Sample records for radiat prot dosim

  1. Searching and Navigating UniProt Databases.

    PubMed

    Pundir, Sangya; Magrane, Michele; Martin, Maria J; O'Donovan, Claire

    2015-01-01

    The Universal Protein Resource (UniProt) is a comprehensive resource for protein sequence and annotation data. The UniProt Web site receives ?400,000 unique visitors per month and is the primary means to access UniProt. It provides ten searchable datasets and three main tools. The key UniProt datasets are the UniProt Knowledgebase (UniProtKB), the UniProt Reference Clusters (UniRef), the UniProt Archive (UniParc), and protein sets for completely sequenced genomes (Proteomes). Other supporting datasets include information about proteins that is present in UniProtKB protein entries such as literature citations, taxonomy, and subcellular locations, among others. This paper focuses on how to use UniProt datasets. The basic protocol describes navigation and searching mechanisms for the UniProt datasets, while two alternative protocols build on the basic protocol to describe advanced search and query building. © 2015 by John Wiley & Sons, Inc. PMID:26088053

  2. Activities at the Universal Protein Resource (UniProt)

    PubMed Central

    2014-01-01

    The mission of the Universal Protein Resource (UniProt) (http://www.uniprot.org) is to provide the scientific community with a comprehensive, high-quality and freely accessible resource of protein sequences and functional annotation. It integrates, interprets and standardizes data from literature and numerous resources to achieve the most comprehensive catalog possible of protein information. The central activities are the biocuration of the UniProt Knowledgebase and the dissemination of these data through our Web site and web services. UniProt is produced by the UniProt Consortium, which consists of groups from the European Bioinformatics Institute (EBI), the SIB Swiss Institute of Bioinformatics (SIB) and the Protein Information Resource (PIR). UniProt is updated and distributed every 4 weeks and can be accessed online for searches or downloads. PMID:24253303

  3. The UniProt-GO Annotation database in 2011.

    PubMed

    Dimmer, Emily C; Huntley, Rachael P; Alam-Faruque, Yasmin; Sawford, Tony; O'Donovan, Claire; Martin, Maria J; Bely, Benoit; Browne, Paul; Mun Chan, Wei; Eberhardt, Ruth; Gardner, Michael; Laiho, Kati; Legge, Duncan; Magrane, Michele; Pichler, Klemens; Poggioli, Diego; Sehra, Harminder; Auchincloss, Andrea; Axelsen, Kristian; Blatter, Marie-Claude; Boutet, Emmanuel; Braconi-Quintaje, Silvia; Breuza, Lionel; Bridge, Alan; Coudert, Elizabeth; Estreicher, Anne; Famiglietti, Livia; Ferro-Rojas, Serenella; Feuermann, Marc; Gos, Arnaud; Gruaz-Gumowski, Nadine; Hinz, Ursula; Hulo, Chantal; James, Janet; Jimenez, Silvia; Jungo, Florence; Keller, Guillaume; Lemercier, Phillippe; Lieberherr, Damien; Masson, Patrick; Moinat, Madelaine; Pedruzzi, Ivo; Poux, Sylvain; Rivoire, Catherine; Roechert, Bernd; Schneider, Michael; Stutz, Andre; Sundaram, Shyamala; Tognolli, Michael; Bougueleret, Lydie; Argoud-Puy, Ghislaine; Cusin, Isabelle; Duek-Roggli, Paula; Xenarios, Ioannis; Apweiler, Rolf

    2012-01-01

    The GO annotation dataset provided by the UniProt Consortium (GOA: http://www.ebi.ac.uk/GOA) is a comprehensive set of evidenced-based associations between terms from the Gene Ontology resource and UniProtKB proteins. Currently supplying over 100 million annotations to 11 million proteins in more than 360,000 taxa, this resource has increased 2-fold over the last 2 years and has benefited from a wealth of checks to improve annotation correctness and consistency as well as now supplying a greater information content enabled by GO Consortium annotation format developments. Detailed, manual GO annotations obtained from the curation of peer-reviewed papers are directly contributed by all UniProt curators and supplemented with manual and electronic annotations from 36 model organism and domain-focused scientific resources. The inclusion of high-quality, automatic annotation predictions ensures the UniProt GO annotation dataset supplies functional information to a wide range of proteins, including those from poorly characterized, non-model organism species. UniProt GO annotations are freely available in a range of formats accessible by both file downloads and web-based views. In addition, the introduction of a new, normalized file format in 2010 has made for easier handling of the complete UniProt-GOA data set. PMID:22123736

  4. Retrieving mutation-specific information for human proteins in UniProt/Swiss-Prot Knowledgebase.

    PubMed

    Yip, Yum Lina; Lachenal, Nathalie; Pillet, Violaine; Veuthey, Anne-Lise

    2007-12-01

    The UniProt/Swiss-Prot Knowledgebase records about 30,500 variants in 5,664 proteins (Release 52.2). Most of these variants are manually curated single amino acid polymorphisms (SAPs) with references to the literature. In order to keep the list of published documents related to SAPs up to date, an automatic information retrieval method is developed to recover texts mentioning SAPs. The method is based on the use of regular expressions (patterns) and rules for the detection and validation of mutations. When evaluated using a corpus of 9,820 PubMed references, the precision of the retrieval was determined to be 89.5% over all variants. It was also found that the use of nonstandard mutation nomenclature and sequence positional correction is necessary to retrieve a significant number of relevant articles. The method was applied to the 5,664 proteins with variants. This was performed by first submitting a PubMed query to retrieve articles using gene or protein names and a list of mutation-related keywords; the SAP detection procedure was then used to recover relevant documents. The method was found to be efficient in retrieving new references on known polymorphisms. New references on known SAPs will be rendered accessible to the public via the Swiss-Prot variant pages. PMID:18172926

  5. Genetic variations and diseases in UniProtKB/Swiss-Prot: the ins and outs of expert manual curation.

    PubMed

    Famiglietti, Maria Livia; Estreicher, Anne; Gos, Arnaud; Bolleman, Jerven; Géhant, Sébastien; Breuza, Lionel; Bridge, Alan; Poux, Sylvain; Redaschi, Nicole; Bougueleret, Lydie; Xenarios, Ioannis

    2014-08-01

    During the last few years, next-generation sequencing (NGS) technologies have accelerated the detection of genetic variants resulting in the rapid discovery of new disease-associated genes. However, the wealth of variation data made available by NGS alone is not sufficient to understand the mechanisms underlying disease pathogenesis and manifestation. Multidisciplinary approaches combining sequence and clinical data with prior biological knowledge are needed to unravel the role of genetic variants in human health and disease. In this context, it is crucial that these data are linked, organized, and made readily available through reliable online resources. The Swiss-Prot section of the Universal Protein Knowledgebase (UniProtKB/Swiss-Prot) provides the scientific community with a collection of information on protein functions, interactions, biological pathways, as well as human genetic diseases and variants, all manually reviewed by experts. In this article, we present an overview of the information content of UniProtKB/Swiss-Prot to show how this knowledgebase can support researchers in the elucidation of the mechanisms leading from a molecular defect to a disease phenotype. PMID:24848695

  6. Genetic Variations and Diseases in UniProtKB/Swiss-Prot: The Ins and Outs of Expert Manual Curation

    PubMed Central

    Famiglietti, Maria Livia; Estreicher, Anne; Gos, Arnaud; Bolleman, Jerven; Géhant, Sébastien; Breuza, Lionel; Bridge, Alan; Poux, Sylvain; Redaschi, Nicole; Bougueleret, Lydie; Xenarios, Ioannis

    2014-01-01

    During the last few years, next-generation sequencing (NGS) technologies have accelerated the detection of genetic variants resulting in the rapid discovery of new disease-associated genes. However, the wealth of variation data made available by NGS alone is not sufficient to understand the mechanisms underlying disease pathogenesis and manifestation. Multidisciplinary approaches combining sequence and clinical data with prior biological knowledge are needed to unravel the role of genetic variants in human health and disease. In this context, it is crucial that these data are linked, organized, and made readily available through reliable online resources. The Swiss-Prot section of the Universal Protein Knowledgebase (UniProtKB/Swiss-Prot) provides the scientific community with a collection of information on protein functions, interactions, biological pathways, as well as human genetic diseases and variants, all manually reviewed by experts. In this article, we present an overview of the information content of UniProtKB/Swiss-Prot to show how this knowledgebase can support researchers in the elucidation of the mechanisms leading from a molecular defect to a disease phenotype. PMID:24848695

  7. UNIVERSITA DWI,/ STUN DI Prot car: G .ii fl

    E-print Network

    Bella, Giampaolo

    UNIVERSITA DWI,/ STUN DI CATANIA Prot °car: G .ii fl 2 8 NM 2014 MASI Tit. .1(....CI. uecren /VC 4 della chiamata a professore di seconda fascia ai sensi dell'art. 24, comma 6, della legge 30.12.2010, n in ordine all'avvio della procedura di chiamata di professori di seconda fascia, ai sensi dell'art. 24

  8. DERECHOS DEL EMPLEADO LEy PARA LA PROtECCin

    E-print Network

    Rock, Chris

    DERECHOS DEL EMPLEADO LEy PARA LA PROtECCión DEL EMPLEADO COntRA LA PRuEbA DEL POLígRAfO PROHIBICIONES ExENCIONES DERECHOS DE LOS ExAMINADOS CUMPLIMIENTO Generalmente se le prohíbe al empleador que le aspirante a un trabajo por haberse negado a someterse a la prueba o por haberse acogido a otros derechos

  9. Analysis of the tryptic search space in UniProt databases

    PubMed Central

    Alpi, Emanuele; Griss, Johannes; da Silva, Alan Wilter Sousa; Bely, Benoit; Antunes, Ricardo; Zellner, Hermann; Ríos, Daniel; O'Donovan, Claire; Vizcaíno, Juan Antonio; Martin, Maria J

    2015-01-01

    In this article, we provide a comprehensive study of the content of the Universal Protein Resource (UniProt) protein data sets for human and mouse. The tryptic search spaces of the UniProtKB (UniProt knowledgebase) complete proteome sets were compared with other data sets from UniProtKB and with the corresponding International Protein Index, reference sequence, Ensembl, and UniRef100 (where UniRef is UniProt reference clusters) organism-specific data sets. All protein forms annotated in UniProtKB (both the canonical sequences and isoforms) were evaluated in this study. In addition, natural and disease-associated amino acid variants annotated in UniProtKB were included in the evaluation. The peptide unicity was also evaluated for each data set. Furthermore, the peptide information in the UniProtKB data sets was also compared against the available peptide-level identifications in the main MS-based proteomics repositories. Identifying the peptides observed in these repositories is an important resource of information for protein databases as they provide supporting evidence for the existence of otherwise predicted proteins. Likewise, the repositories could use the information available in UniProtKB to direct reprocessing efforts on specific sets of peptides/proteins of interest. In summary, we provide comprehensive information about the different organism-specific sequence data sets available from UniProt, together with the pros and cons for each, in terms of search space for MS-based bottom-up proteomics workflows. The aim of the analysis is to provide a clear view of the tryptic search space of UniProt and other protein databases to enable scientists to select those most appropriate for their purposes. PMID:25307260

  10. Radiators

    Microsoft Academic Search

    1985-01-01

    A heat-exchange radiator is connected to a fluid flow circuit by a connector which provides one member of an interengageable spigot and socket pair for push-fit, fluid-tight, engagement between the connector and the radiator, with latching formations at least one of which is resilient. Preferably the connector carries the spigot which tapers and engages with a socket of corresponding shape,

  11. Radiation 

    E-print Network

    Unknown

    2011-08-17

    State. s. ABSTRACT This study is an attempt to find a tentative atmospheric index of human comfort and to show its applications for the area of College Station~ Texas. Temperature, relative humidity~ air move- ment, and global short-wave radiation... (direct plus diffuse) were combined into a single numerical expression for outdoor human comfort. The contribution of global short-wave radiation to the heat load on man also is evaluated in a single numerical expression, and expressed as an equivalent...

  12. ProtEx: a toolkit for the analysis of distributed real-time systems 

    E-print Network

    Meylan, Yves Damien Meylan

    2000-01-01

    for the prototyping and schedulability analysis of distributed real-time systems. This toolkit focuses on a wider set of methodologies than the traditional RMA scheduling analysis tools. We also report on the design and implementation of ProtEx....

  13. The neXtProt knowledgebase on human proteins: current status

    PubMed Central

    Gaudet, Pascale; Michel, Pierre-André; Zahn-Zabal, Monique; Cusin, Isabelle; Duek, Paula D.; Evalet, Olivier; Gateau, Alain; Gleizes, Anne; Pereira, Mario; Teixeira, Daniel; Zhang, Ying; Lane, Lydie; Bairoch, Amos

    2015-01-01

    neXtProt (http://www.nextprot.org) is a human protein-centric knowledgebase developed at the SIB Swiss Institute of Bioinformatics. Focused solely on human proteins, neXtProt aims to provide a state of the art resource for the representation of human biology by capturing a wide range of data, precise annotations, fully traceable data provenance and a web interface which enables researchers to find and view information in a comprehensive manner. Since the introductory neXtProt publication, significant advances have been made on three main aspects: the representation of proteomics data, an extended representation of human variants and the development of an advanced search capability built around semantic technologies. These changes are presented in the current neXtProt update. PMID:25593349

  14. Dosimetric properties and stability of thermoluminescent foils made from LiF:Mg,Cu,P or CaSO4:Dy during long-term use

    NASA Astrophysics Data System (ADS)

    K?osowski, M.; Liszka, M.; Kope?, R.; Bilski, P.; K?dzierska, D.

    2014-11-01

    A few dosimetric systems based on thermoluminescence [TL] foils were developed in recent years (Nariyama et al. 2006, Radiat. Prot. Dosim. 120, 213-218; Olko et al. 2006 Radiat. Prot. Dosim. 118, 213-218) (Czopyk et al. 2008, Radiat. Meas., 43, 977-980; K?osowski et al. 2010, Radiat. Meas., 45, 719-721; Kope? et al. 2013, Radiat.Meas., 56, 380-383). Major application of these systems is mapping of 2D dose distribution for medical treatment plan verification, similarly to photochromic or radiochromic films. The advantage of TL foils compared to other films is their re-usability. In this work we present dosimetric properties as dose linearity and fadding of the foils made from LiF:Mg,Cu,P or CaSO4:Dy phosphors and high temperature polymers. Both types of the foils have good linearity in the range 1-20 Gy for LiF:Mg,Cu,P and 0.1-2 Gy for CaSO4:Dy. Their long term fading does not exceed 3.7% and 9% respectively. We additionally investigated effects of sensitivity loss and emission spectra for both types of the foils. One shortcoming of TL foils is that every heat process may have negative influence on their properties, causing changes of their sensitivity. Register signal of the foils after 15 readouts may be reduced by 16% of the initial. We consider that the main reason of these changes is oxidation of organic contamination on the surface and degradation of a polymer which is one of the components of the foils. Effect of sensitivity decreasing may be slowed down by proper use and cleaning detectors by solvent.

  15. Radiation

    Microsoft Academic Search

    Erik Seedhouse

    \\u000a It is more than forty years since astronauts ventured beyond Earth’s protective magnetic shield and travelled to the Moon.\\u000a Although the Apollo missions subjected astronauts to space radiation, the short duration minimized the risk, but an ECM will\\u000a subject astronauts to much longer exposure. In fact, astronauts will be in deep space for so long, they will run the risk

  16. Thermostable bacterial endoglucanases mined from SWISS-PROT database.

    PubMed

    Qiu, Li-Huan; Li, Chun-Xiu; Sun, Jie; Wang, Zhilong; Ye, Qin; Xu, Jian-He

    2011-12-01

    As one critical enzyme in deconstructing complicated cellulose matrix, endoglucanase (EG) is needed to exhibit high activity and thermostability under severe industrial conditions. Driven by this purpose, EGtf1 (Q08166) and EGtf2 (Q7X2N2), with relatively high specific activities, were selected out of 43 putative EG genes from SWISS-PROT database. These distinguished EGs were successfully overexpressed in Escherichia coli and purified by one-step affinity chromatography. The maximal activity was shown at approximate pH 5.0 and 50 °C. It is worth noting that EGtf1 and EGtf2 displayed outstanding thermostability with a half-life of up to 1,386 h at 50 °C, which is almost 100-fold higher than other reported EGs. Furthermore, the presence of various metal ions (1 mM) or organic solvents (50%, v/v) did not cause significant effect on the activities of EGtf1 and EGtf2 and even showed 2.1- and 2.7-fold enhancement in the case of dodecanol. All these features, especially the excellent thermostability of EGtf1 and EGtf2, enable them to become a good candidate for further protein engineering to realize the ultimate practical application in biomass industry. PMID:21989797

  17. J Radiol Prot. Author manuscript Childhood leukaemia incidence below the age of 5 years near French

    E-print Network

    Paris-Sud XI, Université de

    J Radiol Prot. Author manuscript Page /1 3 Childhood leukaemia incidence below the age of 5 years Abstract A recent study indicated an excess risk of leukaemia among children results about the incidence of childhood leukaemia in the vicinity of nuclear power plants in France

  18. SOFTWARE Open Access GPS-Prot: A web-based visualization platform for

    E-print Network

    Martin, Gail

    /purification combined with mass spectrometry (AP-MS) [9], which have been successfully used in other systems [10SOFTWARE Open Access GPS-Prot: A web-based visualization platform for integrating host, including both physical and genetic interactions, has created a need for software tools to integrate

  19. Pro...t with Purpose? A Theory of Social Enterprise with

    E-print Network

    Royal Holloway, University of London

    . This paper develops a model of social enterprise based on selection of citizen-managers with this goalPro...t with Purpose? A Theory of Social Enterprise with Experimental Evidence Timothy Besley LSE organization which se- lects managers based on motivation can be used to balance pro...ts with a social purpose

  20. Data-poor categorization and passage retrieval for Gene Ontology Annotation in Swiss-Prot

    PubMed Central

    Ehrler, Frédéric; Geissbühler, Antoine; Jimeno, Antonio; Ruch, Patrick

    2005-01-01

    Background In the context of the BioCreative competition, where training data were very sparse, we investigated two complementary tasks: 1) given a Swiss-Prot triplet, containing a protein, a GO (Gene Ontology) term and a relevant article, extraction of a short passage that justifies the GO category assignement; 2) given a Swiss-Prot pair, containing a protein and a relevant article, automatic assignement of a set of categories. Methods Sentence is the basic retrieval unit. Our classifier computes a distance between each sentence and the GO category provided with the Swiss-Prot entry. The Text Categorizer computes a distance between each GO term and the text of the article. Evaluations are reported both based on annotator judgements as established by the competition and based on mean average precision measures computed using a curated sample of Swiss-Prot. Results Our system achieved the best recall and precision combination both for passage retrieval and text categorization as evaluated by official evaluators. However, text categorization results were far below those in other data-poor text categorization experiments The top proposed term is relevant in less that 20% of cases, while categorization with other biomedical controlled vocabulary, such as the Medical Subject Headings, we achieved more than 90% precision. We also observe that the scoring methods used in our experiments, based on the retrieval status value of our engines, exhibits effective confidence estimation capabilities. Conclusion From a comparative perspective, the combination of retrieval and natural language processing methods we designed, achieved very competitive performances. Largely data-independent, our systems were no less effective that data-intensive approaches. These results suggests that the overall strategy could benefit a large class of information extraction tasks, especially when training data are missing. However, from a user perspective, results were disappointing. Further investigations are needed to design applicable end-user text mining tools for biologists. PMID:15960836

  1. EasyProt--an easy-to-use graphical platform for proteomics data analysis.

    PubMed

    Gluck, Florent; Hoogland, Christine; Antinori, Paola; Robin, Xavier; Nikitin, Frederic; Zufferey, Anne; Pasquarello, Carla; Fétaud, Vanessa; Dayon, Loïc; Müller, Markus; Lisacek, Frederique; Geiser, Laurent; Hochstrasser, Denis; Sanchez, Jean-Charles; Scherl, Alexander

    2013-02-21

    High throughput protein identification and quantification analysis based on mass spectrometry are fundamental steps in most proteomics projects. Here, we present EasyProt (available at http://easyprot.unige.ch), a new platform for mass spectrometry data processing, protein identification, quantification and unexpected post-translational modification characterization. EasyProt provides a fully integrated graphical experience to perform a large part of the proteomic data analysis workflow. Our goal was to develop a software platform that would fulfill the needs of scientists in the field, while emphasizing ease-of-use for non-bioinformatician users. Protein identification is based on OLAV scoring schemes and protein quantification is implemented for both, isobaric labeling and label-free methods. Additional features are available, such as peak list processing, isotopic correction, spectra filtering, charge-state deconvolution and spectra merging. To illustrate the EasyProt platform, we present two identification and quantification workflows based on isobaric tagging and label-free methods. PMID:23277275

  2. ProtPhylo: identification of protein–phenotype and protein–protein functional associations via phylogenetic profiling

    PubMed Central

    Cheng, Yiming; Perocchi, Fabiana

    2015-01-01

    ProtPhylo is a web-based tool to identify proteins that are functionally linked to either a phenotype or a protein of interest based on co-evolution. ProtPhylo infers functional associations by comparing protein phylogenetic profiles (co-occurrence patterns of orthology relationships) for more than 9.7 million non-redundant protein sequences from all three domains of life. Users can query any of 2048 fully sequenced organisms, including 1678 bacteria, 255 eukaryotes and 115 archaea. In addition, they can tailor ProtPhylo to a particular kind of biological question by choosing among four main orthology inference methods based either on pair-wise sequence comparisons (One-way Best Hits and Best Reciprocal Hits) or clustering of orthologous proteins across multiple species (OrthoMCL and eggNOG). Next, ProtPhylo ranks phylogenetic neighbors of query proteins or phenotypic properties using the Hamming distance as a measure of similarity between pairs of phylogenetic profiles. Candidate hits can be easily and flexibly prioritized by complementary clues on subcellular localization, known protein–protein interactions, membrane spanning regions and protein domains. The resulting protein list can be quickly exported into a csv text file for further analyses. ProtPhylo is freely available at http://www.protphylo.org. PMID:25956654

  3. ProtPhylo: identification of protein-phenotype and protein-protein functional associations via phylogenetic profiling.

    PubMed

    Cheng, Yiming; Perocchi, Fabiana

    2015-07-01

    ProtPhylo is a web-based tool to identify proteins that are functionally linked to either a phenotype or a protein of interest based on co-evolution. ProtPhylo infers functional associations by comparing protein phylogenetic profiles (co-occurrence patterns of orthology relationships) for more than 9.7 million non-redundant protein sequences from all three domains of life. Users can query any of 2048 fully sequenced organisms, including 1678 bacteria, 255 eukaryotes and 115 archaea. In addition, they can tailor ProtPhylo to a particular kind of biological question by choosing among four main orthology inference methods based either on pair-wise sequence comparisons (One-way Best Hits and Best Reciprocal Hits) or clustering of orthologous proteins across multiple species (OrthoMCL and eggNOG). Next, ProtPhylo ranks phylogenetic neighbors of query proteins or phenotypic properties using the Hamming distance as a measure of similarity between pairs of phylogenetic profiles. Candidate hits can be easily and flexibly prioritized by complementary clues on subcellular localization, known protein-protein interactions, membrane spanning regions and protein domains. The resulting protein list can be quickly exported into a csv text file for further analyses. ProtPhylo is freely available at http://www.protphylo.org. PMID:25956654

  4. 2009; doi: 10.1101/pdb.prot5252Cold Spring Harb Protoc Katherine E. Varley and Robi D. Mitra

    E-print Network

    Mitra, Rob

    2009; doi: 10.1101/pdb.prot5252Cold Spring Harb Protoc Katherine E. Varley and Robi D. Mitra Loci.Receive free email alerts when new articles cite this article - Categories Subject Cold Spring Harbor Protocols.Browse articles on similar topics from (136 articles)Polymerase Chain Reaction (PCR), general (61 articles

  5. Annotation of protein residues based on a literature analysis: cross-validation against UniProtKb

    Microsoft Academic Search

    Kevin Nagel; Antonio Jimeno-Yepes; Dietrich Rebholz-Schuhmann

    2009-01-01

    BACKGROUND: A protein annotation database, such as the Universal Protein Resource knowledge base (UniProtKb), is a valuable resource for the validation and interpretation of predicted 3D structure patterns in proteins. Existing studies have focussed on point mutation extraction methods from biomedical literature which can be used to support the time consuming work of manual database curation. However, these methods were

  6. doi: 10.1101/pdb.prot077149Cold Spring Harb Protoc; Edward S. Ruthazer, Anne Schohl, Neil Schwartz, Aydin Tavakoli, Marc Tremblay and Hollis T.

    E-print Network

    Ruthazer, Edward

    doi: 10.1101/pdb.prot077149Cold Spring Harb Protoc; Cline Edward S. Ruthazer, Anne Schohl, Neil of Live Xenopus Tadpoles by Electroporation of Dyes or DNA Edward S. Ruthazer, Anne Schohl, Neil Schwartz

  7. doi: 10.1101/pdb.prot076471Cold Spring Harb Protoc; Edward S. Ruthazer, Anne Schohl, Neil Schwartz, Aydin Tavakoli, Marc Tremblay and Hollis T.

    E-print Network

    Ruthazer, Edward

    doi: 10.1101/pdb.prot076471Cold Spring Harb Protoc; Cline Edward S. Ruthazer, Anne Schohl, Neil. Ruthazer, Anne Schohl, Neil Schwartz, Aydin Tavakoli, Marc Tremblay, and Hollis T. Cline Individual neurons

  8. KnotProt: a database of proteins with knots and slipknots

    PubMed Central

    Jamroz, Michal; Niemyska, Wanda; Rawdon, Eric J.; Stasiak, Andrzej; Millett, Kenneth C.; Su?kowski, Piotr; Sulkowska, Joanna I.

    2015-01-01

    The protein topology database KnotProt, http://knotprot.cent.uw.edu.pl/, collects information about protein structures with open polypeptide chains forming knots or slipknots. The knotting complexity of the cataloged proteins is presented in the form of a matrix diagram that shows users the knot type of the entire polypeptide chain and of each of its subchains. The pattern visible in the matrix gives the knotting fingerprint of a given protein and permits users to determine, for example, the minimal length of the knotted regions (knot's core size) or the depth of a knot, i.e. how many amino acids can be removed from either end of the cataloged protein structure before converting it from a knot to a different type of knot. In addition, the database presents extensive information about the biological functions, families and fold types of proteins with non-trivial knotting. As an additional feature, the KnotProt database enables users to submit protein or polymer chains and generate their knotting fingerprints. PMID:25361973

  9. ProtNA-ASA: Protein-nucleic acid structural database with information on accessible surface area

    NASA Astrophysics Data System (ADS)

    Tkachenko, M. Y.; Boryskina, O. P.; Shestopalova, A. V.; Tolstorukov, M. Y.

    The article describes a new database (ProtNA-ASA), which combines the data on conformational parameters of nucleic acids and calculations of the accessible surface area (ASA) of nucleic acid atoms in protein-DNA/RNA complexes. As for October 2008, the database contains 214 DNA-protein and 28 RNA-protein non-homologous complexes. The database provides structural parameters that describe local geometry of base pairs and base-pair steps as well as backbone torsion angles. Additionally, total ASA of DNA/RNA atoms and the accessible area of atoms in the minor and major grooves are calculated. ProtNA-ASA database facilitates studying the relationship between the DNA/RNA conformation and availability of atoms for contact with proteins either in major or in minor groove for different nucleotides. Such an analysis is important for understanding the principles of molecular recognition including indirect sequence readout. The database is publicly available for use at http://www.protna.bio-page.org.

  10. Secretion and Purification of Recombinant ?1-4 Galactosyltransferase from Insect Cells Using pFmel-protA, a Novel Transposition-Based Baculovirus Transfer Vector

    Microsoft Academic Search

    Dapeng Zhou; Martine Malissard; Eric G. Berger; Thierry Hennet

    2000-01-01

    The palette of transfer vectors available for generation of recombinant baculoviruses based on transposition-mediated recombination has been enlarged by constructing the pFmel–protA vector. The pFmel–protA plasmid includes the honeybee melittin secretion signal and a Staphylococcus aureus protein A fusion protein tag, which allows the secretion and purification of recombinant proteins. Using this system, the human ?1-4 galactosyltransferase-I protein was expressed

  11. Radiation Symbols

    MedlinePLUS

    Radiation Protection Basics Health Effects Ionizing & Non-Ionizing Radiation Understanding Radiation: Radiation Symbols Radiation Protection Basics Main Page History of Radiation Protection Radiation Warning Symbols Radiation Warning Sign Gallery ...

  12. MAPS BANDING Sheet Location Band Size Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS BANDING Sheet Location Band Size Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC.COVS PRIMARIES SECONDS TERTIALS

  13. MAPS BANDING Sheet Location Band Size Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS BANDING Sheet Location Band Size Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR

  14. MAPS UNBANDED Sheet Location Band Size U Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS UNBANDED Sheet Location Band Size U Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull BAND NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT

  15. MAPS BANDING Sheet Location Band Size Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS BANDING Sheet Location Band Size Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull S Feather NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR

  16. MAPS UNBANDED Sheet Location Band Size U Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS UNBANDED Sheet Location Band Size U Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

  17. MAPS RECAPTURES Sheet Location Band Size R Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS RECAPTURES Sheet Location Band Size R Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI

  18. MAPS UNBANDED Sheet Location Band Size U Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS UNBANDED Sheet Location Band Size U Year 2012 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

  19. MAPS RECAPTURES Sheet Location Band Size R Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS RECAPTURES Sheet Location Band Size R Year Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI

  20. MAPS RECAPTURES Sheet Location Band Size R Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS RECAPTURES Sheet Location Band Size R Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI

  1. MAPS BANDING Sheet Location Band Size Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS BANDING Sheet Location Band Size Year 2013 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Local 4 Skull NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR

  2. MAPS UNBANDED Sheet Location Band Size U Year 2014 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS UNBANDED Sheet Location Band Size U Year 2014 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Local 4 Skull HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

  3. MAPS RECAPTURES Sheet Location Band Size R Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    MAPS RECAPTURES Sheet Location Band Size R Year 2011 Page # CODE AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Local 4 Skull BANDER'S INITIALS CODE BAND NUMBER SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR

  4. Characterisation of OSL and OSLN droplets for dosimetry.

    PubMed

    Nascimento, L F; D'Agostino, E; Vaniqui, A C S; Saldarriaga, C; Vanhavere, F; De Deene, Y

    2014-10-01

    In spite of considerable progress in neutron dosimetry, there is no dosemeter that is capable of measuring neutron doses independently of the neutron spectrum with good accuracy. Carbon-doped aluminium oxide (Al2O3:C) is a sensitive material for ionising radiation (beta-ray, X ray and electron) and has been used for applications in personal and medical dosimetry as an optically stimulated luminescence (OSL) dosemeter. Al2O3:C has a low sensitivity to neutron radiation; this prevents its application to neutron fields, representing a disadvantage of Al2O3:C-OSL when compared with LiF, which is used as a thermoluminescent detector. Recently an improvement for neutron dosimetry (Passmore and Kirr. Neutron response characterisation of an OSL neutron dosemeter. Radiat. Prot. Dosim. 2011; 144: 155-60) uses Al2O3:C coated with (6)Li2CO3 (OSLN),which gives the high-sensitive response as known for Al2O3:C with the advantage of being also sensitive to thermal neutrons. In this article, the authors compare small-size detectors (droplets) of Al2O3:C (OSL) and of Al2O3:C+(6)Li2CO3 (OSLN) and discuss the advantages and drawbacks of both materials, regarding size vs. response. PMID:24381203

  5. Measurement of dose equivalent distribution on-board commercial jet aircraft.

    PubMed

    Kuban?ák, J; Ambrožová, I; Ploc, O; Pachnerová Brabcová, K; Št?pán, V; Uchihori, Y

    2014-12-01

    The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them [International Commission on Radiation Protection. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21: (1-3), (1991)]. According to the Monte Carlo simulations [Battistoni, G., Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the doses to aircrew members taking into consideration the aircraft structures. Adv. Space Res. 36: , 1645-1652 (2005) and Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the influence of aircraft shielding on the aircrew exposure through an aircraft mathematical model. Radiat. Prot. Dosim. 108: (2), 91-105 (2004)], the ambient dose equivalent rate H?*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate H?*(10) on-board selected types of aircraft. The authors found that H?*(10) values are higher in the front and the back of the cabin and lesser in the middle of the cabin. Moreover, total dosimetry characteristics obtained in this way are in a reasonable agreement with other data, in particular with the above-mentioned simulations. PMID:24344348

  6. Computational analysis of position-dependent disorder content in DisProt database.

    PubMed

    Kova?evi?, Jovana J

    2012-06-01

    A bioinformatics analysis of disorder content of proteins from the DisProt database has been performed with respect to position of disordered residues. Each protein chain was divided into three parts: N- and C- terminal parts with each containing 30 amino acid (AA) residues and the middle region containing the remaining AA residues. The results show that in terminal parts, the percentage of disordered AA residues is higher than that of all AA residues (17% of disordered AA residues and 11% of all). We analyzed the percentage of disorder for each of 20 AA residues in the three parts of proteins with respect to their hydropathy and molecular weight. For each AA, the percentage of disorder in the middle part is lower than that in terminal parts which is comparable at the two termini. A new scale of AAs has been introduced according to their disorder content in the middle part of proteins: CIFWMLYHRNVTAGQDSKEP. All big hydrophobic AAs are less frequently disordered, while almost all small hydrophilic AAs are more frequently disordered. The results obtained may be useful for construction and improving predictors for protein disorder. PMID:22917189

  7. ProtSweep, 2Dsweep and DomainSweep: protein analysis suite at DKFZ

    PubMed Central

    del Val, C.; Ernst, P.; Falkenhahn, M; Fladerer, C.; Glatting, K. H.; Suhai, S.; Hotz-Wagenblatt, A.

    2007-01-01

    The wealth of transcript information that has been made publicly available in recent years has led to large pools of individual web sites offering access to bioinformatics software. However, finding out which services exist, what they can or cannot do, how to use them and how to feed results from one service to the next one in the right format can be very time and resource consuming, especially for non-experts. Automating this task, we present a suite of protein annotation pipelines (tasks) developed at the German Cancer Research Centre (DKFZ) oriented to protein annotation by homology (ProtSweep), by domain analysis (DomainSweep), and by secondary structure elements (2Dsweep). The aim of these tasks is to perform an exhaustive structural and functional analysis employing a wide variety of methods in combination with the most updated public databases. The three servers are available for academic users at the HUSAR open server http://genius.embnet.dkfz-heidelberg.de/menu/biounit/open-husar/ PMID:17526514

  8. MoSI BANDING Sheet Location Band Size Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP New Band N Male M Local 4 Skull S Feather Wear F None 0 None 0 None 0 None 0 None 0 None N None 0 Juvenal J CODE BAND NUMBER SPECIES NAME SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT

  9. Radiation dosimetry.

    PubMed Central

    Cameron, J

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists. PMID:2040250

  10. Radiation therapy

    MedlinePLUS

    Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. ... radiation is most harmful to quickly growing cells, radiation therapy damages cancer cells more than normal cells. This ...

  11. Atmospheric radiation

    SciTech Connect

    Harshvardhan, M.R. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

    1991-01-01

    Studies of atmospheric radiative processes are summarized for the period 1987-1990. Topics discussed include radiation modeling; clouds and radiation; radiative effects in dynamics and climate; radiation budget and aerosol effects; and gaseous absorption, particulate scattering and surface reflection. It is concluded that the key developments of the period are a defining of the radiative forcing to the climate system by trace gases and clouds, the recognition that cloud microphysics and morphology need to be incorporated not only into radiation models but also climate models, and the isolation of a few important unsolved theoretical problems in atmospheric radiation.

  12. Application of InterPro for the functional classification of the proteins of fish origin in SWISS-PROT and TrEMBL

    Microsoft Academic Search

    Margaret Biswas; Alex Kanapin; Rolf Apweiler

    2001-01-01

    InterPro (http:\\/\\/www.ebi.ac.uk\\/interpro\\/) is an integrated documentation resource for protein families, domains and sites,\\u000a developed initially as a means of rationalizing the complementary efforts of the PROSITE, PRINTS, Pfam and ProDom database\\u000a projects. It is a useful resource that aids the functional classification of proteins. Almost 90% of theactinopterygii protein sequences from SWISS-PROT and TrEMBL can be classified using InterPro. Over

  13. Radiation Hydrodynamics

    Microsoft Academic Search

    Castor

    2003-01-01

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore

  14. Radiation Exposure

    MedlinePLUS

    Radiation is energy that travels in the form of waves or high-speed particles. It occurs naturally in sunlight. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment. If you are exposed to small amounts of radiation over a ...

  15. Radiation proctopathy.

    PubMed

    Grodsky, Marc B; Sidani, Shafik M

    2015-06-01

    Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options. PMID:26034407

  16. Hoja para Aves sin Anillar MoSI Localidad Tamao de anillo U Temporada (p.ej. 2009-10) Pgina # CDIGO SEXO EDAD COMO DETERMINAR LA EDAD Y EL SEXO CRNEO PROT. CLOAC. PARCH. DE INC. GRASA MUDA CUERP. MUDA PL. VUEL. DESGAS. VUEL. LIM. DE MUDA Y PL. TENDENCIA

    E-print Network

    DeSante, David F.

    # CÓDIGO SEXO EDAD COMO DETERMINAR LA EDAD Y EL SEXO CRÁNEO PROT. CLOAC. PARCH. DE INC. GRASA MUDA CUERP SEXO ALFA DELA ESPECIE ANILLOS DE COLORES Lesión vieja, cicatrizad. Herida o enfermedad INICIALESDEL

  17. MoSI RECAPTURES Sheet Location Band Size R Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Recapture R Male M Local 4 Skull S Feather Wear F None 0 None 0 None 0 None 0 None 0 None N None 0 Juvenal J SPECIES NAME SPECIES ALPHA CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT

  18. MoSI UNBANDED Sheet Location Band Size U Season (e.g. 2009-10) Page # CODE SEX AGE HOW AGED AND HOW SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP

    E-print Network

    DeSante, David F.

    SEXED SKULL CL. PROT. BR. PATCH FAT BODY MLT FF MOLT FF WEAR MOLT LIMITS & PLUMAGE DISP Only use 'U' for Male M Local 4 Skull S Feather Wear F None 0 None 0 None 0 None 0 None 0 None N None 0 Juvenal J CODE AGE HOW AGED SEX HOW SEXED SKULL CL.PROT. BR.PATCH FAT BODYMLT FFMOLT FFWEAR JUV.PL. PRI.COVS SEC

  19. Radiation esophagitis.

    PubMed

    Murro, Diana; Jakate, Shriram

    2015-06-01

    The esophagus is frequently exposed to radiation during treatment of advanced stages of common cancers such as lung, breast, and esophagus. However, symptomatic radiation esophagitis requiring endoscopic and histologic evaluation occurs quite rarely, affecting less than 1% of patients receiving radiation treatment. Symptoms occur acutely, generally within the first 2 months. Patients typically present with nonspecific symptoms such as dysphagia and odynophagia. Endoscopic changes such as erythema and ulceration are also nonspecific and nondiagnostic. Biopsies from affected areas show variable inflammatory changes and radiation-related atypia of endothelial and stromal cells. Such atypia mimics cytomegalovirus cytopathic changes, which are ruled out through absence of immunostaining. Radiation esophagitis is thus clinically unsuspected and endoscopically and histologically quite different from the more common and familiar radiation proctitis for which angioectasia is the predominant finding. PMID:26030254

  20. Hawking radiation

    NASA Astrophysics Data System (ADS)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  1. RADIATION BALANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The balance of energy on the earth's surface represents the difference between incoming and outgoing radiation. There are two components in both the incoming and ongoing fractions and are separated by wavelength as shortwave (less than 5 um) and longwave (greater than 5 um). Shortwave radiation or...

