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Sample records for radiat prot dosim

  1. Techniques de dosimétrie physique pour la reconstitution d'accident radiologique

    NASA Astrophysics Data System (ADS)

    Bottollier-Depois, J. F.; Chau, Q.; Gaillard-Lecanu, E.; Médioni, R.; Roux, A.

    1998-04-01

    When a radiological accident occurred, the distribution of the dose received in the organism must be assessed within a short time. This information, which completes the clinical and biological investigations, is useful for the medical team. In this way, the physical dosimetry makes use of experimental and numerical reconstitution techniques which are generally complementary. The numerical technique consists in simulating the particles transport with a calculation code based on the Monte-Carlo method in a geometry which represents the injured person and the environment. The experimental reconstitution is performed with tissue equivalent phantoms and special dosemeters. Suite à un accident radiologique, il est important d'estimer rapidement la distribution de la dose reçue par l'organisme. Cette information, qui vient en complément des investigations cliniques et biologiques, s'avère d'une grande utilité pour les médecins. À cette fin, la dosimétrie physique utilise des moyens de reconstitution numériques et expérimentaux, généralement complémentaires. La reconstitution numérique consiste, à l'aide d'un code de calcul basé sur une méthode probabiliste de Monte-Carlo, à simuler le transport des particules dans une géométrie représentant l'accidenté et son evironnement. La reconstitution expérimentale est réalisée à l'aide de fantômes équivalents tissu et de dosimètres adaptés.

  2. UniProt Tools.

    PubMed

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

    2016-01-01

    The Universal Protein Resource (UniProt) is a comprehensive resource for protein sequence and annotation data (UniProt Consortium, 2015). The UniProt Web site receives ∼400,000 unique visitors per month and is the primary means to access UniProt. Along with various datasets that you can search, UniProt provides three main tools. These are the 'BLAST' tool for sequence similarity searching, the 'Align' tool for multiple sequence alignment, and the 'Retrieve/ID Mapping' tool for using a list of identifiers to retrieve UniProtKB proteins and to convert database identifiers from UniProt to external databases or vice versa. This unit provides three basic protocols, three alternate protocols, and two support protocols for using UniProt tools. © 2016 by John Wiley & Sons, Inc. PMID:27010333

  3. Dose measurements in pulsed radiation fields with commercially available measuring components.

    PubMed

    Friedrich, Sabrina; Hupe, Oliver

    2016-03-01

    Dose measurements in pulsed radiation fields with dosemeters using the counting technique are known to be inappropriate. Therefore, there is a demand for a portable device able to measure the dose in pulsed radiation fields. As a detector, ionisation chambers seem to be a good alternative. In particular, using a secondary standard ionisation chamber in combination with a reliable charge-measuring system would be a good solution. The Physikalisch-Technische Bundesanstalt (PTB) uses secondary standard ionisation chambers in combination with PTB-made measuring electronics for dose measurements at its reference fields. However, for general use, this equipment is too complex. For measurements on-site, a mobile special electronic system [Hupe, O. and Ankerhold, U. Determination of ambient and personal dose equivalent for personnel and cargo security screening. Radiat. Prot. Dosim. 121: (4), 429-437 (2006)] has been used successfully. Still, for general use, there is a need for a much simpler but a just as good solution. A measuring instrument with very good energy dependence for H*(10) is the secondary standard ionisation chamber HS01. An easy-to-use and commercially available electrometer for measuring the generated charges is the UNIDOS by PTW Freiburg. Depending on the expected dose values, the ionisation chamber used can be selected. In addition, measurements have been performed by using commercially available area dosemeters, e.g. the Mini SmartION 2120S by Thermo Scientific, using an ionisation chamber and the Szintomat 6134 A/H by Automess, using a scintillation detector. PMID:26056377

  4. UniProtKB/Swiss-Prot, the Manually Annotated Section of the UniProt KnowledgeBase: How to Use the Entry View.

    PubMed

    Boutet, Emmanuel; Lieberherr, Damien; Tognolli, Michael; Schneider, Michel; Bansal, Parit; Bridge, Alan J; Poux, Sylvain; Bougueleret, Lydie; Xenarios, Ioannis

    2016-01-01

    The Universal Protein Resource (UniProt, http://www.uniprot.org ) consortium is an initiative of the SIB Swiss Institute of Bioinformatics (SIB), the European Bioinformatics Institute (EBI) and the Protein Information Resource (PIR) to provide the scientific community with a central resource for protein sequences and functional information. The UniProt consortium maintains the UniProt KnowledgeBase (UniProtKB), updated every 4 weeks, and several supplementary databases including the UniProt Reference Clusters (UniRef) and the UniProt Archive (UniParc).The Swiss-Prot section of the UniProt KnowledgeBase (UniProtKB/Swiss-Prot) contains publicly available expertly manually annotated protein sequences obtained from a broad spectrum of organisms. Plant protein entries are produced in the frame of the Plant Proteome Annotation Program (PPAP), with an emphasis on characterized proteins of Arabidopsis thaliana and Oryza sativa. High level annotations provided by UniProtKB/Swiss-Prot are widely used to predict annotation of newly available proteins through automatic pipelines.The purpose of this chapter is to present a guided tour of a UniProtKB/Swiss-Prot entry. We will also present some of the tools and databases that are linked to each entry. PMID:26519399

  5. ENZYMAP: Exploiting Protein Annotation for Modeling and Predicting EC Number Changes in UniProt/Swiss-Prot

    PubMed Central

    Silveira, Sabrina de Azevedo; de Melo-Minardi, Raquel Cardoso; da Silveira, Carlos Henrique; Santoro, Marcelo Matos; Meira Jr, Wagner

    2014-01-01

    The volume and diversity of biological data are increasing at very high rates. Vast amounts of protein sequences and structures, protein and genetic interactions and phenotype studies have been produced. The majority of data generated by high-throughput devices is automatically annotated because manually annotating them is not possible. Thus, efficient and precise automatic annotation methods are required to ensure the quality and reliability of both the biological data and associated annotations. We proposed ENZYMatic Annotation Predictor (ENZYMAP), a technique to characterize and predict EC number changes based on annotations from UniProt/Swiss-Prot using a supervised learning approach. We evaluated ENZYMAP experimentally, using test data sets from both UniProt/Swiss-Prot and UniProt/TrEMBL, and showed that predicting EC changes using selected types of annotation is possible. Finally, we compared ENZYMAP and DETECT with respect to their predictions and checked both against the UniProt/Swiss-Prot annotations. ENZYMAP was shown to be more accurate than DETECT, coming closer to the actual changes in UniProt/Swiss-Prot. Our proposal is intended to be an automatic complementary method (that can be used together with other techniques like the ones based on protein sequence and structure) that helps to improve the quality and reliability of enzyme annotations over time, suggesting possible corrections, anticipating annotation changes and propagating the implicit knowledge for the whole dataset. PMID:24586563

  6. 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

  7. The UniProtKB guide to the human proteome.

    PubMed

    Breuza, Lionel; Poux, Sylvain; Estreicher, Anne; Famiglietti, Maria Livia; Magrane, Michele; Tognolli, Michael; Bridge, Alan; Baratin, Delphine; Redaschi, Nicole

    2016-01-01

    Advances in high-throughput and advanced technologies allow researchers to routinely perform whole genome and proteome analysis. For this purpose, they need high-quality resources providing comprehensive gene and protein sets for their organisms of interest. Using the example of the human proteome, we will describe the content of a complete proteome in the UniProt Knowledgebase (UniProtKB). We will show how manual expert curation of UniProtKB/Swiss-Prot is complemented by expert-driven automatic annotation to build a comprehensive, high-quality and traceable resource. We will also illustrate how the complexity of the human proteome is captured and structured in UniProtKB.Database URL: www.uniprot.org. PMID:26896845

  8. The UniProtKB guide to the human proteome

    PubMed Central

    Breuza, Lionel; Poux, Sylvain; Estreicher, Anne; Famiglietti, Maria Livia; Magrane, Michele; Tognolli, Michael; Bridge, Alan; Baratin, Delphine; Redaschi, Nicole

    2016-01-01

    Advances in high-throughput and advanced technologies allow researchers to routinely perform whole genome and proteome analysis. For this purpose, they need high-quality resources providing comprehensive gene and protein sets for their organisms of interest. Using the example of the human proteome, we will describe the content of a complete proteome in the UniProt Knowledgebase (UniProtKB). We will show how manual expert curation of UniProtKB/Swiss-Prot is complemented by expert-driven automatic annotation to build a comprehensive, high-quality and traceable resource. We will also illustrate how the complexity of the human proteome is captured and structured in UniProtKB. Database URL: www.uniprot.org PMID:26896845

  9. Update on activities at the Universal Protein Resource (UniProt) in 2013

    PubMed Central

    2013-01-01

    The mission of the Universal Protein Resource (UniProt) (http://www.uniprot.org) is to support biological research by providing a freely accessible, stable, comprehensive, fully classified, richly and accurately annotated protein sequence knowledgebase. It integrates, interprets and standardizes data from numerous resources to achieve the most comprehensive catalogue of protein sequences and functional annotation. UniProt comprises four major components, each optimized for different uses, the UniProt Archive, the UniProt Knowledgebase, the UniProt Reference Clusters and the UniProt Metagenomic and Environmental Sequence Database. 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:23161681

  10. Qualities of the ideal protégé.

    PubMed

    Melanson, Mark A

    2009-01-01

    The purpose of this paper is to share what I view as 10 important qualities of an ideal protégé. First, protégés must have a deep-seated love of learning that drives them to make the most out of the mentoring partnership. Next, protégés must be self-starters who take personal charge of their mentoring. Confidence is vital so that the junior officer can face the many challenges that lay ahead in any Army career. Careful risk taking is necessary so that the protégé can reach his or her greatest potential. Bouncing back from mistakes and failures is crucial for protégés, so they must be resilient. Ongoing enthusiasm is the fuel that sustains the mentoring relationship over time. By being open-minded, a protégé carefully considers all advice, including constructive criticism, that the mentor shares along the uphill path to wisdom. Remember that commitment is the very glue holding the mentoring relationship together. Also, protégés remain loyal to their mentors by always maintaining confidences. Most important, an ideal protégé is truly grateful for all the things that the mentor has done and repays that debt by also becoming a mentor. In closing, it is hoped that by developing these qualities, present and future protégés will get the most out of their mentoring partnerships and keep the age-old spirit of mentorship alive. PMID:20073364

  11. 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

  12. Reorganizing the protein space at the Universal Protein Resource (UniProt)

    PubMed Central

    2012-01-01

    The mission of UniProt is to support biological research by providing a freely accessible, stable, comprehensive, fully classified, richly and accurately annotated protein sequence knowledgebase, with extensive cross-references and querying interfaces. UniProt is comprised of four major components, each optimized for different uses: the UniProt Archive, the UniProt Knowledgebase, the UniProt Reference Clusters and the UniProt Metagenomic and Environmental Sequence Database. A key development at UniProt is the provision of complete, reference and representative proteomes. UniProt is updated and distributed every 4 weeks and can be accessed online for searches or download at http://www.uniprot.org. PMID:22102590

  13. Genes and proteins of Escherichia coli (GenProtEc).

    PubMed

    Riley, M; Space, D B

    1996-01-01

    GenProtEc is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins with PAM values, percent identity of amino acids, length of alignment and percent aligned. The database is available as a PKZip file by ftp from mbl.edu/pub/ecoli.exe. The program runs under MS-DOS on IMB-compatible machines. GenProtEc can also be accessed through the World Wide Web at URL http://mbl.edu/html/ecoli.html. PMID:8594596

  14. UniProt: a hub for protein information.

    PubMed

    2015-01-01

    UniProt is an important collection of protein sequences and their annotations, which has doubled in size to 80 million sequences during the past year. This growth in sequences has prompted an extension of UniProt accession number space from 6 to 10 characters. An increasing fraction of new sequences are identical to a sequence that already exists in the database with the majority of sequences coming from genome sequencing projects. We have created a new proteome identifier that uniquely identifies a particular assembly of a species and strain or subspecies to help users track the provenance of sequences. We present a new website that has been designed using a user-experience design process. We have introduced an annotation score for all entries in UniProt to represent the relative amount of knowledge known about each protein. These scores will be helpful in identifying which proteins are the best characterized and most informative for comparative analysis. All UniProt data is provided freely and is available on the web at http://www.uniprot.org/. PMID:25348405

  15. UniProt: a hub for protein information

    PubMed Central

    2015-01-01

    UniProt is an important collection of protein sequences and their annotations, which has doubled in size to 80 million sequences during the past year. This growth in sequences has prompted an extension of UniProt accession number space from 6 to 10 characters. An increasing fraction of new sequences are identical to a sequence that already exists in the database with the majority of sequences coming from genome sequencing projects. We have created a new proteome identifier that uniquely identifies a particular assembly of a species and strain or subspecies to help users track the provenance of sequences. We present a new website that has been designed using a user-experience design process. We have introduced an annotation score for all entries in UniProt to represent the relative amount of knowledge known about each protein. These scores will be helpful in identifying which proteins are the best characterized and most informative for comparative analysis. All UniProt data is provided freely and is available on the web at http://www.uniprot.org/. PMID:25348405

  16. Analysis of the tryptic search space in UniProt databases.

    PubMed

    Alpi, Emanuele; Griss, Johannes; da Silva, Alan Wilter Sousa; Bely, Benoit; Antunes, Ricardo; Zellner, Hermann; Ros, Daniel; O'Donovan, Claire; Vizcano, 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

  17. 48 CFR 1819.7204 - Protégé selection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....7204 Section 1819.7204 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7204 Protégé... accordance with 13 CFR part 121 (with respect to size) or 13 CFR part 124 (with respect to...

  18. 48 CFR 1819.7204 - Protégé selection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....7204 Section 1819.7204 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7204 Protégé... accordance with 13 CFR part 121 (with respect to size) or 13 CFR part 124 (with respect to...

  19. 48 CFR 1819.7204 - Protégé selection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....7204 Section 1819.7204 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7204 Protégé... accordance with 13 CFR part 121 (with respect to size) or 13 CFR part 124 (with respect to...

  20. 48 CFR 1819.7204 - Protégé selection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....7204 Section 1819.7204 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7204 Protégé... accordance with 13 CFR part 121 (with respect to size) or 13 CFR part 124 (with respect to...

  1. 48 CFR 1819.7204 - Protégé selection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....7204 Section 1819.7204 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7204 Protégé... accordance with 13 CFR part 121 (with respect to size) or 13 CFR part 124 (with respect to...

  2. 48 CFR 1852.219-77 - NASA Mentor-Protégé Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... companies or nonprofit agencies employing people who are blind or severely disabled as defined in 41 CFR... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false NASA Mentor-ProtégÃ... and Clauses 1852.219-77 NASA Mentor-Protégé Program. As prescribed in 1819.7215, insert the...

  3. 48 CFR 1852.219-77 - NASA Mentor-Protégé Program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... nonprofit agencies employing people who are blind or severely disabled as defined in 41 CFR Chapter 51. (3... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true NASA Mentor-ProtégÃ... and Clauses 1852.219-77 NASA Mentor-Protégé Program. As prescribed in 1819.7215, insert the...

  4. 48 CFR 1852.219-77 - NASA Mentor-Protégé Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... companies or nonprofit agencies employing people who are blind or severely disabled as defined in 41 CFR... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false NASA Mentor-ProtégÃ... and Clauses 1852.219-77 NASA Mentor-Protégé Program. As prescribed in 1819.7215, insert the...

  5. 48 CFR 1852.219-77 - NASA Mentor-Protégé Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... companies or nonprofit agencies employing people who are blind or severely disabled as defined in 41 CFR... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false NASA Mentor-ProtégÃ... and Clauses 1852.219-77 NASA Mentor-Protégé Program. As prescribed in 1819.7215, insert the...

  6. 48 CFR 1852.219-77 - NASA Mentor-Protégé Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... companies or nonprofit agencies employing people who are blind or severely disabled as defined in 41 CFR... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false NASA Mentor-ProtégÃ... and Clauses 1852.219-77 NASA Mentor-Protégé Program. As prescribed in 1819.7215, insert the...

  7. ChemProt: a disease chemical biology database

    PubMed Central

    Taboureau, Olivier; Nielsen, Sonny Kim; Audouze, Karine; Weinhold, Nils; Edsgrd, Daniel; Roque, Francisco S.; Kouskoumvekaki, Irene; Bora, Alina; Curpan, Ramona; Jensen, Thomas Skt; Brunak, Sren

    2011-01-01

    Systems pharmacology is an emergent area that studies drug action across multiple scales of complexity, from molecular and cellular to tissue and organism levels. There is a critical need to develop network-based approaches to integrate the growing body of chemical biology knowledge with network biology. Here, we report ChemProt, a disease chemical biology database, which is based on a compilation of multiple chemicalprotein annotation resources, as well as disease-associated proteinprotein interactions (PPIs). We assembled more than 700 000 unique chemicals with biological annotation for 30 578 proteins. We gathered over 2-million chemicalprotein interactions, which were integrated in a quality scored human PPI network of 428 429 interactions. The PPI network layer allows for studying disease and tissue specificity through each protein complex. ChemProt can assist in the in silico evaluation of environmental chemicals, natural products and approved drugs, as well as the selection of new compounds based on their activity profile against most known biological targets, including those related to adverse drug events. Results from the disease chemical biology database associate citalopram, an antidepressant, with osteogenesis imperfect and leukemia and bisphenol A, an endocrine disruptor, with certain types of cancer, respectively. The server can be accessed at http://www.cbs.dtu.dk/services/ChemProt/. PMID:20935044

  8. MultitaskProtDB: a database of multitasking proteins

    PubMed Central

    Hernández, Sergio; Ferragut, Gabriela; Amela, Isaac; Perez-Pons, JosepAntoni; Piñol, Jaume; Mozo-Villarias, Angel; Cedano, Juan; Querol, Enrique

    2014-01-01

    We have compiled MultitaskProtDB, available online at http://wallace.uab.es/multitask, to provide a repository where the many multitasking proteins found in the literature can be stored. Multitasking or moonlighting is the capability of some proteins to execute two or more biological functions. Usually, multitasking proteins are experimentally revealed by serendipity. This ability of proteins to perform multitasking functions helps us to understand one of the ways used by cells to perform many complex functions with a limited number of genes. Even so, the study of this phenomenon is complex because, among other things, there is no database of moonlighting proteins. The existence of such a tool facilitates the collection and dissemination of these important data. This work reports the database, MultitaskProtDB, which is designed as a friendly user web page containing >288 multitasking proteins with their NCBI and UniProt accession numbers, canonical and additional biological functions, monomeric/oligomeric states, PDB codes when available and bibliographic references. This database also serves to gain insight into some characteristics of multitasking proteins such as frequencies of the different pairs of functions, phylogenetic conservation and so forth. PMID:24253302

  9. enDNA-Prot: identification of DNA-binding proteins by applying ensemble learning.

    PubMed

    Xu, Ruifeng; Zhou, Jiyun; Liu, Bin; Yao, Lin; He, Yulan; Zou, Quan; Wang, Xiaolong

    2014-01-01

    DNA-binding proteins are crucial for various cellular processes, such as recognition of specific nucleotide, regulation of transcription, and regulation of gene expression. Developing an effective model for identifying DNA-binding proteins is an urgent research problem. Up to now, many methods have been proposed, but most of them focus on only one classifier and cannot make full use of the large number of negative samples to improve predicting performance. This study proposed a predictor called enDNA-Prot for DNA-binding protein identification by employing the ensemble learning technique. Experiential results showed that enDNA-Prot was comparable with DNA-Prot and outperformed DNAbinder and iDNA-Prot with performance improvement in the range of 3.97-9.52% in ACC and 0.08-0.19 in MCC. Furthermore, when the benchmark dataset was expanded with negative samples, the performance of enDNA-Prot outperformed the three existing methods by 2.83-16.63% in terms of ACC and 0.02-0.16 in terms of MCC. It indicated that enDNA-Prot is an effective method for DNA-binding protein identification and expanding training dataset with negative samples can improve its performance. For the convenience of the vast majority of experimental scientists, we developed a user-friendly web-server for enDNA-Prot which is freely accessible to the public. PMID:24977146

  10. RaftProt: mammalian lipid raft proteome database

    PubMed Central

    Shah, Anup; Chen, David; Boda, Akash R.; Foster, Leonard J.; Davis, Melissa J.; Hill, Michelle M.

    2015-01-01

    RaftProt (http://lipid-raft-database.di.uq.edu.au/) is a database of mammalian lipid raft-associated proteins as reported in high-throughput mass spectrometry studies. Lipid rafts are specialized membrane microdomains enriched in cholesterol and sphingolipids thought to act as dynamic signalling and sorting platforms. Given their fundamental roles in cellular regulation, there is a plethora of information on the size, composition and regulation of these membrane microdomains, including a large number of proteomics studies. To facilitate the mining and analysis of published lipid raft proteomics studies, we have developed a searchable database RaftProt. In addition to browsing the studies, performing basic queries by protein and gene names, searching experiments by cell, tissue and organisms; we have implemented several advanced features to facilitate data mining. To address the issue of potential bias due to biochemical preparation procedures used, we have captured the lipid raft preparation methods and implemented advanced search option for methodology and sample treatment conditions, such as cholesterol depletion. Furthermore, we have identified a list of high confidence proteins, and enabled searching only from this list of likely bona fide lipid raft proteins. Given the apparent biological importance of lipid raft and their associated proteins, this database would constitute a key resource for the scientific community. PMID:25392410

  11. The neXtProt knowledgebase on human proteins: current status

    PubMed Central

    Gaudet, Pascale; Michel, Pierre-Andr; 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

  12. 48 CFR 1019.202-70 - The Treasury Mentor Protégé Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false The Treasury Mentor Protégé Program. 1019.202-70 Section 1019.202-70 Federal Acquisition Regulations System DEPARTMENT OF THE TREASURY SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 1019.202-70 The Treasury Mentor Protégé Program. (a)-(b) (c) Non-affiliation....

  13. Genes and proteins of Escherichia coli K-12 (GenProtEC).

    PubMed

    Riley, M

    1997-01-01

    GenProtEC is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities amongE.coliproteins with PAM values, percent identity of amino acids, length of alignment and percent aligned. GenProtEC can also be accessed through the World Wide Web at URL http://mbl.edu/html/ecoli.html . PMID:9016503

  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)

    Kłosowski, M.; Liszka, M.; Kopeć, R.; Bilski, P.; Kędzierska, 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; Kłosowski et al. 2010, Radiat. Meas., 45, 719-721; Kopeć 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. 48 CFR 1019.202-70 - The Treasury Mentor Protégé Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false The Treasury Mentor Protégé Program. 1019.202-70 Section 1019.202-70 Federal Acquisition Regulations System DEPARTMENT OF... Contracting Officer shall include language in the solicitation indicating that this adjustment may occur....

  16. 48 CFR 1019.202-70 - The Treasury Mentor Protégé Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false The Treasury Mentor Protégé Program. 1019.202-70 Section 1019.202-70 Federal Acquisition Regulations System DEPARTMENT OF... Contracting Officer shall include language in the solicitation indicating that this adjustment may occur....

  17. 48 CFR 1819.7205 - Mentor-protégé agreements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...© agreements. 1819.7205 Section 1819.7205 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7205 Mentor... agreement as a condition for award of a contract by the mentor, including a subcontract under a...

  18. 48 CFR 1819.7205 - Mentor-protégé agreements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...© agreements. 1819.7205 Section 1819.7205 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7205 Mentor... agreement as a condition for award of a contract by the mentor, including a subcontract under a...

  19. 48 CFR 1819.7205 - Mentor-protégé agreements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...© agreements. 1819.7205 Section 1819.7205 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7205 Mentor... agreement as a condition for award of a contract by the mentor, including a subcontract under a...

  20. 48 CFR 1819.7205 - Mentor-protégé agreements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... 1819.7205 Section 1819.7205 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7205 Mentor... agreement as a condition for award of a contract by the mentor, including a subcontract under a...

  1. 48 CFR 1819.7205 - Mentor-protégé agreements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...© agreements. 1819.7205 Section 1819.7205 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Protégé Program 1819.7205 Mentor... agreement as a condition for award of a contract by the mentor, including a subcontract under a...

  2. ProGlycProt: a repository of experimentally characterized prokaryotic glycoproteins

    PubMed Central

    Bhat, Aadil H.; Mondal, Homchoru; Chauhan, Jagat S.; Raghava, Gajendra P. S.; Methi, Amrish; Rao, Alka

    2012-01-01

    ProGlycProt (http://www.proglycprot.org/) is an open access, manually curated, comprehensive repository of bacterial and archaeal glycoproteins with at least one experimentally validated glycosite (glycosylated residue). To facilitate maximum information at one point, the database is arranged under two sections: (i) ProCGPthe main data section consisting of 95 entries with experimentally characterized glycosites and (ii) ProUGPa supplementary data section containing 245 entries with experimentally identified glycosylation but uncharacterized glycosites. Every entry in the database is fully cross-referenced and enriched with available published information about source organism, coding gene, protein, glycosites, glycosylation type, attached glycan, associated oligosaccharyl/glycosyl transferases (OSTs/GTs), supporting references, and applicable additional information. Interestingly, ProGlycProt contains as many as 174 entries for which information is unavailable or the characterized glycosites are unannotated in Swiss-Prot release 2011_07. The website supports a dedicated structure gallery of homology models and crystal structures of characterized glycoproteins in addition to two new tools developed in view of emerging information about prokaryotic sequons (conserved sequences of amino acids around glycosites) that are never or rarely seen in eukaryotic glycoproteins. ProGlycProt provides an extensive compilation of experimentally identified glycosites (334) and glycoproteins (340) of prokaryotes that could serve as an information resource for research and technology applications in glycobiology. PMID:22039152

  3. Protéger les nourrissons contre la coqueluche

    PubMed Central

    Gilley, Meghan; Goldman, Ran D.

    2014-01-01

    Résumé Question Compte tenu du taux à la hausse de la coqueluche chez les enfants, plusieurs familles m’ont demandé quels moyens prendre pour protéger leurs tout-petits de cette infection. Quelles devraient être mes recommandations à ces familles? Réponse La coqueluche est une maladie évitable qui est endémique dans le monde entier. Chez les adultes, la coqueluche cause une maladie bénigne semblable à un rhume, suivie d’une toux persistante. Chez les nourrissons, elle peut causer de l’apnée, des convulsions, une encéphalopathie, une bronchopneumonie et la mort. Les décès dus à la coqueluche se produisent dans 86 % des cas chez des nourrissons de moins de 4 mois. La stratégie du cocooning, c’est-à-dire la vaccination des adultes en étroit contact avec des nourrissons, est recommandée par de nombreuses agences mondiales et nationales, mais elle ne prévient probablement que 20 % des cas de coqueluche chez les nourrissons. La vaccination durant la grossesse est plus efficace, mais elle n’est pas encore approuvée au Canada. Il n’a pas été démontré que la vaccination à la naissance soit uniformément efficace et elle n’est donc pas recommandée à l’heure actuelle.

  4. Expert curation in UniProtKB: a case study on dealing with conflicting and erroneous data

    PubMed Central

    Poux, Sylvain; Magrane, Michele; Arighi, Cecilia N.; Bridge, Alan; ODonovan, Claire; Laiho, Kati

    2014-01-01

    UniProtKB/Swiss-Prot provides expert curation with information extracted from literature and curator-evaluated computational analysis. As knowledgebases continue to play an increasingly important role in scientific research, a number of studies have evaluated their accuracy and revealed various errors. While some are curation errors, others are the result of incorrect information published in the scientific literature. By taking the example of sirtuin-5, a complex annotation case, we will describe the curation procedure of UniProtKB/Swiss-Prot and detail how we report conflicting information in the database. We will demonstrate the importance of collaboration between resources to ensure curation consistency and the value of contributions from the user community in helping maintain error-free resources. Database URL: www.uniprot.org PMID:24622611

  5. 48 CFR 619.202-70 - The Department of State Mentor-Protégé Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false The Department of State Mentor-Protégé Program. 619.202-70 Section 619.202-70 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 619.202-70 The Department of State Mentor-Protégé Program. (a) Purpose....

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

    PubMed Central

    Ehrler, Frdric; Geissbhler, 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

  7. Dasty and UniProt DAS: a perfect pair for protein feature visualization.

    PubMed

    Jones, Philip; Vinod, Nisha; Down, Thomas; Hackmann, Andre; Kahari, Andreas; Kretschmann, Ernst; Quinn, Antony; Wieser, Daniela; Hermjakob, Henning; Apweiler, Rolf

    2005-07-15

    In this study, we present two freely available and complementary Distributed Annotation System (DAS) resources: a DAS reference server that provides up-to-date sequence and annotation from UniProt, with additional feature links and database cross-references from InterPro and a DAS client implemented using Java and Macromedia Flash that is optimized for the display of protein features. PMID:15905273

  8. Protótipo do primeiro interferômetro brasileiro - BDA

    NASA Astrophysics Data System (ADS)

    Cecatto, J. R.; Fernandes, F. C. R.; Neri, J. A. C. F.; Bethi, N.; Felipini, N. S.; Madsen, F. R. H.; Andrade, M. C.; Soares, A. C.; Alonso, E. M. B., Sawant, H. S.

    2004-04-01

    A interferometria é uma poderosa ferramenta usada para investigar estruturas espaciais de fontes astrofísicas fornecendo uma riqueza de detalhes inatingível pelas técnicas convencionais de imageamento. Em particular, a interferometria com ondas de rádio abre o horizonte de conhecimento do Universo nesta ampla banda do espectro eletromagnético, que vai de cerca de 20 kHz até centenas de GHz já próximo ao infravermelho, e que está acessível a partir de instrumentos instalados em solo. Neste trabalho, apresentamos o interferômetro designado por Arranjo Decimétrico Brasileiro (BDA). Trata-se do primeiro interferômetro a ser desenvolvido no Brasil e América Latina que já está em operação na fase de protótipo. Apresentamos o desenvolvimento realizado até o momento, o sítio de instalação do instrumento, o protótipo e os principais resultados dos testes de sua operação, as perspectivas futuras e a ciência a ser desenvolvida com o instrumento nas fases II e III. Neste trabalho é dada ênfase ao desenvolvimento, testes de operação e principais resultados do protótipo. É discutida brevemente a ciência que pode ser feita com o instrumento. Tanto os detalhes técnicos quanto os principais parâmetros estimados para o instrumento nas próximas fases de desenvolvimento e o desempenho do protótipo serão publicados em breve.

  9. Protégés' Personality Traits, Expectations, the Quality of the Mentoring Relationship and Adjustment: A Big Five Analysis

    ERIC Educational Resources Information Center

    Goldner, Limor

    2016-01-01

    Background: Community-based mentoring interventions can benefit high-risk youth. However, meta-analyses suggest that these benefits may be conditioned by protégés' personality. Objectives: Associations between protégés' personality traits and mentoring expectations, the quality of the mentoring relationship, the perceived mentoring contribution,…

  10. What Do Hispanic Students Want in a Mentor? A Model of Protégé Cultural Orientation, Mentorship Expectations, and Performance

    ERIC Educational Resources Information Center

    Cox, Cody B.; Yang, Yan; Dicke-Bohmann, Amy K.

