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1

SWISS-PROT  

NSDL National Science Digital Library

SWISS-PROT, provided by the Swiss Institute of Bioinformatics, is a "curated protein sequence database" that provides, with minimal redundancy and "a high level of integration with other databases," descriptions of "the function of a protein, its domains structure, post-translational modifications" and variants, as well as a host of other information. Access to the SWISS-PROT database is available via "description or identification (any word in the DE, OS, OG, GN and ID lines)," by accession number (AC line), author (RA line), citation (RL line), or full text search. Lengthy returns offer information in several dozen fields, including taxonomic hierarchy, journal references, and sequence information.

1998-01-01

2

The Universal Protein Resource (UniProt).  

PubMed

The Universal Protein Resource (UniProt) provides the scientific community with a single, centralized, authoritative resource for protein sequences and functional information. Formed by uniting the Swiss-Prot, TrEMBL and PIR protein database activities, the UniProt consortium produces three layers of protein sequence databases: the UniProt Archive (UniParc), the UniProt Knowledgebase (UniProt) and the UniProt Reference (UniRef) databases. The UniProt Knowledgebase is a comprehensive, fully classified, richly and accurately annotated protein sequence knowledgebase with extensive cross-references. This centrepiece consists of two sections: UniProt/Swiss-Prot, with fully, manually curated entries; and UniProt/TrEMBL, enriched with automated classification and annotation. During 2004, tens of thousands of Knowledgebase records got manually annotated or updated; we introduced a new comment line topic: TOXIC DOSE to store information on the acute toxicity of a toxin; the UniProt keyword list got augmented by additional keywords; we improved the documentation of the keywords and are continuously overhauling and standardizing the annotation of post-translational modifications. Furthermore, we introduced a new documentation file of the strains and their synonyms. Many new database cross-references were introduced and we started to make use of Digital Object Identifiers. We also achieved in collaboration with the Macromolecular Structure Database group at EBI an improved integration with structural databases by residue level mapping of sequences from the Protein Data Bank entries onto corresponding UniProt entries. For convenient sequence searches we provide the UniRef non-redundant sequence databases. The comprehensive UniParc database stores the complete body of publicly available protein sequence data. The UniProt databases can be accessed online (http://www.uniprot.org) or downloaded in several formats (ftp://ftp.uniprot.org/pub). New releases are published every two weeks. PMID:15608167

Bairoch, Amos; Apweiler, Rolf; Wu, Cathy H; Barker, Winona C; Boeckmann, Brigitte; Ferro, Serenella; Gasteiger, Elisabeth; Huang, Hongzhan; Lopez, Rodrigo; Magrane, Michele; Martin, Maria J; Natale, Darren A; O'Donovan, Claire; Redaschi, Nicole; Yeh, Lai-Su L

2005-01-01

3

The UniProtKB/Swiss-Prot Tox-Prot program: a central hub of integrated venom protein data  

PubMed Central

Animal toxins are of interest to a wide range of scientists, due to their numerous applications in pharmacology, neurology, hematology, medicine, and drug research. This, and to a lesser extent the development of new performing tools in transcriptomics and proteomics, has led to an increase in toxin discovery. In this context, providing publicly available data on animal toxins has become essential. The UniProtKB/Swiss-Prot Tox-Prot program (http://www.uniprot.org/program/Toxins) plays a crucial role by providing such an access to venom protein sequences and functions from all venomous species. This program has up to now curated more than 5000 venom proteins to the high-quality standards of UniProtKB/Swiss-Prot (release 2012_02). Proteins targeted by these toxins are also available in the knowledgebase. This paper describes in details the type of information provided by UniProtKB/Swiss-Prot for toxins, as well as the structured format of the knowledgebase.

Jungo, Florence; Bougueleret, Lydie; Xenarios, Ioannis; Poux, Sylvain

2012-01-01

4

Tox-Prot, the toxin protein annotation program of the Swiss-Prot protein knowledgebase.  

PubMed

The Tox-Prot program was initiated in order to provide the scientific community a summary of the current knowledge on animal protein toxins. The aim of this program is to systematically annotate all proteins which act as toxins and are produced by venomous and poisonous animals. Venomous animals such as snakes, scorpions, spiders, jellyfish, insects, cone snails, sea anemones, lizards, some fish, and platypus are equipped with a specialized organ to inject venom in their prey. In contrast, poisonous animals such as some fish or worms, lack such organs. Each toxin is annotated according to the quality standards of Swiss-Prot. This means providing a wealth of information that includes the description of the function, domain structure, subcellular location, tissue specificity, variants, similarities to other proteins, keywords, etc. In the framework of this program, particular care has been made to capture what is known on the function and mode of action, posttranslational modifications and 3D structural data which are all relatively abundant in the field of protein toxins. Researchers are welcome to contribute their knowledge to the scientific community by submitting relevant findings to Swiss-Prot concerning toxins at Tox-Prot@isb-sib.ch. More information on Tox-Prot can be found at http://www.expasy.org/sprot/tox-prot. PMID:15683867

Jungo, Florence; Bairoch, Amos

2005-03-01

5

ENZYMAP: exploiting protein annotation for modeling and predicting EC number changes in UniProt/Swiss-Prot.  

PubMed

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

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

2014-01-01

6

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

PubMed Central

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.

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

2014-01-01

7

Automatically extracting functionally equivalent proteins from SwissProt  

PubMed Central

Background There is a frequent need to obtain sets of functionally equivalent homologous proteins (FEPs) from different species. While it is usually the case that orthology implies functional equivalence, this is not always true; therefore datasets of orthologous proteins are not appropriate. The information relevant to extracting FEPs is contained in databanks such as UniProtKB/Swiss-Prot and a manual analysis of these data allow FEPs to be extracted on a one-off basis. However there has been no resource allowing the easy, automatic extraction of groups of FEPs for example, all instances of protein C. We have developed FOSTA, an automatically generated database of FEPs annotated as having the same function in UniProtKB/Swiss-Prot which can be used for large-scale analysis. The method builds a candidate list of homologues and filters out functionally diverged proteins on the basis of functional annotations using a simple text mining approach. Results Large scale evaluation of our FEP extraction method is difficult as there is no gold-standard dataset against which the method can be benchmarked. However, a manual analysis of five protein families confirmed a high level of performance. A more extensive comparison with two manually verified functional equivalence datasets also demonstrated very good performance. Conclusion In summary, FOSTA provides an automated analysis of annotations in UniProtKB/Swiss-Prot to enable groups of proteins already annotated as functionally equivalent, to be extracted. Our results demonstrate that the vast majority of UniProtKB/Swiss-Prot functional annotations are of high quality, and that FOSTA can interpret annotations successfully. Where FOSTA is not successful, we are able to highlight inconsistencies in UniProtKB/Swiss-Prot annotation. Most of these would have presented equal difficulties for manual interpretation of annotations. We discuss limitations and possible future extensions to FOSTA, and recommend changes to the UniProtKB/Swiss-Prot format, which would facilitate text-mining of UniProtKB/Swiss-Prot.

McMillan, Lisa EM; Martin, Andrew CR

2008-01-01

8

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

PubMed Central

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.

2012-01-01

9

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

PubMed

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

2012-01-01

10

48 CFR 819.7106 - Eligibility of Mentor and Protégé firms.  

Code of Federal Regulations, 2013 CFR

...b) of this section. Mentors shall confirm eligibility by documenting the verified status of the protégé in the VetBiz.gov VIP database. Protégés must maintain verified status throughout the term of the Mentor-Protégé Agreement. Failure to do so...

2013-10-01

11

48 CFR 1819.7204 - Protégé selection.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Prot©g© Program...minority institutions of higher education, an active NASA SBIR Phase II company or a nonprofit...protégé may have only one active NASA mentor-protégé agreement,...

2009-10-01

12

48 CFR 1819.7204 - Protégé selection.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Prot©g© Program...minority institutions of higher education, an active NASA SBIR Phase II company or a nonprofit...protégé may have only one active NASA mentor-protégé agreement,...

2010-10-01

13

48 CFR 3052.219-71 - DHS mentor-protégé program.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false DHS mentor-prot©g© program. 3052...Provisions and Clauses 3052.219-71 DHS mentor-protégé program. As prescribed...708-70(b), insert the following clause: DHS Mentor-Protégé Program (JUN...

2010-10-01

14

48 CFR 3052.219-71 - DHS mentor-protégé program.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false DHS mentor-prot©g© program. 3052...Provisions and Clauses 3052.219-71 DHS mentor-protégé program. As prescribed...708-70(b), insert the following clause: DHS Mentor-Protégé Program (JUN...

2009-10-01

15

48 CFR 1819.7204 - Protégé selection.  

Code of Federal Regulations, 2013 CFR

...SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Prot©g© Program 1819...institutions of higher education, an active NASA SBIR Phase II company or a nonprofit agency...d) A protégé may have only one active NASA mentor-protégé agreement, and may...

2013-10-01

16

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false NASA Mentor-Prot©g© Program. 1852...Provisions and Clauses 1852.219-77 NASA Mentor-Protégé Program. As prescribed...7215, insert the following clause: NASA Mentor-Protégé Program...

2013-10-01

17

The Universal Protein Resource (UniProt): an expanding universe of protein information.  

PubMed

The Universal Protein Resource (UniProt) provides a central resource on protein sequences and functional annotation with three database components, each addressing a key need in protein bioinformatics. The UniProt Knowledgebase (UniProtKB), comprising the manually annotated UniProtKB/Swiss-Prot section and the automatically annotated UniProtKB/TrEMBL section, is the preeminent storehouse of protein annotation. The extensive cross-references, functional and feature annotations and literature-based evidence attribution enable scientists to analyse proteins and query across databases. The UniProt Reference Clusters (UniRef) speed similarity searches via sequence space compression by merging sequences that are 100% (UniRef100), 90% (UniRef90) or 50% (UniRef50) identical. Finally, the UniProt Archive (UniParc) stores all publicly available protein sequences, containing the history of sequence data with links to the source databases. UniProt databases continue to grow in size and in availability of information. Recent and upcoming changes to database contents, formats, controlled vocabularies and services are described. New download availability includes all major releases of UniProtKB, sequence collections by taxonomic division and complete proteomes. A bibliography mapping service has been added, and an ID mapping service will be available soon. UniProt databases can be accessed online at http://www.uniprot.org or downloaded at ftp://ftp.uniprot.org/pub/databases/. PMID:16381842

Wu, Cathy H; Apweiler, Rolf; Bairoch, Amos; Natale, Darren A; Barker, Winona C; Boeckmann, Brigitte; Ferro, Serenella; Gasteiger, Elisabeth; Huang, Hongzhan; Lopez, Rodrigo; Magrane, Michele; Martin, Maria J; Mazumder, Raja; O'Donovan, Claire; Redaschi, Nicole; Suzek, Baris

2006-01-01

18

DeltaProt: a software toolbox for comparative genomics  

Microsoft Academic Search

BACKGROUND: Statistical bioinformatics is the study of biological data sets obtained by new micro-technologies by means of proper statistical methods. For a better understanding of environmental adaptations of proteins, orthologous sequences from different habitats may be explored and compared. The main goal of the DeltaProt Toolbox is to provide users with important functionality that is needed for comparative screening and

Steinar Thorvaldsen; Tor Fl; Nils P Willassen

2010-01-01

19

EST2Prot: Mapping EST sequences to proteins  

PubMed Central

Background EST libraries are used in various biological studies, from microarray experiments to proteomic and genetic screens. These libraries usually contain many uncharacterized ESTs that are typically ignored since they cannot be mapped to known genes. Consequently, new discoveries are possibly overlooked. Results We describe a system (EST2Prot) that uses multiple elements to map EST sequences to their corresponding protein products. EST2Prot uses UniGene clusters, substring analysis, information about protein coding regions in existing DNA sequences and protein database searches to detect protein products related to a query EST sequence. Gene Ontology terms, Swiss-Prot keywords, and protein similarity data are used to map the ESTs to functional descriptors. Conclusion EST2Prot extends and significantly enriches the popular UniGene mapping by utilizing multiple relations between known biological entities. It produces a mapping between ESTs and proteins in real-time through a simple web-interface. The system is part of the Biozon database and is accessible at .

Shafer, Paul; Lin, David M; Yona, Golan

2006-01-01

20

DeltaProt: a software toolbox for comparative genomics  

PubMed Central

Background Statistical bioinformatics is the study of biological data sets obtained by new micro-technologies by means of proper statistical methods. For a better understanding of environmental adaptations of proteins, orthologous sequences from different habitats may be explored and compared. The main goal of the DeltaProt Toolbox is to provide users with important functionality that is needed for comparative screening and studies of extremophile proteins and protein classes. Visualization of the data sets is also the focus of this article, since visualizations can play a key role in making the various relationships transparent. This application paper is intended to inform the reader of the existence, functionality, and applicability of the toolbox. Results We present the DeltaProt Toolbox, a software toolbox that may be useful in importing, analyzing and visualizing data from multiple alignments of proteins. The toolbox has been written in MATLAB to provide an easy and user-friendly platform, including a graphical user interface, while ensuring good numerical performance. Problems in genome biology may be easily stated thanks to a compact input format. The toolbox also offers the possibility of utilizing structural information from the SABLE or other structure predictors. Different sequence plots can then be viewed and compared in order to find their similarities and differences. Detailed statistics are also calculated during the procedure. Conclusions The DeltaProt package is open source and freely available for academic, non-commercial use. The latest version of DeltaProt can be obtained from http://services.cbu.uib.no/software/deltaprot/. The website also contains documentation, and the toolbox comes with real data sets that are intended for training in applying the models to carry out bioinformatical and statistical analyses of protein sequences. Equipped with the new algorithms proposed here, DeltaProt serves as an auxiliary analysis tool capable of visualizing and comparing orthologus protein sequences. The framework of the algorithms also enables easy incorporation of extra information on structure, if such data is available.

2010-01-01

21

GraphProt: modeling binding preferences of RNA-binding proteins  

PubMed Central

We present GraphProt, a computational framework for learning sequence- and structure-binding preferences of RNA-binding proteins (RBPs) from high-throughput experimental data. We benchmark GraphProt, demonstrating that the modeled binding preferences conform to the literature, and showcase the biological relevance and two applications of GraphProt models. First, estimated binding affinities correlate with experimental measurements. Second, predicted Ago2 targets display higher levels of expression upon Ago2 knockdown, whereas control targets do not. Computational binding models, such as those provided by GraphProt, are essential for predicting RBP binding sites and affinities in all tissues. GraphProt is freely available at http://www.bioinf.uni-freiburg.de/Software/GraphProt.

2014-01-01

22

Automated annotation of microbial proteomes in SWISS-PROT  

Microsoft Academic Search

Large-scale sequencing of prokaryotic genomes demands the automation of certain annotation tasks currently manually performed in the production of the SWISS-PROT protein knowledgebase. The HAMAP project, or 'High-quality Automated and Manual Annotation of microbial Proteomes', aims to integrate manual and automatic annotation methods in order to enhance the speed of the curation process while preserving the quality of the database

Alexandre Gattiker; Karine Michoud; Catherine Rivoire; Andrea H. Auchincloss; Elisabeth Coudert; Tania Lima; Paul Kersey; Marco Pagni; Christian J. A. Sigrist; Corinne Lachaize; Anne-lise Veuthey; Elisabeth Gasteiger; Amos Bairoch

2003-01-01

23

49 CFR Appendix D to Part 26 - Mentor-Protégé Program Guidelines  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Mentor-Prot©g© Program Guidelines D Appendix D to Part 26 Transportation Office of the Secretary of...TRANSPORTATION FINANCIAL ASSISTANCE PROGRAMS Pt. 26, App. D Appendix D to Part 26Mentor-Protégé Program...

2013-10-01

24

enDNA-Prot: Identification of DNA-Binding Proteins by Applying Ensemble Learning  

PubMed Central

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 3.979.52% in ACC and 0.080.19 in MCC. Furthermore, when the benchmark dataset was expanded with negative samples, the performance of enDNA-Prot outperformed the three existing methods by 2.8316.63% in terms of ACC and 0.020.16 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.

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

2014-01-01

25

MS analysis and molecular characterization of Botrytis cinerea protease Prot-2. Use in bioactive peptides production.  

PubMed

Prot-2 protease previously purified to homogeneity from Botrytis cinerea showed potentiality to be used in detergency and for production of bioactive peptides. To extend the characterization of Prot-2 protease, antifungal and antibacterial assays were performed in vitro using protein hydrolysates prepared from muscle of mackerel (Scomber scomborus) treated with this enzyme. The most active hydrolysate (degree of hydrolysis of 8%) exhibited inhibition effect towards bacteria and phytopathogenic fungi, demonstrating that Prot-2 proteolysis generated bioactive peptides. Biochemical and molecular characterization of the purified Prot-2, by SDS-PAGE/Tryptic in gel-digestion and LC-MS/MS analysis, was investigated. The peptide amino acid sequence alignment search in database revealed a moderate homology between the determined amino acid sequence of Prot-2 protease and the known fungal trypsin/chymotrypsin in particular from Glomerella, Metarhizium and Streptomyces. From peptide sequence data obtained by mass spectrometry and sequences homologies, primers were defined and a cDNA fragment of 786bp was amplified by RT-PCR. The cDNA nucleotide sequence analysis revealed an open reading frame coding for 262 amino acid residues. The deduced amino acid sequence of Prot-2 showed moderate identity with trypsin of Glomerella graminicola (74%) and with chymotrypsin from Metarhizium anisopliae (71%). Prot-2 exhibited a Ser protease homology and showed in addition the specific His motif of trypsin/chymotrypsin family. PMID:23494220

Abidi, Ferid; Aissaoui, Nayssene; Gaudin, Jean-Charles; Chobert, Jean-Marc; Haertl, Thomas; Marzouki, Mohamed Nejib

2013-05-01

26

Radiation  

Cancer.gov

DCEG researchers carry out a broad-based research program designed to identify, understand, and quantify the risk of cancer in populations exposed to medical, occupational, or environmental radiation. They study ionizing radiation exposures (e.g., x-rays,

27

48 CFR 852.219-71 - VA mentor-protégé program.  

Code of Federal Regulations, 2011 CFR

(c) Mentor participation in the program means providing business developmental assistance to aid protégés in developing the requisite expertise to effectively compete for and successfully perform VA prime contracts and...

2013-10-01

28

The SWISS-PROT protein sequence data bank and its supplement TrEMBL.  

PubMed Central

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotations (such as the description of the function of a protein, structure of its domains, post-translational modifications, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include: an increase in the number and scope of model organisms; cross-references to two additional databases; a variety of new documentation files and the creation of TrEMBL, a computer annotated supplement to SWISS-PROT. This supplement consists of entries in SWISS-PROT-like format derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, except the CDS already included in SWISS-PROT.

Bairoch, A; Apweiler, R

1997-01-01

29

48 CFR 1819.7205 - Mentor-protégé agreements.  

Code of Federal Regulations, 2013 CFR

...SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS NASA Mentor-Prot©g© Program 1819...mentor, including a subcontract under a NASA contract awarded to the mentor. ...program. (2) Award of subcontracts under NASA contracts or other contracts on a...

2013-10-01

30

The SWISS-PROT protein knowledgebase and its supplement TrEMBL in 2003  

Microsoft Academic Search

The SWISS-PROT protein knowledgebase (http:\\/\\/ www.expasy.org\\/sprot\\/ and http:\\/\\/www.ebi.ac.uk\\/ swissprot\\/) connects amino acid sequences with the current knowledge in the Life Sciences. Each protein entry provides an interdisciplinary overview of relevant information by bringing together experi- mental results, computed features and sometimes even contradictory conclusions. Detailed expertise that goes beyond the scope of SWISS-PROT is made available via direct links to

Brigitte Boeckmann; Amos Bairoch; Rolf Apweiler; Marie-claude Blatter; Anne Estreicher; Elisabeth Gasteiger; Maria Jesus Martin; Karine Michoud; Claire O'donovan; Isabelle Phan; Sandrine Pilbout; Michel Schneider

2003-01-01

31

UniProtKB amid the turmoil of plant proteomics research  

PubMed Central

The UniProt KnowledgeBase (UniProtKB) provides a single, centralized, authoritative resource for protein sequences and functional information. The majority of its records is based on automatic translation of coding sequences (CDS) provided by submitters at the time of initial deposition to the nucleotide sequence databases (INSDC). This article will give a general overview of the current situation, with some specific illustrations extracted from our annotation of Arabidopsis and rice proteomes. More and more frequently, only the raw sequence of a complete genome is deposited to the nucleotide sequence databases and the gene model predictions and annotations are kept in separate, specialized model organism databases (MODs). In order to be able to provide the complete proteome of model organisms, UniProtKB had to implement pipelines for import of protein sequences from Ensembl and EnsemblGenomes. A single genome can be the target of several unrelated sequencing projects and the final assembly and gene model predictions may diverge quite significantly. In addition, several cultivars of the same species are often sequenced 1001 Arabidopsis cultivars are currently under way and the resulting proteomes are far from being identical. Therefore, one challenge for UniProtKB is to store and organize these data in a convenient way and to clearly defined reference proteomes that should be made available to users. Manual annotation is one of the landmarks of the Swiss-Prot section of UniProtKB. Besides adding functional annotation, curators are checking, and often correcting, gene model predictions. For plants, this task is limited to Arabidopsis thaliana and Oryza sativa subsp. japonica. Proteomics data providing experimental evidences confirming the existence of proteins or identifying sequence features such as post-translational modifications are also imported into UniProtKB records and the knowledgebase is cross-referenced to numerous proteomics resource.

Schneider, Michel; Consortium, the UniProt; Poux, Sylvain

2012-01-01

32

Radiation  

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...

33

Radiators  

SciTech Connect

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

Webster, D. M.

1985-07-30

34

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

Code of Federal Regulations, 2013 CFR

...be handled in accordance...mentor-protégé teams to participate in the program...Department of State Mentor-Protégé...and extent of technical and managerial...and, (v) Technical assistance...Rent-free use of facilities...However, in no event...

2013-10-01

35

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

Code of Federal Regulations, 2013 CFR

...assistance. The forms of developmental assistance...development, and technical assistance. ...3) Rent-free use of facilities and...conclusion of each year in the Mentor-Protégé...of the Treasury team regarding program...to develop the technical and corporate...

2013-10-01

36

48 CFR 519.7007 - Protégé firms.  

Code of Federal Regulations, 2013 CFR

...business concern, HUBZone small business concern, or women-owned small business concern; (2) Small...Registration (CCR) at www.ccr.gov to verify that the self-representation...protégé meets the specified small business and socioeconomic...

2013-10-01

37

The SWISS-PROT protein sequence data bank and its new supplement TREMBL  

Microsoft Academic Search

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotation (such as the description of the function of a protein, its domain structure, post-translational modifications, variants, etc), a minimal level of redundancy and a high level of integration with other databases. Recent developments of the database include: an increase in the number and scope

Amos Bairoch; Rolf Apweiler

1996-01-01

38

The SWISS-PROT protein sequence data bank and its supplement TrEMBL  

Microsoft Academic Search

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotations (such as the description of the function of a protein, structure of its domains, post-translational modifica- tions, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include: an increase in the number and

Amos Bairoch; Rolf Apweiler

1997-01-01

39

Conference on Overlapping Effects of Ultraviolet and Ionizing Radiation, London, 31 May 1968.  

National Technical Information Service (NTIS)

This report covers a joint meeting of the British Inst. of Radiology and the Photobiology Group, held in London on 31 May 1968. Papers covered the overlapping genetic effects of ultraviolet radiation and ionizing radiation of single organisms such as prot...

L. M. Libber

1968-01-01

40

Prot-Prop: J-tool to predict the subcellular location of proteins based on physiochemical characterization.  

PubMed

PROT-PROP is a computational tool to characterize 27 physicochemical properties of a protein along with its subcellular location (intra or extra) in a single-window application. Other significant features of this software include calculation of numerical values for hydrophobicity, hydrophilicity; composition of small and large amino acids; net hydrophobic content in terms of low/high; and Navie's algorithm to calculate theoretical pI. PROT-PROP is an easy-to-install platform independent implementation of JAVA under a user-friendly interface. It is a standalone version as a virtual appliance and source code for platforms supporting Java 1.5.0 and higher versions, and downloadable from the web http://www.mzu.edu.in/schools/biotechnology.html . PROT-PROP can run under Windows and Macintosh Operating Systems. PROT-PROP is distributed with its source code so that it may be adapted or customized, if desired. PMID:23354819

Senthilkumar, Brindha; Sailo, Sangzuala; Guruswami, Gurusubramanian; Nachimuthu, Senthilkumar

2012-12-01

41

Indoor/outdoor radon decay products associated aerosol particle-size distributions and their relation to total number concentrations.  

