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Sample records for conducted conventional radiation

  1. Radiative thermal conduction fronts

    International Nuclear Information System (INIS)

    Borkowski, K.J.; Balbus, S.A.; Fristrom, C.C.

    1990-01-01

    The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence

  2. Standardizing Naming Conventions in Radiation Oncology

    Energy Technology Data Exchange (ETDEWEB)

    Santanam, Lakshmi [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Hurkmans, Coen [Department of Radiation Oncology, Catharina Hospital, Eindhoven (Netherlands); Mutic, Sasa [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Vliet-Vroegindeweij, Corine van [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Brame, Scott; Straube, William [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Galvin, James [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Tripuraneni, Prabhakar [Department of Radiation Oncology, Scripps Clinic, LaJolla, CA (United States); Michalski, Jeff [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Bosch, Walter, E-mail: wbosch@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Advanced Technology Consortium, Image-guided Therapy QA Center, St. Louis, MO (United States)

    2012-07-15

    Purpose: The aim of this study was to report on the development of a standardized target and organ-at-risk naming convention for use in radiation therapy and to present the nomenclature for structure naming for interinstitutional data sharing, clinical trial repositories, integrated multi-institutional collaborative databases, and quality control centers. This taxonomy should also enable improved plan benchmarking between clinical institutions and vendors and facilitation of automated treatment plan quality control. Materials and Methods: The Advanced Technology Consortium, Washington University in St. Louis, Radiation Therapy Oncology Group, Dutch Radiation Oncology Society, and the Clinical Trials RT QA Harmonization Group collaborated in creating this new naming convention. The International Commission on Radiation Units and Measurements guidelines have been used to create standardized nomenclature for target volumes (clinical target volume, internal target volume, planning target volume, etc.), organs at risk, and planning organ-at-risk volumes in radiation therapy. The nomenclature also includes rules for specifying laterality and margins for various structures. The naming rules distinguish tumor and nodal planning target volumes, with correspondence to their respective tumor/nodal clinical target volumes. It also provides rules for basic structure naming, as well as an option for more detailed names. Names of nonstandard structures used mainly for plan optimization or evaluation (rings, islands of dose avoidance, islands where additional dose is needed [dose painting]) are identified separately. Results: In addition to its use in 16 ongoing Radiation Therapy Oncology Group advanced technology clinical trial protocols and several new European Organization for Research and Treatment of Cancer protocols, a pilot version of this naming convention has been evaluated using patient data sets with varying treatment sites. All structures in these data sets were

  3. Standardizing Naming Conventions in Radiation Oncology

    International Nuclear Information System (INIS)

    Santanam, Lakshmi; Hurkmans, Coen; Mutic, Sasa; Vliet-Vroegindeweij, Corine van; Brame, Scott; Straube, William; Galvin, James; Tripuraneni, Prabhakar; Michalski, Jeff; Bosch, Walter

    2012-01-01

    Purpose: The aim of this study was to report on the development of a standardized target and organ-at-risk naming convention for use in radiation therapy and to present the nomenclature for structure naming for interinstitutional data sharing, clinical trial repositories, integrated multi-institutional collaborative databases, and quality control centers. This taxonomy should also enable improved plan benchmarking between clinical institutions and vendors and facilitation of automated treatment plan quality control. Materials and Methods: The Advanced Technology Consortium, Washington University in St. Louis, Radiation Therapy Oncology Group, Dutch Radiation Oncology Society, and the Clinical Trials RT QA Harmonization Group collaborated in creating this new naming convention. The International Commission on Radiation Units and Measurements guidelines have been used to create standardized nomenclature for target volumes (clinical target volume, internal target volume, planning target volume, etc.), organs at risk, and planning organ-at-risk volumes in radiation therapy. The nomenclature also includes rules for specifying laterality and margins for various structures. The naming rules distinguish tumor and nodal planning target volumes, with correspondence to their respective tumor/nodal clinical target volumes. It also provides rules for basic structure naming, as well as an option for more detailed names. Names of nonstandard structures used mainly for plan optimization or evaluation (rings, islands of dose avoidance, islands where additional dose is needed [dose painting]) are identified separately. Results: In addition to its use in 16 ongoing Radiation Therapy Oncology Group advanced technology clinical trial protocols and several new European Organization for Research and Treatment of Cancer protocols, a pilot version of this naming convention has been evaluated using patient data sets with varying treatment sites. All structures in these data sets were

  4. Standardizing naming conventions in radiation oncology.

    Science.gov (United States)

    Santanam, Lakshmi; Hurkmans, Coen; Mutic, Sasa; van Vliet-Vroegindeweij, Corine; Brame, Scott; Straube, William; Galvin, James; Tripuraneni, Prabhakar; Michalski, Jeff; Bosch, Walter

    2012-07-15

    The aim of this study was to report on the development of a standardized target and organ-at-risk naming convention for use in radiation therapy and to present the nomenclature for structure naming for interinstitutional data sharing, clinical trial repositories, integrated multi-institutional collaborative databases, and quality control centers. This taxonomy should also enable improved plan benchmarking between clinical institutions and vendors and facilitation of automated treatment plan quality control. The Advanced Technology Consortium, Washington University in St. Louis, Radiation Therapy Oncology Group, Dutch Radiation Oncology Society, and the Clinical Trials RT QA Harmonization Group collaborated in creating this new naming convention. The International Commission on Radiation Units and Measurements guidelines have been used to create standardized nomenclature for target volumes (clinical target volume, internal target volume, planning target volume, etc.), organs at risk, and planning organ-at-risk volumes in radiation therapy. The nomenclature also includes rules for specifying laterality and margins for various structures. The naming rules distinguish tumor and nodal planning target volumes, with correspondence to their respective tumor/nodal clinical target volumes. It also provides rules for basic structure naming, as well as an option for more detailed names. Names of nonstandard structures used mainly for plan optimization or evaluation (rings, islands of dose avoidance, islands where additional dose is needed [dose painting]) are identified separately. In addition to its use in 16 ongoing Radiation Therapy Oncology Group advanced technology clinical trial protocols and several new European Organization for Research and Treatment of Cancer protocols, a pilot version of this naming convention has been evaluated using patient data sets with varying treatment sites. All structures in these data sets were satisfactorily identified using this

  5. 7 CFR 7.10 - Conduct of county convention.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Conduct of county convention. 7.10 Section 7.10 Agriculture Office of the Secretary of Agriculture SELECTION AND FUNCTIONS OF AGRICULTURAL STABILIZATION AND... other purpose. (e) The county committee shall give advance public notice of the county convention which...

  6. Unconventional Military Advising Mission Conducted by Conventional US Military Forces

    OpenAIRE

    Hajjar, Remi M.

    2016-01-01

    This article examines how and why many contemporary US mainstream military advisors—as compared to Special Forces advisors—often work from a position of disadvantage when conducting unconventional advising missions. Post-9/11 deployments to Iraq and Afghanistan have caused the US military to adapt to myriad complexities, including a renewed need for the widespread execution of the unconventional military advising mission by the Special Forces and conventional units. Although Special Forces ty...

  7. Anisotropic conducting films for electromagnetic radiation applications

    Science.gov (United States)

    Cavallo, Francesca; Lagally, Max G.; Rojas-Delgado, Richard

    2015-06-16

    Electronic devices for the generation of electromagnetic radiation are provided. Also provided are methods for using the devices to generate electromagnetic radiation. The radiation sources include an anisotropic electrically conducting thin film that is characterized by a periodically varying charge carrier mobility in the plane of the film. The periodic variation in carrier mobility gives rise to a spatially varying electric field, which produces electromagnetic radiation as charged particles pass through the film.

  8. Patient radiation dose in conventional and xerographic cephalography

    International Nuclear Information System (INIS)

    Copley, R.L.; Glaze, S.A.; Bushong, S.C.; West, D.C.

    1979-01-01

    A comparison of the radiation doses for xeroradiographic and conventional film screen cephalography was made. Alderson tissue-equivalent phantoms were used for patient simulation. An optimum technique in terms of patient dose and image quality indicated that the dose for the Xerox process ranged from five to eleven times greater than that for the conventional process for entrance and exit exposures, respectively. This dose, however, falls within an acceptable range for other dental and medical radiation doses. It is recommended that conventional cephalography be used for routine purposes and that xeroradiography be reserved for situations requiring the increased image quality that the process affords

  9. Radiation enhanced conduction in insulators: computer modelling

    International Nuclear Information System (INIS)

    Fisher, A.J.

    1986-10-01

    The report describes the implementation of the Klaffky-Rose-Goland-Dienes [Phys. Rev. B.21 3610,1980] model of radiation-enhanced conduction and describes the codes used. The approach is demonstrated for the data for alumina of Pells, Buckley, Hill and Murphy [AERE R.11715, 1985]. (author)

  10. Radiation-induced conductivity of polynaphthoyl benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Tiutnev, A P; Berlin, A M; Saenko, V S; Rusanov, A L; Korshak, V V

    1985-01-01

    The nonstationary radiation-induced conductivity of polynaphthoyl benzimidazole, synthesized by single-stage high-temperature catalytic polycondensation, is investigated experimentally. It is shown that the radiation-induced conductivity of this material is characterized by an anomalous (non-Gaussian) transfer of excess charge carriers. The activation energy of the delayed component (0.1 ms after pulse termination) is determined to be 0.12 eV; the volt-ampere characteristic of this component is nonlinear, with the coefficient of nonlinearity increasing with the intensity of the external electric field. Experimental results are interpreted on the basis of the phenomenological theory of jump conductivity proposed by Zviagin. 15 references.

  11. Direct cost of monitoring conventional hemodialysis conducted by nursing professionals.

    Science.gov (United States)

    Lima, Antônio Fernandes Costa

    2017-04-01

    to analyze the mean direct cost of conventional hemodialysis monitored by nursing professionals in three public teaching and research hospitals in the state of São Paulo, Brazil. this was a quantitative, explorative and descriptive investigation, based on a multiple case study approach. The mean direct cost was calculated by multiplying (clocked) time spent per procedure by the unit cost of direct labor. Values were calculated in Brazilian real (BRL). Hospital C presented the highest mean direct cost (BRL 184.52), 5.23 times greater than the value for Hospital A (BRL 35.29) and 3.91 times greater than Hospital B (BRL 47.22). the costing method used in this study can be reproduced at other dialysis centers to inform strategies aimed at efficient allocation of necessary human resources to successfully monitor conventional hemodialysis.

  12. Direct cost of monitoring conventional hemodialysis conducted by nursing professionals

    Directory of Open Access Journals (Sweden)

    Antônio Fernandes Costa Lima

    Full Text Available ABSTRACT Objective: to analyze the mean direct cost of conventional hemodialysis monitored by nursing professionals in three public teaching and research hospitals in the state of São Paulo, Brazil. Method: this was a quantitative, explorative and descriptive investigation, based on a multiple case study approach. The mean direct cost was calculated by multiplying (clocked time spent per procedure by the unit cost of direct labor. Values were calculated in Brazilian real (BRL. Results: Hospital C presented the highest mean direct cost (BRL 184.52, 5.23 times greater than the value for Hospital A (BRL 35.29 and 3.91 times greater than Hospital B (BRL 47.22. Conclusion: the costing method used in this study can be reproduced at other dialysis centers to inform strategies aimed at efficient allocation of necessary human resources to successfully monitor conventional hemodialysis.

  13. Direct cost of monitoring conventional hemodialysis conducted by nursing professionals

    OpenAIRE

    Lima, Antônio Fernandes Costa

    2017-01-01

    ABSTRACT Objective: to analyze the mean direct cost of conventional hemodialysis monitored by nursing professionals in three public teaching and research hospitals in the state of São Paulo, Brazil. Method: this was a quantitative, explorative and descriptive investigation, based on a multiple case study approach. The mean direct cost was calculated by multiplying (clocked) time spent per procedure by the unit cost of direct labor. Values were calculated in Brazilian real (BRL). Results: H...

  14. Radiative shocks with electron thermal conduction

    International Nuclear Information System (INIS)

    Borkowski, Kazimierz.

    1988-01-01

    The authors studies the influence of electron thermal conduction on radiative shock structure for both one- and two-temperature plasmas. The dimensionless ratio of the conductive length to the cooling length determines whether or not conduction is important, and shock jump conditions with conduction are established for a collisionless shock front. He obtains approximate solutions with the assumptions that the ionization state of the gas is constant and the cooling rate is a function of temperature alone. In the absence of magnetic fields, these solutions indicate that conduction noticeably influences normal-abundance interstellar shocks with velocities 50-100 km s -1 and dramatically affects metal-dominated shocks over a wide range of shock velocities. Magnetic fields inhibit conduction, but the conductive energy flux and the corresponding decrease in the post-shock electron temperature may still be appreciable. He calculates detailed steady-state radiative shock models in gas composed entirely of oxygen, with the purpose of explaining observations of fast-moving knots in Cas A and other oxygen-rich supernova remnants (SNRs). The O III ion, whose forbidden emission usually dominates the observed spectra, is present over a wide range of shock velocities, from 100 to 170 kms -1 . All models with conduction have extensive warm photoionization zones, which provides better agreement with observed optical (O I) line strengths. However, the temperatures in these zones could be lowered by (Si II) 34.8 μm and (Ne II) 12.8 μm cooling if Si and Ne are present in appreciable abundance relative to O. Such low temperatures would be inconsistent with the observed (O I) emission in oxygen-rich SNRs

  15. Bases for protection against radiation and conventional hazards

    International Nuclear Information System (INIS)

    Ganguly, A.K.

    1977-01-01

    The living and working environment of man is polluted by : (1) ionizing radiations, both natural and man-made, (2) man-made non-ionizing radiations e.g. microwaves, and (3) man-made chemicals. Many of these agents are carcinogenic and mutagenic. The basic radiation safety standards laid down by the ICRP have long-term objectives and take into account all aspects of radiation protection problem, but in the case of other agents the safety standards, whatever few are available, have short-term objectives and differ widely from country to country. If the paramountcy of man's health is accepted as the objective of all safety programmes i.e. either for radiation hazards or conventional hazards, the above disparity must be removed. In order to achieve this goal, just as assessment of damage to organs and tissues of man is available in the case of ionizing radiations, similar assessment in the case of conventional hazards must be made available by collecting relevant data. (M.G.B.)

  16. A proposal for an international convention on radiation safety

    International Nuclear Information System (INIS)

    Ahmed, J.U.

    1998-01-01

    One century has passed since harmful effects of radiation on living tissues were recognized. Organized efforts to reduce radiation hazards began in early 1920s. Major efforts by the ICRP since 1928, aided by ICRU, greatly helped in formulating principles, policies and guidance for radiation protection. The WHO formally recognized ICRP in 1956 and began implementing ICRP recommendations and guidance throughout the world. The IAEA, after it took office in 1957, began to establish or adopt standards of safety based on ICRP recommendations and provide for application of these standards in the field of atomic energy. Later on, other pertinent international organizations joined IAEA in establishing the Basic Safety Standards on radiation safety. The IAEA has issued, until now, nearly couple of hundred safety related documents on radiation safety and waste management. However, in spite of all such international efforts for three quarter of a century, there has been no effective universal control in radiation safety. Problems exist at the user, national, international and manufacturers and suppliers levels. Other problems are management of spent sources and smuggling of sources across international borders. Although, radiation and radionuclides are used by all countries of the world, regulatory and technical control measures in many countries are either lacking or inadequate. The recommendations and technical guidance provided by the international organizations are only advisory and carry no mandatory force to oblige countries to apply them. Member States approve IAEA safety standards and guides at the technical meetings and General Conference, but many of them do not apply these. An International Convention is, therefore, essential to establish international instrument to ensure universal application of radiation safety. (author)

  17. Risks and hazards from conventional and radiation sources

    International Nuclear Information System (INIS)

    Iyer, P.S.; Ganguly, A.K.

    1978-01-01

    Beneficial uses of radioisotopes in medicine, industry, agriculture and research are discussed. In absence of adequate safety precautions, uses of radiation may also result in harmful biological effects or genetic effects. Radiation risks and hazards are evaluated by comparing with other risks and hazards which are routinely encountered. The risk of fatality per year by various causes in U.S.A. is given. It is stated with examples and observations that some of the routine habits and necessities and minor luxuries are more risky than radiation risks. Countrywide radiation safety program in India by the Department of Atomic Energy is described in brief. Data are given to show that the risks from radiation are much lower in comparison with many conventional sources. More efficient equipment such as image intensifier is recommended to help to reduce the patient dose. It is stated that caution has to be exercised while handling the X-ray machines which may be harmful not only to patients but to doctors also. As regards, nuclear medicine, it is mentioned that though it is a fast expanding speciality in India, the number of procedures carried out in various centres is small as compared to U.S.A. and France. Some instances are given to show the consequences of the ignorance of the radiation hazards in operating machines in X-ray and gamma ray beam therapy facilities. A survey made by DRP, BARC revealed that some research laboratories lacked basic radiation protection requirements in using X-ray crystallography or analytical equipment. (B.G.W.)

  18. Radiation dose evaluation in patients submitted to conventional radiological examinations

    International Nuclear Information System (INIS)

    Tilly Junior, Joao G.

    1997-01-01

    This work presents the results of the evaluation of radiation dose delivered to the patients undergoing conventional radiological procedures. Based in the realized measurement some indicators are settled to quantitative appraisal of the radiological protection conditions offered to the population. Data assessment was done in the county of Curitiba, in Parana State, Brazil, from 12/95 to 04/96, in ten rooms of three different institutions, under 101 patients, adults with 70 ± 10 kg, during real examinations of chest PA, chest LAT and abdomen AP. (author)

  19. Conducted and radiated noise in detection devices

    International Nuclear Information System (INIS)

    Moisa, D.

    2001-01-01

    Conducted and radiated noise is an external noise which affects the quality of the signals of the detectors. An external noise can be reduced, usually, by shielding. This was the situation with 'older fashion' devices which uses boxes and coaxial cables. As the devices becomes more complex, the shielding of the detectors is more and more difficult and the transmission lines evolves from coaxial cables to twisted pair cables which are no more shielded. In such situation, the conducted and radiated noise (C and R noise) becomes important. Due to complexity of a real detector, the main work is based on experiments with components and simulations of some specific problems, associated with CDC detector. The first experiment was done to understand how the C and R noise is propagated. The emission device was a set of coils (between 3 and 5 turns with diameter from 10 to 50 mm) feed by an 74S140 driver. A pulse of about 8 ns width was generated. A coil of reception of about the same physical characteristics was used to see the emitted pulse. When the two coils are separated by about 80 cm, the receiver generated no signal. But, if along the two coils, a conductive material is introduced (a wire for instance), the receiver senses a signal. This signal is not changed too much if the wire is or not connected to ground. The explanation is simple: the pulse in the emitting coil produces an EM pulse which spreads in space. If a conductive material is around, the EM energy is received by that conductor and it is propagated at tens of meters with small attenuation. When this energy reaches the end of the conductor, it is radiated in space. If some other conductors are around, the energy is received and propagated by that conductors. This experiment was done for about 20 kinds of conductors (different coax cables, twisted-pair ribbons, power cables, metallic bars) and with many coils (different diameters and numbers of turns). It was measured the pk-to-pk level, decay constant and

  20. Radiation Hardened NULL Convention Logic Asynchronous Circuit Design

    Directory of Open Access Journals (Sweden)

    Liang Zhou

    2015-10-01

    Full Text Available This paper proposes a radiation hardened NULL Convention Logic (NCL architecture that can recover from a single event latchup (SEL or single event upset (SEU fault without deadlock or any data loss. The proposed architecture is analytically proved to be SEL resistant, and by extension, proved to be SEU resistant. The SEL/SEU resistant version of a 3-stage full-word pipelined NCL 4 × 4 unsigned multiplier was implemented using the IBM cmrf8sf 130 nm 1.2 V process at the transistor level and simulated exhaustively with SEL fault injection to validate the proposed architectures. Compared with the original version, the SEL/SEU resilient version has 1.31× speed overhead, 2.74× area overhead, and 2.79× energy per operation overhead.

  1. Late toxicities after conventional radiation therapy alone for nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Tuan, Jeffrey Kit Loong, E-mail: ntrtkl@nccs.com.sg [Department of Radiation Oncology, National Cancer Centre Singapore (Singapore); Ha, Tam Cam [Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre Singapore (Singapore); Duke-NUS Graduate Medical School (Singapore); Ong, Whee Sze [Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre Singapore (Singapore); Siow, Tian Rui [Department of Radiation Oncology, National Cancer Centre Singapore (Singapore); Tham, Ivan Weng Keong [National University Health System Singapore (Singapore); Yap, Swee Peng; Tan, Terence Wee Kiat; Chua, Eu Tiong; Fong, Kam Weng [Department of Radiation Oncology, National Cancer Centre Singapore (Singapore); Wee, Joseph Tien Seng [Department of Radiation Oncology, National Cancer Centre Singapore (Singapore); Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre Singapore (Singapore); Duke-NUS Graduate Medical School (Singapore)

    2012-09-15

    Background and purpose: We sought to evaluate the nature and frequency of late toxicities in a cohort of nasopharyngeal cancer (NPC) patients treated with conventional radiotherapy alone. Methods and materials: Seven-hundred and ninety-six consecutive NPC patients treated using conventional radiotherapy at a single center from 1992 to 1995 were retrospectively analyzed. Patients with histology proven, completely staged, Stage I-IVB World Health Organization Type I-III NPC and completed radical radiotherapy were included. Patients with incomplete staging investigations, distant metastases at diagnosis, previous treatment, and incomplete radiotherapy were excluded. Radiotherapy-related complications were categorized using the RTOG Late Radiation Morbidity Scoring Criteria. Results: Median follow-up was 7.2 years. The 5-year overall survival and disease free survival were 69% and 56%, respectively, and the corresponding 10-year rates were 52% and 44%. Among 771 patients with at least 3 months of follow-up post treatment, 565 (73%) developed RT-related complications. Diagnosed neurological complications were cranial nerve palsies (n = 70; 9%), temporal lobe necrosis (n = 37; 5%), Lhermitte's syndrome (n = 7; 1%), and brachial plexopathy (n = 2; 0.3%). Non-neurological complications included xerostomia (n = 353; 46%), neck fibrosis (n = 169; 22%), hypo-pituitarism (n = 48; 6%), hearing loss (n = 120; 16%), dysphagia (n = 116; 15%), otorrhea (n = 101; 13%), tinnitus (n = 94; 12%), permanent tube feeding (n = 61; 8%), trismus (n = 45; 6%), second malignancies within treatment field (n = 17; 2%), and osteo-radionecrosis (n = 13; 2%). Conclusions: While radiotherapy is curative in NPC, many patients suffer significant late treatment morbidities with conventional radiotherapy techniques.

  2. Late toxicities after conventional radiation therapy alone for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Tuan, Jeffrey Kit Loong; Ha, Tam Cam; Ong, Whee Sze; Siow, Tian Rui; Tham, Ivan Weng Keong; Yap, Swee Peng; Tan, Terence Wee Kiat; Chua, Eu Tiong; Fong, Kam Weng; Wee, Joseph Tien Seng

    2012-01-01

    Background and purpose: We sought to evaluate the nature and frequency of late toxicities in a cohort of nasopharyngeal cancer (NPC) patients treated with conventional radiotherapy alone. Methods and materials: Seven-hundred and ninety-six consecutive NPC patients treated using conventional radiotherapy at a single center from 1992 to 1995 were retrospectively analyzed. Patients with histology proven, completely staged, Stage I–IVB World Health Organization Type I–III NPC and completed radical radiotherapy were included. Patients with incomplete staging investigations, distant metastases at diagnosis, previous treatment, and incomplete radiotherapy were excluded. Radiotherapy-related complications were categorized using the RTOG Late Radiation Morbidity Scoring Criteria. Results: Median follow-up was 7.2 years. The 5-year overall survival and disease free survival were 69% and 56%, respectively, and the corresponding 10-year rates were 52% and 44%. Among 771 patients with at least 3 months of follow-up post treatment, 565 (73%) developed RT-related complications. Diagnosed neurological complications were cranial nerve palsies (n = 70; 9%), temporal lobe necrosis (n = 37; 5%), Lhermitte’s syndrome (n = 7; 1%), and brachial plexopathy (n = 2; 0.3%). Non-neurological complications included xerostomia (n = 353; 46%), neck fibrosis (n = 169; 22%), hypo-pituitarism (n = 48; 6%), hearing loss (n = 120; 16%), dysphagia (n = 116; 15%), otorrhea (n = 101; 13%), tinnitus (n = 94; 12%), permanent tube feeding (n = 61; 8%), trismus (n = 45; 6%), second malignancies within treatment field (n = 17; 2%), and osteo-radionecrosis (n = 13; 2%). Conclusions: While radiotherapy is curative in NPC, many patients suffer significant late treatment morbidities with conventional radiotherapy techniques.

  3. COMPARISON OF HYPOFRACTIONATED RADIATION THERAPY VERSUS CONVENTIONAL RADIATION THERAPY IN POST MASTECTOMY BREAST CANCER

    Directory of Open Access Journals (Sweden)

    Abhilash

    2016-03-01

    Full Text Available INTRODUCTION Breast cancer is the most common cancer in women worldwide and a leading cause of cancer death in females and accounts for 1.8 million new cases and approximately 0.5 million deaths annually. Patients who present with locally advanced breast cancer (LABC require multidisciplinary team approach that incorporates diagnostic imaging, surgery, chemotherapy and histopathological assessment, including molecular-based studies, radiation, and, if indicated, biologic and hormonal therapies. Hypofractionated radiation therapy following mastectomy has been used in many institutions for several decades and have demonstrated equivalent local control, cosmetic and normal tissues between 50 Gy in 25 fractions and various hypofractionated radiotherapy prescriptions employing 13-16 fractions. Evidence suggests that hypofractionated radiotherapy may also be safe and effective for regional nodal disease. AIMS AND OBJECTIVES To compare the local control and side effects of hypofractionated radiation therapy with conventional radiation therapy in post mastectomy carcinoma breast with stage II and III and to compare the tolerability and compliance of both schedules. MATERIALS AND METHODS The study was conducted on 60 histopathologically proven patients of carcinoma of breast, treated surgically with modified radical mastectomy. Group I patients were given external radiation to chest flap and drainage areas, a dose of 39 Gy/13 fractions/3.1 weeks, a daily dose 3 Gy for 13 fractions in 4 days a week schedule and Group II patients were given external radiation to chest flap and drainage areas, a dose of 50 Gy/25 fractions/5 weeks, to receive a daily dose 2 Gy for 25 fractions in a 5 days a week schedule. RESULTS The median age at presentation in Group I and II was 48 and 50 years respectively. Locoregional control after completion of radiotherapy in Group I vs. Group II was 26/30 (86.7% vs. 27/30 (90% respectively. Acute reactions and their grades in Group

  4. Radiation damages on superionic conducting glasses

    International Nuclear Information System (INIS)

    Awano, T.; Handa, K.; Matsuyama, T.

    2000-01-01

    We measured ESR spectra of color centers on AgI-AgPO 3 , AgI-Ag 2 O-B 2 O 3 , AgI-Ag 2 MoO 4 , AgI-Ag 2 WO 4 , (CH 3 ) 4 NI-(C 2 H 5 ) 4 NI-AgI (TMAI-TEAI-AgI) and its derivatives of superionic conducting glasses. In organic-inorganic mixed glasses, organic ion radicals were observed. They were not affected by ionic conductivity. On the contrary, Ag 2+ , Ag 0 and aggregated Ag 0 were observed in inorganic glasses. These color centers in inorganic glasses were affected by ionic conductivity. (author)

  5. Hopping Conductivity Enhanced by Microwave Radiation

    International Nuclear Information System (INIS)

    Ovadyahu, Z

    2012-01-01

    Hopping conductivity is enhanced when exposed to microwave (MW) fields. Data taken on several Anderson-localized systems and granular-aluminium are presented to illustrate the generality of the phenomenon. It is suggested that the effect is due to a field-enhanced hopping, which is the ac version of a non-ohmic effect familiar from studies in the dc transport regime.

  6. Radiative heat conduction and the magnetorotational instability

    CERN Document Server

    Araya-Gochez, R A; 10.1111/j.1365-2966.2004.08329.x

    2004-01-01

    A photon or a neutrino gas, semicontained by a non-diffusive particle species through scattering, comprises a rather peculiar magnetohydrodynamic fluid where the magnetic field is truly frozen only to the comoving volume associated with the mass density. Although radiative diffusion precludes a formal adiabatic treatment of compressive perturbations, we cast the energy equation in quasi- adiabatic form by assuming a negligible rate of energy exchange among species on the time-scale of the perturbation. This leads to a simplified dispersion relation for toroidal, non-axisymmetric magnetorotational modes when the accretion disc has comparable stress contributions from diffusive and non-diffusive components. The properties of the modes of fastest growth are shown to depend strongly on the compressibility of the mode, with a reduction in growth rate consistent with the results of Blaes & Socrates for axisymmetric modes. A clumpy disc structure is anticipated on the basis of the polarization properties of the ...

  7. Evaluation of radiation protection in conventional x-ray departments in diagnostic radiography (Kartoum City)

    International Nuclear Information System (INIS)

    Elhussien, Nuha Yousif Osman

    2016-08-01

    This study was conducted in a number of governmental and private hospitals in the city of Khartoum in order to evalute radiation protection in conventional X-ray departments. The number of governmental hospitals was and 4 private 69% and 31&, respectivly, and the number of X-rays rooms that have been evaluted was 19, 15 gvernmental and private by rate of 79% and 21% respectively. And found that many of the hospitals fullfilled the requirements of radiation protection, also we have been observed that all radiology rooms are built well, but their control rooms was mostly not fulfilled the requirements of radiation protection due to either were not build inclimed to reflect the scattered radiation due to either they were not build inclimed to reflect the scattered radiation from the patient or their size was small that not enable workers to exerciese their work safely, as well as some height less than recommended by the competent authorities. Also found that most hospitals have lead aprons axcept three, but some they are old that means do not protect against radiation due they were broke or not put it in the that means do not protect against radiation due they were broke or not put it in the right way. Even the good ares not used by most of the technician and co-patients. All the hoapitals have not the following radiation tools (thyroid collar, lead glasses, lead gloves. TLDs, and gonad shields). The scattered radiation (leakage) was evaluted in the control room, the door of the control room, the dark room, behind chest stand, staff office, and the waiting area. We found that the higher readings in the door of the control rooms (<10 μSv/hr) in the five control rooms from 19, also the readings exceeded the limits in three hospitals in control rooms 13 rooms. And also the readings exceeded the limits in two hospitals in the staff office, and the waiting area. (Author)

  8. Radiation induced synthesis of conducting polymer nanocomposite

    International Nuclear Information System (INIS)

    Sayed, T.A.M.

    2013-01-01

    irradiation dose is increased, a gradual red shift in was observed. This indicates formation of larger particles with increasing irradiation dose. With increase in Ag concentration the absorption maximum shifts towards longer wavelengths (larger particle size formation). The XRD pattern of irradiated PANI exhibits four new diffraction peaks, corresponding to face centered cubic structure (fcc) of silver. With increasing of either AgNO 3 concentration or irradiation dose the particle size was increased. FTIR spectra of Ag/PANI nano composites illustrate that the incorporation of silver nanoparticles in poly aniline matrix leads to small shift of some peaks to the higher wavelengths and also decreases in the intensity of other peaks, which indicates that the structural change of polymer occurs with doping. The variation of dc electrical conductivity for pure PANI and irradiated Ag/PANI nano composites showed that the dc electrical conductivity of the irradiated Ag/PANI nano composites is higher than that of pure PANI and also it increases with increasing either irradiation dose or AgNO 3 concentrations. Catalytic evaluation of Ag/PANI and Ag/PVA in the reduction of 4-Nitro phenol (4-NP) showed that, either Ag/PANI or Ag/PVA is successive catalyst for a reduction of 4-nitrophenol which a carcinogenic material present in waste water and some petroleum product.

  9. Open cell conducting foams for high synchrotron radiation accelerators

    Directory of Open Access Journals (Sweden)

    S. Petracca

    2014-08-01

    Full Text Available The possible use of open cell conductive foams in high synchrotron radiation particle accelerators is considered. Available materials and modeling tools are reviewed, potential pros and cons are discussed, and preliminary conclusions are drawn.

  10. Nonsteady heat conduction code with radiation boundary conditions

    International Nuclear Information System (INIS)

    Fillo, J.A.; Benenati, R.; Powell, J.

    1975-01-01

    A heat-transfer model for studying the temperature build-up in graphite blankets for fusion reactors is presented. In essence, the computer code developed is for two-dimensional, nonsteady heat conduction in heterogeneous, anisotropic solids with nonuniform internal heating. Thermal radiation as well as bremsstrahlung radiation boundary conditions are included. Numerical calculations are performed for two design options by varying the wall loading, bremsstrahlung, surface layer thickness and thermal conductivity, blanket dimensions, time step and grid size. (auth)

  11. Effect of dose on radiation-induced conductivity in polymers

    International Nuclear Information System (INIS)

    Tyutnev, A.P.; Saenko, V.S.; Pozhidaev, E.D.; Ikhsanov, R.Sh.

    2007-01-01

    Numerical simulation of radiation-induced conductivity in polymers upon long-term irradiation on the basis of the generalized Rose-Fowler-Vaisberg model, which allows for both dipolar carrier transport and generation of radiation traps during irradiation, was performed. The unusual properties of radiation-induced conductivity, such as the appearance of a maximum on current transients, the absence of a steady state, and a substantial difference between these curves for the first and subsequent irradiation, are rationalized in terms of the formation of free radicals, the major feature of radiolysis in the chemical aspect. This interpretation does not require the involvement of degradation or crosslinking processes, unlike other interpretations that appear in the literature. With the use of low-density polyethylene as an example, it was shown that radiation-induced conductivity both upon pulse and continuous irradiation can satisfactorily be described with the unified set of parameters of the generalized Rose-Fowler-Vaisberg model [ru

  12. Global Harmonization of Quality Assurance Naming Conventions in Radiation Therapy Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Melidis, Christos, E-mail: christos.melidis@eortc.be [European Organization for the Research and Treatment of Cancer–Radiation Oncology Group (EORTC-ROG), Radiation Therapy Quality Assurance (RTQA), Brussels (Belgium); Bosch, Walther R. [Washington University, representing Advanced Technology Consortium, Radiation Oncology, St. Louis, Missouri (United States); Izewska, Joanna [Dosimetry Laboratory, International Atomic Energy Agency, Vienna (Austria); Fidarova, Elena; Zubizarreta, Eduardo [Applied Radiation Biology and Radiotherapy Section, International Atomic Energy Agency, Vienna (Austria); Ulin, Kenneth [Department of Radiation Oncology, University of Massachusetts Medical School, Representing Quality Assurance Review Center, Worcester, Massachusetts (United States); Ishikura, Satoshi [Department of Radiation Oncology, Juntendo University, Representing Japan Clinical Oncology Group, RTQA, Tokyo (Japan); Followill, David [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Representing Radiological Physics Center, RTQA, Houston, Texas (United States); Galvin, James [Department of Radiation Oncology, Thomas Jefferson University, Representing Radiation Therapy Oncology Group, RTQA, Philadelphia, Pennsylvania (United States); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, representing TransTasman Radiation Oncology Group (TROG) Cancer Research, Newcastle (Australia); Besuijen, Deidre [North West Cancer Centre, Representing TROG Cancer Research, Newcastle (Australia); Clark, Clark H. [Department of Medical Physics, St. Luke' s Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey and National Physical Laboratory, Teddington, Middlesex, representing Radiation Therapy Trials Quality Assurance (RTTQA) (United Kingdom); Miles, Elizabeth; Aird, Edwin [Mount Vernon Cancer Centre, Northwood, Middlesex representing RTTQA (United Kingdom); and others

    2014-12-01

    Purpose: To review the various radiation therapy quality assurance (RTQA) procedures used by the Global Clinical Trials RTQA Harmonization Group (GHG) steering committee members and present the harmonized RTQA naming conventions by amalgamating procedures with similar objectives. Methods and Materials: A survey of the GHG steering committee members' RTQA procedures, their goals, and naming conventions was conducted. The RTQA procedures were classified as baseline, preaccrual, and prospective/retrospective data capture and analysis. After all the procedures were accumulated and described, extensive discussions took place to come to harmonized RTQA procedures and names. Results: The RTQA procedures implemented within a trial by the GHG steering committee members vary in quantity, timing, name, and compliance criteria. The procedures of each member are based on perceived chances of noncompliance, so that the quality of radiation therapy planning and treatment does not negatively influence the trial measured outcomes. A comparison of these procedures demonstrated similarities among the goals of the various methods, but the naming given to each differed. After thorough discussions, the GHG steering committee members amalgamated the 27 RTQA procedures to 10 harmonized ones with corresponding names: facility questionnaire, beam output audit, benchmark case, dummy run, complex treatment dosimetry check, virtual phantom, individual case review, review of patients' treatment records, and protocol compliance and dosimetry site visit. Conclusions: Harmonized RTQA harmonized naming conventions, which can be used in all future clinical trials involving radiation therapy, have been established. Harmonized procedures will facilitate future intergroup trial collaboration and help to ensure comparable RTQA between international trials, which enables meta-analyses and reduces RTQA workload for intergroup studies.

  13. USING HOT WIRE TECHNIQUE FOR MEASURING THERMAL CONDUCTIVITY OF INFUSIONS OF ORGANIC AND CONVENTIONAL COFFEE

    Directory of Open Access Journals (Sweden)

    Fernando Gordillo-Delgado

    2016-07-01

    Full Text Available The technique of hot wire, a versatile method of low cost and high accuracy for measuring the thermal conductivity of fluids through the increasing temperature of a wire that is immersed into the liquid and between its ends a potential difference is abruptly applied. Using well-known conductivity liquids: water, ethylene glycol and glycerine, the system was tested and calibrated. In this work, this procedure was used to measure the thermal conductivity of the infusion samples of organic and conventional coffee. The same roast degree of the beans was verified with a colorimeter and the preparation was made by pressing 22g of coffee powder in 110mL of water. The obtained data were subjected to Analysis of Variance (ANOVA and this confirmed that the differences in the thermophysical parameter in the two samples are significant with a confidence level of 95\\%. On this way, it was proved that the thermal conductivity value of the coffee infusion allows differentiate between organic and conventional coffee.

  14. Reduction in thermal conductivity of ceramics due to radiation damage

    International Nuclear Information System (INIS)

    Klemens, P.G.; Hurley, G.F.; Clinard, F.W. Jr.

    1976-01-01

    Ceramics are required for a number of applications in fusion reactors. In several of these applications, the thermal conductivity is an important design parameter as it affects the level of temperature and thermal stress in service. Ceramic insulators are known to suffer substantial reduction in thermal conductivity due to neutron irradiation damage. The present study estimates the reduction in thermal conductivity at high temperature due to radiation induced defects. Point, extended, and extended partly transparent defects are considered

  15. Predicting Radiation Pneumonitis After Stereotactic Ablative Radiation Therapy in Patients Previously Treated With Conventional Thoracic Radiation Therapy

    International Nuclear Information System (INIS)

    Liu Hui; Zhang Xu; Vinogradskiy, Yevgeniy Y.; Swisher, Stephen G.; Komaki, Ritsuko; Chang, Joe Y.

    2012-01-01

    Purpose: To determine the incidence of and risk factors for radiation pneumonitis (RP) after stereotactic ablative radiation therapy (SABR) to the lung in patients who had previously undergone conventional thoracic radiation therapy. Methods and Materials: Seventy-two patients who had previously received conventionally fractionated radiation therapy to the thorax were treated with SABR (50 Gy in 4 fractions) for recurrent disease or secondary parenchymal lung cancer (T 10 and mean lung dose (MLD) of the previous plan and the V 10 -V 40 and MLD of the composite plan were also related to RP. Multivariate analysis revealed that ECOG PS scores of 2-3 before SABR (P=.009), FEV1 ≤65% before SABR (P=.012), V 20 ≥30% of the composite plan (P=.021), and an initial PTV in the bilateral mediastinum (P=.025) were all associated with RP. Conclusions: We found that severe RP was relatively common, occurring in 20.8% of patients, and could be predicted by an ECOG PS score of 2-3, an FEV1 ≤65%, a previous PTV spanning the bilateral mediastinum, and V 20 ≥30% on composite (previous RT+SABR) plans. Prospective studies are needed to validate these predictors and the scoring system on which they are based.

  16. Influence of prehistory of polymer samples on radiation electric conductivity induced by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aleksanina, O S; Sichkar' , V P; Vajsberg, S Eh [Nauchno-Issledovatel' skij Fiziko-Khimicheskij Inst., Moscow (USSR)

    1984-05-01

    Radiation electric conductivity of PS films prepared from solutions in various solvents at various initial concentrations and temperatures and various power of absorbed dose (..gamma..-radiation of /sup 60/Co) has been measured. The results are compared with the change of density of films and existing theoretical concepts of the role of microvoids and free volume in electrical conductivity of a polymer.

  17. Influence of prehistory of polymer samples on radiation electric conductivity induced by ionizing radiation

    International Nuclear Information System (INIS)

    Aleksanina, O.S.; Sichkar', V.P.; Vajsberg, S.Eh.

    1984-01-01

    Radiation electric conductivity of PS films prepared from solutions in various solvents at various initial concentrations and temperatures and various power of absorbed dose (γ-radiation of 60 Co) has been measured. The results are compared with the change of density of films and existing theoretical concepts of the role of microvoids and free volume in electrical conductivity of a polymer

  18. Risk evaluation - conventional and low level effects of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.; Varma, M.N.

    1984-04-01

    Any discussion of the risk of exposure to potentially-hazardous agents in the environment inevitably involves the question of whether the dose effect curve is of the threshold or linear, non-threshold type. A principal objective of this presentation is to show that the function is actually two separate relationships, each representing distinctly different functions with differing variables on the axes, and each characteristic of quite different functions with differing variables on the axes, and each characteristic of quite different disciplines (i.e., the threshold function, of Pharmacology, Toxicology and Medicine [PTM]; the linear, non-threshold function, of Public Health including safety and accident statistics [PHS]). It is shown that low-level exposure (LLE) to radiation falls clearly in the PHS category. A function for cell dose vs. the fraction of single cell quantal responses is characterized, which reflects the absolute and relative sensitivities of cells. Acceptance of this function would obviate any requirement for the use in Radiation Protection of the concepts of a standard radiation, Q, dose equivalent and rem. 9 references, 4 figures

  19. Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jeppesen, Stefan Starup; Schytte, Tine; Jensen, Henrik R

    2013-01-01

    Abstract Introduction. Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single...... and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients....

  20. Risk and value of conventional myelography with regard to radiation exposure of the patient

    International Nuclear Information System (INIS)

    Hentschel, F.

    1989-01-01

    To estimate the effective equivalent dose with reference to the area under examination and the foils employed, fifty patients underwent conventional diagnostic myelography, after which, by means of thermoluminescence surface dosimetry, the mean organ dose was ascertained from the radiation field size, using the computer program ORDOS. Effective equivalent dose can be used to determine the inherent risk of radiation injury involved. The risk-benefit ratios obtained would suggest that conventional myelography, prospectively in the form of digital myelography, and spinal computer tomography are not opposing but complementary approaches to spinal diagnosis. Spinal NMR imaging must not be discussed under the aspect of radiation exposure but under the aspect of availability. (author)

  1. Radiative contribution to the thermal conductivity of fibrous insulations

    Science.gov (United States)

    Linford, R. M. F.; Schmitt, R. J.; Hughes, T. A.

    1974-01-01

    An approach is shown for using a simple two-flux model to interpret infrared transmission data for a variety of reuseable surface insulations materials and to calculate the radiation transmission. A description is given of preliminary experiments on mullite and silica-based materials. The calculated parameters are compared with the measured values of the total thermal conductivity, as determined on guarded hot plate equipment. It is pointed out that for many samples the newly developed four-flux model must be utilized because the scattering properties of the fibers are often dependent on the wavelength of the radiation.

  2. Effect of electrodes in the radiation induced conductivity for polymers

    International Nuclear Information System (INIS)

    Gregorio Filho, R.; Gross, B.

    1988-01-01

    Samples of PET with 23 μm thickness were exposed to continuous X-rays and the radiation-induced conductivity (RIC) as a function of time were measured, using electrodes of evaporated aluminum and gold. The results showed that the use of higher atomic number metal electrodes increase the received dose rate by sample, without almost modifying the time evolution of the RIC or its dependence with the applied electric field intensity. It is also showed that this increase is caused by the electrode placed in the face of the sample where the radiation strikes, as well as by the one placed in the oposite face. (author) [pt

  3. Thermal computations for electronics conductive, radiative, and convective air cooling

    CERN Document Server

    Ellison, Gordon

    2010-01-01

    IntroductionPrimary mechanisms of heat flowConductionApplication example: Silicon chip resistance calculationConvectionApplication example: Chassis panel cooled by natural convectionRadiationApplication example: Chassis panel cooled only by radiation 7Illustrative example: Simple thermal network model for a heat sinked power transistorIllustrative example: Thermal network circuit for a printed circuit boardCompact component modelsIllustrative example: Pressure and thermal circuits for a forced air cooled enclosureIllustrative example: A single chip package on a printed circuit board-the proble

  4. A Phase III Study of Conventional Radiation Therapy Plus Thalidomide Versus Conventional Radiation Therapy for Multiple Brain Metastases (RTOG 0118)

    International Nuclear Information System (INIS)

    Knisely, Jonathan P.S.; Berkey, Brian; Chakravarti, Arnab; Yung, Al W.K.; Curran, Walter J.; Robins, H. Ian; Movsas, Benjamin; Brachman, David G.; Henderson, Randall H.; Mehta, Minesh P.

    2008-01-01

    Purpose: To compare whole-brain radiation therapy (WBRT) with WBRT combined with thalidomide for patients with brain metastases not amenable to resection or radiosurgery. Patients and Methods: Patients with Zubrod performance status 0-1, MRI-documented multiple (>3), large (>4 cm), or midbrain brain metastases arising from a histopathologically confirmed extracranial primary tumor, and an anticipated survival of >8 weeks were randomized to receive WBRT to a dose of 37.5 Gy in 15 fractions with or without thalidomide during and after WBRT. Prerandomization stratification used Radiation Therapy Oncology Group (RTOG) Recursive Partitioning Analysis (RPA) Class and whether post-WBRT chemotherapy was planned. Endpoints included overall survival, progression-free survival, time to neurocognitive progression, the cause of death, toxicities, and quality of life. A protocol-planned interim analysis documented that the trial had an extremely low probability of ever showing a significant difference favoring the thalidomide arm given the results at the time of the analysis, and it was therefore closed on the basis of predefined statistical guidelines. Results: Enrolled in the study were 332 patients. Of 183 accrued patients, 93 were randomized to receive WBRT alone and 90 to WBRT and thalidomide. Median survival was 3.9 months for both arms. No novel toxicities were seen, but thalidomide was not well tolerated in this population. Forty-eight percent of patients discontinued thalidomide because of side effects. Conclusion: Thalidomide provided no survival benefit for patients with multiple, large, or midbrain metastases when combined with WBRT; nearly half the patients discontinued thalidomide due to side effects

  5. Ionizing radiation induced conductivity in Mylar (PET) and Kapton (Polyimide)

    International Nuclear Information System (INIS)

    Gregorio Filho, R.

    1986-01-01

    The extensive results of measurements of the prompt and delayed radiation-induced conductivity of samples of PET and Kapton are presented. Experimental parameters, such as the effective energy of the radiation, the exposure rate, the total dose, the value of the applied electric field, the nature of the electrodes, and the ambiental conditions were changed within wide limits. We also report measurement of thermally stimulated currents for non-irradiated and for irradiated samples which allowed us to investigate the trap-structure of the materials. Measurements of photo-Compton currents with different electrode materials and sample thicknesses gave information about the relation between the nature of the electrodes and the amplitudes of the currents. Based on the generalized rate theory of radiation-induced conduction we developed a theoretical model which includes the effect of the applied electric field on the carrier generation yield (geminate recombination, Onsager effect). Comparison of experimental and theoretical curves allowed us to determine the values of the main conduction parameters, such as carrier mobility, recombination coefficient, trap densities, for the materials under investigation. (Author) [pt

  6. Heat Rejection from a Variable Conductance Heat Pipe Radiator Panel

    Science.gov (United States)

    Jaworske, D. A.; Gibson, M. A.; Hervol, D. S.

    2012-01-01

    A titanium-water heat pipe radiator having an innovative proprietary evaporator configuration was evaluated in a large vacuum chamber equipped with liquid nitrogen cooled cold walls. The radiator was manufactured by Advanced Cooling Technologies, Inc. (ACT), Lancaster, PA, and delivered as part of a Small Business Innovative Research effort. The radiator panel consisted of five titanium-water heat pipes operating as thermosyphons, sandwiched between two polymer matrix composite face sheets. The five variable conductance heat pipes were purposely charged with a small amount of non-condensable gas to control heat flow through the condenser. Heat rejection was evaluated over a wide range of inlet water temperature and flow conditions, and heat rejection was calculated in real-time utilizing a data acquisition system programmed with the Stefan-Boltzmann equation. Thermography through an infra-red transparent window identified heat flow across the panel. Under nominal operation, a maximum heat rejection value of over 2200 Watts was identified. The thermal vacuum evaluation of heat rejection provided critical information on understanding the radiator s performance, and in steady state and transient scenarios provided useful information for validating current thermal models in support of the Fission Power Systems Project.

  7. Effect of helium-neon laser radiation on conventionally - pathogenous microorganisms

    International Nuclear Information System (INIS)

    Shesterina, M.V.; Kalyuk, A.N.; Maliev, B.M.

    1987-01-01

    Results are reported of single and multiple irradiation with low-energy helium-neon lasers (different doses and regimens) on growth and properties of conventionally-pathogenous microflora isolated from patients with pulmonary tuberculosis and cultures of standard microorganisms. The above mentioned laser radiation produced an inhibitory effect on some strains of conventionally-pathogenous microflora manifested in inhibition of the growth properties of cultures as the energy dose increased

  8. Temperature dependence of nonsteady radiation conductivity of polymers

    International Nuclear Information System (INIS)

    Tyutnev, A.P.; Saenko, V.S.; Dunaev, A.F.; Sichkar', V.P.; Vannikov, A.V.

    1984-01-01

    Influence of temperature on non-steady radiation conductivity (NRC) of polymeric dielectrics is investigated. It is revealed that the temperature effects first of all delayed NRC constituent. Temperature increase up to 100 deg C is followed by certain slowing down the rate of current drop of induced conductivity, in this case the nature of the volt-ampere characteristic of delayed NRC constituent does not essentially change, as a rule. The obtained experimental results interpreted in the frames of the band model permitted to make conclusions on the effect of chemical structure of the polymer on its NRC. Presence of carbazole or phenylic groups in the elementary chain is shown to increase the delayed constituent of induced conductivity and to ensure prevailing yield of free charges. Appearance of methyl groups in the composition of the chain essentially suppresses the delayed constituent and results in high values of activation energy and rather slowed down current drop

  9. Motor conduction velocity in the human spinal cord: slowed conduction in multiple sclerosis and radiation myelopathy

    International Nuclear Information System (INIS)

    Snooks, S.J.; Swash, M.

    1985-01-01

    Transcutaneous electrical stimulation of the central nervous system was used to measure motor conduction velocity in the human spinal cord in 21 subjects aged 22 to 75 years (mean 55 years), none of whom had neurological disease. The motor conduction velocity between the sixth cervical (C6) and first lumbar (L1) vertebral levels was 67.4+-9.1 m/s. This probably represents conduction velocity in the corticospinal tracts. In these subjects the motor conduction velocity in the cauda equina, between the first lumbar (L1) and fourth lumbar (L4) vertebral levels, was 57.9+-10.3 m/s. In four of five patients with multiple sclerosis, all with corticospinal signs in the legs, motor conduction velocity between C6 and L1 was slowed (41.8+-16.8 m/s), but cauda equina conduction was normal (55.8+-7.8 m/s). Similar slowing of spinal cord motor conduction was found in a patient with radiation myelopathy. This method should provide a relevant, simple clinical test in patients with spinal cord disease. (author)

  10. Combined conduction and radiation with phase change in teflon slabs

    International Nuclear Information System (INIS)

    Shih, T.M.; Hsu, I.C.; Cunnington, G.R. Jr.

    1986-01-01

    A new approach to investigate, numerically, an one-dimensional Stefan problem with combined radiation and conduction has been developed. This numerical scheme is a modified version of the heat flux method and the scheme tracks the moving phase changing interface by coordinate transformation. The physical problem involves the radiative heating on one side of a Teflon slab; causing the material to melt and sublime as the melt-solid interface recedes. The other side of the Teflon slab is insulated. The results of this numerical scheme has been compared with results reported in the literature; before attempting to use this scheme to predict the experimental data. Satisfactory agreement between numerical results and the results in the literature as well as the experimental data has been obtained in both comparisons

  11. Assessing unregulated ionizing radiation exposures of U.S. populations from conventional industries

    International Nuclear Information System (INIS)

    Pennington, Charles W.

    2006-01-01

    During the latter twentieth century, the public learned to fear perceived threats from emerging technologies. Concern about ionizing radiation became a persistent fear, causing protracted and often pointless debate. The twenty-first century offers new opportunities for this fear to cause public and political upset. Citizens and politicians know little about 'normal' radiation exposures caused by conventional industries. This paper summarizes ionizing radiation exposure assessments of several such industries, showing they deliver multiples of background radiation annually to millions of people, with even higher subpopulation doses due to lognormally distributed exposures. Such information may be useful in educating the public and in supporting comparative assessments or other forms of research on potential sources of public radiation exposure in the twenty-first century. By exposing people to information about normal radiation, we may hope to avoid some unfortunate policies and unnecessary regulatory responses, while abating needless public fear during this technologically challenging century

  12. The effect of radiation induced electrical conductivity (RIC) on the thermal conductivity

    International Nuclear Information System (INIS)

    White, D.P.

    1993-01-01

    Microwave heating of plasmas in fusion reactors requires the development of microwave windows through which the microwaves can pass without great losses. The degradation of the thermal conductivity of alumina in a radiation environment is an important consideration in reliability studies of these microwave windows. Several recent papers have addressed this question at higher temperatures and at low temperatures. The current paper extends the low temperature calculations to determine the effect of phonon-electron scattering on the thermal conductivity at 77 K due to RIC. These low temperature calculations are of interest because the successful application of high power (>1 MW) windows for electron cyclotron heating systems in fusion reactors will most likely require cryogenic cooling to take advantage of the low loss tangent and higher thermal conductivity of candidate window materials at these temperatures

  13. Homogenization of a Conductive-Radiative Heat Transfer Problem

    Directory of Open Access Journals (Sweden)

    Habibi Zakaria

    2012-04-01

    Full Text Available This paper focuses on the contribution of the second order corrector in periodic homogenization applied to a conductive-radiative heat transfer problem. Especially, for a heat conduction problem in a periodically perforated domain with a non-local boundary condition modelling the radiative heat transfer, if this model contains an oscillating thermal source and a thermal exchange with the perforations, the second order corrector helps us to model the gradients which appear between the source area and the perforations. Ce papier est consacré à montrer l’influence du correcteur de second ordre en homogénéisation périodique. Dans l’homogénéisation d’un problème de conduction rayonnement dans un domaine périodiquement perforé par plusieurs trous, on peut voir une contribution non négligeable de ce correcteur lors de la présence d’une source thermique oscillante et d’un échange thermique dans les perforations. Ce correcteur nous permet de modéliser les gradients qui apparaissent entre la zone de la source thermique et les perforations.

  14. Radiation Characteristics of the Cavity Backed Antenna in Conducting Cone

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A technique using finite element and boundary integral method (FE-BI) and reciprocity theorem is presented to analyze the radiation characteristics of cavity backed antenna mounted on a conducting cone. The electric fields inside the cavity and on the aperture are obtained using finite element and boundary integral method. The far-field characteristic of the antenna is computed using reciprocity theorem. The paper begins with a general description of the method. An application of this method is given and the numerical result is compared with the experimental result.

  15. A multilevel method for conductive-radiative heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Banoczi, J.M.; Kelley, C.T. [North Carolina State Univ., Raleigh, NC (United States)

    1996-12-31

    We present a fast multilevel algorithm for the solution of a system of nonlinear integro-differential equations that model steady-state combined radiative-conductive heat transfer. The equations can be formulated as a compact fixed point problem with a fixed point map that requires both a solution of the linear transport equation and the linear heat equation for its evaluation. We use fast transport solvers developed by the second author, to construct an efficient evaluation of the fixed point map and then apply the Atkinson-Brakhage, method, with Newton-GMRES as the coarse mesh solver, to the full nonlinear system.

  16. Postoperative Radiation Therapy for Prostate Cancer: Comparison of Conventional Versus Hypofractionated Radiation Regimens.

    Science.gov (United States)

    Tandberg, Daniel J; Oyekunle, Taofik; Lee, W Robert; Wu, Yuan; Salama, Joseph K; Koontz, Bridget F

    2018-06-01

    To compare acute/late toxicity and biochemical control in contemporaneous prostate cancer patient cohorts treated with hypofractionated postprostatectomy radiation therapy (hypoPORT) or conventional PORT (coPORT). Consecutive patients treated with intensity modulated hypoPORT (2.5 Gy per fraction, median cumulative dose 65 Gy [range, 57.5-70 Gy]) or coPORT (1.8-2.0 Gy per fraction, median cumulative dose 66 Gy [range, 60-74 Gy]) between 2005 and 2016 at 2 institutions constituted the study cohort. Acute toxicity and cumulative late grade 2 and ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity incidences were calculated for all patients using the Kaplan-Meier method and compared between cohorts. Biochemical progression-free survival (bPFS) was calculated in patients with ≥12 months' follow-up. Median follow-up for all 461 patients was 38.6 months. Of the 461 patients, 167 (36%) received hypoPORT, and 294 (64%) patients received coPORT. The hypoPORT cohort had significantly worse baseline urinary incontinence. Acute grade ≥2 GU toxicity was more common after hypoPORT (22% vs 8%) (P = .0001). Late grade ≥3 GU toxicity cumulative incidence at 6 years was 11% (hypoPORT) and 4% (coPORT) (P = .0081). However, hypoPORT was not associated with late grade ≥2 GU toxicity on multivariate analysis (hazard ratio 1.39, 95% confidence interval 0.86-2.34) (P = .18). There was no difference in acute or late GI toxicity. In the subset of patients with ≥12 month's follow-up (n = 364, median follow-up 52 months), 4-year bPFS was 78% (95% CI 69.4-85.0) after hypoPORT (P = .0038) and 65% (95% CI 57.6-71.1) after coPORT. HypoPORT was not significant for bPFS on multivariate analysis (hazard ratio 0.64, 95% CI 0.41-1.02, P = .059). HypoPORT shows promising early biochemical control. After controlling for baseline urinary function, hypoPORT was not associated with greater GU toxicity than coPORT. © 2018 Elsevier Inc. Copyright © 2018 Elsevier Inc. All

  17. A conductive surface coating for Si-CNT radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, Antonio, E-mail: antonio.valentini@ba.infn.it [Dipartimento di Fisica, Università degli Studi di Bari, Via Orabona 4, 70125 Bari (Italy); Valentini, Marco [INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Ditaranto, Nicoletta [Dipartimento di Chimica, Università degli Studi di Bari, Via Amendola 173, 70126 Bari (Italy); Melisi, Domenico [INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Aramo, Carla, E-mail: aramo@na.infn.it [INFN, Sezione di Napoli, Via Cintia 2, 80126 Napoli (Italy); Ambrosio, Antonio [CNR-SPIN U.O.S. di Napoli and Dipartimento di Scienze Fisiche, Università degli Studi di Napoli “Federico II”, Via Cintia 2, 80126 Napoli (Italy); Casamassima, Giuseppe [Dipartimento di Fisica, Università degli Studi di Bari, Via Orabona 4, 70125 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Cilmo, Marco [INFN, Sezione di Napoli, and Dipartimento di Scienze Fisiche, Università degli Studi di Napoli “Federico II”, Via Cintia 2, 80126 Napoli (Italy); Fiandrini, Emanuele [INFN, Sezione di Perugia, and Dipartimento di Fisica, Università degli Studi di Perugia, Piazza Università 1, 06100 Perugia (Italy); Grossi, Valentina [INFN, Sezione di L’Aquila, and Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio 10 Coppito, 67100 L’Aquila (Italy); and others

    2015-08-01

    Silicon–Carbon Nanotube radiation detectors need an electrically conductive coating layer to avoid the nanotube detachment from the silicon substrate and uniformly transmit the electric field to the entire nanotube active surface. Coating material must be transparent to the radiation of interest, and must provide the drain voltage necessary to collect charges generated by incident photons. For this purpose various materials have been tested and proposed in photodetector and photoconverter applications. In this article interface properties and electrical contact behavior of Indium Tin Oxide films on Carbon Nanotubes have been analyzed. Ion Beam Sputtering has been used to grow the transparent conductive layer on the nanotubes. The films were deposited at room temperature with Oxygen/Argon mixture into the sputtering beam, at fixed current and for different beam energies. Optical and electrical analyses have been performed on films. Surface chemical analysis and in depth profiling results obtained by X-ray Photoelectron Spectroscopy of the Indium Tin Oxide layer on nanotubes have been used to obtain the interface composition. Results have been applied in photodetectors realization based on multi wall Carbon Nanotubes on silicon. - Highlights: • ITO was deposited by Ion Beam Sputtering on MWCNT. • ITO on CNT makes an inter-diffusion layer of the order of one hundred nanometers. • Improvements of quantum efficiency of photon detectors based on CNT with ITO.

  18. Radiation protection principles applied to conventional industries producing deleterious environmental effects

    International Nuclear Information System (INIS)

    Tadmor, J.

    1980-01-01

    Comparison of the radiation protection standards, for the population at large, with the conventional pollutants ambient standards, reveals differences in basic principles which result in more relaxed ambient standards for conventional pollutants and consequently, the penalization of the nuclear industry, due to the increased cost of its safety measures. It is proposed that radiation protection principles should be used as a prototype for pollutants having harmful environmental effects and that radiation health physicists should be active in the application of these principles of population protection. A case study of atmospheric release of SO 2 , under different conditions, is analyzed, to emphasize the importance of consideration of the size of the exposed population. (H.K.)

  19. Radiation dose of cone-beam computed tomography compared to conventional radiographs in orthodontics.

    Science.gov (United States)

    Signorelli, Luca; Patcas, Raphael; Peltomäki, Timo; Schätzle, Marc

    2016-01-01

    The aim of this study was to determine radiation doses of different cone-beam computed tomography (CBCT) scan modes in comparison to a conventional set of orthodontic radiographs (COR) by means of phantom dosimetry. Thermoluminescent dosimeter (TLD) chips (3 × 1 × 1 mm) were used on an adult male tissue-equivalent phantom to record the distribution of the absorbed radiation dose. Three different scanning modes (i.e., portrait, normal landscape, and fast scan landscape) were compared to CORs [i.e., conventional lateral (LC) and posteroanterior (PA) cephalograms and digital panoramic radiograph (OPG)]. The following radiation levels were measured: 131.7, 91, and 77 μSv in the portrait, normal landscape, and fast landscape modes, respectively. The overall effective dose for a COR was 35.81 μSv (PA: 8.90 μSv; OPG: 21.87 μSv; LC: 5.03 μSv). Although one CBCT scan may replace all CORs, one set of CORs still entails 2-4 times less radiation than one CBCT. Depending on the scan mode, the radiation dose of a CBCT is about 3-6 times an OPG, 8-14 times a PA, and 15-26 times a lateral LC. Finally, in order to fully reconstruct cephalograms including the cranial base and other important structures, the CBCT portrait mode must be chosen, rendering the difference in radiation exposure even clearer (131.7 vs. 35.81 μSv). Shielding radiation-sensitive organs can reduce the effective dose considerably. CBCT should not be recommended for use in all orthodontic patients as a substitute for a conventional set of radiographs. In CBCT, reducing the height of the field of view and shielding the thyroid are advisable methods and must be implemented to lower the exposure dose.

  20. Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

    International Nuclear Information System (INIS)

    Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S.

    1998-01-01

    Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. The laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, more than one hundred cases were investigated where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. Also, conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987 have been used. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field

  1. Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S. [Institute of Radioprotection and Dosimetry (IRD), National Commission of Nuclear Energy (CNEN), Av. Salvador Allende, Cx. P. 37750, Rio de Janeiro 22.780-160 (Brazil)

    1998-08-03

    Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. The laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, more than one hundred cases were investigated where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. Also, conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987 have been used. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field

  2. Relaxation model of radiation-induced conductivity in polymers

    Science.gov (United States)

    Zhutayeva, Yu. R.; Khatipov, S. A.

    1999-05-01

    The paper suggests a relaxation model of radiation-induced conductivity (RIC) in polymers. According to the model, the transfer of charges generated in the polymer volume by ionizing radiation takes place with the participation of molecular relaxation processes. The mechanism of electron transport consists in the transfer of the charge directly between traps when they draw close to one another due to the rotation of macromolecule segments. The numerical solutions of the corresponding kinetic equations for different distribution functions Q( τ) of the times of molecular relaxation and for different functions of the probability P( τ, τ') of charge transfer in the `overlapping' regions of the diffusion spheres of the segments are analyzed. The relaxation model provides an explanation of the non-Arrhenius behavior of the RIC temperature dependence, the power dependence of RIC on the dose rate with a power index in the interval 0.5-1.0, the appearance of maxima in the curves of the RIC temporal dependence and their irreversible character in the region of large dose rates (more than 1 Gy/s). The model can be used for interpreting polymer RIC in conditions of kinetic mobility of macromolecules.

