); Drazic, G. [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)] [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Milosavljevic, M.; Todorovic Markovic, B. [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia)] [Vinca Institute of Nuclear Sciences, P.O.B. 522, University of Belgrade, 11001 Belgrade (Serbia)

    2012-10-15

    A systematic study of the gamma irradiation effects on single wall carbon nanotube (SWCNT) structure was conducted. Nanotubes were exposed to different doses of gamma irradiation in three media. Irradiation was carried out in air, water and aqueous ammonia. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and Raman spectroscopy confirmed the changes in the SWCNT structure. TGA measurements showed the highest percentage of introduced groups for the SWCNTs irradiated with 100 kGy. FTIR spectroscopy provided evidence for the attachment of hydroxyl, carboxyl and nitrile functional groups to the SWCNT sidewalls. Those groups were confirmed by EA. All irradiated SWCNTs had hydroxyl and carboxyl groups irrelevant to media used for irradiation, but nitrile functional groups were only identified in SWCNTs irradiated in aqueous ammonia. Raman spectroscopy indicated that the degree of disorder in the carbon nanotube structure correlates with the irradiation dose. For the nanotubes irradiated with the dose of 100 kGy, the Raman I{sub D}/I{sub G} ratio was three times higher than for the pristine ones. Atomic force microscopy showed a 50% decrease in nanotube length at a radiation dose of 100 kGy. Scanning and transmission electron microscopies showed significant changes in the morphology and structure of gamma irradiated SWCNTs. - Highlights: Black-Right-Pointing-Pointer Gamma irradiation causes SWCNT covalent functionalization. Black-Right-Pointing-Pointer Type of covalently attached groups to SWCNT surface depends on irradiation medium. Black-Right-Pointing-Pointer The SWCNT shortening level increases with applied irradiation dose. Black-Right-Pointing-Pointer The average length of carbon nanotubes decreased by 50% at the highest dose. Black-Right-Pointing-Pointer The diameter of SWCNT bundles becomes small as irradiation dose rises.

  20. [The effect of mixed cultivation of lymphocytes irradiated at a dose of 1 Gy and non-irradiated lymphocytes on the frequency of chromosomal aberration].

    PubMed

    Kolesnikova, I S

    2012-01-01

    The mutual influence of irradiated (1 Gy) and non-irradiated cells was demonstrated on the model of the mixed culture oflymphocytes from opposite gender donors using chromosome aberrations (ChA) as an endpoint. The number of ChA in non-irradiated lymphocytes in mixed cultures with irradiated ones increased as compared to the corresponding monocultures. At the same time, the number of induced ChA decreased in the irradiated lymphocytes cultivated with non-irradiated ones. PMID:22891546

  1. The methodology study of time accelerated irradiation of elastomers

    NASA Astrophysics Data System (ADS)

    Ito, Masayuki

    2005-07-01

    The article studied the methods how to shorten the irradiation time by increasing dose rate without changing the relationship between dose versus properties of degraded samples. The samples used were nine kinds of EPDM which have different compounding formula. The different dose of Co-? ray was exposed to the samples. The maximum dose was 2 MGy. The reference condition to be compared with two short time test conditions is irradiation of 0.33 kGy/h at room temperature. Two methods shown below were studied as the time-accelerate irradiation conditions.Irradiation of 4.2 kGy/h in 0.5 MPa oxygen at room temperature. Irradiation of 5.0 kGy/h in air at 70 °C. After irradiation the mechanical properties of samples were measured at room temperature. The changes in 100% modulus suggest that irradiation in 0.5 MPa oxygen increases slightly scission reaction and irradiation at 70 °C increases slightly crosslinking, compared with the results obtained under low dose rate irradiation (the reference condition). The deviation was mostly in ±0.25 for 100% modulus and was ±0.5 for ultimate elongation throughout the all doses, where the value obtained at the reference condition referred to as 1.0. Thus, it was found out that two methods mentioned above are available as time accelerated irradiation conditions.

  2. Osteogenic Matrix Cell Sheets Facilitate Osteogenesis in Irradiated Rat Bone

    PubMed Central

    Akahane, Manabu; Shimizu, Takamasa; Ueha, Tomoyuki; Morita, Yusuke; Nakasaki, Shintaro; Kura, Tomohiko; Tohma, Yasuaki; Kido, Akira; Kawate, Kenji; Tanaka, Yasuhito

    2015-01-01

    Reconstruction of large bone defects after resection of malignant musculoskeletal tumors is a significant challenge in orthopedic surgery. Extracorporeal autogenous irradiated bone grafting is a treatment option for bone reconstruction. However, nonunion often occurs because the osteogenic capacity is lost by irradiation. In the present study, we established an autogenous irradiated bone graft model in the rat femur to assess whether osteogenic matrix cell sheets improve osteogenesis of the irradiated bone. Osteogenic matrix cell sheets were prepared from bone marrow-derived stromal cells and co-transplanted with irradiated bone. X-ray images at 4 weeks after transplantation showed bridging callus formation around the irradiated bone. Micro-computed tomography images at 12 weeks postoperatively showed abundant callus formation in the whole circumference of the irradiated bone. Histology showed bone union between the irradiated bone and host femur. Mechanical testing showed that the failure force at the irradiated bone site was significantly higher than in the control group. Our study indicates that osteogenic matrix cell sheet transplantation might be a powerful method to facilitate osteogenesis in irradiated bones, which may become a treatment option for reconstruction of bone defects after resection of malignant musculoskeletal tumors.

  3. Radiation Sterilization and Food Irradiation Using Gamma Radiation

    NASA Astrophysics Data System (ADS)

    O'Hara, Kevin

    2003-03-01

    Since the introduction of MDS Nordion's first irradiator in the early 1960's, a variety of gamma-processing systems has been developed. Each design is suited to a particular set of requirements - from high-throughput operations of diverse product lots to full automation or batch processing, all using gamma radiation. Gamma irradiator designs include the Centurion irradiator for temperature-sensitive food products like hamburgers and poultry; the Brevion, a compact batch irradiator providing flexibility, timeliness and simplicity on a whole new scale; a JS-10000 irradiator that operates in either automatic or batch mode to enable multipurpose product scheduling and optimum throughput; and, an irradiator that processes full pallets and is ideal for processing high-density products requiring excellent dose uniformity. These innovative irradiator designs help facilities to be more efficient, maximize operating time, improve product turnaround and minimize inventory levels. MDS Nordion's development of improved Point Kernel and Monte Carlo techniques is discussed, including their application in radiation source optimization, production irradiator design and process control. Absorbed-dose calculations also provide insight into the critical areas for dose mapping and routine monitoring, allowing for the optimum placement of dosimeters. Calculations may also be used to determine the absorbed-dose distribution within product, especially in areas of complex geometry such as material interfaces. The use of easily accessible, accurate and validated dose-calculation programs can be used to optimize the irradiation process. Key Words: dosimetry, irradiator design, dose calculation, modelling, modeling, process control, radiation source optimization.

  4. 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 international intercomparisons among NMIs. Ultimately, the spectral irradiance can be realized with expanded measurement uncertainties of far less than 1 % over a wide spectral range. Thus, for customers with high demands on low measurement uncertainties, it is possible to calibrate their working standards directly against the blackbody-radiator, taking into account the higher necessary effort. In special cases it is possible to calibrate the customer's spectroradiometric facilities directly in front of the blackbody-radiator. In the context of the European Metrology Research Project Traceability for surface spectral solar ultraviolet radiation, the traceability chain will be improved and adapted.

  5. 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 ethylene propylene diene monomer (EPDM)) have been exposed in closed containers to tritium gas initially at 1 atmosphere pressure. These studies have demonstrated the degradation of properties when exposed to tritium gas. Also, the radiolytic production of significant amounts of hydrogen has been observed for UHMW-PE and EPDM. The study documented in this report exposes two similar formulations of EPDM elastomer to gamma irradiation in a closed container backfilled with deuterium. Deuterium is chemically identical to protium and tritium, but allows the identification of protium that is radiolytically produced from the samples. The goal of this program is to compare and contrast the response of EPDM exposure to two different types of ionizing radiation in a similar chemical environment.

  6. 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.

  7. Post-irradiation deformation characteristics of heavy-ion irradiated 304L SS

    SciTech Connect

    Cole, J.I. [Washington State Univ., Pullman, WA (United States); Bruemmer, S.M. [Pacific Northwest Lab., Richland, WA (United States)

    1994-06-01

    Post-irradiation deformation behavior in Ni-ion-irradiated 304L stainless steel (SS) is examined as a function of radiation dose and deformation temperature. For similar strain levels, specimens exhibit a transition from dislocation slip to deformation-induced twinning at 25C with increasing radiation dose. At 288C twinning is no longer observed and highly localized slip occurs by the formation of narrow ``channels`` containing a reduced defect density. The observations are discussed in terms of radiation-induced defect character and expected deformation mechanisms.

  8. A comparative study of heavily irradiated silicon and non irradiated SI LEC GaAs detectors

    Microsoft Academic Search

    U. Biggeri; E. Borchi; M. Bruzzi; V. Eremin; C. Leroy; Z. Li; D. Menichelli; S. Pirollo; S. Sciortino; E. Verbitskaya

    1998-01-01

    Silicon p+n junctions irradiated with neutron and proton fluences in the range 5×1011-4×1015 cm-2 and non-irradiated SI LEC GaAs Schottky barriers have been analyzed. In silicon the concentration Nt of the main radiation-induced deep traps (Et≈0.44-0.54 eV) is found to increase as Nt ? f achieving values up to 5×1015 cm-3 and a mobility saturation at 100 cm2\\/Vs has been

  9. Safety evaluation of irradiated foods in China: A condensed report

    SciTech Connect

    Yin, D. (Institute of Food Safety Control and Inspection, Beijing (China))

    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.

  10. Modelling rotational and cyclical spectral solar irradiance variations

    NASA Astrophysics Data System (ADS)

    Unruh, Yvonne

    Solar irradiance changes are highly wavelength dependent: solar-cycle variations in the UV can be on the order of tens of percent, while changes in the visible are typically only of the order of one or two permille. With the launch of a number of instruments to measure spectral solar irradiance, we are now for a first time in a good position to explore the changing solar irradiance over a large range of wavelengths and to test our irradiance models as well as some of their underlying assumptions. I will introduce some of the current modelling approaches and present model-data comparisons, using the SATIRE irradiance model and SORCE/SIM measurements as an example. I will conclude by highlighting a number of outstanding questions regarding the modelling of spectral irradiance and current approaches to address these.

  11. Laser annealing of neutron irradiated boron-10 isotope doped diamond

    SciTech Connect

    Jagannadham, K. [North Carolina State University; Butler, J. E. [North Carolina State University

    2011-01-01

    10B isotope doped p-type diamond epilayer grown by chemical vapor deposition on (110) oriented type IIa diamond single crystal substrate was subjected to neutron transmutation at a fluence of 2.4 9 1020 thermal and 2.4 9 1020 fast neutrons. After neutron irradiation, the epilayer and the diamond substrate were laser annealed using Nd YAG laser irradiation with wave length, 266 nm and energy, 150 mJ per pulse. The neutron irradiated diamond epilayer and the substrate were characterized before and after laser annealing using different techniques. The characterization techniques include optical microscopy, secondary ion mass spectrometry, X-ray diffraction, Raman, photoluminescence and Fourier Transform Infrared spectroscopy, and electrical sheet conductance measurement. The results indicate that the structure of the irradiation induced amorphous epilayer changes to disordered graphite upon laser annealing. The irradiated substrate retains the (110) crystalline structure with neutron irradiation induced defects.

  12. Ion irradiated graphite exposed to fusion-relevant deuterium plasma

    NASA Astrophysics Data System (ADS)

    Deslandes, Alec; Guenette, Mathew C.; Corr, Cormac S.; Karatchevtseva, Inna; Thomsen, Lars; Ionescu, Mihail; Lumpkin, Gregory R.; Riley, Daniel P.