PubMed

The activity size distributions of indoor and outdoor radioactive aerosol associated with short-lived radon decay products were observed at Nagoya, Japan, for some periods from 2010 to 2012, following the indoor observation by Mostafa et al. [Mostafa, A. M. A., Tamaki, K., Moriizumi, J., Yamazawa, H. and Iida, T. The weather dependence of particle size distribution of indoor radioactive aerosol associated with radon decay products. Radiat. Prot. Dosim. 146: (1-3), 19-22 (2011)]. The tendency of smaller indoor activity median aerodynamic diameter (AMAD) after rainfalls showed in the previous study was not consistently obtained, while the consistent tendency of less indoor radioactive particles with diameters in the accumulation mode was observed again after rainfalls. The indoor aerosols showed activity size distributions similar to the outdoor ones. Non-radioactive aerosol particle concentrations measured with a laser particle counter suggested a somewhat liner relationship with AMAD. PMID:24723191

Moriizumi, Jun; Yamada, Shinya; Xu, Yang; Matsuki, Satoru; Hirao, Shigekazu; Yamazawa, Hiromi

2014-07-01

42

The SWISS-PROT protein sequence database and its supplement TrEMBL in 2000  

Microsoft Academic Search

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotation (such as the description of the function of a protein, its domains structure, post-translational modifications, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include format and content enhancements, cross-references to additional databases,

Amos Bairoch; Rolf Apweiler

2000-01-01

43

A Case Study in Using Prot eg e-2000 as a Tool for CommonKADS  

Microsoft Academic Search

This article describes a case study in which Prot ege-2000 was used to build a tool for constructing CommonKADS knowledge models. The case study tries to capitalize on the strong points of both approaches in the tool-support and modeling areas. We specify the CommonKADS knowledge model as an ontol- ogy in the Proteg e specification formalism, and define a

Guus Schreiber; Monica Crubezy; Mark Musen

2001-01-01

44

The SWISS-PROT protein sequence data bank and its supplement TrEMBL in 1999  

Microsoft Academic Search

SWISS-PROT is a curated protein sequence database which strives to provide a high level of annotation (such as the description of the function of a protein, its domain structure, post-translational modifications, variants, etc.), a minimal level of redundancy and high level of integration with other databases. Recent developments of the database include: cross-refer- ences to additional databases; a variety of

Amos Bairoch; Rolf Apweiler

1999-01-01

45

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

PubMed

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

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

2013-02-21

46

Some elements for a revision of the americium reference biokinetic model.  

PubMed

The interpretation of individual activity measurement after a contamination by 241Am or its parent nuclide 241Pu is based on the reference americium (Am) biokinetic model published by the International Commission on Radiological Protection in 1993 [International Commission on Radiological Protection. Age-dependent doses to members of the public from intake of radionuclides: Part 2 Ingestion dose coefficients. ICRP Publication 67. Ann. ICRP 23(3/4) (1993)]. The authors analysed the new data about Am biokinetics reported afterwards to propose an update of the current model. The most interesting results, from the United States Transuranium and Uranium Registries post-mortem measurement database [Filipy, R. E. and Russel, J. J. The United States Transuranium and Uranium Registries as sources for actinide dosimetry and bioeffects. Radiat. Prot. Dosim. 105(1-4), 185-187 (2003)] and the long-term follow-up of cases of inhalation intake [Maltov, I., Foltnov, S., Beckov, V., Filgas, R., Pospsilov, H. and Hlgye, Z. Assessment of occupational doses from internal contamination with 241Am. Radiat. Prot. Dosim. 105(1-4), 325-328 (2003)], seemed to show that the current model underestimates the retention in the massive soft tissues and overestimates the retention in the skeleton and the late urinary excretion. However, a critical review of the data demonstrated that all were not equally reliable and suggested that only a slight revision of the model, possibly involving a change in the balance of activity between massive soft tissues, cortical and trabecular bone surfaces, may be required. PMID:17561524

Blanchardon, E; Leggett, R W; Eckerman, K F

2007-01-01

47

48 CFR 719.273 - The U.S. Agency for International Development (USAID) Mentor-Protégé Program.  

Code of Federal Regulations, 2013 CFR

...The U.S. Agency for International Development (USAID) Mentor-Prot©g© Program...Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS...The U.S. Agency for International Development (USAID) Mentor-Prot©g©...

2013-10-01

48

49 CFR 26.35 - What role do business development and mentor-protégé programs have in the DBE program?  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false What role do business development and mentor-prot©g...Transportation PARTICIPATION BY DISADVANTAGED BUSINESS ENTERPRISES IN DEPARTMENT OF TRANSPORTATION...Contracting § 26.35 What role do business development and mentor-protégé...

2013-10-01

49

The Significance of the ProtDeform Score for Structure Prediction and Alignment  

PubMed Central

Background When a researcher uses a program to align two proteins and gets a score, one of her main concerns is how often the program gives a similar score to pairs that are or are not in the same fold. This issue was analysed in detail recently for the program TM-align with its associated TM-score. It was shown that because the TM-score is length independent, it allows a P-value and a hit probability to be defined depending only on the score. Also, it was found that the TM-scores of gapless alignments closely follow an Extreme Value Distribution (EVD). The program ProtDeform for structural protein alignment was developed recently and is characterised by the ability to propose different transformations of different protein regions. Our goal is to analyse its associated score to allow a researcher to have objective reasons to prefer one aligner over another, and carry out a better interpretation of the output. Results The study on the ProtDeform score reveals that it is length independent in a wider score range than TM-scores and that PD-scores of gapless (random) alignments also approximately follow an EVD. On the CASP8 predictions, PD-scores and TM-scores, with respect to native structures, are highly correlated (0.95), and show that around a fifth of the predictions have a quality as low as 99.5% of the random scores. Using the Gold Standard benchmark, ProtDeform has lower probabilities of error than TM-align both at a similar speed. The analysis is extended to homology discrimination showing that, again, ProtDeform offers higher hit probabilities than TM-align. Finally, we suggest using three different P-values according to the three different contexts: Gapless alignments, optimised alignments for fold discrimination and that for superfamily discrimination. In conclusion, PD-scores are at the very least as valuable for prediction scoring as TM-scores, and on the protein classification problem, even more reliable.

Rocha, Jairo; Alberich, Ricardo

2011-01-01

50

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

NASA Astrophysics Data System (ADS)

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

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

51

Application of text-mining for updating protein post-translational modification annotation in UniProtKB  

PubMed Central

Background The annotation of protein post-translational modifications (PTMs) is an important task of UniProtKB curators and, with continuing improvements in experimental methodology, an ever greater number of articles are being published on this topic. To help curators cope with this growing body of information we have developed a system which extracts information from the scientific literature for the most frequently annotated PTMs in UniProtKB. Results The procedure uses a pattern-matching and rule-based approach to extract sentences with information on the type and site of modification. A ranked list of protein candidates for the modification is also provided. For PTM extraction, precision varies from 57% to 94%, and recall from 75% to 95%, according to the type of modification. The procedure was used to track new publications on PTMs and to recover potential supporting evidence for phosphorylation sites annotated based on the results of large scale proteomics experiments. Conclusions The information retrieval and extraction method we have developed in this study forms the basis of a simple tool for the manual curation of protein post-translational modifications in UniProtKB/Swiss-Prot. Our work demonstrates that even simple text-mining tools can be effectively adapted for database curation tasks, providing that a thorough understanding of the working process and requirements are first obtained. This system can be accessed at http://eagl.unige.ch/PTM/.

2013-01-01

52

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

PubMed

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

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

2005-11-01

53

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

PubMed

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

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

2014-01-01

54

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

PubMed Central

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

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

2007-01-01

55

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

PubMed

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

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

2007-07-01

56

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

PubMed Central

Background A protein annotation database, such as the Universal Protein Resource knowledge base (UniProtKb), is a valuable resource for the validation and interpretation of predicted 3D structure patterns in proteins. Existing studies have focussed on point mutation extraction methods from biomedical literature which can be used to support the time consuming work of manual database curation. However, these methods were limited to point mutation extraction and do not extract features for the annotation of proteins at the residue level. Results This work introduces a system that identifies protein residues in MEDLINE abstracts and annotates them with features extracted from the context written in the surrounding text. MEDLINE abstract texts have been processed to identify protein mentions in combination with taxonomic species and protein residues (F1-measure 0.52). The identified protein-species-residue triplets have been validated and benchmarked against reference data resources (UniProtKb, average F1-measure of 0.54). Then, contextual features were extracted through shallow and deep parsing and the features have been classified into predefined categories (F1-measure ranges from 0.15 to 0.67). Furthermore, the feature sets have been aligned with annotation types in UniProtKb to assess the relevance of the annotations for ongoing curation projects. Altogether, the annotations have been assessed automatically and manually against reference data resources. Conclusion This work proposes a solution for the automatic extraction of functional annotation for protein residues from biomedical articles. The presented approach is an extension to other existing systems in that a wider range of residue entities are considered and that features of residues are extracted as annotations.

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

2009-01-01

57

Radiation Symbols  

MedlinePLUS

... Effects Ionizing & Non-Ionizing Radiation Understanding Radiation: Radiation Symbols Radiation Protection Basics Main Page History of Radiation ... Michigan's Radiation and Health Physics Page . United Nations Symbol In February of 2007, the United Nations introduced ...

58

Preliminary modeling of BNCT beam tube on IRT in Sofia.  

PubMed

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

Belousov, S; Ilieva, K

2009-07-01

59

In situ gamma spectroscopy to characterize building materials as radon and thoron sources.  

PubMed

In situ gamma spectroscopy is widely utilized to determine the outdoor gamma dose rate from the soil and to calculate the natural and artificial radionuclide concentration and their contribution to the dose rate. The application of in situ gamma spectroscopy in indoor environments can not supply quantitative information about activity concentration of radionuclides in building materials, but this technique can provide interesting information about building materials as radon source. In fact, a method based on analyses of gamma spectra data has been developed by the authors to provide, in field, quantitative estimation of disequilibrium in 226Ra and 228Ac sub-chains due to 222Rn and 220Rn exhalation. The method has been applied to data of gamma spectroscopy measurements carried out with HPGe detector (26%) in seven dwellings and one office in Rome. The first results of the data analysis show that, as regards especially the 226Ra sub-chain disequilibrium, different building materials (tuff, concrete, etc.) can show very different characteristics. If, in addition to the spectrometric data, other indoor environment parameters (indoor gamma dose rates, room dimensions, wall thickness, etc.) (Bochicchio et al., Radiat Prot Dosim 1994;56(1-4):137-140; Bochicchio et al., Environ Int 1996a;22:S633-S639) are utilized in a room model, an evaluation of 226Ra, 228Ac and 40K activity concentration and an indication of the exhalation features, by means of estimation of exhaled 222Rn activity concentration, can be achieved. PMID:11379933

Nuccetelli, C; Bolzan, C

2001-05-14

60

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

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

Gonzlez-Daz, Humberto; Muo, Laura; Anadn, Ana M; Romaris, Fernanda; Prado-Prado, Francisco J; Munteanu, Cristian R; Dorado, Julin; Sierra, Alejandro Pazos; Mezo, Mercedes; Gonzlez-Warleta, Marta; Grate, Teresa; Ubeira, Florencio M

2011-06-01

61

Serum Biomarkers of Keshan Disease Assessed Using a Protein Profiling Approach Based on ClinProt Technique.  

PubMed

The etiology of Keshan disease (KD), an endemic myocardiopathy in regions of China, is largely unknown. To show the protein changes in serum from KD patients versus controls and idiopathic dilated cardiomyopathy (IDCM) and to search specific biological markers for differential diagnosis for KD. Serum of 65 patients with KD was compared with 29 patients with IDCM, 62 controls from KD areas and 28 controls from non-KD areas by ClinProt/MALDI-ToF technique. The genetic algorithm, quick classifier algorithm and supervised neural network algorithm methods were used to screen marker proteins and establish diagnostic model. Thirty-four differential peaks were identified in KD patients compared with the healthy controls from non-KD areas. Thirty-eight differentially peaks were identified in KD patients and controls from KD areas; and sixty-seven differentially peaks were identified in patients with KD and patients with IDCM. We believe that marker protein peaks screened in KD patients, healthy controls and IDCM patients may provide clues for the differential diagnosis and treatment of KD. PMID:24841853

Xiang, YouZhang; Xu, Qun; Tan, WuHong; He, ShuLan; Shi, XiaoWei; Zhang, WenMing; Wang, Jing; Wang, XiuHong; Ma, WeiJuan

2014-08-01

62

Understanding how and why the Gene Ontology and its annotations evolve: the GO within UniProt  

PubMed Central

The Gene Ontology Consortium (GOC) is a major bioinformatics project that provides structured controlled vocabularies to classify gene product function and location. GOC members create annotations to gene products using the Gene Ontology (GO) vocabularies, thus providing an extensive, publicly available resource. The GO and its annotations to gene products are now an integral part of functional analysis, and statistical tests using GO data are becoming routine for researchers to include when publishing functional information. While many helpful articles about the GOC are available, there are certain updates to the ontology and annotation sets that sometimes go unobserved. Here we describe some of the ways in which GO can change that should be carefully considered by all users of GO as they may have a significant impact on the resulting gene product annotations, and therefore the functional description of the gene product, or the interpretation of analyses performed on GO datasets. GO annotations for gene products change for many reasons, and while these changes generally improve the accuracy of the representation of the underlying biology, they do not necessarily imply that previous annotations were incorrect. We additionally describe the quality assurance mechanisms we employ to improve the accuracy of annotations, which necessarily changes the composition of the annotation sets we provide. We use the Universal Protein Resource (UniProt) for illustrative purposes of how the GO Consortium, as a whole, manages these changes.

2014-01-01

63

Radiation dosimetry.  

PubMed Central

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

Cameron, J

1991-01-01

64

Radiation Medicine.  

National Technical Information Service (NTIS)

Contents: Physics and dosimetry of ionizing radiation; Pathophysiology of radiation affections; Infection and immunity in irradiated organisms; Toxicology of radioactive substances; Pathologoanatomy of radiation affections; Chemical protection against ion...

A. I. Burnazyan A. V. Lebedinskii

1965-01-01

65

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 ...

66

Lasers Radiation  

MedlinePLUS

Lasers Radiation RadTown USA Topics Personal Exposure : Airport Security Scanning Cosmic Radiation During Flights CT Scans Dental X-ray Diagnostic Nuclear Medicine Electric and Magnetic Fields (EMF) Radiation from Power Lines Internal ...

67

Radiation Therapy  

MedlinePLUS

Radiation Therapy Radiation therapy (sometimes referred to as radiotherapy, x-ray therapy or irradiation) has been used to treat many types of cancer for more than 100 years. Radiation therapy refers to the careful use of various ...

68

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, ...

69

Atmospheric radiation  

SciTech Connect

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.

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

1991-01-01

70

Radiation Laws  

NSDL National Science Digital Library

This site lists physical laws that describe radiation. Topics covered include the Plank Radiation Law, and the Wien and Stefan-Boltzmann Laws. The site also features a table summarizing the blackbody temperatures necessary to give a peak for emitted radiation in various regions of the spectrum, and three Java applets illustrating important properties of blackbody radiation.

Astronomy, Department O.; Knoxville, University O.

71

Compound radiator  

NASA Astrophysics Data System (ADS)

Standard radiator design with a plate facing cold space on one side and the warm spacecraft at the other side suffers from considerable parasitic heat load to the radiator even when the back of the radiator is covered with the best Multi Layer Insulation (MLI) available. In addition, performance of the plate radiator depends crucially on its insulation which might well deteriorate over a long duration mission. In an attempt to address these manifest and potential problems the concept of a compound radiator was worked out. First tests confirm model calculations; the compound radiator marks a very significant improvement over a standard plate radiator.

Thomsen, Knud

1991-12-01

72

Fabric radiators  

NASA Astrophysics Data System (ADS)

The design of large, high-temperature space radiators is still an evolving discipline. Researchers expanded the data base available to a designer by studying a novel class of radiators constructed of ceramic fabrics and/or composite materials. It appears that fabric radiators have features not available in more conventional radiator types, while offering the light weight and stowability of advanced radiators such as liquid droplet types. Experiments show that fabrics can be treated to become impermeable to the working fluid while retaining flexibility. This feature of fabrics, when allied to their low density, provides a material well-adapted to radiator construction.

Antoniak, Zenen I.; Jacox, Michael G.

73

Measuring Radiation  

MedlinePLUS

... or beta particles, gamma rays, x-rays, or neutrons, a quantity of radioactive material is expressed in ... larger than the absorbed dose for alpha and neutron radiation, because these types of radiation are more ...

74

Ionizing Radiation  

MedlinePLUS

... of Ionizing Radiation Sources Not Covered by Atomic Energy Act of 1954 . STD 01-04-001 [STD ... not the most current version. US Department of Energy (DOE) 10 CFR 835 , Occupational Radiation Protection Health ...

75

Radiation Emergencies  

MedlinePLUS

... bromide Methyl isocyanate Nicotine Nitrogen mustard Opioids Organic solvents Osmium tetroxide Paraquat Phosgene Phosgene oxime Phosphine Phosphorus ... Radiation Disasters Public Health Planning for Radiological and Nuclear Terrorism Radiation Basics Made Simple Radiological Terrorism: Just ...

76

Radiation Therapy  

MedlinePLUS

... get email updates Please leave this field empty Radiation Therapy SHARE Share on Facebook Preview your comments ... Treatment and Care > Treatments Listen The goal of radiation therapy is to destroy or stop brain tumor ...

77

Radiation Chemistry  

NASA Astrophysics Data System (ADS)

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.

Wojnrovits, L.

78

Hawking radiation  

NASA Astrophysics Data System (ADS)

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.

Parentani, Renaud; Spindel, Philippe

2011-12-01

79

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

SciTech Connect

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.

Tedgren, Aasa Carlsson; Hedman, Angelica; Grindborg, Jan-Erik; Carlsson, Gudrun Alm [Radiation Physics, Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linkoeping University, SE 581 85 Linkoeping, Sweden and Swedish Radiation Safety Authority, SE 171 16 Stockholm (Sweden); Radiation Physics, Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linkoeping University, SE 581 85 Linkoeping, Sweden and Department of Radiation Physics UHL, County Council of Oestergoetland, SE 581 85 Linkoeping (Sweden); Swedish Radiation Safety Authority, SE 171 16 Stockholm (Sweden); Radiation Physics, Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linkoeping University, SE 581 85 Linkoeping (Sweden)

2011-10-15

80

Ionizing radiation  

NASA Technical Reports Server (NTRS)

The biological effects of ionizing radiation encountered in space are considered. Biological experiments conducted in space and some experiences of astronauts during space flight are described. The effects of various levels of radiation exposure and the determination of permissible dosages are discussed.

Tobias, C. A.; Grigoryev, Y. G.

1975-01-01

81

Understanding Radiation.  

ERIC Educational Resources Information Center

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

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

82

Radiation enteritis  

MedlinePLUS

... seeds to kill cancer cells. Along with the cancer cells, radiation therapy may also damage cells that make up the lining of the intestines. Anyone who receives radiation therapy to the belly or ... pancreatic, prostate, uterine, or colon and rectal cancer.

83

Radiative processes  

NASA Technical Reports Server (NTRS)

Solar radiation and the processes that control its deposition in the Earth atmosphere are considered. The published data obtained since 1978 define a reference solar spectral irradiance for use in atmospheric chemical and dynamical studies, while long term satellite measurements are now providing information on variations in the output of the Sun over a range of time scales. As concerns absorption of solar radiation in the atmosphere, new cross section data for molecular oxygen and ozone are now available. Line-by-line calculations used to predict infrared flux divergences, both as regards assumptions made in radiative transfer calculations and in the spectroscopic parameters used as inputs are examined. Also examined are the influence of radiative processes on planetary scale wave activity, photochemical acceleration of radiative damping, and the breakdown of local thermodynamic equilibrium at mesospheric altitudes.

Frederick, J. E.; Leovy, C.; Anderson, D. E., Jr.; Anderson, G. P.; Dickinson, R. E.; Drayson, S. R.; Fels, S.; Hall, L. A.; Kiehl, J.; Mentall, J. E.

1985-01-01

84

Radiation detector  

DOEpatents

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.

Fultz, B.T.

1980-12-05

85

Radiation detector  

DOEpatents

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.

Fultz, Brent T. (Berkeley, CA)

1983-01-01

86

Synchrotron Radiation  

SciTech Connect

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.

Wiedemann, Helmut

2003-08-11

87

Radiation Fog  

NSDL National Science Digital Library

This is the first instructional component to be published in the Physical Processes Professional Competency Unit of the Forecasting Low-Altitude Clouds and Fog for Aviation Operations Professional Development Series. The learning modules in this professional competency unit will help aviation forecasters gain more familiarity with the physical concepts and atmospheric conditions related to fog and low stratus life cycles. Such understanding, in turn, can help forecasters more efficiently and accurately evaluate the ability of a given atmospheric environment to generate and/or maintain radiation fog. Radiation Fog presents presents the physical processes and life cycle of radiation fog, including its preconditioning environment, initiation, growth, and dissipation. The processes include radiation (both solar and longwave), soil-atmosphere thermal interactions, turbulent mixing, the roles of condensation nuclei, and droplet settling. Each section includes a set of interactive questions based on the learning content presented.

Spangler, Tim

2000-12-01

88

Radiation Therapy.  

National Technical Information Service (NTIS)

Guidelines are presented for the development of radiation therapy capability in northwestern Pennsylvania. A surplus of megavoltage (cobalt therapy, linear accelerator) capability exists in the area, (as of 1976) therefore recommendations are made for one...

1976-01-01

89

Radiation sterilization  

PubMed Central

The sterilization by radiation of disposable medical items has been investigated. Various vegetative and spore-bearing bacteria have been irradiated and results indicate that 25 Mrad can be recommended to give a high degree of sterility. Spores of B. pumilus (E.601) showed such resistance that it might be a suitable test organism for determining the efficiency of a radiation treatment. A high standard of packaging must be demanded for pre-sterilized products.

Darmady, E. M.; Hughes, K. E. A.; Burt, Margaret M.; Freeman, Barbara M.; Powell, D. B.

1961-01-01

90

Radiation Doses in Perspective  

MedlinePLUS

... Health Effects Ionizing & Non-Ionizing Radiation Understanding Radiation: Radiation Doses in Perspective Health Effects Main Page Exposure ... Sources Doses from Common Radiation Sources Average U.S. Radiation Doses and Sources All of us are exposed ...

91

Synchrotron Radiation  

NASA Astrophysics Data System (ADS)

As early as 1900, immediately after the pioneer formulation by Linard and Wiechert of the retarded potentials of a point charge (electron), calculations of the characteristics of the radiation from an accelerated electron or electron beam have been performed. But it was not until 1947 when John Blewett actually observed the synchrotron radiation from the beam in the 70-MeV General Electric electron synchrotron, the phenomenon was accepted as physical reality instead of some interesting mathematical deduction. It was soon recognized that the synchrotron radiation provides an extremely brilliant photon beam over a very broad frequency range from infrared to hard x-ray, and hence makes an ideal tool for use in extranuclear research. By the end of the twentieth century there were dozens of electron storage rings operated around the world at energies from a few hundred MeV to 8 GeV for experiments. Here we will study first the properties of the synchrotron radiation and then the effects of the emission of synchrotron radiation on the electron beam.

Teng, Lee C.

2004-02-01

92

Radiation receiver  

DOEpatents

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.

Hunt, A.J.

1983-09-13

93

Study of The Non-linear Uv Dosimetry In Simulated Extraterrestrial Conditions  

Microsoft Academic Search

In UV biological dosimetry the UV dose scale is additive starting at a value of zero ac- cording to the definition of CIE (Technical Report TC-6-18). The biological dose can be defined by a measured end-effect. In our dosimeters (phage T7 and uracil dosime- ter) exposed to natural (terrestrial) UV radiation the proportion of pyrimidin photo- products among the total

A. Berces; T. Kerekgyarto; G. Ronto; H. Lammer; G. Kargl; N. I. Komle

2002-01-01

94

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

NASA Astrophysics Data System (ADS)

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. Elssser 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).

Elssser, Thilo

95

RADIATION MYELOPATHY  

Microsoft Academic Search

A survey was made of 38 cases of radiation myelopathy with regard to ; early symptoms and signs, differential diagnosis, prognosis, nature of the ; primary lesion irradiated, and latency between irradiation and the development of ; neurological symptoms. Death occurred in 17 of these cases, 1 month to 4 yr ; after the first neurologic symptoms, as a result

CHRISTOPHER A. PALLIS; SYDNEY LOUIS; ROWLAND L. MORGAN

1961-01-01

96

Radiation Therapy  

MedlinePLUS

... the body, making the person very sick. Radiation therapy kills cancer cells and keeps them from growing and multiplying. The ... people may first have surgery to remove cancer cells or tumors and then have ... depends on the kind of cancer he or she has. A doctor called an ...

97

Radiation Models  

ERIC Educational Resources Information Center

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)

James, W. G. G.

1970-01-01

98

Radiation accidents.  

PubMed

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

Saenger, E L

1986-09-01

99

Radiation source  

Microsoft Academic Search

A method is described of generating X-radiation from an apparatus comprised of: (a) at least two electrodes mounted in an evacuable chamber with one of the electrodes positioned above the other electrode; (b) a quantity of a powder of at least one conducting or semi-conducting material supported on the lower of the electrodes when the electrodes have a potential difference

S. G. Szirmai; G. R. Newman; P. L. Kelly

1987-01-01

100

Radiation Therapy  

MedlinePLUS

... after radiation therapy has ended. Skin damage or changes. The skin around the treatment area may be red, sensitive, or easily irritated in the days, weeks, and months during and after treatment. ... texture may change. (Most symptoms of skin damage are temporary, although ...

101

Radiation cataract.  

PubMed

Until very recently, ocular exposure guidelines were based on the assumption that radiation cataract is a deterministic event requiring threshold doses generally greater than 2 Gy. This view was, in part, based on older studies which generally had short follow-up periods, failed to take into account increasing latency as dose decreased, had relatively few subjects with doses below a few Gy, and were not designed to detect early lens changes. Newer findings, including those in populations exposed to much lower radiation doses and in subjects as diverse as astronauts, medical workers, atomic bomb survivors, accidentally exposed individuals, and those undergoing diagnostic or radiotherapeutic procedures, strongly suggest dose-related lens opacification at significantly lower doses. These observations resulted in a recent re-evaluation of current lens occupational exposure guidelines, and a proposed lowering of the presumptive radiation cataract threshold to 0.5 Gy/year and the occupational lens exposure limit to 20 mSv/year, regardless of whether received as an acute, protracted, or chronic exposure. Experimental animal studies support these conclusions and suggest a role for genotoxicity in the development of radiation cataract. Recent findings of a low or even zero threshold for radiation-induced lens opacification are likely to influence current research efforts and directions concerning the cellular and molecular mechanisms underlying this pathology. Furthermore, new guidelines are likely to have significant implications for occupational and/or accidental exposure, and the need for occupational eye protection (e.g. in fields such as interventional medicine). PMID:23089007

Kleiman, N J

2012-01-01

102

Sound Radiation from Cylindrical Radiators  

NSDL National Science Digital Library

The following animations illustrate the radiation of sound waves from a vibrating source in 2-D. The source is a long cylinder which is oscillating in the radial direction only (all vibrations along the length of the cylinder are ignored). In particular, the animations show the vibration of the cylinder in its various modes and the resulting particle displacements of the surrounding fluid.