    2014-01-01

    The purpose of this study was to propose and test a model of the effects of cultural factors on Hispanic protégés' expectations for and experiences with their mentors. Specifically, the proposed model posits that cultural orientation predicts the mentorship functions protégés desire, and the positive impact of these mentorship functions…

  11. FireProt: Energy- and Evolution-Based Computational Design of Thermostable Multiple-Point Mutants

    PubMed Central

    Sebestova, Eva; Bendl, Jaroslav; Khare, Sagar; Chaloupkova, Radka; Prokop, Zbynek; Brezovsky, Jan; Baker, David; Damborsky, Jiri

    2015-01-01

    There is great interest in increasing proteins stability to enhance their utility as biocatalysts, therapeutics, diagnostics and nanomaterials. Directed evolution is a powerful, but experimentally strenuous approach. Computational methods offer attractive alternatives. However, due to the limited reliability of predictions and potentially antagonistic effects of substitutions, only single-point mutations are usually predicted in silico, experimentally verified and then recombined in multiple-point mutants. Thus, substantial screening is still required. Here we present FireProt, a robust computational strategy for predicting highly stable multiple-point mutants that combines energy- and evolution-based approaches with smart filtering to identify additive stabilizing mutations. FireProts reliability and applicability was demonstrated by validating its predictions against 656 mutations from the ProTherm database. We demonstrate that thermostability of the model enzymes haloalkane dehalogenase DhaA and ?-hexachlorocyclohexane dehydrochlorinase LinA can be substantially increased (?Tm = 24C and 21C) by constructing and characterizing only a handful of multiple-point mutants. FireProt can be applied to any protein for which a tertiary structure and homologous sequences are available, and will facilitate the rapid development of robust proteins for biomedical and biotechnological applications. PMID:26529612

  12. ChemProt-3.0: a global chemical biology diseases mapping.

    PubMed

    Kringelum, Jens; Kjaerulff, Sonny Kim; Brunak, Søren; Lund, Ole; Oprea, Tudor I; Taboureau, Olivier

    2016-01-01

    ChemProt is a publicly available compilation of chemical-protein-disease annotation resources that enables the study of systems pharmacology for a small molecule across multiple layers of complexity from molecular to clinical levels. In this third version, ChemProt has been updated to more than 1.7 million compounds with 7.8 million bioactivity measurements for 19 504 proteins. Here, we report the implementation of global pharmacological heatmap, supporting a user-friendly navigation of chemogenomics space. This facilitates the visualization and selection of chemicals that share similar structural properties. In addition, the user has the possibility to search by compound, target, pathway, disease and clinical effect. Genetic variations associated to target proteins were integrated, making it possible to plan pharmacogenetic studies and to suggest human response variability to drug. Finally, Quantitative Structure-Activity Relationship models for 850 proteins having sufficient data were implemented, enabling secondary pharmacological profiling predictions from molecular structure.Database URL: http://potentia.cbs.dtu.dk/ChemProt/. PMID:26876982

  13. PROGRESSION OF REGULATORY GENE EXPRESSION STATES IN FETAL AND ADULT PRO-T CELL DEVELOPMENT

    PubMed Central

    David-Fung, Elizabeth-Sharon; Yui, Mary A.; Morales, Marissa; Wang, Hua; Taghon, Tom; Diamond, Rochelle A.; Rothenberg, Ellen V.

    2014-01-01

    Precursors entering the T-cell developmental pathway traverse a progression of states characterized by distinctive patterns of gene expression. Of particular interest are regulatory genes, which ultimately control the dwell time of cells in each state and establish the mechanisms that propel them forward to subsequent states. Under particular genetic and developmental circumstances, the transitions between these states occur with different timing, and environmental feedbacks may shift the steady-state accumulations of cells in each state. The fetal transit through pro-T cell stages is faster than in the adult, and subject to somewhat different genetic requirements. To explore causes of such variation, this review presents previously unpublished data on differentiation gene activation in pro-T cells of pre-TCR deficient mutant mice, and a quantitative comparison of the profiles of transcription factor gene expression in pro-T cell subsets of fetal and adult wildtype mice. Against a background of consistent gene expression, several regulatory genes show marked differences between fetal and adult expression profiles, including those encoding two bHLH antagonist Id factors, the Ets family factor SpiB, and the Notch target gene Deltex1. The results also reveal global differences in regulatory alterations triggered by the first TCR-dependent selection events in fetal and adult thymopoiesis. PMID:16448545

  14. FireProt: Energy- and Evolution-Based Computational Design of Thermostable Multiple-Point Mutants.

    PubMed

    Bednar, David; Beerens, Koen; Sebestova, Eva; Bendl, Jaroslav; Khare, Sagar; Chaloupkova, Radka; Prokop, Zbynek; Brezovsky, Jan; Baker, David; Damborsky, Jiri

    2015-11-01

    There is great interest in increasing proteins' stability to enhance their utility as biocatalysts, therapeutics, diagnostics and nanomaterials. Directed evolution is a powerful, but experimentally strenuous approach. Computational methods offer attractive alternatives. However, due to the limited reliability of predictions and potentially antagonistic effects of substitutions, only single-point mutations are usually predicted in silico, experimentally verified and then recombined in multiple-point mutants. Thus, substantial screening is still required. Here we present FireProt, a robust computational strategy for predicting highly stable multiple-point mutants that combines energy- and evolution-based approaches with smart filtering to identify additive stabilizing mutations. FireProt's reliability and applicability was demonstrated by validating its predictions against 656 mutations from the ProTherm database. We demonstrate that thermostability of the model enzymes haloalkane dehalogenase DhaA and ?-hexachlorocyclohexane dehydrochlorinase LinA can be substantially increased (?Tm = 24C and 21C) by constructing and characterizing only a handful of multiple-point mutants. FireProt can be applied to any protein for which a tertiary structure and homologous sequences are available, and will facilitate the rapid development of robust proteins for biomedical and biotechnological applications. PMID:26529612

  15. ChemProt-3.0: a global chemical biology diseases mapping

    PubMed Central

    Kringelum, Jens; Kjaerulff, Sonny Kim; Brunak, Søren; Lund, Ole; Oprea, Tudor I.; Taboureau, Olivier

    2016-01-01

    ChemProt is a publicly available compilation of chemical-protein-disease annotation resources that enables the study of systems pharmacology for a small molecule across multiple layers of complexity from molecular to clinical levels. In this third version, ChemProt has been updated to more than 1.7 million compounds with 7.8 million bioactivity measurements for 19 504 proteins. Here, we report the implementation of global pharmacological heatmap, supporting a user-friendly navigation of chemogenomics space. This facilitates the visualization and selection of chemicals that share similar structural properties. In addition, the user has the possibility to search by compound, target, pathway, disease and clinical effect. Genetic variations associated to target proteins were integrated, making it possible to plan pharmacogenetic studies and to suggest human response variability to drug. Finally, Quantitative Structure–Activity Relationship models for 850 proteins having sufficient data were implemented, enabling secondary pharmacological profiling predictions from molecular structure. Database URL: http://potentia.cbs.dtu.dk/ChemProt/ PMID:26876982

  16. A legume specific protein database (LegProt) improves the number of identified peptides, confidence scores and overall protein identification success rates for legume proteomics.

    PubMed

    Lei, Zhentian; Dai, Xinbin; Watson, Bonnie S; Zhao, Patrick X; Sumner, Lloyd W

    2011-07-01

    A legume specific protein database (LegProt) has been created containing sequences from seven legume species, i.e., Glycine max, Lotus japonicus, Medicago sativa, Medicago truncatula, Lupinusalbus, Phaseolus vulgaris, and Pisum sativum. The database consists of amino acid sequences translated from predicted gene models and 6-frame translations of tentative consensus (TC) sequences assembled from expressed sequence tags (ESTs) and singleton ESTs. This database was queried using mass spectral data for protein identification and identification success rates were compared to the NCBI nr database. Specifically, Mascot MS/MS ion searches of tandem nano-LC Q-TOFMS/MS mass spectral data showed that relative to the NCBI nr protein database, the LegProt database yielded a 54% increase in the average protein score (i.e., from NCBI nr 480 to LegProt 739) and a 50% increase in the average number of matched peptides (i.e., from NCBI nr 8 to LegProt 12). The overall identification success rate also increased from 88% (NCBI nr) to 93% (LegProt). Mascot peptide mass fingerprinting (PMF) searches of the LegProt database using MALDI-TOFMS data yielded a significant increase in the identification success rate from 19% (NCBI nr) to 34% (LegProt) while the average scores and average number of matched peptides showed insignificant changes. The results demonstrate that the LegProt database significantly increases legume protein identification success rates and the confidence levels compared to the commonly used NCBI nr. These improvements are primarily due to the presence of a large number of legume specific TC sequences in the LegProt database that were not found in NCBI nr. The LegProt database is freely available for download (http://bioinfo.noble.org/manuscript-support/legumedb) and will serve as a valuable resource for legume proteomics. PMID:21353266

  17. The annotation of both human and mouse kinomes in UniProtKB/Swiss-Prot: one small step in manual annotation, one giant leap for full comprehension of genomes.

    PubMed

    Braconi Quintaje, Silvia; Orchard, Sandra

    2008-08-01

    Biomolecule phosphorylation by protein kinases is a fundamental cell signaling process in all living cells. Following the comprehensive cataloguing of the protein kinase complement of the human genome (Manning, G., Whyte, D. B., Martinez, R., Hunter, T., and Sudarsanam, S. (2002) The protein kinase complement of the human genome. Science 298, 1912-1934), this review will detail the state-of-the-art human and mouse kinase proteomes as provided in the UniProtKB/Swiss-Prot protein knowledgebase. The sequences of the 480 classical and up to 24 atypical protein kinases now believed to exist in the human genome and 484 classical and up to 24 atypical kinases within the mouse genome have been reviewed and, where necessary, revised. Extensive annotation has been added to each entry. In an era when a wealth of new databases is emerging on the Internet, UniProtKB/Swiss-Prot makes available to the scientific community the most up-to-date and in-depth annotation of these proteins with access to additional external resources linked from within each entry. Incorrect sequence annotations resulting from errors and artifacts have been eliminated. Each entry will be constantly reviewed and updated as new information becomes available with the orthologous enzymes in related species being annotated in a parallel effort and complete kinomes being completed as sequences become available. This ensures that the mammalian kinomes available from UniProtKB/Swiss-Prot are of a consistently high standard with each separate entry acting both as a valuable information resource and a central portal to a wealth of further detail via extensive cross-referencing. PMID:18436524

  18. SynProt: A Database for Proteins of Detergent-Resistant Synaptic Protein Preparations.

    PubMed

    Pielot, Rainer; Smalla, Karl-Heinz; Mller, Anke; Landgraf, Peter; Lehmann, Anne-Christin; Eisenschmidt, Elke; Haus, Utz-Uwe; Weismantel, Robert; Gundelfinger, Eckart D; Dieterich, Daniela C

    2012-01-01

    Chemical synapses are highly specialized cell-cell contacts for communication between neurons in the CNS characterized by complex and dynamic protein networks at both synaptic membranes. The cytomatrix at the active zone (CAZ) organizes the apparatus for the regulated release of transmitters from the presynapse. At the postsynaptic side, the postsynaptic density constitutes the machinery for detection, integration, and transduction of the transmitter signal. Both pre- and postsynaptic protein networks represent the molecular substrates for synaptic plasticity. Their function can be altered both by regulating their composition and by post-translational modification of their components. For a comprehensive understanding of synaptic networks the entire ensemble of synaptic proteins has to be considered. To support this, we established a comprehensive database for synaptic junction proteins (SynProt database) primarily based on proteomics data obtained from biochemical preparations of detergent-resistant synaptic junctions. The database currently contains 2,788 non-redundant entries of rat, mouse, and some human proteins, which mainly have been manually extracted from 12 proteomic studies and annotated for synaptic subcellular localization. Each dataset is completed with manually added information including protein classifiers as well as automatically retrieved and updated information from public databases (UniProt and PubMed). We intend that the database will be used to support modeling of synaptic protein networks and rational experimental design. PMID:22737123

  19. 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

  20. SubCellProt: predicting protein subcellular localization using machine learning approaches.

    PubMed

    Garg, Prabha; Sharma, Virag; Chaudhari, Pradeep; Roy, Nilanjan

    2009-01-01

    High-throughput genome sequencing projects continue to churn out enormous amounts of raw sequence data. However, most of this raw sequence data is unannotated and, hence, not very useful. Among the various approaches to decipher the function of a protein, one is to determine its localization. Experimental approaches for proteome annotation including determination of a protein's subcellular localizations are very costly and labor intensive. Besides the available experimental methods, in silico methods present alternative approaches to accomplish this task. Here, we present two machine learning approaches for prediction of the subcellular localization of a protein from the primary sequence information. Two machine learning algorithms, k Nearest Neighbor (k-NN) and Probabilistic Neural Network (PNN) were used to classify an unknown protein into one of the 11 subcellular localizations. The final prediction is made on the basis of a consensus of the predictions made by two algorithms and a probability is assigned to it. The results indicate that the primary sequence derived features like amino acid composition, sequence order and physicochemical properties can be used to assign subcellular localization with a fair degree of accuracy. Moreover, with the enhanced accuracy of our approach and the definition of a prediction domain, this method can be used for proteome annotation in a high throughput manner. SubCellProt is available at www.databases.niper.ac.in/SubCellProt. PMID:19537160

  1. Teachable Agents and the Protégé Effect: Increasing the Effort Towards Learning

    NASA Astrophysics Data System (ADS)

    Chase, Catherine C.; Chin, Doris B.; Oppezzo, Marily A.; Schwartz, Daniel L.

    2009-08-01

    Betty's Brain is a computer-based learning environment that capitalizes on the social aspects of learning. In Betty's Brain, students instruct a character called a Teachable Agent (TA) which can reason based on how it is taught. Two studies demonstrate the protégé effect: students make greater effort to learn for their TAs than they do for themselves. The first study involved 8th-grade students learning biology. Although all students worked with the same Betty's Brain software, students in the TA condition believed they were teaching their TAs, while in another condition, they believed they were learning for themselves. TA students spent more time on learning activities (e.g., reading) and also learned more. These beneficial effects were most pronounced for lower achieving children. The second study used a verbal protocol with 5th-grade students to determine the possible causes of the protégé effect. As before, students learned either for their TAs or for themselves. Like study 1, students in the TA condition spent more time on learning activities. These children treated their TAs socially by attributing mental states and responsibility to them. They were also more likely to acknowledge errors by displaying negative affect and making attributions for the causes of failures. Perhaps having a TA invokes a sense of responsibility that motivates learning, provides an environment in which knowledge can be improved through revision, and protects students' egos from the psychological ramifications of failure.

  2. ProtEx: a novel technology to display exogenous proteins on the cell surface for immunomodulation.

    PubMed

    Singh, Narendra P; Yolcu, Esma S; Askenasy, Nadir; Shirwan, Haval

    2005-11-01

    Gene therapy as an immunomodulatory approach has the potential to treat various inherited and acquired immune-based human diseases. However, its clinical application has several challenges, varying from the efficiency of gene transfer, control of gene expression, cell and tissue targeting, and safety concerns associated with the introduction of exogenous DNA into cells/tissues. Gene therapy is also a time- and labor-intensive procedure. As an alternative, we recently developed a novel technology, ProtEx, that allows for rapid, efficient, and durable display of exogenous proteins on the surface of cells, tissues, and organs without detectable toxicity. This technology exploits the strong binding affinity (Kd = 10(-15) M) of streptavidin with biotin and involves generation of chimeric molecules composed of the extracellular portions of immunological proteins of interest and a modified form of streptavidin, biotinylation of biological surfaces, and decoration of the modified surface with chimeric proteins. Biotin persists on the cell surface for weeks both in vitro and in vivo, thereby providing a platform to display exogenous proteins with extended cell surface kinetics. Two chimeric proteins, rat FasL (SA-FasL) and human CD80 (CD80-SA), were generated and tested for cell surface display and immunomodulatory functions. SA-FasL and CD80-SA molecules persisted on the surface of various cell types for extended periods, varying from days to weeks in vitro and in vivo. The cell surface kinetics, however, were protein and cell type dependent. SA-FasL showed potent apoptotic activity against Fas+ cells as a soluble protein or displayed on the cell surface and effectively blocked alloreactive responses. The display of CD80-SA on the surface of tumor cells, however, converted them into antigen-presenting cells for effective stimulation of autologous and allogeneic T-cell responses. ProtEx technology, therefore, represents a practical and effective alternative to DNA-based gene therapy for immunomodulation. PMID:16387700

  3. Development, implementation and evaluation of a peer review of teaching (PRoT) initiative in nursing education.

    PubMed

    Mager, Diana R; Kazer, Meredith W; Conelius, Jaclyn; Shea, Joyce; Lippman, Doris T; Torosyan, Roben; Nantz, Kathryn

    2014-01-01

    For many years, an area of research in higher education has been emerging around the development and implementation of fair and effective peer evaluation programs. Recently, a new body of knowledge has developed regarding the development and implementation of fair and effective peer evaluation programs resulting in formative and summative evaluations. The purpose of this article is to describe the development, implementation, and evaluation of a peer review of teaching (PRoT) program for nursing faculty, initiated at one small comprehensive university in the northeastern United States. Pairs of nursing faculty evaluated each other's teaching, syllabi, and course materials after collaborating in a pre-evaluation conference to discuss goals of the classroom visit. Qualitative data gathered in post project focus groups revealed that faculty found their modified PRoT process to be a mutually beneficial experience that was more useful, flexible and collegial, and less stressful than their previous evaluation process. PMID:24893326

  4. Involvement of the interleukin 4 pathway in the generation of functional gamma delta T cells from human pro-T cells.

    PubMed Central

    Brcena, A; Snchez, M J; de la Pompa, J L; Toribio, M L; Kroemer, G; Martnez-A, C

    1991-01-01

    We have used the technique of in situ hybridization to investigate the transcription of genes encoding the CD3 complex and the lymphokine interleukin 4 (IL-4) by human pro-T cells--i.e., cells that phenotypically resemble those T-cell precursors that colonize the thymus during early intrathymic development. CD1-2-3-4-7+8-45+ pro-T cells isolated from postnatal thymi via immunoselection with a panel of specific monoclonal antibodies are already committed to the T-cell lineage because most of them transcribe the genes encoding the delta and epsilon chains of the CD3 complex. About half of such pro-T cells synthesize IL-4 mRNA in the absence of any exogenous stimulation. Upon culture with IL-4, pro-T cells extensively proliferate and differentiate into functionally competent, mature gamma delta T cells expressing a T-cell receptor repertoire similar to that of gamma delta T cells that can be found in postnatal thymus. The IL-4 response of pro-T cells is not mediated by induction of the interleukin 2 (IL-2)-IL-2 receptor pathway and, unlike IL-2-driven T-cell differentiation, does not require the presence of stromal cells. Taken altogether, these findings suggest that an autocrine IL-4-mediated pathway might be implicated in early thymocyte differentiation--namely, in the generation of T cells bearing the gamma delta T-cell receptor. Images PMID:1881911

  5. ProtNet: a tool for stochastic simulations of protein interaction networks dynamics

    PubMed Central

    Bernaschi, Massimo; Castiglione, Filippo; Ferranti, Alessandra; Gavrila, Caius; Tinti, Michele; Cesareni, Gianni

    2007-01-01

    Background Protein interactions support cell organization and mediate its response to any specific stimulus. Recent technological advances have produced large data-sets that aim at describing the cell interactome. These data are usually presented as graphs where proteins (nodes) are linked by edges to their experimentally determined partners. This representation reveals that protein-protein interaction (PPI) networks, like other kinds of complex networks, are not randomly organized and display properties that are typical of "hierarchical" networks, combining modularity and local clustering to scale free topology. However informative, this representation is static and provides no clue about the dynamic nature of protein interactions inside the cell. Results To fill this methodological gap, we designed and implemented a computer model that captures the discrete and stochastic nature of protein interactions. In ProtNet, our simplified model, the intracellular space is mapped onto either a two-dimensional or a three-dimensional lattice with each lattice site having a linear size (5 nm) comparable to the diameter of an average globular protein. The protein filled lattice has an occupancy (e.g. 20%) compatible with the estimated crowding of proteins in the cell cytoplasm. Proteins or protein complexes are free to translate and rotate on the lattice that represents a sort of nave unstructured cell (devoid of compartments). At each time step, molecular entities (proteins or complexes) that happen to be in neighboring cells may interact and form larger complexes or dissociate depending on the interaction rules defined in an experimental protein interaction network. This whole procedure can be seen as a sort of "discrete molecular dynamics" applied to interacting proteins in a cell. We have tested our model by performing different simulations using as interaction rules those derived from an experimental interactome of Saccharomyces cerevisiae (1378 nodes, 2491 edges) and we have compared the dynamics of complex formation in a two and a three dimensional lattice model. Conclusion ProtNet is a cellular automaton model, where each protein molecule or complex is explicitly represented and where simple interaction rules are applied to populations of discrete particles. This tool can be used to simulate the dynamics of protein interactions in the cell. PMID:17430571

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

    PubMed

    Kuban?k, J; Ambroov, I; Ploc, O; Pachnerov Brabcov, K; t?pn, 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

  7. 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

  8. An approach to describing and analysing bulk biological annotation quality: a case study using UniProtKB

    PubMed Central

    Bell, Michael J.; Gillespie, Colin S.; Swan, Daniel; Lord, Phillip

    2012-01-01

    Motivation: Annotations are a key feature of many biological databases, used to convey our knowledge of a sequence to the reader. Ideally, annotations are curated manually, however manual curation is costly, time consuming and requires expert knowledge and training. Given these issues and the exponential increase of data, many databases implement automated annotation pipelines in an attempt to avoid un-annotated entries. Both manual and automated annotations vary in quality between databases and annotators, making assessment of annotation reliability problematic for users. The community lacks a generic measure for determining annotation quality and correctness, which we look at addressing within this article. Specifically we investigate word reuse within bulk textual annotations and relate this to Zipf's Principle of Least Effort. We use the UniProt Knowledgebase (UniProtKB) as a case study to demonstrate this approach since it allows us to compare annotation change, both over time and between automated and manually curated annotations. Results: By applying power-law distributions to word reuse in annotation, we show clear trends in UniProtKB over time, which are consistent with existing studies of quality on free text English. Further, we show a clear distinction between manual and automated analysis and investigate cohorts of protein records as they mature. These results suggest that this approach holds distinct promise as a mechanism for judging annotation quality. Availability: Source code is available at the authors website: http://homepages.cs.ncl.ac.uk/m.j.bell1/annotation. Contact: phillip.lord@newcastle.ac.uk PMID:22962482

  9. Structural Bioinformatics Inspection of neXtProt PE5 Proteins in the Human Proteome.

    PubMed

    Dong, Qiwen; Menon, Rajasree; Omenn, Gilbert S; Zhang, Yang

    2015-09-01

    One goal of the Human Proteome Project is to identify at least one protein product for each of the ?20,000 human protein-coding genes. As of October 2014, however, there are 3564 genes (18%) that have no or insufficient evidence of protein existence (PE), as curated by neXtProt; these comprise 2647 PE2-4 missing proteins and 616 PE5 dubious protein entries. We conducted a systematic examination of the 616 PE5 protein entries using cutting-edge protein structure and function modeling methods. Compared to a random sample of high-confidence PE1 proteins, the putative PE5 proteins were found to be over-represented in the membrane and cell surface proteins and peptides fold families. Detailed functional analyses show that most PE5 proteins, if expressed, would belong to transporters and receptors localized in the plasma membrane compartment. The results suggest that experimental difficulty in identifying membrane-bound proteins and peptides could have precluded their detection in mass spectrometry and that special enrichment techniques with improved sensitivity for membrane proteins could be important for the characterization of the PE5 "dark matter" of the human proteome. Finally, we identify 66 high scoring PE5 protein entries and find that six of them were reported in recent mass spectrometry databases; an illustrative annotation of these six is provided. This work illustrates a new approach to examine the potential folding and function of the dubious proteins comprising PE5, which we will next apply to the far larger group of missing proteins comprising PE2-4. PMID:26193931

  10. Radiation enteritis

    MedlinePLUS

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  11. Radiation Basics

    MedlinePLUS

    ... Radiation Protection » Radiation Basics Radiation Basics Radiation is energy. It can come from unstable atoms that undergo ... travels from its source in the form of energy waves or energized particles. There are two kinds ...

  12. Radiative cooler. [spacecraft radiators

    NASA Technical Reports Server (NTRS)

    Petrick, S. W.; Garcia, R. D. (Inventor)

    1984-01-01

    A method and radiative cooling device for use in passively cooling spaces is described. It is applicable to any level of thermal radiation in vacuum and to high-intensity thermal radiation in non-vacuum environments. The device includes an enclosure nested in a multiplicity of thin, low-emittance, highly-reflective shields. The shields are suspended in a casing in mutual angular relation and having V-shaped spaces defined therebetween for redirecting, by reflection, toward the large openings of the V-shaped spaces, thermal radiation entering the sides of the shields, and emitted to the spaces, whereby successively reduced quantities of thermal radiation are reflected by the surfaces along substantially parallel paths extended through the V-shaped spaces to a common heat sink such as the cold thermal background of space.

  13. Preliminary modeling of BNCT beam tube on IRT in Sofia.

    PubMed

    Belousov, S; Ilieva, K

    2009-07-01

    The technical design of the research reactor IRT in Sofia is in progress. It includes an arrangement for a BNCT facility for tumor treatment. Modeling of geometry and material composition of filter/collimator for the BNCT beam tube on IRT has been carried out following the beam tube configuration of the Massachusetts Institute of Technology Reactor [Harling et al., 2002. The fission converter-based epithermal neutron irradiation facility at the Massachusetts Institute of Technology Reactor. Nucl. Sci. Eng. 140, 223-240.] and taking into account an ability to include the tube into the IRT reactor geometry. The results of neutron and gamma transport calculations performed for the model have shown that the facility will be able to supply an epithermal neutron flux of about 5 x 10(9) n cm(-2)s(-1), with low contamination from fast neutrons and gamma rays that would be among the best facilities currently available. An optimiziation study has been performed for the beam collimator, following similar studies for the TAPIRO research reactor in Italy. [Nava et al., 2005. Monte Carlo optimization of a BNCT facility for treating brain gliomas at the TAPIRO reactor. Radiat. Prot. Dosim. 116 (1-4), 475-481.]. PMID:19410473

  14. iDNA-Prot|dis: identifying DNA-binding proteins by incorporating amino acid distance-pairs and reduced alphabet profile into the general pseudo amino acid composition.

    PubMed

    Liu, Bin; Xu, Jinghao; Lan, Xun; Xu, Ruifeng; Zhou, Jiyun; Wang, Xiaolong; Chou, Kuo-Chen

    2014-01-01

    Playing crucial roles in various cellular processes, such as recognition of specific nucleotide sequences, regulation of transcription, and regulation of gene expression, DNA-binding proteins are essential ingredients for both eukaryotic and prokaryotic proteomes. With the avalanche of protein sequences generated in the postgenomic age, it is a critical challenge to develop automated methods for accurate and rapidly identifying DNA-binding proteins based on their sequence information alone. Here, a novel predictor, called "iDNA-Prot|dis", was established by incorporating the amino acid distance-pair coupling information and the amino acid reduced alphabet profile into the general pseudo amino acid composition (PseAAC) vector. The former can capture the characteristics of DNA-binding proteins so as to enhance its prediction quality, while the latter can reduce the dimension of PseAAC vector so as to speed up its prediction process. It was observed by the rigorous jackknife and independent dataset tests that the new predictor outperformed the existing predictors for the same purpose. As a user-friendly web-server, iDNA-Prot|dis is accessible to the public at http://bioinformatics.hitsz.edu.cn/iDNA-Prot_dis/. Moreover, for the convenience of the vast majority of experimental scientists, a step-by-step protocol guide is provided on how to use the web-server to get their desired results without the need to follow the complicated mathematic equations that are presented in this paper just for the integrity of its developing process. It is anticipated that the iDNA-Prot|dis predictor may become a useful high throughput tool for large-scale analysis of DNA-binding proteins, or at the very least, play a complementary role to the existing predictors in this regard. PMID:25184541

  15. iDNA-Prot|dis: Identifying DNA-Binding Proteins by Incorporating Amino Acid Distance-Pairs and Reduced Alphabet Profile into the General Pseudo Amino Acid Composition

    PubMed Central

    Liu, Bin; Xu, Jinghao; Lan, Xun; Xu, Ruifeng; Zhou, Jiyun; Wang, Xiaolong; Chou, Kuo-Chen

    2014-01-01

    Playing crucial roles in various cellular processes, such as recognition of specific nucleotide sequences, regulation of transcription, and regulation of gene expression, DNA-binding proteins are essential ingredients for both eukaryotic and prokaryotic proteomes. With the avalanche of protein sequences generated in the postgenomic age, it is a critical challenge to develop automated methods for accurate and rapidly identifying DNA-binding proteins based on their sequence information alone. Here, a novel predictor, called “iDNA-Prot|dis”, was established by incorporating the amino acid distance-pair coupling information and the amino acid reduced alphabet profile into the general pseudo amino acid composition (PseAAC) vector. The former can capture the characteristics of DNA-binding proteins so as to enhance its prediction quality, while the latter can reduce the dimension of PseAAC vector so as to speed up its prediction process. It was observed by the rigorous jackknife and independent dataset tests that the new predictor outperformed the existing predictors for the same purpose. As a user-friendly web-server, iDNA-Prot|dis is accessible to the public at http://bioinformatics.hitsz.edu.cn/iDNA-Prot_dis/. Moreover, for the convenience of the vast majority of experimental scientists, a step-by-step protocol guide is provided on how to use the web-server to get their desired results without the need to follow the complicated mathematic equations that are presented in this paper just for the integrity of its developing process. It is anticipated that the iDNA-Prot|dis predictor may become a useful high throughput tool for large-scale analysis of DNA-binding proteins, or at the very least, play a complementary role to the existing predictors in this regard. PMID:25184541

  16. Radiation Emergencies

    MedlinePLUS

    ... day from sources such as sunlight. A radiation emergency would involve larger amounts of radiation and could ... are no guarantees of safety during a radiation emergency, you can take actions to protect yourself. You ...

  17. Radiation therapy

    MedlinePLUS

    Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. ... faster than normal cells in the body. Because radiation is most harmful to quickly growing cells, radiation ...

  18. Radiation Therapy

    MedlinePLUS

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  19. Atmospheric radiation

    SciTech Connect

    Harshvardhan, M.R. )

    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.

  20. MISS-Prot: web server for self/non-self discrimination of protein residue networks in parasites; theory and experiments in Fasciola peptides and Anisakis allergens.