    2014-12-01

    Graphite samples were irradiated with 5 MeV carbon ions to simulate the damage caused by collision cascades from neutron irradiation in a fusion environment. The ion irradiated graphite samples were then exposed to a deuterium plasma in the linear plasma device, MAGPIE, for a total ion fluence of ?1 × 1024 ions m-2. Raman and near edge X-ray absorption fine structure (NEXAFS) spectroscopy were used to characterize modifications to the graphitic structure. Ion irradiation was observed to decrease the graphitic content and induce disorder in the graphite. Subsequent plasma exposure decreased the graphitic content further. Structural and surface chemistry changes were observed to be greatest for the sample irradiated with the greatest fluence of MeV ions. D retention was measured using elastic recoil detection analysis and showed that ion irradiation increased the amount of retained deuterium in graphite by a factor of four.

  13. Graphitization of polymer surfaces by scanning ion irradiation

    NASA Astrophysics Data System (ADS)

    Koval, Yuri

    2014-10-01

    Graphitization of polymer surfaces was performed by low-energy Ar+ and He+ ion irradiation. A method of scanning irradiation was implemented. It was found that by scanning ion irradiation, a significantly higher electrical conductivity in the graphitized layers can be achieved in comparison with a conventional broad-beam irradiation. The enhancement of the conductance becomes more pronounced for narrower and better collimated ion beams. In order to analyze these results in more detail, the temperature dependence of conductance of the irradiated samples was investigated. The results of measurements are discussed in terms of weak localization corrections to conductance in disordered metals. The observed effects can be explained by enlargement of graphitic patches, which was achieved with the scanning ion irradiation method.

  14. The live cell irradiation and observation setup at SNAKE

    NASA Astrophysics Data System (ADS)

    Hable, V.; Greubel, C.; Bergmaier, A.; Reichart, P.; Hauptner, A.; Krücken, R.; Strickfaden, H.; Dietzel, S.; Cremer, T.; Drexler, G. A.; Friedl, A. A.; Dollinger, G.

    2009-06-01

    We describe a new setup at the ion microprobe SNAKE ( Superconducting Nanoscope for Applied nuclear ( Kern-) physics Experiments) at the Munich 14 MV Tandem accelerator that facilitates both living cell irradiation with sub micrometer resolution and online optical imaging of the cells before and after irradiation by state of the art phase contrast and fluorescence microscopy. The cells are kept at standard cell growth conditions at 37 °C in cell culture medium. After irradiation it is possible to switch from single ion irradiation conditions to cell observation within 0.5 s. First experiments were performed targeting substructures of a cell nucleus that were tagged by TexasRed labeled nucleotides incorporated in the cellular DNA by 55 MeV single carbon ion irradiation. In addition we show first online sequences of short time kinetics of Mdc1 protein accumulation in the vicinity of double strand breaks after carbon ion irradiation.

  15. 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.

  16. 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.

  17. Irradiation creep induced anisotropy in a/2110 dislocation populations

    NASA Astrophysics Data System (ADS)

    Gelles, D. S.

    1984-05-01

    The contribution of anisotropy in Burgers vector distribution to irradiation creep behavior has been largely ignored in irradiation creep models. However, findings on Frank loops suggest that it may be very important. Procedures are defined to identify the orientations of a 2110 Burgers vectors for dislocations in face-centered cubic crystals. By means of these procedures the anistropy in Burgers vector populations was determined for three Nimonic PE16 pressurized tube specimens irradiated under stress. Considerable anisotropy in Burgers vector population develops during irradiation creep. It is inferred that dislocation motion during irradiaton creep is restricted primarily to a climb of a/2110 dislocations on 100 planes. Effect of these results on irradiation creep modeling and deformation induced irradiation growth is considered.

  18. Stress corrosion cracking on irradiated 316 stainless steel

    Microsoft Academic Search

    Gen Furutani; Nobuo Nakajima; Takao Konishi; Mitsuhiro Kodama

    2001-01-01

    Tests on irradiation-assisted stress corrosion cracking (IASCC) were carried out by using cold-worked (CW) 316 stainless steel (SS) in-core flux thimble tubes which were irradiated up to 5×1026 n\\/m2 (E>0.1 MeV) at 310°C in a Japanese PWR. Unirradiated thimble tube was also tested for comparison with irradiated tubes. Mechanical tests such as the tensile, hardness tests and metallographic observations were

  19. 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 ?-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  20. Hyaluronic acid production by irradiated human synovial fibroblasts

    Microsoft Academic Search

    Michael Yaron; Ilana Yaron; Moshe Levita; Mala Herzberg

    1977-01-01

    Radioactive particles as well as x irradiation from an external source has been used in the treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. In order to clarify effects of ionizing irradiation on synovial cells, radioactive gold (¹⁹⁸Au) and yttrium (⁹°Y) were added to fibroblast cultures derived from human synovial membranes. Other cultures were irradiated by a Picker x-ray machine.

  1. Thermoluminescence of Simulated Interstellar Matter after Gamma-ray Irradiation

    Microsoft Academic Search

    K. Koike; M. Nakagawa; C. Koike; M. Okada; H. Chihara

    2002-01-01

    Interstellar matter is known to be strongly irradiated by radiation and several types of cosmic ray particles. Simulated interstellar matter, such as forsterite $\\\\rm Mg_{2}SiO_{4}$, enstatite $\\\\rm MgSiO_{3}$ and magnesite $\\\\rm MgCO_{3}$ has been irradiated with the $\\\\rm ^{60}Co$ gamma-rays in liquid nitrogen, and also irradiated with fast neutrons at 10 K and 70 K by making use of the

  2. Reflective optics for irradiance redistribution of laser beams: design.

    PubMed

    Scott, P W; Southwell, W H

    1981-05-01

    The output irradiance of a typical unstable resonator with circular symmetry has a central obscuration and is peaked near the obscuration. A method is presented for designing two-mirror optical systems to convert this beam into a beam of arbitrary obscuration ratio and more uniform irradiance. A method is also given for analyzing the alignment sensitivity of such a system. An example shows that useful irradiance redistributions can be achieved with alignment sensitivities comparable to ordinary Cassegrain systems. PMID:20309356

  3. Electron-irradiation-induced gold atom implantation into silicon carbide

    Microsoft Academic Search

    H. Mori; H. Yasuda; T. Sakata; H. Fujita

    1992-01-01

    Bilayer films of Au(target atom)\\/alpha-SiC (substrate) were irradiated with 2 MeV electrons in an ultra-high voltage electron microscope (HVEM), with the electron beam incident on the gold layer. With this irradiation, gold atoms were successfully implanted into the substrate. The implantation process was studied by a combination of HVEM and AES. (1) Irradiation with 2 MeV electrons first induces a

  4. Photoprotection: sunscreens and the immunomodulatory effects of UV irradiation

    Microsoft Academic Search

    John J Finlay-Jones; Prue H Hart

    1998-01-01

    UV-B irradiation (UVR) of the host, in both humans and animal models, induces dose-related acute and chronic changes in skin which include erythema and photoageing, and induction of cancer. It can also induce modulation of immune responses of the host to antigens presented following irradiation. Commercially-available, broad-spectrum, high SPF (15, 15+) sunscreens protect against most effects of UV irradiation. An

  5. 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.

  6. Model for UV irradiance on arbitrarily oriented surfaces

    NASA Astrophysics Data System (ADS)

    Mech, M.; Koepke, P.

    Erythemal weighted solar UV irradiances, responsible for damage to human skin, need to be known for arbitrarily oriented surfaces, since human skin has various orientations to the sun. A model for determining such irradiances is presented with the results in good agreement with measurements. The model gives spectral or biologically weighted irradiances for any user-defined orientation of a flat receiver and for selectable atmospheric and surface conditions.

  7. The fourth SINQ Target Irradiation Program, STIP-IV

    NASA Astrophysics Data System (ADS)

    Dai, Y.; Brun, R.; Gao, W.; Geissmann, K.; Hahl, S.; Hou, H.; Huang, Y.; Linder, H. P.; Long, B.; Spahr, A.; Vontobel, P.; Wagner, W.; Wang, H. L.; Zanini, L.

    2012-12-01

    The 4th SINQ Target Irradiation Program (STIP-IV) was performed in 2004 and 2005. More than 1000 specimens from about 40 kinds of materials were irradiated up to 27 dpa and 2300 appm He in the temperature range of 80-550 °C. The majority of specimens were irradiated in helium gas environment. Some specimens were irradiated in contact with lead and lead-bismuth eutectic. Neutron radiography inspections on specimen and target rods were performed before and after irradiation, which revealed some interesting features of the target rods with thermal couples. Neutronic calculations were performed using the proton distribution profile obtained by ?-mapping on the beam window of the AlMg3 target container after irradiation. Irradiation parameters of the specimens such as proton and neutron spectra and fluxes, heat deposition, irradiation dose in terms of displacement damage (dpa), helium and hydrogen concentrations were calculated. Most of the specimens were retrieved. But, more than 360 tensile and TEM specimens were lost due to a leak in a specimen rod occurred during irradiation.

  8. Inhomogeneous microstructural evolution in ion-irradiated austenitic steel

    NASA Astrophysics Data System (ADS)

    Sekimura, N.; Taguchi, M.; Ishino, S.

    1988-07-01

    Thin foils of Ti-modified austenitic steel (JPCA) are irradiated with heavy ions to investigate characteristic microstructural evolution up to heavy irradiation dose at medium temperature. Ordered arrays of small loops with spacing of about 40 nm are observed in about half of grains with foil edge in the specimen irradiated to 1.0 dpa. This structure is found to be very stable for further irradiation. Elastic interaction of the loops formed in a thin foil is considered to limit the cluster density. Crystallographic orientation of defect arrays is considered to be enhanced to minimize elastic interaction energy between defects clusters.

  9. 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 ?-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas ?-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.

  10. Evaluation of oxidation behavior of ?-irradiated EPDM/PP compounds

    NASA Astrophysics Data System (ADS)

    Zaharescu, T.; Jipa, S.; Setnescu, R.; Setnescu, T.

    2007-12-01

    The oxidation effect of irradiation on ethylene-propylene diene terpolymer/polypropylene blends is presented. The polymer samples consisting of both materials under various ratios (20:80, 40:60, 60:40 and 80:20) were exposed to ?-irradiation ( 137Cs). The irradiation effects were assessed by two methods: oxygen uptake and IR spectroscopy (1720 cm -1 and 3350 cm -1, the characteristic bands for carbonyl and hydroxyl groups, respectively). The carbonyl and hydroxyl indexes were calculated for all formulations. From oxygen uptake investigation the kinetic parameters for thermal oxidation of irradiated samples were calculated. The contribution of each component to the progress of degradation is discussed.

  11. Emulation of reactor irradiation damage using ion beams

    SciTech Connect

    G. S. Was; Z. Jiao; E. Beckett; A. M. Monterrosa; O. Anderoglu; B. H. Sencer; M. Hackett

    2014-10-01

    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 irradiations 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 irradiations establishes the capability of tailoring ion irradiations to emulate the reactor-irradiated microstructure.

  12. Graphitization of polymer surfaces by low-energy ion irradiation

    SciTech Connect

    Lazareva, I.; Koval, Y.; Alam, M.; Stroemsdoerfer, S.; Mueller, P. [Physikalisches Institut III, Universitaet Erlangen-Nuernberg, Erwin-Rommel Strasse 1, 91058 Erlangen (Germany)

    2007-06-25

    The surface of several polymers was graphitized by low-energy ion irradiation. Their conducting properties were studied as a function of the energy of the ions and the irradiation temperature. It was found that at rather modest ion energies ({approx}1000 eV) and irradiation temperatures (<400 deg. C), polymer surfaces transform to a graphitized state. The graphitized layer consists of overlapping graphite islands with a diameter of 1-3 nm and exhibits a semimetallic conductivity. Gradually reducing the energy of the ions and the irradiation temperature, the authors observed a transition from semimetallic to variable range hopping conductivity.

  13. 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

  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. Saturation of irradiance fluctuations in a weakly absorbing turbulent atmosphere

    NASA Astrophysics Data System (ADS)

    Almaev, R. Kh.; Suvorov, A. A.

    2008-06-01

    Statistical characteristics of the irradiance of an electromagnetic wave propagating in a dissipative random medium are studied. For the propagation regime of strong irradiance fluctuations, asymptotic expressions are obtained for the second statistical moment of the irradiance. The behavior of the relative variance of irradiance fluctuations is analyzed for different propagation conditions. It is shown that, if the outer scale of turbulence exceeds the maximum correlation length of irradiance fluctuations because of random attenuation, no saturation of the relative variance of irradiance fluctuations to unity occurs. Depending on the ratio between the structure characteristics of the real and imaginary parts of the permittivity and on the degree of their correlation, the relative variance of irradiance fluctuations in this case may be either an increasing, or a decreasing, or a nonmonotonic function of the path length, deviating from the level corresponding to a transparent turbulent medium. It is found that the saturation of the relative variance of irradiance fluctuations to unity in a randomly absorbing medium occurs in the region of strong fluctuations if the correlation length of irradiance fluctuations is greater than the outer scale of turbulence.