Russell, Dan

103

Radiation Protection Basics  

MedlinePLUS

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

104

Radiation Oncology Treatment Team  

MedlinePLUS

... Prostate Skin Upper GI Latest Research 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 ...

105

Radiation Therapy for Osteosarcoma  

MedlinePLUS

... for osteosarcoma Next Topic Clinical trials for osteosarcoma Radiation therapy for osteosarcoma Radiation therapy uses high-energy ... back or surgery is not possible. External beam radiation therapy This is the type of radiation therapy ...

106

Radiation Protection  

NSDL National Science Digital Library

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

Science Update (AAAS;)

2008-05-01

107

Shortwave Radiation  

NASA Technical Reports Server (NTRS)

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.

Klassen, Steve; Bugbee, Bruce

2005-01-01

108

Radiation dosimeters  

DOEpatents

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.

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

1992-01-01

109

Dosimetry of space radiations  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

110

Radiation Therapy for Cancer  

MedlinePLUS

... basic unit of light and other forms of electromagnetic radiation . It can be thought of as a ... radiation therapy in fewer sessions, using smaller radiation fields and higher doses than 3D-CRT in most ...

111

Solar radiation resource assessment  

SciTech Connect

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

Not Available

1990-11-01

112

Handbook of radiation effects  

Microsoft Academic Search

This book emphasizes radiation effects on solid state devices from exposure to the types of radiation found outside the atmosphere (in space, or in the vicinity of an exploding nuclear device). It contains a basic study of radiation shielding of payload components for payloads in space and specifically covers radiation effects on minority and majority carriers, optical media and organic

A. Holmes-Siedle; L. Adams

1993-01-01

113

Radiation nose concept  

Microsoft Academic Search

The feasibility of a radiation nose concept is demonstrated. In radiation nose system an array of sensors is used to monitor various ranges and types of radiation, therefore increasing the working dose range and the sensitivity of the overall system. Ideally, each material in sensor array should be sensitive to only one type of radiation, which can be achieved via

K. Arshak; O. Korostynska; C. Cunniffe

2006-01-01

114

Radiation Critical Readiness Review  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the radiation preparedness and radiation monitors on the International Space Station (ISS). It includes information on the Tissue Equivalent Proportional Counter (TEPC), Radiation Area Monitors, Extra-Vehicular Charged Particle Directional Spectrometer (EV-CPDS), and the space radiation analysis group.

Misek, William

2010-01-01

115

Advanced radiator concepts  

NASA Technical Reports Server (NTRS)

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.

Diem-Kirsop, P. S.

1985-01-01

116

Radiation and Gut  

Microsoft Academic Search

Two books with very similar titles have been published recently: Radiation and the Gastrointestinal Tract (edited by A Dubois et al) and Radiation and Gut. Despite their rather similar titles, their content is very different. The former is concerned with acute radiation effects and their avoidance or control in the context of radiation therapy and the possible irradiation of military

John D Harrison

1997-01-01

117

Radiation and People  

ERIC Educational Resources Information Center

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)

Freilich, Florence G.

1970-01-01

118

Radiation detection and measurement  

Microsoft Academic Search

Introductory material covers radiation sources, radiation interactions, general properties of radiation detectors, and counting statistics and error prediction. This is followed by detailed sections on gas-filled detectors, scintillation counters, semiconductor detectors, neutron detectors and spectroscopy, detector electronics and pulse processing, and miscellaneous radiation detectors and applications.

Glenn F. Knoll

1979-01-01

119

Operational radiation safety - training  

SciTech Connect

This report was written to supplement NCRP Report No. 59, Operational Radiation Safety Program, which sets forth the basic elements of a radiation safety program. Effective radiation safety programs should include training for workers exposed to either radioactive material or other radiation sources and this report seeks to provide guidance for the development of training in organizations with employees who are exposed to radiation in the course of their work. The guidance provided is intended to cover the basic elements of needed training and thus should be useful to the entire range of radiation users from small single source operations to relatively complex radiation operations.

Not Available

1983-01-01

120

Radiation protection guidelines for radiation emergencies  

SciTech Connect

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.

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

1986-01-01

121

Low Dose Radiation Research  

NSDL National Science Digital Library

The US Department of Energy's Low Dose Radiation Research Program supports research that investigates the health risks from exposure to radiation at low levels. This Web site provides an overview of radiation biology, up-to-date information and archived results from program-related research, and other resources for the benefit of researchers and the general public alike. Some research projects include comparing low dose radiation to endogenous oxidative damage, determining thresholds for radiation exposure, determining genetics factors that make some individuals more susceptible to radiation-induced damage, and more.

122

Plutonium radiation surrogate  

DOEpatents

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.

Frank, Michael I. (Dublin, CA)

2010-02-02

123

Radiation potentials generated by space radiation  

NASA Astrophysics Data System (ADS)

The mechanism for generating electric potentials and currents in conductors of electronic equipment on board spacecraft subjected to space radiation is examined. Radiation potentials and currents are calculated for a system that consists of two insulated conductors. Using the simplest model we obtain results which can be expanded to a more complex geometry of conductors.

Lyubomudrov, A. A.

2013-12-01

124

What Is Radiation Shielding?  

NASA Video Gallery

Kerry Lee, NASA Orion radiation system manager, explains how radiation shielding is used to block harmful particles coming into the spacecraft without producing secondary particles that can cause e...

125

Radiation from hard objects  

SciTech Connect

The inference of the diameter of hard objects is insensitive to radiation efficiency. Deductions of radiation efficiency from observations are very sensitive - possibly overly so. Inferences of the initial velocity and trajectory vary similarly, and hence are comparably sensitive.

Canavan, G.H.

1997-02-01

126

Prostaglandins and Radiation Enteritis.  

National Technical Information Service (NTIS)

A series of experiments was done to test the proposition that radiation to the intestine induces prostaglandin production which turn enhances the radiation injury. The results did not support the hypothesis, in that, pharmacologic blockade of prostaglandi...

J. P. Delaney

1987-01-01

127

Solar Radiation on Mars.  

National Technical Information Service (NTIS)

Detailed information on solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. Presented here is a procedure and solar radiation related data from which the diurn...

J. Appelbaum D. J. Flood

1989-01-01

128

Radiation effects in space  

SciTech Connect

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)

Fry, R.J.M.

1986-01-01

129

Radiation Protection Handbook  

NASA Technical Reports Server (NTRS)

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.

1972-01-01

130

Fluorescent radiation converter  

NASA Technical Reports Server (NTRS)

A fluorescence radiation converter is described which includes a substantially undoped optically transparent substrate and a waveshifter coating deposited on at least one portion of the substrate for absorption of radiation and conversion of fluorescent radiation. The coating is formed to substantially 1000 g/liter of a solvent, 70 to 200 g/liter of an organic polymer, and 0.2 to 25 g/liter of at least one organic fluorescent dye. The incoming incident radiation impinges on the coating. Radiation is absorbed by the fluorescent dye and is re-emitted as a longer wavelength radiation. Radiation is trapped within the substrate and is totally internally reflected by the boundary surface. Emitted radiation leaves the substrate ends to be detected.

Viehmann, W. (inventor)

1981-01-01

131

Prostate radiation - discharge  

MedlinePLUS

... these side effects: Skin problems during or after prostate radiation treatment is rare. Your skin over the ... keeping or getting an erection may occur after prostate radiation therapy but may not be noticed for ...

132

Acute Radiation Syndrome  

MedlinePLUS

... bromide Methyl isocyanate Nicotine Nitrogen mustard Opioids Organic solvents Osmium tetroxide Paraquat Phosgene Phosgene oxime Phosphine Phosphorus ... Radiation Disasters Public Health Planning for Radiological and Nuclear Terrorism Radiation Basics Made Simple Radiological Terrorism: Just ...

133

Synchrotron-radiation research  

SciTech Connect

The use of radiation from synchrotron sources has started a renaissance in materials, physics, chemistry, and biology. Synchrotron radiation has advantages over conventional x rays in that its source brightness is a thousand times greater throughout a continuous energy spectrum, and resonances are produced with specific electron energy levels. Two major synchrotron radiation sources are operated by DOE: the Stanford Synchrotron Radiation Laboratory at SLAC, and the National Synchrotron Light Source at Brookhaven. (DLC)

Cunningham, J.E.

1982-01-01

134

[Radiation induced side effects].  

PubMed

More than half of all people with cancer are treated with radiation therapy. Over the last decade the technical advances, both in therapy beam precision and imaging, have greatly improved the therapeutic ratio and accuracy of modern radiotherapy. However, damaging healthy tissues near the tumor leads to radiation induced injury that develops immediately and continue to progress long after exposure to radiation. Recently dramatic advances have been made in understanding the determinant of tissue response to radiation exposure. PMID:22641879

Henni, Mehdi; Ali, David

2012-04-01

135

Maintaining radiation protection records  

SciTech Connect

This Report is part of a series prepared under the auspices of Scientific Committee 46 on Operational Radiation Safety. It provides guidance on maintaining radiation protection records. Record keeping is an essential element of every radiation protection program. This Report describes the elements that should enter into the design of a program for the maintenance of operational radiation safety records. The problems of the length of time for retention of records for operational, regulatory, epidemiologic and legal uses are discussed in detail.

Not Available

1992-11-30

136

Operational radiation safety program  

SciTech Connect

For many years the National Council on Radiation Protection and Measurements and its predecessors have provided extensive recommendations dealing with the many aspects of radiation protection. The objective of this report is to describe the elements of an operational radiation safety program incorporating many of these recommendations. An effective radiation safety program can do much to reduce exposures to a level as low as practicable within the NCRP recommended dose limits and to minimize the potential for accidental exposures.

Not Available

1980-01-01

137

Dangers of Radiation Exposure  

NSDL National Science Digital Library

This is a lesson about radiation and the various sources of radiation that a spacecraft may encounter in its journey. Learners will calculate their annual exposure to high-energy radiation, identify sources of high-energy radiation, and explain why the near-Mercury environment is a concern for the Mercury MESSENGER mission. This is lesson 2 of 4 in the high school track of a module, titled Staying Cool. Note: the student guide starts on p. 17 of the PDF.

138

The Cosmological Background Radiation  

Microsoft Academic Search

This book provides an introduction to the physics, astrophysics and cosmology of the cosmic microwave background radiation. Adopting the Standard Big Bang model of the universe, the authors cover topics including the origin of the background, intrinsic fluctuations, and the universe and background radiation after recombination. Finally they present measurement of the radiation and its anisotropies, along with a review

Marc Lachize-Rey; Edgard Gunzig

1999-01-01

139

MICROSPHERES FOR RADIATION THERAPY  

Microsoft Academic Search

The treatment of malignant tumors with ionizing radiation using ceramic ; microspheres that can be localized at selected sites for interstitial therapy is ; discussed. Thus, radiation damage in healthy tissues can be minimized by ; tailoring radioactivity to control dose, dose rate, and volume of tissue ; irradiated. The mean life, radiation energies, and beta-gamma dose can be ;

J. F. Perry; M. K. Loken; J. P. Ryan; L. D. MacLean

1962-01-01

140

Radiation Research Program (RRP)  

Cancer.gov

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

141

Geostationary earth radiation budget  

Microsoft Academic Search

The Earth Radiation Budget (ERB), the balance between the incoming solar radiation from the sun and the outgoing reflected and scattered solar radiation and the thermal infrared emission from the Earth, provides information on the fundamental energy source of the climate system. To fulfil global coverage and sampling requirements, the ERB measurements have to be made from space. Broad-band measurements

Ruzbeh Mossavati; Steve Kellock; Johannes Mueller; J. E. Harries; J. E. Murray; Eric C. Sawyer; Martin E. Caldwell; M. Oliver; J. Delderfield; Michael C. Sandford

1997-01-01

142

Radiation port dermatophytosis  

SciTech Connect

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.

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

1988-12-01

143

Space Radiation Environment  

NASA Technical Reports Server (NTRS)

Coupled with the increasing concern over trapped radiation effects on microelectronics, the availability of new data, long term changes in the Earth's magentic field, and observed variations in the trapped radiation fluxes have generated the need for better, more comprehensive tools for modeling and predicting the Earth's trapped radiation environment and its effects on space systems.

Garrett, H.

1998-01-01

144

Solar radiation modelling  

Microsoft Academic Search

The Sun is the main energy source of the life on the Earth. Thus, solar radiation energy data and models are important for many areas of research and applications. Many parameters influence the amount of solar energy at a particular standing point of the Earth's surface; therefore, many solar radiation models were produced in the last few years. Solar radiation

Klemen Zaksek; Tomaz Podobnikar; Kritof Otir

2005-01-01

145

JPL Radiation Effects Facilities  

NASA Technical Reports Server (NTRS)

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.

Thorbourn, Dennis

2013-01-01

146

Radiation: Facts, Risks and Realities  

MedlinePLUS

... to natural radiation comes from other elements in Earths crust, such as thorium and potassium. The radiation ... area. Another natural source is cosmic (space) radiation. Earth is constantly exposed to radiation created by processes ...

147

Radiation Research: Chemistry and Physics.  

National Technical Information Service (NTIS)

Papers in this Proceedings are grouped under the following headings: (1) primary processes in radiation physics and chemistry; (2) radiation chemistry - general chemistry; (3) radiation chemistry - DNA and model systems; (4) radiation chemistry - other mo...

J. J. Broerse G. W. Barendsen H. B. Kal A. J. van der Kogel

1983-01-01

148

Radiation Therapy for Bone Cancer  

MedlinePLUS

... bone cancer Next Topic Chemotherapy for bone cancer Radiation therapy for bone cancer Radiation therapy uses high- ... control symptoms like pain and swelling. Intensity-modulated radiation therapy Intensity-modulated radiation therapy (IMRT) is an ...

149

Solar radiation in Iceland  

NASA Astrophysics Data System (ADS)

Short wave radiation has been observed at several locations in Iceland in recent years. The observations reveal that there is large spatial variability in the incoming radiation. There are indications of a coast-to-inland gradient and there is much greater radiation at central-inland locations than further west as well in the far east. The results are in line with Marks . Einarsson's reports where estimation of radiation was based on manned cloud observations shortly after the middle of the 20th century. Values of radiation retrieved from the operational simulations of the European Centre for Medium-range Weather Forecasts (ECMWF) compare in general well with the observations.

lafsson, Haraldur; Cataldi, Maxime; Zehouf, Hafsa; Plmason, Bolli

2014-05-01

150

Handbook of radiation effects  

SciTech Connect

This book emphasizes radiation effects on solid state devices from exposure to the types of radiation found outside the atmosphere (in space, or in the vicinity of an exploding nuclear device). It contains a basic study of radiation shielding of payload components for payloads in space and specifically covers radiation effects on minority and majority carriers, optical media and organic materials. It also includes some basic information on radioactivity, monitoring equipment and different types of radiation fields. This book is not oriented toward health physics.

Holmes-Siedle, A.; Adams, L.

1993-12-31

151

Solar cell radiation handbook  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

152

Solar radiation measurement project  

NASA Technical Reports Server (NTRS)

The Xavier solar radiation measurement project and station are described. Measurements of the total solar radiation on a horizontal surface from an Eppley pyranometer were collected into computer data files. Total radiation in watt hours was converted from ten minute intervals to hourly intervals. Graphs of this total radiation data are included. A computer program in Fortran was written to calculate the total extraterrestrial radiation on a horizontal surface for each day of the month. Educational and social benefits of the project are cited.

Ioup, J. W.

1981-01-01

153

Fluorescent radiation converter  

NASA Technical Reports Server (NTRS)

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

Viehmann, W.

1980-01-01

154

[The radiation accident].  

PubMed

The reactor accident of Chernobyl in April 1986 has shown us all the dangers which are inherent ever in the peaceful use of atomic energy. The effects of exposure to ionizing radiation are dependent on biological effectiveness, on dose, on duration of exposure and on the age of the exposed person (the younger the graver). Acute ionizing radiation of the whole body leads to radiation disease or radiation syndrome of different stages of severity according to dosage. If the patient survives other consequences of ionizing radiation may arise: non-stochastic effects such as cataracts, keloid formation, fibrosis of the lungs and infertility) and stochastic effects (oncogenesis and mutagenesis). The sensitivity to ionizing radiation is especially high in childhood because of the high velocity of cell metabolism and cell growth, the large body-surface area and because their repair mechanism following radiation damage is not yet. PMID:3188527

Stgmann, W

1988-08-26

155

Gas particle radiator  

NASA Technical Reports Server (NTRS)

The performance of a new space radiator concept, the gas particle radiator (GPR), is studied. The GPR uses a gas containing submicron particles as the radiating medium contained between the radiator's emitting surface and a transparent window. For a modest volume fraction of submicron particles and gas thickness, it is found that the emissivity is determined by the window transmittance. The window must have a high transmittance in the infrared and be structurally strong enough to contain the gas-particle mixture. When the GPR is compared to a proposed titanium wall, potassium heat pipe radiator, with both radiators operating at a power level of 1.01 MW at 775 K, it is found that the GPR mass is 31 percent lower than that of the heat pipe radiator.

Chubb, Donald L.

1987-01-01

156

Radiation-induced gliomas  

PubMed Central

Radiation-induced gliomas represent a relatively rare but well-characterized entity in the neuro-oncologic literature. Extensive retrospective cohort data in pediatric populations after therapeutic intracranial radiation show a clearly increased risk in glioma incidence that is both patient age- and radiation dose/volume-dependent. Data in adults are more limited but show heightened risk in certain groups exposed to radiation. In both populations, there is no evidence linking increased risk associated with routine exposure to diagnostic radiation. At the molecular level, recent studies have found distinct genetic differences between radiation-induced gliomas and their spontaneously-occurring counterparts. Clinically, there is understandable reluctance on the part of clinicians to re-treat patients due to concern for cumulative neurotoxicity. However, available data suggest that aggressive intervention can lead to improved outcomes in patients with radiation-induced gliomas.

Prasad, Gautam; Haas-Kogan, Daphne A.

2013-01-01

157

Identification of missing proteins in the neXtProt database and unregistered phosphopeptides in the PhosphoSitePlus database as part of the Chromosome-centric Human Proteome Project.  

PubMed

The Chromosome-Centric Human Proteome Project (C-HPP) is an international effort for creating an annotated proteomic catalog for each chromosome. The first step of the C-HPP project is to find evidence of expression of all proteins encoded on each chromosome. C-HPP also prioritizes particular protein subsets, such as those with post-translational modifications (PTMs) and those found in low abundance. As participants in C-HPP, we integrated proteomic and phosphoproteomic analysis results from chromosome-independent biomarker discovery research to create a chromosome-based list of proteins and phosphorylation sites. Data were integrated from five independent colorectal cancer (CRC) samples (three types of clinical tissue and two types of cell lines) and lead to the identification of 11,278 proteins, including 8,305 phosphoproteins and 28,205 phosphorylation sites; all of these were categorized on a chromosome-by-chromosome basis. In total, 3,033 "missing proteins", i.e., proteins that currently lack evidence by mass spectrometry, in the neXtProt database and 12,852 unknown phosphorylation sites not registered in the PhosphoSitePlus database were identified. Our in-depth phosphoproteomic study represents a significant contribution to C-HPP. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the data set identifier PXD000089. PMID:23312004

Shiromizu, Takashi; Adachi, Jun; Watanabe, Shio; Murakami, Tatsuo; Kuga, Takahisa; Muraoka, Satoshi; Tomonaga, Takeshi

2013-06-01

158

High-power radiating plasma  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

159

Radiation physics, biophysics, and radiation biology  

SciTech Connect

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.

Hall, E.J.; Zaider, M.

1993-05-01

160

Earth Radiation Measurement Science  

NASA Technical Reports Server (NTRS)

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.

Smith, G. Louis

2000-01-01

161

Environmental Radiation Protection  

NASA Astrophysics Data System (ADS)

The environmental distribution of radionuclides, released from nuclear facilities and other sources, and the principles of the emergency countermeasures for radiation protection of the public and workers are discussed in this chapter. The concentration levels of radionuclides in various aquatic and terrestrial environments and the exposure levels of the population due to the various sources of radiation (natural and artificial radionuclides, cosmic radiation, diagnostic medical examinations, atmospheric nuclear tests, etc.) are presented.

Maeda, Y.; Osaki, S.; Vincze, A.

162

RHOBOT: Radiation hardened robotics  

SciTech Connect

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.

Bennett, P.C.; Posey, L.D. [Sandia National Labs., Albuquerque, NM (United States)

1997-10-01

163

Stereotactic Body Radiation Therapy  

Microsoft Academic Search

\\u000a Technological advancements in imaging and radiation planning and delivery have made it possible for cranial stereotactic radiosurgery\\u000a techniques to be applied to tumors outside of the brain. Although high-dose radiation therapy may be delivered in a single\\u000a fraction, referred to as extracranial stereotactic radiosurgery (SRS), more often, high-precision radiation is delivered in\\u000a more than one fraction, leading to the field

Laura A. Dawson

164

Rotating bubble membrane radiator  

DOEpatents

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.

Webb, Brent J. (West Richland, WA); Coomes, Edmund P. (West Richland, WA)

1988-12-06

165

Solar radiation on Mars  

SciTech Connect

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.

Appelbaum, J.; Flood, D.J. (National Aeronautics and Space Administration, Cleveland, OH (USA))

1990-01-01

166

Radiation view factor program  

NASA Technical Reports Server (NTRS)

Computer program, RAVFAC, calculates diffuse radiation view factors, using contour integrals. Technique is combined with finite difference /double summation/ technique to compose total program package.

Lovin, J. K.; Lubkowitz, A. W.

1971-01-01

167

Solar radiation on Mars  

NASA Technical Reports Server (NTRS)

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

Appelbaum, Joseph; Flood, Dennis J.

1990-01-01

168

Solar radiation on Mars  

NASA Technical Reports Server (NTRS)

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

Appelbaum, Joseph; Flood, Dennis J.

1989-01-01

169

Flexible radiator system  

NASA Technical Reports Server (NTRS)

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.

Oren, J. A.

1982-01-01

170

Charms of radiation research.  

SciTech Connect

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.

Inokuti, M.; Physics

2005-01-01

171

Radiation coloration resistant glass  

DOEpatents

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.

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

1986-01-01

172

Radiation physics, biophysics, and radiation biology  

SciTech Connect

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.

Hall, E.J.

1992-05-01

173

Radiation biology: concepts for radiation protection.  

PubMed

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 pioneering work of Muller, Sax, and McClintock, and many others, has stood the test of time. The idea that x-rays could damage the genetic material and result in interactions that could lead to gene mutations and a range of chromosomal alterations is now interpretable in terms of induced DNA damage and errors of DNA repair. The expanded idea that such genetic alterations can be induced by DNA damage that is produced by one or two tracks of ionizing radiation remains the mainstay of radiation biology. The impact of the more recent molecular approaches to unraveling the mechanism behind this simple concept has confirmed this fundamental observation. The remarkable advances have allowed for a fairly complete understanding of the specific types of DNA damage induced by ionizing radiations and the pivotal role played by the errors of repair of double-strand breaks. Given our considerably enhanced knowledge of the details of the DNA repair processes involved, misrepair is a very unlikely event. The role of potential confounders of the concept of dose-response (e.g., bystander effects, genomic instability, and adaptive responses) is taking on a growing importance to the field. The evolving need is to begin to consider mechanistically-based dose-response models for cancer risk such that any potential impact of confounders on the response at low, environmental doses can be assessed. Thus, radiation biology research has always had a focus on how best to protect human health from radiation exposures and will continue to do so. PMID:15891452

Preston, R Julian

2005-06-01

174

Radiation biology: concepts for radiation protection.  