  3. Comparison of vibrational conductivity and radiative energy transfer methods

    Science.gov (United States)

    Le Bot, A.

    2005-05-01

    This paper is concerned with the comparison of two methods well suited for the prediction of the wideband response of built-up structures subjected to high-frequency vibrational excitation. The first method is sometimes called the vibrational conductivity method and the second one is rather known as the radiosity method in the field of acoustics, or the radiative energy transfer method. Both are based on quite similar physical assumptions i.e. uncorrelated sources, mean response and high-frequency excitation. Both are based on analogies with some equations encountered in the field of heat transfer. However these models do not lead to similar results. This paper compares the two methods. Some numerical simulations on a pair of plates joined along one edge are provided to illustrate the discussion.

  4. Extraction and comparison of proteins from natural rubber latex by conventional and ionizing radiation methods

    International Nuclear Information System (INIS)

    Rogero, Sizue O.; Spencer, Patrick J.; Campos, Vania E.; Lusvarghi, Fabio M.; Higa, Olga Z.

    1997-01-01

    Several proteins in natural rubber latex (NRL) have been assigned to be significant allergens. It is known that proteins submitted to ionizing radiation suffer denaturation and immunochemical modification resulting in low antigenic reactivity. The aim of this study was to extract and compare water extractable proteins from NRL films vulcanized by conventional and by ionizing radiation methods. SDS-polyacrylamide gel electrophoresis (SDS--PAGE) and high pressure liquid chromatography (HPLC) showed a diffuse protein band of about 14 KDa, which we believe is rubber elongation factor (REF), in both eluates, but smaller in latex film vulcanized by ionizing radiation. REF has been suggested to be a major latex allergen. These data suggest that ionizing radiation vulcanization could be an useful method for the production of NRL goods with low antigenicity. (author). 8 refs., 2 figs., 1 tab

  5. Comparing the fundamental physics and device performance of transparent, conductive nanostructured networks with conventional transparent conducting oxides

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Teresa M.; Reese, Matthew O.; Bergeson, Jeremy D.; Larsen, Brian A.; Blackburn, Jeffrey L.; Beard, Matthew C.; Bult, Justin; Van de Lagemaat, Jao [NREL, 1617 Cole Blvd., Golden, CO 80401 (United States)

    2012-03-15

    Networks made of single-walled carbon nanotubes (SWNTs) and metallic nanowire networks, graphene, and ultra-thin metal films have all been proposed as replacements for transparent conducting oxides (TCOs) in photovoltaic and other applications. However, only limited comparisons of nanostructured networks and TCOs are available. Several common figures of merit that are often used to compare the electrical and optical performance of the transparent contacts are evaluated here, and the merits of each method of comparison are discussed. Calculating the current loss due to absorption in the TCO is the most useful metric for evaluating new materials for use in solar cells with well-defined sheet resistance requirements and known quantum efficiencies. The 'Haacke' figure of merit, {phi}{sub H}, correlates fairly well with current loss and is a good metric for evaluating electro-optical performance for more general applications. The analyses presented here demonstrate that silver nanowire networks are much closer to achieving optimal electrical and optical properties than carbon-based networks. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Scientific substantiation of approaches to organization and conducting radiation surveys at the rehabilitated radiation sites

    Directory of Open Access Journals (Sweden)

    I. K. Romanovich

    2017-01-01

    Full Text Available The article is concerned with the scientific justification of approaches to the organization of the final radiation survey of facilities having radioactive contamination, after their rehabilitation. Scientific publications on the previous experience in rehabilitation of facilities contaminated with radionuclides, the organization and conducting a radiation survey before the start of the decontamination, during its implementation and after its completion were analyzed. The experience in the rehabilitation of the site for the temporary storage of spent fuel and radioactive waste in Andreeva Bay in the North-West region of Russia, the locations of peaceful nuclear explosions, experimental nuclear power plants, a radiochemical laboratory, and metallurgical plants, that do not belong to radiation facilities, has been studied. It has been established that, besides the surface contamination of the soil, areas of radioactive contamination on sites of decommissioned radiation facilities with significant depth up to 15 m along the profile are available. These local zones with depth soil contamination are persistent contaminants of the groundwater. The experience in the radiation survey of the peaceful nuclear explosions sites shows the removal of radionuclides from cavities, formed with the use of nuclear explosive technologies for peaceful purposes, on the earth’s surface. An optimized list of radionuclides to be monitored during the radiological survey of rehabilitated facilities was proposed based on the analysis of the composition of radionuclides detected at radiation sites subjected to decontamination. The optimized list includes 14 radionuclides with the half-lives of more than three years. 

  7. Spinal cordd biological safety comparison of intensity modulated radiotherapy and conventional radiation therapy

    International Nuclear Information System (INIS)

    Xilinbaoleri; Xu Wanlong; Chen Gang; Liu Hao; Wang Ruozheng; Bai Jingping

    2010-01-01

    Objective: To compare the spine intensity modulated radiation therapy (IMRT) and the conventional radiation therapy on the beagle spinal cord neurons, in order to prove the biological safety of IMRT of the spinal cord. Methods: Twelve selected purebred beagles were randomly divided into 2 groups. A beagle clinical model of tumor was mimiced in the ninth and tenth thoracic vertebrae. Then the beagles were irradiated by 2 different models of intensity modulated radiotherapy and conventional radiation therapy, with the total irradiation doses of 50 and 70 Gy. The samples of spinal cord were taken out from the same position of the nine and tenth thoracic vertebrae at the third month after radiation.All the samples were observed by the electron microscope, and the Fas and HSP70 expression in spinal cord neurons were evaluated by immunohistochemistry method. Terminal deoxynucleatidyl transferase mediated dUTP nick and labeling (TUNEL) technique was used to examine the apoptotic cells in the spinal cord. Results: The neurons in the spinal cord of IMRT group were mainly reversible injury, and those in the conventional radiation therapy were mainly apoptosis. Compared with the conventional radiation therapy group [50 Gy group, (7.3 ± 1.1)%; 70 Gy group, (11.3 ± 1.4)%], the apoptosis rate of the spinal cord neurons of the intensity modulated radiotherapy group [50 Gy group, (1.2 ± 0.7)%; 70 Gy group (2.5 ± 0.8)%] was much lower[(50 Gy group, t=0.022, P<0.05; 70 Gy group, t=0.017, P<0.05)]. The expression levels of Fas in the IMPT group (50 Gy group, 4.6 ± 0.8; 70 Gy group, 7.4 ± 1.1) were also much lowerthan those in the other group (50 Gy group, 15.1 ± 6.4; 70 Gy group, 19.3 ± 7.6. 50 Gy group, t=0.231, P<0.05; 70 Gy group, t=0.457, P<0.05), while the expression levels of HSP70 in the IMPT group (50 Gy group, 9.1 ± 0.8; 70 Gy group, 7.3 ± 1.4)were much higher than those in the conventional radiation therapy group (50 Gy group, 2.1 ± 0.9; 70 Gy group, 1.7 ± 0

  8. Treatment of waste water by a combined technique of radiation and conventional method

    International Nuclear Information System (INIS)

    Sakumoto, A.; Miyata, T.

    1984-01-01

    Treatment of waste water by radiation in combination with a conventional method such as biological oxidation, coagulation with Fe 2 (SO 4 ) 3 , and ozonation has been studied for reducing necessary dose. Ethylene glycol ethers, polyoxyethylene n-nonyl phenyl ether (NPE), polyvinyl alcohol (PVA), ethylene glycol, phenol, and oxalic acid were used as a model pollutant. The combined use of radiation and biological oxidation markedly improved the removal of TOC in aqueous oxygenated solution of ethylene glycol ethers. The combined use of radiation and coagulation had remarkable effects on the reduction of TOC in aqueous deoxygenated solution of NPE or PVA. The simultaneous use of radiation and ozone gave a synergistic effect on oxidative degradation of organic pollutants. The synergistic effect was suggested to arise from chain reactions having a powerful oxidizing agent (OH radical). The rate of TOC removal by the process depended on dose rate. Aqueous solution of 150 mg/l oxalic acid was treated by the combined use of electron beams and ozone using a new type of irradiation vessel to reduce TOC with G(-TOC) of 87 at 2.3 x 10 7 rad/h. The simultaneous use of radiation and ozone is superior to the removal of TOC by other combined methods and can be applied irrespective of the type of organic matter. (author)

  9. Comparison of Hydraulic Conductivity Determinations in Co-located Conventional and Direct-Push Monitoring Wells

    Science.gov (United States)

    2011-03-08

    and Development Center (ERDC) provided the funding for this project. We wish to thank our project monitors Tony Bednar (ERDC Environmental Laboratory...method for field determination of hy- draulic conductivity at contaminated sites (Butler 1997; Henebry and Robbins 2000; Bartlett et al. 2004). For a...ASTM International. www.astm.org Bartlett, Stephen A., Gary A. Robbins , J. Douglas Mandrick, Michael Barcelona, Wes McCall, and Mark Kram. 2004

  10. A non-conventional technique for evaluating welded joints based on the electrical conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.G.; Sorger, G., E-mail: telmo.santos@fct.unl.pt, E-mail: lgs18243@campus.fct.unl.pt [Universidade Nova de Lisboa, UNIDEMI, Departamento de Engenharia Mecanica e Industrial, Faculdade de Ciencias e Tecnologia, Caparica (Portugal); Vilaca, P., E-mail: pedro.vilaca@aalto.fi [Aalto Univ., Dept. of Engineering Design and Production, School of Engineering, Aalto (Finland); Miranda, R., E-mail: rmiranda@fct.unl.pt [Universidade Nova de Lisboa, UNIDEMI, Departamento de Engenharia Mecanica e Industrial, Faculdade de Ciencias e Tecnologia, Caparica (Portugal)

    2015-01-15

    Recent studies showed that electrical conductivity is a valuable technique to identify the different zones of solid-state welded joints with a good correlation with the microstructure and hardness. This is a relevant result since this technique is fast and, in some cases, non destructive, The concept was applied to other welding processes such as the ones involving fusion to a wide range of materials, For this, a comprehensive study was performed using friction stir welding, tungsten inert gas (TlG) and gas metal arc (MAG) welding processes in either bead on plate or butt joints in: carbon steel, magnesium and titanium, Eddy current nondestructive testing (NDT) was used to measure the electrical conductivity at different depths in transverse sections of the processed materials. The profiles were compared to the hardness profiles in the same sections. As a result, a correlation was observed in most materials welded by solid state and by fusion processes. The variation of the electrical conductivity closely follows that measured in the hardness. Another interesting conclusion is that, even for fusion welding of carbon steels, the technique has potential to complement the hardness measurements and microstructural observations, allowing the identification of the distinct zones of welds in materials commonly used in industry. (author)

  11. Patient radiation doses in upper GI examinations: a comparison between conventional and double-contrast techniques.

    Science.gov (United States)

    Bankvall, G; Owman, T

    1982-01-01

    A total of 60 patients, divided into 3 groups with 20 patients in each, were examined with 3 different techniques: group 1 -- conventional technique, exposure at 120 kV; group 2 -- double-contrast technique (hypotonic gastrography, HG), exposure at 80 kW; group 3 -- HG, exposure at 120 kV. All examinations were performed in the same examination room and by the same radiologist. Absorbed doses to skin, thyroid, breasts, and gonads as well as energy imparted were measured. The only significant dose enhancements found when using double-contrast instead of conventional technique were in the female breasts and then only if the voltage was in the lower range. With exposure at 120 kV there was little difference in absorbed dose, but a significant advantage with respect to energy was imparted when using a double-contrast technique instead of a conventional technique. The testes doses were very low in all 3 types of examinations, and it seems that use of a testes shield is hardly motivated. With regard to both diagnostic accuracy and patient radiation dose, there can be no reason to use a conventional technique for upper GI examinations.

  12. Exploration of the possibility of high LET radiation for non-conventional radiotherapy in cancer

    International Nuclear Information System (INIS)

    1986-12-01

    The report summarizes the results of the researches performed by scientists from six Member States under an Agency-sponsored co-ordinated research programme (CRP) on exploration of the possibility of high linear energy transfer (LET) radiation for non-conventional radiotherapy in cancer. The projects within the CRP were focused on radiobiological and clinical aspects of neutron beam (3 reports) and neutron capture (2 reports), heavy ion beam (2 reports) and proton (1 report) therapy. A summary report is included. A separate abstract was prepared for each of these reports

  13. Radiation exposure in X-ray angiography and comparisons between digital and conventional methods of imaging

    International Nuclear Information System (INIS)

    Schaberg, J.

    1987-01-01

    The more recent developments and techniques in the field of angiography are examined for associated radiation exposure risks for patients and investigators and then compared to the conventional methods of angiography. It could be shown that digital subtraction angiography is generally associated with a lesser risk of somatic exposure of the patient, provided that the equipment used offers an adjustable useful-beam range and focus. The fact that above-table X-ray tubes are now generally replaced with X-ray systems installed under the examination table permits the relatively high doses, to which investigators are exposed during angiography, to be reduced by a factor of 3. (DG) [de

  14. Radiation safety study for conventional facility and siting pre project phase of International Linear Collider

    International Nuclear Information System (INIS)

    Sanami, Toshiya; Ban, Syuichi; Sasaki, Shin-ichi

    2015-01-01

    The International Linear Collider (ILC) is a proposed high-energy collider consisting of two linear accelerators, two dumping rings, electron and positron sources, and a single colliding hall with two detectors. The total length and CMS energy of the ILC will be 31 km and 500 GeV, respectively (and 50 km and 1 TeV after future upgrade). The design of the ILC has entered the pre-project phase, which includes site-dependent design. Radiation safety design for the ILC is on-going as a part of conventional facility and siting activities of the pre-project phase. The thickness of a central wall of normal concrete is designed to be 3.5 m under a pessimistic assumption of beam loss. The beam loss scenario is under discussion. Experience and knowledge relating to shielding design and radiation control operational work at other laboratories are required. (authors)

  15. Radiation interlocks - The choice between conventional hard-wired logic and computer-based systems

    International Nuclear Information System (INIS)

    Crook, K.F.

    1987-01-01

    During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system? Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy (DOE) has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper reviews the status of the committee's recommendations, and describes radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional (relay) approach and designs using computers

  16. Radiation interlocks: The choice between conventional hard-wired logic and computer-based systems

    International Nuclear Information System (INIS)

    Crook, K.F.

    1986-11-01

    During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system. Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper will review the status of the committee's recommendations, and describe radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional relay approach and designs using computers. 6 refs., 6 figs

  17. Monitoring the enzymatic conversion of urea to ammonium by conventional or microchip capillary electrophoresis with contactless conductivity detection.

    Science.gov (United States)

    Schuchert-Shi, Aiping; Hauser, Peter C

    2008-05-15

    Capillary electrophoresis with contactless conductivity detection was used to directly quantify the ammonium produced in the enzymatic conversion of urea with urease. This allowed the characterization of the reaction without having to use more elaborate indirect optical methods for quantification. The maximum rate of reaction, V(max), was determined as 5.1 mmol x mL(-1) x min(-1), and the Michaelis-Menten constant, K(m), was determined as 16 mM. Furthermore, the method was successfully applied to the determination of urea in clinical samples of human blood by using a conventional capillary and a microchip device.

  18. Radiation exposure of the Yazd Population from medical conventional X-ray examinations

    International Nuclear Information System (INIS)

    Bouzarjomehri, F.; Zare, M. H.; Dashti, M. H.

    2007-01-01

    Radiation dose knowledge through X-ray examinations and their distribution in Iran provides useful guidance on patient dose reduction. The results of the entrance skin dose (ESD s ) of five common radiographs in all radiology centers in Yazd province were reported in our previous study (2003). In the present study we have evaluated the collective effective dose of conventional X-ray examinations, as well as the annual per caput of Yazd population.Materials and Methods: The annual frequencies of 18 different types of conventional radiology examinations during April 2005 to March 2006 were recorded from all 35 radiology centers in Yazd province. The exposure conditions consisted of kVp, mAs, and Focus surface distance (FSD) of the examinations for the mode of exposure in each X-ray unit. 620 ESD were measured by diode dosimeter in 35 hospitals and clinics. The real exposure kVp for each radiology unit was measured by a Molt-0-Meter. The conversion coefficient (effective dose - ESD ratio) for each radiology examination was determined by using SR262 tables. Finally, the patients' effective dose was calculated by multiplying the conversion factor to the ESD. Results: The patients' annual collective effective dose due to the conventional radiology examinations was 31.159 man-Sv (0.03 mSv per inhabitant). The frequency of examinations was 311813 i.e. 0.36 examinations per head of the population for one year. Conclusion: According to our findings, the effective per caput dose seems to be optimally relative to HCL-II countries, which may be due to low mean effective dose that could obscure high examination frequency. The number of radiology conventional examinations and frequency of radiologist per1000 population of Yazd was more and lower than HCL-II countries respectively. Thus the justification of radiography requests in this province must be revised

  19. Radiation induced synthesis of conducting polymers and their metal nano-composites

    International Nuclear Information System (INIS)

    Cui, Zhenpeng

    2017-01-01

    The aim of the present work is to demonstrate the versatility of the gamma (γ)-rays based radiolytic method and to extend our methodology to the synthesis of various conducting polymers (CPs) in water in different experimental conditions. Poly(3,4-ethylenedioxy-thiophene) (PEDOT) and poly-pyrrole (PPy) conjugated polymers were successfully prepared and characterized in solution and after deposition by complementary spectroscopic and microscopic techniques. Also their thermal stability and their electrical conductivity were studied and compared with those of CPs prepared by conventional methods. The influence of the nature of radiation-induced oxidizing radicals, of the ionic strength, of the medium, of the pH, of the presence of surfactant-based soft templates on the growth mechanism, on the efficiency of polymerization, on the morphology of the obtained CPs as well as on their absorption and conducting properties was checked. Also, the radiolytic method was extend to the synthesis of CPs/noble metal nano-composites. Different preparation methodologies were developed based on two-step method and one-pot method, by using oxidation route or reduction route. Our new radiolytic strategy described and extended in this manuscript opens the way for the preparation of different kinds of CPs and CPs nano-composites not only in aqueous solutions but also in various environments foreshadowing many promising applications.. (author)

  20. The treatment of prostate cancer by conventional radiation therapy: an analysis of long-term outcome

    Energy Technology Data Exchange (ETDEWEB)

    Zietman, Anthony L; Coen, John J; Dallow, Katherine C; Shipley, William U

    1995-05-15

    Purpose: To assess the long-term outcome of conventional external beam radiation therapy in the management of clinically confined prostate cancer and to examine the proposition that radiation accelerates tumor growth in those who fail treatment. Methods and Materials: One thousand and forty-four men with T1-4NxM0 prostate cancer treated by conventional external beam radiation therapy at the Massachusetts General Hospital between 1977 and 1991 were analyzed. Median follow-up was 49 months. Failure was defined as: two sequential rises in serum prostate specific antigen (PSA) level; or a PSA > 1 ng/ml 2 or more years after radiation; or any clinical failure. Kaplan-Meier actuarial analyses were used to assess outcome. Results: At 10 years only 40% of the T1-2 group remained disease free. When subdivided by grade, the well-differentiated tumors (Gleason 1-2) exhibited a 53% actuarial 10-year disease-free survival, moderately differentiated (Gleason 3) 42%, and poorly differentiated (Gleason 4-5) 20%. The corresponding values for the T3-4 men were 33% for Gleason 1-2, 20% for Gleason 3, and 10% for Gleason 4-5. Overall the value for T3-4 tumors was 18% at 10 years. On relapse the median PSA doubling times for the T1-2 patients were predicted by histology: 18.8 months for Gleason 1-2 patients; 11.1 months for Gleason 3; and 9.6 months for Gleason 5. Significant differences were found between the Gleason 3 and the Gleason 4-5 groups (p = 0.04) and the Gleason 1-2 and the Gleason 4-5 groups (p = 0.03). A wide range of doubling times was seen within each grade group. When compared with recently reported data on selected T1-2 patients who were managed by expectant observation there was no advantage over the first decade (and certainly no disadvantage) in terms of metastasis-free survival or disease-specific survival for the irradiated Gleason 1-3 patients. However, a gain was seen for those with Gleason 4-5 tumors. Conclusion: Less than half of the T1-2NxM0 and less than one

  1. Combined conduction and radiation in a two-layer planar medium with flux boundary condition

    International Nuclear Information System (INIS)

    Ho, C.H.; Ozisik, M.N.

    1987-01-01

    The interaction of conduction and radiation is investigated under both transient and steady-state conditions for an absorbing, emitting, and isotropically scattering two-layer slab having opaque coverings at both boundaries. The slab is subjected to an externally applied constant heat flux at one boundary surface and dissipates heat by radiation into external ambients from both boundary surfaces. An analytic approach is applied to solve the radiation part of the problem, and a finite-difference scheme is used to solve the conduction part. The effects of the conduction-to-radiation parameter, the single scattering albedo, the optical thickness, and the surface emissivity on the temperature distribution are examined

  2. Coupling heat conduction and radiation in complex 2D and 3D geometries

    International Nuclear Information System (INIS)

    Peniguel, C.

    1997-01-01

    Thermal radiation is a very important mode of heat transfer in most real industrial systems. A numerical approach coupling radiation (restricted to non participant medium) and conduction is presented. The code (SYRTHES) is able to handle 2D and 3D problems (including cases with symmetries and periodicity). Radiation is solved by a radiosity approach, and conduction by a finite element method. Accurate and efficient algorithms based on a mixing of analytical/numerical integration, and ray tracing techniques are used to compute the view factors. Validation has been performed on numerous test cases. A conjugate residual algorithm solves the radiosity system. An explicit interactive numerical procedure is then used to couple conduction and radiation. No stability problem has been encountered so far. One specificity of SYRTHES is that conduction and radiation are solved on independent grids. This brings much flexibility and allows to keep the number of independent radiation patches at a reasonable level. Several industrial examples are given as illustration. (author)

  3. Exposure to radiation through the residual activity of waste treated by conventional methods

    International Nuclear Information System (INIS)

    Deckert, A.; Hoppe, G.; John, T.; Thierfeldt, S.

    1993-01-01

    Data obtained by questionnaires provided information on the type, amount, nuclide vector and maximum permissible value of low-level radioactive residues that occur in nuclear installations of due to industrial, scientific and medical uses of radioactive materials and are officially released to be disposed of by conventional methods. The general legal background of waste disposal methods, in particular the official regulations surrounding the waste disposal law, were described. On this basis, parameters and maximum radioactive burdens were specifically defined for garbage dumps for refuse from private households and those for building rubbish. Investigations were carried out into exposure paths that may have a role in the radioactive doses taken up by personnel (inhalation) or the general population (ingestion) through contaminated water. The radiation dose attributable to those exposure paths were expressed in relation to a specific unit activity of waste (1 bq/G). A dose of 10 μ Sv/r was taken as a standard to define a threshold value for each individual nuclide released for conventional waste disposal. It appears reasonable that such values are determined for groups of nuclides. (HP) [de

  4. Measurements of surgeons' exposure to ionizing radiation dose: comparison of conventional and mini C-arm fluoroscopy.

    Science.gov (United States)

    Sung, K H; Min, E; Chung, C Y; Jo, B C; Park, M S; Lee, K

    2016-03-01

    This study was performed to measure the equivalent scattered radiation dose delivered to susceptible organs while simulating orthopaedic surgery using conventional and mini C-arm fluoroscopy. In addition, shielding effects on the thyroid, thymus, and gonad, and the direct exposure delivered to the patient's hands were also compared. A conventional and mini C-arms were installed in an operating room, and a hand and an operator phantom were used to simulate a patient's hand and a surgeon. Photoluminescence dosimeters were used to measure the equivalent dose by scattered radiation arriving at the thyroid, thymus, and gonad on a whole-body phantom in the position of the surgeon. Equivalent scattered radiation doses were measured in four groups: (1) unshielded conventional C-arm group; (2) unshielded mini C-arm group; (3) lead-shielded conventional C-arm group; and (4) lead-shielded mini C-arm group. Equivalent scattered radiation doses to the unshielded group were significantly lower in the mini C-arm group than those in the conventional C-arm group for all organs. The gonad in the lead-shielded conventional C-arm group showed the highest equivalent dose among operator-susceptible organs, and radiation dose was reduced by approximately 96% compared with that in the unshielded group. Scattered radiation was not detected in any susceptible organ in the lead-shielded mini C-arm group. The direct radiation dose to the hand phantom measured from the mini C-arm was significantly lower than that measured from the conventional C-arm. The results show that the equivalent scattered radiation dose to the surgeon's susceptible organs and the direct radiation dose to a patient's hand can be decreased significantly by using a mini C-arm rather than a conventional C-arm. However, protective lead garments, such as a thyroid shield and apron, should be applied to minimize radiation exposure to susceptible organs, even during use of mini C-arm fluoroscopy. © The Author(s) 2015.

  5. Acute radiation dermatitis and pneumonitis in Japanese breast cancer patients with whole breast hypofractionated radiotherapy compared to conventional radiotherapy

    International Nuclear Information System (INIS)

    Osako, Tomo; Oguchi, Masahiko; Kumada, Madoka; Nemoto, Keiko; Iwase, Takuji; Yamashita, Takashi

    2008-01-01

    The objective of this study was to evaluate acute morbidity, radiation dermatitis and pneumonitis, of Japanese patients treated with whole breast hypofractionated radiotherapy (RT) after breast-conserving surgery (BCS), compared to conventional RT. Japanese patients who received whole breast RT after BCS between October 2003 and September 2006 were retrospectively reviewed. Patients who had selected the conventional or hypofractionated schedule received whole breast irradiation of 50 Gy in 25 fractions plus boost or 40 Gy in 16 fractions plus boost. Radiation dermatitis and symptomatic pneumonitis were graded according to the Common Terminology Criteria for Adverse Events version 3.0. Of 443 consecutive patients, 377 (85%) received the conventional schedule and 66 (15%) received the hypofractionated schedule. Of patients treated with the conventional schedule, Grade 0, 1, 2 and 3 radiation dermatitis were observed in 16 (4%), 278 (74%), 77 (20%) and 6 (2%), respectively. Of patients treated with the hypofractionated schedule, Grade 0, 1, 2 and 3 dermatitis were observed in 11 (17%), 49 (74%), 5 (8%) and 1 (1%), respectively. Grade 2-3 dermatitis by the hypofractionated schedule (9%) was observed less frequently than that by the conventional schedule (22%) (chi-square test; P=0.016). Moreover, of patients treated with the conventional schedule, 4 (1%) had Grade 2 radiation pneumonitis. No patient treated with the hypofractionated schedule had symptomatic pneumonitis. Radiation dermatitis and pneumonitis in Japanese patients treated with the hypofractionated schedule is acceptable. Especially, radiation dermatitis by the hypofractionated schedule is milder than that by the conventional schedule. (author)

  6. Discussion of feasibility to carry out intensity modulated radiation therapy in conventional medical electron linear accelerator treatment rooms

    International Nuclear Information System (INIS)

    Yang Haiyou; Liu Liping; Liang Yueqin; Zhang Liang; Yu Shui

    2010-01-01

    Objective: To investigate the feasibility about the shielding effect of conventional medical electron linear accelerator treatment in the existing rooms to carry out intensity modulated radiation therapy (IMRT). Methods: The estimation model given in NCRP REPORT No. 151- S tructural Shielding Design and Evaluation for Megavoltage X-and Gamma-Ray Radiotherapy Facilities i s adopted by linking instances, which presents the calculation methods on radiation level at the ambience of megavoltage medical electron linear accelerator treatment room. Results: The radiation level, as well as the additional annual effect dose of occupational and public at the ambience of accelerator treatment room, in crease to a certain extent, when conventional medical electron linear accelerator treatment room; are used to carry out IMRT. Conclusion: It is necessary to make environmental impact assessment for conventional medical electron linear accelerator treatment rooms, which will be used to execute IMRT. (authors)

  7. Computation of radiation from wire antennas on conducting bodies

    DEFF Research Database (Denmark)

    Albertsen, N. Christian; Hansen, Jesper; Jensen, Niels E.

    1974-01-01

    A theoretical formulation, in terms of combined magnetic and electric field integral equations, is presented for the class of electromagnetic problems in which one or more wire antennas are connected to a conducting body of arbitrary shape. The formulation is suitable for numerical computation...... provided that the overall dimensions of the structure are not large compared to the wavelength. A computer program is described, and test runs on various configurations involving a cylindrical body with one or more straight wires are presented. The results obtained agree well with experimental data....

  8. Dose to radiation therapists from activation at high-energy accelerators used for conventional and intensity-modulated radiation therapy

    International Nuclear Information System (INIS)

    Rawlinson, J. Alan; Islam, Mohammad K.; Galbraith, Duncan M.

    2002-01-01

    The increased beam-on times which characterize intensity-modulated radiation therapy (IMRT) could lead to an increase in the dose received by radiation therapists due to induced activity. To examine this, gamma ray spectrometry was used to identify the major isotopes responsible for activation at a representative location in the treatment room of an 18 MV accelerator (Varian Clinac 21EX). These were found to be 28 Al, 56 Mn, and 24 Na. The decay of the dose rate measured at this location following irradiation was analyzed in terms of the known half-lives to yield saturation dose rates of 9.6, 12.4, and 6.2 μSv/h, respectively. A formalism was developed to estimate activation dose (μSv/week) due to successive patient irradiation cycles, characterized by the number of 18 MV fractions per week, F, the number of MU per fraction, M, the in-room time between fractions, t d (min), and the treatment delivery time t r ' (min). The results are represented by the sum of two formulas, one for the dose from 28 Al≅1.8x10 -3 F M (1-e -0.3t r ' )/t r ' and one for the dose from the other isotopes ≅1.1x10 -6 F 1.7 Mt d . For conventional therapy doses are about 60 μ Sv/week for an 18 MV workload of 60 000 MU/week. Irradiation for QA purposes can significantly increase the dose. For IMRT as currently practiced, lengthy treatment delivery times limit the number of fractions that can be delivered per week and hence limit the dose to values similar to those in conventional therapy. However for an IMRT regime designed to maximize patient throughput, doses up to 330 μSv/week could be expected. To reduce dose it is recommended that IMRT treatments should be delivered at energies lower than 18 MV, that in multienergy IMRT, high-energy treatments should be scheduled in the latter part of the day, and that equipment manufacturers should strive to minimize activation in the design of high-energy accelerators

  9. Radiative and conductive heat transfer in a nongrey semitransparent medium. Application to fire protection curtains

    Energy Technology Data Exchange (ETDEWEB)

    Berour, Nacer; Lacroix, David E-mail: david.lacroix@lemta.uhp-nancy.fr; Boulet, Pascal; Jeandel, Gerard

    2004-06-01

    This paper deals with heat transfer in nongrey media which scatter, absorb and emit radiation. Considering a two dimensional geometry, radiative and conductive phenomena through the medium have been taken into account. The radiative part of the problem was solved using the discrete ordinate method with classical S{sub n} quadratures. The absorption and scattering coefficients involved in the radiative transfer equation (RTE) were obtained from the Mie theory. Conduction inside the medium was linked to the RTE through the energy conservation. Validation of the model has been achieved with several simulation of water spray curtains used as fire protection walls.

  10. Radiation cross-linking of PTC conductive polymers

    International Nuclear Information System (INIS)

    Doljack, F.A.; Jacobs, S.M.; Taylor, J.M.; McTavish, M.S.

    1982-01-01

    An electrical device comprising a PTC conductive polymer is irradiated so that it is very highly cross-linked. A dosage of at least 50 Mrads, preferably at least 80 Mrads, especially at least 120 Mrads is used except that where the device includes planar electrodes which are present during irradiation the minimum dose is 120 Mrads. In this way, for example, it is possible to make a circuit protection device which will continue to provide effective protection even after repeated exposure to a voltage of 200 volts. A PTC protection device may be produced by moulding carbon loaded polymer round three electrodes the centre one of which is then removed to leave an aperture between the other two electrodes. (author)

  11. Radiation and gas conduction heat transport across a helium dewer multilayer insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    This report describes a method for calculating mixed heat transfer through the multilayer insulation used to insulated a 4K liquid helium cryostat. The method described permits one to estimate the insulation potential for a multilayer insulation system from first principles. The heat transfer regimes included are: radiation, conduction by free molecule gas conduction, and conduction through continuum gas conduction. Heat transfer in the transition region between the two gas conduction regimes is also included.

  12. Macroscopic Hematuria After Conventional or Hypofractionated Radiation Therapy: Results From a Prospective Phase 3 Study

    Energy Technology Data Exchange (ETDEWEB)

    Sanguineti, Giuseppe, E-mail: sanguineti@ifo.it [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Arcidiacono, Fabio [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Landoni, Valeria [Department of Physics, Regina Elena National Cancer Institute, Rome (Italy); Saracino, Bianca Maria; Farneti, Alessia; Arcangeli, Stefano; Petrongari, Maria Grazia; Gomellini, Sara [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Strigari, Lidia [Department of Physics, Regina Elena National Cancer Institute, Rome (Italy); Arcangeli, Giorgio [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy)

    2016-10-01

    Purpose: To assess the macroscopic hematuria rates within a single-institution randomized phase 3 trial comparing dose-escalated, conventionally fractionated radiation therapy (CFRT) and moderately hypofractionated radiation therapy (MHRT) for localized prostate cancer. Methods and Materials: Patients with intermediate- to high-risk localized prostate cancer were treated with conformal RT and short-course androgen deprivation. Both the prostate and the entire seminal vesicles were treated to 80 Gy in 40 fractions over 8 weeks (CFRT) or 62 Gy in 20 fractions over 5 weeks (MHRT). The endpoint of the present study was the development of any episode or grade of macroscopic hematuria. The median follow-up period was 93 months (range 6-143). Results: Macroscopic hematuria was reported by 25 of 168 patients (14.9%). The actuarial estimate of hematuria at 8 years was 17.0% (95% confidence interval [CI] 10.7%-23.3%). The number of patients with hematuria was 6 and 19 in the CFRT and MHRT arms, respectively, for an actuarial 8-year estimate of 9.7% and 24.3%, respectively (hazard ratio 3.468, 95% CI 1.385-8.684; P=.008). Overall, 8 of 25 patients were found to have biopsy-proven urothelial carcinoma (3 in the CFRT arm and 5 in the MHRT arm; P=.27). Thus, the 8-year actuarial incidence of macroscopic hematuria (after censoring urothelial cancer–related episodes) was 4.1% and 18.2% after CFRT and MHRT, respectively (hazard ratio 4.961, 95% CI 1.426-17.263; P=.012). The results were confirmed by multivariate analysis after accounting for several patient-, treatment-, and tumor-related covariates. Conclusions: MHRT was associated with a statistically significant increased risk of macroscopic hematuria compared with CFRT.

  13. Macroscopic Hematuria After Conventional or Hypofractionated Radiation Therapy: Results From a Prospective Phase 3 Study

    International Nuclear Information System (INIS)

    Sanguineti, Giuseppe; Arcidiacono, Fabio; Landoni, Valeria; Saracino, Bianca Maria; Farneti, Alessia; Arcangeli, Stefano; Petrongari, Maria Grazia; Gomellini, Sara; Strigari, Lidia; Arcangeli, Giorgio

    2016-01-01

    Purpose: To assess the macroscopic hematuria rates within a single-institution randomized phase 3 trial comparing dose-escalated, conventionally fractionated radiation therapy (CFRT) and moderately hypofractionated radiation therapy (MHRT) for localized prostate cancer. Methods and Materials: Patients with intermediate- to high-risk localized prostate cancer were treated with conformal RT and short-course androgen deprivation. Both the prostate and the entire seminal vesicles were treated to 80 Gy in 40 fractions over 8 weeks (CFRT) or 62 Gy in 20 fractions over 5 weeks (MHRT). The endpoint of the present study was the development of any episode or grade of macroscopic hematuria. The median follow-up period was 93 months (range 6-143). Results: Macroscopic hematuria was reported by 25 of 168 patients (14.9%). The actuarial estimate of hematuria at 8 years was 17.0% (95% confidence interval [CI] 10.7%-23.3%). The number of patients with hematuria was 6 and 19 in the CFRT and MHRT arms, respectively, for an actuarial 8-year estimate of 9.7% and 24.3%, respectively (hazard ratio 3.468, 95% CI 1.385-8.684; P=.008). Overall, 8 of 25 patients were found to have biopsy-proven urothelial carcinoma (3 in the CFRT arm and 5 in the MHRT arm; P=.27). Thus, the 8-year actuarial incidence of macroscopic hematuria (after censoring urothelial cancer–related episodes) was 4.1% and 18.2% after CFRT and MHRT, respectively (hazard ratio 4.961, 95% CI 1.426-17.263; P=.012). The results were confirmed by multivariate analysis after accounting for several patient-, treatment-, and tumor-related covariates. Conclusions: MHRT was associated with a statistically significant increased risk of macroscopic hematuria compared with CFRT.

  14. Dosimetry study on the conventional and three dimensional conformal radiation treatment planning protocols for rectal cancer

    International Nuclear Information System (INIS)

    Cai Yong; He Yuxiang; Han Shukui; Wu Hao; Gong Jian; Xu Bo

    2007-01-01

    Objective: To compare the dose distribution of clinical target volume (CTV), in normal tissues and organs for patients with rectal cancer on the conventional radiotherapy (2D) and three dimension- al conformal radiation treatment (3DCRT). Methods: The CT image data of 36 rectal cancer patients treated with 3DCRT were studied. The CTV, small bowel, colon, bladder, pelvic bone marrow, and femoral head and neck were contoured on consecutive axial slices of CT images. Two 3DCRT and three conventional treatment planning protocols were simulated using three dimensional treatment planning system (CMS Focus 2.31), were defined as 3D-3, 3D-4, 2D-2, 2D-3, 2D-4. The difference of five treatment planning protocols on the CTV and normal structure by analysis of dose-volume histograms (DVHs) were compared. Results: The D 95 and V 95 of these five protocols all exceeded 97%. The conformity index(CI) of 3D was obviously larger than that of 2D protocol. The dose inhomogeneity(DI) in 4 DCRT was less than that of 3 DCRT. The 3D as compared with the 2D, significantly reduced the mean dose of 45 Gy to the small bowel and colon. The 3D-3 as compared with the 2D-3, the 3D-4 as compared with the 2D-4, the mean dose of small bowel and colon was reduced by 28.5% and 25.7%, respectively. The 3D-3 as compared with the 2D-2, the 3D-3 as compared with the 2D-3 and the 3D4 as compared with the 2D-4, the percentage volume of small bowel and colon which received 45 Gy was reduced by 80.8% , 51.1% and 54.7% , respectively. Either the mean dose, or the percentage volume receiving 35 Gy and 45 Gy to the pelvic bone and bladder, the 3D planning protocols had advanage over the 2D planning protocols. The V 45 of bladder in 2D-2 planning proto- col was the highest in all planning protocols, exceeding 98%, but the highest V 45 of bladder was only 50% in the other planning protocols. Conclusions: Even though the difference in pelvic CTV of rectal cancer patients between the conventional radiotherapy and 3

  15. Comparison of the radiobiological effects of Boron neutron capture therapy (BNCT) and conventional Gamma Radiation

    International Nuclear Information System (INIS)

    Dagrosa, Maria A.; Carpano, Marina; Perona, Marina; Thomasz, Lisa; Juvenal, Guillermo J.; Pisarev, Mario; Pozzi, Emiliano; Thorp, Silvia

    2009-01-01

    BNCT is an experimental radiotherapeutic modality that uses the capacity of the isotope 10 B to capture thermal neutrons leading to the production of 4 He and 7 Li, particles with high linear energy transfer (LET). The aim was to evaluate and compare in vitro the mechanisms of response to the radiation arising of BNCT and conventional gamma therapy. We measured the survival cell fraction as a function of the total physical dose and analyzed the expression of p27/Kip1 and p53 by Western blotting in cells of colon cancer (ARO81-1). Exponentially growing cells were distributed into the following groups: 1) BPA (10 ppm 10 B) + neutrons; 2) BOPP (10 ppm 10 B) + neutrons; 3) neutrons alone; 4) gamma-rays. A control group without irradiation for each treatment was added. The cells were irradiated in the thermal neutron beam of the RA-3 (flux= 7.5 10 9 n/cm 2 sec) or with 60 Co (1Gy/min) during different times in order to obtain total physical dose between 1-5 Gy (±10 %). A decrease in the survival fraction as a function of the physical dose was observed for all the treatments. We also observed that neutrons and neutrons + BOPP did not differ significantly and that BPA was the more effective compound. Protein extracts of irradiated cells (3Gy) were isolated to 24 h and 48 h post radiation exposure. The irradiation with neutrons in presence of 10 BPA or 10 BOPP produced an increase of p53 at 24 h maintain until 48 h. On the contrary, in the groups irradiated with neutrons alone or gamma the peak was observed at 48 hr. The level of expression of p27/Kip1 showed a reduction of this protein in all the groups irradiated with neutrons (neutrons alone or neutrons plus boron compound), being more marked at 24 h. These preliminary results suggest different radiobiological response for high and low let radiation. Future studies will permit establish the role of cell cycle in the tumor radio sensibility to BNCT. (author)

  16. The contribution of thermal radiation to the thermal conductivity of porous UO2

    International Nuclear Information System (INIS)

    Bakker, K.; Kwast, H.; Cordfunke, E.H.P.

    1994-09-01

    The influence of cylindrical, spherical and ellipsoidal inclusions on the overall thermal conductivity was computed with the finite element technique. The results of these calculations were compared with equations that describe the effect of inclusions on the overall thermal conductivity. The analytical equation of Schulz that describes the effect of inclusions on the overall thermal conductivity is in good agreement with the results of the finite element computations. This good agreement shows that among a variety of porosity correction formulas, the equation of Schulz gives the best description of the effect of inclusions on the overall thermal conductivity. This equation and the results of finite element calculations allow us to compute the contribution of radiation to the overall thermal conductivity of UO 2 with oblate ellipsoidal porosity. The present radiation calculations show that Hayes and Peddicord overestimated the contribution of thermal radiation to the thermal conductivity. (orig.)

  17. Dependence of radiation electric conductivity on intensity of external electric field in polymeric dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Sichkar, V P; Tyutnev, A P; Vaisberg, S E [Nauchno-Issledovatel' skij Fiziko-Khimicheskij Inst., Moscow (USSR)

    1975-10-01

    The radiational conductivity (Gsub(p)) at different electric field potentials (E) for a number of low- and high-density polymers was investigated. In a number of cases temperature variations were introduced. Measurements were carried out also under conditions of a single impulse of high-power radiation dose. A relationship was obtained between Gsub(p) and E.

  18. Comparison of conventional technology and radiation technology. Final report for the period 1 June 1988 - 31 May 1989

    International Nuclear Information System (INIS)

    Czvikovszky, T.

    1989-01-01

    The project consisted of three parts in which comparison of conventional technology and radiation technology of composite materials was aimed, in the field of impregnated wood-plastics, wood fiber reinforced/filled plastics and UV and EB coated wood products. The report includes 4 papers presented at different meetings. Refs, figs and tabs

  19. Comparison of conventional technology and radiation technology. Final report for the period 1 June 1988 - 31 May 1989

    Energy Technology Data Exchange (ETDEWEB)

    Czvikovszky, T [Research Inst. for the Plastic Industry, Budapest (Hungary)

    1990-12-31

    The project consisted of three parts in which comparison of conventional technology and radiation technology of composite materials was aimed, in the field of impregnated wood-plastics, wood fiber reinforced/filled plastics and UV and EB coated wood products. The report includes 4 papers presented at different meetings. Refs, figs and tabs.

  20. Numerical simulations of a coupled radiative?conductive heat transfer model using a modified Monte Carlo method

    KAUST Repository

    Kovtanyuk, Andrey E.; Botkin, Nikolai D.; Hoffmann, Karl-Heinz

    2012-01-01

    Radiative-conductive heat transfer in a medium bounded by two reflecting and radiating plane surfaces is considered. This process is described by a nonlinear system of two differential equations: an equation of the radiative heat transfer

  1. The efficacy of conventional radiation therapy in the management of pituitary adenoma

    International Nuclear Information System (INIS)

    Sasaki, Ryohei; Murakami, Masao; Okamoto, Yoshiaki; Kono, Koichi; Yoden, Eisaku; Nakajima, Toshifumi; Nabeshima, Sachio; Kuroda, Yasumasa

    2000-01-01

    Purpose: To evaluate the efficacy of conventional radiotherapy for reducing tumor size and endocrine hypersecretion of pituitary adenomas. Methods and Materials: We reviewed the records of 91 patients with pituitary adenoma, who were first treated between 1969 and 1994 and had been followed for more than 2 years (median, 8.2 years.) Of these patients, 86 had received postoperative radiotherapy, and 5 had received radiotherapy alone. The median total dose was 51 Gy. Clinical symptoms related to mass effects or endocrine hypersecretion were assessed. The efficacy of radiotherapy was evaluated before treatment and during the follow-up period (1-14 years; median, 3 years) by estimating tumor size on computed tomography or magnetic resonance imaging in 56 patients, as well as by endocrine testing in the 22 patients who had secreting adenomas. Local control rate, prognostic factors, and side effects were analyzed. Results: Mass-effect symptoms improved in 72% and 79% of patients who had such symptoms due to nonsecreting adenomas and secreting adenomas, respectively. Symptoms of endocrine hypersecretion abated in 67% of patients who had such symptoms. Excessive hormone levels normalized in 74% of patients who showed endocrine hypersecretions. The greatest size reduction was seen 3 years after the completion of radiotherapy (24% CR, 62% PR, 12% NC, and 3% PD in nonsecreting adenomas, and 32% CR, 36% PR, 27% NC, and 5% PD in secreting adenomas). Three patients with secreting adenomas (2 with prolactinoma and 1 with Cushing's disease) showed a mismatch between reduction in tumor size and normalization of endocrine hypersecretion. The 10-year local control rates were 98%, 85%, 83%, and 67% for nonsecreting adenoma, growth-hormone-secreting adenoma, prolactinoma, and Cushing's disease, respectively. Univariate analyses showed that disease type and radiation field size were significant prognostic factors. Brain necrosis occurred in 1 patient who received a 60-Gy dose of

  2. Application of the lattice Boltzmann method to transient conduction and radiation heat transfer in cylindrical media

    International Nuclear Information System (INIS)

    Chaabane, Raoudha; Askri, Faouzi; Ben Nasrallah, Sassi

    2011-01-01

    In this paper, the lattice Boltzmann method (LBM) is applied to solve the energy equation of a transient conduction-radiation heat transfer problem in a two-dimensional cylindrical enclosure filled with an emitting, absorbing and scattering media. The control volume finite element method (CVFEM) is used to obtain the radiative information. To demonstrate the workability of the LBM in conjunction with the CVFEM to conduction-radiation problems in cylindrical media, the energy equation of the same problem is also solved using the finite difference method (FDM). The effects of different parameters, such as the grid size, the scattering albedo, the extinction coefficient and the conduction-radiation parameter on temperature distribution within the medium are studied. Results of the present work are compared with those available in the literature. LBM-CVFEM results are also compared with those given by the FDM-CVFEM. In all cases, good agreement has been obtained.

  3. Performance evaluation of the conventional Brazilian industries radiation protection in the small industrial gauges and industrial radiography areas

    International Nuclear Information System (INIS)

    Santos, Joyra Amaral dos

    1999-08-01

    This works evaluates by punctuation the performance in conventional Brazilian industries radiation protection area which make use of small industrial gauges and industrial radiography. It proposes, procedures for industry self-evaluation, besides a new radiation protection plans pattern for the small industrial gauges area. The data source where inspection reports of Dosimetry Radiation Protection Institute/Nuclear Energy Commission conventional Brazilian industries' radiation protection plans, beyond visitation to the inspection place. The performance evaluation has been realized both in the administrative and operational aspects of the industries. About of 60% of the industries have a satisfactory register control which does not happen to the operational control. The performance evaluation advantage is that industries may self-evaluate, foreseeing Dosimetry Radiation Protection Institute's regulation inspections, correcting its irregularities, automatically improving its services. The number of industries which have obtained satisfactory performance in both areas is below 70%, both in administrative and operational aspects. Such number can be considered a low one as it is radiation protection. The procedures propose in this work aim to improve such a situation. (author)

  4. Using Rouse-Fowler model to describe radiation-induced electrical conductivity of nanocomposite materials

    Science.gov (United States)

    Dyuryagina, N. S.; Yalovets, A. P.

    2017-05-01

    Using the Rouse-Fowler (RF) model this work studies the radiation-induced electrical conductivity of a polymer nanocomposite material with spherical nanoparticles against the intensity and exposure time of gamma-ray, concentration and size of nanoparticles. The research has found the energy distribution of localized statesinduced by nanoparticles. The studies were conducted on polymethylmethacrylate (PMMA) with CdS nanoparticles.

  5. Effective radiation dose from semicoronal CT of the sacroiliac joints in comparison with axial CT and conventional radiography

    Energy Technology Data Exchange (ETDEWEB)

    Jurik, Anne Grethe; Boecker Puhakka, Katriina [Department of Radiology R, Aarhus University Hospital, Aarhus Kommunehospital, Noerrebrogade 44, 8000 Aarhus C (Denmark); Hansen, Jolanta [Department of Medical Physics, Aarhus University Hospital, Aarhus Kommunehospital, Noerrebrogade 44, 8000 Aarhus C (Denmark)

    2002-11-01

    The aim of this study was to evaluate the radiation dose given by semicoronal CT of the sacroiliac joints (SIJs) in comparison with axial CT and conventional radiography. The total effective radiation doses given by serial contiguous semicoronal and axial CT, using 5-mm slices, 120 kV and 330 mAs, were determined by measurement of organ doses using an anthropomorphic Rando Alderson phantom paced with thermoluminescence dosimeters. The doses given by conventional antero-posterior (AP) and oblique projections of the SIJs were determined similarly. In a female the total effective dose by semicoronal CT was found to be more than six times lower than by axial CT and 2.5 times lower than the dose use to obtain a conventional AP radiograph, the values being 102, 678, and 255 {mu}Sv, respectively. The effective dose by semicoronal CT was only a little higher than the dose given to obtain two oblique radiographs. In a male with lead protection of the gonads the dose by semicoronal CT was four times lower than by axial CT, but higher than by conventional radiography. In conclusion, the effective dose by semicoronal CT of the SIJs is lower than by axial CT, and in females a semicoronal CT implies a lower effective radiation dose that used to obtain an AP radiograph. (orig.)

  6. Effect of ionizing radiation on structural and conductive properties of copper nanotubes

    Science.gov (United States)

    Zdorovets, M. V.; Borgekov, D. B.; Kenzhina, I. E.; Kozlovskiy, A. L.

    2018-01-01

    The use of electron radiation is an effective tool for stimulating a controlled modification of structural and conductive properties of nanomaterials in modern materials science. The paper presents the results of studies of the influence of various types of radiation on structural and conductive properties of copper nanotubes obtained by electrochemical synthesis in pores of templates based on polyethylene terephthalate. Such methods as SEM, X-ray diffraction and EDS show that irradiation with a stream of high-energy electrons with doses of 50-250 kGy makes it possible to modify the crystal structure of nanotubes, increasing their conductivity and decreasing the resistance of nanostructures without destroying the structure.

  7. The Lattice and Thermal Radiation Conductivity of Thermal Barrier Coatings: Models and Experiments

    Science.gov (United States)

    Zhu, Dongming; Spuckler, Charles M.

    2010-01-01

    The lattice and radiation conductivity of ZrO2-Y2O3 thermal barrier coatings was evaluated using a laser heat flux approach. A diffusion model has been established to correlate the coating apparent thermal conductivity to the lattice and radiation conductivity. The radiation conductivity component can be expressed as a function of temperature, coating material scattering, and absorption properties. High temperature scattering and absorption of the coating systems can be also derived based on the testing results using the modeling approach. A comparison has been made for the gray and nongray coating models in the plasma-sprayed thermal barrier coatings. The model prediction is found to have a good agreement with experimental observations.

  8. Comparative measurements of external radiation exposure using mobile phones, dental ceramic, household salt and conventional personal dosemeters

    International Nuclear Information System (INIS)

    Ekendahl, Daniela; Bulánek, Boris; Judas, Libor

    2015-01-01

    Because retrospective dosimetry utilises commonly occurring materials and objects, it is particularly useful in cases of large-scale radiation accidents or malevolent acts with radioactive materials where casualties are inflicted on the general public and first emergency responders. The aim of this study was to investigate whether retrospective dosemeters can provide dose estimates with comparable accuracy like conventional personal dosemeters. Using an external source of radiation 137 Cs and an anthropomorphic phantom, we simulated serious irradiation of a human body in anterior-posterior and rotational geometries. Retrospective luminescence dosimetry objects, such as mobile phones, dental ceramic and household salt, and conventional personal dosemeters (thermoluminescent and electronic) were fixed to the anthropomorphic phantom. The doses obtained were compared with specific reference values. In most cases, relative deviations between the measured doses and the reference values did not exceed 20%. As the retrospective and conventional dosemeters show no significant differences in laboratory conditions, the retrospective luminescence dosimetry objects represent a very promising tool if handled properly. - Highlights: • A serious external exposure of human body was simulated. • Doses were measured using both retrospective and conventional dosemeters. • Utilised retrospective dosimetry materials were alumina resistors from mobile phones, household salt and dental ceramic. • Doses obtained were compared with reference values. • Both retrospective and conventional dosemeters gave similar results

  9. Phase II Radiation therapy oncology group trial of weekly paclitaxel and conventional external beam radiation therapy for supratentorial glioblastoma multiforme

    International Nuclear Information System (INIS)

    Langer, Corey J.; Ruffer, James; Rhodes, Harker; Paulus, Rebecca; Murray, Kevin; Movsas, Benjamin; Curran, Walter

    2001-01-01

    Purpose: Fractionated external beam radiotherapy (EBRT) ± carmustine (BCNU) is the standard of care for patients with glioblastoma multiforme (GBM), but survival results remain poor. Preclinical studies indicate synergy between RT and paclitaxel (TAX) in astrocytoma cell lines. Phase I studies in GBM have demonstrated a maximum tolerated dose for TAX of 225 mg/m 2 /3 h/week x 6, during EBRT, with no exacerbation of typical RT-induced toxicities. The Radiation Therapy Oncology Group (RTOG) therefore mounted a Phase II study to determine the feasibility and efficacy of conventional EBRT and concurrent weekly TAX at its MTD. Patients and Methods: Sixty-two patients with histologic diagnosis of GBM were enrolled from 8/16/96 through 3/21/97 in a multi-institutional Phase II trial of EBRT and TAX 225 mg/m 2 /3 h (1-3 h before EBRT), administered the first treatment day of each RT week. Total EBRT dose was 60 Gy (200 cGy/fraction), 5 days per week. A smaller treatment field, to include gross disease plus a margin only, was used after 46 Gy. Results: Sixty-one patients (98%) were evaluable. Median age was 55 years (range, 28-78). Seventy-four percent were ≥50 years. Recursive partitioning analysis (RPA) Classes III, IV, V, VI included 10 (17%), 21 (34%), 25 (41%), and 5 (8%) patients, respectively. Gross total resection was performed in only 16%. There was no Grade 3 or 4 neutropenia or thrombocytopenia. Hypersensitivity reactions precluding further use of TAX occurred in 4 patients. There were 2 instances of late neurotoxicity (4% Grade 3 or 4). Ninety-one percent of patients received treatment per protocol. Seventy-seven percent completed prescribed treatment (6 weeks). Of 35 patients with measurable disease, CR/PR was observed in 23%, MR in 17%, and SD in 43%. Seventeen percent demonstrated progression at first follow-up. Median potential follow-up time is 20 months. Median survival is 9.7 months, with median survivals for RPA classes III, IV, V, and VI of 16.3, 10

  10. Hypofractionation vs Conventional Radiation Therapy for Newly Diagnosed Diffuse Intrinsic Pontine Glioma: A Matched-Cohort Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, Geert O., E-mail: g.janssens@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Jansen, Marc H. [Pediatric Oncology/Hematology, VU University Medical Center, Amsterdam (Netherlands); Lauwers, Selmer J. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Nowak, Peter J. [Department of Radiation Oncology, Erasmus Medical Centre, Rotterdam (Netherlands); Oldenburger, Foppe R. [Department of Radiation Oncology, Academic Medical Centre, Amsterdam (Netherlands); Bouffet, Eric [Department of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto (Canada); Saran, Frank [Department of Pediatric Oncology, The Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Kamphuis-van Ulzen, Karin [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Lindert, Erik J. van [Department of Neurosurgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Schieving, Jolanda H. [Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Boterberg, Tom [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium); Kaspers, Gertjan J. [Pediatric Oncology/Hematology, VU University Medical Center, Amsterdam (Netherlands); Span, Paul N.; Kaanders, Johannes H. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Gidding, Corrie E. [Department of Pediatric Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Hargrave, Darren [Department of Oncology, Great Ormond Street Hospital, London (United Kingdom)

    2013-02-01

    Purpose: Despite conventional radiation therapy, 54 Gy in single doses of 1.8 Gy (54/1.8 Gy) over 6 weeks, most children with diffuse intrinsic pontine glioma (DIPG) will die within 1 year after diagnosis. To reduce patient burden, we investigated the role of hypofractionation radiation therapy given over 3 to 4 weeks. A 1:1 matched-cohort analysis with conventional radiation therapy was performed to assess response and survival. Methods and Materials: Twenty-seven children, aged 3 to 14, were treated according to 1 of 2 hypofractionation regimens over 3 to 4 weeks (39/3 Gy, n=16 or 44.8/2.8 Gy, n=11). All patients had symptoms for {<=}3 months, {>=}2 signs of the neurologic triad (cranial nerve deficit, ataxia, long tract signs), and characteristic features of DIPG on magnetic resonance imaging. Twenty-seven patients fulfilling the same diagnostic criteria and receiving at least 50/1.8 to 2.0 Gy were eligible for the matched-cohort analysis. Results: With hypofractionation radiation therapy, the overall survival at 6, 9, and 12 months was 74%, 44%, and 22%, respectively. Progression-free survival at 3, 6, and 9 months was 77%, 43%, and 12%, respectively. Temporary discontinuation of steroids was observed in 21 of 27 (78%) patients. No significant difference in median overall survival (9.0 vs 9.4 months; P=.84) and time to progression (5.0 vs 7.6 months; P=.24) was observed between hypofractionation vs conventional radiation therapy, respectively. Conclusions: For patients with newly diagnosed DIPG, a hypofractionation regimen, given over 3 to 4 weeks, offers equal overall survival with less treatment burden compared with a conventional regimen of 6 weeks.

  11. Coupling heat conduction and radiation in complex 2D and 3D geometries

    Energy Technology Data Exchange (ETDEWEB)

    Peniguel, C [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches; Rupp, I [SIMULOG, 78 - Guyancourt (France)

    1998-12-31

    Thermal radiation is a very important mode of heat transfer in most real industrial systems. A numerical approach coupling radiation (restricted to non participant medium) and conduction is presented. The code (SYRTHES) is able to handle 2D and 3D problems (including cases with symmetries and periodicity). Radiation is solved by a radiosity approach, and conduction by a finite element method. Accurate and efficient algorithms based on a mixing of analytical/numerical integration, and ray tracing techniques are used to compute the view factors. Validation has been performed on numerous test cases. A conjugate residual algorithm solves the radiosity system. An explicit interactive numerical procedure is then used to couple conduction and radiation. No stability problem has been encountered so far. One specificity of SYRTHES is that conduction and radiation are solved on independent grids. This brings much flexibility and allows to keep the number of independent radiation patches at a reasonable level. Several industrial examples are given as illustration. (author) 6 refs.

  12. Construction of x-ray Kβ filters to monochromatize the radiation of a conventional x-ray tube

    International Nuclear Information System (INIS)

    Moreira, M.V.B.; Oliveira, A.G.

    1987-01-01

    The construction of Zr and Nb Kβ filters to produce monochromatic radiation of a conventional X-ray Mo-tube (λK a = 0.7107 A) is described. Disks of NB and Zr, 6.4 mm in diameter and 0.03 to 0.06 mm thick, were prepared. The filters performance was tested by means of NaCl powder difraction patterns. (author) [pt

  13. Controlling thermal chaos in the mantle by positive feedback from radiative thermal conductivity

    Directory of Open Access Journals (Sweden)

    F. Dubuffet

    2002-01-01

    Full Text Available The thermal conductivity of mantle materials has two components, the lattice component klat from phonons and the radiative component krad due to photons. These two contributions of variable thermal conductivity have a nonlinear dependence in the temperature, thus endowing the temperature equation in mantle convection with a strongly nonlinear character. The temperature derivatives of these two mechanisms have different signs, with ∂klat /∂T negative and dkrad /dT positive. This offers the possibility for the radiative conductivity to control the chaotic boundary layer instabilities developed in the deep mantle. We have parameterized the weight factor between krad and klat with a dimensionless parameter f , where f = 1 corresponds to the reference conductivity model. We have carried out two-dimensional, time-dependent calculations for variable thermal conductivity but constant viscosity in an aspect-ratio 6 box for surface Rayleigh numbers between 106 and 5 × 106. The averaged Péclet numbers of these flows lie between 200 and 2000. Along the boundary in f separating the chaotic and steady-state solutions, the number decreases and the Nusselt number increases with internal heating, illustrating the feedback between internal heating and radiative thermal conductivity. For purely basal heating situation, the time-dependent chaotic flows become stabilized for values of f of between 1.5 and 2. The bottom thermal boundary layer thickens and the surface heat flow increases with larger amounts of radiative conductivity. For magnitudes of internal heating characteristic of a chondritic mantle, much larger values of f , exceeding 10, are required to quench the bottom boundary layer instabilities. By isolating the individual conductive mechanisms, we have ascertained that the lattice conductivity is partly responsible for inducing boundary layer instabilities, while the radiative conductivity and purely depth-dependent conductivity exert a stabilizing

  14. On the radiative-conductive solution in continuous heterogeneous grey plane-parallel participating medium

    Energy Technology Data Exchange (ETDEWEB)

    Valerio, Felipe L. [Instituto Federal de Educacao Ciencia e Tecnologia do Rio Grande do Sul (IFRGS), Bento Goncalves, RS (Brazil); Segatto, Cynthia F.; Vilhena, Marco T. [Universidade Federal do Rio Grande do Sul (PROMEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos Graduacao em Engenharia Mecanica; Vargas, Rubem M.F., E-mail: felipe.valerio@bento.ifrs.edu.br, E-mail: cynthia.segatto@ufrgs.br, E-mail: marco.vilhena@ufrgs.br, E-mail: rvargas@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Programa de Pos Graduacao em Engenharia e Tecnologia de Materiais

    2017-07-01

    In this work we report an analytical representation for the solution of the radiative-conductive S{sub N} equation in a plane-parallel atmosphere in a heterogeneous domain considering an arbitrary continuous functions for the albedo. The basic idea consists in the application of the decomposition procedure to the non-linear radiative-conductive SN problem that are easily solved by the well know LTSN method. The length of the recursive system is properly chose in order to get a prescribed accuracy for the results. We also present numerical simulations for the results. (author)

  15. Results of a prospective randomised trial comparing conventional radiotherapy to split course bifractionated radiation therapy in patients with nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Daoud, Jamel; Toumi, Nabil; Siala, Wissem; Ghorbel, Abdelmonem; Drira, Mohamed Mokthar; Frikha, Mounir

    2007-01-01

    Background and purpose: Nasopharyngeal carcinoma (NPC) is generally responsive to radiation therapy. However therapeutic results after conventional radiotherapy remain relatively poor especially for patients with locoregional advanced NPC. The aim of this study was to evaluate the impact of a split course bifractionated radiotherapy regimen in a phase III randomised trial. Patients and methods: From January 1997 to September 2003, 154 patients with M0 histologically proven NPC were treated in our institution. They were staged according to the American Joint Committee on Cancer - International Union Against Cancer (AJCC-UICC) 1986 TNM classification. Patients with locally advanced nodal disease (N2-N3) received induction chemotherapy. All patients were randomised to receive either conventional radiotherapy at 2 Gy/fraction/day, 5 days/week to 70 Gy/7 weeks or split course bifractionated radiotherapy at 1.6 Gy/fraction, twice daily, 5 days/week to 70.4 Gy/6 weeks. Response and toxicity were evaluated according to the WHO and RTOG criteria. Results: Patients were well balanced between the two arms. The complete remission rate was 91% in conventional radiotherapy arm and 93% in bifractionated radiotherapy arm (p = 0.3). There was more grade II-III skin fibrosis in experimental arm with a 5 year actuarial probability of 66% vs 52% (p = 0.04). Locoregional and distant relapses occurred in 34% of cases in conventional arm and 38% in experimental arm (p = 0.28). With a median follow-up of 56 months, the 5 year overall survival and the disease free survival rates were, respectively (71% and 61%), in conventional arm and (62% and 60%) in bifractionated arm, the difference being statistically non significant. Comments: The present trial comparing conventional radiotherapy to a split course bifractionated radiation therapy failed to demonstrate significant improvement in locoregional control and survival in experimental arm which was associated with more grade II-III skin

  16. The contribution of thermal radiation to the thermal conductivity of porous UO2

    International Nuclear Information System (INIS)

    Bakker, K.; Kwast, H.; Cordfunke, E.H.P.