  2. Radiation pager

    Microsoft Academic Search

    John L. Warren; Kenneth G. Vadnais

    1997-01-01

    Recent advances in miniature photomultiplier tubes and low power electronics have made possible a new generation of small gamma-ray radiation detectors specifically designed for use by government and law enforcement agencies for the detection and interdiction of concealed nuclear materials. This paper describes an inexpensive pager sized radiation detector that can be worn on the belt or carried in a

  3. Radiation Fronts

    Microsoft Academic Search

    A. R. Fraser

    1958-01-01

    When intense thermal radiation penetrates into a cold fluid the front separating hot and cold fluid may be well defined. When this is so, conservation laws, similar to those which are used across a shock front, can be applied to the radiation front. These conservation laws, together with the second law of thermodynamics, are used to classify the types of

  4. Understanding Radiation.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Nuclear Energy Office.

    Radiation is a natural energy force that has been a part of the environment since the Earth was formed. It takes various forms, none of which can be smelled, tasted, seen, heard, or felt. Nevertheless, scientists know what it is, where it comes from, how to measure and detect it, and how it affects people. Cosmic radiation from outer space and…

  5. Diffuse radiation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A diffuse celestial radiation which is isotropic at least on a course scale were measured from the soft X-ray region to about 150 MeV, at which energy the intensity falls below that of the galactic emission for most galactic latitudes. The spectral shape, the intensity, and the established degree of isotropy of this diffuse radiation already place severe constraints on the possible explanations for this radiation. Among the extragalactic theories, the more promising explanations of the isotropic diffuse emission appear to be radiation from exceptional galaxies from matter antimatter annihilation at the boundaries of superclusters of galaxies of matter and antimatter in baryon symmetric big bang models. Other possible sources for extragalactic diffuse gamma radiation are discussed and include normal galaxies, clusters of galaxies, primordial cosmic rays interacting with intergalactic matter, primordial black holes, and cosmic ray leakage from galaxies.

  6. Radiation dosimeter

    DOEpatents

    Fox, Richard J. (Oak Ridge, TN)

    1983-01-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  7. Radiation Balance

    NSDL National Science Digital Library

    Radiation Balance challenges students to "become a meteorologist" and make predictions about the relationships among ground cover, time of day, altitude and temperature. It is a simulation of radiation processes in the earth's atmosphere caused by solar, terrestrial, and atmospheric radiation transfer. Students analyze temperature data measured by a balloon (radiosonde) that they "launch" both in the morning and evening over four types of terrain (sand, plowed field, grass or fresh snow). As the balloon is dragged and dropped to various heights in the simulated atmosphere, the temperatures at these altitudes are automatically plotted on a graph. Several temperature profiles may be plotted concurrently to compare differences before clearing the graph.

  8. Radiation Therapy

    MedlinePLUS

    ... esophagitis . Since your body uses a lot of energy to heal during radiation therapy, it is important ... surprised if you are more tired, have less energy, or feel weak. Once you have finished treatment, ...

  9. Radiation Glossary

    MedlinePLUS

    ... also discusses radiation protection related to it. Binding Energy(cosmic glue) the amount of energy required to break up a nucleus into its constituent parts, or conversely, the energy released upon formation of the nucleus By-Product ...

  10. CutProtFam-Pred: detection and classification of putative structural cuticular proteins from sequence alone, based on profile hidden Markov models.

    PubMed

    Ioannidou, Zoi S; Theodoropoulou, Margarita C; Papandreou, Nikos C; Willis, Judith H; Hamodrakas, Stavros J

    2014-09-01

    The arthropod cuticle is a composite, bipartite system, made of chitin ?laments embedded in a proteinaceous matrix. The physical properties of cuticle are determined by the structure and the interactions of its two major components, cuticular proteins (CPs) and chitin. The proteinaceous matrix consists mainly of structural cuticular proteins. The majority of the structural proteins that have been described to date belong to the CPR family, and they are identified by the conserved R&R region (Rebers and Riddiford Consensus). Two major subfamilies of the CPR family RR-1 and RR-2, have also been identified from conservation at sequence level and some correlation with the cuticle type. Recently, several novel families, also containing characteristic conserved regions, have been described. The package HMMER v3.0 (http://hmmer.janelia.org/) was used to build characteristic pro?le Hidden Markov Models based on the characteristic regions for 8 of these families, (CPF, CPAP3, CPAP1, CPCFC, CPLCA, CPLCG, CPLCW, Tweedle). In brief, these families can be described as having: CPF (a conserved region with 44 amino acids); CPAP1 and CPAP-3 (analogous to peritrophins, with 1 and 3 chitin-binding domains, respectively); CPCFC (2 or 3 C-x(5)-C repeats); and four of five low complexity (LC) families, each with characteristic domains. Using these models, as well as the models previously created for the two major subfamilies of the CPR family, RR-1 and RR-2 (Karouzou et al., 2007), we developed CutProtFam-Pred, an on-line tool (http://bioinformatics.biol.uoa.gr/CutProtFam-Pred) that allows one to query sequences from proteomes or translated transcriptomes, for the accurate detection and classification of putative structural cuticular proteins. The tool has been applied successfully to diverse arthropod proteomes including a crustacean (Daphnia pulex) and a chelicerate (Tetranychus urticae), but at this taxonomic distance only CPRs and CPAPs were recovered. PMID:24978609

  11. Synchrotron radiation

    SciTech Connect

    Knotek, M.L.

    1987-01-01

    Synchrotron radiation has had a revolutionary effect on a broad range of scientific studies, from physics, chemistry and metallurgy to biology, medicine and geoscience. The situation during the last decade has been one of very rapid growth, there is a great vitality to the field and a capability has been given to a very broad range of scientific disciplines which was undreamed of just a decade or so ago. Here we will discuss some of the properties of synchrotron radiation that makes it so interesting and something of the sources in existence today including the National Synchrotron Light Source (NSLS). The NSLS is one of the new facilities built specifically for synchrotron radiation research and the model that was developed there for involvement of the scientific community is a good one which provides some good lessons for these facilities and others.

  12. Radiation receiver

    DOEpatents

    Hunt, A.J.

    1983-09-13

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.

  13. Radiation accidents.

    PubMed

    Saenger, E L

    1986-09-01

    It is essential that emergency physicians understand ways to manage patients contaminated by radioactive materials and/or exposed to external radiation sources. Contamination accidents require careful surveys to identify the metabolic pathway of the radionuclides to guide prognosis and treatment. The level of treatment required will depend on careful surveys and meticulous decontamination. There is no specific therapy for the acute radiation syndrome. Prophylactic antibodies are desirable. For severely exposed patients treatment is similar to the supportive care given to patients undergoing organ transplantation. For high-dose extremity injury, no methods have been developed to reverse the fibrosing endarteritis that eventually leads to tissue death so frequently found with this type of injury. Although the Three Mile Island episode of March 1979 created tremendous public concern, there were no radiation injuries. The contamination outside the reactor building and the release of radioiodine were negligible. The accidental fuel element meltdown at Chernobyl, USSR, resulted in many cases of acute radiation syndrome. More than 100,000 people were exposed to high levels of radioactive fallout. The general principles outlined here are applicable to accidents of that degree of severity. PMID:3526994

  14. RADIATION COUNTER

    Microsoft Academic Search

    C. L. Jr

    1962-01-01

    A liquid scintillation counter is designed for commercial and industrial ; application. The scintillator liquid is contained within a casing, whlch is ; coated on lts outside with a white material for optimum light refiection. The ; casing may be sectionalized for particular application, e.g., discrimination of ; Co⁶° gamma radiation from background, and may be in the form of

  15. Radiation accidents

    SciTech Connect

    Saenger, E.L.

    1986-09-01

    It is essential that emergency physicians understand ways to manage patients contaminated by radioactive materials and/or exposed to external radiation sources. Contamination accidents require careful surveys to identify the metabolic pathway of the radionuclides to guide prognosis and treatment. The level of treatment required will depend on careful surveys and meticulous decontamination. There is no specific therapy for the acute radiation syndrome. Prophylactic antibodies are desirable. For severely exposed patients treatment is similar to the supportive care given to patients undergoing organ transplantation. For high-dose extremity injury, no methods have been developed to reverse the fibrosing endarteritis that eventually leads to tissue death so frequently found with this type of injury. Although the Three Mile Island episode of March 1979 created tremendous public concern, there were no radiation injuries. The contamination outside the reactor building and the release of radioiodine were negligible. The accidental fuel element meltdown at Chernobyl, USSR, resulted in many cases of acute radiation syndrome. More than 100,000 people were exposed to high levels of radioactive fallout. The general principles outlined here are applicable to accidents of that degree of severity.

  16. Radiation retinopathy

    SciTech Connect

    Parker, R.G.; Withers, H.R.

    1988-01-01

    A letter to the editor discusses the effectiveness and risk of radiation treatment of Grave's ophthalmopathy. The authors are unable to document a single instance in which retinopathy can be attributed to therapy with a total dose of 2000 cGy when delivered in daily increments of 180 to 200 cGy.

  17. RADIATION FRONTS

    Microsoft Academic Search

    A. R. Fraser

    1958-01-01

    When intense thermal radiation penetrates into a cold fluid the front ; separating hot and cold fluid may be well defined. When this is so, conservation ; laws, similar to those which are used across a shock front, can be applied to the ; radintion front. These conservation laws, together with the second law of ; thermodynamics, are used to

  18. Radiation Models

    ERIC Educational Resources Information Center

    James, W. G. G.

    1970-01-01

    Discusses the historical development of both the wave and the corpuscular photon model of light. Suggests that students should be informed that the two models are complementary and that each model successfully describes a wide range of radiation phenomena. Cites 19 references which might be of interest to physics teachers and students. (LC)

  19. Radiation Protection Basics

    MedlinePLUS

    ... Basic Concepts of Radiation Protection time distance shielding Time The amount of radiation exposure increases and decreases ... exposure. How does EPA use the concept of time in radiation protection? When we set a radiation ...

  20. Radiation Protection

    NSDL National Science Digital Library

    Science Update (AAAS; )

    2008-05-01

    Chemotherapy and radiation can be powerful weapons against cancer. But they harm healthy cells as well. Cells of the immune system and G.I. tract are especially vulnerable: instead of repairing the damage, they respond by committing cellular suicide. In contrast, tumor cells have mutations that make them resistant to cell death. Roswell Park Cancer Institute researcher Andrei Gudkov and his colleagues recently harnessed this property to create a new drug.

  1. Radiation Belts

    NSDL National Science Digital Library

    Mendez, J.

    This website, authored and curated by David Stern, provides an outline of the motion of charged particles in the Earth's magnetic fields, and the Van Allen and outer radiation belts. It summarizes their discovery, their properties and their physics, as well as providing links to background materials and additional information. This is part of a large web site on the Exploration of the Earth's Magnetosphere. The page also includes a helpful timeline and glossary to help contextualize some of the information available. A Spanish translation is available.

  2. DynaProt 2D: an advanced proteomic database for dynamic online access to proteomes and two-dimensional electrophoresis gels

    PubMed Central

    Drews, Oliver; Görg, Angelika

    2005-01-01

    DynaProt 2D presents an advanced online database for dynamic access to proteomes and two-dimensional (2D) gels. The database was designed to administer complete in silico proteomes and links them with experimental proteomic data in the manner of 2D electrophoresis gels (IPG-Dalt). The 2D gels serve as reference maps in 2D gel analysis as well as tools for navigation of the database to switch between experimental and predicted data. Therefore, all identified spots in the gels are clickable and linked with summarized protein information. The protein information tables contain calculated characteristics, which are often used in proteomics, such as the molecular weight, isoelectric point, codon adaptation index, grand average of hydropathicity, etc. The design of the database permits online extension of gel data and protein attributes without knowledge of any software language. Besides navigation via 2D gels, the clear graphical user interface permits quick and intuitive searching throughout complete proteomes and supports, e.g. the search for proteins with isoelectric points within pH ranges of interest or protein classes (e.g. ribosomal proteins or transporters). The first organism implemented in the database is Lactococcus lactis. The database is available at www.wzw.tum.de/proteomik/lactis. PMID:15608266

  3. Radiation dosimeters

    DOEpatents

    Hoelsher, James W. (Pullman, WA); Hegland, Joel E. (Pullman, WA); Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA)

    1992-01-01

    Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

  4. Radiation Insulation

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Apollo and subsequent spacecraft have had highly effective radiation barriers; made of aluminized polymer film, they bar or let in heat to maintain consistent temperatures inside. Tech 2000, formerly Quantum International Corporation used the NASA technology in its insulating materials, Super "Q" Radiant Barrier, for home, industry and mobile applications. The insulation combines industrial aluminum foil overlaid around a core of another material, usually propylene or mylar. The outer layer reflects up to 97 percent of heat; the central layer creates a thermal break in the structure and thus allows low radiant energy emission. The Quantum Cool Wall, used in cars and trucks, takes up little space while providing superior insulation, thus reducing spoilage and costs. The panels can also dampen sound and engine, exhaust and solar heat.

  5. Large Current Radiators

    Microsoft Academic Search

    G. P. Pochanin

    2006-01-01

    The work is devoted to investigations aiming at developing special type of radiating antennas which are known as Harmuth's large current radiator. Physical and technical problems encountered when radiators designed and ways for their overcoming are discussed

  6. Dosimetry of space radiations

    NASA Technical Reports Server (NTRS)

    Arkhangelskiy, V. V.; Markelov, V. V.; Skvortsov, S. S.; Smirennyy, L. N.; Turkin, V. N.; Chernykh, I. V.

    1973-01-01

    Harmful effects of space radiation are discussed. Radiation dosimetry methods are given. Dosimetry monitoring is investigated. Methods for measuring space radiation by ionization, thermoluminescence, and nuclear photographic emulsions are described.

  7. Hoja de Recapturas MoSI Localidad Tamao de anillo R Temporada (p.ej 2009-10) Pgina # CODE SEXO EDAD COMO DETERMINAR LA EDAD Y EL SEXO CRNEO PROT. CLOAC. PARCH. DE INC. GRASA MUDA CUERP. MUDA PL. VUEL. DESGAS. VUEL. LIM. DE MUDA Y PL. TENDENCIA

    E-print Network

    DeSante, David F.

    Hoja de Recapturas MoSI Localidad Tamaño de anillo R Temporada (p.ej 2009-10) Página # CODE SEXO EDAD COMO DETERMINAR LA EDAD Y EL SEXO CRÁNEO PROT. CLOAC. PARCH. DE INC. GRASA MUDA CUERP. MUDA PL SEXO Lesión vieja, cicatrizad. Herida o enfermedad PARCH.DEINC. GRASA MUDACUERPO MUDAPL.VUEL. ANILLOS

  8. Hoja de Anillamiento MoSI Localidad Tamao de anillo Temporada (p.ej. 2009-10) Pgina # CDIGO SEXO EDAD COMO DETERMINAR LA EDAD Y EL SEXO CRNEO PROT. CLOAC. PARCH. DE INC. GRASA MUDA CUERP. MUDA PL. VUEL. DESGAS. VUEL. LIM. DE MUDA Y PL. TENDENCIA

    E-print Network

    DeSante, David F.

    Hoja de Anillamiento MoSI Localidad Tamaño de anillo Temporada (p.ej. 2009-10) Página # CÓDIGO SEXO EDAD COMO DETERMINAR LA EDAD Y EL SEXO CRÁNEO PROT. CLOAC. PARCH. DE INC. GRASA MUDA CUERP. MUDA PL SEXO COMODET. ELSEXO Lesión vieja, cicatrizad. Herida o enfermedad MUDAPL.VUEL. DESGAS.VUEL. PLUMAJEJUV

  9. Radiation reaction and radiative frequency shifts

    Microsoft Academic Search

    Jay R. Ackerhalt; Peter L. Knight; J. H. Eberly

    1973-01-01

    The question of quantum-electrodynamic radiative corrections to atomic ; transition frequencies is investigated. It is shown that the Heisenberg ; equations of motion allow a novel and fruitful exploitation of the concept of ; radiation reaction. (auth);

  10. [Neurotoxicity of radiation].

    PubMed

    Suzuki, Keiji

    2015-01-01

    It is well-known that the central nervous system is thoroughly resistant to ionizing radiation as high-dose radiation exposure is required for causing neuronal death. In contrast, recent studies have revealed that the hippocampus, which could be the main organ involved in disorder of higher brain functions after radiation therapy, contains radiation-sensitive cell fractions. In this paper, the basics of radiation effects and the molecular mechanism of neurotoxicity of radiation have been reviewed and discussed. PMID:25585436

  11. Radiation reaction due to magnetic dipole radiation

    Microsoft Academic Search

    Naoki Itoh

    1991-01-01

    The radiation reaction due to magnetic dipole radiation is calculated for a charged-particle system whose magnetic moment changes with time. The explicit expressions for the electric and magnetic fields due to the magnetic dipole radiation reaction are derived, they are found to originate in the fourth-order term in the expansion of the retarded potential, whereas the field due to the

  12. Solar radiation resource assessment

    SciTech Connect

    Not Available

    1990-11-01

    The bulletin discusses the following: introduction; Why is solar radiation resource assessment important Understanding the basics; the solar radiation resource assessment project; and future activities.

  13. Large-current radiators

    Microsoft Academic Search

    H. F. Harmuth; N. J. Mohamed

    1992-01-01

    The paper presents several simple designs of large-current radiators for nonsinusoidal waves, which produce low distortions but can efficiently radiate large powers. The principles of the large-current radiator are discussed, and the characteristics of several design schemes are examined. A circuit diagram of a low-power driver for large-current radiators is presented.

  14. RADIATION HYBRID MAPPING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Radiation hybrid maps are physical maps of genomes that provide an alternative to traditional genetic maps. These radiation hybrid maps have two important advantages over genetic maps. First, distances on a radiation hybrid map are determined by the frequency of radiation-induced breaks between mark...

  15. Radiation and human health

    Microsoft Academic Search

    J. W. Gofman; Karl Z. Morgan

    1983-01-01

    An attempt is made in the book to permit a layman to understand radiation and its effects. A basic presentations of radiation physics, the biology of human cancer, teratogenesis and genetics are considered excellent and concise reviews. A discussion on radiation studies is presented. The most extensive part of the book is a discussion of the risks of radiation-induced cancer.

  16. Second law and radiation

    Microsoft Academic Search

    R. H. Edgerton

    1980-01-01

    The available energy of thermal radiation and solar radiation is examined. The extension of the available energy concept to the evaluation of the potential energy conversion in solar converters is outlined. The fundamental question discussed is how much of a given solar radiation flux is convertible to thermodynamic work. The basic relations for evaluating the available energy in radiation processes

  17. [Ionizing radiation].

    PubMed

    Masse, R

    2000-07-01

    Everyone is exposed to radiation from natural, man-made and medical sources, and world-wide average annual exposure can be set at about 3.5 mSv. Exposure to natural sources is characterised by very large fluctuations, not excluding a range covering two orders of magnitude. Millions of inhabitants are continuously exposed to external doses as high as 10 mSv per year, delivered at low dose rates, very few workers are exposed above the legal limit of 50 mSv/year, and referring to accidental exposures, only 5% of the 116,000 people evacuated following the Chernobyl disaster encountered doses above 100 mSv. Epidemiological survey of accidentally, occupationally or medically exposed groups have revealed radio-induced cancers, mostly following high dose-rate exposure levels, only above 100 mSv. Risk coefficients were derived from these studies and projected into linear models of risk (linear non-threshold hypothesis: LNT), for the purpose of risk management following exposures at low doses and low dose-rates. The legitimacy of this approach has been questioned, by the Academy of sciences and the Academy of medicine in France, arguing: that LNT was not supported by Hiroshima and Nagasaki studies when neutron dose was revisited; that linear modelling failed to explain why so many site-related cancers were obviously non-linearly related to the dose, and especially when theory predicted they ought to be; that no evidence could be found of radio-induced cancers related to natural exposures or to low exposures at the work place; and that no evidence of genetic disease could be shown from any of the exposed groups. Arguments were provided from cellular and molecular biology helping to solve this issue, all resulting in dismissing the LNT hypothesis. These arguments included: different mechanisms of DNA repair at high and low dose rate; influence of inducible stress responses modifying mutagenesis and lethality; bystander effects allowing it to be considered that individual cellular responses reflected in fact the results of multiple cellular interactions. Following the conclusion of the French Academy of medicine, LNT modelling resulted in public anxiety by changing an hypothetical residual risk at low doses into a real one, calling on regulators, continuously, for a more and more severe control of tiny sources which may result in considerable collective doses when considered as being exposed to billions of people for hundreds of years. Examples were provided that showed that the perception of risk of radioactive sources was not related to the severity of the risk itself but to the importance attributed to the situation by the media. In some instances, such as those resulting from the loss of gammagraphy sources, it resulted in a dangerous underestimate of the necessary remedial actions. PMID:10983274

  18. Radiation physics, biophysics, and radiation biology

    SciTech Connect

    Hall, E.J.; Zaider, M.

    1991-05-01

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair.

  19. Radiation Therapy: Preventing and Managing Side Effects

    MedlinePLUS

    ... of radiation therapy outweigh the risks and side effects? How much does radiation treatment cost? Who gives radiation treatments? Informed consent for radiation therapy How is radiation therapy given? External radiation therapy Internal radiation therapy (brachytherapy) Systemic radiation ...

  20. Plutonium radiation surrogate

    DOEpatents

    Frank, Michael I. (Dublin, CA)

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  1. Introduction to radiation transport

    SciTech Connect

    Olson, G.L.

    1998-12-31

    This lecture will present time-dependent radiation transport where the radiation is coupled to a static medium, i.e., the material is not in motion. In reality, radiation exerts a pressure on the materials it propagates through and will accelerate the material in the direction of the radiation flow. This fully coupled problem with radiation transport and materials in motion is referred to as radiation-hydrodynamics (or in a shorthand notation: rad-hydro) and is beyond the scope of this lecture.

  2. Cell Radiation Experiment System

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    2010-01-01

    The cell radiation experiment system (CRES) is a perfused-cell culture apparatus, within which cells from humans or other animals can (1) be maintained in homeostasis while (2) being exposed to ionizing radiation during controlled intervals and (3) being monitored to determine the effects of radiation and the repair of radiation damage. The CRES can be used, for example, to determine effects of drug, radiation, and combined drug and radiation treatments on both normal and tumor cells. The CRES can also be used to analyze the effects of radiosensitive or radioprotectant drugs on cells subjected to radiation. The knowledge gained by use of the CRES is expected to contribute to the development of better cancer treatments and of better protection for astronauts, medical-equipment operators, and nuclear-power-plant workers, and others exposed frequently to ionizing radiation.

  3. Space Radiation Program Element

    NASA Technical Reports Server (NTRS)

    Krenek, Sam

    2008-01-01

    This poster presentation shows the various elements of the Space Radiation Program. It reviews the program requirements: develop and validate standards, quantify space radiation human health risks, mitigate risks through countermeasures and technologies, and treat and monitor unmitigated risks.

  4. Radiation Protection Handbook

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A handbook which sets forth the Kennedy Space Center radiation protection policy is presented. The book also covers administrative direction and guidance on organizational and procedural requirements of the program. Only ionizing radiation is covered.

  5. Environmental Radiation Exposures

    Cancer.gov

    DCEG is investigating cancer risks among populations exposed to radiation from environmental sources, such as nuclear reactor accidents and fallout from weapons testing.   Atomic Bomb Survivors Childhood Leukemia and Background Radiation Semipalatinsk

  6. Radiation and Your Health

    MedlinePLUS

    ... air, airline travel, some medical procedures, computers, and nuclear weapons test fallout. Â Understanding Radiation Radiation, which ... health effects, and ways to reduce its levels Nuclear Medicine Procedures Nuclear medicine procedures include the use ...

  7. Radiation therapy - skin care

    MedlinePLUS

    ... red, peel, or itch. You should treat your skin with care while receiving radiation therapy. ... When you have radiation treatment, a health care provider draws ... they come off, do not redraw them. Tell your provider instead. ...

  8. Radiation Exposure and Cancer

    MedlinePLUS

    ... what we know about these types of high-energy radiation and how they affect cancer risk. Cancer Compensation Programs for People Exposed to Radiation as Part of Nuclear Weapons Testing Between 1945 and 1962, several countries ...

  9. Radiation-induced angiosarcoma

    E-print Network

    Anzalone, C Lane; Cohen, Philip R; Diwan, Abdul H; Prieto, Victor G

    2013-01-01

    and radiation therapy, have largely supplanted radical mastectomy as the preferential treatment of breast cancer [cancer treatment has caused an increase, although still a rare side effect, in the numbers of cutaneous radiation-cancer has altered the average onset of the post-treatment angiosarcoma; radiation-

  10. Radiation protection standards

    Microsoft Academic Search

    Lauriston S. Taylor; Harold O. Wyckoff

    1972-01-01

    The report traces the development of the understanding of radiation hazard, and the philosophy for protection against it. Special attention is given to the work of the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP), form which two organizations most of the basic radiation protection philosphy and criteria in the world today

  11. Radiation port dermatophytosis

    SciTech Connect

    Rosen, T.; Dupuy, J.; Maor, M.; Altman, A.

    1988-12-01

    We report two cases in which dermatophytic infection developed almost entirely within a radiation field mimicking an acute radiation effect. Radiotherapists and dermatologists should be aware of this possibility and be able to differentiate it from radiation dermatitis. Topical antifungal agents are the recommended treatment after diagnosis is established.

  12. Radiation detection and measurement

    Microsoft Academic Search

    G. F. Knoll

    1979-01-01

    The book is a complete, clear and up-to-date text that provides a basic review of instruments and methods of ionizing radiation. The text covers detailed discussion of all detector types; introductory discussions of radiation sources, interactions, and counting statistics; functional analysis of the electronics and pulse processing aspects of radiation detectors in instrumentation systems; and consideration of shielding and background

  13. Radiation and cellular response

    Microsoft Academic Search

    G. P. Scott; H. W. Wahner

    1983-01-01

    This book contains 18 papers. Some of the titles are: Radiation Equivalency for the Radiation Recall Phenomenon; The Induction of Photoreactivatable Damage in E. Coli by Ionizing Radiation: The Role of Cerenkov; Combined Modality Therapy for Limited Inoperable Non-Small Lung Cancer; and Learning and the Single Cell.

  14. Radiation Research Program (RRP)

    Cancer.gov

    The RRP is responsible for NCI’s clinically-related extramural radiation research program. The RRP establishes priorities, allocates resources, and evaluates the effectiveness of such radiation research being conducted by NCI grantees. RRP staff represent the program at NCI management and scientific meetings and provide scientific support to leadership on matters related to radiation research.

  15. Ionizing Radiation: The issue of radiation quality

    NASA Astrophysics Data System (ADS)

    Prise, Kevin; Schettino, Giuseppe

    Types of Ionising radiations are differentiated from each other by fundamental characteristics of their energy deposition patterns when they interact with biological materials. At the level of the DNA these non-random patterns drive differences in the yields and distributions of DNA damage patterns and specifically the production of clustered damage or complex lesions. The complex radiation fields found in space bring significant challenges for developing a mechanistic understanding of radiation effects from the perspective of radiation quality as these consist of a diverse range of particle and energy types unique to the space environment. Linear energy transfer, energy deposited per unit track length in units of keV per micron, has long been used as a comparator for different types of radiation but has limitations in that it is an average value. Difference in primary core ionizations relative to secondary delta ray ranges vary significantly with particle mass and energy leading to complex interrelationships with damage production at the cellular level. At the cellular level a greater mechanistic understanding is necessary, linking energy deposition patterns to DNA damage patterns and cellular response, to build appropriate biophysical models that are predictive for different radiation qualities and mixed field exposures. Defined studies using monoenergetic beams delivered under controlled conditions are building quantitative data sets of both initial and long term changes in cells as a basis for a great mechanistic understanding of radiation quality effects of relevance to not only space exposures but clinical application of ion-beams.

  16. Nuclear Energy: Radiation Exposure

    NSDL National Science Digital Library

    John Pratte

    This lesson provides an overview of the sources and potential effects of radiation exposure. Topics include the history of the United States' domestic nuclear power program, the concept of ionizing radiation, and how radiation dosage is measured. There is also discussion of what constitutes a lethal dose of radiation and potential sources of exposure. The lesson includes an activity in which students measure their individual yearly exposures to radiation by making an inventory of lifestyle factors that affect their potential dosage and using an online calculator to sum up the contributions from the various sources.

  17. Fluorescent radiation converter

    NASA Technical Reports Server (NTRS)

    Viehmann, W.

    1980-01-01

    Fluorescent radiation converter used optically transparent substrate. One side of substrate is coated with plastic film containing fluorescent organic dyes that absorb optical radiation at one wavelength and emit it at longer one. Coating is formulated to respond to specific wavelengths. Emitted radiation is reflected internally inside substrate, amplifying intensity that reaches radiation detector. Converter can be made in several shapes and size; round and square bars coated all round their lengths are useful in converting relatively intense radiation and transmitting it through substrate over lengthy distances.

  18. Radiation protection in space

    SciTech Connect

    Blakely, E.A. [Lawrence Berkeley Lab., CA (United States); Fry, R.J.M. [Oak Ridge National Lab., TN (United States)

    1995-02-01

    The challenge for planning radiation protection in space is to estimate the risk of events of low probability after low levels of irradiation. This work has revealed many gaps in the present state of knowledge that require further study. Despite investigations of several irradiated populations, the atomic-bomb survivors remain the primary basis for estimating the risk of ionizing radiation. Compared to previous estimates, two new independent evaluations of available information indicate a significantly greater risk of stochastic effects of radiation (cancer and genetic effects) by about a factor of three for radiation workers. This paper presents a brief historical perspective of the international effort to assure radiation protection in space.

  19. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Carter, J. R., Jr.; Tada, H. Y.

    1973-01-01

    A method is presented for predicting the degradation of a solar array in a space radiation environment. Solar cell technology which emphasizes the cell parameters that degrade in a radiation environment, is discussed along with the experimental techniques used in the evaluation of radiation effects. Other topics discussed include: theoretical aspects of radiation damage, methods for developing relative damage coefficients, nature of the space radiation environment, method of calculating equivalent fluence from electron and proton energy spectrums and relative damage coefficients, and comparison of flight data with estimated degradation.

  20. Radiation protection and instrumentation

    NASA Technical Reports Server (NTRS)

    Bailey, J. V.

    1975-01-01

    Radiation was found not to be an operational problem during the Apollo program. Doses received by the crewmen of Apollo missions 7 through 17 were small because no major solar-particle events occurred during those missions. One small event was detected by a radiation sensor outside the Apollo 12 spacecraft, but no increase in radiation dose to the crewmen inside the spacecraft was detected. Radiation protection for the Apollo program was focused on both the peculiarities of the natural space radiation environment and the increased prevalence of manmade radiation sources on the ground and onboard the spacecraft. Radiation-exposure risks to crewmen were assessed and balanced against mission gain to determine mission constraints. Operational radiation evaluation required specially designed radiation detection systems onboard the spacecraft in addition to the use of satellite data, solar observatory support, and other liaison. Control and management of radioactive sources and radiation-generating equipment was important in minimizing radiation exposure of ground-support personnel, researchers, and the Apollo flight and backup crewmen.

  1. Americans' Average Radiation Exposure

    SciTech Connect

    NA

    2000-08-11

    We live with radiation every day. We receive radiation exposures from cosmic rays, from outer space, from radon gas, and from other naturally radioactive elements in the earth. This is called natural background radiation. It includes the radiation we get from plants, animals, and from our own bodies. We also are exposed to man-made sources of radiation, including medical and dental treatments, television sets and emission from coal-fired power plants. Generally, radiation exposures from man-made sources are only a fraction of those received from natural sources. One exception is high exposures used by doctors to treat cancer patients. Each year in the United States, the average dose to people from natural and man-made radiation sources is about 360 millirem. A millirem is an extremely tiny amount of energy absorbed by tissues in the body.

  2. The Radiation Transport Conundrum in Radiation Hydrodynamics

    SciTech Connect

    Castor, J I

    2005-03-18

    The summary of this paper is: (1) The conundrum in the title is whether to treat radiation in the lab frame or the comoving frame in a radiation-hydrodynamic problem; (2) Several of the difficulties are associated with combining a somewhat relativistic treatment of radiation with a non-relativistic treatment of hydrodynamics; (3) The principal problem is a tradeoff between easily obtaining the correct diffusion limit and describing free-streaming radiation with the correct wave speed; (4) The computational problems of the comoving-frame formulation in more than one dimension, and the difficulty of obtaining both exact conservation and full u/c accuracy argue against this method; (5) As the interest in multi-D increases, as well as the power of computers, the lab-frame method is becoming more attractive; and (6) The Monte Carlo method combines the advantages of both lab-frame and comoving-frame approaches, its only disadvantage being cost.

  3. High-power radiating plasma

    NASA Technical Reports Server (NTRS)

    Rozanov, V. B.; Rukhadze, A. A.

    1984-01-01

    The physical principles underlying the use of radiating plasmas for the optical pumping of lasers are described. Particular consideration is given to the properties of radiating plasmas; radiation selectivity; the dynamics, equilibrium, and stability of radiating plasmas; the radiative Reynolds number; and experimental results on radiating discharges.

  4. Earth Radiation Measurement Science

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis

    2000-01-01

    This document is the final report for NASA Grant NAG1-1959, 'Earth Radiation Measurement Science'. The purpose of this grant was to perform research in this area for the needs of the Clouds and Earth Radiant Energy System (CERES) project and for the Earth Radiation Budget Experiment (ERBE), which are bing conducted by the Radiation and Aerosols Branch of the Atmospheric Sciences Division of Langley Research Center. Earth Radiation Measurement Science investigates the processes by which measurements are converted into data products. Under this grant, research was to be conducted for five tasks: (1) Point Response Function Measurements; (2) Temporal Sampling of Outgoing Longwave Radiation; (3) Spatial Averaging of Radiation Budget Data; (4) CERES Data Validation and Applications; and (5) ScaRaB Data Validation and Application.

  5. A radiation tolerant photodetector

    SciTech Connect

    Passenheim, B.C.; Ginaven, R.O.

    1987-12-01

    This paper describes the development and test of a radiation tolerant photodetector. This was accomplished by building a single stage photo multiplier tube with a physically small, dielectrically isolated, silicon photodiode array at the anode. In this device the optically generated photocurrent is multiplied by a much larger factor than is the photo-Compton current. Using matched ''sighted'' and ''optically blind'' diodes to differentiate the optical signal from the ''common-mode'' ionizing radiation photocurrent also contributes to radiation tolerance.

  6. Solar radiation on Mars

    NASA Technical Reports Server (NTRS)

    Appelbaum, Joseph; Flood, Dennis J.

    1989-01-01

    Detailed information on solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. Presented here is a procedure and solar radiation related data from which the diurnally, hourly and daily variation of the global, direct beam and diffuse insolation on Mars are calculated. The radiation data are based on measured optical depth of the Martian atmosphere derived from images taken of the sun with a special diode on the Viking cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation.

  7. Flexible radiator system

    NASA Technical Reports Server (NTRS)

    Oren, J. A.

    1982-01-01

    The soft tube radiator subsystem is described including applicable system requirements, the design and limitations of the subsystem components, and the panel manufacturing method. The soft tube radiator subsystem is applicable to payloads requiring 1 to 12 kW of heat rejection for orbital lifetimes per mission of 30 days or less. The flexible radiator stowage volume required is about 60% and the system weight is about 40% of an equivalent heat rejection rigid panel. The cost should also be considerably less. The flexible radiator is particularly suited to shuttle orbiter sortie payloads and also whose mission lengths do not exceed the 30 day design life.

  8. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, Minoru (Troy, NY); Watson, E. Bruce (Troy, NY); Acocella, John (Troy, NY)

    1986-01-01

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.

  9. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, M.; Watson, E.B.; Acocella, J.

    1986-11-04

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

  10. Radiation efficiency of the large current radiators. Electrodynamic simulation

    Microsoft Academic Search

    G. P. Pochanin; I. Ye. Pochanina; P. V. Kholod

    2003-01-01

    The paper presents the results of electrodynamic simulation, using the FDTD method, of the radiation of ultrawideband (UWB) pulse electromagnetic fields by radiators built as Harmuth's large current radiators. The dependencies of the time characteristics of the radiated pulses on a dimension of the radiator are presented.

  11. Radiation physics, biophysics, and radiation biology

    SciTech Connect

    Hall, E.J.

    1992-05-01

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  12. Cerenkov Radiation in Photonic Crystals

    Microsoft Academic Search

    Chiyan Luo; Mihai Ibanescu; Steven G. Johnson; J. D. Joannopoulos

    2003-01-01

    In a conventional material, the coherent Cerenkov radiation due to a moving charged particle is associated with a velocity threshold, a forward-pointing radiation cone, and a forward direction of emission. We describe different behavior for the Cerenkov radiation in a photonic crystal. In particular, this radiation is intrinsically coupled with transition radiation and is observable without any threshold. Within one

  13. Human exposure to ultraviolet radiation

    SciTech Connect

    Passchier, W.F. (Health Council of the Netherlands, The Hague (NL)); Bosnjakovic, B.F.M. (Ministry of Housing, The Hague (NL))

    1987-01-01

    These proceedings contain over 50 selections. Some of the title are: Man and ultraviolet radiation; Effects of ultraviolet radiations on the human skin: emphasis on skin cancer; Human exposure to ultraviolet radiation: Quantitative modelling of skin cancer incidence; Human exposure to ultraviolet radiation: Data; and Share of erythema dose of solar radiation in high mountains.

  14. Method for microbeam radiation therapy

    Microsoft Academic Search

    Daniel N. Slatkin; F. Avraham Dilmanian; Per O. Spanne

    1994-01-01

    A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose

  15. Space Radiation Risk Assessment

    Microsoft Academic Search

    E. Blakely

    2006-01-01

    Evaluation of potential health effects from radiation exposure during and after deep space travel is important for the future of manned missions To date manned missions have been limited to near-Earth orbits with the moon our farthest distance from earth Historical space radiation career exposures for astronauts from all NASA Missions show that early missions involved total exposures of less

  16. Chronic Radiation Enteritis

    Microsoft Academic Search

    V. S. Theis; R. Sripadam; V. Ramani; S. Lal

    2010-01-01

    Chronic radiation enteritis is an increasing problem, as more patients receive radiotherapy as part of their cancer therapy and as the long-term survival of these patients improves. This review addresses the causes, investigation, treatment and prevention of this disease. A review of published studies was carried out using a variety of search terms, including radiation enteritis, investigation, treatment and prevention.

  17. Global radiation oncology waybill

    PubMed Central

    Muñoz-Garzón, Victor; Rovirosa, Ángeles; Ramos, Alfredo

    2013-01-01

    Background/aim Radiation oncology covers many different fields of knowledge and skills. Indeed, this medical specialty links physics, biology, research, and formation as well as surgical and clinical procedures and even rehabilitation and aesthetics. The current socio-economic situation and professional competences affect the development and future or this specialty. The aim of this article was to analyze and highlight the underlying pillars and foundations of radiation oncology, indicating the steps implicated in the future developments or competences of each. Methods This study has collected data from the literature and includes highlights from discussions carried out during the XVII Congress of the Spanish Society of Radiation Oncology (SEOR) held in Vigo in June, 2013. Most of the aspects and domains of radiation oncology were analyzed, achieving recommendations for the many skills and knowledge related to physics, biology, research, and formation as well as surgical and clinical procedures and even supportive care and management. Results Considering the data from the literature and the discussions of the XVII SEOR Meeting, the “waybill” for the forthcoming years has been described in this article including all the aspects related to the needs of radiation oncology. Conclusions Professional competences affect the development and future of this specialty. All the types of radio-modulation are competences of radiation oncologists. On the other hand, the pillars of Radiation Oncology are based on experience and research in every area of Radiation Oncology. PMID:24416572

  18. The Pressure of Radiation

    Microsoft Academic Search

    Oliver Heaviside

    1905-01-01

    THE success of Lebedeff and Nichols and Hull in recognising and measuring the pressure of radiation has aroused much interest in radiation pressure generally, real or apparent. It has some interesting and sometimes somewhat difficult theoretical aspects. In the first place, if the ether is really absolutely at rest (this rigidity is a very difficult idea), the moving force on

  19. Penn Radiation Oncology Newsletter

    E-print Network

    Bushman, Frederic

    . First Year Radiation Oncology Residents Medical: Saumil Gandhi, M.D., Ph.D., Anusha Kalbasi, M.D., JacobWELCOME TO THE Penn Radiation Oncology Newsletter Volume 1 Issue 5SUMMER 2012 There are always have moved on to great opportuni- ties outside the department. We have retained two of our medical

  20. Radiation in the universe

    NASA Technical Reports Server (NTRS)

    Stuhlinger, Ernst; Truemper, Joachim; Weisskopf, Martin

    1992-01-01

    When Wilhelm Conrad Roentgen discovered radiation one hundred years ago, it seemed that what was discovered was one of the rarest and most volatile members of the family of the basic modules of our natural world. Today cosmologists report that a substantial part of the universe's radiation energy consists of X-rays, which travel through cosmic space with the speed of light.

  1. Thallium bromide radiation detectors

    Microsoft Academic Search

    K. S. Shah; J. C. Lund; F. Olschner; L. Moy; M. R. Squillante

    1989-01-01

    Radiation detectors have been fabricated from crystals of the semiconductor material thallium bromide (TlBr) and the performance of these detectors as room temperature photon spectrometers has been measured. These detectors exhibit improved energy resolution over previously reported TlBr detectors. These results indicate that TlBr is a very promising radiation detector material.