PubMed

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 pioneering work of Muller, Sax, and McClintock, and many others, has stood the test of time. The idea that x-rays could damage the genetic material and result in interactions that could lead to gene mutations and a range of chromosomal alterations is now interpretable in terms of induced DNA damage and errors of DNA repair. The expanded idea that such genetic alterations can be induced by DNA damage that is produced by one or two tracks of ionizing radiation remains the mainstay of radiation biology. The impact of the more recent molecular approaches to unraveling the mechanism behind this simple concept has confirmed this fundamental observation. The remarkable advances have allowed for a fairly complete understanding of the specific types of DNA damage induced by ionizing radiations and the pivotal role played by the errors of repair of double-strand breaks. Given our considerably enhanced knowledge of the details of the DNA repair processes involved, misrepair is a very unlikely event. The role of potential confounders of the concept of dose-response (e.g., bystander effects, genomic instability, and adaptive responses) is taking on a growing importance to the field. The evolving need is to begin to consider mechanistically-based dose-response models for cancer risk such that any potential impact of confounders on the response at low, environmental doses can be assessed. Thus, radiation biology research has always had a focus on how best to protect human health from radiation exposures and will continue to do so. PMID:15194918

Preston, R Julian

2004-07-01

175

Plastic plasticizer and radiation  

Microsoft Academic Search

Examination concerning the possibilities of decomposition of ; plasticizers such as phthalic acid esters and phosphoric acid esters or toxicity ; reduction thereof by the radiation has been made. (1) Radiation effects: Sham ; polluted solution having various kinds of concentrations of said ester was ; irradiated with ⁶°Co gamma -ray to 0.3 Mrad\\/hr. The results show that ; with

Sunada

1973-01-01

176

On the Jitter Radiation  

NASA Astrophysics Data System (ADS)

In a small-scale turbulent medium, when the nonrelativistic Larmor radius RL = mc 2/eB exceeds the correlation length ? of the magnetic field, the magnetic Bremsstrahlung radiation of charged relativistic particles unavoidably proceeds to the so-called jitter radiation regime. The cooling timescale of parent particles is identical to the synchrotron cooling time, thus this radiation regime can be produced with very high efficiency in different astrophysical sources characterized by high turbulence. The jitter radiation has distinct spectral features shifted toward high energies, compared to synchrotron radiation. This effect makes the jitter mechanism an attractive broad-band gamma-ray production channel, which, in highly magnetized and turbulent environments, can compete or even dominate over other high-energy radiation mechanisms. In this paper, we present a novel study of the spectral properties of the jitter radiation performed within the framework of perturbation theory. The derived general expression for the spectral power of radiation is presented in a compact and convenient form for numerical calculations.

Kelner, S. R.; Aharonian, F. A.; Khangulyan, D.

2013-09-01

177

Synchrotron Radiation II.  

ERIC Educational Resources Information Center

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)

MOSAIC, 1978

1978-01-01

178

ON THE JITTER RADIATION  

SciTech Connect

In a small-scale turbulent medium, when the nonrelativistic Larmor radius R{sub L} = mc {sup 2}/eB exceeds the correlation length {lambda} of the magnetic field, the magnetic Bremsstrahlung radiation of charged relativistic particles unavoidably proceeds to the so-called jitter radiation regime. The cooling timescale of parent particles is identical to the synchrotron cooling time, thus this radiation regime can be produced with very high efficiency in different astrophysical sources characterized by high turbulence. The jitter radiation has distinct spectral features shifted toward high energies, compared to synchrotron radiation. This effect makes the jitter mechanism an attractive broad-band gamma-ray production channel, which, in highly magnetized and turbulent environments, can compete or even dominate over other high-energy radiation mechanisms. In this paper, we present a novel study of the spectral properties of the jitter radiation performed within the framework of perturbation theory. The derived general expression for the spectral power of radiation is presented in a compact and convenient form for numerical calculations.

Kelner, S. R. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-6917 Heidelberg (Germany); Aharonian, F. A. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Khangulyan, D., E-mail: skelner@rambler.ru, E-mail: Felix.Aharonian@mpi-hd.mpg.de, E-mail: khangul@astro.isas.jaxa.jp [Institute of Space and Astronautical Science/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

2013-09-01

179

Treatment of Radiation Injury  

PubMed Central

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.

Akita, Sadanori

2014-01-01

180

PROTECTION AGAINST RADIATION INJURY  

Microsoft Academic Search

An account is given of the principles of protection against radiation ; injury and of the recommendations of Emergency Health Services, Department of ; National Health and Welfare, to those responsible for the protection of the ; health of persons at risk from nuclear weapon fallout radiations. Protection ; against injury is based on 2 concepts: procedures that result in

F. C. Pace; W. R. Waters

1961-01-01

181

Ultraviolet radiation changes  

NASA Technical Reports Server (NTRS)

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.

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

182

Radiation-induced pneumothorax  

SciTech Connect

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.

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

1983-01-01

183

Radiation-induced enteropathy  

Microsoft Academic Search

The incidence of chronic radiation enteritis appears to have risen in recent years due to the increasing utilization of radiotherapy for abdominal and pelvic malignancies. The etiology, pathogenesis, and management of radiation enteritis are discussed. Two case reports exemplify the progressive nature of the disease. Case 1 demonstrates the classical picture of multiple exacerbations and remissions of partial small bowel

M. E. Sher; J. Bauer

1990-01-01

184

Solar radiation in Lebanon  

Microsoft Academic Search

Solar radiation data for two sites in Lebanon are analyzed and presented in a form suitable for their use by practicing engineers. Correlations of the Angstrom-Page type for daily and monthly data are developed. Probability density functions for daily values of global radiation for each month are compared with the results of Liu and Jordan. The atmospheric model developed by

A. A. Sfeir

1981-01-01

185

Radiation biology of mosquitoes  

Microsoft Academic Search

There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal

Michelle EH Helinski; Andrew G Parker; Bart GJ Knols

2009-01-01

186

Radiation Exposure Compensation Program  

NSDL National Science Digital Library

This is the Justice Department's Radiation Exposure Compensation Program homepage. This site features information about the Radiation Exposure Compensation Act, including claimant categories, claim forms, and the Energy Employees Occupational Illness Compensation Program Act. This site also provides a table illustrating a summary of all claims received and compensation paid to date.

Program, U. S.

187

Earth Radiation Budget Satellite  

Microsoft Academic Search

A satellite to measure the earth's radiation budget is to be integrated, tested, and delivered ready for launch on the space shuttle by April 1984. Although there have been Earth radiation budget instruments in NASA's experimental NIMBUS 6 and 7 spacecraft, this will be the first time this factor can be measured on a global basis over a 24-hour day.

Peter M. Bell

1981-01-01

188

Earth Radiation Budget Experiment  

Microsoft Academic Search

During the past 4 years, instruments of the Earth Radiation Budget Experiment (ERBE) have been collecting data on two satellites. The first of these is the Earth Radiation Budget Satellite (ERBS). The second is the operational NOAA-9 satellite. In addition, ERBE has instruments on the operational NOAA-10. The NOAA-10 instruments have been collecting data for the last 2 years. The

Bruce R. Barkstrom; Edwin F. Harrison; Robert B. Lee III

1990-01-01

189

ARCTIC RADIATION BUDGET CHANGES  

Microsoft Academic Search

Scanning radiometers of the Earth Radiation Budget Experiment provided global measurements for 1985 through 1988 and Clouds and the Earth's Radiant Energy System (CERES) instruments have made measurements from 2000 to the present. These data have been used to study interannual and decadal variations for the Arctic region in July. The satellite record of Earth radiation budget demonstrates that the

G. Louis Smith; T. Dale Bess

190

Chitosan and radiation chemistry  

Microsoft Academic Search

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,

Andrzej G. Chmielewski

2010-01-01

191

Microcircuit Radiation Effects Databank.  

National Technical Information Service (NTIS)

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 e...

1983-01-01

192

Health and Environmental Radiation  

SciTech Connect

This paper discusses health benefits attributed to low-level radiation. Increased immune competence and radiogenic metabolism following low-dose irradiation elicits benefits in reproduction, cancer mortality, and average lifetime. Evidence is cited that suggests 200000 premature cancer deaths in this country would be prevented each year by radiation supplementation.

Luckey, T.D.

1999-06-06

193

Physics for Radiation Protection  

NASA Astrophysics Data System (ADS)

A practical guide to the basic physics that radiation protection professionals need A much-needed working resource for health physicists and other radiation protection professionals, this volume presents clear, thorough, up-to-date explanations of the basic physics necessary to address real-world problems in radiation protection. Designed for readers with limited as well as basic science backgrounds, Physics for Radiation Protection emphasizes applied concepts and carefully illustrates all topics through examples as well as practice problems. Physics for Radiation Protection draws substantially on current resource data available for health physics use, providing decay schemes and emission energies for approximately 100 of the most common radionuclides encountered by practitioners. Excerpts of the Chart of the Nuclides, activation cross sections, fission yields, fission-product chains, photon attenuation coefficients, and nuclear masses are also provided. Coverage includes: * The atom as an energy system * An overview of the major discoveries in radiation physics * Extensive discussion of radioactivity, including sources and materials * Nuclear interactions and processes of radiation dose * Calculational methods for radiation exposure, dose, and shielding * Nuclear fission and production of activation and fission products * Specialty topics ranging from nuclear criticality and applied statistics to X rays * Extensive and current resource data cross-referenced to standard compendiums * Extensive appendices and more than 400 figures

Martin, James E.

2000-06-01

194

Radiative forcing by contrails  

Microsoft Academic Search

A parametric study of the instantaneous radiative impact of contrails is presented using three dierent radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treat- ed as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmosphere. The ice water content is varied as a function of ambient temperature. The model atmospheres

R. Meerkotter; U. Schumann; D. R. Doelling; P. Minnis; T. Nakajima; Y. Tsushima

1999-01-01

195

Radiation of Massive Gravitation.  

National Technical Information Service (NTIS)

The radiation problem in massive and massless linear Einstein gravitation is analyzed for mass discontinuities in the limit of vanishing graviton mass m. It is found that in this limit the radiation into the massive helicity + or - 2 modes becomes equal t...

P. Vannieuwenhuizen

1972-01-01

196

Forecasting Radiation Fog  

NSDL National Science Digital Library

The goal of this training module is to help you increase your understanding of how radiation fog forms, grows, and dissipates. Such understanding, in turn, can help you more efficiently and accurately evaluate the ability of a given atmospheric environment to generate and/or maintain radiation fog.

Spangler, Tim

1999-04-08

197

RADIATION-CURABLE COATINGS  

EPA Science Inventory

The report gives results of an evaluation of radiation-curable coatings as a technology for reducing volatile organic compound (VOC) emissions from surface coating operations. urvey of the literature was conducted to assess the state of the technology and emissions from radiation...

198

Radiation and health*  

PubMed Central

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.

Lindell, B.

1987-01-01

199

Deployable Heat Pipe Radiator  

NASA Technical Reports Server (NTRS)

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.

Edelstein, F.

1975-01-01

200

Ultrasensitive Human Radiation Dosimetry  

NASA Technical Reports Server (NTRS)

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.

Hammen, Richard

1985-01-01

201

Gravitational diffraction radiation  

SciTech Connect

We show that if the visible universe is a membrane embedded in a higher-dimensional space, particles in uniform motion radiate gravitational waves because of spacetime lumpiness. This phenomenon is analogous to the electromagnetic diffraction radiation of a charge moving near to a metallic grating. In the gravitational case, the role of the metallic grating is played by the inhomogeneities of the extra-dimensional space, such as a hidden brane. We derive a general formula for gravitational diffraction radiation and apply it to a higher-dimensional scenario with flat compact extra dimensions. Gravitational diffraction radiation may carry away a significant portion of the particle's initial energy. This allows to set stringent limits on the scale of brane perturbations. Physical effects of gravitational diffraction radiation are briefly discussed.

Cardoso, Vitor; Cavaglia, Marco; Pimenta, Mario [Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677-1848 (United States); Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677-1848 (United States); Departamento de Fisica, IST, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); LIP, Avenida Elias Garcia, 14-1, 1000-149 Lisbon (Portugal)

2006-10-15

202

Chitosan and radiation chemistry  

NASA Astrophysics Data System (ADS)

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.

Chmielewski, Andrzej G.

2010-03-01

203

Fundamentals of Radiation Dosimetry  

SciTech Connect

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.

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

2011-05-05

204

Coherent curvature radiation  

NASA Astrophysics Data System (ADS)

With regard to coherent curvature radiation (CCR), calculations of the exact nature of the coherence requirements and the properties of the resulting radiation are reexamined. It is found that the general theory of CCR from plasma waves, as developed by Buscauer and Benford (1976), is correct only in the limit in which the plasma particles are stationary in the wave frame. In addition, features of their calculations, namely radiated energy which exceeds the product of the square of the number of particles times single particle radiation, as well as the feature of radiation at frequencies higher than the cutoff frequency for single particle emission, can be understood as spurious contributions originating in the boundary conditions.

Kirk, J. G.

1980-02-01

205

Nuclear radiation actuated valve  

DOEpatents

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.

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

1985-01-01

206

Underwater radiation detector  

DOEpatents

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.

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

1986-01-01

207

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...

208

Genetic effects of ionizing radiation.  

National Technical Information Service (NTIS)

Ionizing radiation effects on the gem cells, which can result in genetic abnormalities, are described. The basic mechanisms of radiation interactions with chromosomes, or specifically DNA, which can result in radiation induced mutation are discussed. Meth...

P. A. H. Saunders

1991-01-01

209

Modifying Radiation Damage  

PubMed Central

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.

Kim, Kwanghee; McBride, William H.

2011-01-01

210

Beneficial uses of radiation  

SciTech Connect

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.

Fox, M.R.

1991-10-01

211

Microenvironment and Radiation Therapy  

PubMed Central

Dependency on tumor oxygenation is one of the major features of radiation therapy and this has led many radiation biologists and oncologists to focus on tumor hypoxia. The first approach to overcome tumor hypoxia was to improve tumor oxygenation by increasing oxygen delivery and a subsequent approach was the use of radiosensitizers in combination with radiation therapy. Clinical use of some of these approaches was promising, but they are not widely used due to several limitations. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that is activated by hypoxia and induces the expression of various genes related to the adaptation of cellular metabolism to hypoxia, invasion and metastasis of cancer cells and angiogenesis, and so forth. HIF-1 is a potent target to enhance the therapeutic effects of radiation therapy. Another approach is antiangiogenic therapy. The combination with radiation therapy is promising, but several factors including surrogate markers, timing and duration, and so forth have to be optimized before introducing it into clinics. In this review, we examined how the tumor microenvironment influences the effects of radiation and how we can enhance the antitumor effects of radiation therapy by modifying the tumor microenvironment.

Yoshimura, Michio; Itasaka, Satoshi; Harada, Hiroshi; Hiraoka, Masahiro

2013-01-01

212

Stimulated coherent transition radiation  

SciTech Connect

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.

Hung-chi Lihn

1996-03-01

213

RADIATIVE TRANSFER IN ULTRARELATIVISTIC OUTFLOWS  

SciTech Connect

Analytical and numerical solutions are obtained for the equation of radiative transfer in ultrarelativistic opaque jets. The solution describes the initial trapping of radiation, its adiabatic cooling, and the transition to transparency. Two opposite regimes are examined. (1) Matter-dominated outflow. Surprisingly, radiation develops enormous anisotropy in the fluid frame before decoupling from the fluid. The radiation is strongly polarized. (2) Radiation-dominated outflow. The transfer occurs as if radiation propagated in vacuum, preserving the angular distribution and the blackbody shape of the spectrum. The escaping radiation has a blackbody spectrum if (and only if) the outflow energy is dominated by radiation up to the photospheric radius.

Beloborodov, Andrei M., E-mail: amb@phys.columbia.edu [Physics Department and Columbia Astrophysics Laboratory, Columbia University, 538 West 120th Street New York, NY 10027 (United States)

2011-08-20

214

Human radiation tolerance  

NASA Technical Reports Server (NTRS)

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.

Lushbaugh, C. C.

1974-01-01

215

Radiation Damage Theory  

SciTech Connect

This chapter presents an overview of basic radiation damage theory, including older and more recent models, to provide framework, within which radiation effects, such as void swelling, can be rationalized. A complete review of the literature is not attempted, but sufficient references are given to provide a decent introduction to a quite large number of publications in the field. Many derivations are different from and, in our view, more elegant than in the original publications. The work is directed to both theoreticians and experimentalists, and, especially, to those passionate individuals who are going to take the radiation damage theory (RDT) to the future.

Golubov, Stanislav I [ORNL; Barashev, Aleksandr [University of Liverpool; Stoller, Roger E [ORNL

2012-01-01

216

Radiative forcing of climate  

NASA Technical Reports Server (NTRS)

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.

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

217

Palliative radiation therapy.  

PubMed

Animal owners may be reluctant to have pets with incurable cancer subjected to euthanasia. Palliative radiation therapy may provide significant relief of pain in such pets. Palliative irradiation is comprised of a few radiation treatments, frequently given over a short time and using larger than normal fractional doses. Animals tolerate palliative irradiation well, and recent reports attest to the usefulness of palliative radiation to relieve discomfort associated with both skeletal and extraskeletal tumors. Although there is more to learn regarding the response of canine and feline tumors to palliative irradiation, it is a proven modality for relief of pain in many incurable cancer patients. PMID:8532977

Thrall, D E; LaRue, S M

1995-08-01

218

Microcircuit radiation effects databank  

NASA Technical Reports Server (NTRS)

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).

1983-01-01

219

Liquid sheet radiator  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

220

Composition for radiation shielding  

DOEpatents

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.

Kronberg, James W. (Aiken, SC)

1994-01-01

221

Miniaturized radiation chirper  

DOEpatents

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.

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

1980-01-01

222

Radiation physics, biophysics, and radiation biology  

NASA Astrophysics Data System (ADS)

This annual report contains a summary of our current research. Some highlights include: experimental microdosimetry, track structure, extension of the Dual Radiation Action model to be time dependent, experiments showing that the reverse dose-rate effect for onogenic transformation, first rated for neutrons, has also been observed for charged particles of intermediate LET, an analysis of low dose-rate, research in hyperthermia, studies in molecular cloning, low dose rate studies, experimental studies on high LET, and molecular studies on DNA.

Hall, E. J.; Zaider, M.

1990-05-01

223

Tin Can Radiation Detector.  

ERIC Educational Resources Information Center

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)

Crull, John L.

1986-01-01

224

Radiation Technology, Issue 6.  

National Technical Information Service (NTIS)

The publication deals with theoretical and experimental works on the nuclear-physical basis of radiation technology, isotope thermoelectric generators, equipment irradiation, pulse proton generator, nuclear methods of analysis, gamma flaw detection, radio...

1971-01-01

225

Radiation Dose Uncertainty Code.  

National Technical Information Service (NTIS)

Systems, machine readable storage, and methods for solving a respiratory tract model of radiation dosage. Steps include selecting input parameters associated with a respiratory tract model, computing a probability density function for the input parameters...

E. Houston E. B. Farfan W. E. Bolch W. E. Bolch

2003-01-01

226

Ionizing radiation detector  

DOEpatents

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.

Thacker, Louis H. (Knoxville, TN)

1990-01-01

227

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. ...

228

Pregnancy and Radiation Exposure  

MedlinePLUS

... Study Released . PDS on Radiation Instruments . Update of Nuclear Power Environmental Standards Upcoming Events . NRC Meeting Webcasts - ... Exposure to the Embryo or Fetus from Diagnostic Nuclear Medicine Pregnant women may be administered radioactive materials ...

229

Cataracts and avionic radiations.  

PubMed Central

Nine cases of hertzian radiation cataracts are reported among personnel working in operational aviation environments, where they were irradiated repeatedly at subliminal non-thermal field intensities. The resultant ocular pathology evolved insidiously and slowly over a period of years in a similar way to other forms of radiational injury. By the time of consultation examination, all had progressed to a relatively late state, exhibiting not only capsular cataract but also vesiculation and opacification of the proximal subcapsular lens substance. In addition to the ocular dangers of chronic exposure to nonionising radiation reference is made to the nonthermal effect or the radiation effect per se, as this could relate to general health--for example, as a possible previously unsuspected aetiological or contributory factor in many other disease processes. Images

Zaret, M M; Snyder, W Z

1977-01-01

230

Radiation Therapy (For Parents)  

MedlinePLUS

... temporary, it can be permanent. Sore Mouth and Tooth Decay The tissues of the mouth may be sore ... and there may be an increased risk of tooth decay if a child received radiation therapy to the ...

231

[Genetic effects of radiation].  

PubMed

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

Nakamura, Nori

2012-03-01

232

Radiation Therapy. Guideline Series.  

National Technical Information Service (NTIS)

Guidelines adopted by the Health Systems Agency of Southwestern Pennsylvania to facilitate the development of a radiation therapy program are presented. Using the guidelines, subarea planning councils, in collaboration with health systems agency staff, ar...

1978-01-01

233

Space radiation studies  

NASA Technical Reports Server (NTRS)

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.

Gregory, J. C.

1986-01-01

234

Radiation-Induced Bioradicals  

NASA Astrophysics Data System (ADS)

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.

Lahorte, Philippe; Mondelaers, Wim

235

Amorphous silicon radiation detectors  

DOEpatents

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.

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

1992-01-01

236

Radiation myelopathy: a review  

SciTech Connect

Radiation myelopathy is a serious potential complication associated with radiation therapy to the spinal cord. Its exact cause is unknown. It represents a spectrum of syndromes, the most common of which are acute transient radiation myelopathy and chronic progressive radiation myelitis. A review of the literature indicates that cord damage is related to a number of controllable factors including dose fraction size, treatment time, total dose, length of cord irradiated, technical and clerical errors. Other less well understood factors that appear to contribute to the risk such as combined chemoradiotherapy effects and hyperthermia should also be recognized. A better awareness and understanding of these factors should ultimately lead to safer and more effective treatments. 56 references.

Goldwein, J.W.

1987-01-01

237

Monte Carlo radiative transfer  

NASA Astrophysics Data System (ADS)

I outline methods for calculating the solution of Monte Carlo Radiative Transfer (MCRT) in scattering, absorption and emission processes of dust and gas, including polarization. I provide a bibliography of relevant papers on methods with astrophysical applications.

Whitney, B. A.

2011-03-01

238

Monte Carlo radiative transfer  

NASA Astrophysics Data System (ADS)

I outline methods for calculating the solution of Monte Carlo Radiative Transfer (MCRT) in scattering, absorption and emission processes of dust and gas, including polarization. I provide a bibliography of relevant papers on methods with astrophysical applications.

Whitney, Barbara A.

2011-12-01

239

Gas particle radiator  

NASA Technical Reports Server (NTRS)

A gas particle radiator adapted to operate in a microgravity space environment having a transparent boundary which transmits energy in the infrared spectrum, and a gas particle mixture that yields high absorption and emittances are described.

Chubb, Donald L. (inventor)

1988-01-01

240

EM Radiation Program  

NSDL National Science Digital Library

The EM Radiation program displays the electric field vectors (in the x-y plane) and magnetic field contours (for the field in the z direction) calculated from the Lienard-Wiechert potentials for a charged particle. The default scenario shows the resulting radiation from a charged particle in simple harmonic motion. Additional particle trajectories can be specified using the Display | Switch GUI menu item. EM Radiation is an Open Source Physics program written for the teaching of electromagnetism. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the em_radiation.jar file will run the program if Java is installed. Other electromagnetism programs are also available. They can be found by searching ComPADRE for Open Source Physics, OSP, or electromagnetism.

Christian, Wolfgang

2008-05-20

241

Amorphous silicon radiation detectors  

DOEpatents

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.

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

1992-11-17

242

Environmental Radiation Exposures  

Cancer.gov

Atomic Bomb Survivors Semipalatinsk Nuclear Test Site, Kazakhstan Study of Radiation Doses and Cancer Risks Resulting from the 1945 "Trinity" Atomic Weapon Test Thyroid Disease in Young Persons Near Chernobyl Techa River Print This Page Environmental

243

Brookhaven Radiation Effects Facility.  

National Technical Information Service (NTIS)

The Neutral Particle Beam (NPB) Radiation Effects Facility (REF), funded by the Strategic Defense Initiative Office (SDIO) through the Defense Nuclear Agency (DNA) and the Air Force Weapons Laboratory (AFWL), has been constructed at Brookhaven National La...

C. L. Snead P. Grand T. Ward

1988-01-01

244

Method of enhancing radiation response of radiation detection materials  

DOEpatents

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.

Miller, Steven D. (Richland, WA) [Richland, WA

1997-01-01

245

Auditing radiation sterilization facilities  

NASA Astrophysics Data System (ADS)

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

Beck, Jeffrey A.

246

Nanocomposites for radiation sensing  

NASA Astrophysics Data System (ADS)

The use of light emitting nanoparticles in polymer and glass matrices was studied for the detection of radiation. These nanocomposite scintillators were produced by various approaches including quantum dot/polymer, fluoride nanophosphor/epoxy and halide nanophosphor containing glass-ceramic composites. The synthesis and characterization of these nanoparticles as well as their incorporation into composites is discussed. Further, the application of these composites for radiation detection and spectroscopy is described.

Wagner, Brent K.; Kang, Zhitao; Nadler, Jason; Rosson, Robert; Kahn, Bernd

2012-05-01

247

Dynamic hohlraum radiation hydrodynamics  

Microsoft Academic Search

Z-pinch dynamic hohlraums are a promising indirect-drive inertial confinement fusion approach. Comparison of multiple experimental methods with integrated Z-pinch\\/hohlraum\\/capsule computer simulations builds understanding of the hohlraum interior conditions. Time-resolved x-ray images determine the motion of the radiating shock that heats the hohlraum as it propagates toward the hohlraum axis. The images also measure the radius of radiation-driven capsules as they

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

2006-01-01

248

Radiation environment mapping  

NASA Technical Reports Server (NTRS)

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.

Benton, E. Y.

1981-01-01

249

Radiation Color Plot  

NSDL National Science Digital Library

Energy from the sun reaches the Earth and some is absorbed by the air, land, and water. Some of the energy is reflected back into space, meaning it does not heat the land, air, or water. In this lesson students will read a color plot of Earth's absorption of the sun's radiation. They will evaluate causes for difference in absorption rates at different points around the world and draw conclusions about factors effecting absorption of sun's radiation.