  16. Solar irradiance short wave radiation users guide. Final report

    SciTech Connect

    Martinolich, P.; Arnone, R.A.

    1995-05-19

    Solar irradiance for short wave radiation (400-700 nm) at the sea surface can be calculated using inputs obtained from satellite systems and model estimates. The short wave solar irradiance is important for estimating the surface heating that occurs in the near surface and estimating the available irradiance for biological growth in the upper ocean. The variability of the solar irradiance is believed to have significant influence on the global carbon cycle. This users guide provides an understanding of the models and operational procedures for using the software and understanding the results.

  17. Selective crystallization of metastable phase of acetaminophen by ultrasonic irradiation

    NASA Astrophysics Data System (ADS)

    Mori, Yoichiro; Maruyama, Mihoko; Takahashi, Yoshinori; Ikeda, Kenji; Fukukita, Suguru; Yoshikawa, Hiroshi Y.; Okada, Shino; Adachi, Hiroaki; Sugiyama, Shigeru; Takano, Kazufumi; Murakami, Satoshi; Matsumura, Hiroyoshi; Inoue, Tsuyoshi; Yoshimura, Masashi; Mori, Yusuke

    2015-06-01

    A new method for selective crystallization of the metastable phase (form II) of acetaminophen is described. To obtain form II, we prepared a highly supersaturated solution (?I = 3.7) and then applied ultrasonic irradiation at different frequencies. Without ultrasonic irradiation, spontaneous crystallization did not occur within one month in the highly supersaturated condition (?I = 3.7). When ultrasonic irradiation at 28 kHz was applied, form II preferentially crystallized. Therefore, we conclude that ultrasonic irradiation can be an effective technique for selectively crystallizing the metastable phase.

  18. 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.

  19. Control of fouling formation in membrane ultrafiltration by ultrasound irradiation.

    PubMed

    Naddeo, Vincenzo; Belgiorno, Vincenzo; Borea, Laura; Secondes, Mona Freda N; Ballesteros, Florencio

    2015-05-01

    The increasing application of membrane filtration in water and wastewater treatment necessitates techniques to improve performance, especially in fouling control. Ultrasound is one promising technology for this purpose as cavitational effects facilitate continuous cleaning of the membrane. This research studied the ultrafiltration of lake water in systems with constant permeate flux under medium frequency (45?kHz) ultrasound irradiation. Fouling was investigated by monitoring transmembrane pressure (TMP) using continuous or intermittent ultrasound irradiation and dead-end or crossflow operation. Best performance was observed with continuous ultrasound irradiation in crossflow mode. Intermittent irradiation reduced the rate of TMP build-up but nevertheless allowed irreversible fouling to develop. PMID:25384626

  20. A study of irradiation in the treatment of wastewater

    NASA Astrophysics Data System (ADS)

    Bao, Huaying; Liu, Yuanxia; Jia, Haishun

    2002-03-01

    A grafting copolymer of starch and acrylamide was prepared by 60Co- ? pre-irradiation. After purification, the copolymer was modified by a cationic reaction to form a cationic copolymer. The structure of the cationic copolymer was identified by IR and NMR spectroscopy. Using the industrial and sanitary municipal wastewater from the Factory of Wastewater Treatment of Gaobeidian in Beijing as the study sample, three-treatment methods: flocculation deposition, flocculation deposition combined with ? irradiation and the direct irradiation were carried out. COD was applied to evaluate the treatment effect. The preliminary results show that the method of flocculation deposition combined with ? irradiation was effective than the other two.

  1. Pretransfusion blood irradiation: Clinical rationale and dosimetric considerations

    SciTech Connect

    Masterson, M.E.; Febo, R. (Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York 10021 (United States))

    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.

  2. 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.

  3. Food irradiation: Technology transfer in Asia, practical experiences

    NASA Astrophysics Data System (ADS)

    Kunstadt, Peter; Eng, P.

    1993-10-01

    Nordion International Inc., in cooperation with the Thai Office of Atomic Energy for Peace (OAEP) and the Canadian International Development Agency (CIDA) recently completed a unique food irradiation technology transfer project in Thailand. This complete food irradiation technology transfer project included the design and construction of an automatic multipurpose irradiation facility as well as the services of construction and installation management and experts in facility operation, maintenance and training. This paper provides an insight into the many events that led to the succesful conclusion of the world's first complete food irradiation technology transfer project.

  4. [2-dimensional ultrasonic scanning for irradiation planning].

    PubMed

    Merkle, K; Khlebnikova, N L

    1983-06-01

    The paper is concerned with the results of the utilization of echotomography in the topometric preparation of patients with malignant tumors for irradiation. Proceeding from the examination of 600 cancer patients in the All-Union Cancer Research Center. USSR AMS, it has been established that echotomography makes it possible not only to define the borders of pathology in the peritoneal cavity and retroperitoneal space but also to specify the relative position of the adjacent internal organs. Some practical aspects of the use of ultrasound for topometry are discussed. A possibility of using this method for the three-dimensional planning of irradiation is indicated. Using an echotomoscope one can obtain a contour of the section of a soft phantom with an accuracy of 5 +/- 1 mm that significantly exceeds the limits of precision of a contour measured with the help of a lead band where it equals 10 +/- 7 mm. Echotomography makes it possible to get a contour in any plane. In view of certain limitations of the echotomographic method one should also resort to x-ray methods for the topometric planning of irradiation to specify the position and size of the bearing osseous structures. While converting reduced ultrasound images in the scale of 1:1 the optic method with an episcope proved to be the most accurate one where an error of reproducibility of a contour reaches 1 mm. In the use of an optical-electronic device this value exceeds 10 mm and corresponds to 4 mm while utilizing a pantograph. PMID:6865685

  5. CDOM retrieval using measurements of downwelling irradiance

    NASA Astrophysics Data System (ADS)

    Linnemann, K.; Gege, P.; Rößler, S.; Schneider, T.; Melzer, A.

    2013-10-01

    As it can strongly influence the availability of light and thus primary production, coloured dissolved organic matter (CDOM) affects the function of lake ecosystems. Therefore reliable methods are required for the monitoring of CDOM concentration. A new method using downwelling irradiance was tested for applicability in four selected lakes of the Bavarian Osterseen Lake District, which consists of 19 naturally connected freshwater lakes of different trophic level. The method separates between the direct and diffuse part of the incident light in order to handle the strong variability of the underwater light field. It is implemented in the software WASI, which is capable to retrieve water constituents by inverse modeling. During field campaigns downwelling irradiance measurements using RAMSES sensors were made in different depths. Simultaneously, water samples were taken in three depths (0.5 m, 2 m and Secchi disk depth), from which the absorption coefficient of CDOM, aY, was derived in the range from 190 to 900 nm using photometric absorption measurements. Concentration (defined as aY at 440 nm) ranged from 0.33 to 1.55 m-1 with a mean of 0.71 m-1 +/- 0.04 m-1, the spectral slope at 440 nm from 0.0120 to 0.0184 nm-1 with a mean of 0.0145 +/- 0.0008 nm-1. These laboratory measurements from water samples were compared to CDOM concentration obtained by inverse modeling of downwelling irradiance measurements using WASI. For sensor depths lower than 1 to 1.5 m large uncertainties were observed. The measurements in 2 m depth and at Secchi disk depth yielded good correlation between water sample and WASI derived data (R2 = 0.87) with a mean standard deviation of 0.06 m-1 for the determined CDOM concentrations. This new method is an alternative to laboratory analysis of water samples from in situ measurements of CDOM concentration.

  6. Solar Irradiance and Thermospheric Airglow Rocket Experiments

    NASA Technical Reports Server (NTRS)

    Solomon, Stanley C.

    1998-01-01

    This report describes work done in support of the Solar Irradiance and Thermospheric Air-glow Rocket Experiments at the University of Colorado for NASA grant NAG5-5021 under the direction of Dr. Stanley C. Solomon. (The overall rocket program is directed by Dr. Thomas N. Woods, formerly at the National Center for Atmospheric Research, and now also at the University of Colorado, for NASA grant NAG5-5141.) Grant NAG5-5021 provided assistance to the overall program through analysis of airglow and solar data, support of two graduate students, laboratory technical services, and field support. The general goals of the rocket program were to measure the solar extreme ultraviolet spectral irradiance, measure the terrestrial far-ultraviolet airglow, and analyze their relationship at various levels of solar activity, including near solar minimum. These have been met, as shown below. In addition, we have used the attenuation of solar radiation as the rocket descends through the thermosphere to measure density changes. This work demonstrates the maturity of the observational and modeling methods connecting energetic solar photon fluxes and airglow emissions through the processes of photoionization and photoelectron production and loss. Without a simultaneous photoelectron measurement, some aspects of this relationship remain obscure, and there are still questions pertaining to cascade contributions to molecular and atomic airglow emissions. However, by removing the solar irradiance as an "adjustable parameter" in the analysis, significant progress has been made toward understanding the relationship of far-ultraviolet airglow emissions to the solar and atmospheric conditions that control them.

  7. Interfractional Target Variations for Partial Breast Irradiation

    SciTech Connect

    Ahunbay, Ergun E., E-mail: eahunbay@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Robbins, Jared; Christian, Robert; Godley, Andrew; White, Julia; Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2012-04-01

    Purpose: In this work, we quantify the interfractional variations in the shape of the clinical target volume (CTV) by analyzing the daily CT data acquired during CT-guided partial breast irradiation (PBI) and compare the effectiveness of various repositioning alignment strategies considered to account for the variations. Methods and Materials: The daily CT data for 13 breast cancer patients treated with PBI in either prone (10 patients) or supine (3 patients) with daily kV CT guidance using CT on Rails (CTVision, Siemens, Malvern, PA) were analyzed. For approximately 25 points on the surface of the CTV, deformation vectors were calculated by means of deformable image registration and verified by visual inspection. These were used to calculate the distances along surface normals (DSN), which directly related to the required margin expansions for each point. The DSN values were determined for seven alignment methods based on volumetric imaging and also two-dimensional projections (portal imaging). Results: The margin expansion necessary to cover 99% of all points for all days was 2.7 mm when utilizing the alignment method based on deformation field data (the best alignment method). The center-of-mass based alignment yielded slightly worse results (a margin of 4.0 mm), and shifts obtained by operator placement (7.9 mm), two-dimensional-based methods (7.0-10.1 mm), and skin marks (13.9 mm) required even larger margin expansions. Target shrinkage was evident for most days by the negative values of DSN. Even with the best alignment, the range of DSN values could be as high as 7 mm, resulting in a large amount of normal tissue irradiation, unless adaptive replanning is employed. Conclusion: The appropriate alignment method is important to minimize the margin requirement to cover the significant interfractional target deformations observed during PBI. The amount of normal tissue unnecessarily irradiated is still not insignificant, and can be minimized if adaptive radiotherapy is applied.

  8. Forecasting solar extreme and far ultraviolet irradiance

    NASA Astrophysics Data System (ADS)

    Henney, C. J.; Hock, R. A.; Schooley, A. K.; Toussaint, W. A.; White, S. M.; Arge, C. N.

    2015-03-01

    A new method is presented to forecast the solar irradiance of selected wavelength ranges within the extreme ultraviolet (EUV) and far ultraviolet (FUV) bands. The technique is similar to a method recently published by Henney et al. (2012) to predict solar 10.7 cm (2.8 GHz) radio flux, abbreviated F10.7, utilizing advanced predictions of the global solar magnetic field generated by a flux transport model. In this and the previous study, we find good correlation between the absolute value of the observed photospheric magnetic field and selected EUV/FUV spectral bands. By evolving solar magnetic maps forward 1 to 7 days with a flux transport model, estimations of the Earth side solar magnetic field distribution are generated and used to forecast irradiance. For example, Pearson correlation coefficient values of 0.99, 0.99, and 0.98 are found for 1 day, 3 day, and 7 day predictions, respectively, of the EUV band from 29 to 32 nm. In the FUV, for example, the 160 to 165 nm spectral band, correlation values of 0.98, 0.97, and 0.96 are found for 1 day, 3 day, and 7 day predictions, respectively. In the previous study, the observed F10.7 signal is found to correlate well with strong magnetic field (i.e., sunspot) regions. Here we find that solar EUV and FUV signals are significantly correlated with the weaker magnetic fields associated with plage regions, suggesting that solar magnetic indices may provide an improved indicator (relative to the widely used F10.7 signal) of EUV and FUV nonflaring irradiance variability as input to ionospheric and thermospheric models.