  2. Radar frequency radiation

    Microsoft Academic Search

    E. Malowicki

    1981-01-01

    A method is presented for the determination of radar frequency radiation power densities that the PAVE PAWS radar system could produce in its air and ground environment. The effort was prompted by the concern of the people in the vicinity of OTIS AFB MA and BEALE AFB CA about the possible radar frequency radiation hazard of the PAVE PAWS radar.

  3. Microwave oven radiation hazards

    Microsoft Academic Search

    Prakash Bhartia; Oliver OReilly

    1975-01-01

    This paper presents the results of a survey on the radiation leakage from a representative sample of microwave ovens in Regina. A brief review of potential hazards of microwave radiation is presented and the results of the survey are analyzed with a view of initiating further research in this area.

  4. Radiation-resistant microorganism

    DOEpatents

    Fliermans, Carl B.

    2007-01-09

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  5. Sensible radiation protection

    SciTech Connect

    Rossi, H.H.

    1996-03-01

    This report describes eight general principles of radiation protection. The first principle is based on the idea that the ICRP derivation of risk coefficients are meaningless when applied to routine radiation exposure. The other principles describes what should be acceptable exposures.

  6. Radiative Flux Analysis

    SciTech Connect

    Long, Chuck [NOAA

    2008-05-14

    The Radiative Flux Analysis is a technique for using surface broadband radiation measurements for detecting periods of clear (i.e. cloudless) skies, and using the detected clear-sky data to fit functions which are then used to produce continuous clear-sky estimates. The clear-sky estimates and measurements are then used in various ways to infer cloud macrophysical properties.

  7. Radiation effects in space

    SciTech Connect

    Fry, R.J.M.

    1987-07-01

    As more people spend more time in space, and the return to the moon and exploratory missions are considered, the risks require continuing examination. The effects of microgravity and radiation are two potential risks in space. These risks increase with increasing mission duration. This document considers the risk of radiation effects in space workers and explorers. 17 refs., 1 fig., 4 tabs.

  8. Nuclear radiation actuated valve

    DOEpatents

    Christiansen, David W. (Kennewick, WA); Schively, Dixon P. (Richland, WA)

    1985-01-01

    A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  9. Deployable Heat Pipe Radiator

    NASA Technical Reports Server (NTRS)

    Edelstein, F.

    1975-01-01

    A 1.2- by 1.8-m variable conductance heat pipe radiator was designed, built, and tested. The radiator has deployment capability and can passively control Freon-21 fluid loop temperatures under varying loads and environments. It consists of six grooved variable conductance heat pipes attached to a 0.032-in. aluminum panel. Heat is supplied to the radiator via a fluid header or a single-fluid flexible heat pipe header. The heat pipe header is an artery design that has a flexible section capable of bending up to 90 degrees. Radiator loads as high as 850 watts were successfully tested. Over a load variation of 200 watts, the outlet temperature of the Freon-21 fluid varied by 7 F. An alternate control system was also investigated which used a variable conductance heat pipe header attached to the heat pipe radiator panel.

  10. Estimate flare radiation intensity

    SciTech Connect

    De Faveri, D.M.; Ferraiolo, G.; Fumarola, G.; Zonato, C.

    1985-05-01

    Thermal radiation intensity from flares is more accurately determined when the flame source is considered as a surface. Flares show very peculiar engineering and hygienic problems compared with other combustion equipment for conversion of toxic or polluting substances into less or non-noxious products. Experimental methods for predicting radiation have been researched in scale models dealing with observed flame shape and size. Prediction of jet diffusion flame shape and size in crosswind is of practical interest to assess radiative heat flux to neighboring plant structures or operating personnel. Since luminous flame radiation depends on parameters which are generally difficult to assess, empirical equations are usually applied, giving radiative heat flux as a function of molecular mass and calorific value of waste gas.

  11. Radiation Damage Workshop

    NASA Technical Reports Server (NTRS)

    Stella, P. M.

    1984-01-01

    The availability of data regarding the radiation behavior of GaAs and silicon solar cells is discussed as well as efforts to provide sufficient information. Other materials are considered too immature for reasonable radiation evaluation. The lack of concern over the possible catastrophic radiation degradation in cascade cells is a potentially serious problem. Lithium counterdoping shows potential for removing damage in irradiated P-type material, although initial efficiencies are not comparable to current state of the art. The possibility of refining the lithium doping method to maintain high initial efficiencies and combining it with radiation tolerant structures such as thin BSF cells or vertical junction cells could provide a substantial improvement in EOL efficiencies. Laser annealing of junctions, either those formed ion implantation or diffusion, may not only improve initial cell performance but might also reduce the radiation degradation rate.

  12. Ultrasensitive Human Radiation Dosimetry

    NASA Technical Reports Server (NTRS)

    Hammen, Richard

    1985-01-01

    The problem we are addressing concerns the astronauts, and their exposure to radiation during spaceflight. The amount of this radiation is a variable depending on solar events and orbital characteristics. Our goal is to measure the total integrated quantity of radiation damage to the cell nucleus in astronauts or other people exposed to radiation. In my lab, we are turning up the microscope from the level of the chromosome, about eight orders of magnitude, to the molecular level. It is well known that radiation causes DNA and chromosome damage. We are developing methods to measure a specific molecular lesion. The lesion that we have selected to measure is thymidine diol, which is created by hydroxyl radicals adding across the 5.6 double bond of thymidine in DNA.

  13. Broadband optical radiation detector

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Hong, S. D.; Moacanin, J. (inventors)

    1981-01-01

    A method and apparatus for detecting optical radiation by optically monitoring temperature changes in a microvolume caused by absorption of the optical radiation to be detected is described. More specifically, a thermal lens forming material is provided which has first and second opposite, substantially parallel surfaces. A reflective coating is formed on the first surface, and a radiation absorbing coating is formed on the reflective coating. Chopped, incoming optical radiation to be detected is directed to irradiate a small portion of the radiation absorbing coating. Heat generated in this small area is conducted to the lens forming material through the reflective coating, thereby raising the temperature of a small portion of the lens forming material and causing a thermal lens to be formed therein.

  14. Fundamentals of Radiation Dosimetry

    SciTech Connect

    Bos, Adrie J. J. [Delft University of Technology, Faculty of Applied Sciences, Mekelweg 15, 2629JB Delft (Netherlands)

    2011-05-05

    The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

  15. RADIATION PROTECTION AT SYNCHROTRON RADIATION FACILITIES

    Microsoft Academic Search

    James C. Liu; Vaclav Vylet

    A synchrotron radiation (SR) facility typically consists of an injector, a storage ring, and SR beamlines. The latter two features are unique to SR facilities, when compared to other types of accelerator facilities. The SR facilities have the characteristics of low injection beam power, but high stored beam power. The storage ring is generally above ground with people occupying the

  16. RADIATION BIOLOGY: CONCEPTS FOR RADIATION PROTECTION

    EPA Science Inventory

    ABSTRACT The opportunity to write a historical review of the field of radiation biology allows for the viewing of the development and maturity of a field of study, thereby being able to provide the appropriate context for the earlier years of research and its findings. The...

  17. Radiation Protection and the Human Radiation Experiments

    Microsoft Academic Search

    David Lloyd

    1998-01-01

    This book from the Los Alamos National Laboratory is largely a response to recent revelations and public concern about radiation experiments performed on human beings there and elsewhere, starting about 50 years ago. It is written for an intelligent lay person rather than for the specialist scientist and seeks to clarify the objectives and conduct of these human studies. The

  18. Prot. 413 / Visto il R

    E-print Network

    Guidoni, Leonardo

    pubbli nte insegna TO DELLE ATT sono partec sionale e sc e o perfezion el teatro soc percorso di r vo coo nte procedu Università 80. ENTO DI UN TUDI DI ROM LL'ARTE E SP E E DRAMM TIVA n. 14 / ORE 3 ni; esso . n. erse dal le e tivo pia" a di a o ioni tori sei tto, i di nte

  19. Synchrotron radiation sources and research

    SciTech Connect

    Teng, L.C.

    1995-12-31

    This is an introduction and a review of Synchrotron Radiation sources and the research performed using synchrotron radiation. I will begin with a brief discussion of the two principal uses of particle storage rings: for colliding beams (Collider) and for synchrotron radiation (Radiator). Then I will concentrate on discussions of synchrotron radiation topics, starting with a historical account, followed by descriptions of the features of the storage ring and the features of the radiation from the simplest source -- the bending magnet. I will then discuss the special insertion device sources -- wigglers and undulators -- and their radiations, and end with a brief general account of the research and other applications of synchrotron radiation.

  20. Stimulated coherent transition radiation

    SciTech Connect

    Hung-chi Lihn

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed.

  1. Teflon electret radiation dosimeter

    NASA Astrophysics Data System (ADS)

    Parada, M. A.; de Almeida, A.

    2002-05-01

    Electrets are insulating materials with a quasi-permanent electric polarization. Since charge compensation occurs when subjected to ionizing radiation, electrets may be used for ?, ?, ?, X, e - and neutron radiation dosimetry. The compensating charge may either be produced in the electret material itself or by interaction by the radiation field with surrounding insulating material. We report the results of investigations of electrets produced from Teflon ® polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexa-fluoropropylene (FEP) and tetrafluoroethylene-per-fluoromethoxyethylene (PFA) films. The electret state was produced uniformly on one surface of the films by a corona method with a negative 15 kV potential applied to multiple pointed electrodes facing the film on a grounded plate. After polarization, the films were exposed to a known X radiation and the uncompensated charge was nondestructively measured with capacitive probes. The area of the probe was designed in accordance with the spatial resolution desired. The resolution and sensitivity of such probe is ultimately limited by the Paschen discharge between the electret and the probe. Response curves compared the ratio of uncompensated charge density after and before exposures to the radiation as a function of exposure. The linearity of these curves shows that the films may be used as a radiation dosimeter. The slope of the response curves indicates the sensitivity to the ionizing radiation. The PFA film displays two linear regions which correspond to two electron trap levels. We demonstrate that the image forming nature of these planar electret dosimeters has a millimeter of spatial resolution. We also report the development of innovative electret geometry for measurements of the directional dependence of the radiation and by choice of the surrounding insulating materials, an almost complete selectivity in mixed radiation fields.

  2. Miniaturized radiation chirper

    DOEpatents

    Umbarger, C. John (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM)

    1980-01-01

    The disclosure relates to a miniaturized radiation chirper for use with a small battery supplying on the order of 5 volts. A poor quality CdTe crystal which is not necessarily suitable for high resolution gamma ray spectroscopy is incorporated with appropriate electronics so that the chirper emits an audible noise at a rate that is proportional to radiation exposure level. The chirper is intended to serve as a personnel radiation warning device that utilizes new and novel electronics with a novel detector, a CdTe crystal. The resultant device is much smaller and has much longer battery life than existing chirpers.

  3. Radiation and Health

    NASA Astrophysics Data System (ADS)

    Evans, Albert E.

    2008-03-01

    This is a shortened version of the Science Teachers' Workshop offered free of charge to primary and secondary teachers at a location of their choice, covering fundamentals of nuclear radiation, natural and man-made sources of radiation, biological effects and risks to health, radioactive waste management, and radiation safety management and regulation. The course includes a hands-on demonstration of use of Geiger Counters, which are given without cost to participants for use in their classes. A CD and notebook of class material are issued to each student. Lunch will be provided. Limited to 20 participants.

  4. Radiation and Health

    NASA Astrophysics Data System (ADS)

    Evans, Albert; Blanchard, Karen

    2007-10-01

    This is a shortened version of the Science Teachers' Workshop offered free of charge to primary and secondary teachers at a location of their choice, covering fundamentals of nuclear radiation, natural and man-made sources of radiation, biological effects and risks to health, radioactive waste management, and radiation safety management and regulation. The course includes a hands-on demonstration of use of Geiger Counters, which are given without cost to participants for use in their classes. A CD and notebook of class material are issued to each student. Lunch will be provided.

  5. Radiation carcinogenesis. Cancergram CK06

    SciTech Connect

    Not Available

    1986-01-01

    The Cancergram deals with all aspects of radiation carcinogenesis. The term radiation here includes uv radiation and the entire electromagnetic spectrum, electron and other charged-particle beams, neutrons, and alpha and beta radiation from radioactive substances. Abstracts included concern relationships between radiation and carcinogenesis in humans, experimental induction of tumors in animals by irradiation, studies on the mechanism of radiation carcinogenesis at the cellular level, studies of RBE, dose response or dose threshold in relation to radiation carcinogenesis, and methods and policies for control of radiation exposure in the general population. In general, this Cancergram excludes abstracts on radiotherapy, radiologic diagnosis, radiation pathology, and radiation biology, where these articles have no bearing on radiation carcinogenesis.

  6. IMPULSE RADIATING ANTENNAS

    Microsoft Academic Search

    Carl E. Baum; Everett G. Farr; Kirtland AFB

    A number of applications require radiation of a short pulse of electromagnetic energy out to large distances. These applications include target discrimination in a cluttered environment (e.g., looking over the ocean), aircraft identification by taking a \\

  7. Space radiation studies

    NASA Technical Reports Server (NTRS)

    Gregory, J. C.

    1986-01-01

    Instrument design and data analysis expertise was provided in support of several space radiation monitoring programs. The Verification of Flight Instrumentation (VFI) program at NASA included both the Active Radiation Detector (ARD) and the Nuclear Radiation Monitor (NRM). Design, partial fabrication, calibration and partial data analysis capability to the ARD program was provided, as well as detector head design and fabrication, software development and partial data analysis capability to the NRM program. The ARD flew on Spacelab-1 in 1983, performed flawlessly and was returned to MSFC after flight with unchanged calibration factors. The NRM, flown on Spacelab-2 in 1985, also performed without fault, not only recording the ambient gamma ray background on the Spacelab, but also recording radiation events of astrophysical significance.

  8. Portal radiation monitor

    DOEpatents

    Kruse, Lyle W. (Albuquerque, NM)

    1985-01-01

    A portal radiation monitor combines 0.1% FAR with high sensitivity to special nuclear material. The monitor utilizes pulse shape discrimination, dynamic compression of the photomultiplier output and scintillators sized to maintain efficiency over the entire portal area.

  9. Space Math: Radiation Math

    NSDL National Science Digital Library

    Sten Odenwald

    This booklet includes 19 problems that explore the topic of radiation and human exposure to its different forms. The problems span math abilities from basic multiplication and unit conversions, to algebra and calculus. For example, students learn about the various natural radiation dosages to which they are exposed daily, work quantitatively with authentic radiation dosage units to estimate the total annual dosages resulting from different lifestyles, and determine probabilities of occurrence for flares and other radiation events in space. Math skills include graph analysis, Venn diagramming, probability and statistics, evaluating equations in more than one variable, extrapolation and forecasting, scientific notation, integral calculus. (8.5 x11, 28 pages, 11 color images, PDF file)

  10. Tin Can Radiation Detector.

    ERIC Educational Resources Information Center

    Crull, John L.

    1986-01-01

    Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

  11. Adaptive multigroup radiation diffusion

    E-print Network

    Williams, Richard B., Sc. D. Massachusetts Institute of Technology

    2005-01-01

    This thesis describes the development and implementation of an algorithm for dramatically increasing the accuracy and reliability of multigroup radiation diffusion simulations at low group counts. This is achieved by ...

  12. RESEARCH SAFETY RADIATION SAFETY

    E-print Network

    RESEARCH SAFETY RADIATION SAFETY ENVIRONMENTAL PROGRAMS HAZARDOUS MATERIALS CONTROLLED SUBSTANCES INTEGRATED WASTE MANAGEMENT LABORATORY SAFETY AUDITS & COMPLIANCE BIOSAFETY and ENVIRONMENTAL HEALTH EMERGENCY MANAGEMENT and MISSION CONTINUITY FIRE PREVENTION and LIFE SAFETY GENERAL SAFETY TRAINING

  13. Nanotechnology in radiation oncology.

    PubMed

    Wang, Andrew Z; Tepper, Joel E

    2014-09-10

    Nanotechnology, the manipulation of matter on atomic and molecular scales, is a relatively new branch of science. It has already made a significant impact on clinical medicine, especially in oncology. Nanomaterial has several characteristics that are ideal for oncology applications, including preferential accumulation in tumors, low distribution in normal tissues, biodistribution, pharmacokinetics, and clearance, that differ from those of small molecules. Because these properties are also well suited for applications in radiation oncology, nanomaterials have been used in many different areas of radiation oncology for imaging and treatment planning, as well as for radiosensitization to improve the therapeutic ratio. In this article, we review the unique properties of nanomaterials that are favorable for oncology applications and examine the various applications of nanotechnology in radiation oncology. We also discuss the future directions of nanotechnology within the context of radiation oncology. PMID:25113769

  14. Nuclear radiation detectors

    Microsoft Academic Search

    Luiz Alexandre Schuch; Daniel Jean Roger Nordemann

    1990-01-01

    Detectors of nuclear radiation, such as gaseous detectors, scintillators, and semiconductors, are presented through their general properties and with their operating systems. The semiconductor detectors are studied with more details.

  15. SOLAR RADIATION, VA

    EPA Science Inventory

    Sterling, Virginia Integrated Surface Irradiance Study (ISIS) solar radiation data files from National Oceanic and Atmospheric Administration (NOAA), zipped from ftp://ftp.atdd.noaa.gov/pub/projects/isis/ste/monthly...

  16. Microwave Radiation Detector

    NASA Technical Reports Server (NTRS)

    Lesh, J. R.

    1984-01-01

    Direct photon detector responds to microwave frequencies. Method based on trapped-ion frequency-generation standards proposed to detect radio-frequency (RF) radiation at 40.5 GHz. Technique used for directdetection (RF) communication, radar, and radio astronomy.

  17. Pregnancy and Radiation Exposure

    MedlinePLUS

    ... Exposure to the Embryo or Fetus from Diagnostic Nuclear Medicine Pregnant women may be administered radioactive materials ... determination be obtained from the health physicist, a nuclear medicine physician, or a radiation oncologist associated with ...

  18. Rf radiation: biological effects

    SciTech Connect

    Lerner, E.J.

    1980-12-01

    The controversy surrounding the biological effects and health hazards of radio-frequency (RF) radiation (below the infrared frequency of 300 gHz) is examined. The average person is exposed to only extremely low levels of RF radiation. However, a substantial fraction of the population receives higher than average exposures because of increased use of microwave ovens and citizens band radios. Possible effects of exposure to RF radiation on brain function are investigated. Results of limited studies of long-term low-level effects are presented. The question of legal liability concerning exposure of the general public to RF radiation generated by microwave ovens and FM antennas is explored. (4 diagrams, 4 graphs, 1 table)

  19. Radiation and Society

    ERIC Educational Resources Information Center

    Shaw, Edward I.

    1974-01-01

    Presents a discussion of the risks, to society, from radiation-associated technologies and urges that science teachers help the public understand the decision-making process relative to nuclear power as well as the problems and alternatives. (PEB)

  20. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Lahorte, Philippe; Mondelaers, Wim

    This chapter represents the second part of a review in which the production and application of radiation-induced radicals in biological matter are discussed. In part one the general aspects of the four stages (physical, physicochemical, chemical and biological) of interaction of radiation with matter in general and biological matter in particular, were discussed. Here an overview is presented of modem technologies and theoretical methods available for studying these radiation effects. The relevance is highlighted of electron paramagnetic resonance spectroscopy and quantum chemical calculations with respect to obtaining structural information on bioradicals, and a survey is given of the research studies in this field. We also discuss some basic aspects of modem accelerator technologies which can be used for creating radicals and we conclude with an overview of applications of radiation processing in biology and related fields such as biomedical and environmental engineering, food technology, medicine and pharmacy.

  1. Photochemistry Radiation and Photolysiss

    E-print Network

    Toohey, Darin W.

    Photochemistry Radiation and Photolysiss Objectives · Review the electromagnetic spectrum · Review #12;The Electromagnetic Spectrum For more information on the electromagnetic spectrum, see this website. #12;Essentials of Electromagnetic Energy The "unit" of electromagnetic energy is the photon

  2. Photochemistry Radiation and Photolysis

    E-print Network

    Toohey, Darin W.

    Photochemistry Radiation and Photolysis Objectives · Review the electromagnetic spectrum · Review covalent) #12;The Electromagnetic Spectrum For more information on the electromagnetic spectrum, see this website. #12;Essentials of Electromagnetic Energy The "unit" of electromagnetic energy is the photon

  3. Occupational Radiation Exposures

    Cancer.gov

    DCEG researchers are studying cancer risks among populations who are occupationally exposed to radiation. Chernobyl Clean-up Workers Mayak Nuclear Facility Workers U.S. Radiologic Technologists Interventional Fluoroscopists Print This Page Occupational

  4. Types of Radiation Emergencies

    MedlinePLUS

    ... a radiation emergency happens in your area. Â Nuclear Emergencies A nuclear emergency involves the explosion of ... their knowledge. Learn more about radiological exposure devices Nuclear Power Plant Accident An accident at a nuclear ...

  5. Pulse radiation of four-element large current radiator

    Microsoft Academic Search

    G. P. Pochanin

    1999-01-01

    One of the most important problems in modern ground penetrating radar design is creating ultra wide band (UWB) antennas for short sounding electromagnetic pulses (SP) of radiation. Important requirements for antennas of this kind are the elimination of “ringing” and efficiency. Promising UWB\\/SP radiators, which satisfy these conditions have been proposed by Harmuth. These radiators are named large current radiators

  6. Radiation Protection and Licensing FNAL Radiation Physics Team

    E-print Network

    McDonald, Kirk

    Radiation Protection and Licensing K. Vaziri, FNAL Radiation Physics Team Proton Accelerators, 2012 #12;January 13, 2012 Radiation Protection and Licensing 2 Radiation Protection and Licensing 1 5. Tritium control and ground-water protection 6. Radioactive component storage 7. Repair

  7. Method of enhancing radiation response of radiation detection materials

    DOEpatents

    Miller, Steven D. (Richland, WA)

    1997-01-01

    The present invention is a method of increasing radiation response of a radiation detection material for a given radiation signal by first pressurizing the radiation detection material. Pressurization may be accomplished by any means including mechanical and/or hydraulic. In this application, the term "pressure" includes fluid pressure and/or mechanical stress.

  8. THz radiation sensors

    Microsoft Academic Search

    F. Sizov

    2010-01-01

    In the paper, issues associated with the development and exploitation of terahertz (THz) radiation detectors are discussed.\\u000a The paper is written for those readers who desire an analysis of the latest developments in different type of THz radiation\\u000a sensors (detectors), which play an increasing role in different areas of human activity (e.g., security, biological, drugs\\u000a and explosions detection, imaging, astronomy

  9. Automated personnel radiation monitor

    Microsoft Academic Search

    1981-01-01

    An automated Personnel Low-Level Radiation Portal Monitor has been developed by UNC Nuclear Industries, Inc. It is micro-computer controlled and uses nineteen large gas flow radiation detectors. By employing a micro-computer, sophisticated mathematical analysis is used on the detector informational data base to determine the statistical probability of contamination. This system provides for: (1) Increased sensitivity to point source contamination;

  10. Radiation resistance of elastomers

    SciTech Connect

    Lee, G.

    1985-10-01

    Various data has indicated that some elastomers have much higher radiation resistance than Viton. Nine samples of elastomers were irradiated with gamma rays. Two Ethylene Propylene Diene compounds, EPDM's, were found to exhibit acceptable properties for o-rings after radiation levels of 5x10Y rads, while Viton failed at 1x10X rads. Vacuum tests also were favorable so EPDM o-rings were chosen as seals in the Energy Saver cryostat vacuum system.

  11. [Radiation protection in radiation oncology. Yesterday, today, and tomorrow].

    PubMed

    Herrmann, Th; Müller, R

    2012-11-01

    Publications about radiation protection issues are not very frequent in the 100-year-old history of Strahlentherapie und Onkologie. While at the beginning of the last century the problems of radiation protection were determined by the technical development of radiation therapy, the importance of radiation protection measures and knowledge about radiation protection by the persons involved has clearly increased. A new challenge is treating patients according to radiation safety issues to avoid the risk of stochastic late effects, such as radiation-induced secondary tumors. PMID:22907582

  12. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles.

    PubMed

    Dörr, Harald; Meineke, Viktor

    2011-01-01

    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed. PMID:22114866

  13. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

    PubMed Central

    2011-01-01

    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed. PMID:22114866

  14. Radiator Design and Installation

    NASA Technical Reports Server (NTRS)

    Brevoort, M.J.; Leifer, M.

    1939-01-01

    The fundamental principles of fluid flow, pressure losses, and heat transfer have been presented and analyzed for the case of a smooth tube with fully developed turbulent flow. These equations apply to tubes with large length-diameter ratios where the f1ow is at a high Reynolds Number. The error introduced by using these equations increases as the magnitude of the tube length and the air-flow Reynolds Number approaches the values encountered in modern radiator designs. Accordingly, heat-transfer tests on radiator sections were made and the results are presented in nondimensional form to facilitate their use and for comparison with other heat-transfer data. In addition, pressure losses were measured along smooth tubes of circular, square, and rectangular cross section and the results were also correlated and are presented in nondimensional form. The problem of a radiator design for a particular installation is solved, the experimental heat-transfer and pressure-loss data being used, on a basis of power chargeable to the radiator for form drag, for propelling the weight, and for forcing the air through the radiator. The case of an installation within a wing or an engine nacelle is considered. An illustration of radiator design is carried through for an arbitrary set of conditions. Sufficient detail is given to enable the reader to reproduce the analysis for any given case.

  15. Radiation disasters and children.

    PubMed

    2003-06-01

    The special medical needs of children make it essential that pediatricians be prepared for radiation disasters, including 1) the detonation of a nuclear weapon; 2) a nuclear power plant event that unleashes a radioactive cloud; and 3) the dispersal of radionuclides by conventional explosive or the crash of a transport vehicle. Any of these events could occur unintentionally or as an act of terrorism. Nuclear facilities (eg, power plants, fuel processing centers, and food irradiation facilities) are often located in highly populated areas, and as they age, the risk of mechanical failure increases. The short- and long-term consequences of a radiation disaster are significantly greater in children for several reasons. First, children have a disproportionately higher minute ventilation, leading to greater internal exposure to radioactive gases. Children have a significantly greater risk of developing cancer even when they are exposed to radiation in utero. Finally, children and the parents of young children are more likely than are adults to develop enduring psychologic injury after a radiation disaster. The pediatrician has a critical role in planning for radiation disasters. For example, potassium iodide is of proven value for thyroid protection but must be given before or soon after exposure to radioiodines, requiring its placement in homes, schools, and child care centers. Pediatricians should work with public health authorities to ensure that children receive full consideration in local planning for a radiation disaster. PMID:12777572

  16. Numerical Radiative Transfer

    NASA Astrophysics Data System (ADS)

    Kalkofen, Wolfgang

    2009-07-01

    Preface; Introduction; Part I. Operator Perturbation: 1. Survey of operator perturbation methods W. Kalkofen; 2. Line formation in expanding atmospheres: multilevel calculations using approximate lambda operators W. R. Hamann; 3. Stellar atmospheres in non-LTE: model construction and line formation calculations using approximate lambda operators K. Werner; 4. Acceleration of convergence L. H. Auer; 5. Line formation in a time-dependent atmosphere W. Kalkofen; 6. Iterative solution of multilevel transfer problems Eugene H. Avrett and Rudolf Loeser; 7. An algorithm for the simultaneous solution of thousands of transfer equations under global constraints Lawrence S. Anderson; 8. Operator perturbation for differential equations W. Kalkofen; Part II. Polarised Radiation: 9. A gentle introduction to polarised radiative transfer David E. Rees; 10. Non-LTE polarised radiative transfer in special lines David E. Rees and Graham A. Murphy; 11. Transfer of polarised radiation using 4x4 matrices E. Landi Degli'Innocenti; 12. Radiative transfer in the presence of strong magnetic fields A. A. van Ballegooijen; 13. An integral operator technique of radiative transfer in spherical symmetry A. Peraiah; 14. Discrete ordinate matrix method M. Schmidt and R. Wehrse.

  17. RADIATION PROTECTION KEYWORDS: equivalent sphere

    E-print Network

    Lin, Zi-wei

    RADIATION PROTECTION KEYWORDS: equivalent sphere model, space radiation, organ dose IMPROVEMENT OF THE EQUIVALENT SPHERE MODEL FOR SPACE RADIATION ENVIRONMENTS Z. W. LIN East Carolina University, Department Accepted for Publication January 21, 2009 In space radiation calculations it is often useful to calculate

  18. Radiation oncogenesis in cell culture

    SciTech Connect

    Borek, C.

    1982-01-01

    This review article examines the oncogenic effects of radiation with emphasis on ionizing radiations. Cell transformation in vitro is examined with respect to culture systems currently used in these studies, initiation and phenotypic expression of transformation and criteria for transformation. The section of radiation oncogenesis in vitro includes ionizing and nonionizing radiation studies and cocarcinogens and modulators of radiogenic transformations.

  19. The Radiation Chemistry Data Center

    NSDL National Science Digital Library

    Madden, K.P.

    The Radiation Chemistry Data Center is an information resource provided by the Notre Dame Radiation Laboratory that is "dedicated to the collection, evaluation, and dissemination of data characterizing the reactions of transient intermediates produced by radiation chemical and photochemical methods." The main page offers links to Compilations of Chemical Property Data, Kinetics Databases, a Bibliographic Database, and Recent Papers in Radiation Chemistry and Photochemistry.

  20. Radiation Sensitization in Cancer Therapy.

    ERIC Educational Resources Information Center

    Greenstock, Clive L.

    1981-01-01

    Discusses various aspects of radiation damage to biological material, including free radical mechanisms, radiation sensitization and protection, tumor hypoxia, mechanism of hypoxic cell radiosensitization, redox model for radiation modification, sensitizer probes of cellular radiation targets, pulse radiolysis studies of free radical kinetics,…

  1. Method for microbeam radiation therapy

    Microsoft Academic Search

    D. N. Slatkin; F. A. Dilmanian; P. O. Spanne

    1994-01-01

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the

  2. Radiation health research, 1986 - 1990

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A collection of 225 abstracts of radiation research sponsored by NASA during the period 1986 through 1990 is reported. Each abstract was categorized within one of four discipline areas: physics, biology, risk assessment, and microgravity. Topic areas within each discipline were assigned as follows: Physics - atomic physics, nuclear science, space radiation, radiation transport and shielding, and instrumentation; Biology - molecular biology, cellular radiation biology, tissue, organs and organisms, radioprotectants, and plants; Risk assessment - radiation health and epidemiology, space flight radiation health physics, inter- and intraspecies extrapolation, and radiation limits and standards; and Microgravity. When applicable subareas were assigned for selected topic areas. Keywords and author indices are provided.

  3. Reducing Radiation Damage

    SciTech Connect

    Blankenbecler, Richard

    2006-06-05

    This talk describes the use of a modified treatment sequence, i.e., radiation dose, geometry, dwell time, etc., to mitigate some of the deleterious effects of cancer radiotherapy by utilizing natural cell repair processes. If bad side effects can be reduced, a more aggressive therapy can be put into place. Cells contain many mechanisms that repair damage of various types. If the damage can not be repaired, cells will undergo apoptosis (cell death). Data will be reviewed that support the fact that a small dose of radiation will activate damage repair genes within a cell. Once the mechanisms are fully active, they will efficiently repair the severe damage from a much larger radiation dose. The data ranges from experiments on specific cell cultures using microarray (gene chip) techniques to experiments on complete organisms. The suggested effect and treatment is consistent with the assumption that all radiation is harmful, no matter how small the dose. Nevertheless, the harm can be reduced. These mechanisms need to be further studied and characterized. In particular, their time dependence needs to be understood before the proposed treatment can be optimized. Under certain situations it is also possible that the deleterious effects of chemotherapy can be mitigated and the damage to radiation workers can be reduced.

  4. Ionizing radiation and life.

    PubMed

    Dartnell, Lewis R

    2011-01-01

    Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wide-ranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and the origins of life. This review surveys the role of CR and mineral radioactivity in star formation, generation of biogenic elements, and the synthesis of organic molecules and driving of prebiotic chemistry. Another major theme is the multiple layers of shielding of planetary surfaces from the flux of cosmic radiation and the various effects on a biosphere of violent but rare astrophysical events such as supernovae and gamma-ray bursts. The influences of CR can also be duplicitous, such as limiting the survival of surface life on Mars while potentially supporting a subsurface biosphere in the ocean of Europa. This review highlights the common thread that ionizing radiation forms between the disparate component disciplines of astrobiology. PMID:21774684

  5. Characteristics of synchrotron radiation

    SciTech Connect

    Thomlinson, W.

    1984-01-01

    Synchrotron radiation is having a very significant impact on the many disciplines that make use of the radiation in the x-ray, vacuum ultraviolet, and infra-red regions of the spectrum. The rapidly increasing demand for beam time at existing facilities, the construction and commissioning of new facilities, and the world wide planning for future sources is clear testimony to the unique, interdisciplinary nature of the research applications. The nature of synchrotron radiation research continues to change and expand. This conference on the application of synchrotron radiation (SR) to polymer research illustrates that point. In this introductory paper it is impossible to cover in depth any of the applications. The intent, instead, is to give a brief, condensed summary of the properties of SR which have brought it to the fore as a research tool. No single source can provide the proper radiation for all applications. This paper should provide enough information and references to allow anyone contemplating a particular experiment to understand the widely varying parameters from different facilities, and thereby make some initial decisions concerning feasibility, and proper source. The NSLS will, in general, be used for illustration purposes since the conference is being held at Brookhaven where the attendees can get first hand familiarity with the facility.

  6. Radiometry Using Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Saloman, E. B.; Ebner, S. C.; Hughey, L. R.

    1981-11-01

    Synchrotron radiation is a source of continuum radiation ranging from the x-ray or soft x-ray region (depending on machine energy) to beyond the visible region. The amount of radiation emitted is a calculable function of machine operating parameters. This makes it possible to use synchrotron radiation from electron synchrotrons and electron storage rings as an absolute source particularly in the VUV and soft x-ray regions where other standards are difficult to find. At the National Bureau of Standards (NBS) an electron storage ring (SURF-II) has been used to calibrate spectrometers and photometers used in solar and aeronomy research and in fusion plasma diagnostics. A large chamber has recently been completed to facilitate such calibrations. The radiation incident on these spectrometers can be calculated to uncertainties of 3%. A technique to exactly determine the number of electrons orbiting in the ring is currently being developed to reduce this uncertainty. Detector calibrations between 5 - 55 nm are routinely carried out at SURF-II and transfer standard detectors with 6-10% uncertainties over the range of 5 - 254 nm are supplied. Special studies of "practical", high efficiency, and disposable photodiodes have been made by NBS in collaboration with other groups.

  7. Radiation Shielding Materials

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    NASA has relied on the materials to provide radiation shielding for astronauts since the first manned flights. Until very recently existing materials in the structure of manned spacecraft as well as the equipment and consumables onboard have been taken advantage of for radiation shielding. With the advent of the International Space Station and the prospect of extended missions to the Moon or Mars, it has been found that the materials, which were included in the spacecraft for other reasons, do not provide adequate shielding. For the first time materials are being added to manned missions solely to improve the radiation shielding. It is now recognized that dual use materials must be identified/developed. These materials must serve a purpose as part of the spacecraft or its cargo and at the same time be good shielding. This paper will review methods for evaluating the radiation shielding effectiveness of materials and describe the character of materials that have high radiation shielding effectiveness. Some candidate materials will also be discussed.

  8. Lunar radiator shade

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (inventor)

    1992-01-01

    An apparatus for rejecting waste heat from a system located on or near the lunar equator is presented. The system utilizes a reflective catenary shaped trough deployed about a vertical radiator to shade the radiator from heat emitted by the hot lunar surface. The catenary shaped trough is constructed from a film material and is aligned relative to the sun so that incoming solar energy is focused to a line just above the vertical radiator and can thereby isolate the radiator from the effects of direct sunlight. The film is in a collapsed position between side by side support rods, all of which are in a transport case. To deploy the film and support rods, a set of parallel tracks running perpendicular to length of the support rods are extended out from the transport case. After the support tracks are deployed, the support rods are positioned equidistant from each other along the length of the support tracks so that the flexible film shade between adjacent support rods is unfolded and hangs in a catenary shaped trough. A heat radiator is supported between each pair of support rods above each hanging reflective trough.

  9. Packet personal radiation monitor

    DOEpatents

    Phelps, J.E.

    1988-03-31

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiatonevents, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible ''chirp''. The rate of the ''chirps'' is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field. 2 figs.

  10. Coherent Nuclear Radiation

    E-print Network

    V. I. Yukalov; E. P. Yukalova

    2004-06-22

    The main part of this review is devoted to the comprehensive description of coherent radiation by nuclear spins. The theory of nuclear spin superradiance is developed and the experimental observations of this phenomenon are considered. The intriguing problem of how coherence develops from initially incoherent quantum fluctuations is analysed. All main types of coherent radiation by nuclear spins are discussed, which are: free nuclear induction, collective induction, maser generation, pure superradiance, triggered superradiance, pulsing superradiance, punctuated superradiance, and induced emission. The influence of electron-nuclear hyperfine interactions and the role of magnetic anisotropy are studied. Conditions for realizing spin superradiance by magnetic molecules are investigated. The possibility of nuclear matter lasing, accompanied by pion or dibaryon radiation, is briefly touched.

  11. Radiation-associated thyrotoxicosis

    SciTech Connect

    Katayama, S.; Shimaoka, K.; Osman, G.

    1986-10-01

    We studied 154 consecutive patients with a diagnosis of thyrotoxicosis seen at Roswell Park Memorial Institute from 1963 to 1982. The retrospective review of the clinical materials revealed that 23 (15%) had a previous history of therapeutic radiation for various diseases. The radiation dose ranged from several to 3600 rads to the thyroid with a mean latency of 14.2 +/- 3.0 years. In 11 out of 16 patients who were tested for antithyroglobulin and antimicrosomal showed positive titers of either or both antibodies (69%). In a small number of patients, thyroid stimulating immunoglobulins were studied; long-acting thyroid stimulators (LATS) were positive in one of six tested and thyrotrophin binding inhibitory immunoglobulins (TBII) in five of eight. The radiation-associated thyroidal dysfunction appears to be associated with the organ-specific autoimmune processes and could manifest as either hypo- or hyperfunction of the gland.

  12. Aerothermodynamic radiation studies

    NASA Technical Reports Server (NTRS)

    Donohue, K.; Reinecke, W. G.; Rossi, D.; Marinelli, W. J.; Krech, R. H.; Caledonia, G. E.

    1991-01-01

    We have built and made operational a 6 in. electric arc driven shock tube which alloys us to study the non-equilibrium radiation and kinetics of low pressure (0.1 to 1 torr) gases processed by 6 to 12 km/s shock waves. The diagnostic system allows simultaneous monitoring of shock radiation temporal histories by a bank of up to six radiometers, and spectral histories with two optical multi-channel analyzers. A data set of eight shots was assembled, comprising shocks in N2 and air at pressures between 0.1 and 1 torr and velocities of 6 to 12 km/s. Spectrally resolved data was taken in both the non-equilibrium and equilibrium shock regions on all shots. The present data appear to be the first spectrally resolved shock radiation measurements in N2 performed at 12 km/s. The data base was partially analyzed with salient features identified.

  13. Radiation rate meter development

    SciTech Connect

    Thacker, L.H.

    1989-01-01

    We are still in a very preliminary stage of examining the potentials of a new series of instruments which may be inexpensive and versatile enough to complement, or conceivably even replace, electroscope dosimeters in Civil Defense and other situations requiring radiation monitoring by the general public. These instruments were developed to provide a qualitative signal so simple to interpret that anyone can tell immediately whether they are in a dangerous radiation field, and whether they are moving into a hotter area or a cooler area. A second goal in the development has been to produce the simplest possible device at minimum cost, without compromise in effectiveness. In the simplest implementation the device is essentially a very inexpensive version of the much older Personal Radiation Monitor (PRM).

  14. Uses of synchrotron radiation

    SciTech Connect

    Gordon, B.M.

    1982-01-01

    X-ray fluorescence has long been used as a technique for elemental analysis. X-ray fluorescence techniques have a number of features that make them attractive for application to biomedical samples. In the past few years synchrotron radiation x-ray sources have been developed and, because of their properties, their use can improve the sensitivity for trace element analysis by two to three orders of magnitude. Also, synchrotron radiation will make possible an x-ray microprobe with resolution in the micrometer range. The National Synchrotron Light Source (NSLS), a dedicated synchrotron radiation source recently built at Brookhaven National Laboratory, will have a facility for trace element analysis by x-ray fluorescence and will be available to all interested users.

  15. Saturn Radiation (SATRAD) Model

    NASA Technical Reports Server (NTRS)

    Garrett, H. B.; Ratliff, J. M.; Evans, R. W.