    1995-01-01

    The influence of cylindrical, spherical and ellipsoidal inclusions on the overall thermal conductivity was computed with the finite element technique. The results of these calculations were compared with equations that describe the effect of inclusions on the overall thermal conductivity. The analytical equation of Schulz [B. Schulz, KfK-1988 (1974)] that describes the effect of inclusions on the overall thermal conductivity is in good agreement with the results of the finite element computations. This good agreement shows that among a variety of porosity correction formulas, the equation of Schulz gives the best description of the effect of inclusions on the overall thermal conductivity. This equation and the results of finite element calculations allow us to compute the contribution of radiation to the overall thermal conductivity of UO 2 with oblate ellipsoidal porosity. The present radiation calculations show that Hayes and Peddicord [S.L. Hayes and K.L. Peddicord, J. Nucl. Mater. 202 (1993) 87] overestimated the contribution of thermal radiation to the thermal conductivity. ((orig.))

  17. Models of thermal transfer by radiation and by conduction, in any geometry, in multiphase multicomponent medium

    International Nuclear Information System (INIS)

    Jeanne, T.

    1990-03-01

    A conduction model and a radiation model are proposed for the calculation of heat transfer. A multiphase multicomponent medium is considered. The conduction model allows the calculation of heat exchanges between two configurations. The heat flow from each component can be obtained. This model is well adapted to the calculation of thermal shocks in an ensemble of materials. The radiation model shows how the radiative transfers can be calculated in a cylinder composed of two opaque surfaces, with the same axis of rotation, and separated by a transparent medium. The form factors are obtained from Herman and Nusselt methods. The parts of the face-to-face surfaces which are seen and not seen are evaluated [fr

  18. Numerical modeling of the conduction and radiation heating in precision glass moulding

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Hattel, Jesper Henri; Hansen, Hans Nørgaard

    2012-01-01

    wafer, heating can be performed by either conduction or radiation. The numerical simulation of these two heating mechanisms in the wafer based glass moulding process is the topic of the present paper. First, the transient heating of the glass wafer is simulated by the FEM software ABAQUS. Temperature...

  19. Radiation-induced conductivity and high-temperature Q changes in quartz resonators

    International Nuclear Information System (INIS)

    Koehler, D.R.

    1981-01-01

    While high temperature electrolysis has proven beneficial as a technique to remove interstitial impurities from quartz, reliable indices to measure the efficacy of such a processing step are still under development. The present work is directed toward providing such an index. Two techniques have been investigated - one involves measurement of the radiation induced conductivity in quartz along the optic axis, and the second involves measurement of high temperature Q changes. Both effects originate when impurity charge compensators are released from their traps, in the first case resulting in ionic conduction and in the second case resulting in increased acoustic losses. Radiation induced conductivity measurements have been carried out with a 200 kV, 14 mA x-ray machine producing 5 rads/s. With electric fields of the order of 10 4 V/cm, the noise level in the current measuring system is equivalent to an ionic current generated by quartz impurities in the 1 ppB range. The accuracy of the high temperature ( 300 to 800 0 K) Q -1 measurement technique will be determined. A number of resonators constructed of quartz material of different impurity contents have been tested and both the radiation induced conductivity and the high temperature Q -1 results compared with earlier radiation induced frequency and resonator resistance changes. 10 figures

  20. Evaluation of conventional and high-performance routine solar radiation measurements for improved solar resource, climatological trends, and radiative modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gueymard, Christian A. [Solar Consulting Services, P.O. Box 392, Colebrook, NH 03576 (United States); Myers, Daryl R. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401-3305 (United States)

    2009-02-15

    The solar renewable energy community depends on radiometric measurements and instrumentation for data to design and monitor solar energy systems, and develop and validate solar radiation models. This contribution evaluates the impact of instrument uncertainties contributing to data inaccuracies and their effect on short-term and long-term measurement series, and on radiation model validation studies. For the latter part, transposition (horizontal-to-tilt) models are used as an example. Confirming previous studies, it is found that a widely used pyranometer strongly underestimates diffuse and global radiation, particularly in winter, unless appropriate corrective measures are taken. Other types of measurement problems are also discussed, such as those involved in the indirect determination of direct or diffuse irradiance, and in shadowband correction methods. The sensitivity of the predictions from transposition models to inaccuracies in input radiation data is demonstrated. Caution is therefore issued to the whole community regarding drawing detailed conclusions about solar radiation data without due attention to the data quality issues only recently identified. (author)

  1. Comparative study of conducting iliac angioplasties with digital subtraction and conventional angiography. Incidence on true (consumable) costs

    International Nuclear Information System (INIS)

    Brenot, P.; Raynaud, A.; Pernes, J.M.; Parola, J.L.; Gaux, J.C.

    1986-01-01

    Differences in time and cost were evaluated between the performance of iliac angioplasty with conventional (AC) and digital subtraction (AN) angiography, after a total of 27 angioplasties (13 with AC and 14 with AN). Excluding amortization of material and personnel costs, findings confirmed a certain number of advantages for AN: gain in time of about 34%, decrease of about 14% in charges, and notably of 83% in expenditure on films and 50% on contrast media [fr

  2. Modeling of the coupled radiative and conductive heat transfer within fibrous media at high temperature

    International Nuclear Information System (INIS)

    Dauvois, Yann

    2016-01-01

    In the present work, the effective heat transfer properties of fibrous medium are determined by taking into account a coupling of heat conduction and radiation. A virtual, statistically homogeneous, two-phase fibrous sample has been built by stacking finite absorbing cylinders in vacuum. These cylinders are dispersed according to prescribed distribution functions defining the cylinder positions and orientations. Cylinder overlappings are allowed. Extinction, absorption and scattering are characterised by radiative statistical functions which allow the Beerian behaviour of a medium to be assessed (or not). They are accurately determined with a Monte Carlo method. Whereas the gaseous phase exhibits a Beerian behaviour, the fibre phase is strongly non Beerian. The radiative power field deposited within the fibrous material is calculated by resolving a model which couples a Generalized Radiative Transfer Equation (GRTE) and a classic Radiative Transfer Equation (RTE). The model of conduction transfer is based on a random walk method without meshing. The simulation of Brownian motion of walkers in fibres allows the energy equation to be solved. The idea of the method is to characterize the temperature in an elementary volume by the density of walkers, which roam the medium. The problem is governed by boundary conditions; A constant concentration of walkers (or a constant flux) is associated with a fixed temperature (or flux). (author) [fr

  3. Radiation doses in examination of lower third molars with computed tomography and conventional radiography.

    Science.gov (United States)

    Ohman, A; Kull, L; Andersson, J; Flygare, L

    2008-12-01

    To measure organ doses and calculate effective doses for pre-operative radiographic examination of lower third molars with CT and conventional radiography (CR). Measurements of organ doses were made on an anthropomorphic head phantom with lithium fluoride thermoluminescent dosemeters. The dosemeters were placed in regions corresponding to parotid and submandibular glands, mandibular bone, thyroid gland, skin, eye lenses and brain. The organ doses were used for the calculation of effective doses according to proposed International Commission on Radiological Protection 2005 guidelines. For the CT examination, a Siemens Somatom Plus 4 Volume Zoom was used and exposure factors were set to 120 kV and 100 mAs. For conventional radiographs, a Scanora unit was used and panoramic, posteroanterior, stereographic (scanogram) and conventional spiral tomographic views were exposed. The effective doses were 0.25 mSv, 0.060 mSv and 0.093 mSv for CT, CR without conventional tomography and CR with conventional spiral tomography, respectively. The effective dose is low when CT examination with exposure factors optimized for the examination of bone structures is performed. However, the dose is still about four times as high as for CR without tomography. CT should therefore not be a standard method for the examination of lower third molars. In cases where there is a close relationship between the tooth and the inferior alveolar nerve the advantages of true sectional imaging, such as CT, outweighs the higher effective dose and is recommended. Further reduction in the dose is feasible with further optimization of examination protocols and the development of newer techniques.

  4. Radiation exposure from conventional radiographic examinations in very and extremely low birth weight patients

    Science.gov (United States)

    Gois, M. L. C.; Schelin, H. R.; Denyak, V.; Bunick, A. P.; Legnani, A.; Paschuk, S. A.

    2017-11-01

    The survival of very premature neonates has improved significantly at the last decades owing to the utilization of modern intensive care interventions that usually requires prolonged hospitalisation and are accompanied by frequent radiographic examinations. Their elevated radiosensitivity and numerous examinations combined with their greater remaining lifetime raise the issue of high risk for radiation-induced malignancies. Because it is presently impossible to substitute this type of examinations with others that do not involve radiation exposure, investigations on a hospital's routine practices becomes relevant. In this work, we present the results of an investigation on the radiation exposure of patients with birth weight lower than 1500 g in one paediatric hospital in Brazil. We analyse some important patient characteristics, like weight, gestational age, length of stay, and number of radiographs performed in the neonatal intensive care unit, in connection with the patient dose. The obtained results are compared with the existing information from other studies.

  5. Analytical theory of coherent synchrotron radiation wakefield of short bunches shielded by conducting parallel plates

    Energy Technology Data Exchange (ETDEWEB)

    Stupakov, Gennady; Zhou, Demin

    2016-04-21

    We develop a general model of coherent synchrotron radiation (CSR) impedance with shielding provided by two parallel conducting plates. This model allows us to easily reproduce all previously known analytical CSR wakes and to expand the analysis to situations not explored before. It reduces calculations of the impedance to taking integrals along the trajectory of the beam. New analytical results are derived for the radiation impedance with shielding for the following orbits: a kink, a bending magnet, a wiggler of finite length, and an infinitely long wiggler. All our formulas are benchmarked against numerical simulations with the CSRZ computer code.

  6. Environmental radiation at the Monte Bello Islands from nuclear weapons tests conducted in 1952 and 1956

    International Nuclear Information System (INIS)

    Moroney, J.R.; Cooper, M.B.

    1982-12-01

    The results from the 1962 and 1968 surveys of environmental radiation at the Monte Bello Islands are presented. These were the first of the series of surveys of radioactive contamination of the Islands to be carried out following nuclear weapons tests conducted in 1952 and 1956. Detailed comparison is made with the results obtained in the subsequent surveys in 1972 and 1978. For more than 20 years, no area at the Monte Bello Islands has presented an acute hazard due to external exposure to environmental radiation

  7. Transistor collector breakdown in the presence of conducted EMP and gamma radiation

    International Nuclear Information System (INIS)

    Rice, D.H.

    1975-01-01

    In this paper we develop expressions which describe breakdown, negative resistance and latch characteristics for a common emitter transistor when exposed to simultaneous conducted EMP and ionizing radiation. These expressions are derived from a modified Ebers-Moll model and show that common emitter breakdown voltage is reduced, latch (or sustaining voltage) remains unchanged, and that the negative resistance characteristics are changed. Using the modified Ebers-Moll model good agreement between predicted and observed circuit response is demonstrated when the circuits are exposed to a rising collector voltage (due to EMP) and simultaneous ionizing (gamma) radiation

  8. Overview of applications of radiation processing in combination with conventional treatments to assure food safety

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, M.; Turgis, M, E-mail: monique.lacroix@iaf.inrs.ca [INRS-Institut Armand-Frappier, Canadian Irradiation Center, Research Laboratories in Sciences Applied to Food, Laval, QC (Canada); Severino, R. [INRS-Institut Armand-Frappier, Canadian Irradiation Center, Research Laboratories in Sciences Applied to Food, Laval, QC (Canada); Univ. of Salerno, Dept. of Industrial Engineering, Fisciano, SA (Italy); Vu, K.D. [INRS-Institut Armand-Frappier, Canadian Irradiation Center, Research Laboratories in Sciences Applied to Food, Laval, QC (Canada); Donsi, F. [Univ. of Salerno, Dept. of Industrial Engineering, Fisciano, SA (Italy); Salmieri, S. [INRS-Institut Armand-Frappier, Canadian Irradiation Center, Research Laboratories in Sciences Applied to Food, Laval, QC (Canada); Ferrari, G. [Univ. of Salerno, Dept. of Industrial Engineering, Fisciano, SA (Italy); ProdAl Scarl, Competence Center on Agro-Food Productions, Fisciano, SA (Italy)

    2014-07-01

    Natural antimicrobials (NA) were tested for their efficiency at increasing bacterial relative radiosensitivity (BRR) and, therefore, reducing the radiation dose necessary to eliminate pathogens in meat and vegetables. In order to evaluate the industrial feasibility of using NA in combination to radiation to increase food shelf life, NA were added to food at low concentrations (which do not affect the sensory properties). Then, a bioactive coating formulation was developed to allow retention of the bioactivity of the NA during storage time. Results showed that NA, can increase BRR from 2 to 4 times and lower the dose necessary to eliminate a pathogen by a factor of 3 to 4. (author)

  9. Overview of applications of radiation processing in combination with conventional treatments to assure food safety

    International Nuclear Information System (INIS)

    Lacroix, M.; Turgis, M; Severino, R.; Vu, K.D.; Donsi, F.; Salmieri, S.; Ferrari, G.

    2014-01-01

    Natural antimicrobials (NA) were tested for their efficiency at increasing bacterial relative radiosensitivity (BRR) and, therefore, reducing the radiation dose necessary to eliminate pathogens in meat and vegetables. In order to evaluate the industrial feasibility of using NA in combination to radiation to increase food shelf life, NA were added to food at low concentrations (which do not affect the sensory properties). Then, a bioactive coating formulation was developed to allow retention of the bioactivity of the NA during storage time. Results showed that NA, can increase BRR from 2 to 4 times and lower the dose necessary to eliminate a pathogen by a factor of 3 to 4. (author)

  10. Comparison between gamma radiation and conventional methods on bacteria removal from sewage sludge

    International Nuclear Information System (INIS)

    El-Motaium, R.A.; Ahmed, A.S.

    2009-01-01

    Digested liquid sludge (3% solid content)was collected from El-Gabal El-Asfar wastewater treatment plant (North East of Cairo City). The sludge was tested, before and after irradiation, for its pathogenic bacteria content (total coliform, faecal coliform, e.coli, salmonellae and shigella). treatment included sludge exposed to different doses of gamma radiation (0.0, 0.5, 1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5,5.0,5.5,6.0 kGy). Determination of the lethal dose of every species was performed. Results indicated that primary, secondary and digestion treatments are not efficient in removing pathogenic bacteria. Digestion for 27 days at 35 degree c resulted in sludge with high content of pathogenic bacteria. Therefore, radiation treatment is recommended. The lethal radiation dose for the different species vary. The lethal doses are as follows: 3.5 kGy for total coliform, 3.0 kGy for faecal coliform,3.0 kGy for e.coli and 2.5 kGy for salmonella and shigella. The re-growth at room temperature indicated that there is a potential for re-growth at the low radiation doses (<3.5 kGy)

  11. Comparison of dental health of patients with head and neck cancer receiving IMRT vs conventional radiation.

    Science.gov (United States)

    Duarte, Victor M; Liu, Yuan F; Rafizadeh, Sassan; Tajima, Tracey; Nabili, Vishad; Wang, Marilene B

    2014-01-01

    To analyze the dental health of patients with head and neck cancer who received comprehensive dental care after intensity-modulated radiation therapy (IMRT) compared with radiation therapy (RT). Historical cohort study. Veteran Affairs (VA) hospital. In total, 158 patients at a single VA hospital who were treated with RT or IMRT between 2003 and 2011 were identified. A complete dental evaluation was performed prior to radiation treatment, including periodontal probing, tooth profile, cavity check, and mobility. The dental treatment plan was formulated to eliminate current and potential dental disease. The rates of dental extractions, infections, caries, mucositis, xerostomia, and osteoradionecrosis (ORN) were analyzed, and a comparison was made between patients treated with IMRT and those treated with RT. Of the 158 patients, 99 were treated with RT and 59 were treated with IMRT. Compared with those treated with IMRT, significantly more patients treated with RT exhibited xerostomia (46.5% vs 16.9%; P radiation treatment (32.2% vs 11.1%; P = .002; OR, 3.8; 95% CI, 1.65-8.73). Patients who were treated with IMRT had fewer instances of dental disease, more salivary flow, and fewer requisite posttreatment extractions compared with those treated with RT. The number of posttreatment extractions has been reduced with the advent of IMRT and more so with a complete dental evaluation prior to treatment.

  12. Improvement of cancer therapy by the combination of conventional radiation and chemical or physical means

    International Nuclear Information System (INIS)

    1989-01-01

    The IAEA has since 1982 supported two co-ordinated research programmes (CRP's) aimed at improving conventional radiotherapy by means of its combination with chemical sensitizers, protectors and hyperthermia. This is a final report on the two CRP's and combines the two final reports prepared by the participants of the two final research co-ordination meetings held in Istanbul and Madras. Refs, figs and tabs

  13. Radiation Effect on Body Weight and Hematological Changes of Hybrid Mice by Conventional Fraction, Large Abdominal Field Irradiation

    International Nuclear Information System (INIS)

    Lee, Sung Heon; Shin, Sei One; Kim, Myung Se

    1985-01-01

    Radiation effect on mammals, especially on hematologic changes, has been studied since discovery of x-ray. Various experimental animals were tried for radiobiological studies. 72 hybrid mice with conventional fraction (5X/week), large abdominal field (2 x 3cm, from symphysis pubic to xyphoid process) were used. Body weight was declined gradually by increasing irradiation doses, nadir was about 29.7% in male ; 30.4% in female at 6000 rad irradiation group. Hemoglobin value was nearly normal throughout entire treatment. Significant dropping of WBC count was noted to 40-50% of pretreatment values by only 1000 rad irradiation. Change of differential count was interesting; lymphocyte proportion showed gradual reduction, instead of gradual increasing of segmented neutrophil. Those proportion were reversed after 6000 rad irradiation. Urinary protein tests showed + - +++, showing no correlation with dosage. Application. of our study in clinical combination therapy (radiation + chemotherapy) was discussed

  14. Accelerated hypofractionated radiation therapy compared to conventionally fractionated radiation therapy for the treatment of inoperable non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Amini Arya

    2012-03-01

    Full Text Available Abstract Background While conventionally fractionated radiation therapy alone is an acceptable option for poor prognostic patients with unresectable stage III NSCLC, we hypothesized that accelerated hypofractionated radiotherapy will have similar efficacy without increasing toxicity. Methods This is a retrospective analysis of 300 patients diagnosed with stage III NSCLC treated between 1993 and 2009. Patients included in the study were medically or surgically inoperable, were free of metastatic disease at initial workup and did not receive concurrent chemotherapy. Patients were categorized into three groups. Group 1 received 45 Gy in 15 fractions over 3 weeks (Accelerated Radiotherapy (ACRT while group 2 received 60-63 Gy (Standard Radiation Therapy 1 (STRT1 and group 3 received > 63 Gy (Standard Radiation Therapy (STRT2. Results There were 119 (39.7% patients in the ACRT group, 90 (30.0% in STRT1 and 91 (30.3% in STRT2. More patients in the ACRT group had KPS ≤ 60 (p 5% (p = 0.002, and had stage 3B disease (p Conclusions Despite the limitations of a retrospective analysis, our experience of accelerated hypofractionated radiation therapy with 45 Gy in 15 fractions appears to be an acceptable treatment option for poor performance status patients with stage III inoperable tumors. Such a treatment regimen (or higher doses in 15 fractions should be prospectively evaluated using modern radiation technologies with the addition of sequential high dose chemotherapy in stage III NSCLC.

  15. Nonlinear vs. bolometric radiation response and phonon thermal conductance in graphene-superconductor junctions

    International Nuclear Information System (INIS)

    Vora, Heli; Nielsen, Bent; Du, Xu

    2014-01-01

    Graphene is a promising candidate for building fast and ultra-sensitive bolometric detectors due to its weak electron-phonon coupling and low heat capacity. In order to realize a practical graphene-based bolometer, several important issues, including the nature of radiation response, coupling efficiency to the radiation and the thermal conductance need to be carefully studied. Addressing these issues, we present graphene-superconductor junctions as a viable option to achieve efficient and sensitive bolometers, with the superconductor contacts serving as hot electron barriers. For a graphene-superconductor device with highly transparent interfaces, the resistance readout in the presence of radio frequency radiation is dominated by non-linear response. On the other hand, a graphene-superconductor tunnel device shows dominantly bolometric response to radiation. For graphene devices fabricated on SiO 2 substrates, we confirm recent theoretical predictions of T 2 temperature dependence of phonon thermal conductance in the presence of disorder in the graphene channel at low temperatures

  16. Second law analysis of coupled conduction-radiation heat transfer with phase change

    International Nuclear Information System (INIS)

    Makhanlall, D.; Liu, L.H.

    2010-01-01

    This work considers an exergy-based analysis of two-dimensional solid-liquid phase change processes in a square cavity enclosure. The phase change material (PCM) concerns a semi-transparent absorbing, emitting and anisotropically scattering medium with constant thermodynamic properties. The enthalpy-based energy equation is solved numerically using computational fluid dynamics. Once the energy equation is solved, local exergy loss due to heat conduction and radiative heat transfer during the phase change process is calculated by post processing procedures. In this work, the radiation exergy loss in the medium and at the enclosure boundary is taken into consideration. It is found that radiation exergy loss is significant in the high-temperature phase change process. Parametric investigation is also carried out to study the effects of Stefan number, Biot number, Planck number, single scattering albedo and wall emissivity on exergy loss. The results show that the total exergy loss increases with Biot number, single scattering albedo and wall emissivity. The second law effects of the conduction-radiation coupling in the energy equation are also shown in this work. (authors)

  17. Coupling conduction radiation and convection phenomena in complex 2D and 3D geometries

    International Nuclear Information System (INIS)

    Rupp, I.; Peniguel, C.

    1997-01-01

    In many industrial applications, convection radiation and conduction participate simultaneously to the heat transfers. A numerical approach able to cope with such problems has been developed. The code SYRTHES is tackling conduction and radiation (limited to non participating medium) while the fluid part is solved by CFD codes like ESTET (Finite volumes) or N3S (Finite elements). SYRTHES relies on an explicit numerical scheme to couple all phenomena. No stability problems has been encountered. To provide further flexibility, the three phenomena are solved on independent grids. All data transfers being automatically taken care of by SYRTHES. Extending the development to multi-physics or multi-code problems it is fairly straightforward thanks to the explicit approach. Illustrating applications show how SYRTHES is managing problems for which several CFD codes are needed simultaneously with message passing tools like PVM and CALCIUM. (author)

  18. Coupling conduction radiation and convection phenomena in complex 2D and 3D geometries

    Energy Technology Data Exchange (ETDEWEB)

    Rupp, I [SIMULOG, Guyancourt Cedex, (France); Peniguel, C [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

    1998-12-31

    In many industrial applications, convection radiation and conduction participate simultaneously to the heat transfers. A numerical approach able to cope with such problems has been developed. The code SYRTHES is tackling conduction and radiation (limited to non participating medium) while the fluid part is solved by CFD codes like ESTET (Finite volumes) or N3S (Finite elements). SYRTHES relies on an explicit numerical scheme to couple all phenomena. No stability problems has been encountered. To provide further flexibility, the three phenomena are solved on independent grids. All data transfers being automatically taken care of by SYRTHES. Extending the development to multi-physics or multi-code problems it is fairly straightforward thanks to the explicit approach. Illustrating applications show how SYRTHES is managing problems for which several CFD codes are needed simultaneously with message passing tools like PVM and CALCIUM. (author) 9 refs.

  19. Near-drift thermal analysis including combined modes of conduction, convection, and radiation

    International Nuclear Information System (INIS)

    Ho, C.K.; Francis, N.D.

    1995-01-01

    The performance of waste packages containing high-level nuclear wastes at underground repositories such as the potential repository at Yucca Mountain, Nevada, depends, in part, on the thermodynamic environment immediately surrounding the buried waste packages. For example, degradation of the waste packages can be caused by corrosive and microbial processes, which are influenced by both the relative humidity and temperature within the emplacement drifts. In this paper, the effects of conduction, convection, and radiation are investigated for a heat-generating waste package in an empty-drift. Simulations explicitly modeling radiation from the waste package to the drift wall are compared simulations using only conduction. Temperatures, relative humidities, and vapor mass fractions are compared at various locations within the drift. In addition, the effects of convection on relative humidity and moisture distribution within the drift are presented

  20. Toxicological evaluation of natural rubber films from vulcanized latex by the conventional process and the alternative process with ionizing radiation

    International Nuclear Information System (INIS)

    Campos, Vania Elisabeth

    1997-01-01

    The industrial vulcanization of natural rubber latex (NRL) is made all over the world by conventional process using sulphur and heat but it can be made by an alternative process using ionizing radiation. In this research the NRL was tested by 13 physical, chemical and mechanical assays which showed its good quality. It was done a preliminary study of the toxicological properties of 4 natural rubber films obtained by casting process of NRL: one non vulcanized, other vulcanized by the conventional process and two vulcanized by the alternative process. In the alternative process the films were obtained by irradiation of NRL by gamma rays from the 60 Co source at 250 kGy in the absence of sensitizer and irradiated NRL at 12 kGy in the presence of 4ph r of n-butyl acrylate / 0.2 phr of KOH. These vulcanization doses were determined from broken tensile strength. In the conventional process, sulphur vulcanized NRL was made using a classical composition. Another film was made with non vulcanized NRL. The preliminary evaluation of the toxicological properties was made from in vitro cytotoxicity and in vivo systemic toxicity assays. The LBN films vulcanized by the alternative process have less cytotoxicity than the NRL film vulcanized by the conventional process. The sensitized vulcanized films by gamma rays and non vulcanized films showed similar cytotoxicity while the vulcanized films without sensitizer showed a slight lower cytotoxicity. The non vulcanized NRL film and the NRL films vulcanized by the alternative process did not show toxic effects int he 72 hours period of the systemic toxicity assay. However the NRL film vulcanized with sulphur induced effects like allaying and motor in coordination on the animals treated with an oil extract at the fourth hour and recovering after that. The alternative process promoted lower toxic effects than conventional process because there was no toxic substances present. (author)

  1. Effective thermal conductivity of a heat generating rod bundle dissipating heat by natural convection and radiation

    International Nuclear Information System (INIS)

    Senve, Vinay; Narasimham, G.S.V.L.

    2011-01-01

    Highlights: → Transport processes in isothermal hexagonal sheath with 19 heat generating rods is studied. → Correlation is given to predict the maximum temperature considering all transport processes. → Effective thermal conductivity of rod bundle can be obtained using max temperature. → Data on the critical Rayleigh numbers for p/d ratios of 1.1-2.0 is presented. → Radiative heat transfer contributes to heat dissipation of 38-65% of total heat. - Abstract: A numerical study of conjugate natural convection and surface radiation in a horizontal hexagonal sheath housing 19 solid heat generating rods with cladding and argon as the fill gas, is performed. The natural convection in the sheath is driven by the volumetric heat generation in the solid rods. The problem is solved using the FLUENT CFD code. A correlation is obtained to predict the maximum temperature in the rod bundle for different pitch-to-diameter ratios and heat generating rates. The effective thermal conductivity is related to the heat generation rate, maximum temperature and the sheath temperature. Results are presented for the dimensionless maximum temperature, Rayleigh number and the contribution of radiation with changing emissivity, total wattage and the pitch-to-diameter ratio. In the simulation of a larger system that contains a rod bundle, the effective thermal conductivity facilitates simplified modelling of the rod bundle by treating it as a solid of effective thermal conductivity. The parametric studies revealed that the contribution of radiation can be 38-65% of the total heat generation, for the parameter ranges chosen. Data for critical Rayleigh number above which natural convection comes into effect is also presented.

  2. Radiation-induced electrical conductivity in MgAl2O4 spinel

    International Nuclear Information System (INIS)

    Pells, G.P.

    1990-12-01

    The d.c. electrical conductivity of high purity, polycrystalline MgAl 2 O 4 spinel of 99.5% theoretical density has been measured during irradiation by 18 MeV protons at reactor relevant ionization dose rates. The radiation-induced conductivity (RIC) at 200 C varied in a slightly sub-linear manner with dose rate. At temperatures between 250-350 C the RIC varied in a complex manner with the dose rate dependence being itself dose rate dependent. At higher temperatures the RIC reverted to an essentially linear variation with dose rate. The complex dose rate dependence is ascribed to the magnesium vacancy concentration introduced by the small Al 2 O 3 excess (MgO:Al 2 O = 1:1.05) and the presence of anti-structure defects producing large concentrations of intrinsic electron and hole traps. There was no evidence that the accumulation of radiation damage influenced the details of radiation-induced conductivity and MgAl 2 O 4 retained reasonable insulating properties at the highest dose rate and temperature. (author)

  3. A methodology to investigate the contribution of conduction and radiation heat transfer to the effective thermal conductivity of packed graphite pebble beds, including the wall effect

    Energy Technology Data Exchange (ETDEWEB)

    De Beer, M., E-mail: maritz.db@gmail.com [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Du Toit, C.G., E-mail: Jat.DuToit@nwu.ac.za [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Rousseau, P.G., E-mail: pieter.rousseau@uct.ac.za [Department of Mechanical Engineering, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa)

    2017-04-01

    Highlights: • The radiation and conduction components of the effective thermal conductivity are separated. • Near-wall effects have a notable influence on the effective thermal conductivity. • Effective thermal conductivity is a function of the macro temperature gradient. • The effective thermal conductivity profile shows a characteristic trend. • The trend is a result of the interplay between conduction and radiation. - Abstract: The effective thermal conductivity represents the overall heat transfer characteristics of a packed bed of spheres and must be considered in the analysis and design of pebble bed gas-cooled reactors. During depressurized loss of forced cooling conditions the dominant heat transfer mechanisms for the passive removal of decay heat are radiation and conduction. Predicting the value of the effective thermal conductivity is complex since it inter alia depends on the temperature level and temperature gradient through the bed, as well as the pebble packing structure. The effect of the altered packing structure in the wall region must therefore also be considered. Being able to separate the contributions of radiation and conduction allows a better understanding of the underlying phenomena and the characteristics of the resultant effective thermal conductivity. This paper introduces a purpose-designed test facility and accompanying methodology that combines physical measurements with Computational Fluid Dynamics (CFD) simulations to separate the contributions of radiation and conduction heat transfer, including the wall effects. Preliminary results obtained with the methodology offer important insights into the trends observed in the experimental results and provide a better understanding of the interplay between the underlying heat transfer phenomena.

  4. Computed and conventional chest radiography: a comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Ramli, K.; Abdullah, B.J.J.; Ng, K-H.; Hussain, A.F.; Mahmud, R.

    2005-01-01

    The aim of this study was to compare the image quality and entrance skin dose (ESD) for film-screen and computed chest radiography. Analysis of the image quality and dose on chest radiography was carried out on a conventional X-ray unit using film-screen, storage phosphor plates and selenium drum direct chest radiography. For each receptor, ESD was measured in 60 patients using thermoluminescent dosemeters. Images were printed on 35 x 43 cm films. Image quality was assessed subjectively by evaluation of anatomic features and estimation of the image quality, following the guidelines established by the protocols of the Commission of the European Communities. There was no statistically significant difference noted between the computed and conventional images (Wilcoxon rank sum test, P>0.05). Imaging of the mediastinum and peripheral lung structures were better visualized with the storage phosphor and selenium drum technique than with the film-screen combination. The patients' mean ESD for chest radiography using the storage phosphor, film-screen combination and selenium drum was 0.20, 0.20 and 0.25 mGy, respectively, with no statistically significant difference with P > 0.05 (χ 2 tests) Copyright (2005) Blackwell Publishing Asia Pty Ltd

  5. Applications of radiation processing in combination with conventional treatments to assure food safety: New development

    International Nuclear Information System (INIS)

    Lacroix, M.; Turgis, M.; Borsa, J.; Millette, M.; Salmieri, S.; Caillet, S.; Han, J.

    2009-01-01

    Spice extracts under the form of essential oils (Eos) were tested for their efficiency to increase the relative bacterial radiosensitivity (RBR) of Listeria monocytogenes, Escherichia coli and Salmonellatyphi in culture media under different atmospheric conditions. The selected Eos were tested for their ability to reduce the dose necessary to eliminate E. coli and S.typhi in medium fat ground beef (23% fat) and Listeria in ready-to-eat carrots when packed under air or under atmosphere rich in oxygen (MAP). Results have demonstrated that depending of the compound added and the combined treatment used, the RBR increased from 2 to 4 times. In order to evaluate the industrial feasibility, EOs were added in ground beef at a concentration which does not affect the taste and treated at a dose of 1.5 kGy. The content of total mesophilic aerobic, E. coli, Salmonella, total coliform, lactic acid bacteria, and Pseudomonas was determined during 28 days. The results showed that the combined treatment (radiation and EOs) can eliminate Salmonella and E. coli when done under air. When done under MAP, Pseudomonas could be eliminated and a shelf life of more than 28 days was observed. An active edible coating containing EOs was also developed and sprayed on ready-to-eat carrots before radiation treatment and Listeria was evaluated. A complete inhibition of Listeria was obtained at a dose of 0.5 kGy when applied under MAP. Our results have shown that the combination of an edible coating, MAP, and radiation can be used to maintain the safety of meat and vegetables.

  6. Applications of radiation processing in combination with conventional treatments to assure food safety: New development

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, M. [Canadian Irradiation Center, Research Laboratory in Sciences Applied to Food, INRS-Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Quebec (Canada)], E-mail: monique.lacroix@iaf.inrs.ca; Turgis, M. [Canadian Irradiation Center, Research Laboratory in Sciences Applied to Food, INRS-Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Quebec (Canada); Borsa, J. [MDS Nordion, 447 March Road, Kanata, Ontario, K2K 2P7 (Canada); Millette, M.; Salmieri, S.; Caillet, S. [Canadian Irradiation Center, Research Laboratory in Sciences Applied to Food, INRS-Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Quebec (Canada); Han, J. [Sungkyunkwan University, Department of Food Science and Biotechnology, Suwon 440-746 (Korea, Republic of)

    2009-11-15

    Spice extracts under the form of essential oils (Eos) were tested for their efficiency to increase the relative bacterial radiosensitivity (RBR) of Listeria monocytogenes, Escherichia coli and Salmonellatyphi in culture media under different atmospheric conditions. The selected Eos were tested for their ability to reduce the dose necessary to eliminate E. coli and S.typhi in medium fat ground beef (23% fat) and Listeria in ready-to-eat carrots when packed under air or under atmosphere rich in oxygen (MAP). Results have demonstrated that depending of the compound added and the combined treatment used, the RBR increased from 2 to 4 times. In order to evaluate the industrial feasibility, EOs were added in ground beef at a concentration which does not affect the taste and treated at a dose of 1.5 kGy. The content of total mesophilic aerobic, E. coli, Salmonella, total coliform, lactic acid bacteria, and Pseudomonas was determined during 28 days. The results showed that the combined treatment (radiation and EOs) can eliminate Salmonella and E. coli when done under air. When done under MAP, Pseudomonas could be eliminated and a shelf life of more than 28 days was observed. An active edible coating containing EOs was also developed and sprayed on ready-to-eat carrots before radiation treatment and Listeria was evaluated. A complete inhibition of Listeria was obtained at a dose of 0.5 kGy when applied under MAP. Our results have shown that the combination of an edible coating, MAP, and radiation can be used to maintain the safety of meat and vegetables.

  7. Spatio-temporal radiation biology with conventionally or laser-accelerated particles for ELIMED

    International Nuclear Information System (INIS)

    Ristić-Fira, A.; Bulat, T.; Keta, O.; Petrović, I.; Romano, F.; Cirrone, P.; Cuttone, G.

    2013-01-01

    The aim of this study is to investigate the behavior of radio-resistant human malignant cells, thus enabling better understanding of radiobiological effects of ions in such a case. Radiation sources such as accelerated continuous ion beams and laser technology-based ultra short radiation sources with energy of around 10 MeV will be used. The HTB140 melanoma cells are chosen since it has been shown that they represent the limit case of cellular radio-resistance among the studied tumor cell lines. These cells are particularly interesting as they provide data on the very edge of inactivation capacity of each beam line that is tested. After exposing the cell monolayers to continuous radiations of low (γ-rays) and high (protons) linear energy transfer, the kinetics of disappearance of the phosphorylated histone H2AX (γ-H2AX) foci per cell will be determined. The same procedure will be performed with the pulsed high dose rate protons. Detection and quantification of γ-H2AX foci will be performed by immunohistochemical 3D time-dependent imaging analyses using laser scanning confocal microscopy. Immunoblotting will enable the follow-up of the relation between γ-H2AX and cell cycle arrest via the p53/p21 pathway. In such a way the spatio-temporal changes on sub-cellular level will be visualized, quantified and compared. These results will show whether there is a difference in the effects on cells between continuous and pulsed irradiation mode. Therefore, they will contribute to the data base that might promote pulsed sources for medical treatments of malignant growths

  8. Applications of radiation processing in combination with conventional treatments to assure food safety: New development

    Science.gov (United States)

    Lacroix, M.; Turgis, M.; Borsa, J.; Millette, M.; Salmieri, S.; Caillet, S.; Han, J.

    2009-11-01

    Spice extracts under the form of essential oils (Eos) were tested for their efficiency to increase the relative bacterial radiosensitivity (RBR) of Listeria monocytogenes, Escherichia coli and Salmonellatyphi in culture media under different atmospheric conditions. The selected Eos were tested for their ability to reduce the dose necessary to eliminate E. coli and S.typhi in medium fat ground beef (23% fat) and Listeria in ready-to-eat carrots when packed under air or under atmosphere rich in oxygen (MAP). Results have demonstrated that depending of the compound added and the combined treatment used, the RBR increased from 2 to 4 times. In order to evaluate the industrial feasibility, EOs were added in ground beef at a concentration which does not affect the taste and treated at a dose of 1.5 kGy. The content of total mesophilic aerobic, E. coli, Salmonella, total coliform, lactic acid bacteria, and Pseudomonas was determined during 28 days. The results showed that the combined treatment (radiation and EOs) can eliminate Salmonella and E. coli when done under air. When done under MAP, Pseudomonas could be eliminated and a shelf life of more than 28 days was observed. An active edible coating containing EOs was also developed and sprayed on ready-to-eat carrots before radiation treatment and Listeria was evaluated. A complete inhibition of Listeria was obtained at a dose of 0.5 kGy when applied under MAP. Our results have shown that the combination of an edible coating, MAP, and radiation can be used to maintain the safety of meat and vegetables.

  9. The effects of ionizing radiation on food, compared to the effects of conventional food treatment: A literature study. Pt. 1

    International Nuclear Information System (INIS)

    Leister, W.; Boegl, K.W.

    1987-08-01

    The extent and quality of changes due to irradiation is described and compared with conventional methods. Effects of radiation treatment on vegetable products as well as pork, beef, any type of fish and poultry product are compared with conventional thermic, micro-wave or smoke treatments, drying processes, ethylene oxide gas treatment, as well as effects from storage, temperature and sealed packaging. In this context the influences of the different treatment methods on various food components and on sensory, physical-chemical or biochemical characteristics were compared. The following tendencies were observed: conventional treatment methods produce partly more pronounced changes than irradiation with standard doses. Heat treatment, for instance, results in a greater weight loss, in altered sugar content, and in higher content of carbonyl and aldehyde releasing compounds. Gas treatment will cut the volatile oil content in half, while it remains nearly constant after irradiation. However, in some cases, an irradiation with standard doses may cause changes which should not be disregarded. In onions, for instance, irradiation is causing a stronger decomposition during storage than only cold storage. (orig./MG) [de

  10. The therapeutic effect of three-dimensional conformal radiation therapy combined with conventional radiotherapy for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Liang Feng; Lu Zhonghong; Yao Zhijun; Cao Yongzhen

    2011-01-01

    Objective: To observe the therapeutic effect of three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC). Methods: 78 patients with NPC was treated by radiation schedule in two phases. In the first phase, nasopharyngeal lesions and metastases of all patients were treated by three-dimensional conformal radiation therapy (3DCRT) with a fraction of 2-5 Gy daily, 5 day per weeks, total dose 30 Gy. The second phase T1N0 or parts of T2N0 patients were done by Conventional radiotherapy with total dose 55 Gy on two small lateral opposing fields + with total dose 50 Gy on neck on tangential field,adding a 3 cm block. Patients with lymph node metastasis were given 55 Gy on the dacio-neck field (After 40 Gy, two small lateral opposing fields were used to boost the primary tumor while the spinal cord shielded) + with total dose 55 Gy on lower neck on tangential field. The upper bound of designed therapeutic field was set to connect with lower bound of main therapeutic field. Results: Three months after treatment,the rate of CR, PR, SD, PD were 38.5%, 55.1%, 5.1%, 1.3%, Total effective rate (CR+PR) were 93.6%. The 1-year, 2-year, 3-year and 5-year local-regional control rates were 92.3%, 88.5%, 78.2%, 70.5%.The 1-year, 2-year , 3-year and 5-year overall survival rate were 96.2%, 89.7%, 83.3%, 71.8%. Appearing early radiation response is well tolerated and no obviously mouth difficulties and cranial nerve damage observed. Conclusion: Clinical result of early-course three-dimensional conformal radiation therapy (3DCRT) for nasopharyngeal carcinoma (NPC) is good. (authors)

  11. Comparative investigations on xeroradiography and conventional X-radiation with chronical polyarthritis

    International Nuclear Information System (INIS)

    Meisl, T.A.

    1980-01-01

    We compared the roentgenologic and xeroradiographic findings of the hands of 50 patients suffering from polyarthritis. Both techniques were compared with respect to their imaging quality of roentgenologically significant alterations occurring with chronical polyarthritis. The superiority of xeroradiography bases on the better contour delineation facilities. Disadvantages are the loss of detailed information due to neutralisation effects and also to the impaired representation of areal density differences and of the absolute density of an object. The conventional roentgenologic method is superior with respect to the more informative imaging of areal density modifications, also to the partly better representation of cystic transluences and to a minor degree with respect to a more distinct reproduction of an atrophy of the subchondral lamina terminalis. However, in general it can be said that the results of the two compared techniques do not differ significantly. Consequently the traditional roentgenologic method appears to be the more suitable technique for the diagnosis of chronical polyarthritis. (orig./MG) [de

  12. Concurrent cisplatin, infusional fluorouracil, and conventionally fractionated radiation therapy in head and neck cancer: Dose-limiting mucosal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Denham, J.W.; Abbott, R.L. (Royal Adelaide Hospital (Australia))

    1991-03-01

    After a preliminary dose-finding study involving 12 patients with advanced or locally recurrent head and neck cancer, 27 patients were treated on a phase II protocol, using fluorouracil 350 mg/m2/d by continuous intravenous (IV) infusion over 5 days, followed on the sixth day by a 2-hour IV infusion of cisplatin 50 mg/m2, administered during the first and fourth weeks of radiation therapy to total doses between 60 and 64 Gy, using 2 Gy daily fractions. Eight of these 27 patients had American Joint Committee on Cancer Staging (AJCC) stage III disease, and 12 had stage IV disease. Four had recurrent disease after surgery. Three-year follow-up is now available. Twenty-one (77.8%) remitted completely following treatment, and 11 remain free of local and regional relapse at 3 years. Four have developed systemic metastases. Following successful salvage treatment in two cases, estimated determinate survival at 3 years is 64%. Acute toxicity was manageable with this regime. Eleven instances of grade 3 Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) mucositis were observed, which caused interruptions to radiotherapy in only four cases. No late sequelae have so far been recorded. It is concluded that the protocol described is tolerable but probably did not cause a greater number of locoregional cures than would have been expected following conventional radiotherapy alone in this group of patients. The use of infusional fluorouracil with concurrent conventionally fractionated radiation therapy and cisplatin infusion results in mucositis that limits the dose of fluorouracil to levels that are probably subtherapeutic.

  13. Mild Lung Restriction in Breast Cancer Patients After Hypofractionated and Conventional Radiation Therapy: A 3-Year Follow-Up

    International Nuclear Information System (INIS)

    Verbanck, Sylvia; Hanon, Shane; Schuermans, Daniel; Van Parijs, Hilde; Vinh-Hung, Vincent; Miedema, Geertje; Verellen, Dirk; Storme, Guy; Fontaine, Christel; Lamote, Jan; De Ridder, Mark; Vincken, Walter

    2016-01-01

    Purpose: To assess the effect of radiation therapy on lung function over the course of 3 years. Methods and Materials: Evolution of restrictive and obstructive lung function parameters was investigated in 108 breast cancer participants in a randomized, controlled trial comparing conventional radiation therapy (CR) and hypofractionated tomotherapy (TT) (age at inclusion ranging 32-81 years). Spirometry, plethysmography, and hemoglobin-corrected diffusing capacity were assessed at baseline and after 3 months and 1, 2, and 3 years. Natural aging was accounted for by considering all lung function parameters in terms of percent predicted values using the most recent reference values for women aged up to 80 years. Results: In the patients with negligible history of respiratory disease or smoking (n=77), the greatest rate of functional decline was observed during the initial 3 months, this acute decrease being more marked in the CR versus the TT arm. During the remainder of the 3-year follow-up period, values (in terms of percent predicted) were maintained (diffusing capacity) or continued to decline at a slower rate (forced vital capacity). However, the average decline of the restrictive lung function parameters over a 3-year period did not exceed 9% predicted in either the TT or the CR arm. Obstructive lung function parameters remained unaffected throughout. Including also the 31 patients with a history of respiratory disease or more than 10 pack-years showed a very similar restrictive pattern. Conclusions: In women with breast cancer, both conventional radiation therapy and hypofractionated tomotherapy induce small but consistent restrictive lung patterns over the course of a 3-year period, irrespective of baseline respiratory status or smoking history. The fastest rate of lung function decline generally occurred in the first 3 months.

  14. Mild Lung Restriction in Breast Cancer Patients After Hypofractionated and Conventional Radiation Therapy: A 3-Year Follow-Up

    Energy Technology Data Exchange (ETDEWEB)

    Verbanck, Sylvia, E-mail: sylvia.verbanck@uzbrussel.be [Respiratory Division, University Hospital UZ Brussel, Brussels (Belgium); Hanon, Shane; Schuermans, Daniel [Respiratory Division, University Hospital UZ Brussel, Brussels (Belgium); Van Parijs, Hilde; Vinh-Hung, Vincent; Miedema, Geertje; Verellen, Dirk; Storme, Guy [Department of Radiotherapy, University Hospital UZ Brussel, Brussels (Belgium); Fontaine, Christel; Lamote, Jan [Department of Senology and Oncologic Surgery, University Hospital UZ Brussel, Brussels (Belgium); De Ridder, Mark [Department of Radiotherapy, University Hospital UZ Brussel, Brussels (Belgium); Vincken, Walter [Respiratory Division, University Hospital UZ Brussel, Brussels (Belgium)

    2016-07-01

    Purpose: To assess the effect of radiation therapy on lung function over the course of 3 years. Methods and Materials: Evolution of restrictive and obstructive lung function parameters was investigated in 108 breast cancer participants in a randomized, controlled trial comparing conventional radiation therapy (CR) and hypofractionated tomotherapy (TT) (age at inclusion ranging 32-81 years). Spirometry, plethysmography, and hemoglobin-corrected diffusing capacity were assessed at baseline and after 3 months and 1, 2, and 3 years. Natural aging was accounted for by considering all lung function parameters in terms of percent predicted values using the most recent reference values for women aged up to 80 years. Results: In the patients with negligible history of respiratory disease or smoking (n=77), the greatest rate of functional decline was observed during the initial 3 months, this acute decrease being more marked in the CR versus the TT arm. During the remainder of the 3-year follow-up period, values (in terms of percent predicted) were maintained (diffusing capacity) or continued to decline at a slower rate (forced vital capacity). However, the average decline of the restrictive lung function parameters over a 3-year period did not exceed 9% predicted in either the TT or the CR arm. Obstructive lung function parameters remained unaffected throughout. Including also the 31 patients with a history of respiratory disease or more than 10 pack-years showed a very similar restrictive pattern. Conclusions: In women with breast cancer, both conventional radiation therapy and hypofractionated tomotherapy induce small but consistent restrictive lung patterns over the course of a 3-year period, irrespective of baseline respiratory status or smoking history. The fastest rate of lung function decline generally occurred in the first 3 months.

  15. Radiation-induced conductivity of doped silicon in response to photon, proton and neutron irradiation

    International Nuclear Information System (INIS)

    Kishimoto, N.; Amekura, H.; Plaksin, O.A.; Stepanov, V.A.

    2000-01-01

    The opto-electronic performance of semiconductors during reactor operation is restricted by radiation-induced conductivity (RIC) and the synergistic effects of neutrons/ions and photons. The RICs of Si due to photons, protons and pulsed neutrons have been evaluated, aiming at radiation correlation. Protons of 17 MeV with an ionizing dose rate of 10 3 Gy/s and/or photons (hν=1.3 eV) were used to irradiate impurity-doped Si (2x10 16 B atoms/cm 3 ) at 300 and 200 K. Proton-induced RIC (p-RIC) and photoconductivity (PC) were intermittently detected in an accelerator device. Neutron-induced RIC (n-RIC) was measured for the same Si in a pulsed fast-fission reactor, BARS-6, with a 70-μs pulse of 2x10 12 n/cm 2 (E>0.01 MeV) and a dose rate of up to 6x10 5 Gy/s. The neutron irradiation showed a saturation tendency in the flux dependence at 300 K due to the strong electronic excitation. Normalization of the electronic excitation, including the pulsed regime, gave a fair agreement among the different radiation environments. Detailed comparison among PC, p-RIC and n-RIC is discussed in terms of radiation correlation including the in-pile condition

  16. Radiation damages and electro-conductive characteristics of Neutron-Transmutation-Doped GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, Kazuo; Sato, Masataka; Sakai, Kiyohiro [Hosei Univ., Koganei, Tokyo (Japan). Coll. of Engineering; Okada, Moritami

    1996-04-01

    Neutron Transmutation Doping (NTD) method made it possible to do homogeneous doping of impurities and to easily control the doping level. Thus, the method has been put into practice for some materials such as silicon. Here, the annealing behavior of anti-site defects generated in neutron-irradiated GaAs was studied. Electric activations of NTD-impurities were started around 550degC in P1 and P2 radiation fields, which were coincident with the beginning of extinction of electron trapping which was caused by anti-site defects due to fast neutron radiation. The electric resistivities of GaAs in neutron radiation fields; P1, P2 and P3 changed depending with the annealing temperature. The electric resistivities of GaAs in P1 and P2 fields indicate the presence of hopping conduction through radiation damages. The resistance of GaAs irradiated in P1 was smaller by nearly 2 orders than that of the untreated control. Further, the electric activation process for NTD-impurities was investigated using ESR and Raman spectroscopy. (M.N.)

  17. Conductive core of radiation-resistant high-pressure electric bushing, especially for nuclear technology

    Energy Technology Data Exchange (ETDEWEB)

    Zajic, V

    1981-09-01

    A radiation-resistant high-pressure electric bushing was developed featuring a conductive core consisting of a hollow moulding. At the point of attachment to the bushing insulator the core moulding is widened, thus forming a ring support of a diameter larger by at least 10% than the diameter of the conductive core cylindrical section. On the outer side of the pressure body the core cavity is narrowed and tightly closed with the conductor. On the side facing the medium of higher pressure, the conductive core is provided with a thread. Core manufacture and connection of the conductor to the bushing is very simple. The bushing can be used for an environment with pressures exceeding 10 MPa.

  18. Conductive core of radiation-resistant high-pressure electric bushing, especially for nuclear technology

    International Nuclear Information System (INIS)

    Zajic, V.

    1981-01-01

    A radiation-resistant high-pressure electric bushing was developed featuring a conductive core consisting of a hollow moulding. At the point of attachment to the bushing insulator the core moulding is widened, thus forming a ring support of a diameter larger by at least 10% than the diameter of the conductive core cylindrical section. On the outer side of the pressure body the core cavity is narrowed and tightly closed with the conductor. On the side facing the medium of higher pressure, the conductive core is provided with a thread. Core manufacture and connection of the conductor to the bushing is very simple. The bushing can be used for an environment with pressures exceeding 10 MPa. (J.B.)

  19. Thermal conductivity of multi-walled carbon nanotube sheets: radiation losses and quenching of phonon modes

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, Ali E; Lima, Marcio H; Baughman, Ray H [Alan G MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083 (United States); Silverman, Edward M, E-mail: Ali.Aliev@utdallas.edu [Northrop Grumman Space Technology, Redondo Beach, CA 90278 (United States)

    2010-01-22

    The extremely high thermal conductivity of individual carbon nanotubes, predicted theoretically and observed experimentally, has not yet been achieved for large nanotube assemblies. Resistances at tube-tube interconnections and tube-electrode interfaces have been considered the main obstacles for effective electronic and heat transport. Here we show that, even for infinitely long and perfect nanotubes with well-designed tube-electrode interfaces, excessive radial heat radiation from nanotube surfaces and quenching of phonon modes in large bundles are additional processes that substantially reduce thermal transport along nanotubes. Equivalent circuit simulations and an experimental self-heating 3{omega} technique were used to determine the peculiarities of anisotropic heat flow and thermal conductivity of single MWNTs, bundled MWNTs and aligned, free-standing MWNT sheets. The thermal conductivity of individual MWNTs grown by chemical vapor deposition and normalized to the density of graphite is much lower ({kappa}{sub MWNT} = 600 {+-} 100 W m{sup -1} K{sup -1}) than theoretically predicted. Coupling within MWNT bundles decreases this thermal conductivity to 150 W m{sup -1} K{sup -1}. Further decrease of the effective thermal conductivity in MWNT sheets to 50 W m{sup -1} K{sup -1} comes from tube-tube interconnections and sheet imperfections like dangling fiber ends, loops and misalignment of nanotubes. Optimal structures for enhancing thermal conductivity are discussed.

  20. Evidence from Animal Models: Is a Restricted or Conventional Intestinal Microbiota Composition Predisposing to Risk for High-LET Radiation Injury?

    Science.gov (United States)

    Maier, Irene; Schiestl, Robert H

    2015-06-01

    Intestinal microbiota affect cell responses to ionizing radiation at the molecular level and can be linked to the development of the immune system, controlled cell death or apoptosis. We have developed a microbiota mouse model and report here that high-linear energy transfer (LET) radiation induced the repair of chromosomal DNA lesions more efficiently in conventional than in restricted intestinal microbiota mice. Based on different phylotype densities after whole-body irradiation, bacterial indicator phylotypes were found to be more abundant in restricted in microbiota than in conventional microbiota. Genotoxic phenotypes of irradiated restricted and conventional microbiota mice were compared with ataxia telangiectasia-deficient restricted and conventional microbiota mice, respectively. Those indicator phylotypes, including Bacteroides (Gram-negative bacterium cTPY-13), Barnesiella intestinihominis and others, which were identified in nonirradiated restricted microbiota mice, increase in radiation-exposed conventional microbiota along with a reduction of persistent DNA double-strand breaks in blood lymphocytes. The dynamic change of phylotype abundances elucidated a feedback mechanism and effect of intestinal microbiota composition on the adaptive response to high-LET radiation. Several other bacterial phylotypes ( Helicobacter hepaticus , Helicobacter spp and others) were found to be more abundant in conventional than restricted microbiota. In this commentary, mouse models used in cancer research and radiotherapy for the study on the effects of intestinal microbiota composition on normal tissue radiation response are characterized and discussed. Highlights of this commentary: 1. Restricted microbiota phylotypes were correlated with persistent DNA double-strand breaks (DSBs) and were found to orchestrate onco-protective controlled cell death after radiation; 2. Restricted microbiota composition reduced proinflammatory extracellular-stimulated immune responses, but

  1. Pushing, pulling and electromagnetic radiation force cloaking by a pair of conducting cylindrical particles

    Science.gov (United States)

    Mitri, F. G.

    2018-02-01

    The present analysis shows that two conducting cylindrical particles illuminated by an axially-polarized electric field of plane progressive waves at arbitrary incidence will attract, repel or become totally cloaked (i.e., invisible to the transfer of linear momentum carried by the incident waves), depending on their sizes, the interparticle distance as well as the angle of incidence of the incident field. Based on the rigorous multipole expansion method and the translational addition theorem of cylindrical wave functions, the electromagnetic (EM) radiation forces arising from multiple scattering effects between a pair of perfectly conducting cylindrical particles of circular cross-sections are derived and computed. An effective incident field on a particular particle is determined first, and used subsequently with its corresponding scattered field to derive the closed-form analytical expressions for the radiation force vector components. The mathematical expressions for the EM radiation force components (i.e. longitudinal and transverse) are exact, and have been formulated in partial-wave series expansions in cylindrical coordinates involving the angle of incidence, the interparticle distance and the expansion coefficients. Numerical examples illustrate the analysis for two perfectly conducting circular cylinders in a homogeneous nonmagnetic medium of wave propagation. The computations for the dimensionless radiation force functions are performed with particular emphasis on varying the angle of incidence, the interparticle distance, and the sizes of the particles. Depending on the interparticle distance and angle of incidence, the cylinders yield total neutrality (or invisibility); they experience no force and become unresponsive to the transfer of the EM linear momentum due to multiple scattering cancellation effects. Moreover, pushing or pulling EM forces between the two cylinders arise depending on the interparticle distance, the angle of incidence and their

  2. Radiation effect on conductivity of oxygen-containing crystals of lithium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Shchepina, L.I.; Alekseeva, L.I.; Lobanov, B.D.; Kostyukov, V.M. (Irkutskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Prikladnoj Fiziki)

    1984-07-01

    The data are presented on an anomalous behaviour of the conductivity, sigma of oxygen-enriched LiF crystals irradiated by approximately 10/sup 5/ J/kg doses. The ultraviolet absorption spectra were used to measure the oxygen content. The samples were exposed to ..gamma..-radiation of a /sup 60/Co source. The anomalous behaviour of tau is manifested by deviation of the sigma temperature dependence from the exponential law and occurrence of the minimum on the curve. The anomalous behaviour covers the range of 580-660 K and terminates by the tau recovery up to the values of an intact samples.

  3. Summary of round robin measurements of radiation induced conductivity in Wesgo AL995 alumina

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    This existing data on radiation induced conductivity (RIC) measurements performed on the same heat of the IEA reference ceramic insulator are summarized. Six different sets of RIC measurements have been performed on Wesgo AL995 at dose rates between 10 Gy/s and 1 MGy/s. In general, good agreement was obtained between the different groups of researchers. The data indicate that the RIC at a test temperature of 400-500{degrees}C is approximately linear with ionizing dose rate up to {approximately}1000 Gy/s, and exhibits an approximately square root dependence on dose rate between 1 kGy/s and 1 MGy/s.

  4. Evaluation of the Anisotropic Radiative Conductivity of a Low-Density Carbon Fiber Material from Realistic Microscale Imaging

    Science.gov (United States)

    Nouri, Nima; Panerai, Francesco; Tagavi, Kaveh A.; Mansour, Nagi N.; Martin, Alexandre

    2015-01-01

    The radiative heat transfer inside a low-density carbon fiber insulator is analyzed using a three-dimensional direct simulation model. A robust procedure is presented for the numerical calculation of the geometric configuration factor to compute the radiative energy exchange processes among the small discretized surface areas of the fibrous material. The methodology is applied to a polygonal mesh of a fibrous insulator obtained from three-dimensional microscale imaging of the real material. The anisotropic values of the radiative conductivity are calculated for that geometry. The results yield both directional and thermal dependence of the radiative conductivity.

  5. Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette

    International Nuclear Information System (INIS)

    Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A.; Sehner, J.

    1999-01-01

    Purpose: How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette? Methods and Materials: A skull phantom (3M) was X-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhoefer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast. Results: The surface entrance dose at 73 kV/22 mAs was 0,432 mGy in conventional screen film system and 0,435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0,308 mGy; SD 0,050); sufficient images were obtained down to an average dose of 31% (0,136 mGy; SD 0,065). The resolution of the line pairs were reduced down to a 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resultde in an improvement of the assessment of bone structures an contrast in higher dose ranges only. Conclusion: For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement the skull the dose can be reduced to at least 56% (31%; SD 14,9%)/40% (27%; SD 9,3%)/18% (14%; SD 4,4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12,5 mAs and to skull measurement 73 kV/4 mAs. (orig.) [de

  6. Accurate Models for Evaluating the Direct Conducted and Radiated Emissions from Integrated Circuits

    Directory of Open Access Journals (Sweden)

    Domenico Capriglione

    2018-03-01

    Full Text Available This paper deals with the electromagnetic compatibility (EMC issues related to the direct and radiated emissions from a high-speed integrated circuits (ICs. These emissions are evaluated here by means of circuital and electromagnetic models. As for the conducted emission, an equivalent circuit model is derived to describe the IC and the effect of its loads (package, printed circuit board, decaps, etc., based on the Integrated Circuit Emission Model template (ICEM. As for the radiated emission, an electromagnetic model is proposed, based on the superposition of the fields generated in the far field region by the loop currents flowing into the IC and the package pins. A custom experimental setup is designed for validating the models. Specifically, for the radiated emission measurement, a custom test board is designed and realized, able to highlight the contribution of the direct emission from the IC, usually hidden by the indirect emission coming from the printed circuit board. Measurements of the package currents and of the far-field emitted fields are carried out, providing a satisfactory agreement with the model predictions.

  7. Conventional external beam radiation therapy and high dose rate afterloading brachytherapy as a boost for patients older than 70 years

    International Nuclear Information System (INIS)

    Pellizzon, Antonio Cassio Assis; Salvajoli, Joao Vitor; Fogaroli, Ricardo Cesar; Novaes, Paulo Eduardo R.S.; Maia, Maria Aparecida Conte; Ferrigno, Robson

    2005-01-01

    The treatment options for patients with non metastatic prostate cancer range from observation, radical prostatectomy, radiation therapy, hormonal therapy to various combination of some to all of them. Objective: we evaluated the impact on biochemical control of disease (bNED), acute and late intestinal (GI) and urological (GU) morbidity for a group of patients older than 70 years presenting initial or locally advanced prostate cancer treated with fractionated high dose rate brachytherapy (HDRB) as a boost to conventional external beam radiation therapy (RT) at the Department of Radiation Oncology from Hospital do Cancer A. C. Camargo, Sao Paulo, Brazil. Methods: a total of 56 patients older than 70 were treated from March, 1997 to June, 2002. All patients had prior to HDRB a course of RT to a median dose of 45 Gy. HDRB doses ranged from 16 Gy to 20 Gy, given in 4 fractions. Results: the median age of the patients was 74.4 years (range 70-83) and the median follow-up 33 months (range 24 to 60). The 5-year actuarial bNED rate was 77%. Acute GU and GI morbidity G1-2 were seen in 17.8% and 7.1% of patients, respectively. Late G1 or G2 GU morbidity was seen in 10.7% of the patients, while late G3 morbidity was observed in 7.1% of the patients, represented by urethral strictures. Conclusion: this group of patients had similar bNED rates when compared to literature, with acceptable morbidity rates. (author)

  8. Near-field radiative heat transfer under temperature gradients and conductive transfer

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Weiliang; Rodriguez, Alejandro W. [Princeton Univ., NJ (United States). Dept. of Electrical Engineering; Messina, Riccardo [CNRS-Univ. de Montpellier (France). Lab. Charles Coulomb

    2017-05-01

    We describe a recently developed formulation of coupled conductive and radiative heat transfer (RHT) between objects separated by nanometric, vacuum gaps. Our results rely on analytical formulas of RHT between planar slabs (based on the scattering-matrix method) as well as a general formulation of RHT between arbitrarily shaped bodies (based on the fluctuating-volume current method), which fully captures the existence of temperature inhomogeneities. In particular, the impact of RHT on conduction, and vice versa, is obtained via self-consistent solutions of the Fourier heat equation and Maxwell's equations. We show that in materials with low thermal conductivities (e.g. zinc oxides and glasses), the interplay of conduction and RHT can strongly modify heat exchange, exemplified for instance by the presence of large temperature gradients and saturating flux rates at short (nanometric) distances. More generally, we show that the ability to tailor the temperature distribution of an object can modify the behaviour of RHT with respect to gap separations, e.g. qualitatively changing the asymptotic scaling at short separations from quadratic to linear or logarithmic. Our results could be relevant to the interpretation of both past and future experimental measurements of RHT at nanometric distances.