  9. 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.

  10. The effect of microwave irradiation on enzymatic hydrolysis of rice straw

    Microsoft Academic Search

    Shengdong Zhu; Yuanxin Wu; Ziniu Yu; Xia Zhang; Hui Li; Ming Gao

    2006-01-01

    A series of experiments involving microwave irradiation were carried out to evaluate the effect of microwave irradiation on enzymatic hydrolysis of rice straw. Compared with microwave irradiation free hydrolysis, rice straw pretreated by combining microwave irradiation with alkali could increase the initial hydrolysis rate but the hydrolysis yield remained unchanged. When the enzyme solution was treated by microwave irradiation, the

  11. 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. PMID:18949599

  12. Effect of irradiation spectrum on the microstructure of ion-irradiated Al{sub 2}O{sub 3}

    SciTech Connect

    Zinkle, S.J. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1994-12-31

    Polycrystalline samples of alpha-alumina have been irradiated with various ions ranging from 3.6 MeV Fe{sup +} to 1 MeV H{sup +} ions at 650 C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructure of the irradiated specimens. The microstructure following irradiation was observed to be dependent on the irradiation spectrum. In particular, defect cluster nucleation was effectively suppressed in specimens irradiated with light ions such as 1 MeV H{sup +} ions. On the other hand, light ion irradiation tended to accelerate the growth rate of dislocation loops. The microstructural observations are discussed in terms of ionization enhanced diffusion processes.

  13. Effects of irradiation on PHA-induced T-lymphocyte colonies: differential effects according to the timing of irradiation

    SciTech Connect

    Woods, G.M.; Lowenthal, R.M.

    1984-06-01

    A T-lymphocyte colony assay was used to investigate the effect of irradiation on lymphocyte mitosis. Irradiation doses in the range of 0.5 to 4 Gy had the effect of decreasing the lymphocytes' capacity to divide as shown by their reduced T-colony-forming ability. This radiosensitivity, however, was found to vary according to the timing of irradiation in relation to the stage of colony growth. Through survival curve analysis it was shown that the colony-forming cells could withstand higher irradiation doses without losing their replicative ability when they were irradiated prior to or during early stages of PHA stimulation. These results provide evidence that the early events associated with PHA stimulation might lead to an improved ability of T-lymphocytes to withstand higher doses or irradiation before mitotic death is registered.

  14. Medical waste irradiation study. Final report

    SciTech Connect

    Adler, R.J.; Stein, J. [North Star Research Corp., Albuquerque, NM (United States); Nygard, J. [Advance Bio-Control (United States)

    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.

  15. Total skin electron irradiation techniques: a review

    PubMed Central

    Milecki, Piotr; Skórska, Ma?gorzata; Fundowicz, Dorota

    2013-01-01

    Total skin electron irradiation (TSEI) has been employed as one of the methods of mycosis fungoides treatment since the mid-twentieth century. In order to improve the effects and limit the complications following radiotherapy, a number of varieties of the TSEI method, frequently differing in the implementation mode have been developed. The paper provides a systematic review of the different varieties of TSEI. The discussed differences concerned especially: (i) technological requirements and geometric conditions, (ii) the alignment of the patient, (iii) the number of treatment fields, and (iv) dose fractionation scheme. PMID:24278046

  16. Total skin electron irradiation techniques: a review.

    PubMed

    Piotrowski, Tomasz; Milecki, Piotr; Skórska, Ma?gorzata; Fundowicz, Dorota

    2013-02-01

    Total skin electron irradiation (TSEI) has been employed as one of the methods of mycosis fungoides treatment since the mid-twentieth century. In order to improve the effects and limit the complications following radiotherapy, a number of varieties of the TSEI method, frequently differing in the implementation mode have been developed. The paper provides a systematic review of the different varieties of TSEI. The discussed differences concerned especially: (i) technological requirements and geometric conditions, (ii) the alignment of the patient, (iii) the number of treatment fields, and (iv) dose fractionation scheme. PMID:24278046

  17. Separation of transuranium elements from irradiated targets

    SciTech Connect

    Wham, R.M.; Benker, D.E.; Felker, L.K.; Chattin, F.R. [Oak Ridge National Laboratory, TN (United States)

    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.

  18. Deformation behavior of ion-irradiated polyimide

    NASA Astrophysics Data System (ADS)

    Kucheyev, S. O.; Felter, T. E.; Anthamatten, M.; Bradby, J. E.

    2004-08-01

    We study nanoindentation hardness, Young's modulus, and tensile strength of polyimide (Kapton H) films bombarded with MeV light ions in the predominantly electronic stopping power regime. Results show that, for all the ion irradiation conditions studied, bombardment increases the hardness and Young's modulus and decreases the tensile strength. These changes depend close to linearly on ion fluence and superlinearly (with a power-law exponent factor of ˜1.5) on electronic energy loss. Physical mechanisms of radiation-induced changes to mechanical properties of polyimide are discussed.

  19. 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.

  20. Irradiated test fuel shipment plan for the LWR MOX fuel irradiation test project

    SciTech Connect

    Shappert, L.B.; Dickerson, L.S.; Ludwig, S.B.

    1998-10-16

    This document outlines the responsibilities of DOE, DOE contractors, the commercial carrier, and other organizations participating in a shipping campaign of irradiated test specimen capsules containing mixed-oxide (MOX) fuel from the Idaho National Engineering and Environmental Laboratory (INEEL) to the Oak Ridge National Laboratory (ORNL). The shipments described here will be conducted according to applicable regulations of the US Department of Transportation (DOT), US Nuclear Regulatory Commission (NRC), and all applicable DOE Orders. This Irradiated Test Fuel Shipment Plan for the LWR MOX Fuel Irradiation Test Project addresses the shipments of a small number of irradiated test specimen capsules and has been reviewed and agreed to by INEEL and ORNL (as participants in the shipment campaign). Minor refinements to data entries in this plan, such as actual shipment dates, exact quantities and characteristics of materials to be shipped, and final approved shipment routing, will be communicated between the shipper, receiver, and carrier, as needed, using faxes, e-mail, official shipping papers, or other backup documents (e.g., shipment safety evaluations). Any major changes in responsibilities or data beyond refinements of dates and quantities of material will be prepared as additional revisions to this document and will undergo a full review and approval cycle.

  1. Solar Irradiance Data Products at the LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Lindholm, D. M.; Ware DeWolfe, A.; Wilson, A.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.

    2011-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) has developed the LASP Interactive Solar IRradiance Datacenter (LISIRD, http://lasp.colorado.edu/lisird/) web site to provide access to a comprehensive set of solar irradiance measurements and related datasets. Current data holdings include products from NASA missions SORCE, UARS, SME, and TIMED-SEE. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as Total Solar Irradiance (TSI). Other datasets include solar indices, spectral and flare models, solar images, and more. The LISIRD web site features updated plotting, browsing, and download capabilities enabled by dygraphs, JavaScript, and Ajax calls to the LASP Time Series Server (LaTiS). In addition to the web browser interface, most of the LISIRD datasets can be accessed via the LaTiS web service interface that supports the OPeNDAP standard. OPeNDAP clients and other programming APIs are available for making requests that subset, aggregate, or filter data on the server before it is transported to the user. This poster provides an overview of the LISIRD system, summarizes the datasets currently available, and provides details on how to access solar irradiance data products through LISIRD's interfaces.

  2. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Kulriya, P. K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A. K.; Avasthi, D. K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd2Ti2O7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd2Ti2O7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd2Ti2O7 is readily amorphized at an ion fluence 6 × 1012 ions/cm2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 1013 ions/cm2. The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures.

  3. The hematological response and survival of acutley irradiated rats previously exposed to continuous and fractionated, low intensity gamma irradiation 

    E-print Network

    Hooper, John Anderson

    1964-01-01

    in Appendix I of this thesis. The high-level gamma irradiation facility, which houses 1300 Curios of Cobalt 60, was utilixed fox the acute gamma irradiation required in this experiment, Yhe animals to be irradiated wore fowered through a hollow aluminum... per mm was maintained. Controls averaged 17, 000 white blood cells per mm ~ The decline in peripheral leukocytes follow ing exposure to gamma rays was attributed to depressed numbers of lymphocytes. Other hematological psxametors were examined...

  4. External irradiation and intraluminal irradiation using middle-dose-rate iridium in patients with roentgenographically occult lung cancer

    Microsoft Academic Search

    Nobukazu Fuwa; Akira Matsumoto; Minoru Kamata; Takeshi Kodaira; Kazuhisa Furutani; Yoshiyuki Ito

    2001-01-01

    Purpose: Therapeutic results were analyzed in 39 patients with roentgenographically occult lung cancer (ROLC), and the significance and optimal dose of this therapy were evaluated.Methods and Materials: The subjects were 39 patients who underwent intraluminal irradiation between May 1987 and August 1999. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using middle-dose-rate iridium (four 370-MBq wires) through a

  5. Effect of neutron irradiation and post-irradiation annealing on microstructure and mechanical properties of OFHC-copper

    NASA Astrophysics Data System (ADS)

    Singh, B. N.; Edwards, D. J.; Toft, P.

    2001-12-01

    Specimens of oxygen-free high conductivity (OFHC) copper were irradiated in the DR-3 reactor at Risø at 100 °C to doses in the range 0.01-0.3 dpa (NRT). Some of the specimens were tensile tested in the as-irradiated condition at 100 °C whereas others were given a post-irradiation annealing treatment at 300 °C for 50 h and subsequently tested at 100 °C. The microstructure of specimens was characterized in the as-irradiated as well as irradiated and annealed conditions both before and after tensile deformation. While the interstitial loop microstructure coarsens with irradiation dose, no significant changes were observed in the population of stacking fault tetrahedra (SFT). The post-irradiation annealing leads to only a partial recovery and the level of recovery depends on the irradiation dose level. However, the post-irradiation annealing eliminates the yield drop and reinstates enough uniform elongation to render the material useful again. These results are discussed in terms of the cascade-induced source hardening (CISH) model.

  6. Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: a prospective randomized clinical study.