    2005-01-01

    The Saturnian radiation belts have not received as much attention as the Jovian radiation belts because they are not nearly as intense-the famous Saturnian particle rings tend to deplete the belts near where their peak would occur. As a result, there has not been a systematic development of engineering models of the Saturnian radiation environment for mission design. A primary exception is that of Divine (1990). That study used published data from several charged particle experiments aboard the Pioneer 1 1, Voyager 1, and Voyager 2 spacecraft during their flybys at Saturn to generate numerical models for the electron and proton radiation belts between 2.3 and 13 Saturn radii. The Divine Saturn radiation model described the electron distributions at energies between 0.04 and 10 MeV and the proton distributions at energies between 0.14 and 80 MeV. The model was intended to predict particle intensity, flux, and fluence for the Cassini orbiter. Divine carried out hand calculations using the model but never formally developed a computer program that could be used for general mission analyses. This report seeks to fill that void by formally developing a FORTRAN version of the model that can be used as a computer design tool for missions to Saturn that require estimates of the radiation environment around the planet. The results of that effort and the program listings are presented here along with comparisons with the original estimates carried out by Divine. In addition, Pioneer and Voyager data were scanned in from the original references and compared with the FORTRAN model s predictions. The results were statistically analyzed in a manner consistent with Divine s approach to provide estimates of the ability of the model to reproduce the original data. Results of a formal review of the model by a panel of experts are also presented. Their recommendations for further tests, analyses, and extensions to the model are discussed.

  16. Radar frequency radiation

    NASA Astrophysics Data System (ADS)

    Malowicki, E.

    1981-11-01

    A method is presented for the determination of radar frequency radiation power densities that the PAVE PAWS radar system could produce in its air and ground environment. The effort was prompted by the concern of the people in the vicinity of OTIS AFB MA and BEALE AFB CA about the possible radar frequency radiation hazard of the PAVE PAWS radar. The method is based on the following main assumptions that: (a) the total field can be computed as the vector summation of the individual fields due to each antenna element; (b) the individual field can be calculated using distances for which the field point is in the far field of the antenna element. An RFR computer program was coded for the RADC HE 6180 digital computer and exercised to calculate the radiation levels in the air and ground space for the present baseline and the possible Six DB and 10 DB growth systems of the PAVE PAWS radar system at OTIS AFB MA. The average radiation levels due to the surveillance fence were computed for three regions: in the air space in front of the radar, at the radar hazard fence at OTIS AFB MA and at representative ground points in the OTIS AFB vicinity. It was concluded that the radar frequency radiation of PAVE PAWS does not present a hazard to personnel provided there is no entry to the air hazard zone or to the area within the hazard fence. The method developed offers a cost effective way to determine radiation levels from a phased array radar especially in the near field and transition regions.

  17. Radiation Hazard Detector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NASA technology has made commercially available a new, inexpensive, conveniently-carried device for protection, of people exposed to potentially dangerous levels of microwave radiation. Microwaves are radio emissions of extremely high frequency. They can be hazardous but the degree of hazard is not yet well understood. Generally, it is believed that low intensity radiation of short duration is not harmful but that exposure to high levels can induce deep internal burns, affecting the circulatory and nervous systems, and particularly the eyes. The Department of Labor's Occupational Safety and Health Administration (OSHA) has established an allowable safe threshold of exposure. However, people working near high intensity sources of microwave energy-for example, radar antennas and television transmitters-may be unknowingly exposed to radiation levels beyond the safe limit. This poses not only a personal safety problem but also a problem for employers in terms of productivity loss, workman's compensation claims and possible liability litigation. Earlier-developed monitoring devices which warn personnel of dangerous radiation levels have their shortcomings. They can be cumbersome and awkward to use while working. They also require continual visual monitoring to determine if a person is in a dangerous area of radiation, and they are relatively expensive, another deterrent to their widespread adoption. In response to the need for a cheaper and more effective warning system, Jet Propulsion Laboratory developed, under NASA auspices, a new, battery-powered Microwave Radiation Hazard Detector. To bring the product to the commercial market, California Institute Research Foundation, the patent holder, granted an exclusive license to Cicoil Corporation, Chatsworth, California, an electronic components manufacturer.

  18. Radiation Monitoring Equipment Dosimeter Experiment

    NASA Technical Reports Server (NTRS)

    Hardy, Kenneth A.; Golightly, Michael J.; Quam, William

    1992-01-01

    Spacecraft crews risk exposure to relatively high levels of ionizing radiation. This radiation may come from charged particles trapped in the Earth's magnetic fields, charged particles released by solar flare activity, galactic cosmic radiation, energetic photons and neutrons generated by interaction of these primary radiations with spacecraft and crew, and man-made sources (e.g., nuclear power generators). As missions are directed to higher radiation level orbits, viz., higher altitudes and inclinations, longer durations, and increased flight frequency, radiation exposure could well become a major factor for crew stay time and career lengths. To more accurately define the radiological exposure and risk to the crew, real-time radiation monitoring instrumentation, which is capable of identifying and measuring the various radiation components, must be flown. This presentation describes a radiation dosimeter instrument which was successfully flown on the Space Shuttle, the RME-3.

  19. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Tada, H. Y.; Carter, J. R., Jr.

    1977-01-01

    Solar cell theory cells are manufactured, and how they are modeled mathematically is reviewed. The interaction of energetic charged particle radiation with solar cells is discussed in detail and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Finally, an extensive body of data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence is presented.

  20. LDEF Satellite Radiation Analyses

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.

    1996-01-01

    Model calculations and analyses have been carried out to compare with several sets of data (dose, induced radioactivity in various experiment samples and spacecraft components, fission foil measurements, and LET spectra) from passive radiation dosimetry on the Long Duration Exposure Facility (LDEF) satellite, which was recovered after almost six years in space. The calculations and data comparisons are used to estimate the accuracy of current models and methods for predicting the ionizing radiation environment in low earth orbit. The emphasis is on checking the accuracy of trapped proton flux and anisotropy models.

  1. Mycosis fungoides: radiation therapy.

    PubMed

    Hoppe, Richard T

    2003-01-01

    Radiation therapy is the most effective single agent for the treatment of mycosis fungoides. There are well-defined dose-response relationships for achieving a complete response as well as the durability of this response. Techniques of electron beam therapy have been developed that permit treatment of the entire skin. Total-skin electron beam therapy is an important form of management, especially for patients who have thick generalized plaque or tumorous disease. Radiation therapy may also be used selectively for treatment of extracutaneous disease. PMID:14686978

  2. Modification of radiation response

    SciTech Connect

    Suit, H.D.

    1984-01-01

    There has been a substantial and intense interest by laboratory and clinical investigators in the development of agents which modify the response of tissue to radiation differentially so as to increase the effect on tumor relative to normal tissue. These have included efforts to increase the response of tumor or to decrease response of normal tissue. The plan of this presentation is to: define radiation response modifiers; consider the impact of response modifiers on dose response curves; comment on problems inherent in assessment of results of clinical trials of response modifiers; and review briefly results of several trials of: sensitizers of hypoxic cells (hyperbaric oxygen, chemical sensitizer), pyrimidine analogs, and protectors.

  3. Wireless passive radiation sensor

    DOEpatents

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  4. Radiation monitor for liquids

    DOEpatents

    Koster, James E. (Los Alamos, NM); Bolton, Richard D. (Los Alamos, NM)

    1999-01-01

    A radiation monitor for use with liquids that utilizes air ions created by alpha radiation emitted by the liquids as its detectable element. A signal plane, held at an electrical potential with respect to ground, collects these air ions. A guard plane or guard rings is used to limit leakage currents. In one embodiment, the monitor is used for monitoring liquids retained in a tank. Other embodiments monitor liquids flowing through a tank, and bodies of liquids, such as ponds, lakes, rivers and oceans.

  5. Radiation Safety in Pediatric Orthopaedics.

    PubMed

    Caird, Michelle S

    2015-01-01

    Patients, surgeons, and staff are exposed to ionizing radiation in pediatric orthopaedic surgery from diagnostic studies and imaging associated with procedures. Estimating radiation dose to pediatric patients is based on complex algorithms and dose to surgeons and staff is based on dosimeter monitoring. Surgeons can decrease radiation exposure to patients with careful and thoughtful ordering of diagnostic studies and by minimizing exposure intraoperatively. Surgeon and staff radiation exposure can be minimized with educational programs, proper shielding and positioning intraoperatively, and prudent use of intraoperative imaging. Overall, better awareness among pediatric orthopaedic surgeons of our role in radiation exposure can lead to improvements in radiation safety. PMID:26049299

  6. Ionizing radiation injuries and illnesses.

    PubMed

    Christensen, Doran M; Iddins, Carol J; Sugarman, Stephen L

    2014-02-01

    Although the spectrum of information related to diagnosis and management of radiation injuries and illnesses is vast and as radiation contamination incidents are rare, most emergency practitioners have had little to no practical experience with such cases. Exposures to ionizing radiation and internal contamination with radioactive materials can cause significant tissue damage and conditions. Emergency practitioners unaware of ionizing radiation as the cause of a condition may miss the diagnosis of radiation-induced injury or illness. This article reviews the pertinent terms, physics, radiobiology, and medical management of radiation injuries and illnesses that may confront the emergency practitioner. PMID:24275177

  7. Cataractogenic effects of proton radiation 

    E-print Network

    Kyzar, James Ronald

    1972-01-01

    Roentgen in 1895 it has been recognized that. ionizing radiation possesses the ability to damage the lens of the eye. A few cases of radiation induced cataracts in early x-ray technicians and in patients re- ceiving radiation therapy to the head were... reported (13) . During this period interest in the phenomenon of radiation damage was limited mainly to x-rays as this was the only type of ionizing radiation having any degree of wide- spread use. Also, study of such radiation cataracts was confined...

  8. RADIATION ALERT User Manual

    E-print Network

    Haller, Gary L.

    · Monitoring possible radiation exposure while working with radionuclides · Screening for environmental not contaminate the Inspector by touching it to radioactive surfaces or materials. If contamination is suspected be sensitive to and may not operate properly in radio frequency, microwave, electrostatic, and electromagnetic

  9. Radiation sources and process

    Microsoft Academic Search

    H. B. Honious; E. F. Janzow; H. A. Malson; S. E. Moyer

    1980-01-01

    The invention relates to radiation sources comprising a substrate having an electrically-conductive non-radioactive metal surface, a layer of a metal radioactive isotope of the scandium group, which in addition to scandium, yttrium, lanthanum and actinium, includes all the lanthanide and actinide series of elements, with the actinide series usually being preferred because of the nature of the radioactive isotopes therein,

  10. Psoriasis and ultraviolet radiation

    SciTech Connect

    Farber, E.M.; Nall, L. (Psoriasis Research Institute, Palo Alto, CA (United States))

    1993-09-01

    Prevention and detection screening programs as a public health service in curtailing the ever-increasing incidence of all forms of skin cancer are reviewed. The effect of solar and artificial ultraviolet radiation on the general population and persons with psoriasis is examined. 54 refs.

  11. Silicon radiation detectors

    Microsoft Academic Search

    Pavel Rehak

    2003-01-01

    A rapid progress of past 20 years in silicon radiation detectors is reviewed. The availability of silicon as almost ideal semiconductor material is one of the main reasons for this progress. The well-defined properties of the silicon-silicon dioxide interface allowed the development of detector structures beyond the structure of a classical diode detector, which was practically the only silicon detector

  12. Nuclear Radiation Detectors

    Microsoft Academic Search

    G. A. Morton

    1962-01-01

    Nuclear radiation detectors are required in all the major fields of nuclear science and technology. They fall into two principal categories, single element detectors and imaging detectors. Single element detectors can be classified into four types, based upon their physical mode of operation. These are 1) Scintillation counters, 2) Gas ionization detectors, a) Ionization chambers, b) Proportional counters, c) Geiger-Mueller

  13. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, D.C.

    1980-12-17

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein in the edge of which closely approaches but is spaced from the current collector strips.

  14. Radiation and human health

    Microsoft Academic Search

    Gofman

    1981-01-01

    A review of a book dealing with the estimation of human health effects of radiation is presented. Risk assessment for carcinogenesis is based on the author's own method of statistics so that standard statistical methods cannot be applied. Several examples of the author's fallacies are discussed in this book review. (KRM)

  15. Compound semiconductor radiation detectors

    Microsoft Academic Search

    Alan Owens; A. Peacock

    2004-01-01

    We discuss the potential benefits of using compound semiconductors for the detection of X- and ?-ray radiation. While Si and Ge have become detection standards for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by one or more of their physical limitations; namely the need for ancillary cooling systems or bulky

  16. Atmospheric Processes--Radiation

    NSDL National Science Digital Library

    2010-01-01

    This activity begins with an explanation of the heat transfer processes in general and then focuses on radiation. In the activity, students investigate how different surfaces absorb heat and apply their experience with the surfaces to interpret real-world situations.

  17. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, Dimitrios C. (Oak Ridge, TN)

    1983-01-01

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein the edge of which closely approaches but is spaced from the current collector strips.

  18. Transition radiation detectors

    Microsoft Academic Search

    Boris Dolgoshein

    1993-01-01

    The use of transition radiation (TR) as a means of identifying high energy particles has now become a subject of intensive experimental investigations and applications. Our intention is first to study the physics of these phenomena and to describe ways of building detectors which can efficiently identify particles.

  19. Cosmic microwave background radiation

    Microsoft Academic Search

    Lyman Page; David Wilkinson

    1999-01-01

    The cosmic microwave background radiation (CMBR) is widely interpreted as the thermal afterglow of a hot big bang. Measurements of the CMBR intensity as a function of frequency constrain the history of cosmic energetics. Measurements of the anisotropy in the CMBR temperature provide a snapshot of the distribution of fluctuations in the gravitational potential at the earliest stages of cosmic

  20. Thermostatic Radiator Valve Evaluation

    SciTech Connect

    Dentz, Jordan [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States); Ansanelli, Eric [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States)

    2015-01-01

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.

  1. Microwave radiation monitor

    SciTech Connect

    Aslan, E.E.

    1984-01-03

    This portable microwave radiation monitor utilizes an antenna formed in a dual Archimedean spiral. The ellipse ratio of the spiral is minimized by selective placement of resistive means over a portion of the antenna and the power density of the electric field is indicated on a meter connected via diode means to the inner terminals of the antenna.

  2. CCTV for radiation environments

    SciTech Connect

    Shaufl, R.A.

    1985-01-01

    The use of closed circuit television (CCTV) within radiation environments requires the system designer to have a thorough knowledge of the application environment and the electronic and optical components expected to survive within the environment. Of all the many ambient conditions to which CCTV components are exposed, from an air-conditioned office complex to 1,000 feet under the ocean, none is as demanding as the radiation encountered in the nuclear industrial field. Unhardened CCTV equipment can fail or degrade to the point of being useless when exposed to ionizing radiation doses of as little as 10/sup 3/ rads (Si) or to a neutron fluence of as little as 10/sup 11/ neutrons per square centimeter. (Rads (Si) stands for roentgens absorbed dose in silicon, while a fluence is defined as the time integral of neutron flux.) The applications for CCTV systems may require that each component within the system withstand a total ionizing radiation dose of 10/sup 8/ rads or greater.

  3. Radiation Dose Estimates from

    E-print Network

    Summary: Radiation Dose Estimates from Hanford Radioactive Material Releases to the Air and the Columbia River April 21,1994 TheTechnid Steering Panel of the Hanford - Environmental Dose Reconstruction HonfordEnvironmental DoseRecartnrczionProject,anddonot necessaii!~rcfrcnthe view ofCDC. ,: :: ::sr

  4. Amorphous silicon radiation detectors

    Microsoft Academic Search

    V. Perez-Mendez; S. N. Kaplan

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of

  5. Surface Radiation Budget

    NASA Technical Reports Server (NTRS)

    Stackhouse, Paul W. (Principal Investigator)

    The Surface Radiation Budget (SRB) data sets contain global 3-hourly, daily and monthly averages of surface longwave and shortwave radiative properties, cloud amount, and meteorological properties computed using models. The main input data for these models include cloud information, top-of-atmosphere radiances and profiles of atmospheric water vapor and temperature. Some of the input data include Earth Radiation Budget Energy (ERBE) top-of-atmosphere clear-sky albedo and International Satellite Cloud Climatology Project (ISCCP) radiances and cloud amount. SRB parameters derived for the renewable energy community are also available from the Surface meteorology and Solar Energy (SSE) data set. Other SRB data are available from Clouds and the Earth's Radiant Energy System (CERES) and Multi-angle Imaging SpectroRadiometer (MISR). [Mission Objectives] The objective of the SRB Project is to produce and archive a global data set of shortwave (SW) and longwave (LW) surface and top of the atmosphere parameters. The data generated in the SRB project may be used in conjunction with other data sets to facilitate the development of renewable energy resources and increase understanding of radiative properties within the meteorological community. [Temporal_Coverage: Start_Date=1983-07-01; Stop_Date=2005-06-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

  6. Hawking Radiation As Tunneling

    Microsoft Academic Search

    Maulik K. Parikh; Frank Wilczek

    2000-01-01

    We present a short and direct derivation of Hawking radiation as a tunneling process, based on particles in a dynamical geometry. The imaginary part of the action for the classically forbidden process is related to the Boltzmann factor for emission at the Hawking temperature. Because the derivation respects conservation laws, the exact spectrum is not precisely thermal. We compare and

  7. IONIZING RADIATION OF EGGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of eggs and egg products by Salmonella is associated with a significant number of illnesses in the U.S. each year. Ionizing radiation can inactivate Salmonella on the egg surface, in the egg white, and in the yolk of shell eggs, and has been approved by the U.S. FDA at doses up to 3.0...

  8. Radiation damage considerations

    Microsoft Academic Search

    B. R. T. Frost; B. R. T

    1975-01-01

    Radiation environments produce unique effects on the composition, microstructure, and defect population of alloys, resulting in time-dependent and time-independent change in mechanical properties. To illustrate these problems, the materials needs of the core of a Liquid Metal Fast Breeder Reactor (LMFBR) and of the first wall of a fusion reactor are discussed. In the case of the LMFBR core, the

  9. Nuclear Radiation Damages Minds!

    ERIC Educational Resources Information Center

    Blai, Boris, Jr.

    Professors Ernest Sternglass (University of Pittsburgh) and Steven Bell (Berry College) have assembled cogent, conclusive evidence indicating that nuclear radiation is associated with impaired cognition. They suggest that Scholastic Aptitude Scores (SATs), which have declined steadily for 19 years, will begin to rise. Their prediction is based on…

  10. Assessing exposure to radiation

    SciTech Connect

    Walter, K.

    1997-01-01

    Since the founding of Lawrence Livermore National Laboratory, we have been world leaders in evaluating the risks associated with radiation. Ultrasensitive tools allow us not only to measure radionuclides present in the body but also to reconstruct the radiation dose from past nuclear events and to project the levels of radiation that will still be present in the body for 50 years after the initial intake. A variety of laboratory procedures, including some developed here, give us detailed information on the effects of radiation at the cellular level. Even today, we are re-evaluating the neutron dose resulting from the bombing at Hiroshima. Our dose reconstruction and projection capabilities have also been applied to studies of Nagasaki, Chernobyl, the Mayak industrial complex in the former Soviet Union, the Nevada Test Site, Bikini Atoll, and other sites. We are evaluating the information being collected on individuals currently working with radioactive material at Livermore and elsewhere as well as previously collected data on workers that extends back to the Manhattan Project.

  11. Radiation: Balancing the Record

    Microsoft Academic Search

    Charles C. Mann

    1994-01-01

    This article reviews the radioactivity experiments performed on humans during the cold war, and examines the ethics of the experiments. The radiation experiments can be broadly classified into three groups: researchers knowingly inflicted potential harm, using methods questionable even by the then-current standards; the investigations involved good work by any standards with appropriate safeguards taken; and a third group which

  12. Radiation proteomics: a brief overview.

    PubMed

    Leszczynski, Dariusz

    2014-03-01

    Acute biological effects caused by the exposure to high doses of radiation, either ionizing or nonionizing, are relatively well-known but the delayed effects, occurring decades after exposure, are difficult to predict. The knowledge of the acute and delayed effects of the low doses of ionizing radiation (e.g. bystander effect) or nonionizing radiation (e.g. radiation emitted by wireless communication devices) is not yet reliably established. Often the acute effects of low doses are small and difficult to discover and replicate in scientific studies. Chronic effects of prolonged exposures to low-dose radiation for decades are virtually unknown and often not possible to predict on the basis of the knowledge gained from acute exposures to high doses of radiation. Physiological significance of the biological effects induced by low doses of radiation is not known. The same lack of predictability of outcomes applies to the delayed effects of high-dose radiation exposures. Proteomics, supplemented with other "omics" techniques, might be the best way forward to find out the target molecules of radiation, the biomarkers of radiation exposure and the physiological and health significance of the acute and delayed biological effects caused by the exposures to high- and low-dose radiation. However, the currently available database of radiation effects on proteomes is far too small to be useful in formulation of new hypotheses concerning health consequences of radiation exposures. PMID:24376023

  13. Solar radiation modeling and comparisons with current solar radiation models

    Microsoft Academic Search

    A. Mujahid; W. D. Turner

    1980-01-01

    Solar radiation models which can be used to predict global radiation from cloud cover data, and direct normal radiation from measurements of global have been developed for Blytheville, Arkansas. These models are compared to the current NOAA models used in the SOLMET weather tapes. The accuracies of the NOAA cloud cover model and the Randall and Whitson direct normal model

  14. Large current radiator for the short electromagnetic pulses radiation

    Microsoft Academic Search

    Gennadiy P. Pochanin

    1998-01-01

    One of the most important problems in modern ground penetrating radar design is creating the ultra wide band (UWB) antennas for short sounding electromagnetic pulses (SP) radiation. One of the promising UWB\\/SP radiators is the Large Current Radiator (LCR). This report discusses the performance of an improved design of a LCR

  15. DCTD — Radiation Research Program (RRP)

    Cancer.gov

    Of the many successful programs within the RRP grant and contract portfolio, several scientific advances are presented below, representing significant advances in treatment development, molecular radiation therapy, quality assurance for high-technology radiation therapy, and international networking.

  16. COLUMBIA UNIVERSITY Radiation Safety Program

    E-print Network

    Jia, Songtao

    this form to Radiation Safety's Dosimetry Program.) ___ Yes ___ No 1. Was the Dosimeter placed or stored ___ No 3. Did you hold a patient during radiation exposure? ___ Yes ___ No 4. Did you work significantly

  17. Glossary of Radiation Therapy Terms

    MedlinePLUS

    ... proper radiation dose for each patient’s cancer treatment Electron beam (ee- leck -tron): a stream of high-energy particles called electrons used to treat some skin cancers External radiation : ...

  18. American Society for Radiation Oncology

    MedlinePLUS

    ... Annual Meeting Annual Refresher Course State of the Art Radiation Therapy Best of ASTRO Multidisciplinary Head and ... Annual Meeting Annual Refresher Course State of the Art Radiation Therapy Best of ASTRO Multidisciplinary Head and ...

  19. gamma. radiation effects on Collembola

    SciTech Connect

    Loring, S.J.

    1985-12-01

    Pitfall traps were used to collect surface-active Collembola at intervals of 10-100 m from a ..gamma.. radiation source on Long Island, N.Y., during the summer of 1968. Thirty-two species of Collembola were collected along the radiation transect. Community diversities were similar at all intervals except 10 m. Collembola appeared resistant to ..gamma.. radiation; only chronic, very high ..gamma.. radiation exposure seriously affected population levels and community diversity of surface Collembola.

  20. Graphite-Fiber Heat Radiators

    NASA Technical Reports Server (NTRS)

    Phillips, Wayne M.

    1995-01-01

    Heat radiators of proposed type feature thermally conductive fibers protruding from metallic surfaces to provide increased heat-dissipation surface areas. Free of leaks and more reliable than radiators incorporating heat pipes. Also lightweight and relatively inexpensive. Radial graphite fibers carry heat away from spherical shell and radiate heat into space. Radiators prove useful on Earth in special industrial and scientific applications involving dissipation of heat in vacuum or in relatively still air.

  1. Gamma radiation field intensity meter

    DOEpatents

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  2. Gamma radiation field intensity meter

    DOEpatents

    Thacker, L.H.

    1995-10-17

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  3. Gamma radiation field intensity meter

    DOEpatents

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  4. Gamma radiation field intensity meter

    DOEpatents

    Thacker, L.H.

    1994-08-16

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  5. Carcinoma of the anal canal: radiation or radiation plus chemotherapy

    SciTech Connect

    Cummings, B.J.

    1983-09-01

    An editorial is presented which discusses the treatment of carcinoma of the anal canal. Following the initial report of the successful preoperative use of combined chemotherapy and radiation by Nigro in 1974, several centers have confirmed the effectiveness of such combinations either as preoperative or as definitive treatment of anal carcinomas, and many patients are now being referred for radiation therapy. The article by Cantril in this issue describe the successful treatment of anal carcinomas by radiation alone, and raises the important issue of whether radiation plus chemotherapy is more effective treatment than radiation alone for squamous or cloacogenic carcinomas arising in the anal canal or perianal area. Several studies are cited.

  6. Polarization properties of boson radiation

    Microsoft Academic Search

    V. G. Bagrov

    1965-01-01

    The polarization properties of boson radiation in a magnetic field have been studied, and expressions obtained for the integral intensity of boson and fermion radiation in a magnetic field which are suitable for random energies. The investigation of boson radiation in an external field is of limited practical interest; however, from the methodological point of view it is very instructive

  7. Radiation Protection in Interventional Radiology

    Microsoft Academic Search

    DECLAN R. JOHNSON; JOHN KYRIOU; EDWARD J. MORTON; ANDREW CLIFTON; MICHAEL FITZGERALD; EMER MACSWEENEY

    2001-01-01

    There is growing concern regarding the radiation dose delivered during interventional procedures, particularly in view of the increasing frequency and complexity of these techniques. This paper reviews the radiation dose levels currently encountered in interventional procedures, the consequent risks to operators and patients and the dose reduction that may be achieved by employing a rigorous approach to radiation protection.Johnson, D.R.

  8. Radiation Protection and Free Radicals

    Microsoft Academic Search

    Bernard Smaller; Eugene C. Avery

    1959-01-01

    FREE radicals formed in biological materials by ionizing radiation may be detected under the proper conditions by paramagnetic resonance techniques. Possibly such free radicals contribute, directly or indirectly, to the radiation damage suffered by living organisms. The various chemicals which have been found to increase the survival of organisms subjected to large doses of radiation may provide protection by action

  9. Possible dosimeter for ultraviolet radiation

    Microsoft Academic Search

    A. Davis; G. H. W. Deane; B. L. DIFFEY

    1976-01-01

    WHILE evaluating the weathering characteristics of the plastics polysulphone and polyphenylene oxide (PPO) we found that they both darkened when exposed to ultraviolet radiation1. We realised the potential of these polymers as monitors for ultraviolet radiation and are developing them for this use. PPO is now being used to monitor continuously solar ultraviolet radiation at forty sites throughout the world2.

  10. Effects Of Radiation On Elastomers

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.

    1988-01-01

    Report provides data on effects of radiation on elastomers. Quantifies effects by giving minimum radiation levels to induce changes of 1 percent and 25 percent in given properties. Electrical, mechanical, and chemical properties included in data. Combined effects of heat and radiation briefly considered. Data summarized in graphic form useful to designers.

  11. Prevention of pelvic radiation disease.

    PubMed

    Fuccio, Lorenzo; Frazzoni, Leonardo; Guido, Alessandra

    2015-02-01

    Pelvic cancers are among the most frequently diagnosed cancers worldwide. Treatment of patients requires a multidisciplinary approach that frequently includes radiotherapy. Gastrointestinal (GI) radiation-induced toxicity is a major complication and the transient or long-term problems, ranging from mild to very severe, arising in non-cancerous tissues resulting from radiation treatment to a tumor of pelvic origin, are actually called as pelvic radiation disease. The incidence of pelvic radiation disease changes according to the radiation technique, the length of follow up, the assessment method, the type and stage of cancer and several other variables. Notably, even with the most recent radiation techniques, i.e., intensity-modulated radiotherapy, the incidence of radiation-induced GI side effects is overall reduced but still not negligible. In addition, radiation-induced GI side effects can develop even after several decades; therefore, the improvement of patient life expectancy will unavoidably increase the risk of developing radiation-induced complications. Once developed, the management of pelvic radiation disease may be challenging. Therefore, the prevention of radiation-induced toxicity represents a reasonable way to avoid a dramatic drop of the quality of life of these patients. In the current manuscript we provide an updated and practical review on the best available evidences in the field of the prevention of pelvic radiation disease. PMID:25664197

  12. Video Display Terminals: Radiation Issues.

    ERIC Educational Resources Information Center

    Murray, William E.

    1985-01-01

    Discusses information gathered in past few years related to health effects of video display terminals (VDTs) with particular emphasis given to issues raised by VDT users. Topics covered include radiation emissions, health concerns, radiation surveys, occupational radiation exposure standards, and long-term risks. (17 references) (EJS)

  13. Coherence and the radiation laws

    Microsoft Academic Search

    H. P. Baltes; Zentrale Forschung; LGZ Landis

    1977-01-01

    A review is presented of various recent investigations on the classical optical radiation laws in the light of the modern\\u000a concepts of coherence and statistical optics. Temporal coherence of black-body radiation, spatial coherence of Lambertian\\u000a and non-Lambertian sources, and the interaction of matter with radiation of any state of coherence are emphasized.

  14. Material Effectiveness for Radiation Shielding

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Materials with a smaller mean atomic mass, such as lithium (Li) hydride and polyethylene, make the best radiation shields for astronauts. The materials have a higher density of nuclei and are better able to block incoming radiation. Also, they tend to produce fewer and less dangerous secondary particles after impact with incoming radiation.

  15. Radiation recall reaction following gemcitabine

    Microsoft Academic Search

    Gerald Fogarty; David Ball; Danny Rischin

    2001-01-01

    A case of dermatitis and myositis in the upper thorax following administration of gemcitabine in a 65-year-old woman with metastatic non small cell lung cancer (NSCLC) is described. The reaction and time course suggest a radiation recall phenomenon. This report joins a small but increasing number of radiation recall events related to gemcitabine. The possibility of a radiation recall reaction

  16. Prevention of pelvic radiation disease

    PubMed Central

    Fuccio, Lorenzo; Frazzoni, Leonardo; Guido, Alessandra

    2015-01-01

    Pelvic cancers are among the most frequently diagnosed cancers worldwide. Treatment of patients requires a multidisciplinary approach that frequently includes radiotherapy. Gastrointestinal (GI) radiation-induced toxicity is a major complication and the transient or long-term problems, ranging from mild to very severe, arising in non-cancerous tissues resulting from radiation treatment to a tumor of pelvic origin, are actually called as pelvic radiation disease. The incidence of pelvic radiation disease changes according to the radiation technique, the length of follow up, the assessment method, the type and stage of cancer and several other variables. Notably, even with the most recent radiation techniques, i.e., intensity-modulated radiotherapy, the incidence of radiation-induced GI side effects is overall reduced but still not negligible. In addition, radiation-induced GI side effects can develop even after several decades; therefore, the improvement of patient life expectancy will unavoidably increase the risk of developing radiation-induced complications. Once developed, the management of pelvic radiation disease may be challenging. Therefore, the prevention of radiation-induced toxicity represents a reasonable way to avoid a dramatic drop of the quality of life of these patients. In the current manuscript we provide an updated and practical review on the best available evidences in the field of the prevention of pelvic radiation disease. PMID:25664197

  17. Martian Radiation Environment Experiment (MARIE)

    Microsoft Academic Search

    Gautam D. Badhwar

    1999-01-01

    Space radiation presents a very serious hazard to crews of interplanetary human missions. The two sources of this radiation are the galactic cosmic rays (GCR) and solar energetic particle (SEP) events. The GCR provides a steady source of low dose rate radiation that is primarily responsible for stochastic effects, such as cancer, and can effect the response of the central

  18. Radiative Equilibrium of the Mesosphere

    Microsoft Academic Search

    Conway Leovy

    1964-01-01

    Results of joint photochemical-radiative equilibrium calculations for the mesosphere and upper stratosphere are presented. The major assumptions were that only oxygen allotropes participate in the chemistry and that the radiative balance is between absorption of solar radiation by molecular oxygen and ozone and infrared emission by carbon dioxide and ozone. Equilibrium temperatures and ozone concentrations for winter and summer were

  19. Lunar radiation environment

    NASA Astrophysics Data System (ADS)

    Schwadron, Nathan; Spence, Harlan; Wilson, Jody

    One of the goals of the CRaTER investigation is to characterize the radiation environment near the Moon in order to enable exploration. The state-of-the-art understanding developed thus far during the LRO mission is documented in a special issue of the Spaceweather Journal entitled “Space Weather: Building the observational foundation to deduce biological effects of space radiation” (Schwadron et al., 2013a). This recently published CRaTER work probes deeper into the physics of the radiation environment at the Moon. It motivates and provides the scientific basis for new investigations in the next phase of the LRO mission. The effects of Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) range from chemical modification of the regolith, the generation of a radiation albedo that is increasingly illuminating chemical properties of the regolith, causing charging of the regolith and hazards to human explorers and robotic missions. Low-lunar orbit provides a platform for measuring SEP anisotropy over timescales of 2 hours both parallel and perpendicular to the ecliptic plane, and so far we have observed more than 18 SEP events with time-variable anisotropies during the LRO mission. Albedo proton maps of the Moon from CRaTER indicate that the flux of lunar albedo protons is correlated with elemental abundances at the lunar surface. The yield of albedo protons from the maria is 1% higher than the yield from the highlands, and there are localized peaks with even higher contrast (that may be co-located with peaks in trace elemental abundances as measured by the Lunar Prospector Gamma Ray Spectrometer). The Moon’s radiation environment both charges and affects the chemistry in the Moon’s polar regions, particularly in PSRs. This makes these regions a prime target for new CRaTER observations, since CRaTER measures GCRs and SEPs that penetrate the regolith down to 10s of cm. Thus, we review emerging discoveries from LRO/CRaTER’s remarkable exploration of moon’s radiation environment, its implications for human exploration, and its interaction with lunar regolith.

  20. Acute Cerebrovascular Radiation Syndrome: Radiation Neurotoxicity , mechanisms of CNS radiation injury, advanced countermeasures for Radiation Protection of Central Nervous System.

    NASA Astrophysics Data System (ADS)

    Popov, Dmitri; Jones, Jeffrey; Maliev, Slava

    Key words: Cerebrovascular Acute Radiation Syndrome (Cv ARS), Radiation Neurotoxins (RNT), Neurotransmitters, Radiation Countermeasures, Antiradiation Vaccine (ArV), Antiradiation Blocking Antibodies, Antiradiation Antidote. Psychoneuroimmunology, Neurotoxicity. ABSTRACT: To review the role of Radiation Neurotoxins in triggering, developing of radiation induced central nervous system injury. Radiation Neurotoxins - rapidly acting blood toxic lethal agent, which activated after irradiation and concentrated, circulated in interstitial fluid, lymph, blood with interactions with cell membranes, receptors and cell compartments. Radiation Neurotoxins - biological molecules with high enzymatic activity and/or specific lipids and activated or modified after irradiation. The Radiation Neurotoxins induce increased permeability of blood vessels, disruption of the blood-brain barrier, blood-cerebrospinal fluid (CSF) barrier and developing severe disorder of blood macro- and micro-circulation. Principles of Radiation Psychoneuro-immunology and Psychoneuro-allergology were applied for determination of pathological processes developed after irradiation or selective administration of Radiation Neurotoxins to radiation naïve mammals. Effects of radiation and exposure to radiation can develop severe irreversible abnormalities of Central Nervous System, brain structures and functions. Antiradiation Vaccine - most effective, advanced methods of protection, prevention, mitigation and treatment and was used for of Acute Radiation Syndromes and elaboration of new technology for immune-prophylaxis and immune-protection against ?, Heavy Ion, Neutron irradiation. Results of experiments suggested that blocking, antitoxic, antiradiation antibodies can significantly reduce toxicity of Radiation Toxins. New advanced technology include active immune-prophylaxis with Antiradiation Vaccine and Antiradiation therapy that included specific blocking antibodies to Radiation Neurotoxins. Antiradiation Vaccine and Antiradiation IgG preparations - prospective effective antidote/countermeasure for ?-irradiation, heavy ions irradiation, neutron irradiation. Recommendations for treatment and immune-prophylaxis of CNS injury, induced by radiation, were proposed. Specific immune therapy and specific immune prophylaxis reduce symptoms of ACvRS. This manuscript summarizes the results of experiments and considering possibility for blocking toxicological mechanisms of action of Radiation and Radiation Neurotoxins and prevention or diminishing clinical signs of injury of CNS. Experimental data suggest that Antiradiation vaccine and Antiradiation IgG with specific antibodies to Radiation Neurotoxins, Cytotoxins protect CNS against high doses of radiation.

  1. Radiation dosimetry and biophysical models of space radiation effects

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wu, Honglu; Shavers, Mark R.; George, Kerry

    2003-01-01

    Estimating the biological risks from space radiation remains a difficult problem because of the many radiation types including protons, heavy ions, and secondary neutrons, and the absence of epidemiology data for these radiation types. Developing useful biophysical parameters or models that relate energy deposition by space particles to the probabilities of biological outcomes is a complex problem. Physical measurements of space radiation include the absorbed dose, dose equivalent, and linear energy transfer (LET) spectra. In contrast to conventional dosimetric methods, models of radiation track structure provide descriptions of energy deposition events in biomolecules, cells, or tissues, which can be used to develop biophysical models of radiation risks. In this paper, we address the biophysical description of heavy particle tracks in the context of the interpretation of both space radiation dosimetry and radiobiology data, which may provide insights into new approaches to these problems.

  2. Radiative B Decays

    SciTech Connect

    Bard, D.; /Imperial Coll., London

    2011-11-23

    I discuss recent results in radiative B decays from the Belle and BaBar collaborations. I report new measurements of the decay rate and CP asymmetries in b {yields} s{gamma} and b {yields} d{gamma} decays, and measurements of the photon spectrum in b {yields} s{gamma}. Radiative penguin decays are flavour changing neutral currents which do not occur at tree level in the standard model (SM), but must proceed via one loop or higher order diagrams. These transitions are therefore suppressed in the SM, but offer access to poorlyknown SM parameters and are also a sensitive probe of new physics. In the SM, the rate is dominated by the top quark contribution to the loop, but non-SM particles could also contribute with a size comparable to leading SM contributions. The new physics effects are potentially large which makes them theoretically very interesting, but due to their small branching fractions they are typically experimentally challenging.

  3. Radiation dose in defecography

    SciTech Connect

    Goei, R.; Kemerink, G. (Univ. Hospital Maastricht (Netherlands))

    1990-07-01

    The effective dose equivalent, as an expression of total patient risk for exposure to limited areas of the body, and gonadal doses associated with hereditary effects were estimated in 67 consecutive subjects (43 women and 24 men) who underwent defecography. With use of measured entrance exposure values and data from Monte Carlo simulations, the mean effective dose equivalent was estimated at 4.9 mSv +/- 1.6 (490 mrem +/- 160) for women and 0.6 mSv +/- 0.2 (60 mrem +/- 20) for men. The ovarian dose was 15 mSv +/- 5 (1.5 rem +/- 0.5). The testes are not within the primary beam and therefore are exposed to scattered radiation only, hence the low received dose of 0.14 mSv or less (14 mrem or less). These data indicate that defecography is among the radiologic procedures associated with a considerable, but not extreme, radiation dose.

  4. TOPEX orbital radiation study

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Barth, J. M.

    1984-01-01

    The space radiation environment of the TOPEX spacecraft is investigated. A single trajectory was considered. The external (surface incident) charged particle radiation, predicted for the satellite, is determined by orbital flux integration for the specified trajectory. The latest standard models of the environment are used in the calculations. The evaluation is performed for solar maximum conditions. The spacecraft exposure to cosmic rays of galactic origin is evaluated over its flight path through the magnetosphere in terms of geomagnetic shielding effects, both for surface incident heavy ions and for particles emerging behind different material thickness. Limited shielding and dose evaluations are performed for simple infinite slab and spherical geometries. Results, given in graphical and tabular form, are analyzed, explained, and discussed. Conclusions are presented and commented on.

  5. Genesis Radiation Environment

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Altstatt, Richard L.; Skipworth, William C.

    2007-01-01

    The Genesis spacecraft launched on 8 August 2001 sampled solar wind environments at L1 from 2001 to 2004. After the Science Capsule door was opened, numerous foils and samples were exposed to the various solar wind environments during periods including slow solar wind from the streamer belts, fast solar wind flows from coronal holes, and coronal mass ejections. The Survey and Examination of Eroded Returned Surfaces (SEERS) program led by NASA's Space Environments and Effects program had initiated access for the space materials community to the remaining Science Capsule hardware after the science samples had been removed for evaluation of materials exposure to the space environment. This presentation will describe the process used to generate a reference radiation Genesis Radiation Environment developed for the SEERS program for use by the materials science community in their analyses of the Genesis hardware.