  9. Critical analysis of soil hydraulic conductivity determination using monoenergetic gamma radiation attenuation

    International Nuclear Information System (INIS)

    Portezan Filho, Otavio

    1997-01-01

    Three soil samples of different textures: LVA (red yellow latosol), LVE (dark red latosol) and LRd (dystrophic dark red latosol) were utilized for unsaturated hydraulic conductivity K(θ) measurements. Soil bulk densities and water contents during internal water drainage were measured by monoenergetic gamma radiation attenuation, using homogeneous soil columns assembled in the laboratory. The measurements were made with a collimated gamma beam of 0.003 m in diameter using a Nal(Tl) (3'' x 3 '') detector and a 137 Cs gamma source of 74 X 10 8 Bq and 661.6 KeV. Soil columns were scanned with the gamma beam from 0.01 to 0.20 m depth, in 0.01m steps, for several soil water redistribution times. The results show a great variability of the unsaturated hydraulic conductivity relation K(θ), even though homogeneous soils were used. The variability among methods is significantly smaller in relation to variability in space. The assumption of unit hydraulic gradient during redistribution of soil water utilized in the methods of Hillel, Libardi and Sisson leads to hydraulic conductivity values that increase in depth. The exponential character of the K(θ) relationship, is responsible for the difficulty of estimating soil hydraulic conductivity, which is a consequence of small variations in the porous arrangement, even in samples supposed to be homogeneous. (author)

  10. Structural, thermal and ion transport properties of radiation grafted lithium conductive polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Nasef, Mohamed Mahmoud [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)]. E-mail: mahmoudeithar@mailcity.com; Saidi, Hamdani [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)

    2006-10-10

    Structural, thermal and ion transport properties of lithium conductive polymer electrolytes prepared by radiation-induced grafting of styrene onto poly(vinylidene fluoride) (PVDF) films and subsequent activation with LiPH{sub 6}/EC/DEC liquid electrolyte were investigated in correlation with the content of the grafted polystyrene (Y%). The changes in the structure were studied using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability. The ionic conductivity was measured by means of ac impedance spectroscopy at various temperatures. The polymer electrolytes were found to undergo considerable structural and morphological changes that resulted in a noticeable increase in their ionic conductivity with the increase in Y% at various temperatures (25-65 deg. C). The ionic conductivity achieved a value of 1.61 x 10{sup -3} S cm{sup -1} when Y of the polymer electrolyte reached 50% and at 25 deg. C. The polymer electrolytes also showed a multi-step degradation behaviour and thermal stability up to 120 deg. C, which suits normal lithium battery operation temperature range. The overall results of this work suggest that the structural changes took place in PVDF matrix during the preparation of these polymer electrolytes have a strong impact on their various properties.

  11. Effect of reactor radiation on the thermal conductivity of TREAT fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Kun, E-mail: kunmo@anl.gov; Miao, Yinbin; Kontogeorgakos, Dimitrios C.; Connaway, Heather M.; Wright, Arthur E.; Yacout, Abdellatif M.

    2017-04-15

    The Transient Reactor Test Facility (TREAT) at the Idaho National Laboratory is resuming operations after more than 20 years in latency in order to produce high-neutron-flux transients for investigating transient-induced behavior of reactor fuels and their interactions with other materials and structures. A parallel program is ongoing to develop a replacement core in which the fuel, historically containing highly-enriched uranium (HEU), is replaced by low-enriched uranium (LEU). Both the HEU and prospective LEU fuels are in the form of UO{sub 2} particles dispersed in a graphite matrix, but the LEU fuel will contain a much higher volume of UO{sub 2} particles, which may create a larger area of interphase boundaries between the particles and the graphite. This may lead to a higher volume fraction of graphite exposed to the fission fragments escaping from the UO{sub 2} particles, and thus may induce a higher volume of fission-fragment damage on the fuel graphite. In this work, we analyzed the reactor-radiation induced thermal conductivity degradation of graphite-based dispersion fuel. A semi-empirical method to model the relative thermal conductivity with reactor radiation was proposed and validated based on the available experimental data. Prediction of thermal conductivity degradation of LEU TREAT fuel during a long-term operation was performed, with a focus on the effect of UO{sub 2} particle size on fission-fragment damage. The proposed method can be further adjusted to evaluate the degradation of other properties of graphite-based dispersion fuel.

  12. Study of the heat transfers spectral radiation - conduction - natural convection in hybrid photovoltaic systems for buildings

    International Nuclear Information System (INIS)

    Muresan, C.

    2005-01-01

    numerical solution of the Radiative Transfer Equation in diffused part in the case of a mono-dimensional plane geometry. The directional discretizations of each layer are selected in such a way that the discrete directions of one of the layers correspond to those refracted of the close layer and this makes it possible to avoid the use of approximations related to non coincidence of the discrete directions of a layer with those refracted by the close layer. Directional quadratures are then established in an adaptive way in each layer and for each spectral frequency. The results obtained are validated by an approach of Monte Carlo type. The coupling of this model with a Low Reynolds number RANS model will be carried out. This will be done in order to study the convective heat transfers in natural convection for configurations of double facade integration under consideration within the framework of PRI CNRS. The comparison of this model is carried out for experimental configurations of vertical channel type uniformly heated in natural convection. The prospects for this stage are multiple and consist of analyzing the influence of the mode of flow on the thermal pulling of the hybrid components, the effects of the positioning of modules statement, the air gap between the two frontages and the boundary conditions thermal generated by the modules. Lastly, in order to supplement the energy balance of such components and more particularly that governs the thermal behavior of a photosensitive cell, the electric phenomenon of conversion is approached in adequacy with the level of modeling of the coupled thermal transfers radiation - conduction within a PV component. To carry this out, we can consider the local power of spectral radiation absorbed and converted into electric output. (author)

  13. Measurements of Prompt Radiation-Induced Conductivity of Pyralux®

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Zarick, Thomas Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; McLain, Michael Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Sheridan, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Preston, Eric F. [ITT Exelis, Colorado Springs, CO (United States); Stringer, Thomas Arthur [ITT Exelis, Colorado Springs, CO (United States)

    2014-01-01

    In this report, measurements of the prompt radiation-induced conductivity (RIC) in 3 mil samples of Pyralux® are presented as a function of dose rate, pulse width, and applied bias. The experiments were conducted with the Medusa linear accelerator (LINAC) located at the Little Mountain Test Facility (LMTF) near Ogden, UT. The nominal electron energy for the LINAC is 20 MeV. Prompt conduction current data were obtained for dose rates ranging from ~2 x 109 rad(Si)/s to ~1.1 x 1011 rad(Si)/s and for nominal pulse widths of 50 ns and 500 ns. At a given dose rate, the applied bias across the samples was stepped between -1500 V and 1500 V. Calculated values of the prompt RIC varied between 1.39x10-8 Ω-1 · m-1 and 2.67x10-7 Ω-1 · m-1 and the prompt RIC coefficient varied between 1.25x10-18 Ω-1 · m-1/(rad/s) and 1.93x10-17 Ω-1 · m-1/(rad/s).

  14. Development and adaptation of conduction and radiation heat-transfer computer codes for the CFTL

    International Nuclear Information System (INIS)

    Conklin, J.C.

    1981-08-01

    RODCON and HOTTEL are two computational methods used to calculate thermal and radiation heat transfer for the Core Flow Test Loop (CFTL) analysis efforts. RODCON was developed at ORNL to calculate the internal temperature distribution of the fuel rod simulator (FRS) for the CFTL. RODCON solves the time-dependent heat transfer equation in two-dimensional (R angle) cylindrical coordinates at an axial plane with user-specified radial material zones and time- and position-variant surface conditions at the FRS periphery. Symmetry of the FRS periphery boundary conditions is not necessary. The governing elliptic, partial differential heat equation is cast into a fully implicit, finite-difference form by approximating the derivatives with a forward-differencing scheme with variable mesh spacing. The heat conduction path is circumferentially complete, and the potential mathematical problem at the rod center can be effectively ignored. HOTTEL is a revision of an algorithm developed by C.B. Baxi at the General Atomic Company (GAC) to be used in calculating radiation heat transfer in a rod bundle enclosed in a hexagonal duct. HOTTEL uses geometric view factors, surface emissivities, and surface areas to calculate the gray-body or composite view factors in an enclosure having multiple reflections in a nonparticipating medium

  15. ANALYSIS, OPTIMAL CONTROL, AND SIMULATION OF CONDUCTIVE-RADIATIVE HEAT TRANSFER

    Directory of Open Access Journals (Sweden)

    Peter Philip

    2011-01-01

    Full Text Available This article surveys recent results regarding the existence of weaksolutions to quasilinear partial differential equations(PDEcouplednonlocally by the integral operator of the radiosity equation, modeling conductive-radiative heat transfer. Both the stationary and the transient case are considered. For the stationary case, an optimal control problem with control constraints is presented withfirst-order necessary optimality conditions, where recent results on the solution theory of the linearized state equation allow to close a previous gap.Afinite volume scheme for the discretization of the stationary system is described and, based on this scheme, a numerical computation of the temperaturefield(solution of the state equationis shown as well as the numerical solution to a realistic control problem in the context of industrial applications in crystal growth.

  16. Solving transient conduction and radiation heat transfer problems using the lattice Boltzmann method and the finite volume method

    International Nuclear Information System (INIS)

    Mishra, Subhash C.; Roy, Hillol K.

    2007-01-01

    The lattice Boltzmann method (LBM) was used to solve the energy equation of a transient conduction-radiation heat transfer problem. The finite volume method (FVM) was used to compute the radiative information. To study the compatibility of the LBM for the energy equation and the FVM for the radiative transfer equation, transient conduction and radiation heat transfer problems in 1-D planar and 2-D rectangular geometries were considered. In order to establish the suitability of the LBM, the energy equations of the two problems were also solved using the FVM of the computational fluid dynamics. The FVM used in the radiative heat transfer was employed to compute the radiative information required for the solution of the energy equation using the LBM or the FVM (of the CFD). To study the compatibility and suitability of the LBM for the solution of energy equation and the FVM for the radiative information, results were analyzed for the effects of various parameters such as the scattering albedo, the conduction-radiation parameter and the boundary emissivity. The results of the LBM-FVM combination were found to be in excellent agreement with the FVM-FVM combination. The number of iterations and CPU times in both the combinations were found comparable

  17. The importance of the time scale in radiation detection exemplified by comparing conventional and avalache semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tove, P A; Cho, Z H; Huth, G C [California Univ., Los Angeles (USA). Lab. of Nuclear Medicine and Radiation Biology

    1976-02-01

    The profound importance of the time scale of a radiation detection process is discussed in an analysis of limitations in energy resolution and timing, with emphasis on semiconductor detectors used for X-ray detection. The basic event detection time involves stopping of the particle and creating a distribution of free electrons and holes containing all desired information (energy, time position) about the particle or quantum, in a time approximately equal to 10/sup -12/s. The process of extracting this information usually involves a much longer time because the signal is generated in the relatively slow process of charge collection, and further prolongation may be caused by signal processing required to depress noise for improving energy resolution. This is a common situation for conventional semiconductor detectors with external amplifiers where time constants of 10/sup -5/-10/sup -4/s may be optimum, primarily because of amplifier noise. A different situation applies to the avalanche detector where internal amplification helps in suppressing noise without expanding the time scale of detections, resulting in an optimum time of 10/sup -9/-10/sup -8/s. These two cases are illustrated by plotting energy resolution vs. time constant, for different magnitudes of the parallel and series type noise sources. The effects of the inherent energy spread due to statistips and spatial inhomogeneities are also discussed to illustrate the potential of these two approaches for energy and time determination. Two constructional approaches for avalanche detectors are briefly compared.

  18. Preparation of a newly microbial polymer using ionizing radiation technique and its conductivity

    Energy Technology Data Exchange (ETDEWEB)

    KIm, Hwa Jung; Song, Aram; Kim, Dong Ho; Park, Hae Jun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongup (Korea, Republic of)

    2016-11-15

    Extracellular polymeric substance (EPS) is produced by microorganisms for a variety of purpose in response to environmental stresses. The EPS are heterogeneous mixture composed dominantly of polysaccharides and proteins, with nucleic acid and lipid as minor constituents. Application of a bacterial EPS is in mostly bioremediation in environment and it applied to pharmaceutical industries including indwelling medical devices. Furthermore, the EPS studies have mostly been performed in the only level of bacterial culture system. In this study, we have first investigated the structural modification of EPS using ionizing radiation technique. The extracted EPS solution from bacterial culture step was exposed to gamma-irradiation at room temperature. Especially, the EPS was given irradiation at various ranges of 0, 2, 10 and 30 kGy from {sup 60}Co gamma-ray source. The structural property and surface morphology were characterized by using Fourier-transform infrared (FTIR) and field emission-scanning electron microscopy (FE-SEM). Also, the conductivity of EPS was determined by using the Van der PauW method, and the polymeric substances turned out to have semi-conductivity (about 5.38*10{sup -7})

  19. Polymerization in situ by means of radiation gamma for the production of conducting polymeric composites

    International Nuclear Information System (INIS)

    Poblete Pulgar, Victor; Pilleux Cepeda, Mauricio; Fuenzalida Escobar, Victor; Alvarez Vargas, Mariela

    2002-01-01

    The nanocomposites synthesis of copper-methyl metacritate is made using copper spheres from 80 to 120 diameter nm, suspended in a methyl metacrilato (MMA) matrix, for different concentrations (5% to 30% of copper-v/v). The polymerization is carried out by means of gamma radiation, with 16 kGy dose applied 'in situ'. A high homogenous samples were obtained. The morphology and formation of the composite was studied by means of scanning electronic microscopy (SEM). The observed electric resistance is analyzed in function of the distance among electric contacts, meeting a strong dependence of the resistance with the homogeneous distribution of the metal in the composite. The obtained specific resistivities, in function of the concentration of the conductive metal, they are in the order of 42 Ωm for 10% v/v, being this critical concentration, the percolation threshold of the system. The obtained results show a material that is able to conserve principally the mechanical properties of the polymer and the electric properties of the conductive metal (author)

  20. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    International Nuclear Information System (INIS)

    Beyreuther, Elke

    2010-01-01

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  1. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Beyreuther, Elke

    2010-09-10

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  2. Individualized Positron Emission Tomography–Based Isotoxic Accelerated Radiation Therapy Is Cost-Effective Compared With Conventional Radiation Therapy: A Model-Based Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, Mathilda L., E-mail: ml.bongers@vumc.nl [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Coupé, Veerle M.H. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); De Ruysscher, Dirk [Radiation Oncology University Hospitals Leuven/KU Leuven, Leuven (Belgium); Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Oberije, Cary; Lambin, Philippe [Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Uyl-de Groot, Cornelia A. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Institute for Medical Technology Assessment, Erasmus University Rotterdam, Rotterdam (Netherlands)

    2015-03-15

    Purpose: To evaluate long-term health effects, costs, and cost-effectiveness of positron emission tomography (PET)-based isotoxic accelerated radiation therapy treatment (PET-ART) compared with conventional fixed-dose CT-based radiation therapy treatment (CRT) in non-small cell lung cancer (NSCLC). Methods and Materials: Our analysis uses a validated decision model, based on data of 200 NSCLC patients with inoperable stage I-IIIB. Clinical outcomes, resource use, costs, and utilities were obtained from the Maastro Clinic and the literature. Primary model outcomes were the difference in life-years (LYs), quality-adjusted life-years (QALYs), costs, and the incremental cost-effectiveness and cost/utility ratio (ICER and ICUR) of PET-ART versus CRT. Model outcomes were obtained from averaging the predictions for 50,000 simulated patients. A probabilistic sensitivity analysis and scenario analyses were carried out. Results: The average incremental costs per patient of PET-ART were €569 (95% confidence interval [CI] €−5327-€6936) for 0.42 incremental LYs (95% CI 0.19-0.61) and 0.33 QALYs gained (95% CI 0.13-0.49). The base-case scenario resulted in an ICER of €1360 per LY gained and an ICUR of €1744 per QALY gained. The probabilistic analysis gave a 36% probability that PET-ART improves health outcomes at reduced costs and a 64% probability that PET-ART is more effective at slightly higher costs. Conclusion: On the basis of the available data, individualized PET-ART for NSCLC seems to be cost-effective compared with CRT.

  3. Design of exceptionally strong and conductive Cu alloys beyond the conventional speculation via the interfacial energy-controlled dispersion of γ-Al2O3 nanoparticles.

    Science.gov (United States)

    Han, Seung Zeon; Kim, Kwang Ho; Kang, Joonhee; Joh, Hongrae; Kim, Sang Min; Ahn, Jee Hyuk; Lee, Jehyun; Lim, Sung Hwan; Han, Byungchan

    2015-11-30

    The development of Cu-based alloys with high-mechanical properties (strength, ductility) and electrical conductivity plays a key role over a wide range of industrial applications. Successful design of the materials, however, has been rare due to the improvement of mutually exclusive properties as conventionally speculated. In this paper, we demonstrate that these contradictory material properties can be improved simultaneously if the interfacial energies of heterogeneous interfaces are carefully controlled. We uniformly disperse γ-Al2O3 nanoparticles over Cu matrix, and then we controlled atomic level morphology of the interface γ-Al2O3//Cu by adding Ti solutes. It is shown that the Ti dramatically drives the interfacial phase transformation from very irregular to homogeneous spherical morphologies resulting in substantial enhancement of the mechanical property of Cu matrix. Furthermore, the Ti removes impurities (O and Al) in the Cu matrix by forming oxides leading to recovery of the electrical conductivity of pure Cu. We validate experimental results using TEM and EDX combined with first-principles density functional theory (DFT) calculations, which all consistently poise that our materials are suitable for industrial applications.

  4. Medulloblastoma: Conventional Radiation Therapy in Comparison to Chemo Radiation Therapy in The Post-operative Treatment of High-Risk Patients

    International Nuclear Information System (INIS)

    Abd El-Aal, H.H.; Mokhtar, M.M.; Habib, E.E.; El-Kashef, A.T.; Fahmy, E.S.

    2005-01-01

    (7%) developed renal impairment, which responded to medical treatment. Late treatment toxicity, manifested as reduction in intelligence quotient (IQ), was noticed, which makes conventional treatment of medulloblastoma unsatisfactory. In group I; 13 patients (62%) suffered a reduction of 8-20% in IQ in comparison to their normal siblings, whereas in Group II; 13 patients (48%) developed a reduction in IQ ranging from 12-21 %. The current treatment of medulloblastoma has a detrimental effect on long-term survivors. Whereas acute toxicity is considered mild and tolerable, late toxicity regarding diminution in IQ makes current treatment unsatisfactory because of the long-term mental disability of the cured patients. We believe that, the poorer outcome in the chemo-radiation group was due to the treatment interruption during radiation therapy caused by myelosuppression since the incidence of myelosuppression was higher in the chemo-radiation group and the recovery time was longer

  5. Efficacy and toxicity of conventionally fractionated pelvic radiation with a hypo fractionated simultaneous versus conventionally fractionated sequential boost for patients with high-risk prostate cancer

    International Nuclear Information System (INIS)

    McDonald, Andrew M.; Jacob, Rojymon; Dobelbower, Michael C.; Kim, Robert Y.; Fiveash, John B.

    2013-01-01

    Purpose: To determine if high-risk prostate cancer responds differently to hypo fractionation. Material and methods: One hundred and fifty-seven men with NCCN high-risk (T3, PSA 20, or Gleason 8) clinically localized prostate cancer treated between 1998 and 2010 met the inclusion criteria for the analysis. Eighty-two were treated with conventional WPRT with a conventionally fractionated sequential boost to the prostate (cRT), with the prostate receiving 75-77 Gy in 1.8 - 2.0 Gy fractions. Seventy-five were treated with pelvic IMRT with a hypo fractionated simultaneous boost to the prostate (hRT), with the prostate receiving 70 Gy in 2.5 Gy fractions. The dose to the pelvic lymph nodes was 45 Gy in the cRT group and 50.4 Gy in the hRT group, both at 1.8 Gy per fraction. Ninety-two percent received neoadjuvant hormonal ablation therapy, typically beginning two months prior to the start of RT. Results: Median follow-up was 6.5 years for men receiving cRT and 3.7 years for those receiving hRT. The actuarial rate of biochemical control at four years was 88% for cRT and 94% for hRT (p=0.82). The rates of early rectal and urinary grade ≥2 toxicities were 35% (29 of 82) and 49% (40 of 82) for the cRT group and 36% (27 of 75) and 44% (33 of 75) for the hRT group. The actuarial rate of late grade 2 rectal toxicity at four years was 25% for the cRT group and 13% for the hRT group (p=0.037). The rate of late grade 3 rectal complications was 4% (3 of 82) for patients receiving cRT and 1% (1 of 75) for patients receiving hRT. Conclusion: Initial follow-up indicates equivalent biochemical control between regimens. Patients receiving hRT experienced fewer late rectal complications

  6. Numerical simulations of a coupled radiative?conductive heat transfer model using a modified Monte Carlo method

    KAUST Repository

    Kovtanyuk, Andrey E.

    2012-01-01

    Radiative-conductive heat transfer in a medium bounded by two reflecting and radiating plane surfaces is considered. This process is described by a nonlinear system of two differential equations: an equation of the radiative heat transfer and an equation of the conductive heat exchange. The problem is characterized by anisotropic scattering of the medium and by specularly and diffusely reflecting boundaries. For the computation of solutions of this problem, two approaches based on iterative techniques are considered. First, a recursive algorithm based on some modification of the Monte Carlo method is proposed. Second, the diffusion approximation of the radiative transfer equation is utilized. Numerical comparisons of the approaches proposed are given in the case of isotropic scattering. © 2011 Elsevier Ltd. All rights reserved.

  7. Numerical studies of heat transfer by simultaneous radiative-conduction and radiative-convection in a two dimensional semi-transparent medium

    International Nuclear Information System (INIS)

    Draoui, Abdeslam

    1989-01-01

    The works we present here are on numerical approaches of heat transfer coupling radiation-conduction and radiation-convection within semi-transparent two-dimensional medium. The first part deals with a review of equations of radiative transfer and introduces three numerical methods (Pl, P3, Hottel's zones) which enable one to solve this problem in a two-dimensional environment. After comparing the three methods in the case where radiation is the only mode of transfer, we introduce in the second chapter a study of the coupling of radiation with conduction. So, a fourth method is used to solve this problem. These comparisons lead us to various methods which enable us to show the interest of the spherical harmonics approximations. In the third part, the Pl approximation is kept because it is simple to use, moreover it enables us to introduce both the coupling of radiative transfers with laminar convective equations in a thermally driven two-dimensional cavity. The results show a significant influence of the radiative participation of the fluid on heat and dynamic transfer we met in this type of problem. (author) [fr

  8. Simple and accurate solution for convective-radiative fin with temperature dependent thermal conductivity using double optimal linearization

    International Nuclear Information System (INIS)

    Bouaziz, M.N.; Aziz, Abdul

    2010-01-01

    A novel concept of double optimal linearization is introduced and used to obtain a simple and accurate solution for the temperature distribution in a straight rectangular convective-radiative fin with temperature dependent thermal conductivity. The solution is built from the classical solution for a pure convection fin of constant thermal conductivity which appears in terms of hyperbolic functions. When compared with the direct numerical solution, the double optimally linearized solution is found to be accurate within 4% for a range of radiation-conduction and thermal conductivity parameters that are likely to be encountered in practice. The present solution is simple and offers superior accuracy compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method. The fin efficiency expression resembles the classical result for the constant thermal conductivity convecting fin. The present results are easily usable by the practicing engineers in their thermal design and analysis work involving fins.

  9. Incidence of and factors related to late complications in conformal and conventional radiation treatment of cancer of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Schultheiss, Timothy E; Hanks, Gerald E; Hunt, Margie A; Lee, W Robert

    1995-06-15

    Purpose: The fundament hypothesis of conformal radiation therapy is that tumor control can be increased by using conformal treatment techniques that allow a higher tumor dose while maintaining an acceptable level of complications. To test this hypothesis, it is necessary first to estimate the incidence of morbidity for both standard and conformal fields. In this study, we examine factors that influence the incidence of late Grade 3 and 4 morbidity in patients treated with conformal and standard radiation treatment for prostate cancer. Methods and Materials: Six hundred sixteen consecutive patients treated with conformal or standard techniques between 1986 and 1994 to doses greater than 65 Gy and with more than 3 months follow-up were analyzed. No patients treated with prostatectomies were included in the analysis. The conformal technique includes special immobilization by a cast, careful identification of the target volume in three dimensions, localization of the inferior border of the prostate using a retrograde urethrogram, and individually shaped portals that conform to the Planning Target Volume (PTV). Multivariate analysis using a proportional hazards model compares differences in the incidence of Radiation Therapy Oncology Group/European Organization for Research and Center Treatment (RTOG/EORTC) Grade 3 and 4 late gastrointestinal (GI) and genitourinary (GU) morbidity by technique, T-stage, grade, age, hormonal treatment, irradiated volume, dose, and comorbid conditions. Grade 3 rectal bleeding was defined as requiring three or more cautery procedures. Results: The overall actuarial incidence of genitourinary (GU) toxicities at 5 years was 3.4%, with the crude incidence being six cases in 616 patients satisfying the selection criteria; for gastrointestinal (GI) toxicities, the overall actuarial incidence was 2.7%, with the crude incidence being 13 cases out of 616 patients. The average time to complication for our patients was 12.8 months for GI toxicity and

  10. Conductivity of ion dielectrics during the mean flux-density electron- and X-ray pulse radiation

    International Nuclear Information System (INIS)

    Vajsburd, D.I.; Mesyats, G.A.; Naminov, V.L.; Tavanov, Eh.G.

    1982-01-01

    Conductivity of ion dielectrics under electron and X-ray pulse radiation is investigated. Investigations have been conducted in the range of average beam densities in which extinction of low-energy conductivity takes place. Thin plates of alkali-halogen crystals have been used as samples. Small-dimensional accelerator with controlled beam parameters: 1-20 ns, 0.1-2000 A/cm 2 , 0.3-0.5 MeV has been used for radiation. Temperature dependence of conductivity current pulse is determined. Time resolution of 10 - 10 s is achieved. In the 70-300 K range it practically coincides with radiation pulse. An essential inertial constituent is observed below 300 K. It is shown that at average beam densities a comparable contribution into fast conductivity is made by intracentre conductivity independent of temperature and high-temperature conductivity which decreases with temperature with activation energy equal to the energy of short-wave background. That is why amplitude of fast constituent decreases with temperature slower than high-energy conductivity

  11. Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT

    International Nuclear Information System (INIS)

    Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G.; Nagel, H.D.

    2004-01-01

    Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [de

  12. Long-term Outcomes of Hypofractionation Versus Conventional Radiation Therapy After Breast-Conserving Surgery for Ductal Carcinoma In Situ of the Breast

    International Nuclear Information System (INIS)

    Lalani, Nafisha; Paszat, Lawrence; Sutradhar, Rinku; Thiruchelvam, Deva; Nofech-Mozes, Sharon; Hanna, Wedad; Slodkowska, Elzbieta; Done, Susan J.; Miller, Naomi; Youngson, Bruce; Tuck, Alan; Sengupta, Sandip; Elavathil, Leela; Chang, Martin C.; Jani, Prashant A.; Bonin, Michel

    2014-01-01

    Purpose: Whole-breast radiation therapy (XRT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) may decrease the risk of local recurrence, but the optimal dose regimen remains unclear. Past studies administered 50 Gy in 25 fractions (conventional); however, treatment pattern studies report that hypofractionated (HF) regimens (42.4 Gy in 16 fractions) are frequently used. We report the impact of HF (vs conventional) on the risk of local recurrence after BCS for DCIS. Methods and Materials: All women with DCIS treated with BCS and XRT in Ontario, Canada from 1994 to 2003 were identified. Treatment and outcomes were assessed through administrative databases and validated by chart review. Survival analyses were performed. To account for systematic differences between women treated with alternate regimens, we used a propensity score adjustment approach. Results: We identified 1609 women, of whom 971 (60%) received conventional regimens and 638 (40%) received HF. A total of 489 patients (30%) received a boost dose, of whom 143 (15%) received conventional radiation therapy and 346 (54%) received HF. The median follow-up time was 9.2 years. The median age at diagnosis was 56 years (interquartile range [IQR], 49-65 years). On univariate analyses, the 10-year actuarial local recurrence–free survival was 86% for conventional radiation therapy and 89% for HF (P=.03). On multivariable analyses, age <45 years (hazard ratio [HR] = 2.4; 95% CI: 1.6-3.4; P<.0001), high (HR=2.9; 95% CI: 1.2-7.3; P=.02) or intermediate nuclear grade (HR=2.7; 95% CI: 1.1-6.6; P=.04), and positive resection margins (HR=1.4; 95% CI: 1.0-2.1; P=.05) were associated with an increased risk of local recurrence. HF was not significantly associated with an increased risk of local recurrence compared with conventional radiation therapy on multivariate analysis (HR=0.8; 95% CI: 0.5-1.2; P=.34). Conclusions: The risk of local recurrence among individuals treated with HF regimens

  13. Long-term Outcomes of Hypofractionation Versus Conventional Radiation Therapy After Breast-Conserving Surgery for Ductal Carcinoma In Situ of the Breast

    Energy Technology Data Exchange (ETDEWEB)

    Lalani, Nafisha; Paszat, Lawrence [University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Institute for Clinical Evaluative Sciences, Toronto, Ontario (Canada); Sutradhar, Rinku; Thiruchelvam, Deva [Institute for Clinical Evaluative Sciences, Toronto, Ontario (Canada); Nofech-Mozes, Sharon; Hanna, Wedad; Slodkowska, Elzbieta [University of Toronto, Toronto, Ontario (Canada); Department of Anatomic Pathology, Sunnybrook Health Sciences Centre and Department of Laboratory Medicine and Pathobiology, Toronto, Ontario (Canada); Done, Susan J. [University of Toronto, Toronto, Ontario (Canada); Laboratory Medicine Program, University Health Network and Department of Laboratory Medicine and Pathobiology, Campbell Family Institute for Breast Cancer Research, Toronto, Ontario (Canada); Miller, Naomi; Youngson, Bruce [University of Toronto, Toronto, Ontario (Canada); Laboratory Medicine Program, University Health Network and Department of Laboratory Medicine and Pathobiology, Toronto, Ontario (Canada); Tuck, Alan [Pathology and Laboratory Medicine, London Health Sciences Centre and Saint Joseph' s Health Care, London, Ontario (Canada); Sengupta, Sandip [Department of Pathology and Molecular Medicine, Kingston General Hospital, Kingston, Ontario (Canada); Elavathil, Leela [Department of Anatomical Pathology, Juravinski Hospital, Hamilton Health Sciences, Hamilton, Ontario (Canada); Chang, Martin C. [Department of Pathology and Laboratory Medicine, Mount Sinai Hospital and Department of Laboratory Medicine and Pathobiology, Toronto, Ontario (Canada); Jani, Prashant A. [Department of Anatomical Pathology, Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario (Canada); Bonin, Michel [Pathology and Laboratory Medicine, Sudbury Regional Hospital, Sudbury, Ontario (Canada); and others

    2014-12-01

    Purpose: Whole-breast radiation therapy (XRT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) may decrease the risk of local recurrence, but the optimal dose regimen remains unclear. Past studies administered 50 Gy in 25 fractions (conventional); however, treatment pattern studies report that hypofractionated (HF) regimens (42.4 Gy in 16 fractions) are frequently used. We report the impact of HF (vs conventional) on the risk of local recurrence after BCS for DCIS. Methods and Materials: All women with DCIS treated with BCS and XRT in Ontario, Canada from 1994 to 2003 were identified. Treatment and outcomes were assessed through administrative databases and validated by chart review. Survival analyses were performed. To account for systematic differences between women treated with alternate regimens, we used a propensity score adjustment approach. Results: We identified 1609 women, of whom 971 (60%) received conventional regimens and 638 (40%) received HF. A total of 489 patients (30%) received a boost dose, of whom 143 (15%) received conventional radiation therapy and 346 (54%) received HF. The median follow-up time was 9.2 years. The median age at diagnosis was 56 years (interquartile range [IQR], 49-65 years). On univariate analyses, the 10-year actuarial local recurrence–free survival was 86% for conventional radiation therapy and 89% for HF (P=.03). On multivariable analyses, age <45 years (hazard ratio [HR] = 2.4; 95% CI: 1.6-3.4; P<.0001), high (HR=2.9; 95% CI: 1.2-7.3; P=.02) or intermediate nuclear grade (HR=2.7; 95% CI: 1.1-6.6; P=.04), and positive resection margins (HR=1.4; 95% CI: 1.0-2.1; P=.05) were associated with an increased risk of local recurrence. HF was not significantly associated with an increased risk of local recurrence compared with conventional radiation therapy on multivariate analysis (HR=0.8; 95% CI: 0.5-1.2; P=.34). Conclusions: The risk of local recurrence among individuals treated with HF regimens

  14. The conversion of the conductivity type of CuGaSe2 monocrystals under the influence of γ-radiation

    International Nuclear Information System (INIS)

    Kasumov, I.G.; Kerimova, T.G.; Mamedova, I.A.

    2003-01-01

    The CuGaSe 2 is a perspective material for use as a solar elements. In the present work the results of investigation of the dependence of current of short circuit from wavelength of incident light in the fundamental absorption range of both initial and radiated p-CuGaSe 2 samples. The investigation were carried out on low resistance (ρ=10 2 Ω·cm) monocrystalline samples at 77 K, obtained by gas transport reactions. The eutectic In-Ga was use as a contacts. Co 60 with 1.25 MeV quantum energy was the source of radiation. The dependence of the short circuit current from wavelength of the non radiated sample has dome-like form with maxima of 730 nm. The dependence of the short circuit current with the wavelength was measured on this sample after continuous radiation by γ-quantum with capacity of 300 R/s within 20 hours. The saturation is observed with the increasing of wavelength from 400 nm to 690 nm, at the further increasing the current of short circuit takes negative magnitude with the minima of 730 nm and increases to 800 nm and further takes positive magnitude. Thus the inverse of the short circuit current is observed. The experiment was repeated. After the radiation the resistance of samples was increased by three order (from kΩ to MΩ). Such behavior of the dependence of the short circuit current with wavelength testifies, on seen, to change the conductivity, i.e. p-CuGaSe 2 samples are got n-type conductivity under the influence of γ-radiation. Under the influence of γ-radiation the the defects increases, which influences as the scattering electronic centers. The number of electronic centres increases with dose and intensity of γ-radiation which changes the conductivity type

  15. A Variationally Formulated Problem of the Stationary Heat Conduction in a Plate with Radiation Reduction Factor Increased under Temperature

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    dependence of the absorption factor on the local intensity of this radiation. Furthermore, it can be a significant dependence of this factor on the local value of the material temperature, reflecting the above-mentioned relationship between the absorption of electromagnetic wave energy and the excitation of material microparticles. This process can be described by Boltzmann distribution function that comprises the energy to activate microparticles and the local value of temperature.This paper presents a variational formulation of the nonlinear problem of stationary heat conduction in a plate for the case when the radiation reduction factor in relation to the Bouguer law depends on the local temperature. This formulation includes a functional that can have several fixed points corresponding to different steady states of the plate temperature. Analysis of the properties of this functional enabled us to identify the stationary points, which correspond to the realized temperature distribution in the plate.

  16. Awareness of radiation exposure of thoracic CT scans and conventional radiographs: what do non-radiologists know?

    International Nuclear Information System (INIS)

    Heyer, C.M.; Peters, S.; Lemburg, S.; Nicolas, V.

    2007-01-01

    Purpose: Assessment of the knowledge of non-radiological physicians concerning radiation exposure during radiological procedures on the thorax. Material and Methods: 124 non-radiological physicians from the departments of surgery, internal medicine, anesthesiology, and neurology at a university hospital were questioned during a four-week period using a standardized questionnaire as to the effective dose (ED) of different radiological procedures on the thorax. The interviewees were asked to estimate the ED of chest X-rays and CT examinations and to compare these with the ED of other radiological methods. Length of professional experience, field of clinical training, and hierarchical position were also documented. The T-test and chi-square test were used for statistical analysis. Results: 119/124 (96.0 %) physicians with an average work experience of 8.2 years (0.3 - 32 years) were willing to participate. 47/119 (39.5 %) correctly estimated the ED of conventional chest X-ray (0.01 - 0.1 mSv), and 40/119 (33.6 %) correctly gauged the ED of adult chest CT (1 - 10 mSv). The ED of cardiac CT and pediatric chest CT without dose reduction (10 - 100 mSv) were correctly judged by 31/119 (26.1 %) and 32/119 (26.9 %), respectively. The correct ratio of the ED of chest X-ray to that of chest CT (factor 100 - 1000) was given by 28/119 (23.5 %), while 86/119 (72.3 %) underestimated the ratio. 50/119 (42.0 %) and 35/119 (29.4 %) correctly stated that the ED of pediatric chest CT without dose reduction and that of cardiac CT are greater than that of adult chest CT. 24/119 (20.2 %) and 10/119 (8.4 %) thought that the ED of low-dose chest CT is smaller than that of chest X-ray or chest MRI, respectively. The length of professional experience, field of clinical training, and hierarchical position of the participants did not have a significant influence on the test results. (orig.)

  17. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Geisel, Dominik; Zimmermann, Elke; Rief, Matthias; Greupner, Johannes; Hamm, Bernd [Charite Medical School, Department of Radiology, Berlin (Germany); Laule, Michael; Knebel, Fabian [Charite Medical School, Department of Cardiology, Berlin (Germany); Dewey, Marc [Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2012-08-15

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 {+-} 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 {+-} 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  18. Higher-Than-Conventional Radiation Doses in Localized Prostate Cancer Treatment: A Meta-analysis of Randomized, Controlled Trials

    International Nuclear Information System (INIS)

    Viani, Gustavo Arruda; Stefano, Eduardo Jose; Afonso, Sergio Luis

    2009-01-01

    Purpose: To determine in a meta-analysis whether the outcomes in men with localized prostate cancer treated with high-dose radiotherapy (HDRT) are better than those in men treated with conventional-dose radiotherapy (CDRT), by quantifying the effect of the total dose of radiotherapy on biochemical control (BC). Methods and Materials: The MEDLINE, EMBASE, CANCERLIT, and Cochrane Library databases, as well as the proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing HDRT with CDRT for localized prostate cancer. To evaluate the dose-response relationship, we conducted a meta-regression analysis of BC ratios by means of weighted linear regression. Results: Seven RCTs with a total patient population of 2812 were identified that met the study criteria. Pooled results from these RCTs showed a significant reduction in the incidence of biochemical failure in those patients with prostate cancer treated with HDRT (p 2 gastrointestinal toxicity after HDRT than after CDRT. In the subgroup analysis, patients classified as being at low (p = 0.007), intermediate (p < 0.0001), and high risk (p < 0.0001) of biochemical failure all showed a benefit from HDRT. The meta-regression analysis also detected a linear correlation between the total dose of radiotherapy and biochemical failure (BC = -67.3 + [1.8 x radiotherapy total dose in Gy]; p = 0.04). Conclusions: Our meta-analysis showed that HDRT is superior to CDRT in preventing biochemical failure in low-, intermediate-, and high-risk prostate cancer patients, suggesting that this should be offered as a treatment for all patients, regardless of their risk status.

  19. Analysis of combined conduction and radiation heat transfer in presence of participating medium by the development of hybrid method

    International Nuclear Information System (INIS)

    Mahapatra, S.K.; Dandapat, B.K.; Sarkar, A.

    2006-01-01

    The current study addresses the mathematical modeling aspects of coupled conductive and radiative heat transfer in the presence of absorbing, emitting and isotropic scattering gray medium within two-dimensional square enclosure. A blended method where the concepts of modified differential approximation employed by combining discrete ordinate method and spherical harmonics method, has been developed for modeling the radiative transport equation. The gray participating medium is bounded by isothermal walls of two-dimensional enclosure which are considered to be opaque, diffuse and gray. The effect of various influencing parameters i.e., radiation-conduction parameter, surface emissivity, single scattering albedo and optical thickness has been illustrated. The adaptability of the present method has also been addressed

  20. An Iterative Method for Solving of Coupled Equations for Conductive-Radiative Heat Transfer in Dielectric Layers

    Directory of Open Access Journals (Sweden)

    Vasyl Chekurin

    2017-01-01

    Full Text Available The mathematical model for describing combined conductive-radiative heat transfer in a dielectric layer, which emits, absorbs, and scatters IR radiation both in its volume and on the boundary, has been considered. A nonlinear stationary boundary-value problem for coupled heat and radiation transfer equations for the layer, which exchanges by energy with external medium by convection and radiation, has been formulated. In the case of optically thick layer, when its thickness is much more of photon-free path, the problem becomes a singularly perturbed one. In the inverse case of optically thin layer, the problem is regularly perturbed, and it becomes a regular (unperturbed one, when the layer’s thickness is of order of several photon-free paths. An iterative method for solving of the unperturbed problem has been developed and its convergence has been tested numerically. With the use of the method, the temperature field and radiation fluxes have been studied. The model and method can be used for development of noncontact methods for temperature testing in dielectrics and for nondestructive determination of its radiation properties on the base of the data obtained by remote measuring of IR radiation emitted by the layer.

  1. Code of practice for conducting radiation work at PINSTECH (revised 1992)

    International Nuclear Information System (INIS)

    Aslam, M.; Atta, M.A.; Orfi, S.D.

    1992-02-01

    The primary objective of this code is to achieve standard of radiation protection and safety set by Pakistan Nuclear Safety and Radiation Protection (PNSRP) ordinance 1984 and PNSRP regulations 1990. Secondary objective remains to make all best efforts to implement latest ICRP recommendations. The revised code of practice sets forth the objective of adequate system radiological safety of radiation workers, environment and general public. The code provides the guidance to persons and authorities who are responsible for the protection of workers and those who are concerned with the planning and management of personnel monitoring services. The procedures set forth in the code are mandatory and in no case should any of them be deviated under normal conditions. All those supervising and performing any kind of radiation work are required to study and adhere to those procedures and shell make all possible efforts to keep the exposure as low as reasonably achievable (ALARA), social and economic factor being taken into account. (author)

  2. Computed tomography scout views vs. conventional radiography in body-packers – Delineation of body-packs and radiation dose in a porcine model

    Energy Technology Data Exchange (ETDEWEB)

    Ziegeler, Edvard, E-mail: edvard.ziegeler@campus.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Grimm, Jochen M., E-mail: jochen.grimm@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Wirth, Stefan, E-mail: tefan.wirth@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Uhl, Michael, E-mail: michael.uhl@polizei.bayern.de [Bavarian State Criminal Police Office, Maillingerstrasse 15, 80636 Munich (Germany); Reiser, Maximilian F., E-mail: Maximilian.Reiser@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Scherr, Michael K., E-mail: Michael.Scherr@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany)

    2012-12-15

    Objective: To compare abdominal computed tomography (CT) scout views with conventional radiography regarding radiation dose and delineation of drug packages in a porcine body-packer model. Materials and methods: Nine samples of illicit drugs packed in ovoid plastic containers were consecutively placed in the rectum of a 121.5 kg pig cadaver. Antero-posterior and lateral scout views were obtained at 120 kVp and 80 mA, 150 mA and 200 mA, respectively, using a 64-row MDCT. Scout views were compared with conventional abdominal antero-posterior radiographs (77 kV and 106 ± 13 mAs). Visibility of three body pack characteristics (wrapping, content, shape) was rated independently by two radiologists and summarized to a delineation score ranging from 0 to 9 with a score ≥6 representing sufficient delineation. Mean delineation scores were calculated for each conventional radiography and single plane scout view separately and for a combined rating of antero-posterior and lateral scout views. Results: Even the lowest single plane scout view delineation score (5.3 ± 2.0 for 80 mA lateral; 0.4 mSv; sensitivity = 44%) was significantly higher than for conventional radiographs (3.1 ± 2.5, p < 0.001; 2.4 ± 0.3 mSv; sensitivity = 11%). Combined reading of antero-posterior and lateral scout views 80 mA yielded sufficient delineation (6.2 ± 1.4; 0.8 mSv; sensitivity = 56%). Conclusions: All CT scout views showed significantly better delineation ratings and sensitivity than conventional radiographs. Scout views in two planes at 80 mA provided a sufficient level of delineation and a sensitivity five times higher than conventional radiography at less than one third of the radiation dose. In case of diagnostic insecurity, CT can be performed without additional logistical effort.

  3. Health-related quality of life after intensity modulated radiation therapy for localized prostate cancer. Comparison with conventional and conformal radiotherapy

    International Nuclear Information System (INIS)

    Namiki, Shunichi; Ishidoya, Shigeto; Tochigi, Tatsuo

    2006-01-01

    No previous studies have reported the longitudinal health-related quality of life (HRQOL) for intensity modulated radiation therapy (IMRT). We compared HRQOL after IMRT with that after conventional and after conformal radiation therapy (XRT). A total of 110 patients underwent XRT (34 patients underwent conventional radiation therapy and 76 underwent conformal radiation therapy) and 30 underwent IMRT for clinically localized prostate cancer between 2000 and 2002. We measured the general and disease-specific HRQOL using the Medical Outcomes Study 36-Item Health Survey and University of California, Los Angeles, Prostate Cancer Index, respectively. There were no significant differences in the preoperative characteristics and HRQOL scores of the two groups. Repeated measure analyses of variance revealed significantly different patterns of alteration in several general HRQOL domains between XRT and the IMRT groups. In the urinary domain, there was no difference in the alteration patterns between the two groups. The XRT group suffered worse bowel function at 3 and 6 months than the IMRT group (P<0.05). In the XRT group, sexual function decreased at 3 months and remained substantially lower than the baseline level. However, the IMRT group showed no significant difference from the baseline level at any of the observation periods. At 18 months the XRT group showed worse sexual function than the IMRT group. The two approaches showed different longitudinal profiles regarding general and disease-specific HRQOL during the first 2 years after treatment. The IMRT approach produced little impairment in bowel and sexual function. (author)

  4. Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer - An updated retrospective study on local failure and survival rates

    International Nuclear Information System (INIS)

    Jeppesen, Stefan S.; Schytte, Tine; Hansen, Olfred; Jensen, Henrik R.; Brink, Carsten

    2013-01-01

    Introduction: Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single-institutional report is to describe survival outcome for medically inoperable patients with early stage NSCLC treated with SBRT compared with high dose conventional RT. Material and methods: From August 2005 to June 2012, 100 medically inoperable patients were treated with SBRT at Odense Univ. Hospital. The thoracic RT consisted of 3 fractions (F) of 15-22 Gy delivered in nine days. For comparison a group of 32 medically inoperable patients treated with conventional RT with 80 Gy/35-40 F (5 F/week) in the period of July 1998 to August 2011 were analyzed. All tumors had histological or cytological proven NSCLC T1-2N0M0. Results: The median overall survival was 36.1 months versus 24.4 months for SBRT and conventional RT, respectively (p = 0.015). Local failure-free survival rates at one year were in SBRT group 93 % versus 89 % in the conventional RT group and at five years 69 % versus 66 %, SBRT and conventional RT respectively (p = 0.99). On multivariate analysis, female gender and performance status of 0-1 and SBRT predicted improved prognosis. Conclusion: In a cohort of patients with NSCLC there was a significant difference in overall survival favoring SBRT. Performance status of 0-1, female gender and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients

  5. Factors related to late GI and GU complications in conformal and conventional radiation treatment of cancer of the prostate

    International Nuclear Information System (INIS)

    Schultheiss, Timothy E.; Lee, W. Robert; Hunt, Margie A.; Hanlon, Alexandra L.; Peter, Ruth S.; Hanks, Gerald E.

    1995-01-01

    Purpose: To assess the factors that predict for late GI and GU morbidity in radiation treatment of the prostate. Materials and Methods: Six hundred sixteen consecutive prostate cancer patients treated between 1985 and 1994 with conformal or conventional techniques were included in the analysis. All patients had at least 3 months followup (median 26 months) and received at least 65 Gy. Late GI morbidity was rectal bleeding (requiring more than 2 procedures) or proctitis. Late GU morbidity was cystitis or stricture. Univariate analysis compared the differences in the incidence of RTOG-EORTC grade 3 and 4 late morbidity by age (<60 versus ≥ 60 years), peracute side effects ≥ grade 1 (during treatment), subacute side effects ≥ grade 1 (0 to 90 days after treatment), irradiated volume parameters, and dose. Multivariate proportional hazards analysis includes these same variables in a model of time to complication. Multivariate logistic regression was used to analyze incidence of peracute and subacute GI and GU side effects by GI and GU comorbidities, performance status, pretreatment procedures (biopsy, TURP, etc.), age, treatment volume parameters, and peracute responses. Results: Peracute GI and GU side effects were noted in 441 and 442 patients, respectively. Subacute GI and GU side effects were noted in 34 and 54 patients, respectively. Subacute GI side effects were highly correlated with subacute GU side effects (p<0.00001). Late morbidities were not correlated with peracute side effects but were correlated with subacute side effects (both GI and GU). Thirteen of the 616 patients expressed grade 3 or 4 GI injuries 3 to 32 months after the end of treatment, with a mean of 13 months. The 6 GU morbidities occurred significantly later (9 - 52 months) with a mean of 33 months. Central axis dose and age less than 60 years were the only independent variables significantly related to the incidence of late GI morbidity on multivariate analysis. Subacute and peracute

  6. Correlation between morphology, water uptake, and proton conductivity in radiation-grafted proton-exchange membranes

    DEFF Research Database (Denmark)

    Balog, Sandor; Gasser, Urs; Mortensen, Kell

    2010-01-01

    An SANS investigation of hydrated proton exchange membranes is presented. Our membranes were synthesized by radiation-induced grafting of ETFE with styrene in the presence of a crosslinker, followed by sulfonation of the styrene. The contrast variation method was used to understand the relationship...

  7. Design and Fabrication of a Composite Morphing Radiator Panel Using High Conductivity Fibers

    Science.gov (United States)

    Wescott, Matthew T.; McQuien, J. Scott; Bertagne, Christopher L.; Whitcomb, John D.; Hart, Darren J.; Erickson, Lisa R.

    2017-01-01

    Upcoming crewed space missions will involve large internal and external heat loads and require advanced thermal control systems to maintain a desired internal environment temperature. Radiators with at least 12:1 turndown ratios (the ratio between the maximum and minimum heat rejection rates) will be needed. However, current technologies are only able to achieve turndown ratios of approximately 3:1. A morphing radiator capable of altering shape could significantly increase turndown capabilities. Shape memory alloys offer qualities that may be well suited for this endeavor; their temperature-dependent phase changes could offer radiators the ability to passively control heat rejection. In 2015, a morphing radiator prototype was constructed and tested in a thermal vacuum environment, where it successfully demonstrated the morphing behavior and variable heat rejection. Newer composite prototypes have since been designed and manufactured using two distinct types of SMA materials. These models underwent temperature cycling tests in a thermal vacuum chamber and a series of fatigue tests to characterize the lifespan of these designs. The focus of this paper is to present the design approach and testing of the morphing composite facesheet. The discussion includes: an overall description of the project background, definition of performance requirements, composite materials selection, use of analytic and numerical design tools, facesheet fabrication, and finally fatigue testing with accompanying results.

  8. Magnetogasdynamic spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes

    Science.gov (United States)

    Nath, G.; Vishwakarma, J. P.

    2016-11-01

    Similarity solutions are obtained for the flow behind a spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes, in the presence of a spatially decreasing azimuthal magnetic field. The shock wave is driven by a piston moving with time according to power law. The radiation is considered to be of the diffusion type for an optically thick grey gas model and the heat conduction is expressed in terms of Fourier's law for heat conduction. Similarity solutions exist only when the surrounding medium is of constant density. The gas is assumed to have infinite electrical conductivity and to obey a simplified van der Waals equation of state. It is shown that an increase of the gravitational parameter or the Alfven-Mach number or the parameter of the non-idealness of the gas decreases the compressibility of the gas in the flow-field behind the shock, and hence there is a decrease in the shock strength. The pressure and density vanish at the inner surface (piston) and hence a vacuum is formed at the center of symmetry. The shock waves in conducting non-ideal gas under gravitational field with conductive and radiative heat fluxes can be important for description of shocks in supernova explosions, in the study of a flare produced shock in the solar wind, central part of star burst galaxies, nuclear explosion etc. The solutions obtained can be used to interpret measurements carried out by space craft in the solar wind and in neighborhood of the Earth's magnetosphere.

  9. Responses of conventional and extended-range neutron detectors in mixed radiation fields around a 150-MeV electron LINAC

    International Nuclear Information System (INIS)

    Lin, Yu-Chi; Sheu, Rong-Jiun; Chen, Ang-Yu

    2015-01-01

    This study analyzed the responses of two types of neutron detector in mixed gamma-ray and neutron radiation fields around a 150-MeV electron linear accelerator (LINAC). The detectors were self-assembled, high efficiency, and designed in two configurations: (1) a conventional moderated-type neutron detector based on a large cylindrical He-3 proportional counter; and (2) an extended-range version with an embedded layer of lead in the moderator to increase the detector’s sensitivity to high-energy neutrons. Two sets of the detectors were used to measure neutrons at the downstream and lateral locations simultaneously, where the radiation fields differed considerably in intensities and spectra of gamma rays and neutrons. Analyzing the detector responses through a comparison between calculations and measurements indicated that not only neutrons but also high-energy gamma rays (>5 MeV) triggered the detectors because of photoneutrons produced in the detector materials. In the lateral direction, the contribution of photoneutrons to both detectors was negligible. Downstream of the LINAC, where high-energy photons were abundant, photoneutrons contributed approximately 6% of the response of the conventional neutron detector; however, almost 50% of the registered counts of the extended-range neutron detector were from photoneutrons because of the presence of the detector rather than the effect of the neutron field. Dose readings delivered by extended-range neutron detectors should be interpreted cautiously when used in radiation fields containing a mixture of neutrons and high-energy gamma rays

  10. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Science.gov (United States)

    2010-07-01

    ... Permitted Tolerance for Conducting Radiative Tests E Table E-2 to Subpart E of Part 53 Protection of... Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Table E-2 Table E-2 to Subpart E of Part 53—Spectral Energy Distribution and Permitted Tolerance for...

  11. Radiation Exposure During Uterine Fibroid Embolization (UFE): A Confounder-Controlled Comparison Between a State-of-the-Art Angiography Unit and a Conventional Angiography unit.

    Science.gov (United States)

    Sommer, Christof-Matthias; Voigt, Wieland; Klapp Oliger, Michel; Schlett, Christopher L; Erpenbach, Stefan; Thomas, Katrina; Hatopp, Andreas; Kurz, Patrick; Richter, Goetz M

    2018-03-01

     To compare radiation exposure of a state-of-the-art and a conventional angiography unit in patients undergoing uterine fibroid embolization (UFE).  Between January 2009 and December 2016, 286 patients underwent UFE in our Interdisciplinary Fibroid Center. The inclusion criteria for this retrospective analysis were first-time transarterial embolization for symptomatic fibroids, bilateral embolization, procedures applying a state-of-the-art (Group 1) or a conventional angiography unit (Group 2), and bilateral technical success with an adequate embolization endpoint after the injection of microspheres. Study endpoints included radiation exposure, major complications, morphological success (MRI), and clinical success (questionnaire on quality-of-life). Propensity score matching controlled for confounders.  The inclusion criteria were met by 58 (Group 1) and 177 (Group 2) patients. After propensity score matching, there was no significant difference between Group 1 (n = 46) and Group 2 (n = 92) regarding age, body-mass index, volume of the dominant fibroid and the uterus, fluoroscopy time, and amount of embolic agent (p ≥ 0.10 each). The dose-area product was significantly lower in Group 1 than in Group 2 (1159.0 cGycm 2 vs. 3123.5 cGycm 2 ; p  0.99). There were no significant differences between both groups regarding shrinkage of the dominant fibroid and the uterus and no relevant differences regarding patient-reported quality-of-life.  A state-of-the-art angiography unit has the potential to reduce radiation exposure in patients undergoing UFE without increasing the risk of major complications and with comparably high morphological and clinical success.   · A state-of-the-art angiography unit potentially reduces radiation exposure in patients undergoing UFE.. · Reduced radiation exposure does not seem to negatively influence the rate of major complications.. · Reduced exposure does not seem to negatively affect morphological and clinical

  12. [Contrastive study on conventional ultrasound, compression elastography and acoustic radiation force impulse imaging in the differential diagnosis of benign and malignant breast tumors].

    Science.gov (United States)

    Zhang, Lu; Zhou, Ping; Deng, Jin; Tian, Shuangming; Qian, Ying; Wu, Xiaomin; Ma, Shuhua; Li, Jiale

    2014-12-01

    To evaluate the diagnostic performance of conventional ultrasound, compression elastography (CE) and acoustic radiation force impulse imaging (ARFI) in differential diagnosis of benign and malignant breast tumors. A total of 98 patients with liver lesions were included in the study. The images of conventional ultrasound, CE and the values of virtual touch tissue quantification (VTQ) of breast lesions were obtained. The diagnostic performance of conventional ultrasound, CE and ARFI were assessed by using pathology as the gold standard, and then evaluate the diagnosis efficiency of these three approaches in differential diagnosing benign and malignant breast tumors. The specificity, sensitivity and accuracy in the diagnosis of malignant breast tumors for conventional ultrasound were 80.0%, 81.1% and 81.7%, respectively, whereas for CE elastic score were 85.7%, 86.7% and 86.3%, respectively. With a cutoff value of 3.71 for the SR, the sensitivity, specificity, accuracy in diagnosis of malignant breast tumors were 97.1%, 83.3% and 88.4%, respectively. With a cutoff value of 3.78 m/s for VTQ, the sensitivity, specificity, accuracy in diagnosis of malignant breast tumors were 94.3%, 91.7% and 92.6%, respectively. The difference in diagnosis efficiency among ARFI, CE and conventional ultrasound in differential diagnosis of benign and malignant breast tumors was significant (Pbenign and malignant breast tumors. But the diagnosis efficiency of ARFI is superior to CE and conventional ultrasound. The three approaches can help each other in differential diagnosis of benign and malignant breast tumors.

  13. Analysis of Information Leakages on Laser Printers in the Media of Electromagnetic Radiation and Line Conductions

    OpenAIRE

    Ulaş, Cihan

    2016-01-01

    In this paper, the emissions of a laser printer, which may process classified information, are investigated in the media of electromagnetic radiation (ER), Power Line Conductors (PLC), and Signal Line Conductors (SLC). First, the candidate frequency points of CE are examined in the frequency domain. Second, the emitted signal is AM-demodulated with the proper bandwidth, and then sampled by a high storage oscilloscope in these frequency points. Third, the collected data is converted to 2D imag...

  14. Basic studies of radiation image diagnosis in veterinary medicine, 1: Comparison of the resolution of computed tomography, scanography and conventional radiography in an equine thoracic phantom

    International Nuclear Information System (INIS)

    Shida, T.; Suganuma, T.; Hashizume, T.

    1984-01-01

    In radiography of the thorax and abdomen of a large animal, the extreme thickness of the body causes a large amount of scattered radiation, which makes it difficult to obtain sharp images. The image resolutions of radiographs obtained by applying conventional radiography, scanography and computed tomography [CT] on an equine thoracic phantom were compared. Tubes of various inside diameters, used to simulate the pulmonary vessels were placed in an equine thoracic phantom and radiographed by CT, scanography and conventional radiography so as to compare the various degrees of resolution of the images of the tubes obtained by these methods. CT and scanography both gave a higher resolution index than conventional radiography, and both provided recognizable images of tubes < 2 mm in diameter, which conventional radiography failed to do. Scanography and CT can be used to obtain high-quality images of the thorax and abdomen of large animals. The image quality was compared using the resolution index (RI). The RI would be a wholly practical and comprehensive index for resolution because it includes 3 factors, contrast, sharpness and magnification, and yet is easy to calculate

  15. A Dosimetric Comparison between Conventional Fractionated and Hypofractionated Image-guided Radiation Therapies for Localized Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Ming Li

    2016-01-01

    Conclusions: To deliver the hypofractionated radiotherapy in prostate cancer, VMAT significantly increased PTV D95% dose and decreased the dose of radiation delivered to adjacent normal tissues comparing to 7-field, step-and-shoot IMRT. Daily online image-guidance and better management of bladder and rectum could make a more precise treatment delivery.

  16. Radiation dose evaluation in patients submitted to conventional radiological examinations; Avaliacoes de doses de radiacao em pacientes submetidos a exames radiologicos convencionais

    Energy Technology Data Exchange (ETDEWEB)

    Tilly, Junior, Joao G

    1997-07-01

    This work presents the results of the evaluation of radiation dose delivered to the patients undergoing conventional radiological procedures. Based in the realized measurement some indicators are settled to quantitative appraisal of the radiological protection conditions offered to the population. Data assessment was done in the county of Curitiba, in Parana State, Brazil, from 12/95 to 04/96, in ten rooms of three different institutions, under 101 patients, adults with 70 {+-} 10 kg, during real examinations of chest PA, chest LAT and abdomen AP. (author)

  17. Prediction of radiation levels in residences: A methodological comparison of CART [Classification and Regression Tree Analysis] and conventional regression

    International Nuclear Information System (INIS)

    Janssen, I.; Stebbings, J.H.

    1990-01-01

    In environmental epidemiology, trace and toxic substance concentrations frequently have very highly skewed distributions ranging over one or more orders of magnitude, and prediction by conventional regression is often poor. Classification and Regression Tree Analysis (CART) is an alternative in such contexts. To compare the techniques, two Pennsylvania data sets and three independent variables are used: house radon progeny (RnD) and gamma levels as predicted by construction characteristics in 1330 houses; and ∼200 house radon (Rn) measurements as predicted by topographic parameters. CART may identify structural variables of interest not identified by conventional regression, and vice versa, but in general the regression models are similar. CART has major advantages in dealing with other common characteristics of environmental data sets, such as missing values, continuous variables requiring transformations, and large sets of potential independent variables. CART is most useful in the identification and screening of independent variables, greatly reducing the need for cross-tabulations and nested breakdown analyses. There is no need to discard cases with missing values for the independent variables because surrogate variables are intrinsic to CART. The tree-structured approach is also independent of the scale on which the independent variables are measured, so that transformations are unnecessary. CART identifies important interactions as well as main effects. The major advantages of CART appear to be in exploring data. Once the important variables are identified, conventional regressions seem to lead to results similar but more interpretable by most audiences. 12 refs., 8 figs., 10 tabs

  18. Assessment of effective radiation dose of an extremity CBCT, MSCT and conventional X ray for knee area using MOSFET dosemeters.

    Science.gov (United States)

    Koivisto, Juha; Kiljunen, Timo; Wolff, Jan; Kortesniemi, Mika

    2013-12-01

    The objective of this study was to assess and compare the organ and effective doses in the knee area resulting from different commercially available multislice computed tomography devices (MSCT), one cone beam computed tomography device (CBCT) and one conventional X-ray radiography device using MOSFET dosemeters and an anthropomorphic RANDO knee phantom. Measurements of the MSCT devices resulted in effective doses ranging between 27 and 48 µSv. The CBCT measurements resulted in an effective dose of 12.6 µSv. The effective doses attained using the conventional radiography device were 1.8 µSv for lateral and 1.2 µSv for anterior-posterior projections. The effective dose resulting from conventional radiography was considerably lower than those recorded for the CBCT and MSCT devices. The MSCT effective dose results were two to four times higher than those measured on the CBCT device. This study demonstrates that CBCT can be regarded as a potential low-dose 3D imaging technique for knee examinations.

  19. Use of a modified GreenScreen tool to conduct a screening-level comparative hazard assessment of conventional silver and two forms of nanosilver

    OpenAIRE

    Sass, Jennifer; Heine, Lauren; Hwang, Nina

    2016-01-01

    Background Increased concern for potential health and environmental impacts of chemicals, including nanomaterials, in consumer products is driving demand for greater transparency regarding potential risks. Chemical hazard assessment is a powerful tool to inform product design, development and procurement and has been integrated into alternative assessment frameworks. The extent to which assessment methods originally designed for conventionally-sized materials can be used for nanomaterials, wh...

  20. A robotic system to conduct radiation and contamination surveys on nuclear waste transport casks

    International Nuclear Information System (INIS)

    Harrigan, R.W.; Sanders, T.L.

    1990-06-01

    The feasibility of performing, numerous spent fuel cask operations using fully integrated robotic systems is under evaluation. Using existing technology, operational and descriptive software and hardware in the form of robotic end effectors are being designed in conjunction with interfacing cask components. A robotic radiation and contamination survey system has been developed and used on mock-up cask hardware to evaluate the impact of such fully automated operations on cask design features and productivity. Based on experience gained from the survey system, numerous health physics operations can be reliably performed with little human intervention using a fully automated system. Such operations can also significantly reduce time requirements for cask-receiving operations. 7 refs., 51 figs., 6 tabs

  1. Assessment of the accuracy of the conventional ray-tracing technique: Implications in remote sensing and radiative transfer involving ice clouds

    International Nuclear Information System (INIS)

    Bi, Lei; Yang, Ping; Liu, Chao; Yi, Bingqi; Baum, Bryan A.; Diedenhoven, Bastiaan van; Iwabuchi, Hironobu

    2014-01-01

    A fundamental problem in remote sensing and radiative transfer simulations involving ice clouds is the ability to compute accurate optical properties for individual ice particles. While relatively simple and intuitively appealing, the conventional geometric-optics method (CGOM) is used frequently for the solution of light scattering by ice crystals. Due to the approximations in the ray-tracing technique, the CGOM accuracy is not well quantified. The result is that the uncertainties are introduced that can impact many applications. Improvements in the Invariant Imbedding T-matrix method (II-TM) and the Improved Geometric-Optics Method (IGOM) provide a mechanism to assess the aforementioned uncertainties. The results computed by the II-TM+IGOM are considered as a benchmark because the II-TM solves Maxwell's equations from first principles and is applicable to particle size parameters ranging into the domain at which the IGOM has reasonable accuracy. To assess the uncertainties with the CGOM in remote sensing and radiative transfer simulations, two independent optical property datasets of hexagonal columns are developed for sensitivity studies by using the CGOM and the II-TM+IGOM, respectively. Ice cloud bulk optical properties obtained from the two datasets are compared and subsequently applied to retrieve the optical thickness and effective diameter from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. Additionally, the bulk optical properties are tested in broadband radiative transfer (RT) simulations using the general circulation model (GCM) version of the Rapid Radiative Transfer Model (RRTMG) that is adopted in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM, version 5.1). For MODIS retrievals, the mean bias of uncertainties of applying the CGOM in shortwave bands (0.86 and 2.13 μm) can be up to 5% in the optical thickness and as high as 20% in the effective diameter, depending on cloud optical

  2. COXPRO-II: a computer program for calculating radiation and conduction heat transfer in irradiated fuel assemblies

    International Nuclear Information System (INIS)

    Rhodes, C.A.