    PubMed

    González-Díaz, Humberto; Muíño, Laura; Anadón, Ana M; Romaris, Fernanda; Prado-Prado, Francisco J; Munteanu, Cristian R; Dorado, Julián; Sierra, Alejandro Pazos; Mezo, Mercedes; González-Warleta, Marta; Gárate, Teresa; Ubeira, Florencio M

    2011-06-01

    Infections caused by human parasites (HPs) affect the poorest 500 million people worldwide but chemotherapy has become expensive, toxic, and/or less effective due to drug resistance. On the other hand, many 3D structures in Protein Data Bank (PDB) remain without function annotation. We need theoretical models to quickly predict biologically relevant Parasite Self Proteins (PSP), which are expressed differentially in a given parasite and are dissimilar to proteins expressed in other parasites and have a high probability to become new vaccines (unique sequence) or drug targets (unique 3D structure). We present herein a model for PSPs in eight different HPs (Ascaris, Entamoeba, Fasciola, Giardia, Leishmania, Plasmodium, Trypanosoma, and Toxoplasma) with 90% accuracy for 15 341 training and validation cases. The model combines protein residue networks, Markov Chain Models (MCM) and Artificial Neural Networks (ANN). The input parameters are the spectral moments of the Markov transition matrix for electrostatic interactions associated with the protein residue complex network calculated with the MARCH-INSIDE software. We implemented this model in a new web-server called MISS-Prot (MARCH-INSIDE Scores for Self-Proteins). MISS-Prot was programmed using PHP/HTML/Python and MARCH-INSIDE routines and is freely available at: . This server is easy to use by non-experts in Bioinformatics who can carry out automatic online upload and prediction with 3D structures deposited at PDB (mode 1). We can also study outcomes of Peptide Mass Fingerprinting (PMFs) and MS/MS for query proteins with unknown 3D structures (mode 2). We illustrated the use of MISS-Prot in experimental and/or theoretical studies of peptides from Fasciola hepatica cathepsin proteases or present on 10 Anisakis simplex allergens (Ani s 1 to Ani s 10). In doing so, we combined electrophoresis (1DE), MALDI-TOF Mass Spectroscopy, and MASCOT to seek sequences, Molecular Mechanics + Molecular Dynamics (MM/MD) to generate 3D structures and MISS-Prot to predict PSP scores. MISS-Prot also allows the prediction of PSP proteins in 16 additional species including parasite hosts, fungi pathogens, disease transmission vectors, and biotechnologically relevant organisms. PMID:21468430

  1. Space Radiation

    NASA Technical Reports Server (NTRS)

    Wu, Honglu

    2006-01-01

    Astronauts receive the highest occupational radiation exposure. Effective protections are needed to ensure the safety of astronauts on long duration space missions. Increased cancer morbidity or mortality risk in astronauts may be caused by occupational radiation exposure. Acute and late radiation damage to the central nervous system (CNS) may lead to changes in motor function and behavior, or neurological disorders. Radiation exposure may result in degenerative tissue diseases (non-cancer or non-CNS) such as cardiac, circulatory, or digestive diseases, as well as cataracts. Acute radiation syndromes may occur due to occupational radiation exposure.

  2. [Serum proteome profiling for ovarion cancer diagnosis using ClinProt magnetic bead technique and MALDI-TOF-mass-spectrometry].

    PubMed

    Ziganshin, R Kh; Alekseev, D G; Arapidi, G P; Ivanov, V T; Moshkovski?, S A; Govorun, V M

    2008-01-01

    Using reverse-phase (MB-HIC 8 and HB-HIC 18) weak cation exchange (MB-WCX) and metal affinity ClinProt magnetoc beads peptides and protein factions were obtained from human sera for their profiling by MALDI-TOF mass spectrometry. Proteome profiling of sera from I-IV stage ovarian cancer patients (47 women, average age 51) and from healthy women (47 subjects, average age 49) using MB-WCX beads allowed calculation of the best diagnostic models based on the Genetic Algorithm and Supervised Neural Network classifiers; these model generated 100% sensitivity and specificity when the test set of subjects was analyzed. Introduction of additional sera from patients with colorectal cancer (19) and ulcerous colitis (5) to the statistical model confirmed 100% ovarian cancer recognition. Statistical mass-spectrometry analysis of mass-spectrometry peak areas included to the diagnostic classifiers showed 3 peaks distinctive for ovarian cancer and 4 peaks distinctive for ovarian and colorectal cancer. PMID:18988457

  3. 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 ...

  4. Radiation hydrodynamics

    SciTech Connect

    Pomraning, G.C.

    1982-12-31

    This course was intended to provide the participant with an introduction to the theory of radiative transfer, and an understanding of the coupling of radiative processes to the equations describing compressible flow. At moderate temperatures (thousands of degrees), the role of the radiation is primarily one of transporting energy by radiative processes. At higher temperatures (millions of degrees), the energy and momentum densities of the radiation field may become comparable to or even dominate the corresponding fluid quantities. In this case, the radiation field significantly affects the dynamics of the fluid, and it is the description of this regime which is generally the charter of radiation hydrodynamics. The course provided a discussion of the relevant physics and a derivation of the corresponding equations, as well as an examination of several simplified models. Practical applications include astrophysics and nuclear weapons effects phenomena.

  5. Radiation Protection

    NASA Astrophysics Data System (ADS)

    Grupen, Claus

    Radiation protection is a very important aspect for the application of particle detectors in many different fields, like high energy physics, medicine, materials science, oil and mineral exploration, and arts, to name a few. The knowledge of radiation units, the experience with shielding, and information on biological effects of radiation are vital for scientists handling radioactive sources or operating accelerators or X-ray equipment. This article describes the modern radiation units and their conversions to older units which are still in use in many countries. Typical radiation sources and detectors used in the field of radiation protection are presented. The legal regulations in nearly all countries follow closely the recommendations of the International Commission on Radiological Protection (ICRP). Tables and diagrams with relevant information on the handling of radiation sources provide useful data for the researcher working in this field.

  6. Radiation Chemistry

    NASA Astrophysics Data System (ADS)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  7. Radiator technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    1993-01-01

    Radiator technology is discussed in the context of the Civilian Space Technology Initiative's (CSTI's) high capacity power-thermal management project. The CSTI project is a subset of a project to develop a piloted Mars nuclear electric propulsion (NEP) vehicle. The following topics are presented in vugraph form: advanced radiator concepts; heat pipe codes and testing; composite materials; radiator design and integration; and surface morphology.

  8. 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.

  9. Radiation carcinogenesis

    SciTech Connect

    Rantanen, J.

    1980-09-01

    In radiation-induced carcinogenesis the stages of initiation, transformation, and promotion can be identified. Radiation carcinogenesis is a stochastic phenomenon that does not exhibit any threshold in the dose-response relationship. The most important risk to be controlled is that of the population - either industrial or medical - exposed to radiation at low levels and low dose rates. Despite the expanding use of radiation, the average doses in most industrialized societies have not been increasing during the last few years. However, sensitive subpopulations with high cancer risks are included within the present low-level average exposure figures.

  10. Plume radiation

    NASA Astrophysics Data System (ADS)

    Dirscherl, R.

    1993-06-01

    The electromagnetic radiation originating from the exhaust plume of tactical missile motors is of outstanding importance for military system designers. Both missile- and countermeasure engineer rely on the knowledge of plume radiation properties, be it for guidance/interference control or for passive detection of adversary missiles. To allow access to plume radiation properties, they are characterized with respect to the radiation producing mechanisms like afterburning, its chemical constituents, and reactions as well as particle radiation. A classification of plume spectral emissivity regions is given due to the constraints imposed by available sensor technology and atmospheric propagation windows. Additionally assessment methods are presented that allow a common and general grouping of rocket motor properties into various categories. These methods describe state of the art experimental evaluation techniques as well as calculation codes that are most commonly used by developers of NATO countries. Dominant aspects influencing plume radiation are discussed and a standardized test technique is proposed for the assessment of plume radiation properties that include prediction procedures. These recommendations on terminology and assessment methods should be common to all employers of plume radiation. Special emphasis is put on the omnipresent need for self-protection by the passive detection of plume radiation in the ultraviolet (UV) and infrared (IR) spectral band.

  11. 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...

  12. 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…

  13. 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.

  14. Radiation detector

    DOEpatents

    Fultz, B.T.

    1980-12-05

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  15. Radiation detector

    DOEpatents

    Fultz, Brent T. (Berkeley, CA)

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  16. Response of LiF:Mg,Ti thermoluminescent dosimeters at photon energies relevant to the dosimetry of brachytherapy (<1 MeV)

    SciTech Connect

    Tedgren, Aasa Carlsson; Hedman, Angelica; Grindborg, Jan-Erik; Carlsson, Gudrun Alm

    2011-10-15

    Purpose: High energy photon beams are used in calibrating dosimeters for use in brachytherapy since absorbed dose to water can be determined accurately and with traceability to primary standards in such beams, using calibrated ion chambers and standard dosimetry protocols. For use in brachytherapy, beam quality correction factors are needed, which include corrections for differences in mass energy absorption properties between water and detector as well as variations in detector response (intrinsic efficiency) with radiation quality, caused by variations in the density of ionization (linear energy transfer (LET) -distributions) along the secondary electron tracks. The aim of this work was to investigate experimentally the detector response of LiF:Mg,Ti thermoluminescent dosimeters (TLD) for photon energies below 1 MeV relative to {sup 60}Co and to address discrepancies between the results found in recent publications of detector response. Methods: LiF:Mg,Ti dosimeters of formulation MTS-N Poland were irradiated to known values of air kerma free-in-air in x-ray beams at tube voltages 25-250 kV, in {sup 137}Cs- and {sup 60}Co-beams at the Swedish Secondary Standards Dosimetry Laboratory. Conversions from air kerma free-in-air into values of mean absorbed dose in the dosimeters in the actual irradiation geometries were made using EGSnrc Monte Carlo simulations. X-ray energy spectra were measured or calculated for the actual beams. Detector response relative to that for {sup 60}Co was determined at each beam quality. Results: An increase in relative response was seen for all beam qualities ranging from 8% at tube voltage 25 kV (effective energy 13 keV) to 3%-4% at 250 kV (122 keV effective energy) and {sup 137}Cs with a minimum at 80 keV effective energy (tube voltage 180 kV). The variation with effective energy was similar to that reported by Davis et al.[Radiat. Prot. Dosim. 106, 33-43 (2003)] with our values being systematically lower by 2%-4%. Compared to the results by Nunn et al.[Med. Phys. 35, 1861-1869 (2008)], the relative detector response as a function of effective energy differed in both shape and magnitude. This could be explained by the higher maximum read-out temperature (350 deg. C) used by Nunn et al.[Med. Phys. 35, 1861-1869 (2008)], allowing light emitted from high-temperature peaks with a strong LET dependence to be registered. Use of TLD-100 by Davis et al.[Radiat. Prot. Dosim. 106, 33-43 (2003)] with a stronger super-linear dose response compared to MTS-N was identified as causing the lower relative detector response in this work. Conclusions: Both careful dosimetry and strict protocols for handling the TLDs are required to reach solid experimental data on relative detector response. This work confirms older findings that an over-response relative to {sup 60}Co exists for photon energies below 200-300 keV. Comparison with the results from the literature indicates that using similar protocols for annealing and read-out, dosimeters of different makes (TLD-100, MTS-N) differ in relative detector response. Though universality of the results has not been proven and further investigation is needed, it is anticipated that with the use of strict protocols for annealing and read-out, it will be possible to determine correction factors that can be used to reduce uncertainties in dose measurements around brachytherapy sources at photon energies where primary standards for absorbed dose to water are not available.

  17. [Radiation carcinogenesis].

    PubMed

    Hosoi, Yoshio

    2013-11-01

    Misrepair of DNA damage induced by ionizing radiation is a potential cause of carcinogenesis following exposure to radiation. Radiation exposure increases the incidence of the same types of mutations that occur spontaneously in a given population. A high incidence of DNA double-strand breaks is characteristic of damage by ionizing radiation compared with those induced by other environmental mutagens. In China, residents living in areas with high level background radiation(6mSv/y) had a significantly higher frequency of dicentric and ring chromosomes compared to that for the residents living in the control areas(2mSv/y). Radiation-associated increases in risk were seen for most sites. Gender-averaged excess absolute risk rates estimated at age 70, after exposure at age 30, differ in the sites, and the risks of gastric cancer, breast cancer, colon cancer, and lung cancer were highly increased, in that order. Latent periods for the development of leukemia and thyroid cancer after radiation exposure at ages younger than 18 were shorter compared to those for other solid cancers. PMID:24231698

  18. Synchrotron Radiation

    SciTech Connect

    Wiedemann, Helmut

    2003-08-11

    This book covers the physical aspects of synchrotron radiation generation and is designed as a textbook and reference for graduate students, teachers and scientists utilizing synchrotron radiation. It is my hope that this text may help especially students and young researchers entering this exciting field to gain insight into the characteristics of synchrotron radiation. Discovered in 1945, synchrotron radiation has become the source of photons from the infrared to hard x-rays for a large community of researchers in basic and applied sciences. This process was particularly supported by the development of electron accelerators for basic research in high energy physics. Specifically, the development of the store ring and associated technologies resulted in the availability of high brightness photon beams far exceeding other sources. In this text, the physics of synchrotron radiation for a variety of magnets is derived from first principles resulting in useful formulas for the practitioner. Since the characteristics and quality of synchrotron radiation are intimately connected with the accelerator and electron beam producing this radiation, a short overview of relevant accelerator physics is included.

  19. 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.

  20. Radiation dosimeter

    DOEpatents

    Fox, R.J.

    1981-09-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through 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.

  1. RADIATION DETECTOR

    DOEpatents

    Wilson, H.N.; Glass, F.M.

    1960-05-10

    A radiation detector of the type is described wherein a condenser is directly connected to the electrodes for the purpose of performing the dual function of a guard ring and to provide capacitance coupling for resetting the detector system.

  2. Radiation Therapy

    MedlinePLUS

    ... Radiation (also called x-rays, gamma rays, or photons) either kills tumor cells directly or interferes with ... treatment per day, five days a week, for two to seven weeks. Potiential Side Effects Most people ...

  3. Radiation Therapy

    MedlinePLUS

    ... your doctor's OK before taking any medicines, including herbal medicines or over-the-counter drugs. Wear loose- ... on the treated area. If you lose your hair because of radiation therapy, protect your head from ...

  4. Healthful radiation

    SciTech Connect

    Agard, E.T.

    1997-01-01

    This title of this article sounds paradoxical to most people because the general public is not fully aware of the many benefits radiation has brought to people`s healthcare. Radiation has provided the most effective means of noninvasive diagnosis of many diseases, thus reducing the need for exploratory surgery, at significantly reduced risks. Furthermore, radiotherapy has been effective in treating many diseases without surgical removal of the diseased part. The breast is one excellent example of the benefits of radiation in both diagnosis and treatment with preservation. Yet the public still regards radiation as mysterious and dangerous, while trained experts regard it as beneficial with manageable risks. This article suggests ways of presenting this material to the public in a manner that is interesting and informative. 11 refs.

  5. Radiation Transport

    SciTech Connect

    Urbatsch, Todd James

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  6. Radiation enteritis

    SciTech Connect

    O'Brien, P.H.; Jenrette, J.M. III; Garvin, A.J.

    1987-09-01

    As the population receiving radiation therapy grows, so does the incidence of chronic radiation enteritis. A review of the pathology of chronic radiation enteritis reveals fibrosis, endarteritis, edema, fragility, perforation, and partial obstruction. Conservative management of patients with this disease is common. Because the obstruction is only partial, decompression is easily achieved with nasogastric suction and parenteral support. The patient is then often discharged on a liquid-to-soft diet. This therapeutic strategy does nothing for the underlying pathology. The problem, sooner or later, will return with the patient further depleted by the chronic radiation enteritis. We think surgical intervention is appropriate when the diagnosis of chronic radiation enteritis is assumed. The surgery in relation to this disease is high risk with a 30% mortality and 100% expensive morbidity. Early intervention seems to decrease these figures. All anastomoses, if possible, should be outside the irradiated area. Trapped pelvic loops of intestine should be left in place and a bypass procedure with decompressing enterostomies accomplished. The surgery should be performed by a surgeon with extensive experience with all kinds of bowel obstruction as well as experience in performing surgery in radiated tissue.

  7. Radiation injuries/ionizing radiation

    SciTech Connect

    Gooden, D.S.

    1991-01-01

    This book was written to aid trial attorneys involved in radiation litigation. Radiologists and medical physicists will also find it helpful as they prepare for trial, either as a litigant or an expert witness. Two chapters present checklists to guide attorneys for both plaintiffs and defendants. Gooden titles these checklists Elements of Damages and Elements of Proof and leads the reader to conclusions about each of these. One section that will be particularly helpful to attorneys contains sample interrogatories associated with a case of alleged radiation exposure resulting in a late radiation injury. There are interrogatories for the plaintiff to ask the defendant and for the defendant to ask the plaintiff.

  8. 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 etal., 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

  9. CutProtFam-Pred: Detection and classification of putative structural cuticular proteins from sequence alone, based on profile Hidden Markov Models

    PubMed Central

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

    2014-01-01

    The arthropod cuticle is a composite, bipartite system, made of chitin filaments 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 profile 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

  10. Radiation enteritis and radiation scoliosis

    SciTech Connect

    Shah, M.; Eng, K.; Engler, G.L.

    1980-09-01

    Any patient with radiation scoliosis should be suspected of having a visceral lesion as well. Chronic radiation enteritis may be manifested by intestinal obstruction, fistulas, perforation, and hemorrhage. Intestinal obstruction is the most common complication, and must be differentiated from postoperative cast or from spinal-traction syndrome. Obstruction that does not respond promptly to conservative measures must be treated surgically. Irradiated bowel is ischemic, and necrosis with spontaneous perforation can only be avoided with early diagnosis and surgical intervention.

  11. Radiation Oncology Treatment Team

    MedlinePLUS

    ... Upper GI What is Radiation Therapy? Find a Radiation Oncologist Last Name: Facility: City: State: Zip Code: ... who specializes in using radiation to treat cancer . Radiation Oncologists Radiation oncologists are the doctors who will ...

  12. SU-E-T-249: Neutron Model Upgrade for Radiotherapy Patients Monitoring Using a New Online Detector

    SciTech Connect

    Irazola, L; Sanchez Doblado, F.; Lorenzoli, M; Pola, A.; Terron, J.A.; Bedogni, R.; Sanchez Nieto, B.; Romero-Exposito, M.

    2014-06-01

    Purpose: The purpose of this work is to improve the existing methodology to estimate neutron equivalent dose in organs during radiotherapy treatments, based on a Static Random Access Memory neutron detector (SRAMnd) [1]. This is possible thanks to the introduction of a new digital detector with improved characteristics, which is able to measure online the neutron fluence rate in the presence of an intense photon background [2]. Its reduced size, allows the direct estimation of doses in specific points inside an anthropomorphic phantom (NORMA) without using passive detectors as TLD or CR-39. This versatility will allow not only to improve the existing models (generic abdomen and H and N [1]) but to generate more specific ones for any technique. Methods: The new Thermal Neutron Rate Detector (TNRD), based on a diode device sensitized to thermal neutrons, have been inserted in 16 points of the phantom. These points are distributed to infer doses to specific organs. Simultaneous measurements of these devices and a reference one, located in front of the gantry, have been performed for the mentioned generic treatments, in order to improve the existing model. Results: These new devices have shown more precise since they agree better with Monte Carlo simulations. The comparison of the thermal neutron fluence, measured with TNRD, and the existing models, converted from events to fluence, shows an average improvement of (3.903.37) % for H and N and (12.619.43) % for abdomen, normalized to the maximum value. Conclusion: This work indicates the potential of these new devices for more precise neutron equivalent dose estimation in organs, as a consequence of radiotherapy treatments. The simplicity of the process makes possible to establish more specific models that will provide a better dose estimation. References[1] Phys Med Biol 2012; 57:61676191.[2] A new active thermal neutron detector. Radiat. Prot. Dosim. (in press)

  13. Indoor inhalation dose estimates due to radon and thoron in some areas of South-Western Punjab, India.

    PubMed

    Kumar, Sanjeev; Singh, Surinder; Bajwa, Bikramjit Singh; Singh, Bhupinder; Sabharwal, Arvind D; Eappen, K P

    2012-08-01

    LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for estimating radon ((222)Rn) and thoron ((220)Rn) concentrations in dwellings of south-western Punjab, India. The present study region has shown pronounced cases of cancer incidents in the public [Thakur, Rao, Rajwanshi, Parwana and Kumar (Epidemiological study of high cancer among rural agricultural community of Punjab in Northern India. Int J Environ Res Public Health 2008; 5(5):399-407) and Kumar et al. (Risk assessment for natural uranium in subsurface water of Punjab state, India. Hum Ecol Risk Assess 2011;17:381-93)]. Radon being a carcinogen has been monitored in some dwellings selected randomly in the study area. Results show that the values of radon ((222)Rn) varied from 21 to 79 Bq m(-3), with a geometric mean of 45 Bq m(-3) [geometric standard deviation (GSD 1.39)], and those of thoron ((220)Rn) from minimum detection level to 58 Bq m(-3) with a geometric mean of 19 Bq m(-3) (GSD 1.88). Bare card data are used for computing the progeny concentration by deriving the equilibrium factor (F) using a root finding method [Mayya, Eappen and Nambi (Methodology for mixed field inhalation dosimetry in monazite areas using a twin-cup dosemeter with three track detectors. Radiat Prot Dosim 1998;77(3):177-84)]. Inhalation doses have been calculated and compared using UNSCEAR equilibrium factors and by using the calculated F-values. The results show satisfactory comparison between the values. PMID:22267272

  14. RADIATION INTEGRATOR

    DOEpatents

    Glass, F.M.; Wilson, H.N.

    1959-02-17

    Radiation detecting and measuring systems, particularly a compact, integrating, background monitor, are discussed. One of the principal features of the system is the use of an electrometer tube where the input of the tube is directly connected to an electrode of the radiation detector and a capacitor is coupled to the tube input. When a predetermined quantity of radiation has been integrated, a trigger signal is fed to a recorder and a charge is delivered to the capacitor to render the tube inoperative. The capacitor is then recharged for the next period of operation. With this arrangement there is a substantial reduction in lead lengths and the principal components may be enclosed and hermetically sealed to insure low leakage.

  15. (Radiation protection)

    SciTech Connect

    Fry, R.J.M.

    1986-12-05

    I undertook this trip to attend the International Committee on Radiation Protection (ICRP) Committee 1 meeting held in Jerusalem. The items on the agenda were a number of reports on the following: (1) radiation effects on the developing brain, (2) RBEs for nonstochastic effects, (3) hereditary effects, (4) RBE for Auger electrons, (5) hormesis, (6) risk coefficient for radiation-induction of bladder cancer, (7) probability of causation of cancer, (8) biological basis for dose limitation to the skin, and (9) responses to questions relating to ICRP 26. On November 20, I visited Dr. S. B. Field at the MRC Cyclotron Unit at Hammersmith to discuss their new directions in research and to discuss journal editorships.

  16. Radiation myelopathy.

    PubMed Central

    Sanyal, B; Pant, G C; Subrahmaniyam, K; Agrawal, M S; Mohanty, S

    1979-01-01

    Five cases of radiation myelopathy were found in a total of 10,000 cases given radiotherapy from 1968 to 1977. The clinical presentation and treatment details including the total dose, treatment volume, number of fractionations, overall time, and the RET value at the spinal cord were calculated and compared with other reports on this subject. The total number of fractionations ranged from 20 to 26 with an overall time of 32 days to 37 days. The dose received by four patients ranged from 1030 to 1900 RET, a little higher than the tolerance level of the spinal cord as compared to reported values. Two patients in this series had high blood pressure. The incidence of radiation myelopathy, already acceptably low, could possibly be reduced further by meticulous planning of radiation. PMID:448380

  17. 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.

  18. Radiation receiver

    DOEpatents

    Hunt, Arlon J.

    1983-01-01

    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.

  19. Radiation dermatitis

    SciTech Connect

    Shack, R.B.; Lynch, J.B.

    1987-04-01

    Even in this era of modern radiotherapy, injuries associated with the medical and industrial use of radiation devices will continue to pose a difficult problem for the reconstructive surgeon. It must be borne in mind that the single most serious hazard to surgery in irradiated tissue is the lodgement of bacteria in tissue rendered avascular by the radiation and the secondary necrosis from the infection itself. The basic principles of wound management must be augmented by thorough knowledge of the use of well-vascularized muscle and musculocutaneous flap to provide adequate, blood-rich, soft-tissue coverage.

  20. Circumsolar radiation

    SciTech Connect

    Watt, A.D.

    1980-04-01

    A quantitative knowledge of circumsolar radiation is important in the design of focusing type solar collectors, and is also of interest to those calculating the performance of all types of collectors. The primary objective of this study is the development of a model which will permit estimation of circumsolar radiation based on solar and meteorological input data. The results of observations are presented including radiance characteristics and time variations of the circumsolar component at a number of locations. The characteristics of the atmosphere are presented with primary emphasis on large particles. Physical models of circumsolar radiation are developed. The results of observed clear day only and all day average monthly values at Albuquerque, NM are shown. Also shown are calculated values for both clear and average days based on the physical model. The model results are based on: long term average turbidity values, derived average pollen loadings, and actual monthly average sky cover values for the years shown. Regression analysis is employed to determine the circumsolar values based on observed solar radiation and atmospheric parameters. The regression derived models show that fairly good agreement can be obtained between observed and calculated monthly average circumsolar ratios by simple expressions employing only the active cavity radiometer values. (WHK)

  1. 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)

  2. 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.

  3. Ionizing radiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter gives a comprehensive review on ionizing irradiation of fresh fruits and vegetables. Topics include principles of ionizing radiation, its effects on pathogenic and spoilage microorganisms, shelf-life, sensory quality, nutritional and phytochemical composition, as well as physiologic and...

  4. Radiation Therapy

    MedlinePLUS

    ... puzzles or needlework. Use headphones to listen to music or recorded books. Meditate, breathe deeply, pray, use imagery , or find other ways to relax. See Learning to Relax for exercises and other ideas on how to relax. External Beam Radiation Therapy Will Not Make You Radioactive People often wonder ...

  5. Radiation effects

    SciTech Connect

    Holden, N.E.

    1985-01-01

    For the meeting of the Commission on Radiochemistry and Nuclear Techniques our chairman has submitted comments on potential problems that the Commission should consider in Lyon which had been posed by various members. In one of these comments, Prof. Roth has mentioned the problem of radiation effects in solids and in water and water solutions. The radiolysis of water has been of concern for a large number of years, but as Prof. Roth notes, the radiation effects on the first wall of fusion reactors is a problem that has arisen only in recent years and for which no critical data compilation is presently available. This paper has been prepared in response to Prof. Roth's comments and indicates a possible area, which the Commission might conceivably address at this meeting and/or in the near future. 7 refs.

  6. Recent Developments of the Local Effect Model (LEM) - Implications of clustered damage on cell transformation

    NASA Astrophysics Data System (ADS)

    Elsässer, Thilo

    Exposure to radiation of high-energy and highly charged ions (HZE) causes a major risk to human beings, since in long term space explorations about 10 protons per month and about one HZE particle per month hit each cell nucleus (1). Despite the larger number of light ions, the high ionisation power of HZE particles and its corresponding more complex damage represents a major hazard for astronauts. Therefore, in order to get a reasonable risk estimate, it is necessary to take into account the entire mixed radiation field. Frequently, neoplastic cell transformation serves as an indicator for the oncogenic potential of radiation exposure. It can be measured for a small number of ion and energy combinations. However, due to the complexity of the radiation field it is necessary to know the contribution to the radiation damage of each ion species for the entire range of energies. Therefore, a model is required which transfers the few experimental data to other particles with different LETs. We use the Local Effect Model (LEM) (2) with its cluster extension (3) to calculate the relative biological effectiveness (RBE) of neoplastic transformation. It was originally developed in the framework of hadrontherapy and is applicable for a large range of ions and energies. The input parameters for the model include the linear-quadratic parameters for the induction of lethal events as well as for the induction of transformation events per surviving cell. Both processes of cell inactivation and neoplastic transformation per viable cell are combined to eventually yield the RBE for cell transformation. We show that the Local Effect Model is capable of predicting the RBE of neoplastic cell transformation for a broad range of ions and energies. The comparison of experimental data (4) with model calculations shows a reasonable agreement. We find that the cluster extension results in a better representation of the measured RBE values. With this model it should be possible to better predict the risk of the complex mixed radiation field occurring in deep space. 1. F. A. Cucinotta and M. Durante, Lancet Oncol. 7, 431-435 (2006). 2. M. Scholz and G. Kraft, Radiat. Prot. Dosim. 52, 29-33 (1994). 3. Th. Els¨sser and M. Scholz, Radiat. Res. 167, 319-329 (2007). a 4. R. C. Miller, S. A. Marino, D. J. Brenner, S. G. Martin, M. Richards, G. Randers-Pehrson, and E. J. Hall, Radiat. Res. 142, 54-60 (1995).

  7. Acute Radiation Syndrome

    MedlinePLUS

    ... Planning Information on Specific Types of Emergencies Acute Radiation Syndrome (ARS): A Fact Sheet for the Public ... is called the radiation dose. People exposed to radiation will get ARS only if: The radiation dose ...

  8. Risk Factors: Radiation

    Cancer.gov

    Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation.

  9. Shortwave Radiation

    NASA Technical Reports Server (NTRS)

    Klassen, Steve; Bugbee, Bruce

    2005-01-01

    Accurate shortwave radiation data is critical to evapotranspiration (ET) models used for developing irrigation schedules to optimize crop production while saving water, minimizing fertilizer, herbicide, and pesticide applications, reducing soil erosion, and protecting surface and ground water quality. Low cost silicon cell pyranometers have proven to be sufficiently accurate and robust for widespread use in agricultural applications under unobstructed daylight conditions. More expensive thermopile pyranometers are required for use as calibration standards and measurements under light with unique spectral properties (electric lights, under vegetation, in greenhouses and growth chambers). Routine cleaning, leveling, and annual calibration checks will help to ensure the integrity of long-term data.

  10. Radiation protection in space.

    PubMed

    Reitz, G; Facius, R; Sandler, H

    1995-01-01

    Radiation environment, basic concepts of radiation protection, and specific aspects of the space radiation field are reviewed. The discussion of physico-chemical and subcellular radiation effects includes mechanisms of radiation action and cellular consequences. The discussion of radiobiological effects includes unique aspects of HZE particle effects, space flight findings, terrestrial findings, analysis of somatic radiation effects and effects on critical organs, and early and delayed effects. Other topics include the impact of the space flight environment, measurement of radiation exposure, establishing radiation protection limits, limitations in establishing space-based radiation exposure limits, radiation protection measures, and recommendations. PMID:11541474

  11. Chromosome-Based Proteomic Study for Identifying Novel Protein Variants from Human Hippocampal Tissue Using Customized neXtProt and GENCODE Databases.