    PubMed

    Sun, Kang; Tian, Shaoqi; Zhang, Jihua; Xia, Changsuo; Zhang, Cailong; Yu, Tengbo

    2009-05-01

    The effect of using gamma irradiation to sterilize bone-patellar tendon-bone (BPTB) allograft on the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with irradiated allograft remains controversial. Our study was aimed to analyze the clinical outcomes of arthroscopic ACL reconstruction with irradiated BPTB allograft compared with non-irradiated allograft and autograft. All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 Mrad of irradiation prior to distribution. A total of 102 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into three groups. The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months follow-up (range 24-47 months) patients were evaluated by the same observer according to objective and subjective clinical evaluations. Of these patients, 99 (autograft 33, non-irradiated allograft 34, irradiated allograft 32) were available for full evaluation. When compared the irradiated allograft group to non-irradiated allograft group or autograft group at 31 months follow-up by the Lachman test, ADT, pivot shift test and KT-2000 arthrometer testing, statistically significant differences were found. Most importantly, 87.8% of patients in the Auto group, 85.3% in the Non-Ir-Auto group and just only 31.3% in the Ir-Allo group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%) and non-irradiated allograft (8.8%). The anterior and rotational stability decreased significantly in the irradiated allograft group. According to the overall IKDC, functional, subjective evaluations and activity level testing, no statistically significant differences were found between the three groups. However, there was a trend that the functional and activity level decreased and the patients felt uncomfortable more often in the irradiated allograft group. The statistical analysis showed no significant difference between the non-irradiated allograft group and the autograft group according to the aforementioned evaluations, except that patients in the allograft group had a shorter operation time and a longer duration of postoperative fever. When comparing the postoperative duration of fever of the two allograft groups, there was also a trend that the irradiated allograft group was longer than the non-irradiated allograft group, but no significant difference was found. When the patients had a fever, the laboratory examinations of all patients were almost normal (Blood routine was normal, the values of ESR were 5 - 16 mm/h, CRP were 3 - 10 mg/l). On the basis of our study, we concluded that patients undergoing ACL reconstruction with BPTB non-irradiated allograft or autograft had similar clinical outcomes. Non-irradiated BPTB allograft is a reasonable alternative to autograft for ACL reconstruction. While the short term clinical outcomes of the ACL reconstruction with irradiated BPTB allograft were adversely affected with an increased failure rate. The less than satisfactory results led the senior authors to discontinue the use of irradiated BPTB allograft in ACL surgery and not to advocate that gamma irradiation be used as a secondary sterilizing method. Further research into alternatives to gamma irradiation is needed. PMID:19139845

  7. Hyaluronan minimizes effects of UV irradiation on human keratinocytes.

    PubMed

    Hašová, Martina; Crhák, Tomáš; Safránková, Barbora; Dvo?áková, Jana; Muthný, Tomáš; Velebný, Vladimír; Kubala, Lukáš

    2011-05-01

    Exposure to ultraviolet (UV) irradiation has detrimental effects on skin accompanied by the increased metabolism of hyaluronan (HA), a linear polysaccharide important for the normal physiological functions of skin. In this study, the modulation of human keratinocyte response to UVB irradiation by HA (970 kDa) was investigated. Immortalized human keratinocytes (HaCaT) were irradiated by a single dose of UVB and immediately treated with HA for 6 and 24 h. The irradiation induced a significant decrease in the gene expression of CD44 and toll-like receptor 2 6 h after irradiation. The expressions of other HA receptors, including toll-like receptor 4 and the receptor for HA-mediated motility, were not detected in either the control or UVB-irradiated or HA-treated HaCaT cells. UVB irradiation induced a significant decrease in the gene expression of HA synthase-2 and hyaluronidase-2 6 h after irradiation. The expressions of HA synthase-3 and hyaluronidase-3 were not significantly modulated by UV irradiation. Interestingly, HA treatment did not significantly modulate any of these effects. In contrast, HA significantly suppressed UVB-induced pro-inflammatory cytokine release including interleukin-6 and interleukin-8. Similarly, HA treatment reduced the UVB-mediated production of transforming growth factor ?1. HA treatment also significantly reduced the UV irradiation-mediated release of soluble CD44 into the media. Finally, HA partially, but significantly, suppressed the UVB-induced decrease in cell viability. Data indicate that HA had significant protective effects for HaCaT cells against UVB irradiation. PMID:21448660

  8. Optimisation of buildings' solar irradiation availability

    SciTech Connect

    Kaempf, Jerome Henri; Montavon, Marylene; Bunyesc, Josep; Robinson, Darren [Solar Energy and Building Physics Laboratory, Station 18, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland); Bolliger, Raffaele [Industrial Energy Systems Laboratory, Station 9, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland)

    2010-04-15

    In order to improve the sustainability of new and existing urban settlements it is desirable to maximise the utilisation of the solar energy incident on the building envelope, whether by passive or active means. To this end we have coupled a multi-objective optimisation algorithm with the backwards ray tracing program RADIANCE which itself uses a cumulative sky model for the computation of incident irradiation (W h/m{sup 2}) in a single simulation. The parameters to optimise are geometric (the height of buildings up to their facade and the height and orientation of roofs), but with the constraint of maintaining an overall built volume, and the objective function is heating season solar irradiation offset by envelope heat losses. This methodology has been applied to a range of urban typologies and produces readily interpretable results. The focus of this work is on the design of new urban forms but the method could equally be applied to examine the relative efficiency of existing urban settlements, by comparison of existing forms with the calculated optima derived from relevant specifications of the building envelope. (author)

  9. 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.

  10. Tritium and helium release from irradiated beryllium

    SciTech Connect

    Anderl, R.A.; Baker, J.D.; Bourne, G.L.; Pawelko, R.J. [Lockheed Martin Idaho Technologies, Idaho falls, ID (United States)

    1995-10-01

    Tritium and helium release behavior has been measured for Be specimens irradiated at 75{degree}C in the Advanced Test Reactor (ATR) to a fast neutron fluence of 5x10{sup 22} n/cm{sup 2}. Stepped-isothermal anneal experiments were conducted from room temperature to above the melting point of Be, with the temperature steps varied from one experiment to the other. In-line ion chambers and quadrupole mass spectrometers were used to measure the gases released to an Ar process gas stream flowing across a heated specimen. Gases released from the specimens included H{sub 2}, {sup 3}He, {sup 4}He, and tritium as HT and T{sub 2}. Release of the hydrogenic and tritium gases were observed to be concurrent with the release of helium, providing direct evidence of these gases in microscopic helium bubbles in the irradiated Be. Tritium and helium release kinetics were dependent on the magnitude of the temperature steps between 600{degree}C and 800{degree}C. 17 refs., 6 figs.

  11. 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. PMID:24407504

  12. WEBEXPIR: Windowless target electron beam experimental irradiation

    NASA Astrophysics Data System (ADS)

    Dierckx, Marc; Schuurmans, Paul; Heyse, Jan; Rosseel, Kris; Van Tichelen, Katrien; Nactergal, Benoit; Vandeplassche, Dirk; Aoust, Thierry; Abs, Michel; Guertin, Arnaud; Buhour, Jean-Michel; Cadiou, Arnaud; Abderrahim, Hamid Aït

    2008-06-01

    The windowless target electron beam experimental irradiation (WEBEXPIR) program was set-up as part of the MYRRHA/XT-ADS R&D effort on the spallation target design to investigate the interaction of a proton beam with a liquid lead-bismuth eutectic (LBE) free surface. In particular, possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on/off transient situations, as well as possible enhanced evaporation were assessed. An experiment was conceived at the IBA TT-1000 Rhodotron, where a 7 MeV electron beam was used to simulate the high power deposition at the MYRRHA/XT-ADS LBE free surface. The geometry and the LBE flow characteristics in the WEBEXPIR set-up were made as representative as possible of the actual situation in the MYRRHA/XT-ADS spallation target. Irradiation experiments were carried out at beam currents of up to 10 mA, corresponding to 40 times the nominal beam current necessary to reproduce the MYRRHA/XT-ADS conditions. Preliminary analyses show that the WEBEXPIR free surface flow was not disturbed by the interaction with the electron beam and that vacuum conditions stayed well within the design specifications.

  13. LISIRD: LASP Interactive Solar Irradiance Data Center

    NASA Astrophysics Data System (ADS)

    Lindholm, D. M.; Wilson, A.

    2013-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder has been involved in numerous space-borne missions to directly measure and understand the variability of the Sun's energy output and its impact on global climate change. The LASP Interactive Solar Irradiance Data Center (LISIRD) provides a web site with interactive graphics to explore, subset, and download these and other solar related datasets. The LISIRD collections include observations of total and spectral irradiance with coverage from the X-ray to the infrared from projects such as SME, UARS SOLSTICE, SNOE, TIMED SEE, SORCE, and SDO EVE plus a growing number of related data products, proxies, and models. The LISIRD data services are backed by the LaTiS data server which presents a unified RESTful web service interface to slice, dice, and perform select server-side operations as the data are dynamically streamed to files of your desired format or directly into your code or analysis tools. Come see the data products and services that LISIRD has available and help us to improve them to better meet your needs.

  14. Effects of X irradiation on angiogenesis

    SciTech Connect

    Prionas, S.D.; Kowalski, J.; Fajardo, L.F.; Kaplan, I.; Kwan, H.H.; Allison, A.C. (Stanford Univ. School of Medicine (USA))

    1990-10-01

    We have evaluated the effect of X irradiation on the mesenchymal tissue growth (blood capillaries and stromal cells) in an angiogenesis system in the mouse. This was accomplished by implanting a polyvinyl alcohol sponge disc in the subcutis of the thorax, and quantifying the extent of growth reduction of capillaries and stromal cells following graded doses of X rays. The sponge disc contained a centrally located pellet impregnated with 20 micrograms of epidermal growth factor and coated with a thin film of slow-releasing compound. Total growth of vessels and fibroblasts was determined by morphometric analysis of histologic sections. The incorporation of ({sup 3}H)TdR was measured during a 24-h period. A dose-response relationship was observed when X irradiation was given on Day 11 after implantation, with the disc removed on Day 20. A single dose of 15 Gy reduced both the rate of incorporation of ({sup 3}H)TdR and the total growth area. These and previous observations point to endothelial cells as important targets of ionizing radiation in the stroma, especially during the period of active proliferation of these cells, induced by growth factors.

  15. Phase transformations in neutron-irradiated Zircaloys

    SciTech Connect

    Chung, H.M.

    1986-04-01

    Microstructural evolution in Zircaloy-2 and -4 spent-fuel cladding specimens after approx.3 years of irradiation in commercial power reactors has been investigated by TEM and HVEM. Two kinds of precipitates induced by the fast-neutron irradiation in the reactors have been identified, i.e., Zr/sub 3/O and cubic-ZrO/sub 2/ particles approximately 2 to 10 nm in size. By means of a weak-beam dark-field ''2-1/2D-microscopy'' technique, the bulk nature of the precipitates and the surficial nature of artifact oxide and hydride phases could be discerned. The Zr(Fe/sub x/,Cr/sub 1-x/)/sub 2/ and Zr/sub 2/(Fe/sub x/,Ni/sub 1-x/) intermetallic precipitates normally present in the as-fabricated material virtually dissolved in the spent-fuel cladding specimens after a fast-neutron fluence of approx.4 x 10/sup 21/ ncm/sup -2/ in the power reactors. The observed radiation-induced phase transformations are compared with predictions based on the currently available understanding of the alloy characteristics. 29 refs.

  16. 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.

  17. Evolution of defect cluster distributions during irradiation

    SciTech Connect

    Wiedersich, H.

    1991-05-01

    Defects produced by irradiation are often strongly spatially correlated. Energetic primary recoil atoms produce cascades with vacant lattice sites predominantly in the central regions, and interstitial atoms at the periphery. A fraction of the defects produced form clusters during cascade events. Because of their spatial distribution more mobile interstitial atoms than vacancies are released into the matrix following the cascade events. Populations of vacancy and interstitial clusters evolve towards quasi-steady-state distributions. As long as vacancy clusters are thermally moderately stable, i.e., at temperatures below rapid self diffusion, an excess interstitial flux persists in the matrix; as a consequence, vacancy clusters formed in cascades shrink, and interstitial clusters grow. We examine the evolution of these cluster distributions, and their effects on sink strength and radiation-enhanced diffusion, as function of dose for irradiations at moderate temperatures. At temperatures at which thermal evaporation from vacancy clusters, can be neglected, the evolution of the cluster densities is characteristic of the primary recoil spectrum, but is independent of temperature or dose rate. The sink strength, radiation-enhanced diffusion, as well as other consequences of the evolving distributions such as the imbalance of the interstitial and vacancy fluxes in the matrix, approach slowly-changing quasi-steady-state values in a fraction of one displacement per atom, although certain details of the cluster distributions, e.g., the development of large interstitial loops, require several dpa's to approach steady state values. 22 refs., 6 figs.

  18. 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.

  19. Dissolution of ordered precipitates under ion irradiation

    SciTech Connect

    Camus, E.; Bourdeau, F.; Abromeit, C.; Wanderka, N.; Wollenberger, H. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    1995-09-01

    The stability of the ordered {gamma}{prime} precipitates under 300-keV Ni{sup +} irradiation was investigated between room temperature and 623 K. The two competing mechanisms of destabilization by cascade producing irradiation, i.e. disordering and dissolution of the {gamma}{prime} precipitates in Nimonic PE16 alloy, has been studied separately by electron microscopy and field-ion microscopy with atom probe. At high temperatures, the precipitates are stable. At intermediate temperatures, the precipitates dissolve by ballistic mixing into the matrix, but the interface is restored by the radiation-enhanced atomic jumps. The order in the precipitates remains stable. At low temperatures, the precipitates are dissolved by atomic mixing. The dissolution proceeds in a diffusional manner with a diffusion coefficient normalized by the displacement rate D/K = 0.75 nm{sup 2}dpa{sup {minus}1}. The precipitates become disordered by a fluence of 0.1 dpa, whereas precipitate dissolution needs much higher fluences.