    1984-12-01

    This report describes the computer program COXPRO-II, which was written for performing thermal analyses of irradiated fuel assemblies in a gaseous environment with no forced cooling. The heat transfer modes within the fuel pin bundle are radiation exchange among fuel pin surfaces and conduction by the stagnant gas. The array of parallel cylindrical fuel pins may be enclosed by a metal wrapper or shroud. Heat is dissipated from the outer surface of the fuel pin assembly by radiation and convection. Both equilateral triangle and square fuel pin arrays can be analyzed. Steady-state and unsteady-state conditions are included. Temperatures predicted by the COXPRO-II code have been validated by comparing them with experimental measurements. Temperature predictions compare favorably to temperature measurements in pressurized water reactor (PWR) and liquid-metal fast breeder reactor (LMFBR) simulated, electrically heated fuel assemblies. Also, temperature comparisons are made on an actual irradiated Fast-Flux Test Facility (FFTF) LMFBR fuel assembly

  3. Propagation of a cylindrical shock wave in a rotating dusty gas with heat conduction and radiation heat flux

    International Nuclear Information System (INIS)

    Vishwakarma, J P; Nath, G

    2010-01-01

    A self-similar solution for the propagation of a cylindrical shock wave in a dusty gas with heat conduction and radiation heat flux, which is rotating about the axis of symmetry, is investigated. The shock is assumed to be driven out by a piston (an inner expanding surface) and the dusty gas is assumed to be a mixture of non-ideal gas and small solid particles. The density of the ambient medium is assumed to be constant. The heat conduction is expressed in terms of Fourier's law and radiation is considered to be of diffusion type for an optically thick grey gas model. The thermal conductivity K and the absorption coefficient α R are assumed to vary with temperature and density. Similarity solutions are obtained, and the effects of variation of the parameter of non-idealness of the gas in the mixture, the mass concentration of solid particles and the ratio of density of solid particles to the initial density of the gas are investigated.

  4. Analytical solution to convection-radiation of a continuously moving fin with temperature-dependent thermal conductivity

    Directory of Open Access Journals (Sweden)

    Moradi Amir

    2013-01-01

    Full Text Available In this article, the simultaneous convection-radiation heat transfer of a moving fin of variable thermal conductivity is studied. The differential transformation method (DTM is applied for an analytic solution for heat transfer in fin with two different profiles. Fin profiles are rectangular and exponential. The accuracy of analytic solution is validated by comparing it with the numerical solution that is obtained by fourth-order Runge-Kutta method. The analytical and numerical results are shown for different values of the embedding parameters. DTM results show that series converge rapidly with high accuracy. The results indicate that the fin tip temperature increases when ambient temperature increases. Conversely, the fin tip temperature decreases with an increase in the Peclet number, convection-conduction and radiation-conduction parameters. It is shown that the fin tip temperature of the exponential profile is higher than the rectangular one. The results indicate that the numerical data and analytical method are in a good agreement with each other.

  5. Effect of swift heavy O7+ ion radiations on conductivity of lithium based polymer blend electrolyte

    Science.gov (United States)

    Joge, Prajakta; Kanchan, D. K.; Sharma, Poonam; Jayswal, Manish; Avasthi, D. K.

    2014-07-01

    In the present work, effect of swift heavy O7+ ion of 80 MeV of different fluences, on conductivity of [PVA(47.5)-PEO(47.5)-LiCF3SO3(5)]-EC(8) polymeric films has been investigated using ac impedance spectroscopy. The power law exponent n, hopping frequency ωh and activation energies for conduction Eac and relaxation Ear, have been investigated for different fluences. The DSC measurements are carried out in order to investigate the variations in the degree of crystallinity and thermal parameters (Tm) of the blend specimen prior and after irradiation. The Fourier Transform Infrared (FT-IR) measurements are carried out in order to investigate the changes in the vibrational modes of molecules upon irradiation. The FT-IR measurements corroborate the formation of amorphous phase in the blend matrix after irradiation. The conductivity is found to be optimum at the fluence of 1×1012 ions/cm2. The enhancement and the improvement in the electrolytic properties of PVA-PEO blend upon O7+ ion irradiation have been observed.

  6. Adjuvant Hypofractionated Versus Conventional Whole Breast Radiation Therapy for Early-Stage Breast Cancer: Long-Term Hospital-Related Morbidity From Cardiac Causes

    International Nuclear Information System (INIS)

    Chan, Elisa K.; Woods, Ryan; McBride, Mary L.; Virani, Sean; Nichol, Alan; Speers, Caroline; Wai, Elaine S.; Tyldesley, Scott

    2014-01-01

    Purpose: The risk of cardiac injury with hypofractionated whole-breast/chest wall radiation therapy (HF-WBI) compared with conventional whole-breast/chest wall radiation therapy (CF-WBI) in women with left-sided breast cancer remains a concern. The purpose of this study was to determine if there is an increase in hospital-related morbidity from cardiac causes with HF-WBI relative to CF-WBI. Methods and Materials: Between 1990 and 1998, 5334 women ≤80 years of age with early-stage breast cancer were treated with postoperative radiation therapy to the breast or chest wall alone. A population-based database recorded baseline patient, tumor, and treatment factors. Hospital administrative records identified baseline cardiac risk factors and other comorbidities. Factors between radiation therapy groups were balanced using a propensity-score model. The first event of a hospital admission for cardiac causes after radiation therapy was determined from hospitalization records. Ten- and 15-year cumulative hospital-related cardiac morbidity after radiation therapy was estimated for left- and right-sided cases using a competing risk approach. Results: The median follow-up was 13.2 years. For left-sided cases, 485 women were treated with CF-WBI, and 2221 women were treated with HF-WBI. Mastectomy was more common in the HF-WBI group, whereas boost was more common in the CF-WBI group. The CF-WBI group had a higher prevalence of diabetes. The 15-year cumulative hospital-related morbidity from cardiac causes (95% confidence interval) was not different between the 2 radiation therapy regimens after propensity-score adjustment: 21% (19-22) with HF-WBI and 21% (17-25) with CF-WBI (P=.93). For right-sided cases, the 15-year cumulative hospital-related morbidity from cardiac causes was also similar between the radiation therapy groups (P=.76). Conclusions: There is no difference in morbidity leading to hospitalization from cardiac causes among women with left-sided early-stage breast

  7. Adjuvant Hypofractionated Versus Conventional Whole Breast Radiation Therapy for Early-Stage Breast Cancer: Long-Term Hospital-Related Morbidity From Cardiac Causes

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Elisa K. [Department of Oncology, Saint John Regional Hospital, Saint John (Canada); Woods, Ryan; McBride, Mary L. [Cancer Control Research Department, BC Cancer Agency, Vancouver (Canada); Virani, Sean [Division of Cardiology, University of British Columbia, Vancouver (Canada); Nichol, Alan [Radiation Therapy Program, BC Cancer Agency, Vancouver (Canada); Speers, Caroline [Breast Cancer Outcomes Unit, BC Cancer Agency, Vancouver (Canada); Wai, Elaine S. [Radiation Therapy Program, BC Cancer Agency, Vancouver (Canada); Tyldesley, Scott, E-mail: styldesl@bccancer.bc.ca [Radiation Therapy Program, BC Cancer Agency, Vancouver (Canada)

    2014-03-15

    Purpose: The risk of cardiac injury with hypofractionated whole-breast/chest wall radiation therapy (HF-WBI) compared with conventional whole-breast/chest wall radiation therapy (CF-WBI) in women with left-sided breast cancer remains a concern. The purpose of this study was to determine if there is an increase in hospital-related morbidity from cardiac causes with HF-WBI relative to CF-WBI. Methods and Materials: Between 1990 and 1998, 5334 women ≤80 years of age with early-stage breast cancer were treated with postoperative radiation therapy to the breast or chest wall alone. A population-based database recorded baseline patient, tumor, and treatment factors. Hospital administrative records identified baseline cardiac risk factors and other comorbidities. Factors between radiation therapy groups were balanced using a propensity-score model. The first event of a hospital admission for cardiac causes after radiation therapy was determined from hospitalization records. Ten- and 15-year cumulative hospital-related cardiac morbidity after radiation therapy was estimated for left- and right-sided cases using a competing risk approach. Results: The median follow-up was 13.2 years. For left-sided cases, 485 women were treated with CF-WBI, and 2221 women were treated with HF-WBI. Mastectomy was more common in the HF-WBI group, whereas boost was more common in the CF-WBI group. The CF-WBI group had a higher prevalence of diabetes. The 15-year cumulative hospital-related morbidity from cardiac causes (95% confidence interval) was not different between the 2 radiation therapy regimens after propensity-score adjustment: 21% (19-22) with HF-WBI and 21% (17-25) with CF-WBI (P=.93). For right-sided cases, the 15-year cumulative hospital-related morbidity from cardiac causes was also similar between the radiation therapy groups (P=.76). Conclusions: There is no difference in morbidity leading to hospitalization from cardiac causes among women with left-sided early-stage breast

  8. Micro-angiographic system using synchrotron radiation and conventional x-ray source for visualizing angiogenic vessels induced by cardiovascular regeneration therapy

    International Nuclear Information System (INIS)

    Mori, H.; Chiku, M.; Nishigami, K.; Tanaka, E.; Kimura, K.; Kawai, T.; Suzuki, K.; Mochizuki, R.; Okawa, Y.

    2004-01-01

    Therapeutic angiogenesis improved critical limb and myocardial ischemia in human, however, angiogenic vessels were not visualized well by conventional angiography, because of its limited spatial resolution of 200 μm. Recently, synchrotron radiation system characterized by high brightness, monochromatic and collimated nature revealed the micro-vessels of heart and lower limb in situ. We developed also an in-house microangiographic system with a relatively low cost. Limb ischemia models were made by ligature of femoral artery and treated by angiogenic growth factor genes and so on. One month after the treatment, we evaluated collateral micro-vessels by using the conventional and micro-angiographic systems. The approach was left femoral artery, and catheter was located in abdominal aorta. Iodine contrast (300 mg/ml) was injected 5 ml by 3 ml/sec with auto-injection system. The imaging was recorded by digital source in 1000 x 1000 pixels. The micro-angiographic system could detect the micro-vessels more precisely than conventional angiographic system and evaluate their function. (author)

  9. Technique and radiation dose of conventional X-rays and computed tomography of the sacroiliac joint; Technik und Strahlendosis konventioneller Roentgenaufnahmen und Computertomographie des Sakroiliakalgelenks

    Energy Technology Data Exchange (ETDEWEB)

    Jurik, A.G. [Department of Radiology R, Aarhus Kommunehospital (Denmark)

    2004-03-01

    Anterior-posterior (a.p.) or posterior-anterior X-rays of the sacroiliac joint, sometimes supplemented by a transverse view, have been the method of choice for diagnosis of patients suspected of having sacroiliitis. The sensitivity and specificity of conventional X-rays are relatively low, which can delay the diagnosis of sacroiliitis. Computed tomography (CT) is superior to conventional X-rays for diagnosis of sacroiliitis, but does emit a relatively higher dose of radiation. For this reason, particularly for females, CT should be optimized by employing semi-coronal planes, which require a lower radiation dose than axial planes. CT in a semi-coronal plane causes minimal radiation to the ovaries, and the effective radiation dose for women might even be lower than with conventional AP X-rays. Therefore, for suspected sacroiliitis in young women, CT in the semi-coronal plane is the preferred imaging method with respect to diagnostics and radiation protection when magnetic resonance imaging (MRI) is not available. Male gonads can be protected from radiation doses in conventional X-rays, and CT as the primary imaging method can only be justified in these cases because of its better diagnostic capabilities. Due to the lack of inherent risk factors, MRI is superior to CT for diagnostics since it provides images of inflammatory signs in addition to joint destruction. Thus, when available, MRI should be given preference for diagnosis of sacroiliitis. (orig.) [German] Roentgenaufnahmen des Sakroiliakalgelenks im anterior-posterioren bzw. posterior-anterioren Strahlengang, gelegentlich ergaenzt durch die Schraegaufnahme, sind seit vielen Jahren die Methode der Wahl fuer die Diagnostik bei Patienten mit Verdacht auf Sakroiliitis. Die Sensitivitaet und Spezifitaet des konventionellen Roentgens sind relativ niedrig, was die Diagnose der Sakroiliitis verzoegern koennte. Die Computertomographie (CT) ist dem konventionellen Roentgen fuer die Diagnostik der Sakroiliitis ueberlegen

  10. Radiative heat exchange of a meteor body in the approximation of radiant heat conduction

    International Nuclear Information System (INIS)

    Pilyugin, N.N.; Chernova, T.A.

    1986-01-01

    The problem of the thermal and dynamic destruction of large meteor bodies moving in planetary atmospheres is fundamental for the clarification of optical observations and anomalous phenomena in the atmosphere, the determination of the physicochemical properties of meteoroids, and the explanation of the fall of remnants of large meteorites. Therefore, it is important to calculate the coefficient of radiant heat exchange (which is the determining factor under these conditions) for large meteor bodies as they move with hypersonic velocities in an atmosphere. The solution of this problem enables one to find the ablation of a meteorite during its aerodynamic heating and to determine the initial conditions for the solution of problems of the breakup of large bodies and their subsequent motion and ablation. Hypersonic flow of an inviscid gas stream over an axisymmetric blunt body is analyzed with allowance for radiative transfer in a thick-thin approximation. The gas-dynamic problem of the flow of an optically thick gas over a large body is solved by the method of asymptotic joined expansions, using a hypersonic approximation and local self-similarity. An equation is obtained for the coefficient of radiant heat exchange and the peculiarities of such heat exchange for meteor bodies of large size are noted

  11. Study of the conductivity induced by radiation in teflon irradiated by X-ray

    International Nuclear Information System (INIS)

    Faria, R.M.

    1980-01-01

    It's measured the X-ray induced currents in teflon FEP which show the following features: a) At the beginning the current increases and reaches a maximum at about 10s, b) It decays slowly during 30 minutes, when a steady state is reached the delayed conductivity was also measured. The sample were 25 μm thick and the irradiated area was 12,5 cm 2 ; the applied field was of the order of 10 4 V/cm and the dose rate of order of 10 2 R/S. It was observed that a new measurement of the induced conductivity does not duplicate the first one, but after a few hours it comes back to the original one. In order to show that the increase and the decrease of the current is not caused by an electric field effect we realized a measurement where we polled the sample intermitently while it was irradiated. The current thus obtained had about the same values of the first measurement, when the voltage was applied all the time during the measurement. The absorption current of a teflon sample which shows after some days the effect of its variation due the variation of the ambiental temperature are measured. (Author) [pt

  12. Long-persistent relaxation and frozen conductivity in Zn Se with radiation-induced defects

    International Nuclear Information System (INIS)

    Blajcu, A.I.; Djuadi, D.; Casian, V.A.; Moseiciuc, G.S.; Nedeoglo, D.D.

    1993-01-01

    In an n-Zn Se crystals which have been preliminarily annealed in liquid Zn and then exposed to irradiation by a flow of electrons with an energy of E = 1.3 MeV and a dose of irradiation from 2.73 x 10 16 to 5.19 x 10 17 el/cm 2 , phenomena of a long-persistent conductivity relaxation (LCR) and frozen conduction (FC) at 77 K have been brought out and examined. It has been shown that the character of the relaxation processes at small doses of irradiation is rather well explained by the two-barrier model of an inhomogeneous semiconductor which represents a low-resistance matrix with high-resistance inclusions (clusters). As the dose of irradiation increases the overlapping of regions of space charge which surrounds the high-resistance inclusions increases and the considered model of high-resistance inclusions must be changed at D = 3 x 10 17 el/cm 2 into of a random potential relief. The temperature quenching of FC is explain in the assumption that, with the temperature increase, the drift and the recombination barriers decrease simultaneously as the result of variation of the sizes of space charge region surrounding the clusters. (Author)

  13. Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Adrian [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); University Hospital Pitie-Salpetriere, Department of Polyvalent and Oncological Radiology, Paris (France); Landau, Julia; Buetikofer, Yanik; Leidolt, Lars; Brela, Barbara; May, Michelle; Heverhagen, Johannes; Christe, Andreas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Ebner, Lukas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2016-10-15

    To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions. In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs. The detection rate was 95.5 % with standard dose (DLP 126 mGy*cm) and 93.3 % with ultralow-dose (DLP: 9 mGy*cm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose. Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible. (orig.)

  14. The acoustic radiation force on a small thermoviscous or thermoelastic particle suspended in a viscous and heat-conducting fluid

    Science.gov (United States)

    Karlsen, Jonas; Bruus, Henrik

    2015-11-01

    We present a theoretical analysis (arxiv.org/abs/1507.01043) of the acoustic radiation force on a single small particle, either a thermoviscous fluid droplet or a thermoelastic solid particle, suspended in a viscous and heat-conducting fluid. Our analysis places no restrictions on the viscous and thermal boundary layer thicknesses relative to the particle radius, but it assumes the particle to be small in comparison to the acoustic wavelength. This is the limit relevant to scattering of ultrasound waves from sub-micrometer particles. For particle sizes smaller than the boundary layer widths, our theory leads to profound consequences for the acoustic radiation force. For example, for liquid droplets and solid particles suspended in gasses we predict forces orders of magnitude larger than expected from ideal-fluid theory. Moreover, for certain relevant choices of materials, we find a sign change in the acoustic radiation force on different-sized but otherwise identical particles. These findings lead to the concept of a particle-size-dependent acoustophoretic contrast factor, highly relevant to applications in acoustic levitation or separation of micro-particles in gases, as well as to handling of μm- and nm-sized particles such as bacteria and vira in lab-on-a-chip systems.

  15. Optical and electrical properties of transparent conductive ITO thin films under proton radiation with 100 keV

    International Nuclear Information System (INIS)

    Wei, Q.; He, S.Y.; Yang, D.Z.; Liu, J.C.

    2005-01-01

    Under the simulation environment for the vacuum and heat sink in space, the changes in optical and electrical properties of transparent conductive indium tin oxide (ITO) thin films induced by radiation of protons with 100 keV were studied. The ITO thin films were deposited on JGS1 quartz substrate by a sol-gel method. The sheet resistance and transmittance spectra of the ITO thin films were measured using the four-point probe method and a spectrophotometer, respectively. The surface morphology was analyzed by AFM. The experimental results showed that the electrical and optical performances of the ITO thin films were closely related to the irradiation fluence. When the fluence exceeded a given value 2 x 10 16 cm -2 , the sheet resistance increased obviously and the optical transmittance decreased. The AFM analysis indicated that the grain size of the ITO thin films diminished. The studies about the radiation effect on ITO thin films will help to predict performance evolution of the second surface mirrors on satellites under space radiation environment. (orig.)

  16. Radiation losses in microwave K_u region by conducting pyrrole/barium titanate and barium hexaferrite based nanocomposites

    International Nuclear Information System (INIS)

    Kaur, Talwinder; Kumar, Sachin; Narang, S.B.; Srivastava, A.K.

    2016-01-01

    Nanocomposites of substituted barium hexaferrite and barium titanate embedded in a polymer were synthesized via emulsion polymerization. The study was performed by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy, a vibrating sample magnetometer and a vector network analyzer. It is found that maximum radiation loss occur at 16.09 GHz (−14.23 dB) frequency owing to the combined effect of conducting polymer, suitable dielectric and magnetic material. This suggests that prepared material is suitable for radiation losses. Micro structural study reveals the presence of all the phases of the compounds comprises composite. Benzene ring absorption band (at 1183 cm"−"1) in FT-IR spectra illustrates the presence of polymer. Surface morphology reveals the presence of array of particles encapsulated by the polymer. - Highlights: • Composites having polymer, barium titanate and hexaferrite have been successfully prepared. • Effective radiation absorption and losses have been achieved. • Magnetic properties have made an impact on shielding effectiveness.

  17. Radiation losses in microwave K{sub u} region by conducting pyrrole/barium titanate and barium hexaferrite based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Talwinder [Department of Physics, Lovely Professional University, Phagwara 144411 (India); Kumar, Sachin [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Narang, S.B. [Department of Electronics Technology, Guru Nanak Dev University, Amritsar 143005 (India); Srivastava, A.K., E-mail: srivastava_phy@yahoo.co.in [Department of Physics, Lovely Professional University, Phagwara 144411 (India)

    2016-12-15

    Nanocomposites of substituted barium hexaferrite and barium titanate embedded in a polymer were synthesized via emulsion polymerization. The study was performed by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy, a vibrating sample magnetometer and a vector network analyzer. It is found that maximum radiation loss occur at 16.09 GHz (−14.23 dB) frequency owing to the combined effect of conducting polymer, suitable dielectric and magnetic material. This suggests that prepared material is suitable for radiation losses. Micro structural study reveals the presence of all the phases of the compounds comprises composite. Benzene ring absorption band (at 1183 cm{sup −1}) in FT-IR spectra illustrates the presence of polymer. Surface morphology reveals the presence of array of particles encapsulated by the polymer. - Highlights: • Composites having polymer, barium titanate and hexaferrite have been successfully prepared. • Effective radiation absorption and losses have been achieved. • Magnetic properties have made an impact on shielding effectiveness.

  18. A multicenter investigation of late adverse events in Japanese women treated with breast-conserving surgery plus conventional fractionated whole-breast radiation therapy

    International Nuclear Information System (INIS)

    Nozaki, Miwako; Kagami, Yoshikazu; Mitsumori, Michihide; Hiraoka, Masahiro

    2012-01-01

    The objective of this study was to investigate late adverse events in Japanese women treated with breast-conserving surgery plus conventional fractionated radiation therapy in 24 hospitals. This is a prospective investigation into patients who have been followed for 3 years or more after the completion of radiation therapy. The women visited hospitals for routine medical follow-up between 1 March and 31 May 2008. All patients underwent interviews and visual/palpating examinations. Their clinical chart, past chest X-rays and laboratory findings were reviewed. Evaluation criteria for late adverse events and breast cosmetic outcome were based on the Common Terminology Criteria for Adverse Events v.3 and the European Organization for Research and Treatment of Cancer Global Cosmetic Rating System. Seven hundred and three women, including 448 treated with whole-breast irradiation and 255 treated with whole-breast and boost irradiation, were examined by radiation oncologists in 24 hospitals. The frequent adverse events were breast pain (Grade 1, 115; Grade 2, 2), breast fibrosis (Grade 1, 72; Grade 2, 8), chest wall pain (Grade 1, 67; Grade 2, 3), telangiectasia (Grade 1, 29; Grade 2, 5) and pneumonitis (Grade 1, 20; Grade 2, 6; Grade 3, 3). Adverse events of Grade 2 or 3 were found in 27 patients (3.8%); 3 presented with radiation pneumonitis of Grade 3. The percentage of patients with an excellent or good cosmetic outcome was 69.1%. In the first multicenter investigation for Japanese women after breast-conserving therapy, the evaluation of late adverse events and breast cosmetic outcome was similar to several other reports from clinical trials in North America and Europe. (author)

  19. Conventional Wisdom versus Actual Outcomes: Challenges in the Conduct of an Ebola Vaccine Trial in Liberia during the International Public Health Emergency.

    Science.gov (United States)

    Larson, Gregg S; Baseler, Beth R; Hoover, Marie L; Pierson, Jerome F; Tegli, Jemee K; Johnson, Melvin P; Kieh, Mark W S; McNay, Laura A; Njoh, Wissedi Sio

    2017-07-01

    Clinical trials are challenging endeavors. Planning and implementing an investigational vaccine trial in Liberia, in the midst of an Ebola virus disease (EVD) epidemic that World Health Organization classified a public health emergency of international concern, presented extraordinary challenges. Normally, years of preparation and a litany of tasks lay the groundwork for a successful, randomized, blinded, placebo-controlled trial focused on safety and efficacy. Difficult research settings, unpredictable events, and other unique circumstances can add complexity. The setting in Liberia was especially problematic due to an infrastructure still badly damaged following a lengthy civil war and a very fragile health-care system that was further devastated by the EVD outbreak. The Partnership for Research on Vaccines in Liberia I EVD vaccine trial was planned and implemented in less than 3 months by a Liberian and U.S. research partnership, and its Phase II substudy was fully enrolled 3 months later. Contrasting conventional wisdom with trial outcomes offers an opportunity to compare early assumptions, barriers encountered, and adaptive strategies used, with end results. Understanding what was learned can inform future trial responses when disease outbreaks, especially in resource-poor locations with minimal infrastructure, pose a significant threat to public health.

  20. Potential for Improved Intelligence Quotient Using Volumetric Modulated Arc Therapy Compared With Conventional 3-Dimensional Conformal Radiation for Whole-Ventricular Radiation in Children

    International Nuclear Information System (INIS)

    Qi, X. Sharon; Stinauer, Michelle; Rogers, Brion; Madden, Jennifer R.; Wilkening, Greta N.; Liu, Arthur K.

    2012-01-01

    Purpose: To compare volumetric modulated arc therapy (VMAT) with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of localized intracranial germinoma. We modeled the effect of the dosimetric differences on intelligence quotient (IQ). Method and Materials: Ten children with intracranial germinomas were used for planning. The prescription doses were 23.4 Gy to the ventricles followed by 21.6 Gy to the tumor located in the pineal region. For each child, a 3D-CRT and full arc VMAT was generated. Coverage of the target was assessed by computing a conformity index and heterogeneity index. We also generated VMAT plans with explicit temporal lobe sparing and with smaller ventricular margin expansions. Mean dose to the temporal lobe was used to estimate IQ 5 years after completion of radiation, using a patient age of 10 years. Results: Compared with the 3D-CRT plan, VMAT improved conformality (conformity index 1.10 vs 1.85), with slightly higher heterogeneity (heterogeneity index 1.09 vs 1.06). The averaged mean doses for left and right temporal lobes were 31.3 and 31.7 Gy, respectively, for VMAT plans and 37.7 and 37.6 Gy for 3D-CRT plans. This difference in mean temporal lobe dose resulted in an estimated IQ difference of 3.1 points at 5 years after radiation therapy. When the temporal lobes were explicitly included in the VMAT optimization, the mean temporal lobe dose was reduced 5.6-5.7 Gy, resulting in an estimated IQ difference of an additional 3 points. Reducing the ventricular margin from 1.5 cm to 0.5 cm decreased mean temporal lobe dose 11.4-13.1 Gy, corresponding to an estimated increase in IQ of 7 points. Conclusion: For treatment of children with intracranial pure germinomas, VMAT compared with 3D-CRT provides increased conformality and reduces doses to normal tissue. This may result in improvements in IQ in these children.

  1. Discrete ordinates solution of coupled conductive radiative heat transfer in a two-layer slab with Fresnel interfaces subject to diffuse and obliquely collimated irradiation

    International Nuclear Information System (INIS)

    Muresan, Cristian; Vaillon, Rodolphe; Menezo, Christophe; Morlot, Rodolphe

    2004-01-01

    The coupled conductive radiative heat transfer in a two-layer slab with Fresnel interfaces subject to diffuse and obliquely collimated irradiation is solved. The collimated and diffuse components problems are treated separately. The solution for diffuse radiation is obtained by using a composite discrete ordinates method and includes the development of adaptive directional quadratures to overcome the difficulties usually encountered at the interfaces. The complete radiation numerical model is validated against the predictions obtained by using the Monte Carlo method

  2. Weekly monitoring of the effects of conventional external beam radiation therapy on patients with head and neck, chest, and pelvis cancer by means of blood cells count

    Energy Technology Data Exchange (ETDEWEB)

    Lundgren, Maria da Salete Fonseca dos Santos [Hospital Universitario Oswaldo Cruz, Recife, PE (Brazil). Radiotherapy Unit]. E-mail: salete@lundgren.med.br; Cavalcanti, Maria do Socorro de Mendonca [Universidade de Pernambuco, Recife, PE (Brazil); Sampaio, Divaldo de Almeida [Centro de Hematologia de Pernambuco (Hemope), Recife, PE (Brazil)

    2008-01-15

    Objective: To evaluate the necessity of weekly monitoring by means of leukocyte and platelet counts of patients with head and neck, chest, and pelvis cancer submitted to conventional radiotherapy. Materials and methods: A hundred and one adult patients with cancer of head and neck (n = 11), chest (n = 35) and pelvis (n = 55), submitted to radiotherapy were assessed by means of leukocyte and platelet counts on a weekly basis, with a comparison between the results before and during the treatment and in correlation with the area treated, patient's sex and age group. Results: The most significant decrease in leukocytes was observed in the fourth week, when lymphocytes, total leukocytes, neutrophils, monocytes and platelets presented a decrease of 53.5%, 26.8%, 19.4%, 22.2% and 14.6%, respectively, in comparison with the values found before the beginning of the therapy. Geometric means for pelvis during the treatment were lower than those for chest, and head and neck. Lymphocytes demonstrated to be more sensitive to radiation therapy. No alteration was found in leukocyte or platelet counts in correlation with patients' sex or age. Conclusion: Based on the results of the present study, weekly leukocyte and platelet counts do not seem to be useful in the assessment patients submitted to conventional radiotherapy for localized cancer. (author)

  3. Radiation dose optimisation for conventional imaging in infants and newborns using automatic dose management software: an application of the new 2013/59 EURATOM directive.

    Science.gov (United States)

    Alejo, L; Corredoira, E; Sánchez-Muñoz, F; Huerga, C; Aza, Z; Plaza-Núñez, R; Serrada, A; Bret-Zurita, M; Parrón, M; Prieto-Areyano, C; Garzón-Moll, G; Madero, R; Guibelalde, E

    2018-04-09

    Objective: The new 2013/59 EURATOM Directive (ED) demands dosimetric optimisation procedures without undue delay. The aim of this study was to optimise paediatric conventional radiology examinations applying the ED without compromising the clinical diagnosis. Automatic dose management software (ADMS) was used to analyse 2678 studies of children from birth to 5 years of age, obtaining local diagnostic reference levels (DRLs) in terms of entrance surface air kerma. Given local DRL for infants and chest examinations exceeded the European Commission (EC) DRL, an optimisation was performed decreasing the kVp and applying the automatic control exposure. To assess the image quality, an analysis of high-contrast resolution (HCSR), signal-to-noise ratio (SNR) and figure of merit (FOM) was performed, as well as a blind test based on the generalised estimating equations method. For newborns and chest examinations, the local DRL exceeded the EC DRL by 113%. After the optimisation, a reduction of 54% was obtained. No significant differences were found in the image quality blind test. A decrease in SNR (-37%) and HCSR (-68%), and an increase in FOM (42%), was observed. ADMS allows the fast calculation of local DRLs and the performance of optimisation procedures in babies without delay. However, physical and clinical analyses of image quality remain to be needed to ensure the diagnostic integrity after the optimisation process. Advances in knowledge: ADMS are useful to detect radiation protection problems and to perform optimisation procedures in paediatric conventional imaging without undue delay, as ED requires.

  4. Influence of γ-radiation on the D.C. conductivity of poly(3-hexadecylthiophene) doped with iron trichloride in an atmosphere of organic agents

    International Nuclear Information System (INIS)

    Cik, G.; Szabo, L.; Merasicky, J.

    1996-01-01

    The influence of γ-radiation on the d.c. conductivity of poly(3-hexadecylthiophene) (PHDT) doped with FeCl 3 in chloroform, toluene, ethanol and nitrobenzene atmospheres has been studied. A different course of d.c. conductivity changes taking place in the atmosphere of solvent vapors (chloroform, toluene) and precipitants (ethanol, nitrobenzene) has been found. The character of changes can be influenced by polymer cross-linking initiated by γ-radiation. (author). 8 refs., 5 figs

  5. Rat testicular impairment induced by electromagnetic radiation from a conventional cellular telephone and the protective effects of the antioxidants vitamins C and E.

    Science.gov (United States)

    Al-Damegh, Mona Abdullah

    2012-07-01

    The aim of this study was to investigate the possible effects of electromagnetic radiation from conventional cellular phone use on the oxidant and antioxidant status in rat blood and testicular tissue and determine the possible protective role of vitamins C and E in preventing the detrimental effects of electromagnetic radiation on the testes. The treatment groups were exposed to an electromagnetic field, electromagnetic field plus vitamin C (40 mg/kg/day) or electromagnetic field plus vitamin E (2.7 mg/kg/day). All groups were exposed to the same electromagnetic frequency for 15, 30, and 60 min daily for two weeks. There was a significant increase in the diameter of the seminiferous tubules with a disorganized seminiferous tubule sperm cycle interruption in the electromagnetism-exposed group. The serum and testicular tissue conjugated diene, lipid hydroperoxide, and catalase activities increased 3-fold, whereas the total serum and testicular tissue glutathione and glutathione peroxidase levels decreased 3-5 fold in the electromagnetism-exposed animals. Our results indicate that the adverse effect of the generated electromagnetic frequency had a negative impact on testicular architecture and enzymatic activity. This finding also indicated the possible role of vitamins C and E in mitigating the oxidative stress imposed on the testes and restoring normality to the testes.

  6. Rat testicular impairment induced by electromagnetic radiation from a conventional cellular telephone and the protective effects of the antioxidants vitamins C and E

    Directory of Open Access Journals (Sweden)

    Mona Abdullah Al-Damegh

    2012-07-01

    Full Text Available OBJECTIVE: The aim of this study was to investigate the possible effects of electromagnetic radiation from conventional cellular phone use on the oxidant and antioxidant status in rat blood and testicular tissue and determine the possible protective role of vitamins C and E in preventing the detrimental effects of electromagnetic radiation on the testes. MATERIALS AND METHODS: The treatment groups were exposed to an electromagnetic field, electromagnetic field plus vitamin C (40 mg/kg/day or electromagnetic field plus vitamin E (2.7 mg/kg/day. All groups were exposed to the same electromagnetic frequency for 15, 30, and 60 min daily for two weeks. RESULTS: There was a significant increase in the diameter of the seminiferous tubules with a disorganized seminiferous tubule sperm cycle interruption in the electromagnetism-exposed group. The serum and testicular tissue conjugated diene, lipid hydroperoxide, and catalase activities increased 3-fold, whereas the total serum and testicular tissue glutathione and glutathione peroxidase levels decreased 3-5 fold in the electromagnetism-exposed animals. CONCLUSION: Our results indicate that the adverse effect of the generated electromagnetic frequency had a negative impact on testicular architecture and enzymatic activity. This finding also indicated the possible role of vitamins C and E in mitigating the oxidative stress imposed on the testes and restoring normality to the testes.

  7. Heat-flow patterns in Tian-Calvet microcalorimeters: Conductive, convective, and radiative transport in gas dosing experiments

    International Nuclear Information System (INIS)

    Vilchiz, Luis Enrique; Pacheco-Vega, Arturo; Handy, Brent E.

    2005-01-01

    Mathematical models of a Tian-Calvet microcalorimeter were solved numerically by the finite-element method in an effort to understand the relative importance of the three basic heat transfer mechanisms operative during gas dosing experiments typically used to determine heats of adsorption on catalysts and adsorbents. The analysis pays particular attention to the quantitative release of heat through various elements of the cell and sensor cups to assess time delays and the deg.ree of thermal shunting that may result in inaccuracies in calorimetric measurements. Conductive transfer predominates in situations where there is high gas headspace pressure. The convection currents that arise when dosing with considerable gas pressure in the cell headspace region are not sufficiently strong to shunt significant amounts of sample heat away from being sensed by the surrounding thermopiles. Therefore, the heat capture fraction (heat sensed/heat produced) does not vary significantly with gas headspace pressure. During gas dosing under very low gas headspace pressure, radiation losses from the top of the sample bed may significantly affect the heat capture fraction, leading to underestimations of adsorption heats, unless the heat radiated from the top of the catalyst bed is effectively reflected back to the sample region or absorbed by an inert packing layer also in thermal contact with the thermopile wall

  8. Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

    Directory of Open Access Journals (Sweden)

    Asif Mahmood

    Full Text Available Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2-water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary. Keywords: Solar energy, Thermal collectors, Maxwell-nanofluid, Thermal radiation, Partial slip, Variable thermal conductivity

  9. Effects of plasma jet parameters, ionization, thermal conduction, and radiation on stagnation conditions of an imploding plasma liner

    Science.gov (United States)

    Stanic, Milos

    The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal expansion rates and leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ≈ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear

  10. Radiation

    International Nuclear Information System (INIS)

    Winther, J.F.; Ulbak, K.; Dreyer, L.; Pukkala, E.; Oesterlind, A.

    1997-01-01

    Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our estimation of avoidable cancers. Under the assumption that the rate of occurrence of malignant melanoma of the buttocks of both men and women and of the scalp of women would apply to all parts of the body in people completely unexposed to solar radiation, it was estimated that approximately 95% of all malignant melanomas arising in the Nordic populations around the year 2000 will be due to exposure to natural ultraviolet radiation, equivalent to an annual number of about 4700 cases, with 2100 in men and 2600 in women, or some 4% of all cancers notified. Exposure to ionizing radiation in the Nordic countries occurs at an average effective dose per capita per year of about 3 mSv (Iceland, 1.1 mSv) from natural sources, and about 1 mSv from man-made sources. While the natural sources are primarily radon in indoor air, natural radionuclides in food, cosmic radiation and gamma radiation from soil and building materials, the man-made sources are dominated by the diagnostic and therapeutic use of ionizing radiation. On the basis of measured levels of radon in Nordic dwellings and associated risk estimates for lung cancer derived from well-conducted epidemiological studies, we estimated that about 180 cases of lung cancer (1% of all lung cancer cases) per year could be avoided in the Nordic countries around the year 2000 if indoor exposure to radon were eliminated, and that an additional 720 cases (6%) could be avoided annually if either radon or tobacco smoking were eliminated. Similarly, it was estimated that the exposure of the Nordic populations to natural sources of ionizing radiation other than radon and to medical sources will each give rise to an annual total of 2120

  11. Performance and optimum design of convective-radiative rectangular fin with convective base heating, wall conduction resistance, and contact resistance between the wall and the fin base

    International Nuclear Information System (INIS)

    Aziz, Abdul; Beers-Green, Arlen B.

    2009-01-01

    This paper investigates the performance and optimum design of a longitudinal rectangular fin attached to a convectively heated wall of finite thickness. The exposed surfaces of the fin lose heat to the environmental sink by simultaneous convection and radiation. The tip of the fin is assumed to lose heat by convection and radiation to the same sink. The analysis and optimization of the fin is conducted numerically using the symbolic algebra package Maple. The temperature distribution, the heat transfer rates, and the fin efficiency data is presented illustrating how the thermal performance of the fin is affected by the convection-conduction number, the radiation-conduction number, the base convection Biot number, the convection and radiation Biot numbers at the tip, and the dimensionless sink temperature. Charts are presented showing the relationship between the optimum convection-conduction number and the optimum radiation-conduction number for different values of the base convection Biot number and dimensionless sink temperature and fixed values of the convection and radiation Biot numbers at the tip. Unlike the few other papers which have applied the Adomian's decomposition and the differential quadrature element method to this problem but give illustrative results for specific fin geometry and thermal variables, the present graphical data are generally applicable and can be used by fin designers without delving into the mathematical details of the computational techniques.

  12. Comparison of radiation absorbed dose in target organs in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography and computed tomography

    Directory of Open Access Journals (Sweden)

    Panjnoush M.

    2009-12-01

    Full Text Available "nBackground and Aim: The objective of this study was to measure and compare the tissue absorbed dose in thyroid gland, salivary glands, eye and skin in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography (CBCT and computed tomography (CT."nMaterials and Methods: Thermoluminescent dosimeters (TLD were implanted in 14 sites of RANDO phantom to measure average tissue absorbed dose in thyroid gland, parotid glands, submandibular glands, sublingual gland, lenses and buccal skin. The Promax (PLANMECA, Helsinki, Finland unit was selected for Panoramic, conventional linear tomography and cone beam computed tomography examinations and spiral Hispeed/Fxi (General Electric,USA was selected for CT examination. The average tissue absorbed doses were used for the calculation of the equivalent and effective doses in each organ."nResults: The average absorbed dose for Panoramic ranged from 0.038 mGY (Buccal skin to 0.308 mGY (submandibular gland, linear tomography ranged from 0.048 mGY (Lens to 0.510 mGY (submandibular gland,CBCT ranged from 0.322 mGY (thyroid glad to 1.144 mGY (Parotid gland and in CT ranged from 2.495 mGY (sublingual gland to 3.424 mGY (submandibular gland. Total effective dose in CBCT is 5 times greater than Panoramic and 4 times greater than linear tomography, and in CT, 30 and 22 times greater than Panoramic and linear tomography, respectively. Total effective dose in CT is 6 times greater than CBCT."nConclusion: For obtaining 3-dimensional (3D information in maxillofacial region, CBCT delivers the lower dose than CT, and should be preferred over a medical CT imaging. Furthermore, during maxillofacial imaging, salivary glands receive the highest dose of radiation.

  13. Magnetogasdynamics shock waves in a rotational axisymmetric non-ideal gas with increasing energy and conductive and radiative heat-fluxes

    Science.gov (United States)

    Nath, Gorakh

    2016-07-01

    Self-similar solutions are obtained for one-dimensional adiabatic flow behind a magnetogasdynamics cylindrical shock wave propagating in a rotational axisymmetric non ideal gas with increasing energy and conductive and radiative heat fluxes in presence of an azimuthal magnetic field. The fluid velocities and the azimuthal magnetic field in the ambient medium are assume to be varying and obeying power laws. In order to find the similarity solutions the angular velocity of the ambient medium is taken to be decreasing as the distance from the axis increases. The heat conduction is expressed in terms of Fourier's law and the radiation is considered to be the diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density. The effects of the presence of radiation and conduction, the non-idealness of the gas and the magnetic field on the shock propagation and the flow behind the shock are investigated.

  14. Development of high pressure-high vacuum-high conductance piston valve for gas-filled radiation detectors

    International Nuclear Information System (INIS)

    Prasad, D N; Ayyappan, R; Kamble, L P; Singh, J P; Muralikrishna, L V; Alex, M; Balagi, V; Mukhopadhyay, P K

    2008-01-01

    Gas-filled radiation detectors need gas filling at pressures that range from few cms of mercury to as high as 25kg/cm 2 at room temperature. Before gas-filling these detectors require evacuation to a vacuum of the order of ∼1 x 10 -5 mbar. For these operations of evacuation and gas filling a system consisting of a vacuum pump with a high vacuum gauge, gas cylinder with a pressure gauge and a valve is used. The valve has to meet the three requirements of compatibility with high-pressure and high vacuum and high conductance. A piston valve suitable for the evacuation and gas filling of radiation detectors has been designed and fabricated to meet the above requirements. The stainless steel body (80mmx160mm overall dimensions) valve with a piston arrangement has a 1/2 inch inlet/outlet opening, neoprene/viton O-ring at piston face and diameter for sealing and a knob for opening and closing the valve. The piston movement mechanism is designed to have minimum wear of sealing O-rings. The valve has been hydrostatic pressure tested up to 75bars and has Helium leak rate of less than 9.6x10 -9 m bar ltr/sec in vacuum mode and 2x10 -7 mbar ltr/sec in pressure mode. As compared to a commercial diaphragm valve, which needed 3 hours to evacuate a 7 litre chamber to 2.5x10 -5 mbar, the new valve achieved vacuum 7.4x10 -6 mbar in the same time under the same conditions

  15. SU-E-T-273: Radiation Shielding for a Fixed Horizontal-Beam Linac in a Shipping Container and a Conventional Treatment Vault

    International Nuclear Information System (INIS)

    Hsieh, M; Balter, P; Beadle, B; Chi, P; Stingo, F; Court, L

    2014-01-01

    Purpose: A fixed horizontal-beam linac, where the patient is treated in a seated position, could lower the overall costs of the treatment unit and room shielding substantially. This design also allows the treatment room and control area to be contained within a reduced space, such as a shipping container. The main application is the introduction of low-cost, high-quality radiation therapy to low- and middle-income regions. Here we consider shielding for upright treatments with a fixed-6MV-beam linac in a shipping container and a conventional treatment vault. Methods: Shielding calculations were done for two treatment room layouts using calculation methods in NCRP Report 151: (1) a shipping container (6m × 2.4m with the remaining space occupied by the console area), and (2) the treatment vault in NCRP 151 (7.8m by 5.4m by 3.4m). The shipping container has a fixed gantry that points in one direction at all times. For the treatment vault, various beam directions were evaluated. Results: The shipping container requires a primary barrier of 168cm concrete (4.5 TVL), surrounded by a secondary barrier of 3.6 TVL. The other walls require between 2.8–3.3 TVL. Multiple shielding calculations were done along the side wall. The results show that patient scatter increases in the forward direction and decreases dramatically in the backward direction. Leakage scatter also varies along the wall, depending largely on the distance between the gantry and the wall. For the treatment room, fixed-beam requires a slightly thicker primary barrier than the conventional linac (0.6 TVL), although this barrier is only needed in the center of one wall. The secondary barrier is different only by 0–0.2 TVL. Conclusion: This work shows that (1) the shipping container option is achievable, using indigenous materials for shielding and (2) upright treatments can be performed in a conventional treatment room with minimal additional shielding. Varian Medical Systems

  16. SU-E-T-273: Radiation Shielding for a Fixed Horizontal-Beam Linac in a Shipping Container and a Conventional Treatment Vault

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, M; Balter, P; Beadle, B; Chi, P; Stingo, F; Court, L [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: A fixed horizontal-beam linac, where the patient is treated in a seated position, could lower the overall costs of the treatment unit and room shielding substantially. This design also allows the treatment room and control area to be contained within a reduced space, such as a shipping container. The main application is the introduction of low-cost, high-quality radiation therapy to low- and middle-income regions. Here we consider shielding for upright treatments with a fixed-6MV-beam linac in a shipping container and a conventional treatment vault. Methods: Shielding calculations were done for two treatment room layouts using calculation methods in NCRP Report 151: (1) a shipping container (6m × 2.4m with the remaining space occupied by the console area), and (2) the treatment vault in NCRP 151 (7.8m by 5.4m by 3.4m). The shipping container has a fixed gantry that points in one direction at all times. For the treatment vault, various beam directions were evaluated. Results: The shipping container requires a primary barrier of 168cm concrete (4.5 TVL), surrounded by a secondary barrier of 3.6 TVL. The other walls require between 2.8–3.3 TVL. Multiple shielding calculations were done along the side wall. The results show that patient scatter increases in the forward direction and decreases dramatically in the backward direction. Leakage scatter also varies along the wall, depending largely on the distance between the gantry and the wall. For the treatment room, fixed-beam requires a slightly thicker primary barrier than the conventional linac (0.6 TVL), although this barrier is only needed in the center of one wall. The secondary barrier is different only by 0–0.2 TVL. Conclusion: This work shows that (1) the shipping container option is achievable, using indigenous materials for shielding and (2) upright treatments can be performed in a conventional treatment room with minimal additional shielding. Varian Medical Systems.

  17. Study on Computerized Treatment Plan of Field-in-Field Intensity Modulated Radiation Therapy and Conventional Radiation Therapy according to PBC Algorithm and AAA on Breast Cancer Tangential Beam

    International Nuclear Information System (INIS)

    Yeom, Mi Suk; Bae, Seong Soo; Kim, Dae Sup; Back, Geum Mun

    2012-01-01

    Anisotropic Analytical Algorithm (AAA) provides more accurate dose calculation regarding impact on scatter and tissue inhomogeneity in comparison to Pencil Beam Convolution (PBC) algorithm. This study tries to analyze the difference of dose distribution according to PBC algorithm and dose calculation algorithm of AAA on breast cancer tangential plan. Computerized medical care plan using Eclipse treatment planning system (version 8.9, VARIAN, USA) has been established for the 10 breast cancer patients using 6 MV energy of Linac (CL-6EX, VARIAN, USA). After treatment plan of Conventional Radiation Therapy plan (Conventional plan) and Field-in-Field Intensity Modulated Radiation Therapy plan (FiF plan) using PBC algorithm has been established, MU has been fixed, implemented dose calculation after changing it to AAA, and compared and analyzed treatment plan using Dose Volume Histogram (DVH). Firstly, as a result of evaluating PBC algorithm of Conventional plan and the difference according to AAA, the average difference of CI value on target volume has been highly estimated by 0.295 on PBC algorithm and as a result of evaluating dose of lung, V 47 Gy and has been highly evaluated by 5.83% and 4.04% each, Mean dose, V 20 , V 5 , V 3 Gy has been highly evaluated 0.6%, 0.29%, 6.35%, 10.23% each on AAA. Secondly, in case of FiF plan, the average difference of CI value on target volume has been highly evaluated on PBC algorithm by 0.165, and dose on ipsilateral lung, V 47 , V 45 Gy, Mean dose has been highly evaluated 6.17%, 3.80%, 0.15% each on PBC algorithm, V 20 , V 5 , V 3 Gy has been highly evaluated 0.14%, 4.07%, 4.35% each on AAA. When calculating with AAA on breast cancer tangential plan, compared to PBC algorithm, Conformity on target volume of Conventional plan, FiF plan has been less evaluated by 0.295, 0.165 each. For the reason that dose of high dose region of ipsilateral lung has been showed little amount, and dose of low dose region has been showed much amount

  18. Dumping convention

    International Nuclear Information System (INIS)

    Roche, P.

    1992-01-01

    Sea dumping of radioactive waste has, since 1983, been precluded under a moratorium established by the London Dumping Convention. Pressure from the nuclear industry to allow ocean dumping of nuclear waste is reported in this article. (author)

  19. Early Clinical Outcomes and Toxicity of Intensity Modulated Versus Conventional Pelvic Radiation Therapy for Locally Advanced Cervix Carcinoma: A Prospective Randomized Study

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, Ajeet Kumar, E-mail: ajeetgandhi23@gmail.com [Department of Radiation Oncology, All India Institute of Medical Sciences, New Delhi (India); Sharma, Daya Nand; Rath, Goura Kisor; Julka, Pramod Kumar; Subramani, Vellaiyan; Sharma, Seema; Manigandan, Durai; Laviraj, M.A. [Department of Radiation Oncology, All India Institute of Medical Sciences, New Delhi (India); Kumar, Sunesh [Department of Obstetrics and Gynecology, All India Institute of Medical Sciences, New Delhi (India); Thulkar, Sanjay [Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi (India)

    2013-11-01

    Purpose: To evaluate the toxicity and clinical outcome in patients with locally advanced cervical cancer (LACC) treated with whole pelvic conventional radiation therapy (WP-CRT) versus intensity modulated radiation therapy (WP-IMRT). Methods and Materials: Between January 2010 and January 2012, 44 patients with International Federation of Gynecology and Obstetrics (FIGO 2009) stage IIB-IIIB squamous cell carcinoma of the cervix were randomized to receive 50.4 Gy in 28 fractions delivered via either WP-CRT or WP-IMRT with concurrent weekly cisplatin 40 mg/m{sup 2}. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events, version 3.0, and late toxicity was graded according to the Radiation Therapy Oncology Group system. The primary and secondary endpoints were acute gastrointestinal toxicity and disease-free survival, respectively. Results: Of 44 patients, 22 patients received WP-CRT and 22 received WP-IMRT. In the WP-CRT arm, 13 patients had stage IIB disease and 9 had stage IIIB disease; in the IMRT arm, 12 patients had stage IIB disease and 10 had stage IIIB disease. The median follow-up time in the WP-CRT arm was 21.7 months (range, 10.7-37.4 months), and in the WP-IMRT arm it was 21.6 months (range, 7.7-34.4 months). At 27 months, disease-free survival was 79.4% in the WP-CRT group versus 60% in the WP-IMRT group (P=.651), and overall survival was 76% in the WP-CRT group versus 85.7% in the WP-IMRT group (P=.645). Patients in the WP-IMRT arm experienced significantly fewer grade ≥2 acute gastrointestinal toxicities (31.8% vs 63.6%, P=.034) and grade ≥3 gastrointestinal toxicities (4.5% vs 27.3%, P=.047) than did patients receiving WP-CRT and had less chronic gastrointestinal toxicity (13.6% vs 50%, P=.011). Conclusion: WP-IMRT is associated with significantly less toxicity compared with WP-CRT and has a comparable clinical outcome. Further studies with larger sample sizes and longer follow-up times are warranted to justify

  20. Effect of peracetic acid, ultraviolet radiation, nanofiltration-chlorine in the disinfection of a non conventional source of water (Tula Valley).

    Science.gov (United States)

    Trujillo, J; Barrios, J A; Jimenez, B

    2008-01-01

    Water supply for human consumption requires certain quality that reduces health risks to consumers. In this sense, the process of disinfection plays an important role in the elimination of pathogenic microorganisms. Even though chlorination is the most applied process based on its effectiveness and cost, its application is being questioned considering the formation of disinfection by-products (DBPs). Therefore, alternative disinfectants are being evaluated and some treatment processes have been proposed to remove DBPs precursors (organic matter. This paper reports the results of disinfection of a non conventional source of water (aquifer recharged unintentionally with raw wastewater) with peracetic acid (PAA) and ultraviolet radiation (UV) as well as nanofiltration (NF) followed by chlorination to produce safe drinking water. The results showed that a dose of 2 mg/L PAA was needed to eliminate total and faecal coliforms. For UV light, a dose of 12.40 mWs/cm2 reduced total and faecal coliforms below the detection limit. On the other hand, chlorine demand of water before NF was 1.1-1.3 mg/L with a trihalomethane formation potential (THMFP) of 118.62 microg/L, in contrast with chlorination after NF where the demand was 0.5 mg/L and THMFP of 17.64 microg/L. The recommended scheme is nanofiltration + chlorination.

  1. Nonlinear undulator tapering in conventional SASE regime at baseline electron beam parameters as a way to optimize the radiation characteristics of the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-09-15

    We demonstrate that the output radiation characteristics of the European XFEL sources at nominal operation point can be easily made significantly better than what is currently reported in the TDRs of scientific instruments and X-ray optics. In fact, the output SASE characteristics of the baseline European XFEL have been previously optimized assuming uniform undulators at a nominal operating point of 5 kA peak current, without considering the potential of undulator tapering in the SASE regime. In order to illustrate this point, we analyze the case of an electron bunch with nominal parameters. Based on start-to-end simulations, we demonstrate that nonlinear undulator tapering allows one to achieve up to a tenfold increase in peak power and photon spectral density in the conventional SASE regime, without modification to the baseline design. The FEL code Genesis has been extensively used for these studies. In order to increase our confidence in simulation results, we cross-checked outcomes by reproducing simulations in the deep nonlinear SASE regime with tapered undulator using the code ALICE.

  2. SU-E-P-58: Dosimetric Study of Conventional Intensity-Modulated Radiotherapy and Knowledge-Based Radiation Therapy for Postoperation of Cervix Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Yin, Y [Shandong Tumor Hospital, Jinan, Shandong Provice (China)

    2015-06-15

    Purpose: To compare the dosimetric difference of the target volume and organs at risk(OARs) between conventional intensity-modulated radiotherapy(C-IMRT) and knowledge-based radiation therapy (KBRT) plans for cervix cancer. Methods: 39 patients with cervical cancer after surgery were randomly selected, 20 patient plans were used to create the model, the other 19 cases used for comparative evaluation. All plans were designed in Eclipse system. The prescription dose was 30.6Gy, 17 fractions, OARs dose satisfied to the clinical requirement. A paired t test was used to evaluate the differences of dose-volume histograms (DVH). Results: Comparaed to C-IMRT plan, the KBRT plan target can achieve the similar target dose coverage, D98,D95,D2,HI and CI had no difference (P≥0.05). The dose of rectum, bladder and femoral heads had no significant differences(P≥0.05). The time was used to design treatment plan was significant reduced. Conclusion: This study shows that postoperative radiotherapy of cervical KBRT plans can achieve the similar target and OARs dose, but the shorter designing time.

  3. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  4. Radiation-induced conduction under high electric field (1 x 106 to 1 x 108 V/m) in polyethylene-terephthalate

    International Nuclear Information System (INIS)

    Maeda, H.; Kurashige, M.; Ito, D.; Nakakita, T.

    1978-01-01

    Radiation-induced conduction in polyethylene-terephthalate (PET) has been measured under high electric field (1.0 x 10 6 to 1.6 x 10 8 V/m). In a 6-μm-thick PET film, saturation of the radiation-induced current occurs at field strengths above 1.2 x 10 8 V/m. This has been demonstrated by the thickness and dose rate dependence of the induced current. Radiation-induced conductivity increases monotonically with field strength, then shows a saturation tendency. This may be explained by geminate recombination. Above 1 x 10 8 V/m, slowly increasing radiation-induced current appears. This may be caused by electron injection from the cathode, enhanced by the accumulation of the hetero space charges near it

  5. Effects of diffuse light on radiation use efficiency depend on the response of stomatal conductance to dynamic light intensity

    Directory of Open Access Journals (Sweden)

    Tao eLi

    2016-02-01

    Full Text Available The stimulating effect of diffuse light on radiation use efficiency (RUE of crops is often explained by the more homogeneous spatial light distribution, while rarely considering differences in temporal light distribution at leaf level. This study investigated whether diffuse light effects on crop RUE can be explained by dynamic responses of leaf photosynthesis to temporal changes of photosynthetic photon flux density (PPFD.Two Anthurium andreanum cultivars (‘Pink Champion’ and ‘Royal Champion’ were grown in two glasshouses covered by clear (control and diffuse glass, with similar light transmission. On clear days, diffusing the light resulted in less temporal fluctuations of PPFD. Stomatal conductance (gs varied strongly in response to transient PPFD in ‘Royal Champion’, whereas it remained relatively constant in ‘Pink Champion’. Instantaneous net leaf photosynthesis (Pn in both cultivars approached steady state Pn in diffuse light treatment. In control treatment this only occurred in ‘Pink Champion’. These cultivar differences were reflected by a higher RUE (8% in ‘Royal Champion’ in diffuse light treatment compared with control, whereas no effect on RUE was observed in ‘Pink Champion’. We conclude that the stimulating effect of diffuse light on RUE depends on the stomatal response to temporal PPFD fluctuations, which response is cultivar dependent.

  6. Diffuse Scattering of the Conduction Electrons of a Metallic Substrate by an Adsorbate: an Experimental Study Using Synchrotron Infrared Radiation

    International Nuclear Information System (INIS)

    Hein, M.; Otto, A.; Dumas, P.; Williams, G. P.

    1999-01-01

    Due to its intrinsic high brightness, high stability, and proportionality to the stored electron beam current, synchrotrons IR spectroscopy has revealed itself as an unique tool to experimentally test a physical phenomenon occurring at metallic interfaces, the theory for which was motivated by previous observations. Any adsorbate induces inelastic scattering of the conduction electrons, which causes a broadband IR reflectance change, and was predicted to induce a concomitant DC resistivity change. By choosing a well ordered single crystal thin film of Cu(111), we have checked that the DC resistivity change, and the asymptotic limit of the IR reflectance change are linearly dependent, but independent of the nature of the adsorbate. Coadsorption experiments which have been used to modify the induced density of states at the Fermi level, have further demonstrated that the friction coefficient, which is responsible for the elastic scattering phenomenon, is chemically specific. This article describes the use of synchrotron radiation as an absolute source and its application to the study of dynamics of adsorbates on surfaces

  7. Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Mahmood, Asif; Aziz, Asim; Jamshed, Wasim; Hussain, Sajid

    Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2 -water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary.

  8. Effect of infrared-C radiation on skin temperature, electrodermal conductance and pain in hemiparetic stroke patients.

    Science.gov (United States)

    Lin, Chun-Chih; Chiang, Yong-Shun; Lung, Chia-Chi

    2015-01-01

    A novel application of infrared-C (IR-C) radiation (3-1000 μm) on hemiparetic stroke patients was evaluated. Hot compresses (HC) were used on the paretic shoulders of patients in this placebo-controlled trial to investigate the effects of IR-C on skin temperature, electrodermal conductance (EC) and pain relief. Skin temperature at the center of the middle deltoid (CMD), Quchi (LI11), and the center of the third metacarpal bone on dorsum of hand (COT) of the subjects at Brunnstrom stage 3-5 before and after IR-C HC, were examined. Meanwhile, EC was measured on Hegu (LI4), Quchi and Juanyu (LI15). Pain intensity was evaluated before and after treatment. Skin temperature increased significantly at the CMD and COT on the paretic side in males. In females after treatment, similar skin temperatures were found in each measured region on both the paretic and non-paretic sides. The EC on the paretic side tended to be higher than the non-paretic side before treatment. After treatment, the EC on paretic side declined in both sexes and became even lower than the non-paretic side in females. Pain intensity was lessened after treatment especially in males, which appeared to correspond with an increase in skin temperature and a decrease in EC. IR-C hot compress is a promising method for stroke patients in rehabilitation. Physiological mechanisms of this treatment were proposed and summarized from this research.

  9. A prospective randomized trial of hyperfractionated versus conventional once daily radiation for advanced squamous cell carcinomas of the larynx and pharynx

    International Nuclear Information System (INIS)

    Cummings, B.J.; Keane, T.J.; Pintilie, M.; O'Sullivan, B.; Payne, D.; Warde, P.; McLean, M.; Waldron, J.; Liu, F.-F.; Gullane, P.

    1996-01-01

    Purpose: To examine the effects of an increased dose of radiation therapy (RT) delivered by a hyperfractionated schedule compared to conventional once daily RT on toxicity, locoregional control and survival in the treatment of squamous cell carcinomas (SCC) of the larynx and pharynx. Materials/Methods: Between 1988 and 1995 336 patients were randomized to receive RT with curative intent. Eligible patients had biopsy proven SCC of the larynx or pharynx, with TN stages (AJC-UICC 1987) T3 or T4 N0, or any T with any N+. All patients were M0. Patients were stratified by site (larynx/oropharynx/hypopharynx), node status (clinically positive/negative), and performance status. Patients were treated with either 51 Gy TAD/20 fractions/4 wk (2.55 Gy 1x/d, conventional RT=CRT) or 58 Gy TAD/40 fractions/4 wk (1.45 Gy 2x/d, hyperfractionated RT=HFRT). Patients underwent EUA and selective biopsies 10 wk after RT; surgical salvage was performed for residual or recurrent cancer whenever possible. Results: The primary cancer arose in the oropharynx (138), larynx (133) or hypopharynx (65). T stages were distributed T1 22, T2 72, T3 133 and T4 109. N stage distribution was N0 127, N1 74, N2 117 and N3 18. The proportion of patients with acute mucosal toxicity (RTOG Grade 3 or 4) was increased by HFRT (60% versus 40%), but other acute and late toxicity was not significantly different. There was no difference in the incidence of morbidity in the two treatment groups in those who underwent surgery following RT. The locoregional control rates at 3 yrs for all cases were 45% (HFRT) vs 40% (CRT) log rank p=0.16; for primary tumors <4 cm 54% (HFRT) vs 42% (CRT) p=0.04; for primary tumors ≥ 4 cm 38% (HFRT) vs 41% (CRT) p=0.73. Local control was improved to some extent in SCC which arose in all sites, but most noticeably in hypopharyngeal cancers. The disease free survival rates at 3 yr for all cases were 37% (HFRT) vs 30% (CRT) p=0.15; for primary tumors < 4 cm 47% (HFRT) vs 34% (CRT) p=0

  10. Analysis of a Steerable Needle for Fine Needle Aspiration and Biopsy: Efficiency and Radiation Dose Compared With a Conventional Straight Needle.

    Science.gov (United States)

    Rutigliano, Sandra; Abraham, John A; Kenneally, Barry E; Zoga, Adam C; Nevalainen, Mika; Roedl, Johannes B

    Percutaneous computed tomography (CT)-guided needle biopsy has proven to be an efficacious method for sampling of many soft tissue lesions, especially deep-seated masses in the abdomen and pelvis. This study sought to test the potential for a novel steerable needle to improve localization and to reduce procedure duration and radiation dose compared with a conventional straight needle. A fresh, raw meat sample (lean bovine flank) was imbedded with cylindrical radiopaque and radiolucent obstacles designed to simulate vessels (radiolucent objects) and bones (radiopaque objects) on CT. A pit-containing olive (partially radiopaque) was imbedded beyond the obstacles to represent the target. Two sites on the surface of the meat were selected and marked to determine initial needle placement. Two radiologists with different levels of experience proceeded to position a straight needle and the steerable needle from each skin site to the target using CT guidance as efficiently as possible, avoiding the obstacles. The total positioning time, the number of CT scans required for positioning, and the number of repositioning events (partial withdrawal followed by advancement) were tracked for the straight and steerable needles. For the straight needle, total time to reach the target was 499 to 667 seconds (mean, 592 seconds); for the steerable needle, total time to reach the target was 281 to 343 seconds (mean, 309 seconds), on average, 48% lower. The number of CT scans needed for needle positioning averaged 6.25 for the straight needle and 3.5 for the steerable needle, which is 44% lower. Repositioning events (withdrawing and readvancing the needle) ranged from 3 to 10 for the straight needle (mean, 6.5) and 0 for the steerable needle. Using an in vitro model embedded with obstacles, the steerable needle performed better than a straight needle with regard to procedure time, needle repositioning events, and CT scans required for placement.