    PubMed

    Hwang, Heeyoun; Park, Gun Wook; Kim, Kwang Hoe; Lee, Ju Yeon; Lee, Hyun Kyoung; Ji, Eun Sun; Park, Sung-Kyu Robin; Xu, Tao; Yates, John R; Kwon, Kyung-Hoon; Park, Young Mok; Lee, Hyoung-Joo; Paik, Young-Ki; Kim, Jin Young; Yoo, Jong Shin

    2015-12-01

    The goal of the Chromosome-Centric Human Proteome Project (C-HPP) is to fully provide proteomic information from each human chromosome, including novel proteoforms, such as novel protein-coding variants expressed from noncoding genomic regions, alternative splicing variants (ASVs), and single amino acid variants (SAAVs). In the 144 LC/MS/MS raw files from human hippocampal tissues of control, epilepsy, and Alzheimer's disease, we identified the novel proteoforms with a workflow including integrated proteomic pipeline using three different search engines, MASCOT, SEQUEST, and MS-GF+. With a <1% false discovery rate (FDR) at the protein level, the 11 detected peptides mapped to four translated long noncoding RNA variants against the customized databases of GENCODE lncRNA, which also mapped to coding-proteins at different chromosomal sites. We also identified four novel ASVs against the customized databases of GENCODE transcript. The target peptides from the variants were validated by tandem MS fragmentation pattern from their corresponding synthetic peptides. Additionally, a total of 128 SAAVs paired with their wild-type peptides were identified with FDR <1% at the peptide level using a customized database from neXtProt including nonsynonymous single nucleotide polymorphism (nsSNP) information. Among these results, several novel variants related in neuro-degenerative disease were identified using the workflow that could be applicable to C-HPP studies. All raw files used in this study were deposited in ProteomeXchange (PXD000395). PMID:26549206

  12. 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.

  13. Radiation Insulation

    NASA Technical Reports Server (NTRS)

    1993-01-01

    An aluminized polymer film is a highly effective radiation barrier for both manned and unmanned spacecraft. Variations of this space-devised material are also used as an energy conservation technique for homes and offices. One commercial company, Tech 2000 (formerly Buckeye Radiant Barrier), markets 'Super R' Radiant Barrier, which finds its origins in the Apollo Mission programs. The material is placed between wall studs and exterior facing before siding or in new roof installation, between roof support and roof sheathing. Successful retrofit installations have included schools and shrink wrap ovens. The radiant barrier blocks 95 percent of radiant energy, thus retaining summer heat and blocking winter cold. Suppliers claim utility bill reductions of 20 percent or more.

  14. 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.

  15. Adaptors for radiation detectors

    SciTech Connect

    Livesay, Ronald Jason

    2015-07-28

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  16. Adaptors for radiation detectors

    SciTech Connect

    Livesay, Ronald Jason

    2014-04-22

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  17. Advanced radiator concepts

    NASA Technical Reports Server (NTRS)

    Diem-Kirsop, P. S.

    1985-01-01

    The liquid droplet radiator and the liquid belt radiator currently under study by the NASA LeRC are discussed. These advanced concepts offer benefits in reduced mass, compact stowage, and ease of deployment. Operation and components of the radiators are described, heat transfer characteristics are discussed, and critical technologies are identified. The impact of the radiators on large power systems is also assessed.

  18. Micromechanical radiation dosimeter

    SciTech Connect

    Thundat, T.; Sharp, S.L.; Fisher, W.G.; Warmack, R.J.; Wachter, E.A. )

    1995-03-20

    We demonstrate the use of microcantilevers coated with ultraviolet cross-linking polymers as optical radiation dosimeters. Upon exposure to radiation, a treated cantilever bends due to stress and its resonance frequency increases due to stiffening. These phenomena can be used to develop sensitive radiation dosimeters which respond to radiation affecting the mechanical properties of the selected coating.

  19. Radiation and People

    ERIC Educational Resources Information Center

    Freilich, Florence G.

    1970-01-01

    Describes the development of radiation as a tool of medicine. Includes topics on history of radiation, electromagnetic spectrum, X-ray tubes, high energy machines, radioactive sources, artificial radioactivity, radioactive scanning, units, present radiation background, and effect of radiation on living tissue. (DS)

  20. Radiation stability in optoelectronics

    NASA Astrophysics Data System (ADS)

    Zaitov, Farit Alimovich; Litvinova, Nadezhda Nikolaevna; Savitskii, Vladimir Grigor'evich; Sredin, Viktor Gennadievich

    The book deals with various aspects of the radiation stability of some commonly used semiconductor optoelectronic instruments, such as radiation sources and detectors, solar energy converters, and certain types of glasses and fibers. In particular, attention is given to the classification and principal physical characteristics of ionizing radiations, principal types of optoelectronic semiconductor instruments, effect of ionizing radiation on photosensitive and light-emitting semiconductor structures, and effect of ionizing radiation on semiconducting materials.

  1. Radiation image photographic apparatus

    SciTech Connect

    Kohno, H.; Sekihara, K.; Shiono, H.; Suzuki, T.; Yanaka, S.

    1984-11-27

    A radiation-image photographing apparatus comprises a radiation source, a radiation detector disposed in opposition to the radiation source for detecting radiation through an object to be examined and to generate an electrical signal proportional to the amount of incident radiation, a scanning device for changing the relative, positional relationship between the radiation source and the radiation detector, an analog-to-digital converter for converting the output signal from the radiation detector to a digital quantity, a memory for storing the digital signal, an arithmetic unit, and a display unit. A plurality of measurements of a two-dimensional radiation absorption distribution of the object disposed between the radiation source and the radiation detector is obtained while the relative positional relationship between the radiation source and the radiation detector is being changed, and a linear arithmetic operation is performed on the plurality of image measurements, or a set of data passing a point within the object to be photographed, thereby displaying a cross-sectional image on a given cross-section approximately parallel to the radiation detector plane within the object to be examined.

  2. Radiation protection guidelines for radiation emergencies

    SciTech Connect

    Lessard, E.T.; Meinhold, C.B.

    1986-01-01

    The system of dose limitation and present guidance for emergency workers and guidance for intervention on behalf of the public are discussed. There are three elements for the system of dose limitation: justification, optimization and dose limits. The first element is basically a political process in this country. Justification is based on a risk-benefit analysis, and justification of the use of radioactive materials or radiation is generally not within the authority of radiation protection managers. Radiation protection managers typically assess detriments or harm caused by radiation exposure and have very little expertise in assessing the benefits of a particular practice involving nuclear material.

  3. Guideline Implementation: Radiation Safety.

    PubMed

    Fencl, Jennifer L

    2015-12-01

    Because radiologic technology is used in a variety of perioperative procedures and settings, it is essential for perioperative RNs to be knowledgeable of the risks related to radiation and the ways to adequately protect patients and health care providers from unintended radiation exposure. The updated AORN "Guideline for radiation safety" provides guidance on preventing injury from ionizing radiation exposure during therapeutic, diagnostic, and interventional procedures. This article focuses on key points of the guideline to help perioperative personnel practice radiation safety. The key points address the requirements for an organization's radiation safety program, measures used to keep radiation exposure as low as reasonably achievable, proper handling and testing of radiation protection devices, and considerations for protecting employees and patients who are pregnant and who will be exposed to radiation. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures. PMID:26616323

  4. Plutonium radiation surrogate

    DOEpatents

    Frank, Michael I.

    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.

  5. 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.

  6. Radiation safety consideration during intraoperative radiation therapy.

    PubMed

    Mobit, Paul N; Rajaguru, Priyadarshini; Brewer, Michael; Baird, Michael; Packianathan, Satyaseelan; Yang, Claus Chunli

    2015-04-01

    Using in-house-designed phantoms, the authors evaluated radiation exposure rates in the vicinity of a newly acquired intraoperative radiation therapy (IORT) system: Axxent Electronic Brachytherapy System. The authors also investigated the perimeter radiation levels during three different clinical intraoperative treatments (breast, floor of the mouth and bilateral neck cancer patients). Radiation surveys during treatment delivery indicated that IORT using the surface applicator and IORT using balloons inserted into patient body give rise to exposure rates of 200 mR h(-1), 30 cm from a treated area. To reduce the exposure levels, movable lead shields should be used as they reduce the exposure rates by >95%. The authors' measurements suggest that intraoperative treatment using the 50-kVp X-ray source can be administered in any regular operating room without the need for radiation shielding modification as long as the operators utilise lead aprons and/or stand behind lead shields. PMID:25267855

  7. Variation de l'albuminémie au cours de la malnutrition protéino-energétique dans une zone urbano-rurale congolaise

    PubMed Central

    Musimwa, Aimée Mudekereza; Kanteng, Gray Wakamb; Mutoke, Gayllord Nkashama; Okito, Kristen Numbe; Shongo, Mick Ya Pongombo; Luboya, Oscar Numbi

    2015-01-01

    Introduction La malnutrition est à ce jour un problème de santé publique majeur, notamment dans les pays en voie de développement. Le diagnostic est fait cliniquement, mais l'intérêt de certains dosages paracliniques ont leur importance pour en évaluer la gravité ou faciliter un dépistage précoce, notamment de l'albuminémie. Cette étude a eu pour objectif de déterminer la variation de l'albuminémie au cours de la malnutrition protéino-calorique de l'enfant et de déterminer les facteurs associés. Méthodes Il s'agit d'une étude descriptive transversale, effectuée prospectivement de juillet 2013 à mars 2014. 154 cas ont été colligés, par échantillonnage de convenance, avec un dépistage actif des enfants malnutris. Résultats 72,7% d'enfants avaient un taux normal d'albuminémie, ce taux bas étant pour la plupart lié à un état inflammatoire et/ou infectieux au cours de la malnutrition. Le taux d'albuminémie a un lien étroit avec l’état nutritionnel, chez le malnutri chronique, l’émacié et chez ceux présentant un déficit pondéral avec respectivement 18,3%; 24,0% et 30,4% d'enfants qui ont présenté un taux bas en albumine plasmatique. Cette hypo albuminémie a été retrouvé chez les malnutris avec ou sans œdèmes. 30 enfants ont présentés des œdèmes et 63% avaient un taux bas d'albumine sérique; contre 124 enfants qui n'ont pas présentés des œdèmes et 18,3% ont présenté un taux bas en albumine sérique. Conclusion La malnutrition est une maladie dont les perturbations impliquent celle de l'albuminémie. Les variations de l'albuminémie sont statistiquement associées au tableau clinique. PMID:26161222

  8. 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.

  9. Radiation effects in space

    SciTech Connect

    Fry, R.J.M.

    1986-01-01

    The paper discusses the radiation environment in space that astronauts are likely to be exposed to. Emphasis is on proton and HZE particle effects. Recommendations for radiation protection guidelines are presented. (ACR)

  10. 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 ...

  11. 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

  12. 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.

  13. Radiation Therapy (For Parents)

    MedlinePLUS

    ... previous continue Common Side Effects of Radiation (continued) Hair Loss Radiation therapy to the head and neck ... you avoid giving your child any medicines, including herbal medicines or over-the-counter (OTC) drugs, without ...

  14. 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.

  15. Chest radiation - discharge

    MedlinePLUS

    ... teaspoon of salt and one quarter teaspoon of baking soda in 8 ounces of warm water. Gargle with ... National Cancer Institute. Radiation therapy and you: support for people with cancer. http://www.cancer.gov/cancertopics/coping/radiation- ...

  16. Radiation measuring instrumentation

    NASA Technical Reports Server (NTRS)

    Piltingsrud, H. V.

    1975-01-01

    Four radiation measuring instruments were developed. These are: (1) improved detector probe, (2) neutron spectrometer--dosimeter, (3) portable ultraviolet spectro-radiometer; and (4) pocket ionization chamber radiation dosimeter. A brief description of each of these devices is presented.

  17. Radiation Therapy (For Parents)

    MedlinePLUS

    ... previous continue Common Side Effects of Radiation (continued) Hair Loss Radiation therapy to the head and neck may cause hair thinning or hair loss shortly after treatment begins. It's important to remember, ...

  18. 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.

  19. JPL Radiation Effects Facilities

    NASA Technical Reports Server (NTRS)

    Thorbourn, Dennis

    2013-01-01

    Radiation Effects Group investigates the effects of space radiation on present and future microelectronic and optoelectronic technologies, evaluate the risk of using them in specific space missions, and recommend component and design techniques for JPL and NASA programs to reduce reliability risk from space radiation.

  20. Spacecraft radiator systems

    NASA Technical Reports Server (NTRS)

    Anderson, Grant A. (Inventor)

    2012-01-01

    A spacecraft radiator system designed to provide structural support to the spacecraft. Structural support is provided by the geometric "crescent" form of the panels of the spacecraft radiator. This integration of radiator and structural support provides spacecraft with a semi-monocoque design.

  1. Radiation Research Program (RRP)

    Cancer.gov

    The RRP is responsible for NCIs 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.

  2. 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.

  3. Radiation detection system

    DOEpatents

    Nelson, Melvin A.; Davies, Terence J.; Morton, III, John R.

    1976-01-01

    A radiation detection system which utilizes the generation of Cerenkov light in and the transmission of that light longitudinally through fiber optic wave guides in order to transmit intelligence relating to the radiation to a remote location. The wave guides are aligned with respect to charged particle radiation so that the Cerenkov light, which is generated at an angle to the radiation, is accepted by the fiber for transmission therethrough. The Cerenkov radiation is detected, recorded, and analyzed at the other end of the fiber.

  4. Mossbauer spectrometer radiation detector

    NASA Technical Reports Server (NTRS)

    Singh, J. J. (inventor)

    1973-01-01

    A Mossbauer spectrometer with high efficiencies in both transmission and backscattering techniques is described. The device contains a sodium iodide crystal for detecting radiation caused by the Mossbauer effect, and two photomultipliers to collect the radiation detected by the crystal. When used in the transmission technique, the sample or scatterer is placed between the incident radiation source and the detector. When used in a backscattering technique, the detector is placed between the incident radiation source and the sample of scatterer such that the incident radiation will pass through a hole in the crystal and strike the sample. Diagrams of the instrument are provided.

  5. Hormesis with ionizing radiation

    SciTech Connect

    Luckey, T.D.

    1982-11-01

    This article reviews a book which summarizes and classifies more than 1250 references to experimental work with low-level radiation between 1898 and 1977; explains that the detailed material is presented in tabular form with type of radiation as the primary classification and type of organism and date of report as subclassifications; notes that an incredible variety of effects are specified for flora and fauna; praises the summaries of background radiation and of overall radiation-dose effects to a variety of organisms; and emphasizes the importance of information dealing with the public perception of radiation and its effects.

  6. 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.

  7. Radiation protection in space

    SciTech Connect

    Blakely, E.A.; Fry, R.J.M.

    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.

  8. 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.

  9. 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.

  10. RF radiation from lightning

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1978-01-01

    Radiation from lightning in the RF band from 3-300 MHz were monitored. Radiation in this frequency range is of interest as a potential vehicle for monitoring severe storms and for studying the lightning itself. Simultaneous measurements were made of RF radiation and fast and slow field changes. Continuous analogue recordings with a system having 300 kHz of bandwidth were made together with digital records of selected events (principally return strokes) at greater temporal resolution. The data reveal patterns in the RF radiation for the entire flash which are characteristic of flash type and independent of the frequency of observation. Individual events within the flash also have characteristic RF patterns. Strong radiation occurs during the first return strokes, but delayed about 20 micron sec with respect to the begining of the return stroke; whereas, RF radiation from subsequent return strokes tends to be associated with cloud processes preceding the flash with comparatively little radiation occurring during the return stroke itself.

  11. 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.

  12. Complications of radiation therapy

    SciTech Connect

    Dalinka, M.K.; Mazzeo, V.P. Jr.

    1985-01-01

    The skeletal effects of radiation are dependent upon many variables, but the pathologic features are consistent. Radiation may cause immediate or delayed cell death, cellular injury with recovery, arrest of cellular division, or abnormal repair with neoplasia. Radiation necrosis and radiation-induced neoplasm still occur despite the use of supervoltage therapy. Complications of radiotherapy are well known and have led to more judicious use of this therapeutic modality. With few exceptions, benign bone tumors are no longer treated with irradiation. Radiation necrosis may be difficult to differentiate from sarcoma arising in irradiated bone. They both occur within the field of irradiation. Radiation necrosis often has a long latent period which is, of course, the rule in radiation-induced neoplasia. A soft tissue mass favors the diagnosis of neoplasia, while its absence suggests radiation necrosis. Lack of pain favors necrosis. Calcification may occur in radiation necrosis and does not indicate neoplasia. A lack of progression on serial roentgenograms also favors radiation necrosis. 76 references.

  13. Radiation physics, biophysics, and radiation biology

    SciTech Connect

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  14. The flying radiation case

    SciTech Connect

    Brownell, J.H.; Bowers, R.L.

    1997-04-01

    The Los Alamos foil implosion program has the goal of producing an intense, high-energy density x-ray source by converting the energy of a magnetically imploded plasma into radiation and material energy. One of the methods for converting the plasma energy into thermal energy and radiation and utilizing it for experiments is called the flying radiation case (FRC). In this paper the authors shall model the FRC and provide a physical description of the processes involved. An analytic model of a planar FRC in the hydrodynamic approximation is used to describe the assembly and shock heating of a central cushion by a conducting liner driver. The results are also used to benchmark a hydrodynamics code for modeling an FRC. They then use a radiation-hydrodynamics computational model to explore the effects of radiation production and transport when a gold plasma assembles on a CH cushion. Results are presented for the structure and evolution of the radiation hohlraum.

  15. RADIATION WAVE DETECTION

    DOEpatents

    Wouters, L.F.

    1960-08-30

    Radiation waves can be detected by simultaneously measuring radiation- wave intensities at a plurality of space-distributed points and producing therefrom a plot of the wave intensity as a function of time. To this end. a detector system is provided which includes a plurality of nuclear radiation intensity detectors spaced at equal radial increments of distance from a source of nuclear radiation. Means are provided to simultaneously sensitize the detectors at the instant a wave of radiation traverses their positions. the detectors producing electrical pulses indicative of wave intensity. The system further includes means for delaying the pulses from the detectors by amounts proportional to the distance of the detectors from the source to provide an indication of radiation-wave intensity as a function of time.

  16. Errors inducing radiation overdoses.

    PubMed

    Grammaticos, Philip C

    2013-01-01

    There is no doubt that equipments exposing radiation and used for therapeutic purposes should be often checked for possibly administering radiation overdoses to the patients. Technologists, radiation safety officers, radiologists, medical physicists, healthcare providers and administration should take proper care on this issue. "We must be beneficial and not harmful to the patients", according to the Hippocratic doctrine. Cases of radiation overdose are often reported. A series of cases of radiation overdoses have recently been reported. Doctors who were responsible, received heavy punishments. It is much better to prevent than to treat an error or a disease. A Personal Smart Card or Score Card has been suggested for every patient undergoing therapeutic and/or diagnostic procedures by the use of radiation. Taxonomy may also help. PMID:24251304

  17. 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.

  18. Radiation-induced ignition

    SciTech Connect

    Park, S.

    1989-01-01

    The effects of gas-phase radiation absorption on radiative ignition of various combustible materials under gravity conditions are studied. The physical models in this study range from a simple gas layer to a complex porous structure. Methyl methacrylate (MMA: C{sub 5}H{sub 8}O{sub 2}) vapor has been selected as a representative of participating gases in gas-phase radiation interactions. Its infrared radiation properties were measured using low-resolution spectral apparatus and then correlated in simple usable forms. As expected from its complex molecular structure, the infrared absorption capabilities of MMA vapor is much stronger than those of simpler hydrocarbon gases as well as water vapor and carbon dioxide. Radiation induced ignition was analyzed on the basis of simple theoretical models. Using Semenov's theory, results indicate a decrease in the critical surrounding temperature for a low Biot number system. For a high Biot number system, ignitability is defined through the use of Frank-Kamenetskii's critical parameter delta. One-dimensional transient models were developed for the analyses of radiation induced ignition of solid and porous solid fuels. The models include gas-phase radiation absorption, in-depth radiation interaction by the solid phase, Arrhenius-type chemical reaction, and natural convection. Predicted transmittance during ignition processes confirms the attenuation of incident radiation by pyrolyzed gases which has been already observed experimentally. An ignition process with gas-phase radiation absorption results in a quite different and widened ignition domain compared to that without gas-phase radiation absorption. Moreover, ignition is totally dependent on gas-phase radiation absorption under unfavorable conditions for a thermal runaway.

  19. RHOBOT: Radiation hardened robotics

    SciTech Connect

    Bennett, P.C.; Posey, L.D.

    1997-10-01

    A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

  20. Flamelet Radiation Modeling

    NASA Astrophysics Data System (ADS)

    Doom, Jeffrey; Mahesh, Krishnan

    2012-11-01

    A flamelet model is proposed that couples soot and radiation. The soot model from Carbonell et al. (Combust. Flame. 2009) is used. The radiation model is the P1 gray and non-grey model from Modest (Academic Press. 2003) which are cast into the flamelet equations. A sooty ethylene flame is studied and a series of canonical calculations are performed. Results associated with the soot and radiation will be shown and compared to experiment.

  1. 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.

  2. 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.

  3. 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.

  4. Rotating bubble membrane radiator

    DOEpatents

    Webb, Brent J.; Coomes, Edmund P.

    1988-12-06

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  5. Solar radiation on Mars

    SciTech Connect

    Appelbaum, J.; Flood, D.J. )

    1990-01-01

    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. In this paper the authors present 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.

  6. Charms of radiation research.

    SciTech Connect

    Inokuti, M.; Physics

    2005-01-01

    Most of my professional efforts over nearly five decades have been devoted to radiation research, that is, studies of the physical, chemical, and biological actions of high-energy radiation on matter. (By the term 'high-energy radiation' I mean here x rays, .GAMMA. rays, neutrons, and charged particles of high enough energies to produce ionization in matter. I exclude visible light, infrared waves, microwaves, and sound waves.) Charms of radiation research lie in its interdisciplinary character; although my training was in basic physics, the scope of my interest has gradually increased to cover many other areas, to my deep satisfaction. High-energy radiation is an important component of the universe, and of our environment. It often provides an effective avenue for characterizing matter and understanding its behavior. Near Earth's surface this radiation is normally present in exceptionally low quantity, and yet it plays a significant role in some atmospheric phenomena such as auroras, and also in the evolution of life. The recent advent of various devices for producing high-energy radiation has opened up the possibility of many applications, including medical and industrial uses. I have worked on some aspects of those uses. At every opportunity to address a broad audience I try to convey a sense of intellectual fun, together with some of the elements of the basic science involved. A goal of radiation education might be to make the word 'radiation' as common and familiar as words such as 'fire' and 'electricity' through increased usage.

  7. [Thyroid and radiation].

    PubMed

    Yamashita, S; Namba, H; Nagataki, S

    1993-11-20

    The topic "Thyroid and Radiation" is both an old and a new area to be solved by human beings. The thyroid is an organ that is usually susceptible to exposure to ionizing radiation, both by virtue of its ability to concentrate radioiodine (internal radiation) and by routine medical examination: Chest X-ray, Dental X-ray, X-irradiation of cervical lymphnodes etc. (external radiation). Iodine-131 is widely used for the therapy of Graves' disease and thyroid cancers, of which the disadvantage is radiation-induced hypothyroidism but not complications of thyroid tumor. The thyroid gland is comparatively radioresistant, however, the data obtained from Hiroshima, Nagasaki and Marshall islands indicates a high incidence of external radiation-induced thyroid tumors as well as hypothyroidism. The different biological effects of internal and external radiation remains to be further clarified. Interestingly, recent reports demonstrate the increased number of thyroid cancer in children around Chernobyl in Belarus. In this review, we would like to introduce the effect of radiation on the thyroid gland at the molecular, cellular and tissue levels. Furthermore the clinical usefulness of iodine-131, including the safety-control for radiation exposure will be discussed. PMID:8282128

  8. Management of radiation proctitis.

    PubMed

    Sarin, Ankit; Safar, Bashar

    2013-12-01

    Radiation damage to the rectum following radiotherapy for pelvic malignancies can range from acute dose-limiting side effects to major morbidity affecting health-related quality of life. No standard guidelines exist for diagnosis and management of radiation proctitis. This article reviews the definitions, staging, and clinical features of radiation proctitis, and summarizes the modalities available for the treatment of acute and chronic radiation proctitis. Because of the paucity of well-controlled, blinded, randomized studies, it is not possible to fully assess the comparative efficacy of the different approaches to management. However, the evidence and rationale for use of the different strategies are presented. PMID:24280407

  9. Potential theory of radiation

    NASA Technical Reports Server (NTRS)

    Chiu, Huei-Huang

    1989-01-01

    A theoretical method is being developed by which the structure of a radiation field can be predicted by a radiation potential theory, similar to a classical potential theory. The introduction of a scalar potential is justified on the grounds that the spectral intensity vector is irrotational. The vector is also solenoidal in the limits of a radiation field in complete radiative equilibrium or in a vacuum. This method provides an exact, elliptic type equation that will upgrade the accuracy and the efficiency of the current CFD programs required for the prediction of radiation and flow fields. A number of interesting results emerge from the present study. First, a steady state radiation field exhibits an optically modulated inverse square law distribution character. Secondly, the unsteady radiation field is structured with two conjugate scalar potentials. Each is governed by a Klein-Gordon equation with a frictional force and a restoring force. This steady potential field structure and the propagation of radiation potentials are consistent with the well known results of classical electromagnetic theory. The extension of the radiation potential theory for spray combustion and hypersonic flow is also recommended.

  10. Living with radiation

    SciTech Connect

    Wagner, H.N. Jr. . Div. of Nuclear Medicine); Ketchum, L.E. )

    1989-01-01

    The authors present an account of the hopes and fears associated with ionizing radiation, extending from nuclear energy and medical radiation to nuclear weapons. They argue that a justified fear of nuclear weapons has led to a widespread, unjustified, and unreasoning fear of the beneficial applications of radiation. Although these two aspects of atomic energy are tied together-they both involve the nucleus of the atom and its radioactive rays-a deep misunderstanding of this relationship by the general public has evolved since the time of the atomic bombing of Hiroshima and Nagasaki. The authors' aim is to place the beneficial applications of nuclear radiation in perspective.

  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. Multiplate Radiation Shields: Investigating Radiational Heating Errors

    NASA Astrophysics Data System (ADS)

    Richardson, Scott James

    1995-01-01

    Multiplate radiation shield errors are examined using the following techniques: (1) analytic heat transfer analysis, (2) optical ray tracing, (3) numerical fluid flow modeling, (4) laboratory testing, (5) wind tunnel testing, and (6) field testing. Guidelines for reducing radiational heating errors are given that are based on knowledge of the temperature sensor to be used, with the shield being chosen to match the sensor design. Small, reflective sensors that are exposed directly to the air stream (not inside a filter as is the case for many temperature and relative humidity probes) should be housed in a shield that provides ample mechanical and rain protection while impeding the air flow as little as possible; protection from radiation sources is of secondary importance. If a sensor does not meet the above criteria (i.e., is large or absorbing), then a standard Gill shield performs reasonably well. A new class of shields, called part-time aspirated multiplate radiation shields, are introduced. This type of shield consists of a multiplate design usually operated in a passive manner but equipped with a fan-forced aspiration capability to be used when necessary (e.g., low wind speed). The fans used here are 12 V DC that can be operated with a small dedicated solar panel. This feature allows the fan to operate when global solar radiation is high, which is when the largest radiational heating errors usually occur. A prototype shield was constructed and field tested and an example is given in which radiational heating errors were reduced from 2 ^circC to 1.2 ^circC. The fan was run continuously to investigate night-time low wind speed errors and the prototype shield reduced errors from 1.6 ^ circC to 0.3 ^circC. Part-time aspirated shields are an inexpensive alternative to fully aspirated shields and represent a good compromise between cost, power consumption, reliability (because they should be no worse than a standard multiplate shield if the fan fails), and accuracy. In addition, it is possible to modify existing passive shields to incorporate part-time aspiration, thus making them even more cost-effective. Finally, a new shield is described that incorporates a large diameter top plate that is designed to shade the lower portion of the shield. This shield increases flow through it by 60%, compared to the Gill design and it is likely to reduce radiational heating errors, although it has not been tested.

  13. Synchrotron Radiation II.

    ERIC Educational Resources Information Center

    MOSAIC, 1978

    1978-01-01

    Synchrotron radiation is a unique form of radiation that spans the electro-magnetic spectrum from X-rays through the ultraviolet and visible into the infrared. Tunable monochromators enable scientists to select a narrow band of wavelengths at any point in the spectrum. (Author/BB)

  14. Radiation-induced pneumothorax

    SciTech Connect

    Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

    1983-01-01

    Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis.

  15. Microcircuit radiation effects databank

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Radiation test data submitted by many testers is collated to serve as a reference for engineers who are concerned with and have some knowledge of the effects of the natural radiation environment on microcircuits. Total dose damage information and single event upset cross sections, i.e., the probability of a soft error (bit flip) or of a hard error (latchup) are presented.

  16. Radiative Flux Analysis

    SciTech Connect

    Long, Chuck

    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.

  17. 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.

  18. Pregnancy and Radiation Exposure

    MedlinePLUS

    ... Health Care Health Care Documents Radiology Q&A Nuclear Medicine Q&A RadiationAnswers.org Health Physics Society ... Physics Video Health Care Documents Radiology Q&A Nuclear Medicine Q&A RadiationAnswers.org Members Only Join ...

  19. Radiation: Doses, Effects, Risks.

    ERIC Educational Resources Information Center

    Lean, Geoffrey, Ed.

    Few scientific issues arouse as much public controversy as the effects of radiation. This booklet is an attempt to summarize what is known about radiation and provide a basis for further discussion and debate. The first four chapters of the booklet are based on the most recent reports to the United Nations' General Assembly by the United Nations

  20. Radiation detection system

    DOEpatents

    Franks, Larry A. (Santa Barbara, CA); Lutz, Stephen S. (Santa Barbara, CA); Lyons, Peter B. (Los Alamos, NM)

    1981-01-01

    A radiation detection system including a radiation-to-light converter and fiber optic wave guides to transmit the light to a remote location for processing. The system utilizes fluors particularly developed for use with optical fibers emitting at wavelengths greater than about 500 nm and having decay times less than about 10 ns.

  1. Ultraviolet radiation changes

    NASA Technical Reports Server (NTRS)

    Mckenzie, Richard L.; Frederick, John E.; Ilyas, Mohammad; Filyushkin, V.; Wahner, Andreas; Stamnes, K.; Muthusubramanian, P.; Blumthaler, M.; Roy, Colin E.; Madronich, Sasha

    1991-01-01

    A major consequence of ozone depletion is an increase in solar ultraviolet (UV) radiation received at the Earth's surface. This chapter discusses advances that were made since the previous assessment (World Meteorological Organization (WMO)) to our understanding of UV radiation. The impacts of these changes in UV on the biosphere are not included, because they are discussed in the effects assessment.

  2. 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.

  3. Radiation curing of polymers

    SciTech Connect

    Randell, D.R.

    1987-01-01

    The contents of this book are: Areas of Application of UV Curing; Areas of Application of EB Curing; Laser Curing of Acrylic Coatings; A User's View of the Application of Radiation Curable Materials; Radiation Curable Offset Inks: A Technical and Marketing Overview; and UV Curable Screen Printing Inks.

  4. The Planck Radiation Functions.

    ERIC Educational Resources Information Center

    Larsen, Russell D.