250

Radiation associated tumors following therapeutic cranial radiation  

PubMed Central

Background: A serious, albeit rare, sequel of therapeutic ionizing radiotherapy is delayed development of a new, histologically distinct neoplasm within the radiation field. Methods: We identified 27 cases, from a 10-year period, of intracranial tumors arising after cranial irradiation. The original lesions for which cranial radiation was used for treatment included: tinea capitis (1), acute lymphoblastic leukemia (ALL; 5), sarcoma (1), scalp hemangioma (1), cranial nerve schwannoma (1) and primary (13) and metastatic (1) brain tumors, pituitary tumor (1), germinoma (1), pinealoma (1), and unknown histology (1). Dose of cranial irradiation ranged from 1800 to 6500 cGy, with a mean of 4596 cGy. Age at cranial irradiation ranged from 1 month to 43 years, with a mean of 13.4 years. Results: Latency between radiotherapy and diagnosis of a radiation-induced neoplasm ranged from 4 to 47 years (mean 18.8 years). Radiation-induced tumors included: meningiomas (14), sarcomas (7), malignant astrocytomas (4), and medulloblastomas (2). Data were analyzed to evaluate possible correlations between gender, age at irradiation, dose of irradiation, latency, use of chemotherapy, and radiation-induced neoplasm histology. Significant correlations existed between age at cranial irradiation and development of either a benign neoplasm (mean age 8.5 years) versus a malignant neoplasm (mean age 20.3; P = 0.012), and development of either a meningioma (mean age 7.0 years) or a sarcoma (mean age 27.4 years; P = 0.0001). There was also a significant positive correlation between latency and development of either a meningioma (mean latency 21.8 years) or a sarcoma (mean latency 7.7 years; P = 0.001). The correlation between dose of cranial irradiation and development of either a meningioma (mean dose 4128 cGy) or a sarcoma (mean dose 5631 cGy) approached significance (P = 0.059). Conclusions: Our study is the first to show that younger patients had a longer latency period and were more likely to have lower-grade lesions (e.g. meningiomas) as a secondary neoplasm, while older patients had a shorter latency period and were more likely to have higher-grade lesions (e.g. sarcomas).

Chowdhary, Abhineet; Spence, Alex M.; Sales, Lindsay; Rostomily, Robert C.; Rockhill, Jason K.; Silbergeld, Daniel L.

2012-01-01

251

Test problems for radiation and radiation-hydrodynamics codes  

NASA Technical Reports Server (NTRS)

A number of test problems for radiation and radiation-hydrodynamics computer codes are described. These include evolution to radiative equilibrium, cooling from radiative equilibrium, subcritical and supercritical radiating shocks, and a radiating blast wave in a power-law density distribution. For each test problem, example input parameters and plots of the results are presented. Some test problems for pure hydrodynamics are also suggested. The radiation-hydrodynamics code used to perform the example test problems and the equations it solves are described in some detail.

Ensman, Lisa

1994-01-01

252

Handbook of radiation effects  

SciTech Connect

This handbook is intended to serve as a tool for designers of equipment and scientific instruments in cases where they are required to ensure the survival of the equipment in radiation environments. High-technology materials, especially semiconductors and optics, tend to degrade on exposure to radiation in many different ways. Intense high-energy radiation environments are found in nuclear reactors and accelerators, machines for radiation therapy, industrial sterilization, and space. Some engineers have to build equipment which will survive a nuclear explosion from a hostile source. Proper handling of a disaster with radioactive materials requires equipment which depends utterly on semiconductor microelectronics and imaging devices. Thus the technology of radiation-tolerant electronics is an instrument for good social spheres as diverse as disaster planning and the exploration of Mars. In order to design equipment for intense environments like those described above, then degradation from high-energy irradiation must be seen as a basic design parameter. The aim of this handbook is to assist the engineer or student in that thought; to make it possible to write intelligent specifications; to offer some understanding of the complex variety of effects which occur when high-technology components encounter high-energy radiation; and to go thoroughly into the balance of choices of how to alleviate the effects and hence achieve the design aims of the project. Separate abstracts were prepared for 15 chapters of this book.

Holmes-Siedle, A. (ed.) (Radiation Experiments and Monitors, Oxford (United Kingdom) Univ. of West London (United Kingdom)); Adams, L. (ed.) (European Space Agency-ESTEC, Noordwijk (Netherlands). Radiation Effects and Analysis Techniques Unit)

1993-01-01

253

Packet personal radiation monitor  

DOEpatents

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.

Phelps, James E. (Knoxville, TN)

1989-01-01

254

ISO radiation sterilization standards  

NASA Astrophysics Data System (ADS)

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

Lambert, Byron J.; Hansen, Joyce M.

1998-06-01

255

[Radiation myelopathy and plexopathy].  

PubMed

Radiation myelopathy (RM) is a relatively rare disorder characterized by white matter lesions of the spinal cord resulting from irradiation. It is divided into two forms by the latent periods: transient RM and delayed RM. The delayed RM develops usually non-transverse myelopathy symptoms such as dissociated sensory disturbance, unilateral leg weakness, and gait disturbance with asymmetric steps. Spinal MRI shows initially cord swelling and long T1/T2 intramedullary lesion with enhancement, then exhibits cord atrophy. Histopathological findings of delayed RM are white matter necrosis, demyelination, venous wall thickening and hyalinization. Glial theory and vascular hypothesis have been proposed to explain its pathophysiology. Several therapies such as adrenocorticosteroid, anticoagulation and hyperbaric oxygen have been tried to this disease with variable benefits. Radiation plexopathy is classified into two major types by the location: radiation-induced brachial plexopathy (BP) and radiation-induced lumbosacral plexopathy (LSP). The BP initially emerges as arm and shoulder pain, whereas LSP as leg weakness. Myokymia and fasciculations are observed in both types. Electrophysiological study reveals findings of peripheral neuropathy. It is often difficult to distinguish the radiation plexopathy from cancer invasion to the plexus, but MRI is useful to differentiate between these diseases. Pathological findings are small vessel obstruction, thick fibrosis, axonal degeneration and demyelination. Its pathomechanism is presumed that radiation-induced fibrous tissue compresses the nerve root as well as microvascular obstruction of the nerve. Adrenocorticosteroid and anticoagulation are considered as the strategy for symptomatic relief. PMID:18306658

Shimazaki, Haruo; Nakano, Imaharu

2008-02-01

256

Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles  

PubMed Central

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

2011-01-01

257

Development of pulse radiation antennas  

Microsoft Academic Search

In this paper, the development of pulse radiation antennas is summarized. Loaded dipole antennas, TEM horn antennas and its variations, and reflector impulse radiating antennas are discussed as the main forms of antennas which can radiate pulse. The advantages and disadvantages concerning pulse radiation antennas are reviewed as well as the history of this technology. Also the improving methods and

Bo Sun; Jinghui Qiu; Chun Zhang; Weibo Deng

2008-01-01

258

Radiation damage in scintillating crystals  

Microsoft Academic Search

Crystal Calorimetry in future high-energy physics experiments faces a new challenge to maintain its precision in a hostile radiation environment. This paper discusses the effects of radiation damage in scintillating crystals, and concludes that the predominant radiation damage effect in crystal scintillators is the radiation-induced absorption, or color center formation, not the loss of scintillation light yield. The importance of

Ren-yuan Zhu

1998-01-01

259

Precaution and Solar Radiation Management  

Microsoft Academic Search

Solar radiation management is a form of geoengineering that involves the intentional manipulation of solar radiation with the aim of reducing global average temperature. This paper explores what precaution implies about the status of solar radiation management. It is argued that any form of solar radiation management that poses threats of catastrophe cannot constitute an appropriate precautionary measure against another

Lauren Hartzell-Nichols

2012-01-01

260

The Radiation Chemistry Data Center  

NSDL National Science Digital Library

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

Madden, K. P.

2007-05-15

261

The Radiation Chemistry Data Center  

NSDL National Science Digital Library

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

2002-01-01

262

Geostationary earth radiation budget  

NASA Astrophysics Data System (ADS)

The Earth Radiation Budget (ERB), the balance between the incoming solar radiation from the sun and the outgoing reflected and scattered solar radiation and the thermal infrared emission from the Earth, provides information on the fundamental energy source of the climate system. To fulfil global coverage and sampling requirements, the ERB measurements have to be made from space. Broad-band measurements are necessary because all spectral regions in both the solar and infrared contribute to the radiative fluxes. Satellite data are used in a wide range of basic studies of the radiative forcing of the climate, such as understanding the effects of variations in trace gases, clouds and the surface. They also provide essential validation for climate models. All such measurements to date have been made from satellites in low earth orbit (LEO). There are strong diurnal variations in the radiation budget, particularly over land, in response to the diurnal variation of solar heating. Four LEO satellites could provide coverage of the diurnal cycle with a temporal resolution of 3 hours. At least hourly measurements are needed to resolve the diurnal cycle of tropical convection properly, and no practicable system of polar orbiting or other LEO satellites can deliver this. From the above, it appears that the only viable solution to the problem of diurnal sampling of the Earth's radiation budget is the inclusion of suitable sensors on the geostationary satellites which would allow for an essentially perfect temporal sampling. Disadvantages include the fact that geostationary satellites are much further from the Earth than polar orbiters, which affects the instrumental design, and each one can only provide a limited coverage of the globe. The Geostationary Earth Radiation Budget instrument (GERB) is a highly accurate visible-infrared radiometer designed to make unique measurements of the outgoing shortwave and longwave components of the Earth's Radiation Budget (ERB) from geostationary orbit. Such measurements have not been achieved previously, and are extremely important, because they will permit a rigorous test of our understanding of the diurnal variations in the ERB: this will enable improved operational weather monitoring and permit further important developments in climate change research. GERB will be launched on the (MSG) geostationary satellite in the year 2000. Both short-wave (0.32 - 4 micrometer) and total (0.32 - 30 micrometer) radiance measurements would be made, with longwave (4 - 30 micrometer) data obtained by subtraction. The accuracy requirements (1% short-wave and 0.5% longwave) are consistent with previous radiation budget measurements. The availability of GERB on MSG will also allow a more accurate calibration of the principal Meteosat Second Generation (MSG) operational sounding instrument, SEVIRI (Spinning, Enhanced Visible and InfraRed Imager).

Mossavati, Ruzbeh; Kellock, Steve; Mueller, Johannes; Harries, J. E.; Murray, J. E.; Sawyer, Eric C.; Caldwell, Martin E.; Oliver, M.; Delderfield, J.; Sandford, Michael C.

1997-12-01

263

Radiation health research, 1986 - 1990  

NASA Technical Reports Server (NTRS)

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.

1991-01-01

264

Radiation in particle simulations  

NASA Astrophysics Data System (ADS)

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 (plane-waves 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.

More, Richard; Graziani, Frank; Glosli, Jim; Surh, Michael

2010-01-01

265

Radiation in Particle Simulations  

SciTech Connect

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.

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

2010-11-19

266

Status of LDEF radiation modeling  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

267

Technical advances in radiation therapy  

SciTech Connect

Substantial advances have been made in radiation therapy. Many of these advances can be applied in most radiation therapy departments without expensive improvements in equipment. Changes in radiation fractionation, chemotherapeutic sensitization, intraoperative radiation, and interstitial implants can be performed with experience and improved physician training in most medium-sized departments. Advances that require investments in expensive equipment such as particle radiation and hyperthermia will need to be evaluated at designated treatment centers. 106 references.

Sause, W.T.

1986-08-01

268

Radiation delivery system and method  

DOEpatents

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.

Sorensen, Scott A. (Overland Park, KS); Robison, Thomas W. (Los Alamos, NM); Taylor, Craig M. V. (Jemez Springs, NM)

2002-01-01

269

Radiation from Relativistic Jets  

NASA Technical Reports Server (NTRS)

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.

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

270

Packet personal radiation monitor  

DOEpatents

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.

Phelps, J.E.

1988-03-31

271

Tachyonic synchrotron radiation  

NASA Astrophysics Data System (ADS)

The emission of superluminal quanta (tachyons) by ultra-relativistic electrons gyrating in magnetic fields is investigated. The tachyonic Linard-Wiechert potentials of helically orbiting charges are derived, as well as the superluminal energy flux and the transversal and longitudinal spectral densities. We calculate the tachyonic synchrotron power, its angular dependence, the mean energy of the superluminal quanta radiated, tachyonic emission rates, the spectral maxima, critical and break frequencies, and we identify the Stokes parameter of the longitudinal radiation. The tachyonic energy densities are averaged with electronic power-law distributions, and the spectral indices are determined. Quantitative estimates are given for superluminal synchrotron radiation generated in storage rings, the Jovian magnetosphere, and supernova remnants. The spectral density of Jupiter's tachyonic X-ray emission is inferred from radio fluxes obtained from SL9 pre-impact observations and the Cassini fly-by, and we identify the tachyonic spectral peak at 2keV in the ROSAT and Einstein spectral maps. We scrutinize multiwavelength observations of galactic supernova remnants, pointing out evidence in their wideband spectra for the TeV ?-radiation to be tachyonic rather than a consequence of inverse Compton scattering or pion decay. In the Crab Nebula, the electronic source population generating this radiation extends beyond the `knee' of the cosmic ray spectrum.

Tomaschitz, Roman

2004-04-01

272

Radiation source search toolkit  

NASA Astrophysics Data System (ADS)

The newly developed Radiation Source Search Toolkit (RSST) is a toolkit for generating gamma-ray spectroscopy data for use in the testing of source search algorithms. RSST is designed in a modular fashion to allow for ease of use while still maintaining accuracy in developing the output spectra. Users are allowed to define a real-world path for mobile radiation detectors to travel as well as radiation sources for possible detection. RSST can accept measured or simulated radiation spectrum data for generation into a source search simulation. RSST handles traversing the path, computing distance related attenuation, and generating the final output spectra. RSST also has the ability to simulate anisotropic shielding as well as traffic conditions that would impede a ground-based detection platform in a real-world scenario. RSST provides a novel fusion between spectral data and geospatial source search data generation. By utilizing the RSST, researchers can easily generate multiple datasets for testing detection algorithms without the need for actual radiation sources and mobile detector platforms.

Young, Jason S.

273

Remote radiation dosimetry  

DOEpatents

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.

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

1991-03-12

274

Remote radiation dosimetry  

DOEpatents

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.

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

1991-01-01

275

Computing radiation exchange  

NASA Astrophysics Data System (ADS)

A computational tool to simulate thermal radiation between surfaces is developed. The output is verified against cases for which the analytical solutions are available. The tool can be used as a stand-alone program, or as an interactive module for CFD. In such an application the module would augment other heat transfer boundary conditions. The tool is demonstrated by post-processing surface temperature field data from a supersonic CFD calculation. The result is a net thermal radiation surface data field - the black body radiative effluxes as functions of temperature, less the integrated influxes multiplied by their geometric view factors from other surface cells. An algorithm to compute blocking, or "shadowing" of surfaces is presented and demonstrated on a simple geometry. Validations using a geometrically complex experimental case from the literature is performed.

Nutzati Fontaine, Jonathan L.

276

Solar cell radiation handbook  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

277

Pediatric radiation oncology  

SciTech Connect

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.

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

1989-01-01

278

Radiation exposure during ureteroscopy  

SciTech Connect

Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room.

Bagley, D.H.; Cubler-Goodman, A. (Thomas Jefferson Univ., Philadelphia, PA (USA))

1990-12-01

279

Paradoxes of thermal radiation  

NASA Astrophysics Data System (ADS)

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, the paper examines the equilibrium temperature reached by objects exposed to solar thermal radiation and the temperature difference between their illuminated and shaded sides. These problems are studied first by analysing the simple ideal case of an isolated object, subsequently by taking into account the thermal radiation emitted by the environment, and finally by considering also the heat exchange with the surrounding air. Some examples are developed and numerical data are provided. The topic is developed in a way that can be suitable for both undergraduate student and general physicist.

Besson, U.

2009-09-01

280

Radiation-associated thyrotoxicosis  

SciTech Connect

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.

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

1986-10-01

281

Earth Radiation Budget Satellite  

NASA Astrophysics Data System (ADS)

A satellite to measure the earth's radiation budget is to be integrated, tested, and delivered ready for launch on the space shuttle by April 1984. Although there have been Earth radiation budget instruments in NASA's experimental NIMBUS 6 and 7 spacecraft, this will be the first time this factor can be measured on a global basis over a 24-hour day. The earth absorbs more solar energy in some regions and emits more thermal energy in others. This heating differential sets wind and ocean currents in motion to transfer heat from heated to cooled areas. Hence, the earth's radiation budget, as a driving force for weather, is one of the factors on which comprehensive data are needed for better weather and climate predictions.

Bell, Peter M.

282

Audible radiation monitor  

DOEpatents

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.

Odell, Daniel M. C. (11 Russellwood Ct., Aiken, SC 29803)

1993-01-01

283

Neptunium: Radiation protection guidelines  

SciTech Connect

The present report reviews the current knowledge of neptunium in areas which are important to radiation protection and makes recommendations on radiation protection guidelines. The report briefly reviews the chemical and physical properties of neptunium, the sources of neptunium in the environment, and potential pathways to man. The limited animal data on health effects are also examined. In addition, animal studies that may serve as a basis for predicting the metabolic behavior of neptunium in humans are considered. On the basis of the information examined, recommendations are made on the fraction of ingested neptunium absorbed from the gastrointestinal tract into blood (f/sub 1/). Finally, the report applies the available data to recommendations on radiation protection guidelines for neptunium.

Not Available

1988-02-28

284

Superlattice electroabsorption radiation detector  

SciTech Connect

This paper provides a preliminary investigation of a new class of superlattice electroabsorption radiation detectors that employ direct optical modulation for high-speed, two-dimensional (2-D), high-resolution imaging. Applications for the detector include nuclear radiation measurements, tactical guidance and detection (laser radar), inertial fusion plasma studies, and satellite-based sensors. Initial calculations discussed in this paper indicate that a 1.5-{mu}m (GaAlAs) multi-quantum-well (MQW) Fabry-Perot detector can respond directly to radiation of energies 1 eV to 10 KeV, and indirectly (with scattering targets) up through gamma, with 2-D sample rates on the order of 20 ps.

Cooke, B.J.

1993-06-01

285

Superlattice electroabsorption radiation detector  

SciTech Connect

This paper provides a preliminary investigation of a new class of superlattice electroabsorption radiation detectors that employ direct optical modulation for high-speed, two-dimensional (2-D), high-resolution imaging. Applications for the detector include nuclear radiation measurements, tactical guidance and detection (laser radar), inertial fusion plasma studies, and satellite-based sensors. Initial calculations discussed in this paper indicate that a 1.5-[mu]m (GaAlAs) multi-quantum-well (MQW) Fabry-Perot detector can respond directly to radiation of energies 1 eV to 10 KeV, and indirectly (with scattering targets) up through gamma, with 2-D sample rates on the order of 20 ps.

Cooke, B.J.

1993-06-01

286

Composition for radiation shielding  

DOEpatents

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.

Kronberg, J.W.

1994-08-02

287

Continuum radiation at Uranus  

NASA Technical Reports Server (NTRS)

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 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. It is argued 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.

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

1990-01-01

288

Precision synchrotron radiation detectors  

SciTech Connect

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.

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

289

Semiconductor radiation detector  

DOEpatents

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.

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

2010-03-30

290

SODA: Solar Radiation Database  

NSDL National Science Digital Library

The Solar Database, or SoDa, is described as an integration and exploitation of networked Solar radiation Databases for environment monitoring and as a project that aims to integrate European-wide solar radiation resources (i.e. databases, processing chains and educational resources) into one, thematically organized, Web site. The search tool allows users to search for data from a variety of sources including Long Term Time Series Data, Climatological Data, Simulation of Radiation Under Clear Skies Data, Solar Energy Systems Data, and much more. Once a particular set is located, the user can view a description of the source and contents of the data, as well as click on the provided links to access them.

291

Radiation Hazard Detector  

NASA Technical Reports Server (NTRS)

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.

1978-01-01

292

Saturn Radiation (SATRAD) Model  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

293

Radiation in Particle Simulations  

SciTech Connect

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.

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

2009-06-15

294

Solar radiation modelling  

NASA Astrophysics Data System (ADS)

The Sun is the main energy source of the life on the Earth. Thus, solar radiation energy data and models are important for many areas of research and applications. Many parameters influence the amount of solar energy at a particular standing point of the Earth's surface; therefore, many solar radiation models were produced in the last few years. Solar radiation energy depends mostly on incidence angle, which is defined by astronomical and surface parameters. Our solar radiation model is based on defining incidence angle by computing normal-to-the-surface tangent plane and direction of the Sun. If a part of the surface is in the shadow, it receives lesser energy than sunny areas. That is why shadow determination is an important part of the model. The sky is usually not completely clear, so meteorological parameters had to be integrated into the model. Meteorological model distinguishes among direct and diffuse Sun radiation. The model was tested and implemented for the whole Slovenia and it was also compared with previous studies. Case study surface data were calculated from the DEM with a 25 m resolution. The astronomical data, which were required for virtual Sun motion simulation around the Earth, were derived from the astronomical almanac. Meteorological data were acquired from observed mean values on 24 meteorological stations between 1961 and 1990. All calculations were made for hours and decades and finally, the annual quasiglobal radiation energy, which is the energy received by inclined plane from the Sun in one year, was calculated from the sum of all the energies of all the decades.

Zakek, Klemen; Podobnikar, Toma; Otir, Kritof

2005-03-01

295

Small Active Radiation Monitor  

NASA Technical Reports Server (NTRS)

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.

Badhwar, Gautam D.

2004-01-01

296

Radar frequency radiation  

NASA Astrophysics Data System (ADS)

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

Malowicki, E.

1981-11-01

297

Wireless passive radiation sensor  

DOEpatents

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.

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

2013-12-03

298

Modification of radiation response  

SciTech Connect

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.

Suit, H.D.

1984-01-01

299

Radiation monitor for liquids  

DOEpatents

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.

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

1999-03-02

300

Radiation monitor for liquids  

DOEpatents

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.

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

1999-01-01

301

LDEF Satellite Radiation Analyses  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

302

Long wavelength end-effect undulator radiation (Transition Undulator Radiation)  

SciTech Connect

As first pointed out by K.-J. Kim, undulator radiation contains a broad-band component in the long wavelength region. This radiation is due to the change in longitudinal velocity of an electron upon entering and leaving an undulator. The radiation pattern is a hollow cone, peaked in the forward direction, with an opening angle of approximately 1/{gamma}, with a spectrum covering a wide range, including the infra-red and the visible. The radiation is radially polarized, analogous to transition radiation, and exhibits interference effects between the entrance and exit ends of the undulator, similar to the interference effects observed for transition radiation from a thin slab of material. A straightforward application of formulas from Jackson ({ital Classical Electrodynamics}) results in a closed form exact expression for the low frequency limit of this novel radiation effect, Transition Undulator Radiation or TUR. 3 refs., 3 figs.

Kincaid, B.M.

1996-01-29

303

Justification in Radiation Protection  

Microsoft Academic Search

In recent years the concept of Justification has increasingly come to the fore of the minds of legislators, users of radioactive materials and radiation protection specialists alike. Perhaps the most well known manifestation of this was the lengthy debate, ending in judicial review, about the Justification for the operation of the Thermal Oxide Reprocessing Plant (Thorp) at Sellafield and, more

David Owen

1999-01-01

304

An Inexpensive Radiation Counter.  

ERIC Educational Resources Information Center

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)

Holton, Brian; Balla, Zsolt

1985-01-01

305

The radiation design handbook  

NASA Astrophysics Data System (ADS)

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.

1993-05-01

306

Future Synchrotron Radiation Sources  

Microsoft Academic Search

Sources of synchrotron radiation (also called synchrotron light) and their associated research facilities have experienced a spectacular growth in number, performance, and breadth of application in the past two to three decades. In 1978 there were eleven electron storage rings used as light sources. Three of these were small rings, all below 500 mega-electron volts (MeV), dedicated to this purpose;

Winick

2003-01-01

307

Cosmic microwave background radiation  

Microsoft Academic Search

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

Lyman Page; David Wilkinson

1999-01-01

308

Radiation curable epoxy resin  

Microsoft Academic Search

A carboxyl containing polymer is either prepared in the presence of a polyepoxide or reacted with a polyepoxide. The polymer has sufficient acid groups to react with only about 1 to 10 percent of the epoxide (oxirane) groups. The remaining epoxide groups are reacted with an unsaturated monocarboxylic acid such as acrylic or methacrylic acid to form a radiation curable

Najvar

1978-01-01

309

Radiation Hard Fiber Optics.  

National Technical Information Service (NTIS)

A study of radiation-inducted absorption in low-loss optical waveguides is reported. Step-index optical fibers were prepared from preforms fabricated by the CVD method. The germanium silicate core glass in the fibers was doped with varying amounts of anti...

R. E. Jaeger M. Aslami

1981-01-01

310

Thermodynamics of Radiation Modes  

ERIC Educational Resources Information Center

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

Pina, Eduardo; de la Selva, Sara Maria Teresa

2010-01-01

311

Alkoxy radical radiation products  

SciTech Connect

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)

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

1982-06-01

312

Radiation and guided waves  

Microsoft Academic Search

An analysis is carried out of the field radiated by a dipole in an arbitrary medium separated from others by parallel plane interfaces. The resulting solution in the form of a contour integral is then examined in relation to the intrinsic properties of the media involved and the position of the antenna. The solution is obtained by splitting the integral

A. Karbowiak

1959-01-01

313

Radiation Research: Biology.  

National Technical Information Service (NTIS)

Papers in Session B of these proceedings are grouped under the following headings: (1) radiation biochemistry-mechanisms of damage; (2) DNA damage and repair in cells; (3) effects on DNA and membranes; (4) mutagenesis and chromosome changes; (5) lethal, s...

J. J. Broerse G. W. Barendsen H. B. Kal A. J. van der Kogel

1983-01-01

314

Vacuum Cerenkov radiation.  

PubMed

Within the classical Maxwell-Chern-Simons limit of the standard-model extension, the emission of light by uniformly moving charges is studied confirming the possibility of a Cerenkov-type effect. In this context, the exact radiation rate for charged magnetic point dipoles is determined and found in agreement with a phase-space estimate under certain assumptions. PMID:15447322

Lehnert, Ralf; Potting, Robertus

2004-09-10

315

Radiation Accidents and Dosimetry.  