  20. Hafnium radioisotope recovery from irradiated tantalum

    DOEpatents

    Taylor, Wayne A. (Los Alamos, NM); Jamriska, David J. (Los Alamos, NM)

    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.

  1. Long-term Observation of 64 Patients with Roentgenographically Occult Lung Cancer Treated with External Irradiation and Intraluminal Irradiation Using Low-dose-rate Iridium

    Microsoft Academic Search

    Nobukazu Fuwa; Takeshi Kodaira; Hiroyuki Tachibana; Tatsuya Nakamura; Natsuo Tomita; Takashi Daimon

    Objective: Therapeutic results of intraluminal irradiation were analyzed in 64 patients with roentgenographically occult lung cancer (ROLC). Methods: The subjects were 64 patients who underwent intraluminal irradiation between 1987 and 2003. Radiotherapy was performed by combining external irradiation with intralum- inal irradiation using low-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer. The doses of radiation were 0

  2. 77 FR 29352 - Agency Information Collection Activities; Proposed Collection; Comment Request; Irradiation in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-17

    ...Irradiation in the Production, Processing, and Handling of Food AGENCY: Food...Irradiation in the Production, Processing, and Handling of Food--21 CFR Part...irradiation in the production, processing, and handling of food are found in...

  3. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...of shipment of irradiated reactor fuel and nuclear waste. 71.97 Section...of shipment of irradiated reactor fuel and nuclear waste. (a...of shipment of irradiated reactor fuel or nuclear waste must contain the...

  4. 10 CFR 73.37 - Requirements for physical protection of irradiated reactor fuel in transit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...of irradiated reactor fuel in transit...37 Energy NUCLEAR REGULATORY COMMISSION...Protection of Special Nuclear Material in Transit...of irradiated reactor fuel in transit...irradiated reactor fuel” and “spent nuclear fuel” are...

  5. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...of shipment of irradiated reactor fuel and nuclear waste. 71.97 Section...of shipment of irradiated reactor fuel and nuclear waste. (a...of shipment of irradiated reactor fuel or nuclear waste must contain the...

  6. 10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...of shipment of irradiated reactor fuel and nuclear waste. 71.97 Section...of shipment of irradiated reactor fuel and nuclear waste. (a...of shipment of irradiated reactor fuel or nuclear waste must contain the...

  7. Modelling irradiance on inclined planes with an anisotropic model

    Microsoft Academic Search

    Luis Robledo; Alfonso soler

    1998-01-01

    The circumsolar (?=25°) and point-source versions of the simplified Perez model were developed to estimate irradiances on inclined planes from values for horizontal planes through the determination of sets of empirical coefficients. This model has been evaluated by us at Madrid. Mean hourly values of irradiances on vertical surfaces facing north, east, south and west were used. A modification in

  8. Alteration of bacteriophage attachment capacity by near-UV irradiation

    SciTech Connect

    Hartman, P.S.; Einsenstark, A.

    1982-08-01

    Near-UV (NUV) (300 to 400 nm) and far-UV (FUV) (254 nm) radiations damage bacteriophage by different mechanisms. Host cell reactivation, Weigle reactivation, and multiplicity reactivation were observed upon FUV, but not upon NUV irradiation. Also, the number of his+ recombinants increased with P22 bacteriophage transduction in Salmonella typhimurium after FUV, but not after NUV irradiation. This loss of reactivation and recombination after NUV irradiation was not necessarily due to host incapability to repair phage damage. Instead, the phage genome failed to enter the host cell after NUV irradiation. In the case of NUV-irradiated T7 phage, this was determined by genetic crosses with amber mutants, which demonstrated that either all or none of a T7 genome entered the Escherichia coli cell after NUV treatment. Further studies with radioactively labeled phage indicated that irradiated phage failed to adsorb to host cells. This damage by NUV was compared with the protein-DNA cross-link observed previously, when phage particles were irradiated with NUV in the presence of H/sub 2/O/sub 2/. H/sub 2/O/sub 2/ (in nonlethal concentration) acts synergistically with NUV so that equivalent phage inactivation is achieved by much lower irradiation doses.

  9. Alteration of bacteriophage attachment capacity by near-uv irradiation

    SciTech Connect

    Hartman, P.S. (Univ. of Minnesota, St. Paul); Eisenstark, A.

    1982-08-01

    Near-uv (NUV) (300 to 400 nm) and far-uv (FUV) (254 nm) radiations damage bacteriophage by different mechanisms. Host cell reactivation, Weigle reactivation, and multiplicity reactivation were observed upon FUV, but not upon NUV irradiation. Also, the number of his/sup +/ recombinants increased with P22 bacteriophage transduction in Salmonella typhimurium after FUV, but not after NUV irradiation. This loss of reactivation and recombination after NUV irradiation was not necessarily due to host incapability to repair phage damage. Instead, the phage genome failed to enter the host cell after NUV irradiation. In the case of NUV-irradiated T7 phage, this was determined by genetic crosses with amber mutants, which demonstrated that either ''all'' or ''none'' of a T7 genome entered the Escherichia coli cell after NUV treatment. Further studies with radioactively labeled phage indicated that irradiated phage failed to adsorb to host cells. This damage by NUV was compared with the protein-DNA cross-link observed previously, when phage particles were irradiated with NUV in the presence of H/sub 2/O/sub 2/. H/sub 2/O/sub 2/ (in nonlethal concentration) acts synergistically with NUV so that equivalent phage inactivation is achieved by much lower irradiation doses.

  10. Effect of swift heavy ion irradiations in polycrystalline aluminum nitride

    Microsoft Academic Search

    J. C. Nappé; M. Benabdesselam; Ph. Grosseau; B. Guilhot

    2011-01-01

    Thanks to its high thermal conductivity, aluminum nitride may be a serious candidate as fuel coating for the Gas Fast Reactor. However, its behavior under irradiation is not entirely well understood. In order to catch a glimpse of this behavior, specimens were irradiated with swift heavy ions of different energies then characterized by both thermally stimulated luminescence and optical absorption

  11. Detection methods for irradiated foods—an overview

    Microsoft Academic Search

    Henry Delincée

    1996-01-01

    At the workshop for Health Impact, Identification, and Dosimetry of Irradiated Foods convened by the WHO in November 1986 in Munich, it was concluded that ``in principle some methods would permit the analyst to distinguish with reasonable certainty between foods that have not been irradiated and those that have''. But that ``much more work is required before methods can be

  12. Raman Microscopic Characterization of Proton-Irradiated Polycrystalline Diamond Films

    NASA Technical Reports Server (NTRS)

    Newton, R. L.; Davidson, J. L.; Lance, M. J.

    2004-01-01

    The microstructural effects of irradiating polycrystalline diamond films with proton dosages ranging from 10(exp 15) to 10(exp 17) H(+) per square centimeter was examined. Scanning Electron Microscopy and Raman microscopy were used to examine the changes in the diamond crystalline lattice as a function of depth. Results indicate that the diamond lattice is retained, even at maximum irradiation levels.

  13. A simple method of alpha irradiation for experiments in radiobiology

    Microsoft Academic Search

    J. Soto; C. Sainz; S. Cos; D Gonzalez Lamuño

    2002-01-01

    This paper presents an irradiation system for radiobiology experiments using alpha particles in vitro. Irradiation is delivered to the cells by the presence of radioactive isotopes previously dissolved in the culture medium. The system uses a source of 226Ra from which the radon (222Rn) generated diffuses through the apparatus and is dissolved in a standard culture medium subsequently used for

  14. Irradiation and heating effects in amethyst crystals from brazil

    Microsoft Academic Search

    Clemencio Teodoro Dotto; Sadao Isotani

    1991-01-01

    In this work we report optical absorption spectroscopy study of thermal and irradiation effects on samples of amethyst from Minas Gerais and Rio Grande do Sul, Brazil. Three bands were studied: 10500 cm?1 (k), 18300 cm?1 (?) and 28000 cm?1 (?). Thermal and irradiation effects shows that the ? and ? bands belongs to a same center and the k

  15. The pros and cons of using irradiation for phytosanitary treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is increasingly being used as a phytosanitary treatment in Asia, Australia and the Americas, but the process is not being used or promoted in the European Union. However, under the current regulatory framework it is possible for food commodities irradiated to prevent the spread of alien...

  16. The pros and cons of using irradiation for phytosanitary treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation is increasingly being used as a phytosanitary treatment in Asia, Australia and the Americas, but the process is not being used or promoted in the European Union. However, under the current regulatory framework it is possible for food commodities irradiated to prevent the spread of alien ...

  17. Total solar irradiance fluctuation effects on sailcraft-Mars rendezvous

    Microsoft Academic Search

    Giovanni Vulpetti

    2011-01-01

    This paper is the second one of a research line whereupon the variations of the total solar irradiance are explicitly included in a large high-precision computer code for sailcraft trajectory optimization. Sailcraft-Mars rendezvous has been chosen for studying such effects. It turns out that irradiance-fluctuation perturbations are large in this trajectory type.

  18. Facilities for studying radiation damage in nonmetals during irradiation

    SciTech Connect

    Levy, P.W.

    1984-08-01

    Two facilities have been developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses /sup 60/Co gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescenc detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and data recording is computerized. Irradiations are made at controlled temperatures between 5K and 900/sup 0/C. The materials studied include glasses, quartz, alkali halides (especially natural rock salt), organic crystals, etc. As determined from color center measurements the damage formation rate in all materials studied at 25/sup 0/C or above is strongly temperature dependent. The defect concentration during irradiation is usually much greater than that measured after irradiation. The fraction of defects annealing after irradiation and the annealing rate usually increases as the irradiation temperature increases. The completed studies demonstrate that, in most cases, the extent of maximum damage and the damage formation and annealing kinetics can be determined only by making measurements during irradiation.

  19. Irradiation effects in high-density polyethylene Jussi Polvia

    E-print Network

    Nordlund, Kai

    medical equipment and preserving food products. Since then, many more practical applications for radiation polymers like polyethylene can be used to produce heat-shrinkable-plastic films for packaging foods irradiation effects in HDPE. 2. Methods Irradiation effects in HDPE were studied using molecular dynamics

  20. The future of irradiation applications on Earth and in space

    NASA Technical Reports Server (NTRS)

    Karel, M.

    1989-01-01

    What needs to be done to establish food irradiation on a truly commercial basis so that those living on planet Earth can fully realize the benefits of this versatile process? This question is answered in the first part of this paper. The second part covers the potential contributions of irradiated foods to feed humans in space.

  1. Radiation hardness of silicon photomultipliers under 60Co ?-ray irradiation

    NASA Astrophysics Data System (ADS)

    Pagano, R.; Lombardo, S.; Palumbo, F.; Sanfilippo, D.; Valvo, G.; Fallica, G.; Libertino, S.

    2014-12-01

    Radiation damage in silicon photomultipliers (SiPM) caused by exposure to 60Co ?-rays is experimentally evaluated and discussed. SiPM devices were irradiated to doses up to 9.4 kGy. Dark current, dark count rate, gain, single photon counting capability, and cross-talk probability among SiPM pixels are evaluated as a function of irradiation dose.

  2. Report of the Materials Irradiation Facilities Improvements Committee

    Microsoft Academic Search

    C. W. Alexander; J. A. Conlin; S. S. Hurt; R. M. Jr. Moon; E. Jr. Newman; A. F. Rowcliffe; K. R. Thoms; C. D. West

    1985-01-01

    Engineering materials irradiations form a substantial program at Oak Ridge National Laboratory (ORNL), relying mainly on the High-Flux Isotope Reactor (HFIR) and the Oak Ridge Research Reactor (ORR). The HFIR neutron flux is high, but the reactor was not designed for materials irradiations; the lack of instrumented positions in the target region and the small size and limited number of

  3. [Systematization of mistakes and errors of irradiation in radiotherapy].