    1985-01-01

    Blackbody radiation is used as an example to illustrate that oversimplification in teaching quantum ideas can result in later misunderstanding. Although textbooks give Planck's distribution function in terms of wavelength, there are actually 12 different radiation functions. Some of the more interesting ones are given and discussed. (JN)

  5. Treatment of Radiation Injury

    PubMed Central

    Akita, Sadanori

    2014-01-01

    Significance: Radiation exposure as a result of radiation treatment, accident, or terrorism may cause serious problems such as deficiency due to necrosis or loss of function, fibrosis, or intractable ulcers in the tissues and organs. When the skin, bone, oral mucous membrane, guts, or salivary glands are damaged by ionizing radiation, the management and treatment are very lengthy and difficult. Critical Issues: In severe and irreversible injuries, surgery remains the mainstay of treatment. Several surgical procedures, such as debridement, skin grafting, and local and free-vascularized flaps, are widely used. Recent Advances: In specific cases of major morbidity or in high-risk patients, a newly developed therapy using a patient's own stem cells is safe and effective. Adipose tissue, normally a rich source of mesenchymal stem cells, which are similar to those from the bone marrow, can be harvested, since the procedure is easy, and abundant tissue can be obtained with minimal invasiveness. Future Directions: Based on the molecular basis of radiation injuries, several prospective treatments are under development. Single-nucleotide polymorphisms focus on an individual's sensitivity to radiation in radiogenomics, and the pathology of radiation fibrosis or the effect of radiation on wound healing is being studied and will lead to new insight into the treatment of radiation injuries. Protectors and mitigators are being actively investigated in terms of the timing of administration or dose. PMID:24761339

  6. Space Radiation Risk Assessment

    NASA Astrophysics Data System (ADS)

    Blakely, E.

    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 than about 20 mSv With the advent of Skylab and Mir total career exposure levels increased to a maximum of nearly 200 mSv Missions in deep space with the requisite longer duration of the missions planned may pose greater risks due to the increased potential for exposure to complex radiation fields comprised of a broad range of radiation types and energies from cosmic and unpredictable solar sources The first steps in the evaluation of risks are underway with bio- and physical-dosimetric measurements on both commercial flight personnel and international space crews who have experience on near-earth orbits and the necessary theoretical modeling of particle-track traversal per cell including the contributing effects of delta-rays in particle exposures An assumption for biologic effects due to exposure of radiation in deep space is that they differ quantitatively and qualitatively from that on earth The dose deposition and density pattern of heavy charged particles are very different from those of sparsely ionizing radiation The potential risks resulting from exposure to radiation in deep space are cancer non-cancer and genetic effects Radiation from

  7. 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

  8. Treatment of Radiation Injury.

    PubMed

    Akita, Sadanori

    2014-01-01

    Significance: Radiation exposure as a result of radiation treatment, accident, or terrorism may cause serious problems such as deficiency due to necrosis or loss of function, fibrosis, or intractable ulcers in the tissues and organs. When the skin, bone, oral mucous membrane, guts, or salivary glands are damaged by ionizing radiation, the management and treatment are very lengthy and difficult. Critical Issues: In severe and irreversible injuries, surgery remains the mainstay of treatment. Several surgical procedures, such as debridement, skin grafting, and local and free-vascularized flaps, are widely used. Recent Advances: In specific cases of major morbidity or in high-risk patients, a newly developed therapy using a patient's own stem cells is safe and effective. Adipose tissue, normally a rich source of mesenchymal stem cells, which are similar to those from the bone marrow, can be harvested, since the procedure is easy, and abundant tissue can be obtained with minimal invasiveness. Future Directions: Based on the molecular basis of radiation injuries, several prospective treatments are under development. Single-nucleotide polymorphisms focus on an individual's sensitivity to radiation in radiogenomics, and the pathology of radiation fibrosis or the effect of radiation on wound healing is being studied and will lead to new insight into the treatment of radiation injuries. Protectors and mitigators are being actively investigated in terms of the timing of administration or dose. PMID:24761339

  9. On Blackbody Radiation.

    ERIC Educational Resources Information Center

    Jain, Pushpendra K.

    1991-01-01

    The interrelationship between the various forms of the Planck radiation equation is discussed. A differential equation that gives intensity or energy density of radiation per unit wavelength or per unit frequency is emphasized. The Stefan-Boltzmann Law and the change in the glow of a hot body with temperature are also discussed. (KR)

  10. Radiation-resistant microorganism

    DOEpatents

    Fliermans, Carl B.

    2010-06-15

    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.

  11. 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.

  12. 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...

  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. Chitosan and radiation chemistry

    NASA Astrophysics Data System (ADS)

    Chmielewski, Andrzej G.

    2010-03-01

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under ?-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  15. 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.

  16. Fundamentals of Radiation Dosimetry

    SciTech Connect

    Bos, Adrie J. J.

    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.

  17. Underwater radiation detector

    DOEpatents

    Kruse, Lyle W. (Albuquerque, NM); McKnight, Richard P. (Albuquerque, NM)

    1986-01-01

    A detector apparatus for differentiating between gamma and neutron radiation is provided. The detector includes a pair of differentially shielded Geiger-Mueller tubes. The first tube is wrapped in silver foil and the second tube is wrapped in lead foil. Both the silver and lead foils allow the passage of gamma rays at a constant rate in a gamma ray only field. When neutrons are present, however, the silver activates and emits beta radiation that is also detected by the silver wrapped Geiger-Mueller tube while the radiation detected by the lead wrapped Geiger-Mueller tube remains constant. The amount of radiation impinging on the separate Geiger-Mueller tubes is then correlated in order to distinguish between the neutron and gamma radiations.

  18. 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.

  19. Nuclear radiation actuated valve

    DOEpatents

    Christiansen, David W.; Schively, Dixon P.

    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.

  20. Radiation and health*

    PubMed Central

    Lindell, B.

    1987-01-01

    Radiation has been a source of fascination and concern ever since Wilhelm Konrad Rntgen discovered X-rays on 8 November 1895. Over the years, health workers as well as the public have been concerned about medical uses of X-rays, the presence of radon in buildings, radioactive waste from nuclear power stations, fallout from nuclear test explosions, radioactive consumer products, microwave ovens, and many other sources of radiation. Most recently, the tragic accident at the Chernobyl nuclear power station in the USSR, and the subsequent contamination over most of Europe, has again wakened interest and concern and also reminded us about a number of misconceptions about radiation. This article describes the essentials about radiation (especially ionizing radiation) and its health effects. PMID:3496982

  1. Radiation Effects In Space

    SciTech Connect

    Tripathi, Ram K.

    2011-06-01

    Protecting space missions from severe exposures from radiation, in general, and long duration/deep space human missions, in particular, is a critical design driver, and could be a limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues and microelectronic devices. One is required to know how every element (and all isotopes of each element) in the periodic table interacts and fragments on every other element in the same table as a function of kinetic energy ranging over many decades. In addition, the accuracy of the input information and database, in general and nuclear data in particular, impacts radiation exposure health assessments and payload penalty. After a brief review of effects of space radiation on materials and electronics, human space missions to Mars is discussed.

  2. Radiation therapy imaging apparatus

    SciTech Connect

    Chou, T.J.; Shoenfeld, H.; Greenway, W.C.

    1991-02-19

    This patent describes a radiation therapy imaging apparatus for providing images in a patient being treated on a radiation therapy apparatus for verification and monitoring of patient positioning and verification of alignment and shaping of the radiation field of the radiation therapy apparatus. It comprises: a high-energy treatment head for applying a radiation dose to a patient positioned on a treatment table, and a gantry rotatable about an isocentric axis and carrying the treatment head for permitting the radiation dose to be applied to the patient from any of a range of angles about the isocentric axis; the radiation therapy imaging apparatus including a radiation therapy image detector which comprises a video camera mounted on the gantry diametrically opposite the treat head, an elongated light-excluding enclosure enveloping the camera to exclude ambient light from the camera, a fluoroscopic plate positioned on a distal end of the enclosure remote from the camera and aligned with the head to produce a fluoroscopic image in response to radiation applied from the head through the patient, mirror means in the enclosure and oriented for reflecting the image to the camera to permit monitoring on a viewing screen of the position of the radiation field in respect to the patient, and means for retracting at least the distal end of the enclosure from a position in which the fluoroscopic plate is disposed opposite the treatment head without disturbing the position of the camera on the gantry, so that the enclosure can be collapsed and kept from projecting under the treatment table when the patient is being positioned on the treatment table.

  3. Radiation Therapy for Testicular Cancer

    MedlinePLUS

    ... chemo and stem cell transplant for testicular cancer Radiation therapy for testicular cancer Radiation therapy uses high-energy rays or particles to ... cells or slow their growth. In testicular cancer, radiation is mainly used to kill cancer cells that ...

  4. [Remote radiation planning support system].

    PubMed

    Atsumi, Kazushige; Nakamura, Katsumasa; Yoshidome, Satoshi; Shioyama, Yoshiyuki; Sasaki, Tomonari; Ohga, Saiji; Yoshitake, Tadamasa; Shinoto, Makoto; Asai, Kaori; Sakamoto, Katsumi; Hirakawa, Masakazu; Honda, Hiroshi

    2012-08-01

    We constructed a remote radiation planning support system between Kyushu University Hospital (KUH) in Fukuoka and Kyushu University Beppu Hospital (KBH) in Oita. Between two institutions, radiology information system for radiotherapy division (RT-RIS) and radiation planning system (RTPS) were connected by virtual private network (VPN). This system enables the radiation oncologists at KUH to perform radiotherapy planning for the patients at KBH. The detail of the remote radiation planning support system in our institutions is as follows: The radiation oncologist at KBH performs radiotherapy planning and the data of the patients are sent anonymously to the radiation oncologists at KUH. The radiation oncologists at KUH receive the patient's data, access to RTPS at KBH, verify or change the radiation planning at KBH: Radiation therapy is performed at KBH according to the confirmed plan by the radiation oncologists at KUH. Our remote radiation planning system is useful for providing radiation therapy with safety and accuracy. PMID:23157128

  5. Modifying Radiation Damage

    PubMed Central

    Kim, Kwanghee; McBride, William H.

    2011-01-01

    Radiation leaves a fairly characteristic footprint in biological materials, but this is rapidly all but obliterated by the canonical biological responses to the radiation damage. The innate immune recognition systems that sense danger through direct radiation damage and through associated collateral damage set in motion a chain of events that, in a tissue compromised by radiation, often unwittingly result in oscillating waves of molecular and cellular responses as tissues attempt to heal. Understanding natures whispers that inform on these processes will lead to novel forms of intervention targeted more precisely towards modifying them in an appropriate and timely fashion so as to improve the healing process and prevent or mitigate the development of acute and late effects of normal tissue radiation damage, whether it be accidental, as a result of a terrorist incident, or of therapeutic treatment of cancer. Here we attempt to discuss some of the non-free radical scavenging mechanisms that modify radiation responses and comment on where we see them within a conceptual framework of an evolving radiation-induced lesion. PMID:20583981

  6. Beneficial uses of radiation

    SciTech Connect

    Fox, M.R.

    1991-10-01

    An overall decline in technical literacy within the American public has come at a time when technological advances are accelerating in the United States and around the world. This had led to a large communication gulf between the general public and the technologists. Nowhere is this more evident then with the topic of radiation. Regrettably, too few people know about sources of radiation, the pervasiveness, amounts, and variabilities, and do not have a true understanding of the environment in which we live. Nor do many people know that radiation has been used in beneficial ways for decades around the world. While the general public does not know of the scientific applications to which radiation has been deployed, it nevertheless had benefited tremendously from these efforts. Thanks to the well know properties of radiation, scientific ingenuity has found many uses of radiation in chemical and agricultural research, biomedical research, in the diagnoses and treatment of hundreds of types of diseases, in industrial applications, food irradiation, and many others. This paper provides a sample of the types of uses to which radiation has been used to help advance the betterment of humankind.

  7. Biological Effects of Ionizing Radiation

    DOE R&D Accomplishments Database

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  8. Federal approach to radiation issues

    SciTech Connect

    Young, A.L.; Dix, G.P.

    1988-07-01

    The Committee on Interagency Radiation Research and Policy Coordination (CIRRPC) was mandated in order to coordinate radiation matters between government agencies, evaluate radiation research, and furnish advice on the formulation of radiation policy. CIRRPC conducts some activities in the area of nonionizing radiation that comes from radio, television, microwaves, and radar emissions. However, most of CIRRPC's activities deal with the higher end of the spectrum. This radiation includes x-rays, gamma rays, and laser photons.

  9. 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.

  10. SYNCHROTRON RADIATION SOURCES

    SciTech Connect

    HULBERT,S.L.; WILLIAMS,G.P.

    1998-07-01

    Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

  11. Microcircuit radiation effects databank

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This databank is the collation of radiation test data submitted by many testers and serves as a reference for engineers who are concerned with and have some knowledge of the effects of the natural radiation environment on microcircuits. It contains radiation sensitivity results from ground tests and is divided into two sections. Section A lists total dose damage information, and section B lists single event upset cross sections, I.E., the probability of a soft error (bit flip) or of a hard error (latchup).

  12. Human radiation tolerance

    NASA Technical Reports Server (NTRS)

    Lushbaugh, C. C.

    1974-01-01

    The acute radiation syndrome in man is clinically bounded by death at high dose levels and by the prodromal syndrome of untoward physiological effects at minimal levels of clinically effective exposure. As in lower animals, man experiences principally three acute modes of death from radiation exposure (Bond et al., 1965). These are known collectively as the lethal radiation syndromes: central nervous system death, gastrointestinal death, and hematopoietic death. The effect of multiple exposure on lethality, the effect of multiple exposure on hematopoietic recovery, and quantitative aspects of cell and tissue repair are discussed.

  13. 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.

  14. Radiation Safety System

    SciTech Connect

    Vylet, Vaclav; Liu, James C.; Walker, Lawrence S.; /Los Alamos

    2012-04-04

    The goal of this work is to provide an overview of a Radiation safety system (RSS) designed for protection from prompt radiation hazard at accelerator facilities. RSS design parameters, functional requirements and constraints are derived from hazard analysis and risk assessment undertaken in the design phase of the facility. The two main subsystems of a RSS are access control system (ACS) and radiation control system (RCS). In this text, a common approach to risk assessment, typical components of ACS and RCS, desirable features and general design principles applied to RSS are described.

  15. Composition for radiation shielding

    DOEpatents

    Kronberg, James W. (Aiken, SC)

    1994-01-01

    A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

  16. Radiative forcing of climate

    NASA Technical Reports Server (NTRS)

    Ramanswamy, V.; Shine, Keith; Leovy, Conway; Wang, Wei-Chyung; Rodhe, Henning; Wuebbles, Donald J.; Ding, M.; Lelieveld, Joseph; Edmonds, Jae A.; Mccormick, M. Patrick

    1991-01-01

    An update of the scientific discussions presented in Chapter 2 of the Intergovernmental Panel on Climate Change (IPCC) report is presented. The update discusses the atmospheric radiative and chemical species of significance for climate change. There are two major objectives of the present update. The first is an extension of the discussion on the Global Warming Potentials (GWP's), including a reevaluation in view of the updates in the lifetimes of the radiatively active species. The second important objective is to underscore major developments in the radiative forcing of climate due to the observed stratospheric ozone losses occurring between 1979 and 1990.

  17. Occupational radiation safety.

    PubMed

    Dewar, Cherie

    2013-01-01

    Radiation has the power to both save and harm lives. Radiologic technologists use radiation to provide quality medical imaging, but they must be aware of potential exposure to radiation's detrimental effects. When proper time, distance, and shielding techniques are used, dangerous exposure levels can be avoided. Protection techniques are even more important for a pregnant radiologic technologist, who must safeguard her fetus from exposure. With an employer's cooperation and appropriate protection in place, a pregnant technologist should be able to work in a radiology setting without harming her fetus. PMID:23687243

  18. Liquid sheet radiator

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; White, K. Alan, III

    1987-01-01

    A new external flow radiator concept, the liquid sheet radiator (LSR), is introduced. The LSR sheet flow is described and an expression for the length/width (l/w), ratio is presented. A linear dependence of l/w on velocity is predicted that agrees with experimental results. Specific power for the LSR is calculated and is found to be nearly the same as the specific power of a liquid droplet radiator, (LDR). Several sheet thicknesses and widths were experimentally investigated. In no case was the flow found to be unstable.

  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. Radiation Injury to the Brain

    MedlinePLUS

    ... AVMs Radiosurgery Gamma Knife Linac Radiotherapy Overview Childhood Brain Tumors IMRT Radiation Therapy Radiation Injury Treatment Day Making a Decision Centers of Excellence Publications Definitions Q & A Brain ...

  1. Nanotechnology in Radiation Oncology

    PubMed Central

    Wang, Andrew Z.; Tepper, Joel E.

    2014-01-01

    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

  2. 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.

  3. 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.

  4. Radiation Exposure and Pregnancy

    MedlinePLUS

    ... Gynecol 200(1):4-24; 2009. International Atomic Energy Agency. Pregnancy and radiation protection in diagnostic radiology, radiotherapy and nuclear medicine. 2010. Available at: http: / / rpop. iaea. org/ ...

  5. Portal radiation monitor

    DOEpatents

    Kruse, L.W.

    1982-03-23

    A portal radiation monitor combines .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.

  6. 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

  7. Radiation - Duration: 31 seconds.

    NASA Video Gallery

    Outside the protective cocoon of Earth's atmosphere, the universe is full of harmful radiation. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radi...

  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. Radiation Therapy for Cancer

    MedlinePLUS

    ... is attached to the eye. In brachytherapy, radioactive isotopes are sealed in tiny pellets or “seeds.” These ... or some other type of carrier. As the isotopes decay naturally, they give off radiation that damages ...

  10. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  11. Radiation Tolerant Antifuse FPGA

    NASA Technical Reports Server (NTRS)

    Wang, Jih-Jong; Cronquist, Brian; McCollum, John; Parker, Wanida; Katz, Rich; Kleyner, Igor; Day, John H. (Technical Monitor)

    2002-01-01

    The total dose performance of the antifuse FPGA for space applications is summarized. Optimization of the radiation tolerance in the fabless model is the main theme. Mechanisms to explain the variation in different products are discussed.

  12. Management of radiation wounds

    SciTech Connect

    Reinisch, J.F.; Puckett, C.L.

    1984-08-01

    Radiation wounds caused by newer high-voltage radiotherapy techniques are very difficult to manage. Recent developments in flap design and transfer aid the surgeon in successfully treating these difficult problems.

  13. The Space Radiation Environment

    NASA Technical Reports Server (NTRS)

    Bourdarie, Sebastien; Xapsos, Michael A.

    2008-01-01

    The effects of the space radiation environment on spacecraft systems and instruments are significant design considerations for space missions. Astronaut exposure is a serious concern for manned missions. In order to meet these challenges and have reliable, cost-effective designs, the radiation environment must be understood and accurately modeled. The nature of the environment varies greatly between low earth orbits, higher earth orbits and interplanetary space. There are both short-term and long-term variations with the phase of the solar cycle. In this paper we concentrate mainly on charged particle radiations. Descriptions of the radiation belts and particles of solar and cosmic origin are reviewed. An overview of the traditional models is presented accompanied by their application areas and limitations. This is followed by discussion of some recent model developments.

  14. Isotopes and radiation

    SciTech Connect

    1999-10-01

    Subjects covered in this section are: (1) Food industry groups petition for expanded use of irradiation; (2) First meeting of BEIR VII committee with new members held; and (3) DOE undertaking 10-yr study of radiation health effects.

  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. Amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17

    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 the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  17. Amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A. (Palo Alto, CA); Perez-Mendez, Victor (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    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 the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  18. Ionizing radiation detector

    DOEpatents

    Thacker, Louis H. (Knoxville, TN)

    1990-01-01

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  19. Radiation risks in pregnancy

    SciTech Connect

    Mossman, K.L.; Hill, L.T.

    1982-08-01

    A major contraindication of radiodiagnostic procedures is pregnancy. Approximately 1% of all pregnant women are given abdominal x-rays during the first trimester of pregnancy. Evaluation of radiation exposure should involve consideration of the types of examinations performed and when performed, as well as radiation dose and risk estimation. This information is then weighed against other possible risks of the pregnancy as well as personal factors. In the authors' experiences, radiation exposures usually result in doses to the embryo of less than 5 cGy (rad); the resulting radiation risks are usually small compared with other risks of pregnancy. Procedures to minimize diagnostic x-ray exposure of the fetus are also discussed.

  20. [Genetic effects of radiation].

    PubMed

    Nakamura, Nori

    2012-03-01

    This paper is a short review of genetic effect of radiation. This includes methods and results of a large-scale genetic study on specific loci in mice and of various studies in the offspring of atomic-bomb survivors. As for the latter, there is no results obtained which suggest the effect of parental exposure to radiation. Further, in recent years, studies are conducted to the offspring born to parents who were survivors of childhood cancers. In several reports, the mean gonad dose is quite large whereas in most instances, the results do not indicate genetic effect following parental exposure to radiation. Possible reasons for the difficulties in detecting genetic effect of radiation are discussed. PMID:22514926

  1. External Radiation Therapy

    MedlinePLUS Videos and Cool Tools

    Narrator: When the cancer is not completely contained in the prostate or when the patient is older the treatment that is frequently used ... There are different forms of radiation for prostate cancer. They really boil down to two different types. ...

  2. 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)

  3. 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.

  4. Radiation detection system

    DOEpatents

    Whited, R.C.

    A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI/sub 2/, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

  5. Liquid sheet radiator apparatus

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L. (Inventor)

    1990-01-01

    An external flow, liquid sheet radiator apparatus adapted for space applications has as its radiating surface a thin stable liquid sheet formed by fluid flow through a very narrow slit affixed to the sheet generator. As a result of surface tension forces, the sheet has a triangular shape and is collected into a simply designed collector positioned at the apex of the triangle. The specific power for the liquid sheet is virtually the same as the droplet sheet specific power.

  6. Lightweight Radiator Fin

    NASA Technical Reports Server (NTRS)

    Long, W. Russ, III; Ungar, Eugene K.

    1992-01-01

    Lightweight radiator fin made of tapered panels bent together at ends and joined to heat pipe in middle. Taper chosen for minimum mass per unit of radiated power. Intended primarily for use as part of cooling system of space station, also used on Earth to cool equipment in laboratory vacuum. Possible to modify basic design equations to design minimum-mass fins for cooling by conduction or convection.

  7. Radiation environment mapping

    NASA Technical Reports Server (NTRS)

    Benton, E. Y.

    1981-01-01

    An experimental set up to map the cosmic radiation field inside the Spacelab vehicle to determine the potential biological hazards present is described. In addition to the integral linear energy transfer (LET) spectrum for protons and HZE particles, the parameters to be determined include the total radiation dose; fluence of neutrons, protons, and high charge and energy (HZE) particles. These results are to be derived from measurements made in passive dosimeters.

  8. 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.

  9. Packet personal radiation monitor

    DOEpatents

    Phelps, James E.

    1989-01-01

    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 radiation events, 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.

  10. 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.

  11. 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.

  12. Fabric space radiators

    SciTech Connect

    Antoniak, Z.I.; Krotiuk, W.J.; Webb, B.J.; Prater, J.T.; Bates, J.M.

    1988-01-01

    Future Air Force space missions will require thermal radiators that both survive in the hostile space environment and stow away for minimal bulk during launch. Advances in all aspects of radiator design, construction, and analysis will be necessary to enable such future missions. Currently, the best means for obtaining high strength along with flexibility is through structures known as fabrics. The development of new materials and bonding techniques has extended the application range of fabrics into areas traditionally dominated by monolithic and/or metallic structures. Given that even current spacecraft heat rejection considerations tend to dominate spacecraft design and mass, the larger and more complex designs of the future face daunting challenges in thermal control. Ceramic fabrics bonded to ultra-thin metal liners (foils) have the potential of achieving radiator performance levels heretofore unattainable, and of readily matching the advances made in other branches of spacecraft design. The research effort documented here indicates that both pumped loops and heat pipes constructed in ceramic fabrics stand to benefit in multiple ways. Flexibility and low mass are the main advantages exhibited by fabric radiators over conventional metal ones. We feel that fabric radiators have intrinsic merits not possessed by any other radiator design and need to be researched further. 26 refs., 16 figs., 17 tabs.

  13. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Mondelaers, Win; Lahorte, Philippe

    This chapter is part one of a review in which the production and application of radiation-induced bioradicals is discussed. Bioradicals play a pivotal role in the complex chain of processes starting with the absorption of radiation in biological materials and ending with the radiation-induced biological after-effects. The general aspects of the four consecutive stages (physical, physicochemical, chemical and biological) are discussed from an interdisciplinary point of view. The close relationship between radiation dose and track structure, induced DNA damage and cell survival or killing is treated in detail. The repair mechanisms that cells employ, to insure DNA stability following irradiation, are described. Because of their great biomedical importance tumour suppressor genes involved in radiation-induced DNA repair and in checkpoint activation will be treated briefly, together with the molecular genetics of radiosensitivity. Part two of this review will deal with modern theoretical methods and experimental instrumentation for quantitative studies in this research field. Also an extensive overview of the applications of radiation-induced bioradicals will be given. A comprehensive list of references allows further exploration of this research field, characterised in the last decade by a substantial advance, both in fundamental knowledge and in range of applications.

  14. Radiation analysis devices, radiation analysis methods, and articles of manufacture

    DOEpatents

    Roybal, Lyle Gene

    2010-06-08

    Radiation analysis devices include circuitry configured to determine respective radiation count data for a plurality of sections of an area of interest and combine the radiation count data of individual of sections to determine whether a selected radioactive material is present in the area of interest. An amount of the radiation count data for an individual section is insufficient to determine whether the selected radioactive material is present in the individual section. An article of manufacture includes media comprising programming configured to cause processing circuitry to perform processing comprising determining one or more correction factors based on a calibration of a radiation analysis device, measuring radiation received by the radiation analysis device using the one or more correction factors, and presenting information relating to an amount of radiation measured by the radiation analysis device having one of a plurality of specified radiation energy levels of a range of interest.

  15. 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,…

  16. 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,

  17. 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.

  18. Radiation in Particle Simulations

    SciTech Connect

    More, R; Graziani, F; Glosli, J; Surh, M

    2010-11-19

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third method is a hybrid molecular dynamics/Monte Carlo (MD/MC) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions. The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc. This approach is inspired by the virial expansion method of equilibrium statistical mechanics. Using a combination of these methods we believe it is possible to do atomic-scale particle simulations of fusion ignition plasmas including the important effects of radiation emission and absorption.

  19. Status of LDEF radiation modeling

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    The current status of model prediction and comparison with LDEF radiation dosimetry measurements is summarized with emphasis on major results obtained in evaluating the uncertainties of present radiation environment model. The consistency of results and conclusions obtained from model comparison with different sets of LDEF radiation data (dose, activation, fluence, LET spectra) is discussed. Examples where LDEF radiation data and modeling results can be utilized to provide improved radiation assessments for planned LEO missions (e.g., Space Station) are given.

  20. Radiation delivery system and method

    DOEpatents

    Sorensen, Scott A.; Robison, Thomas W.; Taylor, Craig M. V.

    2002-01-01

    A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

  1. 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.

  2. Radiative Forcing by Contrails

    NASA Technical Reports Server (NTRS)

    Meerkoetter, R.; Schumann, U.; Doelling, D. R.; Nakajima, T.; Tsushima, Y.

    1999-01-01

    A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmospheres The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, mid-latitude, and subarctic summer and winter atmospheres Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 W/m(exp 2)a daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover.

  3. 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

  4. Synchrotron Radiation Workshop (SRW)

    Energy Science and Technology Software Center (ESTSC)

    2013-03-01

    "Synchrotron Radiation Workshop" (SRW) is a physical optics computer code for calculation of detailed characteristics of Synchrotron Radiation (SR) generated by relativistic electrons in magnetic fields of arbitrary configuration and for simulation of the radiation wavefront propagation through optical systems of beamlines. Frequency-domain near-field methods are used for the SR calculation, and the Fourier-optics based approach is generally used for the wavefront propagation simulation. The code enables both fully- and partially-coherent radiation propagation simulations inmore » steady-state and in frequency-/time-dependent regimes. With these features, the code has already proven its utility for a large number of applications in infrared, UV, soft and hard X-ray spectral range, in such important areas as analysis of spectral performances of new synchrotron radiation sources, optimization of user beamlines, development of new optical elements, source and beamline diagnostics, and even complete simulation of SR based experiments. Besides the SR applications, the code can be efficiently used for various simulations involving conventional lasers and other sources. SRW versions interfaced to Python and to IGOR Pro (WaveMetrics), as well as cross-platform library with C API, are available.« less

  5. Radiation from Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Hardee, P.; Sol, H.; Medvedev, M.; Zhang, B.; Nordlund, A.; Frederiksen, J. T.; Fishman, G. J.; Preece, R.

    2008-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electron-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the presence of relativistic jets, instabilities such as the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability create collisionless shocks, which are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons in small-scale magnetic fields has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation, a case of diffusive synchrotron radiation, may be important to understand the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  6. 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.

  7. Remote radiation dosimetry

    DOEpatents

    Braunlich, P.F.; Tetzlaff, W.; Hegland, J.E.; Jones, S.C.

    1991-03-12

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via a transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission. 8 figures.

  8. Remote radiation dosimetry

    DOEpatents

    Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA); Hegland, Joel E. (Pullman, WA); Jones, Scott C. (Pullman, WA)

    1991-01-01

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission.

  9. Synchrotron Radiation Workshop (SRW)

    SciTech Connect

    2013-03-01

    "Synchrotron Radiation Workshop" (SRW) is a physical optics computer code for calculation of detailed characteristics of Synchrotron Radiation (SR) generated by relativistic electrons in magnetic fields of arbitrary configuration and for simulation of the radiation wavefront propagation through optical systems of beamlines. Frequency-domain near-field methods are used for the SR calculation, and the Fourier-optics based approach is generally used for the wavefront propagation simulation. The code enables both fully- and partially-coherent radiation propagation simulations in steady-state and in frequency-/time-dependent regimes. With these features, the code has already proven its utility for a large number of applications in infrared, UV, soft and hard X-ray spectral range, in such important areas as analysis of spectral performances of new synchrotron radiation sources, optimization of user beamlines, development of new optical elements, source and beamline diagnostics, and even complete simulation of SR based experiments. Besides the SR applications, the code can be efficiently used for various simulations involving conventional lasers and other sources. SRW versions interfaced to Python and to IGOR Pro (WaveMetrics), as well as cross-platform library with C API, are available.

  10. Computer-based radiation safety training for hospital radiation workers.

    PubMed

    Hamilton, D S; Peck, M M; Yu, H; Kearfott, K J

    2000-02-01

    Conducting a hospital-based radiation safety training class may lead to temporary technologist staffing shortages resulting in a reduction of patient services or even the cessation of all routine patient services. Use of an interactive computer-based radiation safety training software program may provide a practical alternative for hospital diagnostic and therapeutic radiation departments, as well as other hospital departments utilizing radiation sources, in meeting annual radiation safety training requirements for radiation workers. Medical radiation workers' participation in computer-based radiation safety training can make a positive impact on radiation safety awareness in the hospital, assist license holders in satisfying regulatory training requirements, ensure maximum participation of staff technologists, and reduce the burden of technologist staffing shortages caused by traditional methods of training. PMID:10651396

  11. Composition for radiation shielding

    DOEpatents

    Kronberg, J.W.