  6. Genetic susceptibility to radiation

    NASA Astrophysics Data System (ADS)

    Hall, E. J.; Brenner, D. J.; Worgul, B.; Smilenov, L.

    In the context of space radiation, it is important to know whether the human population includes genetically predisposed radiosensitive subsets. One possibility is that haploinsufficiency for ATM confers radiosensitivity, and this defect involves 1-3% of the population. Using knock-out mice we chose to study cataractogenesis in the lens and oncogenic transformation in mouse embryo fibroblasts to assay for effects of ATM deficiency. Radiation induced cataracts appeared earlier in the heterozygous versus wild-type animals following exposure to either gamma rays or 1 GeV/nucleon iron ions. In addition, it was found that embryo fibroblasts of Atm heterozygotes showed an increased incidence of oncogenic transformation compared with their normal litter-matched counterparts. From these data we suggest that Ataxia Telangiectasia heterozygotes could indeed represent a societally-significant radiosensitive subpopulation.

  7. Terahertz radiation mixer

    DOEpatents

    Wanke, Michael C. (Albuquerque, NM); Allen, S. James (Santa Barbara, CA); Lee, Mark (Albuquerque, NM)

    2008-05-20

    A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

  8. Radiation shielding composition

    DOEpatents

    Quapp, W.J.; Lessing, P.A.

    1998-07-28

    A composition is disclosed for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm{sup 3} and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile. 5 figs.

  9. Radiation shielding composition

    DOEpatents

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    2000-12-26

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  10. Radiation shielding composition

    DOEpatents

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    1998-01-01

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  11. Quality in radiation oncology

    SciTech Connect

    Pawlicki, Todd; Mundt, Arno J. [Department of Radiation Oncology, University of California, San Diego, La Jolla, California 92093 (United States)

    2007-05-15

    A modern approach to quality was developed in the United States at Bell Telephone Laboratories during the first part of the 20th century. Over the years, those quality techniques have been adopted and extended by almost every industry. Medicine in general and radiation oncology in particular have been slow to adopt modern quality techniques. This work contains a brief description of the history of research on quality that led to the development of organization-wide quality programs such as Six Sigma. The aim is to discuss the current approach to quality in radiation oncology as well as where quality should be in the future. A strategy is suggested with the goal to provide a threshold improvement in quality over the next 10 years.

  12. National Ambient Radiation Database

    SciTech Connect

    Dziuban, J.; Sears, R.

    2003-02-25

    The U.S. Environmental Protection Agency (EPA) recently developed a searchable database and website for the Environmental Radiation Ambient Monitoring System (ERAMS) data. This site contains nationwide radiation monitoring data for air particulates, precipitation, drinking water, surface water and pasteurized milk. This site provides location-specific as well as national information on environmental radioactivity across several media. It provides high quality data for assessing public exposure and environmental impacts resulting from nuclear emergencies and provides baseline data during routine conditions. The database and website are accessible at www.epa.gov/enviro/. This site contains (1) a query for the general public which is easy to use--limits the amount of information provided, but includes the ability to graph the data with risk benchmarks and (2) a query for a more technical user which allows access to all of the data in the database, (3) background information on ER AMS.

  13. Semiconductor radiation detector

    DOEpatents

    Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

    2002-01-01

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  14. Radiation degradation of cellulose

    NASA Astrophysics Data System (ADS)

    Leonhardt, J.; Arnold, G.; Baer, M.; Langguth, H.; Gey, M.; Hübert, S.

    The application of straw and other cellulose polymers as feedstuff for ruminants is limited by its low digestibility. During recent decades it was attempted to increase the digestibility of straw by several chemical and physical methods. In this work some results of the degradation of gamma and electron treated wheat straw are reported. Complex methods of treatment (e.g. radiation influence and influence of lyes) are taken into consideration. In vitro-experiments with radiation treated straw show that the digestibility can be increased from 20 % up to about 80 %. A high pressure liquid chromatography method was used to analyze the hydrolysates. The contents of certain species of carbohydrates in the hydrolysates in dependence on the applied dose are given.

  15. Time encoded radiation imaging

    DOEpatents

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21

    The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

  16. Radiation Effects in Zircon

    SciTech Connect

    Ewing, Rodney C.; Meldrum, Alkiviathes; Wang, L. M.; Weber, William J.; Corrales, Louis R.

    2003-12-11

    The widespread distribution of zircon in the continental crust, its tendency to concentrate trace elements, particularly lanthanides and actinides, its use in age-dating, and its resistance to chemical and physical degradation have made zircon the most important accessory mineral in geologic studies. Because zircon is highly refractory, it also has important industrial applications, including its use as a lining material in high-temperature furnaces. However, during the past decade, zircon has also been proposed for advanced technology applications, such as a durable material for the immobilization of plutonium or, when modified by ion-beam irradiation, as an optic waveguide material. In all of these applications, the change in properties as a function of increasing radiation dose is of critical importance. In this chapter, we summarize the state-of-knowledge on the radiation damage accumulation process in zircon.

  17. Provisional standards of radiation safety during flights

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Radiation effects during space flights are discussed in the context of the sources and dangers of such radiation and the radiobiological prerequisites for establishing safe levels of radiation dosage. Standard safe levels of radiation during space flight are established.

  18. Recombination Radiation from Diamond

    Microsoft Academic Search

    P. J. Dean; I. H. Jones

    1964-01-01

    The spectrum of the recombination radiation from diamond has been measured over the photon energy range 4.9-5.5 eV at 90, 160, 207, and 320°K. At 90°K, recombination emission has been detected from ten samples out of a batch of fifteen single crystals, the majority of which were known to be relatively defect free. The persistent and usually dominant spectral features

  19. Radiation sources and process

    SciTech Connect

    Honious, H.B.; Janzow, E.F.; Malson, H.A.; Moyer, S.E.

    1980-04-08

    The invention relates to radiation sources comprising a substrate having an electrically-conductive non-radioactive metal surface, a layer of a metal radioactive isotope of the scandium group, which in addition to scandium, yttrium, lanthanum and actinium, includes all the lanthanide and actinide series of elements, with the actinide series usually being preferred because of the nature of the radioactive isotopes therein, particularly americium-241, curium-244, plutonium-238, californium-252 and promethium-147, and a non-radioactive bonding metal codeposited on the surface by electroplating the isotope and bonding metal from an electrolytic solution, the isotope being present in the layer in minor amount as compared to the bonding metal, and with or without a non-radioactive protective metal coating covering the isotoype and bonding metal on the surface, the coating being sufficiently thin to permit radiation to pass through the coating. The invention also relates to a process for providing radiation sources comprising codepositing a layer of the metal radioactive isotope with a non-radioactive bonding metal from an electrolytic solution in which the isotope is present in minor molar amount as compared to the bonding metal such that the codeposited layer contains a minor molar amount of the isotope compared to the bonding metal by electroplating on an electrically-conductive non-radioactive metal surface of a cathode substrate, and with or without depositing a nonradioactive protective metal coating over the isotope and bonding metal on the surface, the coating being sufficiently thin to permit radiation to pass through the coating.

  20. Radiation in Yolo County

    NASA Astrophysics Data System (ADS)

    Dickie, H.; Colwell, K.

    2013-12-01

    In today's post-nuclear age, there are many man-made sources of radioactivity, in addition to the natural background we expect from cosmic and terrestrial origins. While all atoms possess unstable isotopes, there are few that are abundant enough, energetic enough, and have long enough half-lives to pose a signicant risk of ionizing radiation exposure. We hypothesize a decreasing relative radiation measurement (in detected counts per minute [CPM]) at nine locations that might pose occupational or environmental hazard: 1. A supermarket produce aisle (living tissue has high concentration of 40K) 2. A hospital (medical imaging uses X-rays and radioactive dyes) 3. The electronics section of a superstore (high voltage electronics have the potential to produce ionizing radiation) 4. An electrical transformer (similar reasons) 5. An antique store (some ceramics and glazes use radioisotopes that are now outlawed) 6. A gasoline pump (processing and terrestrial isotope contamination might leave a radioactive residue) 7. A fertilized eld (phosphate rock contains uranium and thorium, in addition to potassium) 8. A house (hopefully mild background, but potential radon contamination) 9. A school (should be radiologically neutral) We tested the hypothesis by measuring 100 minutes of counts on a self-assembled MightyOhmTM Geiger counter at each location. Our results show that contrary to the hypothesized ordering, the house was the most radiologically active. We present possible explanations for the observed radiation levels, as well as possible sources of measurement error, possible consequences of prolonged exposure to the measured levels, and suggestions for decreasing exposure and environmental impact.

  1. Ultraviolet radiation screening compounds

    Microsoft Academic Search

    CHARLES S. COCKELL; JOHN KNOWLAND

    1988-01-01

    Amongst the diversity of methods used by organisms to reduce damage caused by ultraviolet (UV) radiation, the synthesis of UV-screening compounds is almost ubiquitous. UV-screening compounds provide a passive method for the reduction of UV-induced damage and they are widely distributed across the microbial, plant and animal kingdoms. They share some common chemical features. It is likely that on early

  2. Purely radiative perfect fluids

    E-print Network

    B. Bastiaensen; H. R. Karimian; N. Van den Bergh; L. Wylleman

    2007-05-08

    We study `purely radiative' (div E = div H = 0) and geodesic perfect fluids with non-constant pressure and show that the Bianchi class A perfect fluids can be uniquely characterized --modulo the class of purely electric and (pseudo-)spherically symmetric universes-- as those models for which the magnetic and electric part of the Weyl tensor and the shear are simultaneously diagonalizable. For the case of constant pressure the same conclusion holds provided one also assumes that the fluid is irrotational.

  3. Gravitational Radiation Experiments

    Microsoft Academic Search

    J. Weber

    1970-01-01

    A summary is given of the statistics and coincidences of the Argonne-Maryland gravitational-radiation-detector array. New experiments have been carried out. These include a parallel coincidence experiment in which one coincidence detector had a time delay in one channel and a second coincidence detector operated with no time delays. Other experiments involve observations to rule out the possibility that the detectors

  4. Radiation and human health

    Microsoft Academic Search

    1979-01-01

    The growing controversy over low-level radiation risks stems from challenges to the assumptions that had been made about dose rate, linear theory, and total-body exposure. The debate has focused on whether there is a risk threshold or whether linearity overstates low-level risks, both theories being consistent with the available data. The generally accepted consensus on the risks of cancer and

  5. Ionizing radiation during pregnancy.

    PubMed Central

    Ratnapalan, Savithiri; Bona, Nicole; Koren, Gideon

    2003-01-01

    QUESTION: One of my patients had a computed tomography scan of her abdomen a week ago and has just found out she is 7 weeks pregnant. What should I tell her about the pregnancy and the risk to her fetus? ANSWER: Your patient is not at increased risk of miscarriage or major congenital fetal malformations due to radiation exposure. Her risk is similar to that of the general population (ie, 1% to 3%). PMID:12901480

  6. Integrative radiation systems biology

    PubMed Central

    2014-01-01

    Maximisation of the ratio of normal tissue preservation and tumour cell reduction is the main concept of radiotherapy alone or combined with chemo-, immuno- or biologically targeted therapy. The foremost parameter influencing this ratio is radiation sensitivity and its modulation towards a more efficient killing of tumour cells and a better preservation of normal tissue at the same time is the overall aim of modern therapy schemas. Nevertheless, this requires a deep understanding of the molecular mechanisms of radiation sensitivity in order to identify its key players as potential therapeutic targets. Moreover, the success of conventional approaches that tried to statistically associate altered radiation sensitivity with any molecular phenotype such as gene expression proofed to be somewhat limited since the number of clinically used targets is rather sparse. However, currently a paradigm shift is taking place from pure frequentistic association analysis to the rather holistic systems biology approach that seeks to mathematically model the system to be investigated and to allow the prediction of an altered phenotype as the function of one single or a signature of biomarkers. Integrative systems biology also considers the data from different molecular levels such as the genome, transcriptome or proteome in order to partially or fully comprehend the causal chain of molecular mechanisms. An example for the application of this concept currently carried out at the Clinical Cooperation Group “Personalized Radiotherapy in Head and Neck Cancer” of the Helmholtz-Zentrum München and the LMU Munich is described. This review article strives for providing a compact overview on the state of the art of systems biology, its actual challenges, potential applications, chances and limitations in radiation oncology research working towards improved personalised therapy concepts using this relatively new methodology. PMID:24411063

  7. Solar Radiation Resource Information

    NSDL National Science Digital Library

    This is the Solar Radiation Resource Information page for the RReDC which provides information on several types of renewable energy resources in the United States, in the form of publications, data, and maps. An extensive dictionary of renewable energy related terms is also provided. This page has links to: -Archived Data -NREL Data Collection Activities -Solar Spectra -Solar Codes & Algorithms -Solar Models -Solar Calculators -Publications. Keyword: Photovoltaic, cell, PV.

  8. Radiation-driven inflation

    SciTech Connect

    Davidson, Aharon; Gurwich, Ilya, E-mail: davidson@bgu.ac.il, E-mail: gurwichphys@gmail.com, E-mail: ilyagur@gmail.com [Physics Department, Ben-Gurion University, Beer-Sheva 84105 (Israel)] [Physics Department, Ben-Gurion University, Beer-Sheva 84105 (Israel)

    2008-06-15

    A novel, scalar-field-free approach to cosmic inflation is presented. The inflationary Universe and the radiation-dominated Universe are shown, within the framework of unified brane cosmology, to be two different phases governed by one and the same energy density. The phase transition of second order (the Hubble constant exhibits a finite jump) appears naturally and serves as the exit mechanism. No re-heating is needed. The required number of e-folds is achieved without fine tuning.

  9. Structure in Radiative Shocks

    NASA Astrophysics Data System (ADS)

    Drake, R. Paul; Visco, A.; Doss, F.; Reighard, A.; Froula, D.; Glenzer, S.; Knauer, J.

    2008-05-01

    Radiative shocks are shock waves fast enough that radiation from the shock-heated matter alters the structure of the shock. They are of fundamental interest to high-energy-density physics and also have applications throughout astrophysics. This poster will review the dimensionless parameters that determine structure in these shocks and will discuss recent experiments to measure such structure for strongly radiative shocks that are optically thin upstream and optically thick downstream. The shock transition itself heats mainly the ions. Immediately downstream of the shock, the ions heat the electrons and the electrons radiate, producing an optically thin cooling layer, followed by the downstream layer of warm, shocked material. The axial structure of these systems is of interest, because the transition from precursor through the cooling layer to the final state is complex and difficult to calculate. Their lateral structure is also of interest, as they seem likely to be subject to some variation on the Vishniac instability of thin layers. In our experiments to produce such shocks, laser ablation launches a Be plasma into a tube of Xe or Ar gas, at a velocity above 100 km/s. This drives a shock down the tube. Radiography provides fundamental information about the structure and evolution of the shocked material in Xe. Thomson scattering and pyrometry have provided data in Ar. We will summarize the available evidence regarding the properties of these shocks, and will discuss their connections to astrophysical cases. This research was sponsored by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grants DE-FG52-07NA28058, DE-FG52-04NA00064, and other grants and contracts.

  10. Uninformed Hawking radiation

    NASA Astrophysics Data System (ADS)

    Sakalli, I.; Ovgun, A.

    2015-04-01

    We show in detail that the Parikh-Wilczek tunneling method (PWTM), which was designed for resolving the information loss problem in Hawking radiation (HR) fails whenever the radiation occurs from an isothermal process. The PWTM aims to produce a non-thermal HR which adumbrates the resolution of the problem of unitarity in quantum mechanics (QM), and consequently the entropy (or information) conservation problem. The effectiveness of the method has been satisfactorily tested on numerous black holes (BHs). However, it has been shown that the isothermal HR, which results from the emission of the uncharged particles of the linear dilaton BH (LDBH) described in the Einstein-Maxwell-Dilaton (EMD) theory, the PWTM has vulnerability in having non-thermal radiation. In particular, we consider Painlevé-Gullstrand coordinates (PGCs) and isotropic coordinates (ICs) in order to prove the aforementioned failure in the PWTM. While carrying out calculations in the ICs, we also highlight the effect of the refractive index on the null geodesics.

  11. Intraocular radiation blocking.

    PubMed

    Finger, P T; Ho, T K; Fastenberg, D M; Hyman, R A; Stroh, E M; Packer, S; Perry, H D

    1990-09-01

    Iodine-based liquid radiographic contrast agents were placed in normal and tumor-bearing (Greene strain) rabbit eyes to evaluate their ability to block iodine-125 radiation. This experiment required the procedures of tumor implantation, vitrectomy, air-fluid exchange, and 125I plaque and thermoluminescent dosimetry (TLD) chip implantation. The authors quantified the amount of radiation attenuation provided by intraocularly placed contrast agents with in vivo dosimetry. After intraocular insertion of a blocking agent or sham blocker (saline) insertion, episcleral 125I plaques were placed across the eye from episcleral TLD dosimeters. This showed that radiation attenuation occurred after blocker insertion compared with the saline controls. Then computed tomographic imaging techniques were used to describe the relatively rapid transit time of the aqueous-based iohexol compared with the slow transit time of the oil-like iophendylate. Lastly, seven nontumor-bearing eyes were primarily examined for blocking agent-related ocular toxicity. Although it was noted that iophendylate induced intraocular inflammation and retinal degeneration, all iohexol-treated eyes were similar to the control eyes at 7 and 31 days of follow-up. Although our study suggests that intraocular radiopaque materials can be used to shield normal ocular structures during 125I plaque irradiation, a mechanism to keep these materials from exiting the eye must be devised before clinical application. PMID:2211021

  12. Fundamentals of Atmospheric Radiation

    NASA Astrophysics Data System (ADS)

    Bohren, Craig F.; Clothiaux, Eugene E.

    2006-02-01

    This textbook fills a gap in the literature for teaching material suitable for students of atmospheric science and courses on atmospheric radiation. It covers the fundamentals of emission, absorption, and scattering of electromagnetic radiation from ultraviolet to infrared and beyond. Much of the book applies to planetary atmosphere. The authors are physicists and teach at the largest meteorology department of the US at Penn State. Craig T. Bohren has taught the atmospheric radiation course there for the past 20 years with no book. Eugene Clothiaux has taken over and added to the course notes. Problems given in the text come from students, colleagues, and correspondents. The design of the figures especially for this book is meant to ease comprehension. Discussions have a graded approach with a thorough treatment of subjects, such as single scattering by particles, at different levels of complexity. The discussion of the multiple scattering theory begins with piles of plates. This simple theory introduces concepts in more advanced theories, i.e. optical thickness, single-scattering albedo, asymmetry parameter. The more complicated theory, the two-stream theory, then takes the reader beyond the pile-of-plates theory. Ideal for advanced undergraduate and graduate students of atmospheric science.

  13. Microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Laissue, Jean A.; Lyubimova, Nadia; Wagner, Hans-Peter; Archer, David W.; Slatkin, Daniel N.; Di Michiel, Marco; Nemoz, Christian; Renier, Michel; Brauer, Elke; Spanne, Per O.; Gebbers, Jan-Olef; Dixon, Keith; Blattmann, Hans

    1999-10-01

    The central nervous system of vertebrates, even when immature, displays extraordinary resistance to damage by microscopically narrow, multiple, parallel, planar beams of x rays. Imminently lethal gliosarcomas in the brains of mature rats can be inhibited and ablated by such microbeams with little or no harm to mature brain tissues and neurological function. Potentially palliative, conventional wide-beam radiotherapy of malignant brain tumors in human infants under three years of age is so fraught with the danger of disrupting the functional maturation of immature brain tissues around the targeted tumor that it is implemented infrequently. Other kinds of therapy for such tumors are often inadequate. We suggest that microbeam radiation therapy (MRT) might help to alleviate the situation. Wiggler-generated synchrotron x-rays were first used for experimental microplanar beam (microbeam) radiation therapy (MRT) at Brookhaven National Laboratory's National Synchrotron Light Source in the early 1990s. We now describe the progress achieved in MRT research to date using immature and adult rats irradiated at the European Synchrotron Radiation Facility in Grenoble, France, and investigated thereafter at the Institute of Pathology of the University of Bern.

  14. Optical radiation and visual health

    SciTech Connect

    Waxler, M.; Hitchins, V.M.

    1986-01-01

    This book provides a focus on the parameters of ultraviolet light, visible, and infrared radiation s which could cause long-term visual health problems in humans. It reviews early research on radiation effects on the eye, and gives detailed attention to the hazardous effects of optical radiation on the retinal pigment epithelium and the photoreceptors. These data are further analyzed with regard to five potential long-term visual health problems; retinal degeneration, visual aging, disorder of visual development, ocular drug phototoxicity, and cataracts. Finally, epidemiologic principles for studying the relationships between optical radiation and long-term visual health problems are reviewed, concluding with the implications for future research and radiation protection. The contents include: historical perspectives; optical radiation and cataracts; the involvement of the retinal pigment epithelium (RPE); optical radiation damage to the ocular photoreceptors; possible role of optical radiation in retinal degenerations; optical radiation and the aged eye; optical radiation effects on aging and visual perception; optical radiation effects on visual development; and index.

  15. New Approaches to Radiation Protection

    PubMed Central

    Rosen, Eliot M.; Day, Regina; Singh, Vijay K.

    2015-01-01

    Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or deliberate exposure (e.g., nuclear reactor meltdown, dirty bomb, or nuclear bomb explosion); hence they are called radiation countermeasures. Here, we will review the general principles of radiation injury and protection and describe selected examples of radioprotectors/mitigators ranging from small-molecules to proteins to cell-based treatments. We will emphasize agents that are in more advanced stages of development. PMID:25653923

  16. Ionizing radiation and cancer prevention.

    PubMed Central

    Hoel, D G

    1995-01-01

    Ionizing radiation long has been recognized as a cause of cancer. Among environmental cancer risks, radiation is unique in the variety of organs and tissues that it can affect. Numerous epidemiological studies with good dosimetry provide the basis for cancer risk estimation, including quantitative information derived from observed dose-response relationships. The amount of cancer attributable to ionizing radiation is difficult to estimate, but numbers such as 1 to 3% have been suggested. Some radiation-induced cancers attributable to naturally occurring exposures, such as cosmic and terrestrial radiation, are not preventable. The major natural radiation exposure, radon, can often be reduced, especially in the home, but not entirely eliminated. Medical use of radiation constitutes the other main category of exposure; because of the importance of its benefits to one's health, the appropriate prevention strategy is to simply work to minimize exposures. PMID:8741791

  17. New approaches to radiation protection.

    PubMed

    Rosen, Eliot M; Day, Regina; Singh, Vijay K

    2014-01-01

    Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or deliberate exposure (e.g., nuclear reactor meltdown, dirty bomb, or nuclear bomb explosion); hence they are called radiation countermeasures. Here, we will review the general principles of radiation injury and protection and describe selected examples of radioprotectors/mitigators ranging from small-molecules to proteins to cell-based treatments. We will emphasize agents that are in more advanced stages of development. PMID:25653923

  18. Method for microbeam radiation therapy

    DOEpatents

    Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

    1994-08-16

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

  19. Method for microbeam radiation therapy

    SciTech Connect

    Slatkin, Daniel N. (Sound Beach, NY); Dilmanian, F. Avraham (Yaphank, NY); Spanne, Per O. (Shoreham, NY)

    1994-01-01

    A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue.

  20. Zero Point Energy: Planck Radiation Law

    Microsoft Academic Search

    H. Vic Dannon

    The assumption of discrete radiation energy in Planck's 1901 radiation law, conflicted with Planck's belief in radiation of continuous waves. To reconcile his quantum hypothesis with his conception of wave radiation, he avoided the conclusion that radiation energy must be made of particles, and postulated that radiation is a transition between the energy levels of an oscillator. Furthermore, ignoring the

  1. Anisotropic radiation elds: causality and quantum statistics

    E-print Network

    Honingh, Aline

    radiation transport 5 2.1 Radiation transport equation . . . . . . . . . . . . . . . . . . 5 2.2 Closures The transport of radiation through a medium is described by the radiation transport equation for the radiativeAnisotropic radiation #12;elds: causality and quantum statistics A.K. Honingh #12; #12; Anisotropic

  2. Influence of Extraterrestrial Radiation on Radiation Portal Monitors

    SciTech Connect

    Keller, Paul E.; Kouzes, Richard T.

    2009-06-01

    Cosmic radiation and solar flares can be a major source of background radiation at the Earth’s surface. This paper examines the relationship between extraterrestrial radiation and the detectable background in radiation portal monitors used for homeland security applications. Background radiation data from 13 radiation portal monitor facilities are examined and compared against external sources of data related to extraterrestrial radiation, including measurements at neutron monitors located at 53 cosmic-ray observatories around the Earth, four polar orbiting satellites, three geostationary satellites, ground-based geomagnetic field data from observatories around the Earth, a solar magnetic index, solar radio flux data, and sunspot activity data. Four-years (January 2003 through December 2006) of data are used in this study, which include the latter part of Solar Cycle 23 as solar activity was on the decline. The analysis shows a significant relationship between some extraterrestrial radiation and the background detected in the radiation portal monitors. A demonstrable decline is shown in the average gamma ray and neutron background at the radiation portal monitors as solar activity declined over the period of the study.

  3. DNA fragmentation pattern in human fibroblasts after irradiation with iron ions

    NASA Astrophysics Data System (ADS)

    Campa, Alessandro

    In this work we studied the fragmentation pattern produced by the double stand breaks (DSB) induced in AG1522 primary human fibroblasts by two different iron beams, one of energy 414 MeV/u, and the other of energy 115 MeV/u (with dose-average LET in water equal to 202 keV/µm and 442 keV/µm, respectively). Irradiation with several doses up to 200 Gy was performed at the HIMAC facility of the National Institute of Radiological Sciences, Chiba, Japan. Experimental data, first obtained for fragments belonging to the size ranges 23-1000 kbp and 1000-5700 kbp (Belli et al., 2006), have successively been obtained also for fragments belonging to the size ranges 1-9 kbp and 9-23 kbp; the experimental analysis was performed with pulsed and constant field electrophoresis. The RBE for DSB production was evaluated in two different fragment size ranges (i.e., 23-5700 kbp and 1-5700 kbp), and it was found larger for the wider size range, especially for the beam with the higher LET. The experimental results have been compared to those computed on the basis of the Monte Carlo PARTRAC simulation code, following the line of research started in Campa et al. (2005), and exploiting the recent update of the PARTRAC code to ions heavier than helium (Friedland et al., 2006). Because the agreement has been found satisfactory for both radiation qualities, the spectra outside the experimentally observable fragment size range were also computed in order to evaluate the overall fragmentation pattern. The marked increases of the RBEs for DSB production, obtained when also the very small fragments (< 1 kbp) are included, makes them closer to the RBE values observed for the late cellular effects. This finding is a further indication for the biological significance of the spatial correlation of DSB at short distances. This work was partially supported by ASI (Italian Space Agency, "Mo-Ma/COUNT" project). References M. Belli, A. Campa, V. Dini, G. Esposito, Y. Furusawa, G. Simone, E. Sorrentino and M. A. Tabocchini. DNA fragmentation induced in human fibroblasts by accelerated 56 Fe ions of differing energies. Radiat. Res. 165, 713-720 (2006). A. Campa, F. Ballarini, M. Belli, R. Cherubini, V. Dini, G. Esposito, W. Friedland, S. Gerardi, S. Molinelli, A. Ottolenghi, H. G. Paretzke, G. Simone and M. A. Tabocchini. DNA DSB induced in human cells by charged particles and gamma rays: experimental results and theoretical approaches. Int. J. Radiat. Biol. 81, 841-854 (2005). W. Friedland, P. Jacob, H. G. Paretzke, A. Ottolenghi, F. Ballarini and M. Liotta. Simulation of light ion induced DNA damge patterns. Radiat. Prot. Dosim. 122, 116-120 (2006).

  4. (Radiation protection guidance)

    SciTech Connect

    Richmond, C.R.

    1989-11-16

    The traveler attended the meeting of the International Commission on Radiological Protection (ICRP) and its committees in Oxford, England. This was the first meeting of the Main Commission with all its committees as formed for the 1989--1993 period. The major item of business was to review a draft report that, when finalized, will constitute the revised basic ICRP radiation protection guidance. It is clear that there is much work to be done by ICRP committees and task groups to prepare reports containing information that can be used in conjunction with the revised guidance, e.g., a revised ICRP 30 series of reports. It is extremely important that the US Department of Energy, and other US agencies, including the Commission on Interagency Radiation Research and Policy Coordination (CIRRPC), not repeat the error committed after the previous ICRP general radiation protection guidance was released in 1977 (ICRP Report No. 26). The US had much difficulty in understanding the implications of the recommendations and their impact on federal and other facilities. As a result there was a long delay in US agencies adopting the ICRP 26 terminology and secondary limits. Actually, all DOE contractors were directed this year, via DOE order 5480.11, to comply with what is basically ICRP 26 and 30 by the end of this calendar year. Much of the rest of the world had adopted most or all of the ICRP 26 and 30 guidance years ago. The US position appeared very confused as regards ICRP 26 to the rest of the world.

  5. Dynamic hohlraum radiation hydrodynamicsa)

    NASA Astrophysics Data System (ADS)

    Bailey, J. E.; Chandler, G. A.; Mancini, R. C.; Slutz, S. A.; Rochau, G. A.; Bump, M.; Buris-Mog, T. J.; Cooper, G.; Dunham, G.; Golovkin, I.; Kilkenny, J. D.; Lake, P. W.; Leeper, R. J.; Lemke, R.; MacFarlane, J. J.; Mehlhorn, T. A.; Moore, T. C.; Nash, T. J.; Nikroo, A.; Nielsen, D. S.; Peterson, K. L.; Ruiz, C. L.; Schroen, D. G.; Steinman, D.; Varnum, W.

    2006-05-01

    Z-pinch dynamic hohlraums are a promising indirect-drive inertial confinement fusion approach. Comparison of multiple experimental methods with integrated Z-pinch/hohlraum/capsule computer simulations builds understanding of the hohlraum interior conditions. Time-resolved x-ray images determine the motion of the radiating shock that heats the hohlraum as it propagates toward the hohlraum axis. The images also measure the radius of radiation-driven capsules as they implode. Dynamic hohlraum LASNEX [G. Zimmerman and W. Kruer, Comments Plasma Phys. Control. Fusion 2, 85 (1975)] simulations are found to overpredict the shock velocity by ˜20-40%, but simulated capsule implosion trajectories agree reasonably well with the data. Measurements of the capsule implosion core conditions using time- and space-resolved Ar tracer x-ray spectroscopy and the fusion neutron yield provide additional tests of the integrated hohlraum-implosion system understanding. The neutron yield in the highest performing CH capsule implosions is ˜20-30% of the yield calculated with unperturbed 2D LASNEX simulations. The emissivity-averaged electron temperature and density peak at approximately 900eV and 4×1023cm-3, respectively. Synthetic spectra produced by postprocessing 1D LASNEX capsule implosion simulations possess spectral features from H-like and He-like Ar that are similar in duration to the measured spectra. However, the simulation emissivity-averaged density peaks at a value that is four times lower than the experiment, while the temperature is approximately 1.6 times higher. The agreement with the capsule trajectory measurements and the ability to design capsule implosions that routinely produce implosion cores hot and dense enough to emit fusion neutrons and Ar spectra are evidence for a respectable degree of dynamic hohlraum understanding. The hohlraum shock velocity and implosion core discrepancies imply that calculations of the hohlraum radiation driving capsule implosions require further refinement.

  6. Gravitational Radiation Reaction

    E-print Network

    Yasushi Mino; Misao Sasaki; Takahiro Tanaka

    1997-12-12

    We consider the radiation reaction to the motion of a point-like particle of mass $m$ and specific spin $S$ traveling on a curved background. Assuming $S=O(Gm)$ and $Gm\\ll L$ where $L$ is the length scale of the background curvature, we divide the spacetime into two regions; the external region where the metric is approximated by the background metric plus perturbations due to a point-like particle and the internal region where the metric is approximated by that of a black hole plus perturbations due to the tidal effect of the background curvature, and use the technique of the matched asymptotic expansion to construct an approximate metric which is valid over the entire region. In this way, we avoid the divergent self-gravity at the position of the particle and derive the equations of motion from the consistency condition of the matching. The matching is done to the order necessary to include the effect of radiation reaction of $O(Gm)$ with respect to the background metric as well as the effect of spin-induced force. The reaction term of $O(Gm)$ is found to be completely due to tails of radiation, that is, due to curvature scattering of gravitational waves. In other words, the reaction force is found to depend on the entire history of the particle trajectory. Defining a regularized metric which consists of the back- ground metric plus the tail part of the perturbed metric, we find the equations of motion reduce to the geodesic equation on this regularized metric, except for the spin-induced force which is locally expressed in terms of the curvature and spin tensors. Some implications of the result and future issues are briefly discussed.

  7. Protection from Space Radiation

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, J. W.; Shinn, J. L.; Singleterry, R. C.; Clowdsley, M. S.; Cucinotta, F. A.; Badhwar, G. D.; Kim, M. Y.; Badavi, F. F.; Heinbockel, J. H.

    2000-01-01

    The exposures anticipated for our astronauts in the anticipated Human Exploration and Development of Space (HEDS) will be significantly higher (both annual and carrier) than any other occupational group. In addition, the exposures in deep space result largely from the Galactic Cosmic Rays (GCR) for which there is as yet little experience. Some evidence exists indicating that conventional linear energy transfer (LET) defined protection quantities (quality factors) may not be appropriate [1,2]. The purpose of this presentation is to evaluate our current understanding of radiation protection with laboratory and flight experimental data and to discuss recent improvements in interaction models and transport methods.

  8. ALICE Transition Radiation Detector

    E-print Network

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high P? tracks in one single TRD stack.

  9. Iron, radiation, and cancer.

    PubMed Central

    Stevens, R G; Kalkwarf, D R

    1990-01-01

    Increased iron content of cells and tissue may increase the risk of cancer. In particular, high available iron status may increase the risk of a radiation-induced cancer. There are two possible mechanisms for this effect: iron can catalyze the production of oxygen radicals, and it may be a limiting nutrient to the growth and development of a transformed cell in vivo. Given the high available iron content of the western diet and the fact that the world is changing to the western model, it is important to determine if high iron increases the risk of cancer. PMID:2269234

  10. Gravitational radiation reaction

    E-print Network

    Takahiro Tanaka

    2005-10-04

    We give a short personally-biased review on the recent progress in our understanding of gravitational radiation reaction acting on a point particle orbiting a black hole. The main motivation of this study is to obtain sufficiently precise gravitational waveforms from inspiraling binary compact stars with a large mass ratio. For this purpose, various new concepts and techniques have been developed to compute the orbital evolution taking into account the gravitational self-force. Combining these ideas with a few supplementary new ideas, we try to outline a path to our goal here.

  11. Radiation Field on Superspace

    E-print Network

    P. F. Gonzalez-Diaz

    1994-03-18

    We study the dynamics of multiwormhole configurations within the framework of the Euclidean Polyakov approach to string theory, incorporating a modification to the Hamiltonian which makes it impossible to interpret the Coleman Alpha parameters of the effective interactions as a quantum field on superspace, reducible to an infinite tower of fields on space-time. We obtain a Planckian probability measure for the Alphas that allows $\\frac{1}{2}\\alpha^{2}$ to be interpreted as the energy of the quanta of a radiation field on superspace whose values may still fix the coupling constants.

  12. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    SciTech Connect

    Scott Wilde, Raymond Keegan

    2008-07-01

    The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

  13. [Radiation protection agents to provide the radiation safety of astronauts].

    PubMed

    2013-01-01

    Taking into consideration the complexity of radiation factors and stressogenic factors of non-radiation nature in cosmic flights and prognostic difficulties of radiation situation, the authors propose to distinguish several stages of pharmacological protection for cosmonauts. The preparatory stage is realized on the Earth. The next stage is monitoring and correction of radioresistance during a flight. A possible stage consists of treatment of the radiation damage using a traditional protocol. The permanent stage includes pharmacological prevention of the distant consequences of irradiation. PMID:25507772

  14. Solar radiation on inclined surfaces

    NASA Astrophysics Data System (ADS)

    1980-05-01

    Mean monthly values of daily shortwave radiation on inclined surfaces are presented for 13 locations in India. Values of direct, diffuse sky, reflected, and total shortwave radiation incident on an inclined surface are given for 9 slope angles (measured from the horizontal) and 8 aspects. All the data are computed using measured values of the total shortwave radiation on a horizontal surface according to the techniques described. Maximum and minimum values of direct solar radiation during each month are underlined and marked by asterisk respectively. Actual and potential users of radiation data, particularly those in the fields of agriculture, horticulture, forestry, architecture, heating and ventilating engineering, and photovoltaic systems, it is hoped, would find this publication useful in planning and designing of solar radiation devices.

  15. Malignant mesothelioma following radiation exposure

    SciTech Connect

    Antman, K.H.; Corson, J.M.; Li, F.P.; Greenberger, J.; Sytkowski, A.; Henson, D.E.; Weinstein, L.

    1983-11-01

    Mesothelioma developed in proximity to the field of therapeutic radiation administered 10-31 years previously in four patients. In three, mesothelioma arose within the site of prior therapeutic radiation for another cancer. Mesothelioma in the fourth patient developed adjacent to the site of cosmetic radiation to a thyroidectomy scar. None of these four patients recalled an asbestos exposure or had evidence of asbestosis on chest roentgenogram. Lung tissue in one patient was negative for ferruginous bodies, a finding considered to indicate no significant asbestos exposure. Five other patients with radiation-associated mesothelioma have been reported previously, suggesting that radiation is an uncommon cause of human mesothelioma. Problems in the diagnosis of radiation-associated mesotheliomas are considered.

  16. CRASH: a Radiative Transfer Scheme

    E-print Network

    Maselli, A; Ciardi, B

    2003-01-01

    We present a largely improved version of CRASH, a 3-D radiative transfer code that treats the effects of ionizing radiation propagating through a given inhomogeneous H/He cosmological density field, on the physical conditions of the gas. The code, based on a Monte Carlo technique, self-consistently calculates the time evolution of gas temperature and ionization fractions due to an arbitrary number of point/extended sources and/or diffuse background radiation with given spectra. In addition, the effects of diffuse ionizing radiation following recombinations of ionized atoms have been included. After a complete description of the numerical scheme, to demonstrate the performances, accuracy, convergency and robustness of the code we present four different test cases designed to investigate specific aspects of radiative transfer: (i) pure hydrogen isothermal Stromgren sphere; (ii) realistic Stromgren spheres; (iii) multiple overlapping point sources, and (iv) shadowing of background radiation by an intervening opt...

  17. Radiation-induced thyroid disease

    SciTech Connect

    Maxon, H.R.

    1985-09-01

    Ionizing radiation has been demonstrated to result in a number of changes in the human thyroid gland. At lower radiation dose levels (between 10 and 1500 rads), benign and malignant neoplasms appear to be the dominant effect, whereas at higher dose levels functional changes and thyroiditis become more prevalent. In all instances, the likelihood of the effect is related to the amount and type of radiation exposure, time since exposure, and host factors such as age, sex, and heredity. The author's current approach to the evaluation of patients with past external radiation therapy to the thyroid is discussed. The use of prophylactic thyroxine (T4) therapy is controversial. While T4 therapy may not be useful in preventing carcinogenesis when instituted many years after radiation exposure, theoretically T4 may block TSH secretion and stimulation of damaged cells to undergo malignant transformation when instituted soon after radiation exposure.

  18. Occupational radiation exposure: population studies.

    PubMed

    Schleipman, A Robert

    2005-01-01

    Occupational exposure to ionizing radiation in the medical setting differs from the acute exposure received by survivors of atomic bomb blasts. Yet, atomic bomb survivors' disease and mortality outcomes have been the standard data source on the effects of ionizing radiation on humans. Therefore, the prevailing estimated risks of ionizing radiation may not apply to radiologic technologists and other medical radiation workers. Carefully designed epidemiological trials provide evidence that helps determine the strength of association between exposure and onset of disease in selected populations. This article reviews radiation effects, explains some basic design concepts of epidemiologic trials and surveys the epidemiology literature related to radiation exposure to humans, with special attention to radiology staff. PMID:15732889

  19. Deterministic methods in radiation transport

    SciTech Connect

    Rice, A.F.; Roussin, R.W. (eds.)