  11. Thermal design and validation of radiation detector for the ChubuSat-2 micro-satellite with high-thermal-conductive graphite sheets

    Science.gov (United States)

    Park, Daeil; Miyata, Kikuko; Nagano, Hosei

    2017-07-01

    This paper describes thermal design of the radiation detector (RD) for the ChubuSat-2 with the use of high-thermal-conductive materials. ChubuSat-2 satellite is a 50-kg-class micro-satellite joint development with Nagoya University and aerospace companies. The main mission equipment of ChubuSat-2 is a RD to observe neutrons and gamma rays. However, the thermal design of the RD encounters a serious problem, such as no heater for RD and electric circuit alignment constrain. To solve this issue, the RD needs a new thermal design and thermal control for successful space missions. This paper proposes high-thermal-conductive graphite sheets to be used as a flexible radiator fin for the RD. Before the fabrication of the device, the optimal thickness and surface area for the flexible radiator fin were determined by thermal analysis. Consequently, the surface area of flexible radiator fin was determined to be 8.6×104 mm2. To verify the effects of the flexible radiator fin, we constructed a verification model and analyzed the temperature distributions in the RD. Also, the thermal vacuum test was performed using a thermal vacuum chamber, which was evacuated at a pressure of around 10-4 Pa, and its internal temperature was cooled at -80 °C by using a refrigerant. As a result, it has been demonstrated that the flexible radiator fin is effective. And the thermal vacuum test results are presented good correlation with the analysis results.

  12. Performance evaluation of the conventional Brazilian industries radiation protection in the small industrial gauges and industrial radiography areas; Sistema de avaliacao de desempenho em radioprotecao das industrias convencionais brasileiras nas areas de medidores nucleares e radiografia industrial

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joyra Amaral dos

    1999-08-01

    This works evaluates by punctuation the performance in conventional Brazilian industries radiation protection area which make use of small industrial gauges and industrial radiography. It proposes, procedures for industry self-evaluation, besides a new radiation protection plans pattern for the small industrial gauges area. The data source where inspection reports of Dosimetry Radiation Protection Institute/Nuclear Energy Commission conventional Brazilian industries' radiation protection plans, beyond visitation to the inspection place. The performance evaluation has been realized both in the administrative and operational aspects of the industries. About of 60% of the industries have a satisfactory register control which does not happen to the operational control. The performance evaluation advantage is that industries may self-evaluate, foreseeing Dosimetry Radiation Protection Institute's regulation inspections, correcting its irregularities, automatically improving its services. The number of industries which have obtained satisfactory performance in both areas is below 70%, both in administrative and operational aspects. Such number can be considered a low one as it is radiation protection. The procedures propose in this work aim to improve such a situation. (author)

  13. Ultra-high resolution C-Arm CT arthrography of the wrist: Radiation dose and image quality compared to conventional multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Werncke, Thomas, E-mail: Werncke.Thomas@mh-hannover.de [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Sonnow, Lena; Meyer, Bernhard C. [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Lüpke, Matthias [University of Veterinary Medicine Hannover, Institute for General Radiology and Medical Physics, Bischofsholer Damm 15, 30173 Hannover (Germany); Hinrichs, Jan; Wacker, Frank K.; Falck, Christian von [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany)

    2017-04-15

    Objective: Objective of this phantom and cadaveric study was to compare the effective radiation dose (ED) and image quality (IQ) between C-arm computed tomography (CACT) using an ultra-high resolution 1 × 1 binning with a standard 16-slice CT (MDCT) arthrography of the wrist. Methods: ED was determined with thermoluminescence dosimetry using an anthropomorphic phantom and different patient positions. Imaging was conducted in 10 human cadaveric wrists after tri-compartmental injection of diluted iodinated contrast material and a wire phantom. IQ of MDCT was compared with CACT reconstructed with a soft (CACT1) and sharp (CACT2) kernel. High and low contrast resolution was determined. Three radiologists assessed IQ of wrist structures and occurrence of image artifacts using a 5-point Likert scale. Results: ED of MDCT was comparable to standard CACT (4.3 μSv/3.7 μSv). High contrast resolution was best for CACT2, decreased to CACT1 and MDCT. Low contrast resolution increased between CACT2 and MDCT (P < 0.001). IQ was best for CACT2 (1.3 ± 0.5), decreased to CACT1 (1.9 ± 0.6) and MDCT (3.5 ± 0.6). Non-compromising artifacts were only reported for CACT. Conclusions: The results of this phantom and cadaveric study indicate that ultra-high resolution C-Arm CT arthrography of the wrist bears the potential to outperform MDCT arthrography in terms of image quality and workflow at the cost of mildly increasing image artifacts while radiation dose to the patient is comparably low for both, MDCT and C-Arm CT.

  14. An inverse analysis of a transient 2-D conduction-radiation problem using the lattice Boltzmann method and the finite volume method coupled with the genetic algorithm

    International Nuclear Information System (INIS)

    Das, Ranjan; Mishra, Subhash C.; Ajith, M.; Uppaluri, R.

    2008-01-01

    This article deals with the simultaneous estimation of parameters in a 2-D transient conduction-radiation heat transfer problem. The homogeneous medium is assumed to be absorbing, emitting and scattering. The boundaries of the enclosure are diffuse gray. Three parameters, viz. the scattering albedo, the conduction-radiation parameter and the boundary emissivity, are simultaneously estimated by the inverse method involving the lattice Boltzmann method (LBM) and the finite volume method (FVM) in conjunction with the genetic algorithm (GA). In the direct method, the FVM is used for computing the radiative information while the LBM is used to solve the energy equation. The temperature field obtained in the direct method is used in the inverse method for simultaneous estimation of unknown parameters using the LBM-FVM and the GA. The LBM-FVM-GA combination has been found to accurately predict the unknown parameters

  15. Pulse laser induced change in thermal radiation from a single spherical particle on thermally bad conducting surface : an analytical solution

    International Nuclear Information System (INIS)

    Moksin, M.M.; Grozescu, V.I.; Yunus, W.M.M.; Azmi, B.Z.; Talib, Z.A.; Wahab, Z.A.

    1996-01-01

    A relatively simple analytical expression was derived that provided a description of the radius and thermal properties of a single particle from the change in grey body radiation emission subsequent to pulse laser heating of the particle

  16. Analytical solution of electromagnetic radiation by a vertical electric dipole inside the earth and the effect of atmospheric electrical conductivity inhomogeneity

    Science.gov (United States)

    Mosayebidorcheh, Taha; Hosseinibalam, Fahimeh; Hassanzadeh, Smaeyl

    2017-11-01

    In this paper, the effect of atmospheric electrical conductivity on the electromagnetic waves radiated by a vertical electric dipole located in the earth, near the surface of the earth, is investigated. As far as electrical conductivity is concerned, the atmosphere is divided into three areas, in which the electrical conductivity changes with altitude. The Maxwell equations in these areas are investigated as well. Using the differential transform method, the differential equation is solved in a way that atmospheric electrical conductivity is variable. Solving the problem in these areas indicates that electrical conductivity in the middle and lower areas of atmosphere may be ignored. However, in the upper areas of atmosphere, the magnitude of the magnetic field in the ionosphere at a frequency of 10 kHz at night is five times smaller when electrical conductivity is considered compared to when it is neglected.

  17. Human radiation studies: Remembering the early years: Oral history of radiation biologist Marvin Goldman, Ph.D., conducted December 22, 1994

    International Nuclear Information System (INIS)

    1995-09-01

    This report provides a transcript of an interview of Dr. Marvin Goldman by representatives of DOE's Office of Human Radiation Experiments. Dr. Goldman was chosen for this interview because of his work on bone-seeking radionuclides. After a brief biographical sketch Dr. Goldman related his experiences concerning his training and work at Rochester University, his work at Brookhaven National Laboratory, his participation in the Beagle Studies at University of California at Davis, his work with the Chernobyl Nuclear Plant Accident, his consultation work with Russian authorities on the health and ecological effects in their history, and finally his opinions and recommendations on human radiation research and the environmental cleanup of DOE sites

  18. Human radiation studies: Remembering the early years: Oral history of pathologist Clarence Lushbaugh, M.D., conducted October 5, 1994

    International Nuclear Information System (INIS)

    1995-04-01

    This report provides a transcript of an interview with Dr. Clarance Lushbaugh by representatives of the DOE Office of Human Radiation Experiments. Dr. Lushbaugh was chosen for this interview because of his research involving experimental use of irradiation with human beings at Los Alamos and at the Oak Ridge Institute of Nuclear Science (ORINS). After a brief biographical sketch Dr. Lushbaugh and his assistant Mrs. Ann Swipe defend their use of total body irradiation using the LETBI (Low Exposure Total Body Irradiation) and the LETBI (Medium Energy Total Body Irradiator). Dr. Lushbaugh also discusses his earlier experiments involving use of nitrogen mustards in chemotherapy application, his early interest in the LD50 for man, his early impressions of low-level spray radiation as introduced by Heubline, anedotal information for his duties a pathologist for Los Alamos, and his developing interest in establishing safer radiation limits for human exposure

  19. Combined natural convection and surface radiation in the annular region between a volumetrically heated inner tube and a finite conducting outer tube

    International Nuclear Information System (INIS)

    Gianoulakis, S.; Klein, D.E.

    1993-01-01

    Buoyancy-driven natural-convection heat transfer in enclosures has been the subject of considerable research with applications to electronic packaging, solar collectors, and shipping containers for spent nuclear fuel. A numerical study has been carried out to predict combined natural-convection and radiation heat transfer in the annular region between concentric tubes. The inner tube was volumetrically heated. Both tubes were of finite conductance. The surfaces of the annular region were diffuse and gray. The gas in the annulus was assumed to be nonparticipating. A newly developed hybrid finite element finite difference method was used for the study. This method combines finite element discretization of geometries with finite difference discretized solution procedures for the governing differential equations. This study examined the effects of surface radiative properties and material conductivities on the temperature and velocity fields and on local heat transfer rates. Fluid Raleigh numbers ranging from 10 3 to 10 7 , ratios of solid to fluid region thermal conductivities ranging from 10 to 10 4 , and surface total hemispherical emissivities ranging from 0.0 to 1.0 were examined in this study. It was found that the heat transfer across the annulus was dominated by conduction and radiation for the lower Raleigh number flows. As the fluid Raleigh number increased, convection became a primary mode of heat transfer. As the surface emissivity was increased in the annulus, the average Nusselt number on the inner tube surface decreased

  20. Self similar flow behind an exponential shock wave in a self-gravitating, rotating, axisymmetric dusty gas with heat conduction and radiation heat flux

    Science.gov (United States)

    Bajargaan, Ruchi; Patel, Arvind

    2018-04-01

    One-dimensional unsteady adiabatic flow behind an exponential shock wave propagating in a self-gravitating, rotating, axisymmetric dusty gas with heat conduction and radiation heat flux, which has exponentially varying azimuthal and axial fluid velocities, is investigated. The shock wave is driven out by a piston moving with time according to an exponential law. The dusty gas is taken to be a mixture of a non-ideal gas and small solid particles. The density of the ambient medium is assumed to be constant. The equilibrium flow conditions are maintained and energy is varying exponentially, which is continuously supplied by the piston. The heat conduction is expressed in the terms of Fourier's law, and the radiation is assumed of diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density according to a power law. The effects of the variation of heat transfer parameters, gravitation parameter and dusty gas parameters on the shock strength, the distance between the piston and the shock front, and on the flow variables are studied out in detail. It is interesting to note that the similarity solution exists under the constant initial angular velocity, and the shock strength is independent from the self gravitation, heat conduction and radiation heat flux.

  1. Conducted and radiated emission tests for fault tolerant power distribution system ECPS-100 developed for PHWR700MW C and I

    International Nuclear Information System (INIS)

    Das, Shantanu; Yadav, Ramnayan

    2016-01-01

    Electronics devices when designed to meet specific requirements, the designers do not generally envisage the amount of electromagnetic interference that this particular device may give as power line conducted noise and radiated noise. After the product is developed, the quantification of the same is carried out in certified EMI-EMC set-up to get these figures of conducted emissions (CE) and radiated emissions (RE), and its mitigation as per limits of the chosen standard. In the latest TM embodiment of Fault Tolerant Power Distribution System ECPS"T"M (Electronics Corporation Power Supply) developed for NPCIL (PHWR700MW plant) we carried out CE and RE tests and quantified the spectrum obtained for CE and RE, and mitigated them as per CISPR22 standards. In this short article we bring out the CE and RE results of the latest product ECPS, done at EMI-EMC Centre of ECIL Hyderabad. (author)

  2. A modeling approach for heat conduction and radiation diffusion in plasma-photon mixture in temperature nonequilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-09

    We present a simple approach for determining ion, electron, and radiation temperatures of heterogeneous plasma-photon mixtures, in which temperatures depend on both material type and morphology of the mixture. The solution technique is composed of solving ion, electron, and radiation energy equations for both mixed and pure phases of each material in zones containing random mixture and solving pure material energy equations in subdivided zones using interface reconstruction. Application of interface reconstruction is determined by the material configuration in the surrounding zones. In subdivided zones, subzonal inter-material energy exchanges are calculated by heat fluxes across the material interfaces. Inter-material energy exchange in zones with random mixtures is modeled using the length scale and contact surface area models. In those zones, inter-zonal heat flux in each material is determined using the volume fractions.

  3. A modeling approach for heat conduction and radiation diffusion in plasma-photon mixture in temperature nonequilibrium

    International Nuclear Information System (INIS)

    Chang, Chong

    2016-01-01

    We present a simple approach for determining ion, electron, and radiation temperatures of heterogeneous plasma-photon mixtures, in which temperatures depend on both material type and morphology of the mixture. The solution technique is composed of solving ion, electron, and radiation energy equations for both mixed and pure phases of each material in zones containing random mixture and solving pure material energy equations in subdivided zones using interface reconstruction. Application of interface reconstruction is determined by the material configuration in the surrounding zones. In subdivided zones, subzonal inter-material energy exchanges are calculated by heat fluxes across the material interfaces. Inter-material energy exchange in zones with random mixtures is modeled using the length scale and contact surface area models. In those zones, inter-zonal heat flux in each material is determined using the volume fractions.

  4. Numerical analysis of the transient radiation-induced conductivity in the framework of the Rose-Fowler-Vaisberg formalism

    International Nuclear Information System (INIS)

    Mingaleev, G.S.; Tyutnev, A.P.; Gerasimov, B.P.; Kulchitskaya, I.A.

    1986-01-01

    Computer simulation of the temperature, dose, and trap filling effects of transient RIC is carried out by means of the Rose-Fowler-Vaisberg formalism. These combined effects allow to determine the trap distribution type exponential or Gaussian, an available data favouring the former. It is also shown that the usual Rose-Fowler-Vaisberg theory modified to involve the radiation produced traps provides the basis for a consistent and quantitative understanding of dose effects encountered in repeated irradiations of polymers. (author)

  5. Annular convective-radiative fins with a step change in thickness, and temperature-dependent thermal conductivity and heat transfer coefficient

    Science.gov (United States)

    Barforoush, M. S. M.; Saedodin, S.

    2018-01-01

    This article investigates the thermal performance of convective-radiative annular fins with a step reduction in local cross section (SRC). The thermal conductivity of the fin's material is assumed to be a linear function of temperature, and heat transfer coefficient is assumed to be a power-law function of surface temperature. Moreover, nonzero convection and radiation sink temperatures are included in the mathematical model of the energy equation. The well-known differential transformation method (DTM) is used to derive the analytical solution. An exact analytical solution for a special case is derived to prove the validity of the obtained results from the DTM. The model provided here is a more realistic representation of SRC annular fins in actual engineering practices. Effects of many parameters such as conduction-convection parameters, conduction-radiation parameter and sink temperature, and also some parameters which deal with step fins such as thickness parameter and dimensionless parameter describing the position of junction in the fin on the temperature distribution of both thin and thick sections of the fin are investigated. It is believed that the obtained results will facilitate the design and performance evaluation of SRC annular fins.

  6. Characterization of relative biological effectiveness for conventional radiation therapy: a comparison of clinical 6 MV X-rays and 137Cs.

    Science.gov (United States)

    Howard, Michelle; Beltran, Chris; Sarkaria, Jann; Herman, Michael G

    2017-09-01

    Various types of radiation are utilized in the treatment of cancer. Equal physical doses of different radiation types do not always result in the same amount of biological damage. In order to account for these differences, a scaling factor known as the relative biological effectiveness (RBE) can be used. 137Cesium (137Cs) has been used as a source of radiation in a significant body of radiation therapy research. However, high-energy X-rays, such as 6 MV X-rays, are currently used clinically to treat patients. To date, there is a gap in the literature regarding the RBE comparison of these two types of radiation. Therefore, the purpose of this study was to investigate the RBE of 137Cs relative to that of 6 MV X-rays. To determine the RBE, five cell lines were irradiated [Chinese hamster ovary (CHO); human lung adenocarcinoma (A549); human glioma (U251); human glioma (T98); and human osteosarcoma (U2OS)] by both types of radiation and assessed for cell survival using a clonogenic assay. Three of the five cell lines resulted in RBE values of ~1.00 to within 11% for all survival fractions, showing the physical and biological dose for these two types of radiation were equivalent. The other two cell lines gave RBE values differing from 1.00 by up to 36%. In conclusion, the results show the range in biological effect seen between cell lines, and therefore cell type must be considered when characterizing RBE. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  7. Rectal cancer: assessment of complete response to preoperative combined radiation therapy with chemotherapy--conventional MR volumetry versus diffusion-weighted MR imaging.

    Science.gov (United States)

    Curvo-Semedo, Luís; Lambregts, Doenja M J; Maas, Monique; Thywissen, Thomas; Mehsen, Rana T; Lammering, Guido; Beets, Geerard L; Caseiro-Alves, Filipe; Beets-Tan, Regina G H

    2011-09-01

    To determine diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) imaging for assessment of complete tumor response (CR) after combined radiation therapy with chemotherapy (CRT) in patients with locally advanced rectal cancer (LARC) by means of volumetric signal intensity measurements and apparent diffusion coefficient (ADC) measurements and to compare the performance of DW imaging with that of T2-weighted MR volumetry. A retrospective analysis of 50 patients with LARC, for whom clinical and imaging data were retrieved from a previous imaging study approved by the local institutional ethical committee and for which all patients provided informed consent, was conducted. Patients underwent pre- and post-CRT standard T2-weighted MR and DW MR. Two independent readers placed free-hand regions of interest (ROIs) in each tumor-containing section on both data sets to determine pre- and post-CRT tumor volumes and tumor volume reduction rates (volume). ROIs were copied to an ADC map to calculate tumor ADCs. Histopathologic findings were the standard of reference. Receiver operating characteristic (ROC) curves were generated to compare performance of T2-weighted and DW MR volumetry and ADC. The intraclass correlation coefficient (ICC) was used to evaluate interobserver variability and the correlation between T2-weighted and DW MR volumetry. Areas under the ROC curve (AUCs) for identification of a CR that was based on pre-CRT volume, post-CRT volume, and volume, respectively, were 0.57, 0.70, and 0.84 for T2-weighted MR versus 0.63, 0.93, and 0.92 for DW MR volumetry (P = .15, .02, .42). Pre- and post-CRT ADC and ADC AUCs were 0.55, 0.54, and 0.51, respectively. Interobserver agreement was excellent for all pre-CRT measurements (ICC, 0.91-0.96) versus good (ICC, 0.61-0.79) for post-CRT measurements. ICC between T2-weighted and DW MR volumetry was excellent (0.97) for pre-CRT measurements versus fair (0.25) for post-CRT measurements. Post-CRT DW MR

  8. Application of homotopy perturbation method for a conductive–radiative fin with temperature dependent thermal conductivity and surface emissivity

    Directory of Open Access Journals (Sweden)

    Pranab Kanti Roy

    2015-09-01

    Full Text Available This work aimed at studying the effects of environmental temperature and surface emissivity parameter on the temperature distribution, efficiency and heat transfer rate of a conductive–radiative fin. The Homotopy Perturbation Method (HPM being one of the semi-numerical methods for highly nonlinear and inhomogeneous equations, the local temperature distribution efficiencies and heat transfer rates are obtained using HPM in which Newton–Raphson method is used for the insulated boundary condition. It is found that the results of the present works are in good agreement with results available in the literature.

  9. Natural and gamma radiation-induced conduction of silica and metaphosphate glass layers deposed by radiofrequency cathode sputtering

    International Nuclear Information System (INIS)

    Serra, Andre

    1977-01-01

    We present a study of natural and 60 Co induced conductions in radiofrequency sputtering deposed layers. Capacimetry and electronic microscopy observations permit a knowledge of the physical characteristics, mainly: homogeneity and thickness of these layers. A study of the natural current permit to characterise electrically the deposited films, the electrode and bulk insulator effects. In induced conduction, the behaviour of currents as a function of dose rate is interpreted in terms of ROSE'S and FOWLER'S photoconductivity theories. Induced currents versus applied fields are observed and compared with these obtained in the case of dielectric liquids and glasses. (author) [fr

  10. Heat transfer and thermodynamic performance of convective–radiative cooling double layer walls with temperature-dependent thermal conductivity and internal heat generation

    International Nuclear Information System (INIS)

    Torabi, Mohsen; Zhang, Kaili

    2015-01-01

    Highlights: • First and second laws of thermodynamics have been investigated in a composite wall. • Convective–radiative heat transfer is assumed on both surfaces. • Optimum interface location is calculated to minimize the total entropy generation rate. • Thermal conductivities ratio has great effects on the temperature and entropy generation. - Abstract: Composite geometries have numerous applications in industry and scientific researches. This work investigates the temperature distribution, and local and total entropy generation rates within two-layer composite walls using conjugate convection and radiation boundary conditions. Thermal conductivities of the materials of walls are assumed temperature-dependent. Temperature-dependent internal heat generations are also incorporated into the modeling. The differential transformation method (DTM) is used as an analytical technique to tackle the highly nonlinear system of ordinary differential equations. Thereafter, the local and total entropy generation rates are calculated using the DTM formulated temperature distribution. An exact analytical solution, for the temperature-independent model without radiation effect, is also derived. The correctness and accuracy of the DTM solution are checked against the exact solution. After verification, effects of thermophysical parameters such as location of the interface, convection–conduction parameters, radiation–conduction parameters, and internal heat generations, on the temperature distribution, and both local and total entropy generation rates are examined. To deliver the minimum total entropy generation rate, optimum values for some parameters are also found. Since composite walls are widely used in many fields, the abovementioned investigation is a beneficial tool for many engineering industries and scientific fields to minimize the entropy generation, which is the exergy destruction, of the system

  11. Radiation-hygienic estimation of interstitial gamma therapy conducted according to principle of subsequent introduction of radioactive sources

    International Nuclear Information System (INIS)

    Zamyatin, O.A.; Golikov, V.Ya.; Korenkov, I.P.; Ter-Kazar'yan, N.S.; Mindlin, G.M.

    1978-01-01

    A comparative study of two radiation-hygienic methods of interstitial gamma-therapy: with subsequent introduction of radioactive needles of a standard type; with subsequent manual introduction of 60 Co sources have been carried out. Chronometry-dosimetric methods of investigation and the methods of individual dosimetry underlie the studies. The obtained data showed, that doses of irradiation to which medical personnel is subjected during the use of the method of subsequent manual introduction of the active sources are 3-4 times lower, than those during the introduction of standard radioactive needles with a higher quality of the procedure performance, ensuring a good therapeutic effect. All this makes it possible to consider interstitial gamma-therapy with the use of the principle of subsequent introduction of the source to be a more perspective method than interstitial gamma-therapy with the use standard radioactive needless 60 Co

  12. Human radiation studies: Remembering the early years: Oral history of biochemist William D. Moss, conducted November 30, 1994

    International Nuclear Information System (INIS)

    1995-09-01

    This report is a transcript of an interview with William D. Moss by representatives of the US DOE Office of Human Radiation Experiments. Mr. Moss was selected for this interview because of his work at Los Alamos National Laboratory concerning analytical methods in the chemical determination of plutonium in biological materials. After a brief biographical sketch, Mr. Moss relates his understanding of how occupational exposure limits were determined for the Manhattan Project, how data from those workers who were exposed to plutonium was collected and analyzed, how the experiments were planned and data was gathered from plutonium or polonium injections in man, how problems with analytical procedures compounded health physics aspects of the project, and problems remaining in the interpretation of these data

  13. Quality of Survival and Growth in Children and Young Adults in the PNET4 European Controlled Trial of Hyperfractionated Versus Conventional Radiation Therapy for Standard-Risk Medulloblastoma

    International Nuclear Information System (INIS)

    Kennedy, Colin; Bull, Kim; Chevignard, Mathilde; Culliford, David; Dörr, Helmuth G.; Doz, François; Kortmann, Rolf-Dieter; Lannering, Birgitta; Massimino, Maura; Navajas Gutiérrez, Aurora; Rutkowski, Stefan; Spoudeas, Helen A.; Calaminus, Gabriele

    2014-01-01

    Purpose: To compare quality of survival in “standard-risk” medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Methods and Materials: Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Results: Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Conclusions: Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life

  14. Quality of Survival and Growth in Children and Young Adults in the PNET4 European Controlled Trial of Hyperfractionated Versus Conventional Radiation Therapy for Standard-Risk Medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Colin, E-mail: crk1@soton.ac.uk [University of Southampton Faculty of Medicine and University Hospital Southampton National Health Service Foundation Trust, Southampton (United Kingdom); Bull, Kim [University of Southampton Faculty of Medicine and University Hospital Southampton National Health Service Foundation Trust, Southampton (United Kingdom); Chevignard, Mathilde [Hôpitaux de Saint Maurice, Saint Maurice (France); Neurophysiology, University of Pierre et Marie-Curie Paris 6, Paris (France); Culliford, David [University of Southampton Faculty of Medicine and University Hospital Southampton National Health Service Foundation Trust, Southampton (United Kingdom); Dörr, Helmuth G. [Kinder- und Jugendklinik der Universität Erlangen, Erlangen (Germany); Doz, François [Institut Curie and University Paris Descartes, Sorbonne Paris Cité (France); Kortmann, Rolf-Dieter [Department of Radiation Therapy, University of Leipzig, Leipzig (Germany); Lannering, Birgitta [Department of Pediatrics, The Sahlgren Academy, University of Gothenburg, Gothenburg (Sweden); Massimino, Maura [Fondazione Istituto di Ricovero e Cura a Carattere Scientifico IRCCS Istituto Nazionale dei Tumori, Milan (Italy); Navajas Gutiérrez, Aurora [Hospital Universitario Cruces, Baracaldo-Vizcaya (Spain); Rutkowski, Stefan [University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Spoudeas, Helen A. [Center for Pediatric Endocrinology, University College London, London (United Kingdom); Calaminus, Gabriele [Pediatric Oncology, University of Muenster, Muenster (Germany)

    2014-02-01

    Purpose: To compare quality of survival in “standard-risk” medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Methods and Materials: Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Results: Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Conclusions: Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life.

  15. Quality of survival and growth in children and young adults in the PNET4 European controlled trial of hyperfractionated versus conventional radiation therapy for standard-risk medulloblastoma.

    Science.gov (United States)

    Kennedy, Colin; Bull, Kim; Chevignard, Mathilde; Culliford, David; Dörr, Helmuth G; Doz, François; Kortmann, Rolf-Dieter; Lannering, Birgitta; Massimino, Maura; Navajas Gutiérrez, Aurora; Rutkowski, Stefan; Spoudeas, Helen A; Calaminus, Gabriele

    2014-02-01

    To compare quality of survival in "standard-risk" medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Large-time behavior of the motion of a viscous heat-conducting one-dimensional gas coupled to radiation

    Czech Academy of Sciences Publication Activity Database

    Ducomet, B.; Nečasová, Šárka

    2012-01-01

    Roč. 191, č. 2 (2012), s. 219-260 ISSN 0373-3114 R&D Projects: GA ČR GA201/08/0012 Institutional research plan: CEZ:AV0Z10190503 Keywords : compressible * viscous * heat-conducting Subject RIV: BA - General Mathematics Impact factor: 0.680, year: 2012 http://www.springerlink.com/content/0gw2j0311w430012/

  17. Effects of radiation and thermal conductivity on MHD boundary layer flow with heat transfer along a vertical stretching sheet in a porous medium

    KAUST Repository

    Ferdows, M.

    2017-03-10

    A steady two-dimensional free convective flow of a viscous incompressible fluid along a vertical stretching sheet with the effect of magnetic field, radiation and variable thermal conductivity in porous media is analyzed. The nonlinear partial differential equations, governing the flow field under consideration, have been transformed by a similarity transformation into a systemof nonlinear ordinary differential equations and then solved numerically. Resulting non-dimensional velocity and temperature profiles are then presented graphically for different values of the parameters. Finally, the effects of the pertinent parameters, which are of physical and engineering interest, are examined both in graphical and tabular form.

  18. Numerical investigation of CO{sub 2} emission and thermal stability of a convective and radiative stockpile of reactive material in a cylindrical pipe of variable thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Lebelo, Ramoshweu Solomon, E-mail: sollyl@vut.ac.za [Department of Mathematics, Vaal University of Technology, Private Bag X021, Vanderbijlpark, 1911 (South Africa)

    2014-10-24

    In this paper the CO{sub 2} emission and thermal stability in a long cylindrical pipe of combustible reactive material with variable thermal conductivity are investigated. It is assumed that the cylindrical pipe loses heat by both convection and radiation at the surface. The nonlinear differential equations governing the problem are tackled numerically using Runge-Kutta-Fehlberg method coupled with shooting technique method. The effects of various thermophysical parameters on the temperature and carbon dioxide fields, together with critical conditions for thermal ignition are illustrated and discussed quantitatively.

  19. Conduction mechanism in Polyaniline-flyash composite material for shielding against electromagnetic radiation in X-band & Ku band

    Directory of Open Access Journals (Sweden)

    Avanish Pratap Singh

    2011-06-01

    Full Text Available β–Naphthalene sulphonic acid (β–NSA doped polyaniline (PANI–flyash (FA composites have been prepared by chemical oxidative polymerization route whose conductivity lies in the range 2.37–21.49 S/cm. The temperature dependence of electrical conductivity has also been recorded which shows that composites follow Mott's 3D–VRH model. SEM images demonstrate that β–NSA leads to the formation of the tubular structure with incorporated flyash phase. TGA studies show the improvement in thermal stability of composites with increase in loading level of flyash. Complex parameters i.e. permittivity (ɛ* = ɛ′- iɛ″ and permeability (μ*=μ′- iμ″ of PANI-FA composites have been calculated from experimental scattering parameters (S11 & S21 using theoretical calculations given in Nicholson–Ross and Weir algorithms. The microwave absorption properties of the composites have been studied in X-band (8.2 – 12.4 GHz & Ku–Band (12.4 – 18 GHz frequency range. The maximum shielding effectiveness observed was 32dB, which strongly depends on dielectric loss and volume fraction of flyash in PANI matrix.

  20. Radiations

    International Nuclear Information System (INIS)

    Pujol Mora, J.

    1999-01-01

    The exposition to ionizing radiations is a constant fact in the life of the human being and its utilization as diagnostic and therapeutic method is generalized. However, it is notorious how as years go on, the fear to the ionizing radiation seems to persist too, and this fact is not limited to the common individual, but to the technical personnel and professional personnel that labors with them same. (S. Grainger) [es

  1. Radiation

    International Nuclear Information System (INIS)

    Davidson, J.H.

    1986-01-01

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  2. Electrical Conductivity of Gamma Irradiated Aqueous Urea Solution and its Application for Determination of Absorbed Radiation Dose; Sife-Eldeen Dosimeter

    International Nuclear Information System (INIS)

    Sife- Eldeen, Kh.A.

    2008-01-01

    In This Study, the radiation induced electrical conductivity (RIC) of aqueous urea solutions was investigated after gamma radiolysis. It was found that the RIC depends on preirradiation urea concentration, absorbed radiation dose and storage time. At the same absorbed dose, RIC increases as preirradiation urea concentration increases. The RIC change of aqueous urea solutions reaches a maximum value at 3.5 M aqueous urea solutions. RIC of 0.133 and 3.5 M aqueous urea solutions as a function of dose, have been investigated in the range between 2.18 and 119.4 kGy. RIC of the 0.133 and 3.5 M aqueous urea solutions increased linearly with increasing dose (R 2 =0.9963, 0.9972 respectively). The calibration factors was found to be 2.1448 and 9.53 μS/kGy for sets with 0.133 and 3.5 M urea respectively .The coefficient of variation CV %, associated with RIC measurement of 3.5 M aqueous urea solution as a function of absorbed radiation dose was found to be 1.8025% and the uncertainty was found to be 3.6 % and 5.4 % for 95 % and 99 % confidence levels, respectively. The effective atomic number of 3.5 M aqueous urea solutions is 6.58, which indicates tissue equivalency of this system. The RIC values of 3.5 M aqueous urea solutions were found to be relatively stable over storage period of three weeks at 0 degree C. Accordingly, this system could be considered as a promising radiation-sensitive material for dosimetry of gamma rays in both technical and research fields

  3. Brachytherapy Improves Biochemical Failure–Free Survival in Low- and Intermediate-Risk Prostate Cancer Compared With Conventionally Fractionated External Beam Radiation Therapy: A Propensity Score Matched Analysis

    International Nuclear Information System (INIS)

    Smith, Graham D.; Pickles, Tom; Crook, Juanita; Martin, Andre-Guy; Vigneault, Eric; Cury, Fabio L.; Morris, Jim; Catton, Charles; Lukka, Himu; Warner, Andrew; Yang, Ying; Rodrigues, George

    2015-01-01

    Purpose: To compare, in a retrospective study, biochemical failure-free survival (bFFS) and overall survival (OS) in low-risk and intermediate-risk prostate cancer patients who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. Methods and Materials: Patient data were obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated with primary radiation therapy at four Canadian cancer institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2) intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and OS in the 3 matched groups. Results: Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in OS was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). Conclusions: Propensity score matched analysis showed that BT options led

  4. Proton radiation therapy (prt) for pediatric optic pathway gliomas: comparison with 3d planned conventional photons and a standard photon technique

    International Nuclear Information System (INIS)

    Fuss, Martin; Hug, Eugen B.; Schaefer, Rosemary A.; Nevinny-Stickel, Meinhard; Miller, Daniel W.; Slater, James M.; Slater, Jerry D.

    1999-01-01

    Purpose: Following adequate therapy, excellent long-term survival rates can be achieved for patients with optic pathway gliomas. Therefore, avoidance of treatment-related functional long-term sequelae is of utmost importance. Optimized sparing of normal tissue is of primary concern in the development of new treatment modalities. The present study compares proton radiation therapy (PRT) with a three-dimensional (3D)-planned multiport photon and a lateral beam photon technique for localized and extensive optic pathway tumors. Methods and Materials: Between February 1992 and November 1997, seven children with optic pathway gliomas underwent PRT. For this study, we computed proton, 3D photon, and lateral photon plans based on the same CT data sets, and using the same treatment planning software for all plans. Radiation exposure for normal tissue and discrete organs at risk was quantified based on dose-volume histograms. Results: Gross tumor volume (GTV) ranged from 3.9 cm 3 to 127.2 cm 3 . Conformity index (relation of encompassing isodose to GTV volume) was 2.3 for protons, 2.9 for 3D photons, and 7.3 for lateral photons. The relative increase of normal tissue (NT) encompassed at several isodose levels in relation to NT encompassed by the 95% proton isodose volume was computed. Relative NT volume of proton plan isodoses at the 95%, 90%, 80%, 50%, and 25% isodose level increased from 1 to 1.6, 2.8, 6.4, to a maximum of 13.3. Relative volumes for 3D photons were 1.6, 2.4, 3.8, 11.5, and 34.8. Lateral plan relative values were 6, 8.3, 11.5, 19.2, and 26.8. Analysis for small ( 3 ) and larger (> 80 cm 3 ) tumors showed that protons encompassed the smallest volumes of NT at all isodose levels. Comparable conformity and high-dose gradient were achieved for proton and 3D photon plans in small tumors. However, with increasing tumor volume and complexity, differences became larger. At the 50% isodose level, 3D photons were superior to lateral photons for small tumors; this

  5. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy.

    Science.gov (United States)

    Chang, Amy T Y; Hung, Albert W M; Cheung, Fion W K; Lee, Michael C H; Chan, Oscar S H; Philips, Helen; Cheng, Yung-Tang; Ng, Wai-Tong

    2016-07-01

    Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; Pquality IMRT plans for NPC patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. A randomised trial of accelerated and conventional radiotherapy for stage III and IV squamous carcinoma of the head and neck: a Trans-Tasman Radiation Oncology Group Study

    International Nuclear Information System (INIS)

    Poulsen, Michael G.; Denham, James W.; Peters, Lester J.; Lamb, David S.; Spry, Nigel A.; Hindley, Andrew; Krawitz, Hedley; Hamilton, Chris; Keller, Jacqui; Tripcony, Lee; Walker, Quenten

    2001-01-01

    Purpose: The aims of this randomized controlled trial were to determine whether there were differences in the disease-free survival (DFS) and toxicity between conventional radiotherapy (CRT) and a continuous 3 week accelerated radiotherapy regimen (ART) in stage III and IV squamous cell carcinoma of the oral cavity, oropharynx, larynx and hypopharynx. Patients and methods: Patients from 14 centres throughout Australia and New Zealand were randomly assigned to either CRT, using a single 2 Gy/day to a dose of 70 Gy in 35 fractions in 49 days or to ART, using 1.8 Gy twice a day to a dose of 59.4 Gy in 33 fractions in 24 days. Treatment allocation was stratified for site and stage. The accrual began in 1991 and the trial was closed in 1998 when the target of 350 patients was reached. Results: The median potential follow-up time was 53 months (range, 14-101). The DFS at 5 years was 41% (95% CI, 33-50%) for ART and 35% (95% CI, 27-43%) for CRT (P=0.323) and the hazard ratio was 0.87 in favour of ART (95% CI, 0.66-1.15). The 5-year disease-specific survival rates were 40% for CRT and 46% for ART (P=0.398) and the loco-regional control was 47% for CRT vs. 52% for ART (P=0.300). The respective hazard ratios were 0.88 (95% CI, 0.65-1.2) and 0.85 (0.62-1.16), favouring the accelerated arm. In the ART arm, confluent mucositis was more severe (94 vs. 71%; P<0.001) and peaked about 3 weeks earlier than in the CRT arm, but healing appeared complete in all cases. There were statistically significant reductions in the probability of grade 2 or greater late soft tissue effects over time in the ART arm (P<0.05), except for the mucous membrane where late effects were similar in both arms. Conclusions: Differences in DFS, disease-specific survival and loco-regional control have not been demonstrated. ART resulted in more acute mucosal toxicity, but this did not result in greater prolongation of the treatment time compared with the CRT arm. There were less late effects in the ART arm

  7. Performance analysis and optimization of radiating fins with a step change in thickness and variable thermal conductivity by homotopy perturbation method

    Science.gov (United States)

    Arslanturk, Cihat

    2011-02-01

    Although tapered fins transfer more rate of heat per unit volume, they are not found in every practical application because of the difficulty in manufacturing and fabrications. Therefore, there is a scope to modify the geometry of a constant thickness fin in view of the less difficulty in manufacturing and fabrication as well as betterment of heat transfer rate per unit volume of the fin material. For the better utilization of fin material, it is proposed a modified geometry of new fin with a step change in thickness (SF) in the literature. In the present paper, the homotopy perturbation method has been used to evaluate the temperature distribution within the straight radiating fins with a step change in thickness and variable thermal conductivity. The temperature profile has an abrupt change in the temperature gradient where the step change in thickness occurs and thermal conductivity parameter describing the variation of thermal conductivity has an important role on the temperature profile and the heat transfer rate. The optimum geometry which maximizes the heat transfer rate for a given fin volume has been found. The derived condition of optimality gives an open choice to the designer.

  8. Compensation and trapping in CdZnTe radiation detectors studied by thermoelectric emission spectroscopy, thermally stimulated conductivity, and current-voltage measurements

    International Nuclear Information System (INIS)

    James, Ralph B.

    2000-01-01

    In today's commercially available counter-select-grade CdZnTe crystals for radiation detector applications, the thermal ionization energies of the traps and their types, whether electron or hole traps, were measured. The measurements were successfully done using thermoelectric emission spectroscopy (TEES) and thermally stimulated conductivity (TSC). For reliability, the electrical contacts to the sample were found to be very important and, instead of Au Schottky contacts, In Ohmic contacts had to be used. For the filling of the traps, photoexcitation was done at zero bias, at 20K and at wavelengths which gave the maximum bulk photoexcitation for the sample. Between the temperature range from 20 to 400 K, the TSC current was found to be on the order of ∼ 10,000 times or even larger than the TEES current, in agreement with theory, but only TEES could resolve the trap type and was sensitive to the deep traps. Large concentration of hole traps at 0.1 and 0.6 eV were observed and smaller contraction of electron traps at 0.4 eV was seen. These deep traps cause compensation in the material and also cause trapping that degrades the radiation detection measurement

  9. Detection of electron and hole traps in CdZnTe radiation detectors by thermoelectric emission spectroscopy and thermally stimulated conductivity

    International Nuclear Information System (INIS)

    Lee, E.Y.; Brunett, B.A.; Olsen, R.W.; Van Scyoc, J.M. III; Hermon, H.; James, R.B.

    1998-01-01

    The electrical properties of CdZnTe radiation detectors are largely determined by electron and hole traps in this material. The traps, in addition to degrading the detector performance, can function as dopants and determine the resistivity of the material. Thermoelectric emission spectroscopy and thermally stimulated conductivity are used to detect these traps in a commercially available spectrometer-grade CdZnTe detector, and the electrical resistivity is measured as a function of temperature. A deep electron trap having an energy of 695 meV and cross section of 8 x 10 -16 cm 2 is detected and three hole traps having energies of 70 ± 20 meV, 105 ± 30 meV and 694 ± 162 meV are detected. A simple model based on these traps explains quantitatively all the data, including the electrical properties at room temperature and also their temperature dependence

  10. Human radiation studies: Remembering the early years: Oral history of cell biologist Don Francis Petersen, Ph.D., conducted November 29, 1994

    International Nuclear Information System (INIS)

    1995-08-01

    This report is a transcript of an interview of Dr. Don Francis Petersen by representatives of the US DOE Office of Human Radiation Experiments. Dr. Petersen was selected for this interview because of his long research career at Los Alamos and his knowledge of the Atomic Energy Commission's biomedical program. Dr. Petersen did not personally conduct research on human subjects. After a brief biographical sketch Dr. Petersen discusses his remembrances of the early use of radionuclides as biological tracers, aspects of nuclear weapons testing in the 1940's and 1950's including fallout studies, the means by which research projects were approved, use of humans in the whole-body counter, and the Health Division Biomedical responsibilities

  11. The IAEA code of conduct on the safety of radiation sources and the security of radioactive materials. A step forwards or backwards?

    International Nuclear Information System (INIS)

    Boustany, K.

    2001-01-01

    About the finalization of the Code of Conduct on the Safety and Security of radioactive Sources, it appeared that two distinct but interrelated subject areas have been identified: the prevention of accidents involving radiation sources and the prevention of theft or any other unauthorized use of radioactive materials. What analysis reveals is rather that there are gaps in both the content of the Code and the processes relating to it. Nevertheless, new standards have been introduced as a result of this exercise and have thus, as an enactment of what constitutes appropriate behaviour in the field of the safety and security of radioactive sources, emerged into the arena of international relations. (N.C.)

  12. Mathematical model for thermal and entropy analysis of thermal solar collectors by using Maxwell nanofluids with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Aziz, Asim; Jamshed, Wasim; Aziz, Taha

    2018-04-01

    In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The non-Newtonian Maxwell nanofluid model is utilized for the working fluid along with slip and convective boundary conditions and comprehensive analysis of entropy generation in the system is also observed. The effect of thermal radiation and variable thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for Cu-water and TiO2-water nanofluids. Results are presented for the velocity, temperature and entropy generation profiles, skin friction coefficient and Nusselt number. The discussion is concluded on the effect of various governing parameters on the motion, temperature variation, entropy generation, velocity gradient and the rate of heat transfer at the boundary.

  13. Human radiation studies: Remembering the early years: Oral history of cell biologist Don Francis Petersen, Ph.D., conducted November 29, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This report is a transcript of an interview of Dr. Don Francis Petersen by representatives of the US DOE Office of Human Radiation Experiments. Dr. Petersen was selected for this interview because of his long research career at Los Alamos and his knowledge of the Atomic Energy Commission`s biomedical program. Dr. Petersen did not personally conduct research on human subjects. After a brief biographical sketch Dr. Petersen discusses his remembrances of the early use of radionuclides as biological tracers, aspects of nuclear weapons testing in the 1940`s and 1950`s including fallout studies, the means by which research projects were approved, use of humans in the whole-body counter, and the Health Division Biomedical responsibilities.

  14. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy

    International Nuclear Information System (INIS)

    Chang, Amy T.Y.; Hung, Albert W.M.; Cheung, Fion W.K.; Lee, Michael C.H.; Chan, Oscar S.H.; Philips, Helen; Cheng, Yung-Tang; Ng, Wai-Tong

    2016-01-01

    Purpose: Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. Methods and Materials: RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. Results: RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; P<.001) and the right cochlea (mean dose, 48.6 Gy vs 52.6 Gy; P=.02). The total planning time for RP-2 plans was significantly less than that for manual plans (64 minutes vs 295 minutes, P<.001). Conclusions: This study shows that RapidPlan can significantly improve planning efficiency and produce quality IMRT plans for NPC patients.

  15. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Amy T.Y., E-mail: changty@ha.org.hk [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Hung, Albert W.M. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Cheung, Fion W.K.; Lee, Michael C.H. [Department of Medical Physics, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Chan, Oscar S.H. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Philips, Helen; Cheng, Yung-Tang [Varian Medical Systems, Palo Alto, California (United States); Ng, Wai-Tong [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong)

    2016-07-01

    Purpose: Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. Methods and Materials: RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. Results: RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; P<.001) and the right cochlea (mean dose, 48.6 Gy vs 52.6 Gy; P=.02). The total planning time for RP-2 plans was significantly less than that for manual plans (64 minutes vs 295 minutes, P<.001). Conclusions: This study shows that RapidPlan can significantly improve planning efficiency and produce quality IMRT plans for NPC patients.

  16. Comparison of conventional and 3-dimensional computed tomography against histopathologic examination in determining pancreatic adenocarcinoma tumor size: Implications for radiation therapy planning

    International Nuclear Information System (INIS)

    Qiu Haoming; Wild, Aaron T.; Wang Hao; Fishman, Elliot K.; Hruban, Ralph H.; Laheru, Daniel A.; Kumar, Rachit; Hacker-Prietz, Amy; Tuli, Richard; Tryggestad, Erik; Schulick, Richard D.; Cameron, John L.; Edil, Barish H.; Pawlik, Timothy M.; Wolfgang, Christopher L.; Herman, Joseph M.

    2012-01-01

    Background and purpose: This study seeks to: (a) quantify radiologic-pathologic discrepancy for pancreatic adenocarcinoma by comparing tumor size on conventional computed tomography (C-CT) and 3-dimensional CT (3D-CT) to corresponding pathologic specimens; and (b) to identify clinico-pathologic characteristics predictive of radiologic-pathologic discrepancy to assist radiotherapy planning. Materials and methods: Sixty-three patients with pancreatic adenocarcinoma and preoperative C-CT and volume-rendered 3D-CT imaging within 6 weeks of resection were identified. Maximum tumor diameter (MTD) was measured on pathology, C-CT, and 3D-CT and compared for each patient as well as among different clinico-pathologic subgroups. Results: There was a trend toward C-CT underestimation of MTD compared to final pathology (p = 0.08), but no significant difference between 3D-CT MTD and pathology (p = 0.54). Pathologic tumor size was significantly underestimated by C-CT in patients with larger pathologic tumor size (>3.0 cm, p = 0.0001), smaller tumor size on C-CT ( 90 U/mL, p = 0.008), and location in the pancreatic head (p = 0.015). A model for predicting pathologic MTD using C-CT MTD and CA19-9 level was generated. Conclusions: 3D-CT may allow for more accurate contouring of pancreatic tumors than C-CT. Patients with the above clinico-pathologic characteristics may require expanded margins relative to tumor size estimates on C-CT during radiotherapy planning.

  17. Use of the NASA Space Radiation Laboratory at Brookhaven National Laboratory to Conduct Charged Particle Radiobiology Studies Relevant to Ion Therapy.

    Science.gov (United States)

    Held, Kathryn D; Blakely, Eleanor A; Story, Michael D; Lowenstein, Derek I

    2016-06-01

    Although clinical studies with carbon ions have been conducted successfully in Japan and Europe, the limited radiobiological information about charged particles that are heavier than protons remains a significant impediment to exploiting the full potential of particle therapy. There is growing interest in the U.S. to build a cancer treatment facility that utilizes charged particles heavier than protons. Therefore, it is essential that additional radiobiological knowledge be obtained using state-of-the-art technologies and biological models and end points relevant to clinical outcome. Currently, most such ion radiotherapy-related research is being conducted outside the U.S. This article addresses the substantial contributions to that research that are possible at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), which is the only facility in the U.S. at this time where heavy-ion radiobiology research with the ion species and energies of interest for therapy can be done. Here, we briefly discuss the relevant facilities at NSRL and how selected charged particle biology research gaps could be addressed using those facilities.

  18. DEVELOPMENT OF A NOVEL RADIATIVELY/CONDUCTIVELY STABILIZED BURNER FOR SIGNIFICANT REDUCTION OF NOx EMISSIONS AND FOR ADVANCING THE MODELING AND UNDERSTANDING OF PULVERIZED COAL COMBUSTION AND EMISSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Noam Lior; Stuart W. Churchill

    2003-10-01

    The primary objective of the proposed study was the study and analysis of, and design recommendations for, a novel radiatively-conductively stabilized combustion (RCSC) process for pulverized coal, which, based on our prior studies with both fluid fuels and pulverized coal, holds a high promise to reduce NO{sub x} production significantly. We have primarily engaged in continuing and improving our process modeling and analysis, obtained a large amount of quantitative information about the effects of the major parameters on NO{sub x} production, conducted an extensive exergy analysis of the process, evaluated the practicalities of employing the Radiatively-Conductively Stabilized Combustor (RCSC) to large power and heat plants, and improved the experimental facility. Prior experimental work has proven the feasibility of the combustor, but slagging during coal combustion was observed and should be dealt with. The primary outcomes and conclusions from the study are: (1) we developed a model and computer program that represents the pulverized coal combustion in the RCSC, (2) the model predicts that NO{sub x} emissions can be reduced by a number of methods, detailed in the report. (3) the exergy analysis points out at least a couple of possible ways to improve the exergetic efficiency in this combustor: increasing the effectiveness of thermal feedback, and adjusting the combustor mixture exit location, (4) because of the low coal flow rates necessitated in this study to obtain complete combustion in the burner, the size of a burner operating under the considered conditions would have to be up to an order of magnitude, larger than comparable commercial burners, but different flow configurations of the RCSC can yield higher feed rates and smaller dimensions, and should be investigated. Related to this contract, eleven papers were published in journals and conference proceedings, and ten invited presentations were given at university and research institutions, as well as at

  19. [The reduction of the radiation dosage by means of storage phosphor-film radiography compared to a conventional film-screen system with a grid cassette on a skull phantom].

    Science.gov (United States)

    Heyne, J P; Merbold, H; Sehner, J; Neumann, R; Freesmeyer, M; Jonetz-Mentzel, L; Kaiser, W A

    1999-07-01

    How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette? A skull phantom (3M) was x-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhöfer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast. The surface entrance dose at 73 kV/22 mAs was 0.432 mGy in conventional screen film system and 0.435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0.308 mGy; SD 0.050); sufficient images were obtained down to an average dose of 31% (0.136 mGy; SD 0.065). The resolution of the line pairs were reduced down to 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resulted in an improvement of the assessment of bone structures and contrast in higher dose ranges only. For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement of the skull the dose can be reduced to at least 56% (phi 31%; SD 14.9%)/40% (phi 27%; SD 9.3%)/18% (phi 14%; SD 4.4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12.5 mAs and to skull measurement 73 kV/4 mAs.

  20. High-pitch computed tomography of the lung in pediatric patients. An intraindividual comparison of image quality and radiation dose to conventional 64-MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Tsiflikas, I.; Thomas, C.; Ketelsen, D.; Claussen, C.D.; Schaefer, J.F. [University Hospital of Tuebingen (Germany). Diagnostic and Interventional Radiology; Seitz, G.; Warmann, S. [University Hospital of Tuebingen (Germany). Pediatric Surgery

    2014-06-15

    Purpose: The aim of this study was to investigate frequencies of typical artifacts in low-dose pediatric lung examinations using high-pitch computed tomography (HPCT) compared to MDCT, and to estimate the effective radiation dose (E{sub eff}). Materials and Methods: Institutional review board approval for this retrospective study was obtained. 35 patients (17 boys, 18 girls; mean age 112 ± 69 months) were included and underwent MDCT and follow-up scan by HPCT or vice versa (mean follow-up time 87 days), using the same tube voltage and current. The total artifact score (0-8) was defined as the sum of artifacts arising from movement, breathing or pulsation of the heart or pulmonary vessels (0 - no; 1 - moderate; 2 - severe artifacts). E{sub eff} was estimated according to the European Guidelines on Quality Criteria for Multislice Computed Tomography. The Mann-Whitney U test was used to analyze differences between the patient groups. The Spearman's rank correlation coefficient was used for correlation of ordinal variables. Results: The scan time was significantly lower for HPCT compared to MDCT (0.72 ± 0.13 s vs. 3.65 ± 0.81s; p < 0.0001). In 28 of 35 (80 %) HPCT examinations no artifacts were visible, whereas in MDCT artifacts occurred in all examinations. The frequency of pulsation artifacts and breathing artifacts was higher in MDCT compared to HPCT (100% vs. 17% and 31% vs. 6%). The total artifact score significantly correlated with the patient's age in MDCT (r=-0.42; p=0.01), but not in HPCT (r=-0.32; p=0.07). The estimated E{sub eff} was significantly lower in HPCT than in MDCT (1.29±0.31 vs. 1.47±0.37 mSv; p < 0.0001). Conclusion: Our study indicates that the use of HPCT has advantages for pediatric lung imaging with a reduction of breathing and pulsation artifacts. Moreover, the estimated E{sub eff} was lower. In addition, examinations can be performed without sedation or breath-hold without losing image quality. (orig.)

  1. Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT; Radiologische Bildgebung beim Polytrauma: Dosisvergleich von Ganzkoerper-MSCT und konventionellem Roentgen mit organspezifischer CT

    Energy Technology Data Exchange (ETDEWEB)

    Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Nagel, H.D. [Philips Medizin Systeme GmbH, Hamburg (Germany)

    2004-07-01

    Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [German] Ziel: Dosisvergleich von Ganzkoerper-MSCT und konventioneller Basisdiagnostik mit organspezifischen Ct-Untersuchungen beim Polytrauma. Material und Methoden: Die Ganzkoerper-MSCT-Untersuchung von Schaedel, Mittelgesicht, HWS sowie Thorax, Abdomen und Becken erfolgte an einem Somatom-Volume-Zoom (Siemens). Die konventionelle Bildgebung, bestehend aus Thorax, Becken, HWS, BWS und LWs, wurde an einem Siemens-Polymat durchgefuehrt. Fuer die organspezifischen CT-Untersuchungen wurden 3 Kombinationen ausgewaehlt: (1) CCT + HWS, (2) CCT + HWS

  2. Conventional myelography - evaluation of risk and benefit

    International Nuclear Information System (INIS)

    Hentschel, F.

    1989-01-01

    While the benefit and methodic risk of conventional myelography (KMG) are known, a radiation risk of 0.04 to 0.9 annual radiation-induced cancers can be estimated for all inhabitants of the GDR, dependent on the investigated region and the technique used. An optimized technique can reduce the radiation burden to 50 or 25%. With comparable values of benefit and radiation risk spinal CT and KMG are not contradictory but complementary investigations. Alternative methods (MRT, US) must not be discussed from the standpoint of radiation burden, but according to their availability and their methodic limitations. (author)

  3. Heights integrated model as instrument for simulation of hydrodynamic, radiation transport, and heat conduction phenomena of laser-produced plasma in EUV applications.

    Energy Technology Data Exchange (ETDEWEB)

    Sizyuk, V.; Hassanein, A.; Morozov, V.; Sizyuk, T.; Mathematics and Computer Science

    2007-01-16

    The HEIGHTS integrated model has been developed as an instrument for simulation and optimization of laser-produced plasma (LPP) sources relevant to extreme ultraviolet (EUV) lithography. The model combines three general parts: hydrodynamics, radiation transport, and heat conduction. The first part employs a total variation diminishing scheme in the Lax-Friedrich formulation (TVD-LF); the second part, a Monte Carlo model; and the third part, implicit schemes with sparse matrix technology. All model parts consider physical processes in three-dimensional geometry. The influence of a generated magnetic field on laser plasma behavior was estimated, and it was found that this effect could be neglected for laser intensities relevant to EUV (up to {approx}10{sup 12} W/cm{sup 2}). All applied schemes were tested on analytical problems separately. Benchmark modeling of the full EUV source problem with a planar tin target showed good correspondence with experimental and theoretical data. Preliminary results are presented for tin droplet- and planar-target LPP devices. The influence of three-dimensional effects on EUV properties of source is discussed.

  4. Acute toxicity and cost analysis of a phase III randomized trial of accelerated and conventional radiotherapy for squamous carcinoma of the head and neck: a trans- tasman radiation oncology group study

    International Nuclear Information System (INIS)

    Poulsen, M.; Williamson, S.; Tripcony, L.; Spry, N.; Peters, L.; Penniment, M.; Lamb, D.; Krawitz, H.

    1999-01-01

    The primary purpose of the present analysis was to assess the feasibility and acute toxicity of a pure accelerated fractionation regimen in a cooperative group setting. This analysis included the first 320 patients entered on to the Trans-Tasman Radiation Oncology Group (TROG) randomized controlled trial which compared accelerated radiotherapy (ART) with conventional radiotherapy (CRT) in stage lIl and IV squamous cell carcinoma (SCC) of the head and neck. Patients were randomized to either 59.4 Gy in 33 fractions over 24 days (ART) or to 70 Gy 35 fractions over 49 days (CRT) after being stratified for site and stage. Accrual began in 1991 and the trial was closed on 3 April 1998 with the targeted 350 patients. The 3-year survival for the whole group was 54%, and the 3-year disease-free survival was 41%. Toxicity data were available on 303 patients (148 ART; 155 CRT). Mucosal toxicity was worse in the accelerated grup, and it peaked ∼ 3 weeks earlier than the conventional grup. Skin toxicity was equivalent but occurred ∼ 7 days earlier in the accelerated grup. Acute effects in both grups healed completely. Hospitalization was more common in the ART grup (71 vs 52 patients; P=0.01) but the total bed days in hospital was not greatly different (1707 bed days for ART and 1607 bed days for CRT). Patients were more likely to require nasogastric (NG) feeding in the ART grup (49 vs 33 patients; P = 0.02). There were 1157 NG feeding days for ART and 1154 NG feeding days for CRT. The average cost of radiation treatment per patient including hospitalisation, NG feeding and accommodation was $11 750 in the ART grup and $11 587 in the CRT grup. The accelerated grup has been shown to be a tolerable, practical and cost-equivalent regimen. The assessment of the therapeutic ratio of this accelerated protocol (ART) will be determined when the analysis of late effects and loco-regional control is made when the data are more mature. Copyright (1999) Blackwell Science Pty Ltd

  5. Development of ProCaRS Clinical Nomograms for Biochemical Failure-free Survival Following Either Low-Dose Rate Brachytherapy or Conventionally Fractionated External Beam Radiation Therapy for Localized Prostate Cancer

    Science.gov (United States)

    Warner, Andrew; Pickles, Tom; Crook, Juanita; Martin, Andre-Guy; Souhami, Luis; Catton, Charles; Lukka, Himu

    2015-01-01

    Purpose: Although several clinical nomograms predictive of biochemical failure-free survival (BFFS) for localized prostate cancer exist in the medical literature, making valid comparisons can be challenging due to variable definitions of biochemical failure, the disparate distribution of prognostic factors, and received treatments in patient populations. The aim of this investigation was to develop and validate clinically-based nomograms for 5-year BFFS using the ASTRO II “Phoenix” definition for two patient cohorts receiving low-dose rate (LDR) brachytherapy or conventionally fractionated external beam radiation therapy (EBRT) from a large Canadian multi-institutional database. Methods and Materials: Patients were selected from the GUROC (Genitourinary Radiation Oncologists of Canada) Prostate Cancer Risk Stratification (ProCaRS) database if they received (1) LDR brachytherapy ≥ 144 Gy (n=4208) or (2) EBRT ≥ 70 Gy  (n=822). Multivariable Cox regression analysis for BFFS was performed separately for each cohort and used to generate clinical nomograms predictive of 5-year BFFS. Nomograms were validated using calibration plots of nomogram predicted probability versus observed probability via Kaplan-Meier estimates. Results: Patients receiving LDR brachytherapy had a mean age of 64 ± 7 years, a mean baseline PSA of 6.3 ± 3.0 ng/mL, 75% had a Gleason 6, and 15% had a Gleason 7, whereas patients receiving EBRT had a mean age of 70 ± 6 years, a mean baseline PSA of 11.6 ± 10.7 ng/mL, 30% had a Gleason 6, 55% had a Gleason 7, and 14% had a Gleason 8-10. Nomograms for 5-year BFFS included age, use and duration of androgen deprivation therapy (ADT), baseline PSA, T stage, and Gleason score for LDR brachytherapy and an ADT (months), baseline PSA, Gleason score, and biological effective dose (Gy) for EBRT. Conclusions: Clinical nomograms examining 5-year BFFS were developed for patients receiving either LDR brachytherapy or conventionally fractionated EBRT and

  6. Chemical Weapons Convention

    National Research Council Canada - National Science Library

    1997-01-01

    On April 29, 1997, the Convention on the Prohibition of the Development, Production, Stockpiling, and Use of Chemical Weapons and on Their Destruction, known as the Chemical Weapons Convention (CWC...

  7. The Hague Judgments Convention

    DEFF Research Database (Denmark)

    Nielsen, Peter Arnt

    2011-01-01

    The Hague Judgments Convention of 2005 is the first global convention on international jurisdiction and recognition and enforcement of judgments in civil and commercial matters. The author explains the political and legal background of the Convention, its content and certain crucial issues during...

  8. Pre-trial quality assurance processes for an intensity-modulated radiation therapy (IMRT) trial: PARSPORT, a UK multicentre Phase III trial comparing conventional radiotherapy and parotid-sparing IMRT for locally advanced head and neck cancer.

    Science.gov (United States)

    Clark, C H; Miles, E A; Urbano, M T Guerrero; Bhide, S A; Bidmead, A M; Harrington, K J; Nutting, C M

    2009-07-01

    The purpose of this study was to compare conventional radiotherapy with parotid gland-sparing intensity-modulated radiation therapy (IMRT) using the PARSPORT trial. The validity of such a trial depends on the radiotherapy planning and delivery meeting a defined standard across all centres. At the outset, many of the centres had little or no experience of delivering IMRT; therefore, quality assurance processes were devised to ensure consistency and standardisation of all processes for comparison within the trial. The pre-trial quality assurance (QA) programme and results are described. Each centre undertook exercises in target volume definition and treatment planning, completed a resource questionnaire and produced a process document. Additionally, the QA team visited each participating centre. Each exercise had to be accepted before patients could be recruited into the trial. 10 centres successfully completed the quality assurance exercises. A range of treatment planning systems, linear accelerators and delivery methods were used for the planning exercises, and all the plans created reached the standard required for participation in this multicentre trial. All 10 participating centres achieved implementation of a comprehensive and robust IMRT programme for treatment of head and neck cancer.

  9. Human radiation studies: Remembering the early years: Oral history of health physicist Carl C. Gamertsfelder, Ph.D., conducted January 19, 1995

    International Nuclear Information System (INIS)

    Fisher, T.; Yuffee, M.