    1994-08-02

    A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

  12. Radiation techniques for acromegaly

    PubMed Central

    2011-01-01

    Radiotherapy (RT) remains an effective treatment in patients with acromegaly refractory to medical and/or surgical interventions, with durable tumor control and biochemical remission; however, there are still concerns about delayed biochemical effect and potential late toxicity of radiation treatment, especially high rates of hypopituitarism. Stereotactic radiotherapy has been developed as a more accurate technique of irradiation with more precise tumour localization and consequently a reduction in the volume of normal tissue, particularly the brain, irradiated to high radiation doses. Radiation can be delivered in a single fraction by stereotactic radiosurgery (SRS) or as fractionated stereotactic radiotherapy (FSRT) in which smaller doses are delivered over 5-6 weeks in 25-30 treatments. A review of the recent literature suggests that pituitary irradiation is an effective treatment for acromegaly. Stereotactic techniques for GH-secreting pituitary tumors are discussed with the aim to define the efficacy and potential adverse effects of each of these techniques. PMID:22136376

  13. Radiation Protection in Canada

    PubMed Central

    Brown, John R.; Jarvis, Anita A.

    1964-01-01

    A recent survey was carried out with respect to radiobiological and radiological health projects in Canada. Letters of inquiry, followed by two questionnaires, were sent out to every institution where radiation research was likely to have been undertaken. Approximately 75% of those contacted replied. Of the total of 200 studies, 84% were classified as biological and medical studies, the remaining 16% as environmental radiation studies. Responses to the inquiry stressed the inadequacy of the present governmental budget for radiation research, the need for higher salaries for research workers, and the necessity of a more intensive teaching program for technicians and professional personnel. The granting of longer-term grants, rather than annually renewable grants, is urged. PMID:14226104

  14. Radiation Induced Oral Mucositis

    PubMed Central

    PS, Satheesh Kumar; Balan, Anita; Sankar, Arun; Bose, Tinky

    2009-01-01

    Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene PMID:20668585

  15. 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.

  16. Dosimetry for radiation processing

    NASA Astrophysics Data System (ADS)

    Miller, Arne

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both by international organizations (IAEA) and national laboratories have helped to improve the reliability of dose measurements. Several dosimeter systems like calorimetry, perspex, and radiochromic dye films are being improved and new systems have emerged, e.g. spectrophotometry of dichromate solution for reference and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading to traceable and reliable dosimetry are discussed.

  17. Precision synchrotron radiation detectors

    SciTech Connect

    Levi, M.; Rouse, F.; Butler, J.; Jung, C.K.; Lateur, M.; Nash, J.; Tinsman, J.; Wormser, G.; Gomez, J.J.; Kent, J.

    1989-03-01

    Precision detectors to measure synchrotron radiation beam positions have been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 /mu/m on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely-aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. Also, detectors of synchrotron radiation using the charge developed by the ejection of Compton-recoil electrons from an array of fine wires are being developed. 4 refs., 5 figs., 1 tab.

  18. Solar cell radiation handbook

    SciTech Connect

    Tada, H.Y.; Carter, J.R. Jr.; Anspaugh, B.E.

    1982-11-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed 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. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  19. 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.

  20. Audible radiation monitor

    DOEpatents

    Odell, Daniel M. C.

    1993-01-01

    A method and apparatus for monitoring ionizing radiation comprising radiation detectors in electrical connection with an isotopic analyzer and a device for producing chords to which each isotope is mapped so that the device produces a unique chord for each isotope. Preferably the chords are pleasing to the ear, except for chords representing unexpected isotopes, and are louder or softer depending on the level of radioactivity produced by each isotope, and musical instrument voices may be simulated in producing the chords as an aid to distinguishing similar-sounding chords. Because of the representation by chords, information regarding the level and composition of the radiation in an area can be conveyed to workers in that area more effectively and yet without distracting them.

  1. Semiconductor radiation detector

    DOEpatents

    Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  2. Audible radiation monitor

    SciTech Connect

    Odell, D.M.C.

    1992-12-31

    This invention consists of a method and apparatus for monitoring ionizing radiation comprising radiation detectors in electrical connection with an isotopic analyzer and a device for producing chords to which each isotope is mapped so that the device produces a unique chord for each isotope. Preferably the chords are pleasing to the ear, except for chords representing unexpected isotopes, and are louder or softer depending on the level of radioactivity produced by each isotope, and musical instrument voices may be simulated in producing the chords as an aid to distinguishing similar-sounding chords. Because of the representation by chords, information regarding the level and composition of the radiation in an area can be conveyed to workers in that area more effectively and yet without distracting them.

  3. Pediatric radiation oncology

    SciTech Connect

    Halperin, E.C.; Kun, L.E.; Constine, L.S.; Tarbell, N.J.

    1989-01-01

    This text covers all aspects of radiation therapy for treatment of pediatric cancer. The book describes the proper use of irradiation in each of the malignancies of childhood, including tumors that are rarely encountered in adult practice. These include acute leukemia; supratentorial brain tumors; tumors of the posterior fossa of the brain and spinal canal; retinoblastoma and optic nerve glioma; neuroblastoma; Hodgkin's disease; malignant lymphoma; Ewing's sarcoma; osteosarcoma; rhabdomyosarcoma; Desmoid tumor; Wilms' tumor; liver and biliary tumors; germ cell and stromal cell tumors of the gonads; endocrine, aerodigestive tract, and breast tumors; Langerhans' cell histiocytosis; and skin cancer and hemangiomas. For each type of malignancy, the authors describe the epidemiology, common presenting signs and symptoms, staging, and proper diagnostic workup. Particular attention is given to the indications for radiation therapy and the planning of a course of radiotherapy, including the optimal radiation dose, field size, and technique.

  4. Solar cell radiation handbook

    NASA Technical Reports Server (NTRS)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed 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. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  5. String radiative backreaction

    SciTech Connect

    Battye, R.A.; Shellard, E.P.

    1995-12-01

    We discuss radiative backreaction for global strings described by the Kalb-Ramond action with an analogous derivation to that for the point electron in classical electrodynamics. We show how local corrections to the equations of motion allow one to separate the self-field of the string from that of the radiation field. Modifications to this {open_quote}{open_quote}local backreaction approximation{close_quote}{close_quote} circumvent the runaway solutions, allowing these corrections to be used to evolve string trajectories numerically. Comparisons are made with analytic and numerical radiation calculations from previous work and the merits and limitations of this approach are discussed. {copyright} {ital 1995 The American Physical Society.}

  6. 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.

  7. LDEF Satellite Radiation Analyses

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    This report covers work performed by Science Applications International Corporation (SAIC) under contract NAS8-39386 from the NASA Marshall Space Flight Center entitled LDEF Satellite Radiation Analyses. The basic objective of the study was to evaluate the accuracy of present models and computational methods for defining the ionizing radiation environment for spacecraft in Low Earth Orbit (LEO) by making comparisons with radiation measurements made on the Long Duration Exposure Facility (LDEF) satellite, which was recovered after almost six years in space. The emphasis of the work here is on predictions and comparisons with LDEF measurements of induced radioactivity and Linear Energy Transfer (LET) measurements. These model/data comparisons have been used to evaluate the accuracy of current models for predicting the flux and directionality of trapped protons for LEO missions.

  8. Radiation litigation: future issues

    SciTech Connect

    Jose, D.E.

    1989-02-01

    Scientists and regulators have successfully been able to control exposures to man-made ionizing radiation so that mankind has been able to enjoy its vast benefits without experiencing the significant harm which would occur from high doses. However, thousands of lawsuits have been filed claiming that low occupational levels of ionizing radiation have caused cancer and other illnesses. It will be decades before the legal system determines the rules of law which will apply to this new type of lawsuit and the effects which these cases will have upon those persons who work with sources of ionizing radiation. This article explores some of the issues which are expected to arise as these cases work their way through the courts.

  9. 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.

  10. Radiation in Particle Simulations

    SciTech Connect

    More, R M; Graziani, F R; Glosli, J; Surh, M

    2009-06-15

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known (section 3). The second method expands the electromagnetic field in normal modes (plane-waves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion (section 4). The third method is a hybrid MD/MC (molecular dynamics/Monte Carlo) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions (section 5). The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc.(section 6). This approach is inspired by the Virial expansion method of equilibrium statistical mechanics.

  11. 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.

  12. Small Active Radiation Monitor

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    2004-01-01

    A device, named small active radiation monitor, allows on-orbit evaluations during periods of increased radiation, after extravehicular activities, or at predesignated times for crews on such long-duration space missions as on the International Space Station. It also permits direct evaluation of biological doses, a task now performed using a combination of measurements and potentially inaccurate simulations. Indeed the new monitor can measure a full array of radiation levels, from soft x-rays to hard galactic cosmic-ray particles. With refinement, it will benefit commercial (nuclear power-plant workers, airline pilots, medical technicians, physicians/dentists, and others) and military personnel as well as the astronauts for whom thermoluminescent dosimeters are inadequate. Civilian and military personnel have long since graduated from film badges to thermoluminescent dosimeters. Once used, most dosimeters must be returned to a central facility for processing, a step that can take days or even weeks. While this suffices for radiation workers for whom exposure levels are typically very low and of brief duration, it does not work for astronauts. Even in emergencies and using express mail, the results can often be delayed by as much as 24 hours. Electronic dosimeters, which are the size of electronic oral thermometers, and tattlers, small electronic dosimeters that sound an alarm when the dose/dose rate exceeds preset values, are also used but suffer disadvantages similar to those of thermoluminescent dosimeters. None of these devices fully answers the need of rapid monitoring during the space missions. Instead, radiation is monitored by passive detectors, which are read out after the missions. Unfortunately, these detectors measure only the absorbed dose and not the biologically relevant dose equivalent. The new monitor provides a real-time readout, a time history of radiation exposures (both absorbed dose and biologically relevant dose equivalent), and a count of the number of particles passing through a unit area. Better still, the monitor can be used anywhere.

  13. Tunable terahertz radiation source

    DOEpatents

    Boulaevskii, Lev; Feldmann, David M; Jia, Quanxi; Koshelev, Alexei; Moody, Nathan A

    2014-01-21

    Terahertz radiation source and method of producing terahertz radiation, said source comprising a junction stack, said junction stack comprising a crystalline material comprising a plurality of self-synchronized intrinsic Josephson junctions; an electrically conductive material in contact with two opposing sides of said crystalline material; and a substrate layer disposed upon at least a portion of both the crystalline material and the electrically-conductive material, wherein the crystalline material has a c-axis which is parallel to the substrate layer, and wherein the source emits at least 1 mW of power.

  14. Radiation Detectors and Art

    NASA Astrophysics Data System (ADS)

    Denker, Andrea

    The use of radiation detectors in the analysis of art objects represents a very special application in a true interdisciplinary field. Radiation detectors employed in this field detect, e.g., x-rays, ?-rays, ? particles, and protons. Analyzed materials range from stones, metals, over porcelain to paintings. The available nondestructive and noninvasive analytical methods cover a broad range of techniques. Hence, for the sake of brevity, this chapter will concentrate on few techniques: Proton Induced X-ray Emission (PIXE) and Proton Induced ?-ray Emission (PIGE).

  15. Thermal radiative properties: Coatings.

    NASA Technical Reports Server (NTRS)

    Touloukian, Y. S.; Dewitt, D. P.; Hernicz, R. S.

    1972-01-01

    This volume consists, for the most part, of a presentation of numerical data compiled over the years in a most comprehensive manner on coatings for all applications, in particular, thermal control. After a moderately detailed discussion of the theoretical nature of the thermal radiative properties of coatings, together with an overview of predictive procedures and recognized experimental techniques, extensive numerical data on the thermal radiative properties of pigmented, contact, and conversion coatings are presented. These data cover metallic and nonmetallic pigmented coatings, enamels, metallic and nonmetallic contact coatings, antireflection coatings, resin coatings, metallic black coatings, and anodized and oxidized conversion coatings.

  16. 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.

  17. Wireless passive radiation sensor

    SciTech Connect

    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.

  18. Radiative plateau inflation

    NASA Astrophysics Data System (ADS)

    Ballesteros, Guillermo; Tamarit, Carlos

    2016-02-01

    We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflaton with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

  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. 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.

  1. Radiation monitor for liquids

    DOEpatents

    Koster, J.E.; Bolton, R.D.

    1999-03-02

    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. 4 figs.

  2. 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.

  3. 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.

  4. Space Radiation and the Brain

    NASA Astrophysics Data System (ADS)

    Hampson, R. E.

    Solar and cosmic radiation pose a number of physiological challenges to human spaceflight outside the protective region of Earth's magnetosphere. Aside from well-described effects of radiation on the blood-forming tissues of the hematopoietic system, there is increasing evidence of direct effects of radiation on the brain as evidenced by studies showing longitudinal decline in memory and cognitive function following radiation specifically directed at brain tissue. These indications strengthen the need to more fully research effects of radiation - particular those components associated with solar wind and galactic cosmic radiation - on the nervous system of mammals from rodents to humans.

  5. 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

  6. Problems in astrophysical radiation hydrodynamics

    SciTech Connect

    Castor, J.I.

    1983-09-14

    The basic equations of radiation hydrodynamics are discussed in the regime that the radiation is dynamically as well as thermally important. Particular attention is paid to the question of what constitutes an acceptable approximate non-relativistic system of dynamical equations for matter and radiation in this regime. Further discussion is devoted to two classes of application of these ideas. The first class consists of problems dominated by line radiation, which is sensitive to the velocity field through the Doppler effect. The second class is of problems in which the advection of radiation by moving matter dominates radiation diffusion.

  7. Calculate Your Radiation Dose

    MedlinePLUS

    ... U.S. Environmental Protection Agency) Natural Background Sources (U.S. Nuclear Regulatory Commission) Travel-related Sources Frequently Asked Questions on Cabinet X-ray Systems (U.S. Food and Drug Administration) Radiation and Airport Security Scanning (RadTown, U.S. Environmental Protection ...

  8. Thermodynamics of blackbody radiation

    NASA Astrophysics Data System (ADS)

    Kelly, Robert E.

    1981-08-01

    The thermodynamics of homogeneous, isotropic, unpolarized electromagnetic radiation in a cavity with volume and temperature controllable as the independent variables is analyzed. Internal energy, pressure, chemical potential, enthalpy, Gibbs free energy, heat capacities, expansivity, and compressibility are all derived from the Helmholtz free energy. Topics treated are the third law, isothermal, adiabatic, and free expansion, throttling process, phase equilibrium, stability, and the Carnot cycle.

  9. Alkoxy radical radiation products

    SciTech Connect

    Box, H.C.; Budzinski, E.E.

    1982-06-01

    Single crystals of ribitol and 6-methylpurine-riboside were x-irradiated at 4.2 /sup 0/K. Alkoxy radicals were identified in the radiation products. The g tensor and proton coupling tensors, were determined from ENDOR and ESR studies. (AIP)

  10. Radiation Hardening of Computers

    NASA Technical Reports Server (NTRS)

    Nichols, D. K.; Smith, L. S.; Zoutendyk, J. A.; Giddings, A. E.; Hewlett, F. W.; Treece, R. K.

    1986-01-01

    Single-event upsets reduced by use of oversize transistors. Computers made less susceptible to ionizing radiation by replacing bipolar integrated circuits with properly designed, complementary metaloxide-semiconductor (CMOS) circuits. CMOS circuit chips made highly resistant to single-event upset (SEU), especially when certain feedback resistors are incorporated. Redesigned chips also consume less power than original chips.

  11. Psoriasis and ultraviolet radiation

    SciTech Connect

    Farber, E.M.; Nall, L. )

    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.

  12. Radiation detector spectrum simulator

    DOEpatents

    Wolf, M.A.; Crowell, J.M.

    1985-04-09

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  13. Radiation effects on development.

    PubMed

    De Santis, Marco; Cesari, Elena; Nobili, E; Straface, Gianluca; Cavaliere, Anna Franca; Caruso, Alessandro

    2007-09-01

    It has been widely reported that prenatal exposure to ionizing radiation can interfere with embryonic and fetal development, depending on dose and gestational age in which exposure occurs. According to several studies on animal models, different well-defined stages during prenatal life can be distinguished in relation to teratogenic effects. During the preimplantation stage, elevated doses of radiation can result in abortion, while lower doses may produce genomic damage that is usually repaired. On the other hand, during the organogenesis stage in mice (embryonic day 6.5 [E6.5] to E13.5), irradiation is associated with increased incidence of malformation and intrauterine growth restriction (IUGR). Later exposure is linked to brain damage. Doses used in animal studies are generally higher than those used for diagnostic procedures in humans. Usually, radiation exposure to diagnostic range (<0.05 Gy = 5 rads) is not associated with an increased risk of congenital anomalies. In human studies, elevated doses produce adverse outcomes, depending on stage of development, as in animal studies. Blastogenesis (up to two weeks) is associated with failure to implant or no significant health effects. An increased risk of malformation and growth retardation can be observed for two to seven weeks exposure (organogenesis stage), while exposure at later stages (fetogenesis) is mainly associated with brain damage. In this review we focus on the relevance of estimating the cumulative dose of radiation to the fetus and the gestational age in which exposure occurs, to provide appropriate counseling to pregnant women. PMID:17963274

  14. Paradoxes of Thermal Radiation

    ERIC Educational Resources Information Center

    Besson, U.

    2009-01-01

    This paper presents an analysis of the thermal behaviour of objects exposed to a solar-type flux of thermal radiation. It aims to clarify certain apparent inconsistencies between theory and observation, and to give a detailed exposition of some critical points that physics textbooks usually treat in an insufficient or incorrect way. In particular,

  15. Thermodynamics of Radiation Modes

    ERIC Educational Resources Information Center

    Pina, Eduardo; de la Selva, Sara Maria Teresa

    2010-01-01

    We study the equilibrium thermodynamics of the electromagnetic radiation in a cavity of a given volume and temperature. We found three levels of description, the thermodynamics of one mode, the thermodynamics of the distribution of frequencies in a band by summing over the frequencies in it and the global thermodynamics by summing over all the

  16. Radiations from hot nuclei

    NASA Technical Reports Server (NTRS)

    Malik, F. Bary

    1993-01-01

    The investigation indicates that nuclei with excitation energy of a few hundred MeV to BeV are more likely to radiate hot nuclear clusters than neutrons. These daughter clusters could, furthermore, de-excite emitting other hot nuclei, and the chain continues until these nuclei cool off sufficiently to evaporate primarily neutrons. A few GeV excited nuclei could radiate elementary particles preferentially over neutrons. Impact of space radiation with materials (for example, spacecraft) produces highly excited nuclei which cool down emitting electromagnetic and particle radiations. At a few MeV excitation energy, neutron emission becomes more dominant than gamma-ray emission and one often attributes the cooling to take place by successive neutron decay. However, a recent experiment studying the cooling process of 396 MeV excited Hg-190 casts some doubt on this thinking, and the purpose of this investigation is to explore the possibility of other types of nuclear emission which might out-compete with neutron evaporation.

  17. Radiation Source Replacement Workshop

    SciTech Connect

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  18. Paradoxes of Thermal Radiation

    ERIC Educational Resources Information Center

    Besson, U.

    2009-01-01

    This paper presents an analysis of the thermal behaviour of objects exposed to a solar-type flux of thermal radiation. It aims to clarify certain apparent inconsistencies between theory and observation, and to give a detailed exposition of some critical points that physics textbooks usually treat in an insufficient or incorrect way. In particular,…

  19. The radiation design handbook

    NASA Astrophysics Data System (ADS)

    1993-05-01

    A handbook which provides general engineering guidelines suitable for project groups engaged in the design of spacecraft required to operate in regions of space where they will be exposed to significant doses of radiation is presented. The charged particle environment in geomagnetospheric space, and the physics of radiation effects on solid state devices and materials (including ionization effects, single event upsets and bulk displacement damage) in all the designs of devices likely to be used in spacecraft are discussed. Methods of assessing the impact of these effects are given, including procedures for calculating the orbital radiation environment, dose depth curves within electronic enclosures, and the end of life degradation of devices and circuits. While no rigid procedures for handling these problems can be set out, special attention is given to methods of alleviating the problems presented. These methods cover tradeoff studies of orbit versus shield weight, layout rules for spacecraft, the use of redundancy and housekeeping dosimetry, device selection, device verification, and the design of radiation tolerant circuits.

  20. Radiation detector spectrum simulator

    DOEpatents

    Wolf, Michael A. (Los Alamos, NM); Crowell, John M. (Los Alamos, NM)

    1987-01-01

    A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  1. 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

  2. Thermostatic Radiator Valve Evaluation

    SciTech Connect

    Dentz, Jordan; Ansanelli, Eric

    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.

  3. Acute radiation risk models

    NASA Astrophysics Data System (ADS)

    Smirnova, Olga

    Biologically motivated mathematical models, which describe the dynamics of the major hematopoietic lineages (the thrombocytopoietic, lymphocytopoietic, granulocytopoietic, and erythropoietic systems) in acutely/chronically irradiated humans are developed. These models are implemented as systems of nonlinear differential equations, which variables and constant parameters have clear biological meaning. It is shown that the developed models are capable of reproducing clinical data on the dynamics of these systems in humans exposed to acute radiation in the result of incidents and accidents, as well as in humans exposed to low-level chronic radiation. Moreover, the averaged value of the "lethal" dose rates of chronic irradiation evaluated within models of these four major hematopoietic lineages coincides with the real minimal dose rate of lethal chronic irradiation. The demonstrated ability of the models of the human thrombocytopoietic, lymphocytopoietic, granulocytopoietic, and erythropoietic systems to predict the dynamical response of these systems to acute/chronic irradiation in wide ranges of doses and dose rates implies that these mathematical models form an universal tool for the investigation and prediction of the dynamics of the major human hematopoietic lineages for a vast pattern of irradiation scenarios. In particular, these models could be applied for the radiation risk assessment for health of astronauts exposed to space radiation during long-term space missions, such as voyages to Mars or Lunar colonies, as well as for health of people exposed to acute/chronic irradiation due to environmental radiological events.

  4. ATMOSPHERIC RADIATION MEASUREMENT PROGRAM

    EPA Science Inventory

    The Atmospheric Radiation Measurement Program (ARM) is the largest global change research program supported by the U.S. Department of Energy (DOE). ARM scientists focus on obtaining field measurements and developing models to better understand the processes that control solar and...

  5. 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.

  6. VDT Emissions Radiate Debate.

    ERIC Educational Resources Information Center

    Morgan, Bill

    1990-01-01

    Discusses the possible health effects of electromagnetic fields of radiation that are emitted from video display terminals (VDTs). Responses from vendors in the computer industry are related, steps to reduce possible risks are suggested, and additional sources of information on VDTs are listed. (LRW)

  7. 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.

  8. 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...

  9. Thermodynamics of Radiation Modes

    ERIC Educational Resources Information Center

    Pina, Eduardo; de la Selva, Sara Maria Teresa

    2010-01-01

    We study the equilibrium thermodynamics of the electromagnetic radiation in a cavity of a given volume and temperature. We found three levels of description, the thermodynamics of one mode, the thermodynamics of the distribution of frequencies in a band by summing over the frequencies in it and the global thermodynamics by summing over all the…

  10. 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…

  11. RADIATION: MEDICAL DIAGNOSTIC USES

    PubMed Central

    Dullum, Dell F.

    1961-01-01

    Use of radiologic procedures in diagnosis now contributes a significant dose of ionizing radiation to our population. Whether this presents a real risk to the health of the present and future population cannot be determined with certainty from evidence available at this time. Hence, it appears proper to keep the dose to every patient as low as practical consistent with good medical practice. The average dose can be significantly reduced by having more physicians apply the known techniques for minimizing the exposure to the patient. The medical profession has a direct professional concern for the actual or potential risk of damage resulting from the radiation that patients are exposed to during diagnostic x-ray procedures, since these procedures constitute the largest single man-made source of genetically significant radiation our population is now exposed to. It is important to distinguish two distinctly different types of radiation effectssomatic effect, in which the damage affects the health of the person irradiated, and genetic effect that is capable of producing constitutional defects in future progeny over many generations. PMID:18732398

  12. An Inexpensive Radiation Counter.

    ERIC Educational Resources Information Center

    Holton, Brian; Balla, Zsolt

    1985-01-01

    Describes a radiation counter comparable to commercial units which costs less than $100. It consists of six sections: Geiger-Mueller tube and holder; high voltage supply; low voltage supply; pulse shaping circuit; "start/stop counts" gating circuit; and counter/display. List of materials needed and schematic diagrams are included. (JN)

  13. Continuum radiation at Uranus

    SciTech Connect

    Kurth, W.S.; Gurnett, D.A. ); Desch, M.D. )

    1990-02-01

    Uranus has proven to be a radio source of remarkable complexity with as many as six distinctly different types of emission. One Uranian radio emission which has thus far escaped attention is an analog of continuum radiation at Earth, Jupiter, and Saturn. The emission is found to be propagating in the ordinary mode in the range of one to a few kHz on the inbound leg of the Voyager 2 encounter, shortly after the magnetopause crossing. The continuum radiation spectrum at Uranus also includes bands with frequencies as high as 12 kHz or greater on both the inbound and outbound legs. The Uranian continuum radiation is notably weak, making it more like that detected at Saturn than the extremely intense Jovian continuum radiation. The Uranian emission shows some evidence for narrow-band components lying in the same frequency regime as the continuum, completing the analogy with the other planets, which also show narrow-band components superimposed on the continuum spectrum. The authors argue that the low intensity of the Uranian continuum is most likely related to the lack of a density cavity within the Uranian magnetosphere that is deep relative to the solar wind plasma density.

  14. 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.

  15. Management of ionizing radiation injuries and illnesses, part 1: physics, radiation protection, and radiation instrumentation.

    PubMed

    Christensen, Doran M; Jenkins, Mark S; Sugarman, Stephen L; Glassman, Erik S

    2014-03-01

    Ionizing radiation injuries and illnesses are exceedingly rare; therefore, most physicians have never managed such conditions. When confronted with a possible radiation injury or illness, most physicians must seek specialty consultation. Protection of responders, health care workers, and patients is an absolute priority for the delivery of medical care. Management of ionizing radiation injuries and illnesses, as well as radiation protection, requires a basic understanding of physics. Also, to provide a greater measure of safety when working with radioactive materials, instrumentation for detection and identification of radiation is needed. Because any health care professional could face a radiation emergency, it is imperative that all institutions have emergency response plans in place before an incident occurs. The present article is an introduction to basic physics, ionizing radiation, radiation protection, and radiation instrumentation, and it provides a basis for management of the consequences of a radiologic or nuclear incident. PMID:24567272

  16. Radiative transfer of visible radiation in turbid atmosphere

    NASA Technical Reports Server (NTRS)

    Yamamoto, G.; Tanaka, M.

    1974-01-01

    Methods are presented for solving radiative transfer problems; they include the doubling method and the closely related matrix method, iterative method, Chandrasekhar's method of discrete ordinates, and Monte Carlo method. To consider radiation transport through turbid atmosphere, an atmospheric model was developed characterizing aerosols by parameters. Intensity and polarization of radiation in turbid atmospheres is discussed, as well as lower atmospheric heating due to solar radiation absorption by aerosols.

  17. SSC environmental radiation shielding

    SciTech Connect

    Jackson, J.D.

    1987-07-01

    The environmental radiation shielding requirements of the SSC have been evaluated using currently available computational tools that incorporate the well known processes of energy loss and degradation of high energy particles into Monte Carlo computer codes. These tools permit determination of isodose contours in the matter surrounding a source point and therefore the specification of minimum thicknesses or extents of shielding in order to assure annual dose equivalents less than some specified design amount. For the general public the annual dose equivalent specified in the design is 10 millirem, small compared to the dose from naturally occurring radiation. The types of radiation fall into two classes for the purposes of shielding determinations-hadrons and muons. The sources of radiation at the SSC of concern for the surrounding environment are the interaction regions, the specially designed beam dumps into which the beams are dumped from time to time, and beam clean-up regions where stops remove the beam halo in order to reduce experimental backgrounds. A final, unlikely source of radiation considered is the accidental loss of the full beam at some point around the ring. Conservative choices of a luminosity of 10{sup 34} cm{sup {minus}2}s{sup {minus}1} and a beam current three times design have been made in calculating the required shielding and boundaries of the facility. In addition to determination of minimum distances for the annual dose equivalents, the question of possible radioactivity produced in nearby wells or in municipal water supplies is addressed. The designed shielding distances and beam dumps are such that the induced radioactivity in ground water is safely smaller than the levels permitted by EPA and international agencies.

  18. Apparatus for generating partially coherent radiation

    SciTech Connect

    Naulleau, Patrick P.

    2005-02-22

    Techniques for generating partially coherent radiation and particularly for converting effectively coherent radiation from a synchrotron to partially coherent EUV radiation suitable for projection lithography.

  19. Radiative Forcing of Climate Change

    SciTech Connect

    Ramaswamy, V.; Boucher, Olivier; Haigh, J.; Hauglustaine, D.; Haywood, J.; Myhre, G.; Nakajima, Takahito; Shi, Guangyu; Solomon, S.; Betts, Robert E.; Charlson, R.; Chuang, C. C.; Daniel, J. S.; Del Genio, Anthony D.; Feichter, J.; Fuglestvedt, J.; Forster, P. M.; Ghan, Steven J.; Jones, A.; Kiehl, J. T.; Koch, D.; Land, C.; Lean, J.; Lohmann, Ulrike; Minschwaner, K.; Penner, Joyce E.; Roberts, D. L.; Rodhe, H.; Roelofs, G.-J.; Rotstayn, Leon D.; Schneider, T. L.; Schumann, U.; Schwartz, Stephen E.; Schwartzkopf, M. D.; Shine, K. P.; Smith, Steven J.; Stevenson, D. S.; Stordal, F.; Tegen, I.; van Dorland, R.; Zhang, Y.; Srinivasan, J.; Joos, Fortunat

    2001-10-01

    Chapter 6 of the IPCC Third Assessment Report Climate Change 2001: The Scientific Basis. Sections include: Executive Summary 6.1 Radiative Forcing 6.2 Forcing-Response Relationship 6.3 Well-Mixed Greenhouse Gases 6.4 Stratospheric Ozone 6.5 Radiative Forcing By Tropospheric Ozone 6.6 Indirect Forcings due to Chemistry 6.7 The Direct Radiative Forcing of Tropospheric Aerosols 6.8 The Indirect Radiative Forcing of Tropospheric Aerosols 6.9 Stratospheric Aerosols 6.10 Land-use Change (Surface Albedo Effect) 6.11 Solar Forcing of Climate 6.12 Global Warming Potentials hydrocarbons 6.13 Global Mean Radiative Forcings 6.14 The Geographical Distribution of the Radiative Forcings 6.15 Time Evolution of Radiative Forcings Appendix 6.1 Elements of Radiative Forcing Concept References.