    1992-06-01

    The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

  20. Radiation reaction in various dimensions

    Microsoft Academic Search

    D. V. Gal

    We discuss the radiation reaction problem for an electric charge moving in flat space-time of arbitrary dimensions. It is shown that four is the unique dimension where a local differential equation exists accounting for the radiation reaction and admitting a consistent mass-renormalization (the Dirac-Lorentz equation). In odd dimensions the Huygens principle does not hold; as a result, the radiation reaction

  1. Radiation sterilization of ketoprofen

    NASA Astrophysics Data System (ADS)

    Katušin-Ražem, Branka; Hamitouche, Katia; Maltar-Strme?ki, Nadica; Kos, Karmen; Puci?, Irina; Britvi?-Budicin, Smiljana; Ražem, Dušan

    2005-06-01

    Radiation sterilization of ketoprofen (KP) dry powder was investigated by selected physico-chemical methods. High-performance liquid chromatography, ultraviolet spectrophotometry, infrared spectrophotometry, differential scanning calorimetry, X-ray diffraction and electron spin resonance spectroscopy did not show any significant degradation at sterilization dose 25 kGy. To determine the nature, extent and direction of radiation-induced changes, KP was irradiated to extremely high doses, much higher than necessary to achieve sterility. The irradiated KP did not show any difference of XRD patterns up to 200 kGy; with DSC and IR some changes were detected only above 1000 and 2000 kGy, respectively; HPLC has shown about 5% destruction at 2000 kGy. Acetyl benzophenon (AcBph) was generated by irradiation with G(AcBph)=(1.6±0.1)×10 -8 mol J -1. Ames test has shown no mutagenicity of KP irradiated with 3000 kGy or of the oily mixure of radiolytic products isolated from it. Solid KP has proven to be very stable on irradiation, and irradiation has been found to be a suitable method for its sterilization.

  2. Imaging with terahertz radiation

    NASA Astrophysics Data System (ADS)

    Chan, Wai Lam; Deibel, Jason; Mittleman, Daniel M.

    2007-08-01

    Within the last several years, the field of terahertz science and technology has changed dramatically. Many new advances in the technology for generation, manipulation, and detection of terahertz radiation have revolutionized the field. Much of this interest has been inspired by the promise of valuable new applications for terahertz imaging and sensing. Among a long list of proposed uses, one finds compelling needs such as security screening and quality control, as well as whimsical notions such as counting the almonds in a bar of chocolate. This list has grown in parallel with the development of new technologies and new paradigms for imaging and sensing. Many of these proposed applications exploit the unique capabilities of terahertz radiation to penetrate common packaging materials and provide spectroscopic information about the materials within. Several of the techniques used for terahertz imaging have been borrowed from other, more well established fields such as x-ray computed tomography and synthetic aperture radar. Others have been developed exclusively for the terahertz field, and have no analogies in other portions of the spectrum. This review provides a comprehensive description of the various techniques which have been employed for terahertz image formation, as well as discussing numerous examples which illustrate the many exciting potential uses for these emerging technologies.

  3. Personal Radiation Protection System

    NASA Technical Reports Server (NTRS)

    McDonald, Mark; Vinci, Victoria

    2004-01-01

    A report describes the personal radiation protection system (PRPS), which has been invented for use on the International Space Station and other spacecraft. The PRPS comprises walls that can be erected inside spacecraft, where and when needed, to reduce the amount of radiation to which personnel are exposed. The basic structural modules of the PRPS are pairs of 1-in. (2.54-cm)-thick plates of high-density polyethylene equipped with fasteners. The plates of each module are assembled with a lap joint. The modules are denoted bricks because they are designed to be stacked with overlaps, in a manner reminiscent of bricks, to build 2-in. (5.08-cm)-thick walls of various lengths and widths. The bricks are of two varieties: one for flat wall areas and one for corners. The corner bricks are specialized adaptations of the flat-area bricks that make it possible to join walls perpendicular to each other. Bricks are attached to spacecraft structures and to each other by use of straps that can be tightened to increase the strengths and stiffnesses of joints.

  4. Radiation Embrittlement Archive Project

    SciTech Connect

    Klasky, Hilda B [ORNL] [ORNL; Bass, Bennett Richard [ORNL] [ORNL; Williams, Paul T [ORNL] [ORNL; Phillips, Rick [ORNL] [ORNL; Erickson, Marjorie A [ORNL] [ORNL; Kirk, Mark T [ORNL] [ORNL; Stevens, Gary L [ORNL] [ORNL

    2013-01-01

    The Radiation Embrittlement Archive Project (REAP), which is being conducted by the Probabilistic Integrity Safety Assessment (PISA) Program at Oak Ridge National Laboratory under funding from the U.S. Nuclear Regulatory Commission s (NRC) Office of Nuclear Regulatory Research, aims to provide an archival source of information about the effect of neutron radiation on the properties of reactor pressure vessel (RPV) steels. Specifically, this project is an effort to create an Internet-accessible RPV steel embrittlement database. The project s website, https://reap.ornl.gov, provides information in two forms: (1) a document archive with surveillance capsule(s) reports and related technical reports, in PDF format, for the 104 commercial nuclear power plants (NPPs) in the United States, with similar reports from other countries; and (2) a relational database archive with detailed information extracted from the reports. The REAP project focuses on data collected from surveillance capsule programs for light-water moderated, nuclear power reactor vessels operated in the United States, including data on Charpy V-notch energy testing results, tensile properties, composition, exposure temperatures, neutron flux (rate of irradiation damage), and fluence, (Fast Neutron Fluence a cumulative measure of irradiation for E>1 MeV). Additionally, REAP contains data from surveillance programs conducted in other countries. REAP is presently being extended to focus on embrittlement data analysis, as well. This paper summarizes the current status of the REAP database and highlights opportunities to access the data and to participate in the project.

  5. Split supersymmetry radiates flavor

    NASA Astrophysics Data System (ADS)

    Baumgart, Matthew; Stolarski, Daniel; Zorawski, Thomas

    2014-09-01

    Radiative flavor models where the hierarchies of Standard Model (SM) fermion masses and mixings are explained via loop corrections are elegant ways to solve the SM flavor puzzle. Here we build such a model in the context of mini-split supersymmetry (SUSY) where both flavor and SUSY breaking occur at a scale of 1000 TeV. This model is consistent with the observed Higgs mass, unification, and dark matter as a weakly interacting massive particle. The high scale allows large flavor mixing among the sfermions, which provides part of the mechanism for radiative flavor generation. In the deep UV, all flavors are treated democratically, but at the SUSY-breaking scale, the third, second, and first generation Yukawa couplings are generated at tree level, one loop, and two loops, respectively. Save for one, all the dimensionless parameters in the theory are O(1), with the exception being a modest and technically natural tuning that explains both the smallness of the bottom Yukawa coupling and the largeness of the Cabibbo angle.

  6. Split SUSY Radiates Flavor

    E-print Network

    Matthew Baumgart; Daniel Stolarski; Thomas Zorawski

    2014-09-19

    Radiative flavor models where the hierarchies of Standard Model (SM) fermion masses and mixings are explained via loop corrections are elegant ways to solve the SM flavor puzzle. Here we build such a model in the context of Mini-Split Supersymmetry (SUSY) where both flavor and SUSY breaking occur at a scale of 1000 TeV. This model is consistent with the observed Higgs mass, unification, and WIMP dark matter. The high scale allows large flavor mixing among the sfermions, which provides part of the mechanism for radiative flavor generation. In the deep UV, all flavors are treated democratically, but at the SUSY breaking scale, the third, second, and first generation Yukawa couplings are generated at tree level, one loop, and two loops, respectively. Save for one, all the dimensionless parameters in the theory are O(1), with the exception being a modest and technically natural tuning that explains both the smallness of the bottom Yukawa coupling and the largeness of the Cabibbo angle.

  7. Genetic susceptibility to radiation

    NASA Astrophysics Data System (ADS)

    Hall, E. J.; Brenner, D. J.; Worgul, B.; Smilenov, L.

    In the context of space radiation, it is important to know whether the human population includes genetically predisposed radiosensitive subsets. One possibility is that haploinsufficiency for ATM confers radiosensitivity, and this defect involves 1 3% of the population. Using knock-out mice we chose to study cataractogenesis in the lens and oncogenic transformation in mouse embryo fibroblasts to assay for effects of ATM deficiency. Radiation induced cataracts appeared earlier in the heterozygous versus wild-type animals following exposure to either gamma rays or 1 GeV/nucleon iron ions. In addition, it was found that embryo fibroblasts of Atm heterozygotes showed an increased incidence of oncogenic transformation compared with their normal litter-matched counterparts. From these data we suggest that Ataxia Telangiectasia heterozygotes could indeed represent a societally significant radiosensitive subpopulation. Knock-out mice are now available for other genes including BRCA1 and 2, and Mrad9. An exciting possibility is the creation of double heterozygotes for pairs of mutated genes that function in the same signal transduction pathway, and consequently confer even greater radiosensitivity.

  8. Space radiation studies

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Two Active Radiation Dosimeters (ARD's) flown on Spacelab 1, performed without fault and were returned to Space Science Laboratory, MSFC for recalibration. During the flight, performance was monitored at the Huntsville Operations Center (HOSC). Despite some problems with the Shuttle data system handling the verification flight instrumentation (VFI), it was established that the ARD's were operating normally. Postflight calibrations of both units determined that sensitivities were essentially unchanged from preflight values. Flight tapes were received for approx. 60 percent of the flight and it appears that this is the total available. The data was analyzed in collaboration with Space Science Laboratory, MSFC. Also, the Nuclear Radiation Monitor (NRM) was assembled and tested at MSFC. Support was rendered in the areas of materials control and parts were supplied for the supplementary heaters, dome gas-venting device and photomultiplier tube housing. Performance characteristics of some flight-space photomultipliers were measured. The NRM was flown on a balloon-borne test flight and subsequently performed without fault on Spacelab-2. This data was analyzed and published.

  9. The THz Radiation from Undulator

    SciTech Connect

    Gabrielyan, L. A.; Garibyan, Y. A.; Nazaryan, Y. R.; Oganesyan, K. B.; Oganesyan, M. A.; Petrosyan, M. L.; Ananikyan, N. S. [Yerevan Physics Institute, Alikhanyan Br.2, 0036 Yerevan (Armenia); Fedorov, M. V.; Artemiev, A. I.; Klochkov, D. N. [Moscow General Physics Institute, Vavilov 38, 119991 Moscow (Russian Federation); Rostovtsev, Yu. V.; Scully, M. O. [Texas A and M University, Departament of Physics, Collage Station, Texas (United States)

    2010-02-03

    The experimental device for generation of undulator radiation in terahertz wavelength region by use of undulator with ferromagnets is created. The device is based on a beam of a microtron with the energy 7.5 MeV. The radiation wavelength is 200 mu. Registered spontaneous radiation has a power 10{sup -6} W at a current of a beam 2 mA in a pulse. With the optical resonator, in a mode, the amplification of 6% is received, that in sometimes is more than the expected value. This effect is explained as a result of partial coherence of radiation.

  10. Ionizing radiation promotes protozoan reproduction

    SciTech Connect

    Luckey, T.D.

    1986-11-01

    This experiment was performed to determine whether ionizing radiation is essential for maximum growth rate in a ciliated protozoan. When extraneous ionizing radiation was reduced to 0.15 mrad/day, the reproduction rate of Tetrahymena pyriformis was significantly less (P less than 0.01) than it was at near ambient levels, 0.5 or 1.8 mrad/day. Significantly higher growth rates (P less than 0.01) were obtained when chronic radiation was increased. The data suggest that ionizing radiation is essential for optimum reproduction rate in this organism.

  11. Coherent tunable far infrared radiation

    NASA Technical Reports Server (NTRS)

    Jennings, D. A.

    1989-01-01

    Tunable, CW, FIR radiation has been generated by nonlinear mixing of radiation from two CO2 lasers in a metal-insulator-metal (MIM) diode. The FIR difference-frequency power was radiated from the MIM diode antenna to a calibrated InSb bolometer. FIR power of 200 nW was generated by 250 mW from each of the CO2 lasers. Using the combination of lines from a waveguide CO2 laser, with its larger tuning range, with lines from CO2, N2O, and CO2-isotope lasers promises complete coverage of the entire FIR band with stepwise-tunable CW radiation.

  12. Radiation Belts and Trapped Particles

    NSDL National Science Digital Library

    This tutorial introduces students to Earth's radiation belts, also known as the Van Allen Belts after their discoverer. Topics include the structure of the radiation belts and the currents of particles trapped in Earth's magnetic fields, their properties, and where they come from. There is also a set of classroom activities for exploring radiation belts and solar storms and a set of illustrations and movies of the belts. Other materials include news items related to the radiation belts, recordings of 'space sounds' related to the influence of lightning on Earth's magnetic field, and a frequently-asked-questions feature.

  13. Electromagnetic radiation by gravitating bodies

    E-print Network

    Iwo Bialynicki-Birula; Zofia Bialynicka-Birula

    2008-05-06

    Gravitating bodies in motion, regardless of their constitution, always produce electromagnetic radiation in the form of photon pairs. This phenomenon is an analog of the radiation caused by the motion of dielectric (or magnetic) bodies. It is a member of a wide class of phenomena named dynamical Casimir effects, and it may be viewed as the squeezing of the electromagnetic vacuum. Production of photon pairs is a purely quantum-mechanical effect. Unfortunately, as we show, the emitted radiation is extremely weak as compared to radiation produced by other mechanisms.

  14. Enhanced radiation resistant fiber optics

    DOEpatents

    Lyons, P.B.; Looney, L.D.

    1993-11-30

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  15. Radiosensitizers, radioprotectors, and radiation mitigators.

    PubMed

    Raviraj, Jayam; Bokkasam, Vijay Kumar; Kumar, Venkata Suneel; Reddy, Uday Shankar; Suman, Venkata

    2014-01-01

    Radiotherapy is regarded as one of the most important therapeutic modality for the treatment of malignant lesions. This field is undergoing rapid advancements in the recent times. With the use of radiosensitizers and radioprotective agents, the course of radiotherapy has improved the sensitization of tumor cells and protection of normal cells, respectively. The aim of this paper was to critically review and analyze the available compounds used as radiosensitizers, radioprotectors, and radiation mitigators. For reviewing, the author used the electronic search for the keywords 'Radiosensitizers', 'Radioprotectors', 'Radiation mitigators' on PubMed for inclusion of previously published articles and further search of reference papers on individual radiosensitizing and radioprotecting agents was done. Radiosensitizers are agents that sensitize the tumor cells to radiation. These compounds apparently promote fixation of the free radicals produced by radiation damage at the molecular level. The mechanism of action is similar to the oxygen effect, in which biochemical reactions in the damaged molecules prevent repair of the cellular radiation damage. Free radicals such as OH + are captured by the electron affinity of the radiosensitizers, rendering the molecules incapable of repair. Radioprotectors are compounds that are designed to reduce the damage in normal tissues caused by radiation. These compounds are often antioxidants and must be present before or at the time of radiation for effectiveness. Other agents, termed mitigators, may be used to minimize toxicity even after radiation has been delivered. This article tries to discuss the various aspects of radiosensitizers, radioprotectors, and radiation mitigators including the newer agents. PMID:24748306

  16. Radiation Shielding for Space Flight

    NASA Technical Reports Server (NTRS)

    Blattnig, Steve R.; Norbury, John W.; Norman, Ryan B.

    2003-01-01

    A safe and efficient exploration of space requires an understanding of space radiations so that human life and sensitive equipment can be protected. On the way to these sensitive sites, the radiation is modified in both quality and quantity. Many of these modifications are thought to be due to the production of pions and muons in the interactions between the radiation and intervening matter. A method to predict the effects of the presence of these particles on the transport of radiation through materials is presented.

  17. Scintillator Waveguide For Sensing Radiation

    DOEpatents

    Bliss, Mary (West Richland, WA); Craig, Richard A. (West Richland, WA); Reeder; Paul L. (Richland, WA)

    2003-04-22

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  18. Cardiac imaging: does radiation matter?

    PubMed Central

    Einstein, Andrew J.; Knuuti, Juhani

    2012-01-01

    The use of ionizing radiation in cardiovascular imaging has generated considerable discussion. Radiation should not be considered in isolation, but rather in the context of a careful examination of the benefits, risks, and costs of cardiovascular imaging. Such consideration requires an understanding of some fundamental aspects of the biology, physics, epidemiology, and terminology germane to radiation, as well as principles of radiological protection. This paper offers a concise, contemporary perspective on these areas by addressing pertinent questions relating to radiation and its application to cardiac imaging. PMID:21828062

  19. Enhanced radiation resistant fiber optics

    DOEpatents

    Lyons, Peter B. (Los Alamos, NM); Looney, Larry D. (Los Alamos, NM)

    1993-01-01

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  20. Therapeutic Applications of Ionizing Radiations

    NASA Astrophysics Data System (ADS)

    Sánchez-Santos, María Elena

    The aim of radiation therapy is to deliver a precisely measured dose of radiation to a defined tumour volume with minimal damage to the surrounding healthy tissue, resulting in the eradication of the tumour, a higher quality of life with palliation of symptoms of the disease, and the prolongation of survival at competitive cost. Together with surgery and pharmacology, radiotherapy is presently one of the most important therapeutical weapons against cancer. This chapter provides an overview of the clinical use of radiation, with emphasis on the optimisation of treatment planning and delivery, and a top level summary of state-of-the-art techniques in radiation therapy.

  1. Cataractogenic effects of proton radiation

    E-print Network

    Kyzar, James Ronald

    1972-01-01

    Roentgen in 1895 it has been recognized that. ionizing radiation possesses the ability to damage the lens of the eye. A few cases of radiation induced cataracts in early x-ray technicians and in patients re- ceiving radiation therapy to the head were...CATARACTOGENIC EFFECTS OF PROTON RADIATION A Thesis by James Ronald Kyzar Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1972 Major Subject...

  2. Estimating shortwave solar radiation using net radiation and meteorological measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shortwave radiation has a wide variety of uses in land-atmosphere interactions research. Actual evapotranspiration estimation that involves stomatal conductance models like Jarvis and Ball-Berry require shortwave radiation to estimate photon flux density. However, in most weather stations, shortwave...

  3. Using radiation risk for assessment of space radiation hazard

    NASA Astrophysics Data System (ADS)

    Petrov, V. M.

    2011-05-01

    Radiation hazard caused by exposure during a spaceflight is characterized by radiobiological consequences at all levels of organism. These consequences have a stochastic nature. Even deterministic effects are basically random quantity having all attributes of such mathematical values. The radiation risk is defined in this case as an additional probability of health damage or as a death probability in extreme case. For the manned spaceflight additional peculiarity of a human's exposure is added. A natural space radiation environment has a stochastic character because solar particle events and crew of a spacecraft can be exposed to dose from background level up to lethal one. The report presents a procedure of radiation risk assessment for quantitative expression of radiation hazard level during a flight and using this value for developing protection recommendations. It is emphasized that the risk value is connected specifically with the time interval of possible hazard's existent. The form of risk representation must be chosen depending on a time scale of radiobiological processes induced by the exposure (expressing in fact the radiation hazard model). Surviving function specified for the crewmember mortality rate changed by the professional exposure must be used for risk calculation. Solar particle events determine a stochastic character of radiation environment in space that must be taken into account for a risk assessment. The reliability of radiation risk assessment can be used for this goal.

  4. Radiation Protection for Manned Interplanetary Missions - Radiation Sources, Risks, Remedies

    Microsoft Academic Search

    R. Facius; G. Reitz

    2006-01-01

    Health risks in interplanetary explorative missions differ in two major features significantly from those during the manned missions experienced so far. For one, presently available technologies lead to durations of such missions significantly longer than so far encountered - with the added complication that emergency returns are ruled out. Thus radiation exposures and hence risks for late radiation sequelae like

  5. Compound semiconductor radiation detectors

    NASA Astrophysics Data System (ADS)

    Owens, Alan; Peacock, A.

    2004-09-01

    We discuss the potential benefits of using compound semiconductors for the detection of X- and ?-ray radiation. While Si and Ge have become detection standards for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by one or more of their physical limitations; namely the need for ancillary cooling systems or bulky cryogenics, their modest stopping powers and radiation intolerance. Compound semiconductors encompass such a wide range of physical properties that it is technically feasible to engineer a material to any application. Wide band-gap compounds offer the ability to operate in a wide range of thermal and radiation environments, whilst still maintaining sub-keV spectral resolution at hard X-ray wavelengths. Narrow band-gap materials, on the other hand, offer the potential of exceeding the spectral resolution of both Si and Ge, by as much as a factor of 3. Assuming that the total system noise can be reduced to a level commensurate with Fano noise, spectroscopic detectors could work in the XUV, effectively bridging the gap between the ultraviolet and soft X-ray wavebands. Thus, in principle, compound semiconductor detectors can provide continuous spectroscopic coverage from the far infrared through to ?-ray wavelengths. However, while they are routinely used at infrared and optical wavelengths, in other bands, their development has been plagued by material and fabrication problems. This is particularly true at hard X- and ?-ray wavelengths, where only a few compounds (e.g., GaAs, CdZnTe and HgI2) have evolved sufficiently to produce working detection systems. In this paper, we examine the current status of research in compound semiconductors and by a careful examination of material properties and future requirements, recommend a number of compounds for further development. In the longer term, when material problems are sufficiently under control, we believe the future lies in the development of heterostructures and inserted interface layers to overcome contacting problems and quantum heterostructures and superlattices to facilitate low-noise readout.

  6. RELATIVISTIC RADIATION MEDIATED SHOCKS

    SciTech Connect

    Budnik, Ran; Katz, Boaz; Sagiv, Amir; Waxman, Eli, E-mail: ranny.budnik@weizmann.ac.i, E-mail: boaz.katz@weizmann.ac.i, E-mail: eli.waxman@weizmann.ac.i [Physics Faculty, Weizmann Institute, Rehovot 76100 (Israel)

    2010-12-10

    The structure of relativistic radiation mediated shocks (RRMSs) propagating into a cold electron-proton plasma is calculated and analyzed. A qualitative discussion of the physics of relativistic and non-relativistic shocks, including order of magnitude estimates for the relevant temperature and length scales, is presented. Detailed numerical solutions are derived for shock Lorentz factors {Gamma}{sub u} in the range 6 {<=} {Gamma}{sub u} {<=} 30, using a novel iteration technique solving the hydrodynamics and radiation transport equations (the protons, electrons, and positrons are argued to be coupled by collective plasma processes and are treated as a fluid). The shock transition (deceleration) region, where the Lorentz factor {Gamma} drops from {Gamma}{sub u} to {approx}1, is characterized by high plasma temperatures T {approx} {Gamma}m{sub e}c {sup 2} and highly anisotropic radiation, with characteristic shock-frame energy of upstream (US) and downstream (DS) going photons of a few x m{sub e}c {sup 2} and {approx}{Gamma}{sup 2} m{sub e}c {sup 2}, respectively. Photon scattering is dominated by e {sup {+-}} pairs, with the pair-to-proton density ratio reaching {approx}10{sup 2{Gamma}}{sub u}. The width of the deceleration region, in terms of Thomson optical depths for US-going photons, is large, {Delta}{tau} {approx} {Gamma}{sup 2}{sub u} ({Delta}{tau} {approx} 1 neglecting the contribution of pairs) due to Klein-Nishina suppression of the scattering cross section. A high-energy photon component, narrowly beamed in the DS direction, with a nearly flat power-law-like spectrum, {nu}I{sub {nu} {proportional_to}} {nu}{sup 0}, and an energy cutoff at {approx}{Gamma}{sup 2}{sub u} m{sub e}c {sup 2} carries a fair fraction of the energy flux at the end of the deceleration region. An approximate analytic model of RRMS, reproducing the main features of the numerical results, is provided.

  7. Microanalysis using synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Kwiatek, Wojciech M.; Cichocki, Tadeusz; Galka, Marek; Paluszkiewicz, Czeslawa

    1992-05-01

    The SRIXE (synchrotron radiation induced X-ray emission) technique has been applied for several years in different fields of science. Since it has a number of useful advantages [1] it has been applied to microanalysis of thin tissue sections in order to investigate the trace element distribution in normal and cancerous kidneys. All the samples were surgically obtained in the Clinic of Urology at the Academy of Medicine in Cracow, Poland and were investigated in Hasylab at DESY, Hamburg, Germany with the synchrotron beam of 70 ?m × 100 ?m. Although only a few samples were measured so far, the results obtained seem to be promising. Enhanced trace element concentrations in cancerous parts of kidneys have been observed.

  8. Martian atmospheric radiation budget

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1994-01-01

    A computer model is used to study the radiative transfer of the martian winter-polar atmosphere. Solar heating at winter-polar latitudes is provided predominately by dust. For normal, low-dust conditions, CO2 provides almost as much heating as dust. Most heating by CO2 in the winter polar atmosphere is provided by the 2.7 micron band between 10 km and 30 km altitude, and by the 2.0 micron band below 10 km. The weak 1.3 micron band provides some significant heating near the surface. The minor CO2 bands at 1.4, 1.6, 4.8 and 5.2 micron are all optically thin, and produce negligible heating. O3 provides less than 10 percent of the total heating. Atmospheric cooling is predominantly thermal emission by dust, although CO2 15 micron band emission is important above 20 km altitude.

  9. The IRAS radiation environment

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.

    1978-01-01

    Orbital flux integration for three selected mission altitudes and geographic instantaneous flux-mapping for nominal flight-path altitude were used to determine the external charged particle radiation predicted for the Infrared Astronomy Satellite. A current field model was used for magnetic field definitions for three nominal circular trajectories and for the geographic mapping positions. Innovative analysis features introduced include (1) positional fluxes as a function of time and energy for the most severe pass through the South Atlantic Anomaly; (2) total positional doses as a function of time and shield thickness; (3) comparison mapping fluxes for ratios of positional intensities to orbit integrated averages; and (4) statistical exposure-time history of a trajectory as a function of energy indicating, in percent of total mission duration, the time intervals over which the instantaneous fluxes would exceed the orbit integrated averages. Results are presented in tables and graphs.

  10. Stationary radiation of objects with scattering media

    Microsoft Academic Search

    Inna A Vasileva

    2001-01-01

    The radiation observed inside or outside a stationary radiator with a scattering medium is a sum of components, each being determined by, first, the primary radiation from some part of the radiator and, second, the probability of this radiation reaching the region where it is observed. In this review, general and rather simple relations between these components are discussed. These

  11. Therapy of radiation injury.

    PubMed

    MacVittie, T J

    1997-01-01

    It is apparent from preclinical and clinical research to date that continued evaluation of new and alternative treatment strategies is required to eliminate the obligate periods of neutropenia and thrombocytopenia after acute high-dose irradiation. Future treatment strategies may involve new combinations of cytokines to affect hematopoietic stem cell proliferation and "engineered" cellular grafts to provide short-term in vivo expansion of neutrophils and platelets in an effort to bridge the cytopenic gap until endogenous or transplanted stem cells regenerate the hematopoietic and immune systems. Cytokine-mobilized peripheral blood and cord blood will provide alternative sources of allogeneic stem and progenitor cells in support of primary engraftment, delayed engraftment or secondary failure of the initial graft, as well as starting populations for various ex vivo expansion protocols. Further insights into the relative quality of stem cell populations and the factors that regulate their survival and self renewal, and the identification and roles of adhesion molecules in stem cell mobilization, engraftment, and interaction with the adult marrow microenvironment will provide the basis for future treatment strategies for the radiation-induced hematopoietic syndrome. As our ability to treat the hematopoietic syndrome improves, damage to other organ systems such as the skin, lung, and/or gastrointestinal tissue will emerge as dose-limiting. At the same time, the characterization of receptors for inflammatory cytokines, cytokine receptor antagonists, and anti-endotoxin antibodies has allowed significant insights into the mechanisms and pathogenesis of sepsis. However, translation of this knowledge into a treatment modality for septic patients is precluded by the lack of any clear-cut beneficial effect from the many clinical trials. The research and clinical results presented in this volume and recent conferences reflect the body of knowledge that will lead to further developments in assessment, prophylaxis, and treatment of radiation injuries in the areas of infectious disease and the hematopoietic, gastrointestinal, and cutaneous syndromes. PMID:9368312

  12. Design experience: CRBRP radiation shielding

    Microsoft Academic Search

    R. K. Disney; T. C. Chan; F. G. Gallo; L. R. Hedgecock; C. A. McGinnis; G. N. Wrights

    1978-01-01

    The Clinch River Breeder Reactor Plant (CRBRP) is being designed as a fast breeder demonstration project in the U.S. Liquid Metal Fast Breeder Reactor (LMFBR) program. Radiation shielding design of the facility consists of a comprehensive design approach to assure compliance with design and government regulatory requirements. Studies conducted during the CRBRP design process involved the aspects of radiation shielding

  13. Multiple-layer Radiation Absorber

    NASA Astrophysics Data System (ADS)

    Baker, Robert M. L.; Baker, Bonnie Sue

    A structure is discussed for absorbing incident radiation, either electromagnetic (EM) or sound. Such a surface structure is needed, for example, in a highly sensitive high-frequency gravitational wave or HFGW detector such as the Li-Baker. The multi-layer absorber, which is discussed, is constructed with metamaterial [MM] layer or layers on top. This MM is configured for a specific EM or sound radiation frequency band, which absorbs incident EM or sound radiation without reflection. Below these top MM layers is a substrate of conventional EM-radiation absorbing or acoustical absorbing reflective material, such as an array of pyramidal foam absorbers. Incident radiation is partially absorbed by the MM layer or layers, and then it is more absorbed by the lower absorbing and reflecting substrate. The remaining reflected radiation is even further absorbed by the MM layers on its "way out_ so that essentially all of the incident radiation is absorbed _ a nearly perfect black-body absorber. In a HFGW detector a substrate, such as foam absorbers, may outgas into a high vacuum and reduce the capability of the vacuum-producing equipment, however, the layers above this lowest substrate will seal the absorbing and reflecting substrate from any external vacuum. The layers also serve to seal the absorbing material against air or water flow past the surfaces of aircraft, watercraft or submarines. Other applications for such a multiple-level radiation absorber include stealth aircraft, missiles and submarines.

  14. Radiative Corrections to Fermi Interactions

    Microsoft Academic Search

    Toichiro Kinoshita; Alberto Sirlin

    1959-01-01

    The radiative correction to the decay spectrum of polarized muons is recalculated taking into account a mistake in our previous work which was recently pointed out by Berman. The revised values for the radiative correction to delta, xi, and integrated asymmetries for the high- as well as low-energy decay electrons have turned out to be practically identical with the old

  15. Hawking Radiation in Dispersive Media

    Microsoft Academic Search

    Scott James Robertson

    2011-01-01

    Hawking radiation, despite its presence in theoretical physics for over thirty years, remains elusive and undetected. It also suffers, in its original context of gravitational black holes, from conceptual difficulties. Of particular note is the trans-Planckian problem, which is concerned with the apparent origin of the radiation in absurdly high frequencies. In order to gain better theoretical understanding and, it

  16. Radiation carcinogenesis: radioprotectors and photosensitizers

    SciTech Connect

    Fry, R.J.M.

    1982-01-01

    This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer.

  17. Effects Of Radiation On Insulators

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.

    1988-01-01

    Report presents data on responses of electrically insulating thermosetting and thermoplastic polymers to radiation. Lowest-threshold-dose (LTD) levels and 25-percent-change levels presented for such properties as tensile strength and electrical resistivity. Data on radiation-induced outgassing also given.

  18. Radiative transfer in protoplanetary disks

    Microsoft Academic Search

    C. Pinte; F. Ménard; G. Duchêne

    2006-01-01

    We present a new 3D continuum radiative transfer code, MCFOST, based on a Monte-Carlo method. The reliability and efficiency of the code is tested by comparison with five different radiative transfer codes previously tested by Pascucci et al. (2004), using a 2D disk configuration. When tested against the same disk configuration, no significant difference is found between the temperature and

  19. Radiation epidemiology: Past and present

    SciTech Connect

    Boice, J.D. Jr. [International Epidemiology Institute, Rockville, MD (United States)

    1997-03-01

    Major advancements in radiation epidemiology have occurred during the last several years in studies of atomic bomb survivors, patients given medical radiation, and radiation workers, including underground miners. Risks associated with the Chernobyl accident, indoor radon and childhood exposure to I-131 have yet to be elucidated. Situations in the former Soviet Union around Chelyabinsk, a nuclear installation in the southern Urals, and in the Altai, which received radioactive fallout from weapons testing at Semipalatinsk, Kazakhstan, have the potential to provide information on the effects of chronic radiation exposure. Since Roentgen`s discovery of x-rays just 100 years ago, a tremendous amount of knowledge has been accumulated about human health effects following irradiation. The 1994 UNSCEAR report contains the latest compilation and synthesis of radiation epidemiology. This overview will cover epidemiology from a radiation perspective. The different types of study methodologies will be described, followed by a kaleidoscope coverage of past and present studies; ending with some remaining questions in radiation epidemiology. This should set the stage for future chapters, and stimulate thinking about implications of the new data on radiation cancer risks.

  20. Radiated noise of ducted fans

    Microsoft Academic Search

    Walter Eversman

    1992-01-01

    The differences in the radiated acoustic fields of ducted and unducted propellers of the same thrust operating under similar conditions are investigated. An FEM model is created for the generation, propagation, and radiation of steady, rotor alone noise and exit guide vane interaction noise of a ducted fan. For a specified number of blades, angular mode harmonic, and rotor angular

  1. Integrating fiber optic radiation dosimeter

    SciTech Connect

    Soltani, P.K.; Wrigley, C.Y.; Storti, G.M.; Creager, R.E.

    1989-03-01

    The purpose of this research effort was to determine the feasibility of forming a radiation sensor coupled to an optical fiber capable of measuring gamma photon, x-ray, and beta particle dose rates and integrated dose, and to construct a prototype dosimeter read-out system utilizing the fiber optic sensor. The key component of the prototype dosimeter system is a newly developed radiation sensitive storage phosphor. When this phosphor is excited by energetic radiation, a proportionate population of electron-hole pairs are created which become trapped at specific impurities within the phosphor. Trapped electrons can subsequently be stimulated optically with near-infrared at approximately 1 micrometer wavelength; the electrons can recombine with holes at luminescent centers to produce a luminescence which is directly proportional to the trapped electron population, and thus to the radiation exposure. By attaching the phosphor to the end of an optical fiber, it is possible to transmit both the IR optical stimulation and the characteristic phosphor luminescence through the fiber to and from the read-out instrument, which can be located far (e.g., kilometers) from the radiation field. This document reports on the specific design of the prototype system and its operating characteristics, including its sensitivity to various radiation dose rates and energies, its dynamic range, signal-to-noise ratio at various radiation intensities, and other system characteristics. Additionally, the radiation hardness of the phosphor and fiber are evaluated. 17 refs., 29 figs., 5 tabs.

  2. Radiative heating in contrail cirrus

    Microsoft Academic Search

    Ulrich Schumann; Bernhard Mayer; Ulrich Hamann; Kaspar Graf

    2010-01-01

    In the course of analysis and modeling of aviation induced contrail cirrus, we found that observed time scales of contrail cirrus and thin cirrus in general requires particle losses by radiative heating besides other loss processes. For thin cirrus near the tropopause, radiative warming dominates over cooling in most cases, in particular in the lower part of cirrus layers. Both

  3. DCTD — Radiation Research Program (RRP)

    Cancer.gov

    Synopsis of partial-body radiation diagnostic biomarkers and medical management of radiation injury workshop. Prasanna PG, Blakely WF, Bertho JM, Chute JP, Cohen EP, Goans RE, Grace MB, Lillis-Hearne PK, Lloyd DC, Lutgens LC, Meineke V, Ossetrova NI, Romanyukha A, Saba JD, Weisdorf DJ, Wojcik A, Yukihara EG, Pellmar TC.

  4. Ultraviolet radiation from electric lighting

    Microsoft Academic Search

    Audin

    1993-01-01

    Concerns about the health and materials degradation impacts of ultraviolet radiation (UV) from electric lighting are being raised with increasing frequency. If ultraviolet radiation from the sun causes skin cancers and eye problems, and degrades light-sensitive artifacts, could the UV emitted from fluorescent and high intensity discharge lamps also cause such problems? UV emissions from electric lighting are more than

  5. The cosmic microwave background radiation

    Microsoft Academic Search

    Joseph Silk

    1981-01-01

    Because angular anisotropies and spectral distortions of the cosmic microwave background radiation are judged to be inevitable at some level, in a realistic cosmological model, the evidence for spectral distortions and its theoretical implications are described. The evidence for anisotropy is then discussed, and theoretical predictions of radiation anisotropy are summarized and compared with the data available. It is found

  6. The cosmic microwave background radiation

    Microsoft Academic Search

    R. W. Wilson

    1979-01-01

    The discovery of the cosmic microwave background radiation is discussed beginning with radio astronomical measuring techniques, followed by the history of the detection of background radiation, and a summary of some of its properties. Attention is given to the design and operation of a radiotelescope, its antenna and radiometer, exhibiting its advantages, including the ability to measure a collecting area

  7. Radiation transport in diffractive media

    E-print Network

    Mattias Marklund

    2005-03-24

    We consider radiation transport theory applied to non-dispersive but refractive media. This setting is used to discuss Minkowski's and Abraham's electromagnetic momentum, and to derive conservation equations independent of the choice of momentum definition. Using general relativistic kinetic theory, we derive and discuss a radiation gas energy-momentum conservation equation valid in arbitrary curved spacetime with diffractive media.

  8. Radiation Belt Analysis and Modeling

    Microsoft Academic Search

    J. N. Bass; U. Dasgupta; C. A. Hein; J. M. Griffin; D. S. Reynolds

    1995-01-01

    Efforts have been conducted in modeling of radiation belts, and cosmic radiation, principally in connection with the CRRES mission. Statistical studies of solar particle events have been conducted in a search for predictors of the occurrence of geomagnetic storms. Certain spectral and temporal properties of protons and electrons were found to correlate with the occurrence of storms. Comparative studies of

  9. Review Article RADIATION SHIELDING TECHNOLOGY

    E-print Network

    Shultis, J. Kenneth

    Review Article RADIATION SHIELDING TECHNOLOGY J. Kenneth Shultis and Richard E. Faw* Abstract--An historical review of the development of shielding techniques for indirectly ionizing radiation is presented and analysis. Health Phys. 88(4):297­322; 2005 Key words: reviews; shielding; historical profiles; Health

  10. Radiation Reactions of Unsaturated Polyesters

    Microsoft Academic Search

    A. Charlesby; V. Wycherley; T. T. Greenwood

    1958-01-01

    The polymerization of monomers containing more than one double bond may lead to the formation of crosslinked polymers. The monomers involved in this work were unsaturated polyesters. Ionizing radiation was found to initiate polymerization and, at the same time, lead to an insoluble network by causing crosslinking between the polyester chains. The effect of both low- and high-intensity radiation, additives,

  11. Get the Facts about Radiation

    MedlinePLUS

    ... don’t let fear get in your way. Learn about the risks and benefits, and know what questions to ask. If medical radiation is really needed, take steps to ensure that it’s done as safely as possible. Radiation, simply put, is the transfer of energy through space. The energy may be ...

  12. Radiation treatment for rectal cancer

    Microsoft Academic Search

    B. J. Cummings

    1995-01-01

    Radiation treatment is widely used in the management of adenocarcinomas of the rectum, either alone or more frequently as part of multimodality treatment protocols. External beam radiation is capable of eradicating about one-third of bulky but mobile primary rectal cancers and is an alternative to be considered when standard surgery is not possible. Endorectal irradiation, either alone or combined with

  13. DCTD — Radiation Research Program (RRP)

    Cancer.gov

    Based in large measure on the CDRP grantees and their mentors, the Radiation Therapy Oncology Group (RTOG) now has a robust Cancer Disparities Committee, and the American Society for Therapeutic Radiology and Oncology (ASTRO) has incorporated a symposium on health disparities into its annual meeting so that addressing health disparities is a strong focus of radiation oncology.

  14. Radiation Reaction in Quantum Vacuum

    E-print Network

    Keita Seto

    2014-11-02

    From the development of the electron theory by H. A. Lorentz in 1906, many authors have tried to reformulate this model named "radiation reaction". P. A. M. Dirac derived the relativistic-classical electron model in 1938, which is now called the Lorentz-Abraham-Dirac model. But this model has the big difficulty of the run-away solution. Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. Therefore, it is desirable to stabilize this model of the radiation reaction for estimations. Via my recent research, I found a stabilized model of radiation reaction in quantum vacuum. This leads us to an updated Fletcher-Millikan's charge to mass ratio including radiation, de/dm, derived as the 4th order tensor measure. In this paper, I will discuss the latest update of the model and the ability of the equation of motion with radiation reaction in quantum vacuum via photon-photon scatterings.