National Technical Information Service (NTIS)

On September 2nd 1982 one of the employees of the gamma-irradiation facility at Institute for Energy Technology, Kjeller, Norway entered the irradiation cell with a 65.7 kCi *sp60*Co- source in unshielded position. The victim received an unknown radiation...

E. Sagstuen, H. Theisen, T. Henriksten

1982-01-01

316

Compensation for radiation risks  

SciTech Connect

Several years ago tables of estimates of the so-called probability of causation were prepared and published to facilitate the compensation of cancer victims with an exposure to radiation prior to the diagnosis of cancer. The probability of causation is defined as the probability that a particular cancer in an individual was caused by an identified radiation exposure prior to diagnosis of the cancer. Probability of causation estimates were intended to be used to compensate victims of radiogenic cancers. We propose offering compensation to persons who received certain clearly identifiable exposures to ionizing radiation above natural background before some of them become cancer victims. First we discuss some types and circumstances of radiation exposures for which such compensation should be offered. The {open_quotes}equity postulate,{close_quotes} that compensation should restore the expected quality of life-measured in dollars-of an exposed person to that of an unexposed person, yields a formula for estimating the appropriate compensation. Interestingly this formula, first stated by D.V. Lindley, contains the probability of causation as a factor. An application of the formula to A-bomb survivor data on leukemia and discussion of estimation problems associated with this formula conclude the paper.

Groer, P.G. [Univ. of Tennessee, Knoxville, TN (United States)

1996-06-01

317

Radiation Hazard in Space  

NASA Astrophysics Data System (ADS)

This book gives a modern picture of the Earth's radiation environment and dynamics of radiation conditions in the heliosphere. The present monograph, unlike the reviews published earlier, treats the problem in self-contained form, in all its associations - from fundamental astrophysical, geophysical, and biological aspects to technical, engineering, aircraft and astronautical applications. The monograph includes a large amount of new data on the main sources of natural radiation hazard (terrestrial radiation belts, solar cosmic rays and galactic cosmic rays), accumulated during the last several decades of space research. As a result of the "information burst" in space physics, there are a lot of new interesting theoretical concepts, prediction models and ideas that deserve attention. The author gives an extensive bibliography, which covers impartially the main achievements, failures, problems and prospects in this field. The book will be helpful for a wide audience of space physicists, designers, engineers and other specialists in the practical cosmonautics (astronautics). It also will be relevant for a number of graduate courses on solar physics, geophysics, solar-terrestrial physics, and other branches of space research.

Miroshnichenko, L. I.

2003-10-01

318

Radiation decontamination of spices.  

National Technical Information Service (NTIS)

In this report effect of gamma irradiation and storage of fungal infestation and moisture of red chilies and black pepper has has been discussed. The sample were collected from local market and radiation treatment with 8 kGy of gamma rays completely inhib...

T. Akhtar A. Sattar M. Khan I. Khan

1992-01-01

319

Radiation belts of Jupiter  

Microsoft Academic Search

Pioneer 10 courted relativistic electrons throughout the magnetosphere ; of Jupiter, with the greatest fluxes being inside 20 Jupiter radii. The peak ; flux of electrons with energy greater than 50 MeV was 1.3 x 107 per square ; centimeter per second at the innermost penetration of the radiation belts. ; (auth);

R. W. Fillius; C. E. McIlwain

1974-01-01

320

Fan casing noise radiation  

Microsoft Academic Search

The extent of the fan-casing noise radiation of a centrifugal fan, relative to the aeroacoustic sources associated with the inlet box of the fan was investigated using a boundary element program for computing the acoustic pressures on the surfaces of the fan casing in terms of its experimentally measured surface vibration. As the starting point for the study, data were

G. H. Koopmann; K. A. Cunefare; W. Neise

1991-01-01

321

Foundations of radiation hydrodynamics  

Microsoft Academic Search

This book is the result of an attempt, over the past few years, to gather the basic tools required to do research on radiating flows in astrophysics. The microphysics of gases is discussed, taking into account the equation of state of a perfect gas, the first and second law of thermodynamics, the thermal properties of a perfect gas, the distribution

D. Mihalas; B. W. Mihalas

1984-01-01

322

Bayesian Radiation Source Localization  

Microsoft Academic Search

We present an approach to localizing radiological sources that uses numerical adjoints and a Bayesian formulation and demonstrate the approach on two simple example scenarios. Results indicate accurate estimates of source locations. We briefly study the effect of neglecting the contribution of all scattered radiation in the adjoints, as analytical transport approximations do, for a case with moderately attenuating material

Kenneth D. Jarman; Richard S. Wittman; Erin A. Miller; Christopher J. Gesh

2010-01-01

323

VDT Emissions Radiate Debate.  

ERIC Educational Resources Information Center

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)

Morgan, Bill

1990-01-01

324

Radiation and immunotherapy  

PubMed Central

Anticancer immunotherapy holds great promises, as long-term responses to interleukin-2 have been observed in metastatic melanoma and renal cell carcinoma patients. However, improving the relative low rates of such responses has constituted a great challenge. In our experience, high-dose radiation combined with interleukin-2 provided encouraging results that are worth exploring further.

Seung, Steven K.; Curti, Brendan; Crittenden, Marka; Urba, Walter

2012-01-01

325

Radiation detector spectrum simulator  

DOEpatents

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.

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

1985-04-09

326

Radar Frequency Radiation.  

National Technical Information Service (NTIS)

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

E. Malowicki

1981-01-01

327

Electromagnetic Radiation and Epilepsy  

Microsoft Academic Search

People report adverse health symptoms which they attribute to the radiation of microwave signals from mobile phone and TETRA masts. The validity of such reports cannot be safely rejected, either on the grounds of current safety compliance, nor on the grounds that such symptoms cannot be replicated in laboratory experiments in search of a simplified mechanism. Biological effects caused by

Andy Davidson

328

Cosmological radiative transfer  

NASA Astrophysics Data System (ADS)

In this thesis, we present a new code SPHRAY to calculate the transfer of ionizing radiation through an arbitrary smoothed particle hydrodynamics density field. This represents a unique application in that it is the only particle based radiative transfer code with the speed to be applied to cosmological simulations with 512 3 particles. In Chapter 2 we lay out the numerical algorithms the code is based on. In Chapter 3 we validate the results of our code on a set of standard radiative transfer tests that have been set in front of the community in the form of a comparison project. In Chapter 4 we describe an application of SPHRAY in calculating the neutral Hydrogen density field in the proximity zone of an accretion powered active galaxy. This scenario is especially well suited for our code in the sense that it requires the inclusion of shadowing effects, the treatment of a background as well as strong local sources, and the accurate calculation of very low neutral fractions. In Chapter 5 we present a large cosmological reionization application in which we explore the effect of smoothing the density field prior to doing radiative transfer as has been done in many previous works to lessen the computational cost.

Altay, Gabriel

2009-06-01

329

Radiation Hardening of Computers  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

330

Cambridge Cosmology: Relic Radiation  

NSDL National Science Digital Library

This section of Cambridge Cosmology discusses cosmic background radiation present in our Universe. Also covered are topics such as the present temperature of the Universe as taken by the COBE satellite, fluctuations seen at the 'edge' of the Universe, and possible causes of these fluctuations.

Shellard, Paul

331

Radiative Decay Engineering  

Microsoft Academic Search

Metallic surfaces can have unusual effects on fluorophores such as increasing or decreasing the rates of radiative decay and the rates of resonance energy transfer (RET). In the present article we describe the effects of metallic silver island films on the emission spectra, lifetimes, and energy transfer for several fluorophores. The fluorophores are not covalently coupled to the silver islands

Joseph R. Lakowicz; Yibing Shen; Sabato D'Auria; Joanna Malicka; Jiyu Fang; Zygmunt Gryczynski; Ignacy Gryczynski

2002-01-01

332

Radiations from hot nuclei  

NASA Technical Reports Server (NTRS)

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.

Malik, F. Bary

1993-01-01

333

Psoriasis and ultraviolet radiation  

SciTech Connect

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.

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

1993-09-01

334

Radiative transfer of visible radiation in turbid atmosphere  

NASA Technical Reports Server (NTRS)

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.

Yamamoto, G.; Tanaka, M.

1974-01-01

335

Radiation litmus paper  

SciTech Connect

Colorimetric radiation measurement has certain advantages over other methods; these advantages include the ability to measure extremely high doses and fluxes that would saturate other instrumentation. Colorimetry offers the possibility of inexpensive real-time measurements without the need for bulky or heavy equipment. The author is investigating the use of colorimetric threshold radiation measurement for first responders to potential radiological incidents, where advanced radiation measurement equipment would be inappropriate in terms of its size, weight, and complexity of operations. The author developed several new autocatalytic reactions for use in colorimetric radiation measurement. An autocatalytic reaction is one in which the products of the reaction further catalyze the reaction to produce a reaction that proceeds at an exponential rate. The autocatalytic reactions that were developed are triggered by gamma, neutron, or beta radiation. The products of these reactions are visualized with the unaided eye or measured spectrometrically. He achieved visible color changes in response to doses as low as 1.7 x 10{sup {minus}4} Gy (17 mR) of {sup 137}Cs gamma irradiation. By varying the chemical reaction parameters, such as concentrations, reagents, and reaction inhibitors, he can control the threshold dose at which the color change becomes visible. For example, by adjusting the equivalent of the chain length of the autocatalytic reaction two otherwise identical materials possess thresholds of 4.4 x 10{sup {minus}3} Gy (440 mR) or 3.0 x 10{sup {minus}3} Gy (300 mR). Alternatively, by controlling the concentration of the reagents or the volume of the reaction medium, the threshold dose can be varied linearly from 1.2 x 10{sup {minus}3} Gy (120 mR) to 5.8 x 10{sup {minus}3}Gy (580 mR). In summary, he developed the first viable low-dose colorimetric method for measuring ionizing radiation. The reagents are easy to synthesize and handle, and the method provides visible changes. Further experiments to determine dose rate responses and calibration for beta and neutron radiation are underway.

Warner, B.P.

1999-07-01

336

Drug Information Related to Radiation Emergencies  

MedlinePLUS

... Radiation Emergencies (Centers for Disease Control and Prevention) Radiation Emergencies Drug Information Related to Radiation Emergencies Potassium Iodide ("KI") Information . Potassium Iodide (KI) ...

337

Radiation sterilization of hydrocortisone acetate.  

National Technical Information Service (NTIS)

The feasibility of using high energy ionizing radiation for the sterilization of hydrocortisone acetate was investigated. Hydrocortisone acetate in the form of powder was exposed to different dose levels of gamma radiation using a Cobalt-60 source. The ir...

A. Charef A. Boussaha

1989-01-01

338

Radiation Measurements on Magnesium Flames.  

National Technical Information Service (NTIS)

The radiation of a diffusely radiating Mg0 flame is characterized by four parameters, which are initially unknown: temperature, optical thickness, and dispersion (wavelength dependence) of the absorption and scattering coefficients. The black body tempera...

F. Roessler

1968-01-01

339

The Radiation Belt Storm Probes  

NASA Video Gallery

The Radiation Belt Storm Probe mission (RBSP) will explore the Van Allen Radiation Belts in the Earth's magnetosphere. The charge particles in these regions can be hazardous to both spacecraft and ...

340

Radiation protection during space flight.  

PubMed

The problem of ensuring space flight safety arises from conditions inherent to space flights and outer space and from the existing weight limitations of spacecraft. In estimating radiation hazard during space flights, three natural sources are considered: the Earth's radiation belt, solar radiation, and galactic radiation. This survey first describes the major sources of radiation hazard in outer space with emphasis on those source parameters directly related to shielding manned spacecraft. Then, the current status of the safety criteria used in the shielding calculations is discussed. The rest of the survey is devoted to the rationale for spacecraft radiation shielding calculations. The recently completed long-term space flights indicate the reliability of the radiation safety measures used for the near-Earth space exploration. While planning long-term interplanetary flights, it is necessary to solve a number of complicated technological problems related to the radiation protection of the crew. PMID:6318715

Kovalev, E E

1983-12-01

341

Course on the Synchrotron Radiation.  

National Technical Information Service (NTIS)

The physical concepts on the synchrotron radiation and its utilization in several branches of science are presented in four main points, e.g.; a general introduction on the synchrotron radiation and electron lasers; experiments on ondulator and electron l...

Y. Petroff

1983-01-01

342

Radiation Enteritis PDQ Spanish Redirect  

Cancer.gov

Radiation Enteritis PDQ Spanish Redirect El sumario de informacin del PDQ Enteritis por radiacin ha sido incorporado al sumario de informacin Complicaciones gastrointestinales. Para proseguir utilice unos de los siguientes enlaces.(The Radiation Enteritis

343

Simple device measures solar radiation  

NASA Technical Reports Server (NTRS)

Simple inexpensive thermometer, insolated from surroundings by transparent glass or plastic encasement, measures intensities of solar radiation, or radiation from other sources such as furnaces or ovens. Unit can be further modified to accomplish readings from remote locations.

Humphries, W. R.

1977-01-01

344

Biomarkers for human radiation exposure.  

PubMed

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

Chaudhry, M Ahmad

2008-09-01

345

Radiation Therapy for Testicular Cancer  

MedlinePLUS

... testicular cancer Next Topic Chemotherapy for testicular cancer Radiation therapy for testicular cancer This treatment uses high- ... cells or slow their growth. In testicular cancer, radiation is mainly used to kill cancer cells that ...

346

Conical electromagnetic radiation flux concentrator  

NASA Technical Reports Server (NTRS)

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.

Miller, E. R.

1972-01-01

347

Gamma radiation field intensity meter  

DOEpatents

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.

Thacker, Louis H. (Knoxville, TN)

1995-01-01

348

Gamma radiation field intensity meter  

DOEpatents

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.

Thacker, Louis H. (Knoxville, TN)

1994-01-01

349

Graphite-Fiber Heat Radiators  

NASA Technical Reports Server (NTRS)

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.

Phillips, Wayne M.

1995-01-01

350

Coherence and the radiation laws  

Microsoft Academic Search

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

H. P. Baltes; Zentrale Forschung; LGZ Landis

1977-01-01

351

Solar radiation statistics for Iran  

Microsoft Academic Search

Various prediction methods for calculating the mean monthly solar radiation parameters are examined. A suitable method is proposed for predicting the mean monthly values of direct, diffuse, and total solar radiation at different locations in Iran. This method is based on the assumption that the direct and diffuse components of solar radiation are primarily functions of solar zenith angle and

M DANESHYAR

1978-01-01

352

Video Display Terminals: Radiation Issues.  

ERIC Educational Resources Information Center

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)

Murray, William E.

1985-01-01

353

Self Indicating Radiation Alert Dosimeter.  

National Technical Information Service (NTIS)

Described as a self-indicating instant radiation dosimeter for monitoring high energy radiations, such as X-ray. The dosimeter contains a radiation sensitive, color changing, indicating composition, e.g., a diacetylene (R--C=C--C=C--R', where R and R' are...

G. N. Patel

2004-01-01

354

Material Effectiveness for Radiation Shielding  

NASA Technical Reports Server (NTRS)

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

2003-01-01

355

Meson Production and Space Radiation  

Microsoft Academic Search

Protecting astronauts from the harmful effects of space radiation is an important priority for long duration space flight. The National Council on Radiation Protection (NCRP) has recently recommended that pion and other mesons should be included in space radiation transport codes, especially in connection with the Martian atmosphere. In an interesting accident of nature, the galactic cosmic ray spectrum has

John Norbury; Steve Blattnig; Ryan Norman; Sukesh Aghara

2010-01-01

356

Radiation Effects: Core Project  

NASA Technical Reports Server (NTRS)

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.

Dicello, John F.

1999-01-01

357

Space Radiation Cancer Risks  

NASA Technical Reports Server (NTRS)

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.

Cucinotta, Francis A.

2007-01-01

358

Pregnancy and Radiation Protection  

NASA Astrophysics Data System (ADS)

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.

Gerogiannis, J.; Stefanoyiannis, A. P.

2010-01-01

359

Radiation dosimetry and biophysical models of space radiation effects  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

360

Diffuse UV Background Radiation  

NASA Astrophysics Data System (ADS)

The diffuse UV sky is expected to glow with significant amounts of starlight that is scattered from the interstellar dust. The albedo and scattering pattern of the dust in the ultraviolet are both well established, and are both fairly independent of wavelength from 912 to 3000 . We present 1943 Voyager spectra of the diffuse cosmic background radiation from 500 to 1200 , and we compare their brightnesses, and their distribution on the sky, to those observed (Murthy et al., ApJ 724, 1389, 2010) from the GALEX mission at longer wavelengths (1530 ). Significant differences appear, suggesting that background radiation components in addition to dust-scattered starlight may be present in both spectral regions.

Conn Henry, Richard; Murthy, J.

2012-01-01

361

Pathology of radiation myelopathy  

PubMed Central

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

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

1972-01-01

362

Radiation shielding composition  

DOEpatents

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.

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

2000-12-26

363

Blocking the Hawking radiation  

NASA Astrophysics Data System (ADS)

Some severe constraints on asymmetric dark matter are based on the scenario that certain types of weakly interacting massive particles can form mini-black holes inside neutron stars that can lead to their destruction. A crucial element for the realization of this scenario is that the black hole grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star.

Autzen, Martin; Kouvaris, Chris

2014-06-01

364

Electromagnetic Radiation: On Trial  

NSDL National Science Digital Library

This activity introduces students to the properties of electromagnetic radiation in a variety of ways. For example, they put the different types of the electromagnetic radiation on trial, selecting the judge, prosecutor, defense counsel, and jury, and learning about electromagnetic energy by arguing the pros and cons of each wavelength. During this activity, students are introduced to the general properties of electromagnetic waves, learn to analyze the relation between the specific properties of waves and their position in the electromagnetic spectrum, and discuss methods used to detect and analyze different waves. Students also learn about scientists whose work contributed to our understanding of electromagnetic energy. Students are encouraged to use an electronic bulletin board to communicate with each other, posting insights, ideas, evidence and questions on electromagnetic energy.

365

Genetic susceptibility to radiation  

NASA Astrophysics Data System (ADS)

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.

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

366

Ultraviolet radiation effects  

NASA Technical Reports Server (NTRS)

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.

Slemp, Wayne S.

1989-01-01

367

Innovations in radiation oncology  

SciTech Connect

The book contains reports of areas of growth in radiation oncology written for the practising radiation oncologist. Early chapters review conservative treatments that preserve the function and maintain or improve tumor control rates in breast, rectum, anus, head and neck, soft tissues and bones, and the eye. This is followed by a section dealing with extended field therapy encompassing total body irradiation, half body irradiation and systemic therapy with radionuclide-labelled antibodies. The potential roles of three new diagnostic imaging technologies (CT, MRI and PET) in radiotherapy are considered. Various modifications of treatment are reviewed, including hyperfractionation, accelerated treatment, accelerated hyperfractionation and neutron therapy. Also discussed is the clinical use of adjuvants to radiotherapy, such as radiosensitizers, cytotoxic drugs, interstitial and external hyperthermia and bone fixation in metastatic disease.

Withers, H.R.; Peters, L.J.

1988-01-01

368

Radiative B Decays  

SciTech Connect

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.

Bard, D.; /Imperial Coll., London

2011-11-23

369

Semiconductor radiation detector  

DOEpatents

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.

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

370

Relativistic coherent curvature radiation  

NASA Astrophysics Data System (ADS)

The objections raised by Kirk (1980) to the formalism describing the coherent curvature radiation of charged particles proposed by Benford and Buschauer (1977) are examined. It is shown that Kirk's results arise from qualitative calculations of boundary effects. Exact calculations are presented which show that the non-curvature radiation comes from the body of the plasma due to the longitudinal acceleration it is experiencing. In general, it is found that the introduction of moving plasma waves into relativistic systems will increase the emitted power and broaden the spectrum. These results are applicable to the coherent radio pulsar emission which may come from plasma columns moving along the curved magnetic fields lines of pulsar magnetospheres.

Benford, G.; Buschauer, R.

1983-02-01

371

Radiation shielding composition  

DOEpatents

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.

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

1998-01-01

372

Radiation shielding composition  

DOEpatents

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.

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

1998-07-28

373

Treatise on Acoustic Radiation. Volume 1.  

National Technical Information Service (NTIS)

Chapter headings: Fundamentals; Three dimensional harmonic radiation; The calculation of acoustic radiation fields by use of Green's functions; The calculation of acoustic radiation by use of Fourier expansions; Multipole analysis and radiation from surfa...

S. Hanish

1989-01-01

374

International Conference of Radiation Research (11th).  

National Technical Information Service (NTIS)

Topics discussed in the conference included the following: Radiation Physics, Radiation Chemistry and modelling--Radiation physics and dosimetry; Electron transfer in biological media; Radiation chemistry; Biophysical and biochemical modelling; Mechanisms...

1999-01-01

375

Ionizing and Non-Ionizing Radiation  

MedlinePLUS

... Decay Modes Radiation has a wide range of energies that form the electromagnetic spectrum (illustrated below). The ... ionizing radiation ionizing radiation Radiation that has enough energy to move around atoms in a molecule or ...

376

Role of Radiation in Polymer Chemistry.  

National Technical Information Service (NTIS)

The very important role which polymer chemistry plays in radiation technology is discussed. The present status of radiation processing and the radiation sources that are used by industry are described. The process by which ionising radiation interacts wit...

T. A. Du Plessis

1977-01-01

377

Provisional standards of radiation safety during flights  

NASA Technical Reports Server (NTRS)

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.

1977-01-01

378

Nuclear Radiation and the Properties of Concrete.  

National Technical Information Service (NTIS)

Concrete is used for structures in which the concrete is exposed to nuclear radiation. Exposure to nuclear radiation may affect the properties of concrete. The report mentions the types of nuclear radiation while radiation damage in concrete is discussed....

M. F. Kaplan

1983-01-01

379

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, ...

380

Structure in Radiative Shocks  

NASA Astrophysics Data System (ADS)

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.

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

2008-05-01

381

Ionizing radiation during pregnancy.  

PubMed Central

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

Ratnapalan, Savithiri; Bona, Nicole; Koren, Gideon

2003-01-01

382

Supersymmetrization of radiation damping  

NASA Astrophysics Data System (ADS)

We construct a supersymmetrized version of the model to the radiation damping introduced by the present authors (Mendes, Neves, Oliveira and Takakura 2005 Preprint hep-th/0503135). We discuss its symmetries and the corresponding conserved Noether charges. It is shown that this supersymmetric version provides a supersymmetric generalization of the Galilei algebra of the model. We have shown that the supersymmetric action can be split into dynamically independent external and internal sectors.

Mendes, A. C. R.; Neves, C.; Oliveira, W.; Takakura, F. I.

2005-10-01

383

Solar Radiation Resource Information  

NSDL National Science Digital Library

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

2012-10-15

384

Ultraviolet radiation screening compounds  

Microsoft Academic Search

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

CHARLES S. COCKELL; JOHN KNOWLAND

1988-01-01

385

Radiative interactions in nonequilibrium flows  

NASA Technical Reports Server (NTRS)

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.

Tiwari, S. N.; Chandrasekhar, R.

1992-01-01

386

Radiation belt probes launched  

NASA Astrophysics Data System (ADS)

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.

Showstack, Randy

2012-09-01

387

Intraocular radiation blocking.  

PubMed

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

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

1990-09-01

388

Community Radiation Monitoring Program  

SciTech Connect

The Community Radiation Monitoring Program began its ninth year in the summer of 1989, continuing as an essential portion of the Environmental Protection Agency's long-standing off-site monitoring effort. It is a cooperative venture between the Department of Energy (DOE), the Environmental Protection Agency (EPA), the University of Utah (U of U), and the Desert Research Institute (DRI) of the University of Nevada System. The objectives of the program include enhancing and augmenting the collection of environmental radiation data at selected sites around the Nevada Test Site (NTS), increasing public awareness of that effort, and involving, in as many ways as possible, the residents of the off-site area in these and other areas related to testing nuclear weapons. This understanding and improved communication is fostered by hiring residents of the communities where the monitoring stations are located as program representatives, presenting public education forums in those and other communities, disseminating information on radiation monitoring and related subjects, and developing and maintaining contacts with local citizens and elected officials in the off-site areas. 8 refs., 4 figs., 4 tabs.

Lucas, R.P. Jr.; Cooper, E.N.; McArthur, R.D.

1990-05-01

389

[Radiation-induced neuropathy].  

PubMed

Radiation-induced neuropathy is commonly observed among oncological patients. Radiation can affect the nervous tissue directly or indirectly by inducing vasculopathy or dysfunction of internal organs. Symptoms may be mild and reversible (e.g., pain, nausea, vomiting, fever, drowsiness, fatigue, paresthesia) or life-threatening (cerebral oedema, increased intracranial pressure, seizures). Such complications are clinically divided into peripheral (plexopathies, neuropathies of spinal and cranial nerves) and central neuropathy (myelopathy, encephalopathy, cognitive impairment). The degree of neuronal damages primarily depends on the total and fractional radiation dose and applied therapeutic methods. The conformal and megavoltage radiotherapy seems to be the safeties ones. Diagnostic protocol includes physical examination, imaging (in particular magnetic resonance), electromyography, nerve conduction study and sometimes histological examination. Prevention and early detection of neurological complications are necessary in order to prevent a permanent dysfunction of the nervous system. Presently their treatment is mostly symptomatic, but in same cases a surgical intervention is required. An experimental and clinical data indicates some effectiveness of different neuroprotective agents (e.g. anticoagulants, vitamin E, hyperbaric oxygen, pentoxifylline, bevacizumab, methylphenidate, donepezil), which should be administered before and/or during radiotherapy. PMID:24490474

Kolak, Agnieszka; Staros?awska, Elzbieta; Kieszko, Dariusz; Cisek, Pawe?; Patyra, Krzysztof Ireneusz; Surdyka, Dariusz; Dobrzy?ska-Rutkowska, Aneta; ?opacka-Szatan, Karolina; Burdan, Franciszek

2013-12-01

390

[Problems after radiation therapy].  