    PubMed

    Va?nberg, M Sh

    1989-08-01

    The paper is devoted to a search for and scientific substantiation of practical measures to enhance the quality of irradiation in radiotherapy of cancer patients aimed at the reduction of the frequency of tumor recurrences, radiation reactions and complications. Inaccuracies, errors and faults in irradiation of cancer patients were analyzed and classified with regard to topometric, dosimetric, technical, technological and other features. PMID:2770447

  4. SENSITISATION OF BLOOD VESSELS TO HYPERTENSIVE DAMAGE BY X IRRADIATION

    Microsoft Academic Search

    A. W. Asscher; C. Wilson; S. G. Anson

    1961-01-01

    Investigations were made to test the hypothesis that x radiation ; increased the susceptibility of the renal arteries to hypertensive damage. A ; loop of mesentery was irradiated, and, at monthiy intervals thereafter, ; hypertension was produced by renal artery constriction. The incidence of ; vascular lesions in the irradiated loop was then compared with that in the ; remainder

  5. ARTERIAL HYPERTENSION AND IRRADIATION DAMAGE TO THE NERVOUS SYSTEM

    Microsoft Academic Search

    A. W. Asscher; S. G. Anson

    1962-01-01

    On the basis of previous studies it appeared that irradiation damage to ; the nervous system might be more severe and more easily produced in hypertensive ; than in normotensive subjects. This hypothesis was investigated by studying the ; frequency of neurological complications and vascular lesions in the spinal cord ; after x irradiation of the cord in hypertensive and

  6. Commercialization of irradiation on fresh fruits and vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter describes current applications of irradiation on fresh fruits and vegetables. Major applications of irradiation around the world include disinfestation of fresh fruits to eliminate pests and reduction of tuber crop losses by inhibiting sprouting. In recent years, a number of irrad...

  7. Volatile organic compounds produced during irradiation of mail.

    PubMed

    Smith, Philip A; Sheely, Michael V; Hakspiel, Shelly J; Miller, Stephen

    2003-01-01

    In 2001, Bacillus anthracis spores were delivered through the United States postal system in a series of bioterrorist acts. Controls proposed for this threat included sanitization with high-energy electrons. Solid phase microextraction was used with gas chromatography/mass spectrometry for field sampling and analysis of volatile compounds apparently produced from polymeric materials such as cellulose and plastics, immediately following processing of mail at a commercial irradiation facility. Solid phase microextraction and direct sampling of air into a cryogenically cooled temperature programmable inlet were used in the laboratory for gas chromatography/mass spectrometry analysis of air in contact with irradiated mail, envelopes only (packaged identically to mail), and air inside irradiated plastic mail packaging bags (with neither mail nor envelopes). Irradiated mail or envelope systems produced hydrocarbons such as propane, butane, pentane, hexane, heptane, methylpentanes, and benzene; and oxygen-containing compounds such as acetaldehyde, acrolein, propionaldehyde, furan, 2-methylfuran, methanol, acetone, 2-butanone, and ethanol. In addition to hydrocarbons, methyl and ethyl nitrate were detected in irradiated bags that contained only air, suggesting reactive nitrogen species formed from air irradiation reacted with hydroxy-containing compounds to give nitro esters. The similarities of volatile compounds in irradiated systems containing paper to those observed by researchers studying cellulose pyrolysis suggests common depolymerization and degradation mechanisms in each case. These similarities should guide additional work to examine irradiated mail for chemical compounds not detectable by methods used here. PMID:12688843

  8. Up-to-date status of food irradiation

    Microsoft Academic Search

    Mainuddin Ahmed

    1993-01-01

    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

  9. Progress of food irradiation in the United States

    Microsoft Academic Search

    Donald D. Derr

    1996-01-01

    Irradiated foods have not yet made a significant impact in the United States marketplace. Some progress has occurred, however, to make them more accessible in the marketplace. Activity in U.S. regulatory agencies and other government agencies also may be an indicator of further commercial expansion of food irradiation in the U.S. in the near future. Several regulatory agencies are involved

  10. Dosimetry and radiobiological studies of automated alpha-particle irradiator.

    PubMed

    M V, Jyothish Babu; Shinde, Sanjay G; S, Sunil Kumar; Ali, Manjoor; Vasumathy, R; Kumar, Amit; Kolekar, R; Kumar, Manish; Nema, P; Bhagwat, P V; Pandey, Badri N

    2013-01-01

    Understanding the effect of alpha radiation on biological systems is an important component of radiation risk assessment and associated health consequences. However, due to the short path length of alpha radiation in the atmosphere, in vitro radiobiological experiments cannot be performed with accuracy in terms of dose and specified exposure time. The present paper describes the design and dosimetry of an automated alpha-particle irradiator named 'BARC BioAlpha', which is suitable for in vitro radiobiological studies. Compared to alpha irradiators developed in other laboratories, BARC BioAlpha has integrated computer-controlled movement of the alpha-particle source, collimator, and electronic shutter. The diaphragm blades of the electronic shutter can control the area (diameter) of irradiation without any additional shielding, which is suitable for radiobiological bystander studies. To avoid irradiation with incorrect parameters, a software interlock is provided to prevent shutter opening, unless the user-specified speed of the source and collimator are achieved. The dosimetry of the alpha irradiator using CR-39 and silicon surface barrier detectors showed that ~4 MeV energy of the alpha particle reached the cells on the irradiation dish. The alpha irradiation was also demonstrated by the evaluation of DNA double-strand breaks in human cells. In conclusion, 'BARC BioAlpha' provides a user-friendly alpha irradiation system for radiobiological experiments with a novel automation mechanism for better accuracy of dose and exposure time. PMID:24266413

  11. INFLUENCE OF X-RAY IRRADIATION UPON SERUM PROTEINS

    Microsoft Academic Search

    Shibata

    1960-01-01

    Changes of serum proteins of x irradiatsd rabbits were used, total ; protein and albumin decreased as the total dose increased. In the early period, ; alpha globuin increased and gamma globulin decreased, wbile in the later ; period, alpha globulin decreased and gamma globulin increased. More marked ; changes were observed after liver irradiation than after irradiation of the

  12. Endrin-induced toxicity in normal and irradiated rats

    Microsoft Academic Search

    K. Meena; P. K. Gupta; S. R. Bawa

    1978-01-01

    In this investigation, enzymatic changes were investigated after a single dose of endrin (10 mg\\/kg) administered to normal and irradiated rats (900 rads). In both normal and irradiated rats, endrin caused a significant increase in serum GOT and GPT, and adenosine triphosphatase; acid and alkaline phosphatase, succinic dehydrogenase and glucose-6-phosphatase decreased significantly during varying periods of 2 to 48 hr

  13. Influence of Surface Waves on Measured and Modeled Irradiance Profiles

    Microsoft Academic Search

    J. Ronald V. Zaneveld; Emmanuel Boss; Andrew Barnard

    2001-01-01

    Classical radiative transfer programs are based on the plane-parallel assumption. We show that the Gershun equation is valid if the irradiance is averaged over a sufficiently large area. We show that the equation is invalid for horizontal areas of the order of tens of meters in which horizontal gradients of irradiance in the presence of waves are much larger than

  14. Irradiation performance of FFTF drivers using the D9 alloy

    SciTech Connect

    Pitner, A.L.; Gneiting, B.C.; Bard, F.E.

    1994-12-31

    Five test assemblies similar in design to the Fast Flux Test Facility driver fuel assembly , but employing the alloy D9 in place of stainless steel 316 for duct, cladding, and wire wrap compnents were irradiated to demonstrate the improved performance of the new design. Results of post-irradiation examinations are discussed.

  15. Reflected and Transmitted Irradiance from Area Sources using Vertex Tracing

    E-print Network

    Utah, University of

    irradiance analytically from polygonal luminaires in polygonal environments has proven effective for direct of the luminaire. In this work we extend the vertex tracing technique to the analytic computation of irradiance from a polygonal luminaire in other indirect lighting applications: transmission through non

  16. Electron spin resonance of proton-irradiated graphite.

    PubMed

    Lee, Kyu Won; Lee, Cheol Eui

    2006-09-29

    In the case of colossal magnetoresistance in the perovskite manganites, "double exchange" mediated by the itinerant spins is believed to play a key role in the ferromagnetism. In contrast, the conventional "Heisenberg" interaction, i.e., direct (unmediated) interaction between the localized spins produced by the proton irradiation, is identified as the origin of proton irradiation-induced ferromagnetism in graphite. PMID:17026071

  17. Conformal irradiation by proton beam scanning and multilayer energy filter

    Microsoft Academic Search

    Takeji Sakae; Akihiro Nohtomi; Yoshikazu Tsunashima; Toshiyuki Terunuma; Masaru Sato; Yoshinori Hayakawa; Akira Maruhashi

    2003-01-01

    Using a new energy filter, three-dimensional conformal irradiation for proton therapy can be realized by monoenergetic beam scanning. It is a big advantage that the method does not necessitate energy scanning from the viewpoint of shortening the scanning time for cancer treatment of a moving organ. The new filter can yield an irradiation field where the width of the spread-out

  18. Effects of irradiation on the microstructure of INCONEL 600 alloy

    NASA Astrophysics Data System (ADS)

    Kai, Ji-Jung; Lee, R. D.

    1992-09-01

    INCONEL alloy 600 specimens were irradiated with 2 MeV protons at 300°C to doses of 0.01, 0.1, and 1.0 dpa, at about 6 ?m depth, to study the effect of irradiation on the microstructural evolution of this alloy. Two types of specimens were examined; namely, mill-annealed (MA) and solution-annealed and sensitized (SAS). In the mill-annealed specimen, the dislocation structure reached an equilibrium value of 1.2 × 1014 m-2 by 1.0 dpa. M7C3 carbides were the major precipitates and coarsened slightly during irradiation. The void swelling increased sharply with irradiation dose. At 1 dpa, the total swelling was about 0.3%. Previous study showed that the SAS specimens were very susceptible to intergranular stress corrosion cracking (IGSCC) due to the chromium depletion at grain boundaries. Irradiation enhanced the reprecipitation of the M23C6 precipitates in the matrix. Dislocation density increased with increasing irradiation dose due to dislocation loop formation and growth. The chromium depletion was increased by irradiation, which may increase the IGSCC susceptibility of this alloy. It is believed that void swelling and irradiation-assisted stress corrosion cracking will be the major problems for using this alloy for fusion reactor components such as piping.

  19. 21 CFR 179.25 - General provisions for food irradiation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) IRRADIATION...accomplish its intended technical effect and not more than the maximum...radiation to achieve its intended effect on a specific product and...distribution in the product, and the date of irradiation. [51...

  20. 21 CFR 179.25 - General provisions for food irradiation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) IRRADIATION...accomplish its intended technical effect and not more than the maximum...radiation to achieve its intended effect on a specific product and...distribution in the product, and the date of irradiation. [51...

  1. Qualitative and quantitative thermoluminescence analysis on irradiated oregano

    Microsoft Academic Search

    M. C. D’Oca; A. Bartolotta; M. C. Cammilleri; M. Brai; M. Marrale; A. Triolo; A. Parlato

    2007-01-01

    Thermoluminescence (TL) dosimetry is one of the physical methods used for the identification of irradiated food, suitable for foods from which silicate minerals can be extracted. The aims of the present work were to apply the TL analysis for a qualitative identification of irradiated oregano, and to set up a quantitative procedure to estimate the original treatment dose on the

  2. Susceptibility of irradiated bovine aortic endothelial cells to injury

    SciTech Connect

    Zhou, M.H.; Dong, Q.; Ts'ao, C.

    1988-11-01

    Using cultured bovine aortic endothelial cells (BAEC), the authors attempted to determine whether prior irradiation would alter the susceptibility of these cells to three known injurious stimuli and, if so, whether the alteration would be related to radiation dose. BAEC were irradiated with 0, 5, or 10 Gy of gamma rays and, on the third postirradiation day, exposed to fibrin, nicotine, or bacterial endotoxin (lipopolysaccharide, LPS). Release of prelabeled 51Cr, representing cell lysis, cell detachment, or a combination of the two, was determined. Significant differences between irradiated and control cells were determined by using paired Student's t-tests. Irradiation did not appear to have altered the sensitivity of BAEC to fibrin-induced injury. Cells irradiated with 10 Gy of gamma rays, but generally not those irradiated with half this dose, showed a heightened susceptibility to nicotine. Contrary to the nicotine results, irradiated cells showed less cell detachment and lysis after exposure to LPS. These results suggest that the susceptibility of irradiated BAEC to harmful stimuli depends largely on the nature of the stimulus as well as the radiation dose.