  15. Radiation reaction in quantum vacuum

    NASA Astrophysics Data System (ADS)

    Seto, Keita

    2015-02-01

    Since the development of the radiating electron theory by P. A. M. Dirac in 1938 [P. A. M. Dirac, Proc. R. Soc. Lond. A 167, 148 (1938)], many authors have tried to reformulate this model, called the "radiation reaction". Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. In our recent research, we found a stabilized model of the radiation reaction in quantum vacuum [K. Seto et al., Prog. Theor. Exp. Phys. 2014, 043A01 (2014)]. It led us to an updated Fletcher-Millikan charge-to-mass ratio including radiation. In this paper, I will discuss the generalization of our previous model and the new equation of motion with the radiation reaction in quantum vacuum via photon-photon scatterings and also introduce the new tensor d{E}^{? ? ? ? }/dm, as the anisotropy of the charge-to-mass ratio.

  16. Rainbow Radiating Single-Crystal Ag Nanowire Nanoantenna Taejoon Kang,

    E-print Network

    Kim, Bongsoo

    Rainbow Radiating Single-Crystal Ag Nanowire Nanoantenna Taejoon Kang, Wonjun Choi, Ilsun Yoon rainbow antenna radiation in the Fresnel region. Detailed antenna radiation properties, such as radiating

  17. Nanoscale thermal radiation between two gold surfaces

    E-print Network

    Shen, Sheng

    In this letter, we measured the nanoscale thermal radiation between a microsphere and a substrate which were both coated with thick gold films. Although gold is highly reflective for thermal radiation, the radiative heat ...

  18. Page left intentionally blank RADIATION CONTROL MANUAL

    E-print Network

    and Distributed by the Radiation Control Office Environmental Health Services 141 General Services Building and human and veterinary medicine. The beneficial applications of radiation continue to grow as scientists.................................................................................................................. 7 RADIATION-INDUCED HEALTH EFFECTS

  19. THE UNIVERSITY OF UTAH RADIATION PROTECTION PROGRAM

    E-print Network

    Tipple, Brett

    : 45 Medical US: 53 Industrial US: FUNDAMENTALS OF RADIATION by which energy is emitted or propagated through space as particles or waves. Ionizing radiations are those molecular bonds. The radiations most commonly encountered are free electrons and photons of electromagnetic

  20. Contact RRP | Radiation Research Program (RRP)

    Cancer.gov

    Skip to Content Search this site Radiation Research Program (RRP) Contact RRP Radiation Research Program (RRP) primary telephones & Fax: 240-276-5690 Main telephone number for Office of the Associate Director, Molecular Radiation Therapeutics Branch

  1. Quantitative photoacoustic imaging in radiative transport regime

    E-print Network

    Ren, Kui

    Quantitative photoacoustic imaging in radiative transport regime Alexander V. Mamonov Kui Ren July reconstruction algorithms for multi- source QPAT in the radiative transport regime with energy data collected, radiative transport equation, inverse transport problem, interior data, Born approximation, iterative

  2. 78 FR 5813 - 2013 Assuring Radiation Protection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ...include: (1) Responding to radiation accidents or incidents...evaluating the adequacy of State radiation control programs; overseeing radiation laboratory capabilities...decontamination and decommissioning of nuclear facilities; (4)...

  3. The risks of radiation

    NASA Astrophysics Data System (ADS)

    Miettenen, Jorma K.

    1988-01-01

    The risks of radioactivity are a really complicated matter, yet they are much better known than are the risks relating to thousands of chemical poisons that occur in our environment. The greatest mistakes are probably made in the definition of safety margins. Except for the bombs dropped in Japan and one other case in the Marshall Islands, there has always—luckily—been a wide safety margin between fallout radiation and doses dangerous to health; the margin has actually been about 1000-fold. The Chernobyl dose of 0.5 mGy/year that we received is only 1/1000 of the acute dose of 0.5 Gy which would cause a slight and nonpermanent change in the blood picture. There is no such safety margin with respect to many air pollutants. The safety standards for sulfuric or nitric oxides, ozone and so on, have been set only just below the level that already causes a health hazard, and these standards are exceeded once in a while. Otherwise, traffic would have to be forbidden and many industrial plants, especially power stations using coal, would have to stop working whenever a low-temperature inversion occurred. Environmental radioactivity does not represent a likely health risk in Finland unless a nuclear war breaks out. Air pollutants, on the contrary, are a real and almost daily health risk that should be carefully considered when decisions about our energy production are being made. In spite of what happened at Chernobyl, global consumption of nuclear power will double by the year 2000, since there are about 140 nuclear power plants presently under construction. It is not likely that another catastrophe like Chernobyl will happen, yet nuclear plant accidents are of course possible, even if their likelihood is diminished by improving reactor safety and even if any eventual damage could be expected to be smaller. If a reactor is hooded by a containment structure, no significant release of radioactive materials should be possible even in case of an accident. However, we must be prepared to protect the population with carefully planned civil defense and radiation protection measures.

  4. Radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

    Kronenberg, A.

    1994-01-01

    Quantitative assessment of the heritable somatic effects of ionizing radiation exposures has relied upon the assumption that radiation-induced lesions were 'fixed' in the DNA prior to the first postirradiation mitosis. Lesion conversion was thought to occur during the initial round of DNA replication or as a consequence of error-prone enzymatic processing of lesions. The standard experimental protocols for the assessment of a variety of radiation-induced endpoints (cell death, specific locus mutations, neoplastic transformation and chromosome aberrations) evaluate these various endpoints at a single snapshot in time. In contrast with the aforementioned approaches, some studies have specifically assessed radiation effects as a function of time following exposure. Evidence has accumulated in support of the hypothesis that radiation exposure induces a persistent destabilization of the genome. This instability has been observed as a delayed expression of lethal mutations, as an enhanced rate of accumulation of non-lethal heritable alterations, and as a progressive intraclonal chromosomal heterogeneity. The genetic controls and biochemical mechanisms underlying radiation-induced genomic instability have not yet been delineated. The aim is to integrate the accumulated evidence that suggests that radiation exposure has a persistent effect on the stability of the mammalian genome.

  5. Radiation-induced thermoacoustic imaging

    SciTech Connect

    Bowen, T.

    1983-05-31

    The acoustic wave generated by sudden thermal stress is used to obtain information non-invasively on the composition and structure of the stressed body. One or more acoustic transducers are coupled with the surface of the body to intercept the acoustic wave and generate a corresponding electrical signal. The sudden thermal stress is induced by a pulse of radiation which deposits energy causing a rapid, but very small, rise of temperature. The radiation may be ionizing radiation, such as high energy electrons, photons (x-rays), neutrons, or other charged particles. The radiation may also be non-ionizing radiation, such as rf and microwave electromagnetic radiation and ultrasonic radiation. The electrical signal from the acoustic transducer is amplified and supplied to a digitizer, which provides a continuous stream of digital words corresponding to samples of the amplified signal. Because in most situations of practical interest the s/n ratio of a single pulse is much less than unity, it is necessary to signalaverage the signals from many successive pulses. This is accomplished with a minicomputer or data processor suitably interfaced with the digitizer. The resulting data can then be suitably displayed as an image on a crt display or plotted or numerically printed out.

  6. Synchrotron radiation from massless charge

    E-print Network

    D. V. Gal'tsov

    2015-05-25

    Classical radiation power from an accelerated massive charge diverges in the zero-mass limit, while some general arguments suggest that strictly massless charge does not not radiate at all. On the other hand, the regularized classical radiation reaction force, though looking odd, is non-zero and finite. To clarify this controversy, we consider radiation problem in massless scalar quantum electrodynamics in the external magnetic field. In this framework, synchrotron radiation is found to be non-zero, finite, and essentially quantum. Its spectral distribution is calculated using Schwinger's proper time technique for {\\em ab initio} massless particle of zero spin. Provided $E^2\\gg eH$, the maximum in the spectrum is shown to be at $\\hbar \\omega=E/3$, and the average photon energy is $4E/9$. The normalized spectrum is universal, depending neither on $E$ nor on $H$. Quantum nature of radiation makes classical radiation reaction equation meaningless for massless charge. Our results are consistent with the view (supported by the renormalization group argument) that the correct classical limit of massless quantum electrodynamics is free theory.

  7. Synchrotron radiation from massless charge

    E-print Network

    Gal'tsov, D V

    2015-01-01

    Classical radiation power from an accelerated massive charge diverges in the zero-mass limit, while some general arguments suggest that strictly massless charge does not not radiate at all. On the other hand, the regularized classical radiation reaction force, though looking odd, is non-zero and finite. To clarify this controversy, we consider radiation problem in massless scalar quantum electrodynamics in the external magnetic field. In this framework, synchrotron radiation is found to be non-zero, finite, and essentially quantum. Its spectral distribution is calculated using Schwinger's proper time technique for {\\em ab initio} massless particle of zero spin. Provided $E^2\\gg eH$, the maximum in the spectrum is shown to be at $\\hbar \\omega=E/3$, and the average photon energy is $4E/9$. The normalized spectrum is universal, depending neither on $E$ nor on $H$. Quantum nature of radiation makes classical radiation reaction equation meaningless for massless charge. Our results are consistent with the view (sup...

  8. Estimated Radiation Dosage on Mars

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This global map of Mars shows the estimated radiation dosages from cosmic rays reaching the surface, a serious health concern for any future human exploration of the planet.

    The estimates are based on cosmic-radiation measurements by the Mars radiation environment experiment, an instrument on NASA's Mars 2000 Odyssey spacecraft, plus information about Mars' surface elevations from the laser altimeter instrument on NASA's Mars Global Surveyor. The areas of Mars expected to have the lowest levels of cosmic radiation are where the elevation is lowest, because those areas have more atmosphere above them to block out some of the radiation. Earth's thick atmosphere shields us from most cosmic radiation, but Mars has a much thinner atmosphere than we have on Earth.

    The colors in the map refer to the estimated annual dose equivalent in rems, a unit of radiation dose. The range is generally from 10 rems(color-coded dark blue) to 20 rems (color coded dark red). Radiation exposure for astronauts on the International Space Station in Earth orbit is typically equivalent to an annualized rate of 20 to 40 rems.

    NASA's Jet Propulsion Laboratory, Pasadena, Calif. manages the 2001 Mars Odyssey and Mars Global Surveyor missions for NASA's Office of Space Science, Washington D.C. The Mars radiation environment experiment was developed by NASA's Johnson Space Center, Houston. Lockheed Martin Astronautics, Denver, is the prime contractor for Odyssey, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  9. Radiation Treatment of Foods

    PubMed Central

    Epps, N. A.; Idziak, Edmund S.

    1970-01-01

    Salmonellae resistant to gamma irradiation were developed by repeated irradiation and subculturing in a nutrient broth-yeast extract medium. Few differences were noted in the biochemical characteristics of parent and resistant cultures; however, microculture studies revealed variations in morphology and in cell division patterns. A considerable decrease in pathogenicity for day-old chicks was apparent with resistant cultures, but their phenol-water extracts were as toxic as parent material for 10-day chick embryos. Five serial chick passages did not reverse the reduced pathogenicity or aberrant morphology of a resistant Salmonella typhimurium culture. Results of phage typing of both parent and serially irradiated S. typhimurium were inconclusive, whereas the O-1 genus-specific phage lysed all parent serotypes tested but only one of the serially irradiated cultures. Agglutination of parent S. typhimurium cells with their homologous rabbit antiserum was unaffected by prior absorption with resistant strains. The results indicate that radiation recycling altered Salmonella into strains of lesser public health significance. Images PMID:4908532

  10. Radiative effects in radiative shocks in shock tubes

    NASA Astrophysics Data System (ADS)

    Drake, R. P.; Doss, F. W.; McClarren, R. G.; Adams, M. L.; Amato, N.; Bingham, D.; Chou, C. C.; DiStefano, C.; Fidkowski, K.; Fryxell, B.; Gombosi, T. I.; Grosskopf, M. J.; Holloway, J. P.; van der Holst, B.; Huntington, C. M.; Karni, S.; Krauland, C. M.; Kuranz, C. C.; Larsen, E.; van Leer, B.; Mallick, B.; Marion, D.; Martin, W.; Morel, J. E.; Myra, E. S.; Nair, V.; Powell, K. G.; Rauchwerger, L.; Roe, P.; Rutter, E.; Sokolov, I. V.; Stout, Q.; Torralva, B. R.; Toth, G.; Thornton, K.; Visco, A. J.

    2011-09-01

    Using modern high-energy-density facilities it is straightforward to produce radiative shock waves in which the transfer of energy by radiation controls the hydrodynamic structure of the system. Some of these experiments use shock tubes. This paper discusses such experiments, with an emphasis on the simple physical relations that determine the primary features of such shocks and on the details and impact of radiative energy transfer in such systems. Notable aspects include the creation of high-density shocked layers, the flow of radiative energy toward regions of higher energy density, and the creation of secondary shocks by ablation of the tube walls ahead of the primary shock front. Simulations of one such experimental system are also shown.

  11. Transition radiation from relativistic electrons in periodic radiators

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.; Mueller, D.; Prince, T. A.; Hartmann, G.

    1974-01-01

    The generation and detection of transition radiation have been studied in a series of experiments with electrons from 1 to 15 GeV at SLAC and at the Cornell Synchrotron. Periodic radiators, consisting of thin plastic foils stretched in air at constant spacings, were used, and proportional chambers filled with krypton or xenon served as detectors. A detailed discussion of the theoretical predictions is given, and the measurements are systematically compared with the predictions by varying the most critical parameters, such as configuration of radiators and detectors, and energy of the electrons. In general, good agreement between theory and experiment has been found. On the basis of these results, the criteria are summarized under which transition radiation can readily be observed.

  12. Induction linacs as radiation processors

    SciTech Connect

    Birx, D.L.

    1986-04-14

    Experiments at the Lawrence Livermore National Laboratory (LLNL), University of California, in conjunction with the University of California at Davis have shown induction linear accelerators (linacs) to be suitable for radiation processing of food. Here we describe how it might be possible to optimize this technology developded for the Department of Defense to serve in radiation processing. The possible advantages of accelerator-produced radiation over the use of radioisotopes include a tailor-made energy spectrum that can provide much deeper penetration and thereby better dose uniformity.

  13. Modeling of explosion thermal radiation

    NASA Astrophysics Data System (ADS)

    Stepanov, K. L.; Stanchits, L. K.; Stankevich, Yu. A.

    2011-01-01

    The hydrodynamic and radiation processes accompanying explosions of chemical explosives and fuel-air mixtures have been considered. Computer modeling of the radiation from a fire ball of explosion and a flame of diffusion combustion of a hydrocarbon fuel has been performed. The dependences of the heat flux density from the region occupied by explosion and combustion products on its temperature and geometric characteristics have been determined. Thermal load distributions on targets of different orientations in the vicinity of the energy release zone have been obtained. A comparison of the thermal parameters on radiation detectors with the criteria of thermal affection of people and ignition of combustible materials has been made.

  14. Actively driven thermal radiation shield

    DOEpatents

    Madden, Norman W. (Livermore, CA); Cork, Christopher P. (Pleasant Hill, CA); Becker, John A. (Alameda, CA); Knapp, David A. (Livermore, CA)

    2002-01-01

    A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

  15. Modeling the Space Radiation Environment

    NASA Technical Reports Server (NTRS)

    Xapsos, Michael A.

    2006-01-01

    There has been a renaissance of interest in space radiation environment modeling. This has been fueled by the growing need to replace long time standard AP-9 and AE-8 trapped particle models, the interplanetary exploration initiative, the modern satellite instrumentation that has led to unprecedented measurement accuracy, and the pervasive use of Commercial off the Shelf (COTS) microelectronics that require more accurate predictive capabilities. The objective of this viewgraph presentation was to provide basic understanding of the components of the space radiation environment and their variations, review traditional radiation effects application models, and present recent developments.

  16. Radiation recall dermatitis and radiation pneumonitis during treatment with vemurafenib.

    PubMed

    Forschner, Andrea; Zips, Daniel; Schraml, Christina; Röcken, Martin; Iordanou, Eleni; Leiter, Ulrike; Weide, Benjamin; Garbe, Claus; Meier, Friedegund

    2014-10-01

    The basis of radiation recall reactions (RRR) is a subclinical radiation damage that is uncovered later by treatment with anticancer agents. Several drugs have been associated with RRR, in particular taxanes and anthracyclines. Recently, a few cases were reported concerning radiation recall dermatitis caused by vemurafenib. Up to now, there have been no reports of RRR in the lung induced by vemurafenib. We describe the occurrence of RRR in three melanoma patients who had undergone radiotherapy for metastases followed by systemic treatment with the BRAF inhibitor vemurafenib. Two patients developed radiation recall pneumonitis (RRP) and one patient developed radiation recall dermatitis (RRD) 5-7 weeks after the radiation treatment was finished and 2-4 weeks after vemurafenib was started. The early application of systemic (RRP) and topical corticosteroids (RRD) enabled us to continue the treatment with vemurafenib without dose reduction. Caution is needed when vemurafenib is planned for patients who have undergone previous radiotherapy, and RRR of the skin and the lung have to be taken into account. PMID:24743051

  17. Survivable pulse power space radiator

    DOEpatents

    Mims, J.; Buden, D.; Williams, K.

    1988-03-11

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometerorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length. 5 figs.

  18. Medical applications of synchrotron radiation

    SciTech Connect

    Thomlinson, W.

    1991-10-01

    Ever since the first diagnostic x-ray was done in the United States on February 3, 1896, the application of ionizing radiation to the field of medicine has become increasingly important. Both in clinical medicine and basic research the use of x-rays for diagnostic imaging and radiotherapy is now widespread. Radiography, angiography, CAT and PETT scanning, mammography, and nuclear medicine are all examples of technologies developed to image the human anatomy. In therapeutic applications, both external and internal sources of radiation are applied to the battle against cancer. The development of dedicated synchrotron radiation sources has allowed exciting advances to take place in many of these applications. The new sources provide tunable, high-intensity monochromatic beams over a wide range of energies which can be tailored to specific programmatic needs. This paper surveys those areas of medical research in which synchrotron radiation facilities are actively involved.

  19. Silicone Cerenkov-Radiator Material

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V.; Ormes, J. F.; Streitmatter, R. E.

    1984-01-01

    Dyes enhance visible output. Three fluorescent dyes combine to increase output of silicone material that normally has low yield of visible Cerenkov radiation by converting large amount of available ultraviolet photons into visible light.

  20. Radiation Detector Materials: An Overview

    SciTech Connect

    Milbrath, Brian D.; Peurrung, Anthony J.; Bliss, Mary; Weber, William J.

    2008-10-10

    This review describes the current state of radiation detection material science, with particular emphasis on national security needs and the goal of identifying the challenges and opportunities that this area represents for the materials science community. Radiation detector materials physics is reviewed, which sets the stage for performance metrics that determine the relative merit of existing and new materials. Semiconductors and scintillators represent the two primary classes of radiation detector materials that are of interest. The state-of-the-art and limitations for each of these materials classes are presented, along with possible avenues of research. Novel materials that could overcome the need for single crystals will also be discussed. Finally, new methods of material discovery and development are put forward – the goal being to provide more predictive guidance and faster screening of candidate materials – and thus ultimately the faster development of superior radiation detection materials.

  1. Doses from Medical Radiation Sources

    MedlinePLUS

    ... suggested below for some typical diagnostic radiology and nuclear medicine studies. It is important to note that ... the machine used to produce the radiation, in nuclear medicine on the amount of activity administered and ...

  2. Radiative cooling for solar cells

    NASA Astrophysics Data System (ADS)

    Zhu, Linxiao; Raman, Aaswath; Wang, Ken X.; Anoma, Marc A.; Fan, Shanhui

    2015-03-01

    Standard solar cells heat up under sunlight, and the resulting increased temperature of the solar cell has adverse consequences on both its efficiency and its reliability. We introduce a general approach to radiatively lower the operating temperature of a solar cell through sky access, while maintaining its sunlight absorption. We present first an ideal scheme for the radiative cooling of solar cells. For an example case of a bare crystalline silicon solar cell, we show that the ideal scheme can passively lower the operating temperature by 18.3 K. We then show a microphotonic design based on realistic material properties, that approaches the performance of the ideal scheme. We also show that the radiative cooling effect is substantial, even in the presence of significant non-radiative heat change, and parasitic solar absorption in the cooling layer, provided that we design the cooling layer to be sufficiently thin.

  3. Structural/Radiation-Shielding Epoxies

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Smith, Joseph G.; Hinkley, Jeffrey; Blattnig, Steve; Delozier, Donavon M.; Watson, Kent A.; Ghose, Sayata

    2009-01-01

    A development effort was directed toward formulating epoxy resins that are useful both as structural materials and as shielding against heavy-ion radiation. Hydrogen is recognized as the best element for absorbing heavy-ion radiation, and high-hydrogen-content polymers are now in use as shielding materials. However, high-hydrogen-content polymers (e.g. polyethylene) are typically not good structural materials. In contrast, aromatic polymers, which contain smaller amounts of hydrogen, often have the strength necessary for structural materials. Accordingly, the present development effort is based on the concept that an ideal structural/ heavy-ion-radiation-shielding material would be a polymer that contains sufficient hydrogen (e.g., in the form of aliphatic molecular groups) for radiation shielding and has sufficient aromatic content for structural integrity.

  4. Radiation effects on structural materials

    SciTech Connect

    Ghoniem, N.M.

    1991-06-28

    This report discusses the following topics on the effect radiation has on thermonuclear reactor materials: Atomic Displacements; Microstructure Evolution; Materials Engineering, Mechanics, and Design; Research on Low-Activation Steels; and Research Motivated by Grant Support.

  5. Calculating Risk: Radiation and Chernobyl.

    ERIC Educational Resources Information Center

    Gale, Robert Peter

    1987-01-01

    Considers who is at risk in a disaster such as Chernobyl. Assesses the difficulty in translating information regarding radiation to the public and in determining the acceptability of technological risks. (NKA)

  6. Dissecting Soft Radiation with Factorization

    E-print Network

    Tackmann, Frank J.

    An essential part of high-energy hadronic collisions is the soft hadronic activity that underlies the primary hard interaction. It includes soft radiation from the primary hard partons, secondary multiple parton interactions ...

  7. Radiation effects in solar cells

    NASA Astrophysics Data System (ADS)

    Imaizumi, Mitsuru; Ohshima, Takeshi

    2013-05-01

    Two types of space solar cells, silicon single-junction and InGaP/GaAs/Ge triple-junction (3J) solar cells, have been primarily adopted for spacecraft. The conversion efficiencies of the solar cells under AM0, 1 sun condition are ~17% for silicon and ~30% for 3J cells. Radiation degradation occurs in space due to high-energy electrons and protons existing in space environment. The degradation is caused by radiation induced crystal defects which act as minority-carrier recombination centers and majority-carrier trap centers. The 3J cells are superior radiation resistant to the silicon cells, and this is mainly because the InGaP top-subcell has property of very high radiation resistance.

  8. Issues in the Radiation Controversy

    ERIC Educational Resources Information Center

    Tamplin, Arthur R.

    1971-01-01

    Examines the competing claims of safe" radiation levels from nuclear power plants and analyzes some of the arguments used by protagonists and antagonists. Claims that the real question, Why more power?", is becoming obscured. (AL)

  9. Radiation reaction in various dimensions

    E-print Network

    D. V. Gal'tsov

    2001-12-12

    We discuss the radiation reaction problem for an electric charge moving in flat space-time of arbitrary dimensions. It is shown that four is the unique dimension where a local differential equation exists accounting for the radiation reaction and admitting a consistent mass-renormalization (the Dirac-Lorentz equation). In odd dimensions the Huygens principle does not hold; as a result, the radiation reaction force depends on the whole past history of a charge (radiative tail). We show that the divergence in the tail integral can be removed by the mass renormalization only in the 2+1 theory. In even dimensions higher than four, divergences can not be removed by a renormalization.

  10. Survivable pulse power space radiator

    DOEpatents

    Mims, James (Albuquerque, NM); Buden, David (Albuquerque, NM); Williams, Kenneth (Albuquerque, NM)

    1989-01-01

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometeorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length.

  11. Radiation damage evolution in ceramics

    SciTech Connect

    Devanathan, Ramaswami

    2009-09-15

    A review is presented of recent results on radiation damage production, defect accumulation and dynamic annealing in a number of ceramics, such as silicon carbide, zircon and zirconia. Under energetic particle irradiation, ceramics can undergo amorphization by the accumulation of point defects and defect clusters (silicon carbide) or direct impact amorphization (zircon). Ceramics that resist radiation-induced amorphization have mechanisms to dissipate the primary knock-on atom energy, such as replacement collision sequences that leave the lattice undisturbed and low-energy cation site exchange. The presence of engineered mobile defects, such as structural vacancies in stabilized zirconia, can dynamically anneal radiation damage. Thus, defect engineering is a promising strategy to design radiation tolerance for applications such as nuclear waste disposal.

  12. Radiation tolerant power converter controls

    NASA Astrophysics Data System (ADS)

    Todd, B.; Dinius, A.; King, Q.; Uznanski, S.

    2012-11-01

    The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to significantly increased radiation induced effects in materials close to the accelerator, including the FGC. Recent radiation tests indicate that the current FGC would not be sufficiently reliable. A so-called FGClite is being designed to work reliably in the radiation environment in the post-LS1 era. This paper outlines the concepts of power converter controls for machines such as the LHC, introduces the risks related to radiation and a radiation tolerant project flow. The FGClite is then described, with its key concepts and challenges: aiming for high reliability in a radiation field.

  13. Acoustic radiation stress in solids

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.; Yost, William T.

    1986-01-01

    It is shown that the radiation-induced static strains associated with acoustic waves propagating in solids are obtained directly from the virial theorem for an elastic continuum and that the radiation stresses result from combining the virial theorem with the Boltzmann-Ehrenfest principle of adiabatic invariance. The experimental confirmation of critical theoretical predictions in solids is reported. The implications of the results for the fundamental thermal properties of crystals are addressed.

  14. Radiation Resistances of Dielectric Liquids

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.; Somoano, Robert B.

    1987-01-01

    Report presents data on effects of ionizing radiation on dielectric liquids for high-energy-density, pulsed-power capacitors. Based on Jet Propulsion Laboratory test results, search of NASA and Department of Energy computer files, survey of open literature, and contacts with manufacturers and suppliers. Covers 22 organic liquids, although detailed data found for only one compound, polydimethyl siloxane. Generic data on effects of radiation on compounds with similar chemical structures provided where data on specific compounds lacking.

  15. Radiative transfer in protoplanetary disks

    Microsoft Academic Search

    Christophe Pinte; Francois Menard; Gaspard Duchene

    2006-01-01

    We present a new 3D continuum radiative transfer code, MCFOST, based on a\\u000aMonte-Carlo method. The reliability and efficiency of the code is tested by\\u000acomparison with five different radiative transfer codes previously tested by\\u000aPascucci et al., 2004, using a 2D disk configuration. When tested against the\\u000asame disk configuration, no significant difference is found between the\\u000atemperature and

  16. The ALICE transition radiation detector

    Microsoft Academic Search

    Tariq Mahmoud

    2003-01-01

    The ALICE Transition Radiation Detector (TRD) is equipped with 750m2 total area of gas chambers with radiators for particle tracking and electron identification above 1GeV\\/c, divided in 540 modules organized in 18 sectors and 6 layers, in a barrel geometry between 2.9 and 3.7m from the beam axis. The TRD will also serve as a trigger on high-pte+e- pairs in

  17. Radiation source for helium magnetometers

    NASA Technical Reports Server (NTRS)

    Slocum, Robert E. (Inventor)

    1991-01-01

    A radiation source (12) for optical magnetometers (10) which use helium isotopes as the resonance element (30) includes an electronically pumped semiconductor laser (12) which produces a single narrow line of radiation which is frequency stabilized to the center frequency of the helium resonance line to be optically pumped. The frequency stabilization is accomplished using electronic feedback (34, 40, 42, 44) to control a current sources (20) thus eliminating the need for mechanical frequency tuning.

  18. Acoustic Radiation Losses in Busbars

    Microsoft Academic Search

    Johanna Meltaus; Seong Su Hong; Victor P. Plessky

    Radiation of acoustic waves from the contact elec- trodes (busbars) of surface acoustic wave devices on high- coupling piezoelectric substrates, such as 42 ? -LiTaO3, is demon- strated both with Finite-Element-Method simulations and with experimental data. This acoustic radiation, as well as resistive losses, significantly decrease the Q-value of the busbars. Exper- imental measurements on test structures show Q-values as

  19. Solar Radiation and Asteroidal Motion

    E-print Network

    Jozef Klacka

    2000-09-07

    Effects of solar wind and solar electromagnetic radiation on motion of asteroids are discussed. The results complete the statements presented in Vokrouhlick\\'{y} and Milani (2000). As for the effect of electromagnetic radiation, the complete equation of motion is presented to the first order in $v/c$ -- the shape of asteroid (spherical body is explicitly presented) and surface distribution of albedo should be taken into account. Optical quantities must be calculated in proper frame of reference.

  20. Radiation crosslinking of biodegradable hydroxypropylmethylcellulose

    Microsoft Academic Search

    Nursel Pekel; Fumio Yoshii; Tamikazu Kume; Olgun Güven

    2004-01-01

    In general, cellulose and its derivatives irradiated with ionizing radiation in solid state or in dilute aqueous solution undergo mainly degradation by the cleavage of glycoside bonds in its main chain. Hydroxypropylmethylcellulose (HPMC) with different degree of substitution (1.9 and 1.4) was irradiated with electron beam (EB) radiation at ambient temperature and different doses (0–100kGy) and concentrations (0.5–60wt%). Irradiation of

  1. [Solar radiation--physicochemical aspects].

    PubMed

    De Lima, J J

    1992-09-01

    The solar radiation spectrum and the properties of its components are studied in the present paper. The history of the sun rays before reaching earth surface is analysed. A simplified analysis of the interaction mechanisms of these components with molecules, the energy absorption capabilities of the latter and the expected biological consequences are considered. Special emphasis are given to the properties of ultra-violet and infra-red radiations and their production considered. PMID:1442194

  2. MR evaluation of radiation otomastoiditis

    Microsoft Academic Search

    Ryuichi Nishimura; Yuji Baba; Ryuji Murakami; Takashi Baba; Mitsuhiro Furusawa; Takeshi Ishikawa; Yukitaka Ushio; Mutsumasa Takahashi

    1997-01-01

    Purpose: The purpose of this study was to evaluate the incidence of radiation otomastoiditis, on using T2-weibted magnetic resonance (MR) imaging, in relation to radiation fields, doses, intervals, and clinical symptoms after radiotherapy that included the temporal bone in the fields.Methods and Materials: We performed follow-up MR examinations at various intervals after radiotherapy including the temporal bones for 270 ears

  3. Proton synchrotron radiation at Fermilab

    SciTech Connect

    Thurman-Keup, Randy; /Fermilab

    2006-05-01

    While protons are not generally associated with synchrotron radiation, they do emit visible light at high enough energies. This paper presents an overview of the use of synchrotron radiation in the Tevatron to measure transverse emittances and to monitor the amount of beam in the abort gap. The latter is necessary to ensure a clean abort and prevent quenches of the superconducting magnets and damage to the silicon detectors of the collider experiments.

  4. Picosecond photoconductors as radiation detectors

    Microsoft Academic Search

    R. S. Wagner; J. M. Bradley; R. B. Hammond

    1986-01-01

    A new class of extremely high-speed radiation detectors has been developed. They are simple and inexpensive to fabricate, rugged, and reliable. Their sensitivity to gamma-rays, X-rays, soft X-rays, charged particles, and light has been demonstrated, and response speeds of less than 100 ps have been obtained. Their current response is proportional to incident-radiation intensity. The detectors are not used for

  5. Picosecond Photoconductors as Radiation Detectors

    Microsoft Academic Search

    Ronald S. Wagner; Jeffrey M. Bradley; Robert B. Hammond

    1986-01-01

    We have developed a new class of extremely high-speed radiation detectors. They are simple and inexpensive to fabricate, rugged, and reliable. We have demonstrated their sensitivity to gamma-rays, x-rays, soft x-rays, charged particles, and light and have obtained response speeds of <100 ps. Their current response is proportional to incident-radiation intensity. The detectors are not used for detecting single particles

  6. Radiation-Associated Liver Injury

    SciTech Connect

    Pan, Charlie C., E-mail: cpan@umich.ed [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado, Aurora, CO (United States); Dawson, Laura A. [Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Das, Shiva K. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Miften, Moyed [Department of Radiation Oncology, University of Colorado, Aurora, CO (United States); Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States)

    2010-03-01

    The liver is a critically important organ that has numerous functions including the production of bile, metabolism of ingested nutrients, elimination of many waste products, glycogen storage, and plasma protein synthesis. The liver is often incidentally irradiated during radiation therapy (RT) for tumors in the upper- abdomen, right lower lung, distal esophagus, or during whole abdomen or whole body RT. This article describes the endpoints, time-course, and dose-volume effect of radiation on the liver.

  7. Radiation Protection for Manned Interplanetary Missions - Radiation Sources, Risks, Remedies

    NASA Astrophysics Data System (ADS)

    Facius, R.; Reitz, G.

    Health risks in interplanetary explorative missions differ in two major features significantly from those during the manned missions experienced so far. For one, presently available technologies lead to durations of such missions significantly longer than so far encountered - with the added complication that emergency returns are ruled out. Thus radiation exposures and hence risks for late radiation sequelae like cancer increase proportional to mission duration - similar like most other health and many technical risks too. Secondly, loss of the geomagnetic shielding available in low earth orbits (LEO) does increase the radiation dose rates from galactic cosmic rays (GCR) since significant fractions of the GCR flux below about 10 GeV/n now can reach the space vehicle. In addition, radiation from solar particle events (SPE) which at most in polar orbit segments can contribute to the radiation exposure during LEO missions now can reach the spaceship unattenuated. Radiation doses from extreme SPEs can reach levels where even early acute radiation sickness might ensue - with the added risks from potentially associated crew performance decrements. In contrast to the by and large predictable GCR contribution, the doses and hence risks from large SPEs can only stochastically be assessed. Mission designers face the task to contain the overall health risk within acceptable limits. Towards this end they have to transport the particle fluxes of the radiation fields in free space through the walls of the spaceship and through the tissue of the astronaut to the radiation sensitive organs. To obtain a quantity which is useful for risk assessment, the radiobiological effectiveness as well as the specific sensitivity of a given organ has to be accounted for in such transport calculations which of course require a detailed knowledge of the spatial distribution and the atomic composition of the surrounding shielding material. In doing so the mission designer encounters two major difficulties in addition to those connected with the knowledge of the external radiation fields and the cross sections necessary for the transport calculations. The radiobiological effectiveness of the GCR heavy ions is to a large extent only nominally known with large error margins. Furthermore, the reference risk, late cancer mortality, usually only materializes many years after the mission, in contrast to the risk from early radiation sickness or the other health risks, including those from prolonged exposure to weightlessness. 1 Given these large radiobiological uncertainties of space radiation risk assessment, a first and most effective countermeasure consists of research directed at their diminishment. Furthermore, a new risk criterion is needed which allows a unified quantitative treatment of all health and technical risks arising during the mission as well as the risk of late radiogenic cancer mortality many years after the mission. Countermeasures to reduce radiation exposure comprise judicious planning of the mission with respect to solar activity, skilful utilization and optimization of shielding materials, and research into advanced propulsion systems capable to cut down transit times in free space. Finally, research into means to reduce sensitivity to radiation health effects e.g. by chemical substances and nutritional additives constitutes the third class of possible countermeasures. Arguably, the single most effective among these measures would be reduction of transit time in free space. 2

  8. Radiation recall dermatitis with pemetrexed.

    PubMed

    Hureaux, J; Le Guen, Y; Tuchais, C; Savary, L; Urban, T

    2005-11-01

    Pemetrexed has recently been approved for use in combination with cisplatin as first-line chemotherapy for malignant pleural mesothelioma (MPM). Radiation therapy is frequently administered to the thoracic orifices and no data are available about the interactions between radiotherapy and pemetrexed. We report the first case of radiation recall dermatitis occurring after pemetrexed chemotherapy in a patient with MPM previously treated with radiation therapy to the thoracoscopy and drainage orifices. The patient received chemotherapy with pemetrexed and cisplatin 19 days after completion of chest wall radiation therapy delivering 21 gray in 3 days. Conventional premedication by folic acid and intramuscular administration of Vitamin B12 and prednisolone was correctly performed. Twelve days later, confluent erythematous and pruritus rash of the irradiated skin was observed. The toxicity grade of this lesion was evaluated at 2 according to the Acute Radiation Morbidity Scoring Criteria proposed by the Radiation Therapy Oncology Group. Pemetrexed challenge was performed without worsening of skin lesions. Three weeks later, skin cicatrisation was observed after a desquamative phase. Persistent hyperpigmentation was seen in the irradiated skin. Pemetrexed could also act as a radiosensitizing agent that should be used with care for several weeks after radiotherapy. PMID:16111784

  9. Radiofrequency radiation: activities and issues

    SciTech Connect

    Elder, J.A.

    1986-07-01

    The question of human safety relative to exposure to RF radiation obviously predates the first ANSI guideline established in 1966, but no enforceable Federal standards or guidelines exist for RF radiation exposure; the ANSI guideline revised in 1982 is voluntary or advisory. EPA has been pursuing the goal of promulgating guidance to control exposure of the public to RF radiation. In support of the regulatory activity, a report entitled Biological Effects of Radiofrequency Radiation was published in September 1984. The conclusion of the report was that biological effects occurred at a dose rate of about 1 W/kg, and that these effects may be significant under certain environmental conditions. Examples of adverse biological effects that occur in laboratory animals at dose rates of 2-6 W/kg are death and temporary male sterility. These effects as well as the behavioral changes that are the basis for the ANSI guideline can be attributed to heat stress in animals caused by absorption of RF energy. Some experimental results occur at very low exposure conditions that cause no significant thermal input; these responses are called nonthermal effects. The mechanisms of interaction of nonthermal effects and their physiological significance are a subject of scientific debate. RF radiation research budget reductions, which reflect changes in funding priorities, will leave unresolved many of the questions concerning the biological effects of RF radiation and their possible health implications.

  10. Space radiation health program plan

    SciTech Connect

    Not Available

    1991-11-01

    The Space Radiation Health Program intends to establish the scientific basis for the radiation protection of humans engaged in the exploration of space, with particular emphasis on the establishment of a firm knowledge base to support cancer risk assessment for future planetary exploration. This document sets forth the technical and management components involved in the implementation of the Space Radiation Health Program, which is a major part of the Life Sciences Division (LSD) effort in the Office of Space Science and Applications (OSSA) at the National Aeronautics and Space Administration (NASA). For the purpose of implementing this program, the Life Sciences Division supports scientific research into the fundamental mechanisms of radiation effects on living systems and the interaction of radiation with cells, tissues, and organs, and the development of instruments and processes for measuring radiation and its effects. The Life Sciences Division supports researchers at universities, NASA field centers, non-profit research institutes and national laboratories; establishes interagency agreements for cooperative use and development of facilities; and conducts a space-based research program using available and future spaceflight vehicles.