    1995-09-01

    This report is a transcript of an interview of Dr. Carl C. Gamertsfelder by representatives of the DOE Office of Human Radiation Experiments. Dr. Gamertsfelder was selected for this interview because of experiences with contractors to the Manhattan Project and to the Atomic Energy Commission. Following a brief biographical sketch, Dr. Gamertsfelder related his remembrances of University of Chicago, of Oak Ridge, and of Hanford during world war II. He also describes his postwar experiences at Hanford, with the Nuclear- Powered Aircraft Program, and with the Apollo Project. Some subjects discussed include the Green Run, radiation accidents, radiation monitoring, Health Physics, and the storage tanks at Hanford

  10. Human radiation studies: Remembering the early years: Oral history of radiologist Henry I. Kohn, M.D., Ph.D., conducted September 13, 1994

    International Nuclear Information System (INIS)

    1995-06-01

    This report is a transcript of an interview of Dr. Henry I. Kohn by representatives of the US DOE Office of Human Radiation Experiments. Dr. Kohn was selected for this interview because of the positions he held at Oak Ridge National Laboratory, University of California at San Francisco, and Harvard Medical School. Dr. Kohn discussed his remembrances of his experiences in blood chemistry of animals and patients exposed to radiation, and his remembrances of several radiobiologists

  11. Reduction of radiation dose by using digital luminescence radiography compared to conventional screen film system with grid cassette; Reduktion der Strahlendosis mittels Speicherfolienradiographie im Vergleich zum konventionellen Film-Folien-System mit Rasterkassette am Schaedelphantom

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, J.P.; Merbold, H.; Neumann, R.; Freesmeyer, M.; Jonetz-Mentzel, L.; Kaiser, W.A. [Friedrich-Schiller-Univ. Jena, Inst. fuer Diagnostische und Interventionelle Radiologie (Germany); Sehner, J. [AGFA-Deutschland, Vertriebsgesellschaft (Germany)

    1999-07-01

    Purpose: How much can the radiation dose be reduced for skull radiography by using digital luminescence radiography (DLR) compared to a conventional screen film system with a grid cassette? Methods and Materials: A skull phantom (3M) was X-rayed in anterior-posterior orientation using both a conventional screen film system with grid cassette and DLR (ADC-70, Agfa). The tube current time product (mAs) was diminished gradually while keeping the voltage constant. The surface entrance dose was measured by a sensor of Dosimax (Wellhoefer). Five investigators evaluated the images by characteristic and critical features, spatial resolution and contrast. Results: The surface entrance dose at 73 kV/22 mAs was 0,432 mGy in conventional screen film system and 0,435 mGy in DLR. The images could be evaluated very well down to an average dose of 71% (0,308 mGy; SD 0,050); sufficient images were obtained down to an average dose of 31% (0,136 mGy; SD 0,065). The resolution of the line pairs were reduced down to a 2 levels depending on the investigator. Contrast was assessed as being very good to sufficient. The acceptance of the postprocessed images (MUSICA-software) was individually different and resultde in an improvement of the assessment of bone structures an contrast in higher dose ranges only. Conclusion: For the sufficient assessment of a possible fracture/of paranasal sinuses/of measurement the skull the dose can be reduced to at least 56% (31%; SD 14,9%)/40% (27%; SD 9,3%)/18% (14%; SD 4,4%). Digital radiography allows question-referred exposure parameters with clearly reduced dose, so e.g. for fracture exclusion 73 kV/12,5 mAs and to skull measurement 73 kV/4 mAs. (orig.) [Deutsch] Ziel: Wie weit kann unter Einsatz der rasterlosen Speicherfolienradiographie bei einer Schaedelaufnahme die Strahlendosis im Vergleich zum Film-Folien-System (FFS) mit Rasterkassette (RK) fragestellungsbezogen gesenkt werden? Material und Methode: Ein Schaedelphantom (3M) wurde konventionell

  12. Super Conducting and Conventional Magnets Test & Mapping Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — Vertical Magnet Test Facility: Accommodate a device up to 3.85 m long, 0.61 m diameter, and 14,400 lbs. Configured for 5 psig sub-cooled liquid helium bath cooling...

  13. Radiation watchdog

    International Nuclear Information System (INIS)

    Manning, R.

    1984-01-01

    Designated by WHO as a Collaborating Centre, the Radiation Emergency Assistance Center/Training Site (REAC/TS) in Oak Ridge, Tennessee provides assistance to all countries of the Americas in radiation accidents including human contamination or overexposure. It also conducts courses in radiation emergency response for health professionals from throughout the world

  14. Convention on nuclear safety

    International Nuclear Information System (INIS)

    1994-01-01

    The Convention on Nuclear Safety was adopted on 17 June 1994 by Diplomatic Conference convened by the International Atomic Energy Agency at its Headquarters from 14 to 17 June 1994. The Convention will enter into force on the ninetieth day after the date of deposit with the Depository (the Agency's Director General) of the twenty-second instrument of ratification, acceptance or approval, including the instruments of seventeen States, having each at leas one nuclear installation which has achieved criticality in a reactor core. The text of the Convention as adopted is reproduced in the Annex hereto for the information of all Member States

  15. Minamata Convention on Mercury

    Science.gov (United States)

    On November 6, 2013 the United States signed the Minamata Convention on Mercury, a new multilateral environmental agreement that addresses specific human activities which are contributing to widespread mercury pollution

  16. Conducting Polymers

    Indian Academy of Sciences (India)

    would exhibit electronic conductivity, their conductivities (of compressed pellets) were indeed measured by others, and were found to be .... Polyaniline. Polyphenylene. Polypheny lene- vinylene. Table 1. G!NeRAl I ARTICl! structure. Maximum conductivity Stem Stability. Processability. ~. 1.5 x 105. Reacts with Film not n air.

  17. The radiation and variable viscosity effects on electrically conducting fluid over a vertically moving plate subjected to suction and heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Malekzadeh, P., E-mail: malekzadeh@pgu.ac.i [Department of Mechanical Engineering, Persian Gulf University, Bushehr 75168 (Iran, Islamic Republic of); Center of Excellence for Computational Mechanics, Shiraz University, Shiraz (Iran, Islamic Republic of); Moghimi, M.A. [Department of Mechanical Engineering, School of Engineering, Shaid Bahonar University, Kerman (Iran, Islamic Republic of); Nickaeen, M. [K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2011-05-15

    Research highlights: {yields} A new application of the differential quadrature method in thermo-fluid fields. {yields} Moving vertical plate with suction and heat flux is considered. {yields} Fluid with variable viscosity subjected to thermal radiation is studied. -- Abstract: In this paper, firstly, the applicability of the differential quadrature method (DQM) as an efficient and accurate numerical method for solving the problem of variable viscosity and thermally radiative unsteady magneto-hydrodynamic (MHD) flow over a moving vertical plate with suction and heat flux is investigated. The spatial as well as the temporal domains are discretized using the DQM. The fast rate of convergence of the method is demonstrated and for the cases that a solution is available, comparison is done. Then, effects of the temperature dependence of viscosity and different fluid parameters on the velocity and temperature of transient MHD flow subjected to the above mentioned boundary condition are studied.

  18. Human radiation studies: Remembering the early years: Oral history of radiologist Hymer L. Friedell, M.D., Ph.D., conducted January 28, 1995

    International Nuclear Information System (INIS)

    Fisher, D.; Melamed, E.

    1995-07-01

    NThis report is a transcript of an interview with Hymer L. Friedell by representatives of the US DOE Office of Human Radiation Experiments. Dr. Friedell was selected for this interview because of his participation in the early stages of the medical use of radioisotopes, his important role in the Manhattan Engineer District Medical Division, and his distinguished medical career and his involvement in the distribution of isotopes and the approval for their use in humans. After a brief biographical sketch Dr. Friedell discusses his remembrances on a wide range of subjects. Topics discussed include pre-war radiation therapy, information provided to patients, the Army Medical Corps and the Manhattan Project, his work at the Chicago Metallurgical Laboratory, inspection visits of Manhattan Project facilities and proposed sites, Plutonium injection studies, and actions of the AEC Isotope Distribution Committee

  19. Human radiation studies: Remembering the early years: Oral history of health physicist Karl Z. Morgan, Ph.D., conducted January 7, 1995

    International Nuclear Information System (INIS)

    1995-06-01

    This report provided a transcript of an interview of Dr. Karl. Z. Morgan by representatives of the DOE Office of Human Radiation Experiments. Dr. Morgan was selected for this interview because of his research for the Manhattan Project at the Metallurgical Laboratory in Chicago and his work at the Oak Ridge National Laboratory (ORNL). The oral history covers Dr. Morgan's work as a pioneer in the field of Health Physics, his research at ORNL and his work since he retired from ORNL

  20. The effects of UV radiation on the content of phenolic acid and flavonoid, stomatal conductance and taste in red lettuce 'Lollo Rosso'

    OpenAIRE

    Almeida De Oliveira, Dinalva

    2016-01-01

    The use of supplementary light to improve the quality of red lettuce is common practice in today’s greenhouse production. Fluorescent lamps that emit Ultraviolet (UV) radiation have been shown to increase the synthesis of phenolic acids and flavonoids as well to control stomata movements in red lettuce. In the work presented here, I ran experiments which showed that the use of UV treatments lead to higher concentrations of these health-promoting compounds. The objective was to evaluate the ef...

  1. One year follow-up reveals no difference in quality of life between high dose and conventional dose radiation: a quality of life assessment of RTOG 94-05

    International Nuclear Information System (INIS)

    Kachnic, L.A.; Scott, C.; Ginsberg, R.; Pisansky, T.; Martenson, J.; Komaki, R.; Okawara, G.; Rosenthal, S.; Kelsen, D.; Minsky, B.

    2001-01-01

    Purpose: This study evaluated and compared the quality of life (QOL) outcomes for patients with esophageal cancer receiving combined modality therapy (CMT) with conventional dose radiation (RT) vs. high dose RT as used in RTOG study 94-05. Materials and Methods: Between June 12, 1995 and July 1, 1999, 236 patients with cT1-4NxM0 esophageal cancers were randomized on RTOG 94-05 to conventional dose (CD) CMT: 50.4 Gy RT + concurrent 5-FU and cisplatin administered on weeks 1 and 5 and repeated 4 weeks post RT vs. high dose (HD) CMT: 64.8 Gy RT + the same chemotherapy. QOL was assessed using the Functional Assessment of Cancer Therapy (FACT) - Head and Neck (version 2). This questionnaire was administered to patients pre-treatment, post-treatment, at 8 months from the start of CMT, at 1 year and at 6-month intervals to year 5. Results: Of 209 eligible protocol patients, 169 (81%) participated in the pre-treatment QOL component of RTOG 94-05 (83 in the HD arm and 86 in the CD arm). The principle reason for non-participation was institutional error. The distribution of pre-treatment characteristics by participation in QOL assessment was similar in both treatment arms. African-Americans, patients with ≥ 10% weight loss, and patients with low performance status were significantly less likely to complete QOL forms (p=0.04, p=0.01 and p=0.004 respectively). Baseline QOL parameters were similar in the two treatment arms. Pulmonary symptoms were the most significant pre-treatment dysfunction reported. Female gender and ≥10% pre-treatment weight loss correlated with pre-treatment total QOL scores. Women reported lower overall QOL as well as worse physical and emotional well-being in the HD arm as compared to the CD arm (p=0.07, p=0.01 and p=0.03 respectively). Patients with ≥10% weight loss reported decreased QOL in nearly all domains in both treatment groups, although more pronounced in the 64.8 Gy arm. Treatment arm assignment, age, performance status, tumor size and

  2. Human radiation studies: Remembering the early years: Oral history of medical physicist Katherine L. Lathrop and physician Paul V. Harper, conducted January 26, 1995

    International Nuclear Information System (INIS)

    1995-09-01

    This report provides a transcript of an interview with Ms. Katherine L. Lathrop and Dr. Paul V. Hopper by representatives of the DOE Office of Human Radiation Research. Ms. Lathrop and Dr. Hopper were chosen for this interview because of their long-standing interest and research experience in the development of nuclear medicine. After brief biographical sketches the researchers provide a broad and interesting description of their roles in the initial uses of many radiopharmaceuticals, their experiences in human experimentation, and interactions with many other pioneers in nuclear medicine

  3. Human radiation studies: Remembering the early years: Oral history of Dr. Patricia Wallace Durbin, Ph.D., conducted November 11, 1994

    International Nuclear Information System (INIS)

    1995-07-01

    This report is a transcript of an interview of Dr. Patricia Wallace Durbin by representatives of the US DOE Office of Human Radiation Research. Dr. Durbin was selected for this interview because of her knowledge of the human plutonium injections and her recollections of key figures, especially Joseph Hamilton. After a brief biographical sketch Dr. Durbin discusses her loss of research funding from DOE, her recollections concerning research into strontium metabolism as part of Project Sunshine, her recollections relating to the rationale for studies of human metabolism of radionuclides, her remembrances of Dr. Hamilton's Astatine and Plutonium research, and her experiences in gathering archival records concerning these researches

  4. Human radiation studies: Remembering the early years: Oral history of medical physicist Katherine L. Lathrop and physician Paul V. Harper, conducted January 26, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This report provides a transcript of an interview with Ms. Katherine L. Lathrop and Dr. Paul V. Hopper by representatives of the DOE Office of Human Radiation Research. Ms. Lathrop and Dr. Hopper were chosen for this interview because of their long-standing interest and research experience in the development of nuclear medicine. After brief biographical sketches the researchers provide a broad and interesting description of their roles in the initial uses of many radiopharmaceuticals, their experiences in human experimentation, and interactions with many other pioneers in nuclear medicine.

  5. Climate change convention

    International Nuclear Information System (INIS)

    Russell, D.

    1992-01-01

    Principles that guide Canada's Green Plan with respect to global warming are outlined. These include respect for nature, meeting environmental goals in an economically beneficial manner, efficient use of resources, shared responsibilities, federal leadership, and informed decision making. The policy side of the international Framework Convention on Climate Change is then discussed and related to the Green Plan. The Convention has been signed by 154 nations and has the long-term objective of stabilizing anthropogenic greenhouse gas concentrations in the atmosphere at levels that prevent dangerous interference with the climate system. Some of the Convention's commitments toward achieving that objective are only applicable to the developed countries. Five general areas of commitment are emissions reductions, assistance to developing countries, reporting requirements, scientific and socioeconomic research, and education. The most controversial area is that of limiting emissions. The Convention has strong measures for public accountability and is open to future revisions. Canada's Green Plan represents one country's response to the Convention commitments, including a national goal to stabilize greenhouse gas emissions at the 1990 level by the year 2000

  6. Conventional radiology and genetic dose

    International Nuclear Information System (INIS)

    Gonzalez-Vila, V.; Fernandez, A.; Rivera, F.; Martinez, M.; Gomez, A.; Luis, J.

    1992-01-01

    A research project was established in 1984 to evaluate the expected genetic abnormalities due to radiation received by the population attending the Outpatient Radiological Service due to medical radiological practices. The study was conducted in 1985 (12 weeks chosen by random). The equivalent gonadal dose was the chosen parameter, representing the social cost of the radiology. Samples of 2945 men and 2929 women were considered in the study. The number of genetic abnormalities, in relation to the mean age of reproduction (a generation every 30 years), was 2.13 cases per million in the first generation and 15.97 cases per million at equilibrium. The authors interpretation is that both the method and the expected genetic detriment are suitable procedures for the characterisation of the Radiological Service as a radiation source. (author)

  7. Human radiation studies: Remembering the early years: Oral history of physician James S. Robertson, M.D., Ph.D., conducted January 20, 1995

    International Nuclear Information System (INIS)

    1995-09-01

    This report is a transcript of in interview of Dr. James S. Robertson by representatives of the DOE Office of Human Radiation Experiments. Dr. Robertson was chosen for this interview because of his research at Brookhaven National Laboratory, especially on Boron Neutron Capture Therapy (BNCT); his work at the United States Naval Defense Laboratory; and his work at the Atomic Energy Commission. After a brief biographical sketch Dr. Robertson discusses research on human subjects at Berkeley, his contributions to the beginnings of Neutron Capture Therapy at Brookhaven, his participation with the Brookhaven Human Use Committee, his involvement in the study of the effects of Castle Bravo event on the Marshallese, and his work with the Naval Radiological Defense Laboratory

  8. Human radiation studies: Remembering the early years: Oral history of health physicist Constantine J. Maletskos, Ph.D., conducted January 20, 1995

    International Nuclear Information System (INIS)

    1995-09-01

    This report is a transcript of an interview with Dr. Constatine J. Maletskos by representatives of the DOE Office of Human Radiation Experiments. Dr. Maletskos was selected for this interview because of his research at the Radioactivity Center of the Massachusetts Institute of Technology (MIT), at the Harvard Medical School, and at the New England Deaconess Hospital. After a brief biographical sketches Dr. Maletskos discusses at length about his work at the Center on research that used subjects from the Walter E. Fernald State School in Waverly, Massachusetts and the New England Center for Aging, as well as blood volume work involving pregnant women. He further discusses his work with radium Dial Painters, his work with Dr. Robley Evans, and various other subjects concerning experiments with human subjects under the auspices of the AEC

  9. Human radiation studies: Remembering the early years: Oral history of physician James S. Robertson, M.D., Ph.D., conducted January 20, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This report is a transcript of in interview of Dr. James S. Robertson by representatives of the DOE Office of Human Radiation Experiments. Dr. Robertson was chosen for this interview because of his research at Brookhaven National Laboratory, especially on Boron Neutron Capture Therapy (BNCT); his work at the United States Naval Defense Laboratory; and his work at the Atomic Energy Commission. After a brief biographical sketch Dr. Robertson discusses research on human subjects at Berkeley, his contributions to the beginnings of Neutron Capture Therapy at Brookhaven, his participation with the Brookhaven Human Use Committee, his involvement in the study of the effects of Castle Bravo event on the Marshallese, and his work with the Naval Radiological Defense Laboratory.

  10. Heat conduction

    International Nuclear Information System (INIS)

    Grigull, U.; Sandner, H.

    1984-01-01

    Included are discussions of rates of heat transfer by conduction, the effects of varying and changing properties, thermal explosions, distributed heat sources, moving heat sources, and non-steady three-dimensional conduction processes. Throughout, the importance of thinking both numerically and symbolically is stressed, as this is essential to the development of the intuitive understanding of numerical values needed for successful designing. Extensive tables of thermophysical properties, including thermal conductivity and diffusivity, are presented. Also included are exact and approximate solutions to many of the problems that arise in practical situations

  11. Tritium and OSPAR convention

    International Nuclear Information System (INIS)

    2009-01-01

    The missions and the organisation of the OSPAR convention on protection of the NE Atlantic marine environment are given. The OSPAR strategy for the radioactive substances is stated. The results of work programme of the radioactive Substances committee are described and the consensus reached by contracting parties on the appropriate arrangements for this radionuclide is presented. (authors)

  12. Revised C++ coding conventions

    CERN Document Server

    Callot, O

    2001-01-01

    This document replaces the note LHCb 98-049 by Pavel Binko. After a few years of practice, some simplification and clarification of the rules was needed. As many more people have now some experience in writing C++ code, their opinion was also taken into account to get a commonly agreed set of conventions

  13. Global climate convention

    International Nuclear Information System (INIS)

    Simonis, U.E.

    1991-01-01

    The effort of negotiate a global convention on climate change is one of mankind's great endeavours - and a challenge to economists and development planners. The inherent linkages between climate and the habitability of the earth are increasingly well recognized, and a convention could help to ensure that conserving the environment and developing the economy in the future must go hand in hand. Due to growing environmental concern the United Nations General Assembly has set into motion an international negotiating process for a framework convention on climate change. One the major tasks in these negotiations is how to share the duties in reducing climate relevant gases, particularly carbon dioxide (CO 2 ), between the industrial and the developing countries. The results and proposals could be among the most far-reaching ever for socio-economic development, indeed for global security and survival itself. While the negotiations will be about climate and protection of the atmosphere, they will be on fundamental global changes in energy policies, forestry, transport, technology, and on development pathways with low greenhouse gas emissions. Some of these aspects of a climate convention, particularly the distributional options and consequences for the North-South relations, are addressed in this chapter. (orig.)

  14. Therapeutic Cancer Vaccines in Combination with Conventional Therapy

    DEFF Research Database (Denmark)

    Andersen, Mads Hald; Junker, N.; Ellebaek, E.

    2010-01-01

    The clinical efficacy of most therapeutic vaccines against cancer has not yet met its promise. Data are emerging that strongly support the notion that combining immunotherapy with conventional therapies, for example, radiation and chemotherapy may improve efficacy. In particular combination...

  15. Therapeutic cancer vaccines in combination with conventional therapy

    DEFF Research Database (Denmark)

    Andersen, Mads Hald; Junker, Niels; Ellebaek, Eva

    2010-01-01

    The clinical efficacy of most therapeutic vaccines against cancer has not yet met its promise. Data are emerging that strongly support the notion that combining immunotherapy with conventional therapies, for example, radiation and chemotherapy may improve efficacy. In particular combination...

  16. Electrical Conductivity.

    Science.gov (United States)

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  17. Conduct Disorder

    Science.gov (United States)

    ... objections runs away from home often truant from school Children who exhibit these behaviors should receive a comprehensive evaluation by an experience mental health professional. Many children with a conduct disorder may ...

  18. Asymptotic behavior of the motion of a viscous heat-conducting one-dimesional gas with radiation: the pure scattering case

    Czech Academy of Sciences Publication Activity Database

    Ducomet, B.; Nečasová, Šárka

    2013-01-01

    Roč. 11, č. 1 (2013), s. 1350003 ISSN 0219-5305 R&D Projects: GA ČR GA201/08/0012 Institutional research plan: CEZ:AV0Z10190503 Keywords : compressible fluids * viscous * conducting fluids Subject RIV: BA - General Mathematics Impact factor: 1.500, year: 2013 http://www.worldscientific.com/doi/abs/10.1142/S0219530513500036

  19. Establishment of a cohort for the long-term clinical follow-up with dose reconstruction under the joint medical research project conducted by Sasakawa Memorial Health Foundation (Japan) and the Research Institute of Radiation Hygiene (Russia)

    International Nuclear Information System (INIS)

    Konstantinov, Y.O.; Bruk, G.Y.; Ershov, E.B.

    2000-01-01

    The cohort of children in the western districts of the Bryansk Region of Russia exposed to radiation following the Chernobyl accident is described in this paper. The cohort was selected under the Joint Medical Research Project on Dosimetry Associated with the Chernobyl Accident conducted by Sasakawa Memorial Health Foundation (SMHF, Japan) and the Research Institute of Radiation Hygiene (RIRH, Russia). The subjects of the Research Project are those people residing in the most contaminated areas of Russia who was 0 to 10 years old at the time of exposure. At the moment the cohort comprises 1210 subjects, though this number may slightly decrease in course of a follow-up in view of migration of population. Most of cohort subjects were examined on their health status within the framework of the Chernobyl Sasakawa Health and Medical Cooperation Project (CSHMCP) from 1991-1996. In view of the main findings of studies in CSHMCP were thyroid abnormalities, selection of subjects was conducted on the basis of the credible estimates of thyroid dose. Preference for subjects to be included into the cohort was defined by the availability of health examination data from previous study (1991-1996) and individual dosimetry, environmental and social data that may prove useful for reconstruction of individual dose. The primary data analyzed for subjects selection are measurements of iodine-131 in the thyroid in May-June 1986, questionnaire data on individual food habits and early measurements of radiocesium in the body of subjects made by RIRH from May to September 1986. Plausible analytical models were applied to calculate thyroid dose from available data. Previously worked out methods of thyroid dose reconstruction using early measurement data of radiocesium content in the body and questionnaire data on individual consumption of locally produced milk were reevaluated. Basing on these analytical procedures, the individual thyroid dose was ascribed to each member of the cohort. The

  20. Radiation safety

    International Nuclear Information System (INIS)

    Jain, Priyanka

    2014-01-01

    The use of radiation sources is a privilege; in order to retain the privilege, all persons who use sources of radiation must follow policies and procedures for their safe and legal use. The purpose of this poster is to describe the policies and procedures of the Radiation Protection Program. Specific conditions of radiation safety require the establishment of peer committees to evaluate proposals for the use of radionuclides, the appointment of a radiation safety officer, and the implementation of a radiation safety program. In addition, the University and Medical Centre administrations have determined that the use of radiation producing machines and non-ionizing radiation sources shall be included in the radiation safety program. These Radiation Safety policies are intended to ensure that such use is in accordance with applicable State and Federal regulations and accepted standards as directed towards the protection of health and the minimization of hazard to life or property. It is the policy that all activities involving ionizing radiation or radiation emitting devices be conducted so as to keep hazards from radiation to a minimum. Persons involved in these activities are expected to comply fully with the Canadian Nuclear Safety Act and all it. The risk of prosecution by the Department of Health and Community Services exists if compliance with all applicable legislation is not fulfilled. (author)

  1. Conventions and Institutional Logics

    DEFF Research Database (Denmark)

    Westenholz, Ann

    Two theoretical approaches – Conventions and Institutional Logics – are brought together and the similarities and differences between the two are explored. It is not the intention to combine the approaches, but I would like to open both ‘boxes’ and make them available to each other with the purpose...... of creating a space for dialog. Both approaches were developed in the mid-1980s as a reaction to rational-choice economic theory and collectivistic sociological theory. These two theories were oversimplifying social life as being founded either in actor-micro level analyses or in structure-macro level...... analyses. The theoretical quest of both Conventions and Institutional Logics has been to understand the increasing indeterminacy, uncertainty and ambiguity in people’s lives where a sense of reality, of value, of moral, of feelings is not fixed. Both approaches have created new theoretical insights...

  2. Manado Convention Centre (Megastructures)

    OpenAIRE

    Anggianto, Rio M; Rate, Johannes Van

    2013-01-01

    Proyek Manado Convention Center ini pada dasarnya merupakan wadah atau sarana komunikasi antara dua pihak dengan penerapkan berbagai metode komunikasi langsung tatap muka baik itu dari perorangan terhadap kelompok, kelompok terhadap kelompok atau kelompok terhadap masyarakat. Dan pada era kini hal ini menjadi suatu kebutuhan yang dianganggap penting. Kota Manado seringkali menjadi tuan rumah suatu konverensi dengan jumlah peserta yang tergolong besar karena cakupannya sampai manca negara....

  3. The conventional quark picture

    International Nuclear Information System (INIS)

    Dalitz, R.H.

    1976-01-01

    For baryons, mesons and deep inelastic phenomena the ideas and the problems of the conventional quark picture are pointed out. All observed baryons fit in three SU(3)-multiplets which cluster into larger SU(6)-multiplets. No mesons are known which have quantum numbers inconsistent with belonging to a SU(3) nonet or octet. The deep inelastic phenomena are described in terms of six structure functions of the proton. (BJ) [de

  4. Radiation meter

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, P H

    1990-05-30

    Measuring means comprising first and second silicon PIN diode detectors both being covered with a thin layer of conducting material and the second detector being additionally covered with a relatively thick layer of material, the thickness being chosen such that beta radiation dose rate can be measured in beta radiation fields of high or medium energy, and in the presence of X and gamma radiation. (author). 2 figs.

  5. Conduct disorders

    NARCIS (Netherlands)

    Buitelaar, J.K.; Smeets, K.C.; Herpers, P.; Scheepers, F.; Glennon, J.; Rommelse, N.N.J.

    2013-01-01

    Conduct disorder (CD) is a frequently occurring psychiatric disorder characterized by a persistent pattern of aggressive and non-aggressive rule breaking antisocial behaviours that lead to considerable burden for the patients themselves, their family and society. This review paper updates diagnostic

  6. High Thermal Conductivity Composite Structures

    National Research Council Canada - National Science Library

    Bootle, John

    1999-01-01

    ... applications and space based radiators. The advantage of this material compared to competing materials that it can be used to fabricate high strength, high thermal conductivity, relatively thin structures less than 0.050" thick...

  7. Ionizing radiation

    Science.gov (United States)

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

    1975-01-01

    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.

  8. Comparison of digital radiography and apex locator with the conventional method in root length determination of primary teeth

    Directory of Open Access Journals (Sweden)

    I E Neena

    2011-01-01

    Full Text Available Aim: The purpose of this study was to compare the Working length in primary teeth endodontics using intra oral digital radiovisiography and apex locator with conventional method for accuracy. Materials and Methods: This in vivo study was conducted on 30 primary teeth which were indicated for pulpectomy in the patients of the age group of 5-11 years All experimental teeth had adequate remaining tooth structure for rubber dam isolation and radiographicaly visible canals. Endodontic treatment was required due to irreversible pulpitis or pulp necrosis. A standardized intraoral periapical radiograph of the tooth was taken using conventional method by paralleling technique. The distance between the source and the tooth, tooth and the films were standardized using X-ray positioning device. During the pulpectomy procedure, the working length was determined by digital radiograph and apex locator. The measurements were then compared with the conventional method of root canal measurement technique for accuracy Result: From the results obtained we can conclude that Working length determined in primary molars using digital radiography and Apex locator did not show any significant difference in the mean working length measurements when compared with the conventional radiographic method. Conclusions: Apex locator is comparable to conventional radiograph in determining the working length without radiation in the primary teeth. Intraoral digital radiography is the safest method in determining the working length with significant reduction in radiation exposure.Hence, both the techniques can be safely used as alternatives to conventional radiographic methods in determining working length in primary teeth.

  9. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  10. Digitization of conventional radiographs

    International Nuclear Information System (INIS)

    Wenz, W.; Buitrago-Tellez, C.; Blum, U.; Hauenstein, K.H.; Gufler, H.; Meyer, E.; Ruediger, K.

    1992-01-01

    The diagnostic value of a digitization system for analogue films based on a charge-coupled-device (CCD) scanner with adjustable resolution of 2.5 or 5 lp/mm was assessed. Some 110 skeletal radiographs, 50 contrast studies, including 25 of patients with Crohn's disease, and 70 abdominal plain films before and after successful lithotripsy for renal stones were digitized. Receiver operating characteristic (ROC) studies showed improved detection of cortical and trabecular defects with contrast-optimized digitized films. Edge enhancement algorithms yielded no additional information. Inflammatory lesions of Crohn's disease were detected equally well by conventional films and digitized images. A statistically significant improvement (p [de

  11. Conventional RF system design

    International Nuclear Information System (INIS)

    Puglisi, M.

    1994-01-01

    The design of a conventional RF system is always complex and must fit the needs of the particular machine for which it is planned. It follows that many different design criteria should be considered and analyzed, thus exceeding the narrow limits of a lecture. For this reason only the fundamental components of an RF system, including the generators, are considered in this short seminar. The most common formulas are simply presented in the text, while their derivations are shown in the appendices to facilitate, if desired, a more advanced level of understanding. (orig.)

  12. Conventional magnets. Pt. 1

    International Nuclear Information System (INIS)

    Marks, N.

    1994-01-01

    The design and construction of conventional, steel-cored, direct-current magnets are discussed. Laplace's equation and the associated cylindrical harmonic solutions in two dimensions are established. The equations are used to define the ideal pole shapes and required excitation for dipole, quadrupole and sextupole magnets. Standard magnet geometries are then considered and criteria determining the coil design are presented. The use of codes for predicting flux density distributions and the iterative techniques used for pole face design are then discussed. This includes a description of the use of two-dimensional codes to generate suitable magnet end geometries. Finally, standard constructional techniques for cores and coils are described. (orig.)

  13. Ionic conductivity in irradiated KCL

    International Nuclear Information System (INIS)

    Vignolo Rubio, J.

    1979-01-01

    The ionic conductivity of X and gamma irradiated KCl single crystals has been studied between room temperature and 600 deg C. The radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 deg C respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. Howewer, it has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that small radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (auth)

  14. Ionic conductivity in irradiated KCL

    International Nuclear Information System (INIS)

    Vignolo Rubio, J.

    1979-01-01

    The ionic conductivity of X and gamma irradiated KCL single crystals has been studied between room temperature and 600 degree centigree. the radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 degree centigree respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. However. It has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that, samples radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (Author)

  15. Conductivity Probe

    Science.gov (United States)

    2008-01-01

    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. Toxicological evaluation of natural rubber films from vulcanized latex by the conventional process and the alternative process with ionizing radiation; Avaliacao toxicologica de filmes de borracha natural obtidos do latex vulcanizado pelo processo convencional e pelo processo alternativo com radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Vania Elisabeth

    1997-07-01

    The industrial vulcanization of natural rubber latex (NRL) is made all over the world by conventional process using sulphur and heat but it can be made by an alternative process using ionizing radiation. In this research the NRL was tested by 13 physical, chemical and mechanical assays which showed its good quality. It was done a preliminary study of the toxicological properties of 4 natural rubber films obtained by casting process of NRL: one non vulcanized, other vulcanized by the conventional process and two vulcanized by the alternative process. In the alternative process the films were obtained by irradiation of NRL by gamma rays from the {sup 60} Co source at 250 kGy in the absence of sensitizer and irradiated NRL at 12 kGy in the presence of 4ph r of n-butyl acrylate / 0.2 phr of KOH. These vulcanization doses were determined from broken tensile strength. In the conventional process, sulphur vulcanized NRL was made using a classical composition. Another film was made with non vulcanized NRL. The preliminary evaluation of the toxicological properties was made from in vitro cytotoxicity and in vivo systemic toxicity assays. The LBN films vulcanized by the alternative process have less cytotoxicity than the NRL film vulcanized by the conventional process. The sensitized vulcanized films by gamma rays and non vulcanized films showed similar cytotoxicity while the vulcanized films without sensitizer showed a slight lower cytotoxicity. The non vulcanized NRL film and the NRL films vulcanized by the alternative process did not show toxic effects in the 72 hours period of the systemic toxicity assay. However the NRL film vulcanized with sulphur induced effects like allaying and motor in coordination on the animals treated with an oil extract at the fourth hour and recovering after that. The alternative process promoted lower toxic effects than conventional process because there was no toxic substances present. (author)

  17. Synchrotron-radiation research

    International Nuclear Information System (INIS)

    Cunningham, J.E.

    1982-01-01

    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

  18. IRSN methodological guide to conducting workplace studies in compliance with French regulations

    International Nuclear Information System (INIS)

    Donadille, L.; Rehel, J. L.; Deligne, J. M.; Queinnec, F.; Aubert, B.; Bottollier-Depois, J. F.; Clairand, I.; Jourdain, J. R.; Rannou, A.

    2007-01-01

    Under French regulations governing radiation protection of workers, dosimetric workplace studies are mandatory. However, their practical implementation is not described. IRSN has developed a guide to help stakeholders in the radiological protection of workers conduct such studies. It proposes a general methodology applicable to most cases and 'workplace sheets', which apply this methodology to specific occupational settings. At present, two sheets are available: Conventional radiology and interventional radiology. (authors)

  19. Dose in conventional radiography

    International Nuclear Information System (INIS)

    Acuna D, E.; Padilla R, Z. P.; Escareno J, E.; Vega C, H. R.

    2011-10-01

    It has been pointed out that medical exposures are the most significant sources of exposure to ionizing radiation for the general population. Inside the medical exposures the most important is the X-ray use for diagnosis, which is by far the largest contribution to the average dose received by the population. From all studies performed in radiology the chest radiography is the most abundant. In an X-ray machine, voltage and current are combined to obtain a good image and a reduce dose, however due to the workload in a radiology service individual dose is not monitored. In order to evaluate the dose due to chest radiography in this work a plate phantom was built according to the ISO recommendations using methylmethacrylate walls and water. The phantom was used in the Imaging department of the Zacatecas General Hospital as a radiology patient asking for a chest study; using thermoluminescent dosimeters, TLD 100 the kerma at the surface entrance was determined. (Author)

  20. Conduct disorders.

    Science.gov (United States)

    Buitelaar, Jan K; Smeets, Kirsten C; Herpers, Pierre; Scheepers, Floor; Glennon, Jeffrey; Rommelse, Nanda N J

    2013-02-01

    Conduct disorder (CD) is a frequently occurring psychiatric disorder characterized by a persistent pattern of aggressive and non-aggressive rule breaking antisocial behaviours that lead to considerable burden for the patients themselves, their family and society. This review paper updates diagnostic and therapeutic approaches to CD in the light of the forthcoming DSM-5 definition. The diagnostic criteria for CD will remain unchanged in DSM-5, but the introduction of a specifier of CD with a callous-unemotional (CU) presentation is new. Linked to this, we discuss the pros and cons of various other ways to subtype aggression/CD symptoms. Existing guidelines for CD are, with few exceptions, already of a relatively older date and emphasize that clinical assessment should be systematic and comprehensive and based on a multi-informant approach. Non-medical psychosocial interventions are recommended as the first option for the treatment of CD. There is a role for medication in the treatment of comorbid syndromes and/or in case of insufficient response to psychosocial interventions and severe and dangerous aggressive and violent behaviours.

  1. Efforts for improvement in radiotherapy of cancer using metronidazole with special regard to head and neck. Part of a coordinated programme on improvement of cancer therapy by the combination treatment of conventional radiation and physical and chemical means

    International Nuclear Information System (INIS)

    Patricio, M.B.

    1984-03-01

    A great effort has been expended in the search for means which would be of immediate practical interest to the radiotherapist in order to achieve improvement of the result of cancer treatment. These means include modifiers which are sensitizers to potentiate radiation effects on tumour cells without affecting normal tissue. We started a controlled therapeutic trial on locally advanced head and neck carcinomas using metronidazole. There was good tolerance to metronidazole although improvement of local tumour control with this drug was not observed. We also observed that irradiation with fractions daily gave a better tumour control than single fractions a day

  2. ESD and the Rio Conventions

    Science.gov (United States)

    Sarabhai, Kartikeya V.; Ravindranath, Shailaja; Schwarz, Rixa; Vyas, Purvi

    2012-01-01

    Chapter 36 of Agenda 21, a key document of the 1992 Earth Summit, emphasised reorienting education towards sustainable development. While two of the Rio conventions, the Convention on Biological Diversity (CBD) and the United Nations Framework Convention on Climate Change (UNFCCC), developed communication, education and public awareness (CEPA)…

  3. Ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The law covering ionising radiation in Luxembourg is summarised under the headings: introduction (the outline law of 25 March 1963, and the Grand-Ducal Decree of 8 February 1967); the control of establishments (the authorisation procedure; emergency measures, suspension and withdrawal of the authorisation; alterations to the establishment); the importation, distribution and transit of radioactive substances; the transport of radioactive substances; the protection and safety of the population as a whole; sanctions; international conventions. (U.K.)

  4. Convention on nuclear safety. Final act

    International Nuclear Information System (INIS)

    1994-01-01

    The Diplomatic Conference, which was convened by the International Atomic Energy Agency at its Headquarters from 14 to 17 June 1994, adopted the Convention on Nuclear Safety reproduced in document INFCIRC/449 and the Final Act of the Conference. The text of the Final Act of the Conference, including an annexed document entitled ''Some clarification with respect to procedural and financial arrangements, national reports, and the conduct of review meetings, envisaged in the Convention on Nuclear Safety'', is reproduced in the Attachment hereto for the information of all Member States

  5. Conducting Polymer Based Nanobiosensors

    Directory of Open Access Journals (Sweden)

    Chul Soon Park

    2016-06-01

    Full Text Available In recent years, conducting polymer (CP nanomaterials have been used in a variety of fields, such as in energy, environmental, and biomedical applications, owing to their outstanding chemical and physical properties compared to conventional metal materials. In particular, nanobiosensors based on CP nanomaterials exhibit excellent performance sensing target molecules. The performance of CP nanobiosensors varies based on their size, shape, conductivity, and morphology, among other characteristics. Therefore, in this review, we provide an overview of the techniques commonly used to fabricate novel CP nanomaterials and their biosensor applications, including aptasensors, field-effect transistor (FET biosensors, human sense mimicking biosensors, and immunoassays. We also discuss prospects for state-of-the-art nanobiosensors using CP nanomaterials by focusing on strategies to overcome the current limitations.

  6. Biological effects of particle radiation

    International Nuclear Information System (INIS)

    Sakamoto, Kiyohiko

    1988-01-01

    Conventional radiations such as photons, gamma rays or electrons show several physical or biological disadvantages to bring tumors to cure, therefore, more and more attentions is being paid to new modalitie such as fast neutrons, protons, negative pions and heavy ions, which are expected to overcome some of the defects of the conventional radiations. Except for fast neutrons, these particle radiations show excellet physical dose localization in tissue, moreover, in terms of biological effects, they demonstrate several features compared to conventional radiations, namely low oxygen enhancement ratio, high value of relative biological effectiveness, smaller cellular recovery, larger therapeutic gain factor and less cell cycle dependency in radiation sensitivity. In present paper the biological effects of particle radiations are shown comparing to the effects of conventional radiations. (author)

  7. CFD analysis of heat transfer performance of graphene based hybrid nanofluid in radiators

    Science.gov (United States)

    Bharadwaj, Bharath R.; Sanketh Mogeraya, K.; Manjunath, D. M.; Rao Ponangi, Babu; Rajendra Prasad, K. S.; Krishna, V.

    2018-04-01

    For Improved performance of an automobile engine, Cooling systems are one of the critical systems that need attention. With increased capacity to carry away large amounts of wasted heat, performance of an engine is increased. Current research on Nano-fluids suggests that they offer higher heat transfer rate compared to that of conventional coolants. Hence this project seeks to investigate the use of hybrid-nanofluids in radiators so as to increase its heat transfer performance. Carboxyl Graphene and Graphene Oxide based nanoparticles were selected due to the very high thermal conductivity of Graphene. System Analysis of the radiator was performed by considering a small part of the whole automobile radiator modelled using SEIMENS NX. CFD analysis was conducted using ANSYS FLUENT® for the nanofluid defined and the increase in effectiveness was compared to that of conventional coolants. Usage of such nanofluids for a fixed cooling requirement in the future can lead to significant downsizing of the radiator.

  8. Adding intelligence to conventional industrial robots

    International Nuclear Information System (INIS)

    Harrigan, R.W.

    1993-01-01

    Remote systems are needed to accomplish many tasks such as the clean up of waste sites in which the exposure of personnel to radiation, chemical, explosive, and other hazardous constituents is unacceptable. In addition, hazardous operations which in the past have been completed by technicians are under increased scrutiny due to high costs and low productivity associated with providing protective clothing and environments. Traditional remote operations have, unfortunately, proven to also have very low productivity when compare with unencumbered human operators. However, recent advances in the integration of sensors and computing into the control of conventional remotely operated industrial equipment has shown great promise for providing systems capable of solving difficult problems

  9. Conducted interference on smart meters

    NARCIS (Netherlands)

    Keyer, Cornelis H.A.; Leferink, Frank

    2017-01-01

    The increasing conducted interference caused by modern electronic equipment is causing more problems for electronic, or static, energy meters. These meters are called smart meters when equipped with a communication link, and are replacing the conventional electromechanical meters. It is known that

  10. Compact Ignition Tokamak conventional facilities optimization

    International Nuclear Information System (INIS)

    Commander, J.C.; Spang, N.W.

    1987-01-01

    A high-field ignition machine with liquid-nitrogen-cooled copper coils, designated the Compact Ignition Tokamak (CIT), is proposed for the next phase of the United States magnetically confined fusion program. A team of national laboratory, university, and industrial participants completed the conceptual design for the CIT machine, support systems and conventional facilities. Following conceptual design, optimization studies were conducted with the goal of improving machine performance, support systems design, and conventional facilities configuration. This paper deals primarily with the conceptual design configuration of the CIT conventional facilities, the changes that evolved during optimization studies, and the revised changes resulting from functional and operational requirements (F and ORs). The CIT conventional facilities conceptual design is based on two premises: (1) satisfaction of the F and ORs developed in the CIT building and utilities requirements document, and (2) the assumption that the CIT project will be sited at the Princeton Plasma Physics Laboratory (PPPL) in order that maximum utilization can be made of existing Tokamak Fusion Test Reactor (TFTR) buildings and utilities. The optimization studies required reevaluation of the F and ORs and a second look at TFTR buildings and utilities. Some of the high-cost-impact optimization studies are discussed, including the evaluation criteria for a change from the conceptual design baseline configuration. The revised conventional facilities configuration are described and the estimated cost impact is summarized

  11. Application of the Aarhus Convention

    Directory of Open Access Journals (Sweden)

    Tubić Bojan

    2011-01-01

    Full Text Available Convention on access to information, public participation in decision-making and access to justice in environmental matters (Aarhus Convention has been adopted in 1998 and entered into force three years later. It envisages three elements for strengthening democratic procedures in decision-making: access to information, public participation and access to justice. At the first meeting of the Member States the Aarhus Convention Compliance Committee was founded. The European Union is a party of the Convention and it has implemented the provisions in its legal order. After entering into force of the Convention, several Directives that regulate these issues in the EU have been enacted. Republic of Serbia has ratified the Convention in 2009 and it is currently in the process of its implementation by involving private subjects in decision-making on environmental issues.

  12. The change of radiation doses to the patient when switching from conventional technique to digital technique without films in barium enema and IVU examinations. Final report SSI research project P933

    CERN Document Server

    Sjöholm, B

    2003-01-01

    X-ray examinations of the colon (barium enema) and the kidneys (IVU) are combined with rather high radiation doses to the patients when using analogue technique with film-screen systems. It is therefore of great interest to see if the change from analogue to digital technique involves a reduction of doses. Barium enema and IVU examinations were monitored with DAP-meters before and after the X-ray department changed to digital techniques. For IVU also the change from storage phosphor plates to a Direct Digital detector is included. The study comprises between 53 and 87 patients for each modality of the two examinations. A considerable dose reduction was observed. In barium enema the overview images with large field sizes were omitted when using digital technique. On the other hand the number of spot images was increased from 6 to 22. The fluoroscopy time was increased from 4 minutes to 6 minutes. The DAP value was reduced from 54,3 Gy cm sup 2 to 21,9 Gy cm sup 2. For IVU a dose reduction from 44,5 Gy cm sup 2...

  13. Modification of radiosensitivity of mammalian cells by means of hyperthermia and chemical agent. Coordinated programme on improvement of cancer therapy by the combination of treatment by conventional radiation and physical or chemical means

    International Nuclear Information System (INIS)

    Djordjevic, O.

    1984-11-01

    The effect of the treatment of the cultured mammalian cells with a relatively new anti-cancer drug teniposide (VM26), radiation (4 Gy), hyperthermia (42 deg. C and 45 deg. C) and caffeine, in various combinations, has been studied. The following conclusions can be drawn from the data obtained: The cultured mammalian cells respond to the anti-cancer drug VM26 treatment in a dose and time dependent manner. Significant potentiation of cell killing was demonstrated when they are exposed simultaneously to VM26 and hyperthermia. Post-treatment incubation of the cells in non-toxic concentration of caffeine (2 mM) has produced a marked potentiation of the lethal effect, indicating that caffeine interferes with the repair processes in these cells. Combination of VM26, hyperthermia and caffeine produced a maximum killing effect compared to VM26 treatment only. When the cells are exposed to initial (90 min. at 42 deg. C or 40 min. at 45 deg. C) and subsequent hyperthermia (60 min. at 42 deg. C or 60 min. at 45 deg. C) the thermotolerance will develop depending on the degree of initial and subsequent temperature. The combination of hyperthermia with irradiation results in a potentiation of the effect of treatment compared to the treatment with only irradiation or hyperthermia. Maximum killing of the cells will be obtained when irradiation is applied immediately after hyperthermia. The results obtained should be regarded as useful in case of clinical application of the tested agents

  14. Understanding the conventional arms trade

    Science.gov (United States)

    Stohl, Rachel

    2017-11-01

    The global conventional arms trade is worth tens of billions of dollars every year and is engaged in by every country in the world. Yet, it is often difficult to control the legal trade in conventional arms and there is a thriving illicit market, willing to arm unscrupulous regimes and nefarious non-state actors. This chapter examines the international conventional arms trade, the range of tools that have been used to control it, and challenges to these international regimes.

  15. Comparison of Conventional and Semi-Conventional Management ...

    African Journals Online (AJOL)

    Comparison of Conventional and Semi-Conventional Management Systems on the Performance and Carcass Yield of Broiler Chickens. ... TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... Journal Home > Vol 20, No 1 (2018) >. Log in or ...

  16. Prospective ECG-triggered axial CT at 140-kV tube voltage improves coronary in-stent restenosis visibility at a lower radiation dose compared with conventional retrospective ECG-gated helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Horiguchi, Jun; Fujioka, Chikako; Kiguchi, Masao; Kohno, Shingo [Hiroshima University Hospital, Department of Clinical Radiology, Hiroshima (Japan); Yamamoto, Hideya; Kitagawa, Toshiro [Hiroshima University, Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima (Japan); Ito, Katsuhide [Hiroshima University, Department of Radiology, Division of Medical Intelligence and Informatics, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima (Japan)

    2009-10-15

    The purpose of this study was to compare coronary 64-slice CT angiography (CTA) protocols, specifically prospective electrocardiograph (ECG)-triggered and retrospective ECG-gated CT acquisition performed using a tube voltage of 140 kV and 120 kV, regarding intracoronary stent imaging. Coronary artery stents (n=12) with artificial in-stent restenosis (50% luminal reduction, 40 HU) on a cardiac phantom were examined by CT at heart rates of 50-75 beats per minute (bpm). The subjective visibility of in-stent restenosis was evaluated with a three-point scale (1 clearly visible, 2 visible, and 3 not visible), and artificial lumen narrowing [(inner stent diameter - measured lumen diameter)/inner stent diameter], lumen attenuation increase ratio [(in-stent attenuation - coronary lumen attenuation)/coronary lumen attenuation], and signal-to-noise ratio of in-stent lumen were determined. The effective dose was estimated. The artificial lumen narrowing (mean 43%), the increase of lumen attenuation (mean 46%), and signal-to-noise ratio (mean 7.8) were not different between CT acquisitions (p=0.12-0.91). However, the visibility scores of in-stent restenosis were different (p<0.05) between ECG-gated CTA techniques: (a) 140-kV prospective (effective dose 4.6 mSv), 1.6; (b) 120-kV prospective (3.3 mSv), 1.8; (c) 140-kV retrospective (16.4-18.8 mSv), 1.9; and (d) 120-kV retrospective (11.0-13.4 mSv), 1.9. Thus, 140-kV prospective ECG-triggered CTA improves coronary in-stent restenosis visibility at a lower radiation dose compared with retrospective ECG-gated CTA. (orig.)

  17. Defect Detectability Improvement for Conventional Friction Stir Welds

    Science.gov (United States)

    Hill, Chris

    2013-01-01

    This research was conducted to evaluate the effects of defect detectability via phased array ultrasound technology in conventional friction stir welds by comparing conventionally prepped post weld surfaces to a machined surface finish. A machined surface is hypothesized to improve defect detectability and increase material strength.

  18. Interactive Translation Prediction versus Conventional Post-editing in Practice

    DEFF Research Database (Denmark)

    Sanchis-Trilles, German; Alabau, Vicent; Buck, Christian

    2014-01-01

    We conducted a field trial in computer-assisted professional translation to compare Interactive Translation Prediction (ITP) against conventional post- editing (PE) of machine translation (MT) output. In contrast to the conventional PE set-up, where an MT system first produces a static translatio...

  19. A comparative entropy based analysis of Cu and Fe3O4/methanol Powell-Eyring nanofluid in solar thermal collectors subjected to thermal radiation, variable thermal conductivity and impact of different nanoparticles shape

    Science.gov (United States)

    Jamshed, Wasim; Aziz, Asim

    2018-06-01

    The efficiency of any nanofluid based thermal solar system depend on the thermophysical properties of the operating fluids, type and shape of nanoparticles, nanoparticles volumetric concentration in the base fluid and the geometry/length of the system in which fluid is flowing. The recent research in the field of thermal solar energy has been focused to increase the efficiency of solar thermal collector systems. In the present research a simplified mathematical model is studied for inclusion in the thermal solar systems with the aim to improve the overall efficiency of the system. The flow of Powell-Eyring nanofluid is induced by non-uniform stretching of porous horizontal surface with fluid occupying a space over the surface. The thermal conductivity of the nanofluid is to vary as a linear function of temperature and the thermal radiation is to travel a short distance in the optically thick nanofluid. Numerical scheme of Keller box is implemented on the system of nonlinear ordinary differential equations, which are resultant after application of similarity transformation to governing nonlinear partial differential equations. The impact of non dimensional physical parameters appearing in the system have been observed on velocity and temperature profiles along with the entropy of the system. The velocity gradient (skin friction coefficient) and the strength of convective heat exchange (Nusselt number) are also investigated.

  20. Towards a Theory of Convention

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg

    2006-01-01

    Some thirty years ago Lewis published his Convention: A philosophical Study (Lewis 1969). Besides exciting the logical community by providing the seminal analysis work on common knowledge, it also laid the foundations for the formal approach to the study of social conventions by means of game the...

  1. Roselle improvement through conventional and mutation breeding

    International Nuclear Information System (INIS)

    Mohamad Omar; Mohd Nazir Basiran; Azhar Mohamad; Shuhaimi Shamsuddin

    2002-01-01

    Roselle (Hibiscus sabdariffa L.) from Malvaceae family is relatively a new crop in Malaysia. The origin is not fully known but believed to be from West Africa, although the plant is found native from India to Malaysia. The calyxes, stems and leaves are acid and closely resemble the cranberry (Vaccinium spp.) in flavour. Anthocyanins, which are now receiving a growing importance as natural food colorant, are responsible for the red to purple color of the calyx and other parts of the plant. The calyxes from the flowers are processed to produce juice for drink containing very high vitamin C (ascorbic acid), and also into jam, jelly and dried products. Interestingly, many other parts of the plant are also claimed to have various medicinal values. Presently, roselle is planted in Terengganu (175 ha in 2002) on bris soils, but its planting has spread to some parts of Kelantan, Pahang, Johor and also Sarawak. The number of roselle varieties available for planting is very limited; however, the effort carried out for roselle improvement thus far is equally very limited. There has been very little serious conventional breeding attempted, although varietal evaluation has had been carried out, particularly in form of agronomic trials. Since 1999, several studies on induced mutations have been attempted at UKM. A preliminary polyploidization study was conducted to determine the effects of colchicine concentrations of 0%, 0.04%, 0.08%, 0.12% and 0.16% and soaking times of 2 and 4 hours at room temperature (30 degree C) on 2-day old germinated seeds on morpho-agronomic traits (e.g. number of branches, internode length, leaf length, leaf width, number of flowers and days to flowering), ploidy level and pollen grain size in treated and also derived generations. Flow cytometric analyses of nuclear DNA AT content of leaf samples using LB01 lysis buffer and DNA specific fluorochrome DAPI (4',6-diamidino-2-phenylindole) staining were carried out using a flow cytometer at MINT, Bangi

  2. Convention on nuclear safety. Questions posted to Switzerland in 2008

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    nuclear safety for each NPP based on the analysis of events, inspection results and operator licensing reviews. The assurance of low radiation doses to both NPP workers and the general public is an additional goal that is directly associated with the safe operation of NPPs. In case of an accident in a nuclear installation, contingency plans are in place and are continually updated. Emergency drills are conducted at regular intervals. The international alerting system is also in a mature stage. This report on 2008 presents the 91 questions asked by the reviewers of the Swiss report and the answers provided by the Swiss delegation represented by the Swiss Federal Nuclear Safety Inspectorate (ENSI)

  3. Convention on nuclear safety. Questions posted to Switzerland in 2008

    International Nuclear Information System (INIS)

    2008-01-01

    for each NPP based on the analysis of events, inspection results and operator licensing reviews. The assurance of low radiation doses to both NPP workers and the general public is an additional goal that is directly associated with the safe operation of NPPs. In case of an accident in a nuclear installation, contingency plans are in place and are continually updated. Emergency drills are conducted at regular intervals. The international alerting system is also in a mature stage. This report on 2008 presents the 91 questions asked by the reviewers of the Swiss report and the answers provided by the Swiss delegation represented by the Swiss Federal Nuclear Safety Inspectorate (ENSI)

  4. Industrial processing with radiation

    International Nuclear Information System (INIS)

    Du Plessis, T.A.

    1976-01-01

    The use of large isotopic radiation sources and accelerators in industry is reviewed. The advantages of various sources of ionizing radiation are indicated, and the development and present status of radiation technology are briefly described. Attention is given to the role played by radiation processing in the cross-linking of polymers as applied to cable insulation, artificial limbs and packaging materials, as well as for improving natural rubber. In addition, attention is given to radiation as a possible means of synthesizing polymers, of hardening non-conventional coatings and of manufacturing polymer-wood composites, thereby improving the properties of softwoods. The possibility of improving natural fibres by means of radiation is discussed, and attention is given to the important role already played by radiation in the sterilization of medical products. Finally, reference is made to the role which radiation can play in reducing food spoilage, as well as in making sewage sludge suitable for agricultural purposes [af

  5. Survey of international personnel radiation dosimetry programs

    International Nuclear Information System (INIS)

    Swaja, R.E.

    1985-04-01

    In September of 1983, a mail survey was conducted to determine the status of external personnel gamma and neutron radiation dosimetry programs at international agencies. A total of 130 agencies participated in this study including military, regulatory, university, hospital, laboratory, and utility facilities. Information concerning basic dosimeter types, calibration sources, calibration phantoms, corrections to dosimeter responses, evaluating agencies, dose equivalent reporting conventions, ranges of typical or expected dose equivalents, and degree of satisfaction with existing systems was obtained for the gamma and neutron personnel monitoring programs at responding agencies. Results of this survey indicate that to provide the best possible occupational radiation monitoring programs and to improve dosimetry accuracy in performance studies, facility dosimetrists, regulatory and standards agencies, and research laboratories must act within their areas of responsibility to become familiar with their radiation monitoring systems, establish common reporting guidelines and performance standards, and provide opportunities for dosimetry testing and evaluation. 14 references, 10 tables

  6. Thermal conduction and gravitational collapse

    International Nuclear Information System (INIS)

    Herrera, L.; Jimenez, J.; Esculpi, M.

    1987-01-01

    A method used to study the evolution of radiating spheres, reported some years ago by Herrera, Jimenez, and Ruggeri, is extended to the case in which thermal conduction within the sphere is taken into account. By means of an explicit example it is shown that heat flow, if present, may play an important role, affecting the final outcome of collapse

  7. Revision of the Paris Convention and the Brussels Supplementary Convention

    International Nuclear Information System (INIS)

    Busekist, Otto von.

    1977-01-01

    The Paris Convention and the Brussels Supplementary Convention have in substance remained unchanged since their adoption in 1960 and 1963, respectively. During that period, nuclear industry and technology have developed considerably while the financial and monetary bases of the Conventions have been shattered. The amounts of liability and compensation have been eroded by inflation, and the gold-based unit of account in which these amounts are expressed has lost its original meaning after the abolition of the official gold price. The question of revising the Conventions, in particular of raising those amounts and of replacing the unit of account, is therefore being studied by the Group of Governmental Experts on Third party Liability in the Field of Nuclear Energy of the OECD Nuclear Energy Agency. (auth.) [fr

  8. National Inspection Program of Conventional Industries: implement, results and evaluation- 1981 to 1984

    International Nuclear Information System (INIS)

    Gloria, M.B.; Silva, F.C.A. da; Leocadio, J.C.; Valenca, J.R.M.; Farias, C.

    1986-01-01

    The methodology adopted by the Instutute of Radiation Protection and Dosimetry to implement the National Inspection Program of Conventional Industries is present. This methodology is being efficient because of many technical and administrative problems about radiation protection could be identified, analysed and solved gradually. Many workplaces of gammagraphy are analysed in relation to radiation safety, geographyc localization and social-economics aspects. (Author) [pt

  9. Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

    Science.gov (United States)

    Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

    2017-08-01

    The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

  10. The nuclear liability conventions revised

    International Nuclear Information System (INIS)

    Reyners, P.

    2004-01-01

    The signature on 12 February 2004 of the Protocols amending respectively the 1960 Paris Convention and the 1963 Brussels Supplementary Convention was the second step of the process of modernisation of the international nuclear liability regime after the adoption in September 1997 of a Protocol revising the 1963 Vienna Convention and of a new Convention on Supplementary Compensation for Nuclear Damage. The common objective of the new instruments is to provide more funds to compensate a larger number of potential victims in respect of a broader range of damage. Another goal of the revision exercise was to maintain the compatibility between the Paris and Vienna based systems, a commitment enshrined in the 1988 Joint Protocol, as well as to ascertain that Paris/Brussels countries could also become a Party to the Convention on Supplementary Compensation. However, while generally consistent vis a vis the Joint Protocol, the provisions of the Paris and Vienna Conventions, as revised, differ on some significant aspects. Another remaining issue is whether the improved international nuclear liability regime will succeed in attracting in the future a larger number of countries, particularly outside Europe, and will so become truly universal. Therefore, the need for international co-operation to address these issues, to facilitate the adoption of new implementing legislation and to ensure that this special regime keeps abreast of economic and technological developments, is in no way diminished after the revision of the Conventions.(author)

  11. The evolution of development conventions

    Directory of Open Access Journals (Sweden)

    Fabio Stefano Erber

    2012-04-01

    Full Text Available This paper presents a conceptual view on development and its translation into development policies. It argues that society's perception of development is structured by conventions, which provide a view of the past, present and future and, at the same time, allows a certain hierarchy of problems and solutions to such problems. The prevalence of a specific convention depends on the international conditions faced by this society and on the distribution of economic and political power within that society. Therefore, in complex societies there is always a struggle for hegemony between competing development conventions.

  12. Accounting conventions for discounting in the optimisation of protection

    International Nuclear Information System (INIS)

    Fleishman, A.B.

    1983-01-01

    Some of the implications which arise from the use of accounting conventions in the cost benefit framework for optimization of radiation protection are briefly examined. Some accounting techniques which appear not to discount future detriment costs do so, in fact, at a hidden fixed rate; others give a free choice over whether to discount and at what rate. (U.K.)

  13. Are nuclear ships environmentally safer than conventionally powered ships

    International Nuclear Information System (INIS)

    Bone, C.A.; Molgaard, C.A.; Helmkamp, J.C.; Golbeck, A.L.

    1988-01-01

    An epidemiologic analysis was conducted to determine if risk of hospitalization varied by age, ship type, or occupation between nuclear and conventional powered ship crews in the U.S. Navy. Study cohorts consisted of all male enlisted personnel who served exclusively aboard conventional or nuclear powered aircraft carriers and cruisers during the years 1975-1979; cases were those men hospitalized during this period (N = 48,242). Conventional ship personnel showed significantly elevated rates of injury and disease when compared to nuclear ship personnel. The largest relative risks by age occurred for conventional ship crewmen less than 30 years old. Seaman, logistics (supply), and healthcare personnel serving aboard conventional ships comprised the occupational groups exhibiting the highest hospitalization rate differentials. The results strongly suggest that nuclear ships provide a healthier, safer working and living environment than conventional ships

  14. Evolutionary Games and Social Conventions

    DEFF Research Database (Denmark)

    Hansen, Pelle Guldborg

    2007-01-01

    -defined metaphors of individual learning and social imitation processes, from which a revised theory of convention may be erected (see Sugden 2004, Binmore 1993 and Young 1998). This paper makes a general argument in support of the evolutionary turn in the theory of convention by a progressive exposition of its...... in Aumann (1976) and which, together with the assumptions of perfect rationality, came to be defining of classical game theory. However, classical game theory is currently undergoing severe crisis as a tool for exploring social phenomena; a crisis emerging from the problem of equilibrium selection around......Some thirty years ago Lewis published his Convention: A Philosophical Study (Lewis, 2002). This laid the foundation for a game-theoretic approach to social conventions, but became more famously known for its seminal analysis of common knowledge; the concept receiving its canonical analysis...

  15. Radiation sterilization

    International Nuclear Information System (INIS)

    Jacobs, G.P.

    1989-01-01

    In view of the application of ionizing radiation to sterilize pharmaceutical products, and the particular advantages of using this mode of sterilization for powders for injection, which cannot be sterilized by more conventional methods, it is important to recognise the possibility of modification of radiation response of bacteria when in close contact with various drug powders. For this study, bacterial spores, which lend themselves to dessication, and which can be dried onto an inert powder matrix, were chosen as the test system. The results of this work indicate that the additives tested have a modest protective effect on the spores. However, when considering a bacterial inactivation for sterilization purposes of between six and ten orders of magnitude, that is, a desired sterility assurance level of an expected maximum probability of a product item being non-sterile of 10 -6 , then the slight protective effect observed in this study approaches insignificance

  16. Paris convention - Decisions, recommendations, interpretations

    International Nuclear Information System (INIS)

    1990-01-01

    This booklet is published in a single edition in English and French. It contains decisions, recommendations and interpretations concerning the 1960 Paris Convention on Third Party Liability in the Field of Nuclear Energy adopted by the OECD Steering Committee and the OECD Council. All the instruments are set out according to the Article of the Convention to which they relate and explanatory notes are added where necessary [fr

  17. Tolerance of the brain and spinal cord to conventional irradiation

    International Nuclear Information System (INIS)

    Leibel, S.A.; Sheline, G.E.

    1991-01-01

    In this paper, the authors discuss the clinical features and time-dose relations associated with radiation injury of the brain and spinal cord. Limits of radiation tolerance have not been well defined. In general, the literature on central nervous system (CNS) injury is anecdotal and incomplete. Relevant information such as total dose at the site of injury, size and number of treatment fractions, overall treatment time, radiation field arrangement, and volume treated is often omitted. Therefore, it is difficult to formulate firm conclusions regarding the risk of radiation injury and its association with any given set of therapeutic approaches and patient characteristics. The material presented in this chapter is based on conventional photon and gamma irradiation, and does not apply to large single dose fractions used in stereotaxic small-field external irradiation (radiosurgery) or to other forms of ionizing radiation such as neutrons or heavy particles

  18. The impact of conventional and novel metaphor in news on issue viewpoint

    NARCIS (Netherlands)

    Boeynaems, A.; Burgers, C.; Konijn, E.A.; Steen, G.J.