  20. Conical electromagnetic radiation flux concentrator

    NASA Technical Reports Server (NTRS)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  1. Radiation Therapy: Additional Treatment Options

    MedlinePLUS

    ... go through the bloodstream to the entire body. Immunotherapy Some treatments are designed to help your own ... fights off infections. This is refered to as immunotherapy . Intraoperative Radiation Therapy Radiation therapy given during surgery ...

  2. 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.

  3. RADIATION ENVIRONMENT OF GROWTH CHAMBERS

    EPA Science Inventory

    Radiation measurements with different types of meters in several controlled environment facilities have been compiled to demonstrate the problems associated with insuring uniform radiation levels in separate facilities. Data are provided for a quantum meter, three photometers, a ...

  4. Biomarkers for human radiation exposure.

    PubMed

    Chaudhry, M Ahmad

    2008-09-01

    There is a concern over the potential use of radioactive isotopes as a weapon of terror. The detonation of a radiation dispersal device, the so-called "dirty bomb" can lead to public panic. In order to estimate risks associated with radiation exposure, it is important to understand the biological effects of radiation exposure. Based on this knowledge, biomarkers to monitor potentially exposed populations after a radiological accident can be developed and would be extremely valuable for emergency response. While the traditional radiation exposure biomarkers based on cytogenetic assays serve as standard, the development of rapid and noninvasive tests for radiation exposure is needed. The genomics based knowledge is providing new avenues for investigation. The examination of gene expression after ionizing radiation exposure could serve as a potential molecular marker for biodosimetry. Microarray based studies are identifying new radiation responsive genes that could potentially be used as biomarkers of human exposure to radiation after an accident. PMID:18454354

  5. Radiation-Driven Astrophysical Jets

    NASA Astrophysics Data System (ADS)

    Fukue, Jun

    2000-10-01

    Radiative winds and jets from luminous accretion disks/tori are reviewed. Among various models of astrophysical jets, plasma outflows emanating from accretion disks/tori and accelerated by the radiation pressure is the most promising one. Here explained are the roles of radiation pressure force and radiation drag force. Rise and fall of a torus model are also discussed, following its revenge. Finally, the millennium jet model, where the multistage acceleration takes place, is proposed.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Stromal mediation of radiation carcinogenesis.

    PubMed

    Barcellos-Hoff, Mary Helen

    2010-12-01

    Ionizing radiation is a well-established carcinogen in human breast and rodent mammary gland. This review addresses evidence that radiation elicits the critical stromal context for cancer, affecting not only frequency but the type of cancer. Recent data from the breast tumors of women treated with radiation therapy and the cellular mechanisms evident in experimental models suggest that radiation effects on stromal-epithelial interactions and tissue composition are a major determinant of cancer development. PMID:21181431

  12. Pregnancy and Radiation Protection

    SciTech Connect

    Gerogiannis, J.; Stefanoyiannis, A. P.

    2010-01-21

    Several modalities are currently utilized for diagnosis and therapy, by appropriate application of x-rays. In diagnostic radiology, interventional radiology, radiotherapy, interventional cardiology, nuclear medicine and other specialties radiation protection of a pregnant woman as a patient, as well as a member of the operating personnel, is of outmost importance. Based on radiation risk, the termination of pregnancy is not justified if foetal doses are below 100 mGy. For foetal doses between 100 and 500 mGy, a decision is reached on a case by case basis. In Diagnostic Radiology, when a pregnant patient takes an abdomen CT, then an estimation of the foetus' dose is necessary. However, it is extremely rare for the dose to be high enough to justify an abortion. Radiographs of the chest and extremities can be done at any period of pregnancy, provided that the equipment is functioning properly. Usually, the radiation risk is lower than the risk of not undergoing a radiological examination. Radiation exposure in uterus from diagnostic radiological examinations is unlikely to result in any deleterious effect on the child, but the possibility of a radiation-induced effect can not be entirely ruled out. The effects of exposure to radiation on the foetus depend on the time of exposure, the date of conception and the absorbed dose. Finally, a pregnant worker can continue working in an x-ray department, as long as there is reasonable assurance that the foetal dose can be kept below 1 mGy during the pregnancy. Nuclear Medicine diagnostic examinations using short-lived radionuclides can be used for pregnant patient. Irradiation of the foetus results from placental transfer and distribution of radiopharmaceuticals in the foetal tissues, as well as from external irradiation from radioactivity in the mother's organ and tissues. As a rule, a pregnant patient should not undergo therapy with radionuclide, unless it is crucial for her life. In Radiotherapy, the patient, treating oncologist, other team and family members should carefully discuss for the decision of abortion. Important factors must be considered such as the stage and aggressiveness of the tumour, the location of the tumour, the stage of pregnancy, various therapies etc.

  13. Pregnancy and Radiation Protection

    NASA Astrophysics Data System (ADS)

    Gerogiannis, J.; Stefanoyiannis, A. P.

    2010-01-01

    Several modalities are currently utilized for diagnosis and therapy, by appropriate application of x-rays. In diagnostic radiology, interventional radiology, radiotherapy, interventional cardiology, nuclear medicine and other specialties radiation protection of a pregnant woman as a patient, as well as a member of the operating personnel, is of outmost importance. Based on radiation risk, the termination of pregnancy is not justified if foetal doses are below 100 mGy. For foetal doses between 100 and 500 mGy, a decision is reached on a case by case basis. In Diagnostic Radiology, when a pregnant patient takes an abdomen CT, then an estimation of the foetus' dose is necessary. However, it is extremely rare for the dose to be high enough to justify an abortion. Radiographs of the chest and extremities can be done at any period of pregnancy, provided that the equipment is functioning properly. Usually, the radiation risk is lower than the risk of not undergoing a radiological examination. Radiation exposure in uterus from diagnostic radiological examinations is unlikely to result in any deleterious effect on the child, but the possibility of a radiation-induced effect can not be entirely ruled out. The effects of exposure to radiation on the foetus depend on the time of exposure, the date of conception and the absorbed dose. Finally, a pregnant worker can continue working in an x-ray department, as long as there is reasonable assurance that the foetal dose can be kept below 1 mGy during the pregnancy. Nuclear Medicine diagnostic examinations using short-lived radionuclides can be used for pregnant patient. Irradiation of the foetus results from placental transfer and distribution of radiopharmaceuticals in the foetal tissues, as well as from external irradiation from radioactivity in the mother's organ and tissues. As a rule, a pregnant patient should not undergo therapy with radionuclide, unless it is crucial for her life. In Radiotherapy, the patient, treating oncologist, other team and family members should carefully discuss for the decision of abortion. Important factors must be considered such as the stage and aggressiveness of the tumour, the location of the tumour, the stage of pregnancy, various therapies etc.

  14. Radiation Effects: Core Project

    NASA Technical Reports Server (NTRS)

    Dicello, John F.

    1999-01-01

    The risks to personnel in space from the naturally occurring radiations are generally considered to be one of the most serious limitations to human space missions, as noted in two recent reports of the National Research Council/National Academy of Sciences. The Core Project of the Radiation Effects Team for the National Space Biomedical Research Institute is the consequences of radiations in space in order to develop countermeasure, both physical and pharmaceutical, to reduce the risks of cancer and other diseases associated with such exposures. During interplanetary missions, personnel in space will be exposed to galactic cosmic rays, including high-energy protons and energetic ions with atomic masses of iron or higher. In addition, solar events will produce radiation fields of high intensity for short but irregular durations. The level of intensity of these radiations is considerably higher than that on Earth's surface, and the biological risks to astronauts is consequently increased, including increased risks of carcinogenesis and other diseases. This group is examining the risk of cancers resulting from low-dose, low-dose rate exposures of model systems to photons, protons, and iron by using ground-based accelerators which are capable of producing beams of protons, iron, and other heavy ions at energies comparable to those encountered in space. They have begun the first series of experiments using a 1-GeV iron beam at the Brookhaven National Laboratory and 250-MeV protons at Loma Linda University Medical Center's proton synchrotron facility. As part of these studies, this group will be investigating the potential for the pharmaceutical, Tamoxifen, to reduce the risk of breast cancer in astronauts exposed to the level of doses and particle types expected in space. Theoretical studies are being carried out in a collaboration between scientists at NASA's Johnson Space Center and Johns Hopkins University in parallel with the experimental program have provided methods and predictions which are being used to assess the levels of risks to be encountered and to evaluate appropriate strategies for countermeasures. Although the work in this project is primarily directed toward problems associated with space travel, the problem of protracted exposures to low-levels of radiation is one of national interest in our energy and defense programs, and the results may suggest new paradigms for addressing such risks.

  15. 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 Moons radiation environment both charges and affects the chemistry in the Moons 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/CRaTERs remarkable exploration of moons radiation environment, its implications for human exploration, and its interaction with lunar regolith.

  16. Space Radiation Cancer Risks

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.

    2007-01-01

    Space radiation presents major challenges to astronauts on the International Space Station and for future missions to the Earth s moon or Mars. Methods used to project risks on Earth need to be modified because of the large uncertainties in projecting cancer risks from space radiation, and thus impact safety factors. We describe NASA s unique approach to radiation safety that applies uncertainty based criteria within the occupational health program for astronauts: The two terrestrial criteria of a point estimate of maximum acceptable level of risk and application of the principle of As Low As Reasonably Achievable (ALARA) are supplemented by a third requirement that protects against risk projection uncertainties using the upper 95% confidence level (CL) in the radiation cancer projection model. NASA s acceptable level of risk for ISS and their new lunar program have been set at the point-estimate of a 3-percent risk of exposure induced death (REID). Tissue-averaged organ dose-equivalents are combined with age at exposure and gender-dependent risk coefficients to project the cumulative occupational radiation risks incurred by astronauts. The 95% CL criteria in practice is a stronger criterion than ALARA, but not an absolute cut-off as is applied to a point projection of a 3% REID. We describe the most recent astronaut dose limits, and present a historical review of astronaut organ doses estimates from the Mercury through the current ISS program, and future projections for lunar and Mars missions. NASA s 95% CL criteria is linked to a vibrant ground based radiobiology program investigating the radiobiology of high-energy protons and heavy ions. The near-term goal of research is new knowledge leading to the reduction of uncertainties in projection models. Risk projections involve a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. The current model for projecting space radiation cancer risk relies on the three assumptions of linearity, additivity, and scaling along with the use of population averages. We describe uncertainty estimates for this model, and new experimental data that sheds light on the accuracy of the underlying assumptions. These methods make it possible to express risk management objectives in terms of quantitative metrics, i.e., the number of days in space without exceeding a given risk level within well defined confidence limits. The resulting methodology is applied to several human space exploration mission scenarios including lunar station, deep space outpost, and a Mars mission. Factors that dominate risk projection uncertainties and application of this approach to assess candidate mitigation approaches are described.

  17. Radiation effect on implanted pacemakers

    SciTech Connect

    Pourhamidi, A.H.

    1983-10-01

    It was previously thought that diagnostic or therapeutic ionizing radiation did not have an adverse effect on the function of cardiac pacemakers. Recently, however, some authors have reported damaging effect of therapeutic radiation on cardiac pulse generators. An analysis of a recently-extracted pacemaker documented the effect of radiation on the pacemaker pulse generator.

  18. Radiation Propulsion For Maintaining Orbits

    NASA Technical Reports Server (NTRS)

    Richter, Robert

    1995-01-01

    Brief report proposes radiative propulsion systems for maintaining precise orbits of spacecraft. Radiation from electrical heaters directed outward by paraboloidal reflectors to produce small forces to oppose uncontrolled drag and solar-radiative forces perturbing orbits. Minimizes or eliminates need to fire rocket thrusters to correct orbits.

  19. 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)

  20. 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.

  1. 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

  2. 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 ϒ, 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 ϒ-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.

  3. 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.

  4. Accepting space radiation risks.

    PubMed

    Schimmerling, Walter

    2010-08-01

    The human exploration of space inevitably involves exposure to radiation. Associated with this exposure are multiple risks, i.e., probabilities that certain aspects of an astronaut's health or performance will be degraded. The management of these risks requires that such probabilities be accurately predicted, that the actual exposures be verified, and that comprehensive records be maintained. Implicit in these actions is the fact that, at some point, a decision has been made to accept a certain level of risk. This paper examines ethical and practical considerations involved in arriving at a determination that risks are acceptable, roles that the parties involved may play, and obligations arising out of reliance on the informed consent paradigm seen as the basis for ethical radiation risk acceptance in space. PMID:20414667

  5. 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.

  6. Ultraviolet radiation effects

    NASA Technical Reports Server (NTRS)

    Slemp, Wayne S.

    1989-01-01

    Solar ultraviolet testing was not developed which will provide highly accelerated (20 to 50X) exposures that correlate to flight test data. Additional studies are required to develop an exposure methodology which will assure that accelerated testing can be used for qualification of materials and coatings for long duration space flight. Some conclusions are listed: Solar UV radiation is present in all orbital environments; Solar UV does not change in flux with orbital altitude; UV radiation can degrade most coatings and polymeric films; Laboratory UV simulation methodology is needed for accelerated testing to 20 UV solar constants; Simulation of extreme UV (below 200 nm) is needed to evaluate requirements for EUV in solar simulation.

  7. Radiation Environment Inside Spacecraft

    NASA Technical Reports Server (NTRS)

    O'Neill, Patrick

    2015-01-01

    Dr. Patrick O'Neill, NASA Johnson Space Center, will present a detailed description of the radiation environment inside spacecraft. The free space (outside) solar and galactic cosmic ray and trapped Van Allen belt proton spectra are significantly modified as these ions propagate through various thicknesses of spacecraft structure and shielding material. In addition to energy loss, secondary ions are created as the ions interact with the structure materials. Nuclear interaction codes (FLUKA, GEANT4, HZTRAN, MCNPX, CEM03, and PHITS) transport free space spectra through different thicknesses of various materials. These "inside" energy spectra are then converted to Linear Energy Transfer (LET) spectra and dose rate - that's what's needed by electronics systems designers. Model predictions are compared to radiation measurements made by instruments such as the Intra-Vehicular Charged Particle Directional Spectrometer (IV-CPDS) used inside the Space Station, Orion, and Space Shuttle.

  8. Time encoded radiation imaging

    SciTech Connect

    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.

  9. Radiation Induced Genomic Instability

    SciTech Connect

    Morgan, William F.

    2011-03-01

    Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a mutator phenotype (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend themselves to prolonged study, many tend to eliminate or rearrange the target chromosome until it is too small for further rearrangement. The observed frequency of induced instability by low and high linear-energy-transfer radiations greatly exceeds that observed for nuclear gene mutations at similar doses; hence, mutation of a gene or gene family is unlikely to be the initiating mechanism. Once initiated however, there is evidence in the GM10115 model system that it can be perpetuated over time by dicentric chromosome formation followed by bridge breakage fusion cycles (Marder and Morgan 1993), as well as recombinational events involving interstitial telomere like repeat sequences (Day et al. 1998). There is also increasing evidence that inflammatory type reactions (Lorimore et al. 2001, Lorimore and Wright 2003), presumably involving reactive oxygen and nitrogen species as well as cytokines and chemokines might be involved in driving the ustable phenotype (Liaikis et al. 2007, Hei et al. 2008). To this end there is very convincing evidence for such reactions being involved in another non-targeted effect associated with ionizing radiation, the bystander effect (Hei et al. 2008). Clearly the link between induced instability and bystander effects suggests common processes and inflammatory type reactions will likely be the subject of future investigation.

  10. Terahertz radiation mixer

    DOEpatents

    Wanke, Michael C.; Allen, S. James; Lee, Mark

    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.

  11. Biochemistry of ionizing radiation

    SciTech Connect

    Walden, T.L.; Nushin, F.K.

    1990-01-01

    This volume examines the biochemical changes occurring in normal tissue after irradiation. A review of radiation chemistry is followed by an analysis of factors affecting biochemical responses and a timely discussion of radiobiology in space flight. The authors then describe the effects of radiation on lipid peroxidation, amino acids, peptides, proteins, polysaccharides, DNA, thiols, and body fluids. Close attention is given to alterations in biological mediators such as eicosanoids, cyclic nucleotides, angiotensin, histamine, polyamines, catecholamines, and serotonin and in hormones such as adrenocorticotropic hormone, testosterone, estrogens, follicle-stimulating hormone, luteinizing hormone, thyroid hormones, insulin and glucagon, gastrin, and melatonin. Other chapters focus on changes in carbohydrate metabolism, oxidative phosphorylation, protein synthesis, and serum proteins. A chapter on biological dosimeters discusses prodromal syndrome, hematological dosimeters, serum composition, urine, chromosomal aberrations, and fluorometric and immunoassays.

  12. On source radiation

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1980-01-01

    The power output from given sources is usually ascertained via an energy flux integral over the normal directions to a remote (far field) surface; an alternative procedure, which utilizes an integral that specifies the direct rate of working by the source on the resultant field, is described and illustrated for both point and continuous source distribution. A comparison between the respective procedures is made in the analysis of sound radiated from a periodic dipole source whose axis performs a periodic plane angular movement about a fixed direction. Thus, adopting a conventional approach, Sretenskii (1956) characterizes the rotating dipole in terms of an infinite number of stationary ones along a pari of orthogonal directions in the plane, and through the far field representation of the latter, arrives at a series development for the instantaneous radiated power, whereas the local manner of power calculation dispenses with the equivalent infinite aggregate of sources and yields a compact analytical result.

  13. Handheld CZT radiation detector

    SciTech Connect

    Murray, William S.; Butterfield, Kenneth B.; Baird, William

    2004-08-24

    A handheld CZT radiation detector having a CZT gamma-ray sensor, a multichannel analyzer, a fuzzy-logic component, and a display component is disclosed. The CZT gamma-ray sensor may be a coplanar grid CZT gamma-ray sensor, which provides high-quality gamma-ray analysis at a wide range of operating temperatures. The multichannel analyzer categorizes pulses produce by the CZT gamma-ray sensor into channels (discrete energy levels), resulting in pulse height data. The fuzzy-logic component analyzes the pulse height data and produces a ranked listing of radioisotopes. The fuzzy-logic component is flexible and well-suited to in-field analysis of radioisotopes. The display component may be a personal data assistant, which provides a user-friendly method of interacting with the detector. In addition, the radiation detector may be equipped with a neutron sensor to provide an enhanced mechanism of sensing radioactive materials.

  14. Radiation measuring system

    SciTech Connect

    Eldering, H.G.; Kliman, A.W.

    1984-02-07

    A system for measuring radiation in the laboratory or at a site to aid in determining whether to erect a solar energy installation at that site includes a positioner and a sensor. The sensor, which is mounted on the positioner, includes a rotating semispherical chopper and an integrating sphere for collecting radiation in three modes. A broad-band detector measures the irradiance from the integrating sphere to monitor for anomalies. A pair of monochromators simultaneously measure, one in the visible range and the other in the infrared range, the spectral irradiance from the integrating sphere. Processing electronics process the measured spectral irradiance from the monochromators and generate data signals for providing an absolute irradiance spectrum at the plane of the entrance aperture. The absolute irradiance spectrum is inputted to an X-Y plotter and a magnetic disc and tape. The system further includes internal reference sources providing continuous wavelength and irradiance calibration.

  15. Cerebral radiation necrosis.

    PubMed

    Na, Angelika; Haghigi, Neda; Drummond, Katharine J

    2014-03-01

    Cerebral radiation-induced injury ranges from acute reversible edema to late irreversible radiation necrosis (RN). Cerebral RN is poorly responsive to treatment, is associated with permanent neurological deficits and occasionally progresses to death. We review the literature regarding cerebral RN after radiotherapy for various brain and head and neck lesions and discuss its clinical features, imaging characteristics, pathophysiology and treatment. For new enhancing lesions on computed tomography or magnetic resonance imaging, apart from tumor progression or recurrence, RN needs to be considered in the differential diagnosis. Further studies are required to design chemoradiotherapy protocols that are effective in treating tumors while minimizing risk of RN. Current available treatments for RN, steroid and surgery, only relieve the mass effect. None of the experimental treatments to date have consistently been shown to reverse the pathologic process of RN. PMID:24175987

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Pathology of radiation myelopathy

    PubMed Central

    Burns, R. J.; Jones, A. N.; Robertson, J. S.

    1972-01-01

    After nothing the rarity of papers describing the pathology of delayed radiation necrosis of the spinal cord, the clinical and pathological findings from four cases are presented. The main pathological features are asymmetric demyelination of the lateral columns and to a lesser degree the posterior and anterior columns of white matter, with coagulative necrosis at the level of irradiation which affected the grey matter to a lesser degree. There is ascending and descending secondary tract degeneration, and poor glial response in the lesions themselves. Vascular changes, mainly hyalilne thickening of arteriolar walls, are present, but not in degree sufficient to explain the primary lesion. The discussion of the pathogenesis of the myelopathy weighs the merits of a primary vascular lesion against those of a primary effect of the radiation on neural tissue. The latter is favoured. Images PMID:4647860

  1. 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.

  2. Quality in radiation oncology

    SciTech Connect

    Pawlicki, Todd; Mundt, Arno J.

    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.

  3. 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.

  4. Multilayer radiation shield

    DOEpatents

    Urbahn, John Arthur; Laskaris, Evangelos Trifon

    2009-06-16

    A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

  5. 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.

  6. 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.

  7. Sector 30 collimator radiation

    SciTech Connect

    Namito, Y. ); Nelson, W.R.; Benson, E.

    1990-02-22

    The collimators at Sector 30 of the SLAC accelerator are designed to scrape off a significant fraction (e.g., {approximately}20%) of the SLC beam. The electromagnetic cascade shower that develops in the collimator, and in the scraper and waveguide downbeam, leads to very high radiation exposures of TV cameras (and other devices) located nearby. The collimator (point) source accounts for one-third of the dose and is best shielded by extending the radius of the copper scraper. Radiation from the waveguide accounts for the remaining two-thirds of the dose, and is difficult to shield since it is a line source. However, the spectrum from the waveguide is expected to be softer than that from the collimator. This paper discusses shielding of these sources.

  8. 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.

  9. Radiation optic neuropathy

    SciTech Connect

    Kline, L.B.; Kim, J.Y.; Ceballos, R.

    1985-08-01

    Following surgery for pituitary adenoma, radiation therapy is an accepted treatment in reducing tumor recurrence. However, a potential therapeutic complication is delayed radionecrosis of perisellar neural structures, including the optic nerves and chiasm. This particular cause of visual loss, radiation optic neuropathy (RON), has not been emphasized in the ophthalmologic literature. Four cases of RON seen in the past five years are reported. Diagnostic criteria include: (1) acute visual loss (monocular or binocular), (2) visual field defects indicating optic nerve or chiasmal dysfunction, (3) absence of optic disc edema, (4) onset usually within three years of therapy (peak: 1-1 1/2 years), and (5) no computed tomographic evidence of visual pathway compression. Pathologic findings, differential diagnosis and therapy will be discussed in outlining the clinical profile of RON.

  10. 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.

  11. Radiofrequency and microwave radiation

    SciTech Connect

    Hileman, B.

    1982-08-01

    This paper deals with the controversy and disagreement surrounding the issue of harm from radiofrequency (RF) and microwaves. The radiation standards adopted by different countries are quite divergent with the least strict standard for microwave exposure differing from the most strict by a factor of 100. Among the most powerful sources of RF and microwave radiation are radar systems used for tracking and guidance purposes, as well as transmiters used in satellite communication systems. RF and microwaves are nonionizing because the energy of each photon is relatively low. Biological systems exposed to RF and microwaves acquire induced electric and magnetic fields which can be focused by a combination of high refractive index within an animal and convex body contours. The effects on animals and humans are summarized. (KRM)

  12. 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.

  13. 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 Mnchen 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

  14. Radiation-induced schwannomas

    SciTech Connect

    Rubinstein, A.B.; Reichenthal, E.; Borohov, H.

    1989-06-01

    The histopathology and clinical course of three patients with schwannomas of the brain and high cervical cord after therapeutic irradiation for intracranial malignancy and for ringworm of the scalp are described. Earlier reports in the literature indicated that radiation of the scalp may induce tumors in the head and neck. It is therefore suggested that therapeutic irradiation in these instances was a causative factor in the genesis of these tumors.

  15. Radiation-driven inflation

    SciTech Connect

    Davidson, Aharon; Gurwich, Ilya E-mail: gurwichphys@gmail.com

    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.

  16. 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.

  17. 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 Painlev-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.

  18. 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.

  19. 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

  20. 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.

  1. Radiation belt probes launched

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-09-01

    Storms on Earth delayed by only a few days the launch of NASA's Radiation Belt Storm Probes (RBSP), which blasted off on 30 August for a 2-year tour to explore the Van Allen radiation belts. The two satellites will help scientists learn about the processes that affect electrons and ions in the donut-shaped belts and how the belts change in the context of geomagnetic storms. “The information collected from these probes will benefit the public by allowing us to better protect our satellites and understand how space weather affects communications and technology on Earth,” said John Grunsfeld, associate administrator for NASA's Science Mission Directorate. Each probe carries an identical suite of instruments, including an Energetic Particle, Composition, and Thermal Plasma Suite; Electric and Magnetic Field Instrument Suite and Integrated Science; Electric Field and Waves Suite; Radiation Belt Storm Probes Ion Composition Experiment; and Relativistic Proton Spectrometer. RBSP is part of NASA's Living With a Star program and is managed for NASA by the Johns Hopkins University's Applied Physics Laboratory. For more information, see http://rbsp.jhuapl.edu.

  2. Radiation takes its Toll.

    PubMed

    Ratikan, Josephine A; Micewicz, Ewa D; Xie, Michael W; Schaue, Dörthe

    2015-11-28

    The ability to recognize and respond to universal molecular patterns on invading microorganisms allows our immune system to stay on high alert, sensing danger to our self-integrity. Our own damaged cells and tissues in pathological situations activate similar warning systems as microbes. In this way, the body is able to mount a response that is appropriate to the danger. Toll-like receptors are at the heart of this pattern recognition system that initiates innate pro-oxidant, pro-inflammatory signaling cascades and ultimately bridges recognition of danger to adaptive immunity. The acute inflammatory lesions that are formed segue into resolution of inflammation, repair and healing or, more dysfunctionally, into chronic inflammation, autoimmunity, excessive tissue damage and carcinogenesis. Redox is at the nexus of this decision making process and is the point at which ionizing radiation initially intercepts to trigger similar responses to self-damage. In this review we discuss our current understanding of how radiation-damaged cells interact with Toll-like receptors and how the immune systems interprets these radiation-induced danger signals in the context of whole-body exposures and during local tumor irradiation. PMID:25819030

  3. Intraocular radiation blocking

    SciTech Connect

    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.

  4. Understanding Radiation Thermometry. Part I

    NASA Technical Reports Server (NTRS)

    Risch Timothy K.

    2015-01-01

    This document is a two-part course on the theory and practice of radiation thermometry. Radiation thermometry is the technique for determining the temperature of a surface or a volume by measuring the electromagnetic radiation it emits. This course covers the theory and practice of radiative thermometry and emphasizes the modern application of the field using commercially available electronic detectors and optical components. The course covers the historical development of the field, the fundamental physics of radiative surfaces, along with modern measurement methods and equipment.

  5. Radiative interactions in nonequilibrium flows

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N.; Chandrasekhar, R.

    1992-01-01

    The influence of vibrational and chemical nonequilibrium upon infrared radiative energy transfer in nonisothermal gases is investigated. Essential information is provided on rate equations, relaxation times, transfer equations, band absorption, and radiative flux equations. The methodology developed is applied to three specific cases. These are, absorbing-emitting species between isothermal parallel plates, radiating gases in the earth's atmosphere, and supersonic flow of premixed hydrogen and air in an expanding nozzle. The results obtained for different cases reveal that the extent of radiative interactions is reduced significantly under nonequilibrium conditions. The method developed can be easily extended to investigate radiative interactions in complex nonequilibrium flows.

  6. Understanding Radiation Thermometry. Part II

    NASA Technical Reports Server (NTRS)

    Risch, Timothy K.

    2015-01-01

    This document is a two-part course on the theory and practice of radiation thermometry. Radiation thermometry is the technique for determining the temperature of a surface or a volume by measuring the electromagnetic radiation it emits. This course covers the theory and practice of radiative thermometry and emphasizes the modern application of the field using commercially available electronic detectors and optical components. The course covers the historical development of the field, the fundamental physics of radiative surfaces, along with modern measurement methods and equipment.

  7. Josephson-vortex Cherenkov radiation

    SciTech Connect

    Mints, R.G.; Snapiro, I.B.

    1995-10-01

    We predict the Josephson-vortex Cherenkov radiation of an electromagnetic wave. We treat a long one-dimensional Josephson junction. We consider the wavelength of the radiated electromagnetic wave to be much less than the Josephson penetration depth. We use for calculations the nonlocal Josephson electrodynamics. We find the expression for the radiated power and for the radiation friction force acting on a Josephson vortex and arising due to the Cherenkov radiation. We calculate the relation between the density of the bias current and the Josephson vortex velocity.

  8. Radiation Therapy for Soft Tissue Sarcomas

    MedlinePLUS

    ... sarcomas Next Topic Chemotherapy for soft tissue sarcomas Radiation therapy for soft tissue sarcomas Radiation therapy uses ... spread. This is called palliative treatment . Types of radiation therapy External beam radiation therapy: For this treatment, ...

  9. 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.

  10. Utrecht Radiative Transfer Courses

    NASA Astrophysics Data System (ADS)

    Rutten, R. J.

    2003-01-01

    The Utrecht course ``The Generation and Transport of Radiation'' teaches basic radiative transfer to second-year students. It is a much-expanded version of the first chapter of Rybicki & Lightman's ``Radiative Processes in Astrophysics''. After this course, students understand why intensity is measured per steradian, have an Eddington-Barbier feel for optically thick line formation, and know that scattering upsets LTE. The text is a computer-aided translation by Ruth Peterson of my 1992 Dutch-language course. My aim is to rewrite this course in non-computer English and make it web-available at some time. In the meantime, copies of the Peterson translation are made yearly at Uppsala -- ask them, not me. Eventually it should become a textbook. The Utrecht course ``Radiative Transfer in Stellar Atmospheres'' is a 30-hour course for third-year students. It treats NLTE line formation in plane-parallel stellar atmospheres at a level intermediate between the books by Novotny and Boehm-Vitense, and Mihalas' ``Stellar Atmospheres''. After this course, students appreciate that epsilon is small, that radiation can heat or cool, and that computers have changed the field. This course is web-available since 1995 and is regularly improved -- but remains incomplete. Eventually it should become a textbook. The three Utrecht exercise sets ``Stellar Spectra A: Basic Line Formation'', ``Stellar Spectra B: LTE Line Formation'', and ``Stellar Spectra C: NLTE Line Formation'' are IDL-based computer exercises for first-year, second-year, and third-year students, respectively. They treat spectral classification, Saha-Boltzmann population statistics, the curve of growth, the FAL-C solar atmosphere model, the role of H-minus in the solar continuum, LTE formation of Fraunhofer lines, inversion tactics, the Feautrier method, classical lambda iteration, and ALI computation. The first two sets are web-available since 1998; the third will follow. Acknowledgement. Both courses owe much to previous Utrecht courses taught by the late Kees Zwaan. The third exercise set was developed by Phil Judge, Mandy Hagenaar, and Thijs Krijger. Reverse acknowledgement. If you are a user of this free material you might refer to this summary and so boost my citation standing. Corrections are also welcome.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Method for microbeam radiation therapy

    DOEpatents

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

    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.