PubMed

The rate of severe late adverse effects has decreased with the highly accurate administration of radiation therapy; however, the total number of patients who suffer from late effects has not decreased because of the increased total number of patients and better survival rates. Late adverse effects, occurring more than a few months after irradiation, include the extension and collapse of capillaries, thickening of the basement membrane, and scarring of tissue due to loss of peripheral vessels. The main causes of these late effects are the loss of stromal cells and vascular injury. This is in contrast to early reactions, which occur mainly due to the reorganization of slow-growing non-stem cell renewal systems such as the lung, kidney, heart, and central nervous system. In addition, the patient's quality of life is impaired if acute reactions such as mouth or skin dryness are not alleviated. Most adverse effects are radiation dose dependent, and the thresholds differ according to the radiosensitivity of each organ. These reactions occur with a latency period of a few months to more than 10 years. Understanding the clinical and pathological status, through discussion with radiation oncologists, is the essential first step. Some of the late effects have no effective treatment, but others can be treated by steroids or hyperbaric oxygen therapy. An appropriate decision is important. PMID:24423950

Karasawa, Kumiko

2014-01-01

391

Advances in radiation grafting  

NASA Astrophysics Data System (ADS)

Graft copolymerization is an attractive means for modifying base polymers because grafting frequently results in the superposition of properties relating to the backbone and pendent chains. Among the various methods for initiating the grafting reaction, ionizing radiation is the cleanest and most versatile method of grafting available. Ion-exchange membranes play an important role in modern technology, especially in separation and purification of materials. The search for improved membrane composition has considered almost every available polymeric material because of its great practical importance. Grafting of polymers with a mixture of monomers is important since different types of chains containing different functional groups are included. A great deal is focused on the waste treatment of heavy and toxic metals from wastewater because of the severe problems of environmental pollution. Functionalized polymers suitable for metal adsorption with their reactive functional groups such as carboxylic and pyridine groups suitable for waste treatment were prepared by radiation grafting method. More reactive chelating groups were further introduced to the grafted copolymer through its functional groups by chemical treatments with suitable reagents. The advances of radiation grafting and possible uses are briefly discussed.

Hegazy, El-Sayed A.; AbdEl-Rehim, H. A.; Kamal, H.; Kandeel, K. A.

2001-12-01

392

Method for microbeam radiation therapy  

DOEpatents

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.

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

1994-01-01

393

Method for microbeam radiation therapy  

DOEpatents

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

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

1994-08-16

394

Utrecht Radiative Transfer Courses  

NASA Astrophysics Data System (ADS)

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.

Rutten, R. J.

2003-01-01

395

Zero Point Energy: Planck Radiation Law  

Microsoft Academic Search

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

H. Vic Dannon

396

Non-LTE Radiation Transport in High Radiation Plasmas  

SciTech Connect

A primary goal of numerical radiation transport is obtaining a self-consistent solution for both the radiation field and plasma properties. Obtaining such a solution requires consideration of the coupling between the radiation and the plasma. The different characteristics of this coupling for continuum and line radiation have resulted in two separate sub-disciplines of radiation transport with distinct emphases and computational techniques. LTE radiation transfer focuses on energy transport and exchange through broadband radiation, primarily affecting temperature and ionization balance. Non-LTE line transfer focuses on narrowband radiation and the response of individual level populations, primarily affecting spectral properties. Many high energy density applications, particularly those with high-Z materials, incorporate characteristics of both these regimes. Applications with large radiation fields including strong line components require a non-LTE broadband treatment of energy transport and exchange. We discuss these issues and present a radiation transport treatment which combines features of both types of approaches by explicitly incorporating the dependence of material properties on both temperature and radiation fields. The additional terms generated by the radiation dependence do not change the character of the system of equations and can easily be added to a numerical transport implementation. A numerical example from a Z-pinch application demonstrates that this method improves both the stability and convergence of the calculations. The information needed to characterize the material response to radiation is closely related to that used by the Linear Response Matrix (LRM) approach to near-LTE simulation, and we investigate the use of the LRM for these calculations.

Scott, H A

2005-01-07

397

Radiation shielding quality assurance  

NASA Astrophysics Data System (ADS)

For the radiation shielding quality assurance, the validity and reliability of the neutron transport code MCNP, which is now one of the most widely used radiation shielding analysis codes, were checked with lot of benchmark experiments. And also as a practical example, follows were performed in this thesis. One integral neutron transport experiment to measure the effect of neutron streaming in iron and void was performed with Dog-Legged Void Assembly in Knolls Atomic Power Laboratory in 1991. Neutron flux was measured six different places with the methane detectors and a BF-3 detector. The main purpose of the measurements was to provide benchmark against which various neutron transport calculation tools could be compared. Those data were used in verification of Monte Carlo Neutron & Photon Transport Code, MCNP, with the modeling for that. Experimental results and calculation results were compared in both ways, as the total integrated value of neutron fluxes along neutron energy range from 10 KeV to 2 MeV and as the neutron spectrum along with neutron energy range. Both results are well matched with the statistical error +/-20%. MCNP results were also compared with those of TORT, a three dimensional discrete ordinates code which was developed by Oak Ridge National Laboratory. MCNP results are superior to the TORT results at all detector places except one. This means that MCNP is proved as a very powerful tool for the analysis of neutron transport through iron & air and further it could be used as a powerful tool for the radiation shielding analysis. For one application of the analysis of variance (ANOVA) to neutron and gamma transport problems, uncertainties for the calculated values of critical K were evaluated as in the ANOVA on statistical data.

Um, Dallsun

398

Dynamic hohlraum radiation hydrodynamics  

NASA Astrophysics Data System (ADS)

Z-pinch dynamic hohlraums are a promising indirect-drive inertial confinement fusion approach. Comparison of multiple experimental methods with integrated Z-pinch/hohlraum/capsule computer simulations builds understanding of the hohlraum interior conditions. Time-resolved x-ray images determine the motion of the radiating shock that heats the hohlraum as it propagates toward the hohlraum axis. The images also measure the radius of radiation-driven capsules as they implode. Dynamic hohlraum LASNEX [G. Zimmerman and W. Kruer, Comments Plasma Phys. Control. Fusion 2, 85 (1975)] simulations are found to overpredict the shock velocity by ~20-40%, but simulated capsule implosion trajectories agree reasonably well with the data. Measurements of the capsule implosion core conditions using time- and space-resolved Ar tracer x-ray spectroscopy and the fusion neutron yield provide additional tests of the integrated hohlraum-implosion system understanding. The neutron yield in the highest performing CH capsule implosions is ~20-30% of the yield calculated with unperturbed 2D LASNEX simulations. The emissivity-averaged electron temperature and density peak at approximately 900 eV and 41023 cm-3, respectively. Synthetic spectra produced by postprocessing 1D LASNEX capsule implosion simulations possess spectral features from H-like and He-like Ar that are similar in duration to the measured spectra. However, the simulation emissivity-averaged density peaks at a value that is four times lower than the experiment, while the temperature is approximately 1.6 times higher. The agreement with the capsule trajectory measurements and the ability to design capsule implosions that routinely produce implosion cores hot and dense enough to emit fusion neutrons and Ar spectra are evidence for a respectable degree of dynamic hohlraum understanding. The hohlraum shock velocity and implosion core discrepancies imply that calculations of the hohlraum radiation driving capsule implosions require further refinement.

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

2006-05-01

399

Dynamic hohlraum radiation hydrodynamics  

SciTech Connect

Z-pinch dynamic hohlraums are a promising indirect-drive inertial confinement fusion approach. Comparison of multiple experimental methods with integrated Z-pinch/hohlraum/capsule computer simulations builds understanding of the hohlraum interior conditions. Time-resolved x-ray images determine the motion of the radiating shock that heats the hohlraum as it propagates toward the hohlraum axis. The images also measure the radius of radiation-driven capsules as they implode. Dynamic hohlraum LASNEX [G. Zimmerman and W. Kruer, Comments Plasma Phys. Control. Fusion 2, 85 (1975)] simulations are found to overpredict the shock velocity by {approx}20-40%, but simulated capsule implosion trajectories agree reasonably well with the data. Measurements of the capsule implosion core conditions using time- and space-resolved Ar tracer x-ray spectroscopy and the fusion neutron yield provide additional tests of the integrated hohlraum-implosion system understanding. The neutron yield in the highest performing CH capsule implosions is {approx}20-30% of the yield calculated with unperturbed 2D LASNEX simulations. The emissivity-averaged electron temperature and density peak at approximately 900 eV and 4x10{sup 23} cm{sup -3}, respectively. Synthetic spectra produced by postprocessing 1D LASNEX capsule implosion simulations possess spectral features from H-like and He-like Ar that are similar in duration to the measured spectra. However, the simulation emissivity-averaged density peaks at a value that is four times lower than the experiment, while the temperature is approximately 1.6 times higher. The agreement with the capsule trajectory measurements and the ability to design capsule implosions that routinely produce implosion cores hot and dense enough to emit fusion neutrons and Ar spectra are evidence for a respectable degree of dynamic hohlraum understanding. The hohlraum shock velocity and implosion core discrepancies imply that calculations of the hohlraum radiation driving capsule implosions require further refinement.

Bailey, J.E.; Chandler, G.A.; Slutz, S.A.; Rochau, G.A.; Cooper, G.; Lake, P.W.; Leeper, R.J.; Lemke, R.; Mehlhorn, T.A.; Nash, T.J.; Nielsen, D.S.; Peterson, K.L.; Ruiz, C.L.; Varnum, W. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1196 (United States); Mancini, R.C.; Buris-Mog, T.J. [University of Nevada, Reno, Nevada 89557 (United States); Bump, M.; Dunham, G.; Moore, T.C. [K-tech Corporation, Albuquerque, New Mexico 87185 (United States); Golovkin, I. [Prism Computational Sciences, Madison, Wisconsin 53703 (United States)] (and others)

2006-05-15

400

Management of Radiation Proctitis.  

PubMed

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

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

2013-03-11

401

Radiative Gaunt factors  

NASA Astrophysics Data System (ADS)

Numerical methods for the evaluation of radiative Gaunt factors for complex ions, and for the calculation of the principal integrals over the Gaunt factors relevant to plasma spectroscopy, are presented. The present techniques are suitable for the computation of intermediate accuracy results for large numbers of ions over extended parameter ranges, and they cover bound-bound, bound-free, and free-free cases in both hydrogenic and nonhydrogenic approximations. The results demonstrate the reliability of the numerical methods and their advantages over the methods of Peach (1965, 1967) and Burgess and Seaton (1960). Significant differences from hydrogenic results at low and moderate z values are pointed out.

Burgess, Alan; Summers, Hugh P.

1987-05-01

402

Management of radiation wounds.  

PubMed

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

Iyer, Subramania; Balasubramanian, Deepak

2012-05-01

403

[Radiation induced carcinogenesis].  

PubMed

Intense research after Hiroshima and Nagasaki atomic bomb (A-bomb) tragedy and Chernobyl nuclear plant accident revealed that ionizing radiation (IR) more than 100 mSv induces cancers that are indistinguishable from sporadic tumors. It remains controversial whether low dose IR (less than 100 mSv) is oncogenic or not. Among IR-induced malignancies, leukemia (A-bomb) and thyroid cancers (Chernobyl), in which chimeric(fusion) oncogenes formed by chromosome translocations play a critical role, develop with relatively short latency. All other cancers develop after long latency. Age-related epigenetic changes, as well as additional genetic alterations, would contribute to IR-induced carcinogenesis. PMID:22514919

Inaba, Toshiya

2012-03-01

404

Primary Radiation Damage Formation  

SciTech Connect

The physical processes that give rise to changes in the microstructure, and the physical and mechanical properties of materials exposed to energetic particles are initiated by essentially elastic collisions between atoms in what has been called an atomic displacement cascade. The formation and evolution of this primary radiation damage mechanism are described to provide an overview of how stable defects are formed by displacement cascades, as well as the nature and morphology of the defects themselves. The impact of the primary variables cascade energy and irradiation temperature are discussed, along with a range of secondary factors that can influence damage formation.

Stoller, Roger E [ORNL

2012-01-01

405

Radiation: Balancing the record  

SciTech Connect

This article reviews the radioactivity experiments performed on humans during the cold war, and examines the ethics of the experiments. The radiation experiments can be broadly classified into three groups: researchers knowingly inflicted potential harm, using methods questionable even by the then-current standards; the investigations involved good work by any standards with appropriate safeguards taken; and a third group which falls between the other two, the experiments provided useful information but had ethical flaws. The article also examines the experiments in the light of changing knowledge and moral standards.

Mann, C.C.

1994-01-28

406

Radiation imaging apparatus  

DOEpatents

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.

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

1983-07-26

407

Radiation imaging apparatus  

DOEpatents

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.

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

1983-01-01

408

LDEF satellite radiation study  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

409

Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture  

SciTech Connect

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.

Scott Wilde, Raymond Keegan

2008-07-01

410

Relativistic Radiative Winds from an Accretion Disk under Radiation Drag  

NASA Astrophysics Data System (ADS)

We examine the steady relativistic winds which are emanating from a luminous accretion disk and driven by disk radiation fields under the influence of radiation drag. For wind flows we use a streamline approach where the dynamical equations are expressed by the streamline coordinates, and a cold approximation where the pressure-gradient force is ignored. For radiation fields, on the other hand, we use a near-disk approximation where the radiation stress-energy tensors are evaluated from the disk region just below the flows. The streamlines may widen, since the wind flows gain angular momentum from the disk radiation field just below them. The wind terminal speed is smaller than the Icke's magic speed of (4-sqrt {7})c/3 ~ 0.45c, because the streamlines are generally inclined, and therefore the radiative force is smaller than in the case of vertical streamlines. The conditions that the radiative wind blows are obtained for the control parameters: the radius of the wind base and the normalized disk luminosity. The radiative wind can blow from the inner region (r_0 ~ 5--8 r_g) if the disk is sufficiently luminous. %A collimation effect of winds by radiation drag, %which is found in the previous work (Tajima and Fukue 1995), %is also confirmed. %Configuration instability of streamlines is found. We also briefly discuss pure electron-positron pair winds, where the acceleration takes place very close to the disk.

Fukue, Jun

1996-08-01

411

Ionizing radiation: mechanisms and therapeutics.  

PubMed

Abstract While chemotherapy and radiation therapy have been integral components of cancer management for decades, the issues of local recurrence, clinical resistance, and toxicities resulting from these treatment modalities have increased the interest in novel therapeutic approaches that could attenuate tumor progression and prevent recurrences. This Forum highlights current research focused on elucidation of the mechanisms of response to radiation treatment and the development of out-of-the-box therapeutic strategies for cancer treatment with radiation. Experts in the field of radiation research contribute with review articles describing the current knowledge on DNA damage response mechanisms, regulation of signaling involved in the DNA damage response by miRNA, the function of tumor hypoxia in tumor response to radiation, and the role of stem cells in protection of normal tissue against radiation damage. Antioxid. Redox Signal. 21, 218-220. PMID:24702164

Furdui, Cristina M

2014-07-10

412

RADIATIVE RAYLEIGH-TAYLOR INSTABILITIES  

SciTech Connect

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.

Jacquet, Emmanuel [Laboratoire de Mineralogie et Cosmochimie de Museum (LMCM), CNRS and Museum National d'Histoire Naturelle, UMR 7202, 57 rue Cuvier, 75005 Paris (France); Krumholz, Mark R., E-mail: ejacquet@mnhn.fr, E-mail: krumholz@ucolick.org [Department of Astronomy, University of California, Santa Cruz, CA 95064 (United States)

2011-04-01

413

Gravitational scattering of electromagnetic radiation  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

414

Biologically efficient solar radiation  

PubMed Central

Solar ultraviolet (UV) radiation is the main source of vitamin D production and is also the most important environmental risk factor for cutaneous malignant melanoma (CMM) development. In the present study the relationships between daily or seasonal UV radiation doses and vitamin D status, dietary vitamin D intake and CMM incidence rates at different geographical latitudes were investigated. North-South gradients of 25-hydroxyvitamin D (25(OH)D) generation and CMM induction were calculated, based on known action spectra, and compared with measured vitamin D levels and incidence rates of CMM. The relative roles of UVA and UVB in CMM induction are discussed. Latitudinal dependencies of serum 25(OH)D levels and CMM incidence rates can only partly be explained by ambient UV doses. The UV sensitivity is different among populations with different skin color. This is well known for CMM, but seems also to be true for vitamin D status. The fact that UV-induced vitamin D may reduce the risk of CMM complicates the discussion. To some extent high dietary vitamin D intake seems to compensate low UV doses.

Grigalavicius, Mantas; Juzeniene, Asta; Baturaite, Zivile; Dahlback, Arne; Moan, Johan

2013-01-01

415

Chandra Radiation Environment Modeling  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

416

Genetic susceptibility to radiation  

NASA Astrophysics Data System (ADS)

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.

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

417

Management of radiation ulcers  

SciTech Connect

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.

Shack, R.B.

1982-12-01

418

All field simultaneous radiation therapy  

US Patent & Trademark Office Database

This invention describes a system for generating multiple simultaneous tunable electron and photon beams and monochromatic x-rays for all field simultaneous radiation therapy (AFSRT), tumor specific AFSRT and screening for concealed elements worn on to the body or contained in a container. Inverse Compton scattering renders variable energy spent electron and tunable monochromatic x-rays. It's spent electron beam is reused for radiation with electron beam or to generate photon beam. Tumor specific radiation with Auger transformation radiation is facilitated by exposing high affinity tumor bound heavy elements with external monochromatic x-rays. Heavy elements like directly iodinated steroid molecule that has high affinity binding to estrogen receptor in breast cancer and to iodinated testosterone in prostate cancer or with directly implanted nanoparticles into the tumor are exposed with tuned external monochromatic x-rays for tumor specific radiation therapy. Likewise, screening element's atom's k, l, m, n shell specific Auger transformation radiation generated by its exposure to external monochromatic x-rays is used to screen for concealed objects. Multiple beam segments from a beam storage ring or from octagonal beam lines are simultaneously switched on for simultaneous radiation with multiple beams. The beam on time to expose a tumor or an object is only a few seconds. It also facilitates breathing synchronized radiation therapy. The intensity modulated radiation therapy (IMRT) and intensity modulated screening for concealed objects (IMSFCO) is rendered by varying beam intensities of multiple simultaneous beams. The isocentric additive high dose rate from simultaneously converging multiple beams, the concomitant hyperthermia and chemotherapy and tumor specific radiation therapy and the AFSRT's very low radiation to the normal tissue all are used to treat a tumor with lower radiation dose and to treat a radioresistant and multiple times recurrent tumors that heave no other alternative treatments.

2012-05-08

419

Boltzmann factor and Hawking radiation  

NASA Astrophysics Data System (ADS)

Hawking radiation has thermal spectrum corresponding to the temperature TH=(8, where M is the mass (energy) of the black hole. Corrections to the Hawking radiation spectrum were discovered by Kraus and Wilczek (1995) and Parikh and Wilczek (2000). Here I show that these corrections follow directly from the basic principles of thermodynamics and statistical mechanics. In essence, it is the Boltzmann factor that ought to be corrected; corrections to the Hawking (or any other) radiation spectrum then follow necessarily.

Ryskin, Gregory

2014-06-01

420

Radiation effects in nanoelectronic elements  

SciTech Connect

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.

Gromov, D. V.; Elesin, V. V.; Petrov, G. V. [Moscow Engineering Physics Institute (National Research Nuclear University) (Russian Federation); Bobrinetskii, I. I.; Nevolin, V. K., E-mail: vkn@miee.ru [Moscow Institute of Electronic Technology (Technical University) (Russian Federation)

2010-12-15

421

Biomarkers for human radiation exposure  

Microsoft Academic Search

There is a concern over the potential use of radioactive isotopes as a weapon of terror. The detonation of a radiation dispersal\\u000a device, the so-called dirty bomb can lead to public panic. In order to estimate risks associated with radiation exposure,\\u000a it is important to understand the biological effects of radiation exposure. Based on this knowledge, biomarkers to monitor\\u000a potentially

M. Ahmad Chaudhry

2008-01-01

422

Trends in Emissions of Ozone-Depleting Substances, Ozone Layer Recovery, and Implications for Ultraviolet Radiation Exposure. Synthesis and Assessment Product 2.4.  

National Technical Information Service (NTIS)

Depletion of the stratospheric ozone layer by human-produced ozone depleting substances has been recognized as a global environmental issue for more than three decades, and the international effort to address the issue via the United Nations Montreal Prot...

2004-01-01

423

Space Radiation and Bone Loss.  

PubMed

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

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

2011-01-01

424

Scintillator Waveguide For Sensing Radiation  

DOEpatents

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.

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

2003-04-22

425

Enhanced radiation resistant fiber optics  

DOEpatents

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.

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

1993-01-01

426

Operational Aspects of Space Radiation  

NASA Technical Reports Server (NTRS)

In this session, Session FA4, the discussion focuses on the following topics: Solar Particle Events and the International Space Station; Radiation Environment on Mir and ISS Orbits During the Solar Cycle; New approach to Radiation Risk Assessment; An Industrial Method to Predict Major Solar Flares for a Better Protection of Human Beings in Space; Description of the Space Radiation Control System for the Russian Segment of ISS; Orbit Selection and Its Impact on Radiation Warning Architecture for a Human Mission to Mars; and Space Nuclear Power - Technology, Policy and Risk Considerations in Human Missions to Mars.

1997-01-01

427

MONTHLY RADIATION SURVEY TECHNICAL BASIS  

SciTech Connect

This document details the technical basis, analysis, and justification for rescheduling radiation surveys in occupied radiation areas within Tank Farm Facilities from a weekly to a monthly frequency. The purpose of this document is to provide the technical basis, analysis, and justification for seeking a technical equivalency determination (TED) to TFRCM Article 552.1.b. The scope of this document limited to radiation surveys in occupied areas, no equivalency is being sought for high radiation area boundary surveys, radiological buffer area surveys, active ventilations surveys, or work coverage surveys.

BROWN, R.L.

2003-06-13

428

Epidemiology of accidental radiation exposures.  

PubMed Central

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.

Cardis, E

1996-01-01

429

Laser-driven Undulator Radiation  

SciTech Connect

An electromagnetic wake of infra-red radiation can be generated by an intense laser pulse, propagating through an underdense plasma in the presence of a magnetostactic undulator. As opposed to undulator radiation from a charged bunch propagating in a periodic magnetic field, here radiation comes from almost stationary plasma electrons, ponderomotively pushed by the laser pulse. Such laser-driven undulator radiation can be produced by either a single ultra-short pulse, or by two frequency-detuned long pulses. In the latter case the difference frequency is efficiently produced by quasi phase-matched optical heterodyning.

Fisch, N.J.; Shvets, G.; and Pukhov, A.

1998-08-01

430

Radiation Environments for Lunar Programs  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

431

Therapeutic Applications of Ionizing Radiations  

NASA Astrophysics Data System (ADS)

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.

Snchez-Santos, Mara Elena

432

Cardiac imaging: does radiation matter?  

PubMed Central

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

Einstein, Andrew J.; Knuuti, Juhani

2012-01-01

433

Coherent tunable far infrared radiation  

NASA Technical Reports Server (NTRS)

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.

Jennings, D. A.

1989-01-01

434

Elemental bio-imaging of thorium, uranium, and plutonium in tissues from occupationally exposed former nuclear workers.  

PubMed

Internal exposure from naturally occurring radionuclides (including the inhaled long-lived actinides (232)Th and (238)U) is a component of the ubiquitous background radiation dose (National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States; NCRP Report No. 160; NCRP: Bethesda, MD, 2009). It is of interest to compare the concentration distribution of these natural alpha-emitters in the lungs and respiratory lymph nodes with those resulting from occupational exposure, including exposure to anthropogenic plutonium and depleted and enriched uranium. This study examines the application of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) to quantifying and visualizing the mass distribution of uranium and thorium isotopes from both occupational and natural background exposure in human respiratory tissues and, for the first time, extends this application to the direct imaging of plutonium isotopes. Sections of lymphatic and lung tissues taken from deceased former nuclear workers with a known history of occupational exposure to specific actinide elements (uranium, plutonium, or americium) were analyzed by LA-ICPMS. Using a previously developed LA-ICPMS protocol for elemental bio-imaging of trace elements in human tissue and a new software tool, we generated images of thorium ((232)Th), uranium ((235)U and (238)U), and plutonium ((239)Pu and (240)Pu) mass distributions in sections of tissue. We used a laboratory-produced matrix-matched standard to quantify the (232)Th, (235)U, and (238)U concentrations. The plutonium isotopes (239)Pu and (240)Pu were detected by LA-ICPMS in 65 mum diameter localized regions of both a paratracheal lymph node and a sample of lung tissue from a person who was occupationally exposed to refractory plutonium (plutonium dioxide). The average (overall) (239)Pu concentration in the lymph node was 39.2 ng/g, measured by high purity germanium (HPGe) gamma-spectrometry (Lynch, T. P.; Tolmachev, S. Y.; James, A. C. Radiat. Prot. Dosim. 2009, 134, 94-101). Localized mass concentrations of thorium ((232)Th) and uranium ((238)U) in lymph node tissue from a person not occupationally exposed to these elements (chronic natural background inhalation exposure) ranged up to 400 and 375 ng/g, respectively. In lung samples of occupationally nonexposed to thorium and uranium workers, (232)Th and (238)U concentrations ranged up to 200 and 170 ng/g, respectively. In a person occupationally exposed to air-oxidized uranium metal (Adley, F. E.; Gill, W. E.; Scott, R. H. Study of atmospheric contaminiation in the melt plant buiding. HW-23352(Rev.); United States Atomic Energy Commission: Oakridge, TN, 1952, p 1-97), the maximum (235)U and (238)U isotopic mass concentrations in a lymph node, measured at higher resolution (with a 30 mum laser spot diameter), were 70 and 8500 ng/g, respectively. The ratio of these simultaneously measured mass concentrations signifies natural uranium. The current technique was not sufficiently sensitive, even with a 65 mum laser spot diameter, to detect (241)Am (at an overall tissue concentration of 0.024 ng/g, i.e., 3 Bq/g). PMID:20218581

Hare, Dominic; Tolmachev, Sergei; James, Anthony; Bishop, David; Austin, Christine; Fryer, Fred; Doble, Philip

2010-04-15

435

Induction of radioresistance in Escherichia coli. [X radiation, uv radiation  

Microsoft Academic Search

The effect of prior treatment by inducing agents on the radioresistance of cells of Escherichia coli has been studied. In order to separate the induction process from the radiation-damage process, cells were first treated with inducing agents such as ultraviolet light, ionizing radiation, or nalidixic acid, allowed to become induced by incubation for 50 min and then given rifampin to

E. C. Pollard; P. M. Achey

1975-01-01

436

Uniqueness of the radiation amplitude zero in radiative W decay.  