    2017-01-01

    Metaphors are often used to frame news. Different types of metaphor (conventional, novel) can affect issue viewpoint via different underlying mechanisms (cognitive and affective text perception). We conducted a single-factor (type of expression: conventional metaphor, novel metaphor, nonmetaphorical

  19. The impact of conventional and novel metaphors in news on issue viewpoint

    NARCIS (Netherlands)

    Boeynaems, A.; Burgers, C.F.; Konijn, E.A.; Steen, G.J.

    2017-01-01

    Metaphors are often used to frame news. Different types of metaphor (conventional, novel) can affect issue viewpoint via different underlying mechanisms (cognitive and affective text perception). We conducted a single-factor (type of expression: conventional metaphor, novel metaphor, nonmetaphorical

  20. Radiation shielding plate

    International Nuclear Information System (INIS)

    Kobayashi, Torakichi; Sugawara, Takeo.

    1983-01-01

    Purpose: To reduce the weight and stabilize the configuration of a radiation shielding plate which is used in close contact with an object to be irradiated with radiation rays. Constitution: The radiation shielding plate comprises a substrate made of lead glass and a metallic lead coating on the surface of the substrate by means of plating, vapor deposition or the like. Apertures for permeating radiation rays are formed to the radiation shielding plate. Since the shielding plate is based on a lead glass plate, a sufficient mechanical strength can be obtained with a thinner structure as compared with the conventional plate made of metallic lead. Accordingly, if the shielding plate is disposed on a soft object to be irradiated with radiation rays, the object and the plate itself less deform to obtain a radiation irradiation pattern with distinct edges. (Moriyama, K.)

  1. Industrial applications of radiations

    International Nuclear Information System (INIS)

    Gallien, C.L.

    1988-01-01

    Radiation processing refers to the use of ionizing radiation to initiate chemical or biological changes in various materials as a substitute for conventional thermal or chemical processes. The method was inroduced in the industrial field 30 years ago and is now being widely used for numerous applications, among which industrial radiography, polymer modification, sterilization or decontamination, and food preservation. Both electron beam accelerators and gamma sources can be used, depending mainly of the amount of radiation and the penetration required. Radiation processing presents an increasing economical importance; in 1986 the market volume of ionized products ranged 3 billion $ [fr

  2. Radiation shielding

    International Nuclear Information System (INIS)

    Aitken, D.

    1979-01-01

    Shields for equipment in which ionising radiation is associated with high electrical gradients, for example X-ray tubes and particle accelerators, incorporate a radiation-absorbing metal, as such or as a compound, and are electrically non-conducting and can be placed in the high electrical gradient region of the equipment. Substances disclosed include dispersions of lead, tungsten, uranium or oxides of these in acrylics polyesters, PVC, ABS, polyamides, PTFE, epoxy resins, glass or ceramics. The material used may constitute an evacuable enclosure of the equipment or may be an external shield thereof. (U.K.)

  3. Biomedical applications of ionizing radiation

    International Nuclear Information System (INIS)

    Rosiak, J.M.; Pietrzak, M.

    1997-01-01

    Application of ionizing radiation for sterilization of medical devices, hygienization of cosmetics products as well as formation of biomaterials have been discussed. The advantages of radiation sterilization over the conventional methods have been indicated. The properties of modern biomaterials, hydrogels as well as some ways of their formation and modification under action of ionizing radiation were presented. Some commercial biomaterials of this kind produced in accordance with original Polish methods by means of radiation technique have been pointed out. (author)

  4. Conventional radiology: fixed installations in medical environment

    International Nuclear Information System (INIS)

    2010-01-01

    This document presents the different procedures, the different types of specific hazards, the analysis of risks, their assessment and the preventive methods with regard to radioprotection in the case of fixed conventional radiology equipment in medical environment. It indicates and describes the concerned personnel, the course of procedures, the hazards, the identification of the risk associated with ionizing radiation, the risk assessment and the determination of exposure levels (definition of regulated areas, personnel categories), the strategy aimed at controlling the risk (risk reduction, technical measures concerning the installation or the personnel, teaching and information, prevention, incident), the different measures of medical monitoring, the assessment of risk control, and other risks. An appendix proposes an example of workstation assessment

  5. Overview of the IAEA Joint Convention and Implementation Status of the Obligation as the Contracting Party of the 5th Joint Convention

    International Nuclear Information System (INIS)

    Lee, Jeong Ken; Lee, Youn Keun; Ahn, Sang Myeon

    2016-01-01

    The Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (Joint Convention) was adopted on 5 September 1997 by a Diplomatic Conference convened by the International Atomic Energy Agency (IAEA). The Joint Convention was opened for signature at Vienna in September 1997 and will remain open for signature until its entry into force. Korean government signed the Joint Convention in 1997 and this Convention was effective in 2002 as the Convention No. 1612. This paper will show overview of the Joint Convention and implementation status of the obligation as a Contracting Party of the 5th Joint Convention. The Joint Convention is the inter-national convention organized by the IAEA. All contracting parties shall comply with rules of the Joint Convention and conduct the obligation of this convention. Korean government successfully conducted all obligation (attending Organization Meeting and Review Meeting, submitting paper including National Report, question paper and answer paper) of the 5th Joint Convention from May 2014 to May 2015, and will prepare the obligation of the 6th Joint Convention

  6. Radiation effects on polyaniline

    International Nuclear Information System (INIS)

    Oki, Yuichi; Kondo, Kenjiro; Suzuki, Takenori; Numajiri, Masaharu; Miura, Taichi; Doi, Shuji; Ohnishi, Toshihiro.

    1992-01-01

    Effects of γ-irradiation on electrical conductivity of polyaniline were investigated. A drastic increase of the conductivity due to radiation-induced doping was observed in combined systems of polyaniline films and halogen-containing polymers. This effect can be applied to measure an integrated radiation dose. (author)

  7. Novel versus conventional antipsychotic drugs.

    Science.gov (United States)

    Love, R C

    1996-01-01

    Novel antipsychotic agents differ from conventional ones in several key characteristics, including effectiveness, adverse reactions, and receptor-binding profile. Most of the newer agents have an affinity for the serotonin 5HT2 receptor that is at least 10 times greater than that for the dopamine D2 receptor. This increased affinity for the serotonin receptor may be responsible for another distinguishing characteristic of novel antipsychotic agents--decreased frequency of extrapyramidal side effects. These side effects, which include pseudoparkinsonism, acute dystonias, and akathisia, frequently are the reason for noncompliance with conventional drug therapy. The newer drugs are often effective in patients resistant to treatment with conventional agents. They also appear to reduce the negative symptoms of schizophrenia in many patients.

  8. Radiation chemistry

    International Nuclear Information System (INIS)

    Rodgers, F.; Rodgers, M.A.

    1987-01-01

    The contents of this book include: Interaction of ionizing radiation with matter; Primary products in radiation chemistry; Theoretical aspects of radiation chemistry; Theories of the solvated electron; The radiation chemistry of gases; Radiation chemistry of colloidal aggregates; Radiation chemistry of the alkali halides; Radiation chemistry of polymers; Radiation chemistry of biopolymers; Radiation processing and sterilization; and Compound index

  9. Tomographs based on non-conventional radiation sources and methods

    International Nuclear Information System (INIS)

    Barbuzza, R.; Fresno, M. del; Venere, Marcelo J.; Clausse, Alejandro; Moreno, C.

    2000-01-01

    Computer techniques for tomographic reconstruction of objects X-rayed with a compact plasma focus (PF) are presented. The implemented reconstruction algorithms are based on stochastic searching of solutions of Radon equation, using Genetic Algorithms and Monte Carlo methods. Numerical experiments using actual projections were performed concluding the feasibility of the application of both methods in tomographic reconstruction problem. (author)

  10. The prospect of conventional disarmament

    International Nuclear Information System (INIS)

    Adeniji, O.

    1989-01-01

    The prospect of conventional disarmament in Europe holds out great consequences not only for the continent but also for the entire world. The arms race both in its nuclear and conventional aspects has been the single most important element of the destabilizing factors in international relations since 1945. Though initially borne out of the ideological division of Europe and the consequent quest for strategic military superiority, it soon developed a technological momentum of its own, becoming more the cause than the effect of the distrust in the relationship of the two alliances. The issue of conventional weapons was raised for negotiations side by side with that of nuclear weapons when the United Nations took up the question of disarmament in 1946. Due, however, to the unforeseen and most dangerous advance in nuclear weaponry, the fear engendered shifted all attention at the multilateral level to nuclear weapons. Except in Europe where the Mutual and Balanced Force Reduction Talks in Central Europe were initiated, conventional weapons disarmament did not attract multilateral attention again until the First Special Session of the United nations General Assembly Devoted to Disarmament in 1978. The Final Document of the Special Session did accord highest priority to negotiations on nuclear weapons. However, it also affirmed that side by side with negotiations on nuclear weapons, the limitation and gradual reduction of armed forces and conventional weapons should be resolutely pursued within the framework of general and complete disarmament. States with the largest military arsenals, it was stated, had a special responsibility in pursuing conventional armaments reduction. Underscoring the central role of Europe further, the Final Document postulated that the achievement of a more stable situation at a lower level of military potential would contribute toward strengthening of security in Europe and constitute a significant step toward international peace and security

  11. Conventional imaging in paediatric uroradiology

    International Nuclear Information System (INIS)

    Riccabona, M.; Lindbichler, F.; Sinzig, M.

    2002-01-01

    Objective: To briefly describe basic conventional imaging in paediatric uroradiology. Method: The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included. Result and conclusion: Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options

  12. Conventional imaging in paediatric uroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Riccabona, M. E-mail: michael.riccabona@kfunigraz.ac.at; Lindbichler, F.; Sinzig, M

    2002-08-01

    Objective: To briefly describe basic conventional imaging in paediatric uroradiology. Method: The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included. Result and conclusion: Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options.

  13. The European Convention on bioethics.

    Science.gov (United States)

    Byk, C

    1993-03-01

    Benefiting from a widely recognised experience of the field of bioethics, the Council of Europe which represents all the democratic countries of Europe, has embarked on the ambitious task of drafting a European Convention on bioethics. The purpose of this text is to set out fundamental values, such as respect for human dignity, free informed consent and non-commercialisation of the human body. In addition to this task, protocols will provide specific standards for the different fields concerned with the application of biomedical sciences. The convention and the first two protocols (human experiments and organ transplants) are due to be ready for signature by mid 1994.

  14. Conventional and unconventional political participation

    International Nuclear Information System (INIS)

    Opp, K.D.

    1985-01-01

    A non-recursive model is proposed and empirically tested with data of opponents of nuclear power. In explaining conventional and unconventional participation the theory of collective action is applied and modified in two respects: the perceived influence on the elimination of collective evils are taken into account; the selective incentives considered are non-material ones. These modifications proved to be valid: the collective good variables and non-material incentives were important determinants for the two forms of participation. Another result was that there is a reciprocal causal relationship between conventional and unconventional participation. (orig./PW) [de

  15. Radiation exposure analysis of female nuclear medicine radiation workers

    International Nuclear Information System (INIS)

    Lee, Ju Young; Park, Hoon Hee

    2016-01-01

    In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus

  16. Radiation exposure analysis of female nuclear medicine radiation workers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju Young [Dept. of Biomedical Engineering Graduate School, Chungbuk National University, Cheongju (Korea, Republic of); Park, Hoon Hee [Dept. of Radiological Technologist, Shingu College, Sungnam (Korea, Republic of)

    2016-06-15

    In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus

  17. Environmental impact of non-conventional energy sources

    International Nuclear Information System (INIS)

    Abbasi, S.A.; Abbasi, Naseema; Nipaney, P.C.; Ramasamy, E.V.

    1995-01-01

    Whereas the global attention has always been focused on the adverse environmental impacts of conventional energy sources, only a few studies have been conducted on the clean environment image of the non-conventional energy sources, particularly the renewable ones. The question whether the non-conventional sources are really as benign as they are made out to be is addressed in the present paper in the background of a classical paradigm developed by Lovin which had postulated the hard (malignant) and soft (benign) energy concepts in the first place. It then assesses the likely environmental impacts of several major non-conventional energy sources and comes up with the note of caution that in many cases the adverse impacts may not be insubstantial; indeed in some cases they can be as strongly negative as the impacts of the conventional energy sources. (author). 31 refs

  18. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

    The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current regula...

  19. The nuclear safety convention. Results for Argentine as contracting party

    International Nuclear Information System (INIS)

    Caruso, Gustavo

    2002-01-01

    A powerful mechanism for increasing safety worldwide is through the development and adoption of legally binding Safety Conventions. Since 1986 four Conventions were ratified in the areas of Nuclear, Radiation and Waste Safety. The Nuclear Safety Convention establishes an international co-operation mechanism to maintain safety nuclear installations, focused on: to achieve and maintain a high level of nuclear safety worldwide through the enhancement of national measures and international co-operation including, where appropriate, safety-related technical co-operation; to establish and maintain effective defences in nuclear installations against potential radiological hazards in order to protect individuals, society and the environment from harmful effects of ionizing radiation from such installations and to prevent accidents with radiological consequences and to mitigate such consequences should they occur. Each contracting party shall take, within the framework of its national law, the legislative, regulatory and administrative measures and other steps necessary for implementing its obligations under this Convention. Moreover, each contracting parties shall submit for review prior to each review meeting, a National Report on the measures it has taken to implement each of the obligations of the Convention. The contracting parties concluded that the review process had proven to be of great value to their national nuclear safety programmes. (author)

  20. Conventional and Non-Conventional Yeasts in Beer Production

    Directory of Open Access Journals (Sweden)

    Angela Capece

    2018-06-01

    Full Text Available The quality of beer relies on the activity of fermenting yeasts, not only for their good fermentation yield-efficiency, but also for their influence on beer aroma, since most of the aromatic compounds are intermediate metabolites and by-products of yeast metabolism. Beer production is a traditional process, in which Saccharomyces is the sole microbial component, and any deviation is considered a flaw. However, nowadays the brewing sector is faced with an increasing demand for innovative products, and it is diffusing the use of uncharacterized autochthonous starter cultures, spontaneous fermentation, or non-Saccharomyces starters, which leads to the production of distinctive and unusual products. Attempts to obtain products with more complex sensory characteristics have led one to prospect for non-conventional yeasts, i.e., non-Saccharomyces yeasts. These generally are characterized by low fermentation yields and are more sensitive to ethanol stress, but they provide a distinctive aroma and flavor. Furthermore, non-conventional yeasts can be used for the production of low-alcohol/non-alcoholic and light beers. This review aims to present the main findings about the role of traditional and non-conventional yeasts in brewing, demonstrating the wide choice of available yeasts, which represents a new biotechnological approach with which to target the characteristics of beer and to produce different or even totally new beer styles.

  1. Radiation and radiation protection

    International Nuclear Information System (INIS)

    Landfermann, H.H.; Solbach, C.

    1992-11-01

    The brochure explains the major types of radiation, the radiation sources, effects, uses, and risks, as well as the regulatory system adopted by the government in order to keep the risks as low as possible. (orig./DG) [de

  2. Quasisymmetry equations for conventional stellarators

    International Nuclear Information System (INIS)

    Pustovitov, V.D.

    1994-11-01

    General quasisymmetry condition, which demands the independence of B 2 on one of the angular Boozer coordinates, is reduced to two equations containing only geometrical characteristics and helical field of a stellarator. The analysis is performed for conventional stellarators with a planar circular axis using standard stellarator expansion. As a basis, the invariant quasisymmetry condition is used. The quasisymmetry equations for stellarators are obtained from this condition also in an invariant form. Simplified analogs of these equations are given for the case when averaged magnetic surfaces are circular shifted torii. It is shown that quasisymmetry condition can be satisfied, in principle, in a conventional stellarator by a proper choice of two satellite harmonics of the helical field in addition to the main harmonic. Besides, there appears a restriction on the shift of magnetic surfaces. Thus, in general, the problem is closely related with that of self-consistent description of a configuration. (author)

  3. Radiation measurement

    International Nuclear Information System (INIS)

    Go, Sung Jin; Kim, Seung Guk; No, Gyeong Seok; Park, Myeong Hwan; Ann, Bong Seon

    1998-03-01

    This book explains technical terms about radiation measurement, which are radiation, radiation quantity and unit such as prefix of international unit, unit for defence purposes of radiation, coefficient of radiation and interaction, kinds and principles of radiation detector, ionization chamber, G-M counter, G-M tube, proportional counter, scintillation detector, semiconductor radiation detector, thermoluminescence dosimeter, PLD, others detector, radiation monitor, neutron detector, calibration of radiation detector, statistics of counting value, activation analysis and electronics circuit of radiation detector.

  4. Reframing less conventional speech to disrupt conventions of "compulsory fluency": A conversation analysis approach

    Directory of Open Access Journals (Sweden)

    Camille Duque

    2018-05-01

    Full Text Available Our purpose is to illuminate compliances with, and resistances to, what we are calling "compulsory fluency" which we define as conventions for what constitutes competent speech. We achieve our purpose through a study of day-to-day communication between a woman with less conventional speech and her support providing family members and friends. Drawing from McRuer's (2006 compulsory ablebodiedness and Kafer's (2013 compulsory able-mindedness, we use "compulsory fluency" to refer to a form of articulation that is standardized and idealized and imposed on all speakers including those whose speech is less conventional. We see compulsory fluency as central to North American conceptions of personhood which are tied to individual ability to speak for one's self (Brueggemann, 2005. In this paper, we trace some North American principles for linguistic competence to outline widely held ideals of receptive and expressive language use, namely, conventions for how language should be understood and expressed. Using Critical Disability Studies (Goodley, 2013; McRuer, 2006 together with a feminist framework of relational autonomy (Nedelsky, 1989, our goal is to focus on experiences of people with less conventional speech and draw attention to power in communication as it flows in idiosyncratic and intersubjective fashion (Mackenzie & Stoljar, 2000; Westlund, 2009. In other words, we use a critical disability and feminist framing to call attention to less conventional forms of communication competence and, in this process, we challenge assumptions about what constitutes competent speech. As part of a larger qualitative study, we conduct a conversation analysis informed by Rapley and Antaki (1996 to examine day-to-day verbal, vocal and non-verbal communications of a young woman who self identifies as "having autism" - pseudonym Addison - in interaction with her support-providing family members and friends. We illustrate a multitude of Addison's compliances with

  5. A multileaf collimator field prescription preparation system for conventional radiotherapy

    International Nuclear Information System (INIS)

    Du, M.N.; Yu, C. X.; Symons, M.; Yan, D.; Taylor, R.; Matter, R.C.; Gustafson, G.; Martinez, A.; Wong, J.W.

    1995-01-01

    Purpose: The purpose of this work is to develop a prescription preparation system for efficient field shaping using a multileaf collimator that can be used in community settings as well as research institutions. The efficiency advantage of the computer-controlled multileaf collimator, over cerrobend blocks, to shape radiation fields has been shown in conformal treatments, which typically require complete volumetric computerized tomographic data for three-dimensional radiation treatment planning--a utility not readily available to the general community. As a result, most patients today are treated with conventional radiation therapy. Therefore, we believe that it is very important to fully use the same efficiency advantage of multileaf collimator as a block replacement in conventional practice. Methods and Material: The multileaf collimator prescription preparation system developed by us acquires prescription images from different sources, including film scanner and radiation treatment planning systems. The multileaf collimator angle and leaf positions are set from the desired field contour defined on the prescription image, by minimizing the area discrepancies. Interactive graphical tools include manual adjustment of collimator angle and leaf positions, and definition of portions of the field edges that require maximal conformation. Data files of the final leaf positions are transferred to the multileaf collimator controller via a dedicated communication link. Results: We have implemented the field prescription preparation system and a network model for integrating the multileaf collimator and other radiotherapy modalities for routine treatments. For routine plan evaluation, isodose contours measured with film in solid water phantom at prescription depth are overlaid on the prescription image. Preliminary study indicates that the efficiency advantage of the MLC over cerrobend blocks in conformal therapy also holds true for conventional treatments. Conclusion: Our

  6. ''Intelligent'' radiation measurements

    International Nuclear Information System (INIS)

    Ward, A.

    1980-01-01

    A description is given of three applications of current microprocessor technology which are characterized by the use of the microprocessor to impart a degree of intelligence to conventional radiation detection techniques. In the first application the microcomputer computes the radiation dose from the observed counting rate in a Geiger counter. In the second application the microcomputer provides the pulse height distribution and the radioisotopes used, from the spectrum of pulses from a scintillation counter. The third application is an arrangement for radiation monitor calibration. (H.K.)

  7. Late temporal lobe necrosis after conventional radiotherapy for carcinoma of maxillary sinus.

    Science.gov (United States)

    Kanakamedala, Madhava R; Mahta, Ali; Liu, Jianlin; Kesari, Santosh

    2012-12-01

    Cerebral radiation necrosis is a serious late complication after conventional radiotherapy that can present with focal neurologic deficits or with more generalized signs and symptoms of increased intracranial pressure, depending on the location. The incidence and severity of radionecrosis are dose-volume dependent. We report a case of cerebral radiation necrosis 5 years after radiotherapy for a maxillary sinus carcinoma.

  8. Determining the suitability of materials for disposal at sea under the London Convention 1972: A radiological assessment procedure

    International Nuclear Information System (INIS)

    2003-10-01

    on conducting specific assessments to determine whether candidate materials for disposal at sea contained de minimis levels of radioactivity. This report contains guidance on performing specific assessments of candidate materials to determine whether the materials are de minimis in the meaning of the London Convention 1972. It follows the guidelines adopted by the Twenty-first Consultative Meeting of the London Convention 1972 that incorporate a Stepwise Evaluation Procedure for screening candidate material to determine if it can be treated as 'non-radioactive' (i.e. de minimis) under the Convention. Material that cannot be readily defined as de minimis on the basis of Steps 1 to 5 of the Stepwise Evaluation Procedure require a specific assessment at Step 6. Such an assessment is the subject of this report. The assessment process described in this report is based on an inherently conservative procedure consistent with the precautionary approach, provided for under the London Convention 1972. Its purpose is to ensure the use of conservative models and cautious assumptions that result in the overestimation of the doses due to candidate materials that might be disposed of at sea in near coastal waters under de minimis provisions. Accordingly, the radiological consequences of disposal at sea of de minimis materials in other areas of the continental shelf and deeper waters will result in much lower radiation exposures than those considered here. It must be stressed that any candidate materials designated as de minimis must comply with all other provisions of the Convention. Section 2 provides a summary of the Stepwise Evaluation Procedure as detailed in the guidelines and background information necessary to understand the context of this guidance. Section 3 describes in detail a procedure to conduct the specific radiological assessment of the disposal of a candidate material. It contains a schematic diagram illustrating the specific assessment process and components of

  9. Conventional versus virtual radiographs of the injured pelvis and acetabulum

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Julius A.; Rao, Allison J.; Pouliot, Michael A.; Bellino, Michael [Stanford University School of Medicine, Department of Orthopaedic Surgery, Stanford, CA (United States); Beaulieu, Christopher [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

    2015-09-15

    Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans. Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA). Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p = 0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p = 0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well. Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs. (orig.)

  10. Dilution Confusion: Conventions for Defining a Dilution

    Science.gov (United States)

    Fishel, Laurence A.

    2010-01-01

    Two conventions for preparing dilutions are used in clinical laboratories. The first convention defines an "a:b" dilution as "a" volumes of solution A plus "b" volumes of solution B. The second convention defines an "a:b" dilution as "a" volumes of solution A diluted into a final volume of "b". Use of the incorrect dilution convention could affect…

  11. Apocryphal Angels in Nun Convents

    Directory of Open Access Journals (Sweden)

    Mario Ávila Vivar

    2018-01-01

    Full Text Available The preponderance of studies about viceregal angelic series, and the widespread belief that the representation of apocryphal angels is a specific peculiarity of viceregal angelology, have created such a close relation between it and the apocryphal angels, that they are even considered as synonymous. However, both the texts and the presence of this angels in the spanish convents of the XVII century, evidence that the apocryphal angels appeared and they were represented in Spain long before that in its american viceregal. Therefore, it is here where their origins and their meaning should be sought.

  12. Radiation protection

    International Nuclear Information System (INIS)

    Koelzer, W.

    1975-01-01

    Physical and radiological terms, quantities, and units. Basic principles of radiation protection (ICRP, IAEA, EURATOM, FRG). Biological effects of ionizing radiation. Objectives of practical radiation protection. (HP) [de

  13. Radiation shielding apparatus

    International Nuclear Information System (INIS)

    McCullagh, R.J.

    1977-01-01

    The disclosure pertains to a clamping apparatus having a stud capturing portion and a stud facing portion bolted together so as to compressively support a radiation-proof sheet material, such as lead sheeting, there-in-between. The interior wall covering material, such as panelling or wall board, is secured to the external surface of the stud facing portion. No nails are required to support the radiation-proof sheeting material, thereby minimizing accidental leakage due to harmful radiation passing through openings inadvertently disposed in the radiation-proof sheeting in the conventional nail securing supporting thereof. A pair of radiation-proof tracks capture the free ends of the stud capturing portion and the stud facing portion

  14. Diverticular Disease: Reconsidering Conventional Wisdom

    Science.gov (United States)

    Peery, Anne F.; Sandler, Robert S.

    2013-01-01

    Colonic diverticula are common in developed countries and complications of colonic diverticulosis are responsible for a significant burden of disease. Several recent publications have called into question long held beliefs about diverticular disease. Contrary to conventional wisdom, studies have not shown that a high fiber diet protects against asymptomatic diverticulosis. The risk of developing diverticulitis among individuals with diverticulosis is lower than the 10–25% commonly quoted, and may be as low as 1% over 11 years. Nuts and seeds do not increase the risk of diverticulitis or diverticular bleeding. It is unclear whether diverticulosis, absent diverticulitis or overt colitis, is responsible for chronic gastrointestinal symptoms or worse quality of life. The role of antibiotics in acute diverticulitis has been challenged by a large randomized trial that showed no benefit in selected patients. The decision to perform elective surgery should be made on a case-by-case basis and not routinely after a second episode of diverticulitis, when there has been a complication, or in young people. A colonoscopy should be performed to exclude colon cancer after an attack of acute diverticulitis but may not alter outcomes among individuals who have had a colonoscopy prior to the attack. Given these surprising findings, it is time to reconsider conventional wisdom about diverticular disease. PMID:23669306

  15. Implementing the chemical weapons convention

    Energy Technology Data Exchange (ETDEWEB)

    Kellman, B.; Tanzman, E. A.

    1999-12-07

    In 1993, as the CWC ratification process was beginning, concerns arose that the complexity of integrating the CWC with national law could cause each nation to implement the Convention without regard to what other nations were doing, thereby causing inconsistencies among States as to how the CWC would be carried out. As a result, the author's colleagues and the author prepared the Manual for National Implementation of the Chemical Weapons Convention and presented it to each national delegation at the December 1993 meeting of the Preparatory Commission in The Hague. During its preparation, the Committee of CWC Legal Experts, a group of distinguished international jurists, law professors, legally-trained diplomats, government officials, and Parliamentarians from every region of the world, including Central Europe, reviewed the Manual. In February 1998, they finished the second edition of the Manual in order to update it in light of developments since the CWC entered into force on 29 April 1997. The Manual tries to increase understanding of the Convention by identifying its obligations and suggesting methods of meeting them. Education about CWC obligations and available alternatives to comply with these requirements can facilitate national response that are consistent among States Parties. Thus, the Manual offers options that can strengthen international realization of the Convention's goals if States Parties act compatibly in implementing them. Equally important, it is intended to build confidence that the legal issues raised by the Convention are finite and addressable. They are now nearing competition of an internet version of this document so that interested persons can access it electronically and can view the full text of all of the national implementing legislation it cites. The internet address, or URL, for the internet version of the Manual is http: //www.cwc.ard.gov. This paper draws from the Manual. It comparatively addresses approximately thirty

  16. Implementing the chemical weapons convention

    International Nuclear Information System (INIS)

    Kellman, B.; Tanzman, E. A.

    1999-01-01

    In 1993, as the CWC ratification process was beginning, concerns arose that the complexity of integrating the CWC with national law could cause each nation to implement the Convention without regard to what other nations were doing, thereby causing inconsistencies among States as to how the CWC would be carried out. As a result, the author's colleagues and the author prepared the Manual for National Implementation of the Chemical Weapons Convention and presented it to each national delegation at the December 1993 meeting of the Preparatory Commission in The Hague. During its preparation, the Committee of CWC Legal Experts, a group of distinguished international jurists, law professors, legally-trained diplomats, government officials, and Parliamentarians from every region of the world, including Central Europe, reviewed the Manual. In February 1998, they finished the second edition of the Manual in order to update it in light of developments since the CWC entered into force on 29 April 1997. The Manual tries to increase understanding of the Convention by identifying its obligations and suggesting methods of meeting them. Education about CWC obligations and available alternatives to comply with these requirements can facilitate national response that are consistent among States Parties. Thus, the Manual offers options that can strengthen international realization of the Convention's goals if States Parties act compatibly in implementing them. Equally important, it is intended to build confidence that the legal issues raised by the Convention are finite and addressable. They are now nearing competition of an internet version of this document so that interested persons can access it electronically and can view the full text of all of the national implementing legislation it cites. The internet address, or URL, for the internet version of the Manual is http: //www.cwc.ard.gov. This paper draws from the Manual. It comparatively addresses approximately thirty

  17. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  18. Limits of radiobiology in conventional postirradiation of breast cancer

    International Nuclear Information System (INIS)

    Wall, H. van der

    1982-01-01

    The conventional postirradiation of breast cancer including radiation pneumonitis in relation to age and irradiation method, are discussed. The risk of radiation pneumonitis is with a single surface dose of 65 mC/kg higher than with 52 mC/kg. The dose at the chest wall is for the development of a radiation pneumonitis of lower importance than the dose at the supra- and intraclavicular field. At both these fields intersections of the cones of radiation in the lungs, which could cause dose peaks not possible to evaluate, must be taken into consideration. At the reported and wanted tumor dose of 1032 mC/kg at the deferent axillary lymph tracts a more indulgent method with a single dose of 65 mC/kg and with a prolongation by 3 series a pneumonitis could not be avoided in 30% of the irradiated women. Because of the harmless process one could answer for the risk of a radiation pneumonitis, if other therapeutic possibilities are not available. The age of the patients is not a special risk as to radiation pneumonitis. (author)

  19. Limits of radiobiology in conventional postirradiation of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    van der Wall, H [Bezirkskrankenhaus Schwerin (German Democratic Republic)

    1982-08-01

    The conventional postirradiation of breast cancer including radiation pneumonitis in relation to age and irradiation method, are discussed. The risk of radiation pneumonitis is with a single surface dose of 65 mC/kg higher than with 52 mC/kg. The dose at the chest wall is for the development of a radiation pneumonitis of lower importance than the dose at the supra- and intraclavicular field. At both these fields intersections of the cones of radiation in the lungs, which could cause dose peaks not possible to evaluate, must be taken into consideration. At the reported and wanted tumor dose of 1032 mC/kg at the deferent axillary lymph tracts a more indulgent method with a single dose of 65 mC/kg and with a prolongation by 3 series a pneumonitis could not be avoided in 30% of the irradiated women. Because of the harmless process one could answer for the risk of a radiation pneumonitis, if other therapeutic possibilities are not available. The age of the patients is not a special risk as to radiation pneumonitis.

  20. RHOBOT: Radiation hardened robotics

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  1. RHOBOT: Radiation hardened robotics

    International Nuclear Information System (INIS)

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

    1997-10-01

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

  2. Radiation protection

    International Nuclear Information System (INIS)

    Kamalaksh Shenoy, K.

    2013-01-01

    Three main pillars underpin the IAEA's mission: Safety and Security - The IAEA helps countries to upgrade their infrastructure for nuclear and radiation safety and security, and to prepare for and respond to emergencies. Work is keyed to international conventions, the development of international standards and the application of these standards. The aim is to protect people and the environment from the harmful effects of exposure to ionizing radiation. Science and Technology - The IAEA is the world's focal point for mobilizing peaceful applications of nuclear science and technology for critical needs in developing countries. The work contributes to alleviating poverty, combating disease and pollution of the environment and to other goals of sustainable development. Safeguards and Verification - The IAEA is the nuclear inspectorate, with more than four decades of verification experience. Inspectors work to verify that nuclear material and activities are not diverted towards military purposes. Quantities and Units: Dose equivalent is the product of absorbed dose of radiation and quality factor (Q). For absorbed dose in rads, dose equivalent is in rems. If absorbed dose is in gray, the dose equivalent is in sievert. Quality factor is defined without reference to any particular biological end point. Quality factors are recommended by committees such as the International Commission on Radiological Protection (ICRP) or the National Council on Radiation Protection and Measurements (NCRP), based on experimental RBE values but with some judgment exercised. Effective Dose Equivalent: It is the sum of the weighted dose equivalents for all irradiated tissues, in which the weighting factors represent the different risks of each tissue to mortality from cancer and hereditary effects. Committed dose equivalent: It is the integral over 50 years of dose equivalent following the intake of a radionuclide. Collective effective dose equivalent: It is a quantity for a population and is

  3. Experimental radiation carcinogenesis is studies at NIRS

    International Nuclear Information System (INIS)

    Sado, Toshihiko

    1992-01-01

    Experimental radiation carcinogenesis studies conducted during the past decade at NIRS are briefly reviewed. They include the following: 1) Age dependency of susceptibility to radiation carcinogenesis. 2) Radiation-induced myeloid leukemia. 3) Mechanism of fractionated X-irradiation (FX) induced thymic lymphomas. 4) Significance of radiation-induced immunosuppression in radiation carcinogenesis in vivo. 5) Other ongoing studies. (author)

  4. A randomized clinical trial of hyperthermia and radiation versus radiation alone for superficially located cancers

    International Nuclear Information System (INIS)

    Egawa, Sunao; Tsukiyama, Iwao; Watanabe, Shaw

    1989-01-01

    A randomized clinical trial was performed in order to evaluate the effect of combined hyperthermia and radiation for superficially located tumors. Ten institutions participated in this study and 92 evaluable patients were entered from September 1985 to March 1987 (44 patients for radiation plus hyperthermia and 48 for radiation only). Superficially located tumors, more than 3x3 cm in diameter, regardless of whether they were primary or metastatic, and of their histology, were included in the study. Radiotherapy was performed by the conventional fractionation method (2 Gyx5/week). Hyperthermia was conducted once a week. There was no statistical difference between the two groups regarding age, sex, the distribution of tumors and treatment parameters. The complete response (CR) and partial response (PR) rate for the hyperthermia plus radiation group was 81.8%, while the rate for the radiation alone group was 62.6% (p<0.05). Six factors were selected for analysis of the above effect by a multiple logistic model. Sex contributed the most (p=0.001), then the site of the tumor (p=0.016) and the method of treatment (p=0.023). Sex and the site influenced the results. Age, irradiation dose and frequency and duration of heating were not significant factors for response to treatment. (author)

  5. Comparative Cost/Benefit of Alternative/Conventional Feedstuff in ...

    African Journals Online (AJOL)

    benefit of the use of conventional (corn/soya bean based) and alternative (less of corn and soya bean substituted with agro-allied and industrial by-products) feedstuffs. Completely randomized design was used and the experiment conducted for a ...

  6. Conventional and serological detection of Fasciolosis in ruminants ...

    African Journals Online (AJOL)

    The study was conducted to determined seasonal prevalence of fasciolosis and compare between its conventional diagnosis and serological identification in ruminants slaughtered at Maiduguri abattoir, northeastern Nigeria. Nine hundred samples each of faeces and blood; that is 300 each from cattle, sheep and goats was ...

  7. Temperature distributions of a conductively heated filament

    International Nuclear Information System (INIS)

    Tamura, Koji; Ohba, Hironori; Shibata, Takemasa

    1999-07-01

    Temperature distributions of a heated filament were measured. A W-Re(5%) filament (0.25 mm in diameter, 24.7 mm in length) was conductively heated by currents between 5A and 7A with a DC power supply, and the surface of the filament was imaged with a charge coupled device (CCD) camera through a monochromatic filter. The spectral radiation intensity at the filament center region was almost uniform. Since the temperature distribution was also uniform and the energy loss by thermal conduction was negligible, temperature in this region was determined from the energy balance between applied power and radiation loss. Temperature distribution of the filament was determined based on the Planck's law of radiation from the spectral radiation intensity ratio of the filament surface using obtained temperature as a reference. It was found that temperature distribution of a filament was easily measured by this method. (author)

  8. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  9. Environmental radiation data, 7

    International Nuclear Information System (INIS)

    Nagaoka, Toshi; Sakamoto, Ryuichi; Saito, Kimiaki; Tsutsumi, Masahiro; Moriuchi, Shigeru

    1989-10-01

    The Environmental Radiation Physics Laboratory has conducted a large number of background radiation surveys in these years, aiming at the analysis of characteristics and behaviour of environmental radiation, the development of measurement techniques and instruments of environmental radiation, and the evaluation of environmental radiation dose. The environmental radiation data obtained by these surveys are useful for broad purposes as actual survey data. Therefore, it is desirable to make the recording media and the FORMAT of these data available for usual computers. In the light of this circumstance, these data were rearranged and recompiled systematically to meet the demand. This report mentions about the data obtained by the background radiation surveys in and around Tokyo performed during 1982 - 1988 using portable instruments, as well as the information necessary for the data handling. (author)

  10. Conventional power sources for colliders

    International Nuclear Information System (INIS)

    Allen, M.A.

    1987-07-01

    At SLAC we are developing high peak-power klystrons to explore the limits of use of conventional power sources in future linear colliders. In an experimental tube we have achieved 150 MW at 1 μsec pulse width at 2856 MHz. In production tubes for SLAC Linear Collider (SLC) we routinely achieve 67 MW at 3.5 μsec pulse width and 180 pps. Over 200 of the klystrons are in routine operation in SLC. An experimental klystron at 8.568 GHz is presently under construction with a design objective of 30 MW at 1 μsec. A program is starting on the relativistic klystron whose performance will be analyzed in the exploration of the limits of klystrons at very short pulse widths

  11. Laparoscopic splenectomy using conventional instruments

    Directory of Open Access Journals (Sweden)

    Dalvi A

    2005-01-01

    Full Text Available INTRODUCTION : Laparoscopic splenectomy (LS is an accepted procedure for elective splenectomy. Advancement in technology has extended the possibility of LS in massive splenomegaly [Choy et al., J Laparoendosc Adv Surg Tech A 14(4, 197-200 (2004], trauma [Ren et al., Surg Endosc 15(3, 324 (2001; Mostafa et al., Surg Laparosc Endosc Percutan Tech 12(4, 283-286 (2002], and cirrhosis with portal hypertension [Hashizume et al., Hepatogastroenterology 49(45, 847-852 (2002]. In a developing country, these advanced gadgets may not be always available. We performed LS using conventional and reusable instruments in a public teaching the hospital without the use of the advanced technology. The technique of LS and the outcome in these patients is reported. MATERIALS AND METHODS : Patients undergoing LS for various hematological disorders from 1998 to 2004 were included. Electrocoagulation, clips, and intracorporeal knotting were the techniques used for tackling short-gastric vessels and splenic pedicle. Specimen was delivered through a Pfannensteil incision. RESULTS : A total of 26 patients underwent LS. Twenty-two (85% of patients had spleen size more than 500 g (average weight being 942.55 g. Mean operative time was 214 min (45-390 min. The conversion rate was 11.5% ( n = 3. Average duration of stay was 5.65 days (3-30 days. Accessory spleen was detected and successfully removed in two patients. One patient developed subphrenic abscess. There was no mortality. There was no recurrence of hematological disease. CONCLUSION : Laparoscopic splenectomy using conventional equipment and instruments is safe and effective. Advanced technology has a definite advantage but is not a deterrent to the practice of LS.

  12. Biocompatibility of Er:YSGG laser radiated root surfaces

    Science.gov (United States)

    Benthin, Hartmut; Ertl, Thomas P.; Schmidt, Dirk; Purucker, Peter; Bernimoulin, J.-P.; Mueller, Gerhard J.

    1996-01-01

    Pulsed Er:YAG and Er:YSGG lasers are well known to be effective instruments for the ablation of dental hard tissues. Developments in the last years made it possible to transmit the laser radiation at these wavelengths with flexible fibers. Therefore the application in the periodontal pocket may be possible. The aim of this study was to evaluate the in-vitro conditions to generate a bioacceptable root surface. Twenty extracted human teeth, stored in an antibiotic solution, were conventionally scaled, root planed and axially separated into two halves. Two main groups were determined. With the first group laser radiation was carried out without and in the second group with spray cooling. The laser beam was scanned about root surface areas. Laser parameters were varied in a selected range. The biocompatibility was measured with the attachment of human gingival fibroblasts and directly compared to conventionally treated areas of the root surfaces. The fibroblasts were qualified and counted in SEM investigations. On conventionally treated areas gingival fibroblasts show the typical uniform cover. In dependance on the root roughness after laser treatment the fibroblasts loose the typical parallel alignment to the root surface. With spray cooling a better in-vitro attachment could be obtained. Without spray cooling the higher increase in temperature conducted to less bioacceptance by the human gingival fibroblasts to the root surface. These results show the possibility of producing bioacceptable root surfaces with pulsed laser radiation in the range of very high water absorption near 3 micrometer.

  13. Conducting compositions of matter

    Science.gov (United States)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  14. Lack of Prophylactic Effects of Aloe Vera Gel on Radiation Induced Dermatitis in Breast Cancer Patients

    OpenAIRE

    Ahmadloo, Niloofar; Kadkhodaei, Behnam; Omidvari, Shapour; Mosalaei, Ahmad; Ansari, Mansour; Nasrollahi, Hamid; Hamedi, Sayed Hasan; Mohammadianpanah, Mohammad

    2017-01-01

    Purpose: Radiotherapy induced dermatitis is a common and sometimes serious side effect. We conducted a randomized study to understand whether the adjunctive use of aloe vera gel might reduce the prevalence and/or severity of radiotherapy induced dermatitis. Methods: One hundred patients with newly diagnosed breast cancer were randomized to receive aloe vera gel or nothing during adjuvant radiotherapy consisting of conventional external beam radiation using 6 MV mega voltage linear accelerator...

  15. Conductive polymeric compositions for lithium batteries

    Science.gov (United States)

    Angell, Charles A [Mesa, AZ; Xu, Wu [Tempe, AZ

    2009-03-17

    Novel chain polymers comprising weakly basic anionic moieties chemically bound into a polyether backbone at controllable anionic separations are presented. Preferred polymers comprise orthoborate anions capped with dibasic acid residues, preferably oxalato or malonato acid residues. The conductivity of these polymers is found to be high relative to that of most conventional salt-in-polymer electrolytes. The conductivity at high temperatures and wide electrochemical window make these materials especially suitable as electrolytes for rechargeable lithium batteries.

  16. Paris Convention on third party liability in the field of nuclear energy and Brussels Convention Supplementary to the Paris Convention

    International Nuclear Information System (INIS)

    1989-01-01

    This new bilingual (English and French) edition of the 1960 Paris Convention and 1963 Brussels Supplementary Convention incorporates the provisions of the Protocols which amended each of them on two occasions, in 1964 and 1982. The Expose des motifs to the Paris Convention, as revised in 1982 is also included in this pubication. (NEA) [fr

  17. Digital and conventional radiology techniques: comparison of dosage and costs

    International Nuclear Information System (INIS)

    Arranza, L.; Albornoz, C. de

    1996-01-01

    To compare the radiation dosage and costs in conventional and digital technologies. The study dealt with transverse sections. The dosage applied with conventional technology was measured in 254 patients who intertwined 402 explorations of 6 anatomic regions in 4 Radiodiagnostic Services. The dosage applied with digital technology was measured in 57 patients who underwent 95 explorations of the same anatomic region in one Radiodiagnostic Service. The costs of the 6 types of conventional and digital explorations performed were calculated for two Radiodiagnostic Service. The doses administered (mGy) using convectional/digital technology were as follows: chest PA 0.2/0.1; chest LAT 0.7/0.3; breast CC 7.0/8.4; breast LAT 7.0/7.8; breast OB 7.0/10.5; cervical spine AP 9.6/9.0; cervical spine LAT 21.9/29.6; pelvis AP 7.3/7.1; plain abdominal 6.5/2.2. The costs incurred (1992 pesetas) with the convectional/digital technologies: chest AP and LAT 1,393/2,973; portable chest 2,027/3,714; mammography 2,357/3,486; phlebography 12,718/14,023; hysterosalpingography 4,876/6,701; bone scientigraphy 1,633/2,839. Compared with conventional technology, digital imaging reduces the radiation doses received by the patients, except in the case of mammography. The costs associated with the use of digital technology are greater than those incurred with conventional technology, mainly due to the costs of amortization. the use of digital technology is more justified when: 1) it is very necessary to reduce the dosage; 2) studies of chest and abdomen predominant; 3) the volume of utilization is high; 4) staff management is flexible , and 5) the cost of purchasing the equipment is lower. (Author) 10 refs

  18. Preparation of conducting solid mixtures

    International Nuclear Information System (INIS)

    Spokas, J.J.

    1978-01-01

    The application of conducting plastic mixtures to the fundamental problem of radiation dosimetry is briefly reviewed. A particular approach to achieving formulations with the necessary characteristics is described. A number of successful mixtures are defined for a number of different specific dosimetry situations. To obtain high quality stable materials requires intense blending and working of the materials at elevated temperatures. One machine that succeeds in this task is the Shonka plastics mixer-extruder. The Shonka mixer is described in complete detail. The procedures used in preparing representative formulations with this device are presented. A number of properties of successful conducting mixtures so prepared are summarized. The conditions required for molding such material are given. Several special welding methods for specific application with these formulations have been devised and are described

  19. Conductivity in transparent oxide semiconductors.

    Science.gov (United States)

    King, P D C; Veal, T D

    2011-08-24

    Despite an extensive research effort for over 60 years, an understanding of the origins of conductivity in wide band gap transparent conducting oxide (TCO) semiconductors remains elusive. While TCOs have already found widespread use in device applications requiring a transparent contact, there are currently enormous efforts to (i) increase the conductivity of existing materials, (ii) identify suitable alternatives, and (iii) attempt to gain semiconductor-engineering levels of control over their carrier density, essential for the incorporation of TCOs into a new generation of multifunctional transparent electronic devices. These efforts, however, are dependent on a microscopic identification of the defects and impurities leading to the high unintentional carrier densities present in these materials. Here, we review recent developments towards such an understanding. While oxygen vacancies are commonly assumed to be the source of the conductivity, there is increasing evidence that this is not a sufficient mechanism to explain the total measured carrier concentrations. In fact, many studies suggest that oxygen vacancies are deep, rather than shallow, donors, and their abundance in as-grown material is also debated. We discuss other potential contributions to the conductivity in TCOs, including other native defects, their complexes, and in particular hydrogen impurities. Convincing theoretical and experimental evidence is presented for the donor nature of hydrogen across a range of TCO materials, and while its stability and the role of interstitial versus substitutional species are still somewhat open questions, it is one of the leading contenders for yielding unintentional conductivity in TCOs. We also review recent work indicating that the surfaces of TCOs can support very high carrier densities, opposite to the case for conventional semiconductors. In thin-film materials/devices and, in particular, nanostructures, the surface can have a large impact on the total

  20. Conventional and advanced liquid biofuels

    Directory of Open Access Journals (Sweden)

    Đurišić-Mladenović Nataša L.

    2016-01-01

    Full Text Available Energy security and independence, increase and fluctuation of the oil price, fossil fuel resources depletion and global climate change are some of the greatest challanges facing societies today and in incoming decades. Sustainable economic and industrial growth of every country and the world in general requires safe and renewable resources of energy. It has been expected that re-arrangement of economies towards biofuels would mitigate at least partially problems arised from fossil fuel consumption and create more sustainable development. Of the renewable energy sources, bioenergy draws major and particular development endeavors, primarily due to the extensive availability of biomass, already-existence of biomass production technologies and infrastructure, and biomass being the sole feedstock for liquid fuels. The evolution of biofuels is classified into four generations (from 1st to 4th in accordance to the feedstock origin; if the technologies of feedstock processing are taken into account, than there are two classes of biofuels - conventional and advanced. The conventional biofuels, also known as the 1st generation biofuels, are those produced currently in large quantities using well known, commercially-practiced technologies. The major feedstocks for these biofuels are cereals or oleaginous plants, used also in the food or feed production. Thus, viability of the 1st generation biofuels is questionable due to the conflict with food supply and high feedstocks’ cost. This limitation favoured the search for non-edible biomass for the production of the advanced biofuels. In a general and comparative way, this paper discusses about various definitions of biomass, classification of biofuels, and brief overview of the biomass conversion routes to liquid biofuels depending on the main constituents of the biomass. Liquid biofuels covered by this paper are those compatible with existing infrastructure for gasoline and diesel and ready to be used in

  1. Digital Versus Conventional Impressions in Fixed Prosthodontics: A Review.

    Science.gov (United States)

    Ahlholm, Pekka; Sipilä, Kirsi; Vallittu, Pekka; Jakonen, Minna; Kotiranta, Ulla

    2018-01-01

    To conduct a systematic review to evaluate the evidence of possible benefits and accuracy of digital impression techniques vs. conventional impression techniques. Reports of digital impression techniques versus conventional impression techniques were systematically searched for in the following databases: Cochrane Central Register of Controlled Trials, PubMed, and Web of Science. A combination of controlled vocabulary, free-text words, and well-defined inclusion and exclusion criteria guided the search. Digital impression accuracy is at the same level as conventional impression methods in fabrication of crowns and short fixed dental prostheses (FDPs). For fabrication of implant-supported crowns and FDPs, digital impression accuracy is clinically acceptable. In full-arch impressions, conventional impression methods resulted in better accuracy compared to digital impressions. Digital impression techniques are a clinically acceptable alternative to conventional impression methods in fabrication of crowns and short FDPs. For fabrication of implant-supported crowns and FDPs, digital impression systems also result in clinically acceptable fit. Digital impression techniques are faster and can shorten the operation time. Based on this study, the conventional impression technique is still recommended for full-arch impressions. © 2016 by the American College of Prosthodontists.

  2. Radiation pager

    International Nuclear Information System (INIS)

    Warren, J.L.; Vadnais, K.G.

    1998-01-01

    Methods of interdicting nuclear materials to date have favored the use of large portal detectors at choke points, or hand carried instruments used by trained personnel for conducting spot searches. Although these methods are effective in some instances, it is often impractical to insert choke points at busy traffic areas, and it is not cost effective to maintain a force of skilled operators whose focus is nuclear interdiction. Recent technology developments are causing profound changes in the philosophy and methods employed for interdicting nuclear materials. Breakthrough advances in the miniaturization of detectors and low power electronics have made possible a new class of small gamma-ray radiation detectors, roughly the size of a message pager, with unprecedented sensitivity for their size. These instruments, named Radiation Pagers TM , are ideally suited for use by untrained individual law enforcement personnel and emergency responders in the course of their regular duties. New tactics that utilize a radiation detector worn by every officer are creating a moving curtain of detection with a significantly higher likelihood of locating illicit nuclear contraband. These individual detectors also provide each officer with a high level of confidence that they are not being unknowingly irradiated in the course of their work. (author)

  3. Experimental determination of thermal conductivity and gap conductance of fuel rod for HTGR

    International Nuclear Information System (INIS)

    Kikuchi, Teruo; Iwamoto, Kazumi; Ikawa, Katsuichi; Ishimoto, Kiyoshi

    1985-01-01

    The thermal conductivity of fuel compacts and the gap conductance between the fuel compact and the graphite sleeve in fuel rods for a high-temperature gas-cooled reactor (HTGR) were measured by the center heating method. These measurements were made as functions of volume percent particle loading and temperature for thermal conductivity and as functions of gap distance and gas composition for gap conductance. The thermal conductivity of fuel compacts decreases with increasing temperature and with increasing particle loading. The gap conductance increases with increasing temperature and decrease with increasing gap distance. A good gap conductance was observed with helium fill gas. It was seen that the gap conductance was dependent on the thermal conductivity of fill gas and conductance by radiation and could be neglected the conductance through solid-solid contact points of fuel compact and graphite sleeve. (author)

  4. Use of synchrotron radiation in radiation biology research

    International Nuclear Information System (INIS)

    Yamada, Takeshi

    1981-01-01

    Synchrotron radiation (SR) holds great expectation as a new research tool in the new areas of material science, because it has the continuous spectral distribution from visible light to X-ray, and its intensity is 10 2 to 10 3 times as strong as that of conventional radiation sources. In the National Laboratory for High Energy Physics, a synchrotron radiation experimental facility has been constructed, which will start operation in fiscal 1982. With this SR, the photons having the wavelength in undeveloped region from vacuum ultraviolet to soft X-ray are obtained as intense mono-wavelength light. The SR thus should contribute to the elucidation of the fundamentals in the biological action of radiation. The following matters are described: synchrotron radiation, experimental facility using SR, electron storage ring, features of SR, photon factory plan and synchrotron radiation experimental facility, utilization of SR in radiation biology field. (J.P.N.)

  5. Teaching of radiation for elementary and junior high students in Kagoshima and its effects on their radiation literacy

    International Nuclear Information System (INIS)

    Fukutoku, Yasuo

    2009-01-01

    Teaching of radiation-related subjects for school children takes an important part in promotion of social radiation literacy; however, the effect of school education on radiation literacy of students, as well as the current status regarding how and when children acquire their knowledge on radiation, have not been elucidated in Japan. In 2005 and 2006, a written surveillance on radiation education was conducted twice in Kagoshima prefecture targeting elementary and junior-high students under the consent of school teachers. Based on the results of these surveillances, the followings were revealed; (1) The elementary and junior-high students receive the information on radiation mainly by the conventional media, including books, television and radio, rather than by school education. (2) More than a half of all junior-high schools are teaching radiation-related subjects, in classes called 'Integrated study', 'Social studies', and 'Science'. (3) The cross tabulation analysis revealed that among the Novel Prize winners on radiation-related fields, 'Pierre and Marie Curie', 'Yukawa' and 'Tomonaga' were recognized by junior-high students by the conventional media, whereas 'Roentgen' and 'Koshiba' appeared to be recognized by school education. (4) Among the scientific terms, junior-high education seems to have some effect on recognition of 'radiation', 'radioactivity' and 'natural radiation'. 'X-rays' was highly recognized, however, the contribution of school education to the recognition was not significant. (5) Among the application examples of radiation, sources other than school education had a large effect on recognition of 'food irradiation', 'sterilization' of medical instruments, 'research on cultural assets' and 'dating', although the recognition was marginal. In contrast, the 'cancer treatment

  6. Conventional and CT angiography in children: dosimetry and dose comparisons

    International Nuclear Information System (INIS)

    Frush, Donald P.; Yoshizumi, Terry

    2006-01-01

    Tremendous advances have been made in imaging in children with both congenital and acquired heart disease. These include technical advances in cardiac catheterization and conventional angiography, especially with advancements in interventional procedures, as well as noninvasive imaging with MR and CT angiography. With rapid advances in multidetector CT (MDCT) technology, most recently 64-detector array systems (64-slice MDCT), have come a number of advantages over MR. However, both conventional and CT angiography impart radiation dose to children. Although the presence of radiation exposure to children has long been recognized, it is apparent that our ability to assess this dose, particularly in light of the rapid advancements, has been limited. Traditional methods of dosimetry for both conventional and CT angiography are somewhat cumbersome or involve a potential for substantial uncertainty. Recent developments in dosimetry, including metal oxide semiconductor field effect transistors (MOSFET) and the availability of anthropomorphic, tissue-equivalent phantoms have provided new opportunities for dosimetric assessments. Recent work with this technology in state-of-the-art cardiac angiography suites as well as with MDCT have offered direct comparisons of doses in infants and children undergoing diagnostic cardiac evaluation. It is with these dose data that assessment of risks, and ultimately the assessment of risk-benefit, can be better achieved. (orig.)

  7. Recent advances in radiation protection instrumentation

    International Nuclear Information System (INIS)

    Babu, D.A.R.

    2012-01-01

    Radiation protection instrumentation plays very important role in radiation protection and surveillance programme. Radiation detector, which appears at the frontal end of the instrument, is an essential component of these instruments. The instrumental requirement of protection level radiation monitoring is different from conventional radiation measuring instruments. Present paper discusses the new type of nuclear radiation detectors, new protection level instruments and associated electronic modules for various applications. Occupational exposure to ionizing radiation can occur in a range of industries, such as nuclear power plants; mining and milling; medical institutions; educational and research establishments; and nuclear fuel cycle facilities. Adequate radiation protection to workers is essential for the safe and acceptable use of radioactive materials for different applications. The radiation exposures to the individual radiation workers and records of their cumulative radiation doses need to be routinely monitored and recorded

  8. Self-powered radiation detector

    International Nuclear Information System (INIS)

    Goldstein, N.P.; Todt, W.H.

    1979-01-01

    Self-powered gamma radiation detector composed of a conducting emitter surrounded by an insulating medium and a conducting tubular collector, the emitter being a hollow tube containing an electrical insulator [fr

  9. Radiation dose assessment for occupationally exposed workers in ...

    African Journals Online (AJOL)

    2017-01-31

    Jan 31, 2017 ... with the legislation and safety requirements, has not yet been established. ... occupational exposure to ionising radiation such as X-rays. This study was hence ..... ionizing radiation), conventional X-ray machines or mobile.

  10. Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

    International Nuclear Information System (INIS)

    Schultz, E.

    1985-01-01

    Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

  11. Emulsion polymerization with high energy radiation

    International Nuclear Information System (INIS)

    Stannett, V.T.; Stahel, E.P.

    1992-01-01

    High energy radiation, particularly that of cobalt-60 or caesium-137 gamma-rays, provides in principle an ideal initiator for emulsion polymerization. The high free radical yields from the radiolysis of the aqueous phase combined with the high kinetic chain lengths associated with emulsion polymerization lead to a highly effective utilization of the radiation. There are other important advantages compared with the use of chemical initiators such as potassium persulfate. These are outlined in the chapter, together with some attendant disadvantages. Radiation-induced initiation is temperature independent, and low temperature polymerizations can be conducted with ease. Monomers that mainly terminate their growing chains by chain transfer to monomer give higher molecular weights at lower temperatures. Industrially, vinyl acetate is an important example of such a monomer, and it has been studied using radiation initiation. Both laboratory and pilot plant studies have been carried out and reported. The results are summarized in this chapter. Styrene is the classical example of a material that under a number of conditions closely obeys the so-called ideal Smith-Ewart kinetics. It has been found that under similar conditions but substituting radiation for potassium persulfate as the initiator, ideal kinetics were closely followed. Most of the conventional and some non-standard vinyl and diene monomers have been studied to some extent with radiation-initiated polymerizations in emulsion. To conserve space however, this chapter presents and discusses the results obtained only with styrene and vinyl acetate, both in laboratory and pilot plant investigations. Other monomers and special situations are referenced either directly or to the other available reviews. (orig.)

  12. Nerve conduction velocity

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003927.htm Nerve conduction velocity To use the sharing features on this page, please enable JavaScript. Nerve conduction velocity (NCV) is a test to see ...

  13. Conducting Polymeric Materials

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2016-01-01

    The overall objective of this collection is to provide the most recent developments within the various areas of conducting polymeric materials. The conductivity of polymeric materials is caused by electrically charged particles, ions, protons and electrons. Materials in which electrons...

  14. Complication of radiation therapy

    International Nuclear Information System (INIS)

    Imajo, Yoshinari; Suematsu, Toru; Narabayashi, Isamu; Gose, Kyuhei; Takimoto, Saeko

    1984-01-01

    The radiation pneumonitis is a major complication for patients recieving thoracic irradiation. This report describe the radiographic recognition, pathological change and imapired pulmonary functions of radiation pneumonitis. The 57 patients with lung cancer treated with radiation are analyzed on the pneumonitis by chest X-P. Among these, 50 patients (88%) develop radiation pneumonitis. Repeated CT scans give more detailed information than conventional radiograms as to exdative changes. The pathological analysis are made on the 35 patients of which affected lungs are resected after pre-operative irradiation. Three phases are recognized in the evolution of pneumonitis, the ongestive, the degenerative, and the fibrotic. Adding to the morphorogical damage, pulmonary functions also detrieorate both in ventilation and perfusion scans. (author)

  15. Atoms, radiation, and radiation protection

    International Nuclear Information System (INIS)

    Turner, J.E.

    1986-01-01

    This book describes basic atomic and nuclear structure, the physical processes that result in the emission of ionizing radiations, and external and internal radiation protection criteria, standards, and practices from the standpoint of their underlying physical and biological basis. The sources and properties of ionizing radiation-charged particles, photons, and neutrons-and their interactions with matter are discussed in detail. The underlying physical principles of radiation detection and systems for radiation dosimetry are presented. Topics considered include atomic physics and radiation; atomic structure and radiation; the nucleus and nuclear radiation; interaction of heavy charged particles with matter; interaction of beta particles with matter; phenomena associated with charged-particle tracks; interaction of photons with matter; neutrons, fission and criticality; methods of radiation detection; radiation dosimetry; chemical and biological effects of radiation; radiation protection criteria and standards; external radiation protection; and internal dosimetry and radiation protection

  16. Conventional treatment planning optimization using simulated annealing

    International Nuclear Information System (INIS)

    Morrill, S.M.; Langer, M.; Lane, R.G.

    1995-01-01

    Purpose: Simulated annealing (SA) allows for the implementation of realistic biological and clinical cost functions into treatment plan optimization. However, a drawback to the clinical implementation of SA optimization is that large numbers of beams appear in the final solution, some with insignificant weights, preventing the delivery of these optimized plans using conventional (limited to a few coplanar beams) radiation therapy. A preliminary study suggested two promising algorithms for restricting the number of beam weights. The purpose of this investigation was to compare these two algorithms using our current SA algorithm with the aim of producing a algorithm to allow clinically useful radiation therapy treatment planning optimization. Method: Our current SA algorithm, Variable Stepsize Generalized Simulated Annealing (VSGSA) was modified with two algorithms to restrict the number of beam weights in the final solution. The first algorithm selected combinations of a fixed number of beams from the complete solution space at each iterative step of the optimization process. The second reduced the allowed number of beams by a factor of two at periodic steps during the optimization process until only the specified number of beams remained. Results of optimization of beam weights and angles using these algorithms were compared using a standard cadre of abdominal cases. The solution space was defined as a set of 36 custom-shaped open and wedged-filtered fields at 10 deg. increments with a target constant target volume margin of 1.2 cm. For each case a clinically-accepted cost function, minimum tumor dose was maximized subject to a set of normal tissue binary dose-volume constraints. For this study, the optimized plan was restricted to four (4) fields suitable for delivery with conventional therapy equipment. Results: The table gives the mean value of the minimum target dose obtained for each algorithm averaged over 5 different runs and the comparable manual treatment

  17. Radiation preservation of cultural and museum objects

    International Nuclear Information System (INIS)

    Urban, J.

    1985-01-01

    The possibilities are summed up of using ionizing radiation for the treatment of museum collections, namely the biocidal effect of radiation on living organisms. An approximate assessment is made of the extent of damage to art and book collections by biological pests. Radiation preservation is compared with conventional methods which are unsatisfactory, because they do not affect deeper layers of materials. Experience is summed up with the use of radiation preservation in the Central Bohemian Museum in Roztoky. (J.C.)

  18. Electrically conductive composite material

    Science.gov (United States)

    Clough, Roger L.; Sylwester, Alan P.

    1989-01-01

    An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistant pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like.

  19. Foundations of radiation hydrodynamics

    Science.gov (United States)

    Mihalas, D.; Mihalas, B. W.

    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 function and Boltzmann's equation, the collision integral, the Maxwellian velocity distribution, Boltzmann's H-theorem, the time of relaxation, and aspects of classical statistical mechanics. Other subjects explored are related to the dynamics of ideal fluids, the dynamics of viscous and heat-conducting fluids, relativistic fluid flow, waves, shocks, winds, radiation and radiative transfer, the equations of radiation hydrodynamics, and radiating flows. Attention is given to small-amplitude disturbances, nonlinear flows, the interaction of radiation and matter, the solution of the transfer equation, acoustic waves, acoustic-gravity waves, basic concepts of special relativity, and equations of motion and energy.

  20. Environmental radiation data, 9

    International Nuclear Information System (INIS)

    Nagaoka, Toshi; Sakamoto, Ryuichi; Saito, Kimiaki; Tsutsumi, Masahiro; Moriuchi, Shigeru

    1993-06-01

    The Environmental Physics Laboratory has conducted a large number of background radiation surveys in these years, aiming at the analysis of characteristics and behaviour of environmental radiation, the development of measurement techniques and instruments of environmental radiation, and the evaluation of environmental radiation dose. As the environmental radiation data obtained by these surveys are useful for broad purposes as actual survey data, it is desirable to arrange these data systematically and to open them to the other scientist. For that, it is necessary to make the recording media and the FORMAT of these data available for usual computers. In the light of this circumstance, these data were rearranged and recompiled systematically to meet the demand. This report mentions about the data obtained by the background radiation surveys in and around Tokyo performed during 1991 - 1993 using portable instruments, as well as the information necessary for the data handling. (author)