  3. Surface activated bonding for copper plate by excimer laser irradiation

    Microsoft Academic Search

    Takashi Suzuki; Takao Araki; Minoru Nishida

    2003-01-01

    When a pair of clean solid surface are brought close to the atoms distance in the vacuum, the solids were bonded by the gravitation and binding force. Such a way of bonding is called a surface activated bonding. In this work, a laser irradiated to a couple of copper plates surface under various conditions of laser irradiation. The surface oxidation

  4. The growth of fission gas bubbles in irradiated uranium dioxide

    Microsoft Academic Search

    R. M. Cornell

    1969-01-01

    The growth of fission gas bubbles from supersaturated solution in irradiated uranium dioxide has been studied by electron microscopy under isothermal annealing conditions between 1300° and 1500°C. Measurements of the kinetics of bubble growth have enabled the diffusion coefficients of atomic xenon and krypton in irradiated uranium dioxide to be determined. The diffusion coefficients obtained may be expressed by the

  5. THE EFFECTS OF CARDIAC IRRADIATION UPON THE NORMAL CANINE HEART

    Microsoft Academic Search

    E. Senderoff; M. Kaneko; A. R. Beck; I. D. Baronofsky

    1961-01-01

    Ligation of the anterior descending coronary artery was performed on 66 ; dogs following varying doses of cardiac irradiation at varying intervals of time. ; A pathologic analysis of the hearts by means of injection and corrosion studies, ; and gross and microscopic examination was carried out. Thirty control dogs, ; similarly ligated but not irradiated, were studied in the

  6. Facular limb-darkening functions for irradiance modeling

    Microsoft Academic Search

    T. Hirayama; T. Okamoto; H. S. Hudson

    1984-01-01

    The limb darkening function of faculae is an important factor in estimating facular contributions to solar irradiance variations. The existing photometric data is reviewed and a synthetic limb darkening function for faculae was generated which was compared with the limb darkening functions currently in use for irradiance modeling. The excess facular flux ranges from 0.017 to 0.0349 of the solar

  7. Laser processing of high-tech materials at high irradiance

    Microsoft Academic Search

    Robert R. Whitlock

    1987-01-01

    The major applications of lasers to the processing of high technology materials are briefly enumerated. It is found that the majority of these applications rely upon the direct thermal effects of irradiating the material with laser light. Several other important interactions of high irradiance lasers with materials are examined. The need for survey and evaluation of the capabilities of lasers

  8. Backscattering measuring system for optimization of intravenous laser irradiation dose

    NASA Astrophysics Data System (ADS)

    Rusina, Tatyana V.; Popov, V. D.; Melnik, Ivan S.; Dets, Sergiy M.

    1996-11-01

    Intravenous laser blood irradiation as an effective method of biostimulation and physiotherapy becomes a more popular procedure. Optimal irradiation conditions for each patient are needed to be established individually. A fiber optics feedback system combined with conventional intravenous laser irradiation system was developed to control of irradiation process. The system consists of He-Ne laser, fiber optics probe and signal analyzer. Intravenous blood irradiation was performed in 7 healthy volunteers and 19 patients with different diseases. Measurements in vivo were related to in vitro blood irradiation which was performed in the same conditions with force-circulated venous blood. Comparison of temporal variations of backscattered light during all irradiation procedures has shown a strong discrepancy on optical properties of blood in patients with various health disorders since second procedure. The best cure effect was achieved when intensity of backscattered light was constant during at least five minutes. As a result, the optical irradiation does was considered to be equal 20 minutes' exposure of 3 mW He-Ne laser light at the end of fourth procedure.

  9. Effects of ultraviolet irradiation on storage of red blood cell

    Microsoft Academic Search

    Wang Baoyan; Zhang Jiangeng; Song Ximei; Yuan Ailian; Zhang Wenli; Zhao Jiefang

    2004-01-01

    Objective To explore effects of ultraviolet irradiation on storage of red blood cell and the safety and feasibility of ultraviolet irradiation on banked blood. Metho ds Paired blood samples were used for contrast . Changes in erythrocyte fragility , blood ion , erythrocyte A TP enzyme activity and erythrocyte immune functions were tested 72 h and 120 h before and

  10. IRRADIATION EFFECTS IN SUPER PURITY ALUMINUM MAGNESIUM ALLOYS

    Microsoft Academic Search

    Piercy

    1959-01-01

    The tensile properties of annealed samples of aluminum -magnesium alloys ; containing 0.001 to 2.8 wt. % magnesium have been determined in the irradiated ; and unirradiated condition. The increase in elastic limit caused by reactor ; irradiation is shown by two effects, an increase proportional to the integrated ; fast-neutron flux that is greater for alloys of lower magnesium

  11. Intraocular inflammation after proton beam irradiation for uveal melanoma

    Microsoft Academic Search

    Livia Lumbroso; Laurence Desjardins; Christine Levy; Corine Plancher; Eric Frau; François DHermies; Pierre Schlienger; Hamin Mammar; Sabine Delacroix; Catherine Nauraye; Régis Ferrand; Claire Desblancs; Alexandre Mazal; Bernard Asselain

    2001-01-01

    AIMTo describe the inflammatory reaction that can occur following proton beam irradiation of uveal melanomas based on a large series of patients and to try to determine the risk factors for this reaction.METHODSData from a cohort of patients with uveal melanoma treated by proton beam irradiation between 1991 and 1994 were analysed. The presence of inflammation was recorded and evaluated.

  12. Bilateral internuclear ophthalmoplegia after intrathecal chemotherapy and cranial irradiation

    SciTech Connect

    Lepore, F.E.; Nissenblatt, M.J.

    1981-12-01

    A 26-year-old man developed transient bilateral internuclear ophthalmoplegia with exotropia after cranial irradiation and intrathecal administration of methotrexate for lymphoma. Resolution of the ophthalmoplegia and the decrease in abnormally high levels of cerebrospinal fluid myelin basic protein after discontinuation of intrathecal medication suggested demyelination from chemotherapy and irradiation.

  13. Post irradiation annealing of uranium-molybdenum ternary alloys

    Microsoft Academic Search

    D. Kramer; W. V. Johnston

    1963-01-01

    The effects of post-irradiation annealing on density changes in U-- Mo ; alloys were investigated. Density changes that occurred in all the alloys ; studied during irradiation were accounted for by the solid fission products ; produced. No further density changes took place in the ternary systems studied ; (U- Mo-- Si and U-- Mo-- Sn) when annealed at 650

  14. Reconstruction of solar irradiance since 1610: Implications for climate change

    Microsoft Academic Search

    Judith Lean; Juerg Beer; Raymond Bradley

    1995-01-01

    Solar total and ultraviolet (UV) irradiances are reconstructed annually from 1610 to the present. This epoch includes the Maunder Minimum of anomalously low solar activity (circa 1645-1715) and the subsequent increase to the high levels of the present Modern Maximum. In this reconstruction, the Schwabe (11-year) irradiance cycle and a longer term variability component are determined separately, based on contemporary

  15. Abortions by chronic gamma irradiation on the prenatal mouse

    E-print Network

    Kowalczyk, Wallace Matthew

    1968-01-01

    of Gestation VILi LIST. OF FIGURi. "S ~Fi ure Pa~e Fmbryonic Mortality Rate of t?e Control and Irradi. ated Grollps 25 Average dumber of Liv Embryos per Litter at 18. 5 Days Gestation for the Control and the Two Irradiated Groups 26 Rate of Abortions...

  16. Effect of Low Dose Gamma Irradiation together with Lipid A on Human Leukocytes Activities In Vitro

    NASA Astrophysics Data System (ADS)

    Belyakova, E.; Dubnickova, M.; Boreyko, A.

    2010-01-01

    The influence of gamma irradiation and of Lipid A from Escherichia coli on phagocytosis, lyzosyme and peroxidase activities of human leukocytes, in vitro was investigated. Leukocytes samples were irradiated with 1 and 5 Gy, respectively. The number of irradiated leukocytes was decreased in the irradiated samples. Only samples with additive Lipid A were not damaged by irradiation. The Lipid A had positive influence on biological activities of the irradiated leukocytes.

  17. ACL reconstruction with BPTB autograft and irradiated fresh frozen allograft*

    PubMed Central

    Sun, Kang; Tian, Shao-qi; Zhang, Ji-hua; Xia, Chang-suo; Zhang, Cai-long; Yu, Teng-bo

    2009-01-01

    Objective: To analyze the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with irradiated bone-patellar tendon-bone (BPTB) allograft compared with non-irradiated allograft and autograft. Methods: All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 mrad of irradiation prior to distribution. A total of 68 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into one of the two groups (autograft and irradiated allograft groups). The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months of follow-up (ranging from 24 to 47 months), patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results: Of these patients, 65 (autograft 33, irradiated allograft 32) were available for full evaluation. When the irradiated allograft group was compared to the autograft group at the 31-month follow-up by the Lachman test, the anterior drawer test (ADT), the pivot shift test, and KT-2000 arthrometer test, statistically significant differences were found. Most importantly, 87.8% of patients in the autograft group and just only 31.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee (IKDC), functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups. Besides, patients in the irradiated allograft group had a shorter operation time and a longer duration of postoperative fever. When the patients had a fever, the laboratory examinations of all patients were almost normal. Blood routine was normal, the values of erythrocyte sedimentation rate (ESR) were 5~16 mm/h and the contents of C reactive protein (CRP) were 3~10 mg/L. Conclusion: We conclude that the short term clinical outcomes of the ACL reconstruction with irradiated BPTB allograft were adversely affected. The less than satisfactory results led the senior authors to discontinue the use of irradiated BPTB allograft in ACL surgery and not to advocate using the gamma irradiation as a secondary sterilizing method. PMID:19353750

  18. Tuning the electronic band structure of PCBM by electron irradiation

    PubMed Central

    2011-01-01

    Tuning the electronic band structures such as band-edge position and bandgap of organic semiconductors is crucial to maximize the performance of organic photovoltaic devices. We present a simple yet effective electron irradiation approach to tune the band structure of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) that is the most widely used organic acceptor material. We have found that the lowest unoccupied molecular orbital (LUMO) level of PCBM up-shifts toward the vacuum energy level, while the highest occupied molecular orbital (HOMO) level down-shifts when PCBM is electron-irradiated. The shift of the HOMO and the LUMO levels increases as the irradiated electron fluence increases. Accordingly, the band-edge position and the bandgap of PCBM can be controlled by adjusting the electron fluence. Characterization of electron-irradiated PCBM reveals that the variation of the band structure is attributed to the molecular structural change of PCBM by electron irradiation. PMID:21970617

  19. Isothermal decomposition of gamma-irradiated palladium acetate

    NASA Astrophysics Data System (ADS)

    Mahfouz, R. M.; Alshehri, S. M.; Monshi, M. A. S.; Abd El-Salam, N. M.

    2004-06-01

    The isothermal decomposition of un-irradiated (pristine) and pre-gamma-irradiated palladium acetate was studied in the temperature range (498-508 K) and in air using the isothermal thermogravimetric technique. The data were analysed using various solid state reaction models. The results showed that the kinetics of isothermal decomposition of palladium acetate was governed by random nucleation reaction (Erofe'ev equation A(3)). The activation energies of the main decomposition process for un-irradiated and pre-gamma-irradiated samples were calculated. The change in texture and crystal structure of the investigated palladium acetate by gamma-irradiation was studied using electron microscopy and X-ray diffraction techniques.

  20. Isothermal decomposition of gamma-irradiated dysprosium acetate

    NASA Astrophysics Data System (ADS)

    Mahfouz, R. M.; Al-Shehri, S. M.; Monshi, M. A. S.; Abd El-Salam, N. M.

    Isothermal decomposition of un-irradiated and pre-gamma-irradiated dysprosium acetate [Dy(CH3COO)(3)] has been investigated at different temperatures between 603-623 K. Irradiation was observed to enhance the rate of decomposition without modifying the mechanism of the thermal decomposition. Thermal decomposition of dysposium acetate is shown to proceed by a nucleation and growth mechanism (Avarmi-Erofe'ev equation) both for un-irradiated and pre-gamma-irradiated samples. The enhancement of the decomposition was found to increase with an increase in the gamma-ray dose applied to the sample and may be attributed to an increase in point defects and formation of additional nucleation centers generated in the host lattice. Thermodynamic values of the main decomposition process were calculated and evaluated.