National Technical Information Service (NTIS)

It is well known that a radiation amplitude zero (RAZ) occurs in radiative W decay (W(sup (minus)) (yields) d(bar u)(gamma) or W(sup (minus)) (yields) e(bar (nu))(gamma)). This RAZ can be used to measure the magnetic moment of the W boson to see if it has...

M. A. Samuel M. Frank C. Hamzaoui D. Pouliot K. B. Samuel

1989-01-01

437

Using radiation risk for assessment of space radiation hazard  

NASA Astrophysics Data System (ADS)

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.

Petrov, V. M.

2011-05-01

438

Efficacy of radiation countermeasures depends on radiation quality.  

PubMed

The detonation of a nuclear weapon or a nuclear accident represent possible events with significant exposure to mixed neutron/?-radiation fields. Although radiation countermeasures generally have been studied in subjects exposed to pure photons (? or X rays), the mechanisms of injury of these low linear energy transfer (LET) radiations are different from those of high-LET radiation such as neutrons, and these differences may affect countermeasure efficacy. We compared 30-day survival in mice after varying doses of pure ? and mixed neutron/? (mixed field) radiation (MF, Dn/Dt = 0.65), and also examined peripheral blood cells, bone marrow cell reconstitution, and cytokine expression. Mixed-field-irradiated mice displayed prolonged defects in T-cell populations compared to mice irradiated with pure ? photons. In mouse survival assays, the growth factor granulocyte colony-stimulating factor (G-CSF) was effective as a (post-irradiation) mitigator against both ?-photons and mixed-field radiation, while the thrombopoietin (TPO) mimetic ALXN4100TPO was effective only against ? irradiation. The results indicate that radiation countermeasures should be tested against radiation qualities appropriate for specific scenarios before inclusion in response plans. PMID:22468705

Cary, Lynnette H; Ngudiankama, Barbara F; Salber, Rudolph E; Ledney, G David; Whitnall, Mark H

2012-05-01

439

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

Microsoft Academic Search

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

R. Facius; G. Reitz

2006-01-01

440

Slope effects on shortwave radiation components and net radiation  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

441

[Radiation therapy in thyroid cancer].  

PubMed

Anaplastic thyroid cancers represent 1-2% of all thyroid tumours and are of very poor prognosis even with multimodality treatment including external beam radiation therapy. Conversely, differentiated thyroid carcinomas (at least 80% of thyroid cancers) hamper good prognosis with surgery with or without radioiodine and there is hardly any room for external beam radiation therapy. Insular and medullar carcinomas have intermediary prognosis and are rarely irradiated. We aimed to update recommendations for external beam irradiation in these different clinical situations and put in light the benefits of new irradiations techniques. A search of the French and English literature was performed using the following keywords: thyroid carcinoma, anaplastic, chemoradiation, radiation therapy, surgery, histology and prognostic. Non-mutilating surgery (often limited to debulking) followed by systematic external beam radiation therapy is the standard of care in anaplastic thyroid cancers (hyperfractionated-accelerated radiation therapy with low-dose weekly doxorubicin with or without cisplatin if possible). Given anaplastic thyroid cancers' median survival of 10 months or less, neoadjuvant and adjuvant chemotherapy may also be discussed. Ten-year survival rates for patients with papillary, follicular and Hrthle-cell carcinomas are 93%, 85%, and 76%, respectively. Massive primary incompletely resected iodine-negative disease indicates external beam radiation therapy. Older age (45 or 60-year-old), poor-prognosis histological variants (including tall cell cancers) and insular cancers are increasingly reported as criteria for external beam radiation therapy. Massive extracapsular incompletely resected nodal medullary disease suggests external beam radiation therapy. Radiation therapy morbidity has been an important limitation. However, intensity modulated radiation therapy (IMRT) offers clear dosimetric advantages on tumour coverage and organ sparing, reducing late toxicities to less than 5%. The role of radiation therapy is evolving for anaplastic thyroid cancers using multimodal strategies and new chemotherapy molecules, and for differentiated cancers using minor criteria, such as histological variants, with IMRT becoming a standard of care. PMID:23763764

Sun, X S; Guevara, N; Fakhry, N; Sun, S-R; Marcy, P-Y; Santini, J; Bosset, J-F; Thariat, J

2013-06-01

442

Radiation protection and radiation recovery with essential metalloelement chelates  

SciTech Connect

This review presents the roles of some essential metalloelement-dependent enzymes in tissue maintenance and function, and their responses to radiation injury in accounting for radiation protection and recovery effects observed for nontoxic doses of essential metalloelement compounds. Effects of biochemicals including water undergoing bond radiolysis and the effects of free radicals derived from diatomic oxygen account for the acute and chronic aspects of radiation injury. Copper chelates have radiation protection and radiation recovery activities and cause rapid recovery of immunocompetency and recovery from radiation-induced histopathology. Mice treated with Cu(II){sub 2}(3,5-disopropylsalicy-late){sub 4}[Cu(II){sub 2}(3,5-DIPS){sub 4}] had increased survival and corresponding increases in numbers of myeloid and multipotential progenitor cells early after irradiation and earlier recovery of immune reactivity. Examination of radiation-induced histopathology in spleen, bone marrow, thymus, and small intestine also revealed Cu(II){sub 2}(3,5-DIPS){sub 4}-mediated rapid recovery of radiation-induced histopathology. Most recently, Fe, Mn, and Zn complexes have also been found to prevent death in lethally irradiated mice. These pharmacological effects of essential metalloelement chelates can be understood as due to facilitation of de novo synthesis of essential metalloelement-dependent enzymes which have roles in preventing the accumulation of pathological concentrations of oxygen radicals or repairing biochemical damage caused by radiation-induced bond homolysis. Essential metalloelement chelates offer a physiological approach to prevention and/or treatment of radiation injury. 97 refs., 5 figs., 1 tab.

Sorenson, J.R.J.; Soderberg, L.S.F.; Chang, L.W. [Univ. of Arkansas for Medical Sciences, Little Rock, AR (United States)

1995-12-01

443

Atmospheric Processes: Radiation  

NSDL National Science Digital Library

In this activity, students investigate how different surfaces absorb heat and apply their experience with the surfaces to interpret real-world situations. From this information, they come to understand that the physical characteristics of a surface have a powerful effect on the way that surface absorbs and releases heat from the sun and that radiation of heat occurs without the involvement of a physical object. The student guide provides an overall description of the activity, a list of materials, the procedure, and observations and questions. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

444

The IRAS radiation environment  

NASA Technical Reports Server (NTRS)

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.

Stassinopoulos, E. G.

1978-01-01

445

Radiation and photochemistry section  

SciTech Connect

The highlights of this past year in the Radiation and Photochemistry Section at Argonne include: (1) picosecond optical studies of radical cations and excited states produced in hydrocarbon radiolysis provided the first kinetic measurements of ion transformation and production of triplet and singlet excited states by ion recombination. (2) studies of radical cations of alkyl-substituted amines and sulfides provided insights into ion-molecule reactions of radical cations in the condensed phase. (3) studies of the behavior of strained alkane radical cations, such as cubane {sup +}{center dot}, revealed new rearrangements and remarkable, medium-dependent differences in their structures. (4) H{center dot}atom reactions yielding e{sub aq}{sup {minus}} provided the first reliable measurements of hydrated-electron enthalpy and entropy and forced the revision of some previous thinking about the driving force in {sub aq}{sup {minus}} reactions.

Not Available

1991-01-01

446

Radiation hormesis in plants  

SciTech Connect

Many reports discuss plant growth stimulation by exposure of seeds or plants to low doses of ionizing radiation. The reported effects include increased height, weight, growth rate, flowering and yield. The magnitude of the effect(s) is usually small, being about 10% of control values; and the effects often are not reproducible. None has been independently confirmed. The exposure level reported to induce such effects is about an order of magnitude greater than that reported for similar hormetic responses in animals. There is no understanding of the mechanism(s) of such responses or of the cellular and physical factor(s) pertinent to the induction of such effect(s). However, observations that certain low-level exposures result in increased yield (e.g. more branches, flowers and fruits) are consistent with known mechanisms of cellular damage and known responses of plants to a compromise in apical dominance. 207 references.

Miller, M.W.; Miller, W.M.

1987-05-01

447

Nanoscintillators for radiation detection  

NASA Astrophysics Data System (ADS)

In the search for faster, more effective methods for detection of and protection against radiological weapons, advances in materials for radiation detection are a critical component of any successful strategy. This work focuses on producing inexpensive, but highly sensitive, nanoparticle alternatives to existing single-crystal installations. Attention is given to particular types of promising inorganic scintillators: LaF3, yttrium-aluminum-garnet (YAG), and SrF2, each one an inorganic host doped with additional elements that encourage luminescent decay and increase effective Z-value. I examine the possible routes to synthesize these compounds, and the difficulties and benefits of each method. After synthesizing these materials, testing was performed to determine comparative performance against each other and commercial solutions, identify structural and compositional characteristics, and explore routes for fixing the scintillators into a detector assembly. The unifying goal is to develop a scintillating material suitable for consistent dosimetry and radio-isotope identification applications.

Hall, Ryan Gregory

448

Conduction, Convection, and Radiation  

NSDL National Science Digital Library

With the help of simple, teacher-led demonstration activities, students learn the basic concepts of heat transfer by means of conduction, convection, and radiation. Students then apply these concepts as they work in teams to solve two problems. One problem requires that they maintain the warm temperature of one soda can filled with water at approximately body temperature, and the other problem is to cause an identical soda can of warm water to cool as much as possible during the same thirty-minute time interval. Students design their solutions using only common, everyday materials. They record the water temperatures in their two soda cans every five minutes, and prepare line graphs in order to visually compare their results to the temperature of an unaltered control can of water.

Engineering K-Ph.d. Program

449

Martian atmospheric radiation budget  

NASA Technical Reports Server (NTRS)

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

Lindner, Bernhard Lee

1994-01-01

450

Sonoluminescence and Vacuum Radiation  

NASA Astrophysics Data System (ADS)

Sonoluminescence is the generation of light from sound. Our goal is to understand why a bubble trapped in water could generate light from sound. In our work we investigate the contribution of the dynamical Casimir effect to this phenomenon. In previous work researchers have approach this problem as a semi static Casimir effect and have not been able to show a significant contribution of the Casimir effect to sonoluminescence. In our approach, we treat the surface of the bubble as a highly reflecting surface, thus, the electric field of the zero-point modes at the surface is zero. Thus, when the bubble collapses the zero-point modes inside and outside are disturbed. Since the dynamics of zero-point mode fields obey Maxwell equations we can simulate their dynamics using programs like Mathematica. We study the radiation of the excited zero-point mode field.

Melunis, Justin; Flores, Eduardo

2012-02-01

451

Earth Radiation Budget Science, 1978. [conferences  

NASA Technical Reports Server (NTRS)

An earth radiation budget satellite system planned in order to understand climate on various temporal and spatial scales is considered. Topics discussed include: climate modeling, climate diagnostics, radiation modeling, radiation variability and correlation studies, cloudiness and the radiation budget, and radiation budget and related measurements in 1985 and beyond.

1978-01-01

452

The Martian Energetic Radiation Environment Models  

Microsoft Academic Search

The Martian Energetic Radiation Environment Models The high energy ionising radiation environment in the solar system consists of three main sources: the planetary radiation belts, galactic cosmic rays and solar energetic particles. Future Mars missions potentially carry significant risk from long-term exposure to ionising radiation. The Martian Energetic Radiation Environment Models, MEREM, were developed in order to simulate the Martian

Patrcia Gonalves; Ana Keating; Pete Truscott; Fan Lei; Laurent Desorgher; Daniel Heynderickx; Norma Bock Crosby; Petteri Nieminen; Giovanni Santin

2010-01-01

453

Estimation of hourly solar radiation for India  

Microsoft Academic Search

The ASHRAE constants predict high values of the hourly beam radiation and very low values of the hourly diffuse radiation when used to predict radiation at Indian locations. Hence a procedure has been developed for the estimation of direct, diffuse and global hourly solar radiation on a horizontal surface for any location in India. To calculate hourly solar radiation, an

G. V. Parishwad; R. K. Bhardwaj; V. K. Nema

1997-01-01

454

An introduction to solar radiation  

Microsoft Academic Search

This book was written for energy analysts, designers of thermal devices, photovoltaic engineers, architects, agronomists, and hydrologists who must calculate an amount of solar radiation incident on a surface. Includes reading lists, diagrams, a subject index and tables with useful data. Contents, abridged: Sun-earth astronomical relationship. The solar constant and its spectral distribution. Extraterrestrial solar irradiation. Solar spectral radiation under

M. Iqbal

1983-01-01

455

The cosmic microwave background radiation  

Microsoft Academic Search

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

R. W. Wilson

1979-01-01

456

The cosmic microwave background radiation  

Microsoft Academic Search

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

Joseph Silk

1981-01-01

457

Radiative Corrections to Fermi Interactions  

Microsoft Academic Search

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

Toichiro Kinoshita; Alberto Sirlin

1959-01-01

458

Acute Radiation Sickness Amelioration Analysis.  

National Technical Information Service (NTIS)

Three tasks were conducted under the Acute Radiation Sickness Amelioration Analysis in support of the Defense Nuclear Agency (DNA) and NATO Army Armaments Group (NAAG) Project Group 29 (PG-29) on drugs for the prevention of radiation-induced nausea and vo...

S. I. Robinson A. J. Feister D. L. Bareis

1994-01-01

459

Ionizing radiation and genetic risks  

Microsoft Academic Search

Genetic risks of radiation exposure of humans are generally expressed as expected increases in the frequencies of genetic diseases over those that occur naturally in the population as a result of spontaneous mutations. Since human data on radiation-induced germ cell mutations and genetic diseases remain scanty, the rates derived from the induced frequencies of mutations in mouse genes are used

K. Sankaranarayanan; R. Chakraborty

2000-01-01

460

Radiation-induced explosive initiation  

NASA Astrophysics Data System (ADS)

A model for explosive initiation under the influence of high energy radiation has been developed. The possibility for comparing explosive initiation conditions under the influence of radiation pulse and shock wave loads of microsecond duration has been shown and the initiation conditions as a function of the radiolysis constants have been determined.

Yakovlev, M.

1999-08-01

461

Radiation-induced explosive initiation  

Microsoft Academic Search

A model for explosive initiation under the influence of high energy radiation has been developed. The possibility for comparing explosive initiation conditions under the influence of radiation pulse and shock wave loads of microsecond duration has been shown and the initiation conditions as a function of the radiolysis constants have been determined.

M. Yakovlev

1999-01-01

462

Ionizing radiation and genetic risks  

Microsoft Academic Search

Estimates of genetic risks of radiation exposure of humans are traditionally expressed as expected increases in the frequencies of genetic diseases (single-gene, chromosomal and multifactorial) over and above those of naturally-occurring ones in the population. An important assumption in expressing risks in this manner is that gonadal radiation exposures can cause an increase in the frequency of mutations and that

K. Sankaranarayanan

1999-01-01

463

Surgical Reconstruction of Radiation Injuries  

PubMed Central

Significance: Patients with cancer receive benefits from radiation therapy; however, it may have adverse effects on normal tissue such as causing radiation-induced ulcer and osteoradionecrosis. The most reliable method to treat a radiation ulcer is wide excision of the affected tissue, followed by coverage with well-vascularized tissue. As usual, radiation-induced skin ulcers are due to therapeutic irradiation for residual cancer or lymph nodes; the locations of radiation ulcers are relatively limited, including the head, neck, chest wall, lumbar, groin, and sacral areas. Thus, suitable reconstructive methods vary according to functional and aesthetic conditions. I reviewed the practices and surgical results for radiation ulcers over the past 30 years, and present the recommended surgical methods for these hard-to-heal ulcers. Recent Advances: At a minimum, flaps are required to treat radiation ulcers. Surgeons can recommend earlier debridement, followed by immediate coverage with axial-pattern musculocutaneous and fasciocutaneous flaps. Free flaps are also a useful soft tissue coverage option. The choice of flap varies with the location and size of the wounds. Critical Issues: The most crucial procedure is the complete resection of the radiation-affected area, followed by coverage with well-vascularized tissue. Future Directions: Recent developments in perforator flap techniques, which are defined as flaps with a blood supply from isolated perforating vessels of a stem artery, have allowed the surgeons to successfully resurface these difficult wounds with reduced morbidity.

Fujioka, Masaki

2014-01-01

464

Radiation-induced transgenerational instability  

Microsoft Academic Search

To date, the analysis of mutation induction has provided an irrefutable evidence for an elevated germline mutation rate in the parents directly exposed to ionizing radiation and a number of chemical mutagens. However, the results of numerous publications suggest that radiation may also have an indirect effect on genome stability, which is transmitted through the germ line of irradiated parents

Yuri E Dubrova

2003-01-01

465

Radiation Therapy for Lung Cancer  

MedlinePLUS

... trials completed in the past proving that radiation therapy kills cancer cells and is safe long term. For more information ... be used to treat lung cancer noninvasively. Radiation therapy works within cancer cells by damaging their ability to multiply. When these ...

466

Models of diffuse solar radiation  

Microsoft Academic Search

For some locations both global and diffuse solar radiation are measured. However, for many locations, only global is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct component on a tilted surface can be calculated from trigonometry, we need to have diffuse on the

John Boland; Barbara Ridley; Bruce Brown

2008-01-01

467

Solar radiation climate of Thailand  

Microsoft Academic Search

Geographical, seasonal, and diurnal variations of global solar radiation in Thailand are surveyed. Seasonal effects are shown by separate studies for eight 1.5 month periods of the year defined by standard solar declination values. Detailed maps are given of the geographical distribution of solar radiation prepared from data on cloudiness at 44 stations, duration of sunshine at 18 stations, and

R EXELL

1976-01-01

468

Radiation-induced intracranial fibrochondrosarcoma.  

PubMed

A 50-year-old patient developed a left temporal fibrochondrosarcoma 27 years after radiation therapy for a suspected pituitary adenoma. The long latency between the irradiation and the development of the sarcoma and the histological nature of the tumour are unusual features for a malignant radiation-induced intracranial tumour. The histogenesis of fibrochondrosarcoma of the brain is discussed. PMID:3772411

Pags, A; Pags, M; Ramos, J; Bnzech, J

1986-10-01

469

Scaling radiative plasmas to ITER  

Microsoft Academic Search

In the radiative regime non-intrinsic impurities have been used to produce divertor power loads which would be considered acceptable when extrapolated to ITER. However, it has been a matter of concern that the maximum Zeff currently deemed acceptable for ITER has been exceeded by a large margin in radiative plasma experiments in large divertor machines such as JET, JT60-U, AUG

G. F. Matthews; S. Allen; N. Asakura; J. Goetz; H. Guo; A. Kallenbach; B. Lipschultz; K. McCormick; M. Stamp; U. Samm; P. C. Stangeby; K.-H. Steuer; A. Taroni; B. Unterberg

1997-01-01

470

DCTD Radiation Research Program (RRP)  

Cancer.gov

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

471

Interfacial Dipoles and Radiated Energy  

Microsoft Academic Search

Electric dipoles radiate an electromagnetic field into their surroundings. The electric and magnetic fields from a point source or from linear dipoles have components parallel to a spherical surface but also a radial component. In most investigations on radiated fields, only the part of the electric field that is parallel to a spherical surface is taken into account. The argument

Evert C. Slob; Jacob T. Fokkema

2002-01-01

472

Freezing by radiation and convection  

NSDL National Science Digital Library

Use radiation and a heat transfer coefficient to estimate the initial rate of solidification of the solid shell at the top of a casting while the temperature in the shell can be considered uniform, then set up the equation for mixed conduction/convection-radiation limited cooling.

Powell, Adam C., IV

2003-11-20

473

BIOLOGICAL EFFECTS OF RADIOFREQUENCY RADIATION  

EPA Science Inventory

The document presents a critical review of the available literature on the biological effects of radiofrequency (RF) radiation. The objective was to summarize and evaluate the existing database for use in developing RF-radiation exposure guidance for the general public. The frequ...

474

RADIOFREQUENCY RADIATION: ACTIVITIES AND ISSUES  

EPA Science Inventory

The question of human safety relative to exposure to RF radiation obviously predates the first ANSI guideline established in 1966, but no enforceable Federal standards or guidelines exist for RF radiation exposure; the ANSI guideline which was revised in 1982 is voluntary or advi...

475

An introduction to radiation chemistry  

Microsoft Academic Search

This book covers developments in the field of radiation chemistry. This text provides a point of entry into the field. The authors promote understanding of the fundamental principles underlying the action of radiation on matter. Both the methodology and the industrial applications are stated.

J. W. T. Spinks; R. J. Woods

1990-01-01

476

Radiation carcinogenesis: radioprotectors and photosensitizers  

SciTech Connect

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

Fry, R.J.M.

1982-01-01

477

Abdominal radiation causes bacterial translocation  

SciTech Connect

The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

1989-02-01

478

The NASA Radiation Health Program  

NASA Technical Reports Server (NTRS)

The NASA program for determining the impact of cosmic radiation on health is described in terms of its long-term goal of reducing the uncertainty of radiation-model prediction to +/- 25 percent by 2010. The Space Radiation Health Program (SRHP) is intended to address fundamental issues for establishing a scientific basis for human radiation protection: (1) the prediction of the probability of biological effects from radiation; (2) the reduction of uncertainty in predicted highly charged energetic particles; and (3) the characterization of background flux from Galactic cosmic rays. Another key objective is to develop related technologies for ground- and space-based solar monitoring to predict events involving solar energetic particles. Although substantial uncertainties are involved in the prediction of such events, the SRHP is essential for determining crucial variables related to launching mass and humans into orbit.

Nicogossian, A. E.; Schimmerling, W.

1991-01-01

479

Sound radiation quantities arising from a resilient circular radiator.  

PubMed

Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are either Stenzel functions (1-(sigma/a)2)n, with sigma the radial coordinate on the radiator, or linear combinations of Zernike functions Pn(2(sigma/a)2-1), with Pn the Legendre polynomial of degree n. Both sets of functions give rise, via King's integral for the pressure, to integrals for the quantities of interest involving the product of two Bessel functions. These integrals have a power series expansion and allow an expression in terms of Bessel functions of the first kind and Struve functions. Consequently, many of the results in [M. Greenspan, J. Acoust. Soc. Am. 65, 608-621 (1979)] are generalized and treated in a unified manner. A foreseen application is for loudspeakers. The relation between the radiated power in the near-field on one hand and in the far field on the other is highlighted. PMID:19813792

Aarts, Ronald M; Janssen, Augustus J E M

2009-10-01

480

Radiation Balance of Soybeans Grown in Brazil.  

National Technical Information Service (NTIS)

The radiation balance over a growing soybean crop at a tropical agricultural experimental station, Sao Paulo, Brazil was described. Incoming shortwave radiation S, net radiation R and shortwave reflection coefficient alpha were measured from Nov. 1976 to ...

R. G. B. Andre Y. Viswanadham

1983-01-01

481

Development of radiation-resistant medical polypropylene.  

National Technical Information Service (NTIS)

In order to develop a radiation resistant polypropylene (PP) which can be sterilized by gamma radiation for medical use, optimal concentrations of various additives in PP were determined by observing the synergistic effect. The radiation durability of the...

J. H. Jin B. M. Yoon Y. K. Lee S. C. Park Y. S. Yoo

1990-01-01

482

77 FR 55199 - Radiation Detection Technologies, Inc.  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF ENERGY Radiation Detection Technologies, Inc. AGENCY...hereby given to an intent to grant to Radiation Detection Technologies, Inc., of Manhattan...before the end of the comment period. Radiation Detection Technologies, Inc., of...

2012-09-07

483

10 CFR 36.57 - Radiation surveys.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Radiation surveys. 36.57 Section 36...REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS...Operation of Irradiators § 36.57 Radiation surveys. (a) A...

2009-01-01

484

The risks of radiation  

NASA Astrophysics Data System (ADS)

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

Miettenen, Jorma K.

1988-01-01

485

Radiation-induced lung injury  

SciTech Connect

The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

Rosiello, R.A.; Merrill, W.W. (Yale Univ. Medical Center, New Haven, CT (USA))