  16. DOE 2011 occupational radiation exposure

    SciTech Connect

    none,

    2012-12-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2011 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past five years.

  17. DOE 2012 occupational radiation exposure

    SciTech Connect

    none,

    2013-10-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site.

  18. 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.

  19. Radiative Magnetic Reconnection in Astrophysics

    NASA Astrophysics Data System (ADS)

    Uzdensky, D. A.

    In this chapter we review a new and rapidly growing area of research in high-energy plasma astrophysics—radiative magnetic reconnection, defined here as a regime of reconnection where radiation reaction has an important influence on the reconnection dynamics, energetics, and/or nonthermal particle acceleration. This influence be may be manifested via a variety of radiative effects that are critical in many high-energy astrophysical applications. The most notable radiative effects in astrophysical reconnection include radiation-reaction limits on particle acceleration, radiative cooling, radiative resistivity, braking of reconnection outflows by radiation drag, radiation pressure, viscosity, and even pair creation at highest energy densities. The self-consistent inclusion of these effects into magnetic reconnection theory and modeling sometimes calls for serious modifications to our overall theoretical approach to the problem. In addition, prompt reconnection-powered radiation often represents our only observational diagnostic tool available for studying remote astrophysical systems; this underscores the importance of developing predictive modeling capabilities to connect the underlying physical conditions in a reconnecting system to observable radiative signatures. This chapter presents an overview of our recent theoretical progress in developing basic physical understanding of radiative magnetic reconnection, with a special emphasis on astrophysically most important radiation mechanisms like synchrotron, curvature, and inverse-Compton. The chapter also offers a broad review of key high-energy astrophysical applications of radiative reconnection, illustrated by multiple examples such as: pulsar wind nebulae, pulsar magnetospheres, black-hole accretion-disk coronae and hot accretion flows in X-ray Binaries and Active Galactic Nuclei and their relativistic jets, magnetospheres of magnetars, and Gamma-Ray Bursts. Finally, this chapter discusses the most critical open questions and outlines the directions for future research of this exciting new frontier of magnetic reconnection research.

  20. Angular radiation pattern of Smith-Purcell radiation

    SciTech Connect

    Gover, A.; Dvorkis, P.; Elisha, U.

    1984-10-01

    The power radiation pattern of Smith-Purcell radiation is measured at various latitudes and azimuth angles relative to the electron beam. The experimental data are used to evaluate the various models and the physical mechanisms previously suggested to describe Smith-Purcell radiation. Good agreement is observed between the experimental data and the theoretical curves derive from Van den Berg's analysis (J. Opt. Soc. Am. 63, 1588 (1973)). The radiation mechanism proposed by Salisbury (J. Opt. Soc. Am. 60, 1279 (1970)) was analyzed an shown to be too small to account for the measured radiation. The experimantal and Van den Berg's theory predict stronger emission at azimuthal angles off the plane perpendicular to the gratings. This observation leads to conclusions regarding the design of optical cavities for Smith-Purcell free-electron lasers and orotron millimeter-wavelength-radiation tube devices.

  1. Radiation Safety System for Stanford Synchrotron Radiation Laboratory

    SciTech Connect

    Liu, J

    2004-03-12

    Radiation Safety System (RSS) at the Stanford Synchrotron Radiation Laboratory is summarized and reviewed. The RSS, which is designed to protect people from prompt radiation hazards from accelerator operation, consists of the Access Control System (ACS) and the Beam Containment System (BCS). The ACS prevents people from being exposed to the lethal radiation level inside the shielding housing (called a PPS area at SLAC). The ACS for a PPS area consists of the shielding housing, beam inhibiting devices, and a standard entry module at each entrance. The BCS protects people from the prompt radiation hazards outside a PPS area under both normal and abnormal beam loss situations. The BCS consists of the active power (current/energy) limiting devices, beam stoppers, shielding, and an active radiation monitor system. The policies and practices in setting up the RSS at SLAC are illustrated.

  2. Structure in Radiating Shocks

    NASA Astrophysics Data System (ADS)

    Doss, Forrest

    2010-11-01

    The basic radiative shock experiment is a shock launched into a gas of high-atomic-number material at high velocities, which fulfills the conditions for radiative losses to collapse the post-shock material to over 20 times the initial gas density. This has been accomplished using the OMEGA Laser Facility by illuminating a Be ablator for 1 ns with a total of 4 kJ, launching the requisite shock, faster than 100 km/sec, into a polyimide shock tube filled with Xe. The experiments have lateral dimensions of 600 ?m and axial dimensions of 2-3 mm, and are diagnosed by x-ray backlighting. Repeatable structure beyond the one-dimensional picture of a shock as a planar discontinuity was discovered in the experimental data. One form this took was that of radial boundary effects near the tube walls, extended approximately seventy microns into the system. The cause of this effect - low density wall material which is heated by radiation transport ahead of the shock, launching a new converging shock ahead of the main shock - is apparently unique to high-energy-density experiments. Another form of structure is the appearance of small-scale perturbations in the post-shock layer, modulating the shock and material interfaces and creating regions of enhanced and diminished aerial density within the layer. The authors have applied an instability theory, a variation of the Vishniac instability of decelerating shocks, to describe the growth of these perturbations. We have also applied Bayesian statistical methods to better understand the uncertainties associated with measuring shocked layer thickness in the presence of tilt. Collaborators: R. P. Drake, H. F. Robey, C. C. Kuranz, C. M. Huntington, M. J. Grosskopf, D. C. Marion.

  3. Nonlinearity of radiation health effects.

    PubMed Central

    Pollycove, M

    1998-01-01

    The prime concern of radiation protection policy since 1959 has been to protect DNA from damage. In 1994 the United Nations Scientific Community on the Effects of Atomic Radiation focused on biosystem response to radiation with its report Adaptive Responses to Radiation of Cells and Organisms. The 1995 National Council on Radiation Protection and Measurements report Principles and Application of Collective Dose in Radiation Protection states that because no human data provides direct support for the linear nonthreshold hypothesis (LNT), confidence in LNT is based on the biophysical concept that the passage of a single charged particle could cause damage to DNA that would result in cancer. Several statistically significant epidemiologic studies contradict the validity of this concept by showing risk decrements, i.e., hormesis, of cancer mortality and mortality from all causes in populations exposed to low-dose radiation. Unrepaired low-dose radiation damage to DNA is negligible compared to metabolic damage. The DNA damage-control biosystem is physiologically operative on both metabolic and radiation damage and effected predominantly by free radicals. The DNA damage-control biosystem is suppressed by high dose and stimulated by low-dose radiation. The hormetic effect of low-dose radiation may be explained by its increase of biosystem efficiency. Improved DNA damage control reduces persistent mis- or unrepaired DNA damage i.e., the number of mutations that accumulate during a lifetime. This progressive accumulation of gene mutations in stem cells is associated with decreasing DNA damage control, aging, and malignancy. Recognition of the positive health effects produced by adaptive responses to low-dose radiation would result in a realistic assessment of the environmental risk of radiation. Images Figure 1 Figure 3 Figure 5 Figure 6 Figure 8 Figure 10 PMID:9539031

  4. Protection from space radiation

    SciTech Connect

    Tripathi, R.K.; Wilson, J.W.; Shinn, J.L.

    2000-07-01

    The exposures anticipated for astronauts in the anticipated human exploration and development of space will be significantly higher (both annual and carrier) than for any other occupational group. In addition, the exposures in deep space result largely from galactic cosmic rays for which there is as yet little experience. Some evidence exists indicating that conventional linear energy transfer defined protection quantities (quality factors) may not be appropriate. The authors evaluate their current understanding of radiation protection with laboratory and flight experimental data and discuss recent improvements in interaction models and transport methods.

  5. Cosmic Tachyon Background Radiation

    NASA Astrophysics Data System (ADS)

    Tomaschitz, Roman

    The equilibrium statistical mechanics of a background radiation of superluminal particles is investigated, based on a vectorial wave equation for tachyons of the Proca type. The partition function, the spectral energy density, and the various thermodynamic variables of an ideal Bose gas of tachyons in an open Robertson-Walker cosmology are derived. The negative mass square in the wave equation changes the frequency scaling in the Rayleigh-Jeans law, and there are also significant changes in the low temperature regime as compared to the microwave background, in particular in the caloric and thermal equations of state.

  6. Carbon-Carbon Radiator

    NASA Technical Reports Server (NTRS)

    Butler, Dan; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Carbon-Carbon (C-C) Radiator was a success and proved that the technology can work to reduce Spacecraft weight. C-C has a niche, especially for high temperatures. C-C still needs further development: reduction in fabrication time and cost - high conductivity "traditional" composites are more competitive, and CTE interface issues with heat pipes. Redundancy a good idea - we flew the spare panel. CSRP was a success -informal inter-agency partnership. Possible follow-on: C-C foam for low CTE mirrors/optical benches.

  7. 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

  8. Management of radiation wounds

    PubMed Central

    Iyer, Subramania; Balasubramanian, Deepak

    2012-01-01

    Radiotherapy forms an integral part in cancer treatment today. It is used alone or in combination with surgery and chemotherapy. Although radiotherapy is useful to effect tumour death, it also exerts a deleterious effect on surrounding normal tissues. These effects are either acute or can manifest months or years after the treatment. The chronic wounds are a result of impaired wound healing. This impairment results in fibrosis, nonhealing ulcers, lymphoedema and radionecrosis amongst others. This article will discuss the pathophysiology in brief, along with the manifestations of radiation-induced injury and the treatment available currently PMID:23162232

  9. Radiation imaging apparatus

    DOEpatents

    Anger, Hal O. (Berkeley, CA); Martin, Donn C. (Berkeley, CA); Lampton, Michael L. (Berkeley, CA)

    1983-01-01

    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally.

  10. Cosmic Background Radiation

    NASA Astrophysics Data System (ADS)

    Sidharth, B. G.; Valluri, S. R.

    2015-08-01

    It is shown that a collection of photons with nearly the same frequency exhibits a "condensation" type of phenomenon corresponding to a peak intensity. The observed cosmic background radiation can be explained from this standpoint. We have obtained analogous results by extremization of the occupation number for photons with the use of the Lambert W function. Some of the interesting applications of this function are briefly discussed in the context of graphene which exhibits an interesting two dimensional structure with several characteristic properties and diverse practical applications.

  11. Iron, radiation, and cancer

    SciTech Connect

    Stevens, R.G.; Kalkwarf, D.R. )

    1990-07-01

    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. 151 references.

  12. Management of radiation proctitis.

    PubMed

    Mendenhall, William M; McKibben, Brian T; Hoppe, Bradford S; Nichols, Romaine C; Henderson, Randal H; Mendenhall, Nancy P

    2014-10-01

    The optimal management of radiation proctitis is ill defined. A variety of alternatives are available and include topical agents (ie, sucralfate enemas, formalin), oral agents (ie, pentoxyfylline, vitamin A), hyperbaric oxygen, and endoscopic interventions (ie, argon plasma coagulation). It is prudent to manage patients conservatively and to intervene only when necessary with the option least likely to exacerbate the proctitis. Rectal biopsies should be avoided as they may precipitate a complication. More aggressive measures, such as argon laser coagulation, should be employed only when more conservative approaches fail. PMID:23241500

  13. 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.

  14. Radiation imaging apparatus

    DOEpatents

    Anger, H.O.; Martin, D.C.; Lampton, M.L.

    1983-07-26

    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally. 15 figs.

  15. LDEF satellite radiation study

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    Some early results are summarized from a program under way to utilize LDEF satellite data for evaluating and improving current models of the space radiation environment in low earth orbit. Reported here are predictions and comparisons with some of the LDEF dose and induced radioactivity data, which are used to check the accuracy of current models describing the magnitude and directionality of the trapped proton environment. Preliminary findings are that the environment models underestimate both dose and activation from trapped protons by a factor of about two, and the observed anisotropy is higher than predicted.

  16. Analysis of Contribution from Edge Radiation to Optical Diffraction Radiation

    SciTech Connect

    C. Liu, P. Evtushenko, A. Freyberger, C. Liu, A.H. Lumpkin

    2009-05-01

    Beam size measurement with near-field optical diffraction radiation (ODR) has been carried out successfully at CEBAF. The ODR station is installed on the Hall-A beam line after eight bending magnets. The ODR images were affected by an unexpected radiation. Some calculations for analyzing the source of the radiation will be presented. Furthermore, two schemes will be proposed to alleviate the contamination.

  17. 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.

  18. Miniature radiation dosimeter for in vivo radiation measurements

    NASA Astrophysics Data System (ADS)

    Hughes, R. C.; Huffman, D.; Snelling, J. V.; Zipperian, T. E.; Ricco, A. J.; Kelsey, C. A.

    The use of ionizing radiation from various sources for the treatment of tumors is widespread. There are no commercial devices for in vivo, real time, dosimetry of patients. The dose to be given a patient is determined from computer modelling and the calibration of the radiation sources. A miniature dosimeter which was mounted in a 1 mm catheter is described. The active device is a radiation sensing field effect transistor (RADFET) which can be used in either an active or passive mode. The RADFET in a catheter is designed to be used during implant radiation therapy of the breast, prostrate, cervix, among other modalities. Its use and operation is described.

  19. 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.

  20. Radiation Embrittlement Archive Project

    SciTech Connect

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

    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.

  1. Chandra Radiation Environment Modeling

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Blackwell, W. C.

    2003-01-01

    CRMFLX (Chandra Radiation Model of ion FluX) is a radiation environment risk mitigation tool for use as a decision aid in planning the operations times for Chandra's Advanced CCD Imaging Spectrometer (ACIS) detector. The accurate prediction of the proton flux environment with energies of 100 - 200 keV is needed in order to protect the ACIS detector against proton degradation. Unfortunately, protons of this energy are abundant in the region of space Chandra must operate, and on-board particle detectors do not measure proton flux levels of the required energy range. This presentation will describe the plasma environment data analysis and modeling basis of the CRMFLX engineering environment model developed to predict the proton flux in the solar wind, magnetosheath, and magnetosphere phenomenological regions of geospace. The recently released CRMFLX Version 2 implementation includes an algorithm that propagates flux from an observation location to other regions of the magnetosphere based on convective ExB and VB-curvature particle drift motions. This technique has the advantage of more completely filling out the database and makes maximum use of limited data obtained during high Kp periods or in areas of the magnetosphere with poor satellite flux measurement coverage.

  2. Management of radiation ulcers

    SciTech Connect

    Shack, R.B.

    1982-12-01

    Despite more efficient and safer technics of radiation therapy, the problem of radiation-induced injury to the skin and soft tissue persists. The problem of adequate coverage of these painful, ischemic, and fibrotic ulcers remains challenging. Split-thickness skin grafts are seldom sufficient coverage, as the graft almost always has areas that do not take. Although these areas may eventually heal by epithelialization, the result is never ideal. Most often flap coverage is required, but elevation of local flaps is jeopardized because the tissue surrounding the ulcer crater frequently has been sufficiently compromised to cause loss of at least part of the flap. In the past, this necessitated use of pedicled flaps, tubed and transposed from a distance. With the development of axial-pattern musculocutaneous and muscle flaps, as well as microvascular free flaps, the difficulty in dealing with these ulcers has been decreased. Surgeons can now recommend earlier use of adequate debridement, many times of the entire irradiated area, and immediate coverage with a well vascularized axial-pattern musculocutaneous flap or revascularized free flap.

  3. Ultraviolet radiation and cyanobacteria.

    PubMed

    Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Hder, Donat-Peter; Han, Taejun

    2014-12-01

    Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. PMID:25463663

  4. 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.

  5. Laser radiation bracket debonding

    NASA Astrophysics Data System (ADS)

    Dostlov, Tat'jana; Jelnkov, Helena; ulc, Jan; Koranda, Petr; Nemec, Michal; Racek, Jaroslav; Miyagi, Mitsunobu

    2008-02-01

    Ceramic brackets are an aesthetic substitute for conventional stainless steel brackets in orthodontic patients. However, ceramic brackets are more brittle and have higher bond strengths, which can lead to bracket breakage and enamel damage during classical type of debonding. This study examined the possibility of laser radiation ceramic brackets removing as well as the possible damage of a surface structure of hard dental tissue after this procedure. Two types of lasers were used for the experiments - a laser diode LIMO HLU20F400 generating a wavelength of 808 nm with the maximum output power 20W at the end of the fiber (core diameter 400 ?m, numerical aperture 0.22). As a second source, a diode-pumped Tm:YAP laser system generating a wavelength of 1.9 ?m, with up to 3.8 W maximum output power was chosen. For the investigation, extracted incisors with ceramic brackets were used. In both cases, laser radiation was applied for 0.5 minute at a maximum power of 1 W. Temperature changes of the irradiated tissue was registered by camera Electrophysics PV320. After the interaction experiment, the photo-documentation was prepared by the stereomicroscope Nikon SMZ 2T, Japan. The surface tissue analysis was processed in "low vacuum" (30 Pa) regime without desiccation. This technique was used to record back-scattered electron images. Selecting the appropriate laser, resin, and bracket combination can minimize risks of enamel degradation and make debonding more safe.

  6. 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.

  7. 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.

  8. 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.

  9. Diffuse gamma radiation

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Simpson, G. A.; Thompson, D. J.

    1977-01-01

    An examination of the intensity, energy spectrum, and spatial distribution of the diffuse gamma-radiation observed by SAS-2 satellite away from the galactic plane in the energy range above 35 MeV has shown that it consists of two components. One component is generally correlated with galactic latitudes, the atomic hydrogen column density was deduced from 21 cm measurements, and the continuum radio emission, believed to be synchrotron emission. It has an energy spectrum similar to that in the plane and joins smoothly to the intense radiation from the plane. It is therefore presumed to be of galactic origin. The other component is apparently isotropic, at least on a coarse scale, and has a steep energy spectrum. No evidence is found for a cosmic ray halo surrounding the galaxy in the shape of a sphere or oblate spheroid with galactic dimensions. Constraints for a halo model with significantly larger dimensions are set on the basis of an upper limit to the gamma-ray anisotropy.

  10. Vanishing torque from radiation pressure

    NASA Astrophysics Data System (ADS)

    Nesvorn, D.; Vokrouhlick, D.

    2008-03-01

    Context: Pioneering works on the effect of solar irradiation on the rotation of small objects in interplanetary space raised the possibility that the radiation pressure from solar photon absorption could modify the objects' spin states. Later numerical studies found that the torque from radiation pressure, when averaged over spin and orbital periods, vanished for all studied asteroid shape models. Aims: We demonstrate that the average torque from radiation pressure vanishes for any surface shape deformation. Methods: We have calculated the torque analytically. The main assumption of our calculation is that the object rotates around its principal axis of inertia. Results: We show that the average torque vanishes for any surface shape deformation because the individual radiation-pressure contributions from configurations separated by ? in orbital longitude cancel each other out. Conclusions: Unlike the thermal radiation and reflection of solar photons from surface, which can produce important effects over planetary timescales, the radiation pressure cannot change asteroid rotation.

  11. RADIATIVE RAYLEIGH-TAYLOR INSTABILITIES

    SciTech Connect

    Jacquet, Emmanuel; Krumholz, Mark R. E-mail: krumholz@ucolick.org

    2011-04-01

    We perform analytic linear stability analyses of an interface separating two stratified media threaded by a radiation flux, a configuration relevant in several astrophysical contexts. We develop a general framework for analyzing such systems and obtain exact stability conditions in several limiting cases. In the optically thin, isothermal regime, where the discontinuity is chemical in nature (e.g., at the boundary of a radiation pressure-driven H II region), radiation acts as part of an effective gravitational field, and instability arises if the effective gravity per unit volume toward the interface overcomes that away from it. In the optically thick 'adiabatic' regime where the total (gas plus radiation) specific entropy of a Lagrangian fluid element is conserved, for example at the edge of radiation pressure-driven bubble around a young massive star, we show that radiation acts like a modified equation of state and derive a generalized version of the classical Rayleigh-Taylor stability condition.

  12. Introduction to clinical radiation oncology

    SciTech Connect

    Coia, L.R. . Dept. of Radiation Oncology); Moylan, D.J. III . Dept. of Medicine)

    1991-01-01

    This book discusses the management of cancer by radiation therapy both for cure and palliation. A wide range of clinical topics are introduced. In the introductory chapters on radiation physics and radiobiology, important terms and concepts used in clinical radiation oncology are covered. The subsequent chapters, which form the core of the book, group tumors predominantly according to major physiologic systems or anatomic site. Acute and chronic complications of treatment are listed along with pertinent information regarding their pathogenesis and management. There are also chapters dealing with radiation oncology emergencies, palliative treatment, combined-modality therapy and quality assurance. The radiation safety chapter presents guidelines for radiation protection. Current areas of promising investigation are presented in the final chapter. Individual chapters have been processed separately for inclusion in the appropriate data bases.

  13. 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.

  14. Poll of radiation health scientists

    SciTech Connect

    Cohen, B.L.

    1986-05-01

    A sampling of 210 university-employed radiation health scientists randomly selected from the membership lists of the Health Physics Society and the Radiation Research Society was polled in a secret ballot. The results support the positions that the public's fear of radiation is substantially greater than realistic, that TV, newspapers and magazines substantially exaggerate the dangers of radiation, that the amount of money now being spent on radiation protection is sufficient, and that the openness and honesty of U.S. government agencies about dangers of radiation were below average before 1972 but have been above average since then. Respondents give very high credibility ratings to BEIR, UNSCEAR, ICRP, and NCRP and to the individual scientists associated with their reports, and very low credibility ratings to those who have disputed them.

  15. Gravitational scattering of electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Brooker, J. T.; Janis, A. I.

    1980-01-01

    The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

  16. DOE 2009 occupational radiation exposure

    SciTech Connect

    none,

    2010-09-01

    The U.S. Department of Energy (DOE) Office of Corporate Safety Analysis (HS-30) within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The DOE 2009 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  17. DOE 2010 occupational radiation exposure

    SciTech Connect

    none,

    2011-11-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The DOE 2010 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  18. DOE 2008 occupational radiation exposure

    SciTech Connect

    none,

    2009-10-01

    The U.S. Department of Energy (DOE) Office of Corporate Safety Analysis (HS-30) within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE. The DOE 2008 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. This report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  19. 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.

  20. Radiation effects in nanoelectronic elements

    SciTech Connect

    Gromov, D. V.; Elesin, V. V.; Petrov, G. V.; Bobrinetskii, I. I.; Nevolin, V. K.

    2010-12-15

    Radiation defects induced in planar nanosized structures by steady and pulsed ionizing radiation have been analyzed. Characteristics of test samples with a planar nanosized structure fabricated by deposition of an ultrathin titanium film onto a semi-insulating GaAs substrate and of field-effect transistor structures based on bundles of carbon nanotubes have been studied. Physical mechanisms responsible for the radiation-induced changes in characteristics of the nanoelectronic elements under consideration have been established.

  1. Deterministic methods in radiation transport

    SciTech Connect

    Rice, A.F.; Roussin, R.W.

    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.

  2. Radiator design system computer programs

    NASA Technical Reports Server (NTRS)

    Wiggins, C. L.; Oren, J. A.; Dietz, J. B.

    1971-01-01

    Minimum weight space radiator subsystems which can operate over heat load ranges wider than the capabilities of current subsystems are investigated according to projected trends of future long duration space vehicles. Special consideration is given to maximum heat rejection requirements of the low temperature radiators needed for environmental control systems. The set of radiator design programs that have resulted from this investigation are presented in order to provide the analyst with a capability to generate optimum weight radiator panels or sets of panels from practical design considerations, including transient performance. Modifications are also provided for existing programs to improve capability and user convenience.

  3. Radiation Environments for Lunar Programs

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Altstatt, Richard L.; Blackwell, Willliam C.; Harine, Katherine J.

    2007-01-01

    Developing reliable space systems for lunar exploration and infrastructure for extended duration operations on the lunar surface requires analysis and mitigation of potential system vulnerabilities to radiation effects on materials and systems. This paper reviews the characteristics of space radiation environments relevant to lunar programs including the trans-Earth and trans-lunar injection trajectories through the Earth's radiation belts, solar wind surface dose environments, energetic solar particle events, and galactic cosmic rays and discusses the radiation design environments being developed for lunar program requirements to assure that systems operate successfully in the space environment.

  4. Epidemiology of accidental radiation exposures.

    PubMed Central

    Cardis, E

    1996-01-01

    Much of the information on the health effects of radiation exposure available to date comes from long-term studies of the atomic bombings in Hiroshima and Nagasaki. Accidental exposures, such as those resulting from the Chernobyl and Kyshtym accidents, have as yet provided little information concerning health effects of ionizing radiation. This paper will present the current state of our knowledge concerning radiation effects, review major large-scale accidental radiation exposures, and discuss information that could be obtained from studies of accidental exposures and the types of studies that are needed. PMID:8781398

  5. Radiation thermometry: The measurement problem

    NASA Technical Reports Server (NTRS)

    Nutter, G. D.

    1988-01-01

    An overview of the theory and techniques of radiometric thermometry is presented. The characteristics of thermal radiators (targets) are discussed along with surface roughness and oxidation effects, fresnel reflection and subsurface effects in dielectrics. The effects of the optical medium between the radiating target and the radiation thermometer are characterized including atmospheric effects, ambient temperature and dust environment effects and the influence of measurement windows. The optical and photodetection components of radiation thermometers are described and techniques for the correction of emissivity effects are addressed.

  6. 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.

  7. Enhanced radiation resistant fiber optics

    DOEpatents

    Lyons, Peter B.; Looney, Larry D.

    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.

  8. Space Radiation and Bone Loss.

    PubMed

    Willey, Jeffrey S; Lloyd, Shane A J; Nelson, Gregory A; Bateman, Ted A

    2011-01-01

    Exposure to ionizing radiation may negatively impact skeletal integrity during extended spaceflight missions to the moon, Mars, or near-Earth asteroids. However, our understanding of the effects of radiation on bone is limited when compared to the effects of weightlessness. In addition to microgravity, astronauts will be exposed to space radiation from solar and cosmic sources. Historically, radiation exposure has been shown to damage both osteoblast precursors and local vasculature within the irradiated volume. The resulting suppression of bone formation and a general state of low bone-turnover is thought to be the primary contributor to bone loss and eventual fracture. Recent investigations using mouse models have identified a rapid, but transient, increase in osteoclast activity immediately after irradiation with both spaceflight and clinically-relevant radiation qualities and doses. Together with a chronic suppression of bone formation after radiation exposure, this acute skeletal damage may contribute to long-term deterioration of bone quality, potentially increasing fracture risk. Direct evidence for the damaging effects of radiation on human bone are primarily demonstrated by the increased incidence of fractures at sites that absorb high doses of radiation during cancer therapy: exposures are considerably higher than what could be expected during spaceflight. However, both the rapidity of bone damage and the chronic nature of the changes appear similar between exposure scenarios. This review will outline our current knowledge of space and clinical exploration exposure to ionizing radiation on skeletal health. PMID:22826632

  9. Observation of stimulated transition radiation

    SciTech Connect

    Lihn, H.; Kung, P.; Settakorn, C.; Wiedemann, H.; Bocek, D.; Hernandez, M.

    1996-05-01

    Stimulated, coherent transition radiation (STR) has been observed at the Stanford SUNSHINE facility. Far-infrared light pulses of coherent transition radiation emitted from femtosecond electron bunches are recycled in a special cavity to arrive back at the radiator coincident with subsequent incoming electron bunches. This overlap enables the electrons to do work on the electromagnetic field, thus stimulating the emission of more radiated energy than would be possible without this external field. The experimental setup to observe STR via cavity detuning measurements and experimental results is discussed. {copyright} {ital 1996 The American Physical Society.}

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Radiation hormesis: Evidence for radiation stimulation and speculation regarding mechanisms

    NASA Astrophysics Data System (ADS)

    Sagan, Leonard A.

    Ionizing radiation is generally believed to be harmful at all levels of exposure, yet, the scientific basis for this assumption is weak to non-existent. Indeed, there is a considerable body of evidence which suggests the contrary, namely, that low doses of radiation, under certain circumtances, may be beneficial. This literature is reviewed, together with some suggested mechanisms.

  15. 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.

  16. 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...

  17. Towards a fast calculator for the radiation characteristics of radiative recombination and radiative electron capture

    NASA Astrophysics Data System (ADS)

    Weber, G.; Ding, H.; Herdrich, M. O.; Surzhykov, A.

    2015-04-01

    The radiative capture of free electrons (radiative recombination) and bound electrons (radiative electron capture) are among the most important charge changing processes for fast, highly-charged ions. While total cross sections can be obtained by an approximate formula with reasonable accuracy, the estimation of angular distributions and polarization properties of the emitted radiation requires a fully relativistic treatment that is numerical expensive. Therefore we recently started the development of a fast calculator for these radiation characteristics. The program is based on a grid of rigorously calculated data points for free- electron capture into bare ions, between which interpolation is performed to obtain radiation characteristics for specific collision systems. Also capture into few-electron systems is taken into account in an approximate way. We present first results from this development.

  18. Slope effects on shortwave radiation components and net radiation

    NASA Technical Reports Server (NTRS)

    Walter-Shea, Elizabeth A.; Blad, Blaine L.; Hays, Cynthia J.; Mesarch, Mark A.

    1992-01-01

    The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions.' The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1978-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used to quantify surface processes. Analysis since our last report has focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989.

  19. Future of Radiation Protection Regulations.

    PubMed

    Doss, Mohan

    2016-03-01

    THERE IS considerable disagreement in the scientific community regarding the carcinogenicity of low-dose radiation (LDR), with publications supporting opposing points of view. However, major flaws have been identified in many of the publications claiming increased cancer risk from LDR. The data generally recognized as the most important for assessing radiation effects in humans, the atomic bomb survivor data, are often cited to raise LDR cancer concerns. However, these data no longer support the linear no-threshold (LNT) model after the 2012 update but are consistent with radiation hormesis. Thus, a resolution of the controversy regarding the carcinogenicity of LDR appears to be imminent, with the rejection of the LNT model and acceptance of radiation hormesis. Hence, for setting radiation protection regulations, an alternative approach to the present one based on the LNT model is needed. One approach would be to determine the threshold dose for the carcinogenic effect of radiation from existing data and establish regulations to ensure radiation doses are kept well below the threshold dose. This can be done by setting dose guidelines specifying safe levels of radiation doses, with the requirement that these safe levels, referred to as guidance levels, not be exceeded significantly. Using this approach, a dose guidance level of 10 cGy for acute radiation exposures and 10 cGy y for exposures over extended periods of time are recommended. The concept of keeping doses as low as reasonably achievable, known as ALARA, would no longer be required for low-level radiation exposures not expected to exceed the dose guidance levels significantly. These regulations would facilitate studies using LDR for prevention and treatment of diseases. Results from such studies would be helpful in refining dose guidance levels. The dose guidance levels would be the same for the public and radiation workers to ensure everyone's safety. PMID:26808881

  20. 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.