  11. Principals Of Radiation Toxicology: Important Aspects.

    NASA Astrophysics Data System (ADS)

    Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

    “All things are poison, and nothing is without poison; only the dose permits something not to be poisonous.” Paracelsus Key Words: Radiation Toxins (RT), Radiation Toxicants (RTc), Radiation Poisons (RP), Radiation Exposure (RE), Radiation Toxicology is the science about radiation poisons. [D.Popov et al. 2012,J.Zhou et al. 2007,] Radiation Toxins is a specific proteins with high enzymatic activity produced by living irradiated mammals. [D.Popov et al. 2012,] Radiation Toxicants is a substances that produce radiomimetics effects, adverse biological effects which specific for radiation. [D.Popov et al. 2012,] Radiation Toxic agent is specific proteins that can produce pathological biological effects specific for physical form of radiation.[D.Popov et al. 1990,2012,V. Maliev 2007] Different Toxic Substances isolated from cells or from blood or lymph circulation. [Kudriashov I. et al. 1970, D.Popov et al. 1990,2012,V. Maliev et al. 2007,] Radiation Toxins may affects many organs or specific organ, tissue, specific group of cells. [Kudriashov I. et al. 1970, D.Popov et al. 1990,2012,V. Maliev et al. 2007] For example: Radiation Toxins could induce collective toxic clinical states to include: systemic inflammatory response syndrome (SIRS),toxic multiple organ injury (TMOI), toxic multiple organ dysfunction syndromes (TMODS),and finally, toxic multiple organ failure (TMOF). [T. Azizova et al. 2005, Konchalovsky et al., 2005, D. Popov et al 2012] However, Radiation Toxins could induce specific injury of organs or tissue and induce Acute Radiation Syndromes such as Acute Radiation Cerebrovascular Syndrome, Acute Radiation Cardiovascular Syndrome, Acute Radiation Hematopoietic Syndrome, Acute Radiation GastroIntestinal Syndrome. [ D.Popov et al. 1990, 2012, V. Maliev et al. 2007] Radiation Toxins correlates with Radiation Exposure and the dose-response relationship is a fundamental and essential concept in classic Toxicology and Radiation Toxicology.[ D.Popov et al. 1990, 2012] Moderate and high doses of radiation induces necrosis of radiosensitive cells with the subsequent formation of radiation toxins and their induced acute inflammatory processes. Radiation necrosis is the most substantial and most severe form of radiation induced injury, and when widespread, has grave therapeutic implications. [D. Popov et al. 1990, 2012,Claudio A. et al. 2002, Robertson J. et al. 2002, ] Relatively small doses of Radiation Toxins induce apoptosis and high doses of Radiation Toxins induce necrosis. [Rastogi P. et al. 2009, D. Popov et al. 1990, 2012,] Threshold of Toxic Effects occurs and can be defined. [D. Popov et al. 2012, ] Radiation Toxins affects Somatic cells and Germ Cells. Radiation Toxins can induce teratogenic processes. Specific Toxicity of Radiation Toxins can affects developing fetus. Material and Methods, Results: http://www.intechopen.com/books/current-topics-in-ionizing-radiation-research/radiation-toxins-molecular-mechanisms-of-toxicity-and-radiomimetic-properties- Conclusion: Radiation is a physical agent - induce activation of some secretory proteins with high enzymatic activity. This proteins called as Radiation Toxins can produce specific for radiation biological and toxic effects after administration to radiation naive mammals. [V. Maliev et al. 2007, D. Popov et al. 1990, 2012] Radiation Toxins are teratogenic and oncogenic. Radiation Toxins effects depend on Administered Dose and Radiation effects depend on Exposure Dose and Absorbed Dose. The levels of Radiation Toxins correlates with Radiation Exposure.

  12. RADIATION PROTECTION KEYWORDS: organ dose, equiv-

    E-print Network

    Lin, Zi-wei

    RADIATION PROTECTION KEYWORDS: organ dose, equiv- alent sphere model, space radiation CAN THE EQUIVALENT-SPHERE MODEL APPROXIMATE ORGAN DOSES IN SPACE RADIATION ENVIRONMENTS? Z. W. LIN East Carolina-4353 Received February 20, 2008 Accepted for Publication January 6, 2009 In space radiation calculations

  13. B-2007 Site environmental report Understanding Radiation

    E-print Network

    nonionizing radiation. Examples of nonionizing radiation include most visible light, infrared light, microB- 2007 Site environmental report appenDiX B Understanding Radiation This section introduces the general reader to some basic concepts of radioactivity and an understanding of the radiation emitted

  14. B-2009 Site environmental report Understanding Radiation

    E-print Network

    nonionizing radiation. Examples of nonionizing radiation include most visible light, infrared light, microB- 2009 Site environmental report appenDiX B Understanding Radiation This section introduces the general reader to some basic concepts of radioactivity and an under- standing of the radiation emitted

  15. B-2005 Site environmental report Understanding Radiation

    E-print Network

    nonionizing radiation. Examples of nonionizing radiation include most visible light, infrared light, microB- 2005 Site environmental report appenDiX B Understanding Radiation This section introduces the general reader to some basic concepts of radioactivity and an understanding of the radiation emitted

  16. Voyager electronic parts radiation program, volume 1

    NASA Technical Reports Server (NTRS)

    Stanley, A. G.; Martin, K. E.; Price, W. E.

    1977-01-01

    The Voyager spacecraft is subject to radiation from external natural space, from radioisotope thermoelectric generators and heater units, and from the internal environment where penetrating electrons generate surface ionization effects in semiconductor devices. Methods for radiation hardening and tests for radiation sensitivity are described. Results of characterization testing and sample screening of over 200 semiconductor devices in a radiation environment are summarized.

  17. Radiation response of the central nervous system

    Microsoft Academic Search

    T. E. Schultheiss; L. E. Kun; K. K. Ang; L. C. Stephens

    1995-01-01

    This report reviews the anatomical, pathophysiological, and clinical aspects of radiation injury to the central nervous system (CNS). Despite the lack of pathognomonic characteristics for CNS radiation lesions, demyelination and malacia are consistently the dominant morphological features of radiation myelopathy. In addition, cerebral atrophy is commonly observed in patients with neurological deficits related to chemotherapy and radiation, and neurocognitive deficits

  18. Spectral modeling of radiation in combustion systems

    Microsoft Academic Search

    Gopalendu Pal

    2010-01-01

    Radiation calculations are important in combustion due to the high temperatures encountered but has not been studied in sufficient detail in the case of turbulent flames. Radiation calculations for such problems require accurate, robust, and computationally efficient models for the solution of radiative transfer equation (RTE), and spectral properties of radiation. One more layer of complexity is added in predicting

  19. BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization of

    E-print Network

    Ohta, Shigemi

    BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization of Nd-Fe-B Permanent Magnets P.K. Job Radiation Physicist NSLS II #12;BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization Irradiation of Sample Magnets MCNPX Calculations for Comparison #12;BROOKHAVEN SCIENCE ASSOCIATES Radiation

  20. Liquid cooled fiber thermal radiation receiver

    DOEpatents

    Butler, B.L.

    1985-03-29

    A radiation-to-thermal receiver apparatus for collecting radiation and converting it to thermal energy is disclosed. The invention includes a fibrous mat material which captures radiation striking the receiver. Captured radiation is removed from the fibrous mat material by a transparent fluid within which the material is bathed.

  1. THE BIOLOGICAL EFFECT OF COSMIC RADIATION

    Microsoft Academic Search

    Gyurdzhian

    1962-01-01

    A review on the biological effects of cosmic radiation is presented and ; includes discussion on: the relative biological activity (REA) of the various ; rays; characteristics of the biological effects of ionizing particles of cosmic ; radiation; characteristics of ionization of body tissues cosmic radiation ; particles; the biological effect of the heavy particles of cosmic radiation; ; genetic

  2. Wayne State University Radiation Therapy Technology

    E-print Network

    Cinabro, David

    Wayne State University Radiation Therapy Technology Memorandum TO: Applicants for Radiation Therapy of professional students in the radiation therapy technology program. We want you to be well informed about what\\2005apl\\tecmem06.sam #12;WAYNE STATE UNIVERSITY RADIATION THERAPY TECHNOLOGY Statement of Technical

  3. Radiation Protection Surveys in Clinical Areas

    E-print Network

    Jia, Songtao

    Radiation Protection Surveys in Clinical Areas Procedure: 7.521 Created: 4/23/2014 Version: 1 as low as reasonably achievable (ALARA) it is necessary to perform routine radiation protection surveys: Radiation Safety Officer D. Policies 1. Ambient radiation levels: survey with ion chamber survey meter

  4. Radiation Shielding for Fusion Reactors

    SciTech Connect

    Santoro, R.T.

    1999-10-01

    Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel.

  5. Microwave Radiation Sources GAtoms Beams and Plasmas Group

    E-print Network

    Strathclyde, University of

    detectors because explosives emit radiation in the THz region of the electromagnetic spectrum. We will use waves, this radiation is called Cherenkov radiation. Cherenkov radiation gives nuclear reactorsMicrowave Radiation Sources GAtoms Beams and Plasmas Group Further information:- alan

  6. Cirrus radiative characteristics and the radiative impact of small particles

    NASA Technical Reports Server (NTRS)

    Stackhouse, Paul W., Jr.; Stephens, Graeme L.; Cox, Stephen K.

    1990-01-01

    An understanding of the way radiation interacts with clouds is vital for understanding the sensitivity of the earth's climate to both natural and anthropogenic changes in the atmosphere. Cirrus clouds are thought to be an important modulator of climate sensitivity. The feedback effect of cirrus on climate can be positive or negative depending upon the microphysics and scattering properties of the cloud. These properties of cirrus clouds are not well understood partly because of their thin tenuous nature and partly because of their microphysical properties. The high altitude and cold temperatures within these clouds along with their transparency greatly increase the difficulty in which accurate measurements can be obtained and interpreted both by aircraft and remote sensing. Therefore, the understanding of the interaction of radiation in cirrus clouds is crucial to determining the ways in which these clouds interact with climate forcings. The sensitivity of the radiative budgets of cirrus cloudiness to their microphysical composition and the environments in which they occur is examined. Especially important is the impact of small particles on the radiative properties of cirrus. Remote sensing estimates of the effective crystal size of cirrus and in situ measurements show large differences up to 100 microns. Thus it becomes important to identify the sources of these differences. For this reason, simulations of actual FIRE cases are compared with the in situ radiative observations and inferences are made concerning the cause of the discrepancies.

  7. Radiative heating in contrail cirrus

    NASA Astrophysics Data System (ADS)

    Schumann, Ulrich; Mayer, Bernhard; Hamann, Ulrich; Graf, Kaspar

    2010-05-01

    In the course of analysis and modeling of aviation induced contrail cirrus, we found that observed time scales of contrail cirrus and thin cirrus in general requires particle losses by radiative heating besides other loss processes. For thin cirrus near the tropopause, radiative warming dominates over cooling in most cases, in particular in the lower part of cirrus layers. Both terrestrial and solar radiances contribute to warming, but the terrestrial part is often the larger one. The radiation is absorbed mainly by the ice particles while a smaller fraction is absorbed by water vapor and other gases inside the cirrus. The heating directly absorbed in the ice particles causes a temperature difference between the ice particles and ambient air. Because of the small heat capacity of the ice particles and because of the small particle scales, local equilibrium between radiative heating and conductive cooling is reached quickly. In agreement with Gierens (1994) and others, this causes a temperature surplus of order 0.1 K for ice particles larger than about 100 micro meters. For smaller particles, the temperature increases about linearly with the particle radius. The contribution is important for very low ice particle concentrations (below 0.1/cm**3) and solar optical depth larger 0.1. After heat exchange with the ambient air, and by additional absorption of radiation in the gas phase, the radiation also causes a bulk warming of the cirrus, again of order 0.1 K. The contribution is important for high ice particle concentrations (> 1 /cm**3) and for rather modest optical depth values (0.01 to 0.1). Quasi equilibrium is reached in proportion to the inverse heating rate, which may take hours. In case of heating the increased ice particle temperature causes reduced water vapor saturation at the ice surface and hence sublimation. Hence, both effects may contribute to a loss of ice particles in cirrus, in particular, when relative humidity inside the cirrus is close to ice saturation. In addition, the radiative heating may cause convective turbulence because of warm air masses rising and cold air masses sinking. Finally, the whole cirrus may rise slowly rise by the diabatic heating. In order to simulate these effects in contrail cirrus we developed an effective model (within our contrail cirrus prediction model, CoCiP) which computes the radiative heating rate in both the longwave and shortwave spectral ranges. The model parameterizes the impact of radiative heating on turbulent mixing and sublimation of ice particles in a thin cirrus layer. The heating rate is modeled as a function of cirrus properties (optical depth, temperature, humidity, effective particle radius, and particle habit), solar radiation, solar zenith angle, and the radiances at the top of the atmosphere (solar direct radiation, reflected solar radiation, and outgoing longwave radiation). The model parameters were determined by least square fits of the model results to the results of forward calculations with the libRadtran system using the DISORT 2.0 solver with 16 streams for about 32000 cases with different atmospheres, surface properties and cloud parameters. The model has been applied for various test cases in comparison to cirrus cover derived from SEVIRI-IR data from Meteosat (MSG) observations. The comparison shows that radiative heating may enhance vertical mixing and reduce the life time of contrail cirrus (and thin cirrus in general) by factors of order two.

  8. EXOMARS IRAS (DOSE) radiation measurements.

    NASA Astrophysics Data System (ADS)

    Federico, C.; Di Lellis, A. M.; Fonte, S.; Pauselli, C.; Reitz, G.; Beaujean, R.

    The characterization and the study of the radiations on their interaction with organic matter is of great interest in view of the human exploration on Mars. The Ionizing RAdiation Sensor (IRAS) selected in the frame of the ExoMars/Pasteur ESA mission is a lightweight particle spectrometer combining various techniques of radiation detection in space. It characterizes the first time the radiation environment on the Mars surface, and provide dose and dose equivalent rates as precursor information absolutely necessary to develop ways to mitigate the radiation risks for future human exploration on Mars. The Martian radiation levels are much higher than those found on Earth and they are relatively low for space. Measurements on the surface will show if they are similar or not to those seen in orbit (modified by the presence of ``albedo'' neutrons produced in the regolith and by the thin Martian atmosphere). IRAS consists of a telescope based on segmented silicon detectors of about 40\\userk\\milli\\metre\\user;k diameter and 300\\user;k\\micro\\metre\\user;k thickness, a segmented organic scintillator, and of a thermoluminescence dosimeter. The telescope will continuously monitor temporal variation of the particle count rate, the dose rate, particle and LET (Linear Energy Transfer) spectra. Tissue equivalent BC430 scintillator material will be used to measure the neutron dose. Neutrons are selected by a criteria requiring no signal in the anti-coincidence. Last, the passive thermoluminescence dosimeter, based on LiF:Mg detectors, regardless the on board operation timing, will measure the total dose accumulated during the exposure period and due to beta and gamma radiation, with a responsivity very close to that of a human tissue.

  9. Ionizing radiation and its risks.

    PubMed

    Goldman, M

    1982-12-01

    Penetrating ionizing radiation fairly uniformly puts all exposed molecules and cells at approximately equal risk for deleterious consequences. Thus, the original deposition of radiation energy (that is, the dose) is unaltered by metabolic characteristics of cells and tissue, unlike the situation for chemical agents. Intensely ionizing radiations, such as neutrons and alpha particles, are up to ten times more damaging than sparsely ionizing sources such as x-rays or gamma rays for equivalent doses. Furthermore, repair in cells and tissues can ameliorate the consequences of radiation doses delivered at lower rates by up to a factor of ten compared with comparable doses acutely delivered, especially for somatic (carcinogenic) and genetic effects from x- and gamma-irradiation exposure. Studies on irradiated laboratory animals or on people following occupational, medical or accidental exposures point to an average lifetime fatal cancer risk of about 1 x 10(-4) per rem of dose (100 per 10(6) person-rem). Leukemia and lung, breast and thyroid cancer seem more likely than other types of cancer to be produced by radiation. Radiation exposures from natural sources (cosmic rays and terrestrial radioactivity) of about 0.1 rem per year yield a lifetime cancer risk about 0.1 percent of the normally occurring 20 percent risk of cancer death. An increase of about 1 percent per rem in fatal cancer risk, or 200 rem to double the "background" risk rate, is compared with an estimate of about 100 rem to double the genetic risk. Newer data suggest that the risks for low-level radiation are lower than risks estimated from data from high exposures and that the present 5 rem per year limit for workers is adequate. PMID:6761969

  10. Ionizing Radiation and Its Risks

    PubMed Central

    Goldman, Marvin

    1982-01-01

    Penetrating ionizing radiation fairly uniformly puts all exposed molecules and cells at approximately equal risk for deleterious consequences. Thus, the original deposition of radiation energy (that is, the dose) is unaltered by metabolic characteristics of cells and tissue, unlike the situation for chemical agents. Intensely ionizing radiations, such as neutrons and alpha particles, are up to ten times more damaging than sparsely ionizing sources such as x-rays or gamma rays for equivalent doses. Furthermore, repair in cells and tissues can ameliorate the consequences of radiation doses delivered at lower rates by up to a factor of ten compared with comparable doses acutely delivered, especially for somatic (carcinogenic) and genetic effects from x- and gamma-irradiation exposure. Studies on irradiated laboratory animals or on people following occupational, medical or accidental exposures point to an average lifetime fatal cancer risk of about 1 × 10-4 per rem of dose (100 per 106 person-rem). Leukemia and lung, breast and thyroid cancer seem more likely than other types of cancer to be produced by radiation. Radiation exposures from natural sources (cosmic rays and terrestrial radioactivity) of about 0.1 rem per year yield a lifetime cancer risk about 0.1 percent of the normally occurring 20 percent risk of cancer death. An increase of about 1 percent per rem in fatal cancer risk, or 200 rem to double the “background” risk rate, is compared with an estimate of about 100 rem to double the genetic risk. Newer data suggest that the risks for low-level radiation are lower than risks estimated from data from high exposures and that the present 5 rem per year limit for workers is adequate. PMID:6761969

  11. Radiation Protection lessonsRadiation Protection lessons Experiences with operating beams for

    E-print Network

    McDonald, Kirk

    Radiation Protection lessonsRadiation Protection lessons Experiences with operating beams, they are exposed to much lower radiation than compared to a storage location in the target chamberchamber. WANF O'rings in pumps and motors were not specified to be radiation resistant. CNGSCNGS only radiation hard components

  12. 30. Radioactivity and radiation protection 1 30. RADIOACTIVITY AND RADIATION PROTECTION

    E-print Network

    30. Radioactivity and radiation protection 1 30. RADIOACTIVITY AND RADIATION PROTECTION Revised;2 30. Radioactivity and radiation protection caused by different radiation types R weighted with so radiation in a volume element of a specified material divided by the mass of this volume element. · Kerma, K

  13. Grating transition radiation: A source of quasimonochromatic radiation P. Henri, O. Haeberle,* and P. Rullhusen

    E-print Network

    Boyer, Edmond

    of quasimonochromatic radiation in the far-infrared to mm wavelength range. S1063-651X 99 13211-2 PACS number s : 41 radiation sources in the far-infrared to mm range using transition radiation and the Smith-Purcell effect 1Grating transition radiation: A source of quasimonochromatic radiation P. Henri, O. Haeberle

  14. Astronaut radiation exposure in low-earth orbit. Part 1. Galactic cosmic radiation

    Microsoft Academic Search

    Letaw

    1988-01-01

    In recent years, there has been increasing concern about the radiation doses that will be suffered by astronauts on present-day and future space missions. In order to characterize radiation exposure risks on space missions one requires models of space-radiation environments, codes for transporting the components of ionizing radiation, and procedures for assessing radiation risks of a given exposure. To verify

  15. Estimation of surface longwave radiation components from ground-based historical net radiation and weather data

    Microsoft Academic Search

    Gi-Hyeon Park; Xiaogang Gao; Soroosh Sorooshian

    2008-01-01

    A methodology for estimating ground upwelling, clear-sky and cloud downwelling longwave radiations (L ?, L sky ?, and L cld ?) and net shortwave radiation (S n ) at 30-min temporal scales based on long-term ground-based net radiations and meteorological observations is described. Components of surface radiation can be estimated from empirical models, cloud radiation models, and remote sensing observations.

  16. Radiation Assurance for the Space Environment

    NASA Technical Reports Server (NTRS)

    Barth, Janet L.; LaBel, Kenneth A.; Poivey, Christian

    2004-01-01

    The space radiation environment can lead to extremely harsh operating conditions for spacecraft electronic systems. A hardness assurance methodology must be followed to assure that the space radiation environment does not compromise the functionality and performance of space-based systems during the mission lifetime. The methodology includes a definition of the radiation environment, assessment of the radiation sensitivity of parts, worst-case analysis of the impact of radiation effects, and part acceptance decisions which are likely to include mitigation measures.

  17. Radiation protection for nurses. Regulations and guidelines

    SciTech Connect

    Jankowski, C.B. (Radiation Safety Office, Brigham and Women's Hospital, Boston, MA (United States))

    1992-02-01

    Rules and regulations of federal agencies and state radiation protection programs provide the bases for hospital policy regarding radiation safety for nurses. Nursing administrators should work with the radiation safety officer at their institutions to ensure that radiation exposures to staff nurses will be as low as reasonably achievable and that special consideration will be given to pregnant nurses. Nurses' fears about their exposure to radiation can be greatly reduced through education.

  18. Predictions for Radiation Shielding Materials

    NASA Technical Reports Server (NTRS)

    Kiefer, Richard L.

    2002-01-01

    Radiation from galactic cosmic rays (GCR) and solar particle events (SPE) is a serious hazard to humans and electronic instruments during space travel, particularly on prolonged missions outside the Earth s magnetic fields. Galactic cosmic radiation (GCR) is composed of approx. 98% nucleons and approx. 2% electrons and positrons. Although cosmic ray heavy ions are 1-2% of the fluence, these energetic heavy nuclei (HZE) contribute 50% of the long-term dose. These unusually high specific ionizations pose a significant health hazard acting as carcinogens and also causing microelectronics damage inside spacecraft and high-flying aircraft. These HZE ions are of concern for radiation protection and radiation shielding technology, because gross rearrangements and mutations and deletions in DNA are expected. Calculations have shown that HZE particles have a strong preference for interaction with light nuclei. The best shield for this radiation would be liquid hydrogen, which is totally impractical. For this reason, hydrogen-containing polymers make the most effective practical shields. Shielding is required during missions in Earth orbit and possibly for frequent flying at high altitude because of the broad GCR spectrum and during a passage into deep space and LunarMars habitation because of the protracted exposure encountered on a long space mission. An additional hazard comes from solar particle events (SPEs) which are mostly energetic protons that can produce heavy ion secondaries as well as neutrons in materials. These events occur at unpredictable times and can deliver a potentially lethal dose within several hours to an unshielded human. Radiation protection for humans requires safety in short-term missions and maintaining career exposure limits within acceptable levels on future long-term exploration missions. The selection of shield materials can alter the protection of humans by an order of magnitude. If improperly selected, shielding materials can actually increase radiation damage due to penetration properties and nuclear fragmentation. Protecting space-borne microelectronics from single event upsets (SEUs) by transmitted radiation will benefit system reliability and system design cost by using optimal shield materials. Long-term missions on the surface of the Moon or Mars will require the construction of habitats to protect humans during their stay. One approach to the construction is to make structural materials from lunar or Martian regolith using a polymeric material as a binder. The hydrogen-containing polymers are considerably more effective for radiation protection than the regolith, but the combination minimizes the amount of polymer to be transported. We have made composites of simulated lunar regolith with two different polymers, LaRC-SI, a high-performance polyimide thermoset, and polyethylene, a thermoplastic.

  19. [Early cell response to radiation].

    PubMed

    Le Péchoux, C; Deniaud-Alexandre, E; Ponette, V; Giocanti, N; Favaudon, V

    1997-01-01

    The early steps of cellular radiation response have been investigated using a linear electron accelerator operated in a split-dose mode, in such a way that the time intervals between pulse exposures to relativistic electrons ranged from fractions of a second to a few minutes. The initial dose brought about large, synchronous changes in radiation sensitivity and generated a tetraphasic, W-shaped time-dependent profile of cell survival upon the second radiation exposure. While this time-related process was observed in most cell lines investigated, its kinetic parameters varied significantly from one cell line to the other. The number of DNA strand breaks (neutral and alkaline DNA filter elution) and the level of apoptosis (gel electrophoresis and flow cytometry) induced at the different phases of the time-dependent profile showed no relationship with the W-effect. It is presently hypothesized that mechanisms involved in molecular recognition of radio-induced lesions and initiation of genomic instability play a major role in this effect. Whatever the mechanism involved, the split-dose irradiation in the range of seconds enables dissecting the early steps of radiation response. The relevance of the W-effect to radiation therapy and technical drawbacks are discussed. PMID:9587382

  20. Surface Power Radiative Cooling Tests

    NASA Astrophysics Data System (ADS)

    Vaughn, Jason; Schneider, Todd

    2006-01-01

    Terrestrial nuclear power plants typically maintain their temperature through convective cooling, such as water and forced air. However, the space environment is a vacuum environment, typically 10-8 Torr pressure, therefore in proposed missions to the lunar surface, power plants would have to rely on radiative cooling to remove waste heat. Also, the Martian surface has a very tenuous atmosphere (e.g. ~5 Torr CO2), therefore, the main heat transfer method on the Martian surface is also radiative. Because of the lack of atmosphere on the Moon and the tenuous atmosphere on Mars, surface power systems on both the Lunar and Martian surface must rely heavily on radiative heat transfer. Because of the large temperature swings on both the lunar and the Martian surfaces, trying to radiate heat is inefficient. In order to increase power system efficiency, an effort is underway to test various combinations of materials with high emissivities to demonstrate their ability to survive these degrading atmospheres to maintain a constant radiator temperature improving surface power plant efficiency. An important part of this effort is the development of a unique capability that would allow the determination of a materials emissivity at high temperatures. A description of the test capability as well as initial data is presented.

  1. [Radiation exposure and thyroid cancer].

    PubMed

    Cannizzaro, Matteo Angelo; Veroux, Massimiliano; Costanzo, Mario; Buffone, Antonino; Okatyeva, Valeriya

    2012-01-01

    Thyroid cancer is the most common malignant tumor of the endocrine system. The most frequent type of thyroid malignancy is papillary carcinoma. Thyroid cancer's incidence rates have increased over the last three decades throughout the world. Numerous studies have documented that radiation exposure is a well-established risk factor for the thyroid cancer. It has been reported that exposure to external medical radiation or to external and internal radiation from atomic bomb explosions, nuclear tests or nuclear accidents leads to an increased risk for thyroid cancer. The risk of thyroid cancer is maximal during the first years of life and decreases with increasing age at exposure due to morphologic and functional heterogeneity in the thyroid tissue of children and adults. Also it has been indicated that iodine deficiency increases the risk of the thyroid cancer related to radioactive iodines in case of exposure to radioactive iodines in childhood and the stable iodine supplementation reduces this risk. Ionizing radiation produces a range of mutations in irradiated cells of the thyroid. The prevalence of RET/PTC mutations is significantly higher in papillary carcinomas from childhood patients with the precedent history of radiation. PMID:23064295

  2. Advances in radiation therapy dosimetry.

    PubMed

    Paliwal, Bhudatt; Tewatia, Dinesh

    2009-07-01

    During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are major challenges for the radiotherapy patient dosimetry and delivery verification. Advanced techniques are less tolerant to poor implementation than are standard techniques. Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients. Instead of presenting a manual on quality assurance for radiation therapy, this manuscript provides an overview of dosimetry verification tools and a focused discussion on breath holding, respiratory gating and the applications of four-dimensional computed tomography in motion management. Some of the major challenges in the above areas are discussed. PMID:20098555

  3. Radiation induced estane polymer crosslinking

    SciTech Connect

    Fletcher, M. [Los Alamos National Lab., NM (United States); Foster, P. [Masson Hanger Pantex Plant, Amarillo, TX (United States)

    1997-12-01

    The exposure of polymeric materials to radiation has been known to induce the effects of crosslinking and degradation. The crosslinking phenomena comes about when two long chain polymers become linked together by a primary bond that extends the chain and increases the viscosity, molecular weight and the elastic modules of the polymer. This process has been observed in relatively short periods of time with fairly high doses of radiation, on the order of several megarads/hour. This paper address low dose exposure over long periods of time to determine what the radiation effects are on the polymeric binder material in PBX 9501. An experimental sample of binder material without explosives will be placed into a thermal and radiation field produced from a W-48 put mod 0. Another sample will be placed in a thermal environment without the radiation. The following is the test plan that was submitted to the Pantex process. The data presented here will be from the first few weeks of exposure and this test will be continued over the next few years. Subsequent data will hopefully be presented in the next compatibility and aging conference.

  4. Medical Applications of Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Prezado, Yolanda; Martínez-Rovira, Immaculada

    This chapter describes the state-of-art of synchrotron radiation therapies in the treatment of radioresistant tumors. The tolerance of the surrounding healthy tissue severely limits the achievement of a curative treatment for some brain tumors, like gliomas. This restriction is especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restrained. One possible solution is the development of new radiotherapy techniques would exploit radically different irradiation modes, as it is the case of synchrotron radiotherapies. Their distinct features allow to modify the biological equivalent doses. In this chapter the three new approaches under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France), will be described, namely: stereotactic synchrotron radiation therapy, microbeam radiation therapy and minibeam radiation therapy. The promising results obtained in the treatment of high grade brain tumors in preclinical studies have paved the way to the forthcoming clinical trials, currently in preparation.

  5. Investigating Undergraduate Students’ Conceptions of Radiation

    NASA Astrophysics Data System (ADS)

    Romine, James M.; Buxner, Sanlyn; Impey, Chris; Nieberding, Megan; Antonellis, Jessie C.

    2014-11-01

    Radiation is an essential topic to the physical sciences yet is often misunderstood by the general public. The last time most people have formal instruction about radiation is as students in high school and this knowledge will be carried into adulthood. Peoples’ conceptions of radiation influence their attitude towards research regarding radiation, radioactivity, and other work where radiation is prevalent. In order to understand students’ ideas about radiation after having left high school, we collected science surveys from nearly 12,000 undergraduates enrolled in introductory science courses over a span of 25 years. This research investigates the relationship between students’ conceptions of radiation and students’ personal beliefs and academic field of study.Our results show that many students in the sample were unable to adequately describe radiation. Responses were typically vague, brief, and emotionally driven. Students’ field of study was found to significantly correlate with their conceptions. Students pursuing STEM majors were 60% more likely to describe radiation as an emission and/or form of energy and cited atomic or radioactive sources of radiation twice as often as non-STEM students. Additionally, students’ personal beliefs also appear to relate to their conceptions of radiation. The most prominent misconception shown was that radiation is a generically harmful substance, which was found to be consistent throughout the duration of the study. In particular, non-science majors in our sample had higher rates of misconceptions, often generalized the idea of radiation into a broad singular topic, and had difficulty properly identifying sources.Generalized ideas of radiation and the inability to properly recognize sources of radiation may contribute to the prevalent misconception that radiation is an inexplicably dangerous substance. A basic understanding of both electromagnetic and particulate radiation and the existence of radiation at various energy levels may substantially deter fear-based generalizations and increase students’ abilities to make rational decisions when encountering various types of radiation in daily life.

  6. Trapping of radiation in plasmas

    SciTech Connect

    Riley, M.E.; Alford, W.J.

    1995-06-01

    The authors analyze the problem of radiation trapping (imprisonment) by the method of Holstein. The process is described by an integrodifferential equation which shows that the effective radiative decay rate of the system depends on the size and the shape of the active medium. Holstein obtains a global decay rate for a particular geometry by assuming that the radiating excited species evolves into a steady state spatial mode. The authors derive a new approximation for the trapped decay which has a space dependent decay rate and is easy to implement in a detailed computer simulation of a plasma confined within an arbitrary geometry. They analyze the line shapes that are relevant to a near-atmospheric-pressure mixture of He and Xe. This line-shape analysis can be utilized in either the Holstein formulae or the space-dependent decay approximation.

  7. The cosmic microwave background radiation

    NASA Technical Reports Server (NTRS)

    Silk, J.

    1981-01-01

    Because angular anisotropies and spectral distortions of the cosmic microwave background radiation are judged to be inevitable at some level, in a realistic cosmological model, the evidence for spectral distortions and its theoretical implications are described. The evidence for anisotropy is then discussed, and theoretical predictions of radiation anisotropy are summarized and compared with the data available. It is found that spectral distortions at the 3-sigma level near the peak of the blackbody spectrum, although inconsistent with the predicted distortions due to Compton scattering in the early universe, are elegantly interpreted in terms of radiation from an early, pregalactic generation of massive stars which had been thermalized by a modest amount of dust at high redshift. The quadrupole anisotropy at the 4-sigma level is most simply interpreted in terms of the large-scale structure of the universe.

  8. Space radiator simulation system analysis

    NASA Technical Reports Server (NTRS)

    Black, W. Z.; Wulff, W.

    1972-01-01

    A transient heat transfer analysis was carried out on a space radiator heat rejection system exposed to an arbitrarily prescribed combination of aerodynamic heating, solar, albedo, and planetary radiation. A rigorous analysis was carried out for the radiation panel and tubes lying in one plane and an approximate analysis was used to extend the rigorous analysis to the case of a curved panel. The analysis permits the consideration of both gaseous and liquid coolant fluids, including liquid metals, under prescribed, time dependent inlet conditions. The analysis provided a method for predicting: (1) transient and steady-state, two dimensional temperature profiles, (2) local and total heat rejection rates, (3) coolant flow pressure in the flow channel, and (4) total system weight and protection layer thickness.

  9. Radiation processing and market economy

    NASA Astrophysics Data System (ADS)

    Zagórski, Z. P.

    1998-06-01

    In the system of totalitarian economy, regulated by bureaucracy, the real value of equipment, materials and services is almost completely unknown, what makes impossible the comparison of different technologies, eliminates competition, disturbs research and development. With introduction of market economy in Central and Eastern Europe, the radiation processing has lost doubtful support, becoming an independent business, subject to laws of free market economy. Only the most valuable objects of processing have survived that test. At the top of the list are: radiation sterilization of medical equipment and radiation induced crosslinking of polymers, polyethylene in particular. New elements of competition has entered the scene, as well as questions of international regulations and standards have appeared.

  10. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, Dimitrios C. (Oak Ridge, TN); Fox, Richard J. (Oak Ridge, TN)

    1981-01-01

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semiconductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  11. Aging and radiation: bad companions

    PubMed Central

    Hernández, Laia; Terradas, Mariona; Camps, Jordi; Martín, Marta; Tusell, Laura; Genescà, Anna

    2015-01-01

    Aging involves a deterioration of cell functions and changes that may predispose the cell to undergo an oncogenic transformation. The carcinogenic risks following radiation exposure rise with age among adults. Increasing inflammatory response, loss of oxidant/antioxidant equilibrium, ongoing telomere attrition, decline in the DNA damage response efficiency, and deleterious nuclear organization are age-related cellular changes that trigger a serious threat to genomic integrity. In this review, we discuss the mechanistic interplay between all these factors, providing an integrated view of how they contribute to the observed age-related increase in radiation sensitivity. As life expectancy increases and so it does the medical intervention, it is important to highlight the benefits of radiation protection in the elderly. Thus, a deep understanding of the mechanistic processes confining the threat of aging-related radiosensitivity is currently of foremost relevance. PMID:25645467

  12. Radiation-viscous boundary layer

    NASA Technical Reports Server (NTRS)

    Arav, Nahum; Begelman, Mitchell C.

    1992-01-01

    A viscous boundary layer (BL) is studied which is most likely to occur in astrophysical systems dominated by radiation pressure, in particular compact objects surrounded by a very optically thick envelope and radiating at close to the Eddington limit. Calculations are reported which show that a BL due to radiation viscosity behaves very differently from a 'classical' incompressible BL for flows with Mach number M much greater than unity far from the BL. In these flows the width of the BL is much larger than its incompressible value and scales as M-squared times the width of the imcompressible BL. The density inside the BL is much lower than that in the undisturbed fluid and scales as 1/M-squared with respect to the value far away from the BL. It is concluded that under certain circumstances a cocoon of low-density material will develop between a jet and its surrounding medium.

  13. Device for detecting ionizing radiation

    SciTech Connect

    Anatychuk, L.I.; Kharitonov, J.P.; Kusniruk, V.F.; Meir, V.A.; Melnik, A.P.; Ponomarev, V.S.; Skakodub, V.A.; Sokolov, A.D.; Subbotin, V.G.; Zhukovsky, A.N.

    1980-10-28

    The present invention relates to ionizing radiation sensors, and , more particularly, to semiconductor spectrometers with thermoelectric cooling, and can most advantageously be used in mineral raw material exploration and evaluation under field conditions. The spectrometer comprises a vacuum chamber with an entrance window for passing the radiation therethrough. The vacuum chamber accommodates a thermoelectric cooler formed by a set of peltier elements. A heat conducting plate is mounted on the cold side of the thermoelectric cooler, and its hot side is provided with a radiator. Mounted on the heat conducting plate are sets of peltier elements, integral with the thermoelectric cooler and independent of one another. The peltier elements of these sets are stacked so as to develop the minimum temperature conditions on one set carrying a semiconductor detector and to provide the maximum refrigeration capacity conditions on the other set provided with the field-effect transistor mounted thereon.

  14. Solar radiation on inclined surfaces

    SciTech Connect

    Gopinathan, K.K. (National Univ. of Lesotho (South Africa))

    1990-01-01

    Measured solar radiation data for one location in Lesotho is used to test the applicability of two theoretical models for computing total solar radiation on inclined surfaces. The models selected for discussion are the isotropic model suggested by Liu and Jordan and the anisotropic model by Hay. The models are compared and tested for their applicability to locations in Lesotho and Southern Africa in general, on the basis of statistical error tests. A comparative study of the models shows that both the models are equally accurate for stations in Lesotho. The isotropic model is then used to estimate total radiation for five other locations on north-facing surfaces of various tilt angles, and the results are presented.

  15. Radiation damage of germanium detectors

    NASA Technical Reports Server (NTRS)

    Pehl, R. H.

    1978-01-01

    Energetic particles can produce interstitial-vacancy pairs in a crystal by knocking the atoms from their normal positions. Detectors are unique among semiconductor devices in depending on very low concentrations of electrically active impurities, and also on efficient transport of holes and electrons over relatively large distances. Because the dense regions of damage produced by energetic particles may result in donors and/or acceptors, and also provide trapping sites for holes and electrons, detectors are very sensitive to radiation damage. In addition to these effects occurring within the detector, radiation may also change the characteristics of the exposed surfaces causing unpredictable effects on the detector leakage current. Radiation-induced surface degradation has rarely, if ever, been observed for germanium detectors. The possibility of minimizing hole trapping in charge collection by the use of a high-purity germanium coaxial detector configured with the p (+) contact on the coaxial periphery is discussed.

  16. National Solar Radiation Data Base

    NSDL National Science Digital Library

    The Renewable Resource Data Center (RReDC) is managed by the Department of Energy and "provides information on several types of renewable energy resources in the United States, in the form of publications, data, and maps." The National Solar Radiation Data Base (NSRDB) contains data from 1961-1990 on solar radiation and supplementary meteorological data from 237 sites in the US, as well as Guam and Puerto Rico. Data includes daily statistics files, hourly data files, a solar radiation data manual for buildings and for flat-plate and concentrating collectors, typical meteorological year (tmy) data, and resource maps. The page also has an online user manual to help decipher and best utilize the files.

  17. Radiation safety in aircraft operations

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Nealy, J. E.

    1992-01-01

    Data from a 7-yr flight experiment program to measure the significant biological components (tissue ionization rates, neutron flux, and nuclear reaction star rates) as a function of solar cycle, altitude, latitude and longitude from which biological risk from radiation is estimated are used to evaluate radiation dose and dose equivalents along specific flight trajectories. The data base used and the corresponding time-dependent global model are described. Ionization rates in air measured by argon filled chambers at solar minimum and maximum, and radiation measurements of the Brookhaven National Laboratory instrument compared to the present model are illustrated in tabular form. The global pressure distribution for solstice conditions at 14 km is shown.

  18. Radiation Shielding Systems Using Nanotechnology

    NASA Technical Reports Server (NTRS)

    Chen, Bin (Inventor); McKay, Christoper P. (Inventor)

    2011-01-01

    A system for shielding personnel and/or equipment from radiation particles. In one embodiment, a first substrate is connected to a first array or perpendicularly oriented metal-like fingers, and a second, electrically conducting substrate has an array of carbon nanostructure (CNS) fingers, coated with an electro-active polymer extending toward, but spaced apart from, the first substrate fingers. An electric current and electric charge discharge and dissipation system, connected to the second substrate, receives a current and/or voltage pulse initially generated when the first substrate receives incident radiation. In another embodiment, an array of CNSs is immersed in a first layer of hydrogen-rich polymers and in a second layer of metal-like material. In another embodiment, a one- or two-dimensional assembly of fibers containing CNSs embedded in a metal-like matrix serves as a radiation-protective fabric or body covering.

  19. Interaction between bisantrene and radiation

    SciTech Connect

    Hernandez, E.; Rosenshein, N.B.

    1985-07-01

    The interaction between Bisantrene, a new anthracene derivative, and radiation was studied in vitro. Chinese hamster lung (V-79-171) cells grown as monolayers were exposed to three different concentrations of Bisantrene for 120 min. during their exponential growth phase. Immediately after drug exposure, the cells were irradiated with escalating doses of radiation. Isoeffect curves (99% cell kill) were calculated using dose-survival curves generated for each modality. Curve I assumed that the agents act by independent mechanisms; Curve II assumed that the agents act by a similar mechanism. The dose combinations of the two modalities producing a 99% kill were plotted against the calculated isoeffect curves. The experimental points were found to lie along the calculated lines. Pre-treatment with Bisantrene prior to radiation resulted in an additive effect, similar to that reported with Adriamycin.

  20. Cosmic Radiation Creates Unfriendly Skies

    NSDL National Science Digital Library

    In this activity students read about the effects of radiation on airline passengers, and discover that during a trip in a jet plane at altitudes of 30,000 feet, cosmic rays and other energetic particles pose a great problem and can lead to significant health risks, especially for airline pilots. Students then apply mathematical concepts to calculate dosages and write a letter to persuade the Federal Aviation Administration or the Department of Transportation why it is important to educate, predict, and notify the public about the harmful effects of solar